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Practical Pictorial Guide to Mechanisms and Machinesb.v S. S. PALESTRANTMed. 8vo. 256 pages containing some 4.000 drawings. 30s.Humaii Relations for Management :The Newer Perspectiveedited h.v E. C . BURSKDeniy 8vo. 372 pages. 27s. 6d.The book brings together the best of current thinking on the con-duct of human relations in business, selected by the editor from thepages of the Hntwwd Biisiness Review.Cheniical Engineering Operations :A n Introduction to the Study of Chemical Plantb.~, F. RUMFORDDemy 8vo. 2nd Edit. 390 pages. Illustrated. 32s. 6d.Engineering Mathematicsh j ? K. S. MILLERDemy 8vo. 47s. 6d.Electrostatic Precipitation in Theory and Practicehj. H. E. ROSE and A. J. WOODEx. Cr. 8vo. lilustrated. 17s. 6d.Refrigeration and Air Conditioning/I!, R.C. JORDAN and G. B. PRIESTERRevised edition. Med. 8vo. Illustrated. 65%.- CONSTABLE & COO LTD. 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ISSN:0365-6217    

DOI:10.1039/AR95653FP001

出版商:RSC    

年代:1956

数据来源: RSC

摘要:

6 CONTENTS ERRATUM VOL. 52, 1955. Page 388, line 24. The clause and is in keeping . . . . . . crude ratio 2 : 1 : 1 should be transposed to follow like tyrosine on line 22.6 CONTENTSERRATUMVOL. 52, 1955.Page 388, line 24. The clause and is in keeping . . . . . . crude ratio 2 : 1 : 1 shouldbe transposed to follow like tyrosine on line 22

ISSN:0365-6217    

DOI:10.1039/AR9565300006

出版商:RSC    

年代:1956

数据来源: RSC

摘要:

ANNUAL REPORTSON THEPROGRESS OF CHEMISTRYGENERAL AND PHYSICAL CHEMISTRY.1. INFRARED AND RAMAN SPECTROSCOPY.THE first part of this Report deals with the spectra of molecules consideredas isolated systems and continues with spectral effects characteristic first ofcondensed phases and then of more specific forms of association, such ashydrogen bonding. Some miscellaneous topics and papers on apparatusand techniques are reported at the end.During the year, Volume IX in the series “ Techniques of OrganicChemistry,” entitled “ Chemical Applications of Spectroscopy,’’ hasappeared. This volume, edited by W. West, contains inter al. chapters onthe theory of infrared and Raman spectroscopy including the application ofgroup theory to molecular vibrations and on the applications of infraredand Raman spectroscopy to the elucidation of molecular structure of organiccompounds.Greater emphasis is given to infrared methods. Complement-ing this treatment, the Raman spectroscopy of inorganic compounds hasbeen reviewed.2 Other reviews have been given on the use of infraredspectroscopy in structural and analytical ~tudies,~ in the study of naturalproduct^,^ and in relation to intramolecular effects (ring strain, conjugation,etc.). A catalogue of infrared spectra of gases has been published andRussian work on the resonance-Raman effect (Raman spectra excited byradiation of frequency close to the resonance frequency of the molecule) hasbeen reviewed.’ Abstracts have been published of papers presented atinternational conferences at Pittsburg Sa on Analytical Chemistry andApplied Spectroscopy and at Ohio 8b on Molecular Structure and Spectro-scopy.Potential Functions.-A new potential function for diatomic moleculeshas been ~uggested,~ applicable to molecules for which data are available1 “ Techniques of Organic Chemistry,” General editor A.Weissburger, Vol. IX,“ Chemical Applications of Spectroscopy,” Interscience Publishers, Inc., New York andLondon, 1956.L. A. Woodward, Quart. Rev., 1956, 10, 185.3 J. Lecomte and Y.-R. Naves, J . Chim. phys., 1956, 53, 462; L. J. Bellamy,A. R. H. Cole, Fortschr. Chem. org. Naturstofle, 1956, 13, 1.R. C. Lord and F. A. Miller, Appl. Spectroscopy, 1956, 10, 115.J. Behringer and J. Brandmiiller, 2. Elektrochem., 1956, 60, 643.(a) Spectrochiwt.Acta, 1966, 8. 107; (b) ibid., p. 280.C. Le R. Beckel, J . Cham. Phys., 1956, 24, 553.Research, 1956, 9, 147 ; A. E. Martin, Ind. Chemist, 1956, 32, 464.6 R. H. Pierson, A. N. Fletcher, and E. St. C. Gantz, Analyt. Chem., 1956, 28, 12188 GENERAL AND PHYSICAL CHEMISTRY.for higher vibrational states. Linnett lo has discussed the internucleardistances and force constants of a number of diatomic molecules in terms ofthe number of electrons in the bonding region and the 0 or x character ofthe electrons. There are still few accurate vibrational data for isotopicallysubstituted molecules other than for deuterium substitution. Such dataare necessary to evaluate the force constants of the most general quadraticpotential-energy function. Thus, for bent XY, molecules, while threefundamental frequencies can be observed there are two primary and twointeraction force constants to be evaluated.Smith and Linnett l1 havediscussed the relation between these when the three frequencies are known,for a number of molecules of this type, and have indicated ways in which,in the absence of isotopic data, one of the force constants can be estimated,so fixing approximately the values of the others. Besides providing morereliable values of the primary constants the interaction constants provideresults of direct chemical interest as they may often be related to electronicchanges in one bond caused by stretching or bending another. Smith andLinnett l1 suggest that the compression of the lone pairs may contributeto the bending constant in such molecules as 0,, NO,-, etc. Simpson l2has pointed out that potential-energy terms linear in angle may occur forthe out-of-plane vibrations of planar molecules and that such terms arelikely to be important where interatomic repulsion is large.Vibration-Rotation Spectra.-Numerous vibration-rotation spectralstudies have been published. Molecules studied include NO l3 (re =1.1506 A), CS, l4 (CS r, 1.553 A), N,O l5 (the four constants in the quadraticpotential-energy expression obtained), HCN and DCN 16- l7 (complete setof vibrational anharmonic constants calcdated),17 0, 18* l9 (with a deter-mination l9 of the four quadratic potential-energy constants from combineduse of infrared data and measurements by microwave spectroscopy ofcentrifugal distortion effects), D,O and HDO 2o (in great detail), H2S 21(re-assignment of strong absorption round 2600 cm.-l to vl), H2Te,22CD,F 23* 24 (compared with that in methane, the C-H bond is lengthenedand the HCH angle enlarged 23) , C10,F 25 (symmetric top), allene,26* 27* 28and deuterated allenes 27* 28 (infrared 26, 28 and Raman 27 studies).lo J.W. Linnett, J., 1956, 276.l 1 S. Smith and J. W. Linnett, Trans. Faruduy SOC., 1956, 52, 891.12 C. J. S. M. Simpson, J . Chem. Phys., 1956, 24, 1109.13 H. W. Thompson and B. A. Green, Spectrochim. Actu, 1956, 8, 129.l4 H. C. Allen, jun. , E. K. Plyler, and L. R. Blaine, J . Amer. Chern. SOC. , 1966, 78,15 E. K. Plyler, E. D. Tidwell, and H.C. Allen, jun., J . Chem. Phys., 1966, 24, 95.113 I. R. Dagg and H. W. Thompson, Trans. Furaday SOL, 1966, 52, 455.l7 H. C. Allen, jun., E. D. Tidwell, and E. K. Plyler, J . Chem. Phys., 1956, 25, 302.18 L. D. Kaplan and L. Neven, ibid., 24, 1183.19 L. Pierce, ibid., p. 139.2O W. S. Benedict, N. Gailar, and E. K. PlyIer, ibid., p. 1139.81 H. C. Allen, jun., L. R. Blaine, and E. K. Plyler, ibid., p. 35.22 K. Rossmann and J. W. Straley, ibid., p. 1276.Z3 F. A. Anderson, B. Bak, and S. Brodersen, ibid., p. 989.24 W. F. Edge11 and L. Parts, J . Amer. Chem. SOC., 1956, 78, 2358.26 R. P. Madden and W. S. Benedict, J . Chem. Phys., 1956, 25, 594.26 K. N. Rao and E. D. Palik, ibid., 1965, 23, 2112.37 B. P. Stoicheff, Canad. J . Phys., 1955, 33, 811.48 J.Overend and H. W. Thompson. Trans. Furaday SOC., 1966, 52, 1295.4843PULLIN : INFRARED AND RAMAN SPECTROSCOPY. 0Vibration Spectra and Force Constants.-Force constants have beenevaluated for series of molecules of the following types : XH, and XD3,29XY, 30 (planar), XY, 31 (pyramidal), XY, 32 (tetrahedral), M(CH3)3,33 andM(CH3)4.34 The solution of the vibration problem of pyramidal moleculesof the type XY(CH,), has been discussed.35 The force constants of BF, andCF, have been compared with those of the other fluorides of the first rowof the Periodic Table.36Increasing attentionis being given to the infrared spectra of inorganic compounds. New orimproved spectra or interpretations of spectra have been reported for thefollowing compounds of the XY, type : AlCl, (and AL&16),37 PI, and ASI,,~~PH,+ 39 (in PH,I), GaC1,- 40 (in aqueous hydrochloric acid solutions ofGaCl, and in fused GaC1,) and BH,- 41 (from these spectra and publisheddata comparison was made of the bond-stretching force constants in thefour series of isoelectronic compounds : BH,- , CH,, NH,+ ; AlH,-, SiH,,PH,' ; AlCl,-, SiCI,, PC14+ ; and ZnCl,2-, GaC14-, GeC1,) ; also for ZIICI,~-and CdC1,2-,42 AlH,- * (in LiAIH,), SF,,@ OSO,,,~ AuC~,-,~~ PF5,4' UF,,,*NpF,, and Among closely related compounds, studies have beenmade of the mixed halides of boron 50 and g e r m a n i ~ m , ~ ~ sulphur di~hloride,~~sulphur and selenium halides of the type S,X,,53 and tetramethyltin.s Ofconsiderable chemical interest is the determination of the infrared absorp-tion spectrum of the N, radical by Pimentel and his co-workers 65 by the'' matrix isolation method " in which the reactive species and a large excessof inert diluent, such as argon, are rapidly condensed on a transparent platemaintained at a low temperature.Also of interest is the report 56 of twoSpectra of inorganic and metallo-organic compounds.a* V. P. Morozov, Zhur. $2. Khim., 1955, 29, 1804.30 K. Venkateswarlu and S. Sundaram, J . Chem. Phys., 1955, 23, 2368.31 Idem, Proc. Phys. Soc., 1956, 69, A , 180.3!4 Idem, J . Chem. Phys., 1955, 23, 2365.33 K. Shimizu, J . Chew. SOC. Japan, 1956, 77, 1103.34 Idem, ibid., p. 1284.3 5 H. C. Beachell, B. Katlafsky, and J. L. Lauer, J . Chem. Phys., 1955, 23, 2171.36 J.Goubeau, W. Bues, and F. Kampmann, 2. anorg. Chem., 1956,283, 123.37 W. Klemperer, J . Chem. Phys., 1956, 24, 353.30 L. A. Woodward and H. L. Roberts, Trans. Faraday SOC., 1956, 52, 1458.40 Idem, J., 1956, 3721, 3723.41 Idem, ibid., p. 1170.42 M. A. Bredig and E. R. Van Artsdalen, J . Chem. Phys., 1956, 24, 478.43 L. D'Or and J. Fuger, Bull. SOC. roy. Sci. LiPge, 1956, 25, 14.R. E. Dodd, L. A, Woodward, and H. L. Roberts, Trans. Faraday SOC., 1956,52,1052.46 L. A. Woodward and H. L. Roberts, ibid., p. 615 ; N. J. Hawkins and W. W. Sabol,46 A. A. Vlkk and P. Beran, Chem. Listy, 1956,50. 1306.4 7 J. P. Pemsler and W. G. Plaget, jun., J . Chem. Phys., 1956, 24, 920.49 Idem, ibid., 1955, 23, 2192; N. J. Hawkins, H. C.Mattraw, and W. W. Sabol,50 L. P. Lindeman and M. K. Wilson, J . Chem. Phys., 1956, 24, 242.51 0. HAlov&, Coll. Czech. Chem. Comm., 1955, 20, 1261.62 C. Otero and J. R. Barcelb, Anales Fis. Quim., 1956, 52, B, 291.63 H. Stammreich and R. Forneris, Spectrochim. Acta, 1956, 8, 46.64 W. F. Edge11 and C. H. Ward, J . Amer. Chem. SOL, 1955, 7'7, 6486.6 6 D. E. Milligan, H. W. Brown, and G. C . Pimentel, J . Chem. Phys.. 1956,245, 1080.66 J. T. Mulhaupt and D. F. Hornig, J . Chem. Phys., 1956, 24, 169.H. Stammreich, R. Forneris, and Y . Tavares, ibid., 25, 580.J . Chem. Phys., 1956, 245, 775.J. G. Malm, B. Weinstock, and H. H. Classen, J . Chem. Phys., 1956, 25, 427.ibid., p. 219110 GENERAL AND PHYSICAL CHEMISTRY.Raman bands in the spectrum of perchloric acid monohydrate which appearto belong to the OH stretching and bending vibration of the hydrosoniumion.Use has been made of infrared emission methods to obtain the spectrumof LiH 57 and of Group I1 halides which show rather unexpected inter-relationships. 58 Metal carbonyls 59 and the interesting compounds, thehydrocarbonyls, 6o for which conflicting structures have been proposed, havereceived attention. Spectral studies have been made of the cyanogenhalides,G1 the isocyanate group,62 trifluoromethyl cyanide,g3 boron cyanide,64alkali cyanides, 65 complex cyanides,66 potassium thi0cyanate,~7 metalammines,6s and nitro- and chl~ro-ammines.~~ Closely related to theammines are the series of mercury-nitrogen compounds investigated byBrodersen and Becher.70 These authors evaluated approximately thestretching force constant of the Hg-N bond and assigned frequencies to thevibrational modes of NH, NH,, and NH, groups. A number of similarstudies of inorganic complex and chelate compounds have been published.That of the complex acetates of uranium and some transuranic elements 71is interesting in that it seems to show that the metal-oxygen stretching forceconstant decreases as the metal-oxygen separation decreases. Otherinorganic compounds investigated include N,OZ2- 72 (trans, planar, fromabsence of coincident frequencies between the infrared and Raman spectra),N0,F 73 (probably planar), various sulphur-nitrogen compounds 74 includingthe ring trimer (NSO,-), analogous to the trimetaphosphate ion, the aqueoussilicate ion,75 di-769 77 penta-, and de~a-borane,~' trimethylb~rane,~~ deuter-5 7 W.Klemperer, J . Chem. Phys., 1955, 23, 2452.5 8 W. Klemperer and L. Lindeman, ibid., 1956, 25, 1066.59 S. L. Shufler, H. W. Sternberg, and R. A. Friedel, J . Amer. Chem. SOC., 1956, 78,2687; F. T. King and E. R. Lippincott, ibid., p. 4192; L. H. Jones, J . Chem. Phys.,1955, 23, 2448.60 W. F. Edgell, C. Magee, and G. Gallup, J . Amer. Chem. SOC., 1956, 78, 4185;F. A. Cotton and G. Wlkinson, Chem. and Ind., 1956, 1305.62 H. Hoyer, Chern. Ber., 1956, 89, 2677.s3 W. F. Edgell and R. M. Potter, J. Chem. Phys., 1956, 24, 80.64 J. Guy and M. Chaigneau, Bull. SOC. chim. France, 1956, 257.66 W. Briigel, G. Daumiller, and 0. Romrnell, Angew.Chem., 1956, 68, 440.66 (a) R. A. Penneman and L. H. Jones, J . Chem. Phys., 1956, 24, 293; (b) L. H.Jones and M. M. Chamberlain, ibid., 25, 365; G. B. Bonino and 0. Salvetti, Atti Accad.naz. Lincei, Rend. Classe Sci. j i s . mat. nut., 1956, 20, 150; M. F. A. Elsayed and R. K.Sheline, -1. Amer. Chem. SOC., 1956,78, 702 : D. M. Sweeney, I. Nakagawa, S. Mizushima,and J. V. Quagliano, ibid., p. 889.6 7 J. R. Saraf, Sci. Light, 1956, 5, 23; L. H. Jones, J . Chem. Phys., 1956, 25, 1069.6s D. B. Powell and N. Sheppard, J., 1956, 3108; D. B. Powell, ibid., 4495; G. M.Barrow, R. H. Krueger, and F. Basolo, J . Inorg. Nuclear Chem., 1956, 2, 340.69 I . R. Beattie and H. J. V. Tyrrell, J . , 1956, 2849; D. G. Hill and A. F. Rosen-berg, J .Chcm. Phys., 1956, 24, 1219; L. H. Jones, ibid., 1955, 23, 2105; R. B. Pent-land, T. J . Lane, and J. V. Quagliano, J . Amer. Chem. SOC., 1956, 78, 887.7O K. Brodersen and H. J . Becher, Chem. Ber., 1956, 89, 1487.71 L. H. Jones, J . Chem. Phys.. 1955, 23, 2105.72 L. Kuhn and E. R. Lippincott, J . Amer. Chem. SOC., 1956, 78, 1820.73 R. E. Dodd, J . A. Rolfe, and L. A. Woodward, Trans. Faraday SOC., 1956,52,145.74 H. J. Hofmann and K. Andress, 2. ar,org. Chem., 1956, 284, 234.7 5 D. Fortnum and J. 0. Edwards, J . Inorg. Nuclear Chem., 1956, 2, 264.76 H. C. Beachell and E. J. Levy, J . Chem. Phys., 1955, 23, 2168; D. A. Brown7 7 P. R. Pondy and H. C. Beachell, J . Chem. Phys., 1956, 25, 238.78 J . E. Stewart, J . Res. Nut. Bur. Stand., 1956, 58, 337.W.0. Freitag and E. R. Nixon, J . Chem. Phys., 1956, 24, 109.and H. C. Longuet-Higgins, J . Inorg. Nuclear Chem., 1955, 1, 352PULLIN : INFRARED AND RAMAN SPECTROSCOPY. 11ated germanes 79 and digermane,80 deuterium-substituted silanes, 61 halogen-substituted silanes,s2 CCl,-SC1,83 NCOSC~,,~~ disiloxane, and [2H,]di~iloxane 85(it is suggested that the Si-0-5 angle is close to 180°, from the absence ofgenuine coincidences between the infrared and Raman spectra).Among the simplerorganic compounds for which detailed assignments are possible, halogen-substituted ethanes, ethylenes, and benzenes continue to receive attention ;papers have appeared on CH3*CC13 and CD3*CCl,, 86 sym-tetrachloro- s7a9and sym-tetrabromo-ethane 87b3 88 (sym-tetrabromoethane will crystallise ineither the trans or the gauche form s7b), 1 : 2-dibromo-2 : 2-difl~oroethane,~~trichloroethylene,w trichlorofluoroeth ~ l e n e , ~ l 1 -chloro- 1 -fluoroet hylenqg2mono ha loge no benzene^,^^ dihalogenoben~enes,~~ and hexafluor~benzene.~~Bellamy and N'illiams 96 discuss relations between the frequencies of halidesof the type CH,X and the corresponding halogen acid HX, and betweenthe halides CH,X and molecules CH,Y, for various groups Y such as -CO,H,-Sic&, -SH, etc.These relations are interpreted largely in terms of changesof hybridisation. Several papers have appeared on the spectra of formicacid and related compounds : formic acid,97 f~rmaldehyde,~~ formate i~n,~ga*formyl fluoride,loo acetate ion, 99b9 lola oxalate ion,l0la8 and osalic acid.101bThe force field for molecules of type X-CH-0 has been discussed.lo2 Othersmall molecules studied include isobutane and [2H1]i~~butane, lo3 proyeneSpectral studies of individual organic compoatnds.79 L.P. Lindeman and M. K. Wilson, 2. phys. Chent. (Frankfurt), 1956, 9, 29.80 D. A. Dows and R. M. Hexter, J . Chern. Phys., 1956, 24, 1029, 1117.8% K. Kawai and H. Murata, ibid., 1955, 23, 2451 ; C. Newnian and J. K. O'Loane,8s F. Feh6r and H. J. Barthold, 2. anorg. Chem., 1956, 284, 60.84 F. FehCr and W. Weber, 2. Naturforsch., 1956, l l b , 426.8S R. C. Lord, D. W. Robinson, and W. C. Schrumb, J . Amer. Chew. Soc., 1956, 78,86 J. C. Evans and H. J. Bernstein, Canad. J . Chern., 1955, 33, 1746.( a ) S. Mizushima and co-workers, J .Chenz. Phys., 1955, 23, 1907; J. P. Zeitlow,F. F. Cleveland, and A. G. Neister, ibid., 1956, 24, 142; (b) K. E. Kagarise, ibid.,J. H. Meal and M. K. Wilson, ibid., p. 385.S. R. Polo, and M. K. Wilson, ibid., 1956, 25, 855; Y . Morino, ibid., 1956, 24, 164.1327.p. 300.88 D. E. Mann, J. H. Meal, and E. K. Z'lyler, ibid., p. 1018.89 R. E. Kagarise, ibid., p. 1264.J. C. Evans and H. J. Bernstein, Canad. J . Chenz., 1955, 33, 1792; T. J. liouser,R. B. Bernstein, R. G. Miekka, and J. C. Angus, J . Amer. Chem. SOC., 1955, 77, 6201.91 D. E. Mann and E. K. Plyler, J . Cltem. Ph-ys., 1955, 23, 1989; J . R. Nielsen,C. W. Gullikson, and A. H. Woolett, ibid., p. 1994.O2 D. E. Mann, N. Acquista, and E. K. Plyler, ibid., p. 2122.Og D.H. Whiffen, J., 1956, 1350; D. 1%'. Scott and co-workers, J . Amer. Chew.SOL., 1956, 78, 5457.A. Narasimham, M. 2. El-Sabban, and J . H. Nielsen, J . Chcm. Phys., 1956, 24,420, 433, 1232; S. L. N. G. Krishnamachari, Current Sci., 1956, 25, 185, 260.95 L. Delbouille, J . Chem. Phys., 1956, 25. 182.g6 L. J. Bellaniy and R. L. Williams, J . , 1956, 2753.87 W. J. Orville-Thomas, Research, 1956, 9, s15; D. Chapman, J . , 1956, 225;9g T. Miyazawa, J . Chem. SOC. Japagz, 1955, 76, 1132.99 K. Ito and H. J. Bernstein, (a) J . Chcm. SOC. Japan, 1956, 77, 381 ; ( b ) Canad.loo H. W. Morgan, P. -4. Staats, and J. H. Goldstein. J . Chem. Phys., 1966, 25, 337.lol (a) K. J. Wilmshurst, ibid., 1955, 23, 2463; (b) H. Murata and K. Kawai, ibid.,lo2 T.Miyazawa, J. Chem. SOC. Japan, 1956, '97, 366.lo9 J. C. Evans and H. J. Bernstein, Canad. J . Chem., 1966, 34, 1037.J. K. Wilmshurst, J . Claem. Phys., 1956, 25, 478.J . Chem., 1956, 34, 170.1966, 25, 58912 GENERAL AND PHYSICAL CHEMISTRY.and deuteropropene ,lO4 cyclohe~ene,~~5 CH,CN, and CD,CN, s6 compoundsrelated to adamantane and urotropinJ106 ethylene oxide,lo7 ozonides ofethylene, propene, and isobutene,los ethylene carbonate log (probably planarin the liquid state), naphthalene,l1° anthracene and tetracene,lll acet-aldehyde,l12 diacetyl,l13 dicyanoacetylene,ll* halogen~picrins,~~~ and somealkyl phosphates and thiophosphates.1l6 It is possible only to refer to asmall fraction of all the organic structures investigated by infrared andRaman spectroscopy : a few of the groups of compounds that have receivedmost attention are referred to below.Characteristic spectra o f g o q 5 s .Ketorces. The carbonyl group continuesto be the subject of numerous spectroscopic investigations. Ha1ford,ll7 in apaper basic to any discussion of variation of the carbonyl stretching fre-quency, investigates the location of the carbonyl frequency in a variety ofmodels applicable to non-conjugated ketones. He shows that in a planarmodel (MC),CO in which the M-C linkage is a normal single bond, thecarbonyl frequency is insensitive to variation of mass or position of M andthat the Y shaped C,CO model can be used with fair accuracy to obtain thecarbonyl force constant. The carbonyl frequency increases linearly withcarbonyl force constant and decreasing C-C-C angle; this is supported byexperimental evidence.Data defining frequency-bond-length correlationsfor CO and CN bonds have been assembled.ll8 Lecomte, Josien, and Las-combe 119 examined a large number of ketones in the KBr region and wereable to trace through the series bands arising from three bending modes.Jones et discuss the origin of some low-frequency bands in steroids.Attention has been drawn to the higher intensity of the Raman spectra andthe lower carbonyl frequency of conjugated ketones compared with thoseof similar uncon j ugated ketones. 121 Shorygin had previously discussed indetail the effect of conjugation on Raman intensities.122 The effects oflo4 L. M. Sverdlov, Doklady Akad.Nauk S.S.S.R., 1956, 106. 80.lo6 K. Sakashita, J . Chem. SOC. Japan, 1956, 77, 1094.lo6 R. Mecke and H. Spiesecke, Chem. Ber., 1955, 88, 1997; Spectrochim. Ada, 1956,7, 387; J . Chem. Phys., 1956, 25, 577; A. Cheutin and J.-P. Mathieu, J. Chim. phys.,1956, 53, 106.lo? R. C. Lord and B. Nolin, J. Chem. Phys., 1956, 24, 656.lo8 D. Garvin and C. Schubert, J. Phys. Chem., 1956, 60, 807.lo9 C . L. Angell, Trans. Faraday SOC., 1956, 52, 1178.110 J. Brandmiiller and E. Schmid, 2. Physik, 1956, 144, 428.111 J. W. Sidman, J. Chem. Phys., 1956, 25, 116, 122.112 J. C. Evans and H. J. Bernstein, Canad. J. Chem., 1956, 34, 1083.113 J. W. Sidman and D. S. McClure, J. Amer. Chem. SOC., 1955, 77, 6471.114 F. A. Miller, R. B. Hannan, jun., and L.R. Cousins, J . Chem. Phys., 1955, 23,115 J. Mason and J . Dunderdale, J . , 1956, 754, 759.1 l 6 M. Baudler, Naturwiss., 1956, 43, 124; J. Michalski, R. Mierzecki, and E.11' J. 0. Halford, J. Chem. Phys., 1956, 24, 830.118 E. M. Layton, jun., R. D. Kross, and V. A. Fassel, ibid., 25, 135.119 J . Lecomte, M.-L. Josien, and J. Lascombe, BulE. SOC. chzm. France, 1956,120 R. N. Jones, B. Nolin, and G. Roberts, J. Amer. Chem. Soc., 1955, 77, 6331.L. Piaux, M. Durand, and L. Henry, Compt. rend., 1956,242, 2650; M. Harrandand H. Martin, Bull. SOC. chim. Fralzce, 1956, 1383.lZ2 P. P. Shorygin, Uspekhi Khim., 1950, 19, 419; English translation, NationalResearch Council of Canada, Technical translation TT-228.2127.Rurarz, Roczniki Chem., 1956, 30, 651.163-165PULLIN INFRARED AND RAMAN SPECTROSCOPY.13conjugation, 123 halogen substitution 124 and transannular interaction lo5(in cyclic ketones) on the carbonyl band have been further investigated.Hydrocarbon and C-H modes. A high proportion of papers on hydro-carbons have been concerned with C-H deformation frequencies.126* 12'9 128* 129Kross, Fassell, and Margoshes have discussed the C-H out-of-planebending frequencies of a large number of mono- and di-substituted benzenes(see also Bellamy 126b and Kakiuti 126c). Groups attracting electrons outof the ring raise the C-H bending frequencies. Kross et aZ.12G" suggest thathigher bending frequencies are to be associated with decreased ability of thex electrons to contribute to sp3 character in the carbon orbitals as thehydrogen atoms move out of the plane.Whiffen127 has shown that thestronger infrared bands in benzene from 1650 to 2000 cm.-l can be interpretedas summation tones of out-of-plane C-H bending modes. The frequenciesof the summation bands agree quite closely with the sum of the fundamentalfrequencies, suggesting low mechanical anharmonicity. Whiflen suggeststhat large electrical anharmonicity is characteristic of out-of-plane bendingmotion of C-H bonds having $2 hybridisation and also of bending motionof C-H bonds having sp hybridisation. The analytical use of the C-Hstretching region has been discussed. 130 Among other groups of compoundsthat have received attention are polynuclear hydrocarbons ll1- 131 andrelated fatty acids,lzo9 133 glycerides,134 glycols,136 ethers,13Ga l k o ~ i d e s , ~ ~ ~ i m i n e ~ , l ~ ~ and compounds containing the nitro-group.lagFurther advance has been made in theinterpretation of the spectra of amides, peptides, and proteins. A thoroughinvestigation of the spectra of a series of A'-monosubstituted amides invarious physical states has been made by Japanese ~ 0 r k e r s . l ~ ~ The spectraldata, together with the results of force-constant calculations, were used toassign to their vibrational modes six bands characteristic of monosubstitutedamides. Other papers have appeared on the doubling of a band near 3p inAmides, $@tides, and proteins.123 S. Inayama, Pharm. Bull. (Japan), 1956, 4, 198.lS4 H. Gerding and H. C. Haring, Rec.Trav. chim., 1955, 74, 1409.125 N. J. Leonard et al., J . Amer. Chem. SOC., 1955, 77, 6234, 6237.126 ( a ) R. D. Kross, V. A. Fassell, and M. Margoshes, J . Amer. Chem. SOC., 1956, 78,1332; ( b ) L. J. Bellamy, J . , 1955, 2818; (c) Y . Kakiuti, J . Chem. Phys., 1956, 25, 777.lP7 D. H. Whiffen, Spectrochim. Actu, 1955, 7, 253.lz8 J. K. Brown and N. Sheppard, Trans. Faraday SOC., 1955, 51, 1611.129 M.-L. Josien and J.-M. Lebas, Bull. SOC. chim. France, 1956, 53, 57, 62.130 D. L. Guertin, S. E. Wiberley, and W. H. Bauer, J . Amer. Oil Chemists' SOC.,131 N. Fuson and M.-L. Josien, J . Amer. Chem. SOC., 1956, 78, 3049.l 3 Z L. Cencelj and D. Hadzi, Spectrochim. Actu, 1955, 7, 274.133 D. L. Guertin, S. E. Wiberley, and W. H. Bauer, Analyt.Chem., 1956, 28, 1194;R. T. O'Connor, J . Amer. Oil Chemists' SOC., 1956, 33, 1 ; 1%'. Fuchs and R. Drieberg,Fette u. Seifen, 1956, 58, 3; R. T. Holman and P. R. Edmondson, Analyt. Chem., 1956,28, 1533.134 D. Chapman, J., 1956, 55, 2522.135 N. Chakhovskoy, R. H. Martin, and (in part) R. Van Nechel, Bull. SOC. chim.belges, 1966, 65, 453.136 G. Lagrange and P. Mastalgi, Compt. rend., 1955, 241, 1947.197 D. L. Guertin et al., J . Phys. Chem., 1956, 60, 1018; F. H. Seubold, jun., J .Org. Chem., 1956, 21, 156.138 J. Fabian, M. Legrand, and P. Poirier, Bull. SOC. chim. France, 1956, 1461, 1499.139 J. F. Brown, J . Amer. Chem. SOC., 1955, 77, 6341.140 T. Miyazawa, T. Shimanouchi, and S. Mizushima, J . Chem. Phys., 1956, 24, 408.1956, 33, 17214 GENERAL AND PHYSIC.11, CHEbIISTR\'.the spectra of some N-monosubstituted amides, which was interpreted asevidence for cis-trans-isomerism : 141 the near-infrared spectrum of thepeptide group,142 the infrared dichroism of acetanilide and the transitionmoment direction of the amide-I charactcristic vibration,143 and the di-chroism of fibrous proteins in the 2p region.144 A summary has been givenof the use of infrared spectroscopy in investigating polypeptide and proteinstructures.145 Blout and Asadourian,146 using infrared methods, examinecritically one case of the supposed a -+ 9 transformation of polypeptidesin the presence of formic acid.Lcnormant 14' has studied by infraredmethods the state of proteins in silk glands and the process by which theybecome insoluble.He suggests that the insolubilisation of the proteins ofsilk glands by mechanical strain corresponds to the same change as thatoccurring in the thermal denaturation of other proteins. Goulden 148 hasused infrared methods to investigate protein-sugar interactions. Severalother papers on proteins and related materials have appeared. 149Compounds of biological interest forwhich infrared spectra have been reported include deoxyribonucleic acid,150vitamin B, and related salts of phosphoglyceric acid,152thymus nucleohi~tone,~~~ adenosine phosphate,lN anhydrous p-lacto~e,l~~charoninsulphuric acid, chrondroitinsulphuric acid, and related poly-saccharides, and halogeno-st eroids .Intensities.-The determination of bond moments and their spatialderivatives from gas-phase infrared intensity measurements has now becomefairly standardised ; however, considerable discretion is usually needed.Abrief critical survey of the position at the end of 1955 has been given byHornig.15* The importance of taking into account movements during thevibration of all thc electrons, especially unshared pairs, is emphasised andillustrated by a consideration of the intensity of v2 (symmetrical bendingmode) of ammonia and the intensity and force constant of the bending modeof hydrogen cyanide. Theoretical calculations 159 indicate that the majorpart of the intensity of the v2 vibration of ammonia is due to the changingSome spectra of bioZogica1 interest.141 R. A. Russell and H. W. Thompzon, Spectvochim.Acta, 1956, 8, 138.142 K. T. Hecht and D. L. Wood, Pruc. Roy. Soc., 1956, A , 235, 174.143 N. B. Abbott and A. Elliott, ibid., 234, 247.144 R. D. B. Fraser, J . Chew. Phys., 1956, 24, 89.146 A. E. Elliott, J . Appl. Chem., 1956, 6, 341.146 E. R. Blout and A. Asadourian, J . Amer. Chew. Sor., 1956, 78, 955.14' H. Lenormant, Trans. Faraday Soc., 1956, 52, 549.148 J. D. S. Goulden, Nature, 1955, 177, 85.149 -4. Elliott and B. R. Malcolm, Trans. Favaday Soc., 1956,52, 528; E. Ellenbogen,J . Amer. Chem. SOC., 1956, 78, 363, 366, 369; H. I?. Schwarz et al., Science, 1956, 123,328.H. Lenormant and C . de Loze, Bull. SOC. chim. France, 1955, 1501, 1504; H. P.Schwarz et al., Science, 1956, 123, 328.H. Hirano, H. Yonemoto, and H.Kamio, J . Pharm. SOC. Japan, 1956, 76, 239.C. de Loze and H. Lenormant, Bull. SOC. chim. France, 1956, 450.K. Nakanishi, N. Takahashi, and F. Egami, Bull. Chem. SOC. Japan, 1956, 29,lS2 A. Rosenberg and B. G. Malmstrom, Acta Chem. Scand., 1955, 9, 1546,lK4 H. Gomahr, W. Miedreich, and A. Reuter, Aqzgew. Chem., 1956, 68, 578.l66 Y. Tsuzuki and N. Mori, J . Chem. SOC. Japan, 1956, 77, 993.lS7 D. H. R. Barton, J. E. Page, and C. W. Shoppee, J . , 1956, 331.l 6 * D. F. Hornig and D. C. McKean, J . Phys. Chem., 1955, 59, 1133.l 6 0 N. V. Cohan and C . -4. Coulson, Trans. Faraday SOC., 1956, 52, 1163.434PULLIN INFKAREI) AND RAMAN SPECTROSCOPY. Idhybridisation of the lone-pair electrons accompanying the motion of theatoms. A more sophisticated and more accurate way of obtaining the trueintensities from the experimental figures has recently been applied to thecarbon dioxide bending vibration.lW The importance of using an adequatepotential function when interpreting infrared intensities is shown by somecalculations of moments for sulphur dioxide.lsl However, a more funda-mental difficulty is revealed by the work of Russell and Thompson 162 whoinvestigated the mechanical and electrical anharmonicity of the N-Hstretching vibration in a series of organic compounds in solution.Theyfound a large variation in the relative intensity R of first overtone to funda-mental, due almost entirely to variation in the intensity of the fundamental.In some cases (dimethylamine and diethylamine) the first overtone wasmore intense. The high values of R were due to high electrical, rather thanhigh mechanical, anharmonicity.From the data given the mechanicalanharmonicity factor x, can be seen to increase slightly with increasing R.Investigations of variation of intensity and frequency of characteristicvibrations of groups, as a function of other substituents in the molecule,continue ; exceptionally large variations of intensity of the CGN stretchingvibration have been found.lGd The intensity of the carbonyl stretchingvibration in cyclic ketones shows an interesting variation with ring s i ~ e . 1 ~ Experimental 165 and theoretical intensity work on paraffins has beenreported. The bond moment and the first and the second derivative of thebond moment were obtained for hydrogen chloride from infrared dispersionmeasurements by E e g a ~ .l ~ ~ Raman intensities have been calculated semi-quantitatively for C,H,X (X = C1, Br, and I) by using the approximationof x electrons in a one-dimensional box with infinite walls.168 Apparatusand methods for determining Raman intensities have been described 169and some depolarisation ratios for CC1,X- and CBr,X-type moleculesca1c~lated.l~~ Raman intensity sum rules have been used as an aid tovibrational assignment. 86Rotational Isomerism.-Rotational isomerism in subs ti tut ed et hanescontinues to receive a t t e n t i ~ n . ~ ~ - ~ ~ Barriers to rotation have been estimatedfor digermane,80 dirnethylaminodib~rane,~~~ CC1,*SC1,83 and diphenylderivatives.172 Internal rotation in polyethylene and its derivatives 173I 6 O L.D. Kaplan and D. F. Eggers, J . Chem. PAYS., 1956, 25, 576.161 D. F. Eggers, 1. C. Hisatsune, and I. Van AIten, J . Phys. Chenz., 1955, 59, 1124.163 H. W. Thompson and G . Steel, Trans. Furaday Soc., 1956, 52, 1451.164 T. Biirer and H. H. Grunthard, Helv. Chzm. Acta, 1956, 39, 356.16s H. Luther and G. Czerwony, 2. phys. Chew. (Frunhfurt), 1956, 6, 286.1 6 6 H. Primas and H. H. Grunthard, Helv. Chim. Ada, 1956, 39, 1182.167 Compt. rend.. 1956, 242, 1593.188 M. V. Vol’kenshtein and S. M. Yazyka, Doklady Akad. Nawk S.S.S.R., 1955, 104,I). A. Long, I>. C. Milner, and A. G. Thomas, Proc. Roy. SOC., 1956, A , 237, 186,A. IVeber and S. M. Ferigle, J . Chem. Ph-w., 1955, 23, 2207; R.H. Krupp,1 7 1 J . E. Stewart, ibid., 1955, 23, 2204.I73 G. Kortiim and H. Maier, 2. fihys. Chem. (Frankfurt), 1956, 7, 207.173 I. J. Novak, Zhur. tekh. Fiz., 1955, 25, 1854; I. M. Ward, Chenz. and Ind., 1956,R. A. Russell and H. W. Thompson, Proc. Roy. Soc., 1956, A , 234, 318.834.197.’3. M. Ferigle, and A. Weber, abid., 1956, 24, 355.90516 GENERAL AND PHYSICAL CHEMISTRY.has been discussed. Calculations made of barriers to internal rotation 174illustrate two quite different approaches to the problem : that the problemis complex is shown by the evidence for the preponderance of attractiveover repulsive forces in some cases of rotational isomerism involving therelative orientation of halide to methyl groups 175 and chloride to carbonylgroups.176 Probably of importance for the investigation of rotationalisomerism are some observations by Orr 177 who examined various trans-stilbene derivatives.The width of the band due to the out-of-plane in-phasevibration of the olefinic hydrogen atoms was greater in derivatives wherethe steric hindrance was greater. The width of this band was supposed tobe due to the short life-time of the vibrational state, which in turn resultedfrom transfer of vibrational energy from this mode to other deformationalmodes.Spectra of Condensed Phases.-The infrared and Raman spectra nowreported are those which show points of interest by virtue of the material’sbeing in a condensed phase. Special effects in gases at high pressures arealso included.Crystals.Several papers on general aspects of crystal spectra haveappeared.178 In a further paper in the series “ Motions of Molecules inCondensed Systems ” Zwerdling and Halford 179 report an investigation ofthe polarisation properties of infrared absorption bands of molecular modesinactive in the free molecule, but active in the crystal because of the lower-ing of the symmetry of the molecule by the crystalline field. The samplestudied was a single crystal of benzene. Polarised infrared studies havebeen made of a large number of salt hydrates and inorganic hydroxyliccompounds 180 and of benzophenone,181 a ~ e t a n i l i d e , ~ ~ ~ KAg(CN),,ls2 andiodoform.ls3 In the study of iodoform, Hexter and Cheung investigated,inter al., the polarisation of the absorption band due to the C-H stretchingmode and found it significantly different from that predicted by the oriented-gas model, that is, the model in which the solid is regarded as a non-interact-ing collection of molecules held rigidly in appropriate relative orientations.This difference was attributed to the effect of combination of the C-Hstretching mode with lattice frequencies.In a further paper, Hexter andDows ls4 consider the effect of libration of the molecular units in the latticeon the polarisation of the infrared absorption bands : with reasonable valuesfor libration frequencies, features of a number of published crystal spectra174 E. A. Mason and M. M. Kreevoy, J . Amer. Chem. Soc., 1955, 77, 5808; B. Bak,175 G.J. Szasz, ibid., 1955, 23, 2449.176 L. J. Bellamy, L. C. Thomas, and R. L. Williams, J.. 1956, 3704.177 S. F. D. Om, Spectrochim. Ada, 1956, 8, 218.l 7 3 (a) C. Haas, ibid., p. 19; (b) H. Poulet, Ann. Phys., 1955, 10, 908.17n S. Zwerdling and R. S. Halford, J . Chem. Phys., 1955, 23, 2221.180 (a) M. Haas and G. B. B. M. Sutherland, Proc. Roy. Soc., 1956, A , 236, 427;( b ) R. E. Rundle, K. Nakamoto, and J. W. Richardson, J . Chem. Phys., 1955, 23, 2460;(t) A.-M. Vergnoux, Compt. rend., 1956, 242, 758; M.-P. Bernard, ibid., p. 1012; H. E.Petch, N. Sheppard, and H. D. Megaw, Acta Cryst., 1956, 9, 29.J . Chem. Phys., 1956, 24, 918.lB1 L. Delbouille, Bull. Classe Sci., Acad. ray. Belg., 1956, 63, 388.lB2 L. H. Jones, J. Chem. Phys., 1956, 25, 379.lB3 R.M. Hexter and H. Cheung, ibid., 1956, 24, 1186.lE4 R. 1%. Hexter and D. A. Dows, ibid., 25, 504PULLIN : INFRARED AND RAMAN SPECTROSCOPY. 17can be accounted for. The most complete study of the infrared spectra ofhydrates was that of gypsum by Haas and Sutherland.l* Reflectionmethods were mainly used to obtain the polarised spectra : the superiorityof reflection over transmission methods for highly absorbing crystals isevident from the results obtained. The coupling of the internal motions ofthe equivalent molecular units (H20 and SO,2-) in the unit cell producedsurprisingly large splittings of frequencies in some cases. The polarisationand relative intensities of bands corresponding to the symmetric and anti-symmetric stretching modes of the H,O units showed interesting anomalies.The polarisation behaviour of v, (the symmetrical bending mode) was foundto agree fairly well with that predicted. In several papers attention isdrawn to the relative constancy in frequency of v2 in different hydrates.lS5The polarisation behaviour of v2 of water has been used as evidence fordeviation from planarity in the system CU-O’~ in CuC&,2H20.Thissuggests some covalent character in the Cu-0 bond.lM Raman spectrahave been reported for gypsum lS6 and several other salt hydrates,ls7hydroxonium salts,188 strontianite,lsg magnesite,lS0 and iodoform.191 Adetailed Raman investigation of single crystals of a- and p-resorcinol byPenot and Mathieu lg2 illustrates the complexity of a detailed analysis ofcrystal spectra and the high standard of experimental work required.Thereported observation of discrete lines in the Raman spectrum of MgO 1g3 has abearing on the theory of crystal spectra. A very detailed discussion of anom-alous effects in the Raman spectra of crystals has been given by Poulet.l7&Compressed gases. A brief review of collision-complex spectra in com-pressed gases and liquids has been given by Ketelaar lg4 (see also ref. 195).Solutions and pure liquids. The intensity of a band of a substance in theliquid phase will differ in general from the gas-phase value, the differencebeing related to the different dielectric constants of the two phases. Thiseffect has been further examined, theoretically for pure liquids l96 andexperimentally for solutions.lS7 It appears that the dielectric theorydeveloped so far for this change of intensity applies strictly only to pureliquids whilst most measurements have been made on solutions. Effectsof molecular interaction on Raman intensities have been examined.lg8\H186 P. J. Lucchesi and W. A. Glasson, J . Amer. Chem. Soc., 1956, 78, 1347; E.186 A. I. Stekhanov, Doklady Akad. Nauk S.S.S.R., 1956, 106, 433.187 A. Weill-Marchand, Compt. rend., 1955, 241, 1456; 1956, 242, 93, 1791.188 D. J. Millen and E. G. Vaal, J., 1956, 2913.189 T. S. Krishnan, Proc. Indian Acad. Sci., 1956, 44, A , 96.lQo D. Krishnamurti, ibid., 43, A , 210.l91 H. Stammreich and R. Forneris, Spectrochim. Ada, 1956, 8, 62.lS2 D. Penot and J.-P.Mathieu, J . Chim. fihys., 1955, 52, 829.lg4 J. A. A. Ketelaar, Rec. Trav. chim., 1956, 75, 857.195 L. Galatry and B. Vodar, Compt. rend., 1956, 242, 1871; A. Michels and H. Delg6 S. R. Polo and M. K. Wilson, J . Chem. Phys., 1955, 23, 2376.197 J. H. Jaffe and S. Kimel, J . Chem. Phys., 1956, 25, 374.lg8 Ya. S. Bobovich et al., Doklady Akad. Nauk S.S.S.R., 1956, 108, 607; Idem,Hartert, Naturwiss., 1956, 43, 275.S. J. KhambMA, Proc. Phys. Soc., 1950, 89. A , 426.Kluiver, Physica, 1956, 22, 919.Zhur. eksp. teoret. Fiz., 1956, 30, 189Evidence for a temperature variation of infrared band intensities has beenput Further, rigorous experimental work is required. Soluteband-widths in mixed solvents have been interpreted in simple statisticalterms.200 Evans and Bernstein 201 measured the polarisation and intensitiesof the two Raman forbidden fundamentals of carbon disulphide in a seriesof cyclopentane solutions.They suggest that interaction between the CS,molecules in solution reduces their symmetry to C, (single plane of symmetryonly). A Raman line suggestive of internzolecztlar vibration has beenobserved with liquid carbon disulphide at - 100°.202 Lafont 203 describesthe Ranian spectrum of a saturated solution of zinc sulphate. The closesimilarity to the complex Raman spectrum of crystalline ZnS0,,7H20 withwhich the solution is in equilibrium, is impressive evidence for regions ofshort-range order in the saturated solution. Solvent effects on characteristicbands of the following groups have been investigated : >C0,Lo2a* -OH,204b>NH,205 -CN,fo6* 163 -NO,, and -CF,.206 Particularly large changes ofintensity with solvent are shown by the -CN group, which are interpretedin terms of changes in the electronic structure of the group.Further papers on interactionin solution are on hydrogen sulphide solutions 207 (including evidence foran H,S-mesitylene complex), sulphur dioxide solutions 208 (includingevidence for an SO,-pyridine complex), association of aldehydes,209 theconcentration-dependent structure of the Raman carbonyl stretching bandin solutions of ketones,2aa complexes between ether and HCl or HRr,210organic complexes with HBr or HI 211 and with aluminium bromide andstaiinic and between benzene and chlorine and bromine 213 (seehowever Murakami 214), Ionic equilibria studied include equilibria in-volving N02+,215 equilibria in molten salts,40* 42 and an outstanding investig-ation of the equilibrium of complex cyanides in aqueous solution.s6aThere is still diversity of opinion about the natureof hydrogen-bonded systems and of their spectral manifestations.Thewidth of OH stretching frequencies in strongly hydrogen-bonded systemshas received much attention in the past, Frisch and Vidale 216 have solvedAssociatiopz and dissociation in solution.Hydrogen bonding.lsB T. 1,. Brown, J . Chem. Phys., 1956, 24, 1281 ; U. Liddel and E . 0. Becker, ibid.,2oo T. Yoshino, ibid., 1956, 24, 76.201 J. C. Evans and H. J. Bernstein, Canad. J . Chem., 1956, 34, 1127.202 S.C, Sirkar and G. S. Kastha, J . Chem. Phys., 1955, 23, 2439.2os R. Lafont, Compt. rend., 1956, 242, 1154.204 ( a ) C. Mangin and M.-M. Bottreau, Compt. rend., 1956, 242, 2637; ( b ) H . Tsubo-205 1'. Mirone and G. F. Fabbri, Gazzetta, 1956, 86, 1079.2O6 E. Lippert and W. Vogel, 2. phys. Chem. (Frankfurt), 1956, 9, 133.207 M.-L. Josien and P. Saumagne, Bull. SOC. chim. France, 1956, 937.208 A. Tramer, Bull. Acad. polon. Sci., CE. 111, 1956, 4, 355.209 W. Suetaka. Gazzetta, 1956, 88, 783.210 G. L. Vidale and R. C. Taylor, J. Amer. Chem. SOC., 1956, 78, 294.311 M.-L. Josien, G. Sourisseau, and U. Castinel, Bull. SOC. chim. France, 1955, 1539.21* V. N. Filimonov and A. N. Terenin, Doklady Akad. Nauk S.S.S.R., 1966, 109.31s E. E. Ferguson, J .Chem. Phys., 1956, 25, 576.214 H. Murakami, ibid., 1955, 23, 1957.216 S. FCnCant and J. Chedin, Cowzpt. rend., 1956, 243, 41.z16 H. L. Frisch and G. L. Vidale, J . Chem. P h p . , 1966, 25, 982.25, 173.mura, J . Chem. SOC., Japan, 1956, 77, 962.799E'ULLIN INFKAKEI) .\NI) KhM;\N SPECTROSCOPY. 19the classical vibration problem of the niodel system X-H * - .Y in which theH Y bond is anharmonic, and show that on these grounds alone consider-able width is to be expected. Barrow217 and Tsubomura218 measurethe intensities of the hydrogen-bonded X-H stretching frequencies(X-H = alcohol or phenol, Y various). The intensities are greater, thegreater the acidity of XH. Barrow derives the high intensity of thisvibration from the increase of ionic character of the X-H bond on extensionand Tsubomura from the transfer of charge (electrons) from Y to X onextension of X-H.Tsubomura points out that the relatively low intensityfound in chelate compounds such as salicylaldehyde can be understood onthe latter basis, as the dipolarity resulting from the above type of chargetransfer can be (formally) eliminated by rearrangement of bonds round theconjugated system. ,4 different explanation seems to be required for theapparent absence of the OH stretching band in the anion of o-hydroxy-benzoic acid.219 Deductions about the nature of hydrogen bonds have beenmade from the observed expansion of crystals containing short hydrogenbonds when the bonding hydrogen is substituted by deuterium. Pirenne 220presents calculations to show that this may be explained without introducingstrongly anharmonic forces or protonic resonance effects if a three-dimensionalmodel of the hydrogen bond is used.Other papers on the nature of thehydrogen bond have appeared.221 Correlations have been suggested be-tween X-H stretching frequencies and X-Y distances for several systems 222and for metallic hydroxides.223 Similar correlations have tentatively beensuggested for the deformation frequencies.22o Sutherland z2* reports on thedeformation frequencies of alcohols. Four bands characteristic of associatedalcohols are found in the region 1450-650 cm.-l. Among specific hydrogenboiiding systems studied were hydrogen bonding by phenols 2 2 5 9 217* 218 andby the thiol g r ~ ~ p .~ ~ ~ ~ ~ ~ ~ ~ It has been noted227 that the spectroscopicevidence does not support C-H * * 0 hydrogen bonding in certain caseswhere molecular interaction is present.Fundamental papers on the normal modes and spectra ofhigh polymers have appeared.228 Spectral changes of polymers consequentPolymers.p17 G. M. Barrow, J . Phys. Chem., 1955, 59, 1129.zl* H. Tsubomura, J . Chem. Phys., 1956, 24, 927.Z19 H. Musso, Chem. Ber., 1955, 88, 1915.220 J. Pirrenne, Physica, 1955, 21, 971.221 V. Von Keussler and G. Rossniy, 2. Elektrochenr., 1956, 60, 136; D. N. Shigorinet ai., Doklady Akad. Nauk S.S.S.R., 1956, 108, 672 ; D. N. Shigorin and N. S.Dokunikhin, Zur. $2. Khim. 1955,29, 1958.p22 N. Nakamoto, M. Margoshes, and R. E. Rundle, J .Amer. Chem. Soc., 1955, 77,6480; G. C. Pimentel and C. H. Sederholm, J . Chem. Phys., 1956, 24, 639.223 0. Glemser and E. Hartert, 2. anoi'g. Cham., 1956, 283, 111.224 G. B. B. M. Sutherland and co-workers, J . Chem. Phys., 1956, 24, 559; 25,778.225 (a) A. Wagner, H. J. Becher, and K.-G. Kottenhahn, Chem. Ber., 1956, 89,1708; ( b ) Y . Sat0 and S. Nakakura, Sci. Light, 1955,4, 120; R. Mecke and G. Rossmy,Z. Elektrochem., 1955, 59, 866.226 A. Menefee, D. A. Aliord, and C . B. Scott, J . Chem. Phys.. 1956, 25, 370.227 W. G. Schneider and H. J. Bernstein, Trans. Faraday SOC., 1956, 52, 13; C.Fauconnier and M. Harrand, Ann. Phys., 1956, 1, 5.228 C. Y. Liang, S. Krimm, and G. B. B. M. Sutherland, J . Chem. Phys., 1956,25, 543; MI. C . Tobin and M.J . Carrano, zbid., p. 1045; E. E. Ferguson, zhid., 24.111520 GENERAL AND PHYSICAL CHEMISTRY.on softening 229 and on irradiation 230 have been described. The effect ofcrystallinity on the infrared spectrum of poly(chlorotrifluoroethy1ene) hasbeen in~estigated.~~lMisceZEaneous applications. A number of papers have appeared on thespectra of adsorbed molecules. These are reported elsewhere in this volume.Infrared spectroscopy has been used to study flames.232 The infraredspectra of glasses,233 clays,234 and coals 235 have been described.Apparatus and Techniques-Evaluations of designs of infrared spectro-photometers have been made,236 and descriptions have appeared of a zir-conium arc source,237 a simple novel slit mechanism,238 a variable-pathabsorption cell for corrosive an apparatus for producing singlecrystals by sublimation,240 an automatic band integrator,241 and Ramanexcitation sources suitable for use with coloured corn pound^.^^^ 242 Otherpapers deal with the matrix isolation method for reactive molecules,243 infra-red measurements out to 140 microns,244 and a method of casting plasticreplica mirrors.245A.D. E. P.2. KINETICS OF CHEMICAL CHANGE.Kinetics in the Gas Phase.-During 1956 the study of chemical reactionsin the gas phase has yielded its usual heavy crop of publications. Thesecan be grouped mainly into a number of well-marked fields-purelytheoretical investigations, experimental studies of molecular decompositionsand isomerisations, reactions between molecules, and reactions involvingfree radicals and atoms.We have omitted here the extensive and ratherspecialised field of combustions, flames, ignitions, and explosions.229 G. S. Markova, G. K. Sadovskaya, and V. A. Kargin, Zhur. fiz. Khim., 1956, 30,437, English summary suppl- No. 2, 9 ; K. A. Fischer and G. Brandes, Naturwiss., 1956,43, 223.230 R. Kaiser, Kolloid Z . , 1956, 148, 168; A. Brockes and R. Kaiser, Naturwiss.,1956, 43, 53.231 I. I. Novak, Zhur. tekh. Fiz., 1955, 25, 1854.232 J . T. Neu, J. Phys. Chem., 1956, 60, 320; T. M. Cawthon and J. D. McKinley,jun., J . Chem. Phys., 1956, 25, 585.233 Ya. S. Bobovich, 0. P. Girin, and T. P. Tulub, Doklady Akad. Nauk S.S.S.R.,1955, 105, 61.234 S. G. GarciB, H. Beutelspacher, and W.Flaig, Anales Fis. QuZm., 1956, 52, B,39, 369; A. Hidalgo and J . M. Serratosa, ibid., p. 101.236 I. G. C. Dryden, Brennstoff-Chem., 1956, 37, 42 ; R. A. Friedel and J . A. Queiser,Analyt. Chem., 1956, 28, 22; G. A. Monnot and A. Ladam, Compt. rend., 1955, 241,1939; K. Kozima, K. Sakashita, and T. Yoshino, J. Chem. SOC. Japan, Ind. Chem.Sect., 1956, 77, 1432.z36 M. J . E. Golay, J. Opt. SOC. Amer., 1956, 46, 422; W. Zehden, S. African Ind.Chemist, 1956, 10, 77; K. Kudo, Sci. Light, 1955, 4, 105; 1956, 5, 1.237 W. H. Cloud, J. Opt. SOC. Amer., 1956, 46, 895.s38 H. M. Crosswhite and W. G. Fastie, ibid., p. 110.239 R. M. Adams and J . J . Katz, ibid., p. 895.240 S. Z. Zwerdling and R. S. Halford, J. Chem. Phys., 1956, 28, 2215.241 F. B. Strauss, Chem.and Ind., 1956, 1140.242 F. T. King and E. R. Lippincott, J . Opt. SOC. Amer., 1956, 46, 661.243 E. D. Becker and G. C. Pimentel, J. Chean. Phys., 1956, 25, 224.244 E. K. Plyler and N. Acquista, J . Res. Nut. Bur. Stand., 1956, 56, 149; C. Y .Liang, S. Krimm, and G. B. B. M. Sutherland, J. Chem. Phys., 1956, 25, 542.245 G. Haas, J . Opt. SOC. Amer., 1955, 45, 945KINETICS OF CHEMICAL CHANGE. 21Theoretical. There have been no entirely new developments in thetheories of rate processes. A few papers extending and clarifying certainaspects of existing theories have appeared ; the remainder are concernedwith the application and testing of established theories. A number ofpapers have been published on mathematical methods of handling certaintypes of mechanism and on the analysis of experimental results.In thefield of unimolecular reactions, Slater has re-emphasised the need for asynthesis of the four main treatments of such reaction processes. He hasmade a contribution in this direction by discussing the r81e of specific disso-ciation probabilities (S.D.P.) in these theories. The “ S.D.P.” is defined asthe probability per second of dissociation of isolated molecules in a givenstate; the state, in the simplest instance, is prescribed solely by a giventotal energy. Slater has shown that m y classical theory based on harmonicvibrations yielding an expression for the high-pressure rate constant of theform k , = A exp (--BIT) has necessarily an S.D.P. identical in form withthat of Kassel’s and must show a pressure dependence of the rate constantidentical with Kassel’s.A similar result is derived for the case correspond-ing to Kassel’s quantum-mechanical treatment. It is pointed out that amore detailed definition of S.D.P., i.e., one in which configuration and theinternal distribution of energy are important, is respoJisible for the fact thatSlater’s theory gives a pressure dependence of the rate constant differentfrom that of Kassel’s theory. Slater concludes that, whereas the conceptof a detailed S.D.P. is inappropriate to Kassel’s theory, it is implicit inEyring’s theory as formulated by Giddings and E ~ r i n g . ~ Slater has de-veloped a quantum-mechanical form of his harmonic-oscillator theory andhas also shown that the effect of anhannonicity on the results of his classicaltheory is negligible.Later, he has treated unimolecular dissociations onthe basis that the activated states are so closely specified that the lifetimeto dissociation is determinate. This “ determinate ” or “ regular ” situationgives different results for the pressure dependence of the rate constant fromthose of his treatment based on the usual assumption that dissociationsoccur at random. He concludes that the “ regular ’’ and “ random ” casesindicate the extremes between which lies the true pressure dependence.The limiting first- and second-order rates, however, are independent of thetype of distribution.The high frequency factors (-10l6 sec.-l) shown by certain moleculardecompositions (see Table 1) have received some attention.has discussed the results for a number of mercury alkyls.Assuming that,in some cases, more than one internal vibrational degree of freedom (up toa maximum of five) can contribute to the activation energy, and usingplausible critical energy values, Pritchard is able to account for the observedfrequency factors and activation energies. This theory has also beenPritchardN. B. Slater, Proc. Leeds Phil. SOC., 1955, 8, 259.Idem, Phil. Trans., 1953, A , 246, 57.J. C. Giddings and H. Eyring, J . Chern. Phys., 1954, 22, 638.N. B. Slater, Proc. Roy. SOC. Edinburgh, 1955, A , 64, 161.Idem, Proc. Leeds Phil. SOC., 1955, 6, 268.Idem, J . Chem. Phys., 1966, 24, 1256.H. 0. Pritchard, J . Chem. Phys., 1956, 25, 26722 GENERAL AND PHYSICAL CHEMISTRY.applied to the thermal decomposition of ketones, a number of which alsoshow high frequency factors (Table 1).The high frequency factors foundfor certain mercury alkyls have also been discussed by Carter, Chappell,and Warhurst in terms of the shape of the potential-energy surface repre-senting the energies of molecular configurations. Both these treatmentsassociate the high frequency factors with decomposition into three fragmentsin a single step, whereas normal ” values, i.e., 1013-1014 sec.-l areassociated with decomposition into two fragments.The ‘ I automatic fundamental calculations of molecular structure ” ofBoys et aL1* are perhaps the most significant theoretical development ofthe past year. Their calculations of the activation energy of the reactionH + H, + H, + H and of the dimensions and vibration frequencies ofthe transition state are the first to be carried out by a direct method withno semi-empirical features. It is claimed that their value for the activationenergy (0-025 atomic unit = 15-6 kcal.mole-l) could be improved withoutan unduly large amount of labour ; further results of this type of work willbe awaited with great interest. Sat0 l1 ha? applied his new semi-empiricalmethod l2 for calculating activation energies to the reactions H + HX +H, + X (X = halogen) and to the energies of X, “ molecules.” The resultsare in closer agreement with experimental values than those of Eyring andhis collaborators and the potential-energy surfaces are free from hollowsnear the saddles.The pre-exponential factors of twelve bimolecular reactions have beencalculated l3 on the basis of simple collision theory and also by using thetransition-state expressions (a) in the partition function form and (b) inthe thermodynamic form, for which the entropies of the activated complexeshave been estimated from analogies with hydrocarbons.Comparing theresults with the experimental values, the authors conclude that method (a)gives results which are a good deal more satisfactory, and method (b) slightlymore satisfactory, than those derived from collision theory. Knox andTrotman-Dickenson l4 have compared the experimental values for therelative pre-exponential factors of pairs of HR molecules in the chlorineatom reactions C1 + HR + CIH + R with the corresponding relativevalues calculated by transition-state theory.These authors consider thatboth the experimental and calculated ratios can be estimated much moreaccurately than absolute values for any one reaction. They are of theopinion that some of the discrepancies between the calculated and observedratios are definitely outside the likely errors in the estimations and may bedue to transmission-coefficient effects. Calculations of the steric factors forthe reactions of hydrogen atoms and radicals with unsaturated moleculeshave been reported.l5. l6D. Clarke and H. 0. Pritchard, J., 1956, 2136.9 H. V. Carter, E. I. Chappell, and E. Warhurst, J., 1956, 106.lo S.F. Boys, G. B. Cook, C. M. Reeves, and I. Shavitt, Nature, 1956, 178, 1207.l1 S. Sato, J . Chem. Phys., 1955, 23, 2465.l a Idem, ibid., p. 592.l3 D. R. Herschbach, H. S. Johnston, K. S. Pitzer,and R. E. Powell, ibid., 1956,25,736.l4 J. H. Knox and A. F. Trotman-Dickenson, J. Phys. Chem., 1956, 60, 1367.lb A. D. Stepukhovich, Doklady Akad. Nauk S.S.S.R., 1953, 92, 127.l6 A. D. Stepukhovich and E. I. Etingof, Z h u r . j z . Khim., 1955, 29, 1974KINETICS OF CHEMICAL CHANGE. 23Further work on the mathematical analysis of chain reaction hasappeared. Blanquet 17 has discussed special cases of chain-branchingmechanisms and Vasil'ev l8 has discussed the integration of the equationsof chain reactions in which the concentrations of active intermediates changewith time.For complex reaction mechanisms, instead of making approxim-ations to the rigorous rate expression so that these may be solved exactly,TABLE 1. A rrhenias parameters of molecular decompositions.Molecule Method (kcal . mole-') (sec .-l) Ref.E ADiethylmercury .............................. F, T 42.5 2 1 x 1014 9Phenylmercury chloride .................... 59 f 3 1 x 1013 ,,Phenylmercury bromide .................... 63 2 2 x 1014 ,,Trifluoroacetone ................................ 67.8 3.0 x 1013Acetophenone ................................... 77.6 11Trifluoroacetophenone ....................... 73.8 1.8 x 10'5 ,,Dibenzfrl ketone ................................ 71.8 1.8 x 1017 ,,72.0 2.4 x 1014 2ii1 -Ni tropropane ................................47.7 2.5 x 1013 ,,2-Nitropropane .............................. 39.0 1 x 1013Diethyl ketone .............................. S,'i(NO) 59.6 3.68 x 1013 IbcycloPenty1 bromide ........................ S 41.4 7.9 x 10'1 33Ethyl nitrate ................................. S 38.0 5.5 x 1014 34Diphen ylmercury ............................. 68 f 4 1 x lOl6 ,,Hexafluoroazomethane ....................... 48.5 9.0 x 1013 85.1 x 10"Benzophenone ................................... 87-5 1-6 x 10" ,,Acetone ......................................... 70.9 1.4 x lo'&NitFoethane .................................... F,"N, 41.4 + 1-1 2.2 x loll 29.......................................Methyl n-propyl ketone ..................... S, I (P) 56.3 1.07 x 1013 31cis- and trans- 1 : 2-Dichloroethylene.. ....S. C 52-7 3.6 x lo1* 32* F, flow system ; S , static system ; T, excess of toluene present ; K2] nitrogen ascarrier gas; I(NO), fully inhibited by nitric oxide; I(€'), inhibited by propene; C,chain reaction suppressed.Morrow l9 has suggested that it is useful to derive an approximate solutionof the rigorous expression by expanding the time variable as a function ofthe concentrations in the form of a Taylor's series. This can avoidintegrations which may be laborious. Papers on the mathematics ofseveral types of consecutive reaction 20i 21, 22* 23 have appeared in one ofwhich 23 the advantages of using matrices are illustrated. A special type ofmechanism involving simultaneous reactions has been discussed.24 Flynn 25has described a method for obtaining the rate constant and order of areaction when the reactant concentrations are unknown and the only availableexperimental information is the rate of formation of an unreactive product.The effect of the products on rates of energy transfer in unimolecular re-actions in the pressure region where the observed rate is determined by thel7 I-'.Blanquet, J. Chim. phys., 1955, 52, 826.S. S. Vasil'ev, Voprosy Khiwz. Kinetiki, Katalizai Keaksionnoi Sposobnosti Akad.J. C. Morrow, J. Chem. Phys., 1955, 23, 2452.Nauk S.S.S.R., 1955, 137.2o M. Talat-Erben, ibid., p. 2445.21 S. Wideqvist, Arkiv Kemi, 1956, 8, 545.22 D. H. McDaniel and C. 13. Smoot, J. Phys. Chem.. 1956, 60, 966.23 A.E. R. Westman and D. B. DeLury, Canad. J. Chem., 1956, 34, 1134.2*1 R. Zahradnik and 0. Schmidt, Chem. Listy, 1956, 50, 180.25 J. H. Flynn, J. Pkys. Chem., 1956, 60, 133224 GENERAL AND PHYSICAL CHEMISTRY.rate of activation has been discussed by Volpe and Johnston.2s They haveapplied their treatment to their recent experimental work27 on the uni-molecular decomposition of nitryl chloride in the presence of various foreigngases at low pressures. In this case, neglect of the energy-transfer efficiencyof the products introduces only small errors in the values of the rate constant.Molecular decompositions. Table 1 gives the values of the activationenergies and frequency factors obtained by new investigations on molecularthermal decompositions.All the examples have been shown to be first-order reactions (at least in the initial stages) and, with one or two doubtfulcases, the figures appear to be reliable for the unimolecular first step in thedecomposition. The results for the three aliphatic nitro-compounds 29and the two ketones 30332 are somewhat doubtful; the former because theauthors suspected that there may be a change of mechanism in the temper-ature range of the investigation; the latter because of the surprising andvariable behaviour shown by several simple ketones towards the presenceof nitric oxide. The decompositions of acetone,35 ethyl methyl ketone,36and methyl fi-propyl ketone31 are all catalysed by nitric oxide, but that ofdiethyl ketone 30 is inhibited by it. The results for cis- and tram-dichloro-ethylene,, are derived from the observations at high pressures when chainreactions are suppressed.These authors give details of the changes in theArrhenius parameters with pressure, and in a further paper 37 discuss thechain mechanism. Clarke and Pritchard have pointed out that theirresults for the series of ketones show that replacement of CH, by CF, hasvery little effect on either the activation energy or the frequency factor andhence the effective number of oscillators contributing to the reaction is notdependent on the physical mass of the relevant groups. Szwarc andTaylor28 identify the value of 72 kcal. mole-l for the activation energy ofthe decomposition of acetone with D(CH3-COCH,) and from this theydeduce a value of 17 kcal.mole-l for D(CH,-CO). These authors have alsoreviewed critically the validity of the toluene carrier technique. Theyconclude that for pyrolyses which yield methyl radicals the method willgive reliable results provided the methyl radical concentration is not veryhigh and that the method is quite reliable for the pyrolysis of bromides andsubstances which yield a large radical which then decomposes into a smallerradical and a stable species, the latter being used to follow the reaction.A value of G5.7 kcal. mole-l has been deduced 38 for the activation energyof the reaction H + H,CO __t H, + HCO from studies of the pyrolysis ofl6 M. Volpe and H. S. Johnston, J . Amer. Chem. SOC., 1956, 78, 3910.28 M. Szwarcand J.W. Taylor, J . Chem. Phys., 1955, 23, 2310.lS K. A. Wilde, Ind. Eng. Chem., 1956, 48, 769.8o C. E. Waring and C. S. Barlow, J . Amer. Chem. Sot., 1956, 78, 2048.81 C. E. Waring and V. L. Garik, ibid., p. 5198.82 A. M. Goodall and K. E. Howlett, J., 1956, 2640.aa S. J. W. Price, R. Shaw, and A. F. Trotman-Dickenson, ibid., p. 3855.34 F. H. Pollard, H. S. B. Marshall, and A. E. Pedler, Trans. Paraday Sot., 1956,35 C. E. Winkler and (Sir) C. N. Hinshelwood, Proc. Roy. Sot.,- 1935, A , 149, 340.s6 C. E. Waring and M. Spector, J . Amer. Chem. SOG., 1955, 77, 6453.87 A. M. Goodall and K. E. HowIett, J., 1956, 3092.98 R. Klein, M. D. Scheer, and L. J. Schoen, J . Amer. Chem. SOC., 1956, 78, 50Idem, ibid., p. 3903.52, 59KINETICS OF CHEMICAL CHANGE.25formaldehyde. Further confirmation of the molecular mechanism for theisomerisation of cyclopropane has been provided by McNesby and Gordon 39and Lindquist and Rollefson.40 The former heated cyclopropane-deuteriummixtures and found that no deuterated cyclopropanes or propenes are formed.The latter investigated the isomerisation of cyclopropane and rHflcyclo-propane, and found that the ratio of the rate constants (cyclopropaneltritiumcompound) = (0.63 & 0-02) exp [(825 -+ lO)/RT] in the range 447-555".The expression derived from transition-state theory is 1.16 exp (800/RT) andthe ratio of the frequency factors calculated from Slater's theory is 1-62.Both theories thus predict a frequency-factor ratio of greater than unity, incontrast to the experimental value of 0.63 & 0.02.A similar effect hasbeen found by Gray and Pritchard 41 who have found that the high-pressurerate constant for the thermal decomposition of octadeuterocyclobutane istwice that for cyclobutane. These authors point out that if the criticalco-ordinate is either a C-H or an H-H distance, and if the two activationenergies are equal, then Slater's theory would predictHowever, the cause of this apparent discrepancy may lie in a small differencein activation energy.The bimolecular decomposition of nitrogen dioxide has been re-examinedby Rosser and Wise 42 and by Ashmore and Le~itt.*~ At all except the lowestpressure the results for the reaction NO, + NO, + 2N0 + 0, agree withthose of Boden~tein.~~" At the lowest pressures and during the initial stagesof the reaction, Ashmore and Levitt found deviations from strict bi-molecularity which they account for by the participation of the reactionsNO, + NO, 4, NO + NO, and NO, + NO, t NO + NO, + 0,.Inboth studies the reaction was followed by measurement of changes in opticaldensity, the latter workers 43 using a logarithmic photometer. The halogen-catalysed thermal decomposition of nitrous oxide has been studied; thereaction was found to be of the first order in nitrous oxide and in halogenatom concentration. The pre-exponential factors and activation energiesfor the three cases of catalysis by C1, Br, and I atoms are 1.3 x 1014 and33.5, 2.0 x 1014 and 37, and 2.8 x 1014 and 38, respectively; the pre-exponential factors are in C.C./(mole sec.) units and the activation energiesin kcal. mole-l. It has also been found45 that the nitric oxide formed inhigh yield in the initial stages of the thermal decomposition of nitrous oxidequickly inhibits its own further formation and that the chemiluminescenceof this decomposition is closely related to this inhibiting effect. The chemi-luminescence is ascribed to the reaction NO + 0 + NO, + hv. A mech-anism for the decomposition is discussed by these workers. The catalysisby nitric oxide of the cis-trans-isomerisation of dideuteroethylene has beenkc0 (C4H8) lk,(C,D*) = 4 23s J. R. McNesby and A. S. Gordon, J . Chem. Ph-ys., 1956, 25, 582.40 R. H. Lindquist and G. K. Rollefson, ibid., 1956, 24, 725.41 B.F. Gray and H. 0. Pritchard, J., 1956, 1002.42 W. A. Rosser and H. Wise, J . Chem. Phys., 1956, 24, 493.43 P. G. Ashmore and B. P. Levitt, Research, 1956, 9, s25.4aa Cf. M. Bodenstein, Z.$hys. Chem., 1922, 100, 68.44 F. Kaufman, N. J. Gerri, and D. A. Pascale, J . Chem. Phys., 1956, 24, 32.46 F. Kaufman, N. J. Gerri, and R. E. Bowman, ibid., 1966, 25, 10626 GENERAL ANL? PHYSICAL CHEMISTRY.studied by Rabinovitch and Looney.46 The reaction is of the first orderin ethylene and in nitric oxide, the activation energy being 27.5 kcal. mole-1.These authors conclude that the isomerisation involves the opening of thedouble bond.Stepukhovich and his collaborators 47 have continued their studies of thethermal decomposition of gaseous hydrocarbons.'They find that tetra-methylethylene greatly accelerates the decomposition of propane at 590°,but the acceleration decreases with decreasing temperature until at 522" thissubstance retards the decomposition of propane. Similar results werefound for the decomposition of isobutane. The thermal decomposition ofbutyl bromides has been inve~tigated.~~ The secondary and tertiarybromides show first-order kinetics whereas the order for the normal andiso-butyl bromides is 1.5, owing to a chain mechanism. The observationsfor the first two bromides are in agreement with those of Maccoll et al. (seeAnnual Reports, 1955, 52, 10). In this field it has also been found49 (inagreement with Maccoll et al.) that the thermal decompositions of n-propyland isopropyl bromide are not straightforward unimolecular eliminations ofHBr.A study of the pyrolysis of [l-14C]propane has shown 50 that the12C-12C bonds in this molecule break about 8% more frequently than12C-14C bonds and this result is unaffected by the presence of nitric oxide.This difference is the same as that found by Stevenson et aL51 between12C-12C bonds and 12C-13C bonds. The velocity constant for the decom-position of photo-excited aniline molecules has been determined ; 52 thefrequency factor and activation energy of the process, which probablyinvolves the breaking of the C-N bond, are 3.6 x 1013 sec.-l and 12 kcal.mole-l, respectively. It is interesting that the frequency factor for thedecomposition of an excited molecule lies in the so-called '' normal range."Results for other excited molecules would be very interesting.A detailedexamination of the mercury-photosensitised decomposition of C,H,, C,D4,and cis-C,H,D, has been made,S3 and the results further confirm earlierwork by the same authors indicating that hydrogen and acetylene areformed from ethylene by direct molecular decomposition and not via theformation of free radicals. This process shows an isotope effect and exten-sive isotopic isomerisation also occurs ; cis-C,H2D2 isomerises to the antias well as the tram form. The change is considered to take place duringcollisional deactivation of energy-rich ethylene molecules. From a quantit-ative study of the rate of production of hydrogen it was concluded that theremust be two types of energy-rich ethylene molecules involved, only one of4 G B.S. Rabinovitch and F. S. Looney, J . Chem. Phys., 1956, 23, 2439.4 7 A. D. Stepukhovich and E. E. Nikitin, Doklady Akad. Nauk S.S.S.R., 1955, 105,48 G. B. Sergeev, ibid., 1966, 106, 299.d9 N. N. Semenov, G. B. Sergeev, and G. A. Kapralova, ibid., 1055, 105, 301.so H. M. Frey, C. J. Danby, and (Sir) C. N. Hinshelwood, Proc. Roy. SOC., 1956, A ,61 D. P. Stevenson, C. D. Wagner, 0. Beeclr, and J. W. Otvos, J . Chem. Phys., 1948,62 B. Stevens, ibid., 1956, 24, 1372.63 A. B. Callear and R. J. Cvetanovic, ibid., p, 873.54 R. J. Cvetanovic and A. B. Callear, ibid., 1955, 23, 1182.997.234, 301.16, 993KINETICS OF CHEMICAL CHANGE. 27which can decompose. In contrast to the above conclusions concerning theproduction of H, and C,H,, Varnerin and D o ~ l i n g , ~ ~ from an investigationof the thermal decomposition of C,H6-CD, mixtures, conclude that ethanedecomposes into two methyl radicals which start a chain mechanism, andthat a negligible amount of H, and D, are formed by direct moleculardecomposition.Benson 56 has given a detailed critical analysis of theTABLE 2. Values of ET - +ED and A,/~/AD for radical reactions involving ahydrogen-atom transfer. E T i s the activation of energy of the reactionR* + HX+ RH + *X and ED that of the dimevisation R- + R*-+R, ; AT and AD are the corresponding fire-exponential factors.RadicalCH,*,,Molecule (HX)D,D,CH,*CO*CH,H,CH,*CD,*CD2*CH,CH,*CH,*CH,CH,*CH,*CH,*CH,CH,*CH(CH,),H,HD (to give CF,H)HD (to give CF,D)D4CH,CH,*CHa*CH,*CH,CH;CH,*CH,*CH,D,H',E T - *ED(kcal .)11.912.1 f 0-69.8 f 0.410.2 f 0.59.311.46.5 f 0.55.1 f 0-34-7 f 0.39.5 f 0.710.5 f 1.510.2 f 1.510.2 f 0.79.5 f 25.5 f 19.78.87.66.25.34.7(3.0)1.78.0(7.7)6.07.2 f 0.58.0 - 9.24.98.5 f 0.1A T / ~ / A D[c.c. /(mole sec. )]4-13-9 x 1048.5 x 104-~3 x 104~ 1 . 5 x 1 0 45.8 x 1048.4 x 10412 x 1049-7 x 1 0 46.0 x 1047.2 x 104(0.73 x 104)0.3 x 104(5.8 x 104)6.8 x lo44.5 x 10'1.8 x 10'C4.8 x 10'(106 - 108)-Ref.58596bfi261, I, I633 ,I ,ii6k, I5 ,,.I 1,.,,#,,66676869(a) For the removal of a secondary H atom.( b ) For the removal of either a primary H atom OY a secondary D atom.(c) Calc.from the published figures for the ratios of the steric factors, PT/~/€'D,by assuming that the collision-number ratio Z , / l / Z , = lo7 [c.c./(mole sec.)]f.available experimental work on the pyrolysis of dimethyl ether. He hasput forward a chain mechanism for the decomposition and has derivedvalues for the rate constants of some of the reactions involved. The thermaldecomposition of some alkyl nitrites has been investigated. 57Reactions involving radicals. The activation energies and pre-exponentialfactors resulting from new investigations of the hydrogen-transfer reactionsof radicals are given in Table 2. The radicals have been produced mainly bythe photolysis of ketones.The agreement between the two schools ofss K. E. Varnerin and J. S. Dooling, J . Amer. Chent. SOC., 1956, 78, 2042.5 6 S. W. Benson, J . Chem. Phys., 1956, 25, 27.6 7 J. B. Levy, J . Amer. Chem. SOC., 1956, 78, 1780; Ind. Eng. Chenz., 1956, 48, 76228 GENERAL AND PHYSICAL CHEMISTRY.workers on the trifluoromethyl radical is very good, particularly sincedifferent methods and radical sources were used; one school 62s 63 usedthe photolysis of (CF,),CO, while the photolysis of CF,*N=N*CF, was usedby the other.B4* 65 Workers in both schools have arrived at the same generalconclusion, that the activation energies for the hydrogen-transfer reactionsof CF, radicals are 2-3 kcal. mole-1 less than those of the correspondingCH, radical reactions. Ayscough and Polanyi 63 have given a detaileddiscussion of their results for trifluoromethyl radical reactions in terms ofcollision theory and transition-state theory, and have calculated the pre-exponential factors of a number of these reactions.The results obtained 64for the reaction of CF, radicals with CH, together with those 70 for thereaction of CD, radicals with CF,H permit an estimation of D(CF,-H). Avalue of 102 & 2 kcal. mole-l was obtainedJ70 based on D(CH,-H) =102.5 & 1 kcal. mole-l.A new theory has been developed for the rotating-sector method ofinvestigating radical recombination rates.71 It includes the situation whenthe radicals are removed by both first- and second-order reactions.Appliedto the case of CH, radicals the recombination rate constant was found to be2.2 x lo1, c.c./(mole sec.) which is about half the value hitherto accepted.The method has also been applied to CF, radicals,72 yielding a rate constantof 2.3 x lo1, c.c./(mole sec.). A collision diameter of 4 A being assumed,this means that ED (Table 2) cannot be greater than 1.5 kcal. mole-l. Hencethe figures given in column 3 of Table 2 must be close to the true values forET. The sector method has also been applied to the recombination ofn-propyl radicals; 73 a value of 6 x 1015 c.c./(mole sec.) was obtained forthe sum of the rate constants of disproportionation and recombination. Theauthors, in discussing likely errors, state that this figure may be as much as20 times too large.It appears probable, however, that n-propyl radicalsrecombine at almost every collision. A very extensive study of the be-haviour of ethyl and propyl radicals at room temperature has been madeby Bradley, Melville, and Robb.',. '59 76 Two different methods were used6 8 J. R. McNesby, A. S. Gordon, and S. R. Smith, J . Amer. Chem. SOG., 1956,78, 1287.69 J. Chanmugam and M. Burton, J . Amer. Chem. SOC., 1956, 78, 509.6o H. Gesser and E. W. R. Steacie, Canad. J . Chenz., 1956, 34, 113.61 J. R. McNesby and A. S. Gordon, J . Amer. Chem. SOC., 1956, 78, 3570.62 P. B. Ayscough and E. W. R. Steacie, Canad. J . Chem., 1956, 34, 103.63 P. B. Ayscough and J. C. Polanyi, Tvans. Faraday SOC., 1956, 52, 960.64 G. 0. Pritchard, H. 0.Pritchard, and A. F. Trotman-Dicltenson, Chem. and Ind.,6 5 G. 0. Pritchard, H. 0. Pritchard, El. I. Schiff, and A. F. Trotman-Dickenson,O 6 R. M. Smith and J. C. Calvert, J. Amer. Cheun. SOG., 1956, 78, 2345.13' R. K. Brinton and E. W. R. Steacie, Canad. J . Chem., 1955, 88, 1840.6 8 C. A. Heller and A. S. Gordon, J . Phys. Chem., 1956, 60, 1315.139 J . T. Gruver and J. C. Calvert, J . Amer. Chem. SOG., 1956, 78, 5209.70 G. 0. Pritchard, H. 0. Pritchard, H. I. Schiff, and A. F. Trotman-Dickenson.71 A. Shepp, J . Chem. Phys., 1956, 24, 939.72 P. B. Ayscough, ibid., p. 944.73 S. G. Whiteway and C. R. Masson, i b i d . , 1956, 25, 233.74 J. N. Bradley, H. W. Melville, and J. C. Robb, Proc. Roy. Sot., 1956, A , 236, 318.76 Idem, ibid., p. 333.76 Idem.ihid.. D. 339.1955, 564.Trans. Faraday Sot., 1956, 52, 849.Chem. and Ind., 1955, 896KINETICS OF CHEMICAL CHANGE. 29for the production of ethyl radicals-the photosensitised decomposition ofhydrogen in presence of ethylene and the photolysis of diethyhercury-andinvestigations were carried out over a wide range of conditions. From thedeterminations of the ethane : butane ratio, these authors conclude 74 that,besides the normal two-body reaction between ethyl radicals, a three-bodyprocess is important at high pressures, while at low pressures wall reactionsbecome important. In addition the behaviour of " hot " ethyl radicalsmust be taken into account, The quantitative effect of these factors agreesclosely for the two methods of production of ethyl radicals.It is suggestedthat these factors are responsible for the varied results obtained in the pastby different workers. Bradley, Melville, and Robb's 74 observationsindicate that hot ethyl radicals only disproportionate and do not dimeriseand it is estimated that 105-106 collisions of a hot radical with neon arerequired for moderation, while ethylene is about five times more efficient.Estimates are also made of the ratio of the rate constants of the threedbodyand normal two-body reactions between ethyl radicals. The extrapolatedvalue of the ratio ethane : butane at zero pressure was found to be 0.86;this ratio decreases with increasing pressure, its average value being 0.43,which is close to that found by Ivin and S t e a ~ i e .~ ~ However, there appearsto be a considerable discrepancy between these results and the value of 0.15,for the ratio kdjqr.lk-mb. which Smith, Beatty, Pinder, and LeRoy 78have concluded is the best estimate from the most reliable investigations inthis field. Bradley, Melville, and Robb 75 studied the collision efficiencyfor the reaction of ethyl radicals by allowing this reaction to compete withthe destruction of the radicals at a molybdenum oxide surface. Mass-spectrometric analysis was used, which obviated the need for quantitativeobservations of the blueing effect of the oxide. The collision efficiency wasfound to be 0.15 -+ 0.03, corresponding to k, + krecomb. = 2.6 x 1013c.c./(mole see.). This is in excellent agreement with the value of 2.2 x 1013found by Ivin and S t e a ~ i e .~ ~ The work on propyl radicals,76 produced bythe photosensitised decomposition of hydrogen in the presence of propene,was carried out under conditions which favoured reaction by the normaltwo-body process. The average propane: hexanes ratio was found to be1.05 & 0.06, showing that propyl radicals disproportionate more readilythan ethyl radicals. It was also shown that the attack of propene byhydrogen atoms produces only 7.5% of m-propyl radicals, the remainderbeing isopropyl radicals. For the latter radical Heller and Gordon 68 findKaiepr./Kmomb. = 0-6 at 200" from studies of the photolysis of diisopropylketone. Brinton and Steacie 67 have studied the reactions of ethyl radicalsproduced by the photolysis of diethyl ketone; at the highest pressures theyfound evidence of a second butane-forming reaction in addition to thedimerisation of the radicals. At high intensities of illumination and lowketone pressures, when the ethylene produced comes solely from the dis-proportionation, the ratio of rate of ethylene production to rate of butaneproduction was 0.12 and constant over a wide range of conditions.This7 7 K. J. Ivin and E. W. R. Steacie, Proc. Roy. SOL, 1951, A , 208, 25.78 M. J. Smith, P. J. M. Beatty, J. A. Pinder, and D. J. LeRoy, Canad. J . Chem.,1955, 33, 82130 GENERAL .\NU PHYSIC.41, CXEMISTHY.result is close to the best value of 0-15 for kdispr./kmcomb. selected by Smithet aZ.78 Brinton and Steacie conclude that both the disproportionation andrecombination of ethyl radicals are homogeneous and independent ofpressure down to 0.01 mm.(cf., however, ref. 74). Results obtained forkdispr./hmcomb. for other radicals are 0.125 at 100" for n-propyl radicals 73and 1-67 at 25' for sec.-butyl radicals.69The free-radical reactions resulting from the photolysis of keten (aloneand in the presence of hydrogen and deuterium) have been studied by twogroups of workers.59* 60* 79 Unfortunately, the conclusions reached differseriously. Chanmugam and Burton 59* 79 consider that their observationsshow that the reaction CH, + CH,+ CH, has a small activation energyand is a significant reaction even at room temperatures, and that the dimeris-ation of methyl radicals cannot account for all the ethane produced in theirsystem.With CD, present they claim that the reaction CH, + CD,+CH,D, + CD, occurs. On the other hand, Gesser and Steacie 6o claim thatthe methylene radicals undergo the reaction CH, + H, + CH, + H(not CH,) and that the dimerisation of methyl radicals is the sole source ofethane. From their observations at the lower temperatures, Gesser andSteacie estimated that the activation energy of the reaction CH, + H, ---tCH, + H is 0.8 kcal. mole-l greater than that for CH, + CH,*CO +C,H, + CO and from this they deduce a lower limit of 103 kcal. mole-l forD(CH,-H). Methylene radicals have also been produced by the flash photo-lysis of keten.8O The observations show that methylene radicals must reactvery rapidly with keten (collision efficiency > to give cyclopropanone inone step, which then decomposes into the radicals *CH,-CH,-CO and*CH,-CO-CH,-, the former having a long life.These authors are of theopinion that the methylene radicals are produced in the singlet state by theflash photolysis. Methylketen has also been photolysed; the productssuggest that the primary act produces ethylidene radicals.From a study of the photolysis of (CF,),CO, Ayscough and Steacie 82have postulated the existence of two types of excited ketone molecules inthe system, only one of which has sufficient energy to decompose. Therelative rate constants of various energy-transfer processes involving thesespecies have been calculated. A new determination of the rate of reactionbetween nitric oxide and methyl radicals, produced by pyrolysis of dimethyl-mercury, has been made.83 A mass spectrometer was used and the values ofthe rate constants obtained are 1-4 x 1011 at 900" and 1.3 x lo1: c.c./(molesec.) at 480".The authors suggest that the rate constant may be higherthan this at higher pressures (they used -1 mm. of helium) and point outthat the results at various temperatures now available for this reactionindicate that the activation energy is probably zero. A similar study 83ahas provided a rough value of 10-3-104 for the collision efficiency of the79 J. Chanmugam and M. Burton, ibid., 1956, 34, 1021.G. B. Kistiakowsky and K. Sauer, J. Amer. Chem. SOL, 1956, 78, 5699.G. B. Kistiakowsky and B. H. Mahon, J - Chem.Phys., 1956, 24, 922.P. B. Ayscough and E. 'CV. R. Steacie, Proc. Roy. SOC., 1956, A , 234, 476.W. A. Bryce and K. U. Ingold, J . Chem. Phys., 1955, 23, 1968.K. U. Ingold and W. -4. Bryce, ibid., 1956, 24, 360reaction between methyl radicals and oxygen. Lossing et aLN have eni-ployed a mass spectrometer to investigate the mercury-photosensitiseddecomposition of olefins into free radicals. Ethylene decomposes primarilyby a molecular split; propene gives mainly allyl radicals and hydrogenatoms; but-l-ene gives allyl and methyl radicals, although splitting at aC-H bond also occurs to a smaller extent, and but-2-ene and isobutene bothdecompose by the splitting of a C-H bond. The subsequent reactions ofthe radicals produced were also studied.The decomposition of primaryand secondary n-butyl radicals has been investigated ; 85 they were producedby photolysis of acetone in the presence of [2 : 2 : 3 : 3-2H,]n-butane andthe products were identified by mass spectrometry and vapour-phasechromatography. The results show that hydrogen atoms in a free radicalcannot wander by an intramolecular process and that the radicals decomposemainly into a small radical (ethyl or methyl) and an olefin (ethylene orpropene). A value of 24 kcal. mole-l for the activation energy of the decom-position of secondary butyl radicals into propene and methyl radicals hasbeen obtained from work on the photolysis of a-methylb~tyraldehyde.~~The rather disturbing suggestion by Boynton and Taylor that studies ofmethyl-radical reactions may be appreciably affected by reaction of theradicals with mercury vapour to give dimethylmercury has been disproved bythe results of Kutshke and McElcheran *’ who havere-examined the photolysisof acetone in a system carefully kept free from mercury contamination.Reactions involviszg atoms.Relatively few quantitative results forvelocity constants and Arrhenius parameters of reactions involving atomshave been published during the past year. Cvetanovic 88 has studied thereaction of oxygen atoms, produced by the mercury-photosensitised decom-position of nitrous oxide, with acetaldehvde and acetaldehyde-ethylenemixtures at room temperature. From the results, together with his results 89for the ethylene reaction, Cvetanovic estimates that the activation energy ofthe acetaldehyde reaction is about 3 kcal.mole-l. has alsoreviewed the work on the reaction of oxygen atoms with various olefins andhas formulated certain rules concerning various possible mechanisms. Hehas estimated the relative rates of reaction at 2 5 O for a number of olefinsbased on n-butane as standard (= These are : cis-but-&ene,4.8 x isobutene, 6.9 x lo3; but-l-ene, 1.4 x ethylene,2-2 x lo4; acetaldehyde, 1.5 x n-butane, A study of thenitrogen afterglow bv a technique involving the simultaneous use of a massspectrometer and a photomultiplier has been made 91 which has provided avalue of 2 x c.c.2/(molecules2 sec.) for the termolecular rate constantfor the recombination of nitrogen atoms.This value is about one tenthof that found for recombination of iodine and bromine atoms. The84 I?. P. Lossing, D. G. H. Marsden, and J . B. Farmer, Canad. J . Chein., 1356, 34,J. R. McNesby, C. M. Drew, and A. S. Cardon, J . Chew Phys., 1956, 24, 1260.C. F. Boynton, jun., and H. A. Taylor, ibid., 1954, 22, 1929.K. 0. Kutschke and D. E. McEIcheran, ibid., 1956, 24, 618.Idem, J . Chem. Phys., 1955, 23, 1376.Idem, ibid., 1956, 25, 376.Cvetanovic701.88 R. J. Cvetanovic, Canad. J . Chem., 1956, 34, 775.91 J. Berkowitz, W. A. Chupka, and G. B. Kistiakowsky, ibid., p. 45732 GENERAL AND PHYSICAL CHEMISTRY.observations indicate that the reaction involves two 4S nitrogen atoms pro-ducing a 52: molecule which then undergoes a collision-induced radiationlesstransition to a 311, molecule.Values for the termolecular recombinationrate constants for iodine atoms 92 and bromine atoms 93 at high temperature(1000-1600" K) have been obtained by the shock-tube technique, Theresults for various gases as third bodies are given. These velocity constants,together with those obtained by flash photolysis at very much lower tem-peratures, establish the reality of a negative temperature coefficient beyondany doubt.An extensive investigation of the rates of reaction of sodium atoms witharomatic halides has been made 94 by use of the diffusion-flame technique.In addition to the halogen atom removed by the sodium, the halides con-tained a second unreactive substituent attached to the benzene ring.Bond-energy effects are shown to be negligible, and the gradations in velocityconstant are discussed in terms of the stabilisation of the transition state bythe participation of additional ionic structures arising from the presence ofthe second substituent. Winkler and his collaborators have continued theirinvestigations of the reactions of active nitrogen with various substrates-alkyl chlorides,95 methane and ethane,96 dimethyl- and diethyl-merc~ry,~~and a~etonitrile.~~ Evans and Winklerg9 have concluded that the mainactive species in this system is atomic nitrogen, but the evidence suggeststhat there is more than one species involved. They consider that vibration-ally excited molecules are the most likely possibility. The reactions ofactive nitrogen with organic substrates have been reviewed as a whole looand a unified mechanism has been outlined to account for the more importantfeatures of these reactions.The relative efficiencies of the addition of hydrogen atoms to ethyleneand propene have been re-investigated by Bradley, Melville, and Robb.lolUsing an improved molybdenum oxide technique, they obtained resultswhich are in satisfactory agreement with those obtained by other methods,and the ratio of the efficiencies H + propene : H + ethylene z 1-5 appearsto be well established. The investigation also shows that the collisionefficiencies of the radical reactions ethyl + ethyl, ethyl + propyl, andpropyl + propyl are all approximately equal.It has been discovered thattraces of oxygen greatly accelerate the hydrogen-deuterium exchangereaction.102 This is due to a chain reaction.This exchange reaction hasalso been very carefully re-investigated lo3 over the temperature range92 D. Britton, N. Davidson, W. German, and G. Schott, J. Chem. Phys., 1956,25,804.93 D. Britton and N. Davidson, ibid., p. 810.94 F. Riding, J. Scanlan, and E. Warhurst, Trans. Faraduy Soc., 1956, 52, 1354.95 B. Dunford, H. G. V. Evans, and C. A. Winkler, Canad. J. Chem., 1956, 34, 1074.9 6 P. A. Gartaganis and C. A. Winkler, ibid., p. 1457.97 D. A. Armstrong and C. A. Winkler, ibid., p. 885.O 8 W. Forst and C. A. WinMer, J. Phys. Chem., 1956, 80, 1424.O9 H. G. V. Evans and C. A. Winkler, Canad. J . Chem., 1956, 34, 1217.loo H. G. V. Evans, G.R. Freeman, and C. A. Winkler, ibid., p. 1271.lol J. N. Bradley, H. W. Melville, and J. C. Robb, Proc. Roy. Soc., 1956, A , 236,lo2 R. Kiein, M. D. Scheer, and L. J. Schoen, J. Amer. Chem. Soc., 1956,78,47.lo3 G. Boato, G. Careri, A. Cimino, E. Molinari, and G. G. Volpi, J. CkeM. Phys.,454, 446.1956, 24, 783KINETICS OF CHEMICAL CHANGE. 33916-1010" K. Irreproducible results were obtained unless the reactionvessel was surrounded by an evacuated quartz jacket which preventeddiffusion of air into the system through the reaction vessel walls. Theexchange rates obtained when diffusion of air was excluded were a factorof 2 lower (cf. ref. 102) than those obtained by previous workers. A valueof 59.8 & 0.4 kcal. mole-l was obtained for the total activation energy.Theauthors consider that the new results provide a stringent test of the transi-tion-state theory and they conclude that the theory can account satisfactorilyfor the observations.has been used to study the reaction H + 0,- OH* + O,, which isfollowed by OH* ---.t OH + hv. The preliminary results indicate that thefirst reaction probably goes at almost every collision and that the life-timeof the excited hydroxyl radical is about 8 xMolecuZeaoZec.uZe reactions. Further details of the work of Ashmoreand Levitt lo5 on the H2-NO, reaction have appeared, together with adescription of the logarithmic photometer lo6 which was used in the investig-ation. At 400" c, nitrogen dioxide in presence of excess of hydrogen israpidly and completely removed without change in total pressure ; the rateis much greater than that of the reaction 2N0, ----t 2N0 + 0,.Theinhibition of the reaction by nitric oxide is not due to the reverse of thereaction NO, + H, + NO + H,O, but is probably due to a chain reaction,the termination involving nitric oxide. Water has very little effect on theinitial rate but it accelerates the final stages of the reaction. Large amountsof oxygen retard the reaction. The authors conclude that further work isnecessary before the nature of the chain reaction can be established. Thekinetics of the CF,-CN-butadiene cyclisation reaction have been studied ; 10'this bimolecular reaction is a modification of the Diels-Alder condensationin which hydrogen is eliminated.The activation energy is 21.5 kcal. mole-1and the pre-exponential factor is 2.1 x lo9 c.c./(rnole sec.), the latter beingconsiderably less than the " normal " value for bimolecular reactions, andis characteristic of this type of condensation. The reaction between diethylether and nitrogen dioxide over the range 120-200" has been shown to bepredominantly bimolecular with an activation energy of 22 kcal. mole-I.The products are numerous and one of them, nitric oxide, acts as an in-hibitor.lo8 Between 0" and loo", pressure measurements indicate theformation of ether complexes with nitrogen dioxide. The inhibiting effectof nitrogen dioxide on the reaction between nitric oxide and dinitrogenpentoxide has been studied with a fast-scanning infrared spectrometer.1mValues of k,[k6 were obtained at various temperatures and total pressures,the rate constants corresponding to the reactions in the mechanism :kl k.klA modified form of the diffusion-flame techniquesec.N205 __L_ NO, + NO,; NO + NO, __)_ 2N02lo4 D.Garvin and J. D. McKinley, J. Chem. Phys., 1956, 24, 1256.lo6 P. G. Ashmore and B. P. Levitt, Trans. Furaduy SOC., 1956, 52, 836.lo6 P. G. Ashmore, B. P. Levitt, and B. A. Thrush, ibid., p. 830.lo' J. M. S. Jarvie and G. J. Janz, J. Phys. Chem., 1956, 60, 1430.108 E. A. Blyumberg, V. L. Pikayeva, and N. M. Emanuel, 2hur.ji.z. Khim., 1966,109 C . Hisatsune, A. P. McHale, R. E. Nightingale, D. L. Rotenburg, and B. Craw-29, 1569.ford, jun., J. Chem. Phys., 1955, %, 2467.REP.-VOL.LIII 34 GENERAL AND PHYSICAL CHEMISTRY.The hydrogen-bromine reaction has been investigated at 1000-1500" Kby the shock-tube technique. The experiments provide qualitativeinformation about the relative rates of the reactions comprising the well-known mechanism under non-steady-state conditions. The exchangereaction between B2D6 and B,H, at 80" has been studied by infrared spectro-scopy and by mass spectrometry.l12 Deuterium enters the pentaboraneby two main processes-by a direct exchange reaction which is almostexclusively restricted to the non-bridge hydrogens of the pentaborane, andb y synthesis following the pyrolysis of the diborane. The deuterium atomsenter singly during the exchange reaction and tracer studies with l0B showthat the boron atoms are not involved in the process.The reaction betweenB,H6 and PH, to give BH,*PH, (solid) has been shown to be a homogeneousgas reaction unaffected by the surface of the solid p r 0 d u ~ t . l ~ ~ A mechanismfor the reaction is suggested and the activation energy of the first stepB,H, + PH, + RH,*PH, + BH, is 11.4 kcal. mole-l with a steric factorof about 3 x [based upon a collision number of lo1* c.c./(mole sec.)].Varnerin and Dooling 114 have investigated the thermal reaction betweenC,H, and D,. The initial rates of formation of the numerous productswere measured by mass spectrometry. A free-radical mechanism is sug-gested and estimates are made of the overall activation energies for therates of disappearance of the reactants and of appearance of various pro-ducts.These are compared with theoretical estimates. Schissler andStevenson 115 have continued their mass-spectrometric studies of the gas-phase reactions between molecules and molecule-ions. In addition toreactions of the type X+ + HY + XH+ + Y, they give results forseveral reactions between simple hydrocarbons and carbonium ions. Forthe latter type, however, they emphasise that the simple interpretation ofthe reaction cross-sections (because of their dependence on certain experi-mental parameters) as bimolecular velocity constants is not strictly valid.Field et aZ.l16 have also published results for some examples of the secondtype of reaction; they concluded that the polarisation force between thecarbonium ion and the molecule is the dominant factor in determining thereaction cross-section.The kinetics of the equilibrium 2HI 4 H, + I, have been carefullyinvestigated from 600 to 775" K with a flow method.l17 The two reactionswere found to be strictly bimolecular and the results agree with extra-polations of previous results obtained at lower temperatures.The velocityconstants of the forward and reverse reactions are, respectively, 3-59 x1015 exp (- 49,2001RT) and 1-23 x 1015 exp (-41,0001RT) c.c./(mole sec.).Graven considers that his results disprove the suggestion 118 that above600" J< an atomic mechanism should play an appreciable part in the110 D. Britton and N. Davidson, J . Chenz. Phys., 1955, 23, 2461.111 J. J. Kaufman and W. S. Koski, ibid., 1956, 24, 403.112 W.S. Koski, J. J . Kaufmau, L. Friedman, and A. P. Irsa, ibid., p. 221.113 H. Brumberger and R. A. Markus. ibid., p. 742.114 R. E. Varnerin and T. S. Dooling, J. Arizey. Chew SOL , 1956, 78, 1119.116 D. 0. Schissler and D. P. Stevenson, J . Chem. Plays., 1956, 24, 926.116 F. H. Field, J . L. Franklin, and F. W. Lamp. J . A ~ M P Y . Chem SOC., 1956, 78, 5697.117 W. N. Graven, ibid., p. 3297.11s S. IV. Eenson and H. Srinivasan, J. CItent. Phys., 1955, 23, 300KINETICS OF CHEMICAL C:HANGE:. 36reactions, becoming dominant above 900" K. An attempt 119 to measurethe rate of exchange of 18F atoms between HF and variaus fluorinatedmethanes has shown, in contrast to the results for similar experiments 120on the exchange of isotopic chlorine between HC1 and chlorinated methanes,that no exchange occurs.The relative rates of exchange of 131 I between I, andcertain alkyl halides have been measured.121 The mathematical analysis ofthis type of system of competitive isotopic exchange reactions is also discussed.Radiation Chemistry.-In addition to the usual annual reviews on thistopic,lB collections of abstracts of the published and unclassified reportliterature have appeared3 and two more accounts of recent Russian workin the field became available at the end of lastDosimetry. The yield for the ferrous sulphate dosimeter has beendetermined more precisely for 2 Mv electrons as G(Fe3+) = 15-45 & 0.11molecules per 100 ev. There are now several independent determinationsof this yield covering 3 Mv electrons, 32P electrons, 1 Mvp X-radiation andMCo y-radiation, which use power output, counting, ionisation chambers,or calorimetric measurements for determining the energy absorption.Allagree within the experimental errors and there seems to be no variationwith intensity from 0.1 to 2 x lo6 R per sec. Slightly lower yields ofG(Fe3+) = 14-15 0.6 and 13.4 & 0.6 are obtained with 10 kv and8 kv X-radiation, respectively, by using 0-1N-sulphuric acid and assumingthe energy for ion-pair production (W) in air to be 34 ev.Hart et aL8 have obtained G(Fe3+) for 3.3-21.2 Mev deuterons and for0-3-2 Mev protons produced by a cyclotron. The former increases from6.90 to 10.86 over this energy range, and the latter from 7-16 to 8.00.Thereis reasonable agreement with previous determinations for particular energies.The methods used to measure the energy inputs in a similar investigationof cyclotron-produced deuterons and wparticles have been described9Pucheault lo finds that, by using ferrous sulphate solutions containingboric acid, the yields of Fe3+ given by y-radiation and neutrons in reactorradiation are additive. Ceric sulphate, ceric sulphate-boric acid, andferriin solutions l1 are recommended for separating the y and neutron119 J. E. Boggs, E. R. Van Artsdalen, and A. R. Brosi, J . Awzer. Chein. SOC., 1956,77,6505.120 J . E. Boggs and I,. 0. Brockway, ibid., p. 3444.lP1 L. R. Darbee, F. E. Jenkins, and G. M. Harris, .I. Chenr. Yhys., 1956, 25, 605.Ann.Reports, 1955, 52, 42.a C. J. Hochanadel and S. C. Lind, Ann. Rev. Phvs. Chem., 1956, 7, 83; F. S. Dain-ton, Ann. Rev. Nuclear Sci., 1955, 5, 213.R. W. Clarke, A.E.R.E. Reports C/R 1575 ; Part 1, Theory, Interpretations, Waterand Aqueous Inorganic Systems. Part 2, Organic Compounds (including Polymeris-ation Reactions). Part 4,Solid Systems (excluding Organic Compounds). Part 5, Biochemistry and Radio-biology (excluding animal studies).Session Acad. Sci. U.S.S.R. on Peaceful Uses of Atomic Energy, July 1955. Part 1,Meetings of Chem. Div.Collection of Papers on Radiation Chemistry, Ahad. Nazrk S.S.S.H., 1955.E. J. Hart, W. J. Ramler, and S. R. Rocklin, Radiatio9z Kes., 1956Part 3, Gaseous Systems (excluding Organic Compounds).Part 6, Miscellaneous.* R.H. Schuler and A. 0. Allen, J . Chem. Phys., 1956, 24, 66.7 M. Cottin and M. Lefort, J . Chint. phys., 1956, 53, 267.9 R. A. Schuler and A. 0. Allen, Rev. Sci. Iizstr., 1955, 26, 1128.10 J. Pucheault, .I. Chim phys., 1956, 53, 705.l 1 Idem, ibid., p. 69736 GENERAL AND PHYSICAL CHEMISTRY.intensities. Nitrous oxide, which on radiolysis gives nitrogen, oxygen, andnitrogen dioxide, makes a convenient gas dosimeter 12 for 5 x 104-1010 Rand has a yield G(-N,O) = 12.Detailed investigations are reported l3 on silver-activated phosphateglass for dosimetry over the range 103-107 R, and Cellophane sheets dyedwith an azo-dye are also suggested.14 The latter show a linear change intransmittance for doses of WCo y-radiation from 2 x 105 to lo7 R, with a1.5% change in transmittance for 1 0 6 ~ .Electrons are 2.2 times moreeffective. A book on radiation dosimetry which is mainly of interest toradiologists has been p~b1ished.l~Gases. Two reviews have appeared 16 on experimental and theoreticalaspects of the excitation and ionisation of molecules by electron impact,mainly in mass-spectrometer conditions. Momigny l7 finds that doubleimpacts by electrons can occur in the ion source, so that excitation may befollowed by ionisation at the second impact. Ionisation and excitationenergies are obtained which agree with spectroscopic values where available.Ionising electrons of energies up to 1100 v have been used in the massspectrometry of several alkyl halides.18 It is observed that the number ofions from molecular fragments decreases with increasing electron energy.Perhaps the most important recent contributions to radiation chemistryfrom mass spectrometry are Schissler and Stevenson’s observations l9 onthe reactions between ions and molecules.The reaction H2+ + H2+H,+ + H is well known and has been used in the interpretation of theradiation-induced reactions of hydrogen. Other types of ion-moleculereactions now found include :Krf + H, __+ KrH+ + H CHS + CH4 + C,H,+ + HSCH4+ + CHI CH,+ + CH, CaHe+ + CaH, C4H$ + C,H(It is also important that specific rate constants have been estimated whichshow that almost every collision is effective in reaction. In similar studiesMeisels et aLZ0 find that charge transfer with bond breaking may occur:A+ + CH, + A + CH,+ + H.These observations confirm the earlysuggestion of Lind that such ion-molecule reactions are important in radi-ation chemistry, and they also point to a likely mechanism for the productionof high-molecular weight products in the irradiation of hydrocarbons.Hickam and Fox 21 have applied the retarding-potential differencemethod, previously used in the study of positive-ion formation, to study thecapture of low-energy electrons (<2 V) by sulphur hexafluoride. Measure-12 P. Harteck and S. Dondes, Nucleonics, 1956, 14, No. 3, 66.1s S. Davison, S. A. Goldblith, and B. €2. Proctor, ibid., No. 1, 34; N. J. Kreidl andG. E. Blair, ibid., No. 1, 50; A. L. Reigert, H. E. Johns, and J. W. T. Spinks, kbid.,No.11, 134.14 E. J. Henly and D. Richman, Analyt. $hem., 1956, 28, 1580.16 G. J. Hine and G. L. Bronnell (ed.), Radiation Dosimetry,’’ Academic PressInc., New York, 1956.l6 J. D. Craggs and C. A. McDowell, Rep. Progr. Phys., 1955, 18, 375; M. Kraus,A. L. Wahrhaftig, and H. Eyring, Ann. Rev. Nuclear Sci., 1955, 5, 241.17 J. Momigny, J. Chem. Phys., 1956, 26, 787.18 N. N. Tunitskii, S . E. Kupriyanov, and M. V. Tikhomirov, ref. 5, p. 223.l9 D. 0. Schissler and D. P. Stevenson, J. Chem. Phys., 1955,B. 1363 ; 1956,24,926.ao G. G. Meisels, W. H. Hamill, and R. R. Williams, ibid., 1956, 25;, 790.a1 W. 31. Hiclrarn and R. E. Fox, ibid., p. 643KINETICS OF CHEMICAL CHANGE. 37ments of W for polonium a-particles in H,, N,, CH,, air, BF,, H,S, NH,,C,H,, CO,, SO,, CCl,, and EtOH have given, in general, good agreementwith previous determinations.22Among induced chemical reactions, the fixation of nitrogen in air asnitrogen dioxide (liquid and gas) by pile radiation 23 and the polymerisationof ethylene by y-radiation have been reported.24 The latter occurs by a chainreaction to give a wax at -20 atm.and room temperature, with yields ofabout lo4 ethylene molecules polymerised per 100 ev absorbed. At 77.6"carbon tetrachloride vapour with a-particles gives an ion-pair yield 26 ofchlorine of 0.14 which is much less than 0.4 obtained in the liquid phase. Inelectron-irradiated mixtures of C,H, and C,D, it is found 26 that the H,, HD,and D, mixture produced is not equilibrated and its composition indicatesthat at least half of the hydrogen and deuterium must be formed as moleculesfrom the hydrocarbon.On the other hand this does not seem to be the casewith methane, for Meisels et aL20 find that electron-irradiated mixtures ofCH, + A + I, do not give much CH,I,. The ethyl group in the largeamounts of C,H,I found here is thought to originate in the ion-moleculereaction CH,+ + CH,+ C2H,' + H,..An interesting study of indirect action caused by tritium @-irradiationof water vapour has been made by Fire~tone.~' When small amounts of D,in H,O vapour containing T,O are used, HD is formed with G(HD) = 11 & 1,independent of the amounts of H,O, D,, or T,O present. The suggestedmechanism for HD formation isfi + Ha0 H + HOH + DZ+ HD + DHO+DI+HOD+DD+D-DaOn this basis G(HD) = G(-H,O).The number of water molecules decom-posed in the vapour is therefore about three times that observed in liquidwater, which is consistent with current ideas that radical recombinationoccurs in the ionisation tracks in liquids.Non-aqueous Ziqztids. There has been a comprehensive review of theradiation chemistry of organic compounds 2s and of reactions which mightbe useful in synthetic organic chemistry.eg Berry et aLso have made amore extensive investigation of the quenching of the racliation-inducedluminescence of 9- and m-terphenyl and 1 : 4-diphenylbutadiene in benzene,cyclohexane, and toluene. The observations are consistent with the earliersuggestion that quenching is due to interaction of the quencher and excited29 C.Biber, P. Huber, and A. Miiller, Helv. Phys. Actu, 1955, 28. 603.23 P. Harteck and S. Dondes, J . Chem. Phys., 1956, 24, 619; Nucleonics, 1966, 14,No. 7, 22; S. Y. Pshezhetsky, I. A. Myasnikov, and N. A. Buneev, ref. 4, p. 64; ref. 5,p. 133.a4 J. C. Hayward, U.S.A.E.C., N.Y.O., 1955, 3313.2ci W. Mund, P. Huyskens, and J. Dedaisieux, Bull. Clusse Sci., Acud. my. Belg.,1955, 41, 929.28 L. M. Dorfman, J. Phys. Chem., 1956, 80, 826.27 R. F. Firestone, J. Amer. Chem. SOL, 1956, 78, 3226.28 E. Collinson and A. J. Swallow, Chem. Rev., 1956, 56, 471.E. J. Bourne, M. Stacey, and G. Vaughan, Chem. and Ind., 1956, 1372.so P. J. Berry, S, Lipsky, and M. Burton, Trans. Furuduy Soc., 1956, 52, 31 13s GENERAL AND PHYSICAL CHEMISTRY.solvent molecules before energy transfer to the scintillator can occur, butthe participation of ionic species cannot be ruled out.The resistance ofpolyphenyls to radiation has led to their consideration as pile moderatorsand coolants. With this in view Colichman and Gercke31 have subjecteddiphenyl, o-, m-, and fi-terphenyls, fi-quaterphenyl, and various mixtures ofthese to electron and pile radiation over the range 30-350". Yields ofgases (SO--SOO/d hydrogen) of 0 ~ 0 0 1 4 ~ 0 1 molecule per 100 ev were observed.Polymers are also produced.D e w h u r ~ t , ~ ~ using vapour-phase chromatography, has found a multi-plicity of products from the irradiation of n-hexane with 800 kv X-rays.Sixteen hydrocarbons from C , to C,, were detected.In contrast, cyclo-hexane gave only three. Schuler 33 finds the yields of hydrogen from irradi-ated liquid cyclohexane and benzene to decrease only slightly when 0 . 2 ~ -iodine is present, indicating that, as mentioned above for ethane, it must beformed as molecules rather than atoms. The acetylene yield from benzenebehaves similarly. In the presence of oxygen, irradiated heptane, 2-methyl-heptane, cyclohexane, toluene, and benzene give peroxy-compounds (RO),,RO,H, and H,O, (100 ev yields 1--2), carbonyl compounds (yields 0.6-2),and acids (yields 0-2-0.6).34 The yields of a variety of products from X -irradiated acetic acid in oxygen have also been measured.35Liquid ethyl iodide and n- and iso-propyl iodide with 120 kvp X-raysgive mainly iodine and hydrocarbons with the same number of carbon atomsas the parent,36 but these do not seem to originate from thermal radicals.The use of radio-iodine reveals that such radicals as are formed originatealmost entirely from the rupture of the C-I bond.The liberation of halogenby 6OCo y-radiation from CCI,, CBr,, C,CI,, and C&I, has also been in-vestigated ., '' T o y-radiation induces 38 the reactions C6H, + NH, + C,H,*NH2(yields up to 0.36) and C&6 + cc1,-+ C,H,*CCl, (yield 0.45). Otherradiation-induced reactions examined are the bromination of toluene byN-bromosuccinimide 39 and the oxidation of various alcohols by CCl, togive HCI, CHCI,, and aldehyde.40 These are chain reactions and in thelatter 100 ev yields as high as 1800 are observed.Radiation-induced polymerisation has received further attention.Callinan4l compared the physical properties of a variety of polymersprepared by radiation and by conventional initiators.The intensity depen-dencies for the radiation polymerisation of liquid vinyl chloride 42 andacrylonitrile (liquid and solutions) 43 are similar to those given by other31 E. L. Colichman and R. H. J. Gercke, NucZeonics, 1956, 14, No. 7, p. 50.s2 H. A. Dewhurst, J . Chem. Phys., 1956, 24, 1254.35 R. H. Schuler, J . Phys. Chem., 1956, 60, 381.34 N. A. Bach, ref. 5, p. 145; N. A. Bach and N. I. Popov, ibid., p. 156.56 N. A. Bach and V. V. Saraeva, ibid., p. 175.36 R. H. Schuler and R. C . Petry, J. Amer. Chem. SOC., 1956, 78, 3954.37 A.V. Zimin and 2. S. Egorova, ref. 5, p. 249.5 8 A4. V. Zimin, S. V. Churmanteev, and A. D. Verina, ref. 5, p. 249.so R. A. Cox and A. J. Swallow, Chem. and Ind., 1956, 1277.4O K. Hannerz, Research, 1956, 9, sl.'1 T. D. Callinan, J . Electrochem. Soc., 1956, 103, 292.45 R, Bensasson and A. PrCvot-Bernas, ibid., p. 93.A. Chapiro, J . Chim. phys., 1966, 53, 35KINETICS OF CHEMICAL CH-ANGE. 39methods of initiation. This argues against any localisation of the radicalsconcerned in the kinetic chain, Le., growing polymer radicals, but does notreveal anything about the spatial distribution of the initiating radicalsproduced by the radiation. A similar comparison of polymerisation rateshas given primary radical yields for the irradiationu of styrene[G(radicals) = 2 2 - 4 1 and methyl methacrylate (28-54) which, relatively,are in agreement with previous determinations.However, absolute valuesmuch lower than these are also reported.45 The formation of graft polymersoccurs when a polymer solution containing a different monomer isirradiated.@ Diphenylpicrylhydrazyl (DPPH) will also attach itself topolymer chains in similar conditions, but the interesting observation ismade that it does not react at the site of the free radical.46 This is con-cluded from the fact that the product still shows the oxidation-reductioncolour changes associated with free diphenylpicrylhydrazyl. The formationof graft copolymers by using ultrasonic radiation is also rep~rted.~'By an extension of Samuel and Magee'smodel, Ganguly and Magee 48 estimated theoretically the extent of primaryradical combination and primary radical-scavenger reactions occurring inwater with electrons, protons, and a-particles of various energies. Coulson 49has discussed the relative stabilities of H2+ and HO+, which have beensuggested as intermediates in irradiated water, and concludes that the latterwould react readily as HO" + H,O ---t HO + H20+.Weiss 50 suggeststhat the equilibrium HO + H,O+ + H20 + H20+ may be responsiblefor the pHdependence of radiation-induced reactions in water and thatH20+ + HO + H,02+- --t H202 -t H+ is a possible source of hydrogenperoxide.Hochanadel and Lind2 have chosen values of primary yields (Gw)for 0.8N-sulphuric acid and for solutions from 0 .0 1 ~ to neutral whichthey consider most representative at present. In 0.8N-sulphuric acid theypropose : &(H) = 3.70, Gw(0H) = 2.90, Gw(H20,) = 0.80, Gw(H2) = 0.4p.By use of these values and G(Fe3+) 7= 15.6 for aerated ferrous solutions in043N-sulphuric acid, a new determination 51 G(Fe3+) = 8.24 for de-aeratedsolutions now gives a quantitatively consistent picture of the oxidation ofFez+, provided that oxidation of Fe2+ by H (possibly as H,+, but see ref. 150)occurs in de-aerated solutions. A value of Gw(H) + Gw(OH) = 6.12 hasbeen obtained 52 from a comparison of the y- and ultraviolet-initiated chainoxidation of formic acid by hydrogen peroxide, and 6 rfr 0.4 is given 53by a new assessment of previous observations on the y- and ultraviolet-initiated chain decomposition of hydrogen peroxide.By measuring Gw(Fe3+)Water aizd aqueous solzitions.44 D. S. Ballantine, A. Glines, D. J. Metz, J . Behr, R. €3. Mesrobian, and A. J.4 5 T. S. Nikitina and K. S. Bagdasaryan, ref. 5, p. 183.46 A. Henglein and M. Boysen, Mukromol. Chem., 1956, 20, 83.4 7 A. Henglein, ibid., 1956, 18/19, 37.4 8 A. K. Ganguly and J. L. Magee, J . Chem. Phys., 1956, 25, 129.49 C. A. Coulson, J., 1956, 778.50 J. Weiss, Experiextia, 1956, 12, 280.5 1 N. F. Barr and C. G. King, J. Amer. Chem. SOC., 1956, 78, 303.s2 J. L. Weeks and M. S. Matheson, ibid., p. 1273.55 F. S. Dainton, ibid., p. 1278.Restaino, J. Polymer Sci., 1956, 19, 21940 GENERAL AND PHYSICAL CHEMISTRY.in aerated Fe2+ and Fe2+-Cu2+ solutions, Hart et aL8 have determined thenumber of water molecules decomposed for the loss of 100 ev by deuteronswith energies of 3-21 Mev and by protons of 0.3-2 MeV.G(H,O) = 3-5for 21 Mev deuterons which lose 100 ev in 224 A, and only decreases to 3.0for 0.5 Mev protons for which the energy is concentrated in 20 A. Donaldsonand Miller have used the Fe2+ + Cu2+ system with and without air toobtain primary yields for polonium a-particles. In the absence of air anappreciable yield of oxygen is found which is considered to originate fromHO, formed by the intra-track reaction HO + H,O, ---+ HO, + H20.The yields G ( H ) = 0.77 ; Gw(H0,) = 0.25 ; Gw (HO) + Gw(H,02) = 3.12 ;and &(H,) = 1-55 are obtained and the last is found to decrease at highCu2+ concentrations owing to the competition between Cu2+ + H andH + H in the track.Ebert et aZ.55 have extended their observations on hydrogen peroxideformation in oxygenated water by fast neutrons and Ghormley56 hasinvestigated the effect of the pulse frequency of 1.5 Mv electrons on thesteady-rate concentration of hydrogen peroxide formed in water.The latterexperiments suggest an intermediate with a lifetime of sec. in theseconditions. Steady-state concentrations of hydrogen and hydrogen peroxideattained in oxygenated water by 65 kv X-rays and %o y-radiation havebeen measured 57 and in general agree with previous observations.LeBail and Sutton 58 find that G(Fe3+) in y-irradiated Fe2+-H,SO,solutions is unaffected by oxygen pressures up to 14 atm.and by acid con-centrations up to 5 ~ , which further emphasises the anomaly of the highyields (up to 60) obtained by Proskurnin et aZ.59 G(Fe3+) is found by Trum-bore and Aten 6O to increase from 15.5 to 18.6 in going from H,O to D,Osolutions, which is more than the 12% reported by McDonell,61 who alsofinds 62 an increase in the rate of the y-initiated hydrogen peroxide decom-position in D,O. It seems probable that these differences originate fromthe different diffusion and recombination rates of the primary radicalsformed.It has been established by using tracers that the exchanges CrlI1-Crmand Tlm-TP are induced by y-radiation 63 and X-radiation respectively.In the thallium system T12+ is suggested as an intermediate. Sworski 66also invokes the formation of T12+ to explain the increase in G(Ce3+) to 7.9when Ce4+ solutions are irradiated with Tl+, compared with 2.39 withoutT1+.In this study it is also found, contrary to a previous report, that Ce3+decreases G(Ce3+) from 2-39 and this is attributed to the reaction54 D. M. Donaldson and N. MilIer, Trans. Faraday Soc., 1956, 52, 652.5 5 M. Ebert, P. Howard-Flanders, and D. Moore, Radiation Res., 1956, 4, 110.56 J. A. Ghormley, ibid., 1956, 5, 247.5 7 P. I. Dolin, ref. 5, p. 7.6 B H. LeBail and J. Sutton, J . Chim. $hys., 1956, 53, 430.6* M. A. Proskurnin, V. D. Orekhov, and E. V. Barelko, ref. 4, p. 41; M. A. Pros-61 W. R. McDonell, USAEC Report ANL5206.63 M. Lefort and M. Lederer, Corn@. rend., 1956, 242, 2458.64 G.E. Challenger and B. J. Masters, J . Amer. Chem. SOC., 1956, 78, 3012.6 5 T. J. Sworski, Radiation Res., 1956, 4, 483.kurnin, V. D. Orekhov, and A. I. Chernova, ref. 5, p. 79.C. N. Trumbore and A. H. W. Aten, J . Amer. Chem. SOC., 1956, 78, 479.Idem, ibid., Report ANL-5207KINETICS OF CHEMICAL CHANGE. 41Ce3+ + HO + Ce4+ + OH occurring in the tracks at the expense ofHO + HO -+ H,O,. Values of G(Ce3+) in CeSf + Cer+ + H2S04 +HCO,H solutions suggest that the reaction HO + H2S04 ---t H20 +HSO, occurs to a significant extent.Further work is reported on the irradiation of solutions of nitrite andnitrate,g7s 68 ferrous and ferric trisphenanthrolines and dipyridyl~,~~ andhydrazine. 70There has been much work on the radiation-induced oxidation of organiccompounds in oxygenated aqueous solution.Ethylene gives mainlyacetaldehyde and, at high pressures (ca. 45 atm.), yields up to 200 areobtained.71 A further examination of benzene solutions 72 confirms thatphenol is the major product (yield 2.2). A small amount of aldehyde isalso formed which appears to be mucondialdehyde, a product which couldresult from oxidative ring opening. In the presence of Fe2+ the phenolyield increases 73 to 6.0, no doubt owing to the utilisation of the hydrogenperoxide which is also produced. Solutions of butyl and benzyl alcoholsgive aldehydes and hydrogen peroxide T4 with a yield of 3.1. With ethanoland pyruvic acid Johnson et aL75 observed yields of aldehyde and lactic acidrespectively which rise as high as 7.0 as the concentration of substrateincreases to 1 .0 ~ . They point out that this is higher than would be expectedif HO alone were the oxidant since G(H0) = 3-35 Ascorbic acid inaerated solutions is found to be oxidised according to the reactionAH, + 0, + A + H20,, and a high oxidation yield of 7.8 is also reportedhere.5l This is accounted for by assuming that HO, also behaves as anoxidant. On the other hand, the high values of G(NH3) and G(g1yoxylicacid) given by the oxidative deamination of 0.5-%O~-glycine in aeratedsolutions 76 are attributed to direct action, possibly by " sub-excitation "electrons. The very high yields of sulphur (>lo3) from thiourea 77 nodoubt arise from a chain reaction. Secondary amines in solution giveprimary amine and aldehyde and it is suggested that the mechanismHO 0, Ha0R-NHCH~R - R-NH~HR RN:CHR - R.NH, + RCHOmay also account for cleavage and post-irradiation effects found withpeptides.78In de-aerated solutions an interesting difference between the effects ofcyclotron-produced helium ions and X-rays on aqueous glycine is observed.The helium ions give amino-derivatives of succinic acid 79 not found with68 T. J. Sworski, J . Amer. Chem. SOC., 1956, 78, 1768.67 V. D. Orekhov, A. I. Chernova, and M. A. Proskurnin, ref. 5, p. 91.6 8 N. A. Bach, ref. 4, p. 23.'O M. Lefort and M. Haissinsky, ibid., p. 527.71 E. J. Henley, W. P. Schiffries, and N. F. Barr, Amer. Inst. Chem. Eng. J., 1956,72 M. Daniels, G. Scholes, and J. Weiss, J . , 1956, 832.73 M.A. Proskurnin and E. V. Barelko, ref. 5, p. 99.74 M. A. Proskurnin, E. V. Barelko, and L. V. Abramova, ref. 5, p. 106.75 G. R. A. Johnson, G. Scholes, and J. ?Veiss, Nature, 1956, 177, 883.76 W. M. Garrison and B. M. Weeks, J . Chem. Phys., 1956, 25, 585.77 W. M. Dale, Nature, 1956, 177, 531.76 M. E. Jayko and W. M. Garrison, J . Chem. Phys., 1956, 25, 1084.J. Pucheault, J . Chirn. phys., 1956, 55, 697.2, 211.W. M. Gamson and B. M. Weeks. ibid., 1956, 24, 61642 GENEKAL AND PHYSICAL CHEMISTRY.X-rays, which is a consequence of the high radical concentrations in theformer case.The kinetics of y-initiated polyinerisation of acrylonitrile in aqueoussolution have been reinvestigated. The rate depends on (Intensity)Q85and it is concluded 8o that, since other methods of initiation give about thesame value of the exponent, the previous explanation of the high exponentin terms of a non-uniform distribution of the radicals is erroneous.Appre-ciable degradation of polymethacrylic acid by X-rays in aqueous solutionoccurs even in the absence of air.81 A parallel kinetic study of the break-down by HO produced from photolysed hydrogen peroxide supports thecontention that HO is responsible in the X-irradiation and not HO, aspreviously reported. These conclusions have been questioned. 82 Oxidativeand hydrolytic degradation of amylose in solution by y-radiation is foundto be accompanied by the production of small fragments of the molecule andof acidic group^.^The presence of glucose enhances the reversible reduction of aqueousmethylene-blue by y-radiation and the decomposition of low concen-trations of chloral hydrate by 200 kv X - r a d i a t i ~ n .~ ~ These effects areprobably due to the reactions of the radicals produced from glucose by Hand HO. Radicals produced in this way from a variety of organic com-pounds have been shown 86 to reduce Fe3+, Cu2+, and quinones, and whenboth H and HO give rise to a radical the amount of reduction produced is ameasure of Gw(H) + Gw(HO). The kinetic analysis of the metal ion-organiccompound systems, previously carried out by Hart for Fe3+ in formic acid,has enabled relative values for the rates of hydrogen abstraction by hydro-gen atoms for a number of substances to be determined.86In the biochemical field Butler has discussed the effects of radiation onimportant biological materials, in particular deoxyribonucleic acid (DNA),and reviewed the theories of radio-biological action.*' Further work onDNA suggests that breaks or weak points are produced in the single nucleo-tide strands. 88 Purine and pyrimidine ribonucleotides give hydroperoxidesin air and form labile phosphate esters, which release inorganic phosphateafter irradiation has ceased.89 High doses are usually required to produceobservable changes in DNA but Cole and Ellis observed that a dose of850 R given to deoxyribonucleoprotein produces a marked increase in theliberation of DNA by trypsin as well as a considerable decrease in swellingcapacity in water.Russian work on DNA and various proteins has alsobeen rep~rted.~l In work on biological iron compounds in solution Barron8O R.Benasson and A. Prkvot-Bernas, J . Chim. phys., 1956, 53, 93.81 J. H. Baxendale and J. K. Thomas, Chem. and Ind., 1956, 377.8a P. Alexander and M. Fox, ibid., p. 1387.8s E. J. Bourne, M. Stacey, and G. Vaughan, ibid., p. 573.a6 A. Hilsenrod, J . Chem. PhJls., 1956, 24, 917.86 J . H. Baxendale and D. Smithies, 2. phys. Chem. (Frankfurt), 1956, 7, 242.J. A. V. Butler, Radiation Res., 1956, 4, 20.08 K. V. Shooter, R. H. Pain,and J. A.V. Butler, Biochim. Bioph-ys. Acta, 1956,20,497.M. Daniels, G. Scholes, and J . Weiss, J . , 1956, 3771.DO L. J. Cole and M. E. Ellis, Rudiafion Res., 1956, 5, 252.91 A. M. Kusin,'Session Acad.Sci., U.S.S.R., on Peaceful Uses of Atomic Energy,V. D. Orekhov, A. I. Chernova, and &I. A. Proskurnin, ref. 5, p. 85.July, 1955 ; Meetings of Biology Division, p. 69; A. G . Passynsky, ibid., p. 104KINETICS OF CHEMICAL CHANGE. 43and Johnson 92 find that the FeII compounds oxyhzmoglobin and myoglobinare oxidised and the FeIII coinpounds hemoglobin, hzemin, cyanide haemo-chromogen, and cytochrome c are reduced. In all cases the porphyrin ringis destroyed. Indirect reduction of cytochrome c by the free radicalsproduced in the irradiation of solutions of ethanol, methanol, and hydrogenis found to give a product different from that of enzyme reduction, butbenzoate or succinate solutions yield the identical product.93 The change inthe catalase activity of irradiated yeast after irradiation has been investig-ated.g4Ghormley et d g 5 9 96 have extended previous observations onirradiated ice at low temperatures. Oxygenated ice gives hydrogen andhydrogen peroxide even at -200".There is evidence for the release of aspecies which decomposes hydrogen peroxide when irradiated ice is warmedto -180" and of another which has an absorption peak at 2800 tf. Thebehaviour of these entities with temperature is paralleled by that of para-magnetic resonance peaks attributed to H and HO respectively, and alsoby certain features of the luminescence which appears when ice warms afterirradiation at - 196".96 Paramagnetic resonance has been used to identifythe ions and radicals formed in the irradiation of a wide variety of com-pounds at -196" including alcohols, amines, amides, t h i ~ l s , ~ ' and alkyls oftin, zinc, and mercury.98 Electron-irradiated solid ferrous ammoniumsulphate gives sulphite, hydrogen, and Fe3+ when dissolved in water.Thehydrogen appears to arise as a result of reaction of the irradiated salt withthe water since anhydrous ferrous sulphate gives the same yield.99 A moredetailed account of the polymerisation of solid acrylamide by y-radiationhas been given.lm The reaction rate is of the first order in dose rate andthe polymer molecular weight independent of it, which suggests that thepolymerisation occurs in localised regions. Other solid monomers whichpolymerise are methacrylamide, methylenebisacrylamide, vinylcarbazole,vinyl stearate, methacrylic acid, and acrylic acid and its K, Ca, and Basalts.lm The polymerisation of hexamethylcydotrisiloxane to a substanceinsoluble in benzene occurs on irradiation with 800 kvp electrons.lO1 This isnot the usual type of polymerisation but rather resembles the formation ofhigh-molecular weight material from solid hydrocarbons.The subjecthas been reviewed by Charlesby lo2 and Russian work has been describedby Karpov.lm Chapiro lo4 has investigated the changes in colour andSolids.The irradiation of polymers continues to be an active field.** E.S . G. Barron and P. Johnson, Radiation Res., 1956, 5, 290.9s L. K. Mee and G. Stein, Biochem. J . , 1956, 62, 377.9' D. L. Aronson, M. J. Fraser, and C . L.Smith, Radiation Kes., 1956, 5, 225.95 J. A. Ghormley and A. C. Stewart, J . Amer. Chem. SOC., 1956, 78, 2934.9 6 J. A. Ghormley, J . Chem. Phys., 1956, 24, 1111.9 7 C. F. Luck and W. Gordy, J . Amer. Chem. SOC., 1956, 78, 3240.98 W. Gordy and C. G. McCormick, ibid., p. 3243.loo A. J. Restaino, R. B. Mesrobian, H. Morawetz, D. S. Ballantine, G. J. Dienes,lol E. J. Lawton, \V. T. Grubb, and J . S. Balwit, J . Polymer Sci., 1956, 19, 455lo* A. Charlesby, Nucleonics, 1956, 14, No. 9, p. 82.los V. L. Karpov, ref. 4, p. 1.lo' A . Chapiro, 3, Chim. phys., 1956, 58, 293, 295, 306.E. R. Johnson, ibid., p. 5196.and D. J. Metz, ibid., p. 293944 GENERAL AND PHYSICAL CHEMISTRY.softening points of poly(rnethy1 methacrylate) and cellulose acetate whenirradiated and finds prolonged post-irradiation effects. He considers thatthe primary reaction with these and with other polymers is the simultaneousbreaking of several C-C bonds, as occurs in mass-spectrometric observationson larger molecules.The changes in physical properties of a wide varietyof polymers after irradiation have been examined by Harrington,lo5 andFowler loti has given a theoretical treatment of the conductivity induced ininsulators such as amber, mica, and plastics. A clear picture of the processeswhich lead to cross-linking, hydrogen formation, and double-bond formationin polyethylene and related substances has not yet emerged, but recent workshows some advances. Several workers lO3*lo7 report a decrease in theextent of the crystalline phase in polyethylene on irradiation, an effectwhich is also observed with low-pressure polyethylene.lO* It is now estab-lished lo7, lo9 that the unsaturation which is produced is entirely trans-vinylene, and moreover these groups are also formed with about the sameyield in polymethylene and octacosane, so that branching in the moleculedoes not affect this process.lOg However, branching is responsible for almostall the gaseous hydrocarbon given by polyethylene.Miller et aLfW concludethat main-chain breaking is absent in unbranched molecules except at theends, that unsaturation- results from the ejection of molecular hydrogen,and that cross-linking occurs by combination between radicals on adjacentchains, these being formed by ejection or abstraction of hydrogen.On theother hand, Pearson 110 suggests that addition of polymer radicals to thedouble bonds formed is responsible for cross-linking. From the effect ofoxygen on gel formation, Alexander and Toms ll1 conclude that cross-linking and chain breaking are not alternative processes and that in thepresence of oxygen there is one break for each cross-link. Okamoto andIsihara 112 have used kinetic analysis to derive relationships between theextents of the various processes.Photochemistry. Work in which photochemical methods have been usedmainly to study the kinetics of gas phase reactions is dealt with under“ Kinetics of Gas Reactions.”It appears that after a run of 26 years aqueous uranyl oxalate is likelyto be replaced by ferrioxalate solution as a general purpose actinometerliquid.In addition to higher sensitivity and greater convenience, ferri-oxalate can be used further into the visible region, and as a result of athorough investigation by Hatchard and Parker values of quantumyields are now available from 509 mp to 254 mp. For special purposes, e.g.,intensity determinations in light of mixed wavelengths, uranyl oxalate isstill useful, and a method of analysis leading to increased accuracy has been105 R. H. Harrington, Nucleonics, 1956, 14, No. 9, p. 70.106 J. F. Fowler, Proc. Roy. SOC., 1956, A , 236, 464.lo’ A. Brockes and R. Kaiser, Nuturwiss., 1956, 48, 53.108 R. Kaiser, Kolloid Z., 1956, 148, 168.109 A. A. Miller, E. J. Lawton, and J. S. Balwit, J .Phys. Ckem., 1956, 60.l10 R. W. Pearson, Chsm. and Ind., 1956, 903.111 P. Alexander and D. Toms, J . Polymer Sci., 1956, 23, 343.112 H. Okamoto and A. Isihara, ibid., 1956, 20, 115.n* C. G. Hatchard and C. A. Parker, Proc. Roy. Soc., 1956, A , 235, 618,599KINETICS OF CHEMICAL CHANCE. 45described.l14 Further progress with light in the far ultraviolet region ismade possible by the development of a sapphire-tube discharge lamp 115with an output of 2 x 1019 quantalsec. in the 1540A region, and by theuse of synthetic BaF, crystals 1l6 which transmit down to 1345 A.Wijnen 117 has photolysed ethane at 1470 A and observed the formationof H,, CH,, C,H,, and C,H,,. The primary reaction is considered to beC,H, + hv --t C,H, + H which may be followed by H + C,H, +C2H6* ---t ZCH,.Further work on photo-ionisation round 1236 A showsthat with nitric oxide 118 dissociative recombination NOf + e + N + 0is important. Other reported photolyses in the gas phase are : CH20 +hv + H + HCO, which is effective at 3650 A and puts a lower limitof 78 kcal. on the C-H bond strength ; 119 CH,*CH:CO + hv + CH,*CH +CO ; l2* cyclooctatetraene + hv + C,H2 + C,H, + polymer; 121 and adetailed investigation of methyl iodide,12, which confirms that " hot ''methyl radicals are responsible for formation of CH, and some C2H6. Noyeset aE.1Z3 have reviewed the photochemistry of ketones with particular refer-ence to the primary act, and in the case of 3-chloro- and 4-chloro-butan-2-ones Taylor and Blacet l Z 4 find evidence that the major reactions areCH,CO*CHCl-CH, + hv __t CH,*CO*CH*CH, + Cl and CH3*COCH2*CH,C1 + hv __c CH,CO + CH,*CH,Cl respectively.The same workers alsoinvestigated 125 the photochemical oxidation of diacetyl by oxygen in whichthe main products are CO, CO,, CH,O, and H,O. Ozone formation fromilluminated NO,-O,-hydrocarbon mixtures has been followed 126 by infraredabsorption in a cell with path-length 430 m. in an attack on the problem ofatmospheric " smog " formation. Volman has analysed previous workon the production of ozone from oxygen and concludes that absorption abovethe convergence limit (1750 A) to give the state of oxygen is followedby dissociation to two 3P atoms as suggested earlier by Flory. In support ofthis, it is found las that the kinetics of H202, H,O, and 0, formation in H2-02mixtures at 1849 A agree with those obtained below the convergence limit.The applications of flash photolysis have been reviewed lZ9 and thetechnique has been used to show the existence of transient species in tetra-ethyl-lead vapour, irradiated aqueous amino-acids, 131 and halide11* G.T. Rogers, Chem. and Ind., 1956, 572.115 L. S. Nelson, J . Opt. SOC. Amer., 1956, 46, 768; L. S. Nelson and D. A. Ramsay,116 T. A. Chubb, J . Opt. SOC. Amer., 1956, 48, 362.117 M. H. J. Wijnen, J . Chem. Phys., 1956, 24, 851.11* M. Zelikoff and L. M. Aschenbrand, ibid., 1956, 25, 674.llS R. Klein and L. J. Schoen, ibid., 1956, 24, 1094.lZo G. B. Kistiakowsky and B. H. Mahan, ibid., p. 922.121 I<.Yamazaki and S. Shida, J . Chem. SOC. Japan, 1956, 77, 500.la2 R. D. Souffie, R. R. Williams, and W. H. Hamill, J . A w v . Ckem. Sot., 1956, 78,lZ3 W. A. Noyes, G. B. Porter, and J. E. Jolley, Cizern. Rev., 1956, MI, 49.lZ1 R. P. Taylor and F. E. Blacet, J . Amer. Chem. SOC., 1966, 78, 706.lZ5 Idem, I d . Eng. Chem., 1956, 48, 1505.12u E. R. Stephens, P. L. Hanst, R. C. Doerr, and W. E. Scott, ibid., p. 1498.lZ7 D. H. Volman. J . Chem. Phys., 1956, 24, 122.128 Idem, ibid., 1966, 25, 288.129 R. G. W. Norrish and B. A. Thrush, Quizrt. Rev., 1956,10, 149.lSo C. L. Cook and J. G. Clouston, Nature, 1956, 177, 1178.131 L. I. Grossweiner, J . Chew. Ph3fs., 1956, 24, 1255.J . Chem. Phys., 1956, %* 372.91746 GENERAL AND PHYSICAL CHEMISTRY.solutions,132 the formation of N, from NH,, and to obtain the spectrumof the radical HCO produced from acetaldehyde. 134In the liquid phase Fillet et ~ ~ 1 .l ~ ~ find that the photochemical oxidationof acetaldehyde to peracetic acid is a chain reaction with a mechanismanalogous to that established for the peroxidation of ethylenic compounds.The decomposition of chromyl chloride to CrO, and C1, in carbon tetra-chloride with 4190 light is also a chain reaction 136 with quantum yields102-103. The proposed primary step is CrO,Cl, + hv --F CrO,C,l + C1.The phenomenon of energy transfer from solvent to solute has been examinedfor irradiated solutions of P-terphenyl in toluene by Cohen and 1Veinreb.l3'They conclude that the transfer must take ca.lOu9 sec., i.e., there is somedelay. They also show that, even in dilute systems, energy is not exchangedbetween solvent molecules before transfer occurs. The transfer from p-terphenyl to other fluorescent compounds in toluene and dioxan-watersolutions has been examined by Gemmill.138 Terenin and Ermolaev 139have continued their studies of this in ethanol-ether glasses at -195", andshow that it is possible to transfer energy from a variety of donors whichabsorb the radiation, such as aromatic aldehydes and ketones, to a varietyof acceptors such as naphthalene, diphenyl, etc. However this is onlypossible when the triplet level of the donor is above that for the acceptor inaccordance with the general thesis that triplet states are the ones concernedin the transfer.Other studies on glasses include an investigation of the colour formationin irradiated spiro-pyran and dianthrane derivatives, 140 and a search forthe products of photolysis of tetramethyltetrazen, sulphur chlorides, bromal,bromopicrin, acetophenone, and dipheny1rner~ury.l~~ The last two, althoughshowing appreciable photolysis in the liquid, are stable in the glass a t 77" K.In aqueous solution reactions induced by the photolysis of hydrogenperoxide have been studied.Burton and Dewhurst compared thekinetics of oxidation of hydrazine induced by photolysed hydrogen peroxidewith the oxidation by ionising radiation studied earlier. Nitrogen, ammonia,and oxygen are produced and a reaction is suggested in which the primarystep H,O, + hv + 2H0 is followed by HO + N,H,+ ---t N,H4+ + H,Oand subsequent reactions of N,H4+ (or N,H,).The alternative primarystep H,O, + hv + H,O + 0 was also considered and rejected. Theprimary quantum yield for photolysis of hydrogen peroxide at 2537 A hasbeen redetermined by Weeks and Matheson 52 using the induced oxidationof formic acid by photolysed hydrogen peroxide in the presence of oxygen.The mechanism proposed by Hart is H,O, + hv ---t 2HO; HO + H*CO,H132 L. I. Grossweiner and M. S. Matheson, J . Chem. Phys., 1956, 23, 2443.133 B. A. Thrush, Proc. Roy. Soc., 1956, A , 235, 143.134 G. Herzberg and D. A. Ramsay, ibid., p. 34.135 P. Fillet, M. Niclause, and M. Letort, J . Chzm. phys., 1956, 53, 8.138 G.-M. Schwab and S. Prakash, 2.Phys. Chem. (Frankfurt), 1956, 6, 387.197 S. G. Cohen and A. Weinreb, Proc. Phys. Soc., 1966, B, 69, 593.138 C. L. Gemmill, Rudiaiio~ Res., 1956, 5, 216.139 A. Terenin and V. Ermolaev, Trans. Faraduy SOC., 1966, 53, 1042.140 Y. Hirshberg, J . -4mer. Chenz. SOC., 1956, 78, 2304.111 K. G. Sowden and N. Davidson, ibid., p. 1291.l42 AT. Burton and H. A. Dewhurst, 2. phj's. Chenz. (Fva7thf7411), 1956, 7, 27KINETICS OF CHEMICAL CHANGE. 47+ H20 + CO2H ; C0,H + H2Og + CO, 4- H2O -+- HO; CO2H -+0, ---t CO, + HO, ; 2H0, ----t H,O, + O,, so that the quantum yield forabsorption of oxygen is the primary yield for photolysis of hydrogen per-oxide. The kinetics are consistent with this scheme and the primaryquantum yield 0.49 is obtained. This agrees with another determination byuse of other aliphatic acids in the absence of oxygen.81 Here it is foundthat the quantum yield for photolysis of peroxide in conditions where thechain reaction is absent is 1-00 at 25" c, but falls to 0.50 in the presence ofaliphatic acids.This is interpreted to mean that the reaction HO +H,O, _.t HO, + H,O, which normally follows the primary step, is replacedby HO + CH,*CO,H --+ H,O + CH,*CO,H and that the radical CH,*CO,Hdoes not, as is the case with formic acid, take part in a chain reaction.Neither of these studies, however, eliminates the possibility of H,O, + hw +H,O + 0 as the primary step, but they do preclude the possibility thatoxygen atoms, if formed, combine to give 0,. Previous work on the ultra-violet-induced oxidation of Fe2 + in aqueous solution had indicated that thereaction Fez+ + H,+ _t Fe3+ + H, was important since the quantumyields were pH-dependent.However a re-investigation has shown thatinitiaZ yields are independent of pH and the alternative reaction Fe2+ + H +H,O+ FeOH2+ + H, is suggested. ofalcohols by oxygen photosensitised by sodium anthraquinone-2-sulphonateindicates that the excited quinone molecule reacts A* + R-CH,*OHAH + R-CH*OH. It is pointed out by Bowen 145 that this parallels pre-vious work with dichromate instead of quinone and suggests that here, too,hydrogen-abstraction occurs. The cross-linking of Polythene photosensitisedby benzophenone and diphenylamine observed by Oster 146 probably alsoinvolves a similar reaction, although cross-linking also occurs in the absenceof photosensitiser. Photosensitised oxidation-reductions induced by chloro-phyll-type compounds 147 and by fluorescein and its halogen derivatives 148are also reported.In the latter there is evidence from quenching experi-ments for a long-lived excited state. High-molecular weight copolymers ofally1 alcohol and acrylonitrile have been prepared by photopolymerisationsensitised by acriflavin and ascorbic acid,149 and the kinetics of polymeris-ation of styrene, initiated by the absorption of 4600 A light by Neutral-redand triphenylmethane-type dyes, have been obtained ; 150 the latter seemto act by energy transfer, but with the former it appears that radicals areproduced on illumination.Polymerisation.-Radical Po1ymerisations.-General.The effect of devi-ations from ideality on the molecular-weight distribution in linear poly-merisations has been considered. The classical network theory of gelationA study of the oxidationIra M. Lefort and P. Daizon, J . Chim. phys., 1956, 53, 536.144 C. F. Wells, Nature, 1956, 177, 482.L45 E. J. Rowen, ibid., p. 889.146 G. Oster, J . Polymer Sci., 1956, 22, 185.lr7 R. Livingston and R. Pariser, J . Amer. Chew. SOC., 1956, 78, 2944, 2948; R.118 A. H. Adelman and G. Oster, ibid., pp. 913, 3977.I5O H. Miyama, J . Chem. SOC. Japan, 1955, 76, 1013, 1361.Livingston and K. E. Owens, ibid., p. 3301.G. Oster and Y . Mizutani, J . Polymer Sci., 1956, 22, 173.F. E. Harris, J . Polymer Sci., 1955.18, 36148 GENERAL AND PHYSICAL CHEMISTRY.has been verified for a model unsaturated polyester cross-polymerisation.2The addition of a cross-linking agent to a very dilute solution of a susceptiblepolymer produces intramolecular cross-linking with the formation of rings.The probability of forming rings of various sizes, given one crosslink permolecule, has been dis~ussed.~ The hydrogen bonding which causes thedimerisation of carboxylic acids in solution also leads to the formation ofinter- and intra-molecular aggregates in polymers containing carboxylgro~ps.~ A thermistor method for the determination of velocity coefficientsin vinyl polymerisations has been developed and applied to reactions inhighly viscous media. The influence of carbons on polymerisation reactionshas been disc~ssed,~ and the presence of free radicals on the surface of carbonblack demonstrated by paramagnetic-resonance measurements.8 The actionof carbon black in stabilising polymeric materials cannot be accounted for bysimple cohesive forces and is probably due to the cross-linking of degradedpolymer radicals by carbon particles.Macromolecular stable free N-poly-radicals have been obtained by the y-irradiation of a number of polymers inthe presence of diphenylpicrylhydrazyl (DPPH) .lo The free radicalsproduced in the polymer combine with the a-N-phenyl nuclei rather thanwith the p-N-radical of DPPH, and subsequent oxidation gives a violetpolymer.Attempts to induce asymmetric radical addition during chain growthby using monomers containing an asymmetric centre close to the doublebond have been unsuccessful in homopolymerisations, l1 but Beredj ick andSchuerch have succeeded in obtaining an optically active copolymer.Thecopolymerisation of (-)-a-methylbenzyl methacrylate with maleic anhydridegives an optically active copolymer containing the asymmetric centresoriginally present in the monomer. When these are removed by reduction,the copolymer remains optically active, but of opposite sign to the unreducedcopolymer. The only apparent explanation is that asymmetry has beeninduced during the process of radical polymerisation. l2The photosensitised polymerisation of acrylonitrile inNN-dimethylformamide has been studied under homogeneous conditions l3at 25' c.The initiator exponent (0.59) found is slightly greater than theapproximate value of 0-5 previously reported,14 and strengthens the evidencefor retardation by chain transfer to the solvent. Constancy of order ismaintained up to at least 70% conversion, but after-effects have beenobserved which are not in conformity with the theoretical expression. WithGeneral kinetics.2 M. Gordon, B. M. Grieveson, and I. D. McBlillan, Trans. Faraday Soc., 1956, 52,3 W. Kuhn and H. Majer, Makromol. Chem., 1956, 18/19, 239.4 Shih-Yen Chang and H. Morawetz, J . Phys. Chem., 1956, 60, 782.5 H. Miyama, Bull. Chem. Soc. Japan, 1956, 29, 711.6 S. Fujii and S. Tanaka, J . Polymer Sci., 1966, 20, 409.9 R. S. Bradley, J . Colloid Sci., 1956. 11, 237.10 A.Henglein and M. Boysen, Makromol. Chem., 1956, 20, 83.11 C. G. Overberger and I,. C. Palmer, J . Amer. Chem. Soc., 1956, 78, 666.l2 N. Beredjick and C. Schuerch, ibid., p. 2646.13 P. F. Onyon, Trans. Faraday Soc., 1956, 62, 80.14 W. M. Thomas, E. H. Gleason, and J. J. Pellon, J . Polymer Sci., 1965, 17, 275.1012.P. Smith, ibid., 1956, 21, 143.M. Szwarc, ibid., 1956, 19, 589KINETICS OF CHEMICAL CHANGE. 49azoisobutyronitrile (AIBN) as catalyst at 60°, ferric chloride acts as anexclusive terminator, the ferric ion being reduced to ferrous.1s The valueof d[Fe2+]/dt gives the rate of initiation, and the rate constant for thedecomposition of AIBN into useful radicals has been determined. The rateof ferric termination depends on the electron-donating properties of thepolymer radicals, and the polymerisation of styrene is strongly inhibited byferric salts.The efficiency of initiation of styrene chains by AIBN has beendetermined in NN-dimethylformamide and in ethyl methyl ketone, and isin good agreement with the results for styrene in benzene obtained byBevington using a tracer technique. Collinson and Dainton have indi-cated the general nature of the redox reaction between organic radicals andmetallic sa1ts.l' The rate of reaction depends on the nature of the metallicion as well as on the polymeric radical,18 and in polymerisation systems inwhich the probability of chain transfer is low the reaction can be used todetermine the number average degree of polymerisation. Rate constantshave been determined for the thermal and photochemical bulk polymeris-ation of methacrylonitrile catalysed by benzoyl peroxide and AIBN.l9A.lthough the polymer comes out of solution as a highly swollen jelly at lowconversions, the rate constants for propagation, termination, and transferare normal. The energies of activation and the temperature-independentfactors, however, are all slightly higher than normal, probably owing to theenmeshing of radicals by the coiled polymer chains.The mechanism of polymerisation in precipitating media is still uncertain.The autocatalytic increase in rate with conversion characteristic of thesesystems has been observed in the y-ray initiated polymerisation of vinylchloride.20 The results can be partly interpreted by the non-stationary-statetreatment proposed by Magat,21 but the problem is complicated by theproduction of initiating radicals from the polymer.The non-stationary-state method has been applied to the bulk polymerisation of acrylonitrile 82based on the long-lived after-eff ects observed in the radiochemical polymer-isati0n.2~~ 249 25 The conventional termination reaction between propagatingradicals is assumed to be prevented by occlusion, leading to a continuedbuild-up in the concentration of these radicals with conversion. Thisapproach has been criticised by Bamford and Jenkins,Zs who show thatgrowing polyacrylonitrile radicals initiated photochemically undergo atermination reaction sufficiently rapid to give stationary-state conditionsat low conversions.The extended period of increase in rate with conversionobserved in both the photochemical and radiochemical polymerisations istherefore unlikely to be due to the gradual accumulation of occluded1 5 C. H. Barnford, A. D. Jenkins, and R. Johnston, Nubuve, 1956, 17'7, 992.16 J . C. Bevington, I'vuns. Furaduy SOC., 1955, 51, 1392.1 7 E. Collinson and F. S. Dainton, A7atura, 1956, 177, 1224.18 E. Collinson, F. S. Dainton, and G. S. McNaughton, J . Chim. phys., 1955, 52, 556.19 N. Grassie and E. Vance, Trans. Favaduv SOC., 1956, 52, 727.2" A. Chapiro, J . Chim. phys., 1956, 53, 512.21 81. Magat, J. Polymer Sci., 1955, 16, 491.24 J. Durup and M. Magat, ibid., 1955, 18, 586.24 I<. Bensasson and A. Prevot-Bernas, J . C h i i ~ .phys., 1956, 53, 93.2 6 A. Prevot-Bernas and J. Sebban-Danon, ibid., p. 418.26 c. €1. Barnford and A. D. Jenkins, J . I'olz'nt~r Sci., 1956, 20, 405.M. Magat, ibid., 1956, 19, 58350 GENERAL AND PHYSICAL CHEMISTRY.radicals. Ham 27 has shown that chain transfer with polymer is probablynegligible, and certainly not sufficient to account for the induction period.The usual stationary-state treatment has been used to derive ratios of kineticconstants in the bulk polymerisation of acrylonitrile 28 by azoisobutyro-nitrite at 25". In contrast to the reaction at 60°, the rate is substantiallyconstant over the range 1-20% conversion, and the results are consistentwith radical termination by disproportionation.Further confirmation of the ceiling-temperature effect has been obtained.29The heat and entropy of polymerisation, and hence the ceiling temperatureof l-enes, is independent of the length of the saturated side-chain, when thiscontains more than one carbon atom.A molecular-orbital theory ofreactivity in radical polymerisation has been presented30 and the effect ofviscosity on polymerisation kinetics examined.31, 32 The onset of diffusioncontrol at high conversion has been studied for the polymerisation of styreneand methyl metha~rylate.~~ The peroxide-catalysed bulk polymerisationof allyl acetate has been re-examined under oxygen-free condition^.^^ Thereaction exhibits the linear relation between. the disappearance of themonomer and the disappearance of peroxide characteristic of allyl polymer-isations, and ascribed to degradative chain transfer.Some induced decom-position of the peroxide occurs in this system, and to a greater degreein the polymerisation of l-methylprop-2-enyl acetate.35 Gaylord hasshown that although degradative chain transfer is the major factorlimiting the molecular weight in allyl polymerisation, effective chaintransfer may also play an important part, and is not excluded by aconstant value of d[monomer] /d[peroxide] .36 In the polymerisation ofl-methylprop-2-enyl propionate, effective chain transfer constitutes92-94% of the total transfer.37 Degradative transfer limits the molecularweight in diallyl polymerisation, but becomes less important beyond the gelpoint.38 There is some evidence that the termination step in the polymer-isation of 2 : 6-dimethylstyrenes is a degradative transfer.39 The use ofNN-dimethylaniline (DMA) as a promoter for the decomposition of peroxideinitiators (see p.50) has led to the investigation of its effect on chainpropagation and termination. The rate of decomposition of azoisobutyro-nitrile is not affected by NN-dimethylaniliiie but the rate of polymerisationof a number of monomers by azoisobutyronitrile is reduced in the presenceof NN-dimethylaniline, which acts as a chain-transfer agent .40 NN-z 7 G. E. Ham, J . Polymer Sci., 1956, 21, 337.28 1'. F. Onyon, ibid., 1956, 22, 19.29 F. S. Dainton, K. J . I ~ i n , and D. R. Sheard, Tvans. Faraday SOC., 1956, 52, 414.80 K. Hayashi, T. Yonezawa, C.Nagata, S. Okamura, and I<. Fukui, J . Polymer31 H. W. Melville, 2. Elektrochem., 1956, 60, 276.32 A. N. Pravednikov, Doklady Akad. Nauk S.S.S.U., 19.56, 108, 495.33 E. R. Robertson, Trans. Faraduy Soc., 1956, 52, 426.34 M. Litt, Diss. Abs., 1956, 16, 1218.35 N. G. Gaylord and F. M. Kujawa, J. Polymer Sci., 1956, 21, 327.36 N. G. Gaylord, ibid., 1956, 22, 71.37 N. G. Gaylord and F. M. Kujawa, zbid., 1956, 21, 329.3 8 H. W. Starkweather and F. R. Eirich, Ind. Eng. Chem., 1965, 47, 2452.39 M. J . Schlatter, J. Amer. Chew%. Soc., 1956, 78, 3440.40 M. Imoto, T. Otsu, T. Ota, H. Takatsugi, and M. Matsuda, J. Polymer Sci., 1966,SCL., 1956, 20, 537.22, 137KINETICS OF CHEMICAL CHANGE. 51Dimethylaniline may also influence the propagation step in the polymeris-ation of $-substituted styrenes by assisting the hyperconjugation effect.41The termination step in the polymerisation of styrene has been studiedwith a model polystyrene radical obtained by decomposing 1 : 1'-azobis-(1 : 3-diphenylpentane) .42 The results confirm termination by combinationrather than disproportionation over the range 25-144".The high ratesand molecular weights obtained with persulphate initiators in emulsionyolymerisations have also been observed under homogeneous conditions.The termination rate is decreased by the mutual repulsion of the ion-radicalactive centres.43 The polymerisation of vinyl acetate by high-energyradiation has been studied44 and a number of monomers have been poly-merised in the crystalline state by y-radiati~n.~~ Other studies include thepolymerisation of ethyl a~rylate,*~ methyl rnetha~rylate,~~ vinyl chloride,48and the dye-sensitised photopolymerisation of styrene.49The initiation constants of nine acyl peroxides have beendetermined for the polymerisation of methyl methacrylate.5o The decom-position of acetyl benzoyl peroxide,51 ethyl methyl ketone peroxide,52a-cumyl peroxide,% and organosilyl peroxides 54 has been studied. Theeffect of oxygen on the decomposition of azoisobutyronitrile and benzoylperoxide in aromatic solvents has been investigated. 55 Cyclic peroxideshave only weak initiating activity under normal conditi~ns,~B but in redoxsystems their activity is comparable with that of other peroxides, indicatingmonoradical initiati~n.~' The incorporation of catalyst fragments inpolymer molecules has been studied by analytical and radioactive-tracermethods. By using 14C-labelled benzoyl peroxide it has been establishedthat benzoate groups can be completely removed from polystyrene chainsby hydrolysis, and the proportion of phenyl to benzoate end-groups accur-ately determined.58 The presence of 1-3-1.6 benzoate units per chain hasbeen ascribed to initiation together with some termination by the benzoyl-o~y-radical,~~ but there is evidence that it may become incorporated in theInitiation.4 1 M.Imoto and K. Takemoto, J . Polymer Sci., 1956, 19, 205.43 C. G. Overberger and A. B. Finestone, J . Amer. Chem. Soc., 1956, 78, 1638.43 I. Jarkovsky, V. Stannett, and M.Szwarc, J . Polymer. Sci., 1955, 18, 515.44 S. Okamura, T. Yamashita, and T. Higashimura, Bull. Chem. SOC. Japan, 1956,4 5 A. J. Restaino, R. B. Mesrobian, H. Morawetz, D. S. Ballantine, G. J. Dienes, and4 6 Y. Hachihama and H. Sumimoto, Technol. Reports Osaka Univ., 1955, 5, 491.4 7 T. E. Ferington and A. V. Tobolsky, J . ColEoid Sci., 1955, 10, 536.4 8 F. Danusso and F. Sabbioni, Chinzica e Industria, 1955, 37, 1032; F. Danusso,49 H. Miyama, J . Chem. SOC. Japan, 1955, 76, 1361; 1956, 77, 601.51 J. Muller, Coll. Czech. Chem. Comm., 1956, 21, 216.53 M. R. Gopalan and M. Santhappa, Current Sci., 1956, 25, 116.53 H. C. Bailey and G. W. Godin, Trans. Faraday SOC., 1956, 52, 68.54 W. Hahn and L. Metzinger, Makromol. Chem., 1956, 21, 113.6 5 G.A. Russell, J . Amer. Chenz. SOC., 1956, 78, 1044.6 6 R. Zand and R. B. Mesrobian, ibid., 1955, 77, 6523.6 7 W. Hahn and A. Fisher, Makromol. Chem., 1956, 21, 106.5 * J. C. Bevington and C. S. Brooks, J . Polymer Sci., 1956, 22, 257.5s M. M. Koton, J. M. Kiselova, and M. J. Bessenov, Doklady Akad. Nazik S.S.S.R.,29, 647.D. J . Metz, J . Amer. Chem. SOC., 1956, 78, 2939.F. Sabbioni, and L. Siliprandi, ibid., 1956, 38, 99.N. G. Saha, U. S. Nandi, and S. R. Palit, J . , 1956, 427.1954, 96, 8552 GENERAL AND PHYSICAL CHEMISTRY.polymer by a mechanism independent of the polymerisation process.@The activity of tetra-alkylthiuram disulphides as thermal initiators hasbeen confirmed. Diphenyl and dibenzoyl disulphides are more effective asphotosensitised initiators for styrene than azoisobutyronitrile or benzoylperoxide, but do not a k t as thermal initiators up to 120O.61 The attack ofthionyl and bromine radicals on double bonds has been discussed in terms ofthe reversible formation of a radical complex as the initial step.62The redox initiations of the polymerisation of methacrylic acid andacrylonitrile by peroxidic compounds has been investigated.The induceddecomposition of peroxides by dimethylaniline has been studied in a numberof systems,a*66*66 but no clear mechanism has yet emerged. Benzoylperoxide with NN-dimethylaniline can initiate the polymerisation of methylmethacrylate in the range -40" to + Z O O , well below the temperatures atwhich the peroxide alone will initiate it.In this range the initial rate de-pends only on the product [Peroxide]i[DMA]i and a bimolecular reaction isp o ~ t u l a t e d . ~ ~ Imoto and Takemoto have found that the rate of decom-position of benzoyl peroxide by a number of di-N-alkylanilines is closelyconnected with the ionisation constant of the base,68 and favour a directattack on the peroxide bond, while Horner and Kirmse consider the first stepto be the formation of an undefined complex which breaks down by electrontransfer to give eventually a DMA radical, a benzoyloxy-radical, and benzoica ~ i d . ~ Q Bond has criticised both mechanisms and has suggested a com-promise. 70Solutions of ceric salts, normally used as photosensitised initiators, willalso polymerise acrylonitrile and methyl methacrylate in the dark.71 Ferric-oxalate complex has been used as a photosensitised initiator, the kineticsindicating initiation by the oxalate radical-ion, and termination by recom-b i n a t i ~ n . ~ ~ The polymerisation of ethylene at 250-300" sensitised by thethermal decomposition of ethyl iodide in the presence of mercury vapour hasbeen studied by using 14C-labelled ethyl iodide. An equilibrium betweenethyl iodide, mercury, mercuric iodide, and ethyl radicals is probablyinvolved. 73Kinetic experiments on the inhibition ofmethyl methacrylate polymerisation by moIecular oxygen show that exactly1 : 1 copolymerisation occurs during the inhibition period. The chain lengthis reduced by a factor of 65 and termination takes place by the Combinationof two oxygenated chain ends.The rate constant for oxygen addition toRetardation and inhibition.60 R. L. Dannley and E. L. Kay, J . Polymer Sci., 1956, 19, 87.til T. Otsu, ibid., 1956, 21, 559.63 C. Sivertz, W. Andrews, W. Elsdon, and K. Graham, ibid., 1956, 19, 587.63 T. M. Gritzenko and S. S. Medvedev, Zhur.fiz. Khim., 1956, 30, 1238, 1513.64 T. Azumi and Y . Okada, J . Chene. Soc. Jafian, Ind. Chem. Sect., 1956,59,30.6 5 H. Takatsugi, ibid., p. 260.6 6 M. Imoto, T. Otsu, and T. Ota, ;bid., p. 700.6 7 K. F. O'Driscoll and A. V. Tobolsky, J . Colloid Sci., 1956, 11, 244.6 8 M. Imoto and K. Takemoto, J . Polymer Sci., 1956, 19, 579.69 L. Horner and W. Kirmse, Annalen, 1966, 597, 48, 66.7O W. B. Bond, J . Polymer Sci., 1966, 22, 181.7 1 J.Saldick, ibid., 1966, 19, 73.'2 R. V. Subramian and M. Sahthappa, Current Sci., 1956, 25, 218.73 V. B. Sefton and D. J. LeRoy, Caiznd. .I. Chew., 1956, 34. 41KINETICS OF CHEMICAL CHANGE. 63the growing chain is at least five orders of magnitude higher than that formonomer additiom7* Similar copolymers have been obtained by the adionof oxygen on metha~rylonitrile,~~ indene,76 and styrene 77 polymerisations.Polymeric styrene peroxide is explosive above 50" c, breaking down to benz-aldehyde and formaldehyde. Peroxidic copolymers are also believed to betransient intermediates in the persulphate-initiated polymerisation ofacrylonitrile, methyl vinyl ketone, and methacrylonitrile in aqueous solu-t i ~ n . ? ~ The addition of sulphur to the bulk thermal polymerisation ofstyrene causes inhibition owing to the formation of polysulphides, whichreact subsequently with growing chains to form disulphides. These canbreak down to free radicals, giving further initiation, so that the rate ofpolymerisation is initially slower than the thermal rate, and eventuallybecomes faster.79 The inhibition of methyl acrylate polymerisations by anumber of substituted benzoquinones has been compared with that ofmethyl methacrylate.sO The redox reaction of metallic salts with growingradicals has been investigated.15* l7 The polymerisations of acrylonitrileand acrylamide are retarded, and that of styrene inhibited, by ferric salts,while growing poly(methy1 methacrylate) radicals react slowly, if at all, withferric ion.In view of the inefficiency of diphenylpicrylhydrazyl as a radical trap,81an attempt has been made to find a more trustworthy inhibitor.A stablefree radical obtained by the oxidaton of the condensation product of acetonewith phenylhydroxylamine gives a well-defined inhibition period in styrenepolymerisation, and the products do not affect the reaction, but the stoicheio-metry during the inhibition period is uncertain.82Transfer constants with eleven solvents have been measuredfor the polymerisation of methyl acrylate. These are found to be consis-tently higher than those obtained with methyl methacrylate, possibly owingto a steric effect. The efficiency of alkylbenzene solvents as chain-transferagents varies with the reactivity of the paraffinic hydrogen atoms in theorder tertiary > secondary > primary, benzene having the lowest transferconstant, and isopropylbenzene the highest.= Measurements of the transferof 2-vinylpyridine radicals with 9-chlorotoluene support the view that thealkyl side-chain rather than the benzene nucleus of the solvent is involved.84Transfer constants for the polymerisation of ethyl acrylate in varioussolvents have been determined,86 and transfer to thiols in the polymerisationof methyl methacrylate has been further investigated.8s A comparisonTransfer.74 G.V. Schulz and G. Henrici, Makrornol. Chem., 1956, 18/19, 437.16 S. F. Strause and E. Dyer, J . Amer. Chem. SOC., 1956, 78, 136.76 G. A. Russell, ibid., pp.1035, 1041.7 7 A. A. Miller and F. R. Mayo, ibid., pp. 1017, 1023.78 E. Dyer, 0. A. Pickett, jun., S. F. Strause, and H. E. Worrell, jun., ibid., p. 3384.79 P. D. Bartlett and D. S. Trifan, J . Polymer Sci., 1956, 20, 457.80 J. L. Kice, ibid., 1956, 19, 123.8 1 J. C. Bevington, J . , 1956, 1127.82 J. C. Bevington and N. A. Ghanem, ibid., p. 3506.83 A. D. Gadkary and S. L. Kapur, Makrornol. Chem., 1955.1'7, 29.84 R. L. Dannlep, J. A. Schufle, I. Cohen, and J. R. Chambers, J . Polymer Sci., 1956,8 6 Y. Hachihama and H. Sumimoto, Teehnol. Beports Osaka Univ., 1955, 5, 485.86 S. Fujii, S. Tanaka, and S. Sutani, J . Polymer Sci., 1956, 20, 584.19, 28554 GENERAL AND PHYSICAL CHEMISTRY.has been made of the transfer activity of a number of tertiary amines in thebulk polymerisation of acrylonitrile, and of triethylamine with five vinylmonomers.87 The chain transfer of styrene with an aliphatic nitrile, thiol,primary and secondary alcohol,88 and Q- and P-bromostyrene 89 has beenmeasured.In vinyl benzoate polymerisations chain transfer to the aromaticnucleus of the polymer and monomer has been confirmed.90Copolymerisation. The copolymerisation of methyl methacrylate andmaleic anhydride behaves abnormally 91 in that an increased rate of reactionis obtained with increasing proportion of maleic anhydride, possibly due tosensitivity of the cross-termination coefficients to a change of environment.In the formation of peroxidic copolymers with acrylonitrile, methyl vinylketone, and methacrylonitrile, the order of reactivity of the monomers withthe peroxy-radical agrees with that of the Alfrey-Price Q-values for thesemonomers.78 An equation has been derived correlating the degree of poly-merisation with the copolymerisation rate and various rate constants,which should permit the experimental determination of cross-terminationand cross-transfer constants.92 Measurements of the heat of copolymeris-ation of methyl methacrylate and acrylonitrile show that the steric strainpresent in 1 : 1-disubstituted polymers is partly relieved by the incorpor-ation of l-monosubstituted monomer units into the chaineg3 The size of thealkyl group in trialkyl aconitates,M and of the acyl chain in vinyl esters,Q5has no effect on their reactivity ratios with a number of vinyl monomers.Monomer reactivity ratios have also been determined in the systems vinylstearate-vinyl acet at e,96 poly (et hylene fumarat e)-met hyl met ha~rylate,~’diethyl vinylphosphonate-styrene,g8 and for the copolymerisation of vinyl-idene cyanide with a wide range of common monomers.9g The results arein good agreement with parameters calculated for vinylidene cyanide bythe Q-e method.A number of simple vinylsiloxanes have been copolymerised with organicvinyl monomers and are shown to have reactivities comparable with that ofvinyl acetate or vinyl chloride.lW Vinyltriethoxysilane and eleven othervinylsilanes give copolymers with vinyl chloride and acrylonitrile.101 Ally1monomers, which give only low-molecular weight homopolymers , have been137 C.H. Bamford and E. F. T. White, Trans. Faraday SOC., 1956, 52, 716.88 M. Morton, J. A. Cala, and I. Piirma, J . Amer. Chem. SOC., 1956, 78,89 M. H. Jones, Canad. J . Chem., 1956, 84, 108.90 G. Smets and A. Hertoghe, Makromol. Chem., 1956, 17, 189.9 1 D. C. Blackley and H. Melville, ibid., 1956, 18/19, 16.92 S. R. Palit, Trans. Faraday SOC., 1955, 51, 1720.93 J . H. Baxendale and G. W. Madras, J . Polymer Sci., 1956, 19, 171.94 C. S. Marvel, J. W. Johnson, jun., J . Economy, G. P. Scott, W. K. Taft, and B. G.95 L. P. Witnauer, N. Watkins, and W. S. Port, ibid., p. 213.96 A. Adicoff and A. Buselli, ibid., 1956, 21, 340.9 7 M. Gordon, B. M. Grieveson, and I . D. McMillan, ibid., 1956, 18, 497.@ * C. L. Arcus and R. J .S. Matthews, J.. 1956, 4607.DD H. Gilbert, F. F. Miller, S. J. Averill, E. J. Carlson, V. L. Folt, H. J . Heller,F. D. Stewart, R. F. Schmidt, and H. L. Trumbull, J. Amer. Chem. SOC., 1956, 78,1669.5394.Iabbe, ibid., 1956, 20, 437.100 R. M. Pike and D. L. Bailey, J. PoZymer Sci., 1966, 23, 66.lo1 B. R. Thompson, ibid., 1956, 19. 373KINETICS OF CHEMICAL CHANGE. 55successfully copolymerised with several monomers to give high-molecularweight compounds.lo2P lo3Branching : block and graft copolymers. The comparative activities inhydrogen abstraction of some initiating radicals have been determined semi-quantitatively.88 Oxy-radicals appear to be only five to ten times moreactive in hydrogen abstraction than carbon radicals, so that primary radicalsderived from peroxide initiators are unlikely to affect the degree of branchingof a polymer chain, in view of the relatively large concentration of growingradicals.The formation of graft and block copolymers has been reviewed l0Q andsome known methods have been improved and extended.lo5 Graft co-polymers of methyl methacrylate and styrene have been made by the ultra-sonic degradation of a solution of the polymers,lo6 by y-irradiation of poly-(methyl methacrylate) in the presence of styrene monomer,lo7 and by usingbrominated polystyrene as a photochemical initiator for methyl methacrylatenionomer.lo8 In the photodegradation of poly(methy1 vinyl ketone) poly-meric free radicals are produced which can form graft polymers in the pre-sence of vinyl monomers.lo9 Amino-groups in poly-(9-aminostyrene) havebeen converted into N-acetyl-N-nitrosoarylamino-groups, which can initiatethe polymerisation of acrylonitrile to give a graft polymer.l1° The methodof cold mastication of a polymer in the presence of a monomer has beenwidely applied.lll Barnard has described a neat method of characterisingthe synthetic chains in interpolymers of natural rubber with syntheticpolymers, involving degradative ozonolysis of the rubber trunk chains,leaving the polymer chains intact .l12Szwarc, Levy, and Milkovich have reported a method for the preparationof block copolymers which is likely to have wide applications. The initiationof the polymerisation of styrene by a sodium-naphthalene complex gives,eventually, a growing chain with an anionic active centre at both ends.The carbanions do not terminate, and a living I' polystyrene is obtainedwhich can initiate polymerisation in other monomers, forming block co-polymers.A number of monomers can be added in succession, and theprocess stopped at any stage, so that considerable controlled variation incomposition is p0ssib1e.l~~Ionic Polymerisation.-The polymerisation of styrene by stannic chloridein benzene and carbon tetrachloride has been investigated. The inductionperiod peculiar to these solvents does not appear to be due to HCI produced102 G. Oster and Y . Mizutsni, J . Polymer Sci, 1956, 22, 173.103 A. Drucker and H. Morawetz, J . Amer. Chem. SOC., 1956, 78, 346.104 E. H.Immergut and H. Mark, Makvomol. Chem., 1956, 18/19, 322.105 P. E. M. Allen, J. M. Downer, G. W. Hastings, H. W. Melville, P. Molyneux, and106 A. Henglein, Makvoniol. Chem., 1956, 18-19. 37.107 D. S. Ballantine, A. Glines, D. J- Metz, J. Rehr, R. B. Mesrobian, and A. J.108 M. H. Jones, Canad. J . Chem., 1956, 34, 948.1L@ J . E. Guillet and R. G. W. Norrish, PYOC. Roy. SOC., 1955, A , 235, 172.110 'w. Hahn and A. Fischer, Makromol. Chem., 1956, 21, 77.111 D. J. Angier and W. F. Watson, J . Polymer Sci., 1956, 20, 235.113 hl. Szwarc, M. Levy, and R. Milkovich, J . Anzer. Chenz. Soc., 1956, 78, 2656.J . K. Urwin, Nature, 1956, 177, 910.Restaino, J . Polyntev Sci., 1956, 19, 219.D. Barnard, ibid., 1956, 22, 21356 GENERAL AND PHYSICAL CHEMISTRY.by hydrolysis of the catalyst, as previously suggested.l14 The kinetic resultsare ill-defined, probably owing to variations in the unknown water content,but there is a distinct difference of order and rate of reaction in the twoLittle is knownabout the stoicheiometry of possible initiating complexes in Friedel-Craftspolymerisation, but some related stable complexes have been reported.With aluminium bromide 116 benzene forms a complex A1,Br6,2C,H, whilealuminium chloride 117 gives 1 : 1 complexes with methanol, ether, and tetra-hydrofuran in benzene solution, and reacts with water to give AlC1,OH.Some progress has been made by the use of simplified systems whichavoid the inherent experimental difficulties of Friedel-Crafts catalysts.Evans, Jones, and Thomas 11* have studied the dimerisation of 1 : l-di-phenylethylene catalysed by trichloroacetic acid, and have shown that thereaction involves three molecules of the catalyst, two of which are believedto contribute to the solvation of the reaction of the monomer ion with asecond monomer molecule, whereas in the dimerisation of di-e-methoxy-phenylethylene the rate-determining step is the formation of the monomerThe polymerisation of styrene by trifluoroacetic acid has beeninvestigated in solvents of varying dielectric constants, and in the undilutedacid.120 In the latter practically instantaneous polymerisation occurs,giving high-molecular weight polymer.The abnormally high rate isascribed to solvation of the anionic half of the active complex by acidmolecules, retarding the recombination which normally terminates thegrowing chain.The molecular termination constants of mono- and fi-di-alkylbenzenes in the cationic polymerisation of styrene indicate that transfertakes place to the aromatic nucleus rather than to the side-chain of the alkyl-benzenes. Any branches arising from transfer to the polymer are thereforelikely to be attached to phenyl nuclei.121The use of a sodium-naphthalene complex to initiate an essentiallyanionic polymerisation of vinyl monomers has been described 113 (see p. 55).With styrene, the naphthalene anion acts as an electron-transfer agent,giving an ion-radical which grows at both ends, one free-radical and theother anionic. As soon as the two ends are appreciably separated theradicals terminate by mutual combination, giving chains with propagatinganions at both ends, which do not terminate.This method of initiation isnot restricted to conjugated monomers, and has been used with methylmethacrylate.f22 In this case, however, the polymer does not remain “ alive,’’owing to a rapid self-terminating reaction. Complexes formed betweensodium and polynuclear aromatic hydrocarbons have been studied. 123although their dielectric constants are similar.114 S. Okamura and T. Higashimura, J . Polymer Sci., 1956, 20, 581.1 1 5 Idem, ibid., 1956, 21, 389.118 F. Fairbrother and K. Field, J., 1956, 2614.117 J . R. Bercaw and A. B. Garrett, J . Amer. Chem. SOC., 1956, 78, 1841.118 A. G. Evans, N.Jones, and J. H. Thomas, J., 1955, 1824.119 A. G. Evans, N. Jones, P. M. S . Jones, and J. H. Thomas, J . , 1956, 2757.120 J. J. Throssell, S. P. Sood, M. Szwarc, and V. Stannett, J . Amer. Chem. SOC.,121 C. G. Overberger, G. F. Endres, and A. Monaci, ibid., p. 1969.112 M. Szwarc and A. Rembaum, J . Polymer Scz., 1956, 22, 189.12s D. E. Paul, D. Lipkin, and S. I. Weissman, J . Anter. Chem. SOC., 1956, 78, 116.1956, 78, 1122KINETICS OF CHEMICAL CHANGE. 67Stereospecific PoLymerisaticm.-A thorough review of the availableinformation on the Ziegler process as applied to ethylene has been given inVol. XI of the Interscience “ High Polymers ” series.124 Further work onthe structure of crystalline poly-a-olefins has appeared 125 and has beensummarised by Natta.1z6 The long-standing problem of synthesising“natural” rubber has been virtually solved by the polymerisation ofisoprene with stereospecific catalysts to give a cis-1 : Ppolyisoprene, whichhas practically the same structure and molecular-weight distribution asHevea r~bber.12~, 128 Details of stereospecific catalysts are scarce, but it isbecoming apparent that there may be a considerably greater range of suchcatalysts than was at first supposed.In addition to variants of the Zieglerpr0cess,1~Q finely-divided lithium metal 127 has been used to make stereo-specific polyisoprene. Other alkali metals give only amorphous polymerunder the same conditions. Chromium oxide supported on a silica-aluminabase gives fairly crystalline polyethylene at moderate pressures,lm but withrt-but-l-ene gives only 1-3% of isotactic polymer, compared with 60-70%obtained with Al(C,H,),-TiCl, complex as ~ a t a 1 y s t .l ~ ~ Schildknecht andDunn 132 have obtained crystalline poly(ksobuty1 vinyl ether) using borontrifluoride-ether complex as catalyst in propane at -70” to -80”. Thepolymer is precipitated as a swollen solid phase, but propagation is believedto take place homogeneously, in contrast with other systems. It is thoughtthat a slow or diffusion-controlled propagation step may allow time for theorientation of polarised monomer molecules approaching the carbonium ion.A new development in both catalyst and monomer is the stereospecificpolymerisation of optically active propene oxide by powdered potassiumhydroxide, and by a ferric chloride-propene oxide complex.133 The stereo-specific reaction is heterogeneous, and does not destroy the asymmetriccentre of the monomer, so that optically active crystalline polymer isobtained. There is also a concurrent homogeneous reaction which is notstereospecific, and gives amorphous inactive polymer, the net productbeing a mixture of amorphous (70%) and crystalline (30%) forms. Withracemic monomer a similar mixture is found, the crystalline portion beingan inactive mixture of chains which have individually either all (+) orall (-) units.la With potassium hydroxide as catalyst, (-)-propene oxide124 R. A. V. Raff and J. B. Allison, “ Polyethylene,” Interscience, New York, 1956.1~ G. Natta and P.Corradini, J. Polymer Sci., 1956, 20, 251 ; Idem, Angew. Chem.,1956, 68, 615; G. Natta, L. Porri, P. Corradini, and D. Morero, Atti Accad. naz. Lincei,Rend. Clusse Sci. fis. mat. nut., 1956, 20, 560; G. Natta, P. Corradini, and L. Porri,ibid., p. 728.lZ6 G. Natta, Chimica e Industria, 1966, 88, 761 ; Angew. Chem., 1956,68, 393.127 F. W. Staveley and co-workers, Ind. Eng. Chem., 1956, 48, 778.1 2 ~ S. E. Home, jun., J . P. Kiehl, J . J. Shipman, V. L. Folt, C. F. Gibbs, E. A.12B C. D. Nenitzescu, C. Huch, and A. Huch, Angew. Chem., 1956, 68, 438; K.130 A. Clark, J. P. Hogan, R. L. Banks, and W. C. Lanning, Ind. Eng. Chem., 1956,131 G. Natta, P. Pino, E. Mantica, F. Danusso, G. Mazzanti, and M. Peraldo, Chimica132 C . E. Schildknecht and P.H. Dunn, J . Polymer Sci., 1966, 20, 697.C. C. Price, M. Osgan, R. E. Hughes, and C. Shambelan, J . Amer. Chem. Soc.,nP C . C. Price and M. Osgan, ibid., p. 4787.Willson, E. B. Newton, and M. A. Reinhart, ibid., p. 784.Ziegler, Bull. SOC. chim. France, 1956, 1.48, 1152.e Industria, 1956, 38, 124.1956, 78, 69058 GENERAL AND PHYSICAL CHEMISTRY.gives a solid, highly crystalline (81%), optically active polymer, but withracemic monomer only liquid polymer is formed.It is generally agreed that in stereospecific polymerisation the propagat-ing active centre is attached to the initiating complex by a polarised bond,the addition of monomer involving the breaking and re-forming of this bondwith severe steric limitations, but whether this necessarily involves a two-phase interface is still an open question.RRirtg Polymerisation.-The heat, entropy, and free-energy changes in thehypothetical polymerisation of liquid cyclo-paraffins and derivatives havebeen estimated.135 Except for cyclohexane, the calculated free energy ofpolymerisation is negative at least up to cyclooctane. The polymerisationof heterocyclic compounds has been discussed in the light of these results.136Although cyclopropane is not affected by free-radical catalysts, it can bepolymerised to a low-molecular weight polymer by mercury photosensitis-ation.Ivin 13' has carried out a thorough analysis of the products of thisreaction, and concludes that diallyl radicals are formed as intermediates,giving a polymer which resembles polypropene rather than polyethylene.The polymerisation of oxacyclobutanes by boron trifluoride gives sub-stantially unbranched chains, but is not stereospecific, and gives normalkinetics for a water-cocatalysed oxonium-ion reaction.138 The existenceof polymeric sulphur radicals in equilibrium with S, rings has been con-firmed 139 by paramagnetic-resonance measurements between 189" and 414".The results are in quantitative agreement with Gee's treatment of this system.The polymerisation of DL-phenylalanine-N-carboxylic anhydride by low-molecular weight polysarcosine gives rates which are several hundred timesfaster than expected from known rate constants for simple primary- orsecondary-base catalysis.Rallard and Bamford 140 consider this to be dueto adsorption of the anhydride on the polysarcosine chain, increasing thecollision frequency with the active centre, and they suggest a possibleanalogy with enzyme action.The base-catalysed polymerisation of opticallyactive ethyl y-benzyl-N-carboxy-L-glutamate is autocatalytic, and proceedsalmost twenty times as fast as the polymerisation of the racemic form.141It has been shown that the optical isomers form helical polymer chains withopposite screw directions, to which they add preferentially, and whichexercise a steric effect on the rate of addition.142Further studies have been made of the equilibrium between linear polymerand water in the polymerisation of 6-hexanolactam. Vapour-pressuremeasurements show that most of the water is present in the liquid ratherthan the vapour phase,143 and Fukumoto has shown that the change of135 F.S. Dainton, T. R. E. Devlin, and P. A. Small, Trans. Favaday SOC., 1955, 51,186 P. A. Small, ibid., p. 1717.197 K. J. Ivin, J., 1956, 2241.la* J. B. Rose, ibid., p. 542.130 D. M. Gardner and G. K. Fraenkel, J . Amei'. Chenz. Soc., 1956, 78, 3279.140 D. G. H. Ballard and C . H. Bamford, Nature, 1956, 177, 477; Pvoc. Rqy. Sor.,1710.1956, A , 236, 384.141 E. R. Blout and M. Idelson, J . Amer, Cham. SOC., 1956, 78, 3857.P. Doty and R. D. Lundberg, ibid., p. 4810.143 F. Wiloth and W. Dietrich, Makromol. Chettr., 1966, 21, 50KINETICS OF CHEMIC-4L CHANGE. 59activity of water with temperature has a much greater effect on the degreeof polymerisation than the change of equilibrium constant with temper-ature.lU Meggy has evaluated the activity coefficients of water andpolymers 145 and has constructed a composition-temperature diagram in therange 200-300".The relative proportions of individual cyclic oligomerspresent have been determined 146 at 221" and 253", and the alkali-catalysedpolymerisation has been studied.147Degradation and Depolymerisatiort.-During the thermal degradation ofpoly(methy1 methacrylate) 148 and of polystyrene,149 slow random splittingoccurs in addition to a fast depolymerisation. The predominant gaseousproducts of the thermal degradation of polyacrylonitrile are hydrogencyanide and ammonia,lS and the heat-stable residue probably consists offused pyridine rings formed by the intramolecular linking of adjacent nitrilegroups. 151 The thermal degradation of poly(propy1ene glycol) is governedby the instability of the radical formed on carbon atoms adjacent to an etherlink. 152and the effect of cross-links on the thermal degradation of rubber i n vacziohas been examined.'"On the basis of quantum-yield measurements for the photochemicaldecomposition of hydrogen peroxide in the presence of poly(methacry1icacid), Baxendale and Thomas 155 conclude that the observed degradation ofthe polymer is due to carbon-carbon splitting by the hydroxyl radical.Alexander and Fox 156 do not consider this explanation likely, and havesuggested that peroxide impurities in the polymer are responsible.Thecharacteristic coloration of polymethacrylonitrile when heated above 120" isshown to be due to a reaction initiated at impurities in the polymer chain,and can be eliminated by polymerisation in vacuo with rigorous purificationof the monomer.1s7 Other studies include the effect of pressure on theultrasonic degradation of polystyrene in benzene solution 158 and the solid-state degradation of poly(methy1 methacrylate) and cellulose acetate byy - r a y ~ .~ ~ ~Simha has discussed the degradation of branched-chain moleculesE. W.J. H. B.R. 0. C.144 0. Fukumoto, J . Polymer Sci., 1956, 22, 263.146 A. B. Meggy, J . , 1956, 4876.146 D. Heikens, Rec. Trav. chim., 1956, 75, 1199.147 Idem, Makromol. Chem., 1956, 18-19, 62.148 A. Brockhaus and E. Jenckel. ibid., p.262.149 I;. W. Morthland and W. G.. Brown, J . Amer. Chem. SOC., 1956, 78, 469.160 H. Nagao, M. Uchida, and T. Yamaguchi, J . Chem. SOC. Japan, Ind. Chem. Sect.,lbl W. J. Burlant and J. L. Parsons, J . Polymer Sci., 1956, 22, 249.162 J. R. Thomas, J . Amer. Chem. SOC., 1955, 77, 6107.163 R. Simha, J . Chew. Phys., 1956, 24, 796.15' S. Straus and S. L. Madorsky, Ind. Eng. Chem., 1956, 48, 1212.166 J . H. Baxendale and J. K. Thomas, Chem. and Ind., 1956, 377.166 P. Alexander and M. Fox, ibid., p. 1385.157 N. Grassie and I. C. McNeill, J., 1956, 3929.168 H. W. W. Brett and H. H. G. Jellinek, J . Polywzev Sci., 1956, 21, 536; H. H. G.lb0 A. Chapiro, J . Chim. phys., 1956, 53, 295.1956, 59, 698, 940.Jellinek, ibid.. 1956, 22, 14960 GENERAL AND PHYSICAL CHEMISTRY.3.ADSORPTION AND HETEROGENEOUS CATALYSIS.This Report has been separated from the section on the Kinetics ofChemical Change this year because it seemed appropriate to include infonn-ation on physical adsorption as well as chemisorption and catalysis. Mostof the work on adsorption reported relates to the gas-solid interface sinceadsorption at other interfaces can be treated more conveniently underColloid Chemistry or Surface Chemistry.Adsorption.--Several important reviews have appeared. One of theseby de Boer is comprehensive; there are others on more specialised topicssuch as chemisorption and catalysis on oxide semiconductors,2 surface-barrier effects in ad~orption,~ the latest techniques in field-emission micro-scopy,4 recent work on metal surfaces including the results obtained byfield-emission studies and the electronic interaction between metalliccatalysts and chemisorbed molecules.g Reyerson has also given a generalreview of various aspects of adsorption.Physical adsorption.Although the methods of measurement of surfacearea have become fairly well standardized, work continues in this field.Rosenberg has shown that an accuracy of 1% can be obtained for surfacesas small as 50 cm.2 by using a thermistor unit to measure adsorption ofkrypton at low pressures. Haulg has confirmed that krypton is moresuitable than nitrogen for measuring low surface areas. The " point-B "method* has been examined for a series of oxides; although differentpressures were observed at low coverages, the same pressure was required togive lOOyo coverage of different samples of the same oxide.It was suggestedthat the pressure corresponding to point-B was determined by the filling ofthe least active regular sites and so was not influenced by differences inthe heterogeneity of samples. MacIver and Emmett l1 showed that the B.E.T.isotherm is obeyed by nitrogen adsorbed on sodium chloride at relativepressures of 0.014.1 in contrast to the usual range of 0-05--0*35 and theysuggested that this was due to the comparative homogeneity of the surface.Several papers have appeared on various aspects of the thermodynamicsof adsorption and in particular on the information which can be derived byentropy measurements. The values of zero-point entropies of kryptonadsorbed on anatase l2 have been shown to be in accord with values expectedfor a heterogeneous surface and the retention of the amount of randomnesscorresponding to 50" K.Similar results have been reported for krypton1 J. H. de Boer, Adv. Catalysis, 1956, 8, 18. * G. Parravano and M. Boudart, ibid., 1955, 7, 50.5 S. R. Momson, ibid., p. 269.4 R. Gomer, ibid., p. 93.6 J. A. Becker, ibid., p. 135.R. Suhrmann, ibid., p. 303.7 L. H. Reyerson, Ann. Rev. Phys. Chem., 1956, 7, 383.8 A. J. Rosenberg, J . Amer. Chem. Soc., 1956, 78, 2929.9 R. A. W. Haul, Angew. Chem., 1956, 68, 238.10 P. Royen, A. Orth, and K. Ruths, 2. anorg. Chem., 1955, 281, 1.11 D. S. MacIver and P. H. Emmett, J . Phys. Chem., 1956, 80, 824.14 E.L. Pace, W. T. Berg, and A. R. Siebert, J . Amer. Chem. Soc., 1956, 78, 1631.* I.e., the method based on the assumption that one layer of adsorbed molecules hasformed at the point where the isotherm bends over sharply and becomes linearKEMBALL ADSORPTION AND HETEROGENEOUS CATALYSIS. 61adsorbed on r~ti1e.l~ Barrer and Stuart l4 have shown that characteristicsigmoid isotherms, such as are found for the sorption of water and methanolby carbon, can be interpreted by a statistical-thermodynamical treatmentbased on localized adsorption on a uniform surface with exothermic lateralinteraction. Various models for intracrystalline sorption, i.e. , localized andmobile with either one or two degrees of translational freedom, have beenexamined.15 ,4pplication l6 of these models to the sorption of argon inchabazites l 7 has shown that from coverages of 0.1 to 0.7 mobile adsorptionwith only one degree of translational freedom and two degrees of vibrationalfreedom appears to operate but that at higher coverages the mutual cagingof the molecules leads to localized adsorption.Very similar conclusionswere obtained from measurements of the thermodynamic properties ofoxygen sorbed in chabazites 18 but some restriction of rotational freedomwas noted even at the lower coverages. Kington l9 has given an explanationof the maximum in the experimental heat of sorption of argon in chabaziteas the coverage is increased, in terms of the packing of the atoms into cagesin the adsorbent. Each cage can hold two atoms at the normal equilibriumspacing but an additional atom can be packed in although this requires somecompression with consequent decrease in heat of sorption at high coverages.Siebert and Pace 2O have measured heat capacities of multimolecular layersof nitrogen trifluoride adsorbed on anatase.Evidence for a transitioncorresponding to fusion of the solid was found to occur between 60" and66" K but only when the coverage was as high as 5.9 monolayers. A newdefinition of a two-dimensional standard state applicable to systems wherethe surface pressure is either measured or calculated has been putVarious papers have been published on physical absorption involving avariety of adsorbates and adsorbents. The adsorption of diborane onboron nitride and on palladium-on-charcoa122 has been shown to fit theLangmuir equation at low pressures and to be limited to van der Waal'sadsorption with no evidence of chemisorption.This work has also beenextended to cover the adsorption of diborane, deuterodiborane, and tri-methylborane on palladium and on charcoal.23 In these cases too, nochemisorption was observed although the heat of adsorption of diborane oncharcoal amounts to 5 to 10 kcal./mole. The heat of adsorption of n-butylalcohol from aqueous solutions on a Graphoii (a commercial graphitisedcarbon black) surface has been obtained by measurement of heats of im-rner~ion.~~ Accommodation coefficients of various gases on glass have beenreported by Schafer and Ger~tacker.~~l3 E.L. Pace, K. S. Dennis, and W. T. Berg, J. Chena. Phys., 1955, 23, 2166.R. M. Barrer and W. I. Stuart, J., 1956, 3307.l6 L. A. Garden and G. L. Kington, Proc. Roy. SOC., 1966, A , 234, 24.l6 L. A. Garden, G. L. Kington, and W. Laing, ibid., p. 35.Idem, Trans. Faraday SOC., 1955, 51, 1558.L. A. Garden and G. L. Kington, ibid., 1966,52, 1397.la G. L. Kington, ibid., p. 475.*O A. R. Siebert and E. L. Pace, J. Phys. Chem., 1956, 80, 828.21 H. L. Harter, P. R. Rider, and P. M. Williamson, J. Chem. Phys., 1955,23, 1966. ** H. C. Beachell and H. S. Veloric, J. Phys. Chem., 1946, 60, 102.2s H. C. Beachelland K. R. Lange, ibid., p. 307. '' G. J. Young, J. J. Cheswick, and F. H. Healey, ibid., p. 394.K. Schafer and H. Gerstacker, 2. Elektuochent., 1956, S9, 102362 GENEK.41.-4ND PHYSICAI, CHEMISTRY.Chemisorption. In addition to the re~iews,l-~ Eley 26 has reportedbriefly on a symposium held on chemisorption at Keele (University Collegeof North Staffordshire) where various recent results and theories werediscussed. Investigations involving new and improved physical techniqueshave continued to yield important results, particularly on the nature ofchemisorbed species and on the electronic interaction between the adsorbateand the substrate.Very interesting developments of the magnetic investigations by Selwoodand his school have appeared. The forms of thermomagnetic curves ofsupported nickel catalysts 27 have been used to determine particle sizedistributions for diameters below 50 and the results obtained were inaccord with measurements from X-ray line-width broadening. However, amore important development from the point of view of chemisorption wasthe demonstration that adsorption of gases on highly dispersed nickelparticles caused changes in magnetization.Hydrogen and ethylene causeda decrease in magnetization because they were acting as electron donors andfilling up holes in the d-band of the metal. The reverse effect was observedon the adsorption of nitrogen and oxygen. Selwood28 improved thetechnique so that changes of magnetization could be measured simultane-ously with adsorption and showed that the adsorption of hydrogen causedthe addition of 0.068 electron per nickel atom. Moore and Seiwood29extended the investigation to the adsorption of other gases-water, likehydrogen, caused a decrease in magnetization and nitrous oxide and carbonmonoxide behaved like oxygen and increased it.There was an excellentcorrelation with the results obtained on resistance changes caused by cherni-sorption reported by Suhrmann and Schulz30 in that those gases whichcaused a decrease in magnetization by contributing electrons to the metalsubstrate showed a decrease in the resistance of the substrate and vice versa.Selwood31 has reported a further improvement in the apparatus and moredetailed results with hydrogen on nickel including the effect of changes intemperature. He has been able to demonstrate the conversion of physicallyadsorbed into chemisorbed hydrogen and has also produced evidence ofchemisorbed hydrogen with a very low heat of adsorption.The techniqueis clearly important, and when extended to other adsorbates will providevaluable information about the nature of the link between adsorbate andmetal adsorbents. French and Howard 32 have shown by magnetic measure-ments that the adsorption of transition-metal ions takes place from solutionson silica gel without change in the electronic configuration of the ions. Theionic character of the adsorption was confirmed by the small amount ofadsorption occurring from weakly ionizing solvents.Resistance changes of nickel films have been followed by Rienacker and24 D. D. Eley, Nature, 1956, 178, 540.2 7 P. W. Selwood, S. Adler, and T. R. Phillips, J. Amer. Chem. SOC., 1955, 77,88 P. W.Selwood, ibid., 1956, 78, 249.89 L. E. Moore and P. W. Selwood, ibid., p. 697.90 R. Suhrmann and K. Schulz, J . CoZZoid Sci., 1964, Suppl. 1, 50.31 C. hI. French and J. P. Howard, Trans. Farads?! SOC., 1056, 52, 712.1462.P. W. Selwood, J . ,4??zer. Chew SOC., 1966, 78, 3893KEMBALL .4I)SORPTIOS AND H E'TEKOGEN EOUS CA'ltZ L Y S IS. 63H a ~ i s e n . ~ ~ ~ 34 As mentioned earlier, hydrogen causes a decrease in resistancebut the addition of oxygen to the hydrogen-covered film restores the resist-ance to a value slightly in excess of the initial value for a clean nickel surfaceowing to the oxidation of the surface, i.e., removal of electrons. Smallquantities of oxygen cause only a transitory increase in resistance and thena decrease as the oxygen is converted into water.Addition of butadiene orbenzene to the Ni-H film also causes an increase in resistance as the hydrogel1is used up. Various other reactions such as the decomposition of formic acidwere also studied but, in general, the main effects appear to be due tochanges in the amount of adsorbed hydrogen. Suhrmann and Schulz35have shown that very thin transparent films of non-oriented nickelbehave anomalously and exhibit a rise in resistance when hydrogen isadmitted.Eischens and his collaborators have continued their investigations on theinfrared spectra of adsorbed molecules. Detailed results have been obtainedfor carbon monoxide on palladium, nickel, and platinum36 over a widerange of pressure and temperature More evidence for a bridged structurefor adsorbed carbon monoxide 37 attached to two metal atoms was obtained.Changes in the spectra with coverage were attributed to interaction betweenthe adsorbed molecules.Most interesting results were obtained whenolefins and acetylenes were chemisorbed on nickel ; 38 the spectra indicatedthe presence of a structure -CH2-CH, on admission of ethylene and therewas no indication of the presence of a double bond with either ethylene orpropene. Admission of hydrogen to chemisorbed ethylene gave spectracorresponding to ethyl radicals and on prolonged pumping evidence wasobtained for C2H2 structures, mainly saturated but also partly with olefiniccharacter. Infrared absorption spectra have also been reported for ordinaryand heavy water on glass.39More results have been reported on the state of nitrogen adsorbed ontungsten determined by simultaneous recording of the rise in pressure andthe temperature of the tungsten wire as it is flashed.40$ 41 According to thelast of these papers there are four states of nitrogen on tungsten : 6 , stablebetween 100" and 140" K ; y, 140-250" K ; a, 300-650" K ; and p, 1400-1900" K. The adsorption of gases on a silicon surface has also been in-vestigated at pressures from to lo4 mm.of Hg by a desorption tech-n i q ~ e . ~ ~ In this case a filament of the adsorbent was flashed in a glassvessel attached to the inlet of a mass spectrometer and the gas desorbedmeasured in the spectrometer. Hydrogen and carbon monoxide werestrongly adsorbed on the silicon but no adsorption of nitrogen, argon, orcarbon dioxide was found, although the last gas decomposed to carbon33 G.Rienacker and N. Hansen, 2. aizorg. Chem., 1956, 284, 162.34 Idem, Angew. Chem., 1956, 08, 41.3 5 R. Suhrmann and K. Schulz, Naturwiss., 1955, 42, 340.36 K. P. Eischens, S . A. Francis, and W. A. Pliskin, J . Phys. Chem., 1956, 80, 104.3 7 Idem, J . Chem. Phys., 1954, 22, 1786.38 W. A. Pliskin and R. P. Eischens, ibid., 1956, 24, 482.39 V. A. Nikitin, A. N. Sidorov, and A. V. Karyakin, Z h w . fir*. K l i Z t ~ , 1956, 30, 117.4u G. Ehrlich, J . Clteni. Plzys., 1956, 24, 482.J1 G. Ehrlich and T. W. Hickmott, Nature, 1956, 177, 1045.42 J . T. Law and E. E. Francis, J . Phm. Chew., 1956, 60, 35364 GENERAL AND PHYSICAL CHEMISTRY.monoxide when the filament was heated to 800" c or above.Similarly, waterdecomposed to hydrogen to a marked extent at high temperatures and alsoto a small extent even at room temperature. Several layers of oxygenwere taken up by the surface and it was shown that there was a sharp fallin the probability of a molecule's being adsorbed on hitting the surface afterthe completion of one layer. In addition to observations obtained by these" rapid desorption " techniques others have followed '' rapid adsorptions "by means of a pressure gauge attached through a capillary tube to an adsorp-tion vessel. Provided sufficiently low pressures are used the rate of adsorp-tion can be obtained by the differences in the change of pressure with timewith and without an adsorbent present.has shown that the '' stick-ing probability " for carbon monoxide on evaporated nickel films is initially0.6 but falls steeply when the coverage of the surface exceeds 0.2, droppingto about This large decrease was explained interms of increasing activation energy for chemisorption as the surface iscovered. Using a similar technique, WagenerM has shown that there israpid adsorption of carbon monoxide and carbon dioxide on barium, stron-tium, and nickel but that the adsorption of the same gases on magnesium,aluminium, and silver is very slow or negligible. Bloomer 46 has investigatedthe effect of the operation of an ionization gauge on the up-take of gases bybarium getters.Detailed results about the diffusion of hydrogen and oxygen on the (011)face of tungsten have been obtained by fiekl-emission studies.46 Nuclearmagnetic resonance has been used to study the relaxation times for" libration " of water and methane adsorbed on anatase.4' Proton relax-ation times for a number of liquids adsorbed on y-alumina and relatedcatalysts have been reported by Hickmott and Selwo~d.~~Theoretical work has been continued on the effect of heterogeneity ofadsorbent surfaces on the adsorption isotherms. Hepler 49 has investigatedthe proper limits which should be used for the integration of the isothermequation when there is a distribution of sites of different energy and hasobtained equations relating the distribution and heat of adsorption.Danon 50 has shown that the distribution function can be obtained in anapproximate form if the isotherm is known for low pressures or concen-trations. An improved method of testing the Elovich equation, which hasbeen shown to be applicable to many systems involving chemisorption onheterogeneous surfaces, has been suggested.s1 Experimental evidence forthe heterogeneity of a platinum catalyst has been found by Bond whoexamined the proportion of chemisorbed deuterium which was readilyexchangeable with hydrogen and showed this proportion decreased withOdafor a coverage of 0.8.43 2. Oda, J . Chem. Phys., 1956, 25, 592.44 S. Wagener, J . Phys. Chem., 1956, 60, 567.4 5 R. N. Bloomer, Nature, 1956, 178, 1000.46 R. Wortman, R. Gomer. and R.Lundy, J. Chem. Phys., 1956, 24, 161.4 7 N. Fuschillo and J. G. Aston, ibid., p. 1277.4 8 T. W. Hickmott and P. W. Seiwood, J . Plays. CAem., 1956, 80, 462.49 L. G. Hepler, J . Chem. Phys., 1955, 23, 2110.60 J. Danon, J . Claim. phys., 1955, 52, 392.61 J. N. Sarmousakis and M. J. D. Law, J . Chern. Phys., 1956, 25, 178.52 G. C. Bond, J . Phys. Chem., 1956, 80, 702KEMBALL ADSORPTION AND HETEROGENEOUS CATALYSIS. 66decreasing temperature. Kubokawa and Toyama 53 have confirmed thetwo types of chemisorption of hydrogen found by earlier work on zinc oxideand have shown that the conductivity is increased only by the high-temperature chemisorption. Gray and Darby % have given a detailedaccount of the relationship between the kinetics of the adsorption of oxygenon an oxide and the variation in the semiconducting properties of the sub-strate.The central feature of the discussion is the assumption of a surfacezone, the relative thickness of which is temperature-dependent and structure-sensitive and which differs significantly from the bulk of the adsorbent.Experimental results on the oxygen-nickel oxide system are reported andanalysed in a second paper.55 Earlier theories of the oxidation of metalshave been modified by Grimley and Trapnell 56 by taking into account theexistence of a strongly held layer of chemisorbed oxygen.The adsorption of oxygen on porous silver has been investigated in detailby Temkin and K~l’kova.~’ In addition to rapid unimolecular adsorptionand slow adsorption they found evidence of a so-called “ deep chemi-sorption ” which they suggested was of general importance in heterogeneouscatalysis.Horiuti and Kita 58 have shown that the kinetics of the adsorptionof nitrogen on a doubly-promoted iron catalyst appear to indicate absorptionof nitrogen into the catalyst in addition to dissociative adsorption. Evidencefor lattice penetration by nitrogen has also been obtained on evaporatedmetallic films.59 Extensive results for the adsorption of ammonia on simplemetal halides have been reported by Huttig and Harth.m,61 The resultson sodium chloride showed that physically adsorbed ammonia was convertedinto chemisorbed ammonia with an activation energy of about 5 kcal./mole.A useful technique for the investigation of the heat of adsorption of oxygenon nickel, platinum, and silver at low surface coverages has been used byGonzalez and Parravano.62 They made use of the decomposition equilibriumof water vapour in order to obtain oxygen at low activity.The heat ofadsorption on nickel was close to that for the formation of the bulk oxidebut much higher values for the surface heats were found for platinum andsilver. No adsorption was detected on gold. Information about theadsorption of hydrogen on platinum-gold alloys has been derived from thecathodic polarization of the alloys in sulphuric acid.63 The ionization ofalkali metals 64 and potassium halides 65 on hitting platinum and tungstensurfaces at high temperatures has been studied by Datz and Taylor.Theadsorption of water on iron oxide has been investigated by heat-of-immersion53 Y. Kubokawa and 0. Toyama, J . Phys. Chem., 1956, 60, 833.64 T. J. Gray and P. W. Darby, ibid., p. 201.6 5 Idem, ibid., p. 209.66 T. B. Grimley and B. M. W. Trapnell, Proc. Roy. SOC., 1956, A , 234, 405.6 7 M. I. Ternkin-and N. V. Kul’kova, Doklady Akad. Nauk S.S.S.R., 1955,105, 1021.6* J. Horiuti and H. Kita, J . Res. Inst. Catalysis, Hokkaido Univ., 1956, 4, 132.E. Greenhalgh, N. Slack, and B. M. W. Trapnell, Trans. Faruduy SOC., 1956, 52,6o G. F. Hiittig and E. Harth, 2. Elektrochem., 1955, 59, 370.61 Idem, 2. anorg. Chern., 1955, 282, 110.62 0. D. Gonzalez and G. Parravano, J . Amer. Chem. Soc., 1956, 78, 4533.63 K. A. Lapteva, T. I. Borisova, and M. G.Slin’ko, Zhur. fiz. Khim., 1956, 30, 61.64 S. Datz and E. H. Taylor, J . Chem. Ph-ys., 1956, 25, 389.06 Idem, ibid., p. 395.865.REP. -VOL . LTIT 66 GEN E 11.4 I> AN 1) I'H YSIC .\I, CIT 17 M I ST HI'.measurements-approximately t wo-t hirds of the water was physicallyadsorbed, the remainder being chemisorbed.66 Entropy measurementsshowed that the physically adsorbed water at 25" c was localized.Catalysis.-A number of review articles have appeared. Baker andJenkins 67 have considered the electronic factor in heterogeneous catalysisand Hauffe 68 has summarized developments of importance in the theory ofsemiconductors. Cremer 69 has given a general account of the correlationsfrequently found between frequency factors and activation energies some-times described as the " compensation effect " or the '' theta rule." *Various specialized topics have also been reviewed : synthesis of ketones,70polymerization of ole fin^,^^ hydrogenation of coal,72 and the catalytic crack-ing of c ~ r n e n e .~ ~ Volume 4 of " Catalysis " 74 has been published and treatsin detail the Fischer-Tropsch and other allied syntheses but it also includesarticles on methanation (i.e., hydrogenation of oxides of carbon to methane) ,'i5liquid-phase hydrogenation of coal,76 and dehydroaromatization of hydro-carb0ns.~7A number of papers have appeared involving studies of properties ofcatalysts. Sabatka and Selwood 78 examined several nickel catalysts bythermomagnetic analysis and showed that disperse nickel has the samemagnetic moment at 0" K as massive nickel.However, amorphous nickelhas been shown to be inactive as a catalyst in the hydrogenation of benzene.7gThe resistance changes observed in evaporated nickel films on chemisorptionand subsequently during catalytic reactions have already been mentioned 33and the mechanism of the decomposition of formic acid has been examinedas we11.80 In an extension of earlier work 81 it has been shown that there is agood correlation between the electrical conductivity of silica-aluminacatalysts and the small amounts of sodium present in the catalyst.82 Theincreased conductivity associated with increased alumina is now attributedto the extra sodium introduced. No increase was observed on introducingpotassium.By examining the water-content of similar catalysts, Haldemanand Emmett 83 have shown that most of the active sites on the catalyst after6 6 F. H. Healey, J. J. Chessick, and A. V. Fraioli, ibid., p. 1001.6 7 M. McD. Baker and G. I. Jenkins, Ad7r. Catalysis, 1955, 7, 2 .Gs E. Cremer, ibid., p. 75.7O V. I. Komarewsky and J . R. Coley, ibid., 1956, 8, 207.71 E. K. Jones, ibid., p. 219.73 E. E. Danath, ibid., p. 239.73 P. H. Emmett (ed.), " Catalysis,7 5 M. Greyson, ibid., p. 473.76 S. W. Weller, ibid., p. 513.7 7 H. Steiner, ibid., p. 529.7 8 J . A. Sabatka and P. W. Selwood, J . Anaev. Chem. Soc., 1955, 77, 5790.79 A . M. Rubinshtein, I>. Kh. Freidlin, and N. V. Rorunova, Izvest. Akad. Nauk80 G. Rienacker and hT. Hansen, %. anorg.Chew)., 1956, 285, 283.81 P. B. Weisz, C. D. Prater, and K. n. Rittenhouse, J . Chem. Phys., 1963, 21, 2236.82 I d e m , ibid., 1955, 23, 1965.83 R. G. Haldeinan and P. H. Emmett, J . Anzer. Chem. SOC., 1956, 78, 2917.* These nanies are used to describe a linear relation between the logarithm of theK. Hauffe, ibid., p. 213.C . D. Prater and K. M. Lago, ibi!.,, p. 294.Vol. 4. Hydrocarbon Synthesis, Hydrogen-ation, and Cyclization, Reinhold Publ. Corp., New York, 1956.S.S.S.R., Otdel. khim. Nauk, 1955, 766.frequency factor and the activation energvKEMBA~LL : ADSORPTION AND HETEROGENEOCJS CAiT.-lI,YSIS. 67evacuation at 500” c are in the form of Lewis acids rather than Bronstedacids. They found g4 that the exchange between isobutane and heavy wateron these catalysts passed through a maximum as the water was added tothe catalyst.It appeared that water molecules had to be available in thesurface before the hydrocarbon could undergo activated adsorption. A veryinteresting feature of the results was the high number of deuterium atomspresent in the products although the water-content of the catalyst was low,indicating that deuterium was available to diffuse easily over the surface.The catalytic activities of copper-nickel and copper-palladium alloys forthe para-hydrogen conversion 85 have been shown to decrease slowlyas the amount of copper is increased to 60 atoms yo and then morerapidly.Interest has been maintained in the theoretical interpretation of kineticdata of catalytic reactions.Boudart 86 has defended the use of kineticequations based on Langmuir isotherms although admitting that the surfacesrarely fulfil the basic requirements for Langmuir-type behaviour. M7eller,87on the other hand, advocates the simpler approach of working in terms ofpower dependencies. Kwan 88 also favours this approach because so manysets of adsorption data can be adequately described in terms of rate expres-sions involving a power of the coverage and hence in terms of the Freundlichtype of isotherm. Foss 89 has derived a relation between heat of adsorptionof a reactant and experimental activation energy for a unimolecular reaction]and has emphasized the difficulty in the experimental determination of theorder of the reaction when the activation energy is varying with the pressure.Molinari has discussed the ‘‘ theta rule ” 69 with particular reference tothe exchange between hydrogen and deuterium and has shown that amechanism of induced desorption, in which the heat of desorption is suppliedby the adsorbing molecules will account for the relationship between theconstants of the Arrhenius equation.Vol’kenshtein 91 has given a generaldiscussion of the electron theory of catalysis by semiconductors, pointingout the analogy between a catalyst acting as a giant polyradical and the partplayed by radicals in homogeneous reactions. Horiuti’s school has reporteda determination 92 of the stoicheiometric number for ammonia synthesis at29.5 atm. The method of evaluating the stoicheiometric number from therates of reaction near equilibrium was put forward originally by Horiuti 93and it gives the number of times the rate-determining step has to take placefor the overall chemical reaction to occur.The new work92 confirms thatthe value is two for high pressures as well as low pressures 94 in the synthesisR. G. Haldeman and P. H. Emmett, J . Amey. Chewz. SOC., 1956, 78, 2922.8 5 G. Rienacker and G Vormum, 2. anorg. Chem., 1956, 283, 287.8 6 M. Boudart, Amer. Inst. Chenz. Eng. J . , 1956, 2, 62.S. Weller, ibid., p. 59.88 T. Kwan, J . Phys. Chem., 1956, 60, 1033.89 J. Foss, t h i d , p. 1012.91 F. I;. Vol’ltenshtein, Probleway. Kinetzki i ICafalz-a Akad. Nazrk S . S . S . R . , 1955,92 S. Enonioto, J . Horiuti, and H. Kobayashi, .J.R e s . Iwsf. Cnfalvsis, Hokkaidos3 J. Horiuti, ibid., 1948, 1, 8.94 S. Enomoto and J. Horinti, ibid., 1953, 2, 117.E. Molinari, 2. fihys. Chem. (Frankfuvt), 1966, 6, 1 .8. 79.Univ., 1955, 3, 18568 GENERAL AND PHYSICAL CHEMISTRY.of ammonia and suggests that the slow step must be the addition of hydrogento adsorbed nitrogen rather than the dissociative adsorption of nitrogen.Several papers have appeared involving the use of either stable or radio-active isotopes to determine the mechanism of catalytic reactions. Bond 95has examined the deuteration of ethylene over a number of platinumcatalysts. He showed that all possible deuteroethanes were formed, andexamined changes in the distribution with temperature and composition ofthe gas.Kemballg6 examined the same reaction a t low temperatures onevaporated metallic films and put forward a theory which accounts satis-factorily for the initial distributions of deuteroethylenes and deutero-ethanes and is based on the assumption that adsorbed ethylene andadsorbed ethyl radicals are the important entities on the catalyst surface.Flanagan and Rabinovitch 97p 98 have examined the exchange and isomeriz-ation of trans-[2HJethylene on nickel catalysts. Detailed kinetic resultswere obtained and shown to be in agreement with one of two mechanismsboth involving adsorbed ethyl radicals. Integration of rate equations onthe assumption of stepwise exchange (one hydrogen atom a t a time) gaveexcellent agreement with the experimental observations of the proportionsof the various deuteroethylenes throughout the reactions.Miyahara 99has given an alternative explanation of the product distributions observedby Anderson and Kernball100 in the exchange of ethane with deuteriumover evaporated metallic catalysts. The activity of various oxides for theexchange of hydrogen with deuterium has been correlated with the electronicconfiguration of the metal ions.lOl By the use of radio-isotopes it has beenshown that very little exchange takes place at 500" on aluminosilicatecatalysts between ethane and propane and between ethylene and methane.lo2Also, the exchange between methyl chloride and hydrogen chloride has beenexamined on tungsten surfaces and shown to involve adsorbed chlorineatoms probably reacting with physically adsorbed r n o l e ~ u l e s .~ ~ ~ ~ lo4An important development in technique has been the combination ofvapour-phase chromatography with radioactive counting methods for theexamination of products from complex reactions such as hydrocarbon crack-ing and olefin polymeri~ation.10~ Franklin and Nicholson lo6 have examinedthe decomposition of a number of hydrocarbons on silica-alumina catalysts ;they found that there was a decrease in activation energy with molecularweight which paralleled changes in the ionization potential of the molecules95 G. C. Bond, Trans. Faraday SOC., 1956, 52, 1235.96 C. Kemball, J . , 1956, 735.97 T. B. Flanagan and B. S. Rabinovitch, J . Phys. Chesn., 1956, 60, 724.98 Idem, ibid., p.730.99 K. Miyahara, J . Res. Inst. Catalysis Hokkaido Univ., 1956, 4, 143.100 J. R. Anderson and C. Kemball, Proc. Roy. SOC., 1954, A , 223, 361.101 D. A. Dowden, N. Mackenzie, and B. M. W. Trapnell, ibid., 1956, A , 231, 245.102 B. V. Klimenok, E. A. Andreev, 0. V. Krylov, and M. M. Sakharov, Doklady103 R. Coekelbergs, A. Frennet, and P. A. Gosselain, Bull. SOC. chiw. belges, 1956,104 J. Adam, R. Coekelbergs, A. Frennet, and P. A. Gosselain, J . Chem. Phys., 1956,Akad. Nauk S.S.S.R., 1954, 95, 101.65, 229.24, 1267.5860.105 R. J. Kokes, H. Tobin, jun., and P. H. Emmett, J . Amer. Chem. Soc., 1955, 77,106 J. L. Franklin and D. E. Nicholson, J . Phys. Chem., 1956, 80, 59KEMBALL : ADSORPTION AND HETEROGENEOUS CATALYSIS. 69and they suggested that alkyl carbonium ions were formed via molecule-ion intermediates.Shiba and Echigoya lo7 examined the activity of analuminium oxide catalyst for the polymerization of ethylene and showed thatthe activity follows closely parallel to the extent of adsorption of pyridineon the catalyst when the catalyst is pre-heated at different temperatures.losThe decomposition of ozone has been studied on a number of oxides andthe activation energies correlated with properties of the oxides.log~Kummer ll1 has found no marked differences in activity for the oxidationof ethylene on different crystal faces of silver but the absolute rate of thereaction confirmed Twigg's mechanisrn.ll2Stoddart and Kemball l13 have shown that the main reduction productof acetone at low temperatures over evaporated metal catalysts is propan-2-01 with small amounts of propane on platinum films.The kinetics ofthe reaction have been investigated and the order of activity of the metalsfollows closely the order already established for the hydrogenation ofethylene. The hydrogenolysis of substituted cyclopropanes and cyclo-butanes has been studied over ~ 1 a t i n u m . l ~ ~ The hydrogenolysis of methyl-amine 115 over evaporated metal films is controlled by the rate of fissionof the carbon-nitrogen bond. The subsequent reactions are complex andinclude the rapid formation of ammonia, formation of methane to a smallerextent, formation of dimethylamine and subsequently trimethylamine, anduptake of carbon by the catalysts.In similar studies of cyclohexylamine,the unexpected formation of benzene was observed at 134" on platinum 116but the hydrogenation of the benzene to cyclohexane followed after most ofthe amine had been used up. The Fischer-Tropsch synthesis has beenstudied on cementite as a catalyst 117 and new results have been obtainedon the kinetics of the " 0x0 synthesis " (the addition of carbon monoxideand hydrogen to olefins to form aldehydes and hence other products con-t aining oxygen).Maxted and Josephs119 have examined the poisoning of platinumcatalysts. The complete revival of the catalyst for the hydrogenation ofethylene can be obtained in three ways: (i) evacuation, (ii) circulatinginert gas, or (iii) circulating ethylene. The heats of adsorption of the twopoisons ethyl sulphide and thiophen were determined calorimetrically andthe difference in the initial heats of adsorption attributed to the loss ofresonance when thiophen is adsorbed.C .K.Io7 T. Shiba and E. Echigoya, J . Chem. SOC. Japan, 1955, 76, 1046.lo8 Idem, ibid., p. 1049.loD G. M. Schwab and G. Hartmann, 2. phys. Chem. (Frankfurt), 1956, 6, 56.110 Idem, ibid., p. 7 2 .ll1 J. T. Kummer, J. Phys. Chem., 1956, 60, 666.113 G. H. Twigg, Trans. Faraday SOC., 1946, 42, 284.113 C. T. H. Stoddart and C. Kemball, J. Colloid Sci., 1956, 11, 532.114 B. A. Kazanskii and M. Yu. Lukina, Kataliticheskoe i Okislemie Akad. Nauk116 C. Kemball and R. L. Moss, Proc. Roy. SOC., 1956, A , 238, 107.116 R. L. Moss and C. Kemball, Nature, 1956, 178, 1069.117 J.F. Shultz, W. K. Hall, T. A. Dubs, and R. B. Anderson, J . Amer. Chem. Soc.,118 G. Natta, R. Ercoli, and S. Castellano, Chimica e Iwdustria, 1955, 37, 6.llQ E. B. Maxted and M. Josephs, J., 1956, 264, 2635.Kazakh S.S.R., 1955, 18.1966, 78, 28270 GENERAL AND PHYSICAL CHEMISTRY.4. ION EXCHANGE.Successes in the separation of fission products achieved, for ion-exchangeresins, wide importance as analytical tools. Recently, however, develop-ments in the fundamental aspects of ion exchange have seen the emergenceof the technique as an important branch of physical chemistry. Thus, whilethe analytical interest is still maintained and extended, ion-exchange resinshave found wide application as physical-chemical tools for the study ofelectrolytic solutions.In this respect they have been used, for example, ininvestigations on the nature of complex ions in solution, the electrochemistryof ion-exchange membranes, and the determination of activity and selectivitycoefficients.This Report emphasises the physical-chemical developments of ionexchange, although its more outstanding achievements as an analyticaltool will also be included. Progress in biochemistry, water treatment, soilanalysis, electrochemistry of ion-exchangers, and investigations with in-organic ion-exchangers are only included insofar as they contribute generallyto information or applicability.Extensive reviews have been given by Juda, Marinsky, and RosenberglSchubertJ2 and Thomas and Fry~inger.~ Winter and Buser et aL5 havereviewed advances in the physical chemistry of ion-exchange resins, Ardentheir uses on an industrial scale, and Griessbach their technological future.Information on the adsorption of organic compounds, and ion inclusion, iscovered by Samuelson.* Some other reviews merit consideration in that theypresent a general picture of work and information relating to ion exchange.In 1953, Samuelson’s book lo appeared; it still gives one of the bestsurveys of almost all the physical-chemical approaches to the subject as wellas the analytical.During 1956 a new text-book on ion exchange by Nachodand Schubert l1 was published ; twenty chapters are devoted to technologicaland engineering aspects of ion-exchange practices but a discussion of funda-mental problems, techniques, and operations is also included.Osborn’sbook l2 appeared in 1955. A report of a symposium on the application ofion exchange in water and waste treatment has also appeared.131 W. Juda, J. A. Marinsky, and N. W. Rosenberg, Ann. Rev. Plq)s. Chem., 1953,2 J. Schubert, ibid., 1954, 5, 413.4 S. S. Winter, J . Chem. Educ., 1956, 33, 246.5 W. Buser, P. Graf, and W. F. Grutter, Claimia (Swidz.), 1955, 9, 73.7 R. Griessbach, Chew,.-Ing.-Tech., 1055, 27, 569. * 0. Samuelson, Iva, 1955, 26, 178.9 H. Deueland K. Hutschneker, Chimia (Switz.), 1955,9, 49; R. Griessbach, Angew.Chem., 1955, 67, 606; J. Biichi, J. Pharm. Pharmacol., 1956, 8, 369; R. Kunin and F.McGarvey, I n d . Eng.‘?hem., 1955, 47, 565.1” 0.Samuelson, Ion Exchangers in Analytical Chemistry,” John Wiley and Sons,Inc., Kew York, 1953.11 F. C. Nachod and J . Schubert, “ Ton Exchange Technology,” Academic Books,Ltd., London, 1956.12 G. H. Osborn, “ Synthetic Ion Exchangers. Recent Developments in Theory13 I n d . E72g. Chena., 1955, 47, 46--101.4, 373.H. C. Thomas and G. R. Frysinger, ibid., 1956, 7, 137.T. V. Arden, J . Roy. Inst. Chem., 1956, 80, 122.and Application,” Chapman and Hall, Ltd., London, 1956MXGEE : ION EXCHANGE. 71Ion-exchange Equilibria.-Ion-exchange equilibria being of great practicalimportance have been frequently investigated. In view of the complicatednature of the exchangers, theories and experimental results have often beencontradictory. One author at least l2 regards it as impossible to reviewfully the theories relating to their action.Gregor l4found an extended Donnan theory with use of the Gibbs-Donnan formul-ations to be of great theoretical interest.Others have applied the law ofmass action to describe ion-exchange equilibria, while Walton,15 Jenny, l6and Rothmund and Kornfeld l7 found that simple mathematical equationswith one or more empirical parameters best expressed their behaviour.Walton l8 claimed that almost all the data available on distribution in ion-exchangers fit the Rothmund-Kornfeld equation. In the period reviewedit is clear that different investigators find that one or other of these theoriesis able to fit the data under their conditions, but in many cases approachesdifferent from those above apparently adequately represent the nature ofequilibria ; it is possible to discover an almost inexhaustible list of equationsto satisfy equilibrium requirements.From the Donnan equilibrium Yamabe l9has derived the following equation which is valid for exchange between ionsof valency 1 and 2 :where N and n are concentrations of the ion in the resin and solution, respec-tively.A further derived relation 20where Q and E are the initial amounts of ion in the resin and solution,respectively, N is the solution concentration at equilibrium, n is a constantand A and B denote the ions, is valid for ions of different valency. Agree-ment with Donnan equilibrium calculations was also found by Hutschnekerand Deuel.21 Stewart and Graydon 22 measured cation- and anion-transferrates across various poly(styrenesu1phoiiic acid) membranes and consideredthe anion-transfer rates in terms of a Donnan equilibrium : further evidencefor its applicability, at least in a qualitative sense, was shown 23 duringinvestigation of the effect of dilution on cation-exchange equilibria. InNaCl-HC1 exchange on an Amberlite IR-120 resin, a Donnan equilibriumexists 24 between resin and solution phases.Although it existed also for theLiC1-HC1 system, its validity only extended between concentrations 0 . 1 ~and 0 . 3 ~ ; anomalies in solutions of higher concentration were explainedby assuming the lithium ion to be dehydrated.Some have regarded ion exchange as a Donnan equilibrium.The Donnan equilibrium.NB/nB == (NA/%A)2 .. . . - * (1)(QA + EA) /(CQB + EB) = ~NA./NB . - . (2)l4 H. P. Gregor, J. Amer. Chenz. SOG., 1948, 70, 1293; 1951, 73, 642.l5 H. F. Walton, J. Phys. Chew., 1943, 47, 371.l6 J. Jenny, ibid., 1932, 36, 2219.l7 V. Rothmund and G. Kornfeld, 2. anorg. Chem., 1918, 103, 129.2o Idern, ibid., p. 191.21 K. Hutschneker and H. Deuel, Helv. Chim. A C ~ L C , 1966, 39, 103%).aa R. J. Stewart and W. F. Graydon, J . Phys. Cheiiz., 1956, 60, 750.23 E. Keiner, K. F. Schulz, and B. Tezak, Arkiv Kemi, 1955, 27, 93.24 H. Kakihana, N. Maruichi, and K. Yaniasalri, J. Phys. Chenz., 1966, 60. 36.H. F. Walton, J. Franklin Inst., 1941, 232, 305.T. Yamabe, J. Chem. SOG. Japan, 1955, 58, 91572 GENERAL AND PHYSICAL CHEMISTRY.Empirical equatiorts.A very valuable and interesting contribution hasbeen made by Hogfeldt 25 who investigated empirical equations of Jenny,Rothmund and Kornfeld, Freundlich, Krocker, Vageler, Weisz, van Dranen,Yamabe and Sato, and Boedeker for which validity has been claimed. Mostof the data were derived from AgH exchange on Dowex-50 and Wofatit K8resins. The Freundlich equation alone represented all types of equilibrium-quotient curves, but the most useful equation was that of Rothmund andKornfeld which could be extended in a very simple way to cover all types.Determinations of the parameters of the Rothmund-Kornfeld equationhave been reported from investigations of exchange equilibria on sulphonatedAssam coal.26Davydov and Levit’skii2’ have found that the Vageler, Gapon, andmodified Nikal’skii equations are applicable to the exchange of Caz+, Mg2+,and Ba2+ for K+ and Naf on Wofatit P.The law of mass actiort.An empirical formula based on the law of massaction is suggested by Yamabe 28 to represent the equilibrium in the exchangeOH-C1 on Amberlite IR-400 or -410. For Ag+-H+ equilibrium on WofatitKS at low silver concentrations29 the equilibrium quotient is defined as({H+)[AgR]) /({Ag+}[HR]) where enclosing { ] and [ 3 represent concentrationsin resin and solution respectively. The coefficient KHAg has a constant valueof 0.26 within the limits 7 x and 4 x for the mole fraction of silverin the resin. Validity of the law of mass action for H-Na exchange onAmberlite IR-120 is also reported.30 Hysteretic effects in the exchangeBa-H on a strongly acidic resin made Vanselow’s law of mass action invalidwith respect to the real behaviour of the resin ~hase.~1 For completecharacterization of the exchange, knowledge of the selectivity coefficientfor the resin and the ion pair is necessary.Simple mass-action considerations were not sufficient to explain theelution behaviour of alkaline-earth and alkali metals on cationic resins ofdifferent ~ross-linking.~~It isknown that the resin phase can be conveniently treated as a concentratedaqueous solution.In such a system, a variation of the activity coefficientswill occur with cross-linking. The dependence of selectivity and swellingon cross-linking is understandable 33 by consideration of resins as poly-electrolytic gels with certain properties.Selectivity and activity-coefficientdeterminations 3437 suggest that ion-exchangers must be treated as poly-Activity coeficients, selectivity coeficients, and degree of cross-linking.26 E. Hogfeldt, Acta Chem. Scand., 1955, 9, 151.26 M. Roy, J . Appl. Chem., 1956, 7 , 335.27 A. T. Davydov and I. Ya. Levit’skii, Trudy Nauch.-lssledovatel. Inst. Khim.28 T. Yamabe, J. Chem. SOC. Japan, 1955, 58, 186, 188.29 E. Hogfeldt, Arkiv Kemi, 1954, 7 , 561.30 T. Yamabe, J . Clzem. SOC. Japan, 1954, 57, 701.31 P. M. Stroechi, Ann. Chim. (Italy), 1954, 44, 147.32 R. M. Diamond, J. Amer. Chem. SOC., 1955, 77, 2978.38 F. E. Harris and S. A. Rice, J . Chem. Phys., 1956, 24, 1258.34 G.E. Mayers and G. E. Boyd, J . Phys. Chem., 1956, 80, 521.35 0. D. Bonner, V. F. Holland, and L. L. Smith, ibid., p. 1102.8 6 H. A. Stroebel and R. W. Gable, J.-Amer. Chem. Soc., 1954, 76, 5911.87 J. S . Mackie and P. Meares, Puoc. Roy. SOC., 1956, A , 282, 485.Klzavkov Univ., 1953, 10, 221MAGEE ION EXCHANGE. 73meric n : 1 electrolytes. Determinations of selectivity coefficients, for anion-exchangers38 as a function of resin and degree of cross-linking, and forcation-exchanger~,~~ are presented.Reichenberg and McCauley 40 have studied equilibria on sulphonatedpolystyrene resins of varying degrees of cross-linking. The order of affinitieswas K > Na > H > Li. Gregor's theory of ion-exchange affinity did notaccount for all the results, a modificatiop being necessary to account for thestatistical variation of cross-linking and relative ease with which hydrationshells can lose some water molecules.On methacrylic acid cation-exchangers of various divinylbenzene con-tents the order of affinity was Li > Na > K, becoming more marked ascross-linking increased.41Undoubtedly, many other factors can change the activity coefficients inthe resin phase.Ion-pair formation offers a probable explanation forabnormal behaviour424 and the uptake of electrolyte by the resin is ofsignificance in activity-coefficient determination^.^^, 32The activity coefficients of sodium and potassium chloride have beenmeasured.46 In this respect, an interesting method is reported by Sobueand Tabata43 who carried out measurements on an ion-exchange film ofcarboxymethylcellulose using infrared spectra.The importance of solvent uptake by the resin phase has now beenrecognized and reports of investigations have recently a~peared.~'-~O Inthe uptake of solvent, ion-hydration has always had a somewhat vaguemeaning.Glueckauf and Kitt 51 have, however, now given informationwhich goes a long way towards clarification of the position. By an isopiesticmethod they investigated the absorption of water by polystyrene sulphonatesand determined the adsorption isotherm and enthalpies and entropies ofhydration. From the shape of the isotherms they conclude that the firstwater molecule absorbed by the resin salt is bound to the sulphonate group.Successive water molecules are then bound with the cations.There seems tobe no basis for the suggestion of a definite shell of water molecules about an ion.Determination of the heats of wetting of ion-exchangers with differentionic species on the resin have led to the view that only a few water mole-cules (five for the hydrogen ion; three for the sodium ion) which can becalled " bound water " take part in the hydration of ions.523a B. A. Soldano and D. Chesnut, J . Amer. Chem. SOC., 1955, 77, 1334.39 B. A. Soldano, Q. V. Larson, and G. E. Myers, ibid., p. 1339.40 D. Reichenberg and D. J. McCauley, J., 1955, 2741.41 H. P. Gregor, M. J. Hamilton, R. J. Oza, and F. Bernstein, J . Phys. Chew., 1956,42 M. H. Gottlieb and H. P. Gregor, J . Amer. Chem.SOC., 1954, 76, 4639.43 H. Sobue and Y . Tabata, J . Polymer Sci., 1956, 20, 567.44 H. P. Gregor, J. Belle, and R. A. Marcus, J . Amer. Chem. SOC., 1955, 77, 2713.4 5 E. W. Baumann and W. J. Argersinger, ibid., 1956, 78, 1130.4 6 J. A. Whitecombe, J. T. Banchero, and R. R. White, Chem. Eng. Prop. Synzp.,4 7 B. A. Soldano and Q. V. Larson, J . Amer. Chem. SOC., 1955, 77, 1331.46 0. D. Bonner, J . Phys. Chem., 1955, 59, 719.49 H. Kakihana and K. Sekiguchi, J . Pharm. SOC. Japan, 1955, 75, 111.so H. P. Gregor, D. Nobel, and M. H. Gottlieb, J . Phys. Chess., 1955, 59, 10.51 E. Glueckauf and G. P. Kitt, PYOC. Boy. SOC., 1955, A , 228, 322.62 T. Matsuura, Bull. Chem. SOC. Japan, 1954, 27, 281.60, 263.1954, No. 14, 7374 GENERAL AND PHYSICAL CHEMISTRY.Howe and Kitchener 53 measured the water sorption isotherms for theH-form of polymethacrylic acid resins and claimed that about 0.1 g.ofwater per g. of dry H-resin was very strongly sorbed, indicating hydrogenbonding on the carboxylic acid groups.The Kinetics of Ion Exchange.-FiZm diffasion. An interesting con-tribution to the theory of ion exchange is that based on the supposition thatthe determining step in the process is diffusion through a film of watersurrounding the resin particles. Support for this concept is presented byDickel and Nieciecki 54 who conclude that at low concentrations the rate-determining process in the exchange of alkali-metal ions against hydrogenions on a Levatit SlOO exchanger is diffusion of exchanging ions through awater film of thickness 3 x lo-* cm.Conditions facilitating film formationare reported by Helfferich 55 who measured self-diffusion coefficients anddeveloped an equation which allowed for film formation.Evidence that the exchange of ion pairs of equal valency followed thistype of kinetics is presented 56-58 but, if one of the exchanging ions is eithervery large or held tightly by the resin, diffusion is best described by gel-diffusion kinetics. On the other hand, in the measurement of the self-diffusion coefficient of sodium,59 evidence is presented for the absence ofliquid-film effects. In the absence of a Donnan electrolyte, two mechanismsfor transport through the resin are suggested: an exchange between siteswith an activation energy about 10 kcal./mole and a diffusion involving afree anion with activation energy about 2 kcal./mole.Sugai and Furuichi 60* 61 have reported a study on theself-diffusion of calcium in Dowex-50.In 1M-SOlUtiOnS particle diffusionwas the controlling step : below 0.5111, film diffusion occurred. Tetenbaumand Gregor 62 have carried out investigations with polystyrenesulphonic acidresins which show agreement with the ideas of particle and film diffusion.They measured the self-diffusion of potassium, non-exchangeable chlorideions, and water. At high rates of flow in a shallow-bed system, the calculatedthickness of the unstirred film was 1.2 p. The diffusion coefficients werepotassium 21%, chloride 37%, and water 85% of the value in free solution.Particle-diffusion kinetics are also reported for chloride-molybdateexchange 63 on Amberlite IR-410, where Boyd, Schubert, and Adamson’sequation 64 was applicable at low concentrations ; sodium-hydrogen ex-change 65 on a monofunctional resin with carboxylic acid groups, whereeffective diffusion coefficients of sodium and hydrogen were 3.92 xPa.rticZe diflusion.53 P.G. Howe and J. A. Kitchener, J . , 1955, 2143.54 G. Dickel and L. Nieciecki, 2. Elektrochem., 1956, 59, 913.55 F. Helfferich, 2. phys. Chem., 1955, 4, 386.5 6 C. Khrishnamoorthy and A. D. Desai, Soil Sci., 1955, 79, 159.5 7 Idem, ibid., p. 215.5 8 Idem, ibid., 1953, 76, 307.59 D. Richman and H. C. Thomas, J . Phys. Chem., 1956, 60, 237.6o S. Sugai and J. Furuichi, J .Phys. SOC. Japan, 1955, 10, 1032.61 Idem, J . Chem. Phys., 1955, 23, 1181.62 M. Tetenbaum and H. P. Gregor, J . Phys. Chem., 1954, 58, 1156.63 T. Nomitsu and J. Hironaka, Yumaguchi J . Sci., 1955, 6, 62.G. E. Boyd, J. Schubert, and A. W. Adamson, .J. Amer. Chem. SOC., 1947,69,2818.6B D. E. Conway, J. H. S. Green, and D. Reichenberg, Tram. Faraday SOC., 1954,50, 611MAGEE ION EXCHANGE. 75c1n.2/sec. ; and the adsorption of nicotine 66 on carboxylic and sulphonicacid-type resins.Mackie and Meares 67 derived an equation for the flux of electrolytethrough a water-swollen cation-resin membrane and concluded that ions inthe resin are transported entirely in an internal aqueous phase. At highconcentrations, however, an electrophoretic effect, and at low concentrations,counter-ion binding, introduces error in the flux theory.Evidence that concentration influences the kinetics of exchange hasbeen obtained.Investigation 68 of the effect of concentration of solution,flow rate, and grain size on the rate of adsorption of sodium and calciumions by Wofatit R showed that the exchange of trace amounts proceeded inthe external diffusion region but, as the number of adsorbed ions increased,the process passed over to particle diffusion.Investigation of the ion-exchange isotherms of cobalt and ferrous iron 69led to the proposal of a mechanism consisting of cation difiusion to theadsorption sites (external and particle diffusion), ion exchange adsorption,formation and decomposition of complex ions, and ion movement on thecolumn.S-Shaped curves were obtained 70 for the exchange ofdifferent cations against hydrogen on a bifunctional exchanger.This typeof curve was due to the bifunctionality of the resin but no interaction betweenthe two kinds of group was detected.Tunit’skii et aZ.71 have derived an equation for sorption with a convexsorption isotherm and for the kinetics of linear isotherms an asymptoticsolution has been obtained.72 The central point of the sorption wave wasfound to move with constant speed along the column and the adsorbed ionspread out at sufficient distance from the column inlet proportionally to thesquare-root of the velocity.Investigations of the kinetics of exchange H-Ba and H-Ca on a Wofatitresin showed a parallel advance of the adsorption front whose displacementwas linear with the volume of the solution passed through the column.73From the rates of exchange of sodium and potassium on Dowex 50,Sulfata E t derived an equation with properly selected rate coefficientsto represent the break-through curves.Adsorption curves of 2.2 x 10-5~-CsC1 and 3.5 X 10-2~-SrCI, inhydrogen-ion concentrations of 0,248 and 0 .4 5 ~ have been determined. 75At lower acidities the curves coincide but at higher acidity, strontium isahead of ca3sium.Column kinetics.G6 H. Kawabe, S. Sugimoto, and nil. Yaniagita, Repovt S c i . Res. Inst. (Japuiz), 1954,30’S. Maclrie and P. Meares, PYOC. Roy. SOC., 1955, A , 232, 498, 510.6 8 M. V. Tobbin and F. G. Dyatlovitskaya, Zhur.$2. Khim., 1954, 28, 1539.70 J. 1’. Cornaz and H. Deuel, Helv. Chim. Acta, 1956, 39, 1227.S. Yu. Elovich and N. N. Motorina, ibid., 1956, 30, 69.N. N. Tunit’skii, E. P. Cherneva, and V. I. Andrew, Zhur. $2. Khini., 1954, 28,2006.7 p V. V. Kachin’skii and 0. M. Toiles, ibid., 1956, 30, 407.i3 A. 1’. Davydov, Yu. A. PuIorozova, and M. R. Kogan, T r d y n;aucli.-lssledovufel.74 A. D. Sulfata, J. T. Banchero, and H . K. White, I H ~ . Eng. Cheru., 1955, 47, 2193.litst. Kiaini. Kharkov Univ., 1053, 10, 189.S. XTu. Elovich, Dokladj1 A k a d . Nnuk S.S.S.H., 1955, 101, 29376 GENERAL AND PHYSICAL CHEMISTRY.Freiling 76 has developed a mathematical treatment of the gradient-elution method for column operation, based upon the plate theory andGaussian approximation to the shape of the elution peak.The equationsinvolve a number of limitations. An application of this method is reported 77for the separation of carrier-free activities.Column operating characteristics for three laboratory-prepared resins aredescribed. 78Exchange capacities, sorption of neutral molecules, and secondary processes.Several determinations of the exchange capacity of ion-exchange resinshave appeared.79 Some interesting facts are reported 80 concerning theresidual capacity and leakage of ion-exchangers. For analytical purposes,Amberlite IR-120 and IR-410 are recommended.Amberlite IR-411 (Cl-form) is reported 81 to have the greatest capacityof the strongly basic exchangers for phenol. A mechanism based on hydro-gen bonding between amine nitrogen groups and molecular phenols issuggested to account for the specificity of sorption of phenol by weakly basicion-exchange resins.Molecular sorption alone cannot explain the sorptionof phenols, bases, or aliphatic and aromatic acids by monofunctional cation-exchangers * 82 ionogenic groups present have a significant r61e. The mole-cular adsorption of some organic molecules on strongly basic Dowex 1 and 2,and Amberlite IR-410 has been measured : 83 interference in the chromato-graphic separation can be overcome by the choice of solvent. The sorptionof acetic, propionic, n-butyric, and benzoic acids on sulphonated crosslinkedpolystyrene resin has been shown 84 to be true and uniform and not confinedto the surface of the resin particles.Riickert and Samuelson 85 have investigated the adsorption of sugarson anion and cation resins from ethanol-water.The uptake by desulphon-ated resins was ascribed to the electric field around the ions in the resinphase; adsorption on the higher-polymeric network seemed to be of verylittle importance. The adsorption of glucose on weakly basic anion-exchangers 86 and large organic molecules such as morphine and codeine 87on Russian resins has been reported.Saldadze 88 found complete reversibility for Ba-Mg, K-Ba, and Zn-Cdexchange on a sulphophenolic resin. Absence of reversibility by others isconsidered to be due to secondary processes on the resin, such as reduction7 6 E. C. Freiling, J . Amer. Chem. SOC., 1955, 77, 2067.7 7 W.E. Nervik, J . Phys. Chem., 1955, 59, 681.H. A. Shah and K. P. Govindan, J . Sci. I n d . Res., India, 1956, 14, B, 222;E. B. Byrne and L. Lapidus, J . Amer. Chem. SOG., 1955, 77, 6506.79 S. Fisher and R. Kunin, Ind. Eng. Chem., 1955, 47, 1191; H. P. Gregor, M. J.Hamilton, J. Becher, and F. Bernstein, J . Plzys. Chem., 1955, 59, 874; E. Leclerc andT. Samuel, Bull. Centre belge Etude et Document. Eaux ( L s g e ) , 1956, NO. 31, 23.H. G. Heitmann and K. R. Schmidt, Mitt. Ver. Grosskesselbesitzer, 1954, 32, 360.81 M. G. Chasanov, R. Kunin, and F. McGarvey, I n d . Eng. Chem., 1956, 48, 305.82 S. L. Bafna and K. P. Govindan, ibid., 1956, 48, 310.s3 C. W. Davies and B. D. R. Owen, J., 1956, 1681.84 D. Reichenberg and W. J.Wall, ibid., p. 3364.85 H. Riickert and 0. Samuelson, Svensk kern. Tidskr., 1954, 66, 337.8 6 T. M. Reynolds, Nature, 1955, 175, 46.8 7 N. A. Izmailov and S. Kh. Mushinskaya, Doklady Akad. Nauk S.S.S.R., 1955,8 8 K. M. Saldadze, Kolloid. Zhur., 1954, 16, 284.loo, 101MAGEE ION EXCHANGE. 77and complex-formation. Other secondary processes have been recognizedand investigated 899 and side reactions in the solution and resin phasehave caused difficulties in the measurement of the exchange equilibria ofheavy-met a1 ions. 91Ion Exchange and the Nature of Ions.-Ion-exchange resins have beenused to a very great extent to investigate the nature of ions and propertiesof substances in solution. Reviews have appeared.92By use of anion- or cation-exchange resins, the nature and behaviour ofthe following ion species have been investigated : germanium complexes ofoxalic acid; 93 nickel,94 and niobium 96 chloride complexes ;borates; 97 metal phosphates; 98 citrates of Periodic Group IIA metals; 99tungstates ; loo chromates ; lol and fluorides.lo2An interesting investigation has been carried out by Herber et aZ.lo3 onthe elution of Mn2+, Co2+, Cu2+, and Zn2+ with hydrochloric acid fromsamples of the anion-exchanger Dowex 1 with reference to the cross-linkage,capacity, water content, and elution behaviour of the resin.Kraus and Nelson lo4 have reported results of a series of extensiveinvestigations on the distribution of a large number of elements betweenhydrochloric acid and anion-exchanger, Dowex 1.A very comprehensivereview of this work is given by Thomas and Frysinger lo5 and considerationof it will not, therefore, be repeated here.Evidence exists which suggests that the resin itself can have a part in theformation of some complexes. Investigations of this type are, however,not numerous, but it is probable that they will grow in number becauseknowledge of the r61e played by the resin could be of great importance inthe separation of ion species.Arden and Wood lo6 have found that uranium is sorbed on an anion-exchanger as a complex, U02(S04)3-4, below pH 2.5. The sorption occursby the formation of this ion on the resin. This information has been appliedin the recovery of uranium from its Stokes and Walton lo8 have89 Yu. Yu. Lure and E.S. Peremyslova, Zhur. priklad. Khim., 1954, 27, 1207.9O N. Krishnaswamy, J . Phys. Chem., 1955, 59, 187.91 J. P. Cornaz and H. Deuel, Helv. Chim. Acta, 1956, 39, 1220.92 J. Schubert, ref. 2, p. 437; H. C. Thomas and G. R. Frysinger, ref. 3, 156; J. E.Salmon, Rev. Pure Appl. Chem. (Australia), 1956, 6, 24; V. V. Fomin, Uspekhi Khim.,1955, 24, 1010.g3 D. A. Everest, J., 1955, 4415.94 R. Herber and J. W. Irvine, J . Amer. Chem. SOC., 1956, 78, 905.96 V. V. Fomin, L. N. Fedotova, V. V. Sin'kovskii, and M. A. Andrieva, Zhur. $2.913 J. Ryan and H. Freund, J . Amer. Chem. Soc., 1956, 78, 3020.97 D. A. Everest and W. J. Popiel, J., 1956, 3183.98 A. Holroyd and J. E . Salmon, J., 1956, 269.99 F. Nelson and K. A. Kraus, J . Amer. Chem.SOC., 1955, 77, 801; I. Feldman,100 A. Iguchi, Sci. Papers Coll. Gen. Educ., Tokyo Univ., 1955, 5, 29.101 2. I. Dizdar and 2. D. Draganic, Bull. Inst. Nuclear Sci. Boris Kidrich, 1955,5, 79.l02 G. B. Kauffman, Diss. Abs., 1956, 16, 863.103 R. H. Herber, K. Tonguc, and J. W. Irvine, J . Amer. Chem. Soc., 1955, 77, 5840.104 K. A. Kraus and F. Nelson, ibid., 1955, 77, 4508.106 H. C. Thomas and G. R. Frysinger, ref. 3, p. 156.lo6 T. V. Arden and G. A. Wood, J., 1956, 1596.107 T. V. Arden, J . Roy. Inst. Chent., 1956, 80, 127.108 R. H. Stokes and H. F. VI'alton, J . Amer. Chern. SOC., 1954, 76, 3327.Khian., 1955, 29, 2042.T. Y. Toribasa, J. R. Havill, and W. F. Neuman, ibid., p. 87878 GENERAL ANI) PHYSIC.11, CHEMISTRYinvestigated the stabilities of copper and silver complexes of ammonia onPermutit Q and Amberlite IR-50.On the latter resin they are just as stableas in aqueous solution. Presumably, either the ions are not covalentlybound to the resin sulphonic acid groups or, if they are so bound, the bindingenergy is far less than that between them and ammonia. On the formerexchanger the ammonia complexes are decidedly less stable owing to thegreater tendency to form metal-carboxylate complexes. Confirmation ofthis work is reportedg1 where, on Amberlite IR-50, Cues was found to bemore selectively taken up against ammonia than against [Cu(NH,),I2+.The exchange behaviour of zirconium and hafnium in perchloric acid hasbeen studied.log The results were interpreted on the basis of unhydrolysedmetal species M4 in the aqueous phase at hydrogen-ion concentrations of1~ and 2 M and very low metal-ion concentration.The sorbability of Pb2+ and Bi3+ in chloride and nitrate so1utions,ll0the exchange of sulphate-bisulphate ll1 on Dowex 1-X8, and the ageing offerric oxide hydrosol 112 have also been reported.Ion Exchange in Non-aqueous Systems.-Interest in ion-exchangebehaviour in non-aqueous systems continues to grow.I t is known that therates of diffusion of ions decrease in organic solvents or in mixtures oforganic solvents and water, and reaction on ion-exchange resins would,therefore, generally be slower. Variation in the nature of exchange, how-ever, in these systems makes the subject one of considerable interest.Bergin and Heyn 113 employed cationic-exchange membrane electrodesto nieasure function potentials in liquid ammonia and alcohols.The ratiosof the activity coefficients of ammonium nitrate in liquid ammonia weredetermined and results agreed well with those obtained by different electro-chemical methods.Davies andOwen 114 have reported results for three resins with varying cross-linking.Swelling was said to be directly proportional to the concentration of organiccomponent in the or largely determined by the dielectric constantof the adsorbed solution.l16An excellent report on the kinetics of non-aqueous exchange systems hasappeared.l17 Studies were made by adsorption of butylamine from aqueousethanol on a strongly acidic exchanger. Conclusions drawn were that thereaction rate was independent of the bulk amine concentration and wascontrolled by particle diffusion. Quantitative rules for cation-exchange inmixed media have been suggested.ll* Gable and Stroebel 119 have obtainedSwelling of resins in mixed solvents has been investigated.log E.M. Larsen and Pei Wang, J . Amer. Chem. Soc., 1954, 76, 6223.110 F. Nelson and K. A. Kraus, ibid., p. 5916.112 K. Meguro, T. Kondo, and Y . Hayashi, J . Chem. Soc. Japan, 1955, 76, 482.113 M. J. Bergin and A. H. A. Heyn, J . Amev. Chem. Soc., 1954, 76, 4765.114 C. W. Davies and B. D. R. Owen, .J., 1956, 1676.115 E. A. Materova, Zh. L. Vert, and G. P. Grinberg, Zhur. ohshchei h'hisn, 1954,116 H. P. Gregor, D. Sobel, and M. H. Gottlieb, J . Phys. Chem., 1955, 59, 10.1 1 7 S.Wilson arid L. Lapidus, I n d . Eng. Chem., 1956, 48, 992.118 A. T. Davydov Bnd R. F. Skoblionok, Tvudzr Nazich.-Issledouafel. ITict. K h i m . ,1 1 9 R. W, Gable and H. A. Stroebel, 1. Phys. Chem., 2956, 60, 513R. E. Anderson, W. C. Baumann, and D. I;. Harrington, I n d . Eng. Chern., 1955,47, 1620.24, 953.Khavkov Univ., 1953, 10, 196hIAGEE ION EXCHANGE. 79equilibrium quotients from Na-H, NH4-H, and AgNa exchange in an-hydrous methanol on Dowex 50. Enhanced selectivities are attributed toalterations in the degree of ion-solvation and ion-pair formation. Selectivesorption is reported l20 for cation-exchangers in investigations with water,ethanol, benzene, or mixed non-aqueous systems. By suitable choice of thecomposition of the liquid medium, selectivity of diffusion of individual ionsinto the resin phase can be obtained.Ketones and alcohols with smaller proportions of water and hydrochloricacid have been used 121 for the elution of sorbed copper and nickel on Zeo-Karb 225.The two metals can be separated quantitatively by use ofacetone containing 4% of hydrochloric acid and 10% of water.Barrer and Raitt 122 have investigated the exchange of a large number ofmetal ions on the inorganic ion-exchanger, ultramarine, in organic solventsand Davydov and Skoblionok 123 have found that in the exchange of adsorbedcations on volchonskoite the tendency for Na+ and K+ to displace Ba2+increased as the organic component of the mixed solvent increased.A review of ion-exchange in non-aqueous solutions has recentlyappeared. 12*New and Modified Ion-exchangers.-The preparation of new or themodification of the more conventional resins allows much to be learnedabout the physical processes of ion exchange.It is rather surprising, there-fore, that little attention has, in the past, been given to details of themechanics of preparation. A considerable amount of evidence exists tosuggest that a particle of the normal commercial resin contains a shell ofrelatively high density and a core of comparatively low density and hard-ness. On swelling, internal tensions are produced which cause the resinbeads to crack and exchange properties are thus affected. These facts arerecognised by Abrams 125 who has reported a unique method of polymeris-ation and a new method of sulphonation which gives homogeneous sulphon-ated copolymers of styrene and divinylbenzene possessing properties dis-similar from and superior to those of the standard copolymers.Preparationof resins in which the aim is selectivity is reported. Parrish 12G has preparedselective ion-exchangers from styrene and divinylbenzene. One of theseresins selectively adsorbed mercury : a second showed selectivity towardscopper, nickel, and cobalt between pH 2 and 3.An anion-exchange resin from formaldehyde and melamine for heavy-metal adsorption 12' and another,12* selective for potassium, from raw rubberdissolved in benzene, are reported. Anion-exchangers of selective perme-ability have also been obtained.129 Developments in the production and120 W.Blaszkowska, W. Wisniewski, and A. Teichert, Roczniki Chem., 1955, 29,lZ1 N. F. Kember, P. J. Macdonald, and R. A. Wells, J . , 1955, 2273.121 R. M. Barrer and J. S . Raitt, J., 1954, 4641.123 A. T. Davydov and R. F. Skoblionok, Zhur. obshchei Khinz., 1956, 26, 350.124 L. Sobczyk, Przemysl Chem., 1956, 12, 389.lZ5 I. Abrams. Ind. Eng. Chem., 1956, 48, 1469.126 J. R. Pamsh, Chem. andInd., 1956, 137.12' S. Yoshikawa and T. Kubotera, J . Chem. SOL. Japan, 1954, 5'7, 676.lZ8 H. Nakazawa, J.P. 8196/1954.laS J. T. Clarke, U.S.P. 2,732,35111956.92180 GENERAL AND PHYSICAL CHEMISTRY.study of electron exchangers, first introduced by Cassidy and his co-w o r k e r ~ , ~ ~ ~ are reviewed.131 The ability of seven cation-exchangers toreduce ferric chloride solutions is r e ~ 0 r t e d .l ~ ~ The reduction process isindependent of the ion-exchange process : exchangers produced by co-polymerisation of methacrylic and acrylic acids with different '' bridgeformers " are not reducing agents.Zirconium phosphate is reported 133- 134 to have cation-exchange pro-perties which are excellent for alkali and alkaline-earth metals, ferric iron,and aluminium 133 and, by mixing a solution of zirconium oxychloride witha large excess of sodium tungstate, a cation-exchange material is obtained.135Anions in mercarbide salts ([(CHg30),n+ + n X ' ] , where X' is exchangeable)have been found to exchange in the following orderThe exchange can be reversed by varying the concentration^.^^^Lignins,partly substituted for phenol and formaldehyde in cationic resins containingphenolsulphonic acid, were found to give a more expanded molecularstructure with higher swelling and greater exchange capacity. 138Champetier et aZ.139 have shown that N-diethylaminohydroxypropyl-cellulose has interesting ion-exchange properties. Claims are also made forresins obtained from coalJZ6 by the condensation of vegetable proteins andforma1dehyde,lm from quebracho extracts,141 by surface treatment of silicagel,142 and from agar.143Ion-exchangers as Catalysts.-Catalysts of chemical reactions by ion-exchange resins has reached the stage of development where some accountof its application must be given in a report on progress in ion-exchange.Reviews on the subject have been presented.144 An approach to funda-mentals has been made by Helfferich 145 who treats the pore liquid of theresin in which the reaction occurs as a homogeneous system and comparesit with a homogeneous solution containing electrolyte as catalyst.Cation-exchangers have been used as catalysts in formation of a ~ e t a 1 s . l ~ ~13* H. G. Cassidy, M. Ezrin, and I. H. Updegraff, J . Amer. Chem. Soc., 1953, '75, 1615.131 J. Schubert, ref. 2, p. 416; H. C. Thomas and G. R. Frysinger, ref. 3, p. 151;132 I. P. Losev and A. S. Tevlina, Trudy Komissii Anal. Khim. Akad. Nauk S.S.S.R.,133 K. A. Kraus and H. 0. Phillips, J . Amer. Chew. Soc., 1956, 78, 249, 694.134 C. B. Amphlett, L. A. McDonald, and M. J. Redman, Chem. and Ind., 1956, 1314.136 K. A. Kraus, T. A. Carlson, and J. S . Johnson, Nature, 1956, 177, 1128.137 S. E. Burkat, Ukrain. khim. Zhur., 1955, 21, 669; I. Gdalia, Bull. Res. Council13* A. Scipioni, Ann. Chim. (Italy), 1955, 45, 358.139 E. Champetier, E. Kelecsenyi-Dumeonil, G. Montegudet, and J. Petit, Compt.140 C. Simionescu, E. Calistrii, and D. Feldman, Studii cercetari sti., 1954, 5, 151.141 E. Virasoro, Rev. Fac. Ing. quim., 1954, 23, 51, 59.142 H. Kautsky and H. Wesslau, 2. Naturforsch., 1954, 9b, 569.143 T. Currie, Chem. and Ind., 1955, 116.144 B. A. Lister, I n d . Chemist, 1956, 8, 369; R. Glenat, Chimie et Industrie, 1956, 75,145 F. Helfferich, J . Amer. Chem. Soc., 1954, 5567..146 G. V. Austerweil and R. Pallaud, Bull. SOC. chzm. France. 1954, 1164.NO,- < C1- < Br- < OH- < CN- < I-Ion-exchange materials have been obtained from peat .13'E. B. Trostyanskaya, I. P. Losev, and A. S. Tevlina, Uspekhi Klzim., 1955, 24, 69.1955, 8, 326.A. Weiss and A. Weiss, 2. anorg. Chem., 1955, 282, 324.Israel, 1953, 3, 250.rend., 1956, 243, 269.292MAGEE ION EXCHANGE. 81The action and subsequent reaction depend on the type of compound : formolecules of less than four carbon atoms, reaction stops at the acetal. Withlarger molecules, the olefinic ether is formed. Catalytic action seems todepend on the acid polarity of the exchanger, the position of the polargroups in the macromolecule, and thermostability of the exchanger. Strictdependence on the method of preparation and size of the resin particle isreported 147 in the use of cation- and anion-exchangers as supports forpalladium catalysts during the hydrogenation of maleic acid.Catalysis may also be brought about by acid ~ 1 a y s . l ~ ~Bafna lP9 has studied the catalysis of the acetone-iodine reaction by ion-exchangers as a function of particle size, degree of cross-linking, and concen-tration of acetone, and Mastagli 150 has shown that both types of exchangerscatalyse chemical reactions, independently of one another.Ion-exchange resins have been used catalytically in the de-esterificationof pectin,151 preparation of butyl b e n ~ o a t e , l ~ ~ and hydrolysis of sucrose. 153Ion-exchangers in Analytical Chemistry.-The last Report on this topicwas in 1954. Recently, reviews on the subject have appeared.lM Themain function of ion-exchange resins in analytical chemistry is to makeseparations; the success achieved in this direction is readily seen by thefollowing selection from the literature of the past two years.Details of the use of anion-exchange for the separation of two short-period activities, 207mPb (0.8 sec.) and l 9 1 m I r (4.9 sec.), from long-lived parents207Bi (8 yr.) and lglOs (16 days) are reported.lS5Interest in the separation of the rare-earth elements still continues.Recent advances are characterized by refinements in techniques.156 Thelanthanides and actinides have been separated on Dowex 50-X4 by usingammonium a-hydroxyisobutyrate as eluant.157Excellent work has been carried out by Spedding et al., applying theoreti-cal and practical knowledge of ion-exchange columns to the separation ofnitrogen isotopes on Dowex 50-X12 using sodium hydroxide as e 1 ~ a n t . l ~ ~A separation of radium isotopes, Ra-D, Ra-El and Ra-F, with a radioactivepurity of almost 99.90/, has been obtained.159Ethylenediaminetetra-acetic acid is an eluant of considerable applicationand success. In this capacity, it has been used in the. cation-exchange147 E. Mariani and F. Spinelli, Ann. Chim. (Italy), 1955, 45, 887.148 C. McAuliffe and N. T. Coleman, Proc. Soil Sci. Soc. Amer., 1955, 19, 156.149 S. L. Bafna, J . Chem. Phys., 1955, 23, 1199.lS0 P. Mastagli, Compt. rend., 1956, 242, 1031.151 A. Sato and K. Aso, J . Fermentation Technol. (Japan), 1955, 33, 362.lS2 S. Kitahara and M. Sugihara, Science and Industry (Japan), 1953, 27, 316.153 J. Fodor and 2. Hajos, Magyar Tudomanyds Akad. Ke'm. Tudomdnyok OsztdlyanakKiizlemenyei, 1955, 5. 545.154 R. Pallaud, Chem. Analyt., 1955, 37, 16; 0. Samuelson, ibid., p. 191; 0. E.Schultz, J . Pharw. Pharmacol., 1956, 8, 382 ; J. E. Salmon, Lab. Practice, 1956, 15, 338.155 E. C. Campbell and F. Nelson, J . Inorg. Nuclear Chem., 1956, 3, 233.J. G. Cuninghame, M. L. Sizeland, H. H. Willis, J. Eakins, and E. R. Mercer,ibid., 1955, 1, 163; N. E. Topp, Chem. and Ind., 1956, 1320; W. E. Nervik, J . Phys.Chew., 1955, 59, 690.157 H. L. Smith and D. C . Hoffman, J . Inorg. Nuclear Chem., 1956, 3, 243.158 F. H. Spedding, J. E. Powell, and H. J. Svec, J . Amer. Chem. Soc., 1955, 7'4,6125.*59 T. Tshimori, Bull. Chem. SOC. Japan, 1955, 28, 43282 GENEKAL ANI) PHYSTCAI, CHEMISTRY.separation of barium and lead,160 the preparation of pure cerium earths,161and the anion-exchange separation of the alkali metals. 162A separation of a different type, but still of great interest, is thatclaimed 163 for geometrical isomers of $auo- and croceo-cobalt salts on theNH,-form of Amberlite IR-120. Analysis of the condensed phosphates onDowex 1-X8 is reported 164 and several giving details of theseparation of fluoride from substances which interfere in its colorimetricdetermination, and a method for the determination 166 of atmosphericfluorine, have appeared.Ion-exchange resins’have great versatility : no combination of metalsappears too difficult to separate if the theoretical and practical knowledgeof the exchangers is applied. Thus, the separation of molybdenum andtechnetiurn,l6’ arsenic, antimony, and tin,168 zirconium and hafnium,169zirconium and p r o t a ~ t i n i u i n , ~ ~ ~ rhodium and iridium,171 and niobium andtantalum,172 have all been achieved.Flaschka and Sadek 173 have employed a cationic resin in the deter-mination of potassium by dissolving the precipitate of potassium tetra-phenylboronate in acetone and passing it through the resin : the free tetra-phenylboronic acid liberated is titrated.Chromatography on paper impregnated with ion-exchange resins isreported 174 and preparations of standard solutions of hydrochloric, sulphuric,and nitric acids have been carried out by means of ion-e~changers.~~~R. j. nf.J. H. BAXENDALE.K. 0. COLCLOUGH.C. KEMBALL.R. J. MAGEE.A. D. E. PULLIN.E. WAIIHURST.lGo T. Taketatsu, J . Chem. SOC. Jupaqa, 1955, 76, 756.161 C. Achard, Compt. rend., 1955, 241, 800.lG2 F. Nelson and K. A. Kraus, J . Amer. Chem. SOC., 1955, 77, 813.1G3 11. Mori, M. Shibata, and J . Azami, J . Chein. SOC. Japan, 1955, 76, 1003.164 T. V. Peters and W. Rieman, Analyt. Chim. Acta, 1956, 14, 131.185 \V. FunasakL, M. Kawase, T. Kojima, and Y . Matsuda, Japan Analyst, 1955, 4,514; J . Saulnier, AnaZJtt. Chzwi. Acta, 1956, 14, 62; C. Mader, Chemist-Analvst, 1955,44, 86.3, 49.I c i c J. 1’. Nielsen and A. D. Dangerfield, ilvch. Iwd. Hcalth, 1955, 11, 61.lC7 E. H. Huffnian, R . I,. Oswalt, and L. A. Wjlliams, J . Inorg. Nuclear Chew., 1956,lG8 R. Klement and A. Kuhn, Z . arzalyd. Chem., 1956, 152, 146.K. S. Rajan and J. Gupta, J . Sci. f n d . Res. (India), 1955, 14, B, 453.170 S. Kahn and D. E. Hawkinson, J . Inoiy. Nuclear Chem., 1956, 3, 155.171 M. L. Cluett, S. S. Berman, and I T T . A. E. McBryde, Analyst, 1955, 80, 204.172 AT. J. Cabell and I. Milner, Analyt. Chim. Acia, 1955, 13, 25s.173 H. Flaschka and F. Sadek, Chemist-Analyst, 1956, 45, 20.M. Lederer and S. Kertes, Analyt. China. Acla, 1956, 15, 226.175 C. J. Keattch, Lab. Pmctice, 1956, 5, 208; S. Hirano and M. Kusobe, . J a p m.4nalyst, 1955, 4, 379

ISSN:0365-6217    

DOI:10.1039/AR9565300007

出版商:RSC    

年代:1956

数据来源: RSC

摘要:

INORGANIC CHEMISTRY.1. INTRODUCTION.THE particular form of the Periodic Table used in inorganic chemistry isstill to some extent a matter of personal preference. Advances in inorganicchemistry during 1956 are presented in this report on the basis of its " longform "; the chemistry of the main groups is discussed first and this isfollowed by a systematic treatment of the transition elements.The list of atomic weights approved by the International Union of Pureand Applied Chemistry includes revised values for 12 elements : Dy, Er,Gd, Hf, In, Ni, Pd, Pt, Re, Sm, W, and Xe. The greatest change is forgadolinium which is altered from 156.9 to 157.26, and substantial modi-fications are also recommended for palladium (from 106.7 to 106.4) andplatinum (from 195.23 to 195.09).The changes reflect a general tendencyto favour values obtained by precise physical methods and it is significantthat most of the elements mentioned above have presented unusual diffi-culties of determination by chemical means either because of difficulties inseparation and purification, or because of difficulties in preparing compoundsof exactly known composition.Two new journals, both Russian, of interest to inorganic chemists beganpublication during 1956, Zhzurnal Neorganicheskoi Khimii and KrystaZZo-gra$yn, Reviews have appeared on the periodicity of thermodynamicproperties of compounds,2 the variations and relationships of some ionizationpotential^,^ the lattice energy of ionic crystal^,^ the Raman spectra ofinorganic compounds, the purification of the rare gases, and the chemistryof non-aqueous ~olutions.~ The last topic is mentioned frequently in thefollowing sections whenever it is relevant to.the chemistry of particularcompounds, but it is convenient here to draw attention to two further moregeneral investigations. The first is the development of diethyl ether as asolvent for ionic reactions.8 The solvent is considered to dissociate to aminute extent as ethyl ethoxide, Et'OEt-, so that compounds like lithiumethoxide behave as bases, and complexes which the solvent forms withelectron acceptors (A), and which may be formulated as E t i [EtO+A]-,behave as acids. The interpretations are based on conductimetric titrationsrather than the isolation and analysis of compounds. The second investig-ation concerns a study of carbonyl chloride as an acid-base solvent ; on thebasis of chlorine-exchange experiments it is concluded that this solvent doesnot undergo self-ionization as C 0 2 &(Cl-), or COCl IC1- but is essentiallycovalent .9E.Wichers, J . Amer. Chena. Soc., 1956, 78, 3235.B. Lakatos, Acta Chim. Acad. Sci. Hwng., 1955, 8, 207.L. H. Ahrens, J . Inorg. Nuclear Chem., 1956, 2, 290.A. F. Kapustinskii, Quart. Rev., 1956, 10, 283.L. A. Woodward, zbid., p. 185.D. S. Gibbs, H. J. Svec, and R. E. Harrington, I n d . Eng. Chem., 1956, 48, 289.V. Gutmann, Svensk kem. Tidskr., 1956, 68, 1; Quart. Rev., 1956, 10, 451.G. Jander and K. Kraffczyk, 2. anorg. Chem., 1956, 282, 121 ; 283, 217.J . L.Huston, .I. Inorg. Nwclrnr Chem., 1956, 2, 12884 INORGANIC CHEMISTRY.An increasing amount is being published on the nature of non-stoicheio-metric compounds and, whilst much of the interest is in the more physicalaspects of the subject, substantial advances are also being made in thechemistry of these systems. The crystal chemistry of non-stoicheiometriccompounds has been reviewed.1° A careful X-ray investigation of theproducts of thermal decomposition of lead dioxide shows that two inter-mediate non-stoicheiometric phases with narrow composition ranges existbetween PbO, and Pb304. The or-phase Pb01.50-1.62 is close to Pb7011 andthe p-phase, Pbl.42-1.50, is close to Pb203.11 Refined phase diagrams in thelead-sulphur system suggest that PbS has 6 x lo1, atoms of excess of Pbper C.C.at the composition of maximum m. p., 1127".12 A series of sevendiscrete phases has been found in the titanium-oxygen system betweenTiO,.,, and TiOl.go. The compositions of these appear to be constantwithin &0.002 and can be represented by the formula Tin02n-l where4 < n < 10.13 A re-investigation of the phases present in the iron-oxygensystem at compositions near FeO has shown that, above lOOO", the composi-tion range of ferrous oxide is from Fe,.,,,O to Fe,.,,,O; below this temper-ature the composition limits converge and at 570" the compound has thecomposition Fe, 930 ; at still lower temperatures a two-phase system(or-Fe + Fe304) separates.14 The cobalt-selenium system has three inter-mediate solid phases : B-CogSe,, which is related to Cogs8 and (Fe,Ni),S,;a y-phase of NiAs structure with some vacant cation sites, which exists overthe composition range CoSe,.,,,.,, at 600" ; and a &phase CoSe,, of pyritesstructure.15 In the cobalt-tellurium system the p-phase has a much widercomposition range (CoTe,.,-,., at 600", CoTe,.,-,., at 335") .16 The ternarycompound Li,Mn,-,O formed by sintering Li,O, and MnO at high temper-atures comprises a single non-stoicheiometric phase of NaCl structure over alarge range of compositions.At higher lithium concentrations, dependingon the temperature, the compound LiMnO, is also f0rrned.l' Strontium-niobium bronzes with the perovskite structure and similar to the sodium-tungsten bronzes have been prepared in the composition range Sr,.,NbO,-Sro.,,Nb03.The colour changes from deep blue to red with increasingstrontium content and compressed-powder specimens have a high electricalconductivity. Other phases, with complex X-ray patterns, exist betweenSr,.,NbO, (white) and Sr,.68Nb0, (black) and there is also evidence forbronzes in the systems Ba,NbO, and Ba,TaO,.ls2. MAIN GROUPS.Group 1.-The dissolution of sodium in methylamine to give a bluesolution has been shown to depend on traces of ammonia in the methyl-lo A. D. Wadsley, Rev. Pure Appl. Chem. (Australia), 1955, 5, 165.l1 G. Butler and J. L. Copp, J . , 1956, 725.12 J. Bloem and F. A. Kroger, 2. phys. Chem. (Frankfurt), 1956, 7 , 1.l3 S. Andersson and A. Magneli, Naturwiss., 1956, 43, 495.l4 J.Aubry and F. Marion, Compt. rend., 1956, 242, 776.l5 F. Bahm, F. Grranvold, H. Haraldsen, and H. Prydz, Acta Chem. Scund., 1955, 9,16 H. Haraldsen, F. Grernvold, and T. Hurlen, 2. anorg. Chem., 1956, 283, 143.1 7 W. D. Johnston and R. R. Heikes, J . Amer. Chem. SOC., 1956, 78, 3255.18 D. Ridgley and R. Ward, ibid., 1956, 77, 6132.1510ADDISON AND GREENWOOD: MAIN GROUPS. 85amine.19 Liquid sodium does not react with zinc phosphate below 160" andthis is also the critical wetting temperature of zinc by liquid sodium if thezinc has been electropolished in a phosphate bath; no such critical temper-ature was found for abraided zinc plates2*Extensive studies of the systems Na20-A120,-Si02 and K,O-A1,0,-SiO,have been reported.21 A new series of crystalline acid metaphosphates hasbeen obtained from a phase study of the system N+O-H,0-P,0,.22Rubidium and casium react with sulphur in liquid ammonia to givecrystalline polysulphides of formula M2S, where x is 2, 3, or 5; these com-pounds and also cs'& were isolated and their physical properties determined.Rb2S4, Rb2S6, and Cs2S4 were not formed under these condition^.^^It has been confirmed that czsium monoxide Cs20 has the anti-CdCI,-typeof crystal structure and it remains the only known example of this structure ;the abnormally large Cs-Cs distance and the short Cs-0 distance indicateconsiderable polarization of the czsium ion.24 The crystal structure oftricasium monoxide has also been determined.25 The Cs-0 bond is ionic asin Cs20 but the Cs-Cs bond length is similar to that in metallic casium.Its semimetallic structure is also reflected by its low m.p. (165") and veryhigh electrical conductivity which is one-third of that of caesium itself.Group II.-Unipositive beryllium is obtained by anodic oxidation duringthe electrolysis of aqueous solutions between beryllium electrodes in adivided cell. In short runs, the Be+ ion is quantitatively oxidized by waterto Be2+ with liberation of hydrogen ; in longer runs some metallic berylliumis formed by disproportionation, 2Be+ _+ Be2+ + Be, and is depositeduniformly throughout the anolyte. The existence of unipositive berylliumwas further demonstrated by its ability to reduce permanganates to man-ganese dioxide and silver salts to metallic silver.26 Similar experiments withorganic oxidants have confirmed that unipositive magnesium Mg+ is formedby anodic oxidation when a solution of sodium iodide in pyridine is electro-lysed between magnesium electrodes2'Beryllium oxymonochloroacetate, Be40 (C1CH2*C02),, has been made andits X-ray cell dimensions found to be approximately the same as those of theoxypropionate Be40(MeCH2*C02)6.28 In the presence of anhydrous ethanol,beryllium oxyacetate splits off acetic anhydride to form higher basic acetatesaccording to the equation :Both the original oxyacetate and the higher basic acetates occlude appreci-able amounts -of the solvent .29Be,O(MeCO,), = Be,O,'+ $- 4MeC0,- + (MeCO),Ole G.Hohlstein and U. Wannagat, 2.anorg. Chem., 1956, 284, 191.2e C. C. Addison, W. E. Addison, D. H. Kerridge, and J. Lewis, J., 1956, 1454.21 J. F. Schairer and N. L. Bowen, Amer. J . Sci., 1955, 253, 681; 1956, 254, 129.22 E. J. Griffith, J . Amer. Chem. SOC., 1956, 78, 3867.23 F. FehCr and K. Naused, 2. anorg. Chem., 1956, 283, 79.Khi-Ruey Tsai, P. M. Harris, and E. N. Lassettre, J . Phys. Chern., 1956, 60, 338.Idem, ibid., p. 345.26 B. D. Laughlin, J. Kleinberg, and A. W. Davidson, J . Ames.. Chem. Soc., 1956,27 W. E. McEwen, J. Kleinberg, D. L. Burdick, W. D. Hoffman, and J. Y . Yang,28 A. V. Novoselova and K. N. Semenenko, Zhur. neorg. Khinz., 1956, 1, 887.2B H. D. Hardt, 2. anorg. Chem., 1956, 286, 254.78, 559.ibid., p. 458786 INORGANIC CHEMISTRY.Magnesium hydride has very different properties depending 011 whetherit is prepared directly from the elements or by pyrolysis of organomagiiesiumcompounds.It has now been shown by X-ray methods that both formshave the rutile crystal structure and that the differences in properties arerelated to the degree of subdivision of the sample.30 Calcium hydridechloride (CaHC1, m. p. 700") and its strontium and barium analogues (m. p.s840" and 850") may be prepared either by melting together the appropriatehydride and anhydrous chloride or by heating the metal and its chloride inan atmosphere of hydrogen. The compounds, which are stable at hightemperatures even under vacuum, resemble mica in appearance and have thePbClF-type crystal structure.31The formation of calcium superoxide Ca(O,), during the dehydration ofcalcium peroxide octahydrate with phosphoric oxide has been discussed.32The possibility of preparing barium superoxide Ba(O,), has also been con-sidered and the equilibrium pressure of oxygen above the compound hasbeen calculated to be 32 atm.at 25", 75 atm. a t loo", and 2300 atm. at 200" 33Group II1.-The boron hydrides and their derivatives continue to attracta great deal of interest. A new B, hydride has been detected by X-raytechniques and a partial elucidation of its structure shows that the boronatoms form an icosahedral fragment similar to that formed by a juxta-position of B4H,, and B,Hl, suitably bridged to give an overall formulaB,H1,.34The effect of nitrogen-bond strain on the chemistry of aminoboronhydrides has been studied by synthesising a series of derivatives in which thenitrogen is in small heterocyclic rings.35 DimethylaminomethylborineMe,NBH*Me, made by treating methylborine with dimethylamine, is pre-dominantly monomeric in the vapour phase but dimeric as aDiborane diammine B,H6,2NH3 reacts with alkali metals in liquid ammoniato give a borohydride and aminoborine :M + B1H,,2NH, + &HZ + NH, + MBH4 -I- BHZ-NH,During removal of the solvent, the aminoborine undergoes ammonolysis toan extent which depends on the metal used, increasing from potassium tolithium.37 The sodium-diborane reaction has been clarified by recognitionof Na,B,H, as an intermediate; the product, which has the empiricalformula NaB,H,, is actually an equimolar mixture of sodium borohydrideand a new borohydride NaB3H, : 382Na + 2B2H6 NaBH, + NaB,H,30 W.Freundlich and B. Claudel, Bull. SOC. chim. France, 1956, 967 ; see also Ann.31 P. Ehrlich, B. Alt, and L. Gentsch, 2. anorg. Chem., 1956, 283, 58.32 C. Brosset and N.-G. Vannerberg, Nature, 1956, 177, 238; S. 2. Makarov and33 I. I. Volnov and A. N. Shatunina, Doklady Akad. Nauk S.S S.R., 1956, 110, 87.34 R. E. Dickerson, 1'. J. Wheatley, P. A. Howell, and W. K. Lipscomb, J . Chew.36 A. B. Burg and C. D. Good, J . Inorg. Nuclear Chem., 1956, 2, 237.36 A. B. Burg and J. L. Boone, J . Amer. Chew SOC., 1956, 78, 1521.37 G. W. Schaeffer, M. D. Adams, and F. J. Koenig, ibid., p. 725.3 8 W. V. Hough, L. J. Edwards, and A. D. McElroy, ibid., p.689.Reports, 1955, 52, 99.N. K. Grigor'eva, Zhur. neorg. Khim., 1956, 1, 1607.Phys., 1956, 25, 606ADDISON AND GREENWOOD : MAIN GROUPS. 87The long-sought monomeric addition compound ammonia-borineH,N,BH, has now been made by the action of lithium borohydride on am-monium salts and its structure is confirmed by X-ray structural analysis.39The preparation, characterization, and chemical reactions of the monomericaddition compounds of borine with pyridine and quinoline are described.mDiborane reacts with phosphorus trifluoride under pressure at room temper-ature to give the addition compound F,P,BH,. The properties of thissomewhat unexpected compound are very similar to those of the carbonylderivative OC,BH, and its ethane-like structure has been confirmed byRaman spectro~copy.~~ The relative ability of borine, boron trifluoride, andtrimethylboron to co-ordinate with the dialkyls of oxygen, sulphur, andselenium has been compared.42A kinetic study of the reaction of decaborane B1,H,, with low-molecularweight alcohols to give borate esters and hydrogen is reported.43 Unlike thelower boranes, decaborane dissolves in aqueous solutions of alcohols ordioxan without rapid hydrolysis and the rate of hydrogen .evolution exhibitsa marked induction period.I t is now found that decaborane forms amonobasic acid in these solutions without the evolution of hydrogen, thatthe decaborane is partly recoverable, and that the solutions can be potentio-metrically titrated with aqueous sodium hydr~xide.~,Borohydrides can be prepared by a new method involving the hydrolysisof magnesium boride MgB, with bases such as potassium hydroxide or tetra-methylammonium hydroxide.45 Trisubstituted borohydrides of the typeNa[B(OR),*H], which are readily prepared by the addition of sodium hydrideto alkyl borate esters, are more powerful reducing agents than sodium boro-hydride itself.This is attributed to the greater ease of removing a hydrideion from [B(OR),*H]-, because B(OR), is a weaker acceptor than borine,BH,.46 Tetra-alkoxyborohydrides are prepared similarly, the sodium hydridebeing replaced by sodium alk~xide.~' The addition compounds of lithiumborohydride and lithium aluminium hydride with tetrahydrofuran and tri-methylamine, and of aluminium hydride itself with tetrahydrofuran, havebeen investigated.An elegant series of experiments on the nuclear magnetic resonancespectrum of aluminium borohydride shows that Al(BH,), dissociates re-versibly at 80" into diborane and a new compound A12B4H1, : 49ZAIB,H,, e.B,H, + AI,B,H,,39 S. G. Shore and R. W. Parry, J . Amer. Chem. SOL., 1955, 77, 502; E. L. 6084;E. W. Hughes, ibid., 1956, 78, Lippert and W. N. Lipscomb, ibid., p. 503.40 V. I. Mikheyeva and Ye. M. Fedneva, Zhur. neorg. Khim., 1956, 1, 894.4 1 R. W. Parry and T. C . Bissot, J . Amer. Chem. SOC., 1956, 78, 1524; R. C. Taylorand T. C. Bissot, J . Chem. Phys., 1956, 25, 780.42 W. A. G. Graham and F. G. A. Stone, Chem. and Ind., 1956, 319.43 H. C. Beachel and T.R. Meeker, J . Amer. Chem. SOC., 1956, 78, 1796.44 G. A. Guter and G. W. Schaeffer, ibid., p. 3546.4 5 A. J. King, F. A. Kanda, V. A. Russell, and W. Katz, ibid., p. 4176.4 6 H. C. Brown, E. J. Mead, and C. J. Shoaf, ibid., p. 3616.4 7 H. C. Brown and E. J. Mead, ibid., p. 3614.4 8 E. Wiberg and W. Gosele, 2. Naturforsch., 1956, l l b , 485; idem, ibid., p. 486;E. Wiberg, H. Noth, and R. Uson, ibid., p. 487; E. Wiberg and A. Jahn, ibid., p. 489;E. Wiberg, H. Noth, and R. Uson, ibid., p. 490.49 R. A. Ogg and J. D. Ray, Discuss. Faraday Soc., 1955, 19, 239, 24688 INORGANIC CHEMISTRY.All protons in aluminium borohydride are chemically equivalent and verysimilar to those in a simple borohydride ion BH,- ; moreover, all the protonsare covalently bonded to both aluminium and boron and the three boronatoms are covalently bonded tetrahedrally to four equivalent protons.These findings cannot be reconciled with a static model of the molecule, orwith intermolecular exchange of borohydride ions or rotation within eachmolecule.The only tenable explanation appears to be in terms of aquantum-mechanical tunnel effect.49 Perhaps the simplest representationof the compound is (1) in which a double line represents bridge-bondingwith two protons between the aluminium atom and a boron atom. Thesecond borohydride may be similarly represented by (2).Boron trifluoride addition compounds have been studied by a variety oftechniques. Nuclear resonance spectra indicate that the structure of borontrifluoride hydrates depends on the rate of crystallization : slowly cooledsamples are un-ionized (BF,,H,O and BF3,2H20) whereas more rapidlycooled samples retain some of the ions which characterize the compounds inthe molten state (e.g., H,0+BF3*OH-).m Boron trifluoride forms a 1 : 1compound with urea which melts at 82"; above 125" the compounddecomposes to ammonium fluoroborate, boron nitride, and polymeric hydro-gen cyanate, from which it is concluded that boron is bonded to nitro-gen rather than oxygen in the complex.51 Boron trifluoride-dinitrogentetroxide, which does not melt in a sealed tube at 300", is insoluble in non-polar solvents, and rapidly nitrates benzene, has been formulated as an ioniccompound N02+(BF3.N0,)-.52 A complete structure determination ofboron trifluoride-pyridine has shown that the B-N bond length (1.53 A) isshorter in this compound that in other boron complexes in which nitrogenis the ligand (167-1.64 A).% It is, however, comparable with the value of1-56 found for H3N,BH,.39 Stable 1 : 1 complexes of boron trifluoride,hydrogen fluoride, and the methylbenzenes have been isolated.These com-pounds melt below room-temperature and have a high specific electrical con-ductivity (about 10-2 ohm-l cm.-l) ; they may be formulated as ArH+BF4-(Ar = Me*C6H5, m-Me,C,H,, s-Me3C6H3, as-Me,C,H,) .54 The correspondingcompounds formed by replacing hydrogen fluoride by either ethyl fluoride orformyl fluoride have also been isolated and have similar proper tie^.^^The molar heats of solution of the boron trihalides in nitrobenzene, andthe heats of reaction of the trihalides with pyridine in nitrobenzene arereported and lead to the unexpected result that, under these conditions, theelectron-acceptor strength increases in the order BF, < BCI, < BBr3.566o P.T. Ford and R. E. Richards, J., 1956, 3870.61 H. J. Becher, Chem. Bey., 1956, 89, 1691.S2 G. B. Bachman, H. Feuer, B. R. Bluestein, and C. M. Vogt, J . Amer. Chem. SOC.,63 2. V. Zvonkova, Kristallograjiya, 1956, 1, 73.b4 G. OlAh, S. Kuhn, and A. PavlAth, Nature, 1956, 178, 693.65 G. OlAh and S. Kuhn, ibid., p. 1344.66 H. C. Brown and R. R. Holmes, J . Amer. Chem. Soc., 1956, 78, 2173.1955, 77, 6188ADDISON AND GREENWOOD MAIN GROUPS. 89Boron trifluoride is not ammonolysed by liquid ammonia in the temper-ature range -78" to +50° unless an alkali metal is also present in thesolution.57 Furthermore, the addition compound boron trifluoride-ammonia,which can be isolated from solutions of boron trifluoride in liquid ammonia,reacts with solutions of the alkali metals in ammonia in a way which variesmarkedly with the particular metal chosen : with potassium and caium thereacting mole-ratio of metal to complex is 1 : 1, with sodium the ratio is 2.5 : 1and with lithium 3 : 1, though in the last case temporary end-points could bedetected at the two smaller ratios as well. The following reaction schemeshave been suggested to represent the overall stoicheiometry and the productsformed : 58BF,,NH, + K = NHZ*BFz + KF + +Ha2BF,,NH3 + 5Na + 2NHB = (NH,),B(NH).BF(NH,) + 5NaF + 24H,2BF,,NH3 + 6Na + 2NH3 = (NH,),B(NH)*B(NH) + 6NaF + 3H,Ammonolysis of boron tri-iodide on the other hand proceeds rapidly inliquid ammonia even in the absence of alkali metals. The products areammonium iodide and boron imide B2(NH),.59 Studies of the effect ofsteric strain on the reaction rate and heat of reaction of substituted pyridinebases with diborane, boron trifluoride, and trimethylborine continue.60Phase studies have confirmed the existence of the addition compoundboron trichloride-acetyl chloride in the solid state despite the fact that abovethe m.p., -54", the vapour pressure of the system shows a positive deviationfrom ideality. There is no compound in the system boron trichloride-benzoyl chloride, and neither system shows catalytic activity, in contrast tothe behaviour of these ligands with gallium trichloride.61 The crystalstructure of the addition compound between diboron tetrachloride andethylene shows that the structure of the molecule is a zig-zag chainC12B*CH2*CH,-BCl,, in agreement with chemical evidence.62A new class of organoboron compound, RBXoOR', in which two of thehalogens in BX, have been replaced by an alkyl (or aryl) and an alkoxy-group has been reported.63 The thermal stability, solvolysis, and co-ordin-ation reactions of these compounds and the related series RB(OR), andRBX, were studied as well as the preparation and stability of dialkyl chloro-boronates C1B(OR),.64 A series of triaryl borates were prepared by thereaction of boron trichloride with substituted phenols or naphthols and theiramine addition compounds investigated for steric and polar influences. 65The studies have also been extended to include the interaction of unsaturatedalcohols and ethers with boron trichloride.66 Some convenient procedures5 7 W.A. Jenkins, J . Amer. Chem. SOC., 1956, 78, 5500.68 W. J. McDowell and C . W. Keenan, ibid., p. 2065.59 Idenz, zbid., p. 2069.6o H. C. Brown, D. Gintis, and H. Podall, ibid., p. 5375; H . C. Brown and D. Gintis,ibid., p. 5378; H . C. Brown and L. Domash, ibid., p. 5384; H . C. Brown, D. Gintis, andL. Domash, ibid., p . 6387.N. N. Greenwood and K. Wade, J., 1966, 1627.Idem, ibid., p. 1540; M . F.Lappert, ibid., p . 1768.6a E. B. Moore and W. N. Lipscomb, Acta Cryst., 1956, 9, 668.63 P. B. Brindley, W. Gerrard, and M. F. Lappert, J., 1956, 824.66 T. Colclough, W. Gerrard, and M. F. Lappert, ibid., p. 3006.66 W. Gerrard, M. F. Lappert, and H. B. Silver, ibid., p . 3286'30 INORGANIC CHEMISTRY.for the preparation of primary, secondary, and tertiary alkyl borate estershave been outlined.67Unipositive aluminium is formed by anodic oxidation when aqueous solu-tions are electrolysed between an aluminium anode and a platinum cathode.68This is similar to the behaviour of beryllium and magnesium anodes men-tioned on p. 85.The Raman spectra of several methylaluminium halides of the typeMe,AlX and MeAlX, (X = C1, Br, or I) indicate that the compounds aredimeric, the bridging occurring via two methyl groups in each case ratherthan via halogen atoms as had formerly been supposed.Trimethylindiumis m0nomeric.6~The crystal structure of the addition compound AlBr,,H,S, and thefact that solutions of the complex in organic solvents are acidic and can beelectrolysed to give hydrogen at the cathode, support the formulationHi (AlBr,*SH)-. 7O The determination of the solubility of aluminium chlorideby a new experimental method reveals weak complex formation with aromatichydrocarbons at room temperature which disappears at about 70°.71 Theinteraction of aluminium bromide with olefins and benzene was furtherstudied. 72 The kinetics of bromine-exchange between ethyl bromide andaluminium bromide in carbon disulphide has been interpreted as indicatingthat carbonium ions are not involved in the reaction.73The constitution of gallium dichloride has been resolved ; Raman spectrashow it to be Ga+GaCl,- in the molten state 74 and X-ray data confirm thisstructure for the solid also.75 Further reduction of the dichloride bymetallic gallium can be achieved in the presence of aluminium trichloride :GaGaCI, + 2Ga + ZAICI, = 4GaAIC1,All the gallium is then present in the unipositive state and the product,GaAlCl,, m.p. 176", is very similar to the dichloride itself, GaGaCl,, m. p.17Oo.''j (Bismuth trichloride may likewise be quantitatively reduced withmetallic bismuth in thepresence of aluminium trichloride to give the uni-valent bismuth salt BiAlCl,, m.p. 253", and cadmium chloride gives 72%conversion into the corresponding CdAlCl,. 76)Addition compounds of gallium trichloride with alkyl halides have beeninvestigated tensimetrically and by phase diagrams, 7 7 and a similar in-vestigation is reported for the addition compounds of gallium trichloridewith acyl chlorides.61Trimethylindium is a stronger electron-acceptor than trimethylthallium6 7 H. C. Brown, E. J. Mead, and C . J. Shoaf, J . Anzer.. Chem. SOC., 1856, 78, 3613.6 8 E. Raijola and A. W. Davidson, ibid., p. 556.69 G. P. van der Kelen and M. A. Herman, Bull. SOC. chim. belges, 1956, 65, 362.70 A. Weiss, R. Plass, and A. Weiss, 2. anorg. Chem., 1956, 283, 390.71 F. Fairbrother, N. Scott, and H. Prophet, J., 1956, 1164.72 F.Fairbrother and K. Field, ibid., p. 2614.73 F. L. J. Sixma, H. Hendriks, and D. HoltzapffeI, Rec. Trav. chim., 1956, 75, 127;74 L. A. Woodward, G. Garton, and H. L. Roberts, J . , 1956, 3723; L. A. Woodwart175 G. Garton and H. &I. l'owell, personal coniniunication ; see also ref. 76.76 J. D. Corbett and K. K. McMullan, J . Amer. Chem. SOC., 1956, 78, 2906.7 7 R. Wong and H. C. Brown, J . Inorg. Nuclear Chenz., 1955, 1, 402.F. L. J. Sixma and H. Hendriks, Proc. k . ned. Akad. Wetemchap., 1956, 59, B, 61.and -4. A. Kord, ibid., p. 3721ADDISON AND GREENWOOD : MAIN GROUPS. 91so that the order of acceptor character of the Group 111 trimethyls towardsa ligand like trimethylamine is B < A1 > Ga > In > T1. The thermal andchemical stability of derivatives such as (Me,Tl*SMe),, obtained from thereaction of Me2T1F with NaSMe in methanol, indicate that thallium andpossibly indium may form dative x bonds to sulphur and selenium.78 Thedipole moments of some addition compounds of indium and thallium tri-halides with ethers and cyclic nitrogen-containing ligands have been pub-lished.79Group 1V.-Considerable progress has been made in the field of graphitecompounds and other molecular compounds of the layer-lattice type whichmay be prepared by intercalation. Over 30 new graphite compounds havebeen prepared : intercalation is most probable with chlorides of multivalenttransition elements in their higher oxidation states but also occurs with thechlorides of certain lanthanide metals and of iodine.In addition, thechlorides of all Group I11 elements form graphite compounds but these canbe hydrolysed, in contrast to the compounds formed by the transitionelements.80 The results suggest that intercalation involves transfer ofelectrons from the conduction band of graphite to the cation of the reactinghalide and cannot be interpreted in terms of sieve action or dipole inter-action.81 It appears that any substance may intercalate any other substanceprovided that electron donor-acceptor interaction is possible and that thehost can provide physical accommodation by lattice expansion-a layerlattice is not essential. On the basis of these ideas it was predicted thatboron nitride, aluminium diboride, and chromium trichloride should be ableto act as host and should be able to occlude oxides, sulphides, and oxyhalidesas well as chlorides.This was found to be the case.82There is no radiochemical exchange between graphite ferric chlorideC,,FeCl, and ferric ions. 83 High-resolution electron diffraction and X-raypowder photography show that single layers of ferric chloride lie betweensuccessive parallel layers of graphite. The infrared spectrum of graphiteoxide has been further i n ~ e s t i g a t e d . ~ ~ It is curious that, although graphitetakes up 24 times its weight of iodine monochloride and about a third of thisamount of bromine, neither chlorine nor iodine alone is noticeably inter-calated.*6 Solutions of the alkali metals in liquid ammonia react withgraphite to give compounds of ideal formuk C12M(NHJ2, in which thereare alternate layers of graphite and alkali ammine, and C,,M(NH,), in whichevery third layer of the graphite lattice is replaced.Lithium and methyl-amine give a similar compound C,2Li(MeNH,),.87Carbon tetraiodide is not solvolysed by liquid ammonia near its b. p.but reversibly forms the addition compound, CI4,2NH,. However, ini 8 G. E. Coates and R. A. Whitcombe, J., 1956, 3351.70 I . A. Sheka, J . Gen. CJzem. (U.S.S.R.), 1956, 26, 25.8o R. C. Croft, Austral. J . Chem., 1956, 9, 184.81 Idem, ibid., p . 194.82 Idem, ibid., p p . 201, 206.83 R. M. Lazo and J . G. Hooley, Caitad. J . CIaem., 1956, 34, 1574.J. M. Cowley and J . A. Ibers, A d a Cryst., 1956, 9, 421.a 6 D. IIadii and A.Novak, Trans. Faraday Soc., 1955, 51, 1614.t ~ * W. Rudorff, V. Sils, and R. Zeller, 2. anorg. Chem., 1956, 283, 299.W. Riidorff, W. Schulze, and 0. Rubisch, ibid., 1966, 282, 23292 INORGANIC CHEMISTRY.the presence of potassium amide there is a base-catalysed reactionCI, + NH,* CHI, + INH,, and the iodine amide reacts further withpotassium amide to give hydrazine : INH, + KNH, + N2H4 + KI.88An improved synthesis of thiocyanogen (CNS), has been described; thecompound forms addition products with boron trifluoride and trichloride,and its derivative potassium cyanosulphite, K(NCSO,), was prepared frompotassium cyanide in liquid sulphur dioxide. 89 Selenosemicarbazide,NH,-CSe*NH*NH,, has been synthesised by isomerising hydrazine seleno-cyanate in the presence of aldehydes or ketones and then hydrolysing theselenosemicarbazone so formed.g0Polymeric silicon subhydride (SiH), is formed by the reaction of tri-bromosilane with magnesium.g1 Silicon tetrabromide and magnesium givethe sub-bromide (SiBr),, but when the tetrabromide reacts with silicon at1200°, silicon dibromide (SiBr,), is formed, together with the well knowncompound Si,Br,.The dibromide gives dialkyls with Grignard reagents, isreduced by lithium aluminium hydride, and hydrolyses to the subsilicicacid [Si(OH),.,],.92In a series of experiments on the hydrolysis of trichlorosilane and itsderivatives, a crystalline silicon oxyhydride (HSiO,.,), was synthesised andshown to have a " mica-like " structure which could be formulated as thetwo-dimensional polymer (3).This could be dehydrogenated at 507" instages which correspond to the reactions :H,Si,Oa __t H4Si,0a H&O, Si,O, (i.e., Si,O,)It is suggested that the structure of the sesquioxide is similar to (3) exceptthat Si-H bonds within each sheet are replaced by Si-Si bonds betweenI0ISiH ,'0, ,o' ' O\ loSiH S i HI I/Y"'i i"' MelSi \ CH2 /siMe2H'C I / siY 742MeS i --CH2- S i MeI IS i Me2adjacent sheets. When alkyltrichlorosilanes RSiCl, were hydrolysed theproduct depended on the size of the alkyl group. The ethyl derivativesgave a sheet polymer like (3) :nEtSiCI, + I-5nH20 + (EtSiOl.&, + 3nHCIThe tert.-butyl derivative on the other hand was sterically hindered fromcomplete polymerization and formed the tetramer (ButSiO,.,) , ; isopropyl-88 G.W. Watt, W. R. McBride, and D. M. Sowards, J. Amer. Chem. SOC., 1956, 78,*O R. Huls and M. Renson, Bull. SOC. chim. belges, 1956, 65, 209, 611.@2 M. Schmeisser and M. Schwarzmann, 2. Naturforsch., 1966, l l b , 278.1562.F. See1 and E. Miiller, Chem. Ber., 1955, 88, 1747,G. Schott, W. Herrmann, and E. Hirschmann, Angew. Chem., 1966, 68, 213ADDISON AND GREENWOOD MAIN GROUPS. 93trichlorosilane gave some tetramer (4) and some mica-like polymer (3) .93The structure of the tetramer has been shown by X-ray analysis to be thesame as that of adamantane and hexamethylenetetramine with which it isisosteric-( RSi) 406, (HC) 4(CH2)6, and N,(CH,),.94 Hexathia-adamantane(CH),S6 also has the same molecular structure, the six sulphur atoms forminga regular octahedron about the tetrahedron of carbon atoms.95Silicon tetrachloride reacts with ammonia to give silicon di-imide andammonium chloride as the only products and the compound formulated asSiC14,6NH, is in fact Si(NH), + 4NH,CLS6The chemistry of silyl compounds has been revie~ed.~' Trisilylamine(SiH,),N has been shown by electron diffraction to have a planar skeleton withthe nitrogen atom surrounded by three silicon atoms at the corners of anequilateral triangle.This shape, together with the abnormally short Si-Nbond length, implies partial double-bonding by back-donation of the nitrogenlone-pair electrons into d orbitals of the silicon atoms, and is consistent withthe chemistry of the compo~nd.~8 The recently prepared tetrasilylhydrazine(SiH,),N*N(SiH,), also has negligible donor or acceptor proper tie^.^^ Silylisocyanide SiH,NC and isothiocyanate SiH,NCS have been prepared andtheir physical properties reported.100 Further work on the infrared andRaman spectra of disiloxane (SiH,),O has been interpreted on the basis of astructure in which the silyl groups rotate freely about a linear 5-0-5 axis.lo1This is at variance with an earlier interpretation on the basis of anasymmetric-top model.A new series of cyclic organosilicon compounds has been obtained byrapid, low-pressure pyrolysis of tetramethylsilicon at 720".The compoundSi,C,H,, has the structure (5), one methyl group of which is sometimesreplaced by hydrogen to give Si,C,H,,.Another compound isolated had theformula Si,C,,H,, ; it melted at 106" and may be assigned the structure (6).lo2The chemistry of germanium has been comprehensively reviewed.lo3Germanium monoxide is formed by the action of carbon dioxide on german-ium at 700-900" : Ge + CO, + GeO + C0.lo4 TrichloromonogermaneGeHCl,, which is best prepared by the low-temperature reaction of hydrogenchloride on germanium sulphide, is more unstable than formerly supposedand readily loses HC1 at -30" to give germanium dichloride; this in turnrapidly disproportionates to germanium and the tetrachloride via inter-mediate polymeric subchlorides. lo5Lead fluoride reacts with alkali fluorides to form addition compoundsE. Wiberg and W. Simmler, 2.anovg. Chew., 1966, 283, 401.94 G.-M. Schwab, J. Grabmaier, and W. Simmler, 2. phys. Chem. (FrankJuyt), 1966,6,96 E. K. Andersen and I. Lindqvist, Arkiv Kemi, 1956, 9, 169.9 7 A. G. MacDiarmid, Quart. Rev., 1966, 10, 208.88 K. Hedberg, J . Amer. Chem. Soc., 1955, 77, 6491.99 B. J. Aylett, J . Inorg. Nuclear Chem., 1956, 2, 325.loo A. G. MacDiarmid, ibid., p. 88.lol R. C. Lord, D. W. Robinson, and W. C. Schumb, J . Amer. Chem. SOC., 1966, 78,lo2 G. Fritz and B. Raabe, 2. Nalurfovsch., 1956, l l b , 57.lo3 E. Gastinger, Fortschr. chem. Forsch., 1955, 8, 603.lo4 Idem, 2. anorg. Chem., 1956, 285, 103.lo6 C. W. Moulton and J. G. Miller, J . Amer. Chem. SOC., 1956, 78, 2702.376.M. Billy, Compt. rend., 1956, 242, 137.132794 I NOKG.\N IC CHEMISTRY.whose formulze depend on the ionic radius of the alkali metal. Potassiumforms K,PbF,, whereas rubidium and czsium form the perowskite-typeMPbF,. In addition, potassium and rubidium also form the non-stoicheio-metric compounds M,,Pb,_,F,-,, where n = 0.2-0.3 ; these crystallize in theanti-a-AgI structure with additional fluoride ions.lo6Group V.-A redetermination of the electrochemical properties of liquidammonia over a range of temperature leads to a specific conductivity of1.97 x Thethermoelectric properties of nietal-ammonia solutions cannot be interpretedon ionic or semiconductive mechanisms and imply a quantum-mechanicaltunnel process for electron transport.lo8Improved syntheses of hydrazine,log NN-disubstituted hydrazines, l10and hydroxylamine ll1 have been described.The product of the reactionof nitric oxide with potassium sulphite (K,SO,,BNO), which was recentlyshown to be the potassium salt of nitrosohydroxylaminesulphonic acidON*N(OH)*SO,H, can also be prepared by nitrosating hydroxylaminemonosulphonate with an alkyl nitrite in alkaline so1ution.ll2 The constitu-tion of hydroxylamine-0-sulphonic acid H,N*O*SO,H (sometimes calledsulphoperamidic acid) ha5 been further studied. The compound, which maybe made by direct addition of hydroxylamine to sulphur trioxide, reacts withdiazomethane to give the trimethyl derivative Me,N*O-SO, rather than theexpected monomethyl derivative H,N-O*SO,Me. Since the trimethylderivative has an X-ray pattern which is identical with that of the additioncompound formed between trimethylamine oxide and sulphur trioxideMe,NO,SO,, the previously rejected formula for sulphoperamidic acidH,&*O*sO, should be re~0nsidered.l~~Several reviews have been written on the structure and reactivity ofdinitrogen tetroxide.ll* The electrical conductivity of the liquid is 1000times less than that of the solid at -20" and is 2-36 x lo-', ohm-l cm.-l at170.115 Molecular addition compounds of dinitrogen tetroxide with cyclicethers 116 and with a range of nitrogen, oxygen, and aromatic hydrocarbondonors 117 have been reported.Certain of these systems, for example thosewith ethyl acetate and 9-tolyl cyanide, show two distinct liquidus ciu-vesand imply that the complexes may have two different m.p.s.l18ohm-l cm.-l at -38.9" and an ionic product of 10-29*1.107lo6 0. Schmitz-Dumont and G. Bergerhoff, 2. anorg. Chem., 1956, 283, 314.lo' J. Cueilleron and RI. Charret, Bull. SOC. chim. France, 1956, 798, 800; Cotupf.Io8 G. Lepoutre and J . F. Dewald, J. Amer. Chem. SOC., 1956, 78, 2953, 2956.IoS L. F. Audrieth, U. Scheibler, and H. Zimmer, ibid., p. 1852.110 R. A. Rowe and L. F. Audrieth, ibid., p. 563.l l 1 R. E. Benson, T. L. Cairns, and G. M. Whitman, ibid., p. 4202.112 E. Degener and F. Seel, 2. anorg. Chem., 1956, 285, 129.113 U. Wannagat and K. Pfeiffenschneider, Naturwiss., 1956, 43, 178.114 P. Gray and A. D. Yoffe, Quart. Rev., 1955, 9, 362; idem, Chem. Rev., 1955, 55,1069; C. M. S. Teese and A . G. Whittaker, J. Chem.Phys., 1956, 24, 776; A. G. Whit-taker, ibid., p. 780; C. C. Addison, Kec. Trav. claim., 1956, 75, 626; 2. G. Szab6, L. G.Bartha, and B. Lakatos, J., 1956, 1784; T. M. Oza and V. T. Oza, J . Arne$/. Chew. SOC.,1956, 78, 3564.rewd., 1956, 242, 521.R. S. Bradley, l'?,ans. Faraday SOC., 1956, 52, 1255.116 H. H. Sisler and P. E. Perkins, J. Awzer. Chem. SOC., 19.56, 78, 1135.1 1 7 C. C. Addison and J . C. Sheldon, J., 1956, 1941.Idp???, ihid., p. 2709ADDISON ANI) GREENW001) : MAIN GROUPS. 95Dinitrogen tetroxide oxidises dialkyl sulphides smoothly to sulphoxidesR2S0 without any formation of the corresponding sulphone K,S02, and alsooxidises trisubstituted phosphines to phosphine oxides R,PO. Since thesulphoxides formed 1 : 1 addition compounds with dinitrogen tetroxide incontrast with the sulphones and phosphine oxides, it was concluded thatsulphur was the electron donor in the s u l p h o ~ i d e s .~ ~ ~ The reactions of di-nitrogen tetroxide with mercury,120 and with copper, zinc, and uranium inthe presence of organic electron-donor solvents have also been investigated.I2lThe electrical conductance of anhydrous nitric acid and of solutions ofwater and dinitrogen pentoxide in nitric acid have been interpreted in termsof the self-ionic dissociation :2HNO3 NO,' -t NOS- -t- HZO.,4t -10" the conductivity of the pure acid is 3-67 x and this corre-sponds to a mole-fraction dissociation constant of 9.30 x in agreementwith the results of cryoscopic measurements. The addition of water lowersthe conductivity of the pure acid owing to a repression of the dissociation.122A systematic study of the ultraviolet spectra of solutions of sodiumnitrite in aqueous sulphuric acid shows that below 40% acid the spectrum isessentially that of nitrous acid and above 70% acid is that of the nit.rosoniumion NO ; at intermediate concentrations the nitrous acidium ion H2N0,+is an important constituent, and equilibria involving the three species havebeen calculated.Similar results were obtained for aqueous phosphoric acidsolutions of sodium nitrite, but in concentrated hydrochloric acid there isalmost total conversion into nitrosyl ch10ride.l~~ The equilibrium betweenthe nitrosonium ion and nitrous acid in aqueous perchloric acid has alsobeen investigated spectrophotometrically.124Additioncompounds of nitrosyl chloride have been studied by chemical exchange ofradioactive chlorine.126 Dinitrosyl pyrosulphate has been formulated as anionic compound (NOi),S20,2- on the basis of its high m.p. 233" and lowmolecular weight in sulphuric acid ; it is rapidly solvolysed by water, alcohols,ammonia, and methylamine, and reacts with a variety of other compounds.12iThe infrared, Raman, and nuclear magnetic spectra of nitryl fluoride allsupport the plane-triangular structure 0,NF rather than the zigzag formulaONOF.l28 The reactions which occur when nitryl fluoride dissolves insulphuric, selenic, and phosphoric acids have been studied by following theconductivity and other physical properties of the NitrylThe chemistry of the nitrosonium ion has been reviewed.12jllS C.C. Addison and J. C. Sheldon, J., 1956, 2705.1x1 E. S. Freeman and S. Gordon, J . Ame7,. Chem. SOL., 1956, '78, 1813.121 C. C. Addison, J . C. Sheldon, and (in part) I?i. Hodge, J . , 1956, 3900.l Z 2 W. H. Lee and D. J. hlillen, ibid., p. 4463.lZ3 N. S. Bayliss and I>. W. Watts, ,4ustral. J . Chem., 1956, 9, 319.lZ4 K. Singer and P. A . Vamplew, J . , 1956, 3971.lZ5 F. Seel, Angew. Chem., 1956, 68, 272; see aleo <*. C . Addison and J . Lewis, Quart.126 J. Lewis and D. B. Sowerby, Rec. l r a v . chim.. 1956, 75, 615.lZ7 U. Wannagat and G. Hohlstein, 2. anorg. Chem., 1956, 284, 177.128 R. E. Dodd, J. A. Rolfe, and L. A. Woodward, Trans. Faraday SOC., 1956, 52,12s G.Hetherington, D. R. Hub, and P. L. Robinson, J . , 1955, 4041.lt'eu., 1955, 9, 115.145; R. A. Ogg and J . R. Ray, J - Chem. Phys., 1956, 25, 79'796 INORGANIC CHEMISTRY.chloride when dissolved in polar solvents chlorinates rather than nitratesalkylbenzenes. This is contrary to expectations and may be due to re-action with traces of moisture to give free chlorine : 3N02C1 + H,O +C1, + NOCl + 2HN0,. In agreement with this, reactive solutions werefound to have the same spectrum as nitrosyl chloride whereas non-reactivesolutions in non-polar solvents were colourless. 130Fluorine analogues of the phosphoronitrile chlorides (PNCl,), cannot besynthesised by methods used for the chlorides or by fluorination of thechlorides with normal reagents ; however, the compounds (PNF,), and(PNF,) have now been successfully prepared by fluorinating the correspond-ing chlorides with solid potassium fluorosulphite KS0,F.Both compoundsare volatile solids melting at 27.1" and 30.4" respectively and boiling at51.8" and 89.7"; they are stable up to 300" but at higher temperatures givecolourless liquid polymers (PNF,),.l31Phosphorus pentachloride PC14+Pc&- reacts with an equivalent amountof arsenic trifluoride in arsenic trichloride to give the compound PCI,+PF,-,a hygroscopic salt which sublimes with some decomposition a t 135". Itshould be noticed that this compound has the same empirical formula as themixed halide PF3Cl, which is a gas at room temperature.132 PCl,+PF6-decomposes above 70" to give phosphorus pentafluoride and the new com-pound PC1,F which exists as a non-polar liquid and an ionic solid PCl4+F-.luConsiderable progress has been made in the formulation of the products ofaddition of bromine to phosphorus trichloride : the stable mixed halide ofempirical formula PC1,.6,Bro.,, has a face-centred cubic lattice with 12phosphorus atoms in the unit cell, P12C156Br4.Further analysis shows thatthe structure is 8PC14+4PC16-4Br-.134 Conductance experiments on solutionsof phosphorus pentabromide in acetonitrile indicate that the compoundiOniSeS in this solvent as PBr4+PBr6-. 135Pyrophosphoryl chloride P,0,C14 and tetraphosphoryl chloride P40,C1,0have been prepared together with phosphoryl chloride by the reaction ofphosphorus trichloride with dinitrogen tetroxide, and their structure,physical properties, and chemical reactions studied.136 The complexmixture of products resulting from the mild alkaline hydrolysis of thephosphorus trihalides has been separated chromatographically and a newisohypophosphate identified.This compound, which has the formulaNa,(HP,O,), has been ascribed the structure (7) and differs from the hypo-phosphate Na,H(P,O,) (8) in having no P-P bond.137The co-ordination chemistry of phosphorus oxychloride and other multi-valent chlorides of elements in Groups V and VI was discussed at theAmsterdam Conference, and new data were presented on the electrical con-lSo M. J. Collis, F. P. Gintz, D. R. Goddard, and E. A. Hebdon, Chem. and Irtd., 1955,lS1 F.Seeland J. Langer, Angew. Chem., 1956, 68, 461.13a L. Kolditz, 2. anorg. Chem., 1956, 284, 144.lSs Idem, ibid., 1956, 286, 307.134 A. I. Popov, D. H. Geske, and N. C. Baenziger, J . Amer. Chem. SOC., 1956, 78,lSb Idem, ibid., p. 4617.lS8 R. Klement and K. H. Wolf, 2. anoug. Chem., 1956, 282, 149.lS7 E. Thilo and D. Heinz, ibid., 1955, 281, 303.1742.1793; see also G. S. Harris and D. S. Payne, J., 1956, 4613ADDISON AND GREENWOOD : MAIN GROUPS. 97ductivity and heat of dissociation of the complex TiC14,2POC1,.138 Theconfusion which has existed about the composition of complexes formedbetween phosphorus oxychloride and the tetrachlorides of zirconium andhafnium has been clarified by a careful phase study of the system ZrC1,-POC13.Two compounds were found, ZrCl,,POCl,, m.p. 205", and ZrC1,,2POC13,m. p. 184-7°.139 This agrees with the results of cryoscopic work in nitro-benzene. 140 Distillation gives a product of constant composition which maybe represented approximately as 321-C1,,2POCl,,~~~ but this is presumably anazeotrope rather than a definite compound. The complexes of phosphorusoxycliloride with ierric chloride have also been investigated.142NaO ONa'P-0--P /" ) / I I I I \H 0 0 ONa( 8 )/ONa'P--PNaO/ll l l \HO 0 0 ONaA general structural theory of condensed phosphates has been developedfor predicting the structures to be expected in various systems and forcalculating the number of P-0-P links they contain. 143 Chromatographicseparation of the products formed by the partial hydrolysis of Graham'ssalt has revealed the existence of ring phosphates higher than the tetra-metaphosphate ; the penta- 2nd possibly the hexa-metaphosphate have beenidentified and it appears probable that a continuous range oi even largerring phosphates is also present.144 The thermal dehydration of alkali-metaldihydrogen monophosphates has been investigated and similar studiesindicate that, with the exception of sodium trimetaphosphate Na,P30,, allthe tri- and tetra-metaphosphates of lithium, sodium, potassium, andammonium and their hydrates are thermally unstable; five types of thermalbehaviour were recognized.145 The first complete X-ray structural analysisof a fibrous colloidal metaphosphate has been carried out on rubidiummetaphosphate, which was shown to consist of continuous chains of (PO,),n-which spiral round the b axis of the crystal with a repeated pattern everytwo PO, The crystal structures of Maddrell's salt (NaPO,), andof lithium and sodium polyarsenate (MASO,).are somewhat similar to thisbut differ in the orientation of the chains and their repeat-patterns.147Phosphoric triamide OP(NH,), may be prepared by the reaction ofphosphorus oxychloride with liquid ammonia ; the use of substituted oxy-chlorides leads to the alkylamides of ortho- and thio-phosphoric acids andto the amides of phosphoric acid esters OP(0Et) (NH&, etc.148 Similarly,1313 W. L. Groeneveld, Rec. Trav. chim., 1956, 75, 594; V. Gutmann, ibid., p. 403;D.S. Payne, ibid., p. 620.139 I. A. Sheka and B. A. Voitovich, Zhzw. neorg. Khim., 1956, 1, 964.140 E. M. Larsen and L. J. Wittenberg, J . Amer. Chem. SOC., 1955, 77, 5850.141 L. A. Nisel'son and B. N. Ivanov-Emin, Zhur. neorg. Khim., 1956, 1, 1766.142 V. V. Dadape and M. R. A. Kao, J . Amer. Claem. SOC., 1955, 7'7, 6192.143 J. R. Van Wazer and E. J. Griffith, ibid., p. 6140.144 J. R. Van Wazer and E. Karl-Kroupa, ibid., 1956, 78, 1772; J. F. McCullough,145 E. Thilo and H. Grunze, 2. u+?.org. Chem.. 1955, 281, 262, 284.146 D. E. C. Corbridge, Acta Cryst., 1956, 9, 308.1 4 7 K. Dornberger-Schiff, F. Liebau, and E. Thilo, ibid., 1955,8,752 ; F. Liebau, ibid.,148 M. Goehring and K. Niedenzu, Chma. Brv , 1956, 89, 1768.J. R. Van Wazer, and E. J.Griffith, ibid., p. 4528.1951, 9, 811; W. Hilmer, ibid., p. 87.KEP.-VOT.. 1.111 st3 INORGANIC CHEMISTRY.pyrophosphoryl chloride gives the tetra-amide of diphosphoric acid(NH,),PO*O*PO(NH,),. This is isotypic with the tetra-amide of imidodi-phosphoric acid (NH,),PO*NH~PO(NH,), which can be prepared fromphosphoric triamide by splitting out ammonium chloride with hydrogenchloride : 2(NH2),P0 + HC1+ (NH,),PO*NH*PO(NH,), + NH,CI. Somepenta-amide of di-imidotriphosphoric acid(NH,),PO*NH*PO( NH,)*NH-PO( N H2) ,is also formed.149 On the other hand, when phosphoric triamide reactswith phosphorus oxychloride the tetramer of orthophosphoric amide imide(9) may be obtained via the chloride intermediate : l503PO(NH,), + POCI, + P4H,oO4N,CI + 2NHdClN H,P,Hl0O4N,CI __t P4HI2O4N8y 2 y 4 2 NaO, yNk!, ,ONaO=P-NH-P=OI I 0 4 P o (10)HN NH( 9 ) YH NH IO=P-NH-P=OI I / ** NH2 NHz NaOSodium monoamidophosphate Na2P03NH2, when heated in vacuuiii at210" for several days, lost ammonia -to give tetrasodium imidodiphosphateNa,(PO,*NH*PO,) which is isotypic with the pyrophosphate Na,P,O,.Further heating to 450" yielded sodium nitrilotriphosphate (Na,P0,),N.151Similarly when sodium diamidophosphate was heated in vacuum to 160°,diamido-imidophosphates of general formula Na,P,O,,(NH) ,- I(NH,)2 (1 1)were formed where IZ = 2-6. Treatment of the products with sodiumnitrite gave sodium imidophosphates of formula Na, + 2P1102n 2(NH), -(lZ).152 The reactions may be written as follows:......... ONa ONa ONa I ............ONa I .. ONa I I I '. I .*.ONaH ~ N - P-NH.~ + H ~ N ~ P-NH:;' + -.--H~N;- P - N H ~ - (n- I NH) + H~N-P~NH~P-NH .. -..P-NH~ It ........... . * I 1 . . . . . . . . * I 1 II II II0 ( 1 1 ) 0 0 0 0ONa ON a ONa ONaI I I 1II II II II0 0 0 0 (12)H~N-P-NH..*-.-P--NH2 + 2NaN02 + 2H20+ ZN2 4- NaO-P-NH*.*-** P-ONaContrary to assertions in the older literature it now appears that hydrolysisof sodium trimetaphosphimate (10) tends to occur by replacement of thering-NH groups by oxygen atoms ; chain imidophosphates are never presentin large a m 0 ~ n t s . l ~ ~R. Klement and L. Benek, 2. anorg. Chem., 1956, 287, 12.149 M. Goehring and K. K. Niedenzu, Chem. Ber., 1956, 99, 1171; see also1-50 M. Goehring and K. Niedenzu, Chem.Ber., 1956, 89, 1774.151 R. Klement and G. Biberacher, 2. amrg. Chem., 1956, 283, 246162 Idew, ibid., 1950, 285, 74.l53 A. Narath, F. H. Lohman, and 0. T. Quimby, J . Amer. Chem. Soc., 1956, 78,4493ADDISON AND GREENWOOD : MAlN GROUPS. 99X-Ray analysis has shown that the compound KAs,O,I has a new typeof layer structure with the following layer sequence parallel to the G axis :. . . I-2As-30-K-30-2As-I . . . ; the As-0 distance corresponds to covalentbonding.lM Arsenic(II1) selenide reacts with liquid ammonia to give asoluble metaselenoarsenite and an insoluble amidoselenide according to theequation As,Se, + 2NH, + NH,AsSe, + AsSeNH2, whereas the corre-sponding arsenic(II1) sulphide gives an imido-derivative : As,S, + 2NH, ----tAs,S,NH + NH,HS.155Two new antimony salts are described: Rb2SbBr5 and Rb,Sb,Br,,.The first is prepared by removing bromine vapour from solid Rb,SbBr,, andthe second by adding bromine to Rb,Sb,Br,.156 Various derivatives ofliexafluoro- and hexachloro-antimonic acids have been made.15' Additionof chlorine to tristrifluoromethylantimony Sb(CF,), gives the compound(CF,),SbCl, which reacts with water to form a mono- and a di-hydrate; asolution of tristrifluoromethylantimonic acid H(CF,),Sb( OH),, which isunique in being the only known strong monobasic acid of antimony(v), canalso be is01ated.l~~ Antimony pentachloride reacts with dialkyl sulphites,(RO),SO, to give C1,SbOR.157 Reaction with a solution of sulphur trioxidein sulphuryl chloride yields pyrosulphuryl chloride and the new compoundSb,CI,SO, which may be formulated as the salt (SbC14+)2S042-.159X-Ray powder photographs show that " sodium metabismuthate '' hasthe ilmenite structure and is best described as sodium bismuth(v) trioxide.160Group V1.-The stereochemistry of the elements in Group VI has beenreviewed.161 The Raman spectrum of the hydroxonium ion H,O+ isreported for the first time,lG2 and the ion is now recognized as a latticecomponent in several hydrated sulphates and phosphates of iron analogousto ferrous ammonium salts.lG3Physicochemical measurements continue on the sulphuric acid system,164and the work has been extended to solutions in disulphuric acid.165 A re-investigation of the system HN0,-H,SO,,nSO, establishes the identity oflive compounds in the range n < 1 ; when n > 1 nitronium hydrogen tetra-sulphate is formed (N02,HS,013).166 With dioxan, sulphuric acid forms thecompound H,S0,,C4H,02 which melts at 100" and has a conductivity of2 x lo-, ohm-l ~ r n .- l . l ~ ~ Two new incongruently melting compounds have154 2. Galdecki, Roczniki Chem., 1956, 30, 355.156 G. Brauer and Ti.-D. Schnell, ibid., 1956, 283, 49.15' A. Meuwsen and H. Mogling, ibid., 1956, 285, 262.158 H. J. Emeleus and J. H. Moss, ibid., 1956, 282, 24.159 R. Appel, ibid., 1956, 285, 114.160 B. Aurivillius, Acta Chem. Scand., 1955, 9, 1219.161 S. C. Abrahams, Quart. Rev., 1956, 10, 407.162 J. T. Mullhaupt and D. F. Hornig, J. Chem. Phys., 1956, 24, 169; see also D. J.Millen and E.G. Vaal, J., 1956, 2913.N. V. Shishkin and Ye. A. Krogius, Zhur. neorg. Khim., 1956, 1, 1252; see alsoF. Halla and E. van Tassel, Natzwwiss., 1956, 43, 80.164 R. J. Gillespie and J. V. Oubridge, J., 1956, 80; R. Flowers, R. J. Gillespie, andS. Wasif, ibid., p. 607; R. Flowers, R. J. Gillespie, and J. V. Oubridge, ibid., p. 1925;R. J. Gillespie and R. C. Passerini, ibid., p. 3850.165 J. R. Brayford and P. A. H. Wyatt, Trans. Faraday Soc., 1956, 52, 642.lo6 V. A. Usol'tseva, Zhur. priklad. Khim., 1956, 29, 302, 306.167 Ya. F. Mezhennyi, J . Gen. Chenz. (U.S.S.R.), 1956, 26, 397.H. Behrens and L. Glasser, 2. anorg. Chenz., 1956, 282, 12100 INORGANIC CHEMISTRY.been detected in the binary system water-selenic acid : H2Se0,,2H,0,m. p. -24", and H2Se0,,6H,O, m. p.-68.4°.168 Thermal analysis of thesystem water-selenium trioxide also reveals two new compounds : H2Se,0,,m. p. 18.8", and H,Se3OIl melting incongruently with a peritectic temper-ature 169 of 25.4".A single-crystal structure analysis of sodium dithionite Na,S,O, revealsthat the anion consists of two SO,- groups joined by a very long S-S bond(2.39 A) ; the sodium ions are also in an unusual, approximately square,co-~rdination.~~~ A considerable amount of work is being published on thechemistry of the sulphanes H,S, and the chlorosulphanes S,C1, and many ofthe lower members of these series (n < 6) can be obtained reasonably pure.171Fluorosulphites are prepared by the addition of gaseous sulphur dioxideto alkali-metal or tetra-alkylammonium fluorides, the reaction being moreready the larger the cation : M F + SO, MS0,F. The fluorosulphiteion, which is isoelectronic with the chlorate ion, is stable in an atmosphereof SO, up to 150" but above this temperature it reacts to give the corre-sponding fluorosulphate : 2MS0,F + SO, --+ ZMSO3F + S.Fluorineand chlorine convert the compounds into S0,F2 and SO,ClF, and a phasestudy of the system HF-SO, demonstrates the existence of the parent acidHSO,F, m. p. -84°.172 The amide of fluorosulphurous acid SO(NH,)F isobtained from ether solutions as the product of the reaction of ammoniawith a large excess of thionyl fluoride; the volatile compound soon forms asolid yellow linear polymer [OS(NH,)F].. Primary amines tend to reactanalogously but the product OS(NHR)F readily splits off hydrogen fluorideto give thionyl imines OSNR ; secondary amines yield stable dialkylamidesof fluorosulphurous acid OS(NR,)F.173The generic relation of pyrosulphuryl fluoride S,05F, as the anhydride offluorosulphuric acid HS0,F has at last been established by using arsenic(v)oxide as a mild dehydrating agent; the reaction proceeds at 300" via theintermediate formation of a volatile arsenic fluorosulphonylfluoi-ide : 174IOHSO3F + As206 __t 2AsF,(SO,F), + HzSO, + HZ0~AsF~(SO~F)~ - 3SaO6Fz + As,O,F,Earlier work on the ammonolysis of pyrosulphuryl choride which had beeninterpreted on the basis of the reaction S,O,Cl, + 6NH, + 2NH,C1 +(NH4)2[S205(NH)2] could not be confirmed and the reaction is now formu-lated as 1752SzOjCIz + I2NHS- 4NHdCI + (NH,)SO,NH, + SO,(NHZ)Z + NH,*SOg.N(NH4)*SO,NH4168 G. Vuillard, Compt.rend., 1956, 242, 1326.189 K. DostAl, COX Czech. Chem. Comm., 1955, 20, 1033; Chem. Listy, 1955, 49,633 ; see also K. DostAl and M. Cernohorsky, ibid., 1956, 50, 702.17O J. D. Dynitz, Acta Cryst., 1956, 9, 579.171 F. Feller, W. Laue, and J. Kraemer, 2. a n o ~ g . Chem., 1955, 281, 151; F. FehQand G. Rempe, ibid., p. 161; F. Feh6r and L. Meyer, 2. Naturforsch., 1956, l l b , 605;F. FehCr and W. Laue, 2. anorg. Chem., 1956, 287, 45; H. P. Meissner, E. R. Conway,and H. S. Mickley, I n d . Eng. Chem., 1956, 48, 1347.172 F. See1 and L. Riehl, 2. anorg. Chem., 1956, 282, 293.173 M. Goehring and G. Voigt, Chem. Ber., 1956, 89, 1050.174 E.Hayek, A. Aignesberger, and A. Engelbrecht, Monatsh., 1956, 86, 735.175 R. Appel, G. Voigt, and E . H . Sadelr, Naturwiss., 1966, 43, 496ADDISON AND GREENWOOD : MAIN GROUPS. 101The last compound is the diammonium salt of a formerly unknown imido-sulphuric acid, and is also formed by the ammonolysis of trisulphurylfluoride : 1752SaOeFZ + IONH:,ZNH,SO,F + 2HF + NH,SO,NH, + SO,(NH,), + NH,*S02.N(NH,).SOa*NH,On the other hand ammonolysis of trisulphuryl chloride appears to giveNH,SO,NH,, SO,(NH,),, and the corresponding triammonium salt(NH4)JN (SO,),]. 17G Finally, NN'-dimethylsulphamidedisulphuric acid an-hydride (13) is completely ammonolysed by ammonia to give sulphamide,dimethylsulphamide, N-methylsulphamic acid, and amidosulphuric acid.17sAll these experiments indicate that the S-0-S system is much less stabletowards ammonlysis than the P-0-P grouping.Sulphur trioxide reacts with cyanogen chloride CNCl to give three newcompounds : N-carbonylsulphamyl chloride OC=N*SO,Cl, which hydrolysesto CO,, NH,.SO,H, and HC1; the corresponding derivative of pyrosulphuricacid OC=N*SO*O*SO,Cl; and the cyclic compound (14).177 Thiazyl bromide(NSBr), reacts with potassium amide to give a yellow reactive solid K,N,Swhich may be considered as a derivative of sulphur di-imide S(NH),.From thiazyl chloride (NSCl), and mercuric iodide in liquid ammonia thecorresponding salt HgN,S was prepared.17*The chemistry of sulphur nitride and its derivatives has been revie~ed.17~Disulphur dinitride can be obtained by the thermal decomposition of tetra-sulphur tetranitride under very carefully controlled conditions ; its structureis thought to be S=N-S=N.lG0 The formation of S,N,Cl from S,N, andacetyl chloride or sulphur chloride is ascribed to traces of free hydrogenchloride in the reagents.lG1 The thermal decomposition of SN,F, gives amixture of sulphur tetrafluoride, nitrogen, and the colourless gas SNF whichis the monomer of (SNF), mentioned in last year's Report (p.117). Undermilder conditions SN,F, disproportionates into SNF and SNF,.l82 The lastcompound, which is the most stable of the sulphur-nitrogen fluorides m-ayalso be prepared by the reaction of a gaseous mixture of SNF and SN,F2with silver difluoride; the sulphur is in the +4 oxidation state and thestructure of the compound is therefore F,S=NF in contrast with thio-phosphoryl fluoride which is S=PF3.ls3+176 H.-A.Lehmann and G. Ladwig, 2. anorg. Chem., 1956, 284, 1.1 7 7 R. Graf, Chern. Ber., 1956, 89, 1 0 7 1 .178 W. Berg, M. Goehring, and H. Malz, 2. anorg. Chem., 1956, 283, 13.179 M. Goehring, Quart. Rev., 1956, 10, 437.160 M. Goehring and D. Voigt, Z . anorg. Chem., 1956, 285, 181.181 A. G. MacDiarmid, J . Amer. Chem. Soc., 1956, 78, 3871.182 0. Glemser and H. Haeseler, 2. anorg. Chem., 1956, 287, 54.18s 0. Glemser and H. Schroder, ibid., 1966, 284, 97102 INORGANIC CHEMISTKY.The tetrafluorides of sulphur and selenium form solid 1 : 1 additioncompounds with boron trifluoride melting at 80" and 46", and there are in-dications that tellurium tetrafluoride reacts similarly.Addition compoundsof these tetrafluorides with arsenic and antimony pentafluorides are alsodescribed.184 A convenient preparation of tellurium tetrafluoride fromtellurium dioxide and selenium tetrafluoride is reported.lS5 The fluorinationof tellurium has been studied under a variety of conditions ; TeF,, TeF,, andTe,F,, were obtained. In the presence of tellurium dioxide a telluriumoxyfluoride Te302F14 is also obtained which may be formulatedTeF5*O*TeF4*O*TeF5 ; this compound has a ratio of molecular weight toboiling point of 1.67 and is therefore even more volatile for its molecularweight than Te,F,,, which previously had the highest value for this ratio(1.36) of any known compound.Another product of the reaction appearsto be Te,05F2,, i.e., TeF5[O*TeF4],*O~TeF5.1s6The extraction of polonium(1v) from nitric acid into ethers depends on thepresence of reducing agents such as SO,, H20,, N2H4, NH20H, and organicperoxides; in the absence of these agents negligible extraction occurs in thedark.187 The preparation of a basic sulphate of polonium 2P002,S03, abasic selenate 2PoO,,SeO,, and a less stable disulphate Po(SO4), is described,and these reflect the increased basicity of polonium compared with itslighter congeners. la8 Polonium tetraiodide has been prepared by directreaction of the elements at 40°/1 mm., by the reaction of PoO, and HI at200", and by the. reaction of the dioxide with aqueous hydriodic acid.Addition of czsium iodide gives a black precipitate of the hexaiodopolonateCs2PoI6 which is isostructural with C S , T ~ I , .~ ~ ~ The potential of the poloniumelectrode (polonium deposited on gold in contact with a solution of Porv inN-HNO,) against a saturated calomel electrode is E, = -/-0.?'6 v.lgoGroup VII.-The purification of hydrogen fluoride in an apparatus con-structed of Fluorethene plastic leads to samples of considerably lowerconductivity than previously obtained; the lowest value was 1.6 xohm-l crn.-l at 0" compared with the accepted vahe of 1-4 x at - 15'.191Antimony pentafluoride behaves as an acid in hydrogen fluoride (SbF, +2HF -e H2Ft + SbF,-) and the mobilities of these ions, together withthose from the strong electrolytes NaF, KF, and NaSbF, have been deter-mined at infinite dilution.The low value for the hydrogen ion eliminatesthe possibility of a chain mechanism involving this species but the rather largemobility of the fluoride ion may indicate an abnormal process for this ion.lg2The fluorides of titanium, niobium, and tantalum are good electron acceptorsin hydrogen fluoride in the sense that they favour the reaction m-xylene +N. Bartlett and P. L. Robinson, Chew. and Ind., 1956, 1352.lE5 R. Campbelland P. L. Robinson, J . , 1956, 785.186 Idem, ibid., p. 3454; see also G. Hetherington and P. L. Robinson, ihid., I>. 3682187 J. Danon and A. A. L. Zamith, Nature, 1956, 177, 746.188 K. W. Bagnalland J. H. Freeman, J., 1956, 4579.189 K.W. Bagnall, R. W. M. D'Eye, and J. H. Freeman, ibid., p. 3385; see also100 K. W. Bagnall and J. H. Freeman, J., 1956, 2770.191 M. E. Runner, G. Balog, and M. Kilpatrick, J . Amer. Chem. Soc., 1956, 78, 5183.182 M. Kilpatrick and T. J. Lewis, ibid., p. 5186.for viscosity of Te,F,,.0. M. JankoviC, Bull. Inst. NucZear Sci. Boris Kidrich, 1956, 6, 143;\I>l)ISON AND GREENWOOL) MAIN GKOUPS. 103H F + (m-xylene H)+ + F- by removing the fluoride ions according toreactions like F- -t NbF, + NbF,-. Phosphorus pentafluoride is lesseffective, and the fluorides of Ba, Si, PbII, SbIII, BPI1, ZrIV, Cr1IT, WF*,and Zn are inactive.lg3Hydrogen chloride forms a hexahydrate, m. p. - 70.0", in addition to theknown di- and tri-hydrates.lg4 The electron-donor capacity of x orbitals inunsaturated hydrocarbons has been studied by using hydrogen chloride as aconvenient, small, acceptor molecule.Phase diagrams with olefins show thepresence of low-melting addition compounds with one and two mols. of acid,acetylenes form compounds at these ratios and also with four mols. of acid,whereas aromatic hydrocarbons tend to form 1 : 1 compounds only.lg5The thermal decomposition of dichlorine hexaoxide in the presence offluorine gives a 70% yield of chloryl fluoride C10,F. The hexaoxide de-composes according to the equations C1206 + ZlO, 2C10, + 0, ;neither Cl,06 nor ClO, reacts with fluorine but the dioxide does and indeedchloryl fluoride may be prepared by the direct reaction of undiluted chlorinedioxide and fluorine.lg6 Perchloryl fluoride ClO,F, which was recentlyobtained in small yields either by electrolysis of perchlorates in H F or bydirect fluorination of chlorates, has now been prepared in 67% yield by thereaction of perchlorates with fluorosulphuric acid. lg7 It is a colourless,inert, thermally stable gas (m. p. -146", b. p. -47.5") in contrast to C10,Fand ClO,OF which are explosive or highly reactive. Perchloryl fluoridereacts slowly with ammonia to give ammonium imidoperchlorate :C10,F + 3NH, + NH,F -t NH,NHC10,.lg8 Analysis of the vibrationspectrum and rotational fine structure of ClO,F indicates a central C1 atomwith the 0 atoms at the base and the F atom at the apes of a trigonalpyramid, FClO,, but the absence of microwave absorption suggests that themolecular dipole is very small and probably much less than 0.09 D.lg9Fluorine fluorosulphonate, prepared by the action of fluorine on sulphurtrioxide in the presence of silver difluoride, is a reactive oxidizing agent,m.p. --158.5", b. p. -31.3"; its chemical reactions and infrared spectrumconfirm the structure S02F*OF.200 The catalytic fluorination of thionylfluoride over silver difluoride yields thionyl tetrafluoride F,S=O (m. p. -99.6",b. p. -49-0") and pentafluorosulphur hypofluorite F,S-OF (m. p. -86-0",b. p. -335.0"); the structures were deduced from chemical reactions andinfrared spectra,201 and confirmed by nuclear magnetic resonance.202The electric dipole moment of gaseous bromine trifluoride suggests aplanar T-shaped molecule similar to that found for chlorine trifluoride.,N193 D.A. McCaulay, W. S. Higley, and A. P. Lien, J. Amer. Chem. SOC., 1956, 78,3009.194 G. Vuillard, Compt. rend., 1955, 241, 1308.195 D. Cook, Y. Lupien, and W. G. Schneider, Canad. J . Chem., 1966, 34, 955, 964.1913 A. J. Arvia, W. H. Basualdo, and H. J. Schumacher, 2. anorg. Chew., 1056, 286,197 G. Barth-Wehrenalp, J . Inorg. Nuclear Chem., 1956, 2, 266.198 A. Engelbrecht and H. Atzwanger, ibid., p. 348.199 R. P. Madden and W. S. Benedict, J . Chem. Phys., 1956, 25, 594; D. R. Lideand D. E. Mann. ibid., p. 595.200 F. B. Dudley, G. H. Cady, and D. F. Eggers, J . Amer. Chem. SOC., 1956, 78, 290.201 Idem, ibid., p. 1553.202 F. B. Dudley, J. N. Shoolery, and G. H. Cady, ibid., p.568.tos M. T. Rogers, R. D. P r i i e t t , and J. L. Speirs, ;bid., 1955, 77, 5280.58; see also J. E. Sicre and H. J. Schumacher, ibid., p. 232104 INORGANIC CHEMISTRY.There are two congruently melting compounds in the system bromine tri-fluoride-antimony pentafluoride ; BrF,,SbF,, m. p. 129.8", and BrF3,3SbF5,m. p. 33.5" ; and also two incongruently melting compounds, 3BrF,,SbF5,m. p. -16.3", and 3BrF,,2SbF5, m. p. 3043".204 An X-ray crystal-structuredetermination has shown that the tetrafluorobromate ion in KBrF, is tetra-hedral 205 in contrast to the tetrachloroiodate ion in KICl, which is planar.The vapour pressures of the addition compounds of bromine trifluoride withpotassium bromide and antimony pentabromide (KBrF, and BrF,,SbF,) havebeen measured up to 350" and are of such a magnitude that the compoundscan be used for high-temperature fluorinations in closed reaction vessels evenup to 500°.206 The electric dipole moments of bromine pentafluoride 207 andiodine pentafluoride 203 are consistent with a square-based-pyramidal struc-ture and exclude trigonal-bipyramidal and plane-pentagonal symmetries.The phase diagrams of the systems bromine pentafluoride-hydrogenfluoride 208 and iodine pentafluoride-hydrogen fluoride 209 each show a singleeutectic; there is no evidence of compound formation.The crystal structure of x-iodine monochloride involves ICl molecules intwo non-equivalent sets; these molecules, of bond length 2.37 and 2.44 Arespectively, are arranged in puckered zigzag chains with strong interactionbetween the molecules in individual chains but with normal van der Waalsdistances between the chains.210 A detailed study of the crystal structuresof the addition compounds of iodine monochloride with pyridine 211 anddioxan has shown that the N-I-C1 bond in Py,ICl and the 0-I-C1 bondin C,I-I8O2,2ICl are both linear and non-ionic By contrast, $-chlorobenzeneiododichloride C1*C6H,*ICI, has a linear Cl-I-Cl group at right-angles to theC-I bond, the whole molecule being planar.The structure is allied to thatof benzene iododichloride except that in this compound the ICl, group isalso at right-angles to the plane of the benzene ring.213 (It may benoted that these two iododichlorides together with chlorine trifluoride andbromine trifluoride constitute the four known examples of T-shapedcovalent bond angles so that chlorine, bromine, and iodine can all adoptthis symmetry.)The cryst a1 structure of t etraeth ylammonium hept aiodide Et ,N I isbuilt up of I,- ions and I, molecules with large holes for the Et,N+ cations;the compound therefore is best written as Et,N+I,-,212; there is no indic-ation of an I,- i0n.214 The structure of tetramethylammonium enneaiodide204 J.Fjscher, R. Liimatainen, and J. Bingle, J . Amer. Chenz. Soc., 1956, 78, 5848.805 S. Siegel, Acta Cryst., 1956. 9. 493.208 I. Sheft, A. F. Martin, and J. J. Kstz, J . Amer. Chem. Soc., 1956, 78, 1557.807 M. T. Rogers, R. D. Pruett, H. B. Thompson, and J. L. Speirs, ibid., p. 44;208 M. T.Rogers, J. L. Speirs, and M. B. Panish, J . Amer. Chenz. SOL, 1956, 78,209 M. T. Rogers, J . L. Speirs, M. B. Panish, and H. B. Thompson, ibid., p. 936;210 K. H. Boswijk, J. van der Heide, A. Vos, and E. H. Wiebenga, Acts Cryst., 1956,211 0. Hassel and C. Rsmming, Acla Chevz. Scand., 1956, 10, 696.212 0. Hassel and J . Hvoslef, ibid., p. 138.213 D. A. Bekoe and R. Hulme, Nature, 1956, 177, 1230.214 E. E. Havinga and E. H. Wiebenga, PYOC. k . ned. Akad. Wetenschafi., 1055, 58, B,see also M. T. Rogers and J. L. Speirs, J . Phys. Chem., 1956, 60, 1462.3288.see also G. Hetherington and P. L. Robinson, J . , 1956, 3681.9, 274.412ADDISON AND GREENWOOD : THE TRANSITION ELEMENTS. 105Me,NI, is more complicated. It consists of planes of densely packed iodineatoms which contain 5/9ths of the iodine atoms in the compound and withinwhich there is some justification for singling out 1,- ions similar to but lesssymmetrical than, the V-shaped ions in h'Ie,NI,.Between these planes,which are 9.1 apart, lie Me,N+ cations each surrounded by six I, molecules ;these molecules also lie between the main planes, normal to them and weaklyassociated with them. Except for the I, molecules between the planes, all1-1 distances are considerably longer than in I, and are comparable withthose found in 13-, 15-, and 182-.2153. THE TRANSITION ELEMENTS.A large proportion of the work published during the year on the chemistryof the transition elements has been concerned with complexes. Work whichillustrates the structure or general properties of particular types of complexis correlated under the heading " Complexes." The remaining chemistryof the transition elements is then discussed systematically ; these sectionscontain references to complexes which are more directly concerned with thechemistry of the particular elements.The paramagnetic resonance ofcrystalline solids containing ions of the transition groups has been reviewed.216The proceedings of the International Conference on Co-ordination Com-pounds (Amsterdam, 1955),217 and a symposium on the chemistry ofcomplex compounds,218 have been published. \V. Klemm has reviewedthe present position regarding valency ranges in the transition elements,particularly the abnormal valencies shown in their oxygen and fluorinec0mplexes.~19Complexes.-Import ant advances have been made in the elucidation ofthe mechanism of substitution in octahedral (mainly CoIII) complexes, and therelated stereochemical changes."O They involve kinetic studies which lieoutside the scope of this Section.The stability and the spectra of complexesof transition metal cations have also been discussed,221 with emphasis on theapplication of crystal field theories.z22The well-known reducing and catalytic properties of a solution of ironpentacarbonyl in aqueous hydroxide solutions are interpreted satisfactorily onW. J. James, R. J. Ilach, D. French, and R. E. Rundle, Acla Cryst., 1955, 8,216 K. D. Bowers and J. Owen, Reports Progr. Phys., 1955, 18, 304; see also Discuss.217 Rec.Trav. chim., 1956, 75, 557-924.218 Chem. Weekblad, 1956, 52, 193.219 W. Klemm, Bull. SOC. chim. France, 1956, 1325.220 S. Akperger and C. K. Ingold, J., 1956, 2862; F. Basolo, W. R. Matoush, andR. G. Pearson, J . Amer. Chem. SOC., 1956, 78, 4883; R. K. Murmann and H. Taube,ibid., p. 4886; A. W. Adamson and F. Basolo, Acta Chena. Scand., 1955, 9, 1261 ; andrefs. therein.814.Faraday Soc., 1955, 19.221 H. Irving and H. Rossotti, ibid., p. 72.222 C. K. Jm-gensen, ibid., p. 887; R. J. P. Williams, J . , 1956, 8 ; P. George, D. S .McClure, J. S. Griffith, and L. E. Orgel, J . Chem. Phys., 1956, 24, 1269; C. J. Ballhausen,Rec. Trav. chim., 1956, 75, 666; and refs. therein106 INORGANIC CHEMISTRY.the basis of an intermediate dimeric ion (15) formed from two [Fe(CO),H]-ions which is oxidised to ion (16) : 223(15) (16)Dirhenium decacarbonyl undergoes a similar reaction : 2241 K[ (OC),R\;/Re(CO), Lo\ R*2(CO)Io + 3KOH + H 2 0 + CO + K2CO3-t 2H1( 1 7 )The compound (17) is diamagnetic, each sexaco-ordinate Re atom maintain-ing its inert-gas configuration.The same product is formed from thecarbonyl chloride :Re,(CO),O,HK + 2KCI + 2CO + H,Oand with thiophenol the carbonyl chloride gives the non-electrolyte2Re(CO),CI + 3KOHll(CO)4Re(S'C6H5)212*The position of the hydrogen atom in cobalt carbonyl hydride has been - -further examined from its infrared spectrum. In the absence of an 0-Hstretching vibration, the spectrum is consistent with a model in which thehydrogen atom bridges three CO groups; its covalent bonding to the COgroups is stronger than to the Co atom.225The compound Ru(CO),I, has high stability and low vapour pressure, inmarked contrast to the iron compound.226 This is consistent with a halogen-bridged polymeric structure (18) in which each Ru atom may also achieveinert-gas configuration.The chemistry of mixed complexes containing isoelectronic groups hasbeen developed.Nitrosylcyano-complexes of iron and nickel are known,and the corresponding cobalt complexes now isolated are correlated asfollows : 227KCN HCN[Co(NH,),NO]CI, __t K3[Co(CN),NO] ___t [Co(CN)dS- + $NzOIn the pentammino-complex the NO group has entered the complex as NO- ;the lower formal valency of the cobalt resulting from electron distribution togive NO+ is revealed by the reduction to nitrous oxide on replacement of theNO group.Again,KCNCo(CO),NO __t [Co(CN)(CO),(NO)]- --j- Co(CO),NO + [Co(CN),(CO)(NO)]-'CN-and [CO(CN),(CO)(NO)]~- __+ [Co(CN)3NOIS-which is directly analogous to the carbonyl nitrosyl.22s H. W. Sternberg, R. Markby, and I. Wender, J . Anzer. Chem. SOC., 1956, 78,224 W. Hieber and L. Schuster, 2. anorg. Chem., 1956, 285, 205.226 W. F. Edgell, C. Magee, and G. Gallup, J . Amer. Chem. SOC., 1956, 78, 4185,2Z8 R. J. Irving, J., 1956, 2879.227 R. Nast and M. Rohmer, 2. anorg. Chem., 1956, 285, 271.5704.4188; see also F. A. Cotton and G. Wilkinson, Chem. and Ind., 1956, 1305A1)I)ISON ANI) GREENWOOD THE TRANSITION ELEMENTS. 107A number of derivatives of iron and cobalt nitrosyl carbonyls withphosphorus, arsenic, and antimony alkyls and aryls are described.228 Theyinclude Co( NO) (CO) (PPh,) ,, Co (NO) (CO) , [As (C,H,Cl) J, Fe (NO),( PPh,),, andFe(NO),[P(OPh),],, and a carbonyl derivative is obtained by the reaction 229Hs[CO(CO),I~ + 2PPh3 HdCo(C0)3(PPhs)l2isocyanides give 1 : 1 replacement of the CO group in carbonyls.Withiron pentacarbonylCIH,-NC CHs.NCFe(CO)5 - Fe( CO)4,C2H5NC ___t Fe(CO)3C2H5NCCH3*NCThis class of compound has been ~urveyed.2~0 Reaction of rhodium tri-chloride with RNC (R = tolyl, 9-chlorophenyl, methoxyphenyl) givescompounds of formula [(RNC),Rh]Cl in which the Rh atom is formallyunivalent .231. The chemistry of metal acetylide complexes has been extended to includeIn liquid ammonia, the compounds analogous to ferro- and ferri-cyanides.following reaction occurs :6MCECR + Fe(SCN)?,4NH3(where M = K, Na and R = H, Me, Ph).in liquid ammoniaM4[Fe(C-CR),] + ZMSCN + 4NH3On reaction with gaseous oxygenand the FeIII product can be reduced again by reaction with a solution ofpotassium in liquid ammonia.232 An analogous series of CoII and COTITcomplexes has been prepared.2aThe trans-directing effect in platinous complexes has been furtherexamined.The elimination of groups in the trans position is attributed tothe high double-bonding capacity of the directing ligand, and occurs by anSN2 mechanism. This is supported by the infrared spectra of a series of squareplanar complexes.234 An electronic interpretation of the lability of groupstrans to the double-bonding ligand has been given which involves a distortedbipyramidal structure for the transition state.235 Advantage has been taken228 M.Malatesta and A. Araneo, -4Iti Accad. naz. Lincei, lie9id. Classc Sci. j s . Inat.229 W. Hieber and R. Breu, Angew. Chem., 1956, 68, 679.230 W. Hieber and D. von Pigenot, Chem. Ber., 1956, 89, 610, 616.231 L. Malatesta and L. Vallarino, J., 1956, 1867.232 R. Nast and F. Urban, 2. anorg. Chem., 1956, 287, 17.233 R. Nast and H. Lewinsky. ibid., 1956, 282, 210.234 J. Chatt, L. A. Duncanson. and L. M. Venanzi, J., 1955, 4456, 4461 ; see alsoD. B. Powell, J., 1956,4495; 0. Y . Zvyagintsev and Y. F. Karandasheva, Doklady Akad.Nauk, S.S.S.R., 1956, 108, 477.235 Id.E. Orgel, J . T w o ~ g . Nuclear Chem., 1956, 2, 137.nnt., 1956, 20, 365108 INORGANIC CHEMISTRY.of the labile nature of the group trans to an ethylene molecule to determineequilibrium constants for the reactionsand trans-C,H,,H20PtC12 + am + tmns-C,H,,amPtCl, + H20and thus the relative tendencies of a series of simple amines (am) to co-ordinate with the meta1.236 The possibility that the cyclobutadiene moleculecan be stabilised by combination with a transition-metal ion has beenexamined by molecular-orbital theory.237 An interesting olefin complex[C,H,,RhCl], is formed by reaction of rhodium trichloride with cycloocta-1 : 5-diene.238 When treated with an amine (am) itgives the mononuclear planar complex C8H1,,Rh amC1, and on treatmentC2H,PtC13- + am trans-C,H,,amPtCl, + C1-It has structure (19).OHwith cyclopentadienylsodium gives the novel derivative C,H,,,RhC,H,(m.p. 108'). Acetylene complexes of some transition metals have beenprepared, but structures are uncertain. The infrared spectrum of the knowncompound Fe,C,,H,O,, prepared by reaction of acetylene with iron carbonylhydricle, indicates that it is binuclear (80) and closely related to the nona-carbonyl. The two acidic hydrogen atoms are attached directly to oxygenatoms.239 A wide range of substituted acetylenes RCGCR, undergo thereactionRC-CR, + CO,(CO), (CO)~CO*RC-CR,*CO(CO)~ + 2CObut the multiplicity of the bonds connecting the two Co atomsthrough the acetylene has not yet been ascertained.240 The complexK[Cl3Pt ,Me,( 0H)C-CrC*C (OH) Me,] has been described.241There have been considerable developments in the chemistry of metal-cyclopentadiene complexes during the year, and many compounds are nowclassified according to whether they form sandwich-type bonds, ionic bondsbetween metal and C,H,- ions, or localised metal-carbon bonds.The twowell-known approaches to the structure of ferrocene-type compounds, i.e.,the single bond concept and that involving multiple bonding (and the attain-ment by the metal of the inert-gas structure), have been compared and arenot necessarily irreconcilable ; 242 in the series (C,H,)V(CO),, (C,H,)Mn(CO),,296 J. Chatt and G. A. Gamlen, J., 1956, 2371.237 H. C. Longuet-Higgins and L. E. Orgel, ibid., p.1969.238 J. Chatt and L. M. Venanzi, Nature, 1956, 177, 852.239 H. W. Sternberg, R. A. Friedel, R. Markby, and I. Wender, J . Amer. Chem. SOC.,240 H. Greenfield, H. W. Sternberg, R. A. Friedel, J. H. Wotiz, R. Markby, and241 S. V. Bukhovets, Izvest. Sekt. Platiny, 1955, No. 29, 55,242 J. W. Linnett, Trans. Faraday Soc., 1956, 52, 904.1956, 78, 3621.I. Wender, ibid., p. 120ADDISON AND GREENWOOD : THE TRANSITION ELEMENTS. 109(C,H,)Co(CO),, C,H,NiNO there is agreement that only the latter concept istenable.243 A detailed crystallographic examination of ferrocene, (x-C,H,),Fe,gives the Fe-C distance, d(Fe-C), as 2.045 & 0.010.02 A; electron-diffraction studies give d(Fe-C) 2-03 & 0.02 andd(C-C) 1.43 & 0.03 H1.245 Crystallographic data are also available fordicycZopentadienylchromium( 11) 246 and for molybdenum, tungsten, and ironcyclopentadienyl ~arbonyls.~*~More metals have been added to the list of those forming cyclopentadienylcomplexes; the usual method of preparation is by reaction of sodiumpentadienide with a salt (e.g., halide) of the metal in an organic solvent(e.g., tetrahydrofuran or dimethylformamide).Scandium, yttrium, lanthan-um, and the lanthanide elements Ce, Pr, Nd, Sm, Gd, Dy, Er, and Yb givecrystalline solids of formula M(C5H5), ; the metal-to-ring bonds are ionic innature.248 Titanium dichloride gives dark green crystals of (x-C,H,),Ti,a ferrocene-type compound.249 The manganese compound (C5H5),Mn showsionic bonding, in contrast to the sandwich structure of neighbouring elements.This is related to the extra stability of the &In2+ ion, with its singly occupied3d orbitals.250 The Cu+ ion might be expected to form sandwich-bondcompounds of the type C5H5CuR, isoelectronic with C,H,NiNO, but theinfrared spectrum of the compound C5H5CuPEt, suggests that it should beformulated with a localised metal-carbon bond,251 as is the case with themercury compound (C,H,),Hg. The dipole moments of the tin252 andlead 253 compounds (C,H,),Sn and (C,H,),Pb, 1-01 D and 1.63 D, indicate thatthey are also normal organometallic compounds.Many derivatives of simple cyclopentadienyl complexes have beenprepared.and d(C-C) 1.403Dicyclopentadienyliron dicarbonyl is obtained by the reactionsBra C,H,Na(C,H,),Fe,( CO), __t 2C,H,Fe(CO),Br ___+_ C,H6Fe( C0)2C5H6Only one C,H, group is symmetrically bonded to the iron atom, and thecompound is useful in the synthesis of unsymmetrically substituted ferrocenederivatives2S4 The carbonyl hydrides C5H5M(C0),H (where A1 = Cr, Mo,W) have been prepared.The tungsten compound (m. p. 66') is the moststable.255 They represent fission of the dimeric complex by hydrogen, andare related in the same way as are the simple carbonyl and carbonyl hydrideof cobalt. The hydrides readily give salts of the anion [C,H,M(CO),]-.Two new nitrosyl derivatives C5H5Cr(NO),C1 and (C,H,),Mn,(NO), havebeen described.25G The former has a sandwich-bonded cyclopentadienyl243 L. E. Orgel, J . Inorg. Nuclear Chern., 1956, 2, 315.244 J.D. Dunitz, L. E. Orgel, and A. Rich, Acta Cryst., 1956, 9, 373.245 E. A. Seibold and L. E. Sutton, J . Chem. Phys., 1955, 23, 1967.246 E. Weiss and E. 0. Fischer, 2. anorg. Chem., 1956, 284, 69.247 F. C. Wilson and D. P. Shoemaker, Naturwiss., 1956, 43, 57.Z48 J. hl. Birmingham and G. Wilkinson, J . Awzer. Chem. Soc., 1956, 78, 42.249 A. K. Fischer and G. Wilkinson, J . Inorg. Nuclear Chem., 1956, 2, 149.250 G. Wilkinson, F. A. Cotton, and J. M. Birmingham, ibid., p. 95.251 G. Wilkinson and T. S. Piper, ibid., p. 32.252 E. 0. Fischer and H. Grubert, 2. Naturforsch., 1956, l l b , 423.253 Idenz, 2. anorg. Chern., 1956, 286, 237.254 B. F. Hallam and P. L. Pauson, J., 1956, 3030.255 E. 0. Fischer, W. Hafner, and H. 0. Stahl, 2. anorg. Chem., 1956, 282, 47.2 5 6 T.S. Piper and G. Wilkinson, J . Inorg. NucZear Chem., 1966, 2, 38, 136110 INORGANIC CHEMISTRY.group, with zero-valent chromium. Structure (21) whicli is suggested forthe latter compound involves the use of nitric oxide as a bridging group.Reaction of (21) with sulphur in carbon disulphide gives a disulphur deriv-ative (C,H,)Mn(NO)S, ; 257 this may represent a cyclopentadienyl derivativeof a Roussin-type salt (Z), with possible polymerisation by linkage throughsulphur at oms.(23) (21) (rl2)Whilst metal-to-carbon CJ bonds are unstable for most transition elements,the presence of a x-cyclopentadienyl ring on the metal so changes the orbitalsthat stable metal-carbon c bonds can be formed. Thus by reaction ofx-C,H,Cr( NO),I with Grignard reagents, x-C5HgMo(C0),H with diazomethane,or x-C,H,Fe(CO),Na with alkyl or aryl halides, a number of derivatives ofgeneral type x-C,H,M(CO),(NO),R have been isolated in which the alkyl oraryl group R is bonded directly to the An analogous silyl-ironcompound x-CSH,Fe(CO),SiMe, has an Fe-Si G bond.259cycZoPentadienylchromium-acetylacetone bromide (23) is novel in that acyclopentadienyl group is bonded to a transition metal which is also part ofa chelateUranium tetrachloride reacts with the sodium derivative of cyclopenta-diene to give the monochloride (x-C,H,),UC1.261 This compound does notreact with ferrous chloride in tetrahydrofuran and the metal-to-ring bondsare therefore not electrostatic.The compound is formulated [(C,H,),U] U-,the cation having three coplanar sandwich-type bonds a t angles of 120".Thorium forms cyclopentadienyl-metal halides analogous to those of titaniumand zirconium.261 Platinum forms a compound (C,H6),PtC1,, but lack of acharacteristic double-bond frequency in the infrared spectrum indicates thatthere may be cross-bonding between the two C,H, molecules.262The isolation of dibenzenechromium(O), (C6H,),Cr,263 in which theelectronic configuration of the chromium atom is the same as that of theiron atom in ferrocene, is of outstanding importance since it indicates thatthe orbitals of suitable transition metals can be filled with all the x-electronsof an aromatic system up to the configuration of the next inert gas.I t isprepared by heating together anhydrous chromic chloride, aluminiumpowder, aluminium chloride, and benzene.Hydrolysis of the product givesthe salt [Cr(C,H6)2]fC1-, which is reduced by sodium dithionite to brown-257 T. s. Piper and G. Wilkinson, J . Amer. Chem. Soc., 1956, 78, 900.258 Idem, J . Iizorg. Nuclear Chem., 1956, 3, 104.259 T. S . Piper, D. Lemal, and G. Wilkinson, Natuvwiss., 1956, 43, 129.260 J. C. Thomas, Chena. and Ind., 1956, 1388.2 6 1 L. T. Reynolds and G. Wilkinson, J . Inorg. Nuclear Chem., 1956, 2, 246.262 J. R. Doyle and H. B. Jonassen, J . Amer. Chem. soc., 1966, 78, 3965.263 E. 0. Fischer and W. Hafner, 2. Naturforsch., 1966, lob, 665ADDISON AND GREENWOOD THE TRANSITION ELEMENTS. 11 1black diamagnetic crystals of dibenzenechromium (m. p.284") which de-compose at 300" to metallic chromium and benzene.264 Crystallographicexamination shows the molecule to be centrosymmetrical, with parallelrings.265 Compounds containing toluene, &-xylene, tetralin, mesitylene, andhexamethylbenzene in place of benzene have also been prepared.265 A similarmethod with molybdenum pentachloride gives dibenzenemolybdenum(0)which is also diamagnetic and has the " doppelkegel structure.'' 266 Re-action with diphenyl gives bisdiphenylchromium iodide [Cr(C6H5*C6H5)2]I,26ithe magnetic properties and spectrum of which are identical with those of" tetraphenyl chromium iodide " prepared by Hein in 1919.268 Reactionstypical of the ferrocinium ion occur also with the Cr(C6H6),' cation; thusdibenzenechromium cyclopentadienylchromium tricarbonyl is found to bethe ionic compound [Cr(C6H6)~+[C5H5Cr(C0)3]- analogous to the cyclo-pentadienyl compound already known.269 The product of the reactionAICI,FeBr, + 2C,H,Me, + [Fe(C,H,Me3),]'+ + 2Br -is a niesitylene-iron(I1) cation which is isoelectronic with the neutralchromium(0)-mesitylene compound, and has the same structure.2i0The Scandium Group and Lanthanides.-By combination of fractionalhydroxide and carbonate precipitation with chromatographic separation ony-A1203, pure yttrium oxide (magnetic susceptibility -0.197 x 10-6/g.)containing < 0.002% of other lanthanides has been prepared.271 Theefficiency of scandium separations has been tested by using the 46Sc isotope;precipitation as the potassium double fluoride, ammonium double tartrate,or by disodium hydrogen phosphate is more efficient than precipitation ashydroxide, oxalate, or pyrophosphate.Solvent extraction of scandiumoxine chelate by chloroform can be made quantitative in one operation.272Conditions of cathode potential and pH have been defined for separation ofsamarium from gadolinium by electrolysis of the citrate complexes with alithium amalgam cathode, which is superior to sodium amalgam for thispurpose.273 The stability constants of lanthanide complexes with hydroxy-ethylethylenediaminetriacetic acid show little variation from samarium toerbium ; 274 separations on cation-exchange resins with 2-hydroxyethylimino-diacetic acid complexes are also described.275 Weight-temperature curvesfor thermal decomposition of the nitrates M(N03),,6H20 give the followingtemperatures for complete conversion into oxide : La 780"; Ce 450";Pr 505" ; Nd 830" ; Sm 750".276Lanthanum, cerium, praseodymium, and neodymium behave similarly264 E.0. Fischer and W. Hafner, 2. anorg. Chem., 1956, 286, 146.265 E. Weiss and E. 0. Fischer, ibid., p. 142.266 E. 0. Fischer and H. 0. Stahl, Chem. B e y . , 1956, 89, 1806.267 E. 0. Fischer and D. Seus, ibid., p. 1809; I?. Hein, ibid., p. 1816.268 Idem, Bey., 1919, 52, 195.269 E. 0. Fischer and H. P. Kogler, Angew. Chem., 1956, 68, 462.270 E. 0. Fischer and R. Bottcher, Chem Bey., 1956, 89, 2397.2 7 1 W. Fischer and K. E. Niemann, Z. anorg. Chem., 1956, 283, 96.272 R. C. Vickery, ./., 1956, 3113.173 E.I. Onstott, J . Anzer. Chem. SOC., 1956, 78, 2070.274 F. H. Spedding, J. E. Powell, and E. J. Wheelwright, ibid., p. 34.275 L. Wolf and J. Massonne, J . prakt. Chenz., 1956, 3, 178.2713 W. W. Wendlandt, Analyt. Chinz. Acfa, 1956, 15, 435112 IN ORGANIC CHEMISTRY.in their systems with hydrogen. For compositions between &I and MH, twosolid phases (metal and hydride) exist ; compositions MH, to MH, representa single solid phase, and in this range these elements, with samarium, forman isomorphous series of hydrides. The MH, hydrides have a fluorite-typestructure, and additional hydrogen is distributed in octahedral inter~tices.~"The deuterides of ytterbium and europium (which give maximum composi-tions YbDl.g8 and EuD,.,J are isostructural with hydrides of alkaline-earthmetals.278 An earlier claim that the hydride Gd,H, is formed on heatinggadolinium in hydrogen is not supported by detailed pressure-temperature-composition data.Two solid phases exist; the first has cubic structure ofideal composition close to GdH,, the second a hexagonal structure of com-position close to GdH,. The system is a counterpart of the plutonium-hydrogen system.279 New borides PrB,, SmB,, GdB,, and YbB, (iso-morphous with CeB,, ThB,, and UB,) have been prepared by heating theoxide M,O, with boron and carbon at 1500-1800", and their lattice constantsmeasured.280 They are less stable than the known borides MB,. The loweroxide of samarium, SmO, has been prepared by distillation from a Sni-Sm,O,mixture at 1100-1300" in an argon atmosphere and in complete absence ofoxygen.An oxide SmOo.,-,, was also obtained, which may imply thepresence of univalent samarium. The oxide EuO is prepared under similarconditions by heating a La-Eu,O, mixture.281Reaction of hydrogen chloride with ceric oxide (in dioxan) precipi-tates orange needles of hexachloroceric acid as the dioxan complexH,CeC16,4C,H802.282 Kinetic study of the reaction between ColI1 and CeIIIions in perchloric acid indicates that a perchlorate complex of CeIII takes partin the rate-determining step CeC10,2i' + CoOH2+ ---9 CeIV + COII."~ Incontrast to the ceric sulphate-hydrogen peroxide reaction, which is fast atpH (1.4, ceric perchlorate solutions above pH 0.7 contain part of theCeIV in the form of a colloidal polymer related to the dimer [Ce-O-CeI6+;this gives a coloured complex with hydrogen peroxide which decomposesDipyridinium cerium hexachloride is sufficiently stable to be dried in aslowly.284vacuum at 120".(C,H6N)2,CeCI, + 4Bu"OH + 6NH3+ Ce(OBuU)* + 2C,H,N + 6NH,CIOn use of isopropyl alcohol, the addition compound Ce(0Pr) ,,PrOH crystal-lises.The pure isopropoxide is used as starting material for the preparation,by alcohol interchange, of alkoxides Ce(OR), where R = Me, Et, Prn, Bun,Bui, Yt-pentyl, and Yteopentyl. Only the neopentyl oxide is volatile (sublimesat 260"/0-05 mm.).285 Apart from this case, the alkoxides resemble the.277 R. N. R. Mulford and C. E. Holley, J. Phys. Chem., 1955, 59, 1222; C.E. Holley,R. N. R. Mulford, F. H. Ellinger, TV. C. Koehler, and W. H. Zachariasen, ibid., p. 1226.278 W. L. Korst and J . C. Warf, Acta Cryst., 1956, 9, 452.279 G. E. Sturdy and R. N. R. Mulford, J . Amer. Chem. Soc., 1956, 78, 1083.280 B. Post, D. Moskowitz, and F. W. Glaser, ibid., p. 1800.281 H. A. Eick, N. C. Baenziger, and L. Eyring, ibid., p. 5147.282 S. S. Moosath and M. R. A. Rao, Current Sci., 1956, 25, 14; S. S. Moosath, Pwc.283 L. H. Sutcliffe and J . R. Weber, Trans. Faraday Soc., 1956, 52, 1225.284 M. Ardon and G. Stein, J., 1956, 104.285 D. C . Bradley, A. K. Chatterjee, and IV. Wardlaw, ibid., p. 2260.It undergoes the reactionIndian Acad. Sci., 1956, 43, A , 272ADDISOX AND GREENWOOD : THE TRANSITION ELEMENTS. 113zirconium derivatives in molecular complexity, but the thorium derivativesin their lack of volatility.Of the ceric secondary alkoxides Ce(OCHMe*R),only the tetraisopropoxide is volatile (sublimes at 160-170"/0~05 mm.) .286The Titanium Group.-At -17" titanium tetraiodide is converted byclinitrogen tetroxide into the anhydrous tetranitrate Ti(NO,),. This isunstable, evolving brown fumes at 10" to give the oxynitrate TiO(NO,),.Zirconium tetraiodide reacts ~imilarly.~~7 The preparation of titanyl amidein liquid ammonia, and some of its reactions, are summarised in the followingscheme.288KSCN KNH, KNHa350" I 000"TiO(NH& + (Ti0)3N2 __t Ti0 + N2TiO(S0,) + K,[TiO(SCN),] ___) TiO(NH,), + TiO(NHKhThe thermodynamic properties of the lower chlorides of titanium havebeen studied in detail.The heats of formation of TiCl,(s) and TiCl,(s) are-172.2 & 0.7 and -123.3 kcal,/mole from measurements of heats of solu-compared with -169.1 & 0.4 and -120-1 & 0.8 kcal./mole deter-mined by direct chlorination.29o The disproportionation of titanium di-chloride has also been r e - e ~ a r n i n e d . ~ ~ ~ ~ 291 The range of molecular additioncompounds which tetrachlorides of titanium-group elements form withorganic compounds has been extended. Fusion diagrams of titanium tetra-chloride with 15 monocarboxylic esters show 1 : 1 addition compounds, ofwhich the complex TiCl,,Me*CO,Me has the highest melting point ( 145°).292Dipole moments of complexes with esters and nitriies have been recorded.2s3Zirconium and hafnium tetrachlorides give with acetonitrile a solid phaseMC1,,2MeCN together with two liquid phases of variable composition ; themaximurn separation factor of hafnium and zirconium between the twophases is Hf/Zr = 1 ~ 8 .~ ~ ~The readiness with which the alkoxy-derivatives (RO),TiCl, - , areobtained by direct reaction of alkyl orthotitanates with titanium tetra-chloride depends upon the reaction medium. Each of the compounds inwhich = 1, 2, 3, or 4 forms an addition compound (RO),TiC1,-,,C,HloNH,and in piperidine the addition compounds are sufficiently stable to be usedin separation of individual products.295 The solvolysis MCl, 4- nROH +=(RO),,MCl,-, + nHCl in methyl or ethyl alcohol is more extensive withhafnium than with zirconium t e t r a c h l ~ r i d e .~ ~ ~ The chemistry of thoriumalkoxides Th(OR), has been extended to include 12-butyl, 92-pentyl, and286 D. C. Bradley, A. K. Chatterjee, and W. Wardlaw, J . , 1956, 3469.2 8 7 V. Gutinann and H. Tannenberger, filonatsh., 1956, 87, 421.288 0. Sclimitz-Dumont and F. Fiichtenbusch, 2. al-zorg. Chem., 1956, 284, 278.289 D. G. Clifton and G. E. MacWood, J . Phys. Chem., 1956, 60, 309, 311; B. S.2Qo W. F. Krieve, S. P. Vango, and D. M. Mason, J . Chem. Phys., 1056, 25, 519;291 A3. Farber and A. J. Darnell, ibid., p. 526.i92 Yu. A. Lysenko, 0. A. Osipov, and Ye. K. Akopov, Zhur. neorg. Khim, 1956,293 0. A. Osipov, J . Geia. Chem. (U.S.S.R.), 1956, 26, 343.294 E. &I. Larsen and LaV. E. Trevorrow, J . Inovg.Nucleav Chem., 1966, 2, 254.295 A. N. Nesmeyanov, R. Kh. Freidlina, and E. M. Brainina, Bull. Acad. Sci.Sanderson and G. E. MacWood, ibid., pp. 314, 316.D. Altman, 11. Farber, and D. M. Mason, ibid., p. 531.1, 536.U.S.S.R., 1954, 861.C. R. Simmons and R. S. Hansen, J . Phys. Chem., 1955, 59, 1072114 INORGANIC CHEMISTRY.lzeopen tyl derivatives. In benzene solution they have molecular com-plexities 6-44, 6.20, and 4.01 respectively ; none will volatilise in a vacuum.285Secondary alkoxides Th(0CHEt-R),, where R = Me or Et, are also non-volatile, and polymeric in benzene.286A mono- and a tri-hydrate of zirconium tetrafluoride have been identifiedby X-ray diffraction. The monohydrate is formed at 100" from the tri-hydrate, and hydrolysis to zirconyl fluoride and zirconium oxide occurs at250°.297 An X-ray investigation of the thorium-silicon system shows theexistence of p-ThSi, (in addition to the known a-ThSi2), ThSi, and Th3Si2.All are unstable in air.298The Vanadium Group.-Dipyridyl complexes of vanadium in the oxid-ation states +1, 0, and -1 have been isolated. When the salt [V11dipy3]12is reduced with magnesium or zinc in aqueous alcohol, the neutral complexpodipy3] is formed ; it gives blue solutions not having appreciable electricalconductivity.299 Oxidation with one equivalent of iodine gives a red-violetsolution containifig the ion [Vrdipy3]-'-, and reduction of a [Vodipy,] solutionin tetrahydrofuran (THF) containing a lithium salt gives black crystals offormula Li[V-Idipy3],4THF.Representation of this as a V-1 compound issupported by its diarnagneti~m.~W The valency of vanadium in its ternarynitrides differs from that in the binary nitride VN (as with titanium, whichgives TIN, but Li,TiN,). When the compounds Li,N and VN are heatedtogether, nitrogen is evolved leaving a product of approximate compositionLi,VN,, the chemical properties of which indicate the presence of vana-dium(v) .301Spectrophotometric and potentiometric studies in perchlorate media at25" indicate that the orange-yellow vanadium(v) species present in acidsolution are relatively few. In the pH range 0.5-1.3, the cation VO,+(aq.)is the only species. In the pH range 1-3-66 the isopolyvanadate ions areH,Vlo0284-(aq.), HVlo02,5-(aq.), and Vlo02,6-(aq.), -in proportions whichdepend on pHO3O2 Niobium pentoxide dissolves (4 g./lOO ml.) in concentratedhydrochloric acid and chloro-complexes are formed.In solutions in whichhydrogen- and chloride-ion concentrations were varied, the three speciesNb(OH),Cl,-, Nb(OH)Cl,+, and Nb(OH),Cl, were identified.303 The degreeof condensation of the isopolytantalate ion has been re-examined. Diffusioncoefficients, cryoscopy, and conductivity measurements indicate that inalkaline solution the only ion present is [Ta5016-j7-(aq.), which undergoes nochange throughout the alkaline pH range. The ion is formulated from theorthotantalate ion TaO,,-, the four oxygen atoms being replaced by TaO,groups.304297 R. VCT. M. D'Eye, J. P. Burden, and E. A. Harper, J .Inorg. Nuclear Chem., 1956,2, 192.29* E. L. Jacobson, R. D. Freeman, A. G. Tharp. and A. W. Searcy, J . Amer. Chem.Soc., 1956, 78, 4850.299 S. Herzog, Naturwiss., 1956, 43, 35.300 S. Herzog and R. Taube, ibid., p. 349.301 I<. Juza and W. Gieren. ibid., p. 225.~2 I;. J. C. Rossotti and H. Rossotti, Acta Chem. Scmd., 1956, 10, 957.303 J . H. Kanzelmeyer, J. Ryan, and H. Freund, J. Amer. Chem. Soc., 1966, 78,3020 ; see also D. I. Kurbatov and N. V. Demenev, Zhur. priklad. Khim., 1966,29,944.30* G. Jander and D. Ertel, J . Inorg. Nuclear Chem., 1956, 3, 139; see also V. I.Spitsyn and N. N. Shavrova, Zhur. obshchei Khim., 1956, 26, 1268ADDlSOK AND GREENWOOD THE TRANSITION ELEMENTS. 115'I'hermal and X-ray analysis of t,he system K20-V20, shows clear evidencefor the five compounds K,0,4V20,, K20,V205, 16K20,9V205, 2K,0,V205 and3K20,V2O5, but reveals no evidence for the existence of the previouslyreported allotropic modifications of vanadium pent~xide.~, The K20-T+0,system shows four compounds K20,5T%05, K20,2Ta205, K,O,Ta,O,, and3K20,Ta,05.Tantalum pentoxide is dimorphic.306Niobium trifluoride has now been prepared by the action of an HF-H,mixture on niobium hydride (NbH,.,) at 570". It is dark-blue and can besublimed in a vacuum.3o7 The oxyfluorides Nb0,F and Ta0,F both havethe Re03 structure, with fluorine and oxygen atoms randomly distributed inoctahedral positions about the metal atom .m8 Tantalum pentaiodide canbe prepared by heating the pentoxide with the stoicheiometric quantity ofaluminium iodide for 24 hr.at 230". A similar reaction with niobiumpentoxide probably gives the pentaiodide as initial product, but only thetri-iodide is i s ~ l a b l e . ~ ~ ~The alkoxides of the vanadium-group elements differ markedly fromthose of the titanium group. The alkoxides Nb(OR), (R = Et, Pr", Run, orn-pentyl) are yellow liquids, and the methoxide is a white crystalline solidof m. p. 60". The methoxides and ethoxides of tantalum are more volatilethan those of niobium, but the reverse becomes the case for the higher~ t - a l k o ~ i d e s . ~ ~ ~ All these ?z-alkoxides are dimeric in benzene, with sexaco-ordinate niobium and tantalum atoms in the molecule. A number ofisomeric butoxides and pentyloxides of niobium have been compared ; 311there is a general increase in volatility with increased branching of the chain.In contrast to tantalum, which forms stable tertiary alkoxides,312 niobiumgives no penta-tert.-alkoxides.Its greater tendency to give oxy-complexesis shown in the formation of oxide-tert.-butoxides of the type Nb,O(OBut),and NbO(OBut),. The molecular complexity of the tantalum alkoxidesTa(OR), is influenced by the donor properties of the solvent. When R = Me,Et, Prn, or Bun the compounds are dimeric in benzene but monomeric in~ y r i d i n e . ~ ~ ~The critical potential for electrodeposition of protactinium from 10-1l~-solutions of the fluoride is -1.20 v in relation to the hydrogen electrode.The normal potential of the Pa-PaF,2- couple is near 1.0 v.Conditions foroptimum deposition on nickel, gold, and platinum cathodes, and on a leaddioxide anode, have been defined.,l*The Chromium Group and Transuranium Elements.-Nitrosyl reineckate,[Cr(NCS),(NCS*NO) (NH3)2], h'as the constitution shown and is not a305 F. Holtzberg, A. Reisman, M. Berry, and M. Berkenblit, J . Amer. Chem. Soc.,1956, 78, 1536; see also V. V. Illarionov, R. P. Ozerov, and Y . V. Kil'disheva, Zhur.ncorg. Khim., 1956, 1, 775.306 A. Reisman, F. Holtzberg, M. Berkenblit, and M. Berry, ibid., p. 4514.307 P. Ehrlich, F. Ploger, and G. Pietzka, 2. anorg. Chem., 1956, 282, 19.308 L. K. Frevel and H. W. Rinn, Acta Cryst.. 1956, 9, 626.309 M. Chaigneau, Compt. relad., 1956, 242, 263.310 I). C. Bradley, B. N. Chakravarti, and W.Wardlaw, J., 1956, 2381.311 Idem, ibid., p. 4439.312 D. C. Bradley, W. ?Yardlaw, and A. Whitley, ibid., p. 1139.313 Idem, ibid., p. 5 .314 C. Ferradini, J . Chin&. Phys., 1956,53, 714; C. Ferradini and M. Haissinsky, ibid.,p. 722116 INORGANIC CHEMISTRY.nitrosonium salt. On being warmed, its soJutions decompose to give binuclearcomplexes :- 2NO2[Cr(NCS),(NCS*N0)(NH8)J ___t [Cr(NH3),(NCS),NCSaSCN(NCS),(NH,),Cr]- (SCNIo - rCr(NHd2(NCS)31,The complexes are linked through sulphur atoms.315 The oxidation ofchromous perchlorate solutions by molecular oxygen involves primaryformation of oxygen-bridged chromic c0mplcxes.~~6Red magnesium peroxychromate, Mg,(CrO,),, 13H,O, and various doublesalts of calcium, strontium, and barium peroxychromates with alkali metalperoxychromates, e.g., Ca5K2(Cr,0,,),,19H,0 and Ca2K2(Cr20,,),7H2O havebeen described.317 The acid H,[Mo,07*0,] has been recognised in concen-trated perchloric acid solutions of molybdenum(v1) containing hydrogenperoxide.'' Perniolybdic acid " is regarded as a salt of this acid with thecation [HM0206]', which itself is not p e r ~ x i d i c . ~ ~ ~New phosphates of sexavaleiit molybdenum have been prepared bycrystallisation from solutions of molybdenum trioxide in glacial phosphoricacid. From mixtures heated at 600", crystals of composition MoO,,P2O5 ( A )and ZMoO,,P,O, (13) are obtained. From mixtures heated at NO",2Mo0,,P20,,3H,0 (C) crystallises ; (C) is inolybdenyl hydrogen phosphate(Mo02)HP0,,H20 which at 300" gives the pyrophosphate (MoO,),P,O, (23) ;( A ) is probably molybdenyl polymetaphosphate ( M O O , ) ~ + ( P O ~ - ) ~ .~ ~ ~ Froma melt of MOO, and Graham's salt (polymeric NaPO,), the compoundNa,0,2Mo03,P205, which is probably inolybdenyl sodium orthophosphate(MoO,)NaPO,, crystallises.320 Analogous tungsten compounds are formed.Unusual heteropoly-anions have been described which contain both cobaltand tungsten in the anion :oxidation H+[co~~co~Iw,zo4Js- ____) [co~~co~'Iwl,o,2]'- ----+ [COIII( W20,)J9-The first two polyanions consist of a CoII ion enclosed in a basket of twelveWO, octahedra ; the other CoT1 ion (which is less readily oxidised but readilyremoved by acid) is in a COO, octahedron outside the basket but attachedby sharing corners with WO,Ternary oxides of quadrivalent molybdenum of formula hI,Mo,O,,(M = Mg2+, Zn2', Co2+, Fe2+) are formed when appropriate oxide mixturesare heated at 1150".322 Thermogravimetric and X-ray analysis of the manystages involved in the reduction of tungsten ti-ioxide by hydrogen have beendescribed.323 The crystal chemistry of oxygen compounds of molybdenum315 F.Seel, A. Hauser, and D. Wesemann, 2. afioi'g. Chem., 1956, 283, 351.316 M. Ardon and G. Stein, J., 1956, 2095.317 J. Beltran Martinez and M. Roca Adell, Publ. Inst. Quim. Aloizso Barba, 1955,316 F. Chauveau, P. Souchay, and G. Tridot, Bull. SOC. chim. France, 1955, 1519.319 I. Schulz, 2. anorg. Chem., 1955, 281, 99.320 Idem, ibid., 1956, 284, 31.321 L. C .W. Balier and T. P. McCutcheon, J . Anzer. Chem. SOC., 1966, 78, 4503.322 R. W. Schmid and C. N. Reilley, ibid., p. 2909.323 A. J. Hegediis, T. Millner, J. Neugebauer, and K. SasvBri, 2. anorg. Chew., 1955,9, 1, 15.281, 64ADI)ISOX AND GREENWOOD : THE TRANSITION ELEMENTS. 117and tungsten having structural elements of ReO, or perovskite type hasbeen reviewed.324 When water vapour-nitrogen mixtures are passed overtungsten trioxide at lOOO", the solid removed is a linear function of the watervapour pressure ; \VO,(OH), is the volatile species.325Complex fluorides of general formula M,[MoF,] and M2DVF,] are formedby condensing molybdenum or tungsten hexafluoride on solid alkali metalfluorides (M = K, Rb, Cs). The complexesare decomposed by bromine trifluoride yielding tetrafl~orobromites.~~~Molybdenum hexafluoride can be handled in normal glass vacuum apparatusif sodium fluoride is used to remove traces of hydrogen Thethermodynamic propertes of the system Moo3-HC1 can be accounted for onthe assumption that gaseous molybdenum oxychloride, MoO,Cl,, is formedwith traces of water present.328 When chlorotungstates [WC1,]G-z arereduced by tin in hydrochloric acid, the equilibrium in solution is representedby 3W,C1,3- + C1- + 2vI',c1145-, and the compounds K,W,Cl, andK,W,Cl,, can be crystallised.The latter, a dark green solid, gives deep-redsolutions in water.329 The former, on refluxing with aniline or pyridine, givesthe non-electrolytes W,C16,(C,H5*NH,), and W,C16,(C5H5N), which have thesame spatial distribution as the parent W,C1,3- ion, i.e., two fused octahedrawith a common triangular face of chlorine ~oIIs.~~O Treatment of eitherpotassium salt with bromine vapour at 450" yields dark crystals of the mixedhalide W B r C1,.331The same uranium mixed halide UClF, is obtained by each of the re-actions UO,F,-CCl,, U0,F2-CCl,~CC1:CC12, UF4-UCl,, UF3-Cl,,and UF,-CCl,,and has been shown to be the product to which the formula UCl,F, waspreviously assigned.332 In perchlorate solution, complex formation takesplace between U0,2+ and F- ions, with the ion UO,F4,- as the upper limit.,,,More extensive information is available on the U03-H,0 system.At 180"an orthorhombic hydrate U03,0.8H,0 is stable; between 200" and 280" thephase UO,,l-OH,O appears, and the hemihydrate U0,,0.5H20 is stableabove 280".33p Solvent-extraction and spectrophotometric studies show thatenhanced extraction of uranyl nitrate into ketonic solvents in the presenceof a substituted ammonium nitrate is due to the formation of the ioniccomplex R+[UO,(NO,),]- (R = alkylammonium, alkylpyridini~m).~~~An important series of papers describe organic compounds ofuranium.sG* Twenty-seven uranium( ~ v ) dicarbonyl chelates324 A.MagnCli, J . Inorg. Nztclear Chesn., 1956, 2, 330.325 0. Glemser and H. G. Volz, Natztrwiss., 1956, 43, 33.326 B. Cox, D. W. -4. Sharp, and A. G. Sharpe, J . , 1956, 1242.327 T. A. O'Donnell, ibid., p. 4681.328 N. Hultgren and L. Brewer, J . Phys. Chem., 1956, 60, 947.329 R. A. Laudise and R.C . Young, J . Amer. Chem. SOC., 1955, 77, 5288.330 H. B. Jonassen, S. Cantor, and A. R. Tarsey, ibid., 1956, 78, 271.331 R. C. Young and R. A. Laudise, ihid., p. 4861.332 A. W. Savage, ihid., p. 2700.333 S. Ahrland, R. Larsson, and K. Rosengren, Acta Chem. Scand., 1956, 10, $05.334 J. K. Dawson, E. Wait, K. Alcock, and D. R. Chilton, J . , 1956, 3531.336 L. Kaplan, R. A. Hildebrandt, and M. Ader, J . Inorg. Nuclear Chem., 1956,2, 153.336 H. Gilman, R. G. Jones, E. Bindschadler, D. Blume, G. Karmas, G. A. Martin,J. F. Nobis, J. R. Thirtle, H. L. Yale, and F. A. Yoeinan, J . Amer. Chem. Soc., 1956, 78,2790.337 R. G. Jones, G. Karmas, and G. A. Martin, and H. Gilman, ibid., p. 4285; R. G.Sodium fluoride does not react118 INORGANIC CHEMISTRY.U(R*CO*CHCO*R1) , and fourteen uranyl compounds UO,( R*CO*CH*CO*R1),have been prepared.The former are mostly volatile but the latter are not.336Uranium diethylamide U(NEt,), is a green volatile compound, m. p. 35.5";attempts to prepare other UIv dialkylamides were unsuccessful. From thediethylamide, reaction with thiols gives Urn ethyl and n-butyl mercaptidesU(SR), as light green pyrophoric solids. The methoxide and ethoxideU(OR), are readily decomposed by moisture. A number of uranium(v)alkoxides U(OR), have also been isolated ; the ethoxide U(OEt), is thermallystable and readily distilled.%,The recent chemistry of the transuranium elements has been reviewedby H. J. Emelkus and A. G . Maddock.338 Plutonium nitrate separates asthe pentahydrate Pu(N0,),,5H20 on slow crystallisation from a concentratedsolution in nitric acid.The dilute aqueous solution is brown, changingrapidly to green as colloidal plutonium is formed.339 Plutonium nitride,PUN, is prepared from the metal and nitrogen above 230". Unlike uraniumnitride, it is completely hydrolysed in moist air in a few hours at 80-90°.340Examination of the plutonium-hydrogen system shows that in the rangePuH,-PuH2.,, hydrogen is in solid solution in the fluorite structure ofPuH,. Between PuH,,, and PuH, a hexagonal hydride phase appears.341Fuller information is now published on the preparation and properties ofplutonium hexafluoride. It may be formed in the following ways :(1) 2Pu0, + 12HF + 0, __t 2PuF, + 6H,O; (2) 2PuF, + 0, +PuF, + PuO,F,; (3) PuF, + F, _t PuF, (AmF, is not produced underthese conditions) ; (4) 2PuF3 + 3F, + 2PuF, ; and (5) Pu0, + 3F, +PuF, + 0,.The hexafluoride is a white crystalline solid, melting at 50.7"to a brown liquid. Low-temperature hydrolysis with traces of moisture givesthe oxyfluoride PuO,F,, but hydrolysis by water at room temperature is vio-lent, giving PuO, and P u F , . ~ ~ The small magnetic susceptibility of the PuF,molecule has been considered in terms of its two non-bonding electrons.343Purv in hydrochloric acid forms the complex ion P U C ~ ~ + . ~ Since separationof tervalent plutonium, americium, and curium occurs on ion-exchangecolumns in chloride solutions, chloride complex-formation has been studiedas a function of hydrochloric acid concentration.Dissociation constants ofthe monochloride complexes MC12+ are identical in dilute acid, but in strongacid the complexing powers (MC1,-) are in the order Pu >Am > Cm.The results are of interest with reference to 5f orbital h y d r i d i s a t i ~ n . ~ ~ ~Conditions have been given for quantitative deposition of ,,lArn onsteel, platinum, or copper electrodes.a6 The 248-isotope of berkeliumJones, E. Bindschadler, G. Karmas, F. A. Yoeman, and H . Gilman, J . Anzer. Chem.SOC., 1956, 78, 4287; R. G. Jones, E. Bindschadler, G. Karmas, G. A. Martin, J. R.Thirtle, F. A. Yoeman, and H. Gilman, ibid., p. 4289.338 H. J. Emel6us and A. G. Maddock, Osterr. Chem.-Ztg., 1956, 57, 153.339 J. L. Drummond and G. A.Welch, J., 1956, 2565.340 F. Brown, H. M. Ockenden, and G. A. Welch, J . , 1955, 4196.341 R. N. R. Mulford and G. E. Sturdy, J . Amer. Chem. Soc., 1956, 78, 3897.342 C. J. Mandleberg, H. K. Rae, R. Hurst, G. Long, D. Davies, and K. E. Francis,J . Inorg. Nuclear Chem., 1956, 2, 358. 368; B. Weinstock and J. G. Malm, ibid., p. 380.843 D. M. Gruen, J. G. Malm, and B. Weinstock, J . Chem. Phys., 1956, 24, 905.344 S. W. Rabideau and H. D. Cowan, J . Amer. Chem. SOC., 1955, 71, 6145.346 M. Ward and G. A. Welch, J . Inorg. Nuclear Chem., 1956, 2, 395.346 R . KO, Nucleonics, 1956, 14, No. 7, 74ADDISON AND GREENWOOD : THE TRANSITION ELEMENTS. 119(half-life 23 & 5 hr.) is formed by 25 Mev-helium-ion bombardment of24QCm ; the berkelium fraction is separated from curium, californium, andfission products by precipitation and ion e~change.3~7 The half-life of245Bk is 5 daysu8 Some nuclides were found in the debris from the 1952thermonuclear test which have not been detected in reactor irradiationproducts. These include 24eCm and 2aCf (spontaneous fission half-life< 1.2 x lo7 yr., and 55 days).a9 Neutron irradiation of plutonium hasyielded isotopes of einsteinium * (253E, 254E, 255E) and fermium * (2aFm,255Fm).350 The decay of 252Fm has been studied.351The Manganese Group.-Manganese shows univalency in its isocyanidecomplexes.Each product of the reaction2Mn12 + I2RNC [Mn(RNC),]I 4- [Mn(RNC)J2contains univalent manganese, and is diamagnetic. The monoiodide is con-verted into the tri-iodide by iodine.Complex isocyanides [Mn(RNC),]Xhave been isolated in which R = MeO*C,H,*NC, Me*C,H,*NC, C,H,-NC,$-C1*C6H4*NC and X = C103-, Cl-, Br-, OH-, PF,-, HCO,-, BF,- andBPh4-.353 The reactivity of the oxyanions MnO,-, Mn0,2-, and MnOd3-has been compared in terms of the free-energy changes involved.353Values for the electrode potentials between different valency states oftechnetium have been revised.3a Radioactive technetium almost certainlyexists in terrestrial substances in minute quantities (e.g., in uranium ores byspontaneous fission of 238U), but the search for primordial technetium hasbeen unsuccessful: The possibility of discovering primordial technetiumdepends on whether the 9 8 T ~ half-life exceeds lo8 years, and there is evidencethat it is near lo5 years.Technetium is believed not to exist in the sun.355Rhenium of high purity (> 99.95%) has been prepared by hydrolysis ofthe pentachloride, and hydrogen reduction of the hydrated rhenium dioxideso formed.356 The yellow solution obtained on reduction of the trichlorideRe,Cl, in sodium cyanide solution with sodium amalgam represents quantita-tive reduction to rhenium(1) cyanide. Potentiometric measurements indicatethat oxidation of this solution by ferricyanide proceeds in two distinct stepsRe1 + Rem and ReITr + ReV.357 Fluororhenic acid H2ReF, cannot be347 E. K. Hulet, Phys. Rev., 1956, 102, 182.348 L. B. Magnusson, A. M. Friedman, D. Engelkemeir, P. R. Fields, and F. Wagner,ibid.. p. 1097.349 P. R. Fields, M.H. Studier, H. Diamond, J. F. Mech, M. G. Inghram, G. L. Pyle,C. M. Stevens, S. Fried, W. M. Manning, A. Ghiorso, S. G. Thompson, G. H. Higgins,and G. T. Seaborg, ibid., p. 180.260 M. Jones, R. P. Schuman, J. P. Butler, G. Cowper, T. A. Eastwood, and H. G.Jackson, ibid.. p. 203.351 A. M. Friedman, J. E. Gindler, R. F. Barnes, R. Sjoblom, and P. R. Fields, ibid.,p. 585.352 A. Sacco and L. Naldini, Gazzelta, 1956, 86, 20'7.353 A. Camngton and M. C. R. Symons, J., 1956, 3373.354 G. H. Cartledge and W. T. Smith, J . Phys. Chem., 1955, 59, 1111.355 F. Daniels, ibid., 1956, 60, 705.356 D. M. Rosenbaum, R. J. Runck, and I. E. Campbell, J . Electrochem. Soc.. 1966.5 5 7 J. Meier and W. D. Treadwell, Helv. Chim. Acta, 19.55, 38, 1679.* The names einsteinium and fermium (E and Fm) for elements of atomic number 99and 100 respectively have been used in the literature, but have not yet receivedapproval from I.U.P.A.C.103, 618120 INORGANIC CHEMISTRY.isolated as a solid by evaporation of its solutions since this results in decomposi-tion to rhenium dioxide.However, many salts "a+, K+, Rb+, Cs+, NH4+,Ba2+, Ni(NH,),2+, CO(NH3)63+] containing the ReF,2- ion are now character-ised. Both the acid and its salts shows a surprising stability towards alkaliesand strongThe Iron Group.-A quadrivalent iron compound is produced by nitric acidoxidation of the complex [FeCl,(diarsine),J [FeCl,] (where diarsine = o-phenylenebisdimethylarsine). I t has the formula [FerVC12(diarsine)J [FeCl,],and a magnetic moment indicating two unpaired electrons as requiredfor FeIV with six d2sp3 bonds.In titration with iodide ions, one equi-valent of iodine is liberated.359 Iron pentacarbonyl is decomposed by nitro-gen sulphide, N,S,, in benzene solution to give a black solid Fe(NS),, andthe magnetic moment again indicates two unpaired electrons.360 The pre-paration of a range of ferrates(vI), orthoferrates(Iv), and metaferrates(1v)of alkali and alkaline-earth metals has been described.361 A new deca-hydrate FeCl,, 10H20, melting incongruently at O", has been recognisedduring phase study of the FeC1,-H20 system.362A series of nitratoaquo-nitrosylruthenium complexes, of general formula[RuNO(NO,),(OH), -g(H20)2] have been identified which further illustratethe pronounced stability of the RuN03+ complex.In aqueous solution theygive rise to both anionic and cationic ruthenium species. The trinitrato-complex [RuN0(NO3),(H2O),] is formed by the action of boiling 8x-nitricacid on nitrosylruthenium and its proton dissociation andhydrolysis has been examined.364 Hydrogen peroxide reduces rutheniumtetroxide in nitric acid to give a deep red solution containing a series ofhydroxyaquo-complexes of general formula [Ru(OH),(H,O), -J(NO,), --2.No evidence was found for the parent compound [RU(H20)6](N03)4,365Potassium fluororuthenate(II1) K,RuF, is prepared by fusing an hydrouspotassium hydrogen fluoride at 250" with ruthenium tri-iodide. Unlessoxygen is rigidly excluded, K,RuF, is formed also.366Some unusual ethylenediamine complexes of osmium ( ~ v ) have beendescribed. Ammonium hexabromo-osmate( ~ v ) , (NH,),[OsBr,], reacts exo-thermally with anhydrous ethylenediamine giving the pink sexacovalent 0sIvcomplex [Os en (en-H),I2+ (BI--)~ [(en-H) represents a molecule of ethylenedi-amine less one proton].This is readily reduced to [Os en,(en-H)]3+(Br-)3,maintaining the 0sIv valency state, and an additional molecule ofethylenediamine can be added to yield the %covalent OsIV complex[Os en2(en-H)2]Br2.365 From the Raman and infrared spectrum of liquid3 6 8 R. D. Peacock, J . , 1956, 1291; E. Weise, 2. anorg. Chem., 1956, 283, 377.359 R. S. Nyholm and R. V. Parish, Chem. and Ind., 1956, 470.360 M. Goehring and K.-W. Daum, 2. anorg. Chem., 1956, 282, 83.361 W.F. Linke, J. Phys. Chem., 1956, 60, 91.362 R. Scholder, F. Kindervater, and W. Zeiss, 2. anorg. Chem., 1056, 283, 338;363 J. M. Fletcher, I. L. Jenkins, F. M. Lever, F. S. Martin, A. R. Powell, and R.364 I. L. Jenkins and A. G. Wain, ibid., 1956, 3, 28.s65 J. S. Anderson and J . D. M. McConnell, ibid., 1955, 1, 371.366 R. D. Peacock, Chem. and Ind., 1956, 1391.367 F. P. Dwyer and J. W. Hogarth, J . Amer. Chem. SOC., 1965, 77, 6152.R. Scholder, H. von Bunsen, F. Kindervater, and W. Zeiss, ibid., 1956, 282, 268.Todd, J . Inorg. Nuclear Chem., 1955, 1, 378ADDISON AND GREENWOOD : THE TRANSITION ELEMENTS. 121osmium tetroxide it is deduced that the molecule is regular tetrahedral.Since the Raman spectra of the Re0,- and WO,,- ions are closely similar,it is concluded that these ions are also tetrahedral, and not octahedralowing to co-ordination of water molecules as previously supposed.368The Cobalt Group.-X-Ray analysis of bis-(NN-dimethy1dithiocarbamato)-nitrosylcobalt(II), [Co(S,CNMeJ,(NO)], has shown this molecule to be anexample of square pyramidal configuration in a quinqueco-ordinate complex.The cobalt atom lies 0-5 A above the plane of the four sulphur atoms (24);in this structure the lines join bonded atomsThe NO group is inclined at an angle of 135"tothe vertical axis of the pyramid, and itsbonding is therefore unusual. It may well Me2N/c\s/ \s /iiNMezbe a r-complex in which the N and 0 atomsare arranged unsymmetrically because of thedifference in their electronegativitie~.~~~ The quadrico-ordinate complex[CO~~CI,, (CH3*c6H4*NH2),] has been shown crystallographically to be planar,370and the infrared spectrum of the complex HIColIIC1,, (dimethylglyoxime),],when normal and deuterated dimethylglyoxime are used, justifies the assump-tion that -0-H-O-bonds are present in the dimethylglyoxime plane.371Outer-sphere association of the cobaltammine ions [CO(NH,),]~+ and[CO(NH,),,H,O]~+ with sulphate ions in solution, which is responsible forimmediate changes in the absorption spectrum, has been studied quanti-tatively and equilibrium constants evaluated.372 The compounds Co30, andZnCo,O, have spinel structures, and the very low paramagnetic suscepti-bility indicates that Co3+ ions are situated in octahedral interstices andcovalently bonded as in other CoIII c0mplexes.~7~The interaction of bromine trifluoride and sodium hexachlororhodate(II1)has been rein~estigated.~,~ The product, identified from its predictedX-ray powder pattern, is the complex Na,RhF6, and not Na3RhF, asoriginally thought.Some sexico-ordinate sulphitoammine complexes ofrhodium and iridium have been described in which the SO3,- ion acts as amono- or a bi-dentate ligand.374The chemistry of iridium fluorides has been re-examined and extended.Iridium hexafluoride (m. p. 44", b. p. 53") gives a deep yellow vapour stableto red heat. Its magnetic moment (3.3 B.M.) is consistent with octahedralconfiguration. When kept in glass rigorously dried, there is no evidence ofthe oxyfluoride IrOF,, thought to be formed by reaction with glass.In itsreactions, reduction to IrV frequently occurs ; thus sulphur tetrafluoride andsulphur dioxide give IrF,,SF, (which may have the ionic form SF3+JrF,-)and IrF,,SO,. Nitric oxide and gaseous dinitrogen tetroxide give thewithout indicating the bond multiplicity. NOI/s -cO - s\ass L. A. Woodward and H. L. Roberts, Trans. Faraday SOC., 1956, 52, 615.368 P. R. H. Alderman and P. G. Owston, Nature, 1956, 178, 1071.370 G. B. Bokii, T. I. Malinovskii, and A. V. Ablov, Kristallografiya, 1956, 1, 49.371 A. Nakahara, J . Fujita, and R. Tsuchida, Bull. Chem. SOC. Japan, 1956, 29, 296.s73 P. Cossee, Rec. Tvav. chim., 1956, 75, 1089.874 V. V. Lebedinskii and 2. M. Novozhenyuk, Izvest.Sekt. PZuatiny, 1955, No. 29,F. A. Posey and H. Taube, J . Amev. Chem. SOC., 1956, 78, 15.66; V. V. Lebedinslrii and Ye. V. Shenderetskaya, ibid., 1955, No. 30, 99122 INOHGANIC CHEMISTRY.nitrosonium and nitronium compounds (NO),IrF, and (NO,),IrF, ; each losesan atom of fluorine on being heated. As with osmium, no simple pentafluorideof iridium has been found. Above ZOO", iridium hexafluoride attacks glassto give the tetrafluoride (m. p. 1 0 6 O ) , which is reduced to the trifluoride byheating in an atmosphere of sulphur tetrafl~oride.,'~The Nickel Group.-In solutions 2-3 molar in alkali-metal chlorate orchloride, electrolytic reduction of Nirl to NiI is the principal process.376The small magnetic moment of the complex fluoride KNiF, has been shownto be due to antiferromagnetism; complexes of the type KMIIF, (M = Mn,Fe, Co, Ni, Cu, Zn) all have perovskite structures and are antiferr~magnetic.~~~Magnetic properties of the complexes Ni(PEt,),X, are consistent with thesquare planar structure when X = C1-, Br-, or I-, and the tetrahedralstructure when X = X-Ray investigation of bisacetylacetone-nickel(r1) shows it to be the trinuclear Ni3(C,H,0,)G with nickel atoms almostc01linea.r.~~~ The infrared spectrum of the [Ni,(cN),l4- ion shows absorptionin the C=N region only.Bridging does not therefore occur by C=N groups,and the nature of this bridging is not so well understood as was thought.It may involve bridging C-N groups using three-centre molecular orbitals.380Exchange of [14C]ethylenediamine with the [Ni enJ2+ ion occurs at a measur-able rate, whereas exchange with [Zn en,]", [Cu en2I2+, and [Hg en,]2t isimmeasurably fast .381The complexes [Pd(diarsine),X,] formed by Pdl[ salts with o-phenylene-bisdimethylarsine present an interesting range of co-ordination numbers.The colourless diperchlorate is the 4-co-ordinated [Pd(diarsine),] (C104),.When X = C1, Br, I, CNS, and NO, highly coloured compounds are obtainedwhich behave as uni-univalent electrolytes in nitrobenzene, and are 5-co-ordinated complexes of the type [Pd(diarsine),X]X.In the solid state,[Pd(diarsine),I,] has a distorted octahedral structure.382 Methods used toprepare isocyanonickel, Ni(RNC),, give diisocyanopalladiuin(0) compoundsPd(RNC), (R = phenyl, 9-tolyl, 9-anisyl) which are not analogous and areprobably polymeric.383 Bridged complexes of palladium containing thiol(e.g., alkylthiobenzoic acid) bridge groups are less reactive (i.e., the bridgingis stronger) than halogen-bridged complexes.384 Successive equilibriumconstants for replacement of rt-octylamine in the complex [PdC1,,(C8H,,NH,)Jby tributylphosphine, by use of trimethylpentane as solvent, have beenevaluated.The system is characteristic of those found useful for studyingequilibrium in water-insoluble complexes.385 The hydroxide Pd(OH),obtained by hydrolysis of sodium palladate(I1) differs from the product375 P. L. Robinson and G. J. Westland, J., 1956, 4481.376 R. H. Sanborn and E. F. Orlemann, J. Amer. Chem. Soc., 1956, 78, 4852.377 R.L. Martin, R. S. Nyholm, and N. C. Stephenson, Chem. and Ind., 1956, 83;378 R. W. Asmussen, A. Jensen, and H. Soling, Acfa Chern. Sca?zd., 1955, 9, 1391.379 G. J. Bullen, Nature, 1956, 177, 537.380 M. F. A. ElSayed and R. K. Sheline, J . Amer. Chenz. SOC., 1956, 78, 702.381 D. S. Popplewell and R. G. Wilkins, J . , 1955, 4098.382 C. M. Harris and R. S. Nyholm, J., 1956, 4375.383 L. Malatesta, Rec. Trav. chim., 1966, 75, 644.384 S. E. Livingstone, J . , 1956, 1989.3 8 5 €3. Rileddings and A . R . Bnrkin, ibid., p . 1116.see also R. W. Asmussen and H. Soling, 2. anorg. Chem., 1956, 283, 3A1)L)ISON AND GREENW001) : THE TRANSITION ELEMENTS. 123PdO,H,O resulting from the action of heat on acid palladium nitrate solution.The latter contains molecules of water within the Pd-0 lattice.366Palladium and platinum form tetrathionitrosyl compounds analogousto those of iron, cobalt, and nickel.Palladium dichloride reacts withnitrogen sulphide (N4S4) in methyl alcohol to give red-brown crystalsof Pd(NS),, m. p. 165". The platinum compound Pt(NS), (m. p. 144")is formed from chloroplatinic acid and nitrogen sulphide in hot dimethyl-formamide. Both are soluble in organic solvents but insoluble in water.387An X-ray examination of sesquiethylenediaminetrimethylplatinic iodide,Pt(CH3),J,1*5en, shows that the molecule is a dimer, the two mononuclearcomplexes being linked through a single ethylenediamine molecule, i.e.,[(CH,), en Pt-en-Pt en (CH,),]2f.388 The equilibrium between cis- andtrans-forms of (MR,),PtX, (where M = P, As, Sb, and X =halogen) inbenzene solution has been studied.The equilibrium shifts towards thetram-form when chlorine is replaced by iodine, and as the homologousseries is ascended from R = Me to Prn.389 A detailed infrared spectroscopicinvestigation of absorption due to N-H stretching modes of vibration hasbeen made, with particular reference to amine complexes of platinous~hloride.~w Development of the use of infrared spectra to determine whetherthiocyanato-groups are in bridge or terminal positions in complexes has madeit possible to re-examine the two known isomers of the compound(PPr,n),Pt,C1,(SCN),. Both isomers are now found to have SCN groups inbridging positions, so that geometric isomerism is involved, with -CN groupscis or trans to each other about the planar PtS,Pt ring.391 The course of thethermal dissociation of platinic chloride and bromide has been described.392The Copper Group.-The remarkably small distance between the twocopper atoms (2.64 A) in binuclear cupric acetate Cu,(CH,*C0,),,2H20 hasstimulated further work on the metal-metal bonding involved.The temper-ature variation of magnetic susceptibility of this and the anhydrous salthas been measured, and it is suggested that Cu-Cu bonding occurs bylateral overlap of 3dz~-yt orbitals.393 A detailed study has been made of anti-ferromagnetic resonance in hydrated cupric chloride CUC~,,~H,O.~~~ The in-frared spectrum of the ethylenediaminetetra-acetato- (edta) and diaspartato-(asp) copper complexes K,[Cu edta] and K,[Cu(asp),] indicates that allnitrogen atoms and carboxyl groups are co-ordinated to the metal, which isthus sexaco-ordinate. This is consistent with the optical activity of theformer.395 For comparison with CuCr204, the ternary chalcogenidesCuV,S,, CuCr,S,, CuCr,Se,, and CuCr,Te,, have been prepared by heating3*6 0.Glemser and G. Peuschel, 2. anorg. Chem., 1955, 281, 44.s87 E. Fluck, M. Goehring, and J. Weiss, ibid., 1956, 287, 51.388 M. R. Truter and E. G. Cox, J., 1956, 948.389 J. Chatt and R. G. Wilkins, ibid., p. 525.3g0 J. Chatt, 1;. A.. Duncanson, and L. M. Venanzi, ibid., p. 2712.391 J. Chatt and L. A. Duncanson, Nature, 1956, 178, 997.39* S. A. Shchukarev, T. A. Tolmacheva, M. A. Oranskaya, and L.V. Komandrov-skaya, Zhwv. neorg. Khim., 1956, 1, 8 ; S. A. Shchukarev, M. A. Oranskaya, and T. S.Shemyakina, ibid., p. 17.398 B. N. Figgis and R. L. Martin, I., 1956, 3837.sg4 H. J. Gerritsen,.M. Garber, and G. W. J. Drewes, Physica, 1966, 22, 213, andrefs. therein.395 S. Kirschner, , J . Anzer. Cheau. SOC., 1956, 78, 2372124 INORGANIC CHEMISTRY.the binary chalcogenides in equivalent quantities at 600-800". All crystal-lise in a normal spinel lattice.396Like the fluoroborate, silver hexafluoro-phosphate, -arsenate, -antimon-ate, -niobate, and -tantalate are soluble in benzene, toluene, and m-xylene.Evaporation of the solution gives addition complexes with the aromatichydrocarbons (e.g., AgPF,,C,H,). Copper displaces silver from the abovesilver salts in toluene, forming corresponding cuprous cornpo~nds.~97 Equi-librium constants for complex formation between the aqueous Ag+ ion andcyclic olefins indicate that the reactivity of the olefin as an electron donorin x-complex formation is a function of ring strain ; the constants are in theorder cydopentene > cycloheptene > cyclohe~ene.~~~ The silver perchlorate-dioxan compound AgC1O4,3C,H,O2 has an interesting structure.Silveratoms at the corners of a cube are surrounded by an octahedron of dioxanoxygen atoms, and the dioxan molecules rotate without hindrance.399Sulphimide silver hydrate AgNS02,H,0 exists as a trimer, and X-rayanalysis has revealed that the basic unit in the structure is a &memberedring of alternate N and S atoms.400In strongly alkaline solution, silver and argentocyanide ions react togive hydroxy-anions [Ag(OH) (CN)]-.401 The ion Ag(IO,),- has beenrecognised in solution by measurement of the solubility of silver iodate inlithium iodate solutions, by use of radioassay techniq~es.~O~ Solubility andpotentiometric methods give evidence for the complex ions Ag132-, Ag143-,and the polynuclear speciesHowever,complex-formation with o-phenylenebisdimethylarsine gives [Au(diarsine),]I,with tetrahedral configuration. Tervalent gold gives the quadricovalentcomplex [Au(diarsine),13+, but in the presence of halide ions the 5- and 6-covalent complexes [Au(diarsine),XI2+ and [Au(diarsine),X,] + have beenidentified.404 The acid HAu(CN), has been prepared as colourless crystalsby passage of a solution of its potassium salt through the €€+-form of Dowex-50 resin, followed by rapid evaporation. It loses hydrocyanic acid rapidlyat 1200.405 X-Ray analysis of gold(1) iodide indicates that the solid consistsof endless zig-zag Au-I-Au-I chains.406The Zinc Group.-Potentiometric titration of the iodides of zinc, cadmium,and mercury with potassium in liquid ammonia showed only reduction tothe metal, and no evidence for the +I oxidation state under these condi-tions.407 The melting-point of anhydrous zinc chloride, for which widelyvarying values have been reported, is 318"; the anhydrous compound wasand Ag3185-.403The co-ordination number 4 for univalent gold is unusual.396 H. Hahn, C . de Lorent, and B. Harder, 2. anorg. Chern., 1956, 283, 138.397 D. W. A. Sharp and A. G. Sharpe, J.. 1956, 1855, 1858.398 J . G. Traynham and M. F. Sehnert, J . Amer. Chenz. SOC., 1956, 78, 4024.388 R. J. Prosen and K. N. Trueblood, Acta Cryst., 1956, 9, 741.400 K. Fischer and K. R. Andress, 2. anorg. Chem., 1955, 281, 169.401 I. M. Kolthoff and J . T. Stock, J . Amer. Chem. SOC., 1956, 78, 2081.402 J. J. Renier and D. S. Martin, zbid., p. 1833.403 I. Leden, Acta Chenz. Scand., 1956, 10, 540, 812.404 C. M. Harris, R. S. Nyholm, and N. A. Stephenson, Rec. Trav. chirn., 1956, 75,405 R. A. Penneman, E. Staritzky, and L. H. Jones, J . Amer. Chem. Soc., 1956,78, 62.408 A. Weiss and A. Weiss, 2. Naturforsch., 1956, llb, 604.407 G. Mr. Watt and P. S. Gentile, J , Amer. Chem. SOC., 1965, 77, 6462.687ADDISON AND GREENWOOD : THE TRANSITION ELEMENTS. 125obtained from zinc and hydrogen chloride, and by dehydration of thehydrated salt in a stream of hydrogen chl0ride.~08 The terpyridyl complex[(terpy)ZnCl,] shows an interesting case of quinquecovalency. The latticeis molecular, the Zn atom being linked in a distorted trigonal bipyramid tothree N and two C1 atoms. The cadmium and copper compounds have thesame ~tructure.~0~ Exchange of 36Cl between zinc, cadmium, and mercurychlorides and liquid nitrosyl chloride is rapid between absorbed nitrosylchloride and the metal halides, followed by a slow heterogeneous exchangewith excess of liquid. This favours the existence of unstable nitrosoniumsalts of the metal chloride complexes. No exchange occurs between nitrosylchloride and a stable nitrosonium salt (e.g., (NO),SnC16) or sodium or potas-sium chlorides.410Cadmium dialkyls CdR, (R = Me, Et, Pri) in liquid propane at < -120"react with hydrogen sulphide giving pure cadmium hydrogen sulphideCd(HS),. Above -40" this decomposes, evolving hydrogen ~ulphide.~llPure anhydrous cadmium chloride can be prepared by the action of chlorinegas on the molten metal, and sublimation of the Formationconstants for the complexes CdI+, CdI,, CdI,-, and CdI,2- have beenevaluated.413Crystallographic studies on mercurous salts give further informationon HgHg bond lengths. In Hg2(N0,),,2H,0 the HgHg distance is2.54 0.01 A, and the close approach of a water molecule to each Hgatom [d(Hg-0) = 2.15 A] suggests the presence of an oxonium ion(H2O*Hg*Hg*OH.J2+. The Hg-Hg distance in mercuroiis fluoride is 2.43 -J=0.04 A, which falls in line with known values 2.53, 2-58, and 2.69 A for thechloride, bromide, and iodide.414 Heptasulphur imide (S,NH) reacts withmercurous nitrate giving the yellow product S,N-Hg*Hg*NS,, which darkensin air and light. Tetrasulphur tetraimide (N4S4H,) yields [HgI(NS)]z.415The compound described in the literature as mercury amidofluoride, HgNH,Fhas been shown to have the constitution (Hg,N)F,NH,F ; when Millon's baseis treated with aqueous ammonium hydrogen difluoride, the compound separ-ates during 24 hr. as a yellow powder.416 A similar compound Hg,NHBr,has a layer lattice of [Hg,(NH),] units; Br- ions are in holes in the layersand HgBr3- groups between the layers.417 Molecules of a compound HgK,have been identified in the vapour of molten potassium amalgam.418C. C . ADDISON.N. N. GREENWOOD.408 D. A. Craw and J. L. Rogers, J., 1956, 217.409 D. E. C. Corbridge and E. G. Cox, ibid., p. 594.410 J. Lewis and D. B. Sowerby, ibid., p. 150.4 l 1 U. Hauschild and 0. GIemser, Naturwiss., 1955, 42, 624.d l 3 J. L. Barton, H. Bloom, and N. E. Richards, Chew. and Ind., 1956, 439.413 M. Quintin and S. Pelletier, Compt. rend., 1956, 242, 768.414 D. GrdeniC, J . , 1956, 1312; D. Grdenib and C. DjordejeviC, ibid., p. 1316.415 M. Goehring and G. Zirker, 2. anorg. Chem., 1956, 285, 70.416 K. Brodersen and W. Rudorff, ibid., 1956, 287, 24.417 K. Brodersen, Acta Cryst., 1955, 8, 723.4 l 8 A. Roeder and W. Morawietz, 2. Elektrochem., 1956, 60, 431

ISSN:0365-6217    

DOI:10.1039/AR9565300083

出版商:RSC    

年代:1956

数据来源: RSC

摘要:

ORGANIC CHEMISTRY.1. INTRODUCTION.THE following Report on Organic Chemistry commences with a brief reviewof work published during the past two years concerning the theoreticalmethods and chemical applications of quantum organic chemistry. There-after, the theoretical section is concerned mainly with (a) the interplay ofsteric and electronic factors, including d-orbital resonance in organic com-pounds containing sulphur and phosphorus, and its effect on the reactionsof organic compounds, (b) transfer of hydride ion, (c) intermediates contain-ing bivalent carbon, (a) intramolecular rearrangements, and (e) electrophilicand nucleophilic substitution processes in the aliphatic field.Physical methods are finding ever wider application to structural prob-lems. The structure of de(oxymethy1ene)lycoctonine has been determinedby X-ray analysis and, in the steroid field, nuclear magnetic resonance hasbeen used for the first time in the structural assignment of helvolic acid.Among the more striking features of recently published work are thedetermination of the structures of methymycin, erythromycin, and magna-mycin, the synthesis of reserpine, and Isler’s industrial synthesis of 8-carotene.Complexes of aromatic hydrocarbon with metal atom or ion,especially dibenzenechromium(0) which can be sublimed and decomposesonly slowly at 300°, will intrigue all chemists. They are included in thesection on Aromatic Compounds though they are discussed in the Report onInorganic Chemistry.In the search for therapeutic agents having increased or selective activity,a great deal of interest has centred on the synthesis of modified hormones.In the terpene field, sesquiterpene lactones and complex diterpenes haveattracted much attention.The Report concludes with a brief review of the chemistry of lignins,which was last reported in 1942.Topics which it has not been possible tocover this year, such as the chemistry of proteins and stereochemistry, willbe reported in Annual Reports for 1957.G. B. rr. G. H.2. QUANTUM ORGANIC CHEMISTRY.THE function of quantum chemistry may be divided into three parts : thequantitative interpretation of physical properties of molecules, the inter-pretation of relative reactivities of related molecules, and the prediction ofabsolute rates of reaction.The third of these targets is not yet in sight, butconsiderable progress has been made towards the other two.Nearly all the work in progress in this field has been based 011 themolecular-orbital (M.O.) approximation and the assumption that 0- andx-electrons can be treated separately. Since the properties of o-bonds areadditive, most of the work has been directed to the study of x-electroDEWAK : QUANTUM ORGANIC CHEMISTRY. 127systems ; and usually some version of the L.C.A.O. (linear combiriatioii ofatomic orbitals) M.O. method has been used.The original Hiickel method involves a number of additional approxim-ations of which the use of product wave functions, the neglect of electronrepulsion, and the neglect of electron correlation have the most seriousconsequences.Moreover, the method is by its nature semi-empirical sincethe integrals involved in it cannot readily be calculated from first principles.The approximations in the Hiickel method can be overcome by usingdeterminantal wave functions (antisymmetrised M.O., A.S.M.O., method) ,by allowing explicitly for electron repulsion using the full x-electron Hamil-tonian and carrying out a self-consistent field (S.C.F.) treatment,2 and byincluding configuration interaction (C.I.). In these refined M.O. treatmentsall the integrals are clearly defined and are evaluated from first principlesby means of explicit A.O. functions (usually Slater functions).The Roothaan S.C.F. treatment is very laborious, and the further stepof including configuration interaction has proved possible only 'for verysimple molecules. Pariser and Parr pointed out that a complete C.I.treatment must give the same result no matter what set of orbitals is takenas a basis ; they therefore used simple Hiickel molecular orbitals to constructdeterrninantal wave functions, and then included configuration interaction.It is not usually possible to carry out a complete C.I.treatment; however,Pariser and Pam found very good results in many cases by including only afew of the least excited configurations. In this form the treatment iscertainly simpler than the S.C.F. method and seems on the whole to givebetter results.A further difficulty arises from the use of the orbital approximation itself,which is known to be inaccurate even for atoms.Two methods have beendevised to minimise these errors.divides the expression for the total energy of a molecule intotwo parts; the first is the energy of the component atoms widely separatedand in their appropriate valency states; the second is the energy liberatedwhen the atoms are allowed to come together to form the molecule. Thesecond is the part of major interest to chemists and is usually only a smallfraction of the total energy of the molecule; Moffitt calculates it directlyby a perturbation method. In this way the energy difference is founddirectly and so the results should be relatively insensitive to errors in thewave functions used. Moffitt describes this method as the " atoms inmolecules '' method; here the abbreviation A.I.M.will be used.The second method, due to Pariser and Parr,l is frankly semi-empirical;they adjust the values of various electron-repulsion integrals to give agree-ment with experiment. The success of their treatment is largely due to thisrefinement.Complete C.I. calculations have been reported for hydrogen cyanide 4For a summary and references see R. Pariser and K. G. Parr, J . Chew. Phi*s.,Moffitt1953, 21, 466.2 C . C . J. Roothaan, Rev. Mod. Phys., 1951, 23, 69.U'. Moffitt, PYOC. Ii03). SOC., 1951, A , 210, 216; 1953, A , 218, 4d6, i V . 3Ioffitt anctI<. Tguchi, J. Chem. Phys., 1955, 23, 1983; 1956, 25, 217.J . Scanlan, ibid., p. 464; 1953, A , 220, 530128 ORGANIC CHEMISTRY.and b~tadiene.~ The dipole moment calculated for hydrogen cyanide(2-66 D) agreed well with experiment (2-77 D).Comparisons of the S.C.F.and the C.I. method have been reported for simple diatomic systems andfor naphthalene. The inclusion of configuration interaction improvescalculations of dipole moments.8 The A.I.M. method has been found betterthan a complete S.C.F.C.I. treatment for a~etylene,~ and the inclusion ofPariser and Pads corrections to integrals improves the S.C.F. treatment ofbutadiene.lo Straightforward S.C.F. calculations have been reported forferrocene,ll various alternant hydrocarbon radicals and ions l2 (allyl,benzyl, etc.), hydrogen fluoride,13 and ammonia and the NH, and the NHradi~al.1~ Good agreement with experiment was obtained for the dipolemoment of hydrogen fluoride, the ionisation potential of hydrocarbon radi-cals, and the bond angles in the N-H compounds.The S.C.F. method hasalso been used successfully to interpret the indirect electron-coupling ofnuclear spin l5 in nuclear magnetic resonance spectroscopy, and to show thatthe negative ion-radicals obtained by single-electron addition to aromatichydrocarbons are stable to disproportionation.16 Fulvene has been syn-thesised and its dipole moment shown to agree with the value calculated bythe S.C.F. method.17 The C.I. method has been applied to acetylene,polyacetylenes, vinylacetylenes, and cumulenes,l* aromatic hydrocarbons, '9 l9quinone,20 fulvene, heptafulvene, and tropylium.21 The general basis oforbital theories, configuration interaction, etc., has been discussed byvarious authors.22 A very interesting development is the calculation ofmolecular properties directly via the densityC.M. Moser, J., 1954, 3455.R. D. Brown and A. Penfold, J . Chem. Phys., 1956, 24, 1259; cf. R. G. Parr andR. Pariser, ibid.,1955, 23, 711; Y. Haya, J . Chern. SOC. Japan, 1956, 77, 314.C . M. Moser, J . Chem. Phys., 1955, 23, 598; J . China. phys., 1955, 52, 24; C. &I.Moser and R. Lefebvre, J., 1956, 1557, 2734.M. Wolfsberg, J . Chem. Phys., 1955, 23, 793.9 J. Serre, Compt. rend., 1956, 242, 1469.lo A. Pullman and H. Berthod, ibid., 1954, 239, 812; J . Chim. phys., 1955, 52, 771.l1 Y . Yamazaki, J . Chern. Phys., 1956, 24, 1260; cf. J. D. Dunitz and L.E. Orgel,ibid., 1955, 23, 954; F. 0. Ellison and H. Shull, J . Chem. Phys., 1955, 23, 2348.l2 A. Brickstock and J. A. Pople, Tmns. Favaday SOC., 1054, 50, 901 ; N. S. Hushand J. A. Pople, ibid., 1955, 51, 600; G. Berthier, J . Chim. phys., 1955, 52, 141; H. C.Lefkovits, J. Fain, and F. A. Blatsen, J . Chem. Phys., 1955, 23, 1690; Y . Mori, ibid.,1956, 27, 1253; C. Komatsu, Y . Mori, and I. Tanaka, J . Chem. SOC. Japan, 1956,7'7, 643. f13 H. Hamano, ibid., p. 985.l4 J. Higuchi, J . Chem. Phys., 1056, 24, 535.l6 H. M. McConnell, ibid., 1955, 23, 760, 2454; 1956, 24, 460.l6 N. S. Hush and J. Blackledge, ibid., 1955, 23, 514; N. S . Hush and J . R. Row-la J. Serre, J . China. phys., 1955, 52, 331; 1956, 53, 284.lQ R. Pariser, J . Chem. Phys., 1956, 24, 250.20 M.Okuda, ibid., 1956, 25, 1083.21 A. Julg and B. Pullman, J . Chim. phys., 1955, 52, 481.22 W. E. Moffitt, J . Chem. Phys., 1954, 22, 1820; R. K. Nesbet, Proc. Roy. SOL,1955, A , 230, 312; R. Lefebvre, Compt. rend., 1965, 240, 1094; A. Laforgue, Cahiersphys., 1955, 57/58. 23; R. G. Parr, F. 0. Ellison, and P. G. Lykos, J . Chew. Phys.,1956, 24, 1106; P. G. Lykos and R. G. Pam, ibid., p. 1166.23 R. McWeeny, Proc. 2 2 0 ~ . SOL, 1955, A , 232, 114; " Electronic Structures ofBlolecules," Techn. Rep. No. 7, Massachusetts Tnst. Technology, 1955.lands, ibid., 1956, 25, 1076.J. Thiec and J. Wiemann, Bztll. SOC. chim. France, 1956, 177DEWAR : QUANTUM ORGANIC CHEMISTRY. 129These methods seem to give good results for the properties of moleculesin their ground states and a tolerable correspondence with experiment in thecase of light absorption.The A.I.M. method seems the most promising butit has not yet been used for any but the simplest molecules. The C.I. methodis the easiest for use with desk machines but rather hard to programme forcomputers. It must be admitted that calculations, by any of these methods,using desk machines are exceedingly laborious, and that there is little imme-diate prospect of using them generally for the solution of chemical problems.They may be useful in specific cases for solving structural problems in simplemolecules; for example, a comparison of the observed light absorption ofmelamine with that predicted by a C.I. treatment suggests very strongly 24that melamine is s-triaminotriazine, rather than the isomeric s-tri-imino-hexahydrotriazine, both structures being consistent with the availableexperimental evidence.In view of the difficulty of A.S.M.O.calcuIations much work has beendone by the simple Hiickel method. Calculations of this kind can be carriedout very simply z5* 26p 27 with digital computers ; so much so that it is prob-ably a waste of time to attempt such calculations for large molecules unlessone has access to a digital computer. There has been much discussion in thepast concerning the inclusion of overlap in Huckel calculations; to includeoverlap is probably pointless, since it hardly ever makes any significantdifferences in practice and its neglect is much less serious than the otherapproximations inherent in the Hiickel method.Overlap 28 can be includedif desired by a simple perturbation method,2g and simple expressions havealso been given for calculating resonance energies 3O and polarisabilities 31by contour integration.The Hiickel method has been used in two distinct ways ; either to obtaindetailed information (bond orders and lengths, charge distributions anddipole moments, self-polarisabilities and mutual polarisabilities) for speciticmolecules, or to obtain general information concerning the way some propertychanges with structure in a group of related molecules. Examples of thefirst kind are provided by calculations for various a~o-cornpounds,~~ all thepossible unsubstituted monocyclic azoles and a ~ i n e s , ~ ~ various polycyclicaromatic hydrocarbon^,^^^ 26s 34~ 35 polynuclear heterocyclic cornpounds,27~ 2980 M.J . S. Dewar and L. Paoloni, Trans. Faraday SOC., in the press.26 H. 0. Pritchard and F. H. Sumner, Proc. Roy. SOL, 1954, A , 226, 128; F. H.20 H. 0. Pritchard and F. H. Sumner, ibid., p. 457.27 H. 0. Pritchard, Proc. Roy. Sot., 1956, A , S, 136; cf. E. Bak, D. Christensen,2* Cf. I. M. Bassett and R. D. Brown, Austral. J . Chew., 1956, 9, 305, 315.D. W. Davies, Trans. Faraday Sot., 1955, 51, 449.80 C. A. Coulson, J., 1954, 3111.81 R. D. Brown, J., 1956, 767.32 B. Pullman and J. Baudel, Ccmpt. rend., 1954, 238, 2529; 0. Chalvet, itrid., 1954,38 S. Basu, Proc. Nut. Inst. Sci. India, 1955, 21, A , 173; R. D. Brown and M.L.34 B. Pullman, Cahiers Phys., 1954, 48, 42; M. A . H. Zarza, Anales Fis Qziim.,36 B. Pullman and G. Eerthier, Compt. rend., 1956, 242, 2563.Sumner, Trans. Faraday SOC., 1955, 51, 315.J. Rastrup-Andersen, and E. Tannenbaum, J . Chem. Phys., 1956, 25, 892.259, 1135.Heffernan, Austral. J . Chem., 1956, 9, 83.1955, 51, B, 305; 0. Chalvet and J. Peltier, J . Chinz. phys., 1056, 53, 402.REP.-VOL. LIII r130 ORGANIC CHELIISTKY.c o u ~ ~ ~ a r i i i , ~ ~ various porpliiiis,3i vinyl ~hloride,3~ benzoic acid,39 the nitro-a n i l i n e ~ , ~ ~ the nitro naphthalene^,^^ the benzotropones,42 and paraffins.43The properties so calculated do not agree well with experiment. Calculateddipole moments are commonly several times too large, and similar errorsappear in calculated spectra. The agreement between calculated andobserved bond lengths is tolerable but not good; 26 it must be rememberedthat an error of 0.02 A in a C-C bond length is relatively large, for the wholerange of variation from pure single to pure double bonds is only 0.2 A.Onemust conclude that calculations by the Hiickel method are of very littlequantitative value.On the other hand, the relative values for a series of related compoundsdo follow experiment, at any rate in a qualitative way; and the Huckelmethod can be very useful in such cases. One of the most striking applic-ations of this kind was described by Heilbronner andSchmid 44 who showed by a comparison of a variety ofphysical and chemical properties with those calculatedby the Hiickel method for possible isomers that thenatural terpene derivative, lactaroviolin, almost cer-tainly has the structure (I).This is the first time thatthe structure of a natural product has been indicated by the use of quantumtheory; previously a different structure had been ascribed on the basis ofthe limited chemical evidence available.A similar comparison indicates 45 that the thermochromism of dianthronyland dixanthylidene is due to thermal excitation to perpendicular tripletstates ; and similar studies have been reported of hyperconjugation 46 andof substituent effects in para-substituted aniline~.~' It has been pre-dicted 48 that cyclobutadiene, the cyclopentadiene radical, and the cationC,H, do not have a symmetrical ring.In most of the simple M.O.calculations listed above various theoreticalquantities 49 (charge distribution, free valency, localisation energy, self-polarisability) have been calculated for comparison with observed chemicalreactivity. This procedure is not strictly justifiable, since the rate of areaction is determined, not by any property of the reactants alone, but bythe difference in energy between the reactants and the transition state;nevertheless, good correlations are found between the various theoreticalquantities and rates of reaction for reasons which will be considered presently.36 I . Samuel, Compt. rend., 1955, 240, 2534.37 S. Basu, Proc. Nut. Inst. Sci. India, 1955, 21, A , 269; S. L. Matlow, J . Chew.38 J. H. Goldstein, J .Chem. Phys., 1956, 24, 507.39 T. H . Goodwin, J., 1955, 4451.40 J. I. F. Alonso and R. Domingo, Andes Fis. Quim.. 1955, 51, B, 321.4 1 G. Favini and S . Carr2, Gazzrtta, 1955, 85, 1029.4 2 T. Gaumann, R. W. Schmid, and E . Heilbronner, HeZv. Chim. A d a , 1956,39, 1985.43 G. Sandorfy, Canad. J . Chem., 1955,33, 1337.44 E. Heilbronner and R. W. Schmid, HeZv. Chim. Acta, 1954, 37, 2018.4 5 S. L. Matlow, J . Ckem. Phys., 1955, 23, 152.46 N. Muller, L. C. Pickett, and R. S . Mulliken, J . Amer. Chem. SOC., 1954, 76, 4770;4 7 J. D. Roberts and D. A. Semenov, J . Amer. Chem. SOC., 1955, '97, 31524 8 A. D. Liehr, 2. phys. Chem., 1956, 9, 338.49 Cf. R. D. Brown, Quart. Rev., 1952, 6, 63.( I )OHC qPhys., 1955, 23, 673; J. R. Barnard and L.M. Jackman, J . , 1956, 1172.Y . I'Haya, J . Chem. Phys., 1955, 23, 1165, 1171DEWAK : QUANTUM ORGANIC CHEMISTRY. 131The correlation of methyl affinities of hydrocarbons with localisation energiesis a striking example.50Since the Huckel method is so inaccurate, and the S.C.F., the C.I., andthe A.I.M. method are so difficult, attempts have been made to find some-thing in between. The S.C.P. method can be simplied 51 in the case ofalternant hydrocarbons, and this simplified treatment has been appliedsuccessfully to a large number of polynuclear aromatic hydrocarbons. 52 Apromising method has been described 53 for including electron repulsionexplicitly in the Hiickel treatment. The free-electron approximatioil(F.E.M.O.) continues to attract interest ; it has the virtues of great simplicityand a relative freedom from empirical parameters.It is, however, equiva-lent to the Huckel treatment and much less flexible; it cannot for examplebe applied rigorously to compounds other than hydrocarbons. Nearly allapplications of the F.E.M.O. method have been to the interpretation ofspectra; attempts 55a to apply it to problems of chemical reactivity are opento criticism.55b The method can however be greatly improved by inclusionof electron repulsion, which can be done by a C.I. method; 56 the resultsfor the spectra of simple hydrocarbons seem superior to those given by theS.C.F. L.C.A.O. treatment.A com-plete V.B. treatment of the nitrogen molecule gave good agreement withexperiment for the bond energy and internuclear distance ;57 and good resultswere obtained for bond energies in hydrocarbons.58 ,4 simplified versionof it has been devised.59 Various methods, including the V.B., have beenused in studies of the hydrogen bond; 6o it is now agreed that the hydrogenbond is normally unsymmetrical, although exceptional cases with sym-metrical bonds (e.g., HF,-) are known.Other work by less popular methodsincludes studies of the carbonyl group by the semilocalised orbital method,61of benzene by the alternant orbital method,62 of simple bonds by thesmoothed potential method,63 and of bond orders, charge distributions, etc.,by the standard excited state method.64 A new potential function 65 hasThe valence bond (V.B.) method has been little used recently.60 C.A. Coulson, J., 1955, 1435; M. Szwarc and F. Leavitt, J . Amer. Chew. Soc.,b2 F. A. Matsen, J . Chem. Phys., 1956, 24, 602.63 L. Goodman and H. Shull, ibid., 1955, 23, 33.64 K. Ruedenberg, ibid., 1954, 22, 1878; 1965, 23, 401; A. A. Frost, ibid., p. 310.5 5 ( a ) S. Basu, ibid., 1954, 22, 1270, 1776, 1952; 1955, 23, 1964; (b) L. S. Bartell66 S. Olszewski, Acta Phys. PoEon., 1955, 14, 419 ; N. S. Ham and K. Ruedenberg,H.-J. Bruchner, J . Chenz. Phys., 1956, 25, 367.6* W. Heitler, Helv. Chim. Acta, 1955, 38, 5.59 G. W. Wheland, J . Chem. Phys., 1955, 23, 79.80 C. A. Coulson and U. Danielsson, Arkiv Fys., 1964, 8, 239; -4. N . Baker, J . ChewPhys., 1954, 22, 1625; T . Oshida, Y . Ooshika, and R. Miyasaka, J . Phys.SOC. Japa?,,1955, 10, 849.61 J. M. Cahill and C. R. Mueller, J . Chew. Phys., 1956, 24, 513.Li2 H. Yohizumi and T. Itoh, ibid., 1955, 23, 412; J . Phys. SOC. Japan, 1955,10, 201.c3 J . R. Arnold, J . Chem. Phys., 1956, 24, 181.64 G. G. Hall, Proc. Roy. SOC., 1955, A , 229, 251 : P. P. Manning, ibid., 1955, - 4 , 230,6 6 E. R. Lippincott, J . Chew. Phys., 1955, 23, 603.1956, 78, 3590.J. A. Pople, Trans. Faraday SOC., 1953, 49, 1375.and R. A. Bonham, ibid., 1956, 24, 909.J . Chem. Phys., 1956, 24, 1, 13; H. Labhart, Helv. Chim. Ada, 1956, 39, 1320.415, 424; H. D. Deas, Phil. Mag., 1955, 46, 670132 ORGANIC CHEMISTRY,been deduced theoretically and is claimed to be superior to the Morse func-tion. The effects of hybridisation and non-orthogonality have been dis-cussed.66 The empirid rules found by Brooker for the light absorptionof cyanine dyes have been interpreted by a generalisation of the resonancetheory.67Many chemical problems are concerned, not with the absolute values ofmolecular properties, but with the manner in which they change withmolecular structure ; the effect of substituents on the properties of a moleculeforms an obvious example.In such cases the required information can becalculated directly by representing the change in structure as a perturbationand using perturbation theory.68v6Q A general treatment of the effects ofsubstituents on light absorption has been developed in this way,70 and similarmethods have been used in investigations of the Hammett relation,?I n--x*tran~itions,'~ and the spectra of cyclooctatetraene derivatives.73Similar methods can be used very effectively in studying chemicalreactivity.69 The activation energy of a reaction can be written in theform :where AEaL, AEa, AE, are the energy differences for electrons in inner shells,in localised bonds, and in multicentre molecular orbitals respectively,between the initial and the transition state. For a series of related reactionsthe first two terms are often constant if additivity of energies of localisedelectrons is assumed; the relative rates are then determined by the delocal-isation energy difference AE,, which can be found very conveniently by aperturbation method.69 The potentialities are shown by recent work onsubstitution in polycyclic aromatic hydrocarbons. 74If Wheland's model 75 for the transition state is assumed, equation (1)becomes :where Cx is a constant characteristic of the reagent X, Nt is the reactivitynumber of atom t at which substitution takes place, and p is the carbonresonance integral.N t can be found by a very simple calc~lation.~~ Thepartial rate factors for nitration at various positions in a number of hydro-carbons have been measured 74 and agree well with equation (2). PartialAE =AE,,+ AE,+ AEw . . . . . (1)AE = Cx + N$ . . . . . . . (2)66 C . A. Coulson and G. R. Lester, Tvans. Favaday SOC., 1955, 51, 1605; R. S.Mulliken, J . Chem. Phys., 1955, 23, 1833, 1841, 2338, 2343.~37 J. R. Platt, ibid., 1956, 25, 80.68 C. A. Coulson and H.C. Longuet-Higgins, Proc. Roy. SOC., 1947, A , 191, 39;1947, A , 192, 16; 1948, A , 193, 447, 456; 1948, A , 195, 188; H. C . Longuet-Higgins,J . Chew. Phys., 1950, 18, 265, 275, 283.69 M. J . S. Dewar, J . Amer. Chem. SOC., 1952, 74, 3341,3345, 3350, 3353, 3355, 3357.70 J. N. Murrell and H. C . Longuet-Higgins, Proc. Plays. Soc., 1955, 68, A , 329, 601 :J . , 1955, 2562; H. C. Longuet-Higgins, Proc. Roy. SOL, 1956, A , 235, 537.7 1 H. H. JaffC, J . Amer. Chem. SOC., 1955, 77, 274.73 L. E. Orgel, J., 1955, 121.73 K. L. McEwen and H. C . Longuet-Higgins, J . Chem. Phys., 1956, 24, 771.74 P. M. G. Bavin and M. J. S. Dewar, J., 1956, 164; M. J. S. Dewar and T. Mole,ibid., p . 1441; M . J. S. Dewar and E. W. T. Warford, ibzd., p. 3570; M.J. S. Dewar,T. Mole, D. S. Urch, and E. W. T. Warford, ibid., p . 3572; M . J . S. Dewar, T. Mole, andE. W. T. Warford, ibid., p . 3576, 3581.7 5 G. IT. Whrland, J . Amev. Chew. SOC., 2942, 64, 900DEWAR : QUANTUM ORGANIC CHEMISTRY. 133rate factors are not known for other reactions; but plots 74 of overallreactivities of hydrocarbons to other reagents against their reactivities fornitration show that chlorination 74 and free-radical methylation andtrichloromethylation 76 also follow equation (2).There is, however, an anomaly; not only is the appropriate numericalvalue of p (3-12 kcal./mole) much less than that (-20 kcal./mole) normallyascribed to the carbon resonance integral, but the value of fi also varies fromone reaction to another. This can be reasonably explained74*75p77 byassuming that the Wheland structure (IV) is not a transition state but astable intermediate, the transition state (111) lying between the initial state(11) and (IV). In that case equation (2) becomes :when Pt* is the value of the resonance integrals for the bonds between atom tand the adjacent carbons in the transition state.If the transition state hasthe same general configuration for various reactions of X, equation (2) willhold, but the a in it will be not the true resonance integral but the numericallysmaller quantity (p - p,*) ; moreover, this will vary with the reagent.Now Pt* should be numerically greater, and so (a -- pt*) numerically smaller,the more reactive the reagent; this relation holds 73* 74 in practice, and canbe used to account for the empirical rule 78 that the selectivity of sub-stituting agents is smaller the more reactive they are.The Wheland structure corresponds to Pt* = 0 : the correspondingdifference in x-energy, AEv, is then by definition the localisation energy 49 ofatom t.Consequently the localisation energy will be an effective measureof reactivity. Since similar situations probably occur generally and it hasbeen shown 69 that the localisation energy is correlated with free valency,self-polarisability, and charge density, it is clear why these quantities alsoshow correlations with r e a ~ t i v i t y . ~ ~ The perturbational transition statetreatment is of course much more powerful, since it not only providescorrelations of this kind but can also throw light on the structure of thetransition state.A similar study has been made 79 of the solvolysis of arylmethyl chlorides.The variation of rate with structure can be interpreted quantitatively bythe P.M.O.(perturbational M.O.) method. The treatment again involves aparameter whose value vanes in a predictable manner with the structure ofthe transition state; p should be smaller the greater the participation of thenucleophile. In practice, p has its maximum value (30 kcal./mole) for the7 6 E. C. Kooyman and E. Farenhorst, Tmns. Faraduy SOL, 1953, 49, 58. '' H. C. Brown and K. L. Nelson, J . Amer. Ckem. SOL, 1953, 75, 6292.7g M. J. S. Dewar and R. J. Sampson, J., 1956, 2789 and unpublished work.M. J. S.Dewar and T. Mole, in the press134 ORGANIC CHEMISTRY.limiting (pure SN1) solvolysis in moist formic acid, dropping to a minimumvalue (5 kcal./mole) for the pure S N 2 reaction with iodide ion in acetone.80No theory of reactivity can be exact at present in view of the impossi-bility of including solvent and entropy effects ; the Huckel P.M.O. methodmay therefore prove adequate in spite of its simplicity. It is possible toapply perturbation theory to the S.C.F. method ; the resulting expressions *lshould be more accurate than those in the Huckel treatment but they are ofcourse much more complicated.Radiospectroscopy, thesubject of a recent Faraday Society Discussion,s2 seems likely to prove ofmajor importance to quantum chemistry. High-resolution nuclear magneticresonance spectra and nuclear quadrupole spectra can provide informationconcerning charge distribution in conjugated 83 and para-magnetic resonance spectra of radicals can give information concerning thedistribution of the odd electrons.84 Nuclear quadrupole spectra can alsogive information concerning double-bond character.82.85 Secondly, somerecent papers seem to suggest that the delocalisation of electrons in moleculesfor which only one classical structure can be written may be much lesssignificant than has been commonly supposed. The heats of formation ofparaffins,86 the spectra of p o l y e n e ~ , ~ ~ and the effects of alkyl substituents 88have been explained on this basis. It would be unwise to ignore thispossibility simply because it clashes with current theory ; the existingquantum-theoretical treatments are by no means so well based that theirconclusions can be accepted without reserve.9.HETEROCYCLIC COMPOUNDS.Small Rings.-The synthesis of simple optically active epoxides has beenstudied; for example, (+)-styrene oxide has been obtained from (-)-mandelic acid.l An ingenious application of ethylene and propyleneoxide as proton-acceptor solvents in certain brominations prevents thedevelopment of acidity.2 Pentaerythritol has been converted into 3 : 3-disubstituted oxacy~lobutanes,~ e.g., (1). Cationic polymerisation ofoxacyclobutanes, e.g., with boron trifluoride, affords linear pol yet her^.^^ 4Ethyleneimines are fairly weak bases (pKb 5.99-5.36) ; the basic strengthsof cyclicimines increases with increasing ring size.Five-membered ringcompounds (2) tend to lose carbon dioxide when heated and react as potential12G Y . Raoul, N. Le Boulch, C. Baron, R. Bazier, and A. Guerillot-Vinet, Bull. Soc.Chim. biol., 1956, 38, 495.1 2 7 Idem, ibid., p. 885.128 D. J. Cram and N. L. Allinger, J . Amer. Chem. Soc., 1956, 78, 5275.129 H. S. Burton, E. P. Abraham, and H. M. E. Cardwell, Bioclzem. J.. 1956, 62,171.1 E. L. Eliel and D. W. Delmonte, J . Org. Chem., 1956, 21, 596.2 D. N. Kirk, D. K. Patel, and V. Petrow, J., 1956, 627, 1184.3 A. C. Farthing, J., 1956, 3648.4 J. B. Rose, J., 1956, 542, 546.5 C. E. O'Rourke, L. B. Clapp, and J. 0. Edwards, J . Amer. Chem. Soc., 1956,78,6 S. Searles, M.Tamres, F. Block, and L. A. Quarterman, ibid., p. 4917.3159WILSON : HETEROCYCLIC COMPOUNDS. 229three-membered ring compounds ; thus, ethylene carbonate (2 ; X = 0)and oxazolid-%one (2; X = NH) exhibit some of the reactions of ethyleneoxide and ethyleneimine respectively. 7 v * Oxazirines (3) have been madefor the first time; they are formed from certain azomethines and peraceticacid, contain active oxygen, and can be assayed iodornetri~ally.~Five-membered Ring Compounds.-Applications of furans and pyrans asintermediates in organic synthesis have been reviewed. lo The rapidlygrowing chemistry and biochemistry of cr-lipoic (6 : 8-thioctic) acid havebeen summarised; l1 the properties of the acid have been investigatedsystematically, and a number of derivatives described.12 Polymers obtain-able from a-lipoic acid by oxidation under certain conditions appear to belinear di~u1phides.l~ The naturally occurring acid has been related to(+)-methylglutaric acid.14 Full details of the Imperial College synthesis l5of a-lipoic acid and an unambiguous synthesis of the isomeric (&-)-5 : 8-thioctic acid l6 (4) have been published.The rates of hydrolysis of N-acyl heterocyclic compounds have beenstudied ; such compounds are involved in certain biological transacylations.l7A number of 2 : 3-dioxopyrrolidines 15) have been made.by a useful one-stepsynthesis from ethyl acrylate, ethyl oxalate, and primary amines.l* Hydro-genation of @-oxo-ester cyanohydrins, e.g., (6)y provides a new route to pyrro-lones, e.g., (7).19 N-Arylpyrroles (8) have been obtained by a new methodfrom arylhydroxylamines and dimethyl acetylenedicarboxylate.20 Im-proved yields of dihydroxyiminoalkanes are obtained from pyrroles by usinga 2 : 1 ratio of hydroxylaniine to hydrogen chloride.21 Quaternary salts(9), obtained from oxazoles and methyl toluene-9-sulphonate, are stableto acids, but with cold alkali rapidly yield a-(acyl-N-methylamino)-ketones(10) .22 The chlorination of pyrazole and several methylpyrazoles has been7 W.H. Carlson and L. H. Cretcher, J . Amer. Chem. Soc., 1947, 69, 1952.8 J. I . Jones, Chem. and Ind., 1956, 1454; S. Sonnerskog, Acta Chem. Scand., 1956,9 W. D. Emmons, J . Amer. Chem. SOC., 1956, 78, 6208.10 R. Paul, Bull. Soc. chim.France, 1956, 838; C. H. Schmidt, AnEew. Chem.. 1956.10, 467.- . ,68, 175.11 H. Grisebach, Anpew. Chem., 1956. 68, 554.1 2 A. F. Wagner; E. Walton, G:E. Boxer; M. P. Pruss, F. W. Holly, and K. Folkers,13 R. C . Thomas and L. J. Reed, ibid., p. 6148.14 K. Mislow and W. C. Meluch, ibid., pp. 2341, 5920.16 E. A. Braude, R. P. Linstead, and K. R. H. Wooldridge, J., 1956, 3074.16 A. Campbell, J . , 1955, 4218.17 H. A. Staab, Chem. HEY., 1956, 89, 1927.18 P. L. Southwick, E. P. Previc, J. Casanova, and E. H. Carlson, J . Org. Chem.,19 H. Plieninger and M. Decker, Annalen, 1956, 598, 198.20 E. H. Huntress, T. E. Lesslie, and W. M. Hearon, J . Amel.. Chem. Soc., 1956, 78,2 l S. P. Findlay, J . Org. Chem., 1956, 21, 644.22 D. G. Ott, F. N.Hayes, and V. N. Kerr, J . Amer. Chem. SOL, 1956, 78, 1941.J . Amer. Chem. SOC., 1956, 78, 5079.1956, 21, 1087.419230 ORGANIC CHEMISTRY.studied ; 23 pyrazole with chlorine in carbon tetrachloride at 0” gives the 4-chloro-compound in 55% yield; at higher temperatures, the trimer (11) isformed, whilst with chlorine water the product (12) is obtained.(10) ( 1 1 )(Ts = p-C,H,Me.SO,.)2-Carboxymethylthiodihydroglyoxaline (13) on treatment with hydro-chloric acid undergoes an interesting rearrangementJ2* probably involvingthe bicyclic intermediate (14) , and forms the thiazolidine derivative (15).0NHThe properties of Hector’s bases, obtained by oxidation of thioureas, areconsistent with the 1 : 2 : 4-thiadiazolidine formulation (16). Ammoniarearranges them to non-basic compounds, first obtained by Dost in 1906,which have been shown 2s to have the structure (17).In a careful study of0the methylation of 5-hydroxytetrazole by means of diazomethane, fourdimethyl derivatives were isolated, and the structures of three of theseestablished unequivocally.26Meso-ionic Compounds.-Sydnones are readily halogenated at position 4,for example, by aqueous hydrobromic acid-potassium br~mate.~’ Theadducts from sydnones and quinones are believed to be indazolequinones,e.g., (18).28 It was concluded that dipole moments are not reliable forQNH.;.... ON o\ MeN-Nl $ + s lN N9 1 1 I II0-co o-c-o-( 1 9 ) (20) ( 2 1 ) ( 2 2 )the diagnosis of meso-ionic structures in the tetrazole series; thus themeso-ionic compound 5-imino-1 : 3-dimethyltetrazole (19) has a smaller dipolemoment than several tetrazoles which can be given conventional covalentre23 R.Hiittel, 0. Schafer, and G. Welzel, Annalen, 1956, 598, 186.24 J. A. Van Allan, J . Org. Chem., 1956, 21, 193.26 F. Kurzer, Chem. and Ind., 1956, 526; J., 1956, 2345.46 K. Hattori, E. Lieber, and J. P. Horwitz, J . Amer. Chem. Soc., 1956, 78, 411.27 J. C. Earl, Rec. Trav. chtim., 1956,75, 1080; H. Kata, K. Nakahara, and M. Ohta,28 D. L1. Hammick and D. J . Voaden, Chem. and I n d . , 1968, 739.J . Chem. SOC. Japan, 1956, 77, 1304WILSON : HETEROCYCLIC COMPOIJNDS. 231~tructures.~~ On being heated, the ethoxycarbonyl compound (20) cyclisesto a product (21), which can also be satisfactorily formulated as the betaine(22) .m cc-Arylazothioalkanoic acids (23) have been treated with aceticanhydride and a tertiary base, to give a series of very stable 3-aryl-4-oxo-l-thia(SIV)-2 : 3-diazolines.31 The unusual structure (24) proposed for theseproducts involves a dsp2-hybridised sulphur atom ; 32 however, the altern-ative meso-ionic formulation (26) has not been convincingly disproved.N=S N- 5( 2 3 )Ph (j 0O ( 2 4 ) -O ( 2 5 )Ph PhSix-membered Ring Compounds.-Condensation of certain pyrones,e.g., (26), with tertiary aromatic amines or with diarylethylenes in phosphorusoxychloride affords pyrylium salts of types (27) and (28) respectively.=2 : 4 : 6-Triarylpyrylium salts (29) are obtainable by a new synthesis fromchalcones and ketones.= Treatment of the products with sodium sulphidein acetone gives the corresponding thiopyrylium salts.35 Hydrochloric acidconverts the oxazine (30), obtainable from a-methylstyrene, formaldehyde,and ammonium chloride, into the base (31); dehydrogenation of the latterprovides a convenient new source of 4-phen~lpyridine.~~ 2-Trifluoromethyl-pyridine3’ is obtained in 88% yield from trifluoromethyl cyanide andbutadiene at 474”.Cleavage of the ring occurs on exposure of pyridine toultrasonic vibration; in 5% aqueous silver nitrate solution, a mixture ofsilver acetylide, diacetylide, and cyanide is produced.38 A new species,believed to be a “ charge transfer complex,’’ e g . , (32), has been identifiedin solutions of N-methypyridinium iodides ; such complexes may be29 M.H. Kaufman, F. M. Emsberger, and W. S. McEwan, J . Amer. Chem. SOC.,30 A. R. Katritzky, J . , 1956, 2063.31 G. F. Duffin and J. D. Kendall, J., 1956, 3189.32 Cf. E. B. Knott, J., 1955, 918; A. Mangani and R. Passerini, Expeuientia, 1956,33 R. Wizinger, A. Grune, and E. Jacbbi, Helv. Chim. A d a , 1956, 39, 1.34 R. Wizinger, S. Losinger, and P. Ulrich, ibid., p. 5.35 R. Wizinger and P. Ulrich, ibid., p. 207.3 6 C . J. Schmidle and R. C. Mansfield, J . Amer. Chem. SOL, 1956, 78, 1702.37 J. M. S. Jarvie, W. E. Fitzgerald, and G. J. Janz, ibid., p. 978.38 L. Zechmeister and E. F. Magoon, ibid., p. 2149.39 E. M. Kosower and P. E. Klinedinst, ihid., p. 3493.1956, 78, 4197.12, 49232 ORGANIC CHEMISTRY.important in the biochemistry of , for example, diphosphopyridinen~cleotide.~~ Treatment of certain pyridine homologues with benzylalcohol and alcoholic potassium hydroxide often causes benzylation of side-chain methyl groups.This unusual reaction has been shown to involve theformation of benzaldehyde, which condenses with certain side-chain methylgroups; reduction to C-benzyl products then occurs. The conversion ofisoquinoline into its 4-benzyl derivative proceeds by a similar mechanism.4lThe ionisation constants of a large number of hydroxypyridines and relatedcompounds have been ~urveyed.~2 In general, tautomeric equilibria in a-and y-hydroxypyridines and analogous compounds favour t he lact am form.The ratio lactam : enol is 340 for 2-hydroxypyridine, and 1 x lo7 for5-hydro~yacridine.~~ Ultraviolet absorption measurements 43 indicate that2 : 4-dihydroxypyridine exists in the a-pyridone form (33).2-Amino-pyridine is obtained in small yield from pyridine and chloramine.uOHA monograph on the chemistry of dioxans has been published.45 1 : 4-Dithiins (34) fairly readily give mono- and di-substitution products withelectrophilic reagents, and readily lose one sulphur atom to yield thiophens.46The yeast pigment pulcherrimin is the chelated ferric complex of pulcherrimicacid ; new analytical and degradative evidence supports the revised structure(35) for this acid.475-Alkylamino-4 : 6-dihydroxypyrimidines have been obtained by theRemfry-Hull synthesis from a-alkylaminomalondiamides and carboxylicesters.48 Several workers have studied the synthesis of 5-hydroxypyrim-idines , including divicine (36).Persulphates introduce a 5-hydroxyl groupdirectly into the pyrimidine ring, if at least one electron-releasing substituentis present.49 In other syntheses of 5-hydroxypyrimidinesJ ethyl glycollate isconverted into the benzyl or tetrahydropyranyl ether ; C-formylation fol-lowed by condensation with guanidine and removal of the benzyl 50 or tetra-hydropyranyl51 group completes the synthesis. The methylation and thetautomeric state of several aminopyrimidines have been investigated ; pK,40 E. M. Kosower, J . Amer. Chem. SOC., 1956, 78, 3497.4 1 M. Avramoff and Y . Sprinzak, ibid., p- 4090.4 p A. Albert and J. N. Phillips, J., 1956, 1294.4 3 H.J. Den Hertog and D. J. Buurman, Rec. Trav. chim., 1956, 75, 257.44 R I . E. Brooks and B. Rudner, J . Amer. Chern. SOL, 1956, 78, 2339.4 5 W. StumDf. “ Chemie und Anwendungen des 1 : 4-Dioxans,” Verlag ChemieWeinheim, 1956. ‘46 W. E. Paxham, I. Nicholson, and V. J. Traynelis, J . Amer. Chem. SOL, 1956, 78,850 ; cf. L. H. Szmant and L. M. Alfonso, ibid., p. 1064.4 7 A. H. Cook and C. A. Slater, J . , 1956, 4130, 4133.- -4 8 D. J. Brown, J., 1956, 2312.49 R. Hull, J . , 1956, 2033.5O J. F. W. McOmie and J. €3. Chesterfield, Chem. and Ind., 1956, 1453.5 1 J. Davoll and D. H. Laney, J., 1056, 2124WILSON : HETEROCYCLIC COMPOUNDS. 233and ultraviolet and infrared measurements indicate that 2- and 4-amino-pyrimidines exist largely in the amino-form.52 The unusual reactionof sodiomalonic ester with 4 : 6-dichloro-5-nitropyrimidine to form the5-amino-compound (37) is regarded as a nucleophilic attack at C,,, withsimultaneous reduction of the nitro-group. 53 Uracil with chlorosulphonicacid gives the 5-sulphonyl chloride 54 (38). On ultraviolet irradiation 1 : 3-dimethyluracil affords a 60-75% yield of the water adduct (39), whichreverts to dimethyluracil with acids or alkalis. 55 Work on s-triazines hasbeen continued, and several simple triazines isolated ; 56* 57 2-methyltriazineis not stable to acids and alkalis, but unlike s-triazine it does not undergoring cleavage with amines. 57 Condensation of arylamine hydrochlorides anddicyandiamide or its N-methyl derivative with a carbonyl compound pro-vides a new route to 1 : 2-dihydro-s-triazines; 58 some of the products arerearranged by alkali or by heat, e.g., (40) + (41).Condensed Ring Systems.-Several penicillin analogues, e.g., (42), havebeen synthesised.59 Benzothiepin 3-dioxide has been made from S-phen-ethylthioacetyl chloride ; the sulphur-containing ring does not have aromaticproperties, and the structure (43), analogous to that of benzotropone, appears,s,I I l lMe2fN?NHR Me2fN\INHR CO-NH-CH-CH CMe2Ar.NwN HN PhO.CH2 HlC, ,N-CH*COzHQN co NHAr(43)NH2(43) (41) ( 4 2 )to be excluded.60 The ultraviolet absorption spectra of a number of aromaticaza-hydrocarbons 61 and related polynuclear systems containing a condensedthiophen, furan, or pyrrole ring 62 have been discussed; they are somewhatsimilar to those of the corresponding aromatic hydrocarbons.Spectro-scopic studies indicate that 2-aminoindole exists in the tautomeric 2-amino-indolenine form.63 Some indoles are readily converted into the 3-aldehydesby hexamine in hot acetic acid.6452 D. J. Brown, E. Hoerger, and S. F. Mason, J . , 1955, 4035.53 F. L. Rose and D. J. Brown, J., 1956, 1953.54 R. R. Herr, T. Enkoji, and T. J. Bardos, J . Amer. Chem. Soc., 1956, 78, 401.55 S. Y. Wang, M. Apicella, and B. R. Stone, ibid., p. 4180.56 C. Grundmann and E. Kober, J . Org. Chem., 1956, 21, 641.5 7 C. Grundmann and E. Kreutzberger, J . Amer. Chem. SOC., 1955, 77, 6559.5 8 E. J . Modest, J. Org. Chem., 1956, 21, 1 ; E. J. Modest and P.Levine, ibid.,p. 14.69 J. C. Sheehan and P. A. Cruickshank, J . Amer. Chem. SOC., 1956, 78, 3677, 3680,3683; H. H. Wasserman, B. Suryanarayana, R. C. Koch, and R. L. Tse, Chem. andInd., 1956, 1022.6O W. E. Truce and F. J. Lotspeich, J . Amev. Chem. SOC., 1956, 78, 848.6 1 G. M. Badger and I. S. Walker, J., 1956, 122.62 G. M. Badger and B. J. Christie, J., 1956, 3438.83 J. Kebrle and K. Hoffmann, Helv. Chim. Acta, 1956, 39, 116.64 S. Swaminathan and S. Ranganathan, Chem. and Ind., 1955, 1774234 ORGANIC CHEMISTRY.The reactions of benziminazole have been discussed from the molecular-orbital viewpoint ; electrophilic substitution occurring in acid solutioninvolves the free base, not the cation, whilst substitutions which occur atC(2) in alkaline media probably involve the benziminazole ani0n.6~ Theantifungal substance 6-methoxybenzoxazolone (44) recently isolated frommaize and wheat plants has been synthesised from 4-phenylazoresorcin01.~6Benzoxazolone itself, which also has antifungal properties, has been isolatedfrom rye seedlings6’The basic strengths and ultraviolet and infrared absorption spectra of aconsiderable number of amino-derivatives of isoquinoline, cinnoline, andquinazoline have been discussed.68 The action of alkali on 3 : 4-dihydro-isoquinolinium salts readily affords 2-acylstyrenes.69 Studies on the form-ation of hexahydropyridocolines and related iminium salts, and on the re-actions of the latter with nucleophilic reagents, have been continued.70 Anovel route to the dehydropyridocolinium ion (46) is provided 71 bydehydration of the ketone (46), obtained from 2-cyanopyridine.Severalnaphthoquinolizinium and more complex compounds (type 47) have beendescribed. 72A valuable new monograph on acridines has been published during theyear. 73 The red pigment polystictin, isolated from the wood-rotting fungusCoriolus sa’lzguineus, is identical with cinnabarin and contains a phenox-azone nucleus (48). The actinomycins have been extensively investig-ated, particularly in Brockmann’s laboratory ; 75-79 the phenoxazone65 R. D. Brown and M. L. Heffernan, J., 1956, 4288.66 P. K. Hietala and 0. Wahlroos, Acta Chem. Scand., 1956,10, 1196; A. I. Virtanen,6 7 A. I. Virtanen and P. K. Hietala, Acta Chem. Scand., 1955, 9, 1543.68 A.R. Osborn, K. Schofield, and L. N. Short, J . , 1956, 4191.69 W. Gensler, E. M. Healy, I. Onshuus, and A. L. Bluhm, J . Amer. Chem. SOC.,1956, 78, 1713.70 N. J. Leonard, R. W. Fulmer, and A. S. Hay, ibid., 1956, 78, 3457; N. J. Leonard,L. A. Miller, and P. D. Thomas, ibid., p. 3463; N. J. Leonard and A. S. Hay, ibid.,p. 1984.7 1 E. E. Glover and G. Jones, Chem. and Ind., 1956, 1456.72 C. K. Brandsher and L. E. Beavers, J . Amer. Chem. SOC., 1956, 78, 2459.73 R. M. Acheson, “The Chemistry of Heterocyclic Compounds. Vol. IX.Acridines,” Interscience Publ. Inc., New York, 1956.74 G. W. K. Cavil1 and J. R. Tetaz, Chew. and Ind., 19.56, 986; J. Grippenberg,E. Houkanen, and 0. Patoharju, ibzd., p. 1505.7 5 H. Brockmann, G.Bohnsack, and C. H. Siiling, Angew. Chem., 1956, 12, 66;H. Brockmann and H. Grone, ibid., p. 66; H. Brockmann and H. Muxfeldt, ibid.,p. 67; H. Brockmann and B. Franck, ibid., pp. 68, 70.7 6 H. Brockmann, G. Bohnsack, B. Franck, H. Grone, H. Muxfeldt, and C. Siiling,Angew. Chem., 1956, 12, 70.7 7 H. Brockmann and K. Vohwinkel, Chew&. Bey., 1956, 89, 1373; H. Brockmannand M. Muxfeldt, ibid., pp. 1379, 1397.78 Idem, Angew. Chem., 1956,12, 69.7 9 G. G. Roussos and L. C. Vining, J., 1956, 2469.P. K. Hietala, and 0. Wahlroos, Suomen Kem., 1956, 29, B, 171WILSON HETEROCYCLIC COMPOUNDS. 235structure, e.g., (49) for actinomycin C,, has been established. 76 Depeptido-actinomycip is the acridonequinone (50) and has been synthesised; 77 itsformation from actinomycins by the action of barium hydroxide is depicted.as involving an unstable intermediate (51).78I Sar:osineL-ProlineIIcoD-alloisoLeucine I IMe- CH - CH - N H -Purines and Pteridines.-Details have been published of the isolation andsynthesis of the plant-growth factor kinetin (6-furf~rylaminopurine),~~ and anumber of kinetin analogues have been synthesised.81 The structure of" 6-succinaminopurine (a-6-purinylaminosuccinic acid) (52 ; R = H),which arises in the hydrolysis of an unusual nucleotide, has been confirmedby synthesis from 2 : 6 : 8-trichloropurine; 82 the latter was condensed withaspartic acid to yield the dichloro-compound ( 5 2 ; R = Cl), which wasdechlorinated by means of phosphine and hydrogen iodide.An alternative synthesis of pteridines is provided by the acylation andcyclisation of 2-aminopyrazine-3-carbox yamides (53), which are obtainablefrom 4 : 5-diamino-3-hydroxypyrazoles (54) by condensation with a-dicarb-onyl compounds and hydrogenation of the resulting pyrazolopyrazines(55).*3' 84 The physical and chemical properties of pteridine and its simplehydroxy- and amino-derivatives have been investigated sy~tematically.8~Pteridine is a weak acid (pK, 12*2), and in dilute hydrochloric acid is hydro-lysed to 2-amino-3-formylpyrazine.s5 Spectroscopic studies indicate thatthe four monohydroxypteridines exist in the lactam form.86 2- and 6-Hydr-oxypteridine bind water strongly, it is believed by addition to the 3 : 4- and7 : %double bond respectively.86 The isolation and characterisation ofbiopterin from human urine has been de~cribed,~' and this pterin has been80 C.0. Miller, F. Skoog, F. S. Okumura, M. H. Von Saltza, and F. M. Strong,81 M. W. Bullock, J. J . Hand, and E. L. R. Stokstad, ibid., p. 3693.8 2 J. Baddiley, J. G. Buchanan, F. J. Hawker, and J. E. Stephenson, J . , 1956, 4659.83 E. C. Taylor, R. B. Garland, and C . F. Howell, J . Amer. Chem. SOC., 1956, 78, 211.84 T. S. Osdene and E. C. Taylor, ibid., p. 5451.86 A. Albert, D. J. Brown, and H. C. S. Wood, J . , 1956, 2066; A. Albert, J . 13.86 D. J. Brown and S. F. Mason, J . , 1956, 3443.87 E. L. Patterson, M. H. Von Saltza, and E. L. R. Stokstad, J . Amer. Chem. SOC.,J . Amer. Chem. Soc., 1956, 78, 1375.Lister, and C.Pedersen, J . , 1956, 4621.1956, 78, 587 1 236 ORGANIC CAEMISTRY.synthesised from 2 : 4 : 5-triamino-6-hydroxyyrimidine and 5-deoxy-~-arabinose.88 The structure assigned to urothione is partially confirmed bythe synthesis of the simple analogue (56).89and theuse of isoindolenines as intermediates for synthesis of phthalocyanines 91have been discussed. Chlorin (57) has been synthesisedg2 in 3.974, yieldPorphyrins.-Recent developments in porphyrin chemistryfrom 2-dimethylaminometh~lpyrrole and ethylmagnesium bromide ino-dichlorobenzene at 180”. Dehydrogenation of chlorin gives porphin ; 93these results are important in connection with the problem of the location ofthe two “ extra ” hydrogens in chl~rophyll.~~ The structure of vitamin B,,has been further refined by X-ray crystallographic studies,95 and more workhas been done on the related “factor 111,” which contains a 5-hydroxy-benziminazole nucleoside fragment .96Complex Cyclic Oxygen Compounds.-The condensation of phenols withcinnamic acid provides a new route t o 3 : 4-dihydro-4-phenylcoumarins.97The reaction products from phenol ethers and malonyl chloride are 4-hydr-oxycoumarins, and not indanediones as hitherto supposed.98 It has beenestablishedg9 that Dianin’s compound, first made in 1914 from phenol,mesityl oxide, and hydrogen chloride, is the phenylchroman derivative (58),and this has been confirmed by independent synthesis.100 Dianin’s com-pound forms inclusion products with a remarkable variety of substances,including iodine, organic solvents, and some inorganic gasesggThe structure of the antibiotic novobiocin (streptonivicin) (59) has been8 8 E.L. Patterson, R. Milstrey, and E. L. R. Stokstad, J . Amer. Chem. SOC,, 1956,89 R. Tschesche and G. Heuschkel, Chem. Bey., 1956, 89, 1054.90 K . Zeile, Angew. Chem., 1956, 68, 193; R. J. P. Williams, Chem. Rev., 1956, 56,9 1 F. Baumann, B. Bienert, G. Rosch, H. Vollmann, and W. Wolf, Angew. Chem.,92 U . Eisner and R. P. Linstead, J . , 1955, 3742.93 Idem, ibid., p. 3749.94 G. E. Ficken, K. B. Johns, and R. P. Linstead, J., 1956, 2272.95 D. C. Hodgkin, J. Kamper, M. Mackay, J. Pickworth, K. N. Trueblood, and J. G.White Nature 1956, 178, 64.96’C. H. ;hunk, F. M. Robinson, J. F. McPherson, M. M.Gasser, and K, Folkers,1. Amer. Chern. SOG., 1956, 78, 3228; W. Friedrich and K. Bernhauer, Angew. Chem.,78, 5868.299.1956, 88, 133.i956, 68, 439.97 J. D. Simpson and H. Stephen, J., 1956, 1382.98 J. F. Garden, N. F..Hayes, and R. H. Thomson, J., 1956, 3315.99 W. Baker, A. J. Floyd, J. F. W. McOmie, G. Pope, A. S. Weaving, and J. H. Wild,J . , 1956, 2010.100 W. Baker, J. F. W. McOmie, and A. S. Weaving, J . , 1956, 2018WILSON : HETEROCYCLIC COMPOUNDS. 237deduced in two laboratories,lOl and the degradation products cyclonovobiocicacid (60) and dihydronovobiocic acid have been synthesised. lo2There has been continued activity in the study of flavonoids and relatedcompounds ; the proceedings of the symposium held last year in Dublin havebeen pub1i~hed.l~~ The natural tannins have been reviewed.lo4 Infraredspectroscopy is a simple method for the identification of anthocyanin pig-ments, especially when only small samples (ca. 1 mg.) are available.lo5 Theultraviolet absorption characteristics of a large number of aurones have beenreported.lO6 3-Aroylcoumarones, a number of which have been synthesised,are labile to acids; they are believed to be formed as intermediate duringthe rapid resinification of 2’-methoxyisoflavones on treatment with acids.lo76 : 8-Dihydroxyflavone has been synthesised for the first time, by two groupsof workers.108 A new synthesis lo9 of flavonols of the quercetagetin seriesinvolves the introduction of the 5-hydroxyl group by treating 5-formylcompounds with alkaline hydrogen peroxide : the formyl group is introducedin the first place by means of hexamine in acetic acid.This procedure wasemployed 110 in the synthesis of oxyanin-B (61). A crystalline Zeuco-anthocyanidin isolated from wattle wood appears to be a trihydroxyflavan-3 : 4-diol,ll1 and the synthesis of flavan-3 : 4-diols, which are important asthe likely precursors of both flavonoids and anthocyanins, has been in-l01 C. H. Shunk, C. H. Stammer, E. A. Kaczka, E. Walton, C. F. Spencer, A. N.Wilson, J. W. Lichter, F. W. Holly, and K. Folkers, J . Amer. Chem. SOC., 1956, 78.1770; H. Hoeksema, E. L. Caron, and J . W. Hinman, ibid., pp. 1072, 2019.l02 C. F. Spencer, C. H. Stammer, J. 0. Rodin, E. Walton, F. W. Holly, and K.Folkers, ibid., p.2655.103 Sci. Proc. Roy. Dublin Soc., 1956, 27, 75-192.1°4 0. T. Schmidt and W. Mayer, Angew. Chem., 1956, 68, 103.105 K. C. Li and A. C. Wagenknecht, J . Amer. Chem. SOC., 1956, 78, 979.106 T. A. Geissman and J. B. Harborne, ibid., p. 832.107 W. B. Whalley and G. Lloyd, J . , 1956, 3213.108 T. H. Simpson, Chem. and Ind., 1955, 1672; J . E. Gowan, S. P. &I. Riogh,G. H. McMahon, B. R. O’Farrell, S. O’Cleirigh, E. M. Philbin, and T. S. Wheeler, ibid.,p. 1672.lo9 A. C. Jain, T. R. Seshadri, and K. R. Sreenivasan, J., 1955, 3908.110 R. N. Goel, A. C,. Jain, and T. R. Seshadri, J . , 1956, 1369.ll1 H. H. Keppler, Chem. and Ind., 1956, 380238 ORGANIC CHEMISTRY.vestigated. 112, 113 Periodic acid oxidation of melacacidin tetramet hyl ether(62) yields the benzofuran derivative (63) by ring contraction.ll* Thesulphonation of chromone derivatives has been studied ; 2 : 3-dimethyl-chromone gives the 6-sulphonic acid, and 7-hydroxyflavone and the iso-flavones give 8-sulphonic and 6 : 8-disulphonic acids.l15 The nuclearmethylation of flavonoids and the natural occurrence of the C-methylderivatives have been reviewed.n6The Wesseley-Moser rearrangement of flavonols, chromonols, andxanthones has been studied : 117 contrary to earlier reports, 5 : 8-dihydroxy-compounds can be rearranged, e.g., (64) + (65), although drastic concli-tions are often required. The structure of the hardwood extractive lapo-chenole (66) has been elucidated 118 and confirmed by synthesis.l19 Thetrimethyl ether of wedelolactone, a new product isolated from Wedeliacalenddacea, is believed 120 to have the structure (67).Details of workreported briefly last year on grevifolin,121 fuscin,122 and usnic acid 123 havenow been published. The oxidation of monohydric phenols, e.g., 9-cresol toYummerer’s ketone (68), by alkaline ferricyanide has been studied by severalworkers : 124 the first stage in the synthesis 122 of usnic acid involves a reactionof this kind. The reactions of porphyrilic acid,125 recently isolated from the112 R. Bogn&r and M. Rtikosi, Chem. and Ind., 1956, 188.113 A. B. Kulkarni and C. G. Joshi, ibid., p. 124.114 W. Bottomley, ibid., p. 170.115 D. V. Joshi, J. R. Merchant, and R. C. Shah, J . Org. Chem., 1956, 21, 1104.116 A.C. Jain and T. R. Seshadri, Quart. Rev., 1956, 10, 169.11’ D. M. Donnelly, E. M. Philbin, and T. S. Wheeler, J., 1956, 4409; E. 1L1. I’hilbin,118 R. Livingstone and M. C. Whiting, J . , 1955, 3631.119 R. Livingstone and R. B. Watson, J . , 1956, 3701.120 T. R. Govindachari, K. Nagarajan, and B. R. Pai, J . , 1956, 629.121 J. Grimshaw and R. D. Haworth, J . , 1956, 418.122 D. H. R. Barton and J . B. Hendrickson, J . , 1956, 1028.123 D. H. K. Barton, A. M. Deflorin, and 0. E. Edwards, J . , 1956, 530.124 V. Arkley, F. M. Dean, A. Robertson, and P. Sidisunthorn, J . , 1956, 2322; C. G.125 11. Erdttnan and C. A . Mrachtmeister, Chem. and Iitd., 1956, 960.J. Swirski, and T. S. Wheeler, J . , 1956, 4455.Haynes, A. H. Turner, and W. A. Waters, J., 1956, 2823SMITH ALKALOIDS. 239lichen Haematomma coccin.eum, Dicks, suggest the structure (69).Flavo-gallol, C21HS02, obtained from gallic acid by oxidation with arsenic acid-sulphuric acid is probably represented by (70) ,126 although this structurehad been considered and rejected many years ago. The constituents ofAmmi visnaga Linn. have been actively studied, and revised structuresproposed for visnagane and k h e l l a ~ t o n e . ~ ~ ~ Visamminol has formula (71) .128The synthesis of (&)-sesamin and of (j-)-asarinin has been accomplished intwo laboratories.129 w. IV.10. ALKALOIDS.A REVIEW of the recent rapid developments in the chemistry and pharmaco-logy of the Rauwolfia alkaloids and another on alkaloids related to anthra-nilic acid have been published.An article in Quarterly Reviews deals withrecent work on indole alkaloids excluding harmine and ~trychnine.~ Fulldetails have now been published of the total synthesis of lysergic acid andof m~rphine.~ Admirable work on 400 mg. of the difficultly accessiblemuscarine has led to the proposal of a probable structure (1) for the alkaloid;one point for which there is as yet no adequate explanation is the failureof the alkaloid to undergo Hofrnann degradation.6 The absolute configur-ation of s'trychnine has been established by a direct X-ray crystallographicmethod. The formation of N-2-carboxyethyl-~-apartic acid by oxidationof (+)-laudanosine leads to the absolute configuration of this and relatedtetrahydroisoquinoline, aporphine, and tetrahydroberberine alkaloids.8 Alecture largely devoted to a review and discussion of the role of biogeneticschemes in alkaloid chemistry has been p~blished.~ Tracer work on thebiogenesis of alkaloids continues : although lysine is a precursor of thepiperidine ring of anabasine, it has been shown not to be a precursor of thepyridine ring of nitotine and anabasine in the species studied.1°Tropane Group.-The total synthesis of scopolamine has been com-pleted : l1 the difficulty surmounted was the epoxidation of (a), the synthesisof which had been announced earlier.12 Interesting results have been126 J.Grimshaw and R. D. Haworth, J . , 1956, 4225.12' L. Fabrini, Ann. Chim. (Italy), 1956, 46, 130, 137; L. W. Bencze, 0. Halpern,and H.Schmidt, Experientia, 1956, 12, 137.128 W. Bencze, J. Eisenbeiss, and H. Schmidt, Helv. Chinz. Acta, 1956, 39, 923.I29 M. Beroza and M. S. Schechter, J . Amer. Chem. SOC., 1956,78, 1242; K. Freuden-berg and E. Fischer, Naturwiss., 1956, 43, 16; Chew&. Ber., 1956, 89, 1230.A. Chatterjee, S. C. Pakrashi, and G. Werner, Forfschr. Chem. org. Natz~rsfofle,1956, 13, 346.J. R. Price, ibid., p. 302.J. E. Saxton, Quart. Rev., 1956, 10, 108.E. C. Kornfeld, E. J. Fornefeld, G. B. Kline, M. J . Mann, D. E. Morrison, R. G.5 &I. Gates and G. Tschudi, ibid., p. 1380.C. H. Eugster, Helv. Chim. Acta, 1956, 39, 1002, 1023.A. F. Peerdeman, Acta Cryst., 1956, 9, 824.8 H. Corrodi and E. Hardegger, Helv. Chim. Acta, 1956, 39, 889.R. B. Woodward, Angew.Chem., 1956, 68, 13.lo E. Leete, J . Amer. Chem. SOC., 1956, 78, 3520.l 1 G. Fodor, J. T6th, I. Koczor, P. Dobo, and I. Vincze, Chem. and Ind., 1956, 764.l2 G. Fodor, J. T6th, I. Koczor, and I. Vincze, ibid., 1955, 1369.Jones, and R. B. Woodward, J . Awer. Chem. SOC., 1956, 78, 3087240 ORGANIC CHEMISTRY.obtained in connection with the stereochemistry of quaternisation of tropanederivatives : thus tropan-a-ol ethiodide has been found to be different fromN-ethylnortropan-a-ol methiodide.13 The degradation of dioscorine is pre-senting considerable difficulties ; a tentative structure (3) has been proposedfor the a1kal0id.l~+H2C-CH*NMe3H? I IMe*CH - HC, ,CH20( 1 ) ( 2 )Lupinane Group.-A second and independent synthesis of (-)-cytisinehas been achieved : l5 the vinylpyridine (4) reacted with sodiomalonic esterto give the Michael adduct, hydrogenated (Raney Ni) to the pyridocoline (5),which with concentrated hydrobromic acid, then ammonia, and finally ringclosure yielded a mixture of stereoisomeric tetrahydrocytisines (6).De-hydrogenation of the acetylated mixture, followed by hydrolysis and distill-ation, gave in low yield (&)-cystkine (7), isolated as the picrate : the basewas resolved as the (+)-camphorsulphonate. The total synthesis of(&)-lupanine (12) has been achieved l6 through a relay (lo), itself preparedfrom naturally occurring lupanine (12) : the pyridocoline derivative (8) washydrogenated to yield, by ring closure, a mixture of stereoisomers of struc-ture (9) which successively with lithium aluminium hydride, thionyl chloride,trimethylamine, and alkali gave, after chromatography, the relay (10) ; thiswas characterised as the crystalline picrate and hydriodide and was thenconverted into the opened derivative (11) by benzoyl chloride in alkali,which with hypobromite, then ethanolic hydrochloric acid, and finallylactamisation yielded (-J-)-lupanine (12).A much neater total synthesisl3 G. Fodor, K. Koczka, and J. Lestyan, J., 1956, 1411.l4 A. R. Pinder, ibid., p. 1577.l5 F. Bohlmann, A. Englisch, N. Ottawa, H. Sander, and W. Weise, Angew. Chern.,16 G. R. Clemo, K. Raper, and J. C. Seaton, J., 1956, 3390.1955, 67, 708; Chem. Ber., 1956, 89, 792SMITH Z ALKALOIDS. 241yields (&)-anagyrine (13) and (&)-thermopsine (a diastereoisomer of 13)as well as (5)-lupanine : compound (14) was condensed with 2 : 3 : 4 : 5-tetrahydropyridine to give the acid (15) which, after epimerization, wastreated with lithium aluminium hydride followed by concentrated hydro-bromic acid; quaternisation in boiling benzene then gave the salt (16),alkaline ferricyanide oxidation of which led to ( &)-anagyrine (13).Thishas already been reduced to (&)-lupanine.18 The synthetic anagyrine wasepimerized to ( f)-thermopsine by oxidation with mercuric acetate, followedby hydr0genation.1~a- and P-Diplospartyrines have been shown to have structure (17) differ-ing by the configuration at C*; the formation of these compounds finds ananalogy in the dimerisation of 2 : 3 : 4 : 5-tetrahydropyridine; l9 supportfor structure (17) comes from a rational synthesis from two sparteine oxid-ation products of known structure.**Nordehydro-cc-matrinidine (1 8) has been synthesised.21 Leontine, analkaloid of Leontice ewersnzannii Bge., has been shown to be closely relatedto matrine by reduction to (-)-matridine (19) 22 by lithium aluminiumhydride.Pyrrole and Pyridine Group.-Bellaradine has been identified withcus~ohygrine.~~ Pinidine is ( -) -cis-2-methy1-6-prop-l -enylylpiperidine ; inPinus sabiniana Dougl.it occurs with (+)-a-pipec~line.~~ Further attemptsto synthesise p-Z-piperidylpropionaldehyde, the supposed pelletierine, havefailed; 25926 a specimen of natural " pelletierine " has been shown to beidentical with isopelletierine : 25 it would seem that the aldehyde alkaloiddoes not exist.The new alkaloid, (+)-sedridine, has been shown to bel i E. E. van Tamelen and J. S . Baran, J . Amer. Chew Soc., 1956, 78, 2913.IR H. R. Ing, I . , 1933, 504.19 C. Schopf and H. L. de Waal, with K. Keller, Chem. Bey., 1956, 89, 909.2o C. Schopf and K. Keller, Naturwiss., 1956, 43, 325.21 K. Tsuda, S. Okuda, S. Saeki, S. I. Mura, Y . Sato, and H. Mishima, J . Org. Chem.,z2 T. F. Platonova and A. D. Kuzovkov, Zhur. obshchei Khim., 1956, 26, 283.23 E. Steinegger and G. Phokas, Phavm. Acta Helv., 1955, 30, 441.z4 W. H. Tallent and E. C. Homing, J . Awer. Chem. SOL, 1956, 78, 4467.25 J. P. Wibaut and M. I. Hirschel, Rec. Tvav. chinz., 1956, '95, 225.2 6 R.E. Bowman and D. D. Evans, J . , 1956, 2553.1956, 21, 598242 ORGANIC CHEMISTRY.%2'-hydro~ypropylpiperidine.~~ Two independent syntheses of ethylcarpyrinate, a dehydrogenation product of ethyl carpamate, have been29 The structure of nicotelline (20), arrived at by oxidativedegradati~n,~~ has been confirmed by an elegant synthesis.31 The structureof gentianine (21), proposed on a new analysis of available data,32 has beenconfirmed by the synthesis of dihydr~gentianine.~~Quinoline Group.-Flindersine 34 (22), dictamnine 351 35a (23 ; R = H),and y-fagarine 3 5 9 35b (23 ; R = OMe) have been synthesised.#( 2 0 )'N'0isoQuinoline Group.-A synthesis of ( &)-isothebaine ethyl ether 36finally proves the structure proposed for the alkaloid itself by Klee.37Structure (24) has been assigned to tasyine, which is thus a most interestinginstance of a " degraded " aporphine system.3s The cactus alkaloid pilo-cereine has structure (25), and is thus the first alkaloid with a C-isobutylIndole Group.-A stereospecific synthesis of (&) -yohimbane 40 has con-firmed the ~ ~ L Z ~ S - D / E ring-junction assigned by Witkop *l to yohimbine on27 H.C. Beyermann and Y . M. F. Muller, Rec. Trav. chim., 1955, 74, 1568.28 T. R. Govindachari, N. S. Narasimhan, and S. Rajadurai, Chem. and Id., 1956,53.29 H. Rapoport and E. J . Volcheck, J . Amer. Chem. Soc., 1956, 78, 2451.30 F. Kuffner and N. Faded, Monatsh., 1956, 86, 71.31 J. Thesing and A. Miiller, Angew. Chem., 1956, 68, 577.32 N.F. Proskurnina and V. V. Shpanov, Zhur. obshchei Khim., 1966, 26, 936.33 T. R. Govindachari, K. Nagarajan, and S. Rajappa, Chem. and Ind., 1956, 1017.34 R. F. C. Brown, (the late) G. K. Hughes, and E. Ritchie, Austral. J . Chern., 1956,35 M. F. Grundon and N. J . McCorkingdale, Chem. and Id., 1956, 1091.35a H. Tuppy and F. Bohm, Monatsh., 1956, 87, 720.358 Idewz, ibid.. p. 774.36 K. W. Bentley and S. F. Dyke, ibid., p. 1054.37 W. Klee, Arch. Pharm., 1914, 252, 211.38 T. F. Platonova, A. D. Kurzovkov, and Yu. N. Sheinker, Zhur. obshchei Khim.,39 C. Djerassi, S. K. Figdor, J. M. Bobbitt, and F. X. Markley, J . Amer. Chem. Soc.,40 E. E. van Tamelen and H. Shamma, ibid., 1964, 76, 950; E. E. van Tamelen,41 B. Witkop, ibid., 1949, 71, 2659.9, 277.1956, 26, 2651.1956, 78, 3861.H. Shamma, and P.E. Aldrich, ibid., p. 4628SMITH ALKALOIDS. 243the basis of the formation of trans-decahydro-2-methylisoquinoline fromchanodeoxydihydroyohimbol : traas-hexahydroindan-2-one (26) was oxidisedby perbenzoic acid to the lactone (27), which was then converted by hydro-bromic acid into the acid (28); this with tryptamine gave the lactam (29)( 2 6 ) 4converted by phosphorus oxychloride into the quaternary pentacyclic base(30), whence hydrogenation gave a high yield of pure ( &)-yohimbane. Noneof these reactions can affect the critical trans-arrangement originally presentin the hexahydroindanone. The same school announced a stereospecificsynthesis of ( &)-dihydrocorynantheane (31), whence it follows that coryn-antheine and dihydrocorynantheine have a 3 : 15 : 20-cis-trans- and coryn-antheidine a 3 : 15 : 20-cis-cis-c0nfiguration.4~ The non-stereospecific syn-thesis of ( &-)-16-methylyohimbane has been unexpectedly achieved as theresult of a most remarkable Wolff-Kishner reduction involving the con-version of the keto-acid (32) into the lactam (33).43Perhaps the most outstanding achievement in the alkaloid field this yearhas been the total synthesis of reserpine by Woodward and his co-workers 44(see chart); the starting material (34) was prepared by the addition ofmethyl penta-2 : 4-dienoate to benzoquinone; the structure of the epoxy-lactone (36) does not follow from the reaction sequence shown, but hadalready been established by a longer series of reactions ; the very remarkablefeature of this compound is that it contains all five of the asymmetric carbonatoms of ring E of reserpine, properly oriented; the conversion into (38) ofthe bromo-keto-lactone, formed by oxidation of the bromo-hydrosy-lactoneJY E.E. van Tamelen, P. E. Aldrich, and T. J. Katz, Chem. aiad Ind., 1956, 793.43 F. L. Weisenborn and H. E. Applegate, ibid., p. 2021.44 R. B. Woodward, F. E. Bader, H. Bickel, A. J. Frey, and R. W. Kierstead, ibid.,p. 2023, 2657244 ORGANIC CHEMISTRY.(37), involves hydrogenolysis both of the lactone 0-C and of the Br-C bond;the position of the carbonyl group in this product (38) is of course of criticalimportance for the success of the synthesis; the diol (39) was converteddirectly in high yield into (41) without the isolation of labile intermediatessuch as (40) ; reduction of the pentacyclic quaternary salt (42) unfortunately( 3 4 )4, O%MeOQ( 4 1 ) OMe - O M e 42) O M e( 4 3 )Reagents : I , AI(OPri),-PriOH.2, Br,-MeOH, then NaOMe. 3, N-Bromosuccinimide.4, Cr0,-AcOH, then Zn-AcOH. 5, CH2N2, then Ac,O-pyridine, then Os04-KCI0,. 6,HIO4. 7, CH,N2, then 6-methoxytryptamine, then NaBH,. 8, POCI,. 9, NaBH,.gave a derivative of isoreserpine (43); this compound was resolved to the(-)-form; the final stages involve an epimerisation at via isoreserpicacid, to isoreserpic lactone, isomerised to reserpic lactone by pivalic acid inboiling xylene, and thence converted by obvious steps into reserpine.Thesynthesis of reserpine is somewhat simplified by the observation that3-dehydroreserpine is reduced to reserpine by zinc and aqueous acid.45 Theinteresting generalisation has been made that in the yohimbine-reserpinegroup, only compounds with an axial hydrogen atom at Col are dehydro-genated by mercuric acetate to the 3-dehydro-deri~atives.~~ isoReserpineis converted into reserpine by equilibration in boiling acetic a ~ i d . ~ 6 Addi-tional evidence for the configuration assigned to the 17-methoxyl group ofreserpine has been presented ; the 17-imethoxyl group of deserpidine hasbeen shown to have the same ~rientation.~’ The Rauwolfia species continueto be the subject of intensive chemical investigation. PseudoReserpine, a45 F. L. Weisenborn and P.A. Diassi, Chem. and Ind., 1956, 2022.46 C. F. Huebner, M. E. Kuehne, B. Korzum, and E. Schlittler, Ex+evientia, 1956,4 7 c. F. Huebner and D. F. Dickez, ibid., p. 250.12, 249SMITH : ALKALOIDS. 245new alkaloid from RazczuoZJia canescens, is an ester of 3 : 4 : 5-trimethoxy-benzoic acid and methyl Pseudoreserpate ; the latter is converted by boilingacetic anhydride into methyl 17-norisoreserpate, and can thus be givenstructure (44) .48Although its structure has been known for seven years, alstyrine (45),the important product of dehydrogenation of many indole alkaloids, has onlyrecently been synthesised : 49 the final step in the synthesis was a Fischerreaction on the phenylhydrazone of 2-butyryl-4 : 5-diethylpyridine. Robin-son's structure for ajmaline has been modified to (46) both on biogeneticgrounds and on the results of the following reactions9 of deoxydihydro-ajmaline (47) : (i) oxidation to a cyclopentanone (identified by its infraredspectrum) ; (ii) oxidation to the aldehyde (48), a most interesting reaction ;OH6H& Me(51)(iii) dehydrogenation under mild conditions to ind-N-methylharman, theharman derivative (49), and the indolylmethylpyridine derivative (50).Both the last two compounds have been synthesised.mTetraphyllicine, from RauwoZJia tetraphylla, has been shown to havestructure (51) ; 51 rauvomitine, from R.vomitoria, is its 3 : 4 : 5-trimethoxy-benzoate; 51 and ajmalidine, from R. seZZozwii is probably correctly repre-sented as (52).51The work of the Zurich group on the calabash-curare alkaloids continues,but there is no major progress to report : curarine has been shown to be aC,, and not a C,, base by the formation of a rnon~methiodide.~~ Alstoniline4 8 M.W. Klohs, F.Keller, R. E. Williams, and G. W. Kusserow, Chem. and Ind.,50 R. B. Woodward, quoted in ref. 1.61 C. Djerassi, M. Gorman, S. C. Pakrashi, and R. B. Woodward, J. Amer. Chem.63 W. von Philipsborn, H. Schmid, and P. Karrer, Helv. Chim. Ada, 1956, 39, 913.1956, 187.T. B. Lee and G. A. Swan, J., 1956, 771.Soc., 1956, 78, 1259246 ORGANIC CHEMISTRY.oxide has formula (53), for alkaline degradation yields 7-methoxynorharmanand toluene-2 : 6-dicarboxylic acid.= The two products of the degradationof folicanthine have been shown to be 9-methylnorharman and l-methyl-3-2'-methylaminoethylindole : this leads to two possible structures for thealkaloid.54 Iboluteine (54) has been shown to be an indoxyl alkaloid related(54) ( 5 5 )to ibogaine (55) : the two are interconvertible.55 Gelsemine has provided asurprise, for what had been considered for some years to be an exocyclicmethylene group has now been proved to be a vinyl group by oxidation toan aldehyde containing one carbon atom less.56 This, and the demonstrationby oxidation with diethyl azodicarboxylate that the grouping *NMe*CH,* ispre~ent,~T is still the only definite information available on the aliphaticportion of the molecule.Erythrina Group.-Direct chemical proof for the presence of theerythrinan skeleton in the aromatic Erythrina alkaloids has been obtainedboth degradatively and synthetically : dihydroerysotrine (56) has beendegraded by the cyanogen bromide method to a secondary amine formulated( 5 9 )as (57) because of its oxidation to the diphenic acid (58) ; 5* two independentsyntheses of ( -J-)-hexahydroapoerysotrine (59), obtained from erysotrine intwo steps not likely to cause skeletal rearra~~gement,~~ have beenannounced.6o> 61 One of them involves a remarkable formation of the53 R.C. Elderfield and 0. L. McCurdy, J . Org. Chem., 1956, 21, 295.54 H. F. Hodson and G. F. Smith, Chem. and Ind.', 1956, 740.5 5 M. Goutarel, M.-M. Janot, F. Mathys, and V. Prelog, Helv. Chim. Acfa, 1966, 39,6 6 L. Marion and K. Sargeant, J .Amer. Chem. SOC., 1956, 78, 5127.5 7 T. Habgood and L. Marion, Canad. J . Chem., 1955, 33, 604,5* V. Prelog, B. C . McKusick, J. R. Merchant, S . Julia, and M. Wilhelm, Helv.59 M. Carmack, B. C. McKusick, and V. Prelog, ibid., 1951, 54, 1601.60 B. Belleau, Chem. and Ind., 1956, 410.6 1 A. Mondon, Angtw. Chem., 1956, 68, 578.742; cf. Ann. Reports, 1955, 52, 245.Chim. Acta, 1956, 39, 498SMITH : ALKALOIDS. 247erythrinan skeleton by the simple heating together of dimethoxyphenethyl-amine and the ethylene ketal of 2-oxocycZohexylacetic ester.61 The completestructure of erythraline (60) has been worked out by X-ray crystallo-graphy.62 This very interesting achievement confirms the results of chemicalstudy and in addition fixes the position and conformation of the aliphaticmethoxyl group.Pyrrolizidine Group.-Work in this field has been limited to the elucid-ation of structure of trichodesmic, junceic, grantianic, sceleranecic, andjaconecic acid, which has led to proposals for the structures of tricho-d e ~ m i n e , ~ ~ j ~ n c e i n e , ~ ~ grantianine,G5 sceleratine, 65* 6G j acobine, andj a ~ o n i n e .~ ~Phenanthridine Group.-This fascinating and rapidly expanding field isbeing intensively studied. As many as 16 new bases have been isolatedthis year by one group alone.68 Structures have been proposed for thefollowing fifteen bases : pseudolycorine, methyl$seudolycorine, 69 galanthine, 7oand ~ a r a n i n e , ~ ~ which are closely related to lycorine ; h ~ r n a n t h i d i n e , ~ ~which is N-demethyltazettine ; crinine 73 (61), powelline, buphanidrine, andbuphanamine, 74 all closely related ; hippeastrin, 75 neronine, clivonine,krigeine, and alboma~uline,7~ which are related to homolycorine.The finaltouches have been put to the structure of lycorine (62; K = H) : the doublebond has been finally proved to be in ring c by allylic oxidation of the mono-acetyl-lycorine (62; R = Ac) to an +unsaturated ketone.77 A convincingOH OH OHconformational analysis 78 of dihydrolycorine results in the stereochemistryof this base being represented by (63). The structure of tazettine (64) nowseems to have been satisfactorily worked out : the most fascinating chemical62 W. Nowacki and G. F. Bonsma, quoted in ref. 58.63 R.Adams and M. Gianturco, J. Amer. Chem. SOC., 1956, 78, 1922.64 Idem, ibid., p. 1926.6 5 Idem, ibid., p. 4458.6 8 H. L. de Waal and B. L. van Duuren, ibid., p. 4464.6 7 R. B. Bradbury and J. B. Willis, Austral. J. Chem., 1956, 9, 258.68 H.-G. Boit, Chem. Ber., 1956, 89, 1129; H.-G. Boit and H. Ehmke, ibid., p. 163;H.-G. Boit and W. Dopke, ibid., p. 3462.69 H. M. Fales, L. D. Giuffrida, and W. C. Wildman, J. Amer. Chem. Soc., 1956, 78,4145.70 H. M. Fales and W. C. Wildman, ibid., p. 4151.7l E. W. Warnhoff and W. C. Wildman, Chem. and Ind., 1956, 348.72 H.-G. Boit and W. Stender, Chem. Ber., 1956,89,161; W. C. Wildman, Chenz. and73 W. C. Wildman, J. Amer. Chem. SOC., 1956, 78, 4180.74 Idem, Chem. and Ind., 1956, 1090.7 5 H.-G. Boit and H.Ehmke, Chem. Ber., 1956, 89, 2093.7 6 C. K. Briggs, P. F. Highet, R. J . Highet, and W. C. Wildman, J. Amer. Chern.7 7 Y. Nakagawa, S. Uyeo, and H. Yajima, Chem. and Ind., 1956, 1238.Ind., 1956, 123.SOC., 1956, 78, 2899.K. Takeda and K. Kotera, ibid., 347248 ORGANIC CHEMISTRY.transformations have come to light in the rationalisation of the degradationsequences.79% 8o For example, there is the methylation of tazettine (64)under alkaline conditions, which leads to (69) : 79 tazettine is visualised asbeing in eqnilibrium with (65) by a series of prototropic changes; methyl-ation of (65) and a prototropic shift lead to (66), which ring-opens to (67), ismethylated to (659, which loses trimethylamine with migration of the acetylOMeOMe 8 L O( 6 9 )H- \-0 (70)OMeNMe2FH2F05)-CH2group to give (69).On the other hand, if tazettine methohydroxide isprepared by the action of silver oxide on the methiodide, the reactionproceeds through (70) to give tazettine methine (71)1 : 2-Benzophenanthridine Group.-The first synthesis in this group,that of chelerythrine chloride, has been achieved. 81Diterpene Group.-Structures assigned earlier to atisine and isoatisinehave received further support from oxidative studies and partial synthesis.82Pyrolysis of diacetylatisine under mild conditions has been found to lead toa volatile fragment from which acetaldehyde 9-nitrophenylhydrazone isformed : the reaction is represented as a concerted cyclic elimination,(72) + (73).s3 The most striking result in this field has been the X-raycrystallographic determination 84 of the structure of de(oxymethy1ene)-lycoctonine (74) : lycoctonine itself is thus represented by (75), which hasbeen found to account for the known reactions of the alkaloid.85 A struc-tural relation between lycoctonine and the diterpenoid atisine group hasbeen pointed out; 86* 87 this relation, not obvious in (74), is brought out in79 K.Wiesner and 2. Valenta, Chem. and Ind., 1956, R 36.T. Ikeda, W. I. Taylor, Y. Tsuda, and S. Uyeo, zbid., p. 411; T. Ikeda, W. I.Taylor, Y . Tsuda, S. Uyeo, and H. Yajima, J., 1956, 4749.81 A. S. Bailey and C. R. Worthing, J . , 1956, 4535.82 S. W. Pelletier and W. A. Jacobs, J . Amer. Chem. SOC., 1956, 7'8, 4139, 4144.83 D. Dvornik and 0.E. Edwards, Chem. and Ind., 1956, 248.84 M. Przybylska and L. Marion, Canad. J . Chem., 1956, 34, 185.85 0. E. Edwards, L. Marion, and D. K. R. Stewart, ibid., p. 1315.R. C. Cookson and M. E. Trevett, J . , 1956, 3121.Z . Valenta and I<. WieLner, Chenz. and Ind., 1956, 354SMITH ALKALOIDS. 249(75). With (75) for lycoctonine as a basis, structure (76) has been proposedfor delpheline ; 8 6 s 88 this structure rationalises the reactions of the alkaloidincluding a very interesting oxidative degradation sequence. A study ofthe reactions of delphinine has shown that they cannot be rationalised interms of either a lycoctonine or an atisine skeleton, and, as the result of avery bold analysis of available data, structure (77) has been proposed for thealkaloid.89 Independent work on delphinine has led to the conclusion thatit must contain system (78) : Rapid this is in conflict with structure (77).( 7 2 ) (73)OAc OAcEtYO-H ..OMeOMe MeO'< 75)(74) OH OH HOsH2; OMe(76)progress is being made in the elucidation of the structure of annotinine byWiesner, Valenta, and their co-workers. That the position is still fluid isobvious from the fact that as many as three different tentative structureshave been proposed this year,g1 the latest being (79) with the carbon marked *attached to position 1, 2, or 3 (2 being preferred). A very important oxid-ation product (80), containing all but two of the carbon atoms of the alkaloid,has been synthesised as the r a ~ e m a t e .~ ~ If partial structure (79) is correct,then the substance (80) must be the product of an obscure rearrangement, forthe ring carrying the epoxide group must be broken and somehow rebuiltwith the -CHMe*CH,- bridge.Morphine Group.-The first conversion of a morphine derivative, dihydro-codeinone, into thebaine has been acc~mplished.~~ With the total synthesisof codeine and the conversion of thebaine into neopine,94 this constitutes a88 R. C. Cookson and M. E. Trevett, J., 1956, 2689, 3864.89 W. A. Jacobs and S. W. Pelletier, J . Amer. Chem. Soc., 1956, 78, 3542.90 W. Schneider, Chern. Ber., 1956, 89, 768.91 2. Valenta, F. W. Stonner, C. Bankiewicz, and K. Wiesner, J . Amer. Chem. SOC.,1956,7$, 2867; K. Wiesner, 2. Valenta, and C. Bankiewicz, Chem.and Ind., 1956, R 41;K. Wiesner, 2. Valenta, W. A. Ayer, and C. Bankiewicz, ibid., p. 1019.9a 2. Valenta, K. Wiesner, C. Bankiewicz, D. R. Henderson, and J . S. Little, ibid.,p. ~ 4 0 .93 H. Rapport, H. N. Reist, and C . H. Lovell, J . Amer. Chem. Soc., 1956,78, 8128.s4 H. Conroy, ibid., 1955, 77, 5960250 ORGANIC CHEMISTKY.formal total synthesis of the last two bases. Thermal decomposition ofnon-phenolic methine N-oxides in this group has been found to be a valuablealternative to Hofmann degradation : the olefin and NN-dimethylhydroxyl-amine are produced.95 An ingenious biogenetic scheme has been proposedto account for the formation of morphine alkaloids directly from a benzyl-isoquinoline alkaloids precur~or.~~ With the observation that all morphinealkaloids with an ether bridge to position 5 carry no oxygen function atposition 7, the suggestion has been made that ether-bridge formation involvesan allylic expulsion of an oxygen group a t position 7 ; in vitro analogies arepre~ented.~' This has been discussed further by different workers, and acyclopropanone intermediate is considered to be a possible alternative toallylic expulsion .98G.F. S.11. SUGARS.General Methods.-Some advantages are obtained by using glass-fibresheets instead of filter paper for the ionophoresis of carbohydrates in boratebuffer. Non-reducing compounds are more readily detected and the greaterelectro-endosmotic flow facilitates the separation of sugars of similar absolutemobilities. 1All of a number of aldohexoses gave, after being heated with aqueoussulphuric acid, the same final, stable ultraviolet spectrum.The ultravioletabsorption is mainly due to ether-soluble compounds which from D-glucose,D-mannose, and D-galactose were found to be formaldehyde, acetaldehyde,propaldehyde, 5-hydroxymethylfurfuraldehyde, and an unidentified com-pound.2 Similar studies with the four aldopentoses showed an identicalultraviolet spectrum from all of them : the ether-soluble products includedformaldehyde, acetaldehyde, and crotonaldehyde as well as f~rfuraldehyde.~Epimerization as a method for preparing methyl ethers of rarer sugarshaving C(2) substituted is illustrated by the preparation of 2 : 4 : 6-tri-O-methyl-D-mannose by treatment of the glucose epimer with dilute aqueousbarium hydr~xide.~Reduction of aldonolactones to the polyhydric alcohols may be carriedout by using sodium borohydride in aqueous or ethanolic solution^.^Whereas reduction of acetobromoglucose with zinc dust gives n-glucal, useof a palladium catalyst in the presence of a tertiary amine gives 1 : 5-anhydro-n-sorbitol, identical with the naturally occurring polygalitol.Hydrogeno-lysis of methyl p-L-arabopyranoside at 240"/250 atm. for about six hours inpresence of copper chromite yields mainly optically inactive forms of tetra-9 5 K. W. Bentley, J. C. Ball, and J. P. Ringe, J., 1956, 1963.96 T. Cohen, Chem. and Ind., 1956, 1391.9 7 K. W. Bentley, Experientia, 1956, 12, 251.M. Gates and G. M. K. Hughes, Chem.and Ind., 1956, 1506.1 E. J. Bourne, A. B. Foster, and P. M. Grant, J . , 1956, 4311.F. A. H. Rice and L. Fishbein, J . Amer. Chem. Soc., 1956, 78, 3731Idem, ibid., p. 1005.J N. Prentice, L. S. Cuendet, and F. Smith, ibid., p. 4439.5 H. L. Frush and H. S. Isbell, ibid., p. 2844.1,. Zervas and C. Zioudrou, J . , 1956, 214HONEYMAN : SUGARS. 25 1hydrodihydroxypyrans (1 and 2), together with 5-methoxypentane-1 : 2-and -2 : 3-dio1, and 1-methoxypentane-2 : 3-di01.~The degradation of sugars through the mercaptals and their oxidationproducts 899 has been further investigated. Oxidation of pentose mercaptalswith peroxypropionic acid in acetone or ether yields 5 : 5-dialkylsulphonyl-pent-4-ene-1 : 2 : 3-triols, which are converted by alkali into dialkyl-sulphonylmethane and aldotetrose.lo This provides a method for preparingD-erythrose from D-arabinose, alternative to the periodate oxidation of4 : 6-O-ethylidene-~-glucose.~~ Oxidation of the diethyl dithioacetals ofn-galactose and D-glucose with aqueous peroxypropionic acid gives, respec-tively, D-hb-2 : 6-epoxy-1 : 1-diethylsulphonyl-3 : 4 : 5-trihydroxyhexane(3) and the D-manno-analogue. When treated similarlyD-mannose diethyl dithioacetal gives the same compoundas D-glucose but, in addition, 1 : l-diethylsulphonyl-and Falk l3 obtained the analogous acyclic compoundby treating D-galactose diethyl dithioacetal withammonium molybdate and hydrogen peroxide but did not find the abovecyclic modification which Hough and Taylor also obtained by recrystallizingthe acyclic form.12 Perlin and his co-workers used the oxidation of hexoseswith lead tetra-acetate in acetic acid solution to prepare sugars with fewercarbon atoms.The mechanism of the stepwise reaction is uncertain but theoxidation appears to involve only the cyclic forms of the sugars. In aldoses,C(l) is eliminated, yielding the formate of the sugar with one carbon atomfewer. Finally the cyclic form of this is attacked, yielding the diformate ofthe aldose with two fewer carbon atoms. This enables D-erythrose to beobtained from ~-glucose.l~ With ketohexoses the bond between C,, and C(3)is broken, yielding glycollic acid; next, is removed to yield as the finalproduct the formate glycollate of the triose. In this way D-glyceraldehydemay be prepared from D-fructose and the enantiomer from ~-sorbose.l5 Thereaction has been applied to hexuronic acids.l6 Degradation of D-glucoseto D-arabinose is achieved by decarboxylation with bromine of the silver saltof the acetylated D-gluconic acid l7 or, better, by treating the correspondingHO H ~ ! ~ ~ ~ 0 2 E t ~ 2 ~-unanno-2 : 3 : 4 : 5 : 6-pentahydroxyhexane.12 Zinner( 3 37 H. F. Bauer and D. E. Stuetz, J . Amer. Chem. Soc., 1956, 78, 4097.8 D. L. McDonald and H. 0. L. Fischer, Biochim. Rio$hys. Acfa, 1953, 12, 203.B L. Hough and T. J. Taylor, J . , 1955, 1212.10 H. Zinner and K.-H. Falk, Chem. Ber., 1956, 89, 2451.11 C. E. Ballou, H. 0. L. Fischer, and D. L. McDonald, J . Amer. Chem. Soc., 1956,12 L. Hough and T.J. Taylor, J . , 1956, 970.13 H. Zinner and K.-H. Falk, Chem. Ber., 1955, 88, 566.14 A. S. Perlin and C . Brice, Canad. J . Chem., 1956, 34, 541.16 Idem, ibid., p . 85.16 Idem, ibid., p. 693.1: F. A . H. Rice and A. R. Johnson, J . Amer. Chem. SOC., 1956, 78, 428.77, 5967252 ORGANIC CHEMISTRY.acid chloride with silver oxide and bromine.l* The initial product of thesereactions, aldehyde-l-bromo-D-arabinose penta-acetate (as 4) may be con-verted into aldehyde-D-arabinose hexa-acetate (as 5) by treatment with silveracetate, or into the pentitol (as 6) by reduction with lithium aluminiumhydride. D-Arabinose also results from decarboxylation of D-galacturonicacid with heavy-metal ions in aqueous or pyridine s o l ~ t i o n s . ~ ~Derivatives of D-Glucosamine.-For the preparation of glycosides, 2-acet-amido-2-deoxy-~-g~ucosy~ chloride triacetate which is stable in dry solventsis particularly useful.20 A study of the acidic hydrolysis of some D-glucos-amine derivatives throws light on the different modes of hydrolysis ofheparin and hyaluronic acid.21 Preparation of 1 : 6-anhydro-~-glucosaminefrom the l-fluoro- or 1-azido-compounds is described.22 N-Acyl derivativesof D-glucosamine are obtained by treating its supersaturated methanolicsolution with the acid anhydride : fully acylated compounds result fromtreatment with acid chloride or anhydride in ~ y r i d i n e .~ ~ Deamination ofD-glucosamine hydrochloride has received further attention 24 and thestructure of the product, chitose, has been firmly established as 2 : 5-anhydro-D-mannose.The reaction follows a course similar to that of the deaminationof tra.ns-2-aminocycZohexano1, suggesting that the sugar reacts in the pyranoseform with the amino-group in the equatorial position.25Compounds obtained from Sugars and Amines, Hydrazines, etc.-Further crystalline derivatives have been isolated illustrating thatreactions of N-arylaldosylamines involve the pyranose form.26 Re-actions of aldehyde-D-galactose and -2-deoxy-~-glucose acetates withprimary aromatic amines give none. of the Schiff 's base but amorphouscompounds of the same type as ~-arabo-3 : 4 : 5 : 6-tetra-acetoxy-1 : l-di-9-toluidinohexane, RvCH(NHR'),.~' N-Glycylglucosylamine, which showsno mutarotation, is oxidized by periodate as a pyranose compound,28 butaldose isonicotinylhydrazones which mutarotate in water are acetylated inthe acyclic forms.29 The structures of the two hexa-acetyl derivatives ofD-fructose oxime (7 and 8) have been elucidated with the help of infraredl8 F.A. H. Rice and A. R. Johnson, J . Amer. Chem. SOC., 1956, 34, 3173.l9 G. Zweifel and H. Deuel, Helv. Chim. Acta, 1956, 39, 662.20 D. H. Leaback and P. G. Walker, Chem. and Ind., 1956, 1017.2 1 A. B. Foster, D. Horton, and M. Stacey, ibid., p. 175.Z 2 F. Micheel and H. Wulff, Chem. Ber., 1956, 89, 1521.23 Y. Inouye, K. Onodera, S. Kitaoka, and S. Hirano, J . Amer. Chem. Soc., 1956,24 A. B. Grant, New Zealand J . Sci. Technol., 1956, 37, 509.2 5 B. C. Bera, A. B. Foster, and M.Stacey, J . , 1956, 4531.26 J. G. Douglas and J. Honeyman, J., 1955, 3674,2 7 J. L. Barclay, A. B. Foster, and W. G. Overend, J . , 1956, 476.2 8 J. Baddiley, J. G. Buchanan, R. E. Handschumacher, and J. F. Prescott, ibid.,29 H. Zinner and W. Bock, Chem. Ber., 1956, 89, 1124.78, 4722.p. 2818HONEYMAN : SUGARS. 253spectra.30, 31 Amadori rearrangement products (1 -arylamino-1-deoxy-D-fructoses) of N-aryl-n-glucosylamines have a characteristic band at 3570 cm.-lin the infrared spectra.32 D-Fructose with anhydrous ethylamine gives N -ethyl-D-fructosylamine but this rearranges very readily, even in methanol atCH~*OAC CH2.OAcI IC = N.OAC C -NAc(OAc)II I1IAcO - C! -\ ACO-C- HH -C- OAc H-C-OAC 0H- C - OAc H- C-OAc ' ' ( 8 ) ( 7 CH2'0Ac CH 225", to the isomer which is considered to be 2-deoxy-2-ethylaniino-a-D-gluco-pyranose. Rearranged products are obtained directly in poor yield fromD-fructose and n-propylamine, n-b~tylamine,~~ or certain amino-acids.=* 35Both types of compound are isolated when benzylaniine is used.36 Therearranged products readily brown when heated and produce the odours ofcooking.Their importance in the non-enzymic browning of foods is furtherillustrated in work with simpler compounds.37Formazans 38 prepared from aldoses through phenylhydrazones have beensuggested as suitable derivatives for characteri~ation.~~ Unfortunately themelting points fall in a narrow temperature range. The structure ofD-glucosazonef ormazan ' ' (1 -phenylazo-D-glucosazone) has been proved,confirming the view that D-glucosazone has reacted as an acyclic com-pound.40 The ultraviolet absorption spectra of the necessarily acyclic3-O-methylglycerosazone is very similar to those of the sugar osazones butappreciably different from those of glyoxal and methylglyoxal osazones.Thus the sugar osazones are acyclic, the difference in their spectra from thoseof methylglyoxal being due, not to the presence of a ring, but to the oxygenatom at C(3).41 Interesting formazans have been obtained fromD-glucosone,401 42 1 : 2-O-~sopropylidene-~-xylofurano$e~~ D-xylotrihydroxy-gl~tardialdehyde?~ and periodate-oxidized cellulose (9), starch, inulin,xylan, and dextriaM The bright red product obtained from oxidizedcellulose, for example, has the structure shown (10) and may be convertedinto the colourless tetrazolium compound (11) by mild treatment with30 H.Bredereck and W. Protzer, Chem. Bey., 1954, 87, 1873.3 1 H. Rredereck, A. Wagner, D. Hummel, and H. Kreiselmeier, ibid., 1956, 89, 1532.32 F. Micheel and B. Schleppinghoff, ibid., p. 1702.33 J. F. Carson, J . Anzev. Chem. SOC., 1955, 77, 5957.34 P. H. Lowey and 13. Borsook, &id., 1956, 78, 3175.3 5 F. Micheel and A. Klemer, Chew. Bey., 1956, 89, 1238.36 J . F. Carson, J . Amev. Chem. SOC., 1956, 78, 3728.3 7 C. D. Hurd and C . M. Buess, ibid., p. 5667.3 8 G. 0. Aspinall and J. C. P. Schwarz, Ann. Repovts, 1955, 52, 257.39 L. Mester and A. Major, J . Amer. Chem. Soc., 1956, 78, 1403.4O Idem, J., 1956, 3227.4 1 J.C. P. Schwarz and (in part) M. Finnegan, ibid., p. 3979.42 G. Henseke and M. Winter, Chem. Ber., 1956, 89, 956.43 L. Mester and E. Mbczbr, J., 1956, 3228.44 L. Mester, J . Amev. Ckem. SOC., 1955, 77, 6452254 ORGANIC CHEMISTRY.N-bromosuccinimide. The reverse process is achieved with L-ascorbicacid.45 Cellulose oxidized with nitrogen dioxide also gives a bright redformazan d e r i ~ a t i v e . ~ ~- .. - .I1 I - P h N+- N P hEsters.--Whereas 2 : 3 : 4 : 6-tetra-O-acetyl-l-O-(2 : 4 : 6-trimethylbenzoy1)-p-D-glucose is converted by alkali into 1 : 6-anhydro-(3-~-glucose,~~ thea-anomer undergoes deacetylation accompanied by migration of the tri-methylbenzoyl group and yields 2-0-(2 : 4 : 6-trimethylbenzoyl)-~-glucose.~~When treated with methanolic hydrogen chloride this ester affords thep-D-glucopyranoside, Le., the bulky group makes the entering methylgroup go into the less hindered equatorial p-position.An example of thegreater reactivity of the hydroxyl group on C(21 of methyl 4 : 6-0-benzyl-idene-X-D-glucoside is also encountered : treatment of this with 2 : 4 : 6-tri-methylbenzoyl chloride in pyridine yields the 2-0-(2 : 4 : 6-trimethylbenzoyl)derivative only.48Further investigation of the compound previously considered to be theortho-acid,has shown it to be D-ribose 1 : 3 : 5-triben~oate.~~ This has also been identi-fied as the 2 : 3 : 5-triben~oate,~~ but this more recent proof shows that duringpreparation a benzoyl group migrates from C(2) to C(l>.Further orthoesterderivatives of D-fructofuranose 509 53 and of a-D-glucopyranose s4 have beendescribed.Use of complexes of the methyl D-glucopyranosides with boron oxide or acertain crystalline form of metaboric acid has enabled the acetates of the2 : 3- and 2 : 6-dibenzoates and of the 2 : 3 : 6-tribenzoate to be obtained,together with smaller quantities of other esters.55Whereas 1 : 6-anhydro-2-0-toluene-~-sulphonyl- and 1 : 6-anhydro-3 : 4-di-O-toluene-$-sulphonyl-~-D-altrose resist conversion into epoxides the3-O-toluene-~-sulphonate slowly reacts with alkali to give 1 : 6-3 : 4-di-anhydro-P-D-altrose. The conformational aspects are discussed 56 and arealso applied to the ready production of methyl 4 : 6-0-benzylidene-2 : 3-3 : 5-di-0-benzoyl-1 : 2-0-( hydroxybenzylidene)-cc-~-ribose,~~~45 L.Mester and E. M6czAr, Chem. and Ind., 1956, 848.46 Idem, ibid., p. 823.47 H. B. Wood, jun., and H. G. Fletcher, jun., J . Ameu. Chem. SOC., 1956, 78, 207.48 Idem, ibid., p. 2849.49 R. K. Ness and H. G. Fletcher, jun., ibid., 1954, 76, 1663.60 G. 0. Aspinall and J. C. P. Schwarz, Ann. Reports, 1955, 52, 259.51 R. K. Ness and H. G. Fletcher, jun., J . Amer. Chem. SOC., 1956, 78, 4710.62 F. Weygand and F. Wirth, Chem. Be?.., 1952, 85, 1000.53 R. K. Ness and H. G. Fletcher, jun., J . Amer. Chem. SOC., 1956, 78, 1001.54 R. U. Lemieux and J. D. T. Cipera, Canad. J . Chem., 1956, 34, 906.6 5 J. M. Sugihara and J. C . Petersen, J . Amel.. Chenz. SOC., 1956, 78, 1760.5 6 F. €I. Newth, J . , 1056, 441HONEYMAN : SUGARS.255didehydro-2 : 3-dideoxy-a-u-glucoside by treatment of methyl 4 : 6-O-benzyl-idene-3-deoxy-3-iodo-2-O-toluene-~-sulphon~l-~-~-glucoside with sodiumiodide in acetone.57The preparation and reactions of a number of nitrate esters have beendescribed, including selective conversion of secondary nitrates into thecorresponding alcohol by their reaction with aqueous sodium nitrite. 58The reductive removal of nitrate groups with hydrazine gives high yields ofthe alcohols,59 but catalytic hydrogenation with Raney nickel, or treatmentwith methylmagnesium iodide or lithium aluminium hydride only partiallydenitrates cellulose nitrate.60Benzenesulphinates, prepared by treating a sugar derivative or its acetatewith sodium benzenesulphinate and acetic anhydride, are hydrolysed by" acyl "-oxygen fission, i.e., without inversion or epoxide formation.5sSome S-methyl dithiocarbonates (xanthates) of D-glucose have beenprepared by treating the sodium alkoxide with carbon disulphide followedby methyl iodide : 61RONa + CS, ROCS,Na 4 RO*CS,MeMethyl 3 : 4-O-isopropylidene-p-~-arabinoside %O-(S-methyl dithiocarb-onate) gives on distillation, not the expected olefin,62 but the isomeric%S-(S-methyl dithiocarbonate) which is converted by reductive desulphur-ization into the 2-deoxy-D-ribose derivative in low yield.63 Methyl 3 : 4-isopropylidene-p-D-arabinoside 2-O-(S-sodium dithiocarbonate) gives theS-methyl and S-triphenylmethyl derivatives normally but with ethyliodide, n- or iso-propyl bromide, or tert.-butyl chloride the product is di-(methyl 3 : 4-O-isopropylidene-p-~-arabinoside) %thionocarbonate, also ob-tained by reaction of thiocarbonyl chloride and the D-arabinose com-pound.640ligosaccharides.-Full details are given of the chemical synthesis ofsucrose together with a discussion of the mode ofCHz'oAc reaction with alcohols of 1 : 2-anhydro-x-u-glucopyr-AcO I\ anose triacetate in its half-chair conforrnatibn~.~~ Withmethanol the p-D-glucoside is obtained, but with bulkyalcohols, as in the sucrose synthesis, the chief productis the a-D-glucoside because the axial CH,*OAc group OAc Y T g,prevents normal trans-addition (12).Stevioside 66 is shown to be a s~phoroside.~~Oxidation of disaccharides by lead tetra-acetate enables the position of57 F.H. Newth, J . , 1956, 471.58 J. Honeyman and J. W. W. Morgan, J., 1956, 3660.59 K. S. Ennor, J . Honeyman, and T. C. Stening, Chem. and Ind., 1956, 1308.E. P. Swan and L. D. Hayward, Canad. J . Chern., 1956, 34, 856.A. K. Sanyal and C. B. Purves, Canad. J . Chem., 1956, 34, 426.62 L. Chugaev, Ber., 1899, 32, 3332.63 M. L. Wolfrom and A. B. Foster, J . 4?)8er. Chem. Soc , 1956, 78, 1399.-4. B. Foster and M. L. Wolfrom, zbid., p. 2493.65 R. U. Lemieux and G. Huber, zbid., 4117.G. 0. Aspinall and J. C. P. Schwarz, Ann. Repovfs, 1955, 52, 258.G i E. Vis and 11, G . Flttclier, jun., J . ,411zcr. Chrnz. Soc., 1956, 78, 470:)256 ORGANIC CHEMISTRY.the linkage between the monosaccharide units to be determined.68* 69 Theoxidation of trisaccharides and higher polymers has also been studied.70The degree of polymerization of reducing oligosaccharides with up to aboutseven monosaccharide units may be found by use of the anthrone-concen-trated sulphuric acid reagent before and after reduction of the sugar withsodium borohydride. 71" Hydrol," the residual mother-liquor from the manufacture of D-ghCOSeby the acid hydrolysis of maize starch, has been examined and 5-O-P-D-glucopyranosyl-D-glucose has been isolated.This is believed to be formedas a reversion product.72 Leucrose, a by-product of the preparation ofbacterial dextran from sucrose, is shown to be 5-O-a-~-glucopyranosyl-D-fructose. 73Miscellaneous.-Phosphorus pentachloride reacts with 1 : 2-5 : 6-di-0-kopropylidene-D-glucose to give, in low yield, not the expected 3-chloro-3-deoxy-derivative, 74 but the 6-chloro-6-deoxy-isomer, the reaction involvingmigration of an isopropylideneCarboxymethyl ethers of n-glucose have been prepared and correlatedwith the products obtained by hydrolysis of O-carboxymethylcellulose. 76Reduction of these D-glucose ethers by lithium aluminium hydride yields thecorresponding hydroxyet hyl compounds.Separations of D-glucose, D-fructose, and sucrose, and of a number ofpartially methylated derivatives of D-glucose and D-xylose, have shown that" Celite " columns have advantages for preparativePreparations of 5-O-methyl-~-glucose 79 (and %O-methyl-~-glyceron-amide from it) and of 2 : 5 : 6-tri-O-methyl-~-glucosePure, but nevertheless non-crystalline, sedoheptulose (D-altroheptulose)has been obtained from its crystalline hexa-acetate.At 20" in dilute acidthe equilibrium solution contains the sugar and 91 % of sedoheptulosan(2 : 7-anhydro-p-~-nltroheptulopyranose). 81 The isomeric anhydro-com-pound 82 has now been crystallized and shown to be 2 : 7-anhydro-P-D-altroheptulofuranose. 81Acetone, like aldehydes, has been found to react with methyl X-D-glucoside to give the 4 : 6-O-isopropylidene compound.83 D-Ribose withacetone yields 1 : 5-anhydro-2 : 3-O-isopropylidene-~-ribofuranose and 2 : 3-O-isopropylidene-D-ribose. The latter yields two isomeric 1 : 5-O-benzyl-are described.6 8 A. S. Perlin, Analyt. Chew., 1955, 27, 306.69 A.J. Charlson and A. S. Perlin, Canad. J . Chew., 1956, 34, 1200.70 A. S. Perlin and A. R. Lansdown, ibid., p. 451.?l S. Peat, W. J. Whelan, and J - G. Roberts, J., 1956, 2258.72 J. C. Sowden and A. S. Spriggs, J . Amer. Chem. Soc., 1956, 78, 2503.7 3 F. H. Stodola, E. S. Sharpe, and H. J. Koepsell, ibid., p. 2514.74 J. B. Allison and R. M. Hixon, ibid., 1926, 48, 406.'5 D. C. C. Smith, J . , 1956, 1244.76 W. P. Shyluk and T. E. Timell, Caaad. J . Chem., 1956, 34, 575.7 7 Idem, ibid., p. 671.78 R. U. Lemieux, C. T. Bishop, and G. E. Pelletier, ibid., p. 1365.79 J. K. N. Jones, ibid., p. 310.C. T. Bishop and J. Schmorak, ibid., p. 845.81 N. K. Richtmyer and J. W. Pratt, J . APner. Chew. SOG., 1966, 78, 4717.82 L. P. Zill and N. E. Tolbert, ibid., 1954, 76, 2929.83 J.K. N. Jones, Canad. J , Chew., 1956, 34, 840SMITH : NATURAL MACROMOLECULES. 257idene derivatives. 84 Methyl D-ribopyranoside condenses with acetone togive a mixture of methyl 2 : 3-O-~sopropylidene-~-ribofuranoside and methyl3 : 4-O-isopropylidene-D-ribopyranoside. The conversion of the pyranoseinto the furanose is believed to occur after condensation with acetone onJ. H.12. NATURAL MACROMOLECULES.Po1ysaccharides.-Since last year's Report, fractionation of naturallyoccurring polysaccharides has continued to attract attention. Fractionalprecipitation with cupric acetate and ethanol has resolved linseed mucilageinto three distinct components.l Acidic polysaccharides form precipitateswith cetyltrimethylammonium bromide which redissolve in salt solutionsand can be fractionated by this rneans.2,3 In the presence of oxalic acid,which suppresses dissociation of carboxyl groups, only polysaccharides con-taining sulphate groups are pre~ipitated,~ and cliff erential estimation ofcarboxyl and sulphate groups on a microgram scale by spectrophotometricestimation of the excess of cetylpyridinium chloride has been des~ribed.~A globulin from Jack-bean meal forms precipitates with glycogens, yeastmannan, and heparin but not with amylopectin, chondroitin sulphate,hyaluronate, or lung gala~tan.~ Gum arabic recovered from its specificprecipitate with type I1 antipneumococcus serum contains only one- thirdto one-fifth as much rhamnose as does the native gum.6 Separation ofamylose and amylopectin by paper ionophoresis in borate solution is hinderedby adsorption of polysaccharides on paper : adsorption is very much lesswhen glass-fibre sheets are used in place of paper,* and detection of thepolysaccharides is ~implified.~A technique for determining the position of 1 : 6-linkages in aldohexosepolymers otherwise containing only 1 : 2-, 1 : 3-, or 1 : 4-linkages utilisesdegradation from the reducing end-groups by buffered periodate at pH 8.- 0- CH,I 1 CHOThe process oxidises away anhydrohexose residues until a 6-linked residue isencountered, and the amount of formaldehyde released indicates the positionof the 1 : 6-linkage relative to the reducing end-group.Clinical dextran84 G. R. Barker and J. W. Spoors, J., 1956, 1192.8 5 Idem, ibid., p.2656.1 A. J. Ersltine and J . K. N. Jones, Canad. J . Chem., 1956,34, 821.3 J. E. Scott, ibid., 1955, 18, 428.A. S. Jones, Biochim. Bioplzys. Acta, 1953, 10, 607.Idem, Chem. and I n d l 1955, 168.J. A. Cifonelli, R. Montgomery, andF. Smith, J . Amer. Chem. SOL, 1956,7$, 2488.M. Heidelberger, J . Adams, and 2. Dische, ibid., 1956, 78, 2853.7 A. B. Foster, P. A. Newton-Hearn, and M. Stacey, J., 1956, 30.E. J. Bourne, A. B. Foster, and P. M. Grant, J., 1956, 4311.D. R. Briggs, E. F. Garner, and F. Smith, Nature, 1966, 173, 164.REP .-VOL. LIII 258 ORGANIC CHEMISTRY ayields no formaldehyde, suggesting lo that the reducing end-group is linkedthrough position 6. Formic acid released in periodate oxidation measuresthe number of 1 : 6-linked residues in the dextran of Leucofiostocmesenteroides.ll Methylation studies l2 on a bacterial dextran indicatepredominantly 1 : 6-linked residues with 1 : 3-linked branches.Partial hydrolysis of polysaccharides to oligosaccharides grows in im-portance as a means of determining structure.A simple technique forisolating disaccharides from partial hydrolysates by adsorption on charcoalis described.13 Care must be taken to ensure that disaccharides are notformed by reversion. Reversion of arabinose gives 3-0- and 4-O-p-arabino-pyranosyl-L-arabinose and another disaccharide ; reversion of xylose gives4-O-~-~-xylopyranosyl-~-xylose and two other disaccharides ; and reversionof mannose gives 3-0- and 6-0-cc-D-mannopyranosy~-~-mannopyranose.~~Treatment of D-arabinose with sulphuric acid gives rise to D-arabinopyrano-syl-~-arabinopyranoside.l~ Condensation of xylose catalysed by hydrogenchloride yields a polysaccharide l6 containing pyranose residues with 1 : 4-,1 : 2-, and 1 : 3-linkages in the ratio of 13 : 6 : 2.Glucose monohydrate,when heated with Amberlite IR-l20(H+), yields a polysaccharide containing60% of a-1 : 6-1inkages.l' Use of the Koenigs-Knorr reaction for controlledsynthesis of gentiodextrins is reported ; 2 : 3 : 4-tri-~-acetyl-a-D-gluco-pyranosyl bromide with silver oxide, iodine, and a dehydrating agentyielded a mixture containing levoglucosan, and the polymeric series ofoligosaccharides containing the p-1 : 6-linkage.Polysaccharides associated with wood cellulose have been reviewed.lgAs an alternative to sodium hydroxide, liquid ammonia 20 and dimethylsulphoxide have been used for extracting hemicellulose from holocellulose.The use of alkali in isolating polysaccharides, while not invalidating thestructures assigned, may profoundly affect biological activity and variousmethods of chain-length determination if a terminal saccharinic acid residueis formed.22 Maize-cob xylan is stable to oxygen-free alkali, presumablybecause the terminal reducing groups were oxidised by sodium chloriteduring delignification.22Xylans containing variously arabinose, galactose, glucuronic, and 4-0-methylglucuronic acid residues from wheat straw,23* 24 wheat bran,25 oat10 L.Hough and M.B. Perry, Chem. and Ind., 1956, 768.11 R. J. Dimler, I. A. Wolff, J. W. Sloan, and C . E. Rist, J . Anzer. Chem. SOL., 1955,12 J. W. Van Cleve, W. C . Schaefer, and C . E. Rist, ibid., 1956, 78, 4435.13 P. Andrews, L. Hough, and D. B. Powell, Chem. and Ind., 1956, 658.14 D. H. Ball, J. K. N. Jones, W. H. Nicholson, and T. J. Painter, T A P P I , 1956,1 5 F. A. H. Rice, J . Amer. Chem. SOC., 1956, 78, 6167.1 6 C. T. Bishop, Canad. J . Chem., 1956, 34, 1255.1 7 P. S. O'Colla and E. Lee, Chem. und Ind., 1956, 522.1 8 S. Haq and W. J. 'Whelan, .J., 1956, 4543.19 W. J. Polglase, Adv. Carbohydrate Chem., 1955, 10, 283.20 J. E. Milks and C. B. Purves, J - Amer. Chem. Soc., 1956, 78, 3738.21 E. Hagglund, B. Lindberg, and J. McPherson, Acta Chew. Scand., 1956,10, 1160.22 R.L. Whistler and W. M. Corbett, J . Amer. Chem. SOC., 1956, 78, 1003.23 G. 0. Aspinall and E. G. Meek, J . , 1956, 3830.24 C. T. Bishop, J. Amer. Chem. Soc., 1956, 78, 2840.z 5 G. A. Adams and C . T. Bishop, ihid., p. 2842.77, 6568.39, 438SMITH : NATURAL MACKOMO1,ECULES. 259straw,26 oat hull,27 maize fibre,"> 29, 30 maize hull,319 3y tamarind andwoods of aspen,2* western hemlock,343 35, 3G and Norway spruce 37 have beenexamined. Methylation studies 23* 26 and the nature of the oligosaccharidesand aldobiuronic and aldotriuronic acids isolated accord with the patternsof structure already sumrnarised,38 though the isolation of a crystallineL-galactopyranosyl-( 1 __t 4) -D-xylopyranosyl-( 1 + 2) -L-arabinose frommaize-fibre hemicellulose is the first indication of such a combination ofsugars in Nature.28 m-Galactose occurs as non-reducing end groups 30 inmaize-fibre gum.Glucomannans have been isolated from western heml0ck,~6lily and AmorPhoPhaZZzGs plants.40 Hemicellulose of plum leaf giveson hydrolysis D-galactose, L-arabinose, D-xylose, L-rhamnose, L-fucose,D-mannose, 2-O-methylxylose, and one other O-methylmonosaccharide ;this is the first discovery of an O-methylpentose occurring in Nature.13* 41Polysaccharides from algz continue to present novel structural features ;L-guluronic acid has been reported for the first time as a natural product inbrown a l p ; 42 and the polysaccharide from a red seaweed contains 6-0-methyl-D-galactose, also previously unknown among natural products, andboth enantiomers of galactose, which incidentally were separable by crystal-lisat ion .43Gums of Khaya grandifoZia,@ Hakea acic~laris,~5 and lemon *6 have beeninvestigated. A polyglucose of Zen mays has been found indistinguishablefrom glycogen of animal and microbial origin.47 Additional evidence fromenzymic degradation indicates that the molecule of p-limit dextrin and henceof the parent amylopectin is multiple branched on the random patternsuggested by K. H.I~Ieyer.~~ Further work on the periodate oxidation ofamylopectin suggests that 1 : 3-linkages are present,49 and this is confirmedby the isolation of nigerose (3-0-a-~-glucopyranosyl-~-glucose) on partialhydrolysis of amylopectin under conditions unfavourable to reversion ; 5 0 ~ 51t 6 G.0. Aspinall and K. C. B. Wilkie, J . , 1956, 1072.27 E. L. Falconer and G. A. Adams, Canad. J . Chem., 1956, 34, 338.28 R. L. Whistler and W. M. Corbett, J . Amer. Chew. SOC., 1955, 77, 6328.2B Idem, J . Org. Chem., 1956, 21, 694.30 R. L. Whistler and J. N. B. Miller, J . Arner. Chem SOC., 1956, 78, 1163.31 R. Montgomery, F. Smith, and H. C. Srivastava, ibid., p. 2837.32 Idem, ibid., p. 6169.33 G. R. Savur, J., 1956, 2600.34 G. G. S. Dutton and F. Smith, J . .41ner. Chem. SOC., 1956, 78, 2506.3G Idem, ibid., p. 3744.36 J. K. Hamilton, H. W. Kircher, and N. S. Thompson, ibid., p. 2508.37 G. 0. Aspinall and M. E. Carter, J., 1956, 3744G. 0. Aspinall, Ann. Reports, 1955, 52, 261.P. Andrews, L. Hough, and J.K. N. Jones, J., 1956, 181.40 F. Smith and M. C. Srivastava, J . Amer. Chern. SOC., 1956, 78, 1404.41 P. Andrews and L. Hough, Chem. and Ind., 1956, 1278.42 F. G. Fischer and H. Dorfel, 2. physiol. Chem., 1955, 302, 186.43 J. R. Nunn and M. M. von Holdt, Chem. and Ind., 1956, 467.44 G. 0. Aspinall, E. L. Hirst, and N. K. Matheson, J . , 1956, 989.4 6 A. M. Stephen, J., 1956, 4487.46 G. G. S. Dutton, Canad. J . Chem., 1956, 34, 406.4 7 S. Peat, W. J. Whelan, and J. R. Turvey, J., 1956, 2317.48 S. Peat, ' A T . J . Whelan, and G. J . Thomas, J . , 1956, 3025.49 J. K. Hamilton and F. Smith, J . Amer. Chem. SOC., 1956, 78, 5910.so M. L. Wolfrom and A. Thompson, ibid., 1955, 77, 6403.Idem, ibid., 1956, 78, 4116260 ORGANIC CHEMISTRY.on the other hand, it is suggested that 1 : 3-linkages may be artefacts ofreversion since, otherwise, new enzymes must be po~tulated.~~ Partialhydrolysis of glycogen has yielded a small amount of isomaltotriose, suggest-ing that some of the 1 : 6-linkages exist on adjacent units.53The termination of fructosan chains by sucrose linkages is further con-firmed by the isolation of kestose and of inulobiosylsucrose from partial acidhydrolysates of inulin under conditions where the formation of reversionproducts such as 6-O-~-~-fructosylfructose is negligible.54 A structure hasbeen proposed for the glucofructan of Cordyline terminaZis. 55 Partialhydrolysis of sugar-beet araban yields 5-O-~-arabinofuranosyl-~-arabino-furanose and 3-0-~-arabinofuranosyl-~-arabinose. l3 It is confirmed bymethyiation that the polysaccharide luteose, produced as its malonic esterby Penicillium Zzdeztm Zukal., is a p-1 : 6-linked glucosan with many 1 : 3-and 1 : 4-linked branches.56 The extracellular polysaccharide of A erobacteraerogenes contains 1 : 4-linked glucose, 1 : 2-linked L-fucofuranose, andglucuronic acid units.67 The chemistry of heparin has been reviewed.5sAn aldoheptose, D-glycero-D-galactoheptose, and a new amino-sugar,C,H,,O,N,H,O, possibly a 3-O-carboxyethylhexosamine, occur in thespecific polysaccharides of Chromobacteriwm violaceum.59 An unidentifiedheptose is the main sugar component of a lipopolysaccharide from Pasteurellapestis. 6ONucleic Acids.-l955 saw the publication of a comprehensive , two-volumetreatise on nucleic acids,61 and the subject has been reviewed severalWith the establishment of the 3’ : 5’-phosphodiester structure of nucleicacids, further work has been mainly directed towards synthesis of oligo-nucleotides, structure in relation to enzyme specificity, degradative workwhich might indicate the sequence of base residues, study of hydrogen bondinteractions between base residues, and indications of the mode of combin-ation between nucleic acids and proteins.Details have been given of the synthesis of thyminenucleosides using a mercury derivative of thymine and poly-O-benzoyl-glycosyl halides.63 Adenylic and guanylic acids-a and -b have been identi-fied by acid hydrolysis to ribose 2’- and S’-phosphate respectively. Similarhydrolysis of pyrimidine nucleotides is precluded by the stability of theirglycosidic linkages,64 but proof of the structures of cytidylic acids-a and -bRibonzccleic acids.52 G.T. Cori, Makrornol. Chem., 1956, 20, 169.63 M. L. Wolfrom and A. Thompson, J . Amer. Chem. Soc., 1956, 78, 4182.54 D. S. Feingold and G. Avigad, Biochim. Biophys. Actu, 1956, 22, 196.6 5 L. A. Boggs and F. Smith, J . Amer. Chem. Soc., 1956, 78, 1880.66 P. F. Lloyd, G. Pon, and M. Stacey, Chem. and Ind., 1956, 172.5 7 G. 0. Aspinall, R. S. P. Jamieson, and J. F. Wilkinson, J., 1956, 3483.59 M. J. Crumpton and D. A. L. Davies, Baochenz. J., 1956, 64, 2 2 ~ ; R. E. Strange,6o D. A. L. Davies, ibid., 1956, 63, 105.61 E. Chargaff and J. N. Davidson, ‘’ The Nucleic hicds,” Academic Press, New62 Sir Alexander Todd in “ Perspectives in Organic Chemistry,” Interscience Publ.63 J.J. Fox, N. Yung, J. Davoll, and G. B. Brown, J . Amer. Chem. Soc., 1956,A. B. Foster and A. J. Huggard, Adv. Carbohydrate Chew.., 1955, 10, 335.ibid., p. 2 3 ~ ; A. P. Maclennan and D. A. L. Davies, 1956, 63, 3 1 ~ .York, 1955.Inc., New York, 1956; Makromol. Chem., 1956, 20, 87 ; Cht~% and Ind., 1956* 802-78, 2117.J. X. Khym and W. E. Cohn, ibid., 1954, 76, 1818, 5523SMITH : NATURAL MACROMOLECULES. 261as the 2‘- and 3’-phosphate respectively has now been obtained by degradingthese pyrimidine nucleotides with hydrazine hydrate, pyrazolone beingobtained with ribose 2- and 3-phosphate respectively. By this same treat-ment uridylic acid-b was converted into 3-aminopyrazole and ribose 3-phos-hate.^^ The ribose phosphates have also been obtained from both uridylicand cytidylic acid via the dihydrouridylic acids which were hydrolysed bydilute alkali to the N-ribosyl phosphates of p-ureidopropionic acid which, inturn, were hydrolysed by dilute acid to the ribose phosphates withoutappreciable migration of the phosphate group66The structures of uridylic acid-a and -b have also been confirmed bysynthesis of the former acid from 3’ : 5’-di-O-acetyluridine, the structure ofwhich was proved by conversion into 3’ : 5’-di-O-acetyl-Z‘-O-toluene-$-sulphonyluridine (1) and O2 : Z’-cycZouridine (2) ; this on hydroly~is,~~ gave3-P-u-arabofuranosyluracil (3), identical with spongouridine isolated fromsponges? This sequence of reactions parallels the conversion of 3’ : 5’-di-0-methanesulphonylthymidine into 5’-0-methanesulphonyl-O2 : 3’-cyclo-thymidine. 69AcO OTs AcO H HO H(Ts = p-C,H,Me-S02)An improved preparation of the crystalline 3’ : 5’-di-@acetyladenosineconsists in fusing equimolar quantities of 5’-0-acetyladenosine and 2’ : 3‘ : 5‘-tri-0-acetyladenosine (resulting in transacetylation), followed by separationof the di-0-acetyl compound from starting material.By starting from thissubstance, adenosine-2’ uridine-5’ phosphate has been synthesised.70 Inview of the labilising effect of the 3‘-hydroxyl of adenosine on the inter-nucleotide linkage the attainment of this dinucleosideI t phosphate by synthesis represents a notable achieve-ment. 0-Benzylphosphorous 00-diphenylphosphoricanhydride converted 3‘ : 5’-O-acetyladenosine into3’ : 5’-O-acetyladenosine-2’ benzyl phosphite, which1 1 with N-chlorosuccinimide yielded 3’ : fi‘-O-acetyl-I i adenosine-2’ benzyl phosphorochloridate. This,when condensed with 2’ : 3’-O-acetyluridine, gave amixture from which the product (4) was separated after removal of theprotecting groups.Conditions for survival of the internucleotide linkageduring removal of the protecting groups are that (a) the benzyl group mustbe removed by hydrogenolysis before the adjacent free 3’-hydroxyl is pro-OAc OAcAdenine - C ,- C3,- Cs,1 2O\ P”OPh. CH,. 6 \U r a c i I - c2 - C’ - c5‘OAc OAc 4 )66 F. Baron and D. M. Brown, J., 1955, 2855.W.E. Cohn and D. G. Doherty, J . Amcr. Chem. SOC., 1966, 78. 2863.6 7 D. M. Brown, Sir Alexander Todd, and S. Varadarajan, J., 1956, 2388.68 W. Bergman and D. C. Burke, J. Org. Chem., 1955, 20, 1501.69 A. M. Michelson and Sir Alexander Todd, J., 1955, 816.70 A. M. Michelson, L. Szab6, and Sir Alexander Todd, J., 1966, 1546262 ORGANIC CHEMISTRY.duced and (b) conditions for removal of the acetyl groups must be sufficientlymild (pH 9.6). Partial acid hydrolysis of cytidine-3’ benzyl phosphate ispreceded by some migration of the phosphate group, since 25% of therecovered diester consists of cytidine-2’ benzyl phosphate. Also, adenos-ine-2’ uridine-5’ phosphate gives some adenosine-3’ uridine-5’ phosphate.Hence a symmetrical transition state, probably a protonated form of (5Aor B) is involved.By contrast, partial alkaline hydrolysis of cytidine-3’benzyl phosphate is not accompanied by migration of the phosphate group,suggesting that there is an unsymmetrical transition state (6). Hence, ifpartial acid hydrolysis of ribonucleic acid gives rise to oligonucleotides con-taining a ribonuclease-resistant 2‘ : 5’-linkage, this will not be evidence forsuch a linkage in ribonucleic acids.’l The properties of uridine-3’ dimethyland dibenzyl phosphate make it unlikely that there are any phosphotriestergroups in ribonucleic acid.72The reversibility of ribonuclease action enables this enzyme to synthesisepyrimidine nucleoside-3’ methyl and ethyl phosphate from either pyrimidinenucleoside-2’ : 3’ cyclic phosphates 73* 74 or pyrimidine nucleoside-3’ benzylphosphates 73 and methyl or ethyl alcohol.An analogous reverse reactioninduced by spleen phosphodiesterase is the replacement of the benzyl groupsin cytidine-3’ benzyl phosphate or adenosine-3’ benzyl phosphate by amethyl or an ethyl group. This enzyme differs from ribonuclease in itsability to utilise the purine nucleoside benzyl phosphate and in its inabilityto utilise nucleoside-2’ : 3‘ cyclic phosphate.73 The ability to act as phosphateacceptors in ribonuclease-catalysed exchange is limited to primary alcohols. 74Cytidine-2’ : 3’ cyclic phosphate can act as an acceptor, leading to thesynthesis of di- and tri-nucleotides of cytidylic acid having a terminal2’ : 3’-cyclic phosphate group.Cytidine can also act as the acceptor, lead-ing to the dinucleoside phosphate and trinucleoside diphosphate. Adenosineand adenosine-2’ : 3’ cyclic phosphate can also act as acceptors, thoughnucleoside-3’ phosphates are very poor acceptors. With ribonuclease underfavourable conditions the synthesis of 3’ : 5’-internucleotide linkages fromnucleoside-2’ : 3’ cyclic phosphates exceeds the hydrolysis to nucleoside-3’phosphates. The reactions are essentially traiisesterifications and neitherribonuclease nor spleen phosphodiesterase is capable unaided of synthesisingphosphodiester linkages from nucleoside-3’phosphates. 75 However , pyrim-idine nucleoside-2’ : 3’ cyclic phosphates are produced in the early stages71 D. M.Brown, D. I. Magrath, A. H. Neilson, and Sir Alexander Todd, Nature,72 D. M. Brown, D. I. Magrath, and Sir Alexander Todd, J., 1955, 4396.73 L. A. Heppel and P. R. Whitfield, Biochem. J., 1955, 60, 1.74 G. R. Barker and M. A. Parsons, Chem. and Ind., 1955, 1009.7 5 L. A. Heppel, P. R. Whitfield, and R. Markham, Biochem. J., 1955, 60, 8 ; M.Holden and N. W. Pirie, abid., p. 39; W. S. Pierpoint, BiocAim. Biophys. Acta, 1966,21, 136.1956,177, 1124SMITH NATURAL MACROMOLECULES. 263of ribonuclease digestion of ribonucleic acid, and Heppel et ul. point out thatpart at least of the dinucleotides with terminal-2’ : 3’ cyclic phosphategroups released under these conditions could be synthetic. Alkaline degrad-ation of ribonucleic acid with sodium tert.-butoxide yields nucleoside-2’ : 3’cyclic phogphates in 65% yield.76The suggestion has been made that one of the active centres in enzymescapable of transferring nucleotide or phosphate groups is the glyoxalinenucleus of histidine ; synthetic 1-phosphoglyoxaline and its esters have beenprepared which can transfer phosphate groups to alcohols, amines, carboxylicacids phosphoric esters, and inorganic phosphate.77Perhaps the most significant advance in the last two years was the dis-covery of an enzyme (polynucleotide phosphorylase) capable of synthesisinghighly polymerised ribonucleic acid-like polynucleotides from nucleoside-5‘pyrophosphates with the release of orthophosphate. The enzyme alsocatalyses the phosphorolysis of polynucleotides to yield nucleoside 5’-pyro-phosphates.Uniform and mixed synthetic polynucleotides have beenprepared. 78 Polyadenylic and polyuridylic acid prepared in this way havealready been used, with striking results, in physicochemical studies : thetwo combine immediately when mixed, with an increase in viscosity and adecrease in optical density at 260 mp. The product forms tough glassyfibres which have been shown by X-ray diffraction to possess a two-strandhelical structure with a helical pitch of 32-36 A, and about ten nucleotideresidues per turn. These results show for the first time that it is possiblefor ribopolynucleotides to assume a configuration similar to that found inundenatured deoxyribonucleic acid. 79 For spontaneous formation of thedouble helix it is probably necessary that each polynucleotide should containonly one type of base residue.There is not much evidence available to showwhether any two-strand helical structures are present in naturally occurringribonucleic acid, but a ribonucleic acid isolated by mild procedures fromA erobacter aerogenes gives a titration curve which is irreversible toward acidand alkali to an extent of 25-30% of that shown by undenatured deoxy-ribonucleic acid. The authors suggest that this is because ribonucleic acidowes part of its structure to hydrogen bonds between the 6-amino- and6-keto-groups of the base residues.s0 Polyadenylic acid has also been usedin experiments with an enzyme preparation from liver nuclei which degradesit to adenosine and a mixture of oligonucleotides in which mono-, di-, trGJand tetra-nucleotides have been identified, all having a terminal 5’-phosphategroup.81Chromatographic separation of the dinucleotides released after brief acidhydrolysis of ribonucleic acid indicates that all the sixteen possible sequences76 D.Lipkin and P. T. Talbert, Chem. and Ind., 1955, 143.77 J. Baddiley, J. G. Buchanan, and R. Letters, J., 1956, 2812.78 M. Grunberg-Manago, P. J. Ortiz, and S. Ochoa, Science, 1955,122,907; Biochim.7B A. Rich and D. R. Davies, J . Amer. Chem. SOC., 1956, 78, 3548; R. C. Warner,Biophys. Acta, 1956, 20, 269.Fed. Proc., 1956. 15, 379.R. A. Cox; A:S. Jones, G. E. Marsh, and A. R. Peacocke, Biochim. Biophys. Acta,L. A. Heppel, P. J. Ortiz, and S. OChQa, Science, 1956, 123, 416.1956, 21, 676264 ORGANIC CHEMISTRY.of dinucleotides are to be found.82 Full details have been published of amethod suitable for stepwise degradation of homogeneous polyribonucleo-tides.83 The most serious obstacle to determination of base sequences isthat ribonucleic acids occur as complex mixtures of moleculesu Difficultyof establishing complete purity hinders analytical work aimed at establishingregularities of base composition.It has been pointed out that ribonucleicacid isolated under mild conditions usudy has a low phosphorus contentand does not give a theoretical yield of mononucleotides on chromatographyof alkaline hydrolysates on anion-exchangers. Additional products of thehydrolysis have now been shown to be recoverable from the anion-exchangeron elution with hydrochloric acid, and to yield on drastic acid hydrolysis theamino-acids, glutamic acid , threonine, valine, serine, alanine, glycine, andleucine or isoleucine, together with adenine and guanine.The amino acid-nucleotide compounds give no ninhydrin reaction and a phosphoamidestructure is tentatively proposed. Their amino-acid : nucleotide ratio isunity.85 The attachment of amino-acids to ribonucleic acid by mixedanhydride linkages has been suggested as a possible stage in peptidesynthesis. G2Deoxyyibonucleic acid. That the sugar of deoxyadenosine , deoxy-guanosine, thymidine, deoxycytidine, and deoxy-5-methylcytidine is%deoxy-~-ribose has been confirmed bypreparation of the benzylphenylhydrazone.863’-Deoxy-3’- and 5’-deoxy-5’-iodothymidine,heated with silver acetate in acetonitrile0 N+ containing a trace of base, yielded halogen- ‘73 free compounds formulated as O2 : 3’-cycZo-thymidine (7) and O2 : 5’-cycZothymidine (8).On hydrolysis, the former gives 3-deoxy-~-xylose whereas the latter gives 2-deoxy-~-ribose.This establishes thestructure of thymidine as 3-p-2’-deoxy-~-ribofuranosylthymine, a conclusionwhich was confirmed by X-ray analysis of 5’-bromo-5’-deoxythyidine. 87The 3‘- and 5’-phosphates of deoxyadenosine and deoxyguanosine 88 andthe 5‘-phosphate of thymidine have been synthesised by unambiguousmethods. The intermediate 3’- and 5’-O-acetylnucleosides were identifiedby conversion into 3’- and 5‘-0-acetyl-~-ribose, respectively, by mild acidhydrolysis. The synthetic 5’-phosphates were identical with the productsobtained in enzymic degradation of deoxyribonucleic acids.Rattlesnakevenom only dephosphorylates the 5’-phosphates. 88The dinucleoside phosphate and the dinucleotide of thymidine having thenaturally occurring terminal 5’-phosphate group have been synthesised. 895’-O-Acetylthyniidine was treated with 0-benzylphosphorous 00-diphenyl-phosphoric anhydride, then with N-chlorosuccinimide, yielding the corre-HO HHO*H,C Hf--& H;aMe(8) 0-TdMe( 7 ) 0-82 W. E. Cohn and R. Markham, Biochcwz. J., 1956, 62, 1 7 ~ .89 D. M. Brown, M. Fried, and Sir Alexander Todd, J., 1955, 2206.84 R. Markham, Biochem. J., 1956, 62, 3 9 ~ .8 5 J. L.Potter and A. L. Dounce, J . Amer. Chem. SOC., 1956, 78, 3078.8 6 I. G. Walker and G. C. Butler, Canad. J . Chem., 1956, 34, 1168.87 A. M. Michelson and Sir Alexander Todd, J., 1955, 816.89 A. M. Michelson and Sir Alexander Todd, J . , 1966, 2632.D. H. Hayes, A. M. Michelson, and Sir Alexander Todd, J., 1955, 808SMITH NATURAL MACROMOLECULES. 265sponding 3’-(benzyl phosphorochloridate) ; this was condensed with 3’-0-acetylthymidine and freed from protecting groups by treatment with acidand alkali and by hydrogenolysis. The resulting dinucleoside phosphate(T3‘-P-5’T according to the symbolism proposed by these authors) wasseparated from some dinucleoside pyrophosphate (T3’-P-P-3’T). Simi-larly, starting with 5’-(dibenzyl phosphoryl) thymine, the dinucleotide(T5’-P-3’T5’-P) was synthesised, accompanied by some dinucleotide pyro-phosphate (P-5’T3‘-P-P-3’T5’-P).Apurinic acids, the non-dialysable products of carefully controlled acid-hydrolysis of deoxyribonucleic acids with the removal of most of the purineresidues and negligible loss of phosphorus, are said to retain the originalinterpyrimidine ratios.g0 Reduction of the free reducing groups of the sugarwith sodium borohydride to the 2-deovyribitol stage renders apurinic acidssufficiently stable for the determination of titration curves.These reveal ahigh proportion of secondary phosphoryl dissociations, suggesting that theapurinic acids are considerably degraded.g1 Simultaneous hydrolysis of de-oxyribonucleic acids and condensation of the free reducing groups of the sugarresidues with mercaptoacetic acid yields aldehydoapurinic acid di(carboxy-methyl) dithioacetals.Use of mercaptoacetic acid in the presence of zincchloride and anhydrous sodium sulphate gave a product with the theoreticalsulphur content and with only 6.2% of the phosphorus rendered dialy~able.~~Wherever a purine residue has been displaced, both the 3’- and the 5’-phosphoester group are situated adjacent to a free hydroxyl group on whatwas the 4’-position of the purine nucleotide. As a result, such phospho-ester residues are labile to alkali, and the dialysable substances produced byalkaline hydrolysis have been separated by chromatography and iono-phoresis into at least twenty components : besides thymidine and deoxy-cytidine, thesc include the dinucleoside phosphates T-P-C, T-P-T, andC-P-C, and the trinucleoside diphosphate whose probable structure isT-P-T-P-C, and sulphur-containing oligonucleotides whose probable struc-tures are given as T- P-S-P, C-P-S-P, T-P-T-P-S-P, T-P-T-P-C-P-S-P,T-P-C-P-S-P, and C-P-S-P, where T = thymidine, C = deoxycytidine,P = phosphate, and S = 2-deoxy-aldehyde-D-ribose di(carboxymethy1) di-thioacetal.Reasons are given for believing that the sulphur-containingcomponents such as (9) and (10) have a terminal 4’-phosphate group blockingthe 4’-hydroxyl group and so removing its labilising action on the adjacentphosphodiester linkage.93 Evidence is given that the sulphur-containingcomponents occur as hitherto inseparable isomeric pairs (9) and (10).Theformer, (9), but not the latter should give formaldehyde when treated suc-cessively with phosphomonoesterase and sodium periodate ; the observedbehaviour of the sulphur-containing components is intermediate in thisrespect, a fraction of a mol. of formaldehyde being formed.94Proposal of the double-helical structure for deoxyribonucleic acids in90 M. E. Hodes and E. Chargaff, Biochim. Biophys. Acta, 1956, 22, 349.91 E. Hurlen, S. G. Laland, R. A. Cox, and A. R. Peacocke, Acta Chew. Scand.,O2 A. S. Jones and D. S. Letham, J., 1956, 2573.O3 Idem, J., 1956, 2579.O4 A. S. Jones, D. S. Letham, and M. Stacey, J., 1966, 2584.1956, 10, 793266 ORGANIC CHEMISTRY.which adenine residues adhere by two hydrogen bonds to thymine residuesof the other helix, and likewise guanine residues adhere by two hydrogenbonds to cytosine, 5-methylcytosine, or 5-hydroxymethylcytosine residues\ ?H2C Ha;( 9 ) HO h(Py = pyrimidine residue)of the other helix,95 has stimulated many physical investigations that havetended to confirm this structure.Titration of deoxyribonucleic acids withacid results, at pH 2.4 in 0.1M-sodium chloride or at pH 3.3 in O-OlM-sodiumchloride, in an abrupt and irreversible increase in optical density at 260 mp.This change has been associated with acceptance of a proton by the amino-group of deoxyguanylic acid 96-99 with concomitant enolisation and simul-taneous breaking of both hydrogen bonds [(ll) --t (lZ)].99 Deoxy-ribonucleic acids so treated are said to be denatured.lW Denaturation hasGuanine Cytosine Guanine + protonalso been induced lol by dialysis against water which lowers the pH to 2.6.Removal of the salt by dialysis at pH 6.5 also causes denaturation becauseit raises the pK, of guanylic acid to this value, whereas removal of the saltat pH 8 does not cause denat~ration.~~ Titration of deoxyribonucleic acidswith alkali produces the same irreversible changes since, contrary to previousobservations,g7* lo2 the back-titration curves after mild acid- and alkali-treatment are found to be coincident with one an0ther.10~ A method has95 G.R. Barker, Ann. Reports, 1954, 51, 279.96 L. F. Cavalieri and A. L. Stone, J . Amer. Chem. Sot., 1955, 77, 6499.97 D. 0. Jordan, A. R.Mathieson, and S. Matty, J., 1956, 154, 158.9s L. F. Cavalieri, M. Rosoff, and B. H. Rosenberg, J . Amer. Chem. Sot., 1956,78,L. F. Cavalieri and B. H. Rosenberg, Biochim. Biehys. Ada, 1966, 21, 202.6239.100 R. Thomas, ibid., 1954, 14, 231.101 C. A. Thomas and P. Doty, J . Amer. Chem. Sac., 1956, 78, 1854.109 W. A. Lee,and A. R. Peacocke, J., 1951, 2361.10s R. A. Cox and A. R. Peacocke, J., 1956, 2499SMITH : NATURAL MACROMOLECULES. 267been described whereby the fraction of hydrogen bonds which have beenruptured is determined by progressive displacement in the forward titrationcurve over pH 7-3; denaturation by heat only occurs above 75” and thereis a linear relation between the fraction of hydrogen bonds permanentlybroken and the increase in extinction at 260 mp.104 X-Rays cause anincreased susceptibility to denaturation by heat,lo5 and there is evidence forformation of hydroperoxides.lo6 The kinetics of enzymic digestion of deoxy-ribonucleic acids have been examined and the results indicate a two-strandstructure in which the number of pre-formed gaps before enzymic attack isnot more than one in three thousand nucleotide residues.106aLignins.-Since our last Report on this subject,lo7 interest in lignins hasincreased with the publication of about six hundred further papers, andseveral recent reviews.lO*-lll At no stage has a point been reached at whichit is possible to deduce a reliable structure for lignins.Lignins occur in their most concentrated form in woodand nearly all investigations have used this source. Methods of extractionfall into two classes, those dissolving the accompanying polysaccharide, andthose dissolving lignins.In the former, alkaline copper solution,lf2 periodicacid,l13? 11* and strong mineral acids 115 have all been shown to react withlignins, so that the preparations are not chemically identical with lignins asthey occurred in wood. In the latter class, reagents which dissolve thegreater part of lignins-sodium hydrogen sulphite, sodium hydrogen sul-phide, mercaptoacetic acid, sodium hydroxide, and mineral acid in organicsolvents-all combine with them and induce partial depolymerisation. Itwas shown recently that extraction of lignins from wood meal with ethanolichydrogen chloride can be carried out under milder conditions than werepreviously used.l16Of great practical significance was the discovery by Brauns l 1 7 that coldalcohol, without any acidic or basic reagent, extracts from wood mealssubstances having all the chemical properties hitherto associated with lignins.Extractions.lo4 R.A. Cox and A. R. Peacocke, J . , 1956, 2646.lo5 K. V. Shooter, R. H. Pain, and‘J. A. V. Butler, Biochim. Biophys. Acta, 1956,lo6 G. Scholes, J . Weiss, and C. M. Wheeler, Nature, 1956, 173, 157.lo60 V. N. Schumaker, E. G. Richards, and H. K. Schachman, J. Amer. Chem. SOC.,lo7 E. G. V. Percival, Ann. Reports, 1942, 39, 142.Io8 R. D. Haworth, “ Thorpe’s Dictionary of Pure and Applied Chemistry,” 4thedn., 1946, Vol. VII, p. 307; E. Hagglund, “ Chemistry of Wood,” Academic Press Inc.,New York, 1951; L.E. Wise and E. C. Jahn, “ Wood Chemistry,” Reinhold Publ.Corp., New York, 1952; K. Freudenberg in “ Moderne Methoden der Pflanzenanalyse,”K. Paech and M. V. Tracey, Springer, Berlin, 1955, Vol. 111, 509; K. Freudenberg,Angew. Chem., 1966, 68, 84.20, 497.1956, 78, 4230.loQ H. Erdtman, Research, 1950, 3, 63.l10 F. E. Brauns, “ Chemistry of Lignin,” Academic Press Inc., New York, 1952.ll1 K. Freudenberg, Fmtschr. Chem. org. Naturstofle,’ 1954, 11, 45.112 I. Pearl, J. Amer. Chem. SOL, 1950, 72, 2309.113 D. Pennington and D. M. Ritter, ibid., 1947, 69, 187; P. F. Ritchie and C. B.114 E. Adler and S. Hernestam, Acta Chem. Scand., 1955, 9, 319.116 H. G. Arlt, K. Sarlranen, and C. Schuerch, ibid., 1956, 78, 1904.117 F.E. Brauns, ibid., 1939, 61, 2120.Purves, Pulp and Paper Mag., Canada, 1947, 48, No. 12, p. 74.D. E. Read and C. B. Purves, J. Amer. Chem. Soc., 1952, 74, 120268 ORGANIC CHEMISTRY.The term " native lignins " has been transferred to these preparations and,though the yield is very small, they have been selected for investigation inmuch subsequent work. Native lignins have been prepared from blacks p r ~ c e , l l ~ - ~ ~ ~ western hemlock,122 a ~ p e n , l ~ ~ * 124 Scots pine,l25~ 126 oak, birch,maple,127* la8 bagasse,lzs9 129 wheat,130* 13l horse chestnut, and Douglas fir.131The question of whether native lignins are truly representative of lignins intheir insoluble condition in wood has been discussed.128 Brown rots, fungiwhich degrade polysaccharide more rapidly than lignins, have been shownto liberate to solvent extraction increasing amounts of material from wood,similar to native lignin~,l~~* 133 but differences between native and fungus-released lignins are sometimes observed.lls The method of extraction doesnot separate native lignins from other macromolecular phenolic substancesand so is unsatisfactory with plant tissues that contain such substances.laThorough crushing of wood meal has been reported to release no morelipins to solvent extraction,llg but Bjorkman has reported that if conditionsfor grinding give the minimum particle size and do not favour swelling of theparticles then two-thirds of the lignins of wood meal become extractable bycarefully chosen solvent mixtures." Milled wood lignins " obtained in thisway are less soluble than, but show only small quantitative differences from,the native lignins of the same wood.121 A native lignin has been separatedinto fractions of varying molecular weight, showing slight systematic vari-ations in composition but essentially the same infrared spectra.120 Nativelignin, as usually prepared, is only one of several fractions in the cold-alcoholic extract of wood ; the ether-soluble fraction rejected during isol-ation of native lignin has been found to resemble native lignin in somerespects at least, and it may contain lignins of low molecular weight.12*Despite the objection that native lignin constitutes only a small percentageof the total lignin of wood, it remains the purest and most convenientmaterial for degradative work and, once a point has been established fornative lignin, it can often then be repeated, providing polysaccharides donot interfere, with whole WOO^.^^^^ 135These are particularly important since they offerthe best hope of establishing the structuie of lignins.Degradation methods.118 A.Apenitis, H. Erdtman, and B. Leopold, Suertsk Kent. TidsFzr., 1951, 65, 195.119 F. E. Brauns and H. Seiler, TAPPI, 1952, 35, 67.121 A. Bjorkman, Nature, 1954, 174, 1057.l2% F. E. Brauns, J . Org. Chew., 1945, 10, 211.l a 3 M. A. Buchanan, F. E. Brauns, and R. L. Leaf, J . Amer. Chem. SOL, 1949, 71,u 4 D. C . C. Smith, J., 1935, 2347.125 W. J. Schubert and F. F.Nord, J . Amer. Chem. SOL, 1950, 72, 977, 3835.126 S. F. Kudzin, R. M. DeBaun, and F. F. Nord, Z%d, 1951, 73, 4615.127 S. F. Kudzin and F. F. Nord, ibid., p. 4619.128 G. DeStevens and F. F. Nord, ibid., p. 4622; 1953, 35, 305.129 D. C. C. Smith, Nature, 1955, 176, 267.130 J. E. Stone and K. G. Tanner, Canad. J . Chem., 1952, 30, 166.131 D. C. C. Smith, Nature, 1955, 176, 927.132 WT. J. Schubert and F. F. Nord, J . Amer. C h m . Soc., 1950, 72, 977, 3835.133 S. F. Kudzin and F. F. Nord, abid., 1951, 73, 4615, 4619.134 R. M. DeBaun and F. F. Nord, ibid., p. 1358.135 J. C. Pew, ibid., 1952, 74, 5784.C. L. Hess, ibid., p. 312.1297SMITH : NATURAL MACROMOLECULES. 269(a) Mild alkaline oxidation. Under these conditions, p-hydroxybenz-aldehyde , vanillin (4-l-iydroxy-3-methoxybenzaldehyde), and syringaldehyde(4-hydroxy-3 : 5-dimethoxybenzaldehyde) are produced, owing their survivalunder oxidising conditions to the stability of their mesomeric anions.Nitro-benzene is most frequently used as the oxidising agent 136 but amine oxides,sulphones , sulph~xides,~~~ cupric salts,138 and cobalt salts 139 have beenused. When silver oxide is used as the oxidising agent vanillic acid ratherthan vanillin is produced 140 and, with mercuric oxide, 5-hydroxymercuri-vanillin is 0btained.1~1Optimum conditions for oxidation of wood with alkali and nitro-benzene have been 143 and this reaction has been adapted forthe determination of lignins.la? 145 Lignins of twenty-seven conifers havebeen found to give mainly vanillin (-30% yield).146 This accords with theirmethoxyl content (-15%) which indicates mainly guaiacyl (4-hydroxy-3-methoxyphenyl) nuclei in these lignins.Minor constituents detected inthe oxidation product of spruce lignin inciude substances linked throughposition 5 to carbon such as 5-f0rmylvanillin,~~~ dehydrodi~anillifi,~~~5-formylvanillic acid ,147 5-carboxyvanillin,136* 148 and dehydrodivanillicacid.138 It is not known whether this linkage through position 5 is anintegral feature of lignin or is established during alkaline oxidation. Oxid-ation of model compounds by alkali and nitrobenzene shows that nearly allsubstances having a guaiacyl or veratryl nucleus give considerable amountsof ani ill in.^^^^ 149-152 It has been established that the yield of aldehydes isdetermined by the mode of linkage of the aldehyde-yielding residues ratherthan by any instability of the aldehydes under the conditions of 0 ~ i d a t i o n .l ~ ~The view has been expressed that there are ‘ I open units ” which are notlinked to carbon through C , and give rise to vanillin, and I ‘ condensed units ”which give rise to small amounts of 5-formylvanillin on oxidation by nitro-benzene in alkali.142 Evidence for some “ open units ” in lignins is affordedby the coupling of lignins with aryldiazonium salts,l10 and the formation of5-iodovanillin by alkaline oxidation of spruce lignin first mercurated withmercuric acetate and then treated with iodine.139 It has also been suggestedthat the majority of aromatic units in spruce lignin are of the uncondensedtype.lB138 K.Freudenberg, W. Lautsch, and K. Engler, Bey., 1940, 73, 167.137 P. Lagally, U.S.P. 2,547,913; Chem. Abs., 1951, 45, 8043.138 I. Pearl, J . Amer. Chem. SOC., 1942, 64, 1429; 1950, 72, 2309.139 W. Lautsch and G. Piazolo, Ber., 1940, 73, 317.140 I. Pearl, U.S.P. 2,483,559; Chew. Abs., 1950, 44, 1706.141 H. F. Lewis and I. Pearl, U.S.P. 2,489,380; Chem. Abs., 1950, 44, 1706.142 B. Leopold, Acta Chem. Scand., 1950, 4, 1523.143 K. €3. Kavanagh and J. M. Pepper, Canad. J . Chem., 1955, 33, 24.Ip4 J. E. Stone and M. J. Blundell, AnaZyt. Chem., 1951, 23, 771.145 F. E. Roadhouse and D. MacDougall, Biochem. J., 1956, 68, 33.146 B. Leopold and I.-L. Malmstriim, Acta Chem. Scand., 1962, 6, 49.lS7 B.Leopold, ibid., p. 38.lp8 K. Freudenberg and F. Klink, Ber., 1940, “3, 1369.140 A. V. Wacek and K. Kratzl, ibid., 1944, 77, 516.150 K. Kratzl and I. Khautz, Monatsh., 1948, ‘98, 376.151 B. Leopold and 1.-L. Malmstrdm, Acta Chem. Scand., 1951, 5, 936.15* B. Leopold, ibid., p. 1393.168 J. C. Pew, J . Amer. Chem. Soc., 1055, ‘97, 2831270 ORGANIC CHEMISTRY.Oxidation of hard-wood lignins by nitrobenzene in alkali yields, underoptimum conditions, mainly syringaldehyde (about 36%) and vanillin(15%).1437 146 The total yield of pure aldehydes reaches its highest in theselignins and accounts for about 60% of the original lignin substance. Theratio of syringaldehyde to vanillin in the product of oxidation is twice aslarge as the ratio of syringyl to guaiacyl residues indicated in the originallignin by its methoxyl content; since syringyl residues cannot form con-densed units by linkage to carbon through position 5, this lends furtherweight to the evidence for condensed units involving guaiacyl residues.The lignins of grasses and cereals yield $-hydroxybenzaldehyde as well asvanillin and ~yringaldehyde.1~~ The yield of P-hydroxybenzaldehyde varieslittle, that of vanillin increases slightly, and that of syringaldehyde increasesmarkedly with the age of the ~lant.14~ Sphagnum moss contains a ligninof very small methoxyl content, yielding mostly 9-hydroxybenzaldehyde onoxidation with nitrobenzene in alkali.155(b) Drastic oxidation.Oxidation of methylated lignins by alkalinepermanganate yields a small amount of isohemipinic acid (1),156 additionalevidence for the presence of condensed guaiacyl residues in lignins.Ligninswhich have been previously exposed to the action of strong acid yield a littlemetahemipinic acid (2) on methylation and 0xidation.1~7 It has been sug-gested that strong acid induces coniferaldehyde groups to condense withguaiacyl residues 158 and the isolation of metahemipinic acid seems to con-firm this. Small amounts of benzene-penta- and -1 : 2 : 3 : 4-tetra-carboxylicacid have been obtained in alkaline permanganate oxidation of lignins, butthe amounts obtained from whole wood were very small, indicating thatthese products result from oxidation of condensed structures producedmainly during the isolation of lignins.l15Alcoholysis of lignins produces products containing C-methyl groups (seebelow) but, since chromic acid yields negligible amounts of acetic acid, thesecan be considered absent from lignins themselves.159Hydrogenation of lignins at elevated temperatureand high pressure renders them entirely soluble in chloroform. Besidesmethanol and a complex residue,lw9 161 compounds (3)-(5) ,162 (6),160(7),161 (8)-(1O),l6O and (11)-(13) 163 have been isolated and characterised.(c) Hydrogenolysis.154 R. H. J. Creighton and H. Hibbert, J . Amer. Chem SOC., 1944, 66, 37.156 B. Leopold and 0. Theander, Acla Chem. Scand., 1952, 6, 311; V. C. Farmer,156 K. Freudenberg, A. Janson, E. Knopf, and A. Haag, Ber., 1936, 69, 1415.lB7 H.Richtzenhain, Acta Chem. Scand., 1950, 4, 589.15* J. C. Pew, J . Amer. Chem. SOC., 1952, 74, 2850.159 W. S. McGregor, T. H. Evans, and H. Hibbert, ibid., 1944, 66, 41.160 C. P. Brewer, L. M. Cooke, and H. Hibbert, ibid., 1948, 70, 57.161 C. Schuerch, ibid., 1950, 72, 3838.162 E. E. Harris, J. D’Ianni, and H. Adkins, ibid., 1938, 60, 1467.163 J. M. Pepper, C . J. Braunstein, and D. A. Shearer, ibid., 1951, 73, 3316.Research, 1953, 6, 475SMITH : NATURAL MACROMOLECULES. 27 1Together with methanol, compounds (3)-(5) accounted for 62% of thesubstance of aspen lignin. 162 Hydrogenolysis under acid conditions yieldsphenylpropane derivatives whereas in alkaline conditions phenylethanederivatives predominate. 163Cleavage of lignin by sodium in liquid ammonia has yielded the phenols(14),164 probably (15),165 and (16)J166 all in small yield together with a com-plex residue.Using potassium in liquid ammonia, Freudenberg et al. wereable to reduce the methoxyl content of spruce lignin from 15% to 6%.16'( d ) Acid-catalysed alcoholysis. Treatment of wood with warm alcoholichydrogen chloride yields three fractions derived from lignin : one ether-soluble and of low molecular weight, one soluble in alcohol but not in ether(" alcohol lignin "), and one insoluble and adhering to the residual poly-saccharide. The ether-soluble fraction has been shown to consist largelyof substances RCHO R*CO*COMe, R*CH,*COMe, and R*CO*CHMe*OR',where R = P-hydroxyphenyl, guaiacyl, or syringyl, and R is the alkylresidue of the alcohol used.In the reaction of ethanolic hydrogen chloridewith maple wood these substances (R = guaiacyl and syringyl) amount to9.8% of the original lignin. 168 Paper-chromatographic methods of separat-164 N. N. Shorygina, T. Ya. Kefeli, and A. F. Semechkina, Zhur. obshchei Khim.,165 N. N. Shorygina and T. Ya. Kefeli, ibid., 1950, 20, 1199.lB6 A. F. Semechkina and N. N. Shorygina, ibid., 1963, 23, 593.ld7 K. Freudenberg, K. Engler, E. Flickinger, A. Sobek, and F. Klink, Bey., 1938,1949,19, 1558.71. 1810.lS8 M. Kulka, E. Fisher, S. B. Baker, and H.66, 39.Hibbert, J . Amer. Chem. Soc., 1944272 ORGANIC CHEMISTRY.ing these substances (R = guaia~yl,16~ 9-hydroxyphenyl, and syringyl I7O)have been described,The lignin of spruce wood has been recovered in 60% yield as " ethanol-lignin " under mild conditions.171 It has a ratio of methoxyl to carbon closeto the theoretical value for a propylguaiacol polymer,172 and has beenallocated an average empirical formula (24).The acquired alkoxyl groups of '' alcohol lignins " are stable to alkaliand hydrolysed in acid.173 There is strong evidence that the alkylatablegroups in lignins are $-hydroxy- and P-alkoxy-benzyl alcohol and -benzylether groups (17)-(20), the group OR' in the ethers, like the hydroxyl groupof the benzyl alcohols, being replaced by the alkoxyl group derived from thes01vent.l~~ Since such benzyl ether linkages may connect parts of thelignin molecule it is not surprising that substances of lower molecular weightare released in alcoholysis.Study of model substances shows that com-pounds of type (17) and (18) react more rapidly with methanolic hydrogenchloride than do their ethers (19) and (2O).17*(e) Sulphonation. Treatment of spruce wood with a solution of sodiumsulphite and sodium hydrogen sulphite (pH 5.25) at 135" dissolves part ofthe lignin as a sulphonic acid derivative and leaves the remainder, alsocontaining sulphonic acid groups, insoluble and adhering to the residualpolysaccharide. 110 Holmberg found that phenylmethanols react withsulphite as ROH + NaHSO, _t R*SO,Na + H,O and suggested thatbenzyl alcohol groups in the lignin react with sulphite in this way.175 Modelcompounds having structural units (17)-(20) have been sulphonated andcompared with lignin with respect to the pH requirements and velocity of~ulphonation.~~~? 177 Lindgren concludes that structures of all types(17)-(20) are present in lignin and that all the sulphonatable groups inlignin have this type of structure.177The water-soluble ligninsulphonic acids have been separated into frac-tions of widely differing molecular weight by dialysis, 17* fractional precipit-a t i ~ n , l ~ ~ $ lSo and fractional elution 181 of their salts.The ratio of sulphoniclo@ K. Kratzl and W. Schweers, Monutsh., 1954, 85, 1046, 1166.170 Idem, ibid., 1956, 89, 186.171 H. G. Arlt, K. Sarkanen, and C. Schuerch, J . Amer. Chem. SOL, 1962, 73, 4996.17a C. Schuerch, ibid., p. 4996.178 F. E. Brauns, ibid., 1946, 68, 1721.17' E.Adler and J. Gierer, Acta Chem. Scand., 1955, 9, 84.176 S. Heden and B. Holmberg, Svensk hem. Tidskr., 1936, 48, 207.176 B. 0. Lindgren, Acta Chem. Scund., 1948,1, 779; 1949, 3, 1011; 1950, 4, 1365.177 I d c m , ibid., 1951, 5, 603.178 K. Schwabe and L. Hasner, Cellulosechem., 1942, 20, 61.179 W. Lautsch and G. Piazolo, ibid., 1944,22, 48.lSo K. Schwabe and L. Hahn, Holzi-foorsch., 1947, 1, 42, 79; E. D. Olleman, D. E.Pennington, and D. M. Ritter, J . Colloid Scz., 1948, 3, 185; A. E. Markham, Q. P.Peniston, and J. L. McCarthy, J . Amer. Chem. Soc., 1949, 71, 3599; J. Moacanin,V. F. Felicetta, W. Haller, and J. L. McCarthy, ibid., 1955, 77, 3470.V. F. Felicetta, A. hhola, and J . L. McCarthy, i b i d . , 1966, 78, 1899SMITH : NATURAL MACROMOLECULES.273acid to guaiacyl groups varies 179 between 0.5 and 1.0, and the lignin sul-phonic acids of lowest molecular weight can be separated by ionophoresisinto four groups of anionic substances of distinct mobilities, presumablycorresponding to simple values of this ratio. In accordance with this, theionophoresis patterns increase in complexity with fractions of increasingmolecular weight The prospect of isolating some of the simpler sulphonicacids by chromatographic procedures seems to be quite good.SulphidesJ1s2 mercaptoacetic acid,lB* l g 4 and thiols la5 have also beenshown to react analogously to sulphite.Reactive Groups in Lipins.-(a) Phenolic groups. Lignins owe theirability to dissolve in aqueous alkali (pH >10-4) to the possession of phenolicgroups.Attempts to carboxylate these according to the Kolbe-Schmittprocedure were unsuccessful. l86 Chemical methods of determining phenolicgroups include reaction with l-fluoro-2 : 4-dinitrobenzeneJ1l1 reaction withtoluene-9-sulphonyl chloride followed by reaction with hydrazine,ls7 anddifferential methylation with trimethylphenylammonium hydroxide.ls8Differential methylation by diazomethane is not successful.lll The absorp-tion band at 280 mp characteristic of phenolic ethers and phenols moves tolonger wavelength in the case of phenols when they ionise. This has beenused to determine free phenolic groups,189v l90 but it is only accurate whenonly one type of phenolic chromophore is present in lignin.The splitting off of methanol from guaiacyl residues when they aredehydrogenated with periodate (cf.reactions of 21) has been made the basisof a method for estimating such groups in lignin.114 Model compounds give90% yields of methan01.l~~Gierer lgl has used the reaction of quinone monochloroimide with @-hydr-oxyphenylmethanol groups (22) to determine the proportion of such groupsin lignins, the amount of indophenol (23) released being estimated colori-metrically.Determination of phenolic groups by titration in acet~ne-ethanol,~~~1 8 2 D. L. Brink, R. L. Hossfeld, and W. M. Sandstrom, J . Amer. Ghem. SOC., 1949,183 B. Holmberg and N. Gralen, Ing. Vetenskaps. Akad. Handl., 1942, No. 162.184 B. Holmberg, Finska Kemistsamfundets Medd., 1945, 54, 124.lS5 F. E. Brauns and M.A. Buchanan, Paper Trade J . , 1946, 122, No. 21, 49.lS6 M. M. Yan and C. B. Purves, Camad. J . Chem., 1956,34, 1582.K. Freudenberg and H. Walch, Ber., 1943, 76, 305.lB8 K. Freudenberg, Das Papier, 1947, 1, 209.lSB G. Aulin-E~dtman, Svensk Papperstidn., 1954, 57, 745.lB0 0. Goldschmid, Analyt. Chem., 1954, 26, 1421.lgl J. Gierer, Acta Chem. Scand., 1954, 8, 1319.lg2 K. Sarliancn and C. Schuerch, Aizal3.t. Chem., 1955, 27, 1245.71, 2275 ; T. Enkvist and E. Hagglund, Svensk Papperstidn., 1950.53, 85274 ORGANIC CHEMISTRY.dimethylformamide, dimethyl sulphoxide,lYd and ethylenediamine 194 hasbeen described. It is also possible to titrate them in aqueous solutionprovided the end-point is approached from the alkaline ~ide.12~Empirical formulae for spruce lignins have been derived from analyses ofethanol lignin (24) ,116 mercaptoacetic acid lignin (25) ,lS3 ligninsulphonicacid (26),lo9 and native lignin (27).loS Native lignin from spruce generally(24) CuH,.,O,.,(OMe)o.a,(OEt)~.~(25) CpH,.o,Oz-es(OMe)o.oz + HS*CHz*CO2H - H,O(26) Cu&.,0z.6(OMe)o.a~ + H,SO, - H,O(27) C B H ~ .~ O ~ . ~ ( O M ~ ) ~ . ~contains 0.5 phenolic hydroxyl group per guaiacyl residue, and 0.9 aliphatichydroxyl group 111 of which approximately two-thirds are primary as judgedby their reactivity.lsS Together, these account for 1.4 oxygen atoms perguaiacyl residue. Most of the oxygen not accounted for as hydroxyl ormethoxyl (1.0 atom per guaiacyl residue) is thought to occur in etherlinkages. 111(b) Carbonyl groups.These have been estimated in lignins by reactionswith hydroxylamine hydrochloride and titration of the liberated acid. 174The presence of 9-hydroxybenzoyl residues (28) has been inferred from theincrease in absorption at 350 mp when lignin is made alkaline; 131* lg5 suchgroups show a shift of the main absorption band from 278-307 to 330-364 mp on ionisation. 9-Alkoxyphenyl ketones (29) ionise in strong sul-phuric acid with a similar shift of absorption, and it has been claimed thatR'= a l k y l ; R'=H or Methe greater increase in absorption at 350 mp when lignin is dissolved instrong sulphuric acid is a measure of the presence of these groups.lg5 Thiscannot be taken as reliable since, at the temperature used, acid of thisstrength induces irreversible changes in the absorption spectrum of lignins.The most characteristic and universal colour reaction of lignins, a redcolour with phloroglucinol and strong acid (" the Wiesner reaction "), hasbeen shown to be given also by coniferyl (ferulic) aldehyde (3O),lg6 which canbe split off from lignins in small yield by heating them with stannic chloridesolution. lg6* lg7 Colorimetric estimations of the number of bound coniferylaldehyde groups in spruce lignin give one per forty 198 and one per thirty-six lg9 guaiacyl residues.The coloured complex given by lignin, resorcinol,and strong acid, and the coloured product formed on acidifying the productla3 J. P. Butler and T. P. Czepiel, AnuZyt. Chem., 1966, 28, 1468.lS4 K.Freudenberg and K. Dall, Nuturwiss., 1955, 42, 606.195 0. Goldscmid, J . Arner. Chem. Soc., 1953, 75, 3780.lS6 E. Adler, K. J. Bjorkqvist, and S . Naggroth, Actu Chem. Scand., 1948, 2, 93.la' F. Czapek, 2. physiol. Chem., 1899, 287, 141.1Q8 E. Adler and L. Ellmer, Actu Chem. Scund., 1948, 2, 839.10a J. C. Pew, J. Amer. Chem. Sot., 1951, 75, 1678SMITH NATUKAL MACROMOLECULES. 275of catalytic hydrogenation of 7 : 4'-dihydroxy-3'-methoxyflavanone, havebeen shown to have identical absorption spectra due to a mesomeric cation(31).19!) The green colour given by lignins in strong acid has been shown toconsist of two absorptioii bands. One absorption max. at 453 mp is due tothe conjugate cation of bound coniferyl aldehyde groups (32) ; the other, at628 mp, fails to appear at -30" and has been attributed to condensation ofconiferyl aldehyde groups with other guaiacyl residues.lS8H o o ; ~ . c H : w O o - H;:CH.CH : m o o -(31) OH OMe OMe (32)That the phenolic oxygen atom is engaged in binding the coniferylaldehyde group to the rest of the molecule is indicated by the reaction of thisgroup with cold dilute alkali. Acetaldehyde is split off in a reversed-aldolreaction, leaving an etherified vanillin residue.200 The reaction can befollowed spectrophotometrically.131 The reaction would not have beenpossible if the phenolic hydroxyl groups of the bound coniferyl aldehydehad been free; instead, a stable yellow anionic group would then have beenformed by ionisation. It has been suggested that the bound coniferylaldehyde residues constitute end-groups of lignin.lg6 They can be deter-mined by reduction with borohydride, followed spectrophotometrically ; theonly other carbonyl-containing residues that absorb at the same wavelengthare anionic in dilute alkali and therefore reduced only very s10wly.l~~ Thebound coniferyl aldehyde groups show a distinct band at 1657-1662 cm.-lin the infrared absorption spectrum of 1igni11s.l~~(c) Ester groups.9-Hydroxybenzoate groups have been detected inaspen lignin. They occur singly, involving aliphatic hydroxyl groups andamount to one-tenth of the 1ig11in.I~~ One-tenth of sugar-cane lignin con-sists of +-coumaric ester groups and there is evidence for +-coumaric andferulic ester groups in wheat-straw lignin.lZ9Biosynthesis of Zignin.Wheat plants began to incorporate 14C intolignin five hours after labelled carbon dioxide was supplied, as judged by theactivity of the vanillin and syringaldehyde obtainable on oxidation withalkali and nitrobenzene.201 The activity of labelled phenylalanine, tyro-sine, and cinnamic acid is incorporated efficiently in p-hydroxybenzaldehyde,vanillin, and syringaldehyde obtainable from wheat lignin.202 There is aparticularly good recovery of activity in the vanillin fraction after wheatplants have been fed with labelled ferulic acid.202 Of ten other speciesexamined, labelled tyrosine was incorporated in only one instance, thoughincorporation of the other substances mentioned was quite general.203Feeding shikimic acid (generally labelled) and phenylalanine (generallylabelled) to cut maple stems, followed by oxidation with nitrobenzene inalkali of the cell-wall fraction, yielded labelled vanillin and labelled syring-aldehyde ; the activity of protocatechuic acid (carboxyl-labelled) was not2oo K.Kratzl and G. Hofbauer, Monatsh., 1956, 87, 617.201 S. A. Brown, K. G. Tanner, and J. E. Stone, Canad. J . Chem., 1953, 31, 755.202 S. A. Brown, F. M. Claire, and M. D. Chisholm, Canad. J . Biochem. Physiol.,203 S. A. Brown and A. C. Neish, ibid., 1956, 54, 749.1955, 33, 948276 ORGANIC CHEMISTRY.incorporated.2a There can be little doubt that shikimic acid can act as adirect precursor of lignin, in view of the discovery 205 of a specific pattern oflabelling in vanillin (34) after sugar-cane plants have been fed with shikimicacid labelled in the 2- and the 6-position (33).$02H CHOS u g a rHO '0 HOH(33)Asterisks indicate '*C, numbers indicate relative radioactivity.Dehydrogenation of p-hydroxycimamyZ alcohols in vitro.Following thesuggestion by P. Klason %06 that lignin is related to coniferyl alcohol (4-hydr-oxy-3-methoxycinnamyl alcohol) which is present as the glucoside coniferin(35) in young tissue and in the cambial sap of trees, Freudenberg discoveredthat a crude extract of mushroom was capable of dehydrogenating coniferylI? OH (35)B: CHY* CH 2- OHalcohol in vitro to an amorphous substance of high molecular weight, whichhe termed " Dehydrierungspolymerisat " (DHP).207 The same mushroomextract had been previously found to have a similar effect on isoeugenol.208DHP of coniferyl alcohol, and the native lignin of black spruce wood, havean impressive similarity which takes in such properties as elementaryanalysis, colour reaction with phloroglucinol, solubility, oxidation to vanillin,hydrolysis in 28% sulphuric acid to small amounts of formaldehyde, methyl-ation followed by oxidative degradation to small amounts of isohemipinicacid, content of phenolic and aliphatic hydroxyl groups, acid-catalysedethanolysis, sulphonation with bisulphite, and ultraviolet and infraredspectra.209 DHP and native spruce lignin are said to differ in their behaviourtowards acetic anhydride in acetic acid.210 Native lignin also containsslightly less mcthoxyl than DWP.l1l 4-Hydroxycinnamyl alcohol,2114-hydroxy-3-methoxycinnamyl methyl ether,212 3 : 4dihydroxycinnamylalcohol, and 3 : 4 : 5-trihydroxycinnamyl alcohol 213 also give DHP's.Neither labelled 3 : 4-dimethoxycinnamyl alcohol nor labelled vanillin is204 S. A. Brown and A. C. Naish, Nature, 1955, 175, 688.206 G. Eberhardt and W. J. Schubert, J . Amer. Chem. SOL, 1956, 78, 283.eo6 P. Klason, Svensk kem. Tidskr., 1897, 9, 135.207 K. Freudenberg, Angew. Chem., 1949, 61, 228.* 0 8 H. Cousin and H. Herissey, Compt. rend., 1908, 147, 247.2oa K. Freudenberg, Sitzungsber. Heidelberg Akad. Wiss., 1949, No. 5; K. Freuden-*1O Idem, Naturwiss., 1954, 41, 232.211 K. Freudenberg and G. Gehrke, Chem. Bey., 1961, 84, 433.212 K. Freudenberg and F. Bittner, ibid., 1952, 85, 86.213 K. Freudenberg and W. Heel, ibid., 1953, 86, 190.berg et al., Chem. Bey., 1950, 83, 519, 530, 533; 1951, 84, 961SMITH : NATURAL MACROMOLECULES. 277incorporated in the DHP formed by coniferyl alcohol,214 demonstrating theimportance of both the free phenolic group and the double bond of the sidechain in DHP formation. Sinapyl alcohol (4-hydroxy-3 : 5-dimethoxy-cinnamyl alcohol) does not give a DHP with mushroom extract, forminginstead nL-synringaresinol (36) 2159 216 whose structure has been proved bysynthesis.217 However, sinapyl alcohol is incorporated in the DHP formedby a mixture of sinapyl and coniferyl alcohol.216Erdtman has suggested that the initial step in dehydrogenation of coni-feryl alcohol is removal of the phenolic hydrogen atom, leaving a phenoxideradical (38), the effect of the double bond in the side chain being to transferfree-radical reactivity to the p-position of the side chain as in (38c).lo9 Theradical (3%) would be expected to combine with another molecule of coni-feryl alcohol in one of the three positions p, 5, and 04, splitting off thephenolic hydrogen of the second coniferyl alcohol residue as a hydrogen atom,and yielding intermediate dimeric products (39), (40b), and (41) respectively.(4Ca) t HCH~.OH+ R'OH OoMe CHeOU'IThe reactive quinone methine structure possessed by (39)-(41) has beensuggested as an integral step in lignificati~n.~O~$ The quinone methinewould be expected to add a group O R at the cc-position of the side chain(cf. 42). In the context of lignification or DHP formation, O R could bethe phenoxide or the y-alkoxide group of another molecule of coniferylalcohol, or OH.214 K. Freudenberg and W. Fuchs, Chem. Ber., 1954, 87, 1824.216 K. Freudenberg et al., ibid., 1951, 84, 472.218 K. Freudenberg and H. €3. Hubner, ibid., 1952, 86, 1181.217 K. Freudenberg and H. Schraube, ibid., 1955, 88, 16.218 K. Freudenberg, Chew.-Ztg., 1960, 74, 12278 ORGANIC CHEMISTRY.Dimeric products representing three of the nine possible combinationsdescribed above have been isolated from the filtrate after DHP formationfrom coniferyl alcohol by mushroom extract. Dehydrodiconiferyl alcohol(43) (successive reaction with the 5-posi-tion of another molecule, and reactionwith the phenoxide group of that same OoMe CH.OH molecule) and m-pinoresinol (37) (suc-cessive reaction with the P-position ofanother molecule, and reaction with the Meo(y::2.0H y-alkoxide group of that same molecule):H have been obtained crystalline.219 InCHz'OH CH :H addition, syrupy cc-guaiacylglycerolaction with the 04-position of anothermolecule and with OH) was isolated by countercurrent distribution 219 andcharacterised by conversion into the 2 : 4-dinitrophenyl ether of its dihydro-derivative and by synthesis.220Freudenberg has suggested that these are intermediates (" sekundareBausteine ") in lignin formation. However, none of the three dimericproducts isolated has retained the reactive P-hydroxystyrene system and sothey may be by-products rather than intermediates in DHP formation.Each of them is, however, further dehydrogenated in mushroom extracts.During the formation of intermediate dimers (39), (40), and (41) a newasymmetric centre is created. If both reacting molecules of coniferylalcohol are engaged in an enzyme complex one would expect the new asym-metric centre to have a single enantiomeric configuration. With the natur-ally occurring lignans this is found to be the case.221 In contrast, both thepinoresinol and the syringaresinol synthesised in mushroom extracts areracemic. Such measurements as have been made l1ll 222 indicate thatnative lignin has no optical activity, suggesting that, though enzymes areconcerned in producing reactive intermediates from coniferyl alcohol, theactual polymerisation step of lignin formation is a more random process.Whether, as the weight of present evidence indicates, lignin and the DHP ofconiferyl alcohol as prepared in vitro have the same structure will be decidedonly when the structural pattern of these substances has been adequatelyestablished.OeMcMeo($: CH2.0H(1 3 ) CH2,0H P ( 4 4 ) p-coniferyl ether (44) (successive re-D. C. C. S.G. BADDELEY. T. G. HALSALL.P. BLADON. J. HONEYMAN.L. CROMBIE. D. C. C. SMITH.M. J. S. DEWAR. G. F. SMITH.R. F. GARWOOD. W. WILSON.A. R. BATTERSBY. H. B. HENBEST.zls K. Freudenberg and H. Schluter, Chem. Bey., 1955, 88, 617.220 K. Freudenberg and W. Eisenhut, ibid., p. 626.221 W. M. Hearon and W. S . MacGregor, Chem. Rev., 1955, 55, 957.232 33. Holmberg, Finska Kemistamfundets Afedd., 1945, 54, 124; D. C. C . Smith,unpublished observation

ISSN:0365-6217    

DOI:10.1039/AR9565300126

出版商:RSC    

年代:1956

数据来源: RSC

摘要:

BIOLOGICAL CHEMISTRY.1. INTRODUCTION.IN the present Report fields of active research in biological chemistry havebeen covered which have not been reported upon before in Annual Reports.The metabolism of aromatic compounds by bacteria is now a growing andimportant field and has applications in relation to the destruction of herbi-cides by soil bacteria and the disposal of aromatic wastes in sewage. Thehighly toxic organophosphorus compounds were originally investigated aspotential chemical-warfare agents, but have now found use in agricultureas insecticides, Many of them are powerful inhibitors of esterases, and astudy of their biochemical behaviour has given an insight into the mechanismof enzyme action and, in particular, has enabled us to characterize theactive centres of esterases.The field of steroid chemistry and metabolismis now expanding at a tremendous rate, and a report on some aspect of thesteroids is almost an annual feature of some section or other of the Reports.It is not surprising, therefore, that a review on some facet of steroid bio-chemistry should be included in these Reports. Perhaps the most fascinat-ing advance in the metabolism of these compounds is the identification ofthe origin in vivo of all the carbon atoms of the cholesterol molecule. In-cluded in these Reports is also a review on the enzymes which split the estersof sulphuric acid. Until recently the sulphatases were a relatively neglectedgroup of enzymes, but in the last five years or so, interest in them has revived,and at present there is a considerable output of work in this field.A numberof sulphatases of very different specificity, have been found. Furthermorean important advance has been made during the year in elucidating thebiological synthesis of sulphuric acid esters, with the characterization of theso-called “ active sulphate.”R. T. W.2. BIOCHEMISTRY OF THE OXIDATIVE METABOLISM OF AROMATICDuring the past decade, fairly precise knowledge has been obtained ofthe way in which certain micro-organisms utilise aromatic compounds inmetabolism. Zobell dealt with the bacteriological aspects of this pheno-menon.and by Stanier ; more recently, Stanier has contributed a valuable chapteron its enzymology. The subject has not been previously reviewed in theseReports; it appears appropriate now to do so.COMPOUNDS BY MICRO-ORGANISMS.The biochemistry of the process was last reviewed by HappoldC.E. Zobell, Bact. Rev., 1946, 10, 1 ; Adv. Enzymol., 1950, 10, 443.a F. C. Happold, Biochem. Soc. Symp., No. 5, 1950, 85.R. Y. Stanier, “ Symposium sur le metabolisme microbien : l l e Congrhs inter-* R. Y. Stanier, ‘‘ Methods in Enzymology,” ed. by S. P. Colowick and N. 0. Kaplan,national de Biochimie,” 1952, p. 64.Academic Press, New York, 1955, Vol. 2, 273280 BIOLOGICAL CHEMISTRY.Ring-cleavage Metabolism of Aromatic Compounds.-( a) Micro-ovgaizisms.Several types of micro-organisms 5* classified into the following six families,Coccaceae, Mycobacteriaceae, Bacteriaceae, Pseudomonadaceae, Spirillaceae,and Bacillaceae, are known, which grow aerobically in a simple mineral-saltmedium, with an aromatic compound as sole source of organic carbon.During growth of the micro-organism the benzene ring undergoes fission, thecompounds formed being utilised in the diverse processes associated with cellmetabolism.Such organisms have been isolated from soil, sewage, andmammalian faxes, and are widely distributed in nature. Indeed, the bio-logical function of these micro-organisms by virtue of this property may beregarded as an essential step in the " carbon " cycle. Their use as industrialscavengers is common, since percolation of phenolic waste products throughsewage beds provides a cheap method of detoxicating aromatic compoundspotentially harmful to aquatic life.That this property is not confined to the lower bacteria (eubacteria), hasbeen amply demonstrated.Thus, amongst the fungi, A s$ergiZZzis ~ p p . ; ~PeTLiciZZizim ~ p p . , ~ * Oospora spp.,lO and Neurospora spp.ll are capable ofsome of these reactions, as well as certain soil l2 and wood-rotting fungi.13(b) Plants. The specific problem of aromatic-ring catabolism has notbeen extensively studied in plants, owing, no doubt, to the experimental diffi-culties involved. A variety of plants form glycosides from certain foreignphenols,l* e.g., o-chlorophenol is converted into o-chlorophenyl P-gentio-bioside ; glycoside formation may be a detoxication mechanism immobilisingtoxic phenolic by-products of metabolism, because the plant has no excretorysystem. The occurrence of a bewildering variety of aromatic compoundsin the plant world, however, shows the presence of a very efficient mechanismfor the synthesis of the benzene nucleus, and enzymes which hydroxylatephenolic substances (e.g., polyphenol oxidases) are abundant in plant tissues.In mammals, unnatural aromatic substances are usuallydetoxicated by hydroxylation and conjugation, before excretion.That thecapacity for ring fission has not been lost entirely is shown by the old observ-ation by Jaffe,15 since confirmed by several workei-s,l6 that the administrationof benzene to rabbits and dogs, gives a small amount of tram-trans-muconicacid in the urine. With the naturally occurring aromatic amino-acids, thereexist in liver tissue fairly well characterised enzyme systems l7 whichdisrupt the benzene ring of tyrosine, after manipulation of the side chain.(c) Mammals.P.H. H. Gray and H. G. Thornton, Zentr. Bakt., 2 Abt., 1028, 73, 74.F. Bernheim, J. Bact., 1941, 41, 387; J , Biol. Chenz., 1942, 143, 383.A. J. Kluyver and J. C. M. van Zijp, Antonie van Leeuwenhoek. J . Microbiol. Serol.,8 D. J. D. Hockenhull, A. D. Walker, G. D. Wilkin, and F. G. Winder, Bioclzem. J , ,1961, 17, 315.1952, 50, 605.M. Isono, J . Agvic. Chem. SOC. (Japan), 1953, 27, 255; 1954, 28, 196.lo S. Landa and J. Eliasek, Chern. Listy, 1956, 50, 1834.11 S. R. Gross, K. D. Gafford, and E. L. Tatum, J . Biol. Chena., 1956, 219, 781.12 M. E. K. Henderson and V. C. Farmer, J.Gen. MicvoEioZ., 1955, 12, 37.l3 G. Fahreus, Kgl. Lantbvukgs-Hogskol. Ann., 1949, 16, 618.14 L. P. Miller, Science, 1940, 92, 42.l5 M. Jaffe, 2. phjsiol. Chem., 1909, 62, 58.16 D. V. Parke and R. T. \Villiams, Biochmz. J., 1952, 51, 339.1' W. E. Knox, ref. 4, p. 207EVANS : OXIDATIVE METABOLISM OF AROMATIC COMPOUNDS. 281A noteworthy fact is the close similarity in the biochemical pathway of ring-cleavage metabolism of the naturally-occurring aromatic amino-acids in allforms of life studied.Criteria Used to Establish the Participation of a Presumed Intermediate ina Metabolic Bathway.-As Kluyver l8 pointed out many years ago, no singleapproach to the analysis of the activities of the living cell can ever justifythe belief that our conceptual schemes bear a one-to-one correspondence tothe real course of events.This is particularly true of the topic underreview ; briefly, the evidence and criteria used are as follows :Most bacterial oxidationsof aromatic compounds are complete, the carbon skeleton of the substratebeing converted exclusively into carbon dioxide and cell material. How-ever, as Evans Is first showed, intermediates sometimes accumulatetransiently in cultures, and may be isolated chemically from the culturefluid. A variant of this traditional method of approach is the study of cell-free enzyme preparations made from organisms after growth on the originalsubstrate, on any likely intermediate in vitro. The interpretation of results,from the point of view of origin of the isolated products, always presentsdifficulty, but the probability of their being real intermediates is vastlyincreased if marked compounds are used.It may be fairly claimed that thisapproach has nearly always given the initial clue.Observationswhich have led to current ideas on the factors which control the enzymaticconstitution of a microbial cell go back to the work of Wortmann.20 It wasKarstromJ21 however, who designated as “ adaptive ” those enzymes whichare produced as a specific response to the presence of the homologous sub-strate in the culture medium. He differentiated them from the “con-stitutive ” enzymes which are always formed by the cells of a given species,irrespective of the composition of the medium.Stanier 22 in 1947 found that the ring-fission enzymes, elaborated by hisPseudomonas strains of aromatic-ring splitters, were strictly adaptive innature ; these enzymes were demonstratively present in the bacterial cellsonly when growth occurred in the presence of the aromatic substrate.Heconceived the idea of using this phenomenon as the basis for a refined typeof kinetic analysis to determine the nature of the intermediates that lie onan adaptively-controlled metabolic pathway. This valuable technique wascalled “ simultaneous ” or “ successive ” adaptation, but for various reasons,Cohn et al.23 now propose the more accurate terminology of “ sequential(a) Chemical isolation from growing czdtwes.(b) The use of the techniqz4e of “ sequential induction.”18 A.J. Kluyver, ‘‘ The chemical activities of micro-organisms,” Univ. London1 9 W. C. Evans, Biochem. J., 1947, 41, 373.2O J. Wortmann, 2. physiol. Chem., 1882, 6, 287.2 1 H. Karstrom, Ergebn. Enzymforsch., 1937-38, 7, 350. See also R. J. Dubos,Bact. Rev., 1940, 4, 1 ; J. Monod, Growth, 1947, 11, 323; “Third Symp. SOC. Gen. Micro-biol.,” ed. by E. F. Gale and R. Davies, Camb. Univ. Press, 1953.22 R. Y . Stanier, J . Bact., 1947, 54, 339. See also R. J. Fitzgerald, F. Bernheim,and D. B. Fitzgerald, J . Biol. Chem., 1948, 175, 195; G. S. Eadie, F. Bernheim, andR. J. Fitzgerald, ibid., 1948, 176, 857.23 M. Cohn, J. Monod, M. R. Pollock, S. Spiegelman, and R. Y . Stanier, Nature,1963, 172, 1096.Press, London, 1931282 BIOLOGICAL CHEMISTRY.induction.” The principle 24 can be illustrated by considering a hypotheticalmetabolic pathway, each step of which is catalysed by a specific, inducedenzyme :A+B---+C+D+E+etc.EA EB EC ED EECells potentially capable of carrying out these reactions will be devoid of therelevant enzymes if they have not been exposed by the conditions of growthto compound A (the inducer).When placed in contact with A, such cellsrespond by producing the enzyme E A , catalysing the step A- B. Theformation of B will in turn provide the necessary activation for the formationof Eg, and so on. Thus, cells fully induced to dissimilate A will also beconditioned to metabolise B, C , D, etc. If one adapts the cells to an inter-mediate in the chain (say C ) , they will then also be adapted to the laterintermediates, D, E, etc., but not necessarily to the earlier ones.Consider,however, the case of a compound X, which may appear on chemical groundsto be a possible intermediate in the dissimilation of A, and which is likewisepotentially attackable by a specific, inducible enzyme Ex. In view of theknown high specificity of the inductive response, it is extremely improbablethat cells specifically adapted by exposure to A will also be adapted to X,if X i s not a member of the reaction chain. Thus, by adapting an organismto a given primary substrate, and then analysing its adaptive patterns withrespect to postulated intermediates, evidence can be obtained as to whichof these compounds are actually operative. It is, of course, necessary tomake a parallel test with “ unadapted ” cells, grown in the absence of allthe compounds under test, in order to make certain that the relevant enzyrnesare not always present in the cells (Le., constitutive).In practice theapplication of this technique is extremely simple ; washed cell suspensionsgrown on the aromatic substrate whose metabolic pathway is under in-vestigation, are incubated separately, the various postulated intermediatesnow being used as substrates, the rate of oxygen uptake being measuredmanometrically. The absence of a lag period indicates compliance withthis criterion of sequential induction ; the presence of a lag period, howeversmall, is taken to mean that the induced enzymes were not originally presentin the cells, the delay representing the time required for their synthesis.The validity of the biochemical inference drawn from sequential-inductionexperiments rests on some assumptions, which may not always be correct,e.g.: (i) Rigid specificity of the inductive response to a particular chemicalstructure ; if this is not so, then false positive conclusions are possible.22* 25-27(ii) Free permeability of the cell to all compounds tested; should this con-dition not hold then false negative results may beIt is now known that these assumptions do not always obtain, and theuse of this method alone cannot provide unequivocal evidence for the2924 R. Y. Stanier, Ann. Rev. MicrobioE., 1961, 5, 36.25 S. Spiegelman, M. Sussman, and B. Taylor, Fed. Proc., 1950, 9, 120.28 R.Y . Stanier, B. P. Sleeper, M. Tsuchida, and D. L. Nacdonald, J. Bact., 1950,27 S. R. Gross and E. L. Tatum, Science, 1955, 122, 1141.2* R. Y. Stanier, Bad. Rev., 1950, 14, 179.59, 137.S. Dagley, M. E. Fewster, and F. C. Happold, J. Gen. MicrobioE., 1963, 8, 1EVANS : OXIDATIVE METABOLISM OF AROMATIC COMPOUNDS. 283existence of a metabolic pathway, but should be supported wherever possibleby other evidence. In spite of these limitations, it is the Reporter’s viewthat Stanier’s technique contributed very materially, by providing inde-pendent evidence, towards the establishment of the evidence of biochemicalpathways of aromatic-ring cleavage first put forward mainly as a result ofisolation.(c) Preparation of the specif;c enzymes catalysing each stt@ in the proposedmetabolic pathway.The purification of the specific enzymes catalysingeach step in the reaction chain is a desirable objective, not always realisedbecause of lability or the particulate nature of some of them. Their use, ina study in vitro of each postulated reaction, usually provides information asto mechanism, co-factor requirements, and identity of intermediates whichdo not accumulate in cultures.Isolation and Selection of Strains.-The isolation of specific microbes withthe required properties (viz., ability to grow freely in pure culture containinga simple salt mixture as basal medium, together with the aromatic compoundas sole substrate) is usually accomplished by the selective culture method,first applied by Winogradsky30 and developed by Beijerin~k.~~ The soilor sewage bed is continuously perfused 32 with the simple medium for a periodof days, the use of toxic amounts of the substrate being guarded against;for aromatic ring splitters, O * O l - O * l ~ & wjv is a suitable strength.It ishelpful to estimate the concentration of the aromatic substrate in the primarymixed culture medium. This may stay constant for days, and nothingseems to be happening ; suddenly its disappearance becomes manifest, andthe whole may be gone in a few hours. When active metabolism of thesubstrate is in progress, subcultures are made into simple media, thuscausing preferential growth of a certain type of germ, ultimately leading toa predominance of the conditionally fittest.From such enrichment cultures,after plating out on simple media (stiffened with either agar or silica gel), thedesired organism is isolated as a pure strain by the traditional methods ofmicrobiology.The initial work on the oxidative metabolism of phenol used Vibrio 0/1,isolated by Happold and Key 33 from sewage effluent containing spent gas-works liquors. Subsequently, Pseudomonad-type organisms isolated fromsoil were also employed in expanding the work to include other aromaticcompounds, since the capacity of Vibrio 011 is limited. Careful selection ofstrain, and appropriate adaptation of the bacterial cells, is an essentialpreliminary to enzymic studies of these metabolic pathways.Chance-isolated and artificially produced mutants of various micro-organisms have become highly successful tools in the elucidation of bio-synthetical pathways, e.g., Davis’s use of several polyauxotrophs of30 S.Winogradsky, “ Microbiologie du sol,” Oeuvres complktes, Masson, Paris, 1949.31 M. W. Beijerinck, “ Verzamelde Geschriften,” Delft, 1921-1940, Vol. 1-6.32 Several perfusion apparatuses have been devised ; Professor F. C. Happold usedminiature sewage-beds in the laboratory in the 1930’s. H. Lees and J. H. Quastel,Chem. and Ind., 1944, 238; L. J. Audus, Nature, 1946, 158, 419; F. M. Collins andC. M. Sims, Nature, 1956, 178, 1073.33 I;. C. Happold and A. Key, J . Hygiene, 1932, 32, 573.34 B. D. Davis, in ref. 3, p. 32; idem, “ Amino Acid Metabolism,” ed. by W. D.McElroy and B.Glass, The Johns Hopkins Press, Baltimore, 1955, p. 799284 BIOLOGICAL CHEMISTRY.Escherichia coli in aromatic biosyntheses. Recently Gross, Gaff ord, andTatum 11 have used a mutant strain of Newospora cyassa, Y7655a, producedby treatment of Neurospora macroconidia with N-methylbis-2-chloroethyl-mine, in a very elegant study of the ring-cleavage metabolism of proto-catechuic acid.AROMATIC SUBSTRATELow energy release reactlolls J,HYDROXY LATEDINTERMED-IATESInduced enzymes [ AROMATICCARRIER 3 FINAL HSYSTEMS ACCEPTORSALIPHATIC c INTERMEDIATESr e l e a s eII materrIe a c t ionsalOxidative metabolism of aromatic compounds.The oxidative metabolism of aromatic compounds, dealt with in thisReport, implies the ability of these micro-organisms to produce enzymeswhich manipulate the benzene ring in such a way that the products formed,at some stage, enter the main terminal respiratory cycle of the cell, expressedschematically above.There exists an anmobic type of microbial metabolismof aromatic compounds, the so-called methane fermentation investigatedinitially by S ~ h n g e n , ~ ~ and later by Buswell and his collaborator^,^^ aboutwhich hardly anything is known; the dissimilation of benzoic acid by thisprocess conforms to the overall equation :4C,H&02H + 18H20 -w 15CH, + 13C0,Oxidative Metabolism of Phenol by Micro-organisms.-Biological oxidationof phenolic compounds by the aerobic oxidases, with quinone formation andsubsequent polyrnerisation leading to coloured complex products, is wellknown since the work of Raper37 and his collaborators.Beijerinck hadisolated Vibrio tyrosiyzatica, which contained a tyrosinase system, from thecanal waters of Delft, and Happol<38 had shown that all bacteria whichgave the " direct oxidase reaction'' of Gordon and McLeod, possessed acatechol oxidase system. This background knowledge indicated that somemicro-organisms possessed enzymes which hydroxylated the aromatic ring.35 N. L. Sohngen, " Het onstaan en verdwijnen van waterstof en methaan onderden invloed van liet organische leven," Thesis, Delft, 1906.36 G. E. Symons and A. M. Buswell, J. Avner. Chewz. Soc., 1953, 55, 2028.37 H. S. Raper, Physiol. Rev., 1928, 8, 245.3* F. C. Happold, Biochem.J., 1930, 24, 1737EVANS : OXIDATIVE METABOLISM OF ARQMATIC COMPOUNDS. 286In 1939, Evans and Happolda9 studied the breakdown of phenol by aVzbrio (called O/l-oxidase l), previously isolated by Happold and Key.This organism had the amazing capacity of growing profusely, with aeration,in a simple mineral-salt medium containing phenol (up to 0.1% w/v) as soleorganic source of energy. During growth, the phenol was metabolised, andno pigment was produced; the biochemistry of this process was unknown atthis time. The transient accumulation of compounds giving (a) reactionscharacteristic of o-dihydric phenols, (b) Rothera and Gerhardt positivereactions indicative of a P-oxo-acid, was established. Catechol was readilyisolated from cultures, but the nature, and isolation of the fi-oxo-acidproved more elusive, although it was known not to be identical with aceto-acetic acid.The isolation was accomplished by Milby40 in 1948, and theoxo-acid identified as fi-oxoadipic acid. Washed cells of Vibrio 011 utilised10 atoms of oxygen per molecule of phenol, approximately 9 atoms permolecule of catechol, with the production of roughly 4 molecules of carbondioxide, in both cases. Evans l9 therefore suggested that the oxidativemetabolism of phenol proceeded via catechol, followed by ring cleavage, to ap-oxo-acid. As far back as 1928, Tausson41 believed that the benzenenucleus was split with the formation of muconic acid, which was thenrapidly oxidised to carbon dioxide, by phenanthrene-oxidising bacteria.Evans had considered this possibility, but the inability of Vibrio O / l togrow or metabolise trans-trans-muconic acid, excluded it from being anintermediate.In 1950, Hayaishi and Hashimoto 42 reported the preparationand purification of an enzyme from Pseudomoizas spp. which acted on catecholyielding an acid, tentatively identified as cis-cis-muconic acid. A crudeenzyme preparation which catalysed the reaction :catechol + 0, + H,O -+ p-oxoadipic acidwas found by Stanier and Hayaishi 43 to be incapable of giving the oxo-acidwhen the muconic acid isolated by the Japanese workers42 was used assubstrate-a fact which excluded it from being a true intermediate in thereaction. At this stage, the investigations by Elvidge, Linstead, Sims, andOrkina on the stereochemistry of the muconic acids threw light on themicrobiological problem.These workers isolated a new cis-trans-muconicacid from the alkali-catalysed isomerisation of a related unsaturated lactone.This new acid resembled very closely the cis-cis-muconic acid which can beprepared by the chemical oxidation of phenol.45 When the cis-cis-acid ismerely boiled with water, it is inverted into the new cis-traPzs-isomeride.This means that many samples of cis-cis-acid used by previous workersmust have been inverted by the usual processes of purification. The roleof these muconic acids in the enzymic ring-cleavage conversion of catecholinto p-oxoadipic acid was settled in 1951 by Evans and Smith; 46 the pure30 W. C. Evans and F. C .Happold, J . SOL. Chem. Ind., 1939, 58, 55.41 W. 0. Tausson, Planta, 1928, 5, 239.42 0. Hayaishi and 2. Hashimoto, Med. J. Osaka Uiziv., 1950, 2, 33.43 R. Y. Stanier and 0. Hayaishi, Science, 1951, 114, 326.44 J. A. Elvidge, R. P. Linstead, P. Sims, and B. A. Orkin, J., 1950, 2235.45 J. Boeseken and R. Engelberts, Proc. Acad. Sci., Amsterdam, 1931, 34, 1292.4 6 W. C. Evans and B. S. W. Smith, Biochem. J . , 1951, 49, x.B. A. Kilby, Biochcm. J., 1948, 43, v; 1951, 49, 671286 BIOLOGICAL CHEMISTRY,cis-cis-isomer (1) is metabolised by intact cells, and is converted non-oxidatively into p-oxoadipic acid (3) by a crude catechol-oxidising cell-freeenzyme preparation, whereas the cis-trans- and the trans-trans-isomer arebiologically inactive. Evans et aL4’ also found that a lactone, y-carboxy:methyl-Aa-butenolide (2), related to cis-cis-muconic acid, was converted bythe same enzyme preparation, into p-oxoadipic acid.Kilby 40 has shownthat intact cells further metabolise this oxo-acid by a C(4)-CtD split, tosuccinate and acetate, which are then capable of entering the terminalcycle of respiration. The scheme 1 below suggested by Evans, Smith,Linstead, and Elvidge 4T is supported by (a) isolation evidence, (b) sequentialinduction, and (c) a study of the individual enzymes concerned.SCHEME 1. Oxidative metabolic pafhway of phewol by micro-ovganisnzs.Nature of the Enzymes Involved in the Individual Steps of Scheme 1.-Some of the enzymes involved in this oxidative pathway4 can now beprepared, cell-free, starting froin fully adapted cells, and by employing theusual disintegration methods, followed by fractionation, at low temperatures.The bacterial enzymes which hydroxylate aromatic substrates are very labile,and active cell-free preparations have not been described. However, this isbelieved to have been accomplished recently by Dagley and Patel 48 in thecase of the enzyme which hydroxylates P-hydroxybenzoic acid to proto-catechuic acid.In view of the interest of biochemists in aromatic hydroxyl-ations generally, advances in this field are to be expected (Udenfriend andhis collaborators 49 have prepared microsomal preparations from liver whichhydroxylate several aromatic compounds in the presence of reduced tri-phosphopyridine nucleotide and oxygen).The Japanese workers 42* 50 purified pyrocatechase from acetone-driedcells of adapted Pseudomonas spp.and showed its dependence on ferrousions. It appears also that mercapto-compounds, e.g., glutathione, alsostimulate activity. The lactonising and lactone-splitting enzymes have beenseparated very elegantly by Sistrom and Stanier,S1 thus completing the step-wise enzymic degradation of cis-cis-muconic acid through y-carboxymethyl-4 7 W. C. Evans, B. S. W. Smith, R. P. Linstead, and J. A. Elvidge, Nature, 1951,48 S . Dagley and M. D. Patel, 1956 (personal communication).49 C. Mitoma, H. S. Posner, H. C . Reitz, and S. Udenfriend, Arch. Biochem. Bio-50 0. Hayaishi, M. Katagiri, and S. Rothberg, J . Amer. Chem. SOC., 1955, 7’7, 2914.61 W.R. Sistrom and R. Y . Stanier, J . Biol. Chem., 1954, 210, 821; Nature, 1954,168, 772.phys.. 1956, 61, 431.174, 513EVANS : 0XID.YrIVE METABOLISM OF -1ROMATIC COhfP0UNI)S. 287h"-butenolide to p-oxoadipic acid. The lactonising enzyme requires eitherMg++ or Mn++ ions for activity, whereas the lactone-splitting enzyme doesnot. The lactonising enzyme catalyses a remarkable pair of reactions :IIHAC'COTc i s - c i s -5 %y 2 -H-C-HI0 rE IICH(+)9 5 %c0,-IH-C-HThe iwo reversible reactions of m u c o ~ i c acid atid y-carboxynzetl~yl-A'-bute~iolide rafalvsedby i'he lactonising enzyme, with the equilib~ium values for pH 8.(a) is the reversible interconversion of cis-cis-muconic acid and the (+)-lactone,at pH 8.0 the equilibrium mixture containing 95% lactone, and in (b) thecis-trans-isomer is converted into an equilibrium mixture with the (-)-lactone(20% of lactone at pH S), although more slowly than the natural substrate.Since the double bond in the lactone ring has a cis-configuration, it is evidentthat the lactonising enzyme must act on the trans-bond of cis-trans-muconicacid. The enzyme cannot interconvert the two geometric isomers or thetwo enantiomorphs.The basis of this pair of reactions is an ability of theenzyme to distinguish between two chemically identical atoms or bonds.Thus in the forward reaction only one of the two component bonds of the@-double bond is split, and in the back reaction only one of the two&hydrogen atoms is removed.The ability of an enzyme to distinguish be-tween chemically identical groups has been demonstrated before 5 2 9 % anda three-point attachment of substrate to enzyme has been proposed as themechanism.Oxidative Metabolic Pathways of the Benzoic Acids by Micro-organisms.-The metabolism of benzoic acid and its derivatives demonstrates the limiteddiversity of pathways employed by these bacteria in manipulating thearomatic ring before cleavage.Benzoic 55-57 and salicylic 593 6o acid give rise to catechol (4) by whatappears to be a single oxidative decarboxylation step. Evidence for thisrests on sequential induction, and isolation of catechol from cultures ofthese substrates. Sleeper 58 subsequently used benzoic acid labelled in thecarboxyl and the C(l) position with 14C, in this bacterial oxidation, and52 V.R. Potter and C. Heidelberger, Nature, 1949, 164, 180.53 H. F. Fischer, E. E. Conn, B. Vennesland, and F. H. Westheimer, J . Biol. Chent.,54 A. G. Ogston, Nature, 1948, 162, 963.5 5 W. H. Parr, R. A. Evans, and W. C. Evans, Biochern. J., 1949, 45, xxis.5 6 R. A. Evans, W. H. Parr, and W. C. Evans, Nature, 1949, 164, 674.5 7 B. P. Sleeper and R. Y . Stanier, J . Uact., 1950, 59, 117.5 8 B. P. Sleeper, ibid., 1951, 62, 657.58 N. Walker and W. C. Evans, Biochem. J . , 1952, 52, xxiii.60 B. S. Roof, T. J. Lannon, and J. C. Turner, Proc. SOC. Exp. Biol. Med., 1953, 84.1953, 202, 687.38288 BIOLOGICAL CHEMISTRY.showed that, (1) catechol derived from [~arboxy-~~C]benzoic acid is inactive,while that derived from [l-14C]benzoic acid has the same specific activityas the parent compound; (2) all the radioactivity of the catechol derivedfrom [l-14C]benzoic acid is in carbon atoms 1 and 2 ; (3) from the completeoxidation of benzoic acid the radioactivity of the carboxyl group is foundalmost exclusively in respiratory carbon dioxide; that of carbon atom 1 islargely found in carbon dioxide, but a significant percentage appears in thebacterial cells and supernatant liquid.Walker and Evans 59 showed that m-hydroxybenzoic acid gives gentisicacid (5) before ring cleavage, by isolation and adaptation evidence ; this wasconfirmed by Roof, Lannon, and Turner.Go Ring cleavage of gentisic acidoccurs through a new pathway and the formation of 4 : 6-diox0hept-~ A-ene-dioic acid (6) as the immediate product has been suggested, but not proved.Q" \6" 0." (4)as schemrz I.C02HCO2H oc0cH'2 asscheme I .I FH2 + o c o 2 2 (3!02H- unknown pathway.H2C, CO2HHO / Co2H (7)OHSCHEME 2.p-Hydroxybenzoic acid gives protocatechuic acid,lS which then under-goes ring cleavage with the formation of p-oxoadipic acid (7).55 UsingPseudomonas fluorescens adapted to protocatechuic acid, Stanier andIngraham 61 prepared a cell-free enzyme, termed " protocatechuic acidoxidase," able to cause cleavage of this substrate with the formation of anextremely labile intermediate, isolated as a crystalline trisodium salt, andidentified as a p-carboxymuconic acid (8) 62 (probably the cis-&isomer).During purification of the oxidase, they obtained, as a by-product, a " de-carboxylase " enzyme preparation, which converted cis-cis-p-carboxy-muconic acid into p-oxoadipic acid.The latter reaction is undoubtedlymore complex, and remains obscure.Oxidative metabolic pathways of the benzoic acids by micro-organisms.131 R. Y . Stanier and J. L. Ingraham, J . BioZ. Chem., 1964, 210, 799.62 D. L. MacDonald, R. Y . Stanier, and J. L. Ingraham, ibid., p. 809EVANS : OXIDATIVE METABOLISM OF AROMATIC COMPOUNDS. 289Recently, Gross, Gafford, and Tatum l1 have shown that a mould,Neurospora crassa, can convert protocatechuic acid into p-oxoadipic acid, bythe aid of enzymes inductively produced. They made a detailed comparativestudy of this reaction, using [2 : 6-14C]protocatechuic acid, and purifiedenzymes prepared from Neurospora and Pseudomonas, with unexpectedresults.From the mould they prepared two enzymes, the first convertingprotocatechuic acid into cis-cis-P-carboxymuconic acid (similar to proto-catechuic oxidase of Pseudomonas) ; the second enzyme converted thecarboxymuconic acid into p-carboxymuconolactone [ (-)-P-ca.rboxyy-carboxymethyl-AQ-butenolide] (9). A delactonising enzyme, or enzymes,then converts p-carboxymuconolactone into b-oxoadipic acid with loss ofcarbon dioxide. The prepared p-carboxymuconolactone was not attackedby extracts of Pseudomonas jaorescens, which were fully capable of convert-ing protocatechuic acid into p-oxoadipic acid ; this lactone, then, cannotbe an intermediate in the latter reaction. Isotopic evidence also showedconclusively that the conversion of p-carboxymuconic acid into p-oxoadipicacid is different in the two enzyme systems. Dagley and Pate14* haveisolated a new substance (m.p. 235"), the constitution of which remains-tobe determined, as a product of reaction of Pseudomonas enzyme on proto-catechuic acid. It contains no phenol or enol groups; analysis gives(C,H,O,),, and alkaline titration indicates two carboxyl groups per moleculeif 12 = 1. The additional carboxyl group on @-carboxymuconic acid intro-duces new possibilities for lactone formation, and it may well be that thePseudomonas enzyme forms a different lactone from p-carboxymucono-lactone, as an intermediate stage on the way to p-oxoadipic acid.Evans 63 made a preliminary study of the breakdown of phthalic acidby a soil Pseudomonad; none of the monohydroxyphthalic acids was de-tected, neither did they satisfy the criteria of sequential induction, but4 : 5-dihydroxyphthalic acid was identified chromatographically in growingcultures, and was adapted.Its subsequent pathway has not been in-vestigated.Oxidative Metabolic Pathways of Phenylalanine, Tyrosine, and theirDerivatives by Micro-organisms-Suda and Takeda 64 found that Pseudo-monas spp. already adapted to tyrosine were also adapted to oxidise homo-gentisic acid ; a cell-free enzyme preparation, homogentisicase, whichcatalysed the rupture of the ring was prepared. Like pyrocatechase, thisenzyme required ferrous ions as a co-factor, implying the existence inbacteria of a pathway for tyrosine metabolism similar to that existing in themammal.Jones, Smith, and Evans 65 isolated homogentisic acid from atyrosine culture of Vibrio 011. Meanwhile, Kluyver and van Zijp 7 hadshown the production of homogentisic acid from phenylacetic acid byAspergillus Niger. Hockenhull et at. ,a working with Penicillium chryso-genum, showed that the acetic acid side chain was partially degraded tobenzaldehyde before ring cleavage. Isono identified o-hydroxyphenyl-acetic acid, from phenylacetate cultures of a similar mould species, and63 W. C . Evans, Biochem. J., 1966,61, x.64 M. Suda and Y. Takeda, Med. J . Osaka Univ., 1950, 2, 37.66 J. D. Jones, B. S. W.Smith, and W. C . Evans, Biochem. J., 1952, 51, xi.REP.-VOL. LIII 290 BIOLOGICAL CHEMISTRY.subsequently produced a mutant strain of Penicillium chrysogenum causingthe accumulation of homogentisic acid.Dagley, Fewster, and Happold 29 carefully examined the adaptivepatterns of Vibrio O / l grown on phenylalanine and tyrosine ; their resultssupport the pathway shown in scheme 3, as far as homogentisic acid. Thefate of this intermediate in the microbial pathway is only presumed to be thesame as that of those catalysed by liver enzymes, recently elucidated byseveral workers,66 i.e., the formation of 4 : 6-dioxo-oct-2-enedioic acid, itsisomerisation and subsequent hydrolysis to fumaric and acetoacetic acid,have not yet been demonstrated by using microbial enzymes.The pathways of metabolism of mandelic acid and P-hydroxymandelicacid were established by Stanier 67 and by Gunter,68 respectively. Gun-salus, Stanier, and Gunsalus 69 succeeded in separating four soluble enzymesconcerned with the conversion of mandelic into benzoic acid, from Pseudo-monasjuorescens, and these reactions can now be formulated as follows :racemase dehydrogenaseD( -)-Mandelic acid 4-t L( -/-)-Mandelic acid - - 2Hcarboxylase dehydrogenase 1Benzoylformic acid -- Benzaldehyde TYNt ____l_t TPNHBenzoic t i acid DPNf - DPNHdehydrogenase 2CO,Abbreviations used are: TPN+, DPN+, TPNH, and DPNH for oxidised andSmith, Jones, and Evans 70 showed that a soil Pseudomonad oxidisedp-cresol to p-hydroxybenzoic acid. Dagley and Patel 71 have investigatedthis pathway in more detail, and confirmed the reaction sequence shown inscheme 3.Oxidative Metabolic Pathway of Tryptophan by Micro-organisms.-Theproduction of indole from tryptophan, through elimination of the alanineside-chain, is carried out by E.coli grown under certain cultural condition^.^^Bacteria of the Pseudomonas group, however, are capable of the completeoxidation of this amino-acid. The adaptive patterns of such organisms wereindependently examined by Suda, Hayaishi, and Oda,73 and Stanier andTsuchidaS7* The former found that Pseudomonas spp. adapted to trypto-phan were fully adapted to oxidise kynurenine, anthranilic acid, andcatechol. Stanier and Hayaishi 75 found marked differences in dissimilatorypatterns between various Pseudomonas strains, with respect to tryptophan ;most of them oxidise it through anthranilic acid and catechol (referred toas the " aromatic pathway "), whilst a few employ a different route, throughreduced triphospho- and diphospho-pyridine nucleotides.6 6 W.E. Knox, ref. 4, p. 292.6 7 R. Y . Stanier, J. Bact., 1948, 55, 477.68 S. E. Gunter, ibid., 1953, 66, 341.69 C. F. Gunsalus, R. Y. Stanier, and I. C. Gunsalus, ibid., 1963, 66, 548.70 B. S. W. Smith, J. D. Jones, and W. C. Evans, Biockem. J., 1952, 50, xxviii.71 S. Dagley and M. D. Patel, ibid., 1955, 60, xxxv.72 F. C. Happold, Adv. Enzymol., 1950, 10, 52.73 M. Suda, 0. Hayaishi, and Y. Oda, Med. J. Osaka Univ., 1950, 2, 21.74 R. Y. Stanier and M.Tsuchida, J . Bact., 1949, 58, 45; 1951, 62, 355.75 R. Y. Stanier and 0. Hayaishi, Science, 1961, 114, 326; J . Biol. Chem., 1962,195, 735EVANS : OXIDATIVE METABOLISM OF AROMATIC COMPOUNDS. 291kynurenic acid (designated the ‘‘ quinoline pathway ”). Yet a few rarestrains carried out various blocked oxidations of tryptophan with accumul-ation of indole, anthranilic acid, or kynurenic acid.CH,. CH-CO, H 0 )(1H2 4OHfCH 2 * CO. CO 1H 0 OHCO2HICH-OH 0- OHC02 HI 6- OH 6 OH7 OH 6“OH \scheme 2 .f lSCHEME 3. Oxidative metabolic pathway of phenylalanine, tyrosine, and derivativesby Micro-organisms .SCHEME 4. Oxidative metabolic pathwa-y of tryptophan by micro-oqanisms.Cell-free extracts capable of oxidising L-tryptophan to $-oxoadipic acidwere obtained by Hayaishi and Stanier; 76 this complex extract containeda tryptophan osidase-peroxidase system, kynureninase, and anthranilic acidoxidase, in addition to the ring-cleavage enzymes.Detailed study of theenzymatic step-reactions which result in the conversion of tryptophan intoanthranilic acid indicates a close similarity to the analogous reactions in themammal; 77 these are depicted in scheme 4.713 0. Hayaishi and R. Y . Stanier, J . Bact., 1951, 62, 691.$7 W. E. Knox, ref. 4, p. 242292 BIOLOGICAL CHEMISTRY.Oxidative Metabolic Pathways of Miscellaneous Aromatic Compounds byMicro-organisms.-An increasing number of synthetic aromatic compoundsare used as herbicides, insecticides, food preservatives, etc., and it is becomingimportant to know something about their metabolism, from a fundamentalpoint of view, since many of them are physiologically active, and because ofthe potential hazards to life should they accumulate in toxic amounts.Acomplex milieu like soil often causes the disappearance of a great varietyof organic chemicals by biological means. Provided such versatile organismscan be grown in simplified media, with a reasonably rapid utilisation of thesubstrates, an attractive biochemical approach to the study of their meta-bolism presents itself. These media will now be summarised.(a) The nitrophenols. An industrial biological purification plant detoxic-ating nitrophenols, afforded Pseudomonad-type organisms capable of growingin a mineral-salt medium containing 0.02% of o- and p-nitrophenol.Evansand Simpson 78 showed that the nitro-group was substituted by hydroxyl inthe aromatic ring, which was further metabolised by ring-fission. Theeliminated nitro-group appeared in the medium as the nitrite ion ; this noveltype of reaction is catalysed by a very labile enzyme. Jensen and Gun-derson 79 isolated soil bacteria capable of decomposing organic nitro-compounds (e.g., dinitro-o-cresol), and confirmed elimination of the nitro-group as nitrite.Benzenesulphonic acid is also attacked by soil Pseudomonads withreplacement of the sulphonic acid group by hydroxyl.80(b) The chlorophenoxyacetic acid herbicides. Several workers 81-88 havedescribed the disappearance of the chlorophenoxyacetic acids when dilutesolutions (0.01 yo wlv) were percolated through soil.Almost as many speciesof organisms were isolated from these enrichment cultures. Audus s2(Bacterium globiforme group), Jensen and Petersen 84 (Flavobacteriumaquatile), Stapp and Spicher 85 (Flavobacterium peregrinum n. sp.), Rogoffand Reid B6 (Corynebacterium), and Steenson and Walker 87 (Achromobactersp.) have all studied the biology of this process. Evans and his collabora-tors,88? 90 in a study of the metabolic pathway of these herbicides, encounteredthe difficulty, mentioned by previous workers, of the poor growth and slowutilisation of the 2 : 4-dichlorophenoxyacetic acid (2 : 4-D) by these organisms,in liquid media containing mineral salts. With P-chlorophenoxyacetic acid(CPAA) this difficulty is not serious, with the Gram-negative motile rod-likeorganism isolated from soil under conifer litter.Evans and Smith 8878 W. C. Evans and J. R. Simpson, Biochem. J., 1953, 55, xxiv.7O H. L. Jensen and K. Gunderson, Nature, 1954, 175, 341; Acta Agric. Scand.,80 J. R. Simpson, MSc. Thesis, Univ. of Wales, 1954.*I P. S. Nutman, H. G. Thornton, and J. H. Quastel, Nature, 1945, 155, 498.88 L. J. Audus, Nature, 1950, 166, 356.83 A. S. Newman and J. R. Thomas, Proc. Soil Sci. Soc. Amer., 1950, 14,84 H. L. Jensen and H. I. Petersen, Acta Agric. Scand., 1962, 2, 216.135 C. Stapp and G. Spicher, Zentr. Bakt., 2 Abt., 1954, 108, 225.86 M. Rogoff and J. J. Reid, J. Bact., 1956, 71. 303.87 T. I. Steenson and N. Walker, Plant and Soil, 1956, 8, 17; J .Gen. Microbial.,8 8 W. C. Evans and B. S. W. Smith, Biochem. J., 1964, 67, xxx.1956, 0, 100.160.1957, 16, 14EVANS : OXIDATIVE METABOLISM OF AROMATIC COMPOUNDS. 293isolated 4-chloro-2-hydroxyphenoxyacetic acid,89 and 4-chlorocatechol,from CPAA cultures, and these presumed intermediates also obeyed thecriteria of sequential induction; recently, Evans and Moss have isolateda p-chloromuconic acid 91 (probably the cis-tram-isomer) as a product ofreaction of washed cells on 4-chlorocatechol, and there is evidence frominfrared spectroscopy of the formation of a related lactone (possibly p-chloro-muconolactone) .92 Biological specificity of the enzymes is again in evidencehere, since the particular isomer of p-chloromuconic acid actually isolatedwas not acted upon by the cells, inversion having presumably occurredduring the process.A point of interest, in view of the behaviour of the cellenzymes towards other substituents in the benzene nucleus, is that withCPAA, the halogen is not eliminated before ring-fission. Chloride-ion pro-duction occurs after the p-chloromuconic acid stage. Progress in the elucid-ation of the microbial metabolic pathway of 2 : 4-D has been slow ; cultureswere shown 93 chromatographically to contain traces of 2 : 4-dichlorophenol,3 : 5-dich1orocatecho1, and a hydroxyaromatic acid with a different RF from2 : 4-dichloro-6-hydroxyphenoxy-acetic acid." Scheme 5 shows intemedi-ates identified to date.HCC I CI CIand furtherO.CH,.CO,H OH i" metabolismunidentifiedr ing- cl e avageC l o - _ _ - + C l o / _3 C'I$OH / _tICI CL CII productsSCHEME 5.Oxidative metabolic pathway of the chlorophenoxyacetic acids bymicro-organisms.(c) Naphthalene and certain halogenated derivatives. Naphthalene and itsderivatives have had limited use as soil insecticides, and TattersfieldQ5studied their persistence in various soils. Since then, numerous authorshave isolated organisms which grow in a medium containing naphthaleneand mineral salts; Strawinski and Stoneg6 in 1943 isolated salicylic acidfrom such cultures. Walker and Wiltshire 97u isolated (+)-trans-1 : 2-di-hydro-1 : 2-dihydroxynaphthalene and salicylic acid from naphthalenecultures of an aerobic motile Gram-negative rod (untyped) , and showed thatthese presumed intermediates also obeyed the criteria of sequential induction.a9 J.P. Brown and E. B. McCall, J., 1955, 3681.90 W. C. Evans and P. Moss, Biochem. J., 1957, 65, SP.9 1 J . Boeseken and C. F. Metz, Rac. Trav. chim., 1935, 54, 345.92 0. Neunhoeffer, Ber., 1935, 68, 1774.ga B. S. W. Smith, Ph.D. Thesis, Univ. of Wales, 1954.94 G. VV. K. Cavil1 and D. L. Ford, J., 1964, 665.95 F. Tattersfield, Ann. Apfil. Biol., 1928, 15, 67.O 6 R. J. Strawinski and R. W. Stone, J . Bact., 1943, 45, 16.97 N. Walker and G. H. Wiltshire, (a) J . Gen. Microbial., 1953, 8, 273; ( b ) ibid.,1955, 12, 478294 BIOLOGICAL CHEMISTRY.The formation of the (+)-tram-diol by micro-organisms has its analogy inthe naphthalene metabolism of mammals, where both (+)- and (-)-isomersare formed.98 They 97b also studied the breakdown of l-chloronaphthaleneby a suitable organism, identifying 8-chloro-1 : 2-dihydro-1 : 2-dihydroxy-naphthalene and 3-chlorosalicylic acid as intermediates.H OHcarechol pathwayCO2H (schemes 1 3nd 2)further metabolized(patthway unknown)SCHEME 6.Oxidative metabolic pathway 01 naphthalene by micro-organisms.The stages between naphthalenediol and salicylic acid remain to be dis-covered ; results with the halogenated hydrocarbon have, however, estab-lished that Cc4) in 8-chloro-1 : 2-dihydro-1 : 2-dihydroxynaphthalene be-comes the carboxyl carbon atom of 3-chlorosalicylic acid. Scheme 6 depictsour knowledge of naphthalene metabolism.W. C. E.3.ORGANOPHOSPHORUS COMPOUNDS AND ESTERASES.Abbreviations used throughout this Report are given below.Before 1939 many organophosphorus compounds were prepared bySchrader in Germany, and the earliest account of their toxicity was pub-lished in 1932.2 These substances are amongst the most toxic known andlittle information was available about their biochemical properties untilafter the war, because of their potential use as chemical-warfare agents.They are used widely in agriculture as insecticides, but they have alsoaroused the interests of chemists and biochemists. Many are powerfulinhibitors of esterases, reacting stoicheiometrically by the straight-forwardkinetics of a bimolecular reaction. The bimolecular rate constants may beas high as 6.3 x lo7 (1. mole-l min.-l a t 25" at pH 7.4) for the reaction ofisopropyl methylphosphonoff ~ o r i d a t e .~ This Report will consider tE emechanism of inhibition by these compounds and of reactivation of theinhibited enzyme, attempts to characterise chemically the active centre ofesterases, and the enzymic hydrolysis of anti-esterase organophosphoruscompounds.Some organophosphorus compounds, e.g., 00-diethyl O-9-nitrophenylphosphorothionate and octamethylpyrophosphoramide, are only weakinhibitors of esterases, but are toxic owing to their conversion by mammals98 Cf. L. Young, Biochenz. SOC. Symp., No. 5, 1950, p. 27; E. Boyland, ibid., p. 40.1 The following abbreviations have been used throughout : Diisopropyl phosphono-fluoridate, DFP ; Tetraethyl pyrophosphate, TEPP ; Diethyl p-nitrophenyl phosphate,E600.* W. Lange and G. Kruger, Ber., 1932, 65, 1698.3 B. J. Jandorf, J . -4grir. Food Chem., 1956, 4, 853ALDRIDGE ORG.4NOPHOSPHORUS COMPOUNDS ANL) ESTEHASES. 295and insects into substances which inhibit cholinesterase. This aspect willnot be considered here and has recently been reviewed.4TABLE 1. Enzymes inhibited by organophosphorus compozcnds.EnzymeCh ymotrypsinTrypsinCholinesterase (true andLiver esterase and milk lipaseAce t yle s terase (orange andpseudo)wheat B-esterase)Cholesterol esteraseOrganophosphorus compoiindDiisopropyl phosphorofluoridateDiphenyl phosphorochloridateDiethyl phosphorofluoridothionateTetraisopropyl pyrophosphateTetrapropyl dithionopyrophosphateTetraethyl pyrophosphateDiethyl p-nitrophenyl phosphateDiisopropyl phosphorofluoridateTetraethyl pyrophosphateDiethyl p-nitrophenyl phosphateOS-diethyl O-p-nitrophenyl phosphorothiolateDiisopropyl phosphorofluoridateDiisopropyl phosphorofluoridate and analogues11 Organophosphorus compoundsDiisopropyl phosphorofluoridateTetraethyl pyrophosphateDiisopropyl phosphorofluoridateTetraethyl pyrophosphateDiisopropyl phosphorofluoridateDiethyl p-nitrophenyl phosphateDiethyl p-nitrophenyl phosphateDiisopropyl p-nitrophenyl phosphateDiisopropyl phosphorofluoridateRef.56,#JP7897101 ,1112131415iii,,.17,,,,Mechanism of Anti-esterase Action.-Organophosphorus compounds aregeneral inhibitors of enzymes which possess carboxylic esterase activity.However, not all esterases are inhibited by organophosphorus compounds,e.g., A-esterase which hydrolyses P-nitrophenyl esters of carboxylic acids.16118It was apparent that theinhibition of esterases was in some ways different fromthat of inhibitors previously studied.It was shown by Jansen, Fellowes-Nutting, Jang, and Balls for chymotrypsin and by Boursnell and Webb 19 forpseudocholinesterase that the phosphorus from the inhibitor was extremelytightly bound and was not removed by treatment with trichloroacetic acid.The inhibited chymotrypsin could be repeatedly recrystallised without losingany phosphorus. When crystalline chymotrypsin is inhibited by DFP,74 J. E. Casida, J . Agric.Food Chem., 1956, 4, 772.6 E. F. Jansen, M. D. Fellowes-Nutting, R. Jang, and A. K. Balls, J . Bid. Chent.,6 E. F. Jansen, A. L. Curl, and A. K. Balls, ibid., 1951, 190, 557.7 E. F. Jansen. M. D. Fellowes-Nutting, R. Jang, and A. K. Balls, ibid., 1950,8 B. S. Hartley and B. A. Kilby, Nature, 1950, 166, 784.B E. F. Jansen and A. K. Balls, J . Biol. Chem., 1952, 194, 721.1949, 179, 189.185, 209.10 B. A. Kilby and G. Youatt, Biochim. Biophys. Acta, 1952, 8, 112.11 A. Mazur and 0. Bodansky, J . BioE. Chem., 1946, 163, 261.12 J . F. Mackworth and E. C. Webb, Biochem. J., 1948, 42, 91.1s W. N. Aldridge, ibid., 1953, 53, 62.14 E. C. Webb, ibid., 1948, 42, 96.18 E. F. Jansen, M. D. Fellowes-Nutting, and A. K. Balls, J . B i d . Chem., 1948,16 W.N. Aldridge, Biochem. J., 1953, fi3, 110.17 D. K. Myers, A. Schotte, H. Boer, H. Borsje-Bakker, ibid., 1955, 61, 621.1) R. Goutier, Biochirn. Biophys. Actu, 19S6, 19. 624.19 J. C. Boursnell and E. C. Webb, Nature, 1949, 164, 875.175, 975296 BIOLOGICAL CHEMISTRY.by TEPP,2O or by one molecule of acid is liberated for each moleculeof enzyme inhibited. This has also been shown to be true for crystallinetrypsin inhibited by E600.1° One molecule of phosphorus is bound to onemolecule 0: enzyme 6* ‘ 9 99 21*22 and in every case the rate of reaction ofinhibitor with enzyme shows the characteristics of a bimolecular re-action.l5~ 22-26 Pure crystalline cholinesterases are not available and soindirect methods have had to be used to gain information on their mechanism.After inhibition of cholinesterases by DFP containing 32P the phosphorus isfirmly bound to the enzyme.19*28-30 From the effect of temperature uponthe rate of reaction, the apparent energies of activation are 10-1 1 kcal./molefor true cholinesterase and E600,27 and 14-15 kcal./mole for pseudo-cholinesterase and NN’N”N”’-tetraisopropylpyrophosphorotetramide.26The evidence so far agrees with phosphorylation of the enzyme and not withsimple absorptive or ionic binding as the mechanism of inhibition for allcarboxylic esterases by organophosphorus compounds.A mechanism has been suggested by Nachmansohn and Wilson31 forthe hydrolysis of acetylcholine by cholinesterase which may be representedas follows :Ac - [ F i - - T C ] + (2) ChOH + + AcOH b c A F’ - -t L h ----Ch + HsO= enzyme, Ac-CH = acetylcholine, ChOH = choline, AcOH = acetic acid.In this process the formation of the acetylated enzyme (reactions 1 and 2)is the rate-limiting step, while its hydrolysis (reaction 3) is comparativelyfast.The inhibition of cholinesterase by organophosphorus compoundswould fit into such a scheme if the phosphorylated enzyme were ~table,3~-34the rate-limiting step being its hydrolysis. It appears that the inhibitorscombine with the enzyme active centre, for the inhibition is easily preventedby the presence of substrate.23* 35-37 Wilson 32 showed that the activity oftrue cholinesterase inhibited by TEPP slowly returned, and Aldridge 2720 A. K. Balls and E. F. Jansen, Adv.Enzynzol., 1952, 13, 321.11 E. F. Jansen, M. D. Fellowes-Nutting, and A. K. Balls, J . Biol. Chem., 1949,179, 201.na B. J. Jandorf, H. 0. Michel, N. K. Schaffer, R. Egan, and W. H. Summerson,Discuss. Faraday Soc., 1955, 20, 134.2s W. N. Aldridge, Biochem. J., 1950, 46, 451.94 Idem, ibid., 1954, 57, 692.86 W. N. Aldridge and A. N . Davison, ibid., 1962, 51, 62.aa A. N . Davison, ibid., 1956;, 60, 339.27 W . N . Aldridge, ibid., 1963, 54, 442.28 H. 0. Michel and S. Krop, J . Biol. Chew., 1961, 190, 119.29 H. 0. Michel, Fed. Proc., 1952, 11, 269.30 E. F. Jansen, R. Jang, and A. K. Balls, J . BioZ. Chem., 1952, 196, 247.*1 D. Nachmansohn and I. B. Wilson, A&. EnzymoE., 1961, 12, 259.32 I. B. Wilson, J . Biol. Chern., 1951, 190, 11.8s Idem, ibid., 1951, 199, 113.34 W.N . Aldridge, Chem. and Ind., 1954, 473.36 J. A. Cohen, M. G. P. J. Wamnga, and B. R. Bovens, Biochim. Biopbys. Ada.3% F. Hobbiger, Brit. J. Phaumacol., 1964, 9, 169.87 A. S. V . Burgen, ibid., 1949, 4, 219.1961, 6, 469ALDRIDGE ORGANOPHOSPHORUS COMPOUNDS AND ESTERASES. 297demonstrated that true cholinesterase inhibited by dimethyl fmitrophenylphosphate produced an inhibited enzyme which was spontaneously reactiv-ated following first-order kinetics, and having a half-life at 37" and pH 7.6of approximately 1.5 hr. The energy of activation of this process was1 6 1 5 kcal./mole. The rate of return of enzyme activity is identical afterinhibition by dimethyl P-nitrophenyl phosphate , dimethyl phosphoro-fluoridate, tetramethyl pyrophosphate, and 00-dimethyl S-$-nitrophenylphosphorothi0late,3~ indicating that in each case a dimethyl phosphorylatedenzyme is produced. Diethyl phosphorylated rat pseudo-cholinesterase isalso unstable s9 and a similar examination has been made.38It is clear therefore that the enzyme is dialkyl phosphorylated, and thisis linked to the enzyme by a covalent bond which may be hydrolysed.Itremains to examine how far the behaviours of esterases with organophosphorusinhibitors and with substrates are similar. With a series of diethyl phenylphosphates where the lability to hydrolysis has been modified by sub-stituents in the aromatic ring, the inhibitory power was directly related totheir rate of hydrolysis under standard conditions.25* 40 This is consistentwith hydrolysis of the phosphate ester being an essential part of the in-hibitory process, though it must be emphasised that such a correlation mayonly be demonstrated when a series of closely related analogues are examined.The scheme given above for the hydrolysis of acetylcholine provides for twosites in the enzyme active centre-an anionic site to bind the quaternarynitrogen atom, and an esteratic site to which the carbonyl oxygen isatta~hed.~l On these grounds it would be expected that variation of thealkoxy-groups attached to the phosphorus would influence the inhibitorypower. In fact, changes of the alkoxy-groups of organophosphorus com-pounds from 00-dimethyl to 00-diisopropyl alter their inhibitory power indifferent directions against true and pseudo-cholinesterase.13 Similarly,lengthening the acyl group of choline esters changes their rates of hydrolysisby true and pseudo-cholinesterase and there is a good parallelism between thesubstrate and inhibitor specificities of these enzymes.13 The esteratic siteis clearly important in determining inhibitor potency.Several compoundshave been prepared containing a quaternary nitrogen atom in the labilegroup. The phosphostigmines m(dialkoxyphosphiny1oxy) -NNN-trimethyl-anilinium methyl sulphate are highly active inhibitors of cholinesterase 4 1 ~ 4 2and the quaternary salts are more active than the tertiary compounds.42~*Methylation of 00-diethyl S-ethylthioethyl phosphorothiolate to produce thesulphonium derivative increased its inhibitory power one hundred-fo1d.u3-(Diethoxyphosphinyloxy)-l-methylquinolinium methyl sulphate is anextremely powerful inhibitor of true cholinesterase (50% inhibition at 37"for 20 min.by 1.5 x 10-lo~) and the quaternary is more active than the36 W. N. Aldridge and A. N. Davison, Biochem. J., 1963, 55, 763.38 A. N. Davison, ibid., 1953, 54, 5S3.40 W. N. Aldridge and A. N. Davison, ibid., 1962, 52, 663.41 A. S . V. Burgen and F. Hobbiger, Brit. J . Pharmacol., 1951, 6, 593.42 K. J. M. Andrews, F. R. Atherton, F. Bergel, and A. L. Momson, J., 1962, 780.43 F. Hobbiger. Chem. and Ifid.. 1954, 1574.44 J. R. Fukuto, R. L. Metcalf, R. B. Marsh. and M. Maxon, J . Amev. Chem. Soc.,1055, 77, 3670298 BIOLOGICAL CHEMISTRY.tertiary comp~und.~~~ 45 Although changing the tertiary atom to aquaternary atom will also influence the stability of the compound, alterationsof the magnitude just described indicate that the anionic site can be utilisedin the inhibitory process.Both factors, lability to hydrolysis and ( ( fit ”upon the enzyme surface, are important as they undoubtedly are with sub-strates. Thus acetylthiocholine is hydrolysed by true cholinesterase at ahigher rate than a~etylcholine.~~ The structures of these compounds are sosimilar that it is unlikely that the ( ( fit ” upon the enzyme active centre isdifferent, but acetylthiocholine is more unstable to hydroly~is.~~ Althoughthese two factors play a part, an inhibitor, di-n-propyl 2 : 2-dichlorovinylphosphate, has been recently e~amined,~ whose activity is difficult to explain.This substance is very stable to hydrolysis, does not react with catechol orpicolinohydroxamic acid (see section on reactivation), and does not possess astructure which would be regarded as in any way resembling that of acetyl-choline.Reaction (I), the formation of the hypothetical reversible complexbetween inhibitor and enzyme, has not been demonstrated.Such a re-versible complex between DFP and cholinesterase was originally claimed tohave been dem~nstrated,~’ but this has now been Thisfailure to detect the reversible complex is not surprising, for enzyme-substrate complexes have been detected onlyIt should be noted that phosphorus is not an essential constituent of amolecule which will produce an inhibition similar to that described above.Myers and Kemp 51 have shown that a variety of organic acid fluorides willinhibit cholinesterase, e.g., NN-dimethylcarbamoyl fluoride, chloromethane-sulphonyl fluoride, and toluene-9-sulphonyl fluoride.Earlier, kineticstudies on the inhibition of cholinesterase by [2-(NN-dimethylcarbamoyl-oxy)-5-phenylbenzyl] trimethylammonium bromide, which had always beenconsidered a typical reversible inhibitor, had indicated that the inhibitionpassed through a stage analogous to the phosphorylated enzyme, Le., thedimethylcarbamoyl-enzyme which is readily hydrolysed to the originalenzyme.52 Myers has now shown that NN-dimethylcarbamoyl fluorideproduces a similarly unstable inhibited enzyme, whereas NN-diethyl-carbamoyl fluoride produces a stable inhibited enzyme and behaves similarlyto organophosphorus inhibitor^.^^ The isolation of chymotrypsin acetate,an intermediate in the hydrolysis of p-nitrophenyl acetate by chymotrypsin,is also of interest (see (‘ degradation of inhibited enzymes ”).Reactivation of the Phosphorylated Enzyme.-For many years the inhibi-tion of esterases by organophosphorus compounds was considered to beirreversible.However, Wilson showed that inhibition of electric-eel5045 K. J. M. Andrews, F. R. Atherton, F. Bergel, and A. L. Morrison, J., 1954, 1638.46 G. B. Koelle, J . Pharmacol., 1950, 100, 158.47 D. Nachmansohn, M. A. Rothenberg, and E. A. Feld, Arch. Biochem., 1946, 14,49 D. Keilin and T.Mann, R o c . Roy. Soc., 1937, B, 122, 119.50 B. Chance, Acta Chem. Scand., 1947, 1, 236.51 D. K. Myers and A. Kemp, Nature, 1954, 173, 33.61 D. K. Myers, Biochem. J . , 1952, 62, 46.53 Idem, ibid.. 1956, 62, 556.197.T. B. Wilson and M. Cohen, Biochim. Biophys. Acta, 1953, 11, 147ALDRIDGE : ORGANOPHOSPHORUS COMPOUNDS AND ESTERASES. 899cholinesterase by TEPP produced an inhibited enzyme which was slowlyreactivated on st0rage.~2 Later it was found that the dimethyl phosphoryl-ated true cholinesterase z7 and the diethyl phosphorylated pseudo-cholin-esterase 39 were much more unstable. Hestrin had previously shown thatcholinesterase will catalyse the formation of acetohydroxamic acid fromacetylcholine and hydroxylamine,54 and Wilson has demonstrated that therate of the spontaneous reactivation of the diethyl phosphorylated enzymecould be increased by hydroxylamine and also by choline.32 TEPP anddiethyl phosphorofluoridate both produced an inhibited enzyme which wasreactivated at the same rate by hydroxylamine, but the enzyme inhibitedby DFP was much more stable.% Diethyl phosphorylated chymotrypsinmay also be partially reactivated by hydr~xylamine,~~* 56 This demon-stration, that in addition to its slow reactivation by hydrolysis, the inhibitedenzyme could be reactivated much faster by hydroxylamine, led to a searchfor more powerful nucleophilic reactivators.A large variety of hydroxamicacids and oximes have now been examined.221 57-69 Pyridine-2-aldoximemethiodide,'* 67 picolinohydroxamic acid,63 bishydroxyiminoacetone andmonohydroxyiminoacetone 579 6O are particularly effective.This reactiv-ation by water,27 by hydr~xylamine,~~~ 56 or by bishydroxyiminoacetone e,~is temperature-dependent and has a high energy of activation. Reactivationby hydroxylamine may be prevented by the addition of positively chargedions such as tetramethyl- or tetraethyl-ammonium,% Trimethylamine willslow down reactivation by nicotinohydroxamic acid methiodide and pyridine-2-aldoxime methiodide,61* 62 and acetylcholine that by pyridine-2-aldoximemethiodide. 67 Such results are entirely consistent with attachment of thereactivator at the anionic site of cholinesterase.68 Although a large numberof oximes which are not positively charged are effective,57 the statementthat the tertiary pyridine-2-aldoxime is a million times less effective thanthe quaternary methiodide for the reactivation of diethyl phosphorylatedcholinesterase (electric eel) 84 is difficult to explain except on the basis of theparticipation of the anionic site.This does not preclude the possibility thatreactivators may act without attachment to the anionic site. Similarsituations exist in the hydrolysis of such esters as triacetin by cholinesterase 70and in the high inhibitory power of DFP for cholinesterase. Reactivation byS. Hestrin, J . Biol. Chem., 1949, 180, 879.~55 L. W. Cunningham and H. Neurath, Biochim. Biophys. Acta, 1953, 11, 310.56 L. W. Cunningham, J . Biol. Chem., 1954, 207, 443.I 7 A. F. Childs, D. R.Davies, A. L. Green, and J. P. Rutland, Brit. J . Pharmacol.,s8 I. B. Wilson, J . Amer. Chew. SOC., 1955, 77, 2383.59 I. B. Wilson and E. K. Meislich, ibid., 1963, 75, 4628.6o D. R. Davies and A. L. Green, Biochem. J., 1956, 63, 529.61 F. Hobbiger, Brit. J . Pharmucol., 1955, 10, 356.6s I. B. Wilson and S. Ginsburg, Arch. Biochem. Biophys., 1955, 54, 569.64 Idem, Biochim. Biophys. Acta, 1955, 18, 168.66 H. Kewitz and I. B. Wilson, Arch. Biochem. Biophys., 1956, 60, 261.67 D. R. Davies and A. L. Green, Discuss. Furuduy Soc., 1955, 20, 269.6a I. B. Wilson, ibid., p. 119.68 B. J. Jandorf, E. A. Crowell, and A. P. Levin, Fed. Proc., 1955, 14, 231.7O D. H. Adams, Biochim. Biophvs. Acta, 1949, 8, 1 .1955, 10, 462.Idem, ibid., 1956, 11, 295.I. B.Wilson, S. Ginsburg, and E. K. Meislich, J . Amer. Chew. Soc., 1955, 77, 4286300 BIOLOGICAL CHEMISTRY.ammonium molybdate is not prevented by trimethylamine,62 and is prob-ably related to the catalysis of the hydrolysis of '' energy-rich " phosphatecompounds 71-73 and also of inhibitors such as DFP.74While reactivation of diethyl phosphorylated cholinesterase has beenrelatively easy to demonstrate, the enzymes inhibited by DFP were muchmore difficult to reactivate 66 It has now been establishedthat this is due to an alteration in the inhibited enzyme and not to experi-mental artifacts. The ease of reactivation of diisopropyl phosphorylatedcholinesterase is related to the time of incubation of the inhibited enzymebefore reactivation.22* so* 61* 62* 68 In most experiments the enzyme has beenincubated in the presence of the inhibitors, but the change is not due tosecondary reactions of the inhibitor with the enzyrne.e2 Experimentalartifacts are eliminated since the change can occur in vivo.Hobbiger62has shown that a human myasthenic after repeated doses of TEPP hadalmost all his blood cholinesterase activity inhibited and in a non-reactivat-able form. This is also true after prolonged administration of dimethylphosphorus inhibitors to rats.7s The conversion of the reactivatable intothe non-reactivatable inhibited enzyme occurs most rapidly withtrue cholinesterase inhibited by 00-dimethyl, 00-diisopropyl, 0-iso-propyl methyl, and is much slower after 00-diethyl phosphorus com-pounds.22* 80, 68v 69* 76 This difference in ease of conversion is unexplained ;it is unexpected both on chemical grounds and when account is taken of theknown substrate specificity of the enzymes.More information is requiredon the rate of transformation for a series of inhibitors and several enzymesof different substrate specificities. It has been demonstrated that diiso-propyl phosphorylated pseudo-cholinesterase (human) is transformed morerapidly than the corresponding inhibited true cholinesterase (human) .61$62In general, the transformation is temperature-dependent 22s 5 8 s 60 and forthe methyl 0-isopropyl phosphorylated cholinesterase (true) it is markedlycatdysed by acid.60Reactivation studies have been almost all upon inhibited cholinesterases.Diethyl phosphorylated chymotrypsin can be partially reactivated byhydroxylamine 55, 513 and diisopropyl phosphorylated chymotrypsin slowlyby nicotinohydroxamic acid methiodidegg There has so far been no con-clusive demonstration of a progressive transformation of a reactivatable intoa non-reactivatable inhibited enzyme with enzymes other than the cholin-esterases.The difference between these two forms of cholinesterase is atthe moment absolute-one form may be reactivated, whereas the othercannot even with the most effective reactivators or by ammonium molybdate.Recently, several papers have been published showing that these re-activators react readily with the inhibitors themselves. Hydroxylaminereacts with a variety of inhibitor^,'^ and detailed studies have been made of7 1 F.Lipmann, Adv. Enzymol., 1941, 1, 112.7' F. Lipmann and L. C. Tuttle, J . BioZ. Chem., 1944,158, 671.T. Winnick and E. M. Scott, Avck. Biochem., 1947, 12, 201.74 T. Wagner-Jauregg. B. E. Hackley, T. A. Lies, 0. 0. Owens, and R. Proper, J .75 M. Vandekar, Biochervt. J., 1957, 65, 1 ~ .76 B. J. Jandorf, J . Amer. Chem. SOC., 1966, 78, 3686.Amer. Chem. SOC., 195s. 77, 922ALDRIDGE : ORGANOPHOSPHORUS COMPOUNDS AND ESTERASES. 301the reaction of hydroxamic acids and oximes with organophosphorus com-pounds. 7-79Degradation of the Inhibited Enzymes,-The straight-forward chemicalreaction of organophosphorus compounds with esterases and the theory thatthey react as substrates for the enzyme, but that the dialkylphosphorusmoiety remains attached to or near to the active centre, have led to attemptsto degrade the enzyme to obtain information of the chemical structure andarchitecture of the active centre.The use of inhibitors containing 32P madeit easier to trace the fragment to which the phosphorus was attached. Forthis work it is essential to have the enzyme of reasonable purity so that forthis aspect of the problem cholinesterase has been little used.When recrystallised diisopropyl phosphorylated chymotrypsin is hydro-lysed by acid, phosphoserine can be isolated from the hydrolysates.80s *lPhosphoserine can also be isolated from diisopropyl phosphorylated pseudo-cholinesterase, liver ali-esterase, trypsin, red-cell ali-esterase, and red-cellcholinesterase.82 It was realised that the radioactive phosphorus may havemigrated during the drastic acid hydrolysis.s0* 81 That this was a distinctpossibility was shown when it was found that a diisopropyl phosphoryl groupon the amino-group of serine will easily migrate to the hydroxy-group,a andthat serine phosphate is a very stable substance. Cohen and his co-workershave used much less drastic methods of degradation. After degradation ofdiisopropyl phosphorylated chymotrypsin with proteolytic enzymes, apeptide has been isolated containing one molecule each of proline, leucine,aspartic acid, and serine, and 2-3 molecules of glycine per diisopropylphosphoryl group.Alkaline hydrolysis of the peptide yielded diisopropylphosphate, whereas acid hydrolysis gave serine phosphate.This work hasbeen extended to diisopropyl phosphorylated trypsin and liver esterase andsimilar peptides were obtainedSa6 A similar result has been obtained withtrypsin inhibited by DFP, with %-labelled isopropyl groups.S6 Althoughthe diisopropyl phosphoryl group has been shown to be attached to serine,many workers believe that the group has migrated since the initial in-hibitory process. Chemically the hydroxyl group of serine does not reactwith DFP 87 and the only amino-acids reacting at all readily with DFP arehistidine 8a and tyrosine.8e Photochemical oxidation of chymotrypsin inthe presence of methylene-blue leads to the loss of one molecule of histidine77 R. Swidler and G. M. Steinberg, J .Amer. Chem. SOC., 1956, 78, 3594.18 B. E. Hackley, P. Plapinger, M. Stolberg, and T. Wagner-Jauregg, ibid., 1966,7O A. L. Green and B. Saville, J., 1966, 3887.80 N. K. Schaffer, S. C. May, and W. H. Summerson, J . Bid. Chem., 1963, m, 69.81 Idem, ibid., 1954, 206, 201.82 J. A. Cohen, R. A. Oosterbaan, M. G. P. J. Warringa, and H. S. Jansz, Discuss.83 P. Plapinger and T. Wagner- Jauregg, J . Amer. Chem. SOC., 1953, 75, 6767.82 R. A. Oosterbaan, P. Kunst. and J. A. Cohen, Biochim. Biofikys. Acta, 1965,16,299.85 R. A. Oosterbaan. H. S. Jansz, and J. A. Cohen, ibid., 1966, 20, 402.86 G. H. Dixon, S. Go, and H. Neurath, ibid., 1956, 19, 193.87 T. Wagner-Jauregg, J. J. O’Neill, and W. H. Summerson, J . Amev. Chem. SOC.,88 T. Wagner- Jauregg and B.E. Hackley, ibid., 1953, 75, 2126.89 R. F. Ashbolt and H. N. Rydon, ibid., 1952, 74, 1865.So L. Weil, S. James, and A. R. Bucbert, Arch. Biochem. Biophys., 1963, (8, 266.77, 3651.Faraday SOC., 1965, 20, 114.1951, 73, 5202302 BIOLOGICAL CHEMISTRY.(out of a total of 2) and approximately 3 of 7 the tryptophan residues.22This photo-oxidised chymotrypsin failed to react with DFP. Also diiso-propyl phosphorylated chymotrypsin was more difficult to oxidise in thisway. From the variation of cholinesterase activity with pH, it has beensuggested that the acylated or phosphorylated site in the enzyme may be thebasic nitrogen atom of the glyoxaline ring in h i ~ t i d i n e , ~ ~ and, by using similarcriteria, histidine has been implicated in the catalytic activity of pseudo-cholinesterase, chymotrypsin, trypsin, and liver e ~ t e r a s e .~ ~ - ~ ~ Hartley andKilby 96 observed that the hydrolysis of 9-nitrophenyl acetate by chymo-trypsin was a two-phase process and was inhibited by organophosphoruscompounds. This has now been clearly demonstrated to be a primaryformation of acetylchymotrypsin followed by a slow hydrolysis of thisintermediate ; the acetylchymotrypsin has been 98 No evidencefor the formation of acetylglyoxaline was obtained by measuring the differ-ence in the ultraviolet spectra of acetylchymotrypsin and chymotryp~in.~~Gutfreund has also concluded from kinetic studies that the evidence pointsto an acetylation of the hydroxyl group of serine followed by its transferto histidine.lW Histidine catalyses the hydrolysis of DFP, and it has beenshown that diisopropyl phosphorylglyoxaline is highly unstable.88 All thisevidence explains the attraction of the idea that histidine is involved in thehydrolysis of substrates by esterases.The suggestion of a transfer of the phosphorus moiety from one group toanother on the enzyme surface has been correlated with the change ofinhibited cholinesterase from a reactivatable to an irreversible stage.61However, such a change has only been conclusively demonstrated for theinhibited cholinesterase.It is, of course, possible that this change occursextremely rapidly with chymotrypsin and trypsin. Only recently havepeptides containing histidine been isolated. Hydrolysis with 12~-hydro-chloric acid at 37" for 3 days of methyl O-isopropyl phosphorylated chymo-trypsin has yielded a peptide containing glycine, aspartic acid, methyl-phosphonylserine, glutamic acid, alanine, and valine.A papain digest ofthe same enzyme gave a peptide containing, in addition to these amino-acids,histidine, proline, leucine, cystine, and threonine.lo1, lo2 It appears from thepeptides so far isolated, that the histidine is some distance from serine. Iftransfer takes place, then it is reasonable to suppose that it must be becausethe peptide chains are so folded that the two amino-acids are in juxta-position. Dixon and Neurath lo3 have attempted to prevent such a migra-91 I. B. Wilson and F. Bergmann, J . Biol. Chem., 1950, 186, 683.92 K. J.Laidler, Trans. Faraday SOC., 1955, 51, 560.93 H. Gutfreund, ibid.. p. 441.94 F. Bergmann, R. Segal, A. Shimoni, and M. Wurzel, Biochem. J., 1966, 63, 684.95 B. R. Hammond and H. Gutfreund, ibid., 1966, 61, 187.96 B. S. Hartley and B. A. Kilby, ibid., 1952, 50, 672.9 7 A. K. Balls and F. L. Aldrich, Proc. Nat. Acad. Sci., U.S.A., 1955, 41, 190.913 A. K. Balls and H. N. Wood, J . Biol. Chem., 1956, 219, 245.99 G. H. Dixon, W. J. Dreyer, and H. Neurath, J . Amer. Chem. SOC., 1956,78, 4810.100 H. Gutfreund and J. M. Sturtevant, Biochem. J., 1956, 83, 656.101 N. K. Schaffer, S. Harshman, R. R. Engle, and R. W. Drisko, Fed. Proc., 1955,102 N. K. Schaffer, R. R. Engle, L. Simet, R. W. Drisko, and S . Harshman, ibid.,108 G. 13. Dixon and H. Neurath, Biochim.Biophys. Acta, 1966, 20, 672.14, 275.1956, 15, 347ALDRIDGE ORGANOPHOSPHORUS COMPOUNDS AND ESTERASES. 303tion in trypsin by treatment with urea immediately after inhibition. Nodifference in labelling by 32P from DFP was found between an inhibitedenzyme so treated and a control. No reaction between trypsin and DFPoccurred in the presence of 8~-urea. Evidence has been given that E600will react with trypsin in 8 M - ~ r e a , ~ ~ * l O ~ but other workers have failed toconfirm these observations.lo6The work described in this section may be summarised : From a varietyof inhibited enzymes, serine phosphate has been isolated. On the basis thatthe phosphate moiety was attached to the serine before degradation of theprotein and, since the enzyme is inhibited, this serine is very near the activecentre, it appears that the amino-acid composition around the active centreof a variety of esterases is very similar.On chemical grounds it is notgenerally considered that the phosphorus is primarily attached to the serine,but attempts to show a two-stage process for enzymes other than cholin-esterases have so far been unsuccessful.Hydrolysis of Organophosphorus Compounds by Enzymes.-Mazur lo7 firstdemonstrated that DFP was hydrolysed by enzymes present inmammals. Since then, the enzymic hydrolysis of a variety of organo-phosphorus compounds has been establi~hed-E600,~~~ lo8 ethyl NN-di-methylphosphoroamidocyanidate,lN* l10 TEPP,25s ll1 isopropyl methyl-phosphonofluoridate,ll28 113 and 3-(diethoxyphosphinyloxy)-l-methylquinol-inium methyl s ~ l p h a t e .~ ~A source of confusion in the examination of these enzymes has beentheir overlapping specificity. ll1 For instance, the enzyme which hydrolysesDFP present in rabbit plasma is not the same enzyme as that present in hogkidney.ll* Water-soluble enzymes of rat and hog liver are activated bymanganese and cobalt, and hydrolyse DFP and its di-rt-butyl analogue atthe same rate. The water-insoluble enzymes of these livers hydrolyse di-n-butyl phosphorofluoridate at a greater rate than DFP and are activated bycalcium and inhibited by manganese, cobalt, and magnesium.l15Of particular interest is the work of Mounter and his co-workers on theenzyme of hog kidney which hydrolyses DFP.This is activated by man-ganese and also by glyoxaline, histidine, and other metal-chelating agentssuch as 2 : 2'-dipyridyl.ll6-ll8 It was concluded 118 that only definitemolecular structures involving glyoxaline or pyridine derivatives activate thehydrolysis of DFP in the presence of manganese. These compounds mayeither prevent or inhibit the activation of the hydrolysis by cobalt; in thelo4 T. Viswanatha and I. E. Liener, J . Biol. Chem., 1955, 215, 777.l o 6 Idem, Nature, 1955, 176, 1120.lo6 J. I. Harris and B. S. Hartley, Biochim. Biophys. Acta, 1956, 21, 201.A. Mazur, J . Biol. Chem., 1946, 164, 271.108 W. N. Aldridge, Biochem. J., 1953, 53, 117.loQ K. B. Augustinsson, Biochim. Biophys. A d a , 1954, 13, 303.K. B. Augustinsson and G.Heimburger, A d a Chem. Scand., 1954, 8, 553.l11 Idem, ibid., p. 1533.I l 2 F. C. G. Hoskin, Canad. J . Biochem. Physiol., 1956, 34, 75.llS P. A. Adie, F. C. G. Hoskin, and G. S. Trick, ibid., p. 80.llP L. A. Mounter, J . Biol. Chem., 1954, 209, 813.116 L. A. Mounter, C . S. Floyd, and A. Chanutin, ibid., 1953, 204, 221.117 L. A. Mounter and A. Chanutin, ibid., 1953, 204, 837.ll@ Idem, ibid., 1954, 210, 219.Idem, ibid., 1955, 215, 705304 BIOLOGICAL CHEMISTRY.presence of cobalt, proline and hydroxyproline are effective activators.118These observations may be compared with the pure chemical studies on thenon-enzymic catalysis of the hydrolysis of DFP by metal chelate com-pounds. 74 Copper sulphate increases the rate of hydrolysis of DFP, whereasother metals such as iron (ferrous), palladium, chromium, nickel, and cobaltare inactive or only slightly active.On the other hand, copper complexesof amino-acids, glyoxaline, ethylenediamine, o-phenanthroline, and 2 : 2‘-dipyridyl are highly active. The half-life of DFP at pH 7.6 at 38”alone or in the presence of glyoxaline or copper sulphate or both is 2 days,5 hr., 5 hr., and 20 min., respectively. It is of interest that copper was byfar the most active metal and chelate compounds of nickel and cobalt weremuch less effective, and iron and manganese were inactive. For the enzymichydrolysis of DFP, manganese is the most active metal.ll6 With bidentatedonor groups, such as 2 : 2’-dipyridyl and ethylenediamine, the 1 : 1 chelatecompounds are more effective than the 1 : 2 compounds.74 Copper ions willalso catalyse the hydrolysis of thiophosphoric esters such as 00-diethylO-P-nitrophenyl phosphorothionate.119It was natural to attempt to find a more physiological substrate for theenzymes which hydrolyse such foreign substrates as DFP and E600. Froma variety of criteria, it was concluded that the enzyme in rabbit plasma whichwill hydrolyse E600 will also hydrolyse 9-nitrophenyl acetate, propionate,and butyrate,lo8 and this has recently been confirmed after electrophoreticseparation of the enzyme.18 The enzyme apparently cannot distinguishbetween carboxyl or phosphate esters. Recently, it has been stated thatthe enzyme in hog kidney which hydrolyses DFP, also hydrolyses acet-amido-acids, such as N-acetyl-valine, -leucine, -methionine, and -alanine. 120With these two enzymes, it seems that enzymes with esterase activity whichare not inhibited by organophosphorus inhibitors also hydrolyse them.Originally it was thought that the enzyme of rat pancreas was an exception;it is not inhibited by a variety of inhibitors such as TEPP, DFP, NN’N”N“’-tetraisopropylpyrophosphoramide, and NN-diisopropylphosphorodiamidicfluoride,24- 121 but is inhibited by E6U0.24 It was originally considered thatthis inhibition was reversible,24 but this has recently been disp~ted.1~9 121Conclusions.-Organophosphorus compounds do not inhibit enzymesother than carboxylic esterases.The inhibitory process may be representedas follows :H = enzyme, R-X = inhibitor with X the labile group, Re = reactivatable,ll@ J.A. A. Ketelaar, H. R. Gersmann, and M. M. Beck, Nature, 1956, 117, 392.1 2 O L. A. Mounter, Fed. Proc., 1966, 15, 317.lal P. Desnuelle, M. J. Constantin, and L. Sarda, BUZZ. SOC. CAim. b i d , 1956, 38, 625CALLOW : METABOLISM OF STEROIDS. 306The evidence is overwhelming, at least for chymotrypsin, trypsin, andtrue and pseudo-cholinesterase, that the organophosphorus inhibitors arehydrolysed (reaction 2) by the enzyme, but that the intermediate, thephosphorylated enzyme, is stable, whereas with natural substrates it isunstable. These esterases therefore do not distinguish between carboxylicand phosphate esters; this is also true for an enzyme which hydrolysesE600 and 9-nitrophenyl acetate, and another hydrolysing DFP and acet-amido-acids.Although it is likely that this reaction scheme applies to thesetwo enzymes no direct evidence has as yet been obtained. This inhibitoryprocess indicates that it should be possible to find organophosphorus com-pounds which act as substrates, the phosphorylated intermediate beingsufficiently unstable. This has been partially achieved with dimethyl-phosphorus inhibitors and true cholinesterase. Although the factors of" fit " (reaction l), stability of inhibitor, and stability of the esterified inter-mediate (reaction 4) are well appreciated for organophosphorus compounds ,they could be more fully considered for substrates. There is no cleardemarcation between substrates and inhibitors of this type and, betweenthese two extremes, there is a spectrum of behaviour.The catalysis of the hydrolysis of DFP by histidine and various copperchelate compounds probably fits into the above reaction scheme.There isalso much circumstantial evidence that histidine participates in the hydro-lytic process of esterases.On degradation of a variety of inhibited esterases the phosphorus isfound to be attached to serine. All attempts to demonstrate phosphorusattached to other groups have so far failed. Treatment of cholinesterasewith nucleophilic reagents has shown that the inhibited enzyme changes froma reactivatable (reaction 4) to an irreversible stage (reaction 3). Furtherwork will undoubtedly tell us of the properties of this irreversible inhibitedenzyme and if such a transformation occurs with other esterases.W.N. A.4. METABOLISM OF STEROIDS.A tremendous volume of work continues to be published in this field.Much deals with experimental techniques-a fact significant of the diffi-culties of the analytical investigation of minute amounts of substances intissues, blood, and excreta. There is no lack of reviews, and attention maybe directed to Zimmermann's booklet on chemical analytical methods, tothe general articles by Lieberman and TeichJ2 by Hechter and Pincus? repre-senting the Worcester Foundation, by Roberts and %ego: and by Rosen-kilde and S~hroeder,~" and to articles on special subjects, such as thebiosynthesis of ch~lesterol,~ hormone metabolites in human urine,6 and1 W.Zimmermann. " Cbemische Bestimmungsmethoden von Steroidhormonm inKorperfliissigkeiten," Springer-Verlag, Berlin, 1955. * S. Lieberman and's. Teich, Pharmacol. Rev., 1953, 5, 285.3 0. Hechter and G. Pincus, Physiol. Rev., 1954, 34, 459.4 S. Roberts and C. M. Szego, Ann. Rev. Biochem., 1955, 24, 543.4a H. Rosenkilde and W. Schroeder, 2. Vitamin-, Hormon-, u. Fermentforsch., 1956,6 R. T. Dorfman and F. Ungar, " Metabolism of Steroid Hormones," Burgess Publ.8, 132.Co., Minneapolis, 1954.J. W. Cornforth, Rev. Pure Appl. Chem., 1954, 4, 216306 BIOLOGICAL CHEMISTRY.steroid hormones and cancer.’ The enzymic hydroxylation of steroids wasreviewed in these Reports in 1955. Reports of conferences also allowthe investigations and speculations of the main centres of research to befollowed.General Trend of Investigation.-Interest in steroid-hormone metabolismhad its origin in the hope that, by analysis of the urine, there might beobtained an index of the hormone levels in the body, and hence assistance begiven to medical diagnosis in suspected endocrine disease.In fact onlygross deviations from the normal levels of excretion have diagnostic value, inmost cases simply confirmatory of clinical indications of under- or over-function of the adrenal cortex or of defects in catabolism due to disease ofthe liver or kidneys. Routine assays are currently of value in the differenti-ation of Cushing’s syndrome of adrenocortical or hypophyseal origin or intests of corticoid excretion before and after administration of adrenocortico-trophin to determine whether apparent adrenocortical insufficiency is primaryor secondary to pituitary failure.l* Application to the diagnosis of neo-plastic growth not affecting specific endocrine organs has been disappointing(cf. Schubert ’).To cite one example only, 3 : ll-dihydroxytestan-l-one, once thought to be a urinary constituent found only in cases ofcancer, is now, with more refined methods of separation, found in theurine of normal subjects and recognised as one of the usual metabolites ofcortisol.llA profound reorientation in the study of metabolism of steroids, par-ticularly in the live animal, but also in vitro, has come about with the useof steroids labelled with radioactive isotopes, particularly those incorporatinglac, which has been introduced into the 3- or the 4-position in cholestenone,testosterone, progesterone, deoxycorticosterone, and cortisone, in the16-position in oestrone and related compounds, in the 21-position in pro-gesterone, and in the 24-, 25-, and 26-positions in cholesterol.In addition,earlier work with deuterated steroids has been succeeded by work with theanalogous tritiated compounds. The work in the hormone field, the firstphases of which were discussed at the Laurentian Hormone Conferencein 1952,12 has recently been summarised by two of the principal research7 K. Schubert, “ Steroide und Krebs,” Steinkopf, Dresden, 1966.* Cf. particularly, Recent Progr. Hormone Res., 12, Proceedings of the LaurentianHormone Conference, 1955, Academic , F s s , New York, 1956 ; containing “ Biogenesisof the Sterols and Steroid Hormones by R.D. H. Heard, E. G. Bligh, M. C. Cann,P. H. Jellinck, V. J. O’Donnell, B. G. F, and J. L. Webb, “ Some Aspects of theBiogenesis o:, Adrenal Steroid Hormones by M. Hayano, N. Saba, R. I. Dorfman, and0. Hechter, Enzymatic Mechanisms of Hormone Metabolism. I. Oxidation-Reduc-tion of the Steroid Nucleus” by G. M. Tomkins, and Enzymatic Mechanismsof Hcrmone Metabolism. Mechanism of Hormonal Glucuronide Formation ” byK. J. Isselbacher.10 A. C . Crooke, Lancet, 1955, ii, 1045; F. T. G. Prunty; Brit. Mad. J., 1956, ii,615, 673.11 L. 0. Plantin and G. Birke, Acta Endocrinot., 1965, 19, 8.19 R. D. H. Heard, R.Jacobs,V. J. O’Donnell, F.G. Peron, J. C . Saffran, S. S. Solomon,L. M. Thompson, H. Willoughby, and C. H. Yates, Aeccnt Progr. Hormone Rcs.,1954, 9, 383; T. F. Gallagher, H. L. Bradlow, D. K. Fukushima, C. T. Beer,T. H. Kritchevsky, M. Stokem, M. L. Eidenoff, L. Hellman, and K. Dobriner, ibid.,p. 411.Ann. Refiorts, 1965, 52, 316.11CALLOW : METABOLISM OF STEROIDS. 307groups.l3~l4 The obvious advantages of these new techniques are the useof “ physiological ” amounts of material, the possibility of assigning alabelled product to a labelled precursor, the ease with which the presence oflabelled products can be detected in fractions separated by some chemicalor physical procedure, and, in particular, the possibility of isolating difficultlyseparable substances present in small amount by adding a non-radioactivecarrier and then separating the substance, albeit in poor yield, admixedwith the radioactive product.Also, the proportion of precursor which isrecovered in various fractions can now be accurately measured ; the variationbetween individuals and from time to time in this proportion is now disclosed,and attention is directed to the fact that in every instance a relatively largeproportion of the material is catabolised by paths which have not beenexplored because hitherto no crystalline compounds have been isolated.Further development in this direction may be expected, and it seems notunlikely that in the near future the contribution of the endocrinologicalchemist to medical diagnosis may be that of investigating the idiosyncraciesof patients in the metabolism of isotopically labelled hormone administeredin a suitable dose.The Biosynthesis of Cholesterol.-The existence of a route of synthesis,involving squalene, from acetic acid to cholesterol in animals, including man,is established, but we are far from knowing all the steps, or of being assuredthat they are all obligatory.In this and other types of steroid synthesis itmay be that the course of metabolism has so many alternative routes thatit is more properly compared with a grid system of electricity supply ratherthan with an arterial road. Popjkk l5 discussed the quantitative aspect ofthe transformation :[ l-14C,]acetate --+ [14C]squalene + [14C]cholesterolin ovarian tissues of the hen, and concluded that the “ squalene ” hypothesiscould only be reconciled with experimental observations by assuming eitherthat squalene had only a transitory existence as an enzyme-substratecomplex, or that some other scheme was operative, such as :acetate ---t isoprenoid unit + X ---t cholesterol!IsqualeneThese considerations still apply.In the very first stages of the biosynthesisthe important discovery has been made l6 that p-hydroxy-p-methyl-8-valerolactone, “ divalonic acid ’’ (l), is converted virtually completely into13 L. Hellman, K. S. Rosenfeld, D. K. Fukushima, H. L. Bradlow, T. F. Gallagher,R. G. Gould, and G. V. Le Roy, ‘‘ Peaceful Uses of Atomic Energy, Proceedings of theInternational Conference at Geneva, August 1955,” United Xations, New York, Vol.XII, p.532.14 G. J. Alexander, E. Bloch, R. I. Dorfman, C. A. Fish, 0. Hechter, G. Pincus,E. Romanoff, N. Saba, K. Savard, E. Schwenk, D. Stevens, D. Stoqe, T. H. Stoudt,and F. Ungar, ibid., p. 539.Is G. Popjkk, Arch. Biochem. Biophys., 1964, 48, 102.16 P. A. Tavormina, M. H. Gibbs, and J. W. Huff, J . Amer. Chews. SOL, 1956, 78,4498; P. A. Tavormina and M. H. Gibbs, ibid.. p. 6210308 BIOLOGICAL CHEMISTRY.cholesterol in cell-free, rat-liver homogenates and is a much better sourcethan B-hydroxy- @-met hylglutaric or 8 p-dimethylacrylic acids. 8-H ydroxy-P-methyl-8-valerolactone either is an important biological precursor of iso-prene units, or is converted by some relatively minor biochemicaltransformation into an " active isoprene '' unit.The completion of one, more strictly chemical, line of investigation canbe recorded.When cholesterol is formed from acetic acid, the acetic acidunits are built up according to a fixed pattern. This has been elucidatedby supplying labelled acetic acid, e g . , CH,-14C0,H or 14CH,*C0,H to rat-liver slices and degrading the resultant cholesterol in such a fashion thatindividual carbon atoms can be recognised in the products. The carbonatoms can be assigned to the methyl- (m) or carboxyl- (c) carbon atom ofthe acetic acid used as source. The last step in this process has been reportedby Cornforth and his co-workers,17 and C(8), C(91, C,,,, C(12), and c(14) cannow be assigned to c, m, c, c, and c, respectively, grving as the final con-clusion the formula (2) for the cholesterol skeleton.3, Squalene. 4, Lanosterol.5, Desmosterol. 6, Cholesterol.This constitution is in complete accord with the hypothesis of the bio-genesis of cholesterol from the squalene molecule condensed as suggested byWoodward and Bloch.18 The stages between squalene and cholesterol are17 J. W. Cornforth, I. Youhotsky Gore, and G. PopjBk, Biochem. J., 1966, 64, 3 8 ~ ;18 R. €3. Woodward and K. Bloch, J . Amer. Ckm. SOC., 1963, 75, 2023.1957.65, 94CALLOW : METABOLISM OF STEROIDS. 309still under investigation : the work of Clayton and Bloch l9 which showedthat lanosterol is formed in rat-liver “ homogenate,” and that it is convertedinto cholesterol, combined with the work of Stokes et aL2* on the “ high-counting companions” which can be isolated from the sterol fraction ofchick embryos from fertile eggs injected with [l-l*C]acetate, suggests thesequence shown in formula (3)-(6).An ionic mechanism for the biological cyclisation of squalene to steroidshas been outlined by Ruzicka.21 In yeast the biosynthesis of sterols wouldseem to follow similar lines, with zymosterol asa precursor of ergosterol and other unidentified‘‘ highcounting companions ” in the sterolfraction.At least some of the intermediatesbetween acetic acid and the sterols in the animaland in the plant are identical and interchange-able, and zymosterol (7) is converted in the ratinto cholesterol (Schwenk et aLZ2). An approachto a purely enzymic synthesis of cholesterol from acetate has been made byRabinowitz and his co-workers23 who claim to have prepared squalene ofhigh specific activity by incubation of labelled acetate with mitochondria1enzymes from rat-liver supplemented with supernatant fluid. The resultingsqualene yielded radioactive cholesterol when incubated with a mito-chondrial extract combined with supernatant fluid.Cholesterol Balance.-The subject of the balance of cholesterol in the bodyhas received much attention recently because of its importance in medicine.Atherosclerosis, a condition in which cholesterol is deposited on the arterialwalls, is associated with hypertensive disease, and the relation of hyper-tension, high blood cholesterol, and atherosclerosis has been the subject ofmany discussions as to which is cause and which effect.Thinking on thesubject was for a long time dominated by the old observation that athero-sclerosis was produced in rabbits by administering cholesterol-a substancethat does not normally form part of its food. The pendulum then swungthe other way, and emphasis was put on the endogenous production ofcholesterol in man and other animals. Here again, the use of isotopicallylabelled materials is beginning to clarify the situation. The synthesis inthe liver of cholesterol from acetate, and migration of the cholesterol tothe plasma, and the incorporation of dietary cholesterol which enters byway of the chyle through the liver into the circulation have been studied 13*24925with [2-14C]acetate, tritiated cholesterol, and [4-14C]cholesterol.Significantdifferences are found between normal and diseased subjects, and the in-vestigations are full of promise but detailed discussion is beyond the scopel9 R. B. Clayton and K. Bloch, J . B i d Chem., 1956, 218, 305, 319; cf. referencesquoted in ref. 8.2o W. M. Stokes, W. A. Fish, and F. C. Hickey, ibid., 1956, 2m, 415.23 E. Schwenk, G. J. Alexander, C. A. Fish, and T. H. Stoudt, Fed. Proc., 1965,14,43 J. L. Rabinowitz. F. Dituri, F. Cobey, and S. Gurin, ibid., p. 760.e4 M. W. Biggs, ref. 13, p. 526.HO &L. Ruzicka, Experientia, 1953, 9, 357.762.N. E. Eckles, C. B. Taylor, D. J. Campbell, and R. G. Gould, J . Lab. Clin. Med.,1955, 46, 359; R. G. Gould, G.V. Le Roy, G. T. Okita. J. J. Kabara, P. Keegan, andD. M. Bergenstal, ibid., p. 372310 BIOLOGICAL CHEMISTRY.of this Report. Investigations with rats by Chevallier 26 show that[4-l4C]cholesterol levels can be brought to a steady state after a daily dose of 5mg. for 8 days, and he has introduced the conception of " cholesterol space."Catabolism of Cholesterol.-Siperstein, Chaikoff, and their co-w~rkers,~'and Bergstrom and his co-workers,28 with isotopically labelled compounds,have mapped out the main course of cholesterol breakdown in the body. Itis now clear that, entirely contrary to what was once the general opinion,coprostanol is but a minor product of cholesterol metabolism; rather, mostof the body cholesterol is converted into bile acids and, moreover, all the bileacids are probably derived from cholesterol. In man, as also in the rat,cholic acid is the chief end-product.In man it is present as the glycineconjugate, whilst the rat forms taurocholic acid. Siperstein and Murray 29have found enzyme systems in guinea-pig liver which form cholyl-coenzymeA (the first activated steroid in a biological system) and transform this, byFIG. 1.HO frihydroxy -acid tincubation with taurine, into taurocholic acid. It is probable that hydroxyl-ation of the nucleus takes place before the degradation of the side chain iscompleted and it is suggested that the hydroxylation may be the rate-determining step. As at present elucidated the scheme of degradation ofcholesterol (8) is shown in Fig. 1.In the rat, deoxycholic acid (10) yieldsa6 F. Chevallier, Avch. Sci. Physiol., 1966, 10, 249.1 7 M. D. Siperstein and I. L. Chaikoff, Fed. Proc., 1956, 14, 767; M. D. Sipersteinand A. W. Murray, J . Clin. Invest., 1965, 34, 1449; earlier references are given in thesepapers.a * For references see S. Bergstriim and B, Borgstriim, Ann. Rev. Biochem., 1956,25, 177.2. 11. D. Siperstein and A. W. Murray, Science, 1956, 123, 377CALLOW METABOLISM OF STEROIDS. 311cholic acid (11). Lithocholic acid (12) is formed, and converted into cheno-deoxycholic acid (13) which, in turn, yields a trihydroxy-acid which is notcholic acid.Fredrickson 3O found that liver mitochondria converted [4-14C]cholesterolinto acids and a 25- or 26-hydroxycholesterol.The conversion of cholesterolinto coprostanol (14) occurs in the gut as a result of microbial action, andanaerobic bacteria have been found in human faeces which carry out ther e d ~ c t i o n . ~ ~ Incubation of [3-2H]cholesterol with faeces 32 yields deuteratedcoprostanol, the deuterium in the product being situated at CQ) and ator or both.The results indicate that a direct stereospecific reduction of the doublebond occurs. In the course of this some of the cholesterol must be used asa deuterium donor for other cholesterol molecules accepting deuterium atthe 5 : 6-double bond.A clue to the degradation of cholesterol to C,,-steroids, discussed below,is given by works showing that material from ox adrenals, testes, andovaries yields an enzyme stable to precipitation with ammonium sulphateand dialysis, which splits off isohexanoic acid from cholesterol.An inter-mediate stage is probably 20-hydroxycholesterol, and the residue is describedas a hydroxypregnenone-like substance with C,,,, “ involved or blocked.”Biogenesis of C,,-Steroids-In their latest review l4 the WorcesterFoundation group give Fig. 2 to summarise their conclusions in the field of“ corticosteroidogenesis. ’ ’The pathways from cholesterol (8) to corticosterone (17) and cortisol (19)can be demonstrated stage by stage in cell-free homogenates prepared fromadrenal glands, but there remains evidence for an alternative pathwaythrough an uncharacterised material “ X,” and the interrupted lines indicatethe alternative possibilities.The origin of aldosterone (18) is still a matterof debate, and conflicting results have been reported. Wettstein and hisco-workers 34 found that deoxycorticosterone (16) could be converted intoaldosterone (18) by adrenal homogenates, but progesterone (15) or cortico-sterone (17) could not. The Worcester Foundation by perfusingcalf adrenal gland, obtained aldosterone-like material from progesterone butdoubtfully from corticosterone and not at all from deoxycorticosterone.Ayres et aZ.,36 on the other hand, by using capsule strippings of ox adrenals,which are mainly zona-glomerulosa tissue, were able to demonstrate thatthere was a route of aldosterone biosynthesis through progesterone, deoxy-corticosterone, and corticosterone, though this was not necessarily the onlyso D.S. Fredrickson, J. Bid. Chew., 1956, 222, 109.81 A. Snog-Kjaer, I. Range, and H. Dam, J. Gen. Microbid., 1956, 14, 266.9% R. S. Rosenfeld, D. K. Fukushima, L. Hellman. and T. F. Gallagher, J. Bid.Chcm., 1954, 211, 301; R. S. Rosenfeld, L. Hellman, and T. F. Gallagher, ibid., 1956,222, 321.33 W. S. Lynn, jun., E. Staple, and S. Gurin, J. Awer. Chem. SOL, 1954, 76. 4048;Fed. Proc., 1955, 14, 783; E. Staple, W. S. Lynn, jun., and S. Gurin, J. Bid. Chem.,1956, 219, 845.34 R. Neher, F. W. Kahnt, and A. Wettstein, Experientia, 1955, 11, 446.8s E. Rosemberg, G. Rosenfeld, F. Ungar, and R. I. Dorfman, Endocrinology, 1956,58. 708.36 P. J. Ayres, 0. Hechter, N. Saba, S. A. Simpson, and J. F. Tait, Biochem.J.,1957, 65, 2 2 ~ 312 BIOLOGICAL CHEMISTRY.pathway. These results exemplify the occasional discrepancies which areencountered when even minor differences in mechanical treatment of tissuesprecede enzymic reactions in vitro and the difficulty in assigning particularII ' I co$H,OH CH2OH '\%I co I \ t o I '\ IIII FHjOHco$HIOHco J. FH3 coenzyme activities to specific cellular 37 although attractive andingenious speculations may be made. It may be relevant to the questionof genesis of aldosterone that there is physiological evidence 38 of stimulationof the secretion of aldosterone but not of glucocorticoids, in heat stress.The total number of compounds which have been isolated from extractsof adrenal cortex of the ox and pig has now reached 41, of which 34 arepregnane deri~atives.~~ The latest compounds are derived from previouslyknown corticoids by hydroxylation in the 6p- or the 19-position, by reductionof the 4 : &double bond or the 2O-oxo-group, and by oxidation of the angular13-methyl group to carboxyl.It is clear that the evidence provided by thechemical examination both of large-scale adrenal-cortical extracts and ofhuman adrenal and peripheral venous efiuent-Pincus and Romanoff 4037 N. Saba and 0. Hechter, Fed. Proc., 1955.14, 775.38 K. Hellman. K. J. Collins, C . H. Gray, R. M. Jones, J. B. Lunnon, and J. S.Weiner, J . Endocrinol., 1956, 14, 209.39 R. Neher and A. Wettstein, He1v;'Chirn. Acta. 1956, 39, 2062.40 G. Pincus and E. B. Romanoff, Ciba Foundation Colloquia on Endocrinology,Vol.VIII. The Human Adrenal Cortex," Churchill, London, 1966. p. 97CALLOW : METABOLISM OF STEROIDS. 313found some M ) substances in this material-must be sifted carefully if asatisfactory, simple, general theory of corticosteroidogenesis is to be con-structed. For one thing, differences between species of animal are onlyrecently receiving much attentionjlBiosynthesis of C,, Steroids.-Both the testis and the adrenal cortex con-tribute to the C,, compounds in the body. However, it seems clear that thetestis is the sole source of testosterone (21) (unless it is essential to supposethat testerone is the precursor of estrogens in the ovary). It appears, onthe one hand, that acetate may be converted into testosterone by testistissue from pig, rabbit, or man in d r o by a path which does not includecholesterol 42 and, on the other, that progesterone may be converted intotestosterone by rat-testis tissue * shown in Fig.3.FIG. 3.CholesterolAcer a t,e \+ H y drox ypr egne none + Frog e s t e ron eHydmx yprogesteroneThe genesis of dehydroepiandrosterone (22) is still a matter for conjecture.It has long been known that in human urine it is of adrenal origin; morerecently 44 it has been isolated from human blood, in which, like androsterone,it is present in conjugated form, probably as the s ~ l p h a t e . ~ ~ It has beendemonstrated 46 that human adrend slices can synthesise dehydroepiandro-sterone from [carboxy-14C]acetate, but only a very low yield seems tohave been obtained.The possibility remains that it is a secondary degrad-ation product of an as yet unidentified adrenal compound. Adrenal venousblood yielded androst-4-ene-3 : 17-dione (20) and the 11 (3-hydroxy-derivative .Catabolism of C,, and C,, Steroids.--“ Paradoxical as it may seem, moreinformation is available about the catabolic fate of the steroid hormonesthan about any other phase of steroid chemistry. This is so, in spite of thefact that the catabolic fate of the hormones may be completely unrelated totheir unique biological functions.” These sentences, witten by Liebermanand Teich three years ago, still adequately summarise the position, but withI. E. Bush, Schweiz. med. Wochenschr., 1955,85, 645; F. G. Hofmann, Endocrino-logy, 1956, 59, 712.48 R.0. Brady, J . Biol. Chem., 1961, 193, 145; cf. K. Savard, R. I. Dorfman, andE. Poutasse, J . Clin. Endocrinol., 1952, 12, 935.43 W. R. Slaunwhite, jun., and L. T. Samuels, J . Biol. Chern., 1966, am, 341.44 C. J. Migeon and J. E. Plager, ibid.. 1954, 209, 767; C. J. Migeon, ref. 40, p. 141.46 Idem, J . Biol. Chem., 1966, 218, 941.p6 E. Bloch, R. I. Dorfman, and G. Pincus, A Y G ~ . Biochm. Biophys., 1966, 61, 245.47 E. B. Romanoff, P. Hudson, and G. Pincus, J . Clin. E ~ f o c r i ~ o l . , 1953, 13, 1546,and ref. 40314 BIOLOGICAL CHEMISTRY.the reservation that the quality of the information available and the validityof the generalisations based on it are under rather critical consideration.The postulation of progesterone as a key compound in the biogenesis ofadrenal corticoids or of androgens has not led to the corollary that adminis-tered progesterone can serve as a source of the other hormones.In fact,injected progesterone disappears rapidly from the blood and the onlyproducts recognised as metabolites are pregnane-3a : 20a-diol, allopregnane-3a : 20a-diol, pregnane-3a-ol-20-oneJ aZZopregnane-3a-ol-20-oneJ and d o -pregnane-3P : 20a-di01.~~ Klopper and Michie 49 have reviewed previouswork in this field; they found rather less than 20% of injected progesteronein the form of pregnane-3a : 20a-diol in the urine, irrespective of sex, stageof the menstrual cycle, pregnancy, or period of dosage. The time seems ripefor investigation with labelled progesterone, e.g., [16-3H]progesterone.50 Inother animals there is clearly a field for enquiry, for, although progesterone,assumed to be essential for the maintenance of pregnancy, has been isolatedfrom the placentz of woman and mare, it has not been found in the late-termplacentE of cow, ewe, sow, or b i t ~ h .~ 1 Moreover, these specific differencesrecall the unanswered question of the origin of the pregnane derivativesfound by Pearlman and his co-workers 52 in cow bile. Some observationshave been recorded that are not in line with the orthodox hypotheses.Kaiser 53 observed low excretion of pregnanediol in a pregnant womanwith Addison’s disease, suggesting that the source of urinary pregnanediolis normally the adrenal cortex and compounds other than progesterone, andthe conversion of deoxycorticosterone into progesterone in the kidneys andadrenal glands has been rep0rted.5~ Taylor 55 found allopregnane-3 : 20-dione, 3a- and 3p-hydroxyaZZopregnan-20-one, 3a-hydroxypregnan-20-one,and pregnane-3a : 20a-diol in the products of incubation of progesterone withrabbit liver, and pregnane-3 : 20-dione and 3a-hydroxypregnan-20-one inthe products of incubation of pregane-3a : 20a-diol with rabbit liver.It seemed at one time that a clue through the maze of urinary meta-bolites and glandular precursors in man was given by Dorfman’s 56 general-isation on the type of reduction undergone by steroids in the course ofHO.HzC0 0 @ (25)(23) (2 41metabolism.(23) and Sp-(testane) (24) forms in essentially equal proportions.4 8 E.J. Plotz and M. E. Davis, Acta Endocrinol., 1966, 21, 259.A. Klopper and €3. A. Michie, J . Endocrinol., 1956, 13, 360.W. H. Pearlman, Biochem. J., 1966. 64, 5 4 ~ .61 R. V. Short, Nature, 1956, 178, 743.62 W. H. Pearlman and E. Cerceo, J . Biol. Chem., 1948, 176, 847.63 I. H . Kaiser, J . Clin. Endocrinol., 1956, 16, 1251.54 E. A. Lazo-Wasem and M. X. Zarrow, EndocrinoZogy, 1966, 56, 511.6 6 W. Taylor, Biochem. J., 1956, 60, 380; 1966, 62, 332.S 6 Ti. I. Dorfman in Recent. Prop,. Hormone Res., 1954, 9, 5.According to this, C,,O, steroids are reduced to 5a-(androstane)C,, steroidCALLOW : METABOLISM OF STEROIOS. 315possessing oxygen functions at C(ll) (in effect this means adrenosterone, orandrost-4-ene-3 : 11 : 17-trione) are reduced primarily to the 5a-forms whilethe presence of the C, side chain, with or without oxygen at orients thereduction of the 4 : &double bond predominantly to the Sb-(pregnane) form.Stimulating as this hypothesis has been, and indicative of some basic patternof reduction, it now seems clear that the modification of the ratio 5B : 5 aby age, sex, or physiological status of the individual, which Dorfmanpostulated from the beginning, is an important and overriding factor.Fukushima and Gallagher and their co-~orkers,~~ using deuteratedtestosterone, found wide variation in the ratio 5p : 5a at different timeintervals after administration and a variation over the range 2.5 to 0 5 indifferent subjects.Engel and his co-workers 58 reported that corticosteroneyielded as much of 5a- as of 5p-compounds.Bush 59 has referred to worknot yet published in detail showing that the 5a-compound 3a : ll(3 : 17a : 21-tetrahydroxyallopregnan-20-one is a normal and fairly plentiful urinaryproduct after cortisone administration and also that administeredadrenosterone gave in one subject, a healthy young man, the expected5p : 5a ratio : in another, an adrenalectomised orchidectomised maleaged 58 with cancer of the prostate the ratio found was the reverse of the‘‘ expected.”It appears that prednisone and prednisolone (17a : 21-dihydroxypregna-1 : 4-diene-3 : 11 : 20-trione and the llp-hydroxy-compound), which are notnatural hormones, are to some extent excreted unchanged or reduced, in thecase of prednisone,60 to the llp-hydroxy-compound, or in both cases to the20p-hydroxy-compounds. 61 Ring A is not immediately affected, and itmay be that this escape from the degradative machinery of the body is atleast partly responsible for the high activity of these compounds.Theearlier view, which would seem to have inspired much of the work on hormonemetabolites, that drugs are metabolised in the organ where they act, is nolonger tenable; 62 metabolic degradation is perhaps most obviously, in thecase of steroid hormones, a regulatory and detoxicatory mechanism fordisposing of any excess. No studies of metabolism of the 9ct-halogenatedcorticoids have appeared : it may be that a different explanation is to befound for the high activity of these compounds, and that it is derived frominfluence on the oxidation-reduction of the oxygen at C(ll), as suggested byBush.63 Fried and his colleagues,@ independently, made a similar sugges-tion, and supported it by showing that 12~~-halogenated corticoids also hadenhanced activity which could be regarded as due to inductive (-1) effecton the C(,,,-substituent.The intense, and purely glucocorticoid, activity67 D. K. Fukushima, K. Dobriner, and T. F. Gallagher, J . Biol. Chem., 1954. 208,845; D. K. Fukushima, H. L. Bradlow, K. Dobriner, and T. F. Gallagher, ibid., p. 863.68 L. L. Engel, P. Carter, and M. J. Springer, Fed. Proc., 1954.13, 204.69 I. E. Bush and M. Willoughby (unpublished), and I. E. Bush (unpublished),quoted by I.E. Bush, ref. 63.80 A. Vermeulen, J . Clin. Endocrinol., 1966, 16, 163.dl C. H. Gray, M. A. S. Green, N. J. Holness, and J. B. Lunnon, J . EndocrinoE.,1956, 14, 146; A. Vermeulen, Actu Endocrinot., 1956, 23, 113.68 B. B. Brodie, J . Pharm. Pharmacol., 1956, 8, 1.63 I. E. Bush, Experiential 1956, 12, 326.64 J. E. Hem, J. Fried, and E. F. Sabo, J . Amar. Chem. Soc., 1966, 78, 2017316 BIOLOGICAL CHEMISTRY.of 16a : 21-diacetoxy-9a-fluoro-ll : 17a-dihydroxypregna-1 : 4diene-3 : 10-dione 66 demands some additional explanation.Biosynthesis of the C,, (Estrogenic Steroids.-The conversion of [carboxy-14C]acetate to oestrone and oestradiol has been observed in perfused sowovaries,66 in minced bitch and in perfused human placenta.68Labelled cholesterol was found in the first two instances, but it was notpossible to decide whether it was an intermediate in the synthesis of cestro-gens.On the other hand, Heard and his co-workers are quite convincedthat cholesterol is not an intermediate. From a series of experiments inwhich pregnant mares were given [carbo~y-~~C]acetate, [4-14C]cholesterol,[16-14C]oestrone, and [4-14C]testosterone they deduce a scheme (shown inFig. 4) in which acetate is converted independently into oestrone (26), testo-FIG. 4.sterone (21), equilin (27), and equilenin (28), but testosterone can be con-verted into cestrone and there is also a very doubtful possibility of a deriv-ation of equilenin (28) from testosterone (21) by way of cestrane-3 : l7-diokand 3-hydroxyoestra-5 : 7 : 9-trien-17-one.Slices of human ovary can alsoaccomplish the transformation of testosterone (21) not only to oestradiol 70(29) but also, it is reportedJ71 to oestrone (as), and cestriol (30). Ovariecto-mised adrenalectomised women excrete cestrone and cestradiol after adminis-tration of testosterone. 72 19-Hydroxyandrost-4-ene-3 : 17-dione (25) is a66 S. Bernstein, R. H. Lenhard, W. S. Allen, M. Heller, R. Littell, S. M. Stolar,L. I. Feldman, and R. H. Blank, J . Amer. Chem. Soc., 1966, 78, 6693.o6 N. T. Werthessen, E. Schwenk, and C. Baker, Science, 1953, 117, 380.67 J. L. Rabinowitz and R. M. Dowben, Biochim. Siophys. Ada, 1966, 16, 96.68 H. Levitz, G. P. Condon, and J. Dancis, Fed. Proc., 1986, 14, 246.69 R. D.H. Heard and V. J. O'Donnell, Endocrinology, 1954, 54, 209; see ref. 9 for70 B. Baggett, L. L. Engel, K. Savard, and R. I. Dorfman, J . Biol. Chem., 1956,921,7l H. H. Wotiz, J. W. Davis, H. M. Lemon, and M. Gut, ibid., 1966, 332, 487.72 C. D. West, B. L. Damast, S. D. Sarro, and 0. H. Pearson, ibid., 1966, 218, 409.urther references.931CALLOW : METABOLISM OF STEROIDS. 317probable intermediate in this transformation, for its conversion into oestronehas been demonstrated 73 in human placenta or, to a lesser extent, in cowfollicular fluid or adrenal gland. Moreover, it has been isolated from oxadrenal gland by mat to^.^^The investigation of urinary metabolites of cestrone and estradiol byorthodox chemical methods, with the aid of new analytical techniques ofchromatographic or countercurrent separation, has led to the recognitionthat there are other metabolites, the presence of which was suspected manyyears ago,75 in the shape of 16-e$icestriol (31) 76 and 16a-hydroxycestrone(32).77 It may be mentioned incidentally that to the natural 16-hydroxy-compounds previously listed 78 there may be added 17-oxoandrost-5-ene-38 : 16a-diol from urine of men 79 and 3p : 1 6 ~ - and 3p : 16p-dihydroxy-androstanes from urine of pregnant mares.80 The occurrence in human urineof 16-oxo-17p-cestradio1 81 and 16-oxooestrone 82 has been reported but,whilst artificial formation during manipulation, of the one by isomerisationand of the other by oxidation of 16a--hydroxycestrone, seems to be excluded,confirmatory evidence would be welcome.A hypothetical scheme ofestrogen catabolism 83 is shown in Fig. 5. The stage 16a-hydroxyestrone+ estriol has been experimentally confirmed recently in man.84FIG. 5.onOHIt has been pointed out 83 that, with the recognition that a hithertounknown major metabolite occurs in human urine, methods of chemical73 A. S. Meyer, BiocAim. BwFhys. Acta, 1956, 17, 441.74 V. R. Mattox, Proc. Mayo Clin., 1955, 30, 180.G. F. Marrian, Bull. N.Y. Acad. Med., 1939,15, 27.7% G. F. Marrian and W. S. Bauld, Biochem. J., 1955, 59, 136; E. J. D. Watson and77 G. F. Maman, K. H. Loke, E. J. D. Watson, and M. Panattoni, quoted in ref. 79;79 K. Fotherby, A. ColQs, S. M. Atherden, and G. F. Marrian, BiocAem. J., 1956, 64,80 R.V. Brooks and W. Klyne, aid., 1966, 63, 2 1 ~ .81 M. Levitz, J. R. Spitzer, and G. H. Twombly, J . Biol. Chem., 1956, 2%, 981.82 W. R. Slaunwhite, jun., and A. A. Sandberg, Avch. Biochem. Biophys., 1956, 63,83 G. F. Maman, public lecture at University College, London, December 9th, 1956.84 G. F. Marrian and J. B. Brown (personal communication).G. F. Maman, ibid., 1856, 68. 64.G. F. Marrian, E. J. D. Watson, and M. Panattoni, Biochem. J., 1957, 65, 12.6 0 ~ .Ref. 8, p. 326.478318 BIOLOGICAL CHEMISTRY.analysis must be revised. In any case, work with labelled estrogens 85 hasshown that, as is the case with other steroid hormones, no inconsiderableproportion of administered material remains to be accounted for in un-charact erised forms.R.K. C .5. SULPHATASES.The sulphatases are a group of hydrolytic enzymes which are capableof liberating sulphuric acid from various monoesters of sulphuric acid.They are widely distributed in Nature but their physiological functionremains obscure. Studies of these enzymes before 1947 have been ade-quately summarized but only certain aspects of developments since thisdate have been r e ~ i e w e d . ~ ~ ~Until recently, four different sulphatases of clearly contrasting specificitywere recognized : arylsulphatase (phenolsulphatase) , capable of hydrolysingaryl sulphates * such as potassium phenyl sulphate ; myrosulphatase,capable of liberating sulphate from potassium myronate (sinigrin) andsimilar mustard-oil glycosides ; chondrosulphatase, capable of desulphatingchondroitin sulphate ; and gluco-(glyco-)sulphatase, capable of hydrolysingglucose 6-sulphate * and certain other simple sulphated carbohydrates.This list has now been extended by the discovery of a highly specificenzyme which hydrolyses certain steroid ~ulphates.~-~ There is also apossibility that two enzymes present in extracts of a flavobacterium may besulphatases of hitherto unknown types, in view of their ability to releasesulphate from heparin.8 The presence of a more general alkylsulphatasealso seems possible since Bacihs cereus var.mycoides, isolated from soil,converts inactive sodium 2-(2 : 4-dich1orophenoxy)ethyl sulphate into theactive herbicide 2 : 4-dichlorophenoxyacetic acid, presumably by hydro-lysis of the ester sulphate linkage followed by oxidation of the primaryalcohol formed.gThe Preparation of Substrates-Both synthetic and naturally-occurringsulphate esters have been used for the study of sulphatases.The preparationof most aryl sulphates is readily accomplished by treatment of the appro-85 C. T. Beer and T. F. Gallagher, J . Biol. Chews;, 1966,214, 336, 361 ; C. Heusghemand W. Verly, I1 Furmaco (Sci.), 1956, 11, 404; Actes de la 3me Reunion d’Endo-crinologie,” 1955, p. 139; A. M. Budy, J . Pharpnacol., 1956, 116, 10.1 C . Neuberg and E. Simon, Ergebn. Physiol., 1932, 34, 896 ; C. Fromageot, Ergebn.Enzymforsch., 1938, 7, 50; T. Soda in “Die Methoden der Ferment Forschung,” byE. Baumann and K. Myrback, Academische Verlag, Leipzig, 1940, Vol.2, p. 1696;C. Fromageot in “ The Enzymes,” by J. B. Sumner and K. Myrback, Academic PressNew York, 1950, Vol. 1, p. 517.2 K. S. Dodgson, A. B. Roy, and B. Spencer in “ Biochemie de Soufre,” ed. byC. Fromageot, Centre National de Recherche Scientifique, Paris, to be published.3 K. S. Dodgson and B. Spencer in ‘‘ Methods in Biochemical Analysis,” ed. byD. Glick, Academic Press, New York, 1957, Vol. IV.R. Henry and M. Thevenet, Bdl. SOC. Chim. biol., 1962, 34, 886.R. Henry, M. Thevenet, and P. Jarrige, ibid., p. 837.S . R. Stitch and I. D. K. Halkerston, Nature, 1953, 172, 398.7 Idem, J , Endocrinol., 1963, 9, xlfxvi:8 A. N. Payza and E. D. Kom, Btochzm. Biophys. Acla, 1966, 20, 596.9 A. J. Vlitos, Contribn. Boyce Thompson Inst., 1953, 17, 127.* Most of these acid sulphates are prepared and used as potassium salts.of the cation is therefore omitted unless it is different from potassium.The namDODGSON AND SPENCER : SULPHATASES. 310priate phenol with chlorosulphonic acid in the presence of diethylaniline orpyridine 10 or with pyridine-sulphur trioxide. 11-13 Occasionally otherprocedures have been employed including direct sulphation with sulphuric l4or chlorosulphonic acid15 a t low temperatures and the use of pyro-sulphate.16* 1' Some aryl sulphates containing amino-groups in the aromaticring have been prepared by the reduction of the corresponding nitro-compound^.^^-^^ The formation of sulphuric esters as intermediates in theElbs persulphate oxidation has led to the use of alkaline persulphate for thepreparation of various o-amino-phenyl sulphates,20 which are formed irre-spective of the orientating influence of other functional groups, and for thepreparation and use of the mono(hydrogen sulphates) of nitroquinol andnitrocatechol.19Dipotassium 2-hydroxy-5-nitrophenyl sulphate, prepared by per-sulphate oxidation of p-nitrophenol, has recently been extensively used asa substrate for arylsulphatases. However, when prepared according toRoy's directions 21 the product is contaminated with nitropyrogallol di-(hydrogen sulphate) 22*23 from which it may be freed by recrystallization asthe monopotassium salt 24 or by paper ionophoresis.22y 24Aryl sulphates in aqueous solution tend to decompose spontaneously andshould be stored in the dark at 0".In the case of the mononitrophenylsulphates, the initial breakdown is photochemically accelerated, the reactionbeing non-sensitized and independent of pH.25 Autocatalytic hydrolysisthen presumably occurs 26 leading eventually to complete decomposition.Apart from analysis, aryl hydrogen sulphates and their alkali salts arenot readily characterized by melting point. In some cases the fi-toluidine z7and 9-bromoaniline 28 salts are fairly insoluble but usually show indefinitemelting points.29 A number of aminoquinoline and aminoacridine deriv-atives form salts with aryl hydrogen sulphates but again the salts do nothave distinct melting points.29 Eufl avin, safranine, and 5-aminoacridinehydrochloride form particularly insoluble salts from which the parent arylhydrogen sulphate can be regenerated.29 These heterocyclic bases can be10 G.N. Burkhardt and A. Lapworth, J., 1926, 684.l1 P. Baumgarten, Bsr., 1926, 59, 1976.la Inorg. Synth., 1946, 2, 173.13 A. E. Sobel and P. E. Spoerri, J . Amer. Chem. SOC., 1941, 63, 1259.l4 H. Fraenkel-Conrat and J. Fraenkel-Conrat, Bioclzim. Biofihys. Acta, 1950, 5, 98.G. N. Burkhardt, J., 1933, 337.16 E. Baumann, Ber., 1878, 11, 1907.17 S. Bernstein and R. W. McGilvery, J . Biol. Chem., 1952, 198, 195.18 G. N. Burkhardt and H. Wood, J., 1929, 141.Is J. N. Smith, J., 1961, 2861; D. Robinson, J. N. Smith, B. Spencer, and R. T.2O E. Boyland, D. Manson, and P. Sims, J., 1953, 3623; E. Boyland and P. Sims,21 A. B. Roy, Biochem. J., 1953, 58, 12.22 Idem, ibid., 1956, 62, 3 5 ~ .23 A.B. Roy and L. M. H. Kerr, Nature, 1956, 178, 376.24 K. S. Dodgson and B. Spencer, Biochim. Biophys. Acta, 1956, 21, 175.2S A. E. Havinga, R. 0. DeJongh, and W. Dorst, Rec. Trav. chim., 1956, 75, 378-26 G. N. Burkhardt, W. G. K. Ford, and E. Singleton, J., 1936, 17.27 A. D. Barton and L. Young, J . Amer. Chem. Soc., 1943, 65, 294.28 D. H. Laughland and L. Young, Trans. Roy. SOC. Canada, 1942, 111, 36, 166.*v K. S. Dodgson, F. A. Rose, and B. Spencer, Natuw, 1956, 174, 599; Biochem. J .Williams, Biochem. J . , 1952, 51, 202.J . , 1954, 980.1955, 60, 346320 BIOLOGICAL CHEMISTRY.used to precipitate some aryl hydrogen sulphates from urine with little inter-ference from other urinary constituents. 5-Aminoacridine hydrochloride,for example, has been used to isolate 4-chloro-2-hydroxyphenyl hydrogensulphate from the urine of rabbits which had been fed with chlorobenzene or4-chlorocatechol.29 Similar procedures may be applicable to the biosyntheticpreparation of useful substrates for arylsulphatase assay (e.g., phenol-phthalein monosulphate) which are not readily obtained by direct chemicalsynthesis.A convenient method for the preparation of steroid sulphates30 and anew method for the isolation of potassium myronate from mustard seedshave been reported.31, 32The impure nature of potassium glucose 6-sulphate when prepared bydirect sulphation of glucose33 has been confirmed.= The main impurityappears to be an isomer, the extent of the contamination being less whenSoda's chlorosulphonic acid method 35 is used than with the pyridine-sulphur trioxide method.= Although glycosulphatase hydrolyses both theglucose 6-sulphate and the contaminant, only the latter is rapidly andcompletely hydrolysed by hydrazine.=*= Small amounts of a second con-taminant have been detected chromatographically in the glucose 6-sulphateprepared by direct sulphation with pyridine-sulphur trioxide.= Con-tamination can be reduced considerably by repeated recrystallization ofglucose 6-sulphate as the corresponding brucine salt 33*34 and in this wayEgami 33 obtained a final preparation which was " hardly hydrolysed byhydrazine." The impure nature of glucose 6-sulphate when prepared bydirect sulphation of glucose appears to have escaped the notice of someworkers.36 Glucose 3-sulphate can be unequivocally prepared by sulphationof diisopropylideneglucose followed by removal of the residues but , althoughit is readily hydrolysed by glycosulphatase, it is unsuitable as an assay sub-strate owing to the labile nature of the ester sulphate group.= This com-pound is completely hydrolysed by hydrazine but is not identical with eitherof the impurities present in preparations of the glucose 6-sulphate obtainedby direct sulphation of glucose.M Adenosine-5' (hydrogen sulphate), whichis also hydrolysed by glycosulphatase , has recently been synthesi~ed.~'Three different types of chondroitin sulphate are now known to bepresent in mammalian tissues 38 and it seems likely that preparations usedin the past for the study of chondrosulphatase 399 40 were mixtures of the3 0 A.B. Roy, Natuve, 1956, 62, 41.sf 0. E. Schultz, R. Gmelin, and A. Keller, 2. Natwrfovsch., 1953, 8b, 14.8s F. Egami, J . Chem. SOC. Japan, 1938, 59, 1034; 1940, 61, 692; 1942, 63, 763.8' K. S. Dodgson and B. Spencer, Biochem. J., 1964, 57, 310.86 T. Soda, Bull. Chem. SOC. Japan, 1933, 8, 37.86 R. B. Duff, J., 1949, 1597; H. L. Wolfrom and R. Montgomery, J . Amer. Chem.87 *F. Egami and N. Takahashi, Bull. Chem. SOC. Japan, 1955, 25, 666.8 8 K. Meyer and M. M. Rapport, Science, 1961, 118, 696; K. Meyer, E. Davidson,8 ) C. Neuberg and E. Hoffman, Natuvwzss., 1931, 19, 484; Biochem. Z., 1931, m,( 0 K. S. Dodgson. A. G.Lloyd, and B. Spencer, Biochem. J., 1967, 85, 131.Cf. J. Gadamer, Arch. Pharm.. 1897,235,44; H. Herisseyand R. Boivin, J . Pharm.Chim., 1927, 6, 337.Soc., 1950, 72, 2869.A. Linker, and P. Hoffman, Biochiun. Biqhys. Acta, 1966, 21, 606.345DODGSON AND SPENCER : SULPHATASES. 321various types. The great difference in the relative activity of bacterialchondrosulphatase towards the polymerized and depolymerized forms ofchondroitin sulphate 41 suggests that it will now be important to devisestandard methods for the isolation of sulphated oligosaccharides fromdepolymerized chondroitin sulphate. The chemical nature of charoninsulphate, a possible substrate for molluscan chondrosulphatase, has beenin~estigated.~~ This glucan polysulphate, which is foufid in the marinegastropod Charonia Zumflas (Triton .nodiferus),43 has been shown to containboth cellulose- and amylose-type structures.The choice of substrates and their use for the assay of sulphatases havebeen recently re~iewed.~Ary1sulphatases.-Although the availability of numerous convenientmethods for the assay of arylsulphatases has led many workers to investigatethese enzymes, their physiological function remains obscure.showed that the arylsulphatases of fungi, molluscs, and mammals werespecific for the sulphates of phenols hut other properties of the enzymeswere not extensively examined.Two types of arylsulphatases are nowrecognized.2* The first (Type I) possesses a7preciable activity and affinitytowards 9-acetylphenyl and p-nitrophenyl sulphates but shows little activitytowards 2-hydroxy-5-nitrophenyl sulphate (nitrocat echo1 hydrogen sulphate) .They are inhibited by cyanide but are not affected markedly by sulphateand phosphate ions.The second type (Type 11) has the converse specificityto the Type I enzymes, showing high activity towards 2-hydroxy-5-nitro-phenyl sulphate but low affinity and activity towards 9-acetylphenylsulphate and 9-nitrophenyl sulphate. They are strongly inhibited bysulphate and phosphate ions but are unaffected by cyanide.Mammalian tissues contain one enzyme of Type I and two of Type II.44s 45The Type I enzyme, arylsulphatase C, is extensively distributed throughoutthe animal body 45* 46 and, in rat liver, is exclusively localized in the micro-somes of the liver cells.@V 47 The enzyme appears to form part of an insolublelipid-protein complex which becomes soluble when incorporated into themicelles of surface-active agents,48 but which resumes its insoluble natureon removal of the detergent.The enzyme can be brought into true solutionby treatment of the insoluble comple:; with crude pancreatic lipase prepar-ations in the presence of detergent.49 The two Type I1 enzymes, aryl-sulphatases A and B, are probably present in all tiss~ies.~j Their distri-bution within the individual cell has been studied in rat 5* and mouse 51Early studies41 K. S. Dodgson and A. G. Lloyd, Biochem. J., 1957, 65, 4 ~ .42 F. Egami, T. Asahi, N. Takahashi, S. Suzuki, S. Shikata, and K. Nisizawa, Bull.Chem.SOC. Japan, 1965, 28, 685; K. Nakanishi, N. Takahashi, and I?. Egami, ibid.,1956, 29, 434.43 T. Soda, J . Chem. SOC. Japan, 1936, 57, 981; T. Soda and F. Egami, Bull. Chem.SOC. Japan, 1938, 13, 652.44 K. S. Dodgson, B. Spencer, and J. Thomas, Biochem. J . , 1955, 59, 29.b5 K. S. Dodgson, B. Spencer, and C. H. Wycn, ibid., 1955, 62, 500.46 K. S. Dodgson, B. Spencer, and J. Thomas, ibid., 1953, 53, 452.4 7 Idem, ibid., 1954, 56, 1 7 7 ; R. Gianetto and R. Viala, Science, 1955, 121, 801.4 8 K. S. Dodgson, F. A. Rose, B. Spencer, and J. Thomas, Biochem. J . , in the press.K. S. Dodgson. F. A. Rose, and B. Spencer, ibid., in the press.8o A. B. Roy, Biochim. Biophys. Acta, 1964, 14, 149.61 Idem, Biochem. J.. 1963, 53, 12.REP .-VOL. LIT1 322 BIOLOGICAL C H E M ISTKY.livers.They occur mainly in the mitochondria of the liver cell althoughappreciable activity also occurs in the microsomes and the soluble materialof the cytoplasm. Arylsulphatases A and B are readily obtained in solutionby any method which ruptures the mitochondria1 membrane uv 511 52 andcan be separated by fractional precipitation with acetone and ammoniumsulphate or by paper electrophoresis.44? 45p 51* 53,The properties of arylsulphatases A and B have been investigated j3-55and the anomalous kinetics shown towards 2-hydroxy-5-nitrophenyl sul-phate by the arylsulphatase A of ox liver have been interpreted by Koy 53as a function of the polymerization of the enzyme. Dodgson and Spencer 56working with the corresponding hunian enzyme have shown that thisexplanation is untenable, the basic anomaly being that the reaction is notof zero order.The anomaly is not due to the presence of an impurity,nitropyrogallol di~ulphate,~~ in the substrate preparation as later suggestedby Roy,57 since anomalous kinetics are still obtained when purified sub-strate is used. 56 Molluscan, fungal, or bacterial arylsulphatases do notshow the anomaly which must be regarded therefore as peculiar tomammalian arylsulphatase A.58Arylsulphatase activity has been demonstrated in a number of bacteria.When phenolphthalein disulphate 599 6o is incorporated into culture media,the presence of arylsulphatase-producing bacteria may be detected byexposing the culture plates to gaseous ammonia and observing the redcolour of the liberated 61* 62 A large number of organismshave been tested by this and similar techniques 63 and it has been concludedthat, apart from rnyc~bacteria,~~~ 64 comparatively few organisms possessthe enzyme.These conclusions may not be valid, however, since the screen-ing procedures have usually failed to take certain factors into account. Forinstance, many bacteria can rapidly metabolize the phenolphthaleinliberated,62 whilst others, known to possess arylsulphatase activity towardsother substrates, are inactive towards phenolphthalein d i ~ u l p h a t e . ~ ~ More-over, Harada and Kono 66 have shown that some bacteria produce aryl-52 R. Viala and R. Gianetto, Canad. J . Biochem. Physiol., 1955, 33, 839.63 A.B. Roy, Biochem. J., 1953, 55, 653.64 Idem, ibid., 1954, 5'7, 465.LS Idem, ibid., 1955, 59, 8.5 6 K. S. Dodgson and B. Spencer, ibid., 1956, 62, 3 0 ~ .5 7 A. B. Roy, ibid., p. 3 5 ~ .68 K. S. Dodgson and €3. Spencer, Biochim. Biophys. A d a , 1956, 21, 175.59 J. E. M. Whitehead, A. R. Morrison, and L. Young, Biochem. J., 1952, 51, 585.61 L. Young, A. R. Morrison, and J . E. M. Whitehead, Nature, 1952, 169, 711.62 K. S. Dodgson, T. H. Melville, B. Spencer, and K. Williams, Biochem. J., 1954,58, 182.63 K. L. Arora, A. T. Dudani, and C. R. Krishnamurti, J . Sci. Ind. Res. (India),1953,12, B, 502; M. Barber, B. W. L. Brooksbank, and S. W. A. Kuper, J . Path. Bact.,1951, 63, 57; M. Chauncey, F. Lionetti, R. A. Winer, and V. F. Lisanti, J .Dent. Res.,1954,33, 321 ; T. Ishikawa, Med. J . Chiba Univ. (Jafian), 1943, 21, 700; G. C. Shrivas-tava, K. L. Arora, and S. S. Bhatanagar, Experientia, 1954,10, 493; R. Hare, P. Wildy,IF. S. Billet, and D. N. Twort, J . Hyg., 1952, 50, 295.64 J. E. M. Whitehead, P. Wildy, and H. C . Engbaeck, J . Path. Bact., 1953, 65, 451.6 5 T. Harada, K. Kono, and K. Yagi, Mem. Inst. Sci. Ind. Res., Osaka Univ., 1955,11, 193 ; T. Harada and K. Kono, J . Agric. Chew. Soc. Japan, 1954, 28, 608.(i6 T. Harada and K. Kono, Mem, Inst. Sci. Ind. Res., Osrrka Univ., 1956, 12, 183.M. Pantlitschko and F. Kaiser, Monatsh., 1952, 83, 1140DODGSON AND SPENCER : SULPHATASES. 323sulphatase only if a certain factor, identified as tyramine,6i is present inthe peptone of the culture medium. Arylsulphatase activity of a fusiformbacillus is similarly dependent on accessory factors which can be providedby addition of cystine or sterile raw potato to the culture medium.68The arylsulphatases of Aerobacter aerogenes 66 and Alcaligenes metal-caligenes 62a 69 show properties which classify them as Type I.From in-vestigations of the variation with pH of the Michaelis constant of theA lcaligenes enzyme acting on 9-acetylphenyl, $-nitrophenyl, and 2-hydroxy-5-nitrophenyl sulphates, it has been concluded that two ionizing substrate-binding groups (pK 8.2 and 9.4, respectively) are present in the enzymemolecule.69 Application of Dixon’s rules 70 to the results obtained hasindicated that the group with pK 8.2 must gain a positive charge (or lose anegative charge) on “ desubstration,” whereas the converse is true of thegroup with pK 9.4.The chemical nature of the former group is obscure,but that with pK 9.4 may be an a- or E-amino-group, and some support forthis suggestion has been obtained by studying the effects of various group-specific protein reagents on enzyme a~tivity.6~ As a result of these in-vestigations, Dodgson et al.69 suggested that the enzyme contains positively-and negatively-charged substrate-binding groups which reactTf with substrate in the form shown inset, where the sulphurArO-s-0- atom, by virtue of its semipolar bonds, possesses some ‘+) degree of positive charge. Further information has beenobtained by examining the eflect on enzyme activity of the introduc-tion of substituents into the benzene ring of phenyl hydrogen sulphate.’lBoth the affinity of the enzyme for the substrate and the rate of hydrolysisshow a progressive increase with increasing electrophilic nature of the sub-stituent group. As a result of these various findings it has been possible tosuggest the following reaction mechanism for the hydrolysis of arylsulphates by the Alcaligenes enzyme, where X and Y are the nucleophilicand electrophilic groups present at the active sites of the enzyme.Theintroduction of electrophilic substituents into the aromatic ring is presumedto facilitate combination of enzyme and substrate by withdrawing electronsfrom the sulphate group. This would lead to an increase in net charge onthe sulphate group, since the loss in negative charge on the ionized oxygenatom would be less than the gain in positive charge on the sulphur atom,the latter being nearer to the benzene ring. An increase in affinity ofenzyme for substrate would be expected to result from this increase in netcharge and this agrees with the experimental findings.i1 The electrophilic6 7 T.Harada and C. Hattori, Bull. Agvic. Chem. SOC. Japan, 1956, 20, 110.6 8 S . D. Schultz-Handt and H. D. Scherp, J . Bact., 1955, 69, 665.69 K. S. Dodgson, B. Spencer, and K. Williams, Biochem. J . , 1956, 61, 374.i o M. Dixon, ibid., 1953, 55, 161.K. S. Dodgson, B. Spencer, and K. Williams, ibid., 1956, 64, 216324 BIOLOGICAL CHEMISTRY.hydroxonium ion is presumed to be responsible €or the breakdown of theenzyme-substrate complex since the acidic hydrolysis of aryl sulphates,which is known to be mediated in this manner,26 is very similar to theenzymic hydrolysi~.~~ The increase in the rate of enzymic hydrolysis whichfollows the introduction of an electrophilic substituent is probably due toincreasing stabilization of the product ArO: formed by rupture of the 0-Sbond.The other product, -O*S(O,) (+), is presumably stabilized by com-bination with the enzyme. It would appear that before a sulphuric estercan be hydrolysed by the Alcaligenes arylsulphatase there must be a strongelectron-withdrawing influence on the sulphate group. The absence ofstrong electrophilic groups in glucose, ethyl, and chondroitin sulphates mightexplain the inactivity of the Alcaligenes enzyme towards these and similarsulphuiic esters.Although the arylsulphatases show an absolute specificity towards thesulphates of phenols (or phenolic-like compounds, cf.the hydrolysis of kojicacid disulphate by glyco- plus aryl-sulphatase '9, the relative specificitytowards various aryl sulphates varies greatly.71 Indeed the arylsulphatasesof human urine (arylsulphatases A and B 73) and Aspergillus oryzae do notattack many o-aminoaryl ~ u l p h a t e s . ~ ~ It has been suggested 74 that thisis related to the ability of these aryl hydrogen sulphates to form zwitterionsat pH's where the enzymes would normally exhibit maximum activity. Therate of hydrolysis of o-, m-, and 9-aminophenyl sulphates by the Alcaligenesenzyme is also very low but the reason for this lies in the nucleophilic natureof the amino-group rather than in the presence of zwitterions since at theoptimum pH (8.75) of this enzyme there is little tendency for zwitterionformation.In any case there are reasons 71 for suspecting that the orthoeffect, rather than zwitterion formation, may be responsible for the resist-ance of o-aminoaryl sulphates to hydrolysis by the enzymes of Aspergilhsand urine, I t is clear irom the observations of Dodgson et aL71 and Boylandet ~ 1 . 7 ~ that the failure of an arylsulphatase to hydrolyse an unknown phenolicconjugate (e.g., Clarke et does not necessarily mean that the conjugateis not an aryl sulphate.Myrosulphatase.-This enzyme has been little studied in recent years.The best known source is mustard seed where it is found in association withits substrates, the mustard-oil glycosides.A thioglycosidase is also presentin the seed and the two enzymes together degrade potassium myronate toglucose, ally1 mustard oil, and inorganic s ~ l p h a t e . ~ ~ The enzyme has beenfound in bacteria 39 and marine molluscs 77 whilst its presence in horse andrabbit tissues has been However, recent work suggests thatniyrosulphatase does not occur in mammalian tissues to any appreciable72 T. Soda, T. Katsura, and 0. Yoda, J . Chem. SOC. Japan, 1940, 61, 1227.73 K. S. Dodgson and B. Spencer, Clin. Chim. Acta, 1956, 1, 478.74 E. Boyland, D. Manson, P. Sims, and D. C . Williams, Biochem. I., 1956, 62, 68.7 5 W.G. Clarke, R. J. Akawie, R. S. P6grund, and T. A. Geissman, J . Pharmacol.,76 C. Neuberg and 0. Schoenbeck, Biochem. 2.. 1933, 265, 223; Nalurwiss., 1933,77 M. Ishimoto and J. Yamashina, Symp. Enzyme Chem. (Japan), 1941, 2, 36.7 a C. Neuberg and J. Wagner, Z. exp. Med.. 1927, fi6, 334.79 H. Baum and K. S. Dodgson, Nature, 1967, 179, 312.1951, 101, 6.21, 404; C. Neuberg and J. Wagner, Biochem. Z., 1926,174, 467DODGSON AND SPENCER : SULPHATASES. 325;extent and has demonstrated that the enzyme is quite distinct from bothTypes I and I1 arylsulphatases.Chondr0sulphatase.-The early observation that certain putrefactivebacteria were able to utilize chondroitin sulphate for growth 80 led to thepreparation of extracts of Pseudomonas JEuomcens non-liquifaciens whichwere able to liberate inorganic sulphate from chondroitin s ~ d p h a t e .~ ~ Com-plete hydrolysis of the substrate to acetic acid, sulphate, glucuronic acid,and galactosamine was achieved by such extractss1 The presence ofchondrosulphatase in Ps. juorescens has since been confirmed 82 and otherorganisms, including Proteus v z i l g a ~ i s , ~ ~ ~ 40* 82-86 Pseudomonas ae~uginosa,~~*Micrococczts pyogenes a u ~ e u s , ~ ~ Peizicillium spindosum a7 and organismsisolated from human gingival crevices,88 have also been shown to possessthe enzyme. Chondrosulphatase also occurs in certain rn0lluscs.8~~Some confusion exists at present as to whether chondrosulphatase occursin mammalian tissues. Early workers could not detect liberation of sul-phate from chondroitin sulphate by macerated tissues 81 and, more recently,negative results have been obtained by using more sensitive detectionmethods.g1 On the other hand, a comparatively rapid metabolic turnoverof the sulphate groups of chondroitin sulphate occurs in the animal body,92and the live rat appears to be able to liberate sulphate from injected chon-droitin sulphate containing isotopic sulphur, since significant amounts ofinorganic sulphate containing isotopic sulphur can be isolated from theurine.g3 There is some indication of the presence of a chondrosulphatase-type enzyme in mammalian pancreas as a result of studies on the degradationof elastic tissue by pancreatic elastase.Preparations of elastic tissue con-tain a metachromatic sulphated polysaccharide which, like chondroitinsulphate, loses its metachromatic properties after incubation with bacterial 86or molluscan g4 chondrosulphatase preparations.The metachromasia alsodisappears after treatment with pancreatic extracts possessing elastaseactivity.86 Other observations 95 have suggested the possibility of someenzymic liberation of sulphate from the sulphated polysaccharide of elastictissue by crude elastase preparations.Both bacterial and molluscan chondrosulphatases are associated with achondroitinase enzyme system which degrades the polysaccharide chain of8o C. Neubergand 0. Rubin, Biochem. Z., 1914, 67, 82.81 C. Neuberg and W. L. Cahill, Enzymologia, 1936, 1, 82.83 H. J.Buehler, P. A. Katzman, and E. A. Doisy, Proc. SOC. Exp. Biol. Med., 1951,83 H. Candelli and A. Tronieri, Bull. SOC. ztal. Biol. sper., 1951, 27, 651.84 W. A. Konetza, AT. J. Pelczar, and G. W. Burnett, Bact. Proc., 1964, 106.R 6 W. J. Pepler and F. A. Brandt, Brit. J . Exp. Path., 1854, 35, 41.87 R. Pincus, Nature, 1950, 166, 187.8 8 S. D. Schultz-Handt and H. W. Scherp, J . Dent. Res., 1956, 35, 229.89 T. Soda and F. Egami, J . Chem. SOC. Japan, 1938, 59, 1202.91 C. H. Dohlman and J. S. Friedenwald, J . Histochem. Cytochem., 1955, 3, 492.92 See, e.g., H. Bostrom, J . Biol. Chem., 1952, 196, 177.93 C. H. Dohlman, personal communication; D. D. Dziewiatkowski, J . Bid. Chew.,94 H. Hayashi, T. Funaki, K. Udaka, and Y . Kato, Mie Med. J., 1956, 4.143.78, 3.0. Reggianini, Bull. SOC. ital. BioE. sper., 1950, 166, 187.Y . Horiguchi and M. Mikaya, Bull. Jap. SOC. Sci. Fish., 1954, 19, 957.1966, 223, 239.D. A. Hall and J. E. Gardiner, Biochem. J., 1966, 69, 465326 BIOLOGICAL CHEMISTRY.chondroitin sulphate with consequent release of reducing substances.Several attempts have been made to determine the extent to which thesulphatase and chondroitinase activities are interdependent. Soda andEgami,89 using mollusc preparations, have succeeded in showing thatsulphatase activity can be completely inhibited without markedly affectingchondroitinase activity. More recently, a study of the effects of inhibitorson the ability of viable cultures of P. vulgaris to degrade chondroitin sulphatehas suggested that liberation of sulphate is secondary to the release ofreducing substances.@This problem of interdependence has now been resolved for the enzymesof P.vulgaris. Dodgson and Lloyd41 have succeeded in obtaining a pre-paration of the sulphatase which is completely free from chondroitinase.The activity of this sulphatase towards polymerized chondroitin sulphate isnegligible. On the other hand the enzyme is extremely active towards thesulphated oligosaccharides which are formed when chondroitin sulphate isexhaustively degraded by testicular hyaluronidase. Inhibitor studies haveconfirmed the earlier observation 89 that chondroitinase activity can pro-ceed independently of the sulphatase. It seems clear that the true substratesfor chondrosulphatase are to be found in the sulphated oligosaccharidesresulting from chondroitinase action.These findings may possibly throwlight on the failure of several workers 81*91 to detect chondrosulphataseactivity in mammalian tissues, and it would now be interesting to repeat thiswork using, as the assay substrate, chondroitin sulphate which has beendegraded by testicular hyaluronidase.It is not yet clear whether all three types of mammalian chondroitinsulphate 38 are substrates for bacterial chondrosulphatase and chondro-itinase. The three types have been separated and occur in different propor-tions in the various tissues.96 Preparations of chondroitin sulphate obtainedby simple extraction procedures will almost certainly contain more thanone type and it is worth noting that Dodgson et a1.,4O using extracts ofP.vulgaris, achieved complete release of sulphate from chondroitin sulphatewhich had been prepared in this way.The finding that Proteus chondrosulphatase, in the absence of chondro-itinase, shows negligible activity towards polymerized chondroitin sulphatereopens the question of the specificity of the enzyme. Enzyme concen-trates containing both sulphatase and chondroitinase are without action onthe polysaccharide sulphates, heparin, agar, carragheenin, fucoidin, Chondrusocellatus mucilage, or sulphated l a m i n a r i ~ ~ . ~ ~ However, since chondroitinaseactivity was not followed during these investigations, the failure to noterelease of sulphate may simply reflect the inability of chondroitinase to degradethese substrates. On the other hand, these compounds do not contain thesulphated acetylgalactosamine residues which are present in chondroitinsulphate.The failure 40 of Protezts concentrates to liberate sulphate fromuridine diphosphate-acetylgalactosamine ~ulyhate,~' or a mixture of uridinediphosphate and acetylgalactosamine sulphate derived from this compound21, 506.K. Meyer, E. Davidson, A. Linker, and P. Hoffman, Biochiw. Biophys. A&, 1966,97 J. L. Strominger, ibid.. 1966, 17, 283DODGSON AND SPENCER : SULPHATASES. 327is unexpected, however, in view of the suggested participation of the coni-pounds in the biosynthesis of chondroitin ~ u l p h a t e . ~ ~ Little work has beendone on the specificity of other chondrosulphatases and it is not certaintherefore whether the release of sulphateg8 from the sulphated poly-saccharideg9 of the jelly coat of sea-urchin's eggs by crude extracts ofCharonia lampas or sea-urchin sperm 100 is due to the enzyme.Some con-fusion also exists on the ability of crude mollusc preparations to hydrolysecharonin sulphate.42 This activity was attributed at first to glyco-sulphatase 101 but recent work suggests that chondrosulphatase isresponsible. l02The available evidence suggests that, whatever the true substrates ofchondrosulphatase may be, they are certainly carbohydrate in Nature. TheProteus enzyme is completely inactive towards simple alkyl sulphates andthe substrates of aryl- and myro-sulphatase and of steroid-s~lphatase.~~ 1 tis interesting also that glucose 6-sulphate is not hydrolysed by the enzymeand early claims that this compound 103 and potassium myronate 39 weresubstrates for chondrosulphatase presumably reflect the presence of specificsulphatases for these substrates in the crude bacterial extracts used.Theclaim lo4 that " cerebron sulphuric acid " (now known to contain galactose6-sulphate lo5) was hydrolysed by the chondrosulphatase of these prepar-ations should also be treated with caution.The reports l1 that extracts of a flavobacterium are able to degradeheparin are interesting since it has been tentatively suggested that a glycos-idase and two distinct sulphatases, an amino- and an alcohol-sulphatase, areinvolved. It will be important in this case also to see whether sulphataseactivity is dependent on preliminary chain degradation by the glycosidase.Probably other enzyme systems containing both sulphatase and chondro-itinase-like activity will be discovered in the future.The sulphatases ofsuch systems may well possess fairly narrow substrate specificities dictatedby the chemical nature of the individual saccharides present in the substratemolecule, their mode of linkage, and the position of the sulphate groups.Glycosu1phatase.-A sulphatase capable of hydrolysing glucose 6-sulphatehas been found in snails,lo6 tropical lo7 and temperate marine molluscs,bacteria,lo6* lo8 and fungi log and in the livers of certain fishes andrnammals.ll0 Apart from a series of studies from Soda's laboratoriesbetween 1931 and 1950, this enzyme has been almost neglected. Soda andhis co-workers studied the distribution of the enzyme in various marineH.Numanoi, Sci. Papers Coll. Gen. Educ., Univ. Tokyo, 1953,3, 55; ibid., p. 71.R9 See J. Runnstrom, Symp. SOC. Ex$. Biol., 1952, 6, 39.loo H. Numanoi, Sci. Pa$ers Coll. Gen. Educ., Univ. Tokyo, 1953, 3, 67.lo1 T. Soda and Y. Yamazaki, BuEZ. Chem. SOC. Japan, 1933, 8, 207 ; C. Hattori andH. Terasaki, J . Chem. SOC. Japan, 1936, 57, 981.lop F. Egami, personal communication.lo3 B. Tankb, Biochem. Z., 1932, 247, 486.lo* C. Neuberg and W. L. Cahill, ibid., 1934-35, 275, 328.loS S. J. Thannhauser, J. Fellig, and G. Schmidt, J . BioZ. Chem., 1955, 215, 211.lo6 T. Soda and C.Hattori, Bull. CJaem. SOC. Japan, 1931, 6, 258.107 T. Soda, J . Fac. Sci. Univ., Tokyo, 1936. 3, 149.lo* Idem, Chern. Res. (Japan), 1948, 1, 51.los J. Yamashina, J . Chem. SOC. Japan, 1951, 72, 124.11O T. Soda, personal communication328 BIOLOGICAL CHEMISTRY.organisms ll1 and described the purification, properties, and specificity ofthe glycosulphatase of Chznronia Zamflas.lo7* 112 The enzyme was separatedfrom aryl- lI3 and chondro-sulphatase 89 and was able to hydrolyse a numberof mono-, di-, and tri-sulphated niono- and di-saccharides. Recently,adenosine-5’ (hydrogen sulphate) has been shown to be a substrate for theenzyme 37 whilst the ability of limpet extracts to hydrolyse cortisone 21-sulphate is probably due to the glycosulphatase present in the extracts.30Synthetic substrates have been used for the study of glycosulphatase,and the natural substrates and physiological function of the enzyme areunknown.It is possible that, like bacterial chondrosulphatase, glyco-sulphatase is normally associated with a chondroitinase-like enzyme, the twoenzymes collectively being responsible for the degradation of an unknownpolysaccharide sulphate.Steroid-su1phatase.--The series of events leading to the recent discoveryof this enzyme are worth recording. The original stimulus came fromworkers interested in finding a specific enzyme for the hydrolysis of urinarysulphate esters before ketosteroid assay, It was considered that enzymichydrolysis of steroid sulphates would be more selective and less liable toartifacts than other available methods.6914 The sulphuric esters of phenolicsteroids (e.g., oestrone sulphate) are hydrolysed by arylsulphatase 115 butnon-phenolic steroid sulphates are not substrates for thisIn attempts to obtain sulphatases capable of hydrolysing the sulphatesof neutral 17-ltetosteroirls, Buehler et al.62 examined 23 different bacteria,but no sulphatase was found able to hydrolyse either androsterone or dehydro-efiiandrosterone sulphates. The high arylsulphatase activity of the snail,Helix pornatia,117 prompted Henry and Thevenet * to use the digestive juiceof this organism for the hydrolysis of the 17-ketosteroid conjugates of urine.Hydrolysis of dehydroefliandrosterone sulphate was observed, but it was notappreciated that an enzyme, hitherto unknown, was responsible.Extractsof the limpet, Patella vulgata, have high arylsulphatase activities similar tothose of the snail 118* 119 and Stitch and his co-workers 6* 73 lZo found thatsuch extracts released sufficiently large amounts of the neutral 17-keto-steroids, which were present in urine as conjugates, to indicate the presenceof a “ steroid alcohol sulphatase.” In other experiments the extracts werefound to hydrolyse dehydroefliandrosterone sulphate. A similar enzymewas subsequently found 121 in the African land snail, Otala punctata.A more complete examination of the purified limpet enzyme has recentlybeen made by R0y.30~ 122 The enzyme is very specific since it will hydrolysell4* 116111 T.Soda and F. Egami, J . Chem. Soc. Japan, 1933, 54, 1069.11$ T. Soda and A. Yoshida, ibid., 1948, 69, 119, 121 ; 1960, 71, 60.113 T. Soda and F. Egami, ibid., 1934, 56, 256.114 R. Henry, Rec. Trav. chim., 1955, 74, 442.115 A. Butenandt and H. Hoffstetter, 2. physiol. Chem., 1939, 259, 222.116 H. Cohen and R. W. Bates, Endocrinology, 1949, 44, 317 : 45, 86.117 P. Jarrige and R. Henry, Bull. SOC. Chim. biol., 1952, 34, 872.11* I<. S. Dodgson, J . I. M. Lewis, and B. Spencer, Biochem. J., 1953, 65, 253.l1S K. S. Dodgson and B. Spencer, ibid., p. 315.lZo S. R. Stitch, 1. D. K. Halkerston, and J. Hillman, ibid., 1956, 83, 706.lZ1 H. Savard, E. Bagnoli, and R. I. Dorfman, Fed. Proc., 1954.13, 289.122 A. B. Roy, Biochim. Biophys. Ada, 1964, 15, 300DODGSON AND SPENCER : SULPHATASES.329the 3P-sulphates of 5cc- and A5-steroids only, other isomeric 3-sulphates beingunattacked. The surprising finding 30 that the enzyme preparation,like that from Otaln,l21 could hydrolyse cortisone 2f-sulphate, neednot necessarily disturb this concept of high specificity since it can beexplained by assuming that the compound was hydrolysed by someother sulphatase present in the preparation. Roy suggests 30 that glyco-sulphatase, which is known to be present in Patella,= may be the enzyme inquestion.The ability of mammalian-liver preparations to hydrolyse dehydro-eeiandrosterone sulphate has recently been reported. 123 The specificity ofthis mammalian enzyme has not been thoroughly examined but it is probablysimilar to that of the molluscan enzyme since androsterone and testosteronesulphates are not attacked.The enzyme preparations also hydrolysedaestrone sulphate but this activity is probably due to arylsulphatase C,which would also have been concentrated during the preparative procedure.In direct contradiction to this explanation is the failure of the preparationsto hydrolyse phenolphthalein disulphate but it is possible that, in commonwith certain other aryl~ulphatases,~~ arylsulphatase C has little activitytowards this substrate.Although steroid sulphatase has been recommended in preference to acidfor the hydrolysis of urinary steroid sulphates?? 6, 114 the marked specificityof the enzyme severely limits its general appli~ation.~~ Lack of knowledgeof the specificity of the snail enzyme led Jayle and Beaulieu 124 to suggestthat a urinary 17-ketosteroid conjugate which was not hydrolysed by thesnail juice was neither an ester sulphate nor a glucuronide. As Roy30points out, it is more likely that the conjugate was androsterone or a similarsulphate, against which steroid sulphatase is inactive. Roy has suggested 30that the specific nature of the enzyme might be useful in determining thestructure of steroid sulphates and gives, as an example, the fact that ranolsulphate lZ5 is not hydrolysed by the limpet enzyme arid is not therefore a3p-sulphate of a 5a- or a A5-steroid. However, a more complete study of thespecificity of the enzyme is necessary before such conclusions can be regardedas unequivocal.Steroid sulphatases from all sources are inhibited by phosphate andsulphate ions,30>120y123 and, if the enzyme is to be used in the presence ofurine, these ions should be removed 126 as the insoluble barium salts 119in order to achieve reasonable enzyme activity.Biosynthesis of Ester Sulphates.-The physiological functions of thevarious sulphatases are obscure, and it is probable that in many cases theselection of substrates for the study of the enzymes in vitro has been fortuitousand the natural substrates have yet to be discovered. The evidence availablesuggests that the sulphatases are distinct enzymes which can be differentiatedfrom many other types of esterase. They are so widely distributed inNature that it seems reasonable to suppose that they fulfil some fundamentall Z 3 H. Gibian and G. Bratfisch, 2. physiol. Chem., 1596, 305, 265.124 M. F. Jayle and E. E. Beaulieu, Bull. SOC. Chim. biol., 1954, 36, 1391.lZ5 G. A. D. Haslewood, Biochem. J., 1952, 51, 139.l z 6 S. R. Stitch and I. D. K. Halkerston, ibid., 1966, 63, 710330 BIOLOGICAL CHEMISTRY.metabolic r81e.2 At the present time all suggestions as t o the nature of thisr81e are speculative.The most obvious suggestion is that, in vivo, the sulphatases catalysethe transfer of sulphate groups to hydroxyl acceptors. From a study iizzdro of the synthesis of arylsulphates by liver ~ l i c e s , l ~ ~ homogenates,128and particle-free solutions,129 it has been shown that the reaction requiresproduction of an activated form of sulphate by a mechanism involvingadenosine triphosphate (ATP), inorganic sulphate, and an activating enzymesystem, followed by sulphate transfer to a hydroxyl acceptor through theagency of a transferase. The activating system and a phenol-specifictransferring enzyme present in mammalian livers have been separated. 17* 130Hilz and Lipmann 131 have shown that Neurospora sitophila possesses astrong sulphate-activating system but no enzyme capable of transferringsulphate to P-nitrophenol. These workers used the activating systems oflamb’s liver and Neurospora to prepare “ active sulphate ” which wasidentified as adenosine-(3’ phosphate)-(5’ phosph~sulphate).~~~ Sega1,lSusing rat-liver preparations, showed that 3-3-34 moles of orthophosphatewere liberated per mole of sulphuric ester formed, suggesting that more thanone ATP molecule is involved. Furthermore, his results show that pyro-phosphate is involved in a reversible reaction during sulphate activation andit seems probable that the formation of “ active sulphate ” is at least a two-stage process. I t is therefore interesting that the sulphate-activating systemof yeast requires at least two separate heat-labile protein f r a ~ t i 0 n s . l ~ ~ Theyeast system will also activate selenate. The arylsulphate-synthesizingsystem of rat liver has been used by Japanese workers for studies in vitro onthe metabolism (detoxication) of various aromatic compounds. 135It is not certain whether adenosine-(3’ phosphate)-(5’ phosphosulphate)can donate sulphate groups for the sulphation of compounds possessing non-phenolic hydroxyl groups. So far no such transference has been observed,but Roy 136 has suggested that the sulphation of non-phenolic steroids bymammalian-liver preparations 137 may be brought about by the same systemas that responsible for the sulphation of phenols. It seems possible that therewill be found a series of specific sulphate-transferases responsible for thetransfer of sulphate from ‘ I active sulphate,” and the ability of a tissue tosynthesize a particular sulphuric ester will depend on the presence of bothactivating system and specific transference. Thus the hen’s oviduct is ablelz7 R. H. De Meio and K. I. Arnolt, J. Biol. Chem., 1944, 156, 577.I z 8 R. H. De Meio and L. Tkacz, Arch. Biochem. Biophys., 1950, 27, 242.lZ9 R. H. De Meio, M. Wizerkaniuk, and E. Fabiani, J. Biol. Chem., 1963, 203, 257.lSo R. H. De Meio, M. Wizerkaniuk, and I. Schreibrnan, ibid., 1956, 213, 439; H. I,.131 H. Hilz and F. Lipmann, Proc. Nut. Acud. Sci. U.S.A., 1955, 41, 880.132 P. W. Robbinsand F. Lipmann, J. Amer. Chem. SOC., 1956, 78, 2652.133 H. L. Segal, Biochim. Biophys. Acta, 1956. 21, 194.13* 1,. G. Wilson and R. S. Bandurski, Arch. Biochem. Bio$hys., 1956, 62, 503.136 T. Sato, M. Yamada, T. Suzuki, and T. Fukuyama, J. Biochem. ( J a p m ) , 1966.43, 25; T. Sato, T. Suzuki, T. Fukuyama, and H. Yoshikawa, ibid., p. 413, 421.136 A. B. Roy, Biochem. J., 1956, 63, 294.13’ R. H. De Meio and C. Lewycka. EwdocrinoZogy, 1955, 56, 489; R. H. De Meio,C. Lewycka, and M. Wizerkaniuk, Fed. P‘Yoc., 1956, 15, 241 ; J. J. Schneider and M. L.Lewbart, J. BioZ. Chem., 1956, 222, 787.Segal, ibid., p. 161DODGSON AND SPENCER SULPHATASES. 33 1to synthesize " active sulphate " but does not possess the required trans-ferase for the transfer of the sulphate group to p-nitrophenol, nor is thesulphate-nitrophenol transferase of liver able to transfer sulphate to anyuridine nucleotide.138The possibility that the sulphatases are actually sulphate transferaseshas not yet been directly investigated. However, some evidence has beenoffered which suggests that the sulphate-nitrophenol transferase of liver isnot identical with arylsulphatase A, B, or C.2K. S. D.B. S.W. N. ALDRIDGE.R. K. CALLOW.K. S. DODGSON.W. C. EVANS.B. SPENCER.R. T. WILLIAMS.J. L. Strominger, Abs. Amer.. Chem. SOC. Meeting, Diu. Carbohydrate Chem.,Sept. 1956, p. 1 8 ~

ISSN:0365-6217    

DOI:10.1039/AR9565300279

出版商:RSC    

年代:1956

数据来源: RSC

摘要:

ANALYTICAL CHEMISTRY.IN this year’s Report it has been considered desirable to treat microwavespectroscopy in some detail, because hitherto it has received but passingmention. The remainder of the Report follows, in general, the pattern ofthe previous two years. It has not been possible to cover every aspect ofthe vast expanding field of analytical chemistry.During the last three years great strides have been made in many branchesof analytical chemistry and it is not an easy matter to look back and singleout a few for special mention. Particular interests will undoubtedly playsome part in making such a selection.Amongst the more interesting trends is the increasing application offlame photometry to the rapid determination of metals other than the alkaliand alkaline-earth metals.More widespread applications are being foundfor the high-frequency titration technique, although at present, mostattention is being focused on the selection of the best type of instrumentand its mode of application. A more general interest in the application ofelectrophoresis to inorganic analysis is now evident. In classical analysis,pride of place must go to the many and varied applications of ethylene-diaminetetra-acetic acid (EDTA), both as a masking agent and as a titrant.There has been a lack of a range of suitable indicators until fairly recently,but during the last year or so, several new indicators have been developed.Future work in this field will undoubtedly lie in the development of furtherindicators, and in a search for reagents inore selective than EDTA itself.Generaladvises caution in the application of statistics to theevaluationof analytical results, because proper consideration is never given to theinherent chemical errors of methods.He recommends that the averageerror (the arithmetical mean of the absolute values of the individual deter-minations from the mean of the results) be calculated and transformed to afigure approximating to the standard deviation by multiplying by 1.25.Benedetti-Pichler has listed a number of rules which should be followedin order to attain the highest precision inherent in a given balance. Recenttrends in the design of niicrobalances have been re~iewed.~A procedure for the concentration of traces of copper, antimony, andbismuth has been de~cribed.~ Lead nitrate is added and the solution istreated with zinc filings.The trace metals are co-precipitated with lead.The metal is filtered off and dissolved in nitric acid. The individual metalsare then determined as follows : bismuth polarographically, antimony colori-metrically by the reaction with methyl-violet, and copper titrimetrically.Babko1 A. K. Babko, Zavodskaya Lab., 1955, 21, 269.a A. A. Benedetti-Pichler, Mikrochim. Acta, 1956, 565.3 G. I?. Hodsman, ibid., p. 591.V. V. Ten’kovtsev, Zavodskaya Lab., 1955, 21, 525BELCHER, SHERIDAN, STEPHEN, AND WEST. 333Lingane and Davis have used argentic oxide as an oxidant to transformmanganese(II), cerium(m), and chromium(Ir1) to higher valency states.Theexcess of oxidant is simply removed by warming to decompose silver(i1).The solution is then titrated with standard ferrous sulphate. The reagenthas an advantage over the conventional bismuthate or persulphate reagentsin that chloride ion does not interfere. The procedure has been applied tothe analysis of alloys.Powdered antimony and nickel have been re-examined as reducingagents6 Antimony reduces iron(II1) and tin(1v) in 3--6~-hydrochlork orsulphuric acid. Titanium(1v) is reduced in 10N-sulphuric acid and can betitrated with methylene-blue without removing the excess of reductant.Uranium(v1) and tungsten(v1) are reduced in 6~-sulphuric acid and are thentitrated with ferric alum solution. Nickel appears to have no advantageover lead in a reductor column : although reduction is as efficient, the colourof the nickel ion may interfere.An alternative to the Zimmermann-Reinhardt reagent for the suppres-sion of interference by chloride in the permanganate titration of iron(r1) hasbeen described.’ Several compounds were examined but the best resultswere obtained with a mixture of potassium fluoride and sodium sulphate.Advantages of the reagent are cheapness, ease of preparation, and improve-ment of the end-point, but it is less effective when hydrochloric acid is presentin excess of the amount usually left after dissolution of an ore.The authorsdo not mention that this mixture was criticised adversely by Follenius 8over 80 years ago.A detailed study has been made of the required cooling period forporcelain crucibles contained in a desiccator.D It was concluded that evenafter cooling for 1 hour significant errors are obtained ; these may be minim-ised by allowing the crucible to cool somewhat before placing it in thedesiccator, by restricting the number of crucibles in the desiccator, and, ifthe substance is non-hygroscopic, by allowing the crucible to stand in thebalance-case before weighing.The interfering effect of induced reactions in titrimetric and colorimetricanalysis has been discussed.1° Two types of reaction are considered:(a) coupled reactions in which substance A (actor) reacts with both B(inductor) and C (acceptor} in a fixed ratio, and (b) chain reactions in whichthe actor A reacts only with the acceptor C.Several examples of each typeare given.The significance of steric factors in the application of organic compoundsas reagents has been discussed.ll Particular reference is made to this effecton the reactions of benzidine, crystal-violet, and various azo-dyes.The analytical properties of substituted 2 : 4 : 6-trinitrophenols haveJ. J. Lingane and D. G. Davis, Analyt. Chim. Acta, 1056, 15, 201.C. Yoshimura, J . Chem. SOC. Japan, 1955, 76, 409.K. M. Somasundarum and C. V. Suryanarayana, 2. anorg. Chena., 1954,277, 181 ;T. Agterdenbos, Analyt. Chim. Acta, 1956, 15, 429.cf. idenz, Acta Chim. Hung., 1956, 8, 423. * 0. Fellenius, 2. analyt. Chem., 1872, 11, 177.lo ’A. I. Medalia, Analyt. Chem., 1955, 27, 1678.11 I. S. Mustafin, T. I.Badayeva, and L. M. Knl’berg, Ukvaiiz. hhim. Zhzcr., 1955,21, 381334 ANALYTICAL CHEMISTRY.been examined.12 Those compounds which were highly hindered stericallyshowed great selectivity : for example, methylpropylpicric and ethylmethyl-picric acids precipitated barium quantitatively, but not strontium ; di-methylpicric acid precipitated strontium and barium but not calcium ; andmethylpropylpicric acid did not precipitate lanthanum, but precipitatedcerium(m), lead, and silver.Henning l3 has reviewed work concerned with the relationships betweenthe analytical properties of an organic reagent and the stability of themetal-ion complex formed ; he details the factors which affect the stability.Several substituted thiocarbazone derivatives have been synthesisedand the absorption maxima with various metals have been determined.l4The complexes with lead, mercury(II), zinc, and silver have a single absorp-tion maximum in the short-wave region at longer wavelengths than thoseformed with diphenylthiocarbazone.The important investigations of G.F. Smith and his co-workers havecontinued. l5 Eleven new substituted 1 : 10-phenanthrolines have beensynthesised ; the wavelengths of maximum absorption and the molecularextinction coefficients of the ferrous and cuprous complexes have beendetermined.Agterdenbos16 has prepared a complete survey of methods based onprecipitation from homogeneous solution. Their applications in gravimetricanalysis and advantages are critically discussed.Wilson l7 has given a general survey of ultramicro-methods with specialreference to the methods used for weighing and titration.The range isdefined as an operation carried out on a sample ofBarcia l8 has reviewed thermogravimetric methods in analysis and thevarious types of thermobalance which are available.g. or ml.ReagentsPrecipitants.-Oxalhydroxamic acid has been used for the gravimetricdetermination of lead; l9 no details of possible interferences are supplied.Mercury(1) can be determined gravimetrically or conductometrically byprecipitation with coumaric acid; 2o large amounts of mercury(I1) do notinterfere.Further new reagents for nickel and copper have been recommended.21S-Methylthiuronium sulphate precipitates both metals as methyl mercaptideswhich can be weighed as such.Separation can be achieved by altering theThe method appears to be very sensitive.l2 C. E. Moore, M. M. Lally, R. L. Anderson, J. L. Brady, and J. J. McLafferty,l* G. J. Henning, Chem. Weekblad, 1955, 51, 519.l4 L. S. Pupko and P. S. Pel'kis, Zhur. obshchei Khim., 1954, 24, 1640.l 5 D. H. Wilkins, A. A. Schilt, and G. F. Smith, Analvt. Cham., 1955, m, 1574.l6 T. Agterdenbos, Chem. Weekblad, 1955, 51, 571.l' C. L. Wilson, Mikrochim. Ada, 1956, 91.l 8 C . G. Rarcia, Iizf. Quim. Anal., 1956, 9, 159.l B I. P. Ryazanov and T. I. Badeeva, Ref. Zhur., Khim., 1955, Abstr. No. 14,219.2o A. Waksmundzki and R. Szucki, Ann. Univ. M . Curie-Sklodowska, A A . 1954.21 S. K. Siddhanter and P. C. Kundu, J . Indian Chem. SOC., 1955, 32, 655Analyt.Chim. Acta, 1956, 15, 1.8, 17BELCHEK, SHEKIDAN, STEPHEN, AND WEST. 335medium, but a double precipitation is necessary. Various thiosemi-carbazones have been recommended as reagents for the same two metalsand for cobalt.22The most promising of the new reagents for nickel is 4-methylcyclo-hexane-1 : 2-dione d i ~ x i m e . ~ ~ The desirability of using water-solubledioximes has been appreciated for many years, but the only one of thistype so far studied in detail, cyclohexane-1 : 2-dione dioxime, is co-precipit-ated with the nickel complex. The corresponding heptoximes, althoughfree from this defect, are difficult to synthesise, and oximes with less than6 carbon atoms in the ring require strict pH control for quantitative pre-cipitation.Accordingly, Banks and Hooker examined some substitutedcyclohexane-1 : 2-dione dioximes. The 4-methyl and the 4-isopropylderivative were found to be suitable. The 4-methyl compound is water-soluble ; it precipitates nickel at pH 3 and the precipitate is uncontaminatedwith excess of reagent. The 4-isopropyl compound has similar properties,but is less soluble in water and is recommended for micro-determinations.Both reagents are also suitable for the determination of palladium.9-Thiocyanatoaniline has been recommended as a reagent for the gravi-metric determination of palladium.24 Sogani and Bhattacharya 25 use3-hydroxy-1 : 3-diphenyltriazen for the same purpose. Certain phthalanilicacids have also been proposed.26New reagents for thorium continue to pour out in what appears to be anever-ending stream. The time has come for all this work to be reviewedand an assessment to be made of the relative merits of these reagents.Datta and Banerjee27 have examined 4-aminosalicylic acid as a pre-cipitant ; the determination may be completed gravimetrically or titri-metrically.Diphenic acid 28 and various organic bases 29 (o-anisidine ando-phenetidine) have also been recommended. Datta 30 examined severalphthalanilic acids and found that three precipitated thorium quantitatively.A further reagent which has been proposed is P-hydroxyamino-p-phenyl-- propionic acid.31 Few ions interfere.Gallium may be determined gravimetrically or nephelometrically byprecipitation with tetramethylenedithiocarbamic acid.32 The method hasbeen applied to the analysis of minerals, in which case gallium is firstextracted with ethyl ether.A new reagent for potassium, 2 : 4-dinitro-N-(2 : 4 : 6-trinitrophenyl)-l-naphthylamine (“ cc-hexyl ”) has been re~ommended.~~ The potassium salt23 G.N. Mitra and S. S. G. Sircar, J. Indian Chem. SOC., 1955, 32, 435.23 C. V. Banks and D. T. Hooker, Analyt. Chem., 1956, 28, 79; cf. R. C. Voter and24 E. S. Przkeval’skii, V. I. Shlenskaya, and N. F. Ogarkova, R e f . Zhur., Khim.,25 N . C. Sogani and S. C. Bhattacharya, Analyt. Chew., 1956, 28, 81.26 S. K. Datta, 2. analyt. Chem., 1955, 148, 259.27 S. K. Datta and G. Banerjee, AnaZyt. Chim. Acta, 1955, 13, 23.28 G. Banerjee, Naturwiss., 1955, 42, 417; cf.idem, 2. analyt. C h e w , 1955, 147,C. V. Banks, ibid., 1949, 21, 1320.1055, Abstr. No. 40,395.404, 409.G. S. Desmukh and J . Xavier, Bull. Chem. SOC. Japan, 1955, 28, 233.30 S. K. Datta, 2. analyt. Chem., 1955, 148, 267.31 G. Banerjee, ibid., 147, 348.32 W. Geilmann, H. Bode, and E. Kunkel, ibid., 148, 161.3a K . Toei, J . Chem. SOC. Japan, 1955, 76, 106336 ANALYTICAL CHEMISTRY.is considerably less soluble than that of dipicrylamine. Excess of sodiumor magnesium (25 : 1) and calcium (5 : 1) is without effect.Sodium has been determined gravimetrically by precipitation withmagnesium 1-naphthylamine-8-sulphonate from an ethanol-water medium.=A bromometric procedure for completing the determination has also beendeveloped.There is no information available as to interferences.Colorimetric.-Various 2 : 3 : 7-trihydroxy-6-fluorone derivatives whensubstituted in the 9-position have been found to give intense colours withtin(rv) and antimony(m) 35 and these reactions have been made the basisof colorimetric determinations. Tin(1v) is separated from antimony(II1) bydistillat ion.Oxalyldihydrazide has been proposed as a highly sensitive reagent forthe colorimetric determination of copper(r1) .36Iron(m) may be determined spectrophotometrically by allowing it toreact with 4-amino4’-methoxydiphenylamine (Variamine-blue) ; 37 a blue-violet meriquinoid compound is formed. There are few interferences.The method gives satisfactory results when applied to the determination ofiron in lead-antimony alloys.Zehner and Sweet 38 recommend 5-sulpho-anthranilic acid; a stable colour is formed with iron(II1) and there are fewinterferences. 4 : 7-Dihydroxy-1 : 10-phenanthroline has been found to besuitable for the determination of iron(I1) in alkaline solution.39, Iron(Ir1) isreduced by means of sodium dithionite (hydrosulphite).Trimethylaurincarboxylic acid (“ trimethyl-aluminon ”) has been pro-posed as a colorimetric reagent to replace a l ~ m i n o n . ~ ~ Ions (e.g., aluminium)which give colour reactions with aluminon behave in the same way with thenew reagent, but the colours are more intense.Peach 41 has used 3-methoxy-5-nitrosophenol for the colorimetricdetermination of iron(m) and cobalt. The complex of the latter is water-insoluble and is extracted with suitable organic solvents.The new reagentis claimed to have advantages over existing reagents for these metals.p-Mercaptopropionic acid has been proposed for the colorimetric deter-mination of 2-5-20 p.p.m. of cobalt.42 A deep green colour is produced;nickel and copper do not interfere.Osmium(v1) has been determined colorinietrically with l-naphthylamine-3 : 5 : 7-trisulphonic acid as reagent.43Clinch recommends 1-(2-arsonophenylazo)-2-naphtho1-3 : 6-disulphonicacid (APANS) for the colorimetric determination of thorium. He hasapplied the method to the analysis of monazite, thorium first being separatedby precipitation as the oxalate.The reaction is extremely sensitive.34 R. M. Dranitskaya, Ref.Zhur., Khim., 1955, Abstr. No. 5,779.35 V. A. Nazarenko and N . V. Lebedeva, Zhur. analif. Khim., 1955, 10, 289.36 G. Gran, Analyt. Chim. Actn, 1956, 14, 150.37 L. Erdey and F. Szabadvary, Acta Chim. Hung., 1955, 6, 131.38 J . M. Zehner and T. R. Sweet, Analyt. Chem., 1956, 28, 198.39 A. A. Schilt, G. F. Smith, and A. Heimbuch, ibid., p. 809.40 L. &I. Kul’herg and L. A. Molot, Ukrain. khim. Zhur., 1955, 21, 250.4 1 S. M. Peach, Analyst, 1956, 81, 371.43 H. C. Wingfield and J. H. Yoe, Aiialyt. Chim. Acfa, 1956, 14, 446.44 J . Clinch, ibid., p. 164.E. Lyons, Analyt. Chem., 1955, 27, 1813BELCHER, SHERIDAN, STEPHEN, AND WEST. 337A new method for the colorimetric determination of borate has beende~cribed.~~ When ferric sulphate and iodine solutions are added to an acidsolution containing polyvinyl alcohol and borate, a blue colour is obtained.The method is of interest in that most other colorimetric methods for boraterequire a concentrated sulphunc acid medium.Grob and Yoe46 haveproposed two new very sensitive reagents, 5-benzamido-6’-chloro-1 : 1’-di-anthrimide and 5-$-toluidino-l : 1‘-dianthrimide. Boron in fruit-tree leavesand lucerne was determined by decomposing the sample with sulphuric acidand then distilling as methyl borate.For the determination of chromate, o-aminophenyldithiocarbamic acidhas been proposed; 47 0-1-1.0 yg. of chromate per ml. may be determined.Svach and Zyka 48 determine nitrite colorimetrically by its reactionwith 2 : 5-diamino-7-ethoxyacridine ( I ‘ Rivanol ”) ; a red complex is formedin the presence of dilute hydrochloric acid.Stephen 49 has reviewed the colorimetric reagents which have beenThe accuracy is within &0.001 pg.proposed during the last few years.R.B.Inorganic Qualitative AnalysisIn last year’s Report, mention was made of the increasing use of thio-acetamide in place of hydrogen sulphide and ammonium sulphide in schemesof qualitative inorganic analysis. Criticism has been made of the in-discriminate use of thioacetamide. For example, Bon has commentedadversely on the paper by Bloemendal and Veerkarn~,~~ recommending thereplacement of H,S and (NH,),S, by thioacetamide. The latter authors,however, have answered these criticisms inIn the Fisher Award Address for 1956, Swift and Butler 53 discuss theprecipitation of sulphides from homogeneous solution by thioacetamide.Measurements have been made of the rate of hydrolysis of thioacetamideand of the Precipitation of lead sulphide by thioacetamide.These studiesprovide a basis for the prediction of the optimum conditions for the use ofthioacetamide in the precipitation and separation of metals as sulphides.It is clear from this work that the assumption that thioacetamide hydrolysesrapidly and completely in hot acid solution and can replace hydrogensulphide without modification of procedure is by no means true.have described a new scheme of qualitative analysisinvolving the use of thio-salts. The present scheme is a modification of theiroriginal one. Briefly, the metals are precipitated with a 1N-solution ofsodium sulphide instead of yellow ammonium sulphide.Calcium andstrontium are precipitated along with the sulphides and hydroxides of the45 R. F. Muraca and E. S. Jacobs, Chemist-Analyst, 1955, 44, 14.46 R. L. Grob and J . H. Yoe. Analyt. Chim. Acta, 1956, 14, 253.4 7 E. Gagliardi and W. Haas, 2. anal-vt. Chew.. 1955, 147, 321.4 s M. Svach and J. Zyka, ibid., 148, 1.49 W. I. Stephen, Ind. Chem. Mfr., 1955, 31, 622; 32, 38.50 W. F. Bon, Chem. Weekhlad, 1955, 51, 677.51 H. Bloemendal and T. A. Veerkamp, ibid., 1953, 49, 147.62 Idem, ibid., 1955, 51, 943.6s E. H. Swift and E. A. Butler, Analyt. Chem., 1956, 28, 146.51 1. K. Taimi and (>. E. S. Salarin, Analyt. Chim. Ada, 1055, 13, 205.Indian worker338 ANALYTICAL CHEMISTRY.Group 111 and I V cations by mixing the sodium sulphide reagent withsodium carbonate.Cerium and thorium are not separated but are testedfor separately within the iron group. Thallium is precipitated as the iodidewith the copper group by the addition of potassium iodide. A subsequentpaper 55 details the group separations of the common cations by formationof sulphides, hydroxides, and thio-salts by using a 1N-solution of sodiumsulphide. The subsequent separation and identification of the individualcations follow the more conventional analytical procedures. The sameworkers 56 have proposed a scheme for the qualitative analysis of the con-stituents of insoluble residues obtained after initial treatment of the sample.A list of likely substances affected and unaffected by various chemicaltreatments is given.A qualitative scheme has been described 57 for the detection of tracesof heavy metals in organic materials, in particular, fibres and syntheticresins. The material is destroyed by oxidation with nitric acid in a sealedtube (Carius’s method).The resulting solution is divided into three partsand colorimetric micro-tests are applied after extraction or volatilisation ofparticular elements from the solutions.Belcher, Farr, and Randles 58 have made certain observations on theprecipitation of Group I1 metals in qualitative analysis. After the separ-ation of Group I metals the filtrate is treated with a 6% solution of hydrogenperoxide and is warmed to reduce permanganate and dichromate ions.Arsenic pentasulphide is first precipitated by making the solution 6~ withrespect to hydrochloric acid and passing hydrogen sulphide into the solution.The remaining Group I1 cations are precipitated at an acidity of 0 .5 ~ withrespect to hydrochloric acid. The Group I1 sulphides are separated intothe A and B sub-groups by using Holness and Trewick’s lithium hydroxidereagent. The hot solution of Group IIB sulphides is poured into twice itsvolume of concentrated hydrochloric acid, and the sulphides of arsenic arefiltered off. The filtrate is cooled and diluted with an equal volume ofwater; hydrogen sulphide is passed into the solution and the antimonysulphide which is precipitated is filtered off.The filtrate is treated with anequal volume of 2~-aqueous ammonia, hydrogen sulphide is passed, and thestannic sulphide is then precipitated.Certain surface-active substances can prevent co-precipitation of ionswith sulphide precipitates. An investigation of this effect has been madeon the co-precipitation of thallium with arsenious sulphide. 59 The mosteflective substances are brilliant-green, malachite-green, and neutral-red.-4 scheme has been given for the qualitative analysis of cations without theuse of hydrogen sulphide.GO The cations are divided into five groups onthe basis of the solubilities of the chlorides, sulphates, basic salts, hydroxides,and ammonia complexes. The cations within the groups are detected inmost cases by fractional reactions.55 I.K. Taimi and G. B. S. Salaria, Ar,n.lyt. Chim. A d a , 1955, 13, 513.56 Idem, ibid., 1956, 14, 4.5 7 M. R. Lardera and A. Mori, Ann. Chim. (Italy), 1955, 45, 869.5* R. Belcher, J. P. G. Farr, and J. E. B. Randles, Analyt. China. Acta, 1955,13, 518.59 N. A. Rudnev, Zhur. analit. Khim., 1955, 10, 217.6O $5. Ya. Schngiderman, Izvest. Kievsk. Politekhn. In.st., 1954, 14, 140BELCHEK, SHEKIDAN, STEPHEN, AND WEST. 339The V:eisz ring-oven technique has been used by Blackman tjl for theseparation and identification of molybdenum and tungsten present in theform of molybdate and tungstate ions in the test solution. Stephen 62 hasextended the ring colorimetric procedures described by Weisz to includealuminium, beryllium magnesium, potassium cadmium, and zinc.Con-ventional organic reagents are used to develop the ring zones. Stephen 63has also described a combination of electrographic analysis and the ring-oven techniques which enables the rapid qualitative analysis of severalalloys to be carried out without apparent destruction of the sample. Themethod can also be used for the semi-quantitative analysis of a few simplealloys. Nall and Scholey describe a similar procedure for the testingand sorting of alloy steels. Their method is particularly suited for use insemi-skilled hands ; the entire apparatus and reagents are portable, thusfacilitating the testing of stored alloys.Weisz G5 has made an interesting study of the reactions suitable for theidentification of chloride, bromide, iodide, and thiocyanate when present inany combination of the four anions.Adsorption reactions have found application in qualitative analysis.66Thus, the desorption of a dye adsorbed on a colloidal solution of a silverhalide by addition of a halide solution can be used to detect traces of iodidein the presence of very large amounts of chloride and bromide.Chloride,bromide, and thiocyanate ions can also be detected, and the method can beextended to include pseudo-adsorption reactions given by sulphate andfluoride ions, and adsorption reactions of phosphate, tungstate, molybdate,and benzoate ions.The usual quota of new qualitative tests has been published during theyear. A new aluminium-type reagent has been proposed for the detectionof aluminium, called alumocresone (trimethylaurintricarboxylic acid).67The colour reactions are similar to those given by aluminon but show agreater intensity. The reagent can also be used for quantitative colorimetricanalyses. Derivatives of thiourea have been examined for use in the detec-tion of bismuth.68 Of the numerous reagents tested, the most sensitive isdi-o-tolylthiourea which forms a yellow complex with bismuth, the intensityof which is about ten times greater than that of the unsubstituted reagent.The reaction between lithium and " thorin " [2-(hydroxy-3 : 6-disulpho-l-naphthy1azo)benzenearsonic acid] has been studied.69 -4t pH 13.5, thereagent combines with lithium in the ratio 1 : 1. The complex is veryweak and does not constitute a very sensitive test for lithium.SimilarL. C. F. Blackman, Mikrochim. Acta, 1956, 1366.62 W. I. Stephen, ibid., p. 1540.ti3 Idem, ibid., p. 1531.+u W. R. Nall and R. Scholey, Metallurgia, 1956, 54, 97.6 5 H. Weisz, Mikrochim. Ada, 1956, 1225.L. M. Kul'berg and I. N. Bulankhe, Uch. Zap. Saratovsk. Univ., 1954, 34,6 7 L. M. Kul'berg and L. A. Molot, Ukrain. khim. Zhur., 1955, 21, 256.68 M. P. Makukha, Sbornik Ref. Nauch. Rabot Teor. Kaf. L'vov Med. Inst., 1954,ciB L. P. Adamovich and T. T. Alekseeva, Uch. Zap. Khar'kov Unirr., 1954. 54;154.94.Trudy Khim. Fak. i Nauch. Issledovntel. I n s t . Khim., 12, 209340 ANALYTICAL CHEMISTRY.studies have been made with beryllium 70 and thorium.71 With beryllium,the constituents react at pH 12.5 in the ratio of 2 : 3.The complex has aformation constant of 4.5 x With thorium, the reaction occurs inthe ratio of 1 : 2 at an optimum pH of 1-65. The formation constant isWest and McCoy 73 describe a new test for gold involving the extractionof chloroauric acid into n-butanol and treating this solution with a-naphthyl-amine. The resulting intense violet colour can be used to detect 1 pg. ofgold. Sen and West 73 detect 0-5 pg. of silver at a concentration of 10 p.p.m.using test papers saturated with the solution obtained by shaking a suspen-sion of nickel dimethylglyoxime with a solution of potassium cyanide. Ontreatment with a neutral silver solution, the test paper becomes red. Feigland Goldstein 74 use the p-nitrophenylhydrazone of diacetyl mono-oxime as aspecific reagent for the detection of cobalt.A violet complex is formed withas little as 0.5 pg. of cobalt at a dilution of 1 in 500,000.New colour adsorption reactions are described for magnesium.75 Theadsorption of dyes on magnesium hydroxide depends largely on the molecularweight of the adsorbed substance and the ageing of the precipitate. Thestability of the colour is increased by the presence of lead compounds,particularly sodium plumbite.A convenient test for cadmium 76 involves heating its neutral solutionwith a saturated solution of sodium thiosulphate, and adding hydrogenperoxide dropwise to the cooled solution. A yellow precipitate of cadmiumsulphide is formed with 2 pg. of cadmium in one drop of solution.Zinc 77can be detected in amounts of 1 pg. per 2 ml. of test solution by meansof the yellow colour formed on adding potassium ferrocyanide to an acidsolution of zinc containing methyl-violet. The reaction can also be usedquantitatively. A blue complex is formed when the red solution of tetra-methyldiaminodiphenylantipyrinylmethanol and ammonium thiocyanate isadded to a solution containing zinc ions.78 The reaction serves to identify2-3 pg. of zinc per ml. of solution. A new specific test is described forcopper(1r) which forms an intense red complex with 5 : 7-dihydroxy-4-methylcoumarin in ammoniacal solution. 79 The complex can be extractedinto organic solvents, The sensitivity is not given. Tetrabromoresorufincan be used for the detection of tin.80 The red acid solution is reduced to agreen colour by tin(I1).SNADS [l : 6-dihydroxy-2-(4-sulpho-l-naphthyl-azo)naphthalene-3 : 6-disulphonic acid] forms coloured complexes withthorium and zirconium and can be used as a spot reagent (sensitivity7.9 x 109.7O L. P. Adamovich and R. S. Didenko, Trudy Khim. Fak. i Nauch. Issledovaiel. Inst.7l L. P. Adamovich and V. M. Rutman, ibid., p. 203; for refs. 69, 70, 71, see Analyt.72 P. W. West and T. C. McCoy, Analyt. Chem., 1955, 27, 1820.73 B. Sen and P. TV. West, Mikrochim. A d a , 1955, 979.74 F. Feigl and D. Goldstein, Analyst, 1966, 81, 709.75 V. I. Kuznetsov, Zhur. analit. Khim., 1956, 11, 81.7 5 L. G. Gein, Trudy Komissii Analit. Khim. Akad. Nauk, S.S.S.R., 1954, 5, 133.7 7 V. I. Kuznetsov and L.S. Kozyreva, ibid., p. 86.7 8 V. P. Zhivopistsev, Uch. Zap. Molotov Univ., 1954, 8, 43.79 A. OlrAC and J. Hor&k, Chem. Listy, 1965, 49, 1403.80 E. RuiiCka, ibid., p. 1729.Khiwt., 12, 195.Abstr., 1956, No. 2631, 2646, 2695BELCHER, SHERIDAN, STEPHEN, AND WEST. 3412-4 pg.) . The 7-nitroso-derivative gives coloured complexes withcerium@), and with cobalt and nickel in ammoniacal solution.81 Flaschkaand Sadek s2 describe a selective test for zirconium using catechol-violet andEDTA. A deep blue colour is formed at a pH of 4-65 with very dilutesolutions of zirconium. Zolotavin 83 describes a qualitative reaction forvanadium based on the interaction of a vanadyl solution with one of ammon-ium molybdate. A deep blue colour results.Vanadium(v) can be detectedby its catalytic action on the oxidation of guaiacol to the coloured o-quinone ;less than 5 pg. of vanadium can be detected.84 2-Mercaptoresorcinol hasbeen studied as a possible analytical reagent.85 The colours given withseveral inorganic ions are generally more intense than those given by pyro-gallol. Wingfield and Yoe use l-naphthylaniine-3 : 5 : '7-trisulphonicacid for the detection of osmium(v1). At pH 1.5, a violet complex is formed,the reaction being sensitive to 1 part of OS(VI) in 1.5 x lo7 parts of solution.Feigl and Stark 87 describe a new test for elementary sulphur. Whenfree sulphur is fused with benzoin, hydrogen sulphide is formed which canbe detected by conventional means. The limit of detection is 0.05 pg.;selenium does not interfere.Schneider 88 reviews methods for the detectionof sulphur and recommends the use of piperidine; a red colour is formeddown to 4 pg. of free sulphur.Llacer 89 has improved the specificity and sensitivity of the rhodizonatetests for barium and strontium. The brown-red spots are treated withdimethylamine hydrochloride, a change in colour to bright red indicatingbarium and a change to blue-violet indicating strontium. Calcium can beidentified by the formation of characteristic crystals when a solution ofrhodizonic and benzoic acids is added to a solution of calcium ions. Llaceralso describes a scheme for the separation and estimation of barium,strontium, calcium, and magnesium.Filter-paper impregnated with zirconium 4-($-dimethylaminophenylazo) -diphenylarsinate is used for the detection of fluoride ions : the colourchange of brown to red occurs with not less than 0.05 pg.of fluoride ion.Common cations and anions do not interfere with the detection of more than4 pg. of fluoride.The nitration product of phenarsazinic acid gives a characteristic redcolour in alkaline solution which provides the basis of a new method for thedetection of not less than 3 pg. of the nitrate The test is not at allspecific.81 S. K. Datta, 2. analyt. Chem., 1956, 149, 270.82 H. Flaschka and F. Sadek, ibid., 150, 339.H3 V. L. Zolotavin, Zhzrr. analit. Khim., 1955, 10, 189.2. Jarabin and B. CsiszAr, Magyar Kkm. Folydirat, 1956, 62, 173.85 V. M. Dziomko and A. I.Dherepakhin, Sbornik Statei Vses. Zaoch. Politekh. Inst.,8 6 H. C. Wingfield and J. H. Yoe, Analyt. Chim. Ada, 1956, 14, 446.87 F. Feigl and C. Stark, Analyt. Chem., 1955, 27, 1838.d9 A. J. Llacer, Mikrochinz. Acta, 1955, 921.90 K. Tsuji and M. Kageyama, J . Pharm. SOC. Japan, 1954, 74, 1184.9 1 R. Pietsch, Mikrochim. Ada, 1956, 1490.1955, 65.W. Schneider, Arch. Pharm., 1956, 289, 299342 ANALYTICAL CHEMISTRY.Inorganic Gravimetric AnalysisThe determination of the alkali metals continues to receive much atten-tion, and classical gravimetric procedures are generally preferred because oftheir accuracy. Thus the gravimetric determination of potassium has beenthe subject of several recent papers. Flaschkag2 has given full details ofthe procedure used for the quantitative precipitation of potassium tetra-phenylboron.He also describes the subsequent alternative to the gravi-metric finish, that is, the non-aqueous titration of the precipitate. This is,perhaps, the most satisfactory of the numerous titrimetric proceduresdescribed in the literature. Berkhout and Jongen 93 also describe the pre-cipitation of potassium with sodium tetraphenylboron. Barnard 94 hasgiven a comprehensive bibliography on the uses and applications of sodiumtetraphenylboron as a gravimetric reagent during 1949-1955. Sykes 95has reviewed the applications of sodium tetraphenylboron in analysis.Wendlandt 96 has studied the pyrolysis of ammonium and alkali-metaltetraphenylborates by using the thermobalance. The potassium, rubidium,and czsium salts decompose between 210" and 265" but the ammoniumsalt sublimes a t 130".The precipitant was prepared according to the direc-tions of Gloss and Olson,97 and Kohler,9* and all the precipitates were driedat room temperature for 24 hours before pyrolysis. Sporekgs describes asimple and rapid method for the determination of potassium in sea waterby use of sodium tetraphenylboron. The method has the advantage ofrequiring no pretreatment of the sample, and only potassium is precipitatedunder the conditions employed.Russian workers loo have given directions for the determination ofpotassium in natural salt deposits by precipitation and weighing as potassiumcaIcium nickelonitrite, K,Ca[Ni( NO,),]. The precipitate is allowed to ageover-night, and is finally dried at 130".The maximum error does not exceed0.2%. The composition of some difficultly soluble cobaltinitrites has alsobeen studied, and a micro-method has been proposed for the determinationof potassium.10l K,Na[Co(NO,),] is recommended as the weighing form for0.1-0.5 mg. amounts of potassium, and K,Ag[Co(NO,),] for amounts inthe range 0.01-0.1 mg.A new procedure is described for the quantitative determination ofstrontium as the secondary phosphate.lo2 The precipitation of SrHPO, isquantitative at pH 6. The precipitate is crystalline, an advantage overstrontium sulphate; it can be filtered off after standing for 1 hour, washed92 H. Flaschka, Chew&-Analyst, 1955, 44, 60.93 H. W. Berkhout and G.H. Jongen, Chem. Weekblad, 1955, 51, 607.R4 A. J. Barnard, jun., Chemist-Analyst, 1955, 44, 104.O 5 A. Sykes, I n d . Chem. Mfr., 1956, 32, 223.96 W. W. Wendlandt, Analyt. Chem., 1956, 28, 1001.97 G. H. Gloss and B. Olson, Chenzist-Analyst, 1954, 43, 70.98 M. Kohler, 2. analyt. Chem., 1953, 138, 9.99 K. F. Sporek, Analyst, 1956, 81, 540.loo G. P. Alexsandrov and M. D. Lyntaya, Uhvain khim. Z h w . , 1956, 21, 518.lol I. M. Korenman, F. R. Sheyanova, and 2. I. Glazunova, Priirzen. Mech. Atom.I o 2 G. Denk, R. Dunkel, and C . Keller, Z . a.na2vt. Chem., 19.56, 152, 31.z'Ana1. Khitn. M., I z d . Akad. Nauk S.S.S.R., 1955, 29BELCHER, SHERIDAN, STEPHEN, AND WEST. 343with a little cold water, and dried at 120-130" for 1 hour. The precipitatecan be ignited to pyrophosphate.The perennial question of the composition of barium sulphate precipitatesagain receives attention.Sgzganova lo3 has studied the effect of a verylarge excess of ferric chloride on the precipitation of barium sulphate. Bestresults are obtained by precipitation at 80" from a solution of 1.2 X 1 O A 2 ~ -hydrochloric acid. Bogan and Moyer have continued the study ofageing in barium chloride solutions as a factor influencing the particle sizeof precipitates of barium sulphate. A large increase in particle size ofbarium sulphate crystals occurs when an aged solution (1-6 days) or afreshly filtered solution of barium chloride is used. Popov lo5 has discussedthe difficulties of removing co-precipitated lead sulphate from bariumsulphate.Bagshawe and Pill lo6 have described an improved barium sulphatemethod for the determination of sulphur in steels, particularly alloychromium steels for which the conventional B.S.method is unsatisfactory.The important stage is the removal of excess of nitrate ions by hydroxyl-amine instead of by baking. The method is precise to within 0.002%.Barium carbonate is almost quantitatively precipitated by passingcarbon dioxide into an ammoniacal solution of barium ions.lo7 The additionof 20% of ethanol makes filtration of the dense precipitate an easy matter.A survey has been given lo8 of methods available for precipitation fromhomogeneous solution. The applications of these methods to gravimetricanalysis are described, and their advantages critically discussed.Russianworkers log have made a comprehensive study of generant reagents used inthe determination of the alkaline-earth metals. Barium can be determinedin the presence of the usual interfering ions, for example, nitrate and fluoride,without detrimental effects by using dimethyl sulphate as reagent. Theprocedure can be modified to enable the determination of barium to besuccessfully carried out in the presence of calcium and strontium.Numerous isolated gravimetric determinations have been describedduring the year, and of these, the following deserve mention. A procedureis described for the gravimetric determination of small amounts of telluriumin sulphur.l1° The free element is precipitated from solution by reductionwith hydrazine and sulphur dioxide.Magnesium (12-160 mg.) is precipit-ated by a three-fold excess of sodium fluoride.lll The precipitate of sodiummagnesium fluoride is centrifuged off, washed with ethanol (70%), and driedat 130". The error is &0.3%. Cadmium 112 can be determined in thepresence of considerable amounts of zinc by precipitation with thioureaFusion with sodium carbonate is recommended.lo3 0. P. Syzganova, Trudy Kazansk. Khim.-Teknol. In-?'a, 1952, 139.lo* E. J. Bogan and H. V. Moyer, Analyt. Chem., 1956, 28, 473.lo5 nil. A. Popov, Zavodskaya Lab., 1955, 21, 1430.lo6 B. Bagshawe and A. L. Pill, Analyst, 1955, 80, 796.lo' H. Teicher, Analyt. Chem., 1955, 27, 1416.lo* J. Agterdenbos, Chem. Weekblad, 1955, 51, 57 1.loQ A.P. Terent'ev, E. G. Rukhadze, and K. I. Litvin, Zhuv. atzalit. Khim., 1956,110 A. Aarenmae and G. 0. Assarsson, Analyt. Chenz., 1955, 27, 1155.ll1 Sh. T. Talipov and A. T. Tashkhodzhayer, Trudy Sredneaziat. Goszidarst. Univ.11* 0. A. Songina, Uch. Za?. Kazakh. Univ., 1954, 18, 58.11, 55.(Tashkent), Khim. Nauk. 1954, 55, 141344 ANALYTICAL CHEMISTRY.and Reinecke's salt. The procedure is empirical and is accurate to &l%.A new weighing form for palladium(I1) and rnercury(I1) is bisethylenediamine-palladium(I1) tetraiodomercurate, Pd(en),HgI4.ll3 The precipitate can bedried at 115'. Most common anions do not interfere with the determin-ation. Milligram amounts of germanium are determined by precipitationof acridine m~lybdogermanate.~~~ No empirical factor need be applied.Inorganic gravimetric analysis has been reviewed by Beamish andWestland 115 in the Analytical Chemistry Annual Review of FundamentalDevelopments in Analysis.Goyanes 116 has reviewed the applications ofthermogravimetric analysis and has described the various types of thermo-balances.A new procedure has been given for the determination of arsenic as thepentasulphide. 117 The precipitate obtained on passing hydrogen sulphideinto an arsenic solution is dissolved in the minimum amount of nearlycolourless ammonium sulphide ; oxidation of As(@ to As(v) occurs, andon adding hydrochloric acid, arsenic pentasulphide and sulphur are pre-cipitated. Washing with carbon disulphide removes the sulphur from theprecipitate, which is then dried at 105" and weighed. Sarudills has in-vestigated Vortmann and Metzl's classical method for the separation ofantimony and tin in order to assess its usefulness as a quantitative method.The method is reliable and gives a sharp separation independently of theamount of either metal present.Several Iiew gravimetric procedures have been developed using 8-hydr-oxyquinoline (oxine) as precipitant. In the presence of EDTA, uranium 119is quantitatively precipitated from a solution containing thorium,zirconium, rare-earth cations, phosphorus, and vanadium. The pre-paration of beryllium 8-hydroxyquinoline dihydrate and the gravimetricdetermination of beryllium in the form of this complex have been studiedby Motojima.120 The method can be used for the separation and determin-ation of beryllium in the presence of aluminium, iron, copper, and zinc.121Wendlandt 122 has given the thermogravimetric data of the pyrolysis of thecomplexes of 8-hydroxyquinoline and its 5 : 7-dichloro- and 5 : 7-dibromo-derivative with scandium, thorium, and uranium.Hahn and Baginski 123 have overcome the difficulties in determiningzirconium with mandelic acid.If the precipitation is carried out at atemperature of 85-90' from a solution not less than 5 M in hydrochloric acid,the zirconium tetramandelate can be filtered off, washed, dried, and weighedas such without the need of a correction factor.113 G. W. Watt, D. M. Sowards, and R. E. McCarley, Analyt. Chetn., 1956, 28, 556.114 P. R.Subbaraman, J . Sci. Ind. Res. India. 1955, B, 14, 640.115 I?. E. Beamish and A. D. Westland, Analyt. Chem., 1956, 28, 694.116 C. B. Goyanes, Inf. Quim. Anal., 1955, 9, 159.117 K. I. Kal'pchiev, Zhur. analit. Khim., 1955, 10, 334.11* I. Sarudi, 2. analyt. Chenz., 1955, 148, 21.119 R. N. Sen Sarma and A. I<. Mallik, ibid., p. 179.120 K. Motojima, J . Chenz. SOC. Japan, Pure Chem. Sec., 1956, 77, 95.lZ1 Idem, ibid., p. 100.W. W. Wendlandt, Analyt. Chem., 1956, 28, 499.R. B. Hahn and E. S. Baginski, Analyt. Chinz. Acta, 1956, 14, 45BELCHER, SHERIDAN, STEPHEN, AND WEST. 346Inorganic Titrimetric AnalysisIndicators.-Few acid-base indicators have been recommended this year,but mention should be made of the following. Four new indicators havebeen synthesised 124 by introducing chlorine or bromine into the molecule oftropzeolin-00.These substances give a colour change similar to that oftropEolin but at a lower pH. They are effective in the range A . 0 3 ~ -hydrochloric acid. Mikhailov 125 gives examples of mixed one-colouracid-alkali indicators which show a colourless pH range between twocoloured ranges. Malowan prefers to use alizarin in place of phenol-phthalein to indicate when an excess of alkali is present in the solutionbefore distillation of ammonia in the Kjeldahl method. Large amounts ofiron do not make the blue-violet colour of the solution less easily seen.Phenol-red screened with methylene-blue gives a sharp colour change fromgreen in acid to violet in alkali; 12' a blue intermediate colour appears atpH 7.3, regardless of the direction of the titration.Pungor and Schulek 12*suggest that the colour changes which occur when fi-ethoxychrysoidine isused as an acid-base indicator arise by formation of quaternary ammoniumbases. Dangl lZ9 lists 23 substances which fluoresce in aqueous solutionunder ultraviolet light with colour intensities depending on the pH. Thesesubstances are useful for titrating strongly coloured solutions. The pHrange 0-14 is covered and the colour changes are given.Potassium rhodizonate is used as an argentimetric indicator in thetitration of bromide, iodide, and cyanide.130 It can also be used in theVolhard titration of silver with thiocyanate. Accuracy and precision aregood. Mixed adsorption indicators are recommended 131 for the titrationof silver with bromide. Good results are obtained in 0~01-0~001N-solutionswith rhodamine-6G and methylene-blue, rhodamine-6G and fluorescein, andmethylene-blue and fluorescein. Titan-yellow 132 behaves reversibly as anadsorption indicator in the titration of chloride and bromide with mercurousnitrate.When p-ethoxychrysoidine is used as an adsorption indicator forthe argentimetric determination of iodide,l= the indicator undergoes anacid-base change at the end-point.When used as a redox indicator, fi-ethoxychrysoidine is oxidised to anazoxy-cornpound.l= The redox potential, E,, is 0.76 volt. Metanil-yellow and Astral-blue-G have been used as indicators in cerimetrictitrations : 135 the first behaves irreversibly and changes from carmine-redto greenish-blue on oxidation; the second is reversible, but the colourlZ4 V.I. Kuznetsov and G. N. Kosheleva, Zhur. analit. Khim., 1956, 11, 208.lZ6 G. I. Mikhailov, ibid., 1955, 10, 382.lZu L. S. Malowan, Chemist-Analyst, 1955, 44, 75.lZ7 M. R. Verma and V. M. Buchar, ibid., p. 73.lZ8 E. Pungor and E. Schulek, 2. analyt. Chew., 1956, 150, 161.130 J . P. Mehlig, Chemist-Analyst, 1955, 44, 87.131 I. N. Bulanzhe and G. A. Mel'nik, Sbornik Trudov. Kievsk. Tekhnol. Inst. Legk.132 V. A. Vorobeichikov, Zavodskaya Lab., 1956, 22, 645.133 E. Pungor and E. Schulek, 2. unalyt. Chm., 1956, 150, 166.la4 Idem. ibid., p. 161.la6 J. Bop& and 2. Ngdler, Magyar Kdm. FoZydtrat, 1966, 61, 372.F. Dangl, Prakt. Chenz., 1955, 6, 249.Prom., 1954, 74346 ANALYTICAL CHEMISTRY.change is less intense and less contrasting.The E, value is about 0.97 volt.Xylene-blue-VS and setoglaucin-0 behave similarly to Astral-blue-G.Phenoxazone 136 is a useful indicator for titrations involving the use ofstrong reducing agents : the red oxidised form changes sharply to blue atan E, value of 0.6 volt; both forms of the indicator are stable in solution.Gibson and White use triphenylmethylarsonium iodide as indicator inthe titration of arsenite and thiosulphate with 0.1 and 0-Olhr-iodine, and inthe reverse titrations. The end-point is marked by the formation or decom-position of the yellow-brown tri-iodide complex of the indicator extractedinto a layer of chloroform or carbon tetrachloride.Presumably the indicatorreaction is more sensitive and easily seen than that of direct observation ofthe violet iodine colour in the organic layer.Most of the recent work on indicators has been concerned with thedevelopment of new indicators for complexometric titrations. The ever-increasing applications of the complexometric methods makes this work ofprime importance, for without suitable indicators, the methods cannot beused with any great selectivity. West 138 has reviewed the uses of theindicators available for complexometric titrations and covers the literatureto the early part of 1956. Suk and Malat 139 describe the properties andapplications of catechol-violet in chelatometry. This important indicatorfinds further applications in the titration of bismuth and thorium in thepresence of iron and mercury,140 and in the determination of thorium in gasmantles, in solutions used for their preparation, and in optical g1a~ses.l~~Pyrogallolcarboxylic acid functions satisfactorily as indicator in thecomplexometric determination of calcium : 142 at the end-point, the violetcolour disappears ; magnesium does not interfere.For other cations theindistinct colour change makes direct titration inadvisable and a back-titration procedure is recommended. Pyrogallolsulphonphthalein (pyro-gallol-red) enables bismuth to be determined in acid solution in the presenceof a large number of common cati0ns.1~3 The solution of bismuth is adjustedto pH 2-3 and is titrated with EDTA in the presence of the indicator untilthe colour change of red to orange-yellow is observed.Small amounts ofnickel and cobalt can be determined in weakly alkaline solution by usingthis indicator, the colour change at the end-point being blue to red.Condensation of iminodiacetic acid and fluorescein gives a product oftrivial name " Calcein " which is superior to murexide as indicator in thecomplexometric titration of calcium.lU Magnesium can be present inamounts 30-40 times that of calcium without affecting the sharpness ofthe end-point. The titration is carried out at pH 1 2 ; the colour change isyellow-green to brown. A sharp stable colour change from wine-red to136 S. Musha and T. Kitagawa, J . Chem. SOC. Japan, Pure Chem. Sect., 1955, 76,13' N.A. Gibson and R. A. White, Analyt. Chim. A d a , 1955, 13, 546.138 T. S. West, Ind. Chem. Mfr.. 1956, 32, 82, 128.13B V. Suk and M. MalAt, Chemist-AnaZyst, 1956, 45, 30.140 J. Cifka, M. MalAt, and V. Suk, Coll. Czech. Chem. Comni., 1956, 21, 412.141 M. MalBt, J. Pelikan, and V. Suk, Chemist-Analyst, 1956, 45, 61.142 M. Kovaiik and M. MouEka, 2. analyt. Chern., 1956, 150, 416.148 V. Suk, M. Makit, and A. JeniEkovA, Coll. Czech. Chem. Comm., 1966, 21, 418.144 H. Diehl and J. L. Ellingboe. Analyt. Chem.. 1956, 28, 882.1289BELCHER, SHERIDAN, STEPHEN, AND WEST. 347pure blue is obtained by using 2-hydroxy-l-(2-hydroxy-4-sulpho-l-naphthyl-azo)-3-naphthoic acid as indicator in the complexometric titration of calciumat pH 12-14; 145 magnesium does not interfere.Cheng 146 has examineda solution of the zinc complex of Eriochrome blue-black-R as an indicatorin chelatometry and finds it superior to other solutions of this and similardyes. He assigns the trivial name " Zinchronie R " to this indicator. Thesolution is stable for prolonged periods and finds use particularly in thedetermination of water hardness.Saj6 14' describes a novel method of indication in complexometrictitrations based on the replacement of vanadium(v) in its complex withEDTA by most cations. The liberated vanadium is detected by usingdiphenylcarbazide or diphenylcarbazone. The method is applied in the pHrange 46-66 and consequently only metals which form chelates withEDTA in this pH range can be determined.Wehber 14* uses the pale brown decomposition product of Bindschedler ' sgreen as redox indicator in the complexometric determination of iron(II1)salts with EDTA at pH 2-5-36 The indicator gives a green colour withoxidising agents and at the end-point it changes sharply to orange.Theindicator has also been used in the indirect determination of chromium(rr1) 149with EDTA.Flaschka and Abdine 1 5 * 9 151 have studied the use of l-(%pyridylazo)-2-naphthol (PAN), introduced by Cheng and Bray,152 as indicator in complexo-metric micro-titrations. The excess of EDTA used to complex the metalsis back-titrated with copper(I1). A subsequent paper 153 details the use ofthe copper-PAN complex as indicator in titrations with EDTA in acidicmedia, and in ammoniacal solutions.Zinc, cadmium, lead, indium, gallium,vanadium, nickel, cobalt, calcium, magnesium , and manganese can all bereadily determined. Cheng describes the titration of scandium and ofindium 155 with EDTA, using PAN as indicator.1 : 8-dihydroxy-2- (9-sulp hophenylazo) napht halene-3 : 6-disulphonic acid (SPADNS) as indicator in the direct complexometricdetermination of zirconium with EDTA. The zirconium-SPADNScomplex is crimson-pink, and at the end-point of the titration the colourchanges to orange red. The thorium-SPADNS lake can also be used in thedetermination of thorium with EDTA.15' Datta 15* has carried outsimilar studies using dyes derived from 1 : 8-dihydroxy-2-(4-sulpho-l-naphthy1azo)naphthalene-3 : 6-disulphonic acid (SNADNS).Certain ofBanerj ee 156 uses145 J. Patton and W. Reeder, AnaZyt. Chem., 1956, 1026.146 K. L. Cheng, Ckemist-AnaZyst, 1956, 45, 79.14' I. Saj6, Magyar KLm. FoZydirat, 1956, 62, 176.14* P. Wehber, 2. analyt. Chem., 1956, 149, 161.140 Idenz, ibid., 150, 186.150 H. Flaschka and H. Abdine, Cheinisf-Analyst, 1956, 45, 2.151 Idem, Mikrochim. Ada, 1956, 770.lS2 K. L. Cheng and R. H. Bray, AnaZyt. Chem., 1955, 27, 782.153 H. FIaschka and H. Abdine, ChemiskAnaZyst, 1956, 45, 58.lb4 K. L. Cheng and T. R. Williams, ibid., 1955, 44, 96.155 K. L. Cheng, Analyt. Chem., 1955, 27, 1582.lb6 G. Banerjee, 2. analyt. Chem., 1955, 147, 105.lS7 Idem, ibid., 148, 349.15* S. K. Datta, ibid., 1966, 149, 328348 ANALYTICAL CHEMISTRY.these substances give lakes with thorium, which facilitate its complexometricdetermination.Standardisation.-Singh and Singh 159 have recommenced diethylenetetra-ammonium sulphatocerate as a suitable oxidimetric standard.It is readilyprepared and shows no tendency to decompose. It has a very high equiv-alent weight (774.7) and has the formula (NH,*CH,*CH,*NH,)2Cl(S04)4,7H20.Singh and Singh use O.O2~-solutions of the substance in 2~-sulphuric acid,but make no mention of its solubility. In the Reporter's experience, it ispossible to dissolve only 20 g. of the substance in 1 1. of 2~-acid, whichrestricts the use of the reagent to O.O2~-solutions. Nevertheless, the reagentshould prove an extremely valuable one as no satisfactory primary standardcontaining cerium( 1v) has hitherto been recommended.Dipyridinezinc dithiocyanate [Zn(C,M,N),] (SCN), can be prepared in apure state.Because of its purity, stability, and high equivalent weight itis recommended as a standard for EDTA solutions.160Standard solutions of iodate, approximately 0 - 0 1 ~ and accurate to threesignificant figures, can be prepared by saturating distilled water withbarium iodate at constant temperature. Barium iodate monohydratecan be obtained in a very pure state. Saturation occurs within 1 hour at 25".Duval and co-workers 162 have continued the therniogravimetric studyof analytical standards. The substances examined include barium hydr-oxide, boric acid, arsenious oxide, potassium sulphate, and sodium tungstate.Sant 163 recommends arsenious oxide-an established standard-as aprimary standard for the iodometric determination of barium and lead afterprecipitation as the chromates.Ion-exchange resins have been used to prepare carbonate-free solutionsof strong bases 164 and of alkali-metal, alkaline-earth metal, and tetra-alkylammonium hydroxides 165 for use in titrimetry.Standard solutionsof nitric, sulphuric, and hydrochloric acids can be readily prepared by pass-ing aqueous solutions of known weights of the appropriate salts through acation exchange column and diluting the eluates to a known volume.lG6The upper limit of concentration recommended for solutions prepared in thisway is 0.25~.The classical acidimetric standard, sodium carbonate, has recently beenthe subject of much controversy.Balk and his co-workers 167 find that thevariation between six different commercial samples of sodium carbonate ofthe highest quality when checked against 1N-sulphuric acid as a referencestandard is less than 1 part in 1000. Because 01 uncertainties in the ignitiontemperature of sodium hydrogen carbonate to form sodium carbonate, doubthas been cast on the reliability of sodium carbonate as a primary standard.159 B. Singh and S. Singh, Analvt. Chem. Acta, 1956, 14, 109, 405.l60 B. BudeSinsk9, CoZZ. Czech. Chem. Comm., 1956, 21, 255.161 S. K. Yasuda and J. L. Lambert, Chemist-Analyst, 1956, 45, 50.lG2 C. Duval, C. Wadier, and Y . Servigne, AnaZyt. Chim. Acta, 1955, 13, 427.163 B. R. Sant, 2. analyt. Chenz., 1955, 148, 176.164 D. M.G. Armstrong, Claem. and Ind., 1055, 1405.165 E. Sandi, Magyar KLm. Folydirat, 1955, 61, 29.166 C. J. Keattch, Lab. Practice, 1056, 5, 208.167 E. W. Balis, L. B. Bronk, H. A. Liebliafsky, and H. G. Pfeiffer, Analyt. Chenz.,1955, 2'4, 1173BELCHER, SHERIDAN, STEPHEN, AND WEST. 349Desjobert and Petek,168 in fact, state that it is inadvisable to use ignitedsodium hydrogen carbonate as a reference standard and they recommendthe use of potassium carbonate obtained by ignition of potassium hydrogencarbonate. This has been accepted by chemical manufacturers in thiscountry, who supply reagents purified for volumetric standardisation. l 6 9The statement that sodium carbonate cannot be used as a working standardhas been refuted by the Analytical Chemists' Committee of ImperialChemical Industries Limited.170 In its experience accurate results can beobtained by using sodium carbonate prepared by heating the sesqui-carbonate to 270".Williams has reviewed the applications of primary standard substancesin micro-volumetric analy~is.17~Reagents.-Amongst the newer titrimetric reagents, ascorbic acid con-tinues to find use as a reducing titrant.Japanese workers 172 describe thedifferential titration of iron(II1) , copper(II), and vanadate. The last can betitrated directly with ascorbic acid, diphenylamine being used as indicator.Gopala Rao and Narayana Rao 173 give the best conditions for preparingstable solutions of ascorbic acid. In a subsequent paper,li4 the reductionof mercury(I1) chloride is described. Erdey and Svehla 175 use ascorbicacid for the determination of ferricyanides at pH 5-6.2 : 6-Dichloro-phenolindophenol can be used as indicator. Iridium(Iv), in the form ofits complex chloride, can be determined by reductometric titration withascorbic acid and diphenylamine as i n d i ~ a t 0 r . l ~ ~ Macdonald 177 hasreviewed the applications of ascorbic acid as a reductant in titrimetry.Erdey, Bodor, and Buzh 178 describe the rapid direct titration of vanadicacid with ascorbic acid using Variamine-blue as indicator ; an indirectprocedure involving iron@) can also be applied to the determination ofvanadium. 179Quinol solutions have been recommended as reductometric reagents.180The solutions are stable even at the low concentration of 0 . 0 0 1 ~ ~ and arereadily standardised by titration with dichromate.An excess of iron(m)does not interfere, since for some unknown reason it is not reduced by quinolunder the conditions of the determination.Solutions of cobalt(m) in dilute sulphuric acid have been investigated aspossible oxidising titrants for iron@) , cerium(II1) , arsenite, oxalate, peroxide,and f errocyanide.16* A. Desjobert and F. Petek, Analyt. Chim. Acta, 1956, 14, 19.lBS Hopkin and Williams Ltd., " P.V.S. Reagents for Volumetric Standardisation,"170 Chem. a i d Ind., 1956, 346.171 M. Williams, INd. Chem. Mfr., 1956, 32, 442, 492.17* C. Yoshimura and T. Fuzitani, J . Chem. SOC. Japan, Pure Chem. Sect., 1955,76,304.173 G. Gopala Rao and V.Narayana Rao, 2. analyt. Chem., 1955, 147, 338.174 G. Gopala Rao and U. Veereswara Rao, ibid., 1956, 150, 29.175 L. Erdey and G. Svehla, ibid., p. 407.176 N. K. Pshenitsw and I. V. Prokof'eva, Izvest. Sektora Platinydrug. blugorod.Metal., Inst. obshchei neorg. Khim., 1955, 176.17' A. Macdonald, Ind. Chem. Mfr., 1956, 32, 545.17* L. Erdey, E. Rodor, and I. BuzAs, Acta Chim. Acad. Sci. Hung., 1955, 7, 277.17D Idem, ibid., p. 287.l a l C . E. Briclier and L. J. Loeffler, Analyt. Chem., 1955, 27, 1419.1955, 7.V. Simon and J. Zyka. ColE. Czech. Chem. Comm.. 1956. 21. 327350 ANALYTICAL CH E MIISTRY.Methods.-Few acid-base methods have been reported during the year.RrandStetr la2 describes the acidimetric determination of hydrazine hydrate,but variable results are obtained as a result of decomposition of the hydrazine.Beryllium lS3 can be determined by acidimetric titration after neutralisationof the solution to phenolphthalein and addition of sodium fluoride.Inter-ference of common ions is prevented by addition of sodium tartrate. Rosen-thaler 184 has continued his studies of bromine-acidimetric methods. Hispresent paper describes the determination of phosphorous acid, hypo-phosphite, sulphurous acid, and thiourea. The sample is oxidised withbromine, and the liberated acid is titrated with standard alkali.Precipitation reactions continue to find use in titrimetric analysis. Theferrocyanide titration of cadmium 185f 186 and manganese 187y lS8 has beendescribed ; o-dianisidine, diphenylamine, and 3 : 3'-dimethylnaphthidineare used as indicators.A simple procedure is given for the titration of leadwith molybdate using diphenylcarbazone as indicator. la9Barium is determined by titration with sodium lauryl sulphate; lgo anexcess of the reagent is added and the barium salt is filtered off, the excessbeing determined by titration with a quaternary ammonium salt usingmethyl-yellow-chloroform as indicator. The procedure can also be usedfor the determination of ~u1phates.l~~Most of the literature on titrimetric analysis concerns coniplexometricand redox titrations. It is not practicable to consider all of these methods inany detail, nor indeed to mention all of them. Nevertheless, an attempt ismade in this Report to select the more important methods.The recentpublications concerning chelatometric titrations are concerned mainly withthe application of established procedures to particular problems, particularlyin the analysis of alloys, ores, natural salts, paints, pigments, etc. Fewcomprehensive reviews have appeared ; Flaschka cites 183 references inhis review of the use of complexones in analysis,lg2 and Yatsimirskii lg3 givesa review of the subject with 181 references. Comparable reviews have notappeared in English. The copper(I1)-EDTA system has been studied byBelcher, Gibbons, and West and by Wehber.lg5 The last worker usesVariamine-blue B as indicator, in the presence of an excess of thiocyanate.Milner and Edwards determine zirconium in its binary alloys with niobiumand tantalum by an indirect procedure; Fritz and Johnson Ig7 also describela* J.Brandgtetr, C'hcm. Zvesti, 1964, 8, 261.ls3 V. K. Zolotulihin, Trit@y Konzissii Anal. Khim. Akad. Nnuk, S.S.S.H.. l!Ki4, 5 ,l a 5 H. Basiliska, Wiadoin. Chem., 1953, 7, 284.la6 G. A . Segar, Analyst, 1956, 81, 65.187 I. Saj6, Magyar Kbm. Folydirat, 1955, 61, 196.188 K. L. Cheng, Analyt. Chem., 1955, 27, 1594.l a g T. 1;. Dubrovskaya and N. A. Fillipova, Zavodskaya Lab., 1955, 21, 523.lg0 J. I<. Gwilt, J . Appl. Chem., 1955, 5, 471.101 W. Davey and J. R. Gwilt, ibid., p. 474.192 H. Flaschka, Fortschi/. Chem. Forsch., 1955, 3, 253.193 K. 13. Yatsimirkii, Zavodskaya Lab., 1955, 21, 1149.194 K. Belcher, D. Gibbons, and T. S. West, Analyt.Chim. A d a , 1955, 13, 226.lQ5 P. Wehber, Mikrochim. Acta, 1955, 927; 2. analyt. Chem., 1956, 149, 244.196 G. W. C . Milner and J. W. Edwards, Analyt. Cham. Acta, 1955, 13, 230.1 8 7 J . S. Fritz and M. Johnson, AnnZyt. Chem., 1955, 27, 1653.224.L. Rosenthsler, Pharm. Acta Helv., 1955, 30, 332RELCHEK, SHERIIJAN, STEPHEN, AND WEST. 35 Ithe indirect determination of zirconium using bismuth in the back-titration.Iron can be determined at pH 1.7-3.0 by using Variamine-blue asindicator.lg8 Flaschka and Sadek 199 use bismuth nitrate and catechol-violet for the indirect complexometric determination of indium, gallium,iron, and thorium at pH 2-3. Takamoto 2oo uses the cobalt thiocyanate-acetone complex as indicator in the titration of cobalt(@ with EDTA.The method can be applied to the indirect determination of several heavymetals with EDTA.Brunisholz and Cahen 201 titrate the rare-earthcations with EDTA in slightly acid solution, using sodium alizarin-sulphonate and methylene-blue as indicator. The titration of nickel hasbeen examined; ter Haar and Bazen 202 find slight interference from cobaltat pH 2.8, but Flaschka and Puschel 203 carry out the titration at pH 2 at 0".Under these conditions the Ni-EDTA complex is stable and will notreact with bismuth ions used to titrate the excess of EDTA. Otherdeterminations of metals include that of aluminium in 205 nickel,magnesium, zinc, and manganese in the presence of titanium,?06 gallium,207gallium in flue dust ,208 calcium in nickel-base alloys,209 aluminium, lead,and zinc in bronze and brass,210 and magnesium in nodular cast-iron.211Eschmann and Brochon 212 determine phosphate by precipitation ofmagnesium ammonium phosphate at pH 9 with 2-aminoethanol; themagnesium in the precipitate is determined by titration with EDTA.Similarly, pyrophosphate 213 can be determined in the presence of ortho-and trimeta-phosphates by precipitating zinc pyrophosphate at pH 3.8-3.9and titrating the zinc with EDTA.Jankovits 214 suggests the use of triphosphoric acid as a complexingtitrant. The solution is stable for about 10 days but quantitative complex-formation takes place only in very dilute solutions.Calcium and magnesiumcan be titrated at pH 10-11 by using Eriochrome-black-T as indicator.Numerous titrimetric procedures involving redox processes have beendescribed.The titrimetric determination of iron(m) has been studied byseveral workers. Iron in the presence of copper and other interfering ionshas been determined by photochemical reduction with sodium ~ x a l a t e . ~ l ~ * 216Small amounts of iron(I1) are determined cerimetrically without interference19* L. Erdey and G. Rfidy, 2. analyt. Chern., 1956, 149, 250.loo H. Flaschka and F. Sadek, ibid., p. 345.200 S. Takamoto, J . Chem. SOC. Japan, Pure Chem. Sect., 1955, 76, 1339.201 G. Brunisholz and R. Cahen, Helv. Chim. Acta, 1956, 39, 324.202 K. ter Haar and J . Bazen, Analyt. Chim. Acta, 1956, 14, 409.%03 H. Flaschka and R. Puschel, 2. analyt. Chem., 1955, 147, 354.204 C.Elliot and J. W. Robinson, Analyt. Chim. A c f a , 1955, 13, 236.) 0 5 Idem, ibid.. p. 309.%06 B. M. Dobkina and E. I. 'Petrova, Zavodskaya Lab., 1956, 22, 525.~7 T. V. Cherkashina, ibid., p. 276.?08 J. Doleial, V. Patrovskq, 2. Sulcek, and J. Svasta, Chem. Listy, 1965, 49, 1517.zo9 V. E. Bukhtiarv, Zavodskaya Lab., 1955, 21, 1042.210 J. Kinnunen and B. Merikanto, Chemist-Analyst, 1955, 44, 75.%11 H. Green, J . Brit. Cast Iron Res. ASSOG., 1955, 6, 20.212 H. Eschmann and R. Brochon, Chemist-Analyst, 1956, 45, 38.T. Kato, Z. Hagiwara, and R. Shinozawa, Japan Analyst, 1955, 4, 486.$14 L. Jankovits, Acta Chim. Acad. Sci. Hung., 1956, 8, 355.%15 M. N. Sastri and L. Subbaraya Sarma, 2. anorg. Chem., 1955, 281, 221.216 M. N. Sastri and C.Kalidas, 2. analyt. Chew., 1956, 149, 181352 ANALYTICAL CHEMISTRY.from arsenic(II1) and antirnony(~~~).~l~ Sodium hypophosphite is proposedas a reductant for iron(II1) ; reduction to iron@) occurs on boiling the acidsolution ( 2 ~ ) for 15-20 minutes.218 The oxidation of iron(I1) in acid-freesolutions by permanganate has been studied.219 The mechanism of theaction of the Zimmermann-Reinhardt reagents has been studied. Boraxand sodium acetate are as effective in the titration of pure iron solutions,but in the analysis of iron ores, a mixture of sodium sulphate and potassiumfluoride is preferred.220In IN-sulphuric acid, uranium(v1) is rapidly reduced by ethanol whenexposed to sunlight or ultraviolet light. Standard sodium vanadate is usedto titrate the uranium(1v) since other oxidants react with the excess ofethanol.221 The uses of vanadium salts in titrimetry have been discussedin a recent review by Macdonald.222 Uranium(1v) can be oxidised touranium(v1) by alkaline iodine; the solution can be acidified, and theexcess of iodine determined by titration with t h i o s ~ l p h a t e . ~ ~ ~ In the pre-sence of telluric acid, manganese(1v) is stabilised in alkaline solution and aprocedure has been developed for the determination of manganese based onthis fact ; 224 the subsequent reductometric titration of the manganese(1v)solution is carried out by using oxalic acid.Iodine chloride catalyses the reduction of vanadium(v) by arsenic(II1)and enables vanadium(v) to be determined titrimetrically.The excess ofarsenic(m) used in the reduction is titrated with standard potassiumbr0mate.~~5Thiosulphate solutions acidified with boric acid can be titrated directlywith iodine using starch indicator, even after standing for 30 minutes.Boric acid can also be used for acidifying the iodine solution, but not foriodid+iodate solutions, because no iodine is liberated.226Bitskei 227 describes the use of sodium hypochlorite and thiosulphatesolutions in oxidimetric determinations in alkaline solutions. Sulphides,cyanides, thiocyanates, and hydrogen peroxide are determined by oxidationwith an excess of sodium hypochlorite; the same volume of sodium thio-sulphate solution is added and the solution is then titrated with sodiumhypochlorite, brazilin being used as indicator.In a later paper, Bitskei 228describes the determination of hydrogen peroxide by oxidation with sodiumhypochlorite; arsenious acid is used in place of sodium thiosulphate.Selenium can be determined by reduction of selenious acid to seleniumby an excess of hydrazine sulphate; the excess of hydrazine is titrated with217 A. Petzold, 2. analyt. Chem., 1956, 149, 250.21* M. N. Sastri and C. Radakrishnamurti, ibid., 1955, 147, 16.z19 I?.-E. Raurich Sas and M. Castillo Cofino, Inf. Quim. A n d . , 1956, 10, 9.z2* K. M. Somasundaram and C . V. Suryanarayana, Acfa Cham. Acad. Sci. Hung.,221 G. Gopala Rao, V. P. Rao, and N. C. Venkatamma, 2. analyt. Chew., 1956,150,z22 A. Macdonald, Ind. Chem. Mfr., 1956, 33, 280, 332.Z z 3 G.S. Deshrnukh and M. K. Joshi, Bull. Chem. SOC. Japan, 1955, 28, 449.224 I. M. Issa and I. F. Hewaidy. Ghemist-Analyst, 1955, 44, 70.?z5 G. S. Deshmukh and M. G. Bapat, 2. annlyt. Chem., 1955, 148, 347.Z z 6 E. A. Kotsis and V. Bizam, Magyar Ii%n. Folydirat, 1955, 61, 17.227 J. Bitskei, ibid., p. 406.z 2 8 Idem, Acla Chim. Acad. Sci. Hung., 1955, 8, 203.1956, 8, 423.175BELCHER, SHERIDAN, STEPHEN, AND WEST. 353potassium iodate to the iodine monochloride e n d - p ~ i n t . ~ ~ ~ Standardsolutions of hydrazine sulphate ( 0 . 1 ~ ) can be prepared from the pure solid.The solutions are stable and can be used for the reductometric titration ofa number of oxidants.230Reductor methods continue to find application in titrimetry. Molyb-denum(v1) is reduced to molybdenum(v) by the bismuth reductor; re-oxidation is effected with standard permanganate or vanadate s o l u t i o n ~ .~ ~ ~Yoshimura 2s2 uses metallic antimony and nickel as reducing agents. Anti-mony reduces iron(rI1) , tin(1v) , titanium(1v) , uranium(vI), and tungsten(v1)in acid solution, but heating is necessary. Nickel can replace lead as areductor, but the colour of the nickel ions produced in the solutions is adisadvantage. Yoshimura 233 also describes the reduction of antimony(v)to antimony(I1) using liquid zinc amalgam in SN-sodium hydroxide in thepresence of sodium pyrophosphate. Uranium(v1) , vanadium(v) , andmolybdenum(v1) can be similarly reduced. Reduction is slower in weakeralkali.The cerimetric determination of pliosphite and hypophosphite has beenstudied ; 234 Bernhardt's method 235 gives irregular results and heating to110" is necessary.However, in the presence of silver sulphate, oxidationproceeds smoothly at the temperature of a boiling-water bath. Sastri andKalidas 236 use a similar method for the determination of hypophosphite ;oxidation is effected at 100" in the presence of silver sulphate. Again,Bernhardt's findings are contradicted. Alternatives to the cerimetricmethods involve Oxidation with permanganate 237 or with d i c h r ~ m a t e . ~ ~ ~Carlyon 239 has made an exhaustive study of the oxidimeti-ic determinationof hypophosphite, phosphite, and hypophosphate.Ceric sulphate can be titrated with mercurous perchlorate by usinggold(II1) chloride as catalyst and N-phenylanthranilic acid as indicator.In 0.5-6~-sulphuric acid, the reaction is stoicheiometric.2'K) The deter-mination of hypobromite solutions can also be effected by using mercury(1)solutions.241 Permanganate is also reduced by mercury(1) in 1--3~-sulphuricThe hydrolysis of beryllium sulphate in a mixture of potassium iodideand iodate is used for the iodometric determination of beryllium.243 Theoxidimetric determination of sulphite has been studied by Indian workers.24422B B.Suseela, 2. analyt. Chem., 1955, 147, 13.230 J. Sjrka and J. Vulterin, CoZZ. Czech. Chent. Comm., 1955, 20, 804.231 E. B. Ankudimova, Trudy Komissii Anal. Khim. Akad. Nauk, S.S.S.R., 1954,232 C. Yoshimura, J . Chem. SOC. Jafan, Pure Chem. Sect., 1955, 76, 409.233 Idem, ibid., p.411.234 K. B. Rao and G. Gopala Rao, 2. nnalyt. Chem., 1955, 147, 274.235 D. N. Bernhardt, AnaZyt. Chem., 1954, 26, 1798.23G M. N. Sastri and C. Kalidas, Rec. Trav. chim., 1955, 74, 1045.2 3 7 D. Koszegi and E. Salg6, 2. analyt. Chem., 1956, 150, 262.238 G. Gopala Rao and K. B. Rao, ibid., p. 333.239 S. J. Carlyon, Diss. Abs., 1955, 15, 2401.250 V. M. Tarayan and M. G. Ekimyan, Nauch. Trudy Erevansk. Univ., 1954,4, 87.241 V. M. Tarayan and E. N. Ovsepyan, ibid., p. 77.242 V. M. Tarayan, ibid., p. 65.2p3 B. Suseela, Zhur. annlit. Khim., 1955, 10, 286.244 1< B. Rao and G. Gopala Rao, Analyl. Chim. Acta. 1955, 13, 313.REP.-VOL. LIII &I5, 197354 ANALYTICAL CHEMISTRY.No persulphate is formed if an excess of potassium permanganate is addedto the solution of the sulphite in the presence of a dilute solution of coppersulphate.Baker and McCutcheon 245 describe the redox determination ofcobalt(II1) and total cobalt in the presence of excess tungstate, using amodification of Sarver's method. When the ratio of tungsten to cobalt isless than 12.5 by weight, diphenylaminesulphonate can be used as indicator ;otherwise, suitable indication of the end-point can only be obtained potentio-metrically. Hara 246 determines periodic acid in the presence of iodic acidby titrating the mixture directly with vanadyl sulphate ; in 10N-sulphuricacid, manganous sulphate is quantitatively oxidised to permanganate byperiodic acid whilst iodic acid has no adverse effect on the reaction.Thedetermination of ammonium salts by oxidation with hypobromite (preparedin situ from 0-1N-potassium bromate and potassium bromide) has beeninvestigated; the method is accurate to *0.09%.24i '4 new iodometricmethod for the determination of gold involves treatment of the gold(rr1)chloride with sodium chlorite ; chlorine dioxide is liberated and is carriedover from the reaction vessel in a stream of carbon dioxide and absorbedin a solution of potassium iodide. The liberated iodine is determined bytitration.248Japanese workers describe the reduction of copper( 11) and iron(m)adsorbed on a column of Amberlite I.R. 180 (H) resin by a solution ofpotassium iodide.249 Reduction is quantitative and the liberated iodine inthe eluate is titrated with sodium thiosulphate.?V.I. s.Classical Organic AnalysisThe advantages of the " empty tube " technique for carbon and hydrogendeterminations have been reviewed, and improvements, based on severalyears of experience, have been suggested.250 The determination of otherelements is also discussed. The procedure has been adapted to the semi-m i ~ r o - s c a l e . ~ ~ ~ An oxygen flow of 150 ml. per minute is used, and a totaltime of 15 minutes. It is necessary to use a larger amount of manganesedioxide for the absorption of nitrogen oxides than on the micro-scale.Carbon, hydrogen, and nitrogen have been determined simultaneouslyby heating the sample covered with copper oxide in an evacuated system.252Water and carbon dioxide are condensed in traps cooled by solid carbondioxide and liquid air respectively.The pressure due to nitrogen is measuredmanometrically and the system is re-evacuated. The liquid air is replacedby water and the carbon dioxide pressure is measured. After furtherre-evacuation the solid carbon dioxide is replaced by water and the pressuredue to water vapour is measured.245 L. C. W. Baker and T. P. McCutcheon, Analyt. Chew., 1956, 27, 1625.246 S. Hara, Japan Analyst, 1956, 5, 163.947 D. Koszegi and g . Salgb, Actu Chim. Acad. Sci. Huiig., 1956, 7, 333.24* C . 33. Riolo and E. Garrini, Ann. Chim. (Italy), 1955, 45, 767.E49 H. Kakihana and K. Katou, J . Chem. Soc. Japan, Pure Chew. Sec., 1955, 76, 499.250 G. Ingram, Chem.and Ind., 1956, 103.251 G. Ingram and M. Lonsdale, ibid., p. 276.z 5 2 W. Schoniger. H P ~ . Chzm. Ado, 19.56, 39, 650BELCHER, SHERIDAN, STEPHEN, AND WEST. 355Carbon, hydrogen, and silicon can be determined simultaneously byigniting the sample in a tube containing chromium oxide-asbestos catalyst,which is placed inside the combustion The increase in weight ofthe tube containing the catalyst is due to silica; carbon and hydrogenare determined by the usual methods.In a new method carbon is determined by heating the compound withbarium nitrate, and determining the carbonate formed.25qThe properties of silver permanganate have received further study, andthe observation has been made yet again that it will absorb sulphur dioxideand nitrogen oxides at room temperature.255 It is now recommended ascatalyst in the determination of carbon and hydrogen,256 the advantagebeing claimed that a working temperature of 450" is adequate.An apparatus for the controlled combustion of spontaneously inflammablegases has been described.257 A number of improvements on the conventionalcarbon and hydrogen apparatus has been proposed by C h a r l t ~ n .~ ~ ~Kainz and ScholJer 259 recommend spongy nickel as a means of reducingnitrogen oxides. A layer 7 cm. long serves for 15-20 analyses and is thenregenerated by reduction in hydrogen.Studies have been continued with the object of improving the methodfor direct determination of oxygen. Drehkopf and Braukmann 260 recom-mend a shorter packing of activated carbon so that side-reactions areminimised.Instead of the usual iodometric finish, the carbon dioxideproduced is passed into a sodium hydroxide solution and the change inconductivity is measured. Other modifications have been proposed byHintermaier and Griiztner.261 These include the use of porcelain in placeof the quartz tube and special purification of the nitrogen. Canales andParks 262 use a palladium thimble heated to 350°, and copper gauze heatedto gooo, to remove compounds of sulphur and hydrogen formed duringpyrolysis of the sample. An amperometric titration is recommended forcompleting the determination.The Ter Meulen hydrogenation method for determination of oxygen hasbeen modified and applied to the analysis of some organic compounds andvarious carbons.263 The accuracy appears to be less than that of theSchiitze-Unterzaucher procedure.A new method for the determination of oxygen has been advanced basedon decomposition of the sample mixed with strontium oxide and graphiteZ53 V.A. Klimova, M. 0. Korshun, and E. G. Bereznitskaya, Z h w . analit. Khiitz.,254 T. S . Lee and R. Meyer, Analyt. Chim. Actn, 1955, 13, 340.255 J. Korbl, Coll. Czech. Chem. Comm., 1955, 20, 948; cf. R. Belcher, J . SOC.Chem. Ind., 1945, 64, 111 : R. Belcher and G. Ingram, Analyt. Chim. Acta, 1950, 4, 401.258 J. Korbl, Coll. Czech. Chem. Comm., 1955, 953, 1026; J. Korbl and K. Blabolil,ibid., 1956, 21, 318.257 H. B. Bradley, Analyt. Ghem., 1955, 27, 2021.26B F. E. Charlton, Analyst, 1956, 81, 582.250 G.Kainz and F. %holler, 2. ana2yt. Chem., 1955, 148, 6.180 K. Drehkopf and B. Braukmann, Bremstoff. Chem., 1955, 36, 203.A. Hintermaier and R. Griiztner, Mikrochim. A d a , 1956, 944.269 A. M. Canales and T. D. Parks, Analyt. Chim. Acta, 1956, 15, 25.283 R. N. Smith, J . Duffiield, R. A. Pierotti, and 1. Mooi, Analzit. Chem., 1956, 28,1956, 11, 223.1161356 ANALYTICAL CHEMISTRY.in a nickel bomb or sealed tube."* Carbonate is formed and is determinedtitrimetrically. The method is applicable only to compounds containingcarbon, hydrogen, and oxygen.A further new method has been described in which the sample is decom-posed in an oxygen bomb and the change in pressure is measured mano-metrically.264 Corrections are necessary when nitrogen and sulphur arepresent.The method of Marcali and R i e ~ n a n , ~ ~ ~ which avoids distillation byapplication of the well-known formaldehyde titration procedure, has beenmodified so that selenium may be used as catalyst.266 After digestion,elemental selenium is precipitated by sulphurous acid and excess of thelatter is boiled out.The titration is then done in the usual way. Inanother method which eliminaies distillation, decomposition is effected inthe presence of mercury catalyst, the solution is neutralised, and theammonium salt is titrated with standard sodium hypochlorite solution.267Chromous sdphate or chloride has been used for the reduction of nitro-groups before applying the conventional Kjeldahl procedure.268 Thereaction is instantaneous. When the reagent was applied to the reductionof azobenzene, recoveries were low.Several new procedures for the determination of sulphur have beendescribed.Iritani and Tanaka 269 heat the sample with fuming nitric acidin a sealed tube for 5 hours at 250". The excess of nitric acid is evaporatedoff and the sulphate is titrated with standard barium chloride solution.Sodium rhodizonate test-paper is used to detect the end-point. Tanaka 270uses a similar decomposition method, but treats the solution with bariumchromate. The chromate liberated, which is equivalent to the sulphatepresent, is titrated with a standard solution of Mohr's salt.In a further modification of the Carius method the sample is decomposedin the presence of barium c h l ~ r i d e .~ ~ l The barium sulphate formed iswashed and treated with an ion-exchanger pretreated with hydrochloric acid.Sulphuric acid is produced and is determined alkalimetrically.Rosenthaler272 determines sulphur in a wide variety of substances byoxidation with sodium hypochlorite at room temperature for 12 hours.Sulphate is finally precipitated as barium sulphate and weighed as such.Oxidation with nitric-perchloric acid mixtures has again been examined ;the sulphate formed is reduced to sulphide and determined iodometrically.Recoveries ranged from 98-7 to 101~4%.~'~Korbl and Piibil 274 absorb sulphur oxides in the catalytic mixture(approximating to silver oxide and manganese dioxide) formed by thermal264 J . W. Whitaker, R.N. Chakravorty, and A. K. Ghosh, J . Sci. Ind. Res., India,1956, B, 15, 72.m5 K. Marcali and W. Rieman, Iwd. Eng. Chem. Anal., 1948, 20, 381.266 C. I. Adams and G. 13. Spaulding, ibid., 1955, 27, 1003.267 R. Belclier and M. K. Bhatty, Mikrochim. Acta, 1956, 1183.268 Idem, Analyst, 1956, 81, 124.268 N. Iritani and Y . Tanaka, Kunzamoto Pharm. Bull., 1955, 30.270 Y . Tanaka, J . Pharm. Soc., Japan, 1955, 75, 653.2 7 1 J. Smith and A. C. Syme, Analyst, 1956, 81, 302.272 L. Rosenthaler, Pharm. Acta HeEv., 1956, 30, 282.273 P. 0. Bethge, Analyt. Chem., 1956, 28, 119.274 J. Korbl and R. Piibil, CoEZ. Czech. Chem. Comm., 1056, 21, 315BELCHER, SHERIDAN, STEPHEN, AND WEST. 357decomposition of silver permanganate. Silver sulphate is formed.I t isconverted into metallic silver and an equivalent amount of manganoussulphate by the addition of urea-hydrogen peroxide. Manganese is thentitrated complexometrically with EDTA in the usual way.Chlorine, bromine, and iodine have been determined by potentiometrictitration after the conventional catalytic combustion procedure.275 Clark'ssilver-amalgamated silver electrode system 276 is recommended. Ionisablehalogen is determined directly in ethanolic solution. A precision of 0.3%can be obtained with 1 - 4 mg. of asmple.Inglis 277 prefers to decompose the sample in a Parr micro-bomb. Thehalide is titrated potentiometrically, a platinum indicator electrode and amercury-mercurous sulphate reference electrode being used.A modified Stepanow procedure has been described.278 The compoundis refluxed with a 15% solution of ethylene glycol in isobutyl alcohol in thepresence of metallic sodium.Halide is then titrated mercurimetrically,diphenylcarbazone being used as indicator.Mercury in organic compounds has been determined by refluxing thesample with hydriodic acid containing iodine; HgI,2- is formed and isprecipitated and weighed as propylenediaminecupric merc~ri-iodide.~~~For the determination of acetyl or benzoyl groups, Tani and Nara280recommend saponification of 4-10 mg. of sample with 1 ml. of S~-sodiurnhydroxide solution and 2 ml. of ethanol. The solution is then passedthrough a column of Amberlite 1.R.-120 (H) resin and the eluate containingacetic or benzoic acid is titrated with 0.01N-alkali.The N-methyl determination has been improved.281 The vapours ofhydriodic acid and iodine, which are produced when N-methyl groups areconverted into quaternary ammonium salts, are trapped in a solution ofsodium thiosulphate.The error is then decreased to &0.3%. It shouldbe pointed out, however, that significant amounts of methyl iodide areabsorbed by this reagent282 and the increased accuracy may be due tocompensation of errors. Bethge and Carlson 283 have described an improvedapparatus for determination of alkoxyl groups. Various types of washsolution were compared. A spectrophotometric method for determinationof methoxyl has been proposed : 284 methoxyl is hydrolysed to give methanolwhich is then oxidised to formaldehyde; the latter is condensed withchromotropic acid and the intensity of colour is measured.Several reviews of developments in particular methods have beenR.B.276 E. C. Cogbill and J. J. Kirkland, AnaZyt. Chem., 1965, 27, 1611.2 7 6 W. Clark, J.. 1926, 749.z 7 ? J. Inglis, Mikrochim. Acta, 1955, 934.2 7 8 L. N. Lapin and R. K. Zamanov, Zhur. analit. Chem., 1955, 10, 364.2i3 H. F. Walton and H. A. Smith, AnaZyt. Chem., 1966, 28, 406.28" H. Tani and A. Nara, J . Pharm. Soc., Jafian, 1954, 74, 1399.R81 F. Sudo, D. Shimoe, and T. Tsujii, Japan Analyst, 1954, 3, 403.283 P. 0. Rethge and 0. T. Carlson, AnaZyt. Chim. Acta, 1956, 15, 279.284 M. I?. Mathers and M. J. Pro, Anal@. Chem., 1955, 27, 1662.285 J. E. Fildes, I n d . Chem., 1955, 31, 355, 412; cf.W. Schtlniger, MikrocAim. Ada,A. Slater, J., 1904, 85, 1286; cf. B. Saville, Chem. and Ind., 1956, 660.1956, 1456358 ANALYTICAL CHEMISTRY.Polarogr ap hyGeneral and Inorganic.-The conventional mercury pool and calomelelectrodes are not generally suitable as reference electrodes in continuouspolarography because they become polarised rather quickly. Two systemshave been described in which it is shown that a dropping-mercury electrodecan function satisfactorily as a reference electrode.286 These methods wereapplied to the determination of carbon monoxide in air and to that of ironand titanium during the automatic control of a process for the preparationof titanium dioxide. The use of reference electrodes with soluble reactionproducts for the continuous analysis of various processes has been examinedby the same A gas-washed mercury pool has been used asindicator electrode for the continuous determination of oxygen in industrialgases in concentrations of <0.1% and for the determination of mercury ineffluents.2a8 An improved apparatus for the observation of current-voltage,reduction, and re-oxidation patterns in oscillographic polarography hasbeen described by Imai and his co-worker~.~~~- 290 Studies were carried outon the characteristics of the peak current and the peak potential of anirreversible d e p ~ l a r i s e r , ~ ~ ~ and on the influence of initial sweep voltage andhead of mercury on the irreversibility of the depolari~er.2~2 An oscillo-graphic polarograph with saw-tooth wave and electrochemical depolarisationof solid amalgamated electrodes by Skobets's short-circuiting method hasbeen de~cribed.2~~ Further application of the sensitive square-wave polaro-graph has been described by Ferrett and Milner.294 Methods for measuringthe wave height of polarograms have been discussed.295 Studies have beenmade of the effects of cell circuit resistance with stationary and droppingelectrodes 296 and of an instrument in which automatic cell voltage controlis used for the accurate determination of half-wave potentials.297 Micro-molar solutions have been investigated by using a mercury-pool cathode instirred s0lutions.~~8 An electrode surface of 3 sq.cm. gave a sensitivity300 times greater than that obtained with a dropping cathode using the samecircuit.Considerable attention continues to be paid to the properties of varioussupporting electrolytes and the merits of various solvents.Thus, reportshave appeared on tetramethylammonium chloride,2N trimetliylphenyl-ammonium hydroxide,3O" hydrazine, pyridine, thiocyanate, pyrophosphate,2a8 J. V. A. NovBk, Coll. Czech. Chem. Comm., 1955, 20, 1076.287 Idem, ibid., p. 1090.288 Idem, Chem. Listy, 1955, 49, 1476.290 M. Shinagawa and H. Imai, ibid., p. 187.291 H. Imai, ibid., p. 530.292 Idem, ibid., p. 583.293 I. I. Tsapiv, Zhur. analit. Khim., 1966, 11, 63.294 D. J . Ferrett and G. W. C. Milner, Analyst, 1966, 81, 193.295 R. S. Subrahmanya, J. Indian Inst. Sci., A , 1956, 38, 26.296 M. M. Nicholson, Analyt. Chem., 1965, 27, 1364.297 R.L. Pecsok and R. W. Farmer, ibid., 1956, 28, 986.298 D. J. Rosie and W. D. Cooke, ibid., 1965, 2'4, 1360.499 P. L. Pickard and W. E. Neptune, ibid., p. 1358.300 M. Friedrich, Chem. Lzsty, 1955, 49, 1241.M. Shinagawa, H. Imai, and S. Chaki, J. EZectrochem. SOC. (Japan), 1955, 23, 132BELCHER, SHERIDAN, STEPHEN, AND WEST. 359et~.,~Ol and on the polarography of various ions in ethanol 302 and ethylene-diamine.303 Japanese workers have investigated the polarography ofvarious cations in the presence of tetramethylammonium iodide,3a tri-phenylselenonium chloride,3o5 triphenyltelluronium chloride,mg dodecyl-trimethylammonium chloride,307 triphenylsulphonium chloride,3O8 andtriphenylphosphonium c h l ~ r i d e .~ ~ Tetrabutylammonium iodide has beenused as supporting electrolyte to permit the polarography of potassiunitetraphenylboron in di~nethylformamide.~~~ The reduction of nitrate atthe dropping electrode in the presence of the glycine complex of chromium(rI1)gives a new wave.311 Iodide, bromide, and sulphide have been determinedpolarographically in petr~leum-water.~~~Oscillographic polarography has been used for the detection of iron andcopper and for the determination of nickel in cobalt salts.313 Iron andcopper have also been determined in high-purity aluminium 314 and in zincand zinc alloys, along with cadmium and lead.315 Iron has similarly beendetermined with several other trace metals in refined copper.316 2 : 2’ : 2”-Trihydroxytriethylamine (triethanolamine) has been used to obtain well-defined waves for the determination of iron and manganese in cement andslags.EDTA was used to suppress the interference of large amounts ofcalcium and magnesium.317 The separate polarographic determination ofmanganese oxides of different valency has been described by a Russianauthor.318 Nickel has been polarographed with calcium chloride as support-ing electrolyte in the presence of pyridine or t h i ~ c y a n a t e . ~ ~ ~ The samesupporting electrolyte has been used for the determination of chromium inthe presence of nickel after suppressing the wave due t o the latter by additionof hydr~xylamine.~~~ Nickel has also been determined polarographically inantimony and tin alloys along with copper, cadmium, lead, and ~inc.~21The last element has been determined polarographically in magnesiumalloys,322 in copper ~ u l p h a t e , ~ ~ ~ and in the presence of aluminium.324 Cad-301 J.W. Grenier and L. Meites, Analyt. Chim. A d a , 1956, 14, 482.302 Ya. I. Turiyan, Zhuu. analit. Khim., 1956, 11, 71.303 J. Dolezal, Chem. Listy, 1955, 49, 1237.304 M. Shinagawa and H. Matsuo, Japan Analyst, 1964, 3, 114.~5 M. Shinagawa, H. Matsuo, and S. Isshiki, ibid., p. 199.306 M. Shinagawa, H. Matsuo, and H. Sunahara, ibid., p. 204.3u7 M. Shinagawa and H. Matsuo, ibid., 1955, 4, 213.308 M. Shinagawa, H. Matsuo, and N. Maki, ibid., 1956, 5, 80.31x2 M. Shinagawa, H. Matsuo, and H. Nezu, ibid., p. 20.310 A. F. Findeis and T. De Vries, Analyt. Chem., 1956, 28, 209.311 R.E. Hamm and C. D. Withrow, ibid., 1955, 27, 1913.312 N. Hemala, J. Marek, and 2. Valcikova, Ref. Zhur., Khim., 1956, Abstr. No. 4098.313 J. Dolezal and P. Hofmann, Chew. Listy. 1954, 48, 1610.y15 J. Dolezal and P. Hofmann, Chem. Listy, 1965, 49, 47.316 A. J. Eve and E. T. Verdier, AnaZyt. Chem., 1956, 28, 537.317 M. Pleva, Chem. Listy, 1965, 49, 262.318 V. S. Fikhtengol’ts, Zavodskaya Lab., 1955, 21, 1036.318 K. P. Privilova, Kh. 2. Avrutova, and N. Ya. Khlopin, ibid., p. 670.320 J. S. Beveridge, G. F. Reynolds, and H. I . Shalgosky, AnaZyt. Chim. Acta, 1955,321 T. V. Aref’eva and R. G. Pats, Ref. Zhur., Khim., 1956, Abstr. No. 7143.322 I. V. Izvekov and N. T. Movchan, ibid., 1955, Abstr. No. 14,207.325 J. W. Menary, Analyst, 1955, 80, 908.324 I.Rozsai, Magyar Kkm. Fol?ldirat, 1956, 62, 139.R. Neumann, 2. anorg. Chem., 1955, 279, 234.13, 494360 ANALYTICAL CHEMISTRY.mium has been determined similarly in zinc salts 325 and copper-containingzinc materials.326 A streaming-mercury cathode and 0.7~-tetramethyl-ammonium chloride base electrolyte gave good results for the polarographyof magnesium between pH 5.4 and 6.8.327 Potassium did not interfere withthis method but calcium and lithium did. Lead and thallium have beendetermined in metallic cadmium 328 by extracting the bromide of thalliumwith ether and polarographing it in aqueous ammonium sulphate solution.The unextracted lead was polarographed in 3~-hydrochloric acid in thepresence of the cadmium.The polarography of molybdenum after ion-exchange separation from interfering ions has been described. The deter-mination may be carried out in the presence of tungsten.329 Kolthoff andWatters's method for cobalt has been modified by Meites; 330 the method isapplicable in the presence of nickel. Antimony has been determined inglass by polarographing a solution of the sample in hydrofluoric acid andoxalic acid.331 The interference of arsenic in the polarographic determin-ation of antimony, and its elimination, have been Methods havebeen reported for the direct 333 and indirect 334 determination of selenium.Uranium has been determined in shale, etc., after extraction of uranylnitrate from the sample dissolved in perchloric acid-nitric a~id.33~ Platinumhas been determined by polarography in O-lN-nitrite solution by usingsolid platinum electrodes.336 The polarography of praseodymium withlithium chloride and tetramethylammonium iodide base-electrolytes hasbeen reported by Japanese workers." Square-wave polarography hasbeen used to study the behaviour of niobium in various complexing media,338and more conventional oscillographic technique to differentiate betweenniobium and titanium in 23~-sulphuric acid.339 Polarographic determin-ation of these two metals in ~ 6 0 % sulphuric acid has been studied byothers.=O Various authors have reported on the polarographic determin-ation of tin in ores,341, a2 in iron and steel,= and in metallic zinc 344 andzinc electrolytes.In the last case, lead and cadmium were simultaneouslydetermined, without using any separation techniques.326 N.I. Solontsev, E. M. Tal, 2. P. Lopatina, and E. I. Dubovitskaya, Ref. ZhZlY.,328 J. Dolezal and P. Hofmann, Chem. Listy, 1955, 49, 1026.327 K. Gyorbiro, L. Poos, and J. Proszt, Magyav I<Lm. Folydivat, 1956, 61, 102.328 T. V. Aref'eva, R. G. Pats, and A. A. Pozdnyakova, Ref. Zhur., Khim., 1956,329 R. L. Pecsok and R. M. Packhurst, AnaJyt. Cham., 1955, 27, 1920.330 L. Meites, ibid., 1956, 28, 404.881 J. P. Williams and T. A. Schwenkler, J . Amer. Ceram. SOC., 1955, 38, 367.332 G. Packman and G. F. Reynolds, Analyst, 1956, 81, 49.333 A. Cervenka and M. Korbovb, Chem. Listy, 1955, 49, 1158.334 H. Hahn and W. Kleinwort, 2. nnalyt. Chem., 1956, 151, 98.335 I<.Kaarik, Suomen Kern., 1966, B, 29, 1.336 hl. B. Bardin and Yu. S. Lyalikov, Zhur. aszalit. Khim., 1955, 10, 305.337 S. Misumi and A. Iwase, J . Chem. SOC. Japan, Pure Chem. Sect., 1955, 76, 1231.338 D. J. Ferrett and G. W. C. Milner, J., 1956, 1186.839 Ya. P. Gokhshtein, Zavodskuya Lab., 1966, 22, 38.340 E. I. Krylov and V. S. Kolevatova, ibid., 1955, 21, 91 1.341 D. L. Love and S. C. Sun, Analyt. Chem., 1955, 27, 1557.342 I. A. Blyum and N. G. Zyryanova, Zavodskaya Lab., 1956, 22, 46.343 H. Goto, S. Ikeda, and S. Watanahe, Jnpan Analyst, 1954, 3, 320.344 F. K. Baev and P. N. Kovalenko, Zavodskaya Lab., 1955, 21, 1170.Khim., 1956, Abstr. No. 7092.Abstr. No. 9099BELCHER, SHERIDAN, STEPHEN, AND WEST. 361Organic.-Considerations of space restrict the review of organic polaro-graphy in this Report to only a very brief survey of the many papers pub-lished during the period covered.Considerable work continues to be doneon the “ functional-group ” aspect of organic polarography. Thus, methodshave been published for the determination of saturated fattyaldehydes,346 carbonyl compo~nds,34~ azo-compounds,34* unsaturated com-p o u n d ~ , ~ ~ purine compounds,35o keto-~teroids,~~~~ 352 monohalogeno-acetones,3= etc. The anodic polarography of phenylenediamines hasbeen studied at a rotating platinum electrode. A semi-quantitative analysiswas obtained for mixtures of the 0- and @-diamine~.~a Methods for vitaminA,356 and thiamine in the presence of vitamin A,356 have been described.Morphine 357 and atropine 358 have also been determined polarographically.Ethyl nitrate and ethyl nitrite have been determined in aqueous solution.The solubility of ethyl nitrate was thus found to be ca.1.3% at Inthe field of polymer chemistry, polarography has been used to determinebenzoyl peroxide in poly(methy1 methac~ylate),~~ and phthalic anhydride inalkyd resins.361 Sulphur in organic compounds has been determined bytreatment with Raney nickel to form sulphide, which is then polarographedin sodium hydroxide. The presence of nitrogen does not interfere with thismeth0d.~*2 Polarography has been used to control the salting out ofproteins. The process depends on the presence of the tervalent cobaltAmperometric Titration.-The amperometric titration of various cationsin micromolar solutions ( 10-5-10-7~) using a mercury-pool indicatorelectrode in conjunction with EDTA as titrant has been des~ribed.~MThe electrode area was 1-2 sq.cm. and stirring was effected by nitrogen.The use of various organic reagents such as (‘ amidopyrine,” diantipyrinyl-methane, and diantipyrinylphenylmethane has been and alsothe use of more conventional reagents such as a-benzoin oxime, l-nitroso-%naphthol, 8-hydroxyquinolineJ and pyrogallol.366 Two- and three-ion .363345 s. Maruta and F. Iwama, J . Chem. SOL. Japan, Pure Chem. Sect., 1955, 76, 548.346 L. N. Petrova and E. N. Novikova, Zhur. priklad. Khim., 1955, 28, 219.347 W. Rogers and S. M . Kipnes, Amlyt. Chem., 1955, 27, 1916.34* G. DuSinsk? and 2.Gruntova, Cesk. Farm., 1955, 4, 445.349 A. V. Ryabov and G. D. Panova, Doklady Akad. Nauk, S.S.S.R., 1954, 99,350 N. G. Luthy and B. Lamb, J . Pharm. Pharmacol., 1956, 8, 410.351 C. J. 0. R. Moms, Rec. Trav. chim., 1955, 74, 476.352 D. M. Robertson, Riochcm. J., 1955, 81, 681.353 P. J. Elvingand R. E. Van Atta, Analyt. Chern., 1955, 27, 1908.354 R. E. Parker and R. N. Adams, ibid., 1956, 28, 828.355 W. Keller and F. Weiss, 2. analyt. Chem., 1955, 148, 26.356 A. M. Shkodin and G. P. Tikhomirova, UKraiTz. Rhim. Zhur., 1955, 21, 265.35i J. Holubek, Pharnz. Zentrallz., 1955, 94, 347.358 B. Novotng, Cesk. Favm., 1955, 4, 448.359 -4. Blyumberg and V. L. Pikaeva, Zhur. analit. Khim., 1955, 10, 310.3c0 T. Takeuchi, N. Yokouchi, and Y. Takayama, Japan Analyst, 1955, 4, 234.3 6 1 P.D. Garn and E. Mi. Halline, Analyt. Chem., 1966, 27, 1563.362 As. Trifonova, Ch. Ivanov, and D. Pavlov, Compt. rend., Acad. Bztl~. Sci., 1954,363 V. Kalous and J. Stokr, Chewz. Listy, 1955, 49, 565.364 3 . G. Nikelly and ‘IV. D. Cooke, AnaZyt. Chenz., 1956, 28, 243.365 A. A. Popel’, Uch. Zap. Kazansk. Uniu., 1955, 115, 69.3ti6 T. K. Musina and 0. A. Songina, Ref. Zhur., Khim., 1956, Abstr. No. 4090.547.7, 1362 ANALYTICAL CHEMISTRY.component mixtures, e.g., Bi-Ca-Pb, have been titrated with EDTA.367EDTA itself has been titrated amperometrically with zinc ions. By thismethod both total and available EDTA can be determined.368 Anthranilicacid has been used as titrant for various cations, e.g., cobalt,37OTitanium was titrated amperometrically with cup-ferron 3739 374 and bismuth by triphenylselenonium chloride 375 and potassiumiodide.376 Zirconium has also been titrated with cupferron 377 in thepresence of magnesium.Manganese and molybdenum in ferromanganeseand ferromolybdenum 378 have been determined amperometrically bytitration with ferrocyanide, and tungsten in ferrotungsten 379 by titrationwith 8-hydroxyquinoline. Amperometric methods for vanadium havebeen described in which vanadium(1v) and iron(I1) have been titrateddifferentially with ceric sulphate 380 and vanadium(v) has been titratedwith i r o n ( ~ ~ ) , ~ * l and in which an oxide electrode of high positive potentialhas been used for the titration of vanadate and chromate with iron(^^).^*^Triphosphate ion has been used for the titration of lead,383 cadmium,384 andnicke1.385 Silver ions have been titrated amperometrically with iodideion 386 and with the organic reagents mercaptophenylthiothiadiazolone andmercaptobenzothiazole.387 Thallium has been determined by the anodicbromide method 388 and copper with rubeanic acid.389 Antimony has beendetermined in alloys by dichromate t i t r a t i ~ n , ~ ~ ~ and magnesium (and possiblyberyllium) by titration with m- and ~-phenylazoresor~inol.~~~Thus,a systematic study of the behaviour of silver halides at a rotating platinumelectrode has been made.The presence of gelatin was shown to be essen-tia1.392 Fluoride ion has been titrated with ferric chloride by varyingandSeveral methods have been proposed for the titration of anions.3'i7 C.N. Reilley, W. G. Scribner, and C. Temple, Analyt. Chem., 1956, 28, 450.368 W. S. Wise and N. 0. Schmidt, ibid., 1955, 27, 1469.368 A. K. Zhdanov and R. T. Tseitlin, Ref. Zhur., Khim., 1955, Abstr. No.370 A. K. Zhdanov and A. M. Yakubov, ibid., Abstr. No. 29,114.371 Idem, ibid., Abstr. No. 29,113.372 Idem, ibid., Abstr. No. 29,112.373 Yu. I . Usatenko and G. E. Bekleshova, Zavodskaya Lab., 1955, 21, 779.374 V. M. Peshkova and 2. A. Gallai, Ref. Zhur., Khim., 1955, Abstr. No. 37,610.376 M. Shinagawa and H. Matsuo, Japan Analyst, 1955, 4, 211.377 P. J. Elving and E. C. Olson, Analyt. Chem., 1956, 28, 261.378 N. M. Degterev, Zavodskaya Lab., 1955, 21, 917.3 7 9 Idem, ibid., 1956, 22, 167.380 I.P. Alimarin and S . I. Terin, ibid., 1955, 21, 777.381 C. L. Rulfs, J. J . Lagowski, and R. E. Rahor, Analyt. Chem., 1956, 28, 84.382 M. Ishibashi, T. Fujinaga, and H. Sinozaka, J. Chem. SOC. Japan, Pure Chem.388 M. Kobayashi, ibid., 1955, 76, 799.384 Idem, ibid., p. 1023.386 Idem, ibid., p. 796.38* 0. A. Songina and A. R. Voiloshnikova, Zavodskaya Lab., 1956, 22, 19.389 A. K. Zhdanov, V. A. Khadeev, and 0. K. Vyakozina, ibid., 1955, 21, 913.yyu I. Bozsai, Magyar Kim. Folydirat, 1955, 61, 305.391 A. I. Kostiomin, Ref. Z h w . , Khim., 1956, Abstr. NO. 1105.392 I . M. Kolthoff and J . T. Stock, A ~ a l y s t , 1955, 80, 860.29,111.A. K. Zhdanov, V. A. Khadeev, and G. F. Murtazinova, Zavodskizya Lab., 1955,21, 518.Sect., 1956, 77, 265.0.A. Songina, Zavodskuya Lab., 1955, 21, 665.M. Malinek and B. RehBk, 2. analyt. Chem., 1956, 150, 329BELCHER, SHERIDAN, STEPHEN, AND WEST. 363techniques.3g3> 394 Ferrocyanide and phosphate have been titrated ampero-metrically with vanadyl ~alts.3~5 Various organic bases, particularlyalkaloids, have been titrated amperometrically with tungstosilicic acid 396and with tungstophosphoric and molybdophosphoric acid.397 Pyridine hasbeen tit rated with copper t h iocyanat e,398 and various photographic develop-ing agents with d i c h r ~ m a t e . ~ ~ ~Absorptiometric MethodsIn this field of analysis, few developments of outstanding importanceare to be reported. As usual, most papers on absorptiometric methods dealwith applications or modifications of existing methods.Copper has beendetermined by various methods: by addition of hydrochloric acid andmeasurement in the near infrared region,400 by use of nitric acid in a similarmanner for the analysis of slags and converter matte,401 by measuring theabsorption of the cuprarnmonium ion for the analysis of non-ferrous alloys,4o2by use of neocuproin in the analysis of tungsten 403 and aluminium andlead-tin solder,404 with diquinolyl in iron and with 2-hydroxy-ethylamine in lead-antimony alloys,406 with a-benzoin oxirne in molybdenumproducts.407 Two new methods for copper use catechol-violet 408 and oxalyl-dihydrazide36 as reagents. Many papers are concerned with the deter-mination of iron. Amongst the reagents described are the following : 1 : 10-phenanthroline for iron in lead-tin alloys 409 and in high-purity aluminium 410and other non-ferrous metals ; 4 : 7-diphenyl-1 : 10-phenanthroline in high-purity tungsten ; 411 4 : 7-dihydroxy-1 : 10-phenanthroline in stronglyalkaline solution; 39 tartaric acid in the ultraviolet region for the analysisof rocks 412 and copper alloys; 413 pyrogallol in the presence of several othercations.414 Three new methods have been described for the determinationof iron.The reagents used are m-methoxy-o-nitrosophenol,415 ethylene-393 S. Musha and T. Higashino, J . Chem. SOC. Japan, Pure Chem. Sect., 1956, 77, 128.394 K. KadiE and 2. hez&E, Chem. Listy, 1955, 49, 570.39L V. L. Zolotavin and V. K. Kuznetsova, Zavodskaya Lab., 1955, 21, 1283.396 M.SouEkovA and J. Zjrka, Cesk. Farm., 1955, 4, 181.397 Idem, ibid., p. 227.398 M. Munemori, J . Chem. SOC. .Japaw, Pure Chent. Sect., 1955, 76, 1173.30B J. Zjrka, Chem. Listy, 1954, 48, 1864.dm D. G. Davis and H. M. Hershenson, Anal$. Chim. Acfa, 1965, 13, 150.401 S. Ikeda, Japan Analyst, 1955, 4, 286.do2 H. Pohl, Metall. 1955, 9, 102.u3 R. H. A. Crawley, Analyt. Chim. Acfa, 1955, 13, 373.404 J . W. Fulton and J . Hastings, Analyt. Chena. ,1956, 28, 174.‘ 0 5 B.I.S.R.A., Methods of Analysis Committee, J . Iroiz Sfeel Inst., 1956, 182, 301.wU I. P. Ryazanov and N. I. Davydova, Ref. Zhu.r., Khivz., 1955, Abstr. KO. 14,198.4 0 7 J . Madera, Analyt. Chem., 1955, 27, 2003.408 V. Svach, 2. aszalyt. Chem., 1956, 149, 417.4u9 I<.Ota, Japan Analyst., 1956, 5 , 3.41n H. Pohl, Aluminium, 1955, 31, 207.R. H. A. Crawley and M. L. Aspinal, Analyf. Chim. Acta, 1955, 13, 376.412 S. Yokosuka, M. Tanaka, and H. hlorikawa, Japan Analyst, 1955, 4, 434.J’s W. Nielsch and G . Boltz, Metall, 1954, 8, 866.414 M. Yana, H. Mochizuki, R. Kajiyama, and T. Misaki, Ja$an Analyst, 1955, 4,‘15 T. Torii, J . Chew. SOC. Japan, Pure Chem. Sect., 1955, 76, 333.606364 ANALYTICAL CHEMISTRY.diaminebis-sulphosalicylaldehyde,416 and 5-sulphoanthranilic a ~ i d . ~ 8 Cobalthas been determined absorptiometrically by means of l-nitroso-2-naphth01,417. m-methoxy-o-nitrosopheno1,418 p-mercaptopropionic potassium ethyl~ a n t h a t e , ~ l ~ thiocyanate, and tributylammonium acetate,420 and as the tetra-phenylphosphonium thiocyanatocobaltic Methods for chromiumuse the following reagents : diphenylcarba~ide,~~~~ 423 o-aminophenyldithio-carbamic acid,47 ethylenediaminetetra-acetic and the intense bluecolour of the perchromic acid complex.425 In the determination of man-ganese, variants of the permanganate (bismuthate) method have been427 and a method based on the catalytic activity of manganousions in the reduction of chromate 428 has been proposed. Dimethylglyoximehas been used for the determination of nickel in tungsten p0wder,42~ and itssodium salt similarly.430 In both cases, the nickel complex was extractedinto a non-miscible solvent.Tin has been determined by means of itsreactions with morin 431 and tol~enedithiol.~~~ Silver has been determinedin photographic emulsions by measuring the absorption of colloidallysuspended silver s ~ l p h i d e .~ ~ An ultramicro-method for halides uses theliberation of diphenylthiocarbazone from its silver complex in an ethylacetate-chloroform solvent as a means of determination.& Thorium hasbeen determined by use of n e ~ t h o r i n , ~ ~ m r e l l i n , ~ ~ ~ catechol-violet ,437n a p h t h a ~ a r i n , ~ ~ ~ phosphom~Iybdate,~~~ and arsenophenylazonaphthol-sulphonic acid.@ Thallium has been determined indirectly after precipit-ation of [Co(NH3),]T1C1, by application of a cobalt-thiocyanate procedure.440Direct determination has been effected by utilising the formation of anextractable thallium-methyl-violet complex.441 Cerium has been deter-mined indirectly by a method using lead dioxide, ferrous sulphate, and1 : 10-phenanthroline.442 Alizarin-S has been used extensively as a4 1 G A.K. Mukherjee, Analyt. Chim. Acta, 1955, 13, 268.417 N. Oi, J . Chem. SOC. Japan, Pure Chem. Sect., 1955, 76, 413.418 T. Torii, ibid., p. 680.419 A. T. Bilinenko and N. V. Ul'ko, Zhur. analit. Khim., 1955, 10, 299.420 M. Ziegler, 0. Glemser, and E. Preisler, Angew. Chem., 1956, 88, 436.421 M. Shinagawa, H. Matsuo, and R. Kohara, Japan Analysf, 1956, 6, 29.422 P. F. Urone, Analyt. Chem., 1955, 27, 1354.423 K. Kitagawa and Y . Aimoto, Japan Analyst, 1955, 4, 144.424 V. G. Goryushina and E. Ya. Gailis, Zavodska-ya Lab., 1955, 21, 642.4 2 5 A. Glasner and M. Steinberg, Analyt.Chem., 1955, 27, 2008.426 T. Ito, K. Hara, and Y . Hoshino, Jafian AnaZyst, 1955, 4, 353.4 2 7 H. Kiyota and T. Yamamoto, J . Chem. SOC. Japan, Pure Chem. Sect., 1956, 76,428 G. Almdssy and I. Dezso, Ada Chim. Acad. Sci. Hung., 1965, 8, 11.429 K. L. Rohrer, Analyt. Chem., 1955, 27, 1200.430 W. Nielsch and L. Giefer, Mikrochim. Acta, 1956, 522.481 V. Patrovsky, Chem. Listy, 1954, 48, 1694.432 H. Onishi and E. B. Sandell, Analyt. Chim. Acta, 1956, 14, 163.433 A. Hulanicki and B. Gluck, Przemysl Chem., 1955, 11, 149.434 W. J. Kirsten, Mikrochim. Acta, 1955, 1086.433 M. Ishibashi and S. Higashi, Japan AnaZyst, 1956, 6, 135.436 B. R. I,. Rao and C. C. Patel, Proc. Indian Acad. Sci., 1955, A , 42, 317.437 M. Svach, 2. analyt. Chem., 1956, 149, 414.438 T.Moeller and M. Tecotzky, Analyt. Chem., 1955, 27, 1056.439 T. Nozaki, J . Chem. SOC. Japan, Pure Chem. Sect., 1955, 76, 996.440 Idem, ibid., 1956, '77, 493.441 S. D. Gurev, Ref. Zhur., Khim., 1956, Abstr. No. 4155.442 L. Gordon and A. M. Feibush, AnaZyt. Chem., 1965, 27, 1050.11 79BELCHER, SHERJDAN, STEPHEN, AND WEST. 365colorimetric reagent for zirconium.m* 4.a 445 Flavano1,446 ar~enazo-reagent,~~and mandelic acid 448 in the ultraviolet region have also been used as reagentsfor this metal. Aluminium has been determined by means of several reagents,e.g., al~inon,449 arsenazo-reagent ,450,451 Erio~hrome-cyanine,"~~ chrome-azurol-S.453 Various methods have been used for the determination of theplatinum metals. Indium has been determined with NN-dimethyl-$-nitrosoaniline 454 and EDTA,455 ruthenium has been determined absorptio-metrically as per-r~thenate?~~ platinum as the stannous-platinous chlorideand rhodium similarly.458 l-Naphthylamine-3 : 5 : 7-trisul-phonic acid has been used for the colorimetric determination of osmium.43Bismuth has been determined by variations of the thiourea459461 and theiodide method461*462 and also by means of catech~l-violet.~~ Zinc hasbeen determined by thiocyanate and rhodamine-C 464 and by methyl-violetand ferrocyanide.465 Cadmium has been determined indirectly by 4-hydroxy-3-nitrophenylarsonic acid 466 in copper and cadmium alloys.Titan-yellow 467 and 3-[3-(2 : 4-dimethy~carboxanilido)-2-hydroxy-l-naphthylazo]-4-hydroxybenzenesulphonate 468 have been used in the absorptiometricdetermination of magnesium.Quercetin 469 and phenylfluorone 470 havebeen used as reagents for germanium. Lead has been determined by meansof q~1inalizarin,4~~ antimony by means of methyl-~iolet,~~~ and lithium 473indirectly, after precipitation as phosphate, by a phosphomolybdate method.Beryllium has been determined indirectly in a similar manner after precipit-ation as beryllium ammonium phosphate.474 It has also been determined44a D. L. Manning and J. C. White, Analyt. Chem., 1955, 21, 1389.441 K. Narita, J - Chem. SOC. Japan, Pure Chem. Ssct., 1955, 76, 1026.445 L. Silverman and D. W. Hawley, Analyt. Chem., 1956, 28, 806.446 L. Horhammer, R. Hansel, and W. Hieber, 2. analyt. Chem., 1955, 148, 251.447 V.I. Kuznetsov, L. M. Budanova, and T. V. Matrovsova, Zavodskaya Lab., 1956,4 4 ~ R. B. Hahn and L. Weber, Analyt. Chem., 1956, 28, 414.449 I. V. Bogdanova, Zavodskaya Lab., 1955, 21, 1043.459 V. I. Kmatsov and R, B. Mnbtsova, ibid., p. 1422.451 Idem, ibid., 1956, 22, 161.45a B. J. MacNultp,G. J-Hunter, and D.G. Barrett, Analyt. Chim. Ada, 1956,14, 1368.453 B. J. MacNulty and L. D. Woolard, ibid., p. 452.4 s 4 A. D. WestIand and F. E. Beamish, Amlyt. Chem., 1955, 27, 1776.4 6 5 W. M. MacNevin and 0. H. Kreige, ibid., 1956, 28, 16.4 5 6 G. A. Stoner, ibid., 1956, 27, 1186.4 5 7 0. I. Milner and G. E. Shipman, ibid., p. 1476.458 G. H. Ayres, B. L. Tuffly, and J. S. Forrester, ibid., p. 1742.450 L. N. Krasil'nikova, Ref. Zhur., Khim., 1956, Abstr.No. 4165.460 M. P. Makukha, ibid., 1955, Abstr. No. 31,889.461 N. M. Lisicki and D. F. Boltz, Awatyt. Chem., 1955, 27, 1732.4 6 3 P. Alberto-Barreto and B. Ortegui, Afinidad, 1955, 32, 149.463 M. Svach. 2. analyt. Chem., 1956, 149, 325.464 L. B. Zaichikova and N. N. Lutchenko, ZavodsRaya Lab., 1965, 21, 1304.4 6 5 V. I. Kuznetsov and L. S. Kozpeva, Ref. Zhur., Khim., 1955, Abstr. No. 26,438.4 6 6 W. Nielsch and G. Boltz, Gem.-Ztg., 1955, 79, 364.4 6 7 A. Bussman, Z . analyt. Chem., 1956, 148, 413.4 6 8 C. K. Mann and J. H. Yoe, Analyt. Chem., 1956, 28, 202.469 Y. Oka and S. Matsuo, J . Chem. SOC. Japan, Pure Chem. Sect., 1955, 76, 610.470 L. B. Ginsburg, S. D. Gurev, and A. P. Shibarenkova, Ref. Zhur., Khim., 1966,4 7 1 V.A. Morozov, ibid., 1955. Abstr. No. 14,220.472 E. I. Ishutchenko and V. M. Eliseeva, Zavodskaya Lab., 1955, 21, 791.473 T. Nozaki, J . Chem. SOC. Japan, Pure Chena. Sect., 1955, 76, 445.4 7 4 M. Sunderasan and M. Sankar-Das, Analyst, 1955, 80, 697.22, 406.Abstr. No. 4160366 ANALYTICAL CHEMISTHY.by means of ~-nitrophenylazo-~rcinol.~~~~ 476 Variations of the arseno-molybdate procedure have been used by several authors for a r ~ e n i c . 4 ~ 7 ~ 7 ~Alizarin-red-S has been employed as colorimetric reagent for the determin-ation of scandium ; 480 samarium has been determined directly at 4016 inchloride solution.481 Ascorbic acid has been used as reagent for goidJ482dipicrylamine for potassium,483 ferrocyanide for diethylditliio-carbarnate for catechol for tantalum,486 and hydrazine forrhenium(v1) in hydrochloric acid.487 Molybdenum has been determined inthe presence of tungsten in a citrate medium by measurement of the redcolour formed with phenylhydra~ine.~~~ Sodium has been determined in-directly after precipitation as sodium zinc uranyl acetate hexahydrate bythe thiocyanate-uranyl ion The thiocyanate reaction has beenapplied to the direct determination of uranium in minerals.4go The conven-tional methods using morin 491 and ferrocyanide 492 have also been utilised,and an ultraviolet method for the uranyl ion in perchloric acid.493 Titaniumhas been determined by use of sulphosalicylic acid,494 " Tiron," 495 dianti-pyrinyl-o-hydro~yphenylmethane,49~ and c ~ p f e r r o i i .~ ~ ~ Niobium has beendetermined in the presence of titanium by a thiocyanate method.498 Nio-bium and tantalum in steel have been determined separately by means oftheir yellow-brown pyrogallol compounds in the presence of sulphite andoxalate respecti~ely.4~9*5'-'O Hydrogen peroxide has also been used in aphotometric method for niobium(v) and tantalum(v) .501 Several methodshave been proposed for the determination of vanadium.These methods4 7 5 J. B. Pollock, Analyst, 1956, 81, 45.476 J. C. White, A. S. Meyer, and D. L. Manning, Analyt. Chem., 1956, 28,4 7 7 M. Jean, Analyt. Chim. Acta, 1956, 14, 172.478 F. L. Hahn and R. Luckhaus, 2. analyt. Chem., 1956, 149, 172.479 H. W. Berkhout, Chemist-AnaZyst, 1956, 45, 24.48O A. R. Eberle and M.W. Lerner, Analyt. Chem., 1955, 27, 1551.4 8 1 R. Rasin-Streden, W. Dauschan, and 0. Zemek, Mikrochim. Acta, 1956,482 S. Ya. Shnaiderman, Ukrain. Khirn. Zhur., 1955, 21, 261.4S3 P. R. Lewis, Analyst, 1955, 80, 768.484 G. d'Amore, Ann. Chim (Italy), 1955, 45, 759.485 H. Got6 and Y . Kakita, Japan Analyst, 1954, 3, 299.486 B. Sarma and J. Gupta, J . Indian Chem. SOC., 1956, 32, 285.487 R. J. Meyer and C. L. Rulfs, Analyt. Chem., 1955, 27, 1387.488 E. M. Goldstein, Chemist-Analyst, 1956, 45, 47.48O P. N. Kovalenko and V. V. Ten'kovtsev, Ref. Zhuv., Khim., 1955, Abstr. KO.490 M. M. Tillu, D. V. Bhatnagar, and T. K. S. Murthy, Proc. Indian Acnd. Sci.,491 M. T. Beck and E. Hanlos, Acta Chim. Acad. Sci. Hung., 1955, 8, 233.492 C. Ujhelyi, Magyar Kkm.Folydirat, 1955, 61, 437.493 L. Silverman and L. Mondy, Analyt. Chem., 1956, 28, 45.494 17. Steuer and H. Dunkel, Aluminium, 1955, 31, 205.405 R. Szarvas and B. Csiszar, Acta Chim. Acad. Sci. Hung., 1955, 7 , 403.4 s i 17. Buscarons and J. L. Marin-Malumbres, Anales real. SOC. Espafi. Fis. Quitn.,498 li. J. Mundy, Analyt. Chem., 1955, 27, 1408.499 A. Eder, Arch. Eisenhiittenw., 1955, 26, 431.5.00 M. Yana, H. Mochizuki, R. Kajiyama, and T. Misaki, Jafian Analyst, 1955, 4,5Ql H . SchBfer and F. Schnlte, Z . nnnlyf. Chem., 1966, 149, $3.956.512.16,552.1955, A , 42, 28.S. I. Gusev and R. G. Beiles, Ref. Zhur., Khim., 1955, Abstr. No. 26,450.1965, B, 51, 121.40!1BELCHER, SHERIDAN, STEPHEN, AND WEST. 367indicate the use of benzohydroxamic acid,502 ferrous dipyridyl,503 diphenyl-aminesulphonic acid,* catech01,~O~ oxidation of aniline,506 and a high-precision variation of the standard peroxy-vanadium procedure.507Numerous methods have been proposed for anionic inorganic substances.Only a few of these can be mentioned here. Fluoride has been determined byits action on the coloured product fokmed by ascorbic acid with titanium,508also on that formed between neothorin and thorium 509 and on the thorium-alizarin c0mplex,5~~ aluminium-Eriochrome-cyanine complex,452 andaluminium-chrome azurol-S complex.453 Methods based on the formationof silicomolybdate have been used for the photometric determination ofsilicate.511~ 512 Nitrite ion has been determined by reaction with“ Rivanol ” 48 (2 : li-diamino-’l-ethoxyacridine), and nitrate ion by reactionwith aniline acetate.513 Tetrathionate has been determined by reactionwith cyanide to form thiocyanate and subsequent application of the ferric-thiocyanate reaction.514 Bromide has been determined by conversion intotetrabromofluorescein, 515 and sulphate ion by reaction with 4-amino-4’-~hlorodiphenyl.~~~ Iodine has been determined by its redox reaction withVariamin-blue-B 517 (4-amino-4’-methoxydiphenylamine). The colorimetricdetermination of minute amounts of phosphoric, arsenic, silicic, and germanicacids has been effected by extraction of their molybdate complexes withvarious water-immiscible solvents. 518 Boron has been determined inuranium, graphite, and beryllia by the curcumin reaction,519 by formationof the poly(viny1 alcohol)-borate-iodine by a method based onthe acceleration by boric acid of the reaction between H-acid and salicyl-aldehyde,520 by reaction with two new reagents, viz., 5-benzamido-6’-chloro-1 : 1’-dianthrimide and 5-$-toluidino-l : l’-dianth~-imide.~~ Traces of oxy-gen in solution have been determined with reduced indigo-~armine,~~’ andin gases by reaction with reduced sodium anthraquinone-2-sulphonate.522High dilutions of ozone have been determined by reaction with potassiumiodide.523 The accurate absorptiometric determination of pH within *O.Olbo2 W. M. Wise and W. W. Brandt, Analyt. Chem., 1955, 27, 1392.503 A. I. Ponomarev and L. L. Ratina, Zavodskaya Lab., 1955, 21, 918.504 S.Hirano and T. Fukazawa, Japan Analyst, 1955, 4, 616.505 V. Patrovsky, Chem. Listy, 1955, 49, 854.506 G. Almkssy and 2. Nagy, Acta Cltim. Acad. Sci. Hung., 1955, 6, 339.507 M. Q. Freeland and J . S. Fritz, Analyt. Chem., 1955, 27, 1737.508 E. D. $hall and H. G. Williamson, J . Ass. O#. Agric. Chem., 1955, 38, 454.500 K. Emi and T. Hayami, J . Chena. SOC. Japan, Pure Chem. Sect., 1955, 76,510 J . J . Lothe, Analyt. Chem., 1956, 28, 949.511 E. Blasius and A. Czekay, Z. analyt. Chem., 1955, 147, 1.j 1 2 K. Jordan and R. W. Fisclier, Tech. Mitt. Krupp, 1055, 13, 39.513 T. Kato, Y. Okinaka, and K. Sakai, Japan Analyst, 1954, 3, 231.614 0. A. Nietzel and M. A. De Sesa, Analyt. Chem., 1955, 27, 1839.515 I?. A. Pohl, 2. analyt. Chem., 1956, 149, 68.516 A.S. Jones and D. S. Letham, Analyst, 1956, 81, 15.617 L. Erdey and F. SzabadvBry, Acta Chim. Acad. Sci. Huwg., 1955, 8, 191.518 T. Kiba and M. Ura, J . Chem. SOC. Japan, Pure Chem. Sect., 1955, 76, 520.510 J. Coursier, J. Hure, and R. Platzer, Rapp. Centre &at, Nucl. Saclay, 1955, No.520 L. M. Kul’berg and T. I. Badeeva, Ref. Zhur., Khim., 1955, Abstr. No. 14,240.521 L. S. Buchoff, N. M. Ingber, and J. H. Brady, Analyl. Chem., 1955, 27, 1401.522 C. Stafford, J. E. Fuckett, M. D. Grimes, and R. J. Heinrich, ibid., p. 2012.623 J. N. Pring, .I. , 4 p p l . ChPnt., 19.55, 5, 888.1291.404368 ANALYTICAL CHEMISTRY.unit has been described.524 The use of a considerable range of new colori-metric reagents has been reviewed by Stephen.49Instrumental Methods of TitrationPhotometric Titration.-The use of a photoelectric cell and the narrowwave-band of a spectrophotometer in place of the human eye for the detectionof the end-point in titrimetric procedures appears to have found less applic-ation during the past year.Bobtelsky and his co-workers have continuedtheir studies in heterometric titration. In this technique measurement ofthe changes in absorption of a finely suspended precipitate reveals theposition of the end-point. The fundamentals of the method have beenreviewed.525 The technique has been applied to the determination of copperwith ~alicylaldoxirne,~~~ calcium in the presence of excess of magnesium with~ u l p h a t e , ~ ~ ~ mercury with diethyldithi~carbarnate,~~~ and in the presence ofmany other metals which can be sequestered by means of ethylenediamine-tetra-acetic acid,529 sulphuric acid with barium r~itrate,~SO copper by diethyl-dithiocarbamate 531 in the presence of many other metals, iron with aluminonin the presence of other metals including aluminium.532 Spectrophotometricend-points have been used in the titration of various ions with a tervalentcobalt titrant 533 and also in the titration of chromate and vanadate by meansof ferrous sulphate and arsenious oxide.534High-frequency Titration.-The continued growth of interest in the useof high-frequency methods of titration is largely reflected by the number ofpapers dealing with fundamental aspects and instrumentation.Studies onconcentration curves with a capacitance-type instrument have been re-ported 535 and a simple heterodyne-type apparatus has been described.536Others have described a stable high-frequency apparatus operating in the100 Mc frequency range.537 High-frequency instrumentation has beengenerally reviewed with particular reference to cell In aninvestigation into the fundamental aspccts of high-frequency titration, theeffect of shielding the solution has been Another type of high-frequency titrimeter has been described,=O and the application of the methodto the titration of halides, etc., in pyridine solution has been investigated.%l524 G. Monod-Herzen, Compt. rend., 1955, 240, 2146.525 M. Bobtelsky, Analyt. Chim. Actn, 1955, 13, 172.526 M. Bobtelsky and E. Jungreis, ibid., p. 449.527 M.Bobtelsky and J. Eisenstadter, ibid., 1956, 14, 89.528 M. Bobtelsky and R. Rafailoff, ihid., p. 247.5z9 Idem, ibid., p. 339.530 M. Bobstelsky and J. Eisenstadter, ibid., p. 189.531 M. Bobstelsky and R. Rafailoff, ibid., p. 558.532 M. Bobtelsky and A. Ben-Bassat, itid., p. 439.533 R. Maurodineann and J. Wrtsman, Centr. Bo-yce Thompson Inst., 1955, 18, 181.534 J. W. Miles and D. T. Englis, Analyt. Chem., 1955, 27, 1906.535 Y. Kamura, Pharm. Bull. Japan, 1955, 3, 138.536 N. Nakamura, Japan Analyst, 1955, 4, 345.537 A. H. Johnson and A. Timnick, Analyt. Chem., 1956, 28, 889.538 J. C. Clayton, J. F. Hazel, \V. M. McNabb, and G. L. Schnable, Analyt. Chim.539 K. Nakano, J . Chem. SOC. Japan, Pure Chem. Sect., 1955, 76, 1096.640 J.C. Clayton, J. F. Hazel, W. M. McNabb, and G. L. Schnable, Analyt. CJzim.5 4 ' J . P. Young, Diss. Abs., 1956, 15, 1302.Acta, 1956, 14, 269.Acta, 1965, 13, 487BELCHER, SHERIDAN, STEPHEN, AND WEST. 369The titration of various organic bases, phenols, and enols has beendescribedea2 The high-frequency titration of phenols forms the subjectof another communication.m The technique has been used for the titrationof sulphur in rubber vulcanisers 544 and for the complexometric titration ofthorium 545 and the rare earths.H6Codometric Titration.-A high-precision coulometric titrator has beendescribed,547 and also an instrument with a low inertia electromechanicalmotor to integrate current and time.54s The application of the technique tomicro-volumes of solution has also been d e ~ c r i b e d .~ ~ Thallium has beendetermined by coulometric titration with f e r r i ~ y a n i d e , ~ ~ ~ titanium withceric ion,551 various oxidised ions by quadrivalent uranium, 552 uranyl ionwith titanous ion,553 various metals with EDTA,554 ammonia withh y p ~ b r o r n i t e , ~ ~ ~ arsenic(II1) with ceric ferric iron with EDTA,557and halides with mercurous 558 and mercuric ion.559 Carbon in steels andcarbides has been determined by potentio-coulometric t i t r a t i ~ n . ~ ~ ~ Quinolhas been titrated coulometrically with iodine,561 and various organic basesin acetonitrile by anodic generation of hydrogen ion from the moisturecontent of the solvent.563Dead-stop End-point Titrations.-Very little use appears to have beenmade of this technique during the period covered by the Report.A tran-sistor amplifier for dead-stop end-points has been described. 563 Factorsinfluencing the flow of current in dead-stop end-point titrations have beeninvestigated and discussed. 564 Cobalt (111) has been titrated with ferroussulphate, and dichromate in the presence of excess of t ~ n g s t a t e . ~ ~ 5 Smallquantities of chloride have been titrated by using silver nitrate and a silver-silver (or gold) amalgam electrode system. 566 Formaldehyde has beentitrated by dead-stop end-point technique, hydroxylamine hydrochloridebeing the titrant.567 The technique has been applied to the acidimetric542 E. S. Lane, Analyst, 1955, 80, 675.543 E. T. Lippmaa, Zhatr.analit. Khim., S.S.S.R., 1955, 10, 169.5‘4 I. Yamaji, Rep. Tokyo Chewz. Ind. Res. Inst., 1955, 50, 203.s45 R. Hara and P. W. West, Analyt. Chim. Acta, 1955, 13, 189.546 Idem, ibid., 1956, 14, 280.547 G. E. Gerhardt, H. C. Lawrence, and J. S. Parsons, Aizalyt. Chem., 1955, 27, 1752.J. S. Parsons, W. Seaman, and R. M. Amick, ibid., p. 1754.549 R. Schreiber and W. D. Cooke, ibid., p. 1475.550 A. M. Hartley and J. J . Lingane, Analyt. Chim. Acta, 1955, 13, 183.551 R. V. Dilts and N. H. Furman, Analyt. Chem., 1955, 27, 1596.552 W. D. Shults, P. F. Thomason, and M. T. Kelley, ibid., p. 1750.553 J. J. Lingane and R. T. Iwamoto, Analyt. Chim. Acta, 1955, 13, 465.554 C. N. Reilley and W. W. Porterfield, Analyt. Chem., 1956, 28, 443.555 G.M. Arcand and E. H. Swift, ibid., p. 440.556 N. H. Furman and A. J. Fenton, ibid., p. 515.6 5 7 R. W. Schmid and C. N. Reilley, ibid., p . 520.558 D. D. DeFord and H. Horn, ibid., p. 797.559 E. P. Przybylowicz and L. B. Rogers, ibid., p. 799.5130 &I. Sicha, H u h . List., 1955, 10, 535.561 I. Bajalovid and K. NikoliC, Bull. SOC. chim. Beograd, 1955, 20, 329.5 6 2 C. A. Streuli, Analyt. Chem., 1956, 28, 130.5G3 J. B. Phillips, Chemist-Analyst, 1955, 44, 80.864 H. L. Kies and T. S. Hein, 2. analyt. Chem., 1966, 148, 91.565 I;. C. W. Baker and T. I-’. McCutcheon. Analyt. Chem., 1955, 27, 1625.5 6 G I?. ill. Deschamps, Bull. Soc. chinz. Frame, 1956, 126.5 6 7 E. SGrebenovskq and 2. Rezar, Chem. Listy, 1355, 49, 1155370 ANALYTICAL CHEMISTRY.and alkalimetric titration of various substances in methanolic, ethanolic, andbutanolic s0lution.~68Conductometric Titration.-Relatively little use has been made of thistechnique during the year.A Russian worker has described an instrumentin which the platinum electrodes of the conductance cell are connected inseries with the lamp of a photo-coiorimeter. The photo-current read on thegalvanometer is proportional to the third power of the change of the voltageof the current to the lamp.569 Conductometric titrations using directcurrent have been described by others. 570 A low-frequency electrodelessconductometer has been described. 571 A conductometric method for thedetermination of phenolic groups in mixtures such as isolated lignins hasbeen reported.572 Certain alkaloids have been determined ~ i m i l a r l y , 5 ~ ~naphthalene-2-sulphonic acid in acetone being used as titrant. The con-ductometric determination of alkali sulphide, hydroxide, and carbonate inthe presence of each other by use of silver nitrate as titrant has been de-scribed. 574 Nickel sulphate, nickel sulphate and sulphuric acid, and nickelsulphate in the presence of sodium sulphate and sulphuric acid have beendetermined by conductometric titration with barium hydroxide. 575 Ex-change cations in clays have been titrated conductometrically with standardhydrochloric acid. 576Potentiometric Titration.-Various devices for automatic potent iome t rictitration have been described 577 and particular attention has been devotedto the selection of electrode systems for use with automatic differentialpotentiometric titrators in aqueous and non-aqueous systems. 578 Investig-ations have been conducted into the oxidation of the surface of platinumelectrodes during redox titrations.The data obtained indicate that thisphenomenon can explain the occurrence of drifting p0tentials.5~~ The glasselectrode has been used as reference electrode in the titration of sodium ionswith zinc uranyl acetate in 85-95% ethanolic solution.580 (The glasselectrode was fabricated from Jena-20 glass.) Other workers have used anindicator glass electrode for the titration of thorium nitrate in 0.001~-solution with 0.01 M-ammonium or sodium oxalate. Four inflections occur.At the first equivalence point, pH 4.3, thorium oxalate is precipitated; theother three between pH 5.4 and 6.3 correspond to thorium oxalate com-p l e x e ~ .~ ~ ~ Several typesof tellurium electrode for acid-base titrations have been examined.582Cerium behaves in a manner similar to thorium.5 6 8 G. Mann, Magyar Kkm. Folydirat, 1955, 61, 26.569 M. I. Kulenok, Zavodskaya Lab., 1955, 21, 1027..i70 J. DCvag and E. Miihlrod, Magyar Kkm. Folydivat, 1956, 62, 153.. j i 1 M. Salamon and 1’. Svitok, Chem. pvumsyl, 1956, 6, 10.5 7 2 K. Starkanen and C. Schuerch, Analyt. Chem., 1955, 27, 1245.573 V. V. Udovenko and L. L. Vvedmskaya, Uhrain. khim. Zhur., 1954, 20, 684.574 R. DomanskL, Chem. Lisly, 1955, 49, 186.5 i 5 M. 1 . [Jsanovich, 2. P. Yakusheva, and S.V. Lebedeva, Ref. Zhur., Khim.,576 2. P. Yakusheva, ibid., Abstr. No. 14,269.5 7 7 R. Audran and D. T. R. Dighton, J. Sci. rnstr., 1956, 33, 92.5713 H. V. Malmstadt and E. R. Fett, Analyt. Chem., 1955, 27, 1767.579 J . W. Ross and I. Shain, ibid., 1956, 28, 548.58O 0. Tomieek and R. Pulpan, Chem. Listy, 1965, 49, 497.j 8 1 K. Pan and T. M. Hseu, Bull. Chem. SOC. Japan, 1955, 28, 309.5p2 A . R . Tourky, 1. M. Tssa, and S . A. Awad. Chim. nnnlvf., 2966, 37, 367.1955, Abstr. KO. 23,981BELCHER, SHERIDAN, STEPHEN, AND WEST. 37 1Variations in the sensitivity of the bromine-bromide end-point have beenexamined with relation to electrode surface area, rate of stirring, magnitudeof potentiometer current, e t ~ . ~ ~ ~ The dependence of the E.M.F. of 12bimetallic electrode systems on the pH has been studied.The systemsTe-Ag, Te-Au, Te-graphite, Sb-Ag, and Sb-Au have hitherto not beendescribed in the l i t e r a t ~ r e . ~ ~Zinc has been determined in ores by the ferrocyanide t i t r a t i ~ n , ~ ~ ~ andcadmium has been titrated with lithium ferro~yanide.~~~ Ascorbic acid hasbeen used as titrant in the potentiometric determination of gold,587 iron,copper, and vanadate. 588 Iron has been titrated potentiometrically withquinquevalent Sexavalent tungsten has been titrated withchromous chloride.590 Dithio-oxamide has been used as titrant for thedetermination of copper 591 with a silver indicator electrode; EDTA, bis-hydroxyethylglycine, and nitrilotriacetic acid as titrants for various cationsusing several electrode systems; 592 manganous ion as titrant for per-manganate ions ; 593 mercuric chloride as titrant for cystine and cysteine,594amalgamated gold electrodes being used.A rapid argentometric deter-mination of the halides by direct potentiometric titration has been de-described. 595 Sulphur trioxide in concentrated sulphuric acid has beentitrated directly with water.596Non-aqueous TitrationsThe topic of non-aqueous titration has been generally revie~ed.~~’l 598The use of the high-frequency method for end-point detection has beendiscussed.=l Polish workers have described a special silver-silver chloridereference electrode for use in non-aqueous procedures. 599 New bimetallicelectrode systems for potentiometric acid-base titrations in non-aqueoussolutions have been described.600 The solvent systems examined in thisinvestigation were methanol and glacial acetic acid.A platinum-silversystem was preferred for the former medium, and graphite used withtungsten, gold, antimony, silver, platinum, or tellurium was successfulin the latter solvent. A spectrophotometric and potentiornetric studya3 W. C. l’urdy, E. A. Burns, and L. B. Rogers, Analyt. Chem., 1955, 27, 1988.584 V. Novdk, Chem. Listy, 1955, 49, 934.585 M. I. Troitskaya and N. F. Sarayeva, Ref. Zhur., Khim., 1956, Abstr. No. 4140.A. Basinski and M. Lango, Przemysl Chem., 1955, 11, 145.j B i N. K. Pshenits9n and S. I. Ginsburg, Ref. Zhur., Khim.. 1956, Abstr. No. 1104.C. Yoshimura and T. Fuzitani, J . Chem.Soc. Japan, Pure Chew. Sect., 1955,6*n ‘I. M. Issa and A. M. Daess, Chemist-AnaZyst, 1955, 44, 89.j 9 0 I. Muraki, J . Chem. SOC. Japan, Pure Chem. Sect., 1955, 76, 193..jgl V. W. Meloche and L. Kalbas, Analyt. Chem., 1956, 28, 1047.jg2 S. Siggia, D. W. Eichlin, and R. C. Reinhart, ibid., 1955, 27, 1745.5B3 I. M. Issa and R. M. Issa, Chemist-Analyst, 1955, 44, 99.jY4 R. Cecil, Biochiw. Biophys. Acta, 1955, 18, 154.;y5 V. J. Shiner and M. L. Smith, AnaZyt. Chem., 1956, 28, 1043.JBi J. Capilla-Rufias and L. GimCnez-EstellCs, Inf. Quim. Anal., 1955, 9, 129.jY* A. H. Beckett and E. H. Tinley, “ Titration in Non-aqueous Solvents,” Rlessrs.SR9 J . Minczewski and 2. Lada, Hoczniki ClLem., 1955, 29, 919.76, 304.H. B. van der Heijde, Chem. Weekblad, 1955, 51, 823.H.D.H., Ltd., Poole, 1956.V.NOV~C, Chenz. L i s t v , 1955, 49, 848372 ANALYTICAL CHEMISTRY.has been made of the behaviour of some thirteen acid-base indicators inan acetic acid solvent system.601 Vanadyl acetate has been used in glacialacetic acid as an amperometric titrant; 602 its application to an inorganicdetermination is described. The use of chelating agents in non-aqueoustitrimetry has been described. An aqueous solution of the metal ionsis evaporated to dryness and treated with methanol and a suitable chelat-ing agent. The hydrogen ion liberated is titrated subsequently withstandard sodium hydroxide In benzene-methanol. 603 The scope of phenol-chloroform-acetonitrile as a solvent system for the salts of organic bases hasbeen examined; 604 perchloric acid in dioxan was used as titrant.Lithiumhas been determined by direct application of the Volhard method to a 2-ethyl-hexanol extract of lithium chloride.605 Potassium has been determined fol-lowing precipitation of its insoluble tetraphenylboron salt by non-aqueoustitrimetric methods in anhydrous acetone 606 and in aqueous acetone-607Compounds containing positive chlorine or bromine have been titrated withsulphur dioxide in pyridine.608 Ammonium hexanitratocerate in glacialacetic acid has been used as titrant for oxalic acid in the sameOrganic bases have been titrated in benzene and methanol with diphenylphosphate as titrant, both potentiometric and visual end-points being usedwith several indicators.610 Weak bases related to nitroguanidine have beentitrated with methoxide in dimethylformamide and ethylenediamine, andwith perchloric acid in trifluoroacetic acid.611 Basic co-polymers of acrylo-nitrile have been titrated in a mixture of nitromethane and formic acid.612Sulphonamides have been titrated in methanol-benzene and pyridine withperchloric acid,G13 morphine, its derivatives, and their acid salts in glacialacetic acid with perchloric a~id,~14 and antihistamine drugs by the samer n e t h ~ d .~ l ~A comprehensive review of methods of titrating weak acids in non-aqueous solvents has been published, the merits of various indicators beingdescribed in detail.616 An anodically polarised platinum wire has been usedas indicator electrode for the titration of very weak acids in ethylenediamine.The reference electrode was a short length of platinum wire inserted into thestream of the titrant.617 Phenols have been titrated in a composite diethyl-amine-pyridine-diethylformamide-thymol solvent by using a conventional601 T.Higuchi, J. A. Feldman, and C. R. Rhem. Analyt. C b m . , 1966,28, 1120.Bo2 J. Novotny, Chem. Listy, 1954, 48, 1865.603 B. D. Brummet and R. M. Hollweg, A.naZyt. Chem., 1956, $38. 448.604 L. G. Chatten, J . Pharwz. PharmacoZ., 1955, 27, 586.605 J. C. White and G. Goldberg, Analyt. Chein., 1955, 27, 1188.606 H. Flaschka, Chemist-Analyst, 1955, 44, 60.608 R. W. Freedman, Analyt. Chem., 1956, 28, 247.609 0. N. Hinsvark and K. G. Stone, ibid., p. 334.6 1 1 J. E.De Vries, S . Schiff, and E. St. C. Gantz, Analyt. Chem., 1955, 27, 1814.612 C. A. Streuli, ibid., p. 1827.Y . Tajika and M. Aikawa, J . Pharm. SOC. Japan, 1954, 74, 1125.614 T. Kashima, A. Asahina, and Y . Shiuchi, ibid., 1955, 75, 329.6 1 5 T. Kashima, ibid., p. 332.K. Backe-Hansen, Med. norsk. Favm. Selsk., 1955, 17, 282.G. A , IIsrlow, C. M. Noble, and G. E. A. Wyld, Analyt. Chem., 1956, 28,H. W. nerkhout and G. H. Joogen, Chem. WeeRbZad, 1955, 51, 607.M. M. Davis and H. B. Hetzer, J . Res. Nut. BUY. Stand., 1956, 54, 309.784BELCHER, SHERIDAN, STEPHEN, AND WEST. 373methoxide titrant and potentiometric detection of the end-point.618 4-Amino-4'-nitroazobenzene has been described as a new indicator for thetitration of phenols in ethylenediamine and pyridine : the red-blue colourtransition is claimed to be very sensitive.619 Various hydroxyanthra-quinones have been titrated in pyridine with sodium methoxide and use of aglass-antimony electrode pair.620 A glass-calomel system and thymol-bluehave been used in the titration of cholic, deoxycholic, and dehydrocholicacids in benzene-methanol or chloroform-dimethylformamide.621 Carb-oxylic acid anhydrides have been determined by reaction with excess ofmorpholine and titration of unreacted base with methanolic hydrochloricacid.622 Tetrabutylammonium hydroxide has been used as a titrant forweak acids in the usual basic solvents, ketones, alcohols, etc.It appears topossess several advantages over potassium methoxide.6s* 624Flame-photometryA general trend is now apparent in which many authors are attempt-ing to extend the scope of the flame-photometry method beyond the usualrange of alkali and alkaline-earth metals.Aluminium has been deter-mined indirectly by its damping effect on the intensity of the 423, 554,and 622 mp calcium lines : 6z5 it can thus be determined in zinc die-castingalloys. Silver has been determined in the presence of cadmium andzinc by using the intensity of the 338 mp line in an oxy-hydrogen flame.Acetone was added to the hydrochloric acid spray to increase sensitivity."GResults have been reported for the analysis of nickel, cobalt, manganese,and chromium in steel after a preliminary removal of bulk iron by solventextraction. The method is not as accurate as chemical procedures, butis rapid and permits simultaneous determination^.^^' Flame-emissionmeasurements at 540 mp permit the determination of phosphorus in organo-phosphorus compounds in ethanolic solution within the concentrationrange 0 - 0 1 4 - 0 3 ~ with an average error of 0 .0 0 0 6 ~ ~ ~ ~ ~ Manganese may bedetermined by measurements at 403-3 mp.629 The analysis of manganesein cement is thus made possible.630 An oxy-acetylene flame with measure-ment at 2860 A has been used for the determination of iron in siliceousmaterials.g31 The iron may be separated from other interfering metals innon-ferrous alloys by acetylacetone extraction and fed directly into an oxy-acetylene flame for measurement at 3720A. Moderate amounts of alu-618 E.T. Lippmaa, Zhur. analit. Khim., 1955, 10, 169.619 K. Takiura and Y . Takino, J . Pharm. SOC. Japan, 1954, 74, 971.620 A. Anastasi, U. Gallo, and E. Mecarelli, Mikrochim. Acta, 1956, 252.621 R. Crisafio and L. G. Chatten, J . Amer. Pharm. Assoc., Sci. Ed., 1955, 44, 529.622 J. B. Johnson and G. L. Funk, Analyt. Chem., 1955, 27, 1464.623 G. A. Harlow, C. M. Noble, and G. E. A. Wyld, ibid., 1966, 28, 787.624 R. H. Cundiff and P. C. Markunas, ibid., p. 792.625 J. Kashima and &I. Rlutaguchi, Japan Anai-vst, 1955, 4, 420.6 2 6 A. 0. Rathje, Analyt. Chem., 1955, 27, 1583.cj27 F. Burriel-Marti, J. Ramirez-Muiioz, and M. C. Asuncion-Omarrementeria,628 D. W. Brite, Andy#. Chem., 1955, 27, 1815.629 W. A. Dippel and C. E. Bricker, ibid., p.1484.830 J. J. Diamond, ibid., 1956, Rs, 328.c31 J. A. Dean and J. C. Burger, ibid., 1965, 27, 1052.Mikvochim. Acfa, 1856, 362374 ANALYTICAL CHEMISTRY.minium, copper, and nickel do not interfere, and the presence of the acetyl-acetone amplifies (about 6-fold) the sensitivity of the 3720 A line.a2 Tetra-ethyl-lead in petrol may be determined by measurement of the intensity ofthe lead 406 m p line in an oxygen-hydrogen enriched flame.633 Magnesiumhas been determined by the flame-photometric method in aluminium,634 inand in plasma after a preliminary separation with 8-hydroxy-q ~ i n o l i n e . ~ ~ ~ The interference of various cations and anions with themagnesium method has been s t ~ d i e d . ~ ' The determination of rubidiumand caesium in the presence of sodium and potassium has been described.e8Many papers are concerned with the determination of the alkali metals 639-644and alkaline-earth The influence of co-solutes in general hasbeen studied 656 and a few papers deal with aspects of in~trumentation.~~~~ 658Flame spectrograms for eighteen common elements have been publishedby two American and of twenty metals by other Americanworkers.660 In both cases the Beckman D.U.spectrophotometer with thephotomultiplier phototube in place of the usual phototube was used asrecording instrument.Ion-exchange Met hodsThe applications of ion-exchangers to inorganic analysis have beenreviewed and g62 and the selectivity and specificity of variousresins examined.6a The elution constants of last traces of metals from an632 J.A. Dean and J. H. Hardy, Analyt. Chem. 1955, 27, 1533.638 W. Meine, Erdol u. Kohle, 1965, 8, 711.634 S. Ikeda, J . Chem. SOC. Japan, Pure Chem. Sect., 1955, 76, 1122.J. F. P. de Albinati, Anales Asoc. qulm. argentina, 1955, 43, 106.636 S. Davies, J . Biol. Chem., 1956, 216, 643.e3' E. Pungor and I. Konkoly-Thege, Magyar Kim. Folydirat, 1956, 61, 17.638 M. J. Pro, R. A. Nelson, and A. P. Mathers, J . Assoc. OH. Agric. Chem., 1966,639 H. F. Hourigan and J. W. Robinson, Analyt. Chim. Ada, 1965, 13, 179.R40 S. Ikeda, J . Chem. SOC. Japan, Pure Chem. Sect., 1965, 76, 354.641 F. Hegemann and B. Pfab, GEastech. Ber., 1965, 28, 86.642 E. Pungor and E. 8. Zapp, Acta Chim. Acad. Sci. Hung., 1955, 7, 186.641 N.Roy, Analyt. Chem.. 1956, 28, 34.646 F. Reich and F. Grabbe, Tonindustr. Ztg., 1965, 79, 127.646 S. Yokosuka, M. Tanaka, and H. Morikawa, Japan Analyst, 1955, 4, 437.647 E. Pungor and A. Hegediis, Magyar Kkm. Folydirat, 1955, 61, 308.d48 C. F. Rothe and L. A. Saperstein, Amer. J . Clin. Path., 1956, 25, 1076.6J9 I. MacIntyre, Rec. Trav. chim., 1965, 74. 498.G50 R. W. R. Baker, ibid., p. 602.8 5 1 H. J. Dulce, 2. physiol. Chem., 1955, 802, 102.669 S. Ikeda, J . Chem. SOC. Japan, Pure Chem. Sect., 1955, 76, 1258.6L3 M. J. Pro and A. P. Mathers, J . Assoc. Ofic. Agric. Chem., 1956, 89, 225.1x4 G. W. Standen and C. B. Tennant, Analyt. Chem., 1956, 28, 868.6 5 5 S. Yokosuka, Japan Analyst, 1956, 5, 74..iii6 J. Fischer and A. Doiwa, Mikrochim.Ada, 1966, 353.6 5 7 B. L. Valee and M. Margoshes, Analyt. Chem., 1966, 28, 175.8 5 8 Idem, ibid., p. 180.659 H. Watanabe and K. K . Kendall, Appl. Spectroscopy, 1955, 9, 132.660 M. Whisman and B. H. Eccleston, Analyt. Chem., 1956, 27, 1861.G 6 L J. Marc6 Piera, Ajinidad, 1966, 32, 47.662 0. E. Schultz, J . Pharm. Pharmacol., 1966, 8, 382.13~3 R. Greissbach, Angear. Chem., 1966, 67, 606.39, 506.Idem, Magyar Kkm. Folydirat, 1955, 61, 421BELCHEK, SHERIDAN, STEPHEN, AND WEST. 376exchange resin (Wofatit L) have been investigated. 664 Critical values forquantitative separations of various cations on this resin have been studiedby the same author and his co-worker.665 Ion-exchangers have been usedin ethanol 666 and acetone.667 A redox resin has been used for the removalof oxygen from aqueous solution.668 Ion-exchange resins have been usedin the desalting of amino-a~ids,~~~ in the separation of antihi~tarnines,~~~ inthe preparation of O .l ~ - a c i d , ~ ~ ~ and in the preparation of silicon-free alkalifor use in silicon analyses.672Ion-exchange resins have been used in the separation of several ions , viz.,niobium and tantalum,673 zirconium and hafnium,674 cadmium, zinc, andcopper,675 cadmium and zinc from other metals,676 calcium and aluminiumfrom iron,677 iron, chromium, manganese, and molybdenum andphosphate and arsenate from cations,680* 681 aluminium fromfluoride,682 thallium and indium,683 rare earths, 684 fluoride from otheranions,685 lead from fluoride,686 mixtures of condensed phosphates,6s7 andzinc from several metals including cadmium, gallium, and indium.688 Zinchas been determined in aluminium alloys 689 and in ferrites in the presence ofnickel after ion-exchange separation.690 Molybdenum in steels has beendetermined after removal of interfering elements by ion-exchange treat-ment.691 Sulphur has been determined after ion-exchange isolation inmaterials such as pyrites 692 and pigments, etc.693 Potassium has beendetermined by dissolving the precipitated tetraphenylboron salt in acetoneand titration of the tetraphenylboron acid released by a cation-exchanger inthe hydrogen form.694 Free acid in ceric solutions may be determined by864 D. Jentzsch, 2. analyt. Chem., 1955, 148, 321 and 325.88s D. Jentzsch and I.Pawlik, ibid., 1955, 147, 20.668 K. K. Caroll, Nature, 1955, 176, 398.867 H. Kakihana and K. Sekiguchi, J . Pharm. SOC. Japan, 1955, 75, 111.668 G. Manecke, Angew. Chem., 1955, 67, 613.669 G. C. Mueller, G. Bowman, and A. Herranen, Analyt. Chem., 1955, 27, 1357.670 S. M. Blaug, Diss. Abs., 1955, 15, 983.1 3 7 ~ S. Hirano and M. Kurobe, Japan Analyst, 1955, 4, 379.672 S. Fisher and R. Kunin, Nature, 1956, 177, 1125.673 M. J. Cabell and I. Milner, Analyt. Chim. Acta, 1955, 13, 258.674 K. S. Rajan and J . Gupta, J . Sci. Ind. Res. India, 1955, B, 14, 453.675 Y. Yoshino and M. Kokima, Japan Analyst, 1955, 4, 311.676 S. Kallmann, C . G. Steele, and N. Y . Chu, Analyt. Chem., 1956, 28, 230.677 0. Samuelson and B. Sjonberg, AnaZyt. Chim.Acta, 1956, 14, 121.678 D. I. Rybachikovand V. F. Osipova, DokZady Akad. Nauk S.S.S.R., 1954,96, 761.67s T. Matsuo and A. Iwase, Japan Analyst, 1955, 4, 148.OB0 Y. Yoshino, ibid., 1954, 3, 121.881 Sh. T. Talipov and T. I. Fedorova, Ref. Zhur., Khim., 1955, Abstr. No. 26,501.682 J. Coursier and J . Saulnier, Analyt. Chim. Ada, 1966, 14, 62.683 L. B. Ginzburg and g . P. Shkrobot, ZavodsRaya Lab., 1955, 21, 1289.684 W. E. Nervik, J . Phys. Chem., 1955, 59, 690.685 W. Funasaka, M. Kawase, T. Kojima, and Y. Matsuda, Japan Analyst, 1955,6a6 C. Mader, Chemist-Analyst, 1955, 44, 86.687 T. V. Peters and \Y. Rieman, Analyt. Chim. Acta, 1956, 14, 131.6 8 8 J. A. Hunter and C. C. Miller, Analyst, 1956, 81, 79.080 K. Kodama and T. Kanie, Japan Analyst, 1955, 4, 627.690 J .Lowen and A. I,. Carney, Analyt. Chem., 1955, 27, 1966.691 I. P. Alimarin and A. M. Medvedeva, Zavodsliaya Lab., 1955, 21, 1416.892 S. Hirano and M. Kurobe, Japan Analyst, 1955, 4, 552.693 S. Hirano, M. Kurobe, and F. Ito, ibid., p. 565.894 H. Flaschka and F. Sadek, Chemist-AnnZyst, 1956, 45, 20.4, 514376 ANALYTICAL CHEMISTRY.cation exchange and deduction of the acid corresponding to the ceric ionknown to be present.695 The application of a cation-exchange resin t o theanalysis of a bronze has been described.606The reduction of ferric and cupric ions adsorbed on a cation resin bysolutions of iodide has been and the detection of germaniumby means of a resin saturated with haematoxylin has been des~ribed.~~8 Thereactions occurring between chromic complexes and cation-exchange resinshave been investigated.G99Inorganic ChromatographyThe practice, technique, and theory of inorganic paper-chromatographyhave been reviewed.700* 701 The behaviour of various cations and theircounter-ions has been examined.702 Other workers have studied factorsaffecting RF and S values with impregnated filter-papers 7w and the r81eof the hydrogen-ion concentration of solvents in inorganic paper-chromato-graphy. 704 The rates of migration of cations during paper-chromatographyunder varying conditions have been studied.705 A new method for cationsof the first group [Ag, Pb, H~(I)] has been described,706 and also a modifiedtechnique for general application to inorganic work.707 German workershave investigated the chromatography of various electrolytes on silica gel.708The location of acid zones on paper strips has been studied with particularreference to organic acids, but the method may also be applied to weaklydissociated inorganic acids.709 A method of precipitation chromatographyon filter-paper impregnated with 8-hydroxyquinoline has been used for thedetection of copper, iron, cobalt, and nickel.710 American authors haveoutlined a method and procedure for the partial acetylation of paper forchr~matography.~~~ The RF values for over forty metal ions, by paper-chromatography with butanol saturated with aqueous molar solutions ofvarious organic complexing acids, have been listed. 712 Yugoslav authorshave published a new method for the separation of certain cations withvarious solvent systems.713 The paper-chromatography of metal chelate695 V. V. Oshchapovskii, Ukrain. khim. Zhur., 1955, 21, 384.696 V. I. Lenskaya and L. I. Penkova, Ref. Zhur., Khim., 1956, Abstr. No. 14,268.697 H. Kakihana and K. Katou, J . Chem. SOL. Japan, Pure Chem. Sect., 1955, 76, 499.698 H. Kakihana, Y. Mori, and K. Yamasaki, ibid., p. 215.699 Y. Inoue, A. Kawamura, K. Wada, and H. Okamura, Japan Analyst, 1955, 4,700 J. Moreno Calvo, Rev. Cienc. apZ., 1955, 9, 510.?O1 M. Lederer, Mikrochim. Ada, 1956, 43.702 S. Harasawa and T. Sakamoto, J . Chem. SOC. Japan, Pure Chem. Sect., 1955, 76,703 A. C. Chatterji and H. Bhagwan, Z. analyt. Chem., 1956, 149, 339.704 G. Alm&ssy and I.Dezso, Magyar Kkm. Folydirat, 1956, 82, 60.705 G. Sommer, 2. analyt. Chern., 1955, 147, 241.706 K. Suzuki, J . Chem. SOC. .Japan, Pure Chem. Sect., 1955, 76, 184.707 K. Krislinamurti and B. V. Dhareshwar, Research, 1955, 8, 526.7 0 8 F. Umland and K. Kirchner, 2. anorg. Chem., 1955, 280, 211.709 A. L. Cochrane, Analyst, 1955, 80, 909.710 H. Nagai, J . Chem. SOC. Japan, Pure Chem. Sect., 1955, 76, 1246.7 1 1 E. hI. Buras and S. R. Hobart, Analyt. Chem., 1955, 27, 1507.712 J . R. A. Anderson and E. C. Martin, Analyt. Chim. Acta, 1955, 13, 253.713 G, StefanoviC, IF. Janjik, and R. Crnojevid, Bull. SOC. chim. Beograd, 1955, 20, 343.277 and 281.1322BELCHER, SHERIDAN, STEPHEN, AND WEST. 377compounds of the P-diketones, acetylacetone, 714 and 2-thenoyl- and 2-furoyl-perfluorobutyrylmethane has been reported.715 Japanese workers havedescribed the application of some organic reagents , viz. , phenylthiosemi-carbazide, gallein, and thiogallein a s detection reagents for metals on paper-chromatograms. 716 The chromatographic separation of different elements indifferent valency states has been studied.717The separation of polythionic acids 718+ 719 and of condensed phos-phates 7209 721 has been studied fairly extensively. Paper-chromatographicmethods have been described for the separation and determination of verymany metals. Thus methods have been described for : the rare earths; 722nickel in cobalt salts ; 723 nickel and cobalt ; 724 cobalt and copper; 725cobalt(II1) compounds ; 726 platinum metals ; 727 lead, mercury, bismuth,copper, and cadmium ; 728 arsenic ; 729* 230 copper and methods for assessingit on paper; 7319 732 boron in the presence of the Group I metals; 733uranium ; 734-736 the alkali and alkaline earths ; 737-741 germanium ; 7429 743titanium, zirconium, and thorium ; 74Q titanium, zirconium, iron, andthallium ; 745 molybdenum ; 746-748 and 750 The quantitativechromatography of 18 anions on alumina-impregnated paper has been714 J.E. Strassner, Diss. Abs., 1955, 15, 1309.715 E. W. Berg and J. E. Strassner, Analyt. Chem.. 1955, 27, 1131.'16 T. Naito and N. Takahashi, Japan Analyst, 1954, 3, 125.717 F. H. Pollard, J. I?. W. McOmie, and A. J. Banister, Chem. and Ind., 1955, 1598.718 F. H. Pollard, J.F. W. McOmie, J. V. Martin, and C . J. Hardy, J., 1955, 4332.719 E. Scaffone and E. Carini, Ricerca sci., 1955, 25, 2109.720 J. Meissner, 2. anorg. Chem., 1955, 281, 293.721 W. Koberlein and H. Mair-Waldburg, 2. Lebensmitt. Untersuch., 1955, 102, 231.722 M. Lederer, Nature, 1955, 176, 462.73s S. Harasawa and I<. Takasu, J . Chem. SOC. Japan, Pure Chem. Sect., 1955, 76,724 E. M. Barilari and M. A. de Uiia de Carletto, Rev. Asoc. bioquim. argentina, 1955,725 A. Lacourt and P. Heyndryckx, Nature, 1955,176, 880.726 M. Lederer, Analyt. Chim. Ada, 1955, 13, 350.727 N. F. Kember and R. A. Wells, Analyst, 1955, 80, 735.728 A. R. Vasudeva-Murthy and V. A. Narayan, Naturwiss., 1955, 42, 439.7ee I. I. M. Elbeih. Chemist-Ana2yst. 1955, 44, 20.730 K.M. Ol'shanova and K. V. Chmutov, Zhur. analit. Khim., 1956, 11, 94.731 G. AlmAssy and I. Dezsij. Magyar Kkm. Folydirat, 1955, 61, 158.732 T. Yamada, Japan Analyst, 1954, 3, 216.733 S. Muto, J . Chem. SOC. Japan, Puve Chem. Sect., 1955, 76, 294.734 G. Almkssy and M. VigvAri, Magyar Kkm. Folydivat, 1955, 61, 109.735 J. Szonntagh, L. Faddy, and A. Jahosi, ibid., p. 312.736 C. Soye, Compt. rend., 1955, 240, 1894.737 H. T. Gordon and C. A. Hewel, Analyt. Chem., 1955, 27, 1471.738 R. J. Magee and J. B. Headridge, AnaZyst, 1955, 80, 785.73R G. StefanoviC and T. JanjiC, Bull. SOC. chim. Beograd, 1955, 20, 569.740 J. Fouarge and G. Duyckaerts, Analyt. Chim. Acta, 1956, 14, 527.741 G. Sommer, 2. analyt. Chem., 1956, 161, 336.742 E. Bertovelle and G.Fanfani, Chirnica e Industria, 1955, 37, 777.743 R. G. decarvalho and M. Lederer, Analyt. Chim. Acta, 1956, 13, 437.744 G. Alm&ssy and 2. Nagy, Acta Chim. Acad. Sci. Hung., 1955, 7, 325.745 S. Harasawa and T. Sakamoto, J . Chem. SOC. Japan, Pure Chem. Sect., 1956,746 G. AlmAssy and J. Straub, Acta Chim. Acad. Sci. Hung., 1955, 7, 253.747 M. I. Candela, E. J. Hewitt, and H. M. Stevens, Analyt. Chim. Acta, 1056, 14, 66.748 H. M. Stevens, ibid., p. 126.750 A. J. Blair and D. A. Pantony, Analyt. ChiPn. Ada, 1956, 14, 545.173.20, 173.77, 165.C . Bighi, Ann. Chim. (Italy), 1955, 45, 1087378 ANALYTICAL CHEMISTRY.described. 751 The chromatography of the halides has also been753Inorganic ElectrophoresisThe technique of zone electrophoresis on paper has been reviewed.754An investigation has been made into the separation of cations by means ofcomplex formation with polyphosphates. 755 A quantitative method hasbeen evolved for the determination of small amounts of barium and alu-minium by measurement of the width of absorption bands. 756 The techniquehas been used to concentrate inorganic ions on paper by applying currentfrom the tip of a platinum wire.757 The complete separation of niobiumand tantalum has been effected by electrophoresis on paper as oxalic acidcomplexes in a citrate buffer at pH 3.42; a current density of 4 mA (220 v)was used for 4-8 Qualitative and quantitative analysis of thealkali metals has been effected by paper electrophore~is.~~~ The simul-taneous determination of ferrous and ferric ions is possible on WhatmanNo.1 paper soaked with 0-lwsulphuric a ~ i d . ~ ~ O Wood has described thepaper electrophoresis of selenodithionates, selenotetrathionates, and telluro-tetrathionates. 761 Japanese authors have described the determination ofhalide ions by electrophoresis in dilute lactic acid at 300 v.762T. s. w.Spectroscopic Methods of AnalysisSpectroscopic methods were last reported in 1954,763 when the varioustechniques were assessed and compared in some detail. The scope ofapplication of each range of wavelength remains essentially as at that time,and it is not possible here to attempt to review details of the great activitywhich continues in all branches of the subject. Recent reviews coveringthe period from 1954 are available on X-ray method^,^^^^ 765 ultravioletspectroscopy,766 emission spectro~copy,76~ and Raman spectroscopy.768More general surveys have also been given.769-771 Infrared spectroscopy751 A. Murata, J. Chem. SOC. Japan. Pure Chem. Sect., 1955, 76, 517.752 S. Harasawa and S. Hayano, ibid., p. 789.753 L. C. Mitchell, J. Assoc. OH. Agric. Chem., 1955, 38, 532.754 L. F. J. Parker, Analyst, 1955, 80, 638.765 M. Maki, Japan Analyst, 1955, 4, 302.768 Idem, ibid., p. 413.757 G . de Vries and E. van Dalen, Analyt. Chim. Acla, 1965, 13, 554.7 5 * E. Bruninx, J . Eeckhout, and J . Gillis, ibid., 1956, 14, 74.759 0. Schier, Angew. Chem., 1956, 68, 63.F. Brom, Chem. Listy, 1955, 49, 938.7 6 1 H. VC'. Wood, Chem. and Ind., 1956, 468.7e2 E.Ohara and H. Nagai, J. Chem. SOC. Japan, Pure Chem. Sect., 1965, 76, 291.783 D. H. Wliiffen, Ann. Reports, 1954, 51, 365.764 H. A. Liebhafsky and E. H. Winslow, Analyf. Chem., 1956, 28, 583.765 B. Post and I. Fankuchen, ibid., p. 591.766 R. C. Hirt, ibid., p. 579.7e7 W. F. Meggers, ibid., p. 616.788 E. J. Rosenbaum, ibid., p. 596.769 R. F. Branch, Research, 1956, 9, 268.77O N. H. E. Ahlers, Chem. and Ind., 1956, 93.7 7 1 E. A. Braude and F. C. Nachod (editors), " Determination of Organic StructureBELCHER, SHERIDAN, STEPHEN, AND WEST. 379has also been reviewed,772 but with relatively slight emphasis on recentanalyses, and accordingly a somewhat fuller outline is given here of the useof infrared methods.Infrared Methods.-Infrared spectroscopy remains prominent amongmethods potentially able to solve outstanding analytical problems, and itsapplications continue to cover a very wide variety of substances.Theaccumulation of data makes it very desirable that fullest use should be madeof the new documentation of molecular spectroscopy, of which details werementioned in the Annual Reports for 1955.773 A number of papers alsocontain collections of numerous infrared data. Thus Pierson, Fletcher, andGantz 774 give spectrograms for 66 gases, classified to assist in the analysisof unknown mixtures.Infrared spectra have been applied to the analysis of many mixtures,including nitro toluene^,^^^ arylsilanes, 776 alkylbenzenes, 777 various nitriles, 778substituted p y r i d i n e ~ , ~ ~ ~ and other heterocyclic substances,780 polyhydricphenols,781 and mixtures of maleic and fumaric esters.782 Two closelyrelated alkaloids, atropine and scopolamine, can be separately determined, 783as can the components of mixtures of alkyd, urea-formaldehyde, andmelamine-formaldehyde resins.784 Other systems studied are condensedphosphates,785 the insecticide allethrin and associated impurities,786 anddigitonin preparations. 787 Water in fuming nitric acid has been determinedby infrared absorption.788 Several papers deal with aldehydes and theinfluence of substituents on their spectra.789* 790In wider fields, considerable work has been done on fatty acids 7919 792and their salts,793 the spectra of which appear more sensitive to structurethan those of the acids themselves.A number of steroid derivatives havebeen studied and bands determined for structures containing the reducedby Physical Methods,” Academic Books Ltd., 1955; E. A. Braude, “ Ultraviolet andVisible Light Absorption ”: R. C. Gore, “ Infrared Light Absorption ”; F. F. Cleve-land, “ Raman Spectra ”; E. B. Wilson, jun., and D. R. Lide, jun., “ MicrowaveSpectroscopy.”772 R. C. Gore, Analyt. Chem., 1956, 28, 577.773 Ann. Reports, 1955, 52, 81.774 R. H. Pierson, A. N. Fletcher, and E. St. C . Gantz, Analyt. Che,m., 1956, 28,776 F. Pristera and M . Halik, ibid., 1955, 27, 217.776 M. Margoshes and V. A. Fassel, ibid., p. 351.777 W. J. Potts, jun., ibid., p. 1027.7 7 8 E. F. Dupre, A. C. Armstrong, E.Klein, and R. T . O’Connor, ibid., p. 1878.G. L. Cook and F. M. Church, ibid., 1956, 28, 993.780 W. H. Tallent and I . J. Siewers, ibid., p . 953.781 C. C. Bard, T. J. Porro, and H. L. Rees, ibid., 1955, 27, 12.782 W. L. Walton and R. B. Hughes, ibid., 1956, 28, 1388.783 R. S. Browning, S. E. Wiberley, and F. C. Nachod, ibid., 1955, 27, 7 .784 C. D. Miller and 0. D. Shreve, ibid., 1956, 28, 200.785 D. E. C. Corbridge and E. J. Lowe, ibid., 1955, 27, 1383.i 8 6 S. I<. Freeman, ibid., p. 1268.i 8 7 0. H. Gaebler, J. Parsons, and W. T. Beher, ibid., p. 441.789 D. F. Eggers and W. E. Lingren, ibid., p. 1328.701 D. L. Guertin, S. E. Wiberley, Mr. H. Bauer, and J. Goldenson, ibid., 1956, 28,702 R. T. Holman and P. R. Edmondson, ibid., p.1533.7B3 E. Childers and G. W. Struthers, ibid., 1955, 27, 737.1218.L. White, jun., and W. J. Barrett, ibid., 1956, 28, 1538.S. Pinchas, ibid., 1955, 27, 2.1194380 ANALYTICAL CHEMISTRY.ring A.7" Spectra of six adrenocortical hormones are discussed 795 inrelation to structural features, and the bands reported for the 3-phenyl-2-thiohydantoins of 22 amino-acids 796 should prove useful in peptide studies.Other collections of data are for 17 dkyl hydro peroxide^,^^^ 10 20-iso-sapogenin acetates,7u8 and 40 2 : 4-dinitrophenylhydra~ones.7~~ An ex-tensive paper on the infrared spectra of bituminous coals and relatedmaterials shows that the technique is contributing to the diagnosis ofsuch complex structures.In the measurement of low concentrations, various means of enrichmentof the desired material are frequently used, such as fractional crystallis-a t i ~ n , ~ ~ ~ or, in particular, absorption on such substances as silica gel orcharcoal.The former absorbant was used to enrich ozone in the measure-ment of its atmospheric concentration,m1 ultraviolet spectroscopy beingused in this example. Traces of alkyl benzenesulphonates in water havebeen determined specifically for the first time, by means of infrared spectro-scopy following enrichment by absorption on charcoal. m2In other cases, emphasis is on continuous monitoring of material withoutany pretreatment. For such purposes, the sensitivity of non-dispersiveinfrared analysers has been made very great, and applied, for example, tocontinuous monitoring of organic chemicals in the atmosphere,803* atconcentrations from 0-1 to 10 parts per million.Technical means of im-proving the selectivity and sensitivity of such analysers have been de-scribed.s05*Spectroscopic technique in the infrared has been the subject of a numberof papers. Kaye has reviewed methods for the near-infrared region.807A device for the automatic measurement of integrated absorbance has beendescribed.8O8 Work has appeared on spectroscopic standards for rneasure-ments on solids, for which powdered calcium carbonate is suggested,809 andfor gaseous spectroscopy.810 Several papers deal with the potassium bromidedisc technique,811 and its theoretical background.*l2. 813 Technique forquantitative estimations in aqueous solution at 6-5-10 p has been de-scribed. 814794 H. Rosenkrantz and P. Skogstrom, Analyt. Chem., 1956, 28, 31.795 A. L. Hayden, ibid., 1955, 27, 1486.79G L. K. Ramachandran, A. Epp, and W. B. McConnell, ibid., p. 1734.7 9 7 H. R. Williamsand H. S. Mosher, ibid., p. 617.' ~ 3 1 3 C. R. Eddy, M.-A. Barnes, and C. S. Fenske, ibid., p. 1067.799 L. A. Jones, J. C . Holmes, and R. B. Seligman, ibid., 1956, 28. 191.800 R. A. Friedel and J. A. Queiser, ibid., p. 22.802 E. M. Salee et al., ibid., p. 1822.SO3 F. E. Littman and J. Q. Denton, ibid., p. 946.SO4 V. C. Shore and &!I. Katz, ibid., p. 1399.S O 5 W. J. Baker, ibid., p. 1391.A. W. Wotnng, R. F. Wall, and T. L. Zinn, ibid., p. 1396.ao7 W. Kaye, Spectrochim. Acta, 1955, 7, 181.V. 2. Williams, V. J. Coates, and F. Gaarde, Analyt. Chem., 1955, 27, 2017.*OD L. E. Kuentzel, ibid., p. 301.F. Pristera and A. Castelli, ibid., p. 457.811 J. J. Kirkland, ibid., p. 1537.G. Duyckaerts, Spectrochim. A d a , 1955, 7, 25.J . Bonhomme, ibid., p. 32.W. J. Potts, jun., and N. Wright, Amz@vt. Chem., 1966, 28, 1265.F. E. Littman and C. W. Marynowski, ibid., p. 819BELCHER, SHERIDAN, STEPHEN, AND WEST. 381Microwave Methods.-The potentialities of microwave spectroscopy 7719 816€or chemical and isotopic andysis were briefly summarised in the AnnualReports for 1954. Though few applications have been made, the past twoyears have seen increased activity in microwave spectroscopy in Europe,and the specialised equipment, such as klystron oscillators, crystal detectors,and waveguide components, has now become more easily available commer-c i d y on this side of the Atlantic. Townes and Schawlow consider analyticalapplications in some detail in their standard work on microwave spectro-scopy.816 To illustrate the advantages of the immense resolving power, theypoint out that, if each of a hundred substances in a mixture has 20 absorptionlines in a 10,000 Mc./sec. interval, then the chance that more than a third ofthe lines of any one substance will be overlapped by others is less than onein a million. This feature is continually utilised by microwave spectro-scopists in the detection of impurities and isotopically substituted molecules.Microwave spectroscopic analysis depends on the availability of extensivetables of observed spectra, and the compilation now being completed bythe National Bureau of Standards will be much larger than any previouslyavailable.Detailed publications have appeared on the theory and technique ofmeasurement of relative and absolute intensities of microwave absorp-tions,sl7* 8181 819 a matter clearly fundamental to all quantitative studies.With further work on specific cases for which the method is suitable, theattainable precision should increase towards that realised in the simplerproblem of isotopic analysis.Since the technique is bound to be more specialised than, for example,infrared spectroscopy, the expense of wide frequency coverage may not benecessary. Townes and Schawlow 816 find that about 60% of the sub-stances for which spectra are known possess one or more lines in any intervalof 5000 Mc./sec., a range which might be covered by one good klystronoscillator. Of these 60%, about half would have lines strong enough to bedetected in a very simple spectrometer. For specific problems, such as theisotopic analysis of nitrogen or carbon, the narrow frequency range requiredcould be obtained cheaply as harmonics of long-lived 3 em. oscillators. Ithas also recently become clear that the expense of commercial crystaldiodes can be avoided, and other advantages gained, by use of adjustablesilicon-tungsten contacts as detectors and harmonic generators.Nuclear Magnetic-resonance Methods.-There is now a wide realisation ofthe potentialities of nuclear magnetic-resonance spectroscopy 7639 7709 815,821for the solution of special analytical problems. The technique derives itspower from the particular causes of the absorptions and their fine structures,815 B. P. Dailey in " Physical Methods of Organic Chemistry. Vol. I11 " (Ed.A. Weissberger), Interscience Publishers, Inc., New York, 1954, p. 2321.810 C. H. Townes and A. L. Schawlow, '' Microwave Spectroscopy," McGraw-HillBook Co. Inc., New York, 1955, Chapter 18.81' D. H. Baird and G. R. Bird, Rev. Sci. Instr., 1954, 25, 319.B18 G. R. Bird, ibid., p. 324.819 H. R. Johnson and M. W. P. Strandberg, J . Chem. Phys., 1952, 20, 687.820 A. L. Southern, H. W. Morgan, G. W. Keilholtz, and W. V. Smith, Analyt. Chem.,s21 J. N. Shoolery, ibid., 1954, 26, 1400.1951, 23, 1000382 ANALYTICAL CHEMISTRY.which are often strikingly effective in revealing structural features andrelationships between groups. It also has fundamentally simple relation-ships between intensities and concentrations. High-resolution spectra dueto proton and fluorine resonances are being rapidly accumulated for a widevariety of materials, and chemical shifts in the spectra of other nuclei arebeing reported. Some of these, for example shifts in the phosphorus,822nitrogen,s23 and oxygen-17 824 resonances, appear to promise ultimatelysome revolutionary changes in analysis and process control. For instance,separate oxygen-17 resonances,824 observed with the small natural concen-tration of this isotope, are resolvable for such substances as water, hydrogenperoxide, nitrates, nitrites, and other important chemicals. A similarresolution of nitrogen resonances in important groupings is whilethe phosphorus resonances have already been discussed specifically foranalytical purposes,822 and relative concentrations of different phosphorus-containing anions measured to within 2-10%. A documentation systemfor high resolution nuclear magnetic-resonance spectra is at present beingdevised by the American Petroleum Institute.825J. S.K. BELCHER.J . SHERIDAN.W. I. STEPHEN.T. s. WEST.822 C. F. Callis, J . R. Van Waser, and J. N. Shoolery, Analyt. Chem., 1956, 28, 269.828 B. E. Holder and M. P. Klein, J. Chem. Phys., 1955, 23, 1956.a24 H. E. Weaver, B. M. Tolbert, and R. C. LaForce, ibid., p. 1956.S 2 j American Petroleum Institute Research Project 44

ISSN:0365-6217    

DOI:10.1039/AR9565300332

出版商:RSC    

年代:1956

数据来源: RSC

摘要:

CRYSTALLOGRAPHY.1. GENERAL.Introduction.-This Report covers the years 1955-56, and follows thebiennial report in the 1954 volume (the special section in 1955, on thecrystallography of proteins, is to be regarded as an intercalation). It isdivided into four sections, one dealing with general topics, two with structures-inorganic and organic-and a fourth giving a short account of recentwork on ferroelectrics.have appeared, covering work published in 194044. The link with thepreceding volumes (1-7) of Strukturbericht is thus completed ; and, whenVol. 14 appears during 1957, the coverage will extend to 1951. A volumeof the Landolt-Bornstein “ Tabellen ’’ 2 issued in 1955 embodies a moreconcise, but remarkably complete, summary of all crystallographic workbefore 1952; the first half of the book (some 500 pages) deals with crystalstructures, the second with spectroscopic data for solids.Volumes of“ Solid State Physics ” are being issued periodically; the first deals mainlywith metals, the second with nuclear magnetic resonance, neutron diffraction,and displacement of atoms by irradiation. “ The Chemistry of the SolidState ” comprises 15 essays on crystal growth, solid reactions, and relatedtopics. Monographs on neutron diffraction and nuclear magnetic reson-ance contain much of interest to the chemist and crystallographer. Kitai-gorodskii’s book deals in particular with the packing of molecules intocrystal lattices. The appearance of the journal KristaZZugraJya betokensthe large amount of crystallographic work being done in the U.S.S.R.-workwhich is not at present adequately known in the West, and which can bebut perfunctorily covered in this Report. Also new is the Journal of thePhysics and Chemistry of the contents of whose first number (Sept.-Oct., 1956) are principally of interest to the crystal physicist.A meetingof the International Union has been reported in summary.1° The FaradaySociety’s Discussion on micro-wave and radiofrequency spectra l1 has sec-tions on paramagnetic and nuclear magnetic resonance, illustrating thevalues of these techniques in the study of crystals, and an informal discussionon melting has been summarised.12 A review summarises the methods forlocating hydrogen atoms in crystals,13 and describes that based on protonicDuring the period under review, Vols.8 and 9 of ‘‘ Structure Reports ”“ Structure Reports,” Vols. 8 and 9, Oosthoek’s Uitgevers, Utrecht.Zahlenwerte und Funktionen, Band I, Teil 4, Berlin, 1954.(Ed.) F. Seitz and D. Turnbull, Academic Press, New York, 1955 etc.G. E. Bacon, “ Neutron Diffraction,” Oxford University Press, 1955.E. R. Andrew, “Nuclear Magnetic Resonance,” Cambridge University Press, 1955. ’ A. I. Kitaigorodskii, “ Organic Crystal Chemistry,” U.S.S.R. .4cademyof Sciences,Published by the U.S.S.R. Academy of Sciences, Moscow.Published by Pergamon Press, New York, 1956.* (Ed.) W. E. Garner, Buttenvorths Scientific Publications, London, 1955.Moscow, 1955.1” A. J. C. Wilson, Nature, 1956, 178, 177.l 1 Discuss.Farada? Soc., 1965, 19.l 2 Tmns. Farads?! Sor., 1956, 52, 882.l 3 I < . E. Richards, vzrarl. Rev., 1956, 10, 480384 CRY STALLOGE4PIIY.resonance in more detail. A translation l4 of a Russian review on thelattice energy of ionic crystals deals in particular with semi-empiricalmethods for assessing these energies and related properties of crystals.In this Report, d(X-Y), or d ( X - - Y), stands for the distance betweenthe bonded, or non-bonded, atoms X and Y, whilst L(X-Y-2) stands forthe bond-angle at Y. Limits of error, when stated, represent standarddeviations (e.s.d.) estimated by a currently accepted procedure for assessingaccuracy.15 The true error is very unlikely to exceed three times e.s.d.‘‘ Analysis ” in the present context means “ crystal structure analysis.”The Phase Problem.-No fundamental advance has been made towards ageneral solution of this critical problem,16 though it has been re-cast into amore satisfactory form by Bertaut.17 (The structure of meyerhofferite,2Ca0,3R,03,7H,0, has been solved by the Hauptman-Karle method ;it contains [B303(OH)J2- ions, with a six-membered ring of alternate boronand oxygen atoms; such a structure could presumably have been solvedby the heavy atom method.) Meanwhile the majority of structures con-tinues to be solved by conventional methods. When all specially favourablefeatures are absent, some form of three-dimensional Patterson synthesis isthe most serviceable method of attack, and is becoming more practicable aselectronic computing aids become more widely available.This develop-ment is also reflected in the increasing proportion of analyses which arebeing refined to a high precision.Absolute Configuration.-This long-standing and formidable problem hasrapidly resolved itself since a method of circumventing Friedel’s law wasintr0d~ced.l~ (A very readable account of the method has recently beenwritten by its discoverer.20) Configurations have been determined for anumber of key-molecules, and thereby absolute configurations are impliedfor a great range of other, stereochemically related systems. The configur-ation of the strychnine molecule lias been shown21 to be the opposite ofthat chosen (arbitrarily) in the original analysis of the hydrobromide. Thescattering of the X-rays from a copper target proved to beMe I ~ sufficiently anomalous at the bromine atom, so that no un-Is-0 orthodox X-ray source was needed.IH...C...H It has been pointed out 22 that the configuration of aIH - C - N H ~ complex molecule can be assigned from a normal X-rayI\o- (,) whose absolute configuration is already known. This principlehas been applied independently23 to a naturally occurringa-amino-acid sulphoxide. Since the configuration in the b-amino-acidgrouping was already known, that for the whole molecule was requiredC analysis, provided the molecule includes an asymmetric group1 4 A. F. Kapustinskii, Quart. Rev., 1956, 10, 288.l5 See, e.g., G. A. Jeffrey and D. W. J. Cruickshank, ibid., 1953, 7, 335.l6 Ann.Reports, 1954, 51, 373.l7 E. F. Bertaut, Acla Cryst., 1955, S , 823; 1956, 9, 769.18 C . L. Christ and J. R. Clark, ibid., 1956, 9, 830.1 9 Ann. Reports, 1951, 48, 361.2O J. M. Bijvoet, Endeavour, 1955, 14, 71.z1 A. I;. Peerdeman, Acln Crysl., 1956, 9, 824.22 A. McL. Mathieson, ibid., 1956, 9, 317.23 R. IIinc and D. Rogers, Chem. and Ind., 1956, 1428SPEAKMAN GENERAL. 385by the X-ray work to be as represented (l).* Thus the stereochemistry atan asymmetric sulphur atom was defined for the first time.makes public forthe first time the Fourier projection derived by Peterson and Levy24 in1953 from their neutron-diffraction study of deuterated ice. This mapshows ‘‘ half-hydrogens ” with d(O+D) = 1.01 A, at each of two positions(very nearly) along the 0 - - - 0 line (d = 2-76 A), and thus graphicallysubstantiates the disordered structure originally proposed by Pauling 25 toaccount for the residual entropy of ice.Objections to this structure onenergetic grounds seem to be removed by a more refined calculation.26 Anumber of acid salts contain short hydrogen bonds which, by crystallo-graphic requirement, are (at least effectively) ~ymmetrical.~~ Sodiumsesquicarbonate, NaHCO3,Na,CO3,2H,O, is a well known case, and thefavourable projection of its structure has been studied by neutron-diff rac-tion,28 and by refined X-ray methods at 18” and at -170°.29 The latterwork reveals a small (and possibly significant) diminution of d ( 0 * - 0) inthe symmetrical bond at lower temperature, though the over-all picture iscomplicated since one of the hydrogen bonds to the water molecule expands.The neutron-diff raction work shows the position of the acidic hydrogen atomwith greater clarity; it appears as a peak centrally placed between the twooxygen atoms, and elongated-though much less so than in KH,P0430-along the direction of the bond.In potassium hydrogen bisphenylacetate,which also possesses a symmetrical bond, neutron diffraction 31 againreveals a centrally placed peak; but now the peak, though considerably‘ I smeared,” shows no elongation along the bond, so that a genuinely sym-metrical bond is not ruled out in this case. On the other hand, the moleculesin solid resorcino132 are linked together by long hydrogen bonds withd(O - 0) = 2.72 A ; here neutron diffraction shows a single hydrogenpeak about 1.02 r f from one oxygen atom.Ubbelohde and Gallagher33have considered the short hydrogen bond in crystals as an acid-basephenomenon, which may imply alternative sites for the proton (e.g.,AH.. . B Z A - . . . HB+), and thus involve co-operative effects ; theyreview a wide range of experimental data from this aspect.Thermal Vibrations--In essence the refinement of a crystal structureimplies minimising the differences between the observed (F,) and calculated(F,) structure amplitudes. In deriving F,-values from the postulatedatomic positions, the atomic scattering functions (f) of the various atoms areHydrogen Bonds.-Vol. 2 of ‘‘ Solid State Physics ”24 S. W. Peterson and H.A. Levy, Phys. Rev., 1953, 92, 1082 ; for a full account of25 L. Pauling, J . Amer. Chem. SOC., 1935, 57, 2680.2G K. S. Pitzer and J. Polissar, J . Ph-ys. Chem., 1956, 60, 1140.2 7 Ann. Reports, 1954, 51, 390; see also Nature, 1948, 162, 695.28 G. E. Bacon and N. A. Curry, Acta Cryst., 1956, 9, 82.29 R. Candlin, ibid., p. 545.30 G. E. Bacon and R. S. Pease, Proc. Roy. SOG., 1953, A , 220, 397.31 Personal communication from Dr. Bacon.32 G. E. Bacon and N. A. Curry, Proc. Roy. Soc., 1956, A , 235, 552.33 A. R. Ubbelohde and K. J. Gallagher, Acta Cryst., 1955, 8, 71.this important work, see Acta Cryst., 1957, 10, 70.* The conventional symbol of a bar alongside represents the lone pair of electrons,in this case on the sulphur atom.REP.-VOL . L III 386 ClCYS'l'Al,l,OGRA PHY.needed. The values of f depend on the distribution of electron-density inthe atom, and they are almost always computed on the assumption that thedistribution is spherically symmetrical, and in fact that obtaining in theisolated atom. These assumptions cannot be valid for a bonded atom,though they work rather well in practice because bonding affects only theouter fringes of the atoms, which make a minor contribution to the totalscattering power. Atoms in a crystal are always vibrating with a mean-square amplitude, s, which in general increases with temperature. Theelectron-density peak is therefore flattened and broadened (" smeared ") ;and this can be taken into account by modifying f with a Debye, or tem-perature, factor, exp [ - (B sin 0) /I2] ; B (often itself referred to as thetemperature factor) is a measure of the smearing and is proportional to 2,and the other symbols have their usual meanings.Various degrees offinesse are then possible in calculating F, : (1) The same parameter, B, canbe used for all the atoms, or for all of the same chemical kind; (2) differentvalues of B can be fitted to each individual atom; either way, the atom,though smeared, still has spherical symmetry; its vibration is taken to beisotropic ; (3) anisotropy of vibration can be introduced by choosing severalvalues of B for each atom ( e g . , along the x-, y,- and z-directions). This lastprocedure implies that the electron-density peak is an ellipsoid, as indeed isoften observed. In its fullest form, it involved introducing up to nine para-meters (three of position, three of anisotropy, and three for its orientation)for each atom in the asymmetric unit; this can be justified only when theexperimental data are adequate in number and accuracy.What has beeiirecognised only recently is the importance of studying the vibrations them-selves in detail. There are two reasons for doing so.First, high accuracyin the atomic co-ordinates is unlikely to be attained until a proper allowancehas been made for vibrations and particularly for their anisotropy if this beconsiderable. When the differences between F, and F, arise mainly froman insufficient recognition of thermal motion, then the normal methods offurther refinement will force errors into the co-ordinates.At one stageduring the analysis of solid benzene this effect led to an erroneous value ofd(C-C), since amended.=The collection of I?,-values at low temperatures is often undertakenbecause more accurate co-ordinates can be determined when thermal motionsare less vigorous.35 Were the vibrations harmonic, the same " mean "structure should be found at any temperature, though the effects of smearingmake atomic peaks harder to locate at higher temperatures. In fact thevibrations are not harmonic (though they are nearly always taken to be soto facilitate theoretical calculations). The mean structures at differenttemperatures therefore differ, but they should converge on the true " rest "structure as temperature falls.It has accordingly been recommended byGilbert and Lonsdale 3G that " complete intensity measurements (should) bemade, at least for simple organic compounds, at more than one temperature,These principles have been understood for some years.s4 E. G. Cox, U. W. J. Cruickshank, and J. A. S. Smith, Nafwre, 1955, 175, 79.35 Anpa. Reports, 1954, 51, 375.36 R . E. Gilbert and K. 1-onsdale, .4cta Cuyst., 1956. 9, 697SPEAKIbl-IN : GENERAL. 387and that a complete structure refinement (should) be carried out at eachtemperature." Most crystallographers would regard this as a counsel ofperfection. These authors and Grenville-Wells 37 have made a thoroughstudy of some of the reflexions from urea crystals at temperatures down to90" K of the thermal motions of its atoms, and of the proper way of allowingfor them.With urea the changes in intramolecular distances with temper-ature appear to be hardly significant, though this may not be generally true.The persistence of zero-point motion limits the usefulness of pursuingmeasurements to very low temperatures, though for typical organic crystalsit should be profitable to go as low as 25" K ; 38 experimental methods forstudying single crystals in this region are being developed.39Secondly, the study of vibrations is now attracting interest for its ownsake. For example, the neutron-diffraction work on KH,PO, at lowtemperatures 40 provides evidence of zero-point vibration. Since neutronsare scattered by the atomic nuclei, a stationary atom should ideally figure inthe derived Fourier map as a point.Because a non-infinite series has to beused, the atom is smeared to a degree that can be calculated. Any furtherspread of the peak is due to thermal motion, whose 2 value can thus beascertained. Extrapolation of 2 for the hydrogen atom indicates a largeamplitude at 0" K. (A similar, but much smaller, effect was recognised inan X-ray study of rock-salt many years Moreover, owing to thesmall mass of the proton, its vibrations are substantially restricted to theground state even at temperatures well above zero. Therefore, " since theFourier plots can be regarded as having been obtained with a neutronmicroscope, [the observed width of the peak] represents a very directdemonstration of the existence of zero-point motion."The electron-density peaks derived from an X-ray study of a covalentnioleciile tend to become lower for atoms far removed from the molecularcentre of gravity.This has been recognised as due to the libration of themolecule as a whole. Higgs 42 has made a quantitative study of this effectin crystals of naphthalene and anthracene. For any atom he divides the2 value (derived from B found experimentally) into two parts : (1) due tointernal vibrations within the molecule, and (2) due to vibrations of thewhole molecule as a rigid body. Calculation shows that (1) accounts foronly about 5% of G, so that it can be neglected for many purposes. Themajor part (2) can be further subdivided into (a) one due to translationalvibration and ( b ) one due to torsional oscillation (libration) ; and these canbe separated since (a) will make the same contribution to 2 for all atoms,whilst ( b ) will contribute the more, the further the atom is from the centre.Thus for naphthalene at room temperature, (G)* is about 0.35 for carbonatoms 9 and 10 (ring junctions), 0.39 for 1, 4, 5, and 8 (w-positions), and0.42 A for 2, 3, 6, and 7 (P-positions). Similar amplitudes have been deduced37 H.J. Grenville-Wells, Acta Cryst., 1956, 9, 709.38 D. W. J. Cruickshank, ibid., p. 1005.Analysis Group ; see Nature, 1956, 177, 1067.4 0 G. E. Bacon and R. S. Pease, Proc. Roy. SOC., 1955, A , 230, 359.4 * I. Waller and R. W. James, ibid., 1927, A , 117, 214.4t P. W. Higgs, A d a Cryst., 1955, 8, 99.E.g., J.H. Robertson's communication to the Oxford meeting of the X-Ra388 CRYSTALLOGRAPHY.for acridine.43 The whole problem has been considered by Cruickshank,awho has developed a systematic procedure for estimating anisotropic Debyefactors during the refinement of the structure, and for expressing the resultsin tensor notation.J. C. S.2. INORGANIC STRUCTURES.The two-year period covered by this Report provides additional and en-couraging evidence of the current resurgence of activity in inorganic crystalchemistry, with over six hundred relevant titles appearing in the literature.'M7e have selected only those papers which contain a significant chemical andcrystallographic contribution, without attempting to be comprehensive.Elements and Simple Molecules.-Recent ly declassified accounts of theinteraction of neutrons with graphite have become available : 45 a detailedmodel of the damage done to the graphite crystal structure is lacking, but itappears that the interstitial atoms or groups produced under irradiation arearranged in a fairly regular array.The allotropes of sulphur continue to bestudied. A redetermination of the molecular parameters of orthorhombicsulphur gives 46 d(S-S) := 2.037 & 0.005 A and L(S-S-S) = 107" 48' 25'in the puckered S, rings. Several other modifications, including the +-,x-, #-, and o-forms, have been shown 47 to possess characteristic diffractionpatterns. The metallic radii of scandium, yttrium, and of all the rare-earthmetals have been remeasured 48 on very pure samples.In the transform-ation of tin, single crystals of the white @-form can produce single crystalsof the grey x-modification , although no regular relationship of orientationbetween the two lattices was found.49 The arguments in the recent contro-versy regarding the structure of @-uranium have beensumrnarised : 50 the general features of the structureare not in doubt, although some bond lengths in thedifferent models appear to differ by about 0.3 A.( I ) The structures of four allotropes of plutonium arenow known : 51 the 10-co-ordinated (1) arrangementin the y-form 52 is unlike that of any other metal.Americium metal, radius 1-82 A, forms a doublehexagonal close packed lattice ; 53 magnetic-susceptibility measurementsindicate three bonding electrons per atom.a-IC1 molecules, d(1-Cl) = 240A, form chains in the crystal,5* withshort I - . - I contacts of 3-05 A (in solid iodine, this distance is 3-54 A) and43 D.C. Phillips, Acla Cryst., 1956, 9, 327.4 4 D. W. J. Cruickshank, ibid., pp. 747, 754.45 G. E. Bacon and B. E. Warren, ibid., p. 1029.46 S. C. Abrahams, ibid., 1955, 8, 661.4 7 J. Schenk, Thesis, Delft, 1966.4 * F. H. Spedding, A. H. Daane, and K. W. Ilerrmann, Acla Cryst., 1956, 9, 659.4 9 K. Kuo and 11'. G. Burgers, Proc. k . m d . Aknd. Wefenschap., 1956, 59, B, 288.50 C. W. Tucker, P. Senio, J. Thewlis, and H. Steeple, Acta Cryst., 1956, 9, 472.5 1 E. R. Jette, J . Chem. Phys., 1955, 23, 365.52 W. 13. Zachariasen and F. H.Ellinger, Acta Cryst., 1055, 8, 431.53 P. Graf, B. €3. Cunningham, C. 13. Dauben, J. C. Wallmann, D. H. Templeton, and54 K. H. Boswijk, J. van der Heide, A. Vos, and E. H. Wiebenga, Acta Cryst.,EI. Ruben, J . Amer. Chesn. Soc., 1966, 78, 2340.19.56, 9. 271ABRAHAMS : INORGANIC STRUCTURES. 389interinolecular I - C1 contacts of 3.00 A. Within the chains there arelinear groups of 3 atoms, I - I-C1, C1- * I-C1, etc., similar to those observedin the 13-, (IC12]-, and [BrIClI- ions. Cyanogen chloride 55 is isostructuralwith the bromide 56 and, like those of the iodide, the molecules form linearchains with rather short distances between molecules along a chain (3.01 Ain NCC1) ; d(N-C) = 1-16, d(C-C1) = 1.57 A. The N, C, and 0 atoms inisocyanic acid 57 are also collinear, d(N-C) = 1.153, d(C-0) = 1.184 A ; themolecules are joined by N-H * N bonds of 3.07 A to form a zig-zag chain,the hydrogen atoms in the bonds being disordered.Hydroxylamine 58probably possesses a tram-configuration, if the third hydrogen atom whichis not involved in hydrogen-bond formation is neglected ; d(N-0) = 1.48 A.Diboron tetrachloride, B,Cl,, forms a planar molecule,59 with a long B-Bbond of 1.80 A, analogous to the long bond in N,0,.60 The hydrogen atomsin ammonia-borine, H3N,BH3,61 probably possess either orientationaldisorder or else rotate; d(B-N) = 1-56 A. The addition product of B2C14and C2H4 is shown62 to be the nearly planar BC12C,H4~BCl, molecule,excluding hydrogen, in which the BC1, groups are in the tram-position andthe boron bonds are trigonally arranged.The sulphur atom bonds in sulphamide 63 form a distorted tetrahedron,with d(S-0) = 1.39 A, an unusually short bond.A very similar structure isfound in sulphamic acid, HS0,*NH,,64 in which one amino-group in sulph-amide is replaced by a hydroxy-group ; d(S-0) = 1-44 if as comparedwith the earlier value of 1.48A. In the phosphorussulphides, P,S, has the same structure (2) in the crys-tal 65 as in the gas state, with d(P-S) = 2.09 andd(P-P) = 2-20 A ; P4S, and P,Slo, with structures pre-viously described in these Reports,66 possess single anddouble P-S bonds, depending on whether they form partof closed rings or not, with d(P-S) = 2.08 and 1.95 A re~pectively.~' InP4S7, d(P-P) = 2-35 & 0.01 A,68 significantly longer than is found in blackphosphorus (2.18 A) or P, (2-21 a).The interesting molecule hexathia-adamantane (CH),S6, has beenshown 69 to possess a structure analogous to hexamethylene tetramine.The trimer of dimethylphosphinoborine io consists of a cyclohexane-like@55 R.B. Heiart and G. B. Carpenter, Acta Cryst., 1956, 9, 889.5 6 S. Geller and A. L. Schawlow, J . Chem. Phys., 1955, 23, 779.5 7 W. C. von Dohlen and G. B. Carpenter, Acta Cryst., 1955. 8, 646.5 8 E. A. Meyers and W. N. Lipscomb, ibid., p. 583.59 M. Atoji, W. N. Lipscomb, and P. J. Wheatley, J . Chem. Phys., 1955, 23, 1176.6o J. S. Broadley and J. M. Robertson, Nature, 1943, 164, 915.61 E. L. Lippert and W. N. Lipscomb, J . Amer.Chem. SOL, 1956, 78, 503; E. W.62 E. B. Moore and W. N. Lipscomb, Acta Cryst., 1956, 9, 668.63 K. N. Trueblood and S. W. Mayer, ibid., p. 628.64 K. Osaki, H. Tadokoro, and I. Nitta, Bull. Chem. SOL. Japan, 1355, 28, 524.6 6 S. van Houten, A. Vos, and G. A. Wiegers, Rec. Trav. chim., 1955, 74, 1167;6 6 Ann. Reports, 1954, 51, 385.6 7 A. Vos and E. H. Wiebenga, Acta Cryst., 1955, 8, 217.69 E. K. Andersen and I. Lindqvist, Arkiv Kemi, 1956, 9, 163.70 W. C. Hamilton, Acta Cryst., 1955, 8, 199.Hughes, ibid., p. 502.Y. C. Leung, J. Waser, and L. R. Roberts, Chem. artd Ind., 1956, 948.Idem, ibid., 1956, 9, 92390 CRYSTALLOGRAPHY.ring of alternating P and B atoms, in the chair configuration, with twomethyl groups attached to each P and two hydrogen atoms to each B atom.Se(SeCN), and S(SCN), are shown 71 to be unbranched non-coplanar mole-cules, taking the cis-form in the crystal.Oxyacids and Acid Salts.-Analyses of two important oxyacids have beenmade : in sulphuric acid 72 the oxygen atoms are arranged in a distortedtetrahedron around the sulphur atom, with L(H0-S-OH) = 103" andL(0-S-0) = 117".There are two kinds of S-0 bond, with d = 1.46 andI-53A, the hydrogen atoms being associated with the longer bonds andforming intermolecular 0 * - 0 contactsof 2-64 and 2.87 A. Phosphoric acid hasbeen the subject of two independent in-vestigations. The PO, group (3) deviates( 3 ) significantly from tetrahedral symmetry; 73 -- L(0-P-0) ~ 1 1 2 " when 0, is involved,otherwise ~ 1 0 6 " ; d(P-0,) = 1-52 & 0.01 A,group is bound by hydrogen bonds of length2.53 A connecting the " keto " 0, with hydroxyl oxygen atoms and 2-84 Ajoining two hydroxyl oxygens.Essentially the same structure with a slightlydifferent set of atomic positions (maximum co-ordinate difference 0.16 A) hasalso been gi~en.~4A study of the infrared spectrum 75 of gypsum crystals reveals two kindsof oxygen atoms in the sulphate group, namely those hydrogen bonded andthose not. The anion in BaTeS40,,2H,O is shown 76 to possess a cis-configuration, in contrast with the tram-configuration observed 77 in(NH,),TeS,O,. The solvate of barium pentathionate with acetone,BaS,0,,H,0,Me,C0,78 has the same internal structure as the correspondingdihydrate, with acetone substituted for a water molecule : the oxygenatoms of the solvate molecules co-ordinate to Ba2+ as do those of the replacedwater molecules. Other recent analyses of acid salts of sulphur, selenium,and tellurium have been described; 79 fuller details of the work on telluriumdibenzenethiosulphonate 8o and on barium pentathionate dihydrate havenow appeared.Redeterminations have been made of the two forms of AlPO,.The veryaccurate intensity measurements on the hexagonal variety indicate 82 thatthe phosphorus atom has two more positive charges than the aluminiumatom. In the tetragonal or low cristobalite form, a regular tetrahedral10, 136.0 HT88 d(P-0) = 1.57 & 0.02 A. Each phosphate71 0. Aksnes and 0. Foss, Acta Chem. Scand., 1954, 8, 1787; 0.Foss, ibid., 1956,72 R. Pascard, Compt. rend., 1955, 240, 2162.i3 S. Furberg, Acta Chem. Scand., 1955, 9, 1667.74 J. P. Smith, W. E. Brown, and J. R. Lehr, J . Amer. Chem. SOC., 1955, 77, 2728.7 5 M. Hass and G. B. B. M. Sutherland, PYOC. Roy. SOC., 1966, A , 236, 427.7 O 0. Foss and 0. Tjomsland, A d a Chem. Scand., 1956,10, 416.7 7 0. Foss and P. A. Larssen, ibid., 1954, 8, 1042.7 8 0. Foss and 0. Tjomsland, ibid., 1956, 10, 424.79 S. C. Abrahams, Quart. Rev., 1966, 10, 407.P. Byum and 0. Foss, Acla Chem. Scand., 1966, 10, 279.81 0. Foss and 0. Tjomsland, ibid., p. 288.82 R. Brill and A. P. de Bretteville, Acla Cryst., 1965, 8, 567ABRAHAMS INORGANIC STRUCTURES. 39 1arrangement is assumed 83 in the PO, group : A1 is co-ordinated to 4 oxy-gen atoms as is Ga in isomorphous GaPO,, with d(A1- - 0) = 1.70 A,d(Ga The PO,group in Ca(H,PO,),,H,O is a regular tetrahedron; 84 d(P-0) = 1.52 A.Each Ca2+ ion is co-ordinated to 8 oxygen atoms, d(Ca * - * 0) = 2.52 A onaverage.In CaHPO, the PO:- ion is again tetrahedral,85 d(P-0) = 1.54 A(mean) : there are two kinds of Ca2+ ion, one co-ordinating with 7, theother with 8, oxygen atoms (Ca - * 0 co-ordination of 6 , 7 , 8 , and 9 is known),d(Ca A cation-oxygen co-ordination of 8, 6, and 6, isreported 86 in ScPO,, InPO,, and TlPO, respectively. The [HP0,I2- ionin MgHP0,,6H20 is tetrahedral 87 with d(P-0) = 1.51 A, and is linkedby hydrogen bonds (2.65-2.86 A) to the octahedral Mg2+(H20), groups.Rubidium metaphosphate, (RbP03),t,88 contains spiral chains of (PO,).heldtogether by Rb+ ions with 7-fold oxygen co-ordination. The chains areformed by tetrahedral PO, groups linked by shared corners; d(P-0) =1.62 A in the chain, otherwise = 1.46 A. Similar arrangements of long andshort bonds have also been observed in chains of (XO,),$, where X = Si, P,As, S, and V. Lithium and sodium polyarsenates form chains of linkedAsO, tetrahedra, with d(As-0) = 1-60-1.68 A and 1-79 A.8s Sodiummetagermanate contains similar chains, d(Ge-0) = 1-84 A. InNH,Cl,As20,,~H,0 double layers of As2O, are interleaved by two layersof NH,Cl; 91 AS-0) = 1-81 A.An electron-diffraction study 92 of basic lead carbonate shows that thecrystal consists of Pb(OH), layers sandwiched between double PbCO,sheets : the sequence of layers varies, giving a disordered structure.Furtherrefinement s3 of the NaNO, crystal structure leads to d(N-0) = 1.236 A,L(0-N-0) = 115.4"; in TINO,, the nitrite ion is probably di~ordered.~,Trigonal pyramidal 10, groups are reportedg5 in the crystal structure ofCe(IO,), and Ce(IO,),,H,O, where d(1-0) = 1.82 A, and L(0-1-0) = (37.2".Trigonal bipyramidal VO, groups share edges to form continuous chains inKVO,,H,O ; d(V-0) = 1.63-1-99 A."Lithium metasilicate 97 contains chains of composition (Si03)7L, similar tothose already described. Among many other silicate analyses are includedthose of d i ~ k i t e , ~ ~ ne~heline,~~ and wadeite.lW0) = 1.78 A, L(A1-O-P) = 145", L(Ga-O-P) = 135".* 0) being 2.46 A.83 R. C.L. Mooney, Acta Cryst., 1956, 9, 728.'.j Idem, ibid., 1955, 8, 579.a 6 R. C. L. Mooney, ibid., 1956, 9, 677, 113.R 7 D. E. C. Corbridge, ibid., p. 991.R9 W. Hilmer and K. Dornberger-Schiff, ibid., p. 87 ; F. Liebau, ibid., p. 811.R 1 M. Edstrand and G. Blomqvist, Arkiv Kemi, 1955, 8, 245.92 J. M. Cowley, Acta Cryst.. 1956, 9, 391.93 G. B. Carpenter, ibid., 1955, 8, 852.94 L. Cavalca, M. Nardelli, and W. Bassi, Gazzettu, 1955, 85, 153.95 D. T. Cromer and A. C. Larson, Acta Cryst., 1956, 9, 1015; J. A. Ibers, ibid.,96 C. L. Christ, J. K. Clark, and H. T. Evans, ibid., 1954, 7, 801.g 7 H. Seemann, ibid., 1956, 9, 251.R. E. Newnham and G. W. Brindley, ibid., p. 759.gD T. Hahn and M. J. Buerger, 2. Kryst.. 1955, 106, 308.G. MacLennan and C.A. Beevers, ibid., p. 187.Idem, ibid., p. 308.Y . Ginetti, Bull. SOC. chim. belges, 1954, 63, 460.p. 225.loo D. E. Henshaw, Min. Mag., 1965, 30, 585392 CRYSTALLOGRAPHY.Oxides, Hydrides, Nitrides, etc.-A review of the structure and propertiesof hydrogen peroxide,lol and a discussion of the oxygen-oxygen bond lengthin terms of bond order 799 lo2 have been made. Two oxides of czsium havebeen examined : Cs,O has a layer-type structure, d(Cs - 0) = 2-86,d(Cs - Cs) = 4.19 A,103 and Cs30 consists of columns of the hypotheticalpyramidal Cs,O+ ion, bound together by " metallic " electrons, in con-formity with the metallic properties of this oxide; d(Cs - - - 0) = 2.89,d(Cs - Cs) = 4.34 It had been reported lo5 that in mercuric oxide,L(Hg-O-Hg) and L(0-Hg-0) were both 109-8", whereas it now appears lo6that the true unit cell should be double, and contains infinite planar zig-zagchains, HgO-HgO - - 0 , with L (HgO-Hg) = log", L (O-HgO) = 179" ;d ( H g - 0 ) = 2-03 A in the chains, and 2-82 A between chains.Essentially thesame dimensions occur in the HgO-Hg-0 chains in 2Hg0,Hg,C1,.107A careful redetermination lo* of the parameters in rutile and anataseleads to d(Ti-0) = 1.946 (4 contacts) and 1-984 (2 contacts) in rutile, and1.937 (4 contacts) and 1.964A (2 contacts) in anatase. The correspondingmetal-oxygen distances in the rutile-type crystals of SnO,, GeO,, MgF,,lo9of VOz,llo and of CrO, ll1 have also been determined. The structure ofV,O,,CaO resembles that of CaTi20,,ll2 the transition metal in both caseshaving an octahedral co-ordination, with Ca2t a t the centres of polyhedraformed by 9 and 6 oxygen atoms respectively.Na, -zVGO1s (x z 1) containszig-zag double strings of VO, octahedra and chains of VO, trigonalbipyramids, the Na+ ions lying in interstitial sites.l13 Each Cu atom inCuCrO, has two near oxygen neighbours in linear array, d(Cu-0) = 1.85 A,and each Cr lies at the centre of a distorted oxygen octahedron, d ( C r 0 ) =1.99 A.114 Endless chains, - Sb-O-Sb-0 - with d(Sb-0) = 2.15 A,are bound together by hydroxyl groups ineach Sb atom is surrounded by four oxygen atoms at the corners of a de-formed trigonal bipyramid, with an unoccupied equatorial corner. Anaccount has been given of the structure of X,O, groups,116 which oftenconsist of two XO, tetrahedra sharing a common oxygen atom, and also ofthe structures of some oxide and hydroxide sulphates and ~hr0rnates.l~~Monograph, No.128, Reinhold Publishing Corp., N.Y., 1055.l o 1 W. C. Schumb, C. N. Satterfield, and R. L. Wentworth, Aaner. Chem. SOC.lo2 S. C. Abrahams and J. Kalnajs, Acta Cryst., 1955. 8, 503.lo3 K.-R. Tsai, P. M. Harris, and E. N. Lassettre, J . Phys. Chem., 1956, 60, 338.lo4 Idem, ibid., p. 345.lo5 W. L. Roth, Acta Cryst., 1956, 9, 277.1 0 6 K. Aurivillius, ibid., p. 685 ; Acta Chern. Scand., 1956, 10, 852.10' S. Sdavnitar, Acta Cryst., 1956, 9, 956.Io8 D. T. Cromer and K. Herrington, J . Amer. Chem. Soc., 1955, 77, 4708.l o 9 W. H. Baur, Acta Cryst., 1956, 9, 515.l 1 0 G.Andersson, Acia CJzem. Scand., 1956, 10, 623.112 F. Bertaut, P. Blum, and G. Magnano, Compt. rend., 1955, 241, 757; E. F.0. Glemser, U. Hauschild, and F. Triipel, 2. anoyg. Chcm., 1954, 277, 113.Ber *taut and P. Blum, Acta Cryst., 1956, 9; 121.113 A. D. Wadsley, ibid., 1955, 8, 695.114 W. Dannhauier and P. A. Vaughan, J . Amer. Chent. Soc., 1115 31. Edstrand, Agfkiv Kemi, 1955, 8, 257.116 G. A. Baxclay, E. G. Cox, and H . Lynton, Chem. and Ind.,1 1 7 G. Lundgren, Rec. Trav. chim.. 1956, 75, 685..955, 77, 896.1966, 178ABRAHAMS INORGANIC STRUCTURES. 393The structures of molybdenum and tungsten compounds containingstructural elements of the perovskite type have been discussed ; 118 M-0 andCu-0 distances are given for compounds of the type M,O,-Cu,O, whereM = Fe, Co, Cr, and Al.l19 A redetermination 120 of the earlier structureof bixbyite (Fe,Mn),O,, gives d[(Fe,Mn) - * 01 = 2-01, 2.67, and 3.00 A inone distorted oxygen octahedron, and 1.90, 1.92, and 2.24A in another.The distorted perovskite GdFeO, has the average d(Gd..*Fe) andd ( G d - * * O ) close to those in an ideal perovskite structure, although in-dividual distances vary by up to 0.4 A from the average : 121 GdFeO, formsthe type structure for a large group of compounds of formula ABO,, whereA is a rare earth and B is a tervalent transition metal element.12, Theferrimagnetic rare-earth ferrites are shown 123 to possess not a pervoskite-type structure with formula AFeO, but instead a garnet-type structure,formula A,Fe,O,,, the iron atoms being distributed over octahedral andtetrahedral sites, in accordance with N@el's theory.12* The shortestd(Fe - * * Fe) between different sites is 3.46 A : d(Fe - - Ooct) = 1-98,d(Fe - Otetr) = 1-86 A.125 Each uranium atom in U,08 is bonded tosix oxygen atoms with d(U-0) = 2.31 A and, in addition, to two otherswith d(U-0) = 2.06 A, the latter forming - - U-0-U-0 - * chains.126A tentative model for a B, hydride (probably B,H,,) has been sug-gested,lZ7 which resembles B1,Hl, with two boron atoms removed and a thirdadded.Magnesium hydride 128 has the rutile-type structure, each Mg atombeing co-ordinated to 6 hydrogen atoms at 1.95 A, d(H - H) = 2.49 and2.76 A (in LiH, the diameter of the H- ion is 2.72 A) : the short H - - Hdistance is characteristic of one anion-anion contact in this type of struc-ture.CuH and CUD have the wurtzite structure 129 while the hydrides ofLa, Ce, Pr, Nd, and Sm all belong to the fluorite type, with compositionMH, (2 < x < 3), the extra hydrogen atoms being distributed over theoctahedral lattice sites. The metallic nature of these rare-earth hydrides isattributed to the presence of valence electrons in excess of the two requiredby the metal atom in M-H bond forrnati0n.1~~ are iso-structural with the alltaline-earth hydrides, although they are not completelystoicheiometric compounds : hafnium forms hydrides and deuterides 132YbD, and EuD,118 A. MagnCli, J. Inorg. Nuclear Chem., 1956, 2, 330.119 C. Delorme, Acta Cryst., 1956, 9, 200.120 H.Dachs, Z. Kryst., 1958, 107, 370.121 S. Geller, J. Chew. Phys., 1956, 24, 1236.lz2 S. Geller and E. A. Wood, Acfa Cryst., 1056, 9, 563; F. Bertaut and F. Forrat,J . Pliys. Radium, 1956. 17, 129.F. Bertaut and F. Forrat, Conzpt. vend., 1956, 242, 382.lZ4 L. NCel, ibid., 1954, 239, 8.lZ5 F. Bertaut, F. Forrat, A. Herpin, and P. M6rie1, ibid., 1956, 243, 808.lZ6 S. Siegel, A d a Cryst., 1955, 8, 617.1 2 7 R. E. Dickerson, P. J. Wheatley, P. A. Howell, and W. N. Lipscomb, J . Chem.128 F. 1-1. Ellinger, C. E. Holley, B. B. McTnteer, D. Pavone, R. M. Potter, E. Starit-129 J. A. Goedkoop and A. F. Andresen, Acta Cryst., 1955, 8, 118.130 C. E. Holley, R. N. R. Mulford, and F. H. Ellinger, J . Phys. Chena., 1955, 59,131 W. L. Korst and J.C . Warf, Acta Cryst., 1956, 9, 452.lsa S. S. Sidhu, L. Heaton, and D. D. Zauberis, &id, p. 607.Phys., 1956, 25, 606.zky, and \V. H. Zachariasen, J . Amer. Chem. Soc., 1955, 77, 2647.1226394 CRYSTALLOGRAPHY.corresponding to Hf Di.63 and Hf D,,,, the former being face-centred cubic,the latter face-centred tetragonal. Zirconium gives analogous hydrides anddeuterides, and titanium apparently forms only the cubic fluorite-typestructure. Like PuO,, PuH,,, is face-centred cubic.133 Aluminium nitride 134departs only slightly from the ideal wurtzite-type structure, and consists ofslightly distorted tetrahedra having atoms of one type at the corners and ofthe other at the centres, d(A1-N) = 1.917 and 1.885 A. Each P atom in Ni3Phas nine Ni neighbours, d(Ni - * P) = 2.30 A, one Ni atom has twelve Nineighbours as in the metal, and the other two have ten Ni neighb0~rs.l~~In CdP,, each P atom has a distorted tetrahedral co-ordination, and eachCd atom a distorted octahedral co-ordination, d(Cd-P) = 2-65-2945 k136Beryllium boride, Be,B, has the fluorite-type structure, d(Be * .- B) = 2-01 Aand d(B - B) = 3-30 A.137 Ga,S, contains the Ga2,+ ion, d(Ga * - - Ga) =2.53 and d(Ga - S) = 2-31 A.138 Stromeyerite, AgCuS, has zig-zagchains of Ag and S atoms, d(Ag - * S) = 2.40 A, L(AgS-Ag) = 113",L(S-Ag-S) = 180°, and triangularly co-ordinated S and Cu atoms,d(Cu - S) = 2.29 (two contacts), 2-26 A (one contact), as building ele-m e n t ~ . ~ ~ ~ Iron carbide, Fe,C, consists of a network of Fe,C tetrahedra,d(Fe-C) = 1.78 A.140 Two independent but mutually consistent analysesof sodamide have been reported.141 The nitrogen atoms form irregulartetrahedra about the sodium atom, d(Na - - N) = 2-44, 2.49 A : there areno hydrogen bonds in NaNH,, as also is true of LiNH,.Halides.-The infrared spectrum of solid NH,F at -195" indicates anaccurately tetrahedral arrangement of F- ions about the NH,+ ion ~ite.1,~The non-planar molecule P,I, has 2/m (C2J symmetry in the solid state,The Ti atom in TiF, lies at the centre of a slightly distorted octahedronof 6 F atoms which are joined together by sharing corners, d(Ti-F) = 1.97 A.The Raman spectrum 145 of fused GaCl, indicates the presence of[Ga]-+[GaCl,]-, there being no evidence for a Ga-Ga bond.Reinvestig-ation 146 of the structure of SnI, shows that a simple distortion of theidealised model is adequate, resulting in SnI, tetrahedra with d(Sn-I) =2.69A. Pyramidal molecules of SbC13 are reported 147 in the crystal,d(Sb-C1) = 2.36, d(C1. - . C1) = 3.49 A, L(C1-Sb-C1) = 95-2", in excellentagreement with the electron-diffraction values. Evidence for a new tellur-d(P-P) = 2.21, d(P-I) = 2.48 A, L(1-P-I) = 102.3", L(I-PAP) = 93*9".la133 F. Brown, H. M. Ockenden, and G. A. Welch, J., 1955, 3932.134 G. A. Jeffrey and G. S. Parry, J . Chem. Phys., 1955, 23, 406.135 B. Aronsson, A d a Chem. Scand., 1965, 9, 137.136 H. Krebs, K.-H. Muller, and G. Ziirn, 2. anorg. Chem., 1956,285, 16.13' L. Ya. Markovskii, Yu. D. Kondrashev, and I. A.Goryacheva, Dokladj' Akad.1 3 * H. Hahn and G. Frank, 2. anorg. Chem., 1955, 278, 340.138 A. J. Frueh, 2. Kryst., 1955, 100, 299.I4O 2. G. Pinsker and S. V. Kaverin, Kristallografiya, 1956, 1, 66.1 4 1 A. Zalkin and D. H. Templeton, J. Phys. Chem., 1956, 00, 821; R. Juza, H. H.142 R. C. Plumb and D. F. Hornig, J . Chem. Phys., 1965, 23, 947.Id3 Y. C. Leung and J. Waser, J. Phys. Chem., 1966, 60, 539.l o 5 L. A. Woodward, G. Garton, and H. L. Roberts, J., 1956, 3723.14R F. Meller and I. Fankuchen, Acta Cryst., 1956, 8, 343.147 I . Lindqvist and A. Niggli, J. Inorg. NucEear Chem., 1966, 2, 346.Nauk, S . S . S . K . , 1955, 101, 97.Weber, and K. Opp, 2. anorg. Chem., 1956, 284, 73.S. Siegel, Acta Cryst., 1956, 9, 684ABRAHAMS INORGANIC STRUCTURES.395ium iodide, TeI, has been offered.148 The I,- ion in CsI, is asymmetricand non-linear, L(1-1-1) = 176.5" & 0*5", d(1-I) = 2-82 -J= 0.02, 3.02 &0.02 A. (cf. the 3-atom sets in a-IC1) : 149 in N(CH,),I,, the V-shaped 1,-ions (apex angle 86.5"), with approximatelylinear arms and structure (4), form sheets withdistances of 3-49 A or more between I,- ions in(4) the sheets.lm NMe; ions and I, molecules liebetween these sheets. There is no evidence forthe existence of an I,- ion in N(C2HJ41,; 151instead there are I,- ions and I, molecules, theNEt, i- ions fitting into the large holes of the iodine lattice. In contrast withthat in CsI,, the 1,- ion is symmetrical and linear, d(1-I) = 2.904 A : in the1, molecules, d(1-I) = 2.735 A.Gold(1) iodide forms infinite chains, - I-Au-I-Au - - -, withL (1-Au-I) = M O O , d(Au-I) = 2.60 a : gold(II1) chloride consists ofplanar Au,Cl, molecules, each gold atom being surrounded by 4 chlorineatoms at the corners of a distorted square, d(Au-C1) = 2.33 (C1 bonded totwo Au atoms), 2-24A (C1 bonded to one Au), L(Au-Cl-Au) = 94.7".Adisordered structure is proposed for PoBr,, with Po in octahedral co-ordination with Br, d(Po-Br) = 2.8 A.The crystal structures of 2HgC12,Hg0,155 of Hg2C1,,2Hg0, lo7 and ofHgC12,2Hg0 156 have been elucidated : the first compound containsthe planar trigonal trischloromercurioxonium group [0( HgCl),] r, withd(Hg-0) = 2.03 A, L(0-HgCl) = 175"; the second contains non-linearHg,Cl, groups with L(C1-Hg-Hg) = 161", d(HgHg) = 2.66 A ; thethird consists of Hg2+ cations and polymeric [OHgClI- anions which linkup to form infinite layers.In mercurous fluoride,15' d(HgHg) = 2-43 A,while in the other halides this distance is 2.53, 8-58, and 2.69 A respectivelyin Hg,Cl,, Hg,Br,, and Hg212, indicating a dependence on the nature of thehalide. The Br- ions in Hg,NHBr, are located 158 in the holes of theslightly puckered [HgJNH),] layers, with [HgBrJ ions lying betweenlayers.form a slightly distorted tetra-hedral arrangement about the central A1 atom, with d(A1-Br) = 2.34,d(A1-S) = 2.40 A. The central atoms in Nb0,F and Ta02F 160 and inTiOF, 161 are octahedrally co-ordinated by randomly distributed 0 and Fl a 8 W. R. Blackmore, S. C . Abrahams, and J . Kalnajs, Acta C y 0 s f ., 1956, 9, 395.'dB H. A. Tasman and K. H. Boswijk, ibid., 1955, 8, 59.*j0 W. J. James, R. J. Hach, D. French, and R. E. Rundle, abid., p. 814.' j l E. E. Havingaand E. H. Wiebenga, Proc. k. ncd. Akad. Mretenscha$., 1955, 58, H ,152 A. Weiss and A. Weiss, 2. Naturforsch., 1956, l l b , 604.153 E. S. Clark, Thesis. Univ. of California, Berkeley, Calif., 1955.154 K. W. Bagnall, R. W. M. D'Eye, and J . H. Freeman, J., 1955. 3039.ls5 S. SCavniEar and D. GrdeniC, Acta Cryst., 1955, 8, 275; A. Weiss, G. Yagorsen,and A. Weiss, 2. anorg. Chew., 1953, 274, 151.156 S. SCavniEar. Acta Cryst., 1955, 8, 379.157 D. GrdeniC and C. DjordjeviC, J . , 1956, 1316.158 K. Brodersen, Acta Cryst., 1955, 8, 723.150 A. Weiss, R. Plass, and A.Weiss, Z. anoug. Chcm., 1956, 283, 390.l a l K. Vorres and J . Donohue, ibid., 1955, 8, 35.2.90 A2-91The four heavier atoms in A1Br,,SH24 1 2 : idem, personal communication.L. K. Frevel and H. W. Rinn, Ada Cryst., 1956. 9, 626396 CRYSTALLOGRAPHY.atoms, forming M(0,F) octahedra, with d(Ta-0,F) = d(Nb-0,F) = 1.95 Aand d(Ti-0,F) = 1.90 A.The halogen atoms in the anions of KBrF, 162 and Cs,CoCl, 163 arearranged in the form of distorted tetrahedra, d(BrF) = 1.81 A andd(Co-Cl) = 2.22-2.41 A, while in K,NiF, the anion consists of NiF,octahedra sharing corners, d(Ni-F) = 2-00 A. Isolated [SbC1,12- ions arereported 165 in (NH,),SbCl,, with a distorted octahedral Sb-Cl bond distri-bution, one of the corners being unoccupied. An octahedral arrangement offluorine atoms has been reported in the anions of a number of compounds offormula ABF,, where B = Zr and Hf,166 As,167 Sb,168 and 0s ; 169 the latticeconstants and structure types of many others have been given.170 Similaranion arrangements are also found in Cs,PoI, and in K4CdC16.172Hydrates.-The complex ion [%r,(OH),J16H,0]8+ is reported 173 in thezirconyl chloride octahydrate crystal ; this complex consists of four Zratoms at the corners of a slightly distorted square linked along each edge bytwo OH groups.Four water molecules are in addition bound to each Zratom, resulting in a distorted square antiprism arrangement for these eightoxygen atoms : there are no Zr-C1 bonds. In HPF,,6H20 174 the watermolecules form cages of 24 oxygen atoms, with the P of the PF, group atthe centre.Two oxygen atoms from water molecules and four from differentdithionate ions, in Na,S20,,2H2O, form 175 the vertices of a distorted octa-hedron of oxygen atoms which contains the Na+ ion. A study176 of thepolarised infrared spectrum of CuC1,,2H20 indicates that the bond betweenH,O and the Cu2+ ion is not ionic, but approaches a covalent link in whichthe oxygen atom has more nearly a tetrahedral bond distribution. Twowater molecules in cupric tetrammine sulphate monohydrate 177 are attachedto each planar Cu(NH,), group, d[Cu - . - O(H,)] = 2-59, 3.37 A, forming adistorted octahedron : each H,O is also linked to two oxygen atoms of anSO, group, d[O * - * O(H2)] = 2.67 A. In chalc~phanite,~~~ ZnMn,0,,3H,0Jthe oxygen and water-oxygen atoms are in irregular octahedral co-ordin-ation with the Zn atom, d(Zn * - * 0) = 1.95, d[Zn * O(H,)] = 2.15 A.The nitrate ions and water molecules in Hg2(N0,),,2H20 together providel m S.Siegel, Acta Cryst., 1956, 9, 493.lBS G. N. Tishchenko and 2. G. Pinsker, Doklady Akad. Nauk, S.S.S.R., 1955, 100,16* D. Balz and K. Plieth, 2. EEeklrochem., 1955, 59, 545.le5 RI. Edstrand, 11. Inge, and N. Ingri, Acta Chem. Scand., 1955, 9, 122.166 H. Bode and G. Teufer, Acta Cryst., 1956, 9, 929; 2. anorg. CJwm., 1956, 283,167 R. B. Roof, Acta Cryst., 1955, 8, 739; J. A. Ibers, ibid., 1956, 9, 967.16E G. Teufer, ibid., p. 539.le9 &I. A. Hepworth, I<. H. Jack, and G. J. Westland, J . Inorg. Nuclear Chem.,170 B.Cox, J., 1956, 876.171 K. W. Bagnall, R. W. M. D’Eye, and J. H. Freeman, ibid., p. 3385.172 G. Bergerhofi and 0. Schmitz-Dumont, 2. anorg. Chem., 1956, 284, 10.173 A. Clearfield and P. A. Vaughan, Acta Cvyst., 1956, 9, 555.174 H. Bode and G. Teufer, ibid., 1955, 8, 611.17j S. Martinez, S. Garcia-Blanco, and L. Rivoir, ibid., 1956, 9, 145.176 R. E. Rundle, K. Nakamoto, and J. W. Richardson, .I. Chew Plays., 1955, 23,177 F. Mazzi, Acta Cryst., 1955, 8, 137.178 A. D. Wadsley, ibid., p. 165.913.18.1056, 2, 79.2450ABRAHAMS INORGANIC STRUCTURES. 397a framework in the holes of which the Hg' ions are located : 17'3 it is sug-gested that a double oxonium ion [H20-Hg-HgH,0]2+ exists in the struc-ture; L(Hg-Hg-0) = 160°, compared with 180" if truly covalent.Co -ordination Compounds.-The recent interest in " sandwich '' com-pounds has been maintained, and the subject reviewed.laO A variety ofcompounds are now known lS1 to be isomorphous with ferrocene, Cr, Co,Ni, Mn, V, and Mg each being able to replace the Fe atom : the pentagonalantiprismatic shape remains throughout, and the metal-carbon distancesare 2.13, 2-22, and 2.30A respectively for the Co, Cr, and V compounds.Dibenzenechromium, Cr(C,H&, forms an analogous " sandwich ''molecule,la2 d(CrC) = 2.19 A.Crystalline K[Co(NH,),(NO,),] is iso-morphous lB3 with Erdmann's salt (in which NH, replaces K) : two NH,molecules in the anion are co-ordinated to Co in the tram-position,d(Co-N) = 2-00 A, and four nitrogen atoms of the NO, groups form a squareabout the Co atom, d(Co-N) = 1-96 A, resulting in an octahedral co-ordin-ation. The Co en33+ ion in DL-trisethylenediaminecobalt (HI) chloridetrihydrate possesses 184 trigonal symmetry, with 6 N atoms of three enmolecules forming a slightly distorted octahedronabout the Co atom.The five-membered Co en ringsare not planar, but are in the " gauche" form.The absolute configuration of the D( +)-[Co en,]3T(5) ion is shown 185 in ( 5 ) . A regular tetrahedralbond distribution about the central Co atomis reported lB6 in di-p-toluidinecobalt dichloride,d(Co-C1) = 2.24, d(Co-N) = 1.92 A. Unlike thetrigonal bipyramidal arrangement about most 5-co-ordinated atoms, a square pyramidal configuration is found in bis-(NN-dimethyldithiocarbamato)nitrosylcobalt(II) ; the central Co atom isabout 4 A above the plane of the four sulphur atoms.lS7The paramagnetic quadricovalent Ni complex bisacetylacetonenickel( 11)is said ls8 to be a trinuclear molecule, Ni,(C5H70,),, the three Ni atomsbeing nearly collinear with d(Ni-Ni) = 2-80 A : the other atoms are un-resolved in the Fourier synthesis.The magnetic moment la9 of the anal-ogous molecule Fe(C5H70,), precludes the use of 3d244s4p3 bond orbitals, butnevertheless there is an octahedral distribution lgo of the Fe-0 bonds,d = 1.95 A. Copper 8-hydroxyquinoline dihydrate, CU(C,H~ON)~,~H,O, isisomorphous lgl with the corresponding zinc salt, and has a square coplanarco-ordination of two oxygen and two nitrogen atoms of 8-hydroxyquinoline,D.GrdeniC, J., 1956, 1312.lSo P. L. Pauson, Qwart. Rev., 1956, 9, 391.l B 1 E. Weiss and E. 0. Fischer, 2. anorg. Chem., 1956, 284, 69.ls2 Idem, ibid., 1956, 286, 142.Y. Komiyama, Bull. Chem. SOC., Japan, 1956, 29, 300.ls4 K. Nakatsu, Y . Saito, and H. Kuroya, ibid., p. 428.Is6 Y . Saito, K. Nakatsu, &I. Shiro, and H. Kuroya, Ada C~yst., 1955, 8, 729.lB6 G. B. Bokii, T. I. Malinovskii, and A. V Ablov, Kristallopajiya, 1956, 1, 49.IB8 G. J. Bullen, ibid., 1956, 177, 537.ls0 F. H. Burstall and R. S. Nyholm, J . , 1952, 3571.ls0 R. B. Roof, Acta Crvst., 195G, 9, 781.lQ1 R. Kruh and C. IV. Dwiggins, J . Atnfr. Chem. Sor., 1955, 77, 806.P. R. H. Alderman and P. G. Owston, Nature, 1956, 178, 1071398 CRYSTALLOGKAPH Y.with two other ligands (H20) weakly bonded in the vertex positions of atetragonal bipyramid.A careful analysis Ig2 of quinquecovalent ter-pyridylzinc dichloride shows that the three terpyridyl nitrogen atoms andthe two chlorine atoms are arranged in the form of a distorted trigonalbipyramid, with two Zn-N bonds in the axial positions; the terpyridylmolecule, which is essentially flat, lies in a plane normal to the equatorialCl-Zn-Cl plane, d(Zn-N) = 2.2, d(Zn-C1) = 2.29 a, L(C1-Zn-Cl) = 112".Similar structures are found for the corresponding cadmium and coppercomplexes, except that in the latter, CuCl,(terpy),2H20, the water moleculeslie in cavities in the structure and do not co-ordinate to the Cu atom. Thesemolecules are probably the first examples of dsp3 bonding for Zn, Cd, or Cuinvolving a chelate group.A study lg3 of bisbenzonitrilopalladium chloride indicates a squarecoplanar complex, the benzonitrile groups being attached through the Natoms in positions trans to each other, d(Pd-C1) = 2-35 A.Each Pt atomin sesquiethylenediaminetrimethylplatinic iodide, Pt (CH3)31, 1 + en, is sur-rounded octahedrally by three N and three C atoms in the cis-configuration,PtA,X3, with d(Pt-C) = d(Pt-N) == 2.45 A on average.l% Dipyridine-mercuric chloride, HgC1,,2C5H,N, has each Hg atom surrounded by four C1and two N atoms, d(Hg-Cl) = 2.34, 3.25 A, d(Hg-N) = 2.60 A, in the formof a distorted 0ctahedr0n.l~~ The Hg-N distance is longer than a covalentbond (ca. 2-03 A) and it is suggested that the pyridine molecules are presentprimarily as solvate of crystallisation.Intermetallic Compounds.-The structure of Li,Pb arid Li,Pb, resemblesthat of lithium metal in which the appropriate number of lithium atoms isreplaced by lead atoms : 196 Li,Pb, is similar although slightly modified.lgiIn KHg and KHg, the mercury atoms tend to assume a square coplanararray, d(Hg-Hg) = 3-00-3.08 A ; lQ8 in KPb, a lattice structure of theMgZn, type is found.lg9 CaSn and CaGe are isotypic ,O0 with CaSi, the Snand Ge bond angles being 96.6" and 100.7" respectively.The structures ofCaZn,, SrZn,, and BaZn, differ although similarities exist : ,01 d(Ca - * - Ca)is 6.5% greater than in the pure alkaline-earth metal while d(Sr - * Sr)is 6.1% less and d(Ba - * Ba) is 11.3% less than in the metal.The com-pound Re,,Ti, occurs in the Re-Ti system,*02 having the a-manganese typeof structure : Nb,X (X = Sn, Os, Ir, Pt), Ta,Sn, and V,Sn have the@-tungsten type of structure,2m for which has been given a set of radii for aneffective co-ordination number of 12.,04 Each Sb atom in Mn,Sb has205lD4 D. E. C. Corbridge and E. G. Cox, J . . 1956, 594.lD3 J. K. Holden and N. C. Baenziger, Acta Cryst., 1966, 9, 194.lD4 M. R. Truter and E. G. Cox, J., 1956, 948.lg5 D. GrdeniC and I. KrstanoviC, Arhiv Kern., 1955, 27, 143.lD6 A. Zalkin and W. J. Ramsey, J . Phys. Chew., 1956, 60, 234.lg7 A. Zalkin, W. J. Ramsey, and D. H. Templeton, ibid.. p. 1275.lD8 E. J. Duwell and N. C. Baenziger, Acta Cryst., 1955, 8, 705.lD9 D.Gilde, 2. anorg. Chem., 1956, 284, 142.P. Eckerlin, H. J. Rleyer, and E. Wolfel, zbzd., 1955, 281, 322.N. C . Baenziger and J . W. Conant, Acta Cryst., 1956, 9, 361.202 W. Trzebiatowski and J. Niemiec, Hocznika Chem., 1955, 29, 277.* O 3 S. Geller, B. T. Matthias, and R. Goldstein, J . Amer. Chem. SOC., 1955, 77, 1502.204 S. Geller, Acta Cryst., 1956, 9, 885.205 Id. Heaton and N. S. Gingrich, ibad., 1955, 8, 207MEGAW : FEKKOELECTKICS AND -1NTIFERROELECTRICS. 3'39four Mn neighbours at 2-75 A, one at 2.79 A, two a t 2.89 A, and one at3.77 A. A shift of electrons from the Mo-Be to the Be-Be bonds in MoBe,,has been suggested to account for the measured interatomic distances.206Recent investigations of the structures of some a-phases 207 indicate thepreference of given kinds of atoms for certain crystallographic sites in theunit cell, leading to a generalisation 208 regarding the nature of this " order-ing '' effect.Analyses of a number of intermetallic compounds of rheniumare reported in Six intermetallic compounds in the Th-A1 systemhave been discovered, and structures suggested.210Compounds of the Transuranic Elements.-The definitive series of papersby Zachariasen on the crystal chemistry of the transuranic elements has nowreached Part 24.52 A full scale review of work in this field is desirable, buta few of the novel structures described may be mentioned here. The(U02F5)3- group in tripotassium uranyl fluoride 211 is pentagonal bipyramidal,the uranyl group (UO,) being collinear, and the five U-F bonds forming anearly regular pentagon normal to the 0-U-0 axis.The (UF7)3- ion inK3UF7, which is isostructural with K,U0,F5, is also a pentagonal bi-pyramid. The uranium atom in U(S0,),,4H20 is surrounded by 8 oxygenatoms in a distorted square Archimidean antiprism.,13 A discussion 214has been given of the crystal chemistry of the (U0J2+, (NPO,)~", (PuO,)~',(Am02)2i, (YuO,)', and (AmO,)' ions, all of which have a symmetricalcollinear shape, the central atoms being able to form additional and longerbonds to 0 or F atoms. The observed bmd lengths can be correlated withthe bond strengths. Collinear uranyl groups have been reported in mag-nesium orthouranate,,15 in (3-uranyl hydroxide,216 in uranyl ~upferrate,~17and in uranyl carbonate.218 Crystals of Cs,ThCl, and Cs2UC1, are iso-structural 219 with Cs,PuCl, : each heavy atom is bonded to 6 chlorine atomsat the corners of slightly distorted octahedra.S.C. A.3. FERROELECTRICS AND ANTIFERROELECTRICS.1ntroduction.-Originally discovered in Rochelle salt,220 ferroelectricityhas now been found in a great variety of different structures; the rate ofdiscovery of new examples shows signs of increasing rather than decreasing.Ferroelectricity consists in a reversible spontaneous polarisation (manifested206 R. F. Raeuchle and F. W. von Batchelder, Acta Cryst., 1956, 9, 691.?07 G. J. Dickens, A. M. B. Douglas, and W. H. Taylor, ibid., 1956, 9, 297; G. Berg-208 J . S. Kasper and R. M. Waterstrat, ibid., 1956, 9, 289.209 S.Geller, ibid., 1955, 8, 15; J . Anzer. Ghem. SOC., 1955, 77, 2641; S. Geller andS. B. Cetlin, Acta Cryst., 1955, 8, 272.210 P. B. Braun and J. H. N. van Vucht, ibid., pp. 117, 246.211 W. H. Zachariasen, ibid., 1954, 7, 783.212 Idem, ibid., p. 792.213 P. Kierkegaard, Acta Chem. Scand., 1956, 10, 699.115 Idem, ibid., p . 788.2 1 6 G. Bergstrom and G. Lundgren, Acta Chem. Scund., 1956, 10, 673.217 W. S. Horton, J. Amer. Chem. SOC., 1956, 78, 897.218 D. T. Cromer and P. E. Harper, Acta Crvst., 1955, 8, 847.21s S. Siegel, ibid., 1956, 9, 827.2p0 J . Valasek, Phys. Rev., 1921, 17, 475.man and D. P. Shoemaker, ibid., 1954, 7, 857.W. H. Zachariasen, Acta Cryst., 1954, 7, 795400 CRYSTALLOGRAPHY.by a dielectric hysteresis loop) which is due to elementary dipoles arrangedso that their resultant dipole moment is not zero.There is characteristic-ally an upper transition temperature at which the dipole moment dis-appears, and there may also be a lower point. The transition is reversiblewithout break-up of the structure, and is displacive in Buerger’s sense,221i.e., it only involves small atomic displacements. It is associated with amarked peak in the dielectric constant and small changes in many otherphysical properties. In many cases, but perhaps not all, the changes arecertainly discontinuous, and the transitions of the first order. Latent heatsvary greatly, e.g., 1150 cal. mole-l in PbTiO, 222 and 12 cal. mole-1 at thelowest transition in BaTi03.223Compounds showing similar transitions without observable spontaneouspolarisation are called antiferroelectrics.First predicted theoretically 224from a rather unreal model, antiferroelectricity is now known in a widevariety of actual structures. They contain elementary dipoles like those ofthe ferroelectrics but so arranged by the symmetry that their resultantmoment is zero. Ferroelectrics may have antiferroelectric properties per-pendicular to their polar axis if the elementary dipoles 225 are not parallelbut are inclined to the axis in an arrangement such that their resultantmoment is not zero; these have been called cone ferroelectrics as distin-guished from Line ferroelectrics with parallel dipoles.Much interesting work, which cannot be surveyed here, has been doneon the physical properties.The chemical interest lies in the nature of thedipoles, the types of structure involved, and the possibility of explainingthem in terms of interatomic forces. Detailed theories,226$ 227 with theexception of Slater’s theory 228 of KH,P04, have all attributed the main r6leto long-range electrostatic forces ; none has proved capable of explaininglater-discovered types of ferroelectrics. Devonshire’s phenomenologicaltreatment 229 has proved stimulating and successful in relating properties 230but cannot help in explaining structures. The question of short-range forcesand the importance of homopolar bonds directed in space has only been dis-cussed q ~ a l i t a t i v e l y . ~ ~ ~ Useful reviews are available of the phenomenologicaltheories,232 of all theories up to about 19!52,227 and of recent experimental andtheoretical work ; 2% a book summarising results and theories is forthcoming.2a221 M.J. Buerger, in “ Phase Transformations in Solids ” (ed. SmoIuchowski),Wiley, New York, 1951.222 G. Shirane and S. Hoshino, J . Phys. SOC. Japan, 1951, 6, 265.223 S. S. Todd and R. E. Lorensen, J . Amer. Ch.em. Soc., 1952, 74, 2043; J. Volger,224 C. Kittel, Phys. Rev., 1961, 82, 729.pP6 L. E. Cross, Phil. Mag., 1956, 1, 76.226 See, for example, W. P. Mason, “ Piezoelectric Crystals,” Van Nostrand, NewYork, 1949; J. C. Slater, Phys. Rev., 1950, 78, 748; J. Pirenne, Physica, 1949, 15, 1019.247 E. T. Jaynes, “ Ferroelectricity,” Princeton Univ. Press, Princeton, 1953.228 J.C. Slater, J . Chem. Phys., 1941, 9, 16.229 A. F. Devonshire, Phil. Mag., 1949, 40, 1040; 1951, 42, 1065.230 W. J. Merz, Phys. Rev., 1953, 91, 513; S. Triebwasser, ibid., 1956, 101, 993;231 H. D. Megaw, A d a Cvyst., 1952, 5, 739; 1054, 7, 187.232 A. F. Devonshire, Phil. Mag. (Suppl.), 1954, 3, 85.233 G. Shirane, F. Jona, and R. Pepinsky, PYOC. Inst. Radio Engrs. N.Y., 1955, 43,234 H. D. Megaw, “ Ferroelectricity in Crvstals,” Methuen, London, 1957.Philips Res. Repoft, 1952, 7, 21.ref. 225.1738MEGAW : FERROELECTRICS AND ANTIFERROELECTRICS. 401A new concept of families of strztctzcres is becoming necessary. Allstructures of a family are derived by different small distortions from thesame high-symmetry form. In one family, two different compounds maybe isostructural, while one compound may have several different structures(it?,, phases) which are truly stable for different ranges of temperature andelectric field but may exist metastably outside these ranges; they may beferroelectric or antiferroelectric or neither.The ideal structure is usuallythe high-temperature form ; the higher its symmetry the greater the possiblevariety of distorted structures. Solid solutions may have phases within thefamily but different from those of either end-member; the possible com-plexity of the phase diagram is thus very great. All transitions within thefamily are displacive.The substances dealt with here fall naturally into two main groups,namely the oxides and the hydrogen-containing compounds.Oxides-The Perovskite family.Detailed analyses, by use of X-rays andneutrons, have been made of tetragonal 235 BaTiO, and the isomorphous 236PbTiO, ; they are qualitatively similar but the displacements are muchlarger in the latter. The oxygen octahedra remain nearly regular, butrelative to their geometrical centres all cations are displaced in the samesense, Ti by 0.12 A and 0.30 A in BaTiO, and PbTiO, respectively, Ba by0.06 A, Pb by 0-47 A. The Ti-0 distances in BaTiO, are 1.87, 2.17, 2-00 Aand in PbTiO, 1.78, 2.38, 1.98A, as compared with 1.96A for the radiussum. The partly homopolar character of the Ti-0 bond in PbTiO, seemscertain, and is evidence for a similar interpretation of the smaller effect inBaTiO,. The relatively large displacement of Pb places it at the apex ofa flat square pyramid, as in PbO, while leaving it close to 4 others of itsoriginal 12 oxygen neighbours.The system KNb0,-NaNbO, has been studied by its electrical and opticalproperties and lattice parameters.225, 237-239 With decreasing temperatureKNbO, is in turn cubic (425"), tetragonal (220") , orthorhombic (- 140" c) ,and rhombohedral, with transition points as indicated ; each structure issmall-cell * and all but the cubic are ferroelectric.NaNbO, is cubic ( ~ 6 4 0 " c),tetragonal small-cell ( * Z O O ) , pseudotetragonal multiple-cell ( ~ 3 6 0 " ) , ortho-rhombic multiple-cell ; all but the cubic are antiferroelectric. Below-120" a new ferroelectric phase can be produced 239 by the application ofa large field in a certain direction; once produced it remains stable up to-55". Another, probably different, phase is produced by a differentlydirected field at or below room temperature but this is never stable withoutthe field. The room-temperature structure 240 shows tilting of octahedra235 B.C . Frazer, H. R. Danner, and R. Pepinsky, Phys. Rev., 1955, 100, 745.236 G. Shirane, R. Pepinsky, and B. C. Frazer, Acta Cryst., 1956, 9, 131.237 G. Shirane, H. Danner, A. Pavlovic, and R. Pepinsky, Phys. Rev., 1954, 93, 672;G. Shirane, R. Newnham, R. Pepinsky, ibid., 1954, 96, 581 ; H. Francombe, Acta Cryst.,1956, 9, 256.238 F. Jona, G. Shirane, and R. Pepinsky, Phys. Rev., 1955, 97, 1584.239 L. E. Cross and B. J. Nicholson, Research Correspondence, 1954, 7, S30; Phil.Mag., 1955, 46, 453.240 P.Vousden, Acla Cryst., 1951, 4, 545. * A small-cell structure can be referred to a primitive unit cell of approximatelythe same dimensions as that of the ideal structure: in a multiple-cell structure the trueprimitive unit cell consists of two or more nearly identical sub-units of that size402 CKYSTALLOGKAYHY.such that Na has probably 6 near oxygen neighbours instead of 12; it alsoshows antiparallel displacements of Nb within the octahedra along one face-diagonal of the original cube. Solid solutions with very small amounts ofKNbO, give structures characteristic of KNbO,. Solid solutions betweenNaNbO, and Cd,Nb,O, also show perovskite-type structures at the NaNbO,end.*1SrTiO, (cubic small-cell) has no transition 242 down to 8" K, but its di-electric constant behaves like that of materials approaching a ferroelectricCurie point.Below 4" K a ferroelectric phase can be induced by a field.2&CaTiO, (distorted, multiple-cell) is somewhat similar electrically,2u but nolow-temperature transition has yet been reported; that z45 at 1260" c ispresumably to a cubic form.Solid solutions of PbTiO, and PbZrO, with each other, or with Ba, Sr,or Ca replacing Pb, give a very complex series of phases. Between PbTiO,(ferroelectric, tetragonal, small-cell) and PbZrO, (antiferr~electric,~~~ ortho-rhombic,23* multiple-cell) there is a Zr-rich ferroelectric rhombohedralwhich can also be induced by an applied field outside its normalcomposition range ; 248 it is isomorphous with rhombohedral BaTiO,, and hasa relative cation displacement of 0.14 I t also occursin (Pb,Ba)21-0,.~~~ The structure of the other phases remains unknown.The high-temperature (tetragonal) form of WO,, which is antiferroelectric,has been studied in Qualitatively it closely resembles BaTiO,with the barium atoms omitted and half the titanium displacements reversedin sense. The displacement of tungsten relative to the centre of symmetryis 0.23 A.The room-temperature form has been re-investigated; 251 it ismonoclinic, but the atomic parameters are not known. A low-temperatureform has been reported as rhombohedral and ferr~electric.,~~LiNbO,, formerly thought to have an ilmenite struc-ture, has now been shown 2% to be a type of its own.The oxygen array, asin ilmenite, approximates to hexagonal close-packing, but the sequence ofcations in octahedral sites parallel to the c-axis is : Li, Nb, empty, Li, Nb,empty. . ., which is compatible with polar symmetry and the reportedferroelectricity. The niobium atoms are displaced 0.28 A from the centresof the octahedra. There is a topological relationship with the perovskitestructure.(cf. 0.17 A in PbTiO,).Lithium niobate.241 B. Lewis and E. A. D. White, Acta Cryst., 1955, 8, 849.242 J. K. Hulm, Proc. Phys. Soc., 1951, 63, 1184.243 H. Granicher, Helv. Phys. Acta, 1956, 29, 211.a44 H. Granicher and 0. Jakits, Nuovo cim. (SuppZ.), 1954, 11, 480.246 B. F. Naylor and 0. A. Cook, J . Amer. Chem. Soc., 1946, 68, 1003.2413 G.Shirane, E. Sawaguchi, and Y . Takagi, Phys. Rev., 1951, 84, 476.247 G. Shirane and A. Takeda, J . Plzys. SOC. Japan, 1952,7,5 ; G. Shirane, K. Suzuki,g4a E. Sawaguchi, ibid., 1953, 8, 615.24s G. Shirane, Phys. Rev., 1952, 86, 219; G. Shirane and S. Hoshino, Acta Cryst.,260 W. L. Kehl, R. G. Hay, and D. Wahl, J . A$$. Phys., 1952, 23, 212.251 C. Rosen, E. Banks, and B. Post, Acia Cryst., 1956, 9, 475; G. Andersson, Acta252 B. T. Matthias and E. A. Wood, Phys. Rev., 1961, 84, 1255.z53 P. Bailey, Thesis, Bristol, 1953, quoted by H. D. Megaw, Acta Cryst., 1954,and A. Takeda, ibid., 1952, 7, 12; G. Shirane and K. Suzuki, ibid., 1952, 7, 333.1954, 7, 203.Chew. Scand., 1953, 7, 154.7, 187hIEGhW FERRUELECTRICS AN 1) ANTIFEHKOELEC lX1CS.403Yyochzlores. Cd,Nb,O,, ferroelectric below about 180" K, has apyrochlore structure at room temperature. This, like perovskite, has aframework of octahedra linked by shared corners, the seventh oxygen atombeing linked only to cadmium. The phase transition makes remarkablylittle difference to the X-ray pattern,255 being detectable only by a veryslight splitting of the highest-angle lines. The ferroelectric phase is probablytetragonal, possibly orthorhombic, but certainly not rhombohedral.Pb2Nb,0,, with a multiple-cell variant of the same structure,2M is anti-f erroelect ric.Though oxides with some oxygen deficiency retain the yyrochlore struc-ture, Cd,Nb,O, has the columbite structure and is not ferroelectric; 255PbNb,06 has been reported with an orthorhombic ferroelectric form,256and with a perovskite form.257Hydrogen-containing Compounds.-New work on Rochelle salt 233 sug-gests that the hydrogen-bond system must be radically revised ; detailedco-ordinates and bond lengths are not yet available.Very careful refine-ment of both high 30 and low-temperature 409 258 forms of KH,PO, has beencarried out, and the reversal of the structure accompanying reversal of thespontaneous polarisation has been elegantly demonstrated. The low-temperature form of ND4D,P0, (presumably isomorphous with NH,H,PO,)has been shown 259 to be antiferroelectric ; the difference in detailed arrange-ment between this and KH2P0, may be attributed2,O to the bonding re-quirements of the NH, group.The periodates Ag2H,I06, (NH,),H,IO,, and(ND,),D,IO, are antiferroelectric ; 261 they have transitions a little belowroom temperature, at which the a-edge is doubled in all three compounds andthe c-edge also in Ag,H,IO,. There is some formal resemblance to KH,PO,,with trigonal symmetry replacing tetragonal and octahedra replacingtetrahedra.Very interesting new ferroelectrics and antiferroelectrics occur aniongthe sulphates. The first group is typified by guanidine aluminium sulphatehexahydrate,262 (CH,N,)Al(SO,),,GH,O. ' I Isomorphous " compounds occurwith Cr, Ga, or V replacing Al, and Se replacing S. These materials areferroelectric at room temperature and remain so up to about 300" c, whenthey decompose. Another interesting family is that of the alums,AJA*1T(S0,),,12H20 ; these have long been known to possess several differenthut closely-related structures at room temperature, and recent work 263 shows264 W.R. Cook and H. Jaffe, Phys. Rev., 1952, 88, 1426; 1953, 89, 1297.y 5 5 F. Jona, G. Shirane, and R. Pepinsky, ibid., 1956, 98, 903.2 5 6 G. Goodman, J . Amer. Ceram. SOC., 1953, 36, 368.257 M. H. Francombe, Acla Cryst., 1956, 9, 683.258 H. A. Levy and S. W. Peterson, Phys. Rev., 1954, 93, 1121,259 E. A. Wood, W. J. Merz, and B. T. Matthias, ibid., 1952, 87, 544.K. 0. Keeling and R. Pepinsky, 2. Krist., 1955, 106, 236.261 G. Busch, W. Kanzig, and W. M. Meier, Helv. Phys. Ada, 1953, 26, 385; H.Granicher, W. M. Meier, and W. Petter, ibid., 1954, 27, 216; D. Aboav, H. Granicher,and W.Petter, ibid., 1955, 28, 299.262 A. N. Holden, B. T. Matthias, W. J. Merz, and J. P. Remeika, Phys. Rev., 1955,98, 546; A. N. Holden, W. J. Merz, J. P. Remeika, and B. T. Matthias, ibid., 1966,101,962 ; J. P. Remeika and W. J. Merz, ibid., 1956, 102, 295.263 For a survey, see for example, K. D. Bowers and J. Owen, ReFort Progr. Ph-ys.,1955, 18, 304404 CRYSTALLOGRAPHY.a very complex series of transitions at low temperatures. Some alums havenow been found to be ferroelectric, e.g., (CH3*NH,)Al(SO,),,12H2O below176" K, and some antiferroelectric.za Other ferroelectric sulphates are 265(NH,),SO, and 266 (NH,),Cd,(SO,), (the latter cubic at room temperature)with Curie points at 223" K and 87" K respectively.Ferroelectricity is also reported in ~olemanite,2~~ CaB,O,(OH),,H,O,below - 2.5".Both room-temperature 268 and low-temperature structuresare monoclinic.Generalisations.-The oxides all have saturation moments about 10-30 PC crn.-,, as compared with 0.1-1-0 PC cm.-2 for compounds of hydrogen.They all contain one of the " cations " Ti4+, Z P , Hf4+, Nb5+, Ta5+, or W6+in octahedral co-ordination, the octahedra being linked by corners. In allthose examined in detail, the octahedra are little distorted, but the " cations "are displaced appreciably from their geometrical centre. It seems likelythat this octahedral group constitutes the elementary dipole, the polaris-ation of the oxygen atoms shielding each from the others. Whether the" cation " is displaced towards a corner, edge, or face of the octahedronseems to depend mainly on the identity of the cation and the temperature,but it is also affected by the polarising power of the other cation present,or, in BaTiO,, by its large size which strains the TiO, framework; nearthe limits of its stability range it may also be influenced by an appliedfield.Tilting of the octahedra about their shared corners is common in themultiple-cell structures.This puckering changes the co-ordination of thesecond cation; the change, so far as available evidence goes, is that re-quired by Goldschmidt's rules of ionic packing, e.g., Na becomes 6- insteadof 12-co-ordinated. There is a tendency for the two framework bonds tooxygen to be non-collinear, as one would expect if they were partly homo-polar. In adjacent octahedra the relative sense of the displacements, andhence of the dipole moments, depends on the bond angle at the oxygenatom.The choice between ferroelectricity and antiferroelectricity thusdepends on how the octahedra can be built together to satisfy the bondangle at the oxygen atom and the packing requirements of the secondcation.The hydrogen compounds have in general more complicated structures,where the symmetry by itself is not as informative as in the oxides, andexcept for KH,PO, none is known in sufficient detail. They all containhydrogen bonds, but these range from short (2-49A in KH,PO,) to long(2.87 A in the alums) and include N-H. . . 0 in (NH,),SO, as well asO-H . . . 0 in many of the others.It seems that the polarisation of eitheror both of the oxygen atoms involved in the bond is important, but inKH,PO, the displacement of phosphorus relative to its neighbours suggeststhat the PO,(OH), group as a whole is the dipole.264 R. Pepinsky, F. Jona, and G. Shirane, Phys. Rev., 1956, 102, 1181.*68 F. Jona and R. Pepinsky, ibid., 1956, 103, 1126.267 J. W. Davisson, Actu Cryst., 1956, 9, 9 ; G. J. Goldsmith, Bull. Amer. Php. SOC.,268 C . I,. Christ, J . R. Clark, and H. T. Evans, A d a Cryst., 1954, 7, 453.B. T. Matthias and J . P. Remeika, ibid., 1956, 103, 262.1956, 1, 322SPEAKMAN ORGANIC STRUCTURES. 405These generalisations, tentative as they are, suggest that the short-rangeor chemical forces play an important part, and that further work in thisfield, especially if it can be made quantitative, will be of considerablechemical interest.H. D.M.4. ORGANIC STRUCTURES.Carboxylic Acids and Related Compounds.-For some years long-chaincompounds have been isolated in a state of high purity a t Uppsala, andphysical measurements on the normal fatty acids have now been sum-marked in two papers by Stenhagen and von S y d o ~ . ~ ~ ~ The first dealswith the melting points and transition points of the acids from C,, to C29;the second with the polymorphic forms and their structures. Six forms areknown with certainty : A, B, and C with acids whose molecules contain aneven number of carbon atoms, and A', B', and C' with the odd members-though all three forms are not necessarily known for every acid.Thestructures of these forms are described, as are also the sub-cells whichcharacterise the two types of packing of the parallel polymethylene chains.The well-known alternation of melting-points (Le., of the C or C' forms) isnot due to any inherent difference in molecular structure; it can be con-vincingly explained as due to differences in crystal structure, which lead tocloser van der Waals contacts between layers of terminal methyl groups inthe even acids (C-form). The molecules of (-+)-9-methyloctadecanoicacid,270 CH,*[CH,],*CHMe*[CH,],CO,H, are much more tilted (72") fromthe normal to the plane occupied by the carboxyl groups than are those ofany other known fatty acid; this is clearly due to the necessity for accom-modating the methyl group, protruding from the middle of the chain, in thegap at the end of the neighbouring molecule.Magnetic measurements 271on cupric laurate and stearate suggest that pairs of copper atoms lie closetogether, and hence that the structure resembles that of cupric acetatedih~drate.,~,The acid, C,H40,,2H,0, formerly supposed to be dihydroxymaleic, isnow thought to be dihydroxyfumaric and this is confirmed in a partialX-ray analysis.273 Acid fumarates of composition M,H,A3 (M = K, Rb;A = fumarate) have been studied.274 One fumarate residue is required tobe centrosymmetric, but, since hydrogen atoms were not located, it is notclear whether the formulation should be BMHA,H,A or M,A,2H& Tiglicacid 275 proves to have the trans-configuration (cis-methyls) (1).Thisimplies that angelic acid, work on which is in progress, has the alternativeconfiguration.The structure of benzoic acid has been determined with considerable268 E. Stenhagen and E. von Sydow, Arkiv Kemi, 1953, 6, 309; 1956, 10, 231.2 T o S. Abrahamsson, Acta Cryst., 1956, 9, 663.2 7 1 R. C. Herron and R. C. Pink, J . , 1956, 3948.272 Anit. Reports, 1954, 51, 390.273 M. P. Gupta, .I. Amer. Chem. Soc., 1953, 75, 612; Canad. J . Chem., 1955, 33,274 Idem, Acta Cryst., 1956, 9, 263.2 7 5 A. L. Porte and J. M. Robertson, Nature, 1965, 176, 1116.1450406 CRYSTALLOGRAPHY.accuracy; 276 and the bond lengths shown to be in good accord with theresults of molecular-orbital calculations.277 Dimeric molecules (2) also existin phenylpropiolic The planar molecules are bisected by a crystallo-graphic plane of symmetry parallel with their length.The two C-0 bondstherefore appear to be equivalent, and the hydrogen atoms more symmetricallylocated than appears in formula (2). This unacceptable conclusion, thoughsupported by a good agreement between F, and Fc, was evaded by the dis-covery in the structure of disorder, allowance for which made the agreementbetter; dimeric molecules lie a t random with respect to the alternativeorientations (2) and (3), and the observed symmetry is merely a statisticalone. [In a similar way the molecule of naphthazarin (4) has been foundto be crystallographically centrosymmetrical by two independent workers.279]Effects of this kind seem to be fairly common ; and crystallographers oughtto be on their guard against being misled by them.9-Aminosalicylic acid 280has been analysed with sufficient accuracy for the hydrogen atoms to belocated, with reasonable certainty, at positions which prove that this aciddoes not adopt the zwitterionic structure generally found in aliphatic amino-acids. A preliminary report 281 has been made of the full-scale analysis ofFeist's acid; the structure now accepted for this compound is also indicatedby nuclear magnetic resonance.282 Silver perfluorobutyrate 283 consists ofdimers, the two carboxyl groups being linked via two silver atoms into eight-membered rings.According to a fairly precise analysis,284 formamidoxime has a planarmolecule. Donohue 285 has cited this work in evidence against the suggestedpolar structure ( R2C=AH-6) for oximes.The structures of succinimide 286and succinamide 287 have been studied, the latter with a precision sufficientto locate the hydrogen atoms and hence to confirm the amide (rather thanthe imidol) grouping. A study of the unstable form of chloroacetamide 288includes a survey of bond lengths and angles in various amides; in all casesL(C-C-N) is less than L(C-C-0), as-in analogy with carboxyl-is to beexpected for the amide group. An analysis of the stable form of chloro-276 G. A. Sim, J. M. Robertson, and T. H. Goodwin, A d a Cyi.d., 1955, 8, 157.277 T. H. Goodwin, J., 1955, 4451.278 J. S. Rollett, Acta Cryst., 1955, 8, 487.279 C. Billy, Compt. rend., 1955, 240, 887; 0.Borgen, A d a Chrnz. Scuud., 1956, 10,280 F. Bertinotti, G. Giacomello, and A. M. Liquori, Acta Cryst., 2954, 7, 807.281 D. R. Petersen, Chem. and Ind., 1956, 904.282 A. S. Kende, ibid., 1956, 437.283 A. E. Blakeslee and J . L. Hoard, J . Amey. Che~n. Soc., 1956, 78, 3029.284 D. Hall and F. J. Llewellyn, Acta Cryst., 1956, 9, 108.285 J. Donohue, J . Amer. Chem. Soc., 1956, 78, 4172.286 R. Mason, Acta Cryst., 1956, 9, 405.287 D. R. Davies and R. A. Pasternak, ibid., p. 334.Z B R M. Katnyama, ibid., 1956, 9, 986.867SPEAKMAN ORGANIC STRUCTURES. 407acetamide led to angles which would have made this substance an excep-tion, but a brief report of a rather more accurate analysis 290 gives anglesthat conform.A study of N-chlorosuccinimide 291 has also been brieflyreported.Though not isomorphous, benzeneseleninic acid (5) 292 and its fi-chloro-derivative 293 have very similar structures, that of the former having beenbeen studied with higher accuracy. The three bonds roundPh-Se /OH the selenium atom are arranged pyramidally, the angles allbeing near to 100"; the two SeO bonds differ in length,d(Se-OH) being 1.765 and d(Se-0) 1.707, each &0.015 A ;the molecules are linked together by strong hydrogen bonds d(OH . . , 0) =2.52 L f , so as to form infinite spiral chains round the 2,-axis. An accurateanalysis of dibenzyl hydrogen phosphate,294 which is of interest as a modelcompound for nucleic acids, shows that d(P-0) = 1.469 -& 0.004 A for theunicovalent oxygen atom, and d(P-0) = 1.545, 1.545, and 1.566A for theother three oxygens.Aromatic Hydrocarbons.-Ant hracene now holds the palm as best illus-trating the evolution of X-ray methods.So long ago as 1921, a comparisonof its unit-cell dimensions with those of naphthalene enabled W. H. Braggto suggest an orientation for the molecule. In 1933 Robertson 295 measuredabout 80 F,-values and used them to compute one of the earliest sets ofelectron-density projections, which clearly showed the molecule and itsposition in the cell, but was not accurate enough to detect differences inbond-lengths. The same author and his collaborators published in 1950 anaccount 296 of a three-dimensional study : nearly 700 F, values had beenmeasured, an electron-density section in the molecular plane (see A m .Reports, 1950, 47, 433) was derived, and bond-lengths were given with anaccuracy estimated at &O.Ol A.(The lengths were later compared withthose calculated by various wave-mechanical procedures.297) The sameexperimental data have now been used by Cruickshank298 in the mostthorough refinement yet applied to a structure of this kind; and thereemerges an extremely detailed picture of the molecule in its crystallineenvironment. The final bond-lengths and angles (e.s.d. & 0.004 A and& 12') are given in Fig. 1. With one exception the lengths differ surprisinglylittle from those estimated in 1950, though the precision is now higher andmore firmly based. The slight deviations of the atoms from their meanplane-also shown in the Fig.-are now highly significant ; and they can bereasonably attributed to the stresses exerted on the various parts of themolecule by identifiable contacts with its neighbours.The vibrations of the\O28B J. Dejace, Acta Cryst., 1955, 8, 851.2D0 B. R. Penfold and W. S. Simpson, ibid., 1956, 9, 831.291 R. N. Brown, ibid., p. 193.292 J . H. Bryden and J . D. McCullough, ibid., 7, 833.2B3 Idem, ibid., 1956, 9, 528.2Br J. D. Dunitz and J . S. Rollett, ibid., p. 327.295 J . M. Robertson, Proc. Roy. Soc., 1933, A , 140, 79.2B6 A. McL. Mathieson, J. M. Robertson, and V. C. Sinclair, Acta Cvyst., 1950, 3, 245.297 C. A. Coulson, R. Daudel, and J. M. Robertson, Proc. Roy. Soc., 1951, A , 207,2BB D.W. J. Cruickshank, Acta Cryst., 1956, 9, 915; for some minor emendation see306.Ada Cvyst., 1957, in the press408 CRYSTALLOGRAPHY.atom can be resolved into translational movements with r.ni.s. amplitudesof 0.20, 0.16, and O*lSA parallel to the respective molecular axes, L, M,and N, and into librations of 2-3" about these axes. The first of thesetranslations is probably significantly greater than the other two, and itcorresponds to movement in the direction in which the molecule might wellFIG. 1.civcles represent the deviations (in 0.001 A) of the atoms f r o m their mean molecular plane.Axis M aBond-lengths (A) and angles i?$ the anthracene molecule. The figures within theexperience least resistance. The final " difference map " shows negativeareas at the centres of the rings and between the " spokes" of the C-Hbonds.It is tempting to ascribe this to the lateral contraction of theatomic orbitals when they enter into a o-bond (see p. 411). Theoreticalcalculations of the electron-density over the benzene molecule do not revealsuch electron-deficient areas,299 but the contraction may not be properlyreproduced in the usual L.C.A.O. approximation.have nowbeen analysed by two-dimensional methods, but with sufficient accuracy toshow that the molecular dimensions do not differ seriously in the two forms.The space-group of azulene (6) was formerly thought to require the moleculeto be effectively centrosymmetric, which would imply randomness of orient-ation in the crystal. But more detailed studies, briefly reported from twolaboratories,301 indicate a different space-group and show projections inwhich the five- and seven-membered rings are easily recognisable.Theimportant question of bond-lengths cannot yet be answered. Analyses ofchrysene 302 and 3 : 4-benzopyrene 303 show these molecules to be planar,or very nearly so. Although the molecule of 9 : 10-dihydroanthracene is" folded " about the line of atoms 9 and 10, that of the related compound (7)appears to be centrosymmetric, and hence presumably planar.304Other work on aromatic hydrocarbons can be considered in relation toovercrowding.305 Projections of certain overcrowded molecules have beenBoth polymorphic forms of 1 : 2-5 : 6-dibenzanthracene299 N. H. March, Acta Cryst., 1952, 5, 187; W.Cochran, ibid., 1956, 9, 924.3OO J. M. Robertson and J. G. White, J., 1947, 1001; 1956, 925.301 J. M,. Robertson and H. M. M. Shearer, Nature, 1956, 177, 885; Y . Takeuchi302 D. M. Burns, Acta Cryst., 1056, 9, 173.303 J. Iball and D. \V. Young, Nature, 1956, 177, 985.804 Personal communication from Dr. Iball.Ann. Reports, 1954, 51, 393.and R. Pepinsky, Science, 2956, 124, 126.(It was there stated that the structures of m- andp-xylylenes were first revealed by X-ray analysis: so far as the m-compound is con-cerned, this is erroneous-see W. Baker, J. F. W. McOmie, and J. M. Norman, J., 1951,11 14.SPEAKMAN : ORGANIC STRUCTURES. 409derived from intensity data at low temperatures; 306 on the maps thus"sharpened" the hydrogen atoms can often be located, and this helpsconsiderably in understanding the stereochemical details of the strain.Anaccurate low-temperature study of diphenyloctatetraene , Ph*[CH:CH],-Ph 307shows the benzene rings to be slightly out of the plane of the zigzag goly-methine chain, a result attributed to repulsion between the ortho-hydrogenatoms and those on the terminal CH-groups; the mean L(C=C-C) =124.2" &- 0.2". Pentacene probably has a planar molecule, as also hascircumanthracene (1 1, the third member of the coi-onene-ovalene series) ; 308but the intermediate compounds (8, 9, and 10) are considerably distorted.3og3 : 4-Benzophenanthrene is well known to have an overcrowded molecule,but, when the interfering atoms are bonded in 2 : 13-benzofluoranthene (la),the molecule becomes planar,31° though the new bond [d(C-C) = 1.49 A]must cause considerable disturbance of the aromatic ring-system.Heterocyclic Systems.-Four important molecules containing nitrogenatoms have been studied with high accuracy.s-Triazine (13) 311 has thehigh molecular symmetry Fm, which is fully used in the crystal structure-arare occurrence. Only four parameters are therefore needed to define the(static) structure, and they may be expressed as d(C-N) = 1.319 & 0.005,d(C-H) = 1.00 A, L(N-C-N) = 126.8" & 0-4", and L(C-N-C) = 113.2" If:0.4". s-Tetrazine (14) has a centrosymmetric which does notdeviate significantly from coplanarity, and whose dimensions correspondclosely with those of triazine : d(C-N) = 1.334 0.007 (mean of two),116.0" & 0.3" (mean of two). Phenazine (15) has been studied in its a-form.313 This molecule too is centrosymmetric, and it does not deviateH(N-N) = 1.321 & 0.010 A, L(N-C-N) = 127.4" & 0*3", L(C-N-N) =306 F.L. Hirshfeld and G. M. J. Schmidt, Acta Cryst., 1956, 9, 233.307 W. Dreuth and E. H. Wiebenga, ibid., 1955, 8, 755.308 E. Clar, W. Kelly, J. M. Robertson, and M. G. Rossmann, J., 1956, 3878.309 Personal communications from Prof. Robertson, Dr. Rossmann, and Mr. Trotter310 H. W. Ehrlich and C . A. Beevers, Acta Cryst., 1956, 9, 602.311 P. J. Wheatley, ibid., 1955, 8, 224.31a F. Bertinotti, G. Giacornello, and A. M. Liquori, ibid., 1696, 9, 610.313 F. H. Herbstein and G. M. J. Schmidt, ibid., 1956, 8, 399, 406610 CRYSTALLOGRAPHY.significantly from mmm symmetry, though this is not a crystallographicrequirement ; L(C-N-C) = 116.6" & 0.6", and the structurally distinctC-C bonds differ in length, in a sense generally in accord with molecular-orbital calculations.Acridine (16) crystakes in a number of polymorphicforms, and that designated I11 has now been analysed in great detail.314Antiparallel pairs of dissymmetric molecules front one another across centresof symmetry ; the polar stresses imposed by this arrangement presumablyaccount for the appreciable and complex molecular distortion from the idealplane. (C-N-C) = 117.2" -j= 0*4", and the bond-lengths are in fair agree-ment with the results of theoretical calculations.Rut, as Phillips pointsout, the observed lengths of corresponding C-C bonds in anthracene, acridine,and phenazine agree amongst themselves strikingly, andthan with the theoretical values.much more closelyAn accurate analysis of 4-nitropyridine 1-oxide has been recently de-scribed; 315 L(C-N-C) = 115.4" -j= 12", and the molecule is strictly co-planar. The molecule of 2 : 2'-dipyridyl is also planar, and has the trans-configuration with respect to the nitrogen though in complexformation it must adopt the cis-form; L(C-N-C) = 116.7". The structureof pteridine (17) has been surveyed by two-dimensional methods,317 and thebond-lengths have been compared with the results of molecular orbitalcalculations.318 The crystal structure, like the molecule, has no centre ofsymmetry, so that refinement proved difficult.The maximum atomic dis-placement from the mean plane was found to be as much as 0.06 A ; butthis is not claimed as significant. The mean of the four L(C-N-C) = 117",compared with 120" for the eight angles at carbon atoms.A fuller account of work on parabanic acid has appeared.319 Difficultiesof refinement limited the accuracy attained with dialuric acid (18) ; 320it is probable that the atoms of the ring are coplanar and that the moleculeadopts the tautomeric form shown, though the hydrogen atoms were notdirectly located. In an analysis of 4 : 5-diamino-2-chloropyrimidine 321314 D. C . Phillips, Acta Cryst., 1956, 9, 237.315 E. L. Eichorn, ibid., 1956, 9, 787.317 T.A. Hamor and J. M. Robertson, J., 1956, 3586.318 T. H. Goodwin and A. L. Porte, J., 1966, 3695.3lS D. R. Davies and J . J . Blum, Acta Cryst., 1956, 8, 129.360 L. E Alexander and D. T. Pitman, ibid., 1956, 9, 501.at1 N. E. White and C . J . B. Clews, ibid., 1956, 9, 586.L. L. Merritt, jun., and E. D. Schroeder, ibid., 1956, 9, 801SPEAKMAN : ORGANIC STRUCTURES. 41 1on the other hand, the positions of the hydrogen atoms unequivocally indi-cate the formula (19). The purine analogue, xanthazole (20), has beenexamined as its d i h ~ d r a t e . ~ ~ ~ The evidence presented makes it probablethat the hydrogen atoms are situated as shown, implying a semi( ?)mesoionicstructure. The paper includes a survey of molecular data for a number ofpurines and pyrimidines.Correlation of the various data leads to the generalisation that thenitrogen valency-angle in a six-membered ring is always less than 120" whenthe ring is of aromatic type (--N=) and nearly always greater when it isnot (-NR-).The former part of this rule was pointed out by Bertinotti,Giacomello, and Liquori,312 in relation to compounds (13)-( 15) and melamine,and attributed to the steric repulsion exerted by the bulkier lone-pair ( ~ $ 2 )orbital on the two more condensed bonding orbitals. The idea323 that abonding orbital may be more restricted in space than was the non-bondedatomic orbital, or than the usual L.C.A.O. calculation implies, is supportedby several lines of evidence (see p. 408). The latter part of the rule is atpresent less well established; if it proves generally true, it may be attribut-able to the fact that, in an unconjugated system, the bonds to >NH willbe considerably shorter than those to >CH2.There is now a more detailed account 324 of work on the mesoioniccation (21).Except for the hydrogen atoms of the methyl groups, themolecule is strictly co-planar ; and the same appears to be true of the relatedsubstance, 5-amin0-2-rnethyltetrazole.~~~ Fuller accounts have been givenof the structures of indigo, thioindigo, and selenoindigo 326 (22 ; X = NH,S, and Se). All three molecules adpot the trans-configuration shown;L (C-X-C) = 1 loo, 92O, and SO", respectively. Similar results have beenreported from U.S.S.R.327 for the first two substances.The eight-memberedring in cydotetramethylenetetranitramine (23) is centrosymmetric andpuckered,328 with L(C-N-C) = 123-124" and L (N-C-N) = 109-1 12".,4 similar eight-membered ring occurs in (CMe2*Si0),,329 in whichL(Si-0-Si) = 142.5". 1 : 4-Dithian wo has a chair-form molecule withd(S-C) = 1.81, d(C-C) = 1-49 A, and L(C-S-C) = 99". A recent accurateanalysis of thianthren confirms the " folding '' of this molecule about theS . . . S-line,=l with L(C-S-C) = 100" 5 1.0" and d(S-C) :-= 1.76 0.01, a.312 W. Nowacki and H. Biirki, Z . Krist., 1955, 106, 339.333 C . E. Mellish and J. W. Linnett, Trans. Faraday SOC., 1954, 50, 667.324 J. H. Bryden, Acta Cryst., 1955, 8, 211.325 Idem, ibid., 1956, 9, 874.326 H. von Eller, Bull. SOC. chim. France, 1955, 1426, 1429, 1433, 1438, 1444.317 Y e .A. Gribova, G. S. Zhdanov, and G. A. Gol'der, Kristallografiya, 1956, 1, 53.328 P. F. Eiland and R. Pepinsky, 2. Krist., 1955, 108, 273.12D H. Steinfink, B. Post, and I. Fankuchen, Acfa Cryst., 1955, 8, 420.3Jo R. E. Marsh, ibid., p. 91.a31 H. Lynton and E. G. Cox, J., 1956, 4886; see also I. Rowe and B. Post, ActaCvyst., 1956, 9, 82741 2 CRYSTALLOGRAPHY.Miscellaneous Compounds.-In the monoclinic form of n-hexatriacontane,C,,H,,, the molecule adopts the form of a regular planar so thatthe mean values of d(C-C) = 1.534 5 0-006 A, and L (C-C-C) = 112"1' & 21', could be assessed with precision. Similar mean values of 1.639 &0.013 and 112-7" -+ 1.0" have been found in ll-aminoundecanoic acidhydrobromide.= Dimethylacetylene possesses a very simple structure thathas been analysed with high accuracy; d(C-C) = 1.457 -J= 0.010,d(C-C) = 1.211 & 0.017 A ; methyl groups of contiguous molecules areseparated by only 3-54 A, so that some " interlocking " of rotating groups ispresumed. The compound, " Rongalite C," made by reducing a mixtureof formaldehyde and sodium hydrogen sulphite, has been shown335 tocontain the anion (24) in which the bonds round the sulphur atom are/O-\O(24) HO*CH,-SMeSOa\,C=C=N-Me (25)PhSOaarranged pyramidally, and the values of d(S-0) = 1.495 & 0.010 A, donot differ appreciably.Di-$-tolyl telluride, selenide, and sulphide formisomorphs, which have been carefully a n a l y ~ e d . ~ ~ ~ The angle at the hetero-atom increases with diminishing atomic number : 101" & 2.7" (Te), 106" &1.9" (Se), and 109" & 1.9" (S) ; and this trend is continued in diphenyl ether(116" & 4°).337 Though diphenyl sulphone and sulphoxide have quitedifferent (though related) unit-cell dimensions, so that strict ismorphism isnot possible, over 90% of the sulphone can be replaced by sulphoxide withoutchange of the lone-pair on the sulphur atom adequately takingthe place of the missing osygen atom.A second vinylideneamine (25) isbeing examined by Wheatley ; 339 it also has a C-C-N-C-chain that is nearlylinear, though in this case L (C-N-C) is significantly less than 180".Unlike that of keten itself, the dimer of dimethylketen has a carbocyclicstructure (26), and this has been confirmed by X-ray diffraction.a0 Themolecular symmetry in the crystal is 21972 and hence the ring is planar,though large out-of-plane vibrations may occur.The structure of cyclo-hexylammonium chloride has been determined with considerable accuracy.a1The ring has the chair-form with d(C-C) averaging 1.55 & 0.02 A, andL(C-C-C) 108" & 2"-a direct confirmation of the Sachse structure in amolecule where the carbon atoms are not overshadowed by heavier sub-stituents. (cycLoHexane itself has a highly disordered crystal structure.a2)In benzene iodochloride, PhIC12,3d3 and its 9-chloro-derivative 344 the332 H. M. M. Shearer and V. Vand, Acta Cryst., 1956, 9, 379.333 G. A. Sim, ibid., 1955, 8, 833.334 E. Pignataro and B.Post, ibid., 1955, 8, 672.338 hl. R. Truter, J.. 1955, 3064.336 \V. R. Blackmore and S. C. Abrahams, Acta Cryst., 1955, 8, 317, 323, 329.337 N. J . Leonard and L. E. Sutton, J. Amer. Chew. SOC., 1948, 70, 1564.338 S. C. Abrahams and J. V. Silverton, Acta Cryst., 1966, 9, 281.33s Personal communication.340 P. H. Friedlander and J . M. Robertson, J., 1956, 3083.341 A. Shimada, Y. Okaya, and M. Nakamura, Acta Cryst., 1955, 8, 819.342 T. Oda, Structure Reports, 1947-48, 11, 611.343 E. M. Archer and T. G. D. Schalkwyk, A d a Cryst., 1953, 6, 88.344 D. A. Rekoe and R. Hulme, Naiure, 1956, 177, 1230SPEAKMAN : ORGANIC STRUCTURES. 413ICl,-group is linear, symmetrical, and nearly perpendicular to the plane ofthe benzene ring; d(1-C1) = 2.45 fi.The chemical properties of di(hydr-oxydury1)methane (27) suggest that there is steric stress at the methylenegroup, and analysis 345 shows that d(Cap-CH2) = 1.60 and L(Ch-C-Car) =119'. The h e r of phenyl isocyanate (28) has been carefully analysed,346 thes;'/ c \'C'Me,C CMeZMe Me Me MeH O ( - J - C H , 0 0 "Me Me Me Me(27)II0 ( 2 8 )phase problem being solved by use of the fact that the dimer is isostructuralwith $-terphenyl. The centrosymmetric molecule has H(C-N) = 1-42,1-49 0.014A and L(N-C-N) = 87", L(C-N-C) = 93" & 1.5" in the four-membered ring, and d(C-0) = 1.15, d(N-Ck) = 1.41 & each somewhat outof the plane of the ring. Unlike some other nitroso-compounds, p-iodo-nitrosobenzene is monomeric, with a planar molecule, which may bestabilised by a polarisation bond, d(I .. . 0) = 3.2 A, between successivehead-to-tail molecules.The very careful analysis of sodium tropolonate has been described inmore detail.s48 The atoms of the anion deviate from planarity only by smalldistances, the greatest of which (0.03 A) is ofdoubtful significance, and can in any case be(&0-013 a) are shown in formula (29) ; they(29) nearly correspond to the anion's having aplane of symmetry, normal to the paper, sothat greater reliance can be placed on the''b 1.379 mean values for pairs of corresponding bonds.The bond between the CO-groups is certainlylonger, and the adjacent C-C bonds are probably longer, than the rest. Allthe hydrogen atoms were located, with d(C-H) = 1-03 (mean).In thetropolonium cation,3qs the C-0 bonds are also equal in length, though longer(1.41 a), whilst in tropolone itself 350 they probably differ (1.26, 1.34 A).Molecular Compounds.-Studies of a number of complexes containingdioxan (D) have been briefly reported by Hassel and his co-workers:D,Br2,351 D,ICl,352 D,HgC12.353 In all there is a close approach between anoxygen atom and a halogen : e.g., d(O . . . Br) = 2.7, d ( 0 . . . I) = 2-6 A.Similar compounds occur with amines-e.g., between hexamethylene-tetramine and Br2,354 with d(N . . . Br) = 2.3 A. These distances are much6-t s-0 \fig 7-+.. %b+ attributed to crystal forces. Bond-lengths20345 B. Chaudhuri and A. Hargreaves, Acta Cryst., 1956, 9, 793.3*0 C.J. Brown, J., 1955, 2931.347 M. S. Webster, J., 1966, 2841.348 Y . Sasada and I. Nitta, Acta Cryst., 1956, 9, 205.*4B Y . Sasada, K. Osaki, and I. Nitta, ibid., 1954, 7, 113.350 M. Kimura and M. Kubo, Bull. Chem. SOC. Japan. 1953, 26, 250.351 0. Hassel and J. Hvoslef, Acta Chem. Scand., 1954, 8, 873.352 Idem, ibid., 1956. 10, 138.353 Idem, ibid., 1954, 8, 1953.354 Idem, ibid., 1056, 10, 1394 1 1 CKYS I’.ILLOCKAPHY.less than the sums of the van der Waals radii, and strong “ polarisationbonds ” are presumably present. [On the other hand, the abnormal inter-molecular contact, d ( N 0 , . . . CH) = 2.6 A, found in fi-nitroaniline hasnow been amended : 355 there is an ambiguity in the structure, and whenthis is correctly resolved, y-co-ordinates of neighbouring molecules becomeinterchanged, with the result that, though intramolecular distances remainas before, all intermolecular contacts are changed, and the anomaly dis-appears.] The lower-melting product of the reaction between 2 : 3-di-chlorodioxan and ethylene glycol was shown by X-ray work not to be theexpected na~hthadioxan.~~~ The higher-melting product did not crystalliseconveniently for X-ray study; but a projection derived from its complexwith HgCl, 357 clearly reveals the presence of a naphthadioxan molecule.Inthe 2 : 1-compound between hexamethylbenzene and c h l ~ r a n i l , ~ ~ ~ pairs ofmolecules of the former sandwich roughly parallel molecules of the latter.Natural Products and Related Compounds.-A review of the X-ray methodfor the direct determination of the structures of moderately complex organiccompounds has appeared,359 and it is illustrated by reference to the analysesof a number of natural products. A full account has now been given of theuse of generalised (“ modulus ”) projections in the analysis of isocrypto-leurine met hiodide .3wThe related structures of morphine (30) 361 and codeine 362 have beenelucidated by studies of their hydrohalide salts.Each consists of two ring-systems (1-11, III-IV) approximately at right angles to one another so as toyield an inverted T-shaped molecule. The stereochemical arrangementsuggested on chemical grounds is confirmed, including the cis-fusion ofrings I1 and 111. A note 363 gives a complete picture of the structure andconformation of the cation in de(oxymethy1ene)lycoctonine hydriodidehydrate.A projection of the quinine molecule can be seen in a preliminaryreport 36* on analyses of the hydrated sulphate and selenate.3 6 5 J. Donohue and K. N. Trueblood, Acta Cvyst., 1956, 9, 960 (see also ibid., p. 966).356 Ann. Reports, 1952, 49, 373.357 0. Hassel and C. Ramming, A d a Chewz. Scand., 1956, 10, 136.358 T. T. Harding and S. C. Wallwork, Acta Cryst., 1955, 8, 787.350 A. McL. Mathieson, Rev. Pure Appl. Chew. (Australia), 1955, 5, 113.360 J. Fridrichsons and A. McL. Mathieson, Actu Cryst., 1955, 8, 760 (see also -4nit.361 M. Mackay and D. C. Hodgkin, J., 1955, 3261.362 J. M. Lindsey and W. H. Barnes, Acta Cryst., 1955, 8, 227.363 M. Przybylska and L. Marion, Canad. J . Chem., 1956, 34, 185.3~ H. Mendel, Proc. k . ned. Akad. Wetenschap., 1055, 58, B, 132.Reports, 1954, 51, 398)Hydroxydihydroeremophilone 365 has the structure represented by (31),which agrees with Simonsen's suggestion and supplies some other stereo-chemical information : there is a cis-fused decalin system; and, since theabsolute configuration of part of the eremophilone molecule has been de-d ~ c e d , ~ ~ ~ the configuration of the whole can now be inferred from formula(31). A more detailed report 367 of the work on (3-caryophyllene chloride isnow available. The structure deduced by chemical methods i s confirmed--in an analysis which is independent of chemical information-whilst thefour-membered ring is shown to be trans-fused to the seven-membered.A number of peptides and amino-acids have been studied, two of themwith high precision, viz., histidine hydrochloride hydrate 368 and glycyl-1,-tryptophan d i h ~ d r a t e . ~ ~ ~ The cation of the former has the tautomericform shown (32 with mesomers) ; d(C-NH,-') = 1.52 0.01 a, and a similarexcess over the standard length (1.47 A) has been noted for this bond ininany other such compounds. There is a preliminary account of a fairlyaccurate analysis of glycyl-L-alanine hydrochloride hydrate.370 The struc-ture of a new (P-)form of L-glutamic acid has been described.371 Thehydrogen atoms were located only with some uncertainty, but their probablepositions agree with other evidence in indicating the zwitterionic structureshown (33). A comparison with glutamine and glutamic acid hydro-chloride shows differences of conformation in these three closely relatedI ~ C - C H I CHI N HT 1. CO; HO,C-CH~.CH,.CH(NH~~ )-co~'+HC=NH( 3 2 ) HN-CH ( 3 3 )molecules, presumably attributable to differing crystalline environments.There is a progress report 372 on the analysis of the tripeptide, glutathione;the two peptide groups are nearly planar, as usual, and mutually at right-angles. Work on methylguanidinium nitrate 373 and nitroguanidine 374 maybe mentioned here; both structures are essentially coplanar, and the latterpossibly includes a bifurcated hydrogen bond.The X-ray analysis of vitamin B,, and related substances 375 is nownearing a phase of completion. According to a report issued in July, 1956,376the molecular formula is almost certainly C63H,,0,4N,,PCo, and the posi-tions found for these atoms are probably essentially correct [Fig. 21. Somewater molecules, which occupy spaces within the structure in both wet andair-dried crystals, are yet to be located. " The molecule that appears is365 D. F. Grant and D. Rogers, Chem. and Ind., 1956, 578.366 W. Klyne, J., 1953, 3072.367 J. M. Robertson and G. Todd, J . , 1055, 1254.368 J. Donohue, L. R. Lavine, and J. S. Rollett, .-lciu Cr?ist., 1956, 9, 655.369 H. A. Pasternak, ibid., 1956, 9, 341.370 T. C. Tranter, Nature, 1956, 177, 37.371 S. Hirokawa, Acta Cryst., 1955, 8, 637.374 W. B. Wright, Chem. and Ind., 1956, 437.373 R. M. Curtis and R. A. Pasternak. Acta Cryst., 1955, 8, 675.374 J. H. Bryden, L. A. Burkhardt, E. W. Hughes, and J. Donohue, ibid.. 1956,9, 573.3 7 5 Ann. Reports, 1954, 51, 399; 1956, 52, 403.y7(r D. C . Hodgkin, J. Kamper, M. Mackay, J. Pickworth, K . N. Trueblood, and5. CT. White, Nature, 1956, 178, 64416 CRYSTALLOGRAPHY.beautifully composed, not far from spherical in form, with all the morechemically reactive groups on its surface. . . ; . . . the atomic positions foundconform in a most convincing way with the stereochemical rules established.! A(Reproduced, with permission, from D. C . Hodgkin et al., Nature, 1956, 178, 65.)by the study of simpler molecules.” There are probably six double bondsin the pseudo-porphin nucleus, and it seems possible that the interventionof the cobalt atom enables them to constitute a resonating system (34, etc.).This ring system is nearly planar, but not quite; and the deviation is perSPEAKMAN ORGANIC STRUCTURES. 417haps due to overcrowding caused by the benziminazole residue co-ordinatedto the cobalt atom on the underside.This work represents the summit of achievement in X-ray analysis sofar. It is understood that a full account is being prepared and that it endswith the sentence : “ And this is not the limit.”J. C . S .S. C . ABRAHAMS.H. D. MEGAW.J. C . SPEAKMAN.REP.-VOL. LIII

ISSN:0365-6217    

DOI:10.1039/AR9565300383

出版商:RSC    

年代:1956

数据来源: RSC

摘要:

INDEX OF AUTHORS'Xarenmae, A., 343.Abbott, N. B., 14.Abdel-Wahab, M. F., 166..$bdine, H., 347.A4be, Y., 206.Abell, P. I., 149.nblov, A. V., 121, 397.-4boav. D., 403.Abraham, E. P., 228.Abrahams, S. C., 99, 388,390, 392, 395, 412.=Ibrahamsson, S., 405.-4bramova, L. V., 41.Abrams, I., 79.hchard, C., 82.-4cheson, R. M., 234.Acklin, W., 210.jlcquista, N., 11, 20.Adam, J., 68.Xdamovich, L. P., 339,340.Adams, C. I., 356.Adams, D. H., 299.Adams, G. A., 258, 259.hdams, J.. 257.-4dams, M. D., 86.Adams, R., 247.Adams, R. M., 20.Adams, R. N., 361.hdams, W. J., 222, 224.Adamson, A. W., 74, 105.Addison, C. C.. 85, 94,95.Addison, W. E., 85.-4del1, M. R., 116.hdelman, A. H., 47.Ader, M., 117.-4dhya, R. N., 204, 216.Adicoff, A., 54.Adie, P.A., 303.Adkins, H., 270.Adler, E., 267, 272, 254.Adler, S., 62.Aebi, A., 216.Aggarwal, J. S., 180.Agnello, E. J., 220, 224.Agterdenbos, J., 333, 334,Ahlers, N. H. E., 378.Ahola, A., 272.Ahranijian, L., 224.Ahrens, L. H., 53.Ahrens. R., 177.Ahrland, S., 117.Aignesberger, A., 100.-4ihara, T., 180.:Iikawa, M.. 372.343.~~Aimoto, Y., 364.Aitken, I. M., 193.Akawie, R. J.. 324.Akopov, Ye. K., 113.Aksnes, 0.. 390.Albert, A., 232, 235.Alberto-Barreto, P., 365.Albisetti, G. J., 184.Alcock, K., 117.Alder, K., 194, 199, 201,Alderman, P. R. H., 121,Aldrich, F. L., 302.Aldrich, P. E., 178, 242.Aldridge, W. N., 296, 296,Alekseeva, T. T., 339.Alexander, G. J., 307, 309.Alexander, L.E., 410.Alexander, P., 42. 44, 59.Alexsandrov, G. P., 342.Alfonso, L. M., 232.Alford, D. A., 19.Alimarin, I. P., 362, 375.Allan, G. G., 213.Allen, A. O., 36.Allen, D. S., jun., 164.Allen, G. D., 148.Allen, H. C., jun., 8.Allen, P. E. M., 55.Allen, R. R., 180.Allen, W. S., 224, 225, 316.Allinger, J., 142.Allinger, N. L., 188, 200,201, 217, 228.Allison, J. B., 57, 256.AlmAssy, G., 364, 367, 376,Alonso, J. I. F., 130.Alt, B., 86.Altman, D., 113.Ambros, D., 192..\miard, G., 171.Amick, R. M., 369.Amiel, Y., 173, 200.Amphlett, C . B., 80.Anantaraman, R., 213.Anastasi, A., 373.Andersen, E. K., 93, 389.Anderson, A. G., 197.Anderson, F. A., 8.Anderson, J. M.. 190.Anderson. T . R.. 68.204.397.297, 303.377.NAMESAnderson, J.S., 120.Anderson, R. B., 69.Anderson, R. E., 78.Anderson, R. L., 334.Andersson, G., 392, 402.Andersson, S., 84.Andreev, E. A., 68.Andresen, A. F., 393.Andress, K., 10.Andress, K. R.. 124.Andrew, E. R., 383.Andrew, V. I., 75.Andrews, K. J . M., 297,Andrews, P., 258, 259.Andrews, W., 52.Andrieva, M. A., 77.Angell, C. L., 12.Angier, D. J., 65.Angus, J. C., 11.Ankudimova, E. B., 353.Anliker, A., 225.Anliker, R., 186.Ansell, M. F., 174, 200.Apenitis, A., 268.Apicella, M., 233.Appel, R., 99, 100.Applegate, H. E., 243.Applequist, D. E., 198.Ariineo, A., 107.Arcand, G. M., 369.Archer, E. M., 412.Arcus, C. L., 54.Ardao, M. I., 190.Arden, T. V., 70, 77.Ardon, M., 112, 116.Aref'eva, T.V.. 359, 360.Argersinger, W. J., 73.Arigoni, D., 165, 302, 206,Arimoto, F. S., 197.Arkley, V., 238.Arlt, H. G., 267, 272.Armarego, W. L. F., 188.Armstrong, A. C., 379.Armstrong, D. A., 32.Armstrong, D. M. G., 348.Armstrong, R., 137.Arnold, H., 197.Arnold, J. R., 131.Arnolt, R. I., 330.Aronson, D. L., 43.Aronsson, B., 394.Arora, K. L., 322.298.212, 213.Anderson; j. R.'A., 376. .lrthur, H. R., 214.41420 INDEX OF AUTHORS’ NAMES.Arvia, A. J., 103.Asadourian. A., 14.Asahi, T., 321.Asahina, A., 372.Asano, T., 196.Aschenbrand, L. M., 45.Ashbolt, R. F., 301.Ashmore, P. G., 25, 33.Asinger, F., 147.Asmussen, R. W., 122.Aso, K., 81.Mperget, S., 105.Aspinal, M. L., 363.Aspinall, G. O., 263, 254,255, 258, 259, 260.Assarsson, G.O., 343.Asselineau, C., 180.Asselineau, J., 180.Aston, J. G., 64.Asuncion-Omarrementeria,M. C., 373.Aten, A. H. W., 40.Atherden, S. M., 317.Atherton, F. R., 297,Atoji, M., 389.Atzwanger, H., 103.Aubry, J., 84.Audran, R., 370.Audrieth, L. F., 94.Audus, L. J., 283, 292.Augustinsson, K. B., 303.Aulin-Erdtman, G., 273.Aurivillius, B., 99.Aurivillius, K., 392.Austerweil, G. V., 80.Averill, S. J., 54.Avigad, G., 260.Avramoff, M., 232.Avrutova, Kh. Z., 359.Awad, S. A., 370.Aycock, B. F., 149, 174.Ayer, W. A., 249.Aylett, B. J., 93.Aylward, F., 181.Ayres, G. H., 365.Ayres, P. J., 311.Ayscough, P. B., 28, 30.Azami, J.. 82.Azumi, T., 62.Babcock, J. C., 167.Babko, A. K., 332.Bach, N.A., 38, 41.Bachman, G. B., 88.Backe-Hansen, K., 372.Bacon, G. E., 383,385,387,Bacon, R. G. R., 187.Badayeva, T. I., 333.Baddeley, G., 190.Baddiley, J., 235, 252, 263.Badeeva, T. I., 334, 367.Bader, F. E., 243.Bader. H., 173.Badger, G. M., 2.33.298.388.Baenziger, N. C., 96, 112,Baer, E., 181, 182.Baev, F. K., 360.Bafna, S. L., 76, 81.Bagdasaryan, K. S., 39.Baggett, B., 318.Baginski, E. S., 344.Bagnall, K. W., 102, 396,Bagnoli, E., 328.Bagshawe, B., 343.Bahor, R. E., 362.Bailey, A. S., 248.Bailey, D. L., W.Bailey, G. A., 224.Bailey, €3. C., 61.Bailey, P. S., 188.Bailey, W. J., 157, 158,Baird, D. H., 381.Baird, R., l62.BajaloviC, I., 369.Bak, B., 8, 16, 129.Baker, A. N., 131.Baker, C., 316.Baker, L.C. W., 116, 354,Baker, M. McD., 66.Baker, R. H., 201.Baker, R. W. R, 374.Baker, S. B., 271.Baker, W., 236, 408.Baker, W. J., 380.Balcom, D., 269.BalenoviC, K., 168, 182,Balis, E. W., 348.Ball, D. H., 258.Ball, J. C., 169, 250.Ballantine, D. S., 39, 43,Ballard, D. G. H., 68.Ballhausen, C. J., 105.W o u , C. E., 261.Balls, A. K., 296, 296, 302.Balog, G., 102.Balwit, J. S., 43, 44.Balz, D., 396.Bamford, C. H., 49, 54, 58.Banchero, J. T., 73, 75.Bandurski, R. S., 330.Banerjee, G., 335, 347.Banister, A. J., 377.Bankiewicz, C., 249.Banks, C. V., 335.Banks, E., 402.Banks, R. L., 57.Bapat, M. G., 352.Barakat, M. 2.. 165.Baran. J. S., 241.Barber, ?vL, 322.Barcel6, J. R., 9.Barcia, C.G., 334.Barday, G, A., 392.398.446.Bailey, P., 402.185, 199.369.183.51, 55.Barclay, J. L., 252.Barclay, R., 185.Bard, C. C., 379.Bardhan, J. C., 204, 216.Bardin, M. B., 360.Bardos, T. J., 233.Barelko, E. V., 40, 41.Barilari, E. M., 377.Barker, C. C., 191.Barker, G. R., 257, 262,Barlow, C. S., 24.Barnard, A. J., jun., 342.Barnard, D., 66.Barnard, J. R., 130.Barnes. C. S., 218, 224.Barnes, M.-A,, 380.Barnes, R. A., 189.Barnes, R. F., 119.Barnes, W. H., 414.Baron, C., 228.Baron, F., 261.Barr, D. H., 163.Barr, N. F., 39, 41.Barrer, R. M., 61, 79.Barrett, D. G., 365.Barrett, W. J., 379.Barron, E. S. G., 43.Barrow, G. M., 10, 19.Bartell, L. S., 131.Barth, P., 195.Bartha, L. G., 94.Barthold, H.J., 11.Barth-Wehrenalp, G., 103.Bartlett, N., 102.Bartlett, P. D., 53, 142,144, 150, 154, 155, 170,204.Barton, A. D., 319.Barton, D. H. R.. 14, 142,148, 165, 193, 201, 206,207, 209, 212, 214, 217,238.266.Barton, J. L., 125.Barton, S., 155.Bartram, K, 174.Bartz, Q. R, 182.Barua, A. K., 214.Basixiska, H., 350.Basinski, A., 371.Basolo, F., 10, 105.Bassett, I. M., 129.Bassi, W., 391.Basu, R. K., 222.Basu, S., 129, 130, 131.Basualdo, W. H., 103.Bates, R. W., 328.Batten, J. J., 148.Batthias, B. T., 403.Baudel, J-, 129.Baudler, M., 12.Bauer, H. F., 251.Bauer, K. B., 212.Bauer, R. S., 174.Bauer, W. H., 13, 379.Bauld, W. S., 317Baum, H., 324.Baumann, E., 318, 319.Baumann, E. W., 73.Baumann, F., 226.Baumann, W.C., 78.Baumgarten, P., 319.Baur, W. H., 392.Bavin, P. M. G., 132, 191.Baxendale, J. H., 42, 64,Baxter, J. N., 171.Bayliss, N. S., 95.Bazen, J., 351.Bazier, R., 228.Beachell, H. C., 9, 10, 61,Beal, P. F., 168.Beamish, F. E., 344,365.Beaton, J. M., 214, 216.Beattie, I. R., 10.Beatty, P. J. M., 30.Beaulieu, E. E., 329.Beavers, D. J., 188.Beavers, L. E., 234.Becher, H. J., 10, 19, 88.-her, J., 76.Beck, M., 184.Beck, M. M., 304.Beck, M. T., 366.Beckel, C. LeR., 7.Becker, E. D., 20.Becker, E. O., 18.Becker, J. A., 60.Beckett, A. H., 371.Beckwith, A. L., 216.Beeck, O., 26.Beer, C. T., 306, 318.Beer, R. J. S., 209.Beevers, C. A., 391, 409.Beher, W. T., 379.Behr, J., 39, 56.Behrens, H., 99.Behringer, J., 7.Beijerinck, M.W., 283.Beiles, R. G., 366.Bekleshova, G. E., 362.Bekoe, D. A., 104, 412.Belcher, R., 338, 350, 355,Bell, I., 171.Bellamy,L. J., 7, 11, 13, 16.Belle, J., 73.Belleau, B., 246.Bellido, H. S., 137.Belohlav, L., 189.Ben-Bassat, A., 368.Bencze, L. W., 239.Bendas, H., 188,208,224.Benedetti-Pichler, A. A.,Benedict, W. S.. 8, 103.Benek, L., 98.Benfrey, 0. T., 136.Benkeser, R. A., 139.Bensasson, R., 38, 48, 49.Benson, R. E., 94.69.87.356.332.INDEX OF AUTHORS’ NAMEBenson, S. W., 27, 34.Bentler, H., 166.Bentley, K. W., 169, 242,Bera, B. C., 252.Beran, P., 9.Bercaw, J. R., 66.Beredjick, N., 48.Bereznitskaya, E. G., 35.6.Berg, E. W., 377.Berg, W., 101.Berg, W.T., 60, 61.Bergel, F., 297, 298.Bergenstal, D. M., 309.Bergerhoff, G., 94, 396.Bergin, M. J., 78.Bergman, G., 399.Bergman, W., 261.Bergmann, E. D., 160.Bergmann, F., 302.Bergstrom, G., 399.BergstrGm, S., 310.Berkenblit, M., 115.Berkhout, H. W., 342,386,Berkowitz, J., 31.Berman, S. S., 82.Bernard, M.-P., 16.Bernhard, K., 171, 178.Bernhardt, D. N., 363.Bernhauer, K., 236.Bernheim, F., 280, 281.Bernstein, F., 73, 76.Bernstein, H. J., 11, 12, 18,Bernstein, R., 221.Bernstein, R. B., 11.Bernstein, S., 222,224,225,Beroza, M., 239.Berry, M., 115.Berry, M. B., 258.Berry, P. J., 37.Berson, J. A., 202.Bertaut, E. F., 384, 392.Bertaut, F., 393.Berthier, G., 128, 129.Berthod, H., 128.Bertinotti, F., 406, 409.Bertorelle, E., 377.Bessenov, M.J., 61.Bestman, H. J., 168.Bethge, P. O., 366, 367.Beton, J. L., 213.Beu telspacher, H., 20.Beveridge, J. S., 359.Bevington, J. C., 49, 51, 53.Beyermann, H. C., 242.Beyler, R. E., 224.Bhagwan, H., 376.Bharucha, K. E., 181.Bharucha, K. R., 220.Bhatanagar, S. S., 322.Bhatnager, D. V., 366.Bhattacharya, S. C., 336.Bhattacharyya, B. K., 209.250.372.19,140.316, 319.421Bhattachkyya, B. K., 215,Bhatty, M. K., 356.Bhuchar, V. M., 345.Biber, C., 37.Biberacher, G., 98.Bickel, H., 243.Biemann, K., 203.Bienert, B., 236.Biggs, M. W., 309.Bighi, C., 377.Bigou, J., 166.Biilmann, E., 139.Bijvoet, J. M., 384.Bilinenko, A. T., 364.Billet, F. S., 322.Billy, C., 406.Billy, M., 93.Bindschadler, E., 117.Bingle, J., 104.Birch, A.J., 161, 162, 189,Bird, G. R., 381.Birke, G., 306.Birmingham, J. M., 109.Bishop, C. T., 256, 258.Bissot, T. C., 87.Bitskei, J., 362.Bittner, F., 276.Bizam, V., 362.Bjorkman, A., 268.Bjorkqvist, K. J., 274.Blabolil, K., 356.Blacet, F. E., 45.Black, C., 204.Blackledge, J . , 128.Blackley, D. C., 54.Blackman, L. C. F., 339.Blackmore, W. R., 396,Blackwood, R. K., 158,Blaine, L. R., 8.Blair, A. J., 377.Blair, G. E., 36.Blakeslee, A. E., 406.Blank, R. H., 224, 316.Blanquet, P., 23.Blanz, E. J., jun., 160, 217.Blasius, E., 367.Blaszkowska, W., 79.Blaug, S. M., 375.Bligh, E. G., 306.Bloch, E., 307, 313.Bloch, K., 203, 308, 309.Block, F., 228.Bloem, J.L.. 84.Bloemendal, H, 337.Blomquist, A. T., 158, 187,198, 199, 201.Blomqvist, G., 391.Bloom, B. M., 224.Bloom, H., 125.Bloomer, R. N., 64.Blout, E. R., 14, 58.Bluestein, B. R., 88.216.196, 199, 206, 216.412.170, 183422 INDEX OF AUTHORS^ NAMES.Bluhm, A. L., 234.Blum, J. J., 410.Blum, P., 392.Blume, D., 117.Blundell, M. J., 269.Blyum, I. A., 360.Blyumberg, E. A., 33, 361.Boato, G., 32.Bobbitt, J. M., 165, 242.Boberg, F., 138.Bobovich, Ya. S., 17, 20.Bobtelsky, M., 368.Bock, W., 252.Bodansky, O., 295.Bode, H., 335, 396.Bodenstein, M., 25.Bodor, E., 349.Bohm, F., 242.Bohme, H., 166.Boekelheide, V., 193.Baar, H., 295.Boeseken, J., 285, 293.Bottcher, R., 111, 198.Bogan, E. J., 343.Bogdanova, I.V., 365.Boggs, J. E., 35.Boggs, L. A., 260.BognBr, J., 346.BognBr, R., 238.Bohlmann, F., 169, 172,174, 179, 240.Bshm, F., 84.Bohnsack, G., 234.Boit, H.-G., 247.Boivin. J. L., 169.Boivin, R., 320.Bokii, G. B., 121, 397.Bollinger, F. W., 221.Boltz, D. F., 365.Boltz, G., 363, 365.Bon, W. F., 337.Bond, G. C., 64, 68.Bond, W. B., 52.Bonham, R. A., 131.Bonhoefer, K. F., 139.Bonhomme, J., 380.Bonino, G. B., 10.Bonner, 0. D., 72, 73.Bonsma, G. F., 247.Boone, J. L., 86.Boozer, C. E., 150.Bordwell, F. G., 138.Borgen, 0.. 406.Borgstrom, B., 310.Borisov, A. E., 141.Borisova, T. I., 65.Borsje-Bakker, H., 295.Borsook, H., 253.Borunova, N. V.. 66.Boston, A., 160.Bostrom, H., 325.Boswijk, K. H., 104, 388,Bothner-By, A.A., 140.Bottini, A. T., 159, 180,395.198.Bottomley, W., 209, 238.Bottreau, M.-M., 18.Boudakian, M. M., 173.Boudart, M., 60, 67.Bourne, E. J., 37, 42, 168,Boursnell, J. C., 295.Ekmtan, P. J., 138.Bovens, B. R., 296.Bowen, E. J., 47.Bowen, N. L., 86.Bowers, A., 185, 208.Bowers, K. D., 106, 403.Bowman, G., 375.Bowman, R. E., 25,241.Boxer, G. E., 229.Boyd, G. E., 72, 74.Boyland. E., 294, 319, 324.Boynton, C. F., jun., 31.Boys, S. F., 22.Boysen, M., 39, 48.Bozsai, I., 359, 362.Brack, A., 197.Brack, K., 178, 203.Bradbury, R. B., 247.Bradley, A., 146.Bradley, D. C., 112, 113,Bradley, H. B., 356.Bradley, J. N., 28, 32.Bradley, R. S., 48, 94.Bradlow, H. L., 306, 307,Bradsher, C. K., 188.Brady, J.H., 367.Brady, J. L., 334.Brady, R. O., 313.Briihler, B., 195.Brauniger, G., 192.Brainina, E. M., 113.Branch, R. F., 378.Brand, J. C. D., 150.Brandes, G., 20.Brandmiiller, J., 7, 12.Brandsher. C. K.. 234.250, 257.115.315.BrandSteG, J., 360.Brandt, C. W., 209.Brandt, F. A., 325.Brandt. W. W.. 357.Brasen, W. R., 152.Bratfisch, G., 329.Braude, E. A., 145,181, 184, 229, 378.Brauer, G., 99.Braukmann, B., 356.Braun, B. H., 207.Braun, P. B., 399.Brauns, F. E., 267,Braunstein, C. J., 270.Bray, P. J., 134.Bray, €2. H., 347.Brayford, J. R., 99.Bredereck, H., 183, 253.Bredig, M. -4., 9.Bregant, N., 183.272, 273.63,68.Brehm, W. J., 138.Brenner, M., 169.Brett, H. W. W., 59.Breu, R., 107.Brewer, C.P., 270.Brewer, L., 117.Brice, C., 251.Bricker, C. E., 349, 373.Brickstock, A., 128.Bridgewater, R. J., 219.Briggs, C. K.. 247.Briggs, D. R., 257.Brill, R., 390.Brindley, G. W., 391.Brindley, P. B., 89.Brink, D. L., 273.Brinton, R. K., 28.Brite, D. W., 373.Britton, D., 32, 34.Broadley, J. S., 389.Brochon, R., 351.Brockes, A,, 20, 44.Brockhaus, A., 59.Brockmann, H., 185, 234.Brockway, L. O., 35.Brodersen, K., 10,125,396.Brodersen, S., 8.Brodie, B. B., 316.Brodig, A. E., 152.Brom, F., 378.Bronk, L. B., 348.Bronnell, G. L., 36.Brooks, B. T., 166.Brooks, C. S.. 51.Brooks, G. T., 200.Brooks, M. E., 232.Brooks, R. V., 317.Brooks, W. B., 166.Brooksbank, B. W. L., 322.Broome, J., 161.Brosset, C., 86.Brotherton, T.K., 192.Brown, B. R., 161.Brown, C. J., 413.Brown, D. A., 10.Brown, D. J., 232,233, 235.Brown, D. M., 261, 262,Brown, F., 118, 394.Brown, G. B., 260.Brown, H. C., 87, 88, 89,90, 133, 135, 136, 143,161, 162.264.Brown, H. W., 9.Brown, J. F., 13.Brown, J. K., 13.Brown, J. P., 293.Brown, P. K., 172.Brown, R. D., 128, 129.Brown, R. F. C., 242.Brown, R. N., 407.Brown, S. A., 275, 276.Brown, T. L., 18.Brown, W. E., 390.Brown, W. G., 59.130, 234I N m x OF AUTHORS’ NAMES. 423Browning, R. S., 379.Brownlie, G., 214.Bruchner, H.-J., 131.Bruderer, H., 165, 205.Briigel, W., 10.Brumberger, H., 34.Brummet, B. D., 372.Brunings, K. J., 220.Bruninx, E., 378.Brunisholz, G., 351.Bryce, W.A., 30.Bryce-Smith. D., 143, 190.Hryden, J. H., 407, 411,Buchanan, G. L., 192, 204.Buchanan, J. G., 235, 252,Buchanan, M. A., 268, 273.Buchert, A. R., 301.Buchman, E. R., 198.Buchnea, D., 182.Buchoff, L. S., 367.Buchta, E., 177, 186.Buckley, D., 145.Buckley, G. C., 220.Budanova, L. M., 365.BudESinsk9, B., 348.Budy, A. M., 318.Biichi, G., 159, 174, 203,206, 207.Biichi, J., 70.Buehler, H. J., 325.Biirer, T., 15.Buerger, M. J., 391, 400.Biirki, H., 411.Bues, W., 9.Buess, C. M., 253.Bukhovets, S. V., 108.Bukhtiarv, V. E., 351.Bulankhe, I. N., 339.Bulanzhe, I. N., 345.Bullen, G. J., 122, 397.Bu’Lock, J. D., 173.Bullock, M. W., 235.Bumgardner, C. L., 200.Buneev, N. A., 37.Bunnett, J. F., 192.Bunton, C.A., 155.Buras, E. M., 376.Burawoy, A., 134.Burden, J. P., 114.Burdick, D. L., 85.Burg, A. B., 86.Burgen, A. S. V., 296, 297.Burger, J. C., 373.Burgers, W. G., 388.Burkat, S. E., 80.Burke, D. C., 261.Burke, H. J., 194, 200.Burkhardt, G. N., 319.Burkhardt, L. A,, 415.Burkin, A. R., 122.Burlant, W. J., 59.Burmistrova, M. S., 210.Burn, D., 208.Burnett, G. W., 325.415.263.Burns, D. M., 408.Bums, E. A., 371.Burriell-Marti, F., 373.Burstall, F. H., 397.Burton, H. S., 228.Burton, M., 28, 30, 37, 46.Buscarons, F., 366.Busch, G., 403.Buselli, A., 54.Buser, W., 70.Bush, I. E., 313, 315.Bussman, A., 365.Buswell, A. M., 284.Butenandt, A., 328.Butler, E. A., 337.Butler, G., 84.Butler, G.C., 264.Butler, J. A. V., 42, 267.Butler, J. P., 119, 274.Buttery, R. G., 151, 183.Buurman, D. J., 232.Buzbs, I., 349.Buzbee, L. R., 186.Byme, E. B., 76.Cabell, M. J., 82. 375.Cadiot, P., 173, 174.Cady, G. H., 103.Cahen, R., 351.Cahill, J . M., 131.Cahill, W. L., 325, 327.Cahn, R. S., 202.Cairns, T. L., 94, 153.Cala, J . *4., 54.Caliezi, A., 178, 203.Calistrii, E., 80.Callear, A. B., 26.Callinan, T. D., 38.Callis, C. F., 382.Callow, R. K., 226.Calvert, J. C., 28.Calvo, J . M., 376.Camerino, B., 224.Campbell, A., 229.Campbell, D. J.. 309.Campbell, E. C., 81.Campbell, I. E., 119.Campbell, J . R. B., 200.Campbell, R., 102.Campos-Neves, A. da S.,Canales, M.. 355.Candela, M. I., 377.Candelli, H., 325.Candlin, R., 385.Cann, M.C., 306.Cantor, S., 117.Capilla-Rufias, J., 371.Carboni, R. A., 135.Cardwell, H. M. E., 228.Careri, G., 32.Carini, E., 377.Carlsmith, L. A., 192.Carlson, A. W., 174.Carlson, E. H., 229.Carlson, E. J., 54.142, 218.Carlson, 0. T., 357.Carlson, T. A., 80.Carlson, W. H., 229.Carlyon, S. J., 353.Carmack, M., 246.Carney, A. L., 375.Caroll, K. K., 375.Caron, E. L., 186, 237.Carpenter, G. B., 389, 391.Carrh, S., 130.Carrano, M. J., 19.Carrington, A., 119.Carruthers, W., 214.Carson, J. F., 253.Carter, H. E., 181.Carter, €3. V., 22.Carter, M. E., 259.Carter, P., 315.Cartledge, G. H., 119.Casanova, J., 229.Casella, J., 180.Casida, J. E., 296.Cassidy, H. G., 80.Castellano, S., 69.Castelli, *4., 380.Castells, J., 217.Castinel, U., 18.Catalano, E., 134.Cava, M.P., 187.Cavalca, L., 391.Cavalieri, L. F., 266.Cavill, G. W. K., 148, 204,234, 293.Cawthon, T. M., 20.Cecil, R., 371.Cekan, Z., 207.Cencelj, L., 13.Cerceo, E., 314.cernohorsky, M.. 100.cervenka. A., 360.Cetlin, B. B., 399.Chaco, M. C., 200.Chaigneau, M., 10, 115.Chaikoff, I. L., 310.Chakhovsky, N., 13.Chaki, S., 358.Chakravarti, B. N., 115.Chakravorty, R. N., 356.Challenger, G. E., 40.Chalmers, M. E., 170.Chalvet, O., 129.Chamberlain, M. M., 10.Chamberlain, N. F., 194.Chambers, J. R., 53.Champetier, E., 80.Chan, W. R., 216.Chance, B., 298.Chang, S.-Y., 48.Chanmugam, J., 28, 30.Chanutin, A., 303.Chapiro, A., 38, 43, 49,Chapman, D., 11, 13.Chapman, J.H., 162.Chapman, 0. L., 195.Chapon, S., 215.59424 INDEX OF AUTHORS' NAMES.Chappell, E. I., 22.Chargaff, E., 260, 265.Charlesby, A., 43.Charlson, A. J., 256.Charlton, F. E., 365.Charret, M., 94.Chasanov, M. G., 76.Chase, B. H., 154.Chatt, J., 107, 108, 123.Chatten, L. G., 372, 373.Chatterjee, A,, 239.Chatterjee, A. K., 112, 113.Chatterji, A. C., 376.Chaudhuri, B., 413.Chaudhuxi, N., 151, 183.Chauncey, M., 322.Chauveau, F., 116.Chedin, J., 18.Chemerda, J . M., 224.Cheng, K. L., 347, 350.Cherepakhin, A. I., 341.Cherkashina, T. V., 351.Cherneva, E. P., 75.Chernova, A. I., 40, 41, 42.Chesnut, D., 73.Chessick, J. J., 65.Chesterfield, J. H., 232.Cheswick, J.J., 61.Cheung, H., 16.Cheutin, A., 12.Chevallier, F., 310.Chicoisne, A,, 181.Childers, E., 379.Childs, A. F., 299.Chilton, D. R., 117.Chisholm, M. D., 275.Chiurdoglu, G., 206.Chmutov, K. V., 377.Chodkiewicz, W.. 173.Chopard-dit-Jean, L., 171,Chopra, N. M., 206.Christ, C. L., 384, 391, 404.Christensen, D., 129.Christie, B. J., 233.Chu, N. Y., 375.Chubb, T. A., 45.Chugaev, L., 255.Chupka, W. A., 31.Church, F. M., 379.Churmanteev, S. V., 38.Cifka, J., 346.Cifonelli, J . A., 257.Cimino, A., 32.Cipera, J. D. T., 254.Claire, F. M., 275.Clapp, L. B., 228.Clar, E., 409.Clark, A., 57.Clark, A. H., 180.Clark, E. S., 395.Clark, J. R., 384, 391, 404.Clark, W., 357.Clarke, D., 22.Clarke, J . T., 79.Clarke, P., 190.178.Clarke, R.W., 35.Clarke, W. G., 324.Clarkson, R., 169.Classen, H. H., 9.Claudel, B., 86.Clayton, J. C., 368.Clearfield, A., 396.Clemo, G. R., 240.Cleveland, F. F., 11, 378.Clews, C. J. B., 410.Clifton, D. G., 1-13.Clinch, J., 336.Closson, W., 202, 217.Cloud, W. H., 20.Clouston, J. G., 45.Cluett, M. L., 82.Clutter, R. J., 170, 183.Coates, G. E., 91.Coates, V. J., 380.Cobey, F., 309.Cochran, W., 408.Cochrane, A. L., 376.Cochrane, C. C., 224.Cocker, J. D., 208, 210.Cocker, W., 205, 206, 208.Coekelbergs, R., 68.Cofino, M. C., 352.Cogbill, E. C., 357.Cohan, N. V., 14.Cohen, H., 328.Cohen, I., 63.Cohen, J. A., 296,298,301.Cohen, S. G., 46.Cohen, T., 250.Cohn, M., 281.Cohn, W. E., 159, 260,261,Col&s, A., 317.Colclough, T., 89.Cole, A.R. H., 7, 204, 209,213, 214, 215.Cole, L. J., 42.Coleman, J. E., 181.Coleman, N. T., 81.Coley, J. R., 66.Colichman, E. L., 38.Collin-Asselineau, C., 203.Collins, D. J., 196.Collins, F. M., 283.Collins, J. C., 213.Collins, K. J., 312.Collinson, E., 37, 49, 158.Collis, M. J., 96.Colombi, L., 179.Conant, J. W., 398.Condon, G. P., 316.Conn, E. E., 287.Conroy, H., 249.Constantin, M. J., 304.Conway, D. E., 74.Conway, E. R., 100.Cook, A. H., 232.Cook, C. D., 148.Cook, C. L., 45.Cook, D., 103.Cook, G. B., 22.264.Cook, G. L., 379.Cook, J. W., 214.Cook, 0. A., 402.Cook, W. R., 403.Cooke, L. M.. 270.Cooke, N. J., 180.Cooke, W. D., 358, 361,Cookson, R.C., 142, 165,Cope, A. C., 156, 169, 200,Copp, J . L., 84.Corbaz, R., 185.Corbellini. A., 220.Corbett, J . D., 90.Corbett, W. M., 258, 259.Corbridge, D. E. C., 97,Cordner, J. P., 146.Corey, E. J., 160, 166, 194,200, 205, 212, 214.Cori, G. T., 260.Corio, P. L., 134.Cornaz, J. P., 75, 77.Cornforth, J. W., 305, 308.Cornubert, R., 201.Corradini, P., 57.Corrodi, H., 239.Corwin, A. H., 141.Cosgrove, S. L., 148.Cossee, P., 121.Cosserat, L., 211.Cottin, M., 35.Cotton, F. A., 10, 106,Coulson, C. A., 14, 39, 129,Coursier, J., 367, 375.Courtney, J . L., 215.Cousin, H., 276.Cousins, L. R., 12.Cowan, H. D., 118.Cowles, E. J., 197.Cowley, J. M., 391.Cowley, J. W., 91.Cowper, G., 119.Cox, B., 117, 396.Cox, E.F., 198.Cox, E. G., 123, 125, 386,392, 398, 411.Cox, J. S. G., 212.Cox, R. A., 38, 263, 265,Craggs, J. D., 36.Craig, D. P., 137.Cram, D. J., 142, 188, 200,Crane, C. W., 137.Craw, D. A., 125.Crawford, B., jun., 33.Crawford, R. J., 189.Crawley, R. 13. A., 363.Creighton, R. H. J., 270.Cremer, E., 66.Cretcher, L. H., 229.369.201, 209, 218, 248.201.125, 379, 391, 398.109.131, 132, 407.266, 267.228INDEX OF AUTHORS’ NAMES. 426Cnegee, R., 146, 147, 164,Criner, G. X., 148.Crisafio, R., 373.Cristol, S. J., 170.Crnojevib. R., 376.Croft, R. C., 91.Crombie. L., 161, 172, 180,Cromer, D. T., 391, 392,Crooke, A. C., 306.Cross, B. E., 210.Cross, C. K., 220.Cross, L. E., 400, 401.Crosswhite, H. M., 20.Crowell, E.A., 299.Cruickshank. D. W. J., 384,386, 387, 388, 407.Cruickshank, P. A., 233.Crumpton, M. J., 260.CsiszAr, B., 341, 366.Cueilleron, J., 94.Cuendet, L. S., 250.Cundiff, R. H., 373.Cuninghame, J. G., 81.Cunningham, B. B., 388.Cunningham, L. W., 299.Curl, A. L., 295.Curphey, J. H., 197.Currell, D., 155.Currie, T.. 80.Curry, N. A., 385.Curtin, D. Y., 157, 189.Curtis, 0. E., jun., 161.Curtis, P. J., 210.Curtis, R. M., 415.Cvetanovic, R. J., 26, 31.Cymennan-Craig, J ., 144,162, 167, 171.Czapek, F., 274.Czekay, A., 367.Czepiel, T. P., 274.Czerwony, G., 15.Cziesla, M., 195.185.184, 185.399.Daane, A. H., 388.Dachs, H., 393.Dadape, V. V., 97.Daess, A. M., 371.Daesslk, C., 203.Dagg, I.R., 8.Dagley, S., 282, 290.Dailey, B. P., 134, 381.Dainton, F. S., 35, 39, 49,Daizon, P., 47.Dale, W. M., 41.Dall, K., 274.Dam, H., 311.Damast, B. L., 316.d’Amore, G., 366.Danath, E. E., 66.Dancis, J., 316.Danby, C. J., 26.Dangerfield, A. D., 82.50, 58.Dangl, F., 345.Daniels, F., 119.Daniels, M., 41, 42.Daniels, R., 170.Danielsson, U., 131.Danner, H. R., 401.Dannhauser, W., 392.Dannley, R. L., 52, 53.Danon, J., 64, 102.Danusso, F., 51, 57.Dao, P. N., 209.Darbee, L. R,, 35.Darby, P. W., 65.Darnell, A. J., 113.Datta, S. K., 335,341, 347.Datz, S., 65.Dauben, C. H., 388.Dauben, W. G., 160, 202,212,217, 220,224.Daudel, R., 407.Daum, K.-W., ‘120.Daumiller, G., 10.Dauschan, W., 366.Davey, W., 350.David, S., 216.Davidson, A.W., 85, 90.Davidson, E., 320, 326.Davidson, N., 32, 34, 46.Davidson, J. N., 260.Davies, C. W., 76, 78.Davies, D., 118.Davies, D. A. L., 260.Davies, D. R., 263, 299,Davies, D. W., 129.Davis, B. D., 283.Davis, D. G., 333, 363.Davis, J. W., 316.Davis, M. E., 314.Davis, M. M., 372.Davis, R. B., 173.Davis, S., 374.Davison, A. N., 296, 297.Davison, S., 36.Davisson, J. W., 404.Davoll, J., 232, 260.Davydov, A. T., 72, 75, 78,Davydova, N. I., 363.Dawson, J. K., 117.Dawson, M. C., 212.de Albinati, J. F. P., 374.Dean, F. M., 238.Dean, J . A., 373, 374.Deas, H. D., 131.DeBaun, R. M., 268.DeBoer, C. E., 139.de Boer, J. H., 60.de Bretteville, A. P., 390.de Carletto, M. A. de U.,decarvalho, R.G., 377.Decker, M., 229.Dedaisieux, J,, 37.Deflorin, A. M., 148, 238.DeFord, D. D., 369.406, 410.79.377.Degener, E., 94.Degterev, N. M., 362.Dejace, J., 407.DeJongh, R. O., 319.De Kluiver, H., 17.Delbouille, L., 11, 16.Delmonte, D. W., 161, 228.de Lorent, C., 124.Delorme, C., 393.de Loze. C., 14.DeLury, D. B., 23.de Mayo, P., 193, 203, 207,De Meio, R. H., 330.Demenev, N. V., 114.Den Hertog, H. J., 232.Denk, G., 342.Denney, D. B., 154, 163.Dennis, K. S., 61.Denton, J. Q., 380.Desai, A. D., 74.Deschamps, P. M., 369.De S e a , M. A., 367.Deshmukh, G. S., 335, 352.Desjobert, A., 349.Desnuelle, P., 304.Dessy, R. E., 173.DeStevens, G., 268.Deuel, H., 70, 71, 75, 77,Dev, S., 196, 205.Dkvag, J., 370.Devlin, T.R. E., 58.Devonshire, A. F., 400.de Vries, G., 378.De Vries, J. E., 372.De Vries, T., 359.de Waal, H. L., 241, 247.Dewald, J. F., 94.Dewar, M. J. S., 129, 132,Dewhurst, H. A., 38, 46.De Winter, M. S., 164, 219.DeWolfe, R. H,, 166.D’Eye, R. W. M., 102, 114,Dezso, I., 364, 376, 377.Dhareshwar, B. V., 376.Diamond, H., 119.Diamond, J. J., 373.Diamond, R. M., 72.D’Ianni, J., 270.Diassi, P. A., 163, 244.Dickel, G., 74.Dickens, G. J., 399.Dicker, D. W., 171, 178.Dickerson, R. E., 86, 393.Dickez, D. F., 244.Didenko, R. S., 340.Diehl, H., 346.Dienes, G. J., 43, 51.Dietrich, P., 208.Dietrich, W., 58.Dighton, D. T. R., 370.Dilts, R. V., 369.Dimler, R. J., 258.214.252.133, 159, 191, 194.395, 396426 INDEX OF AUTHORS’ NAMES.Dimroth, K., 192.Dion, H.W., 182.Dippel, W. A,, 373.Dische, Z., 257.Dituri, F., 309.Dixon, G. H., 301, 302.Dixon, M., 323.Dizdar, 2. I., 77.Djerassi, C., 167, 185, 188,202, 208, 209, 213, 214,217, 222, 224, 242, 245.DjordjeviC, C., 125, 395.Dobkina, B. M., 351.Dobo, P., 239.Dobriner, K., 306, 315.Dobriner, S., 225.Dodd, R. E., 9, 10, 95.Dodgson, K. S., 318, 319,320, 321, 322, 323, 324,328.Dopke, W., 247.Dorfel, H., 259.Doering, W. von E., 137,139, 151, 155, 183, 194.Doerr, R. C., 45.Doherty, D. G., 159, 261.Dohlman, C. H., 325.Doi, K., 196.Doisy, E. A., 325.Doiwa, A., 374.Dokunikhin, N. S., 19.DolejS, L., 207.Doleial, J., 351, 359, 360.Dolin, P.I., 40.Domansky, R., 370.Domash, L., 89.Domingo, R., 130.Donaldson, D. M., 40.Donaruma, L. G., 183.Dondes, S., 36, 37.Donnelly, D. M., 238.Donohue, J., 395,406, 414,Donovan, F. W., 189.Dooling, J . S., 27, 34.D’Or, L., 9.Dorfman, L. M., 37.Dorfman, R. I., 305, 306,307, 311, 313, 314, 316,328.Dornberger-Schiff, K., 97,391.Dornow, A., 174.Dorst, W., 319.Dostkl, K., 100.Doty, P., 58, 266.Douglas, A. M. B., 399.Douglas, J. G., 252.Dounce, A. L., 264.Dowben, R. M., 316.Dowden, D. A., 68.Dowell, A. M.. 140.Downer, J . M., 56.Dows, D. A., 11, 16.Doyle, J . R., 110.Draganic, Z. D., 77.415.Dranitskaya, R. M., 336.Drefahl, G., 190.Drehkopf, K., 355.Drenth, W., 409.Drew, C. M., 31.Drewes, G. W. J., 123.Dreyer, W.J., 302.Drieberg, R., 13.Drisko, R. W., 302.Drucker, A., 55.Drummond, J. L., 118.Dryden, I. G. C . , 20.Dubos, R. J., 281.Dubovitskaya, E. I., 360.Dubrovskaya, T. F., 350.Dubs, T. A., 69.Dudani, A. T., 322.Dudley, F. B., 103.Diinnenberger, M., 224.Duff, R. B., 320.Duffield, J., 355.Duffin, G. F., 231.Duisberg, H., 183.Dulce, H. J., 374.Dulou, R., 181.Duncanson, L. A., 107,123.Dunderdale, J., 12.Dunford, B., 32, 158.Dunitz, J . D., 100, 109,Dunkel, H., 366.Dunkel, R., 342.Dunn, P. H., 57.Dunstan, W. J , , 150.Dupont, G., 181.Dupre, E. F., 379.Durand, M., 12.Durup, J., 49.DuSinskL, G., 361.Dutt, P., 205.Dutta, P. C., 205, 210.Dutton, B. G., 209.Dutton, G. G. S., 259.Duval, C., 348.Duwell, E.J., 398.Duyckaerts, G., 377, 380.Dvornik, D., 186, 248.Dwiggins, C. W., 3%.Dwyer, F. P., 120.Dyakova, H., 220.Dyatlovitskaya, F. G., 75.Dyer, E., 53.Dyke, S. F., 242.Dziewiatkowski, 1). D.,Dziomko, V. M., 341.128, 407.325.Eadie, G. S., 281.Eakins, J., 81.Earl, J . C., 230.Earle, R. H., jun., 199.Eastman, R. H., 204.Eastwood, T. A., 119.Eberhardt, G., 276.Eberle, A. R.. 366.Ebert, M., 40.Eccleston, B. H., 374.Echigoya, E., 69.Ecke, G. G., 143, 186.Eckerlin, P., 398.Eckles, N. E., 309.Economy, J., 54.Eddy, C. R., 380.Eder, A., 366.Edgell, W. F., 8, 9, 10, 106.Edmondson, P. R., 13,Edstrand, M., 391, 393,Edward, J. T., 148, 206,Edwards, J. A., 209.Edwards, J. O., 10, 228.Edwards, J.W., 350.Edwards, L. J., 86.Edwards, 0. E., 148, 209,Eeckhout, J., 378.Egami, F., 14, 320, 321,325, 328.Egan, R., 296.Eggers, D. F., 15, 103, 379.Eglinton, G., 173, 200.Egorova, 2. S., 38.Ehmkc, H., 247.Ehrenstein, M., 224.Ehrlich, G., 63.Ehrlich, H. W., 409.Ehrlich, P., 86, 115.Ehrlich, R., 202, 217.Eicher, J . H., 183.Eichlin, D. W., 371.Eichhorn, E. L., 410.Eick, H. A., 112.Eidinoff, M. L., 306.Eiland, P. F., 411.Eilar, K. R., 170.Eirich, F. R., 50.Eischens, R. P., 63.Eisenbeiss, J., 239.Eisenbraun, E. J., 204.Eisenhut, W., 278.Eisenstadter, J., 368.Eisner, U., 236.Eistert, B., 168.Ekimyan, M. G., 353.Elad, D., 185, 209, 210.Elbeih, I. 1. M., 377.Elderfield, R. C., 246.Eley, D. D., 62.Eliasek, J., 280.Eliel, E.L., 154, 181, 228.Eliseeva, V. M., 365.Elks, j., 162.Ellenbogen, E., 14.Ellingboe, J. L., 346.Ellinger. F. H., 112, 388,Ellis, M. E., 42.Ellison, F. 0.. 128.Elliot, C., 351.Elliott, A., 14.379.396.208.238, 248.393INDEX OF AUTHORS' NAMES. 427Elliott, M., 199.Elliott, P., 216.Ellmer, L., 274.Elovich, S. Yu, 75.Els, H., 218.El-Sabban, M. Z., 11.El-Sadr, M. M., 165.Elsayed, M. F. A., 10, 122.Elsdon, W., 52.Elvidge, J. A., 285, 286.Elving, P. J., 361, 362.Emanuel, N. M., 33.EmelCus, H. J., 99, 118.Emerman, S. L., 144.Emi, K., 367.Emmerson, R. G., 191.Emmett, P. H., 60, 66, 67,Emmons, W. D., 229.Endres, G. F., 56.Engbaeck, H. C., 322.Engel, C. R., 224.Engel, L. L., 315, 316.Engelberts, R., 285.Engelbrecht, A., 100, 103.Engelhardt, V.A., 174.Engelkemeir, D., 119.Engle, R. R., 302.Engler, K., 269. 271.Englis, D. T., 368.Englisch, A., 240.Englund, B. E., 153.Enkoji, T., 233.Enkvist, T., 273.Ennor, K. S., 255.Enomoto, S., 67.Ensor, G. R., 216.Entschel, R., 177.Epp, A., 380.Epsztein, R., 173.Ercoli, R., 69.Erdey, L., 336, 349, 351,Erdmann, D., 178.Erdtman, H., 238, 267,Erickson, R. E., 206.Ermolaev, V., 46.Ernsberger, F. M., 231.Erskine, A. J., 257.Ertel, D., 114.Erxleben, H., 183.Eschenmoser, A., 147, 196,197, 202, 203, 213.Eschmann, H., 351.Esser, H., 183.Esteve, R. M., 139.Etingof, E. I., 22.Ettlinger, L., 185.Ettlinger, M. G., 182, 198.Eugster, C. H., 177, 183,Evans, A.G., 56.Evans, D. D., 241.Evans, D. E., 160, 219.68.367.268.239.Evans, H. G. V., 32, 158.Evans, H. T., 391, 404.Evans, J. C., 11, 12, 18.Evans, R. A., 287.Evans, T. H., 270.Evans, W. C., 281, 285,286, 287, 289, 290, 292,293.Eve, A. J., 359.Everest, D. A., 77.Eyring, H., 21, 36.Eyring, L., 112.Ezrin, M., 80.Fabbri, G. F., 18.Fabian, J.. 13.Fabiani, E., 330.Fabrini, L., 239.Faderl, N., 242.Fagerlund, U. H. M., 227.Fahreus, G., 280.Fain, J., 128.Fairbrother, F., 56, 90.Falconer, E. L., 259.Fales, H. M., 247.Falk, K.-H., 251.Fanfani, G., 377.Fankuchen, I., 378, 394,FarAdy, L., 377.Farber, M., 113.Farenhorst, E., 133.Farkas, E., 213, 222.Farmer, E. H., 147.Farmer, J. B., 31, 147.Farmer, R.W., 358.Farmer, V. C., 189, 270,Farnow, H., 204.Farr, J. P. G., 338.Farthing, A. C., 228.Fassel, V. A., 12, 13, 379.Fastie, W. G., 20.Fauconnier, C., 19.Faulkner, R. D., 152.Faure, P. K., 180.Favini, G., 130.Fayez, M. B. E., 213, 214.Fedneva, Ye. M., 87.Fedorova, T. I., 375.Fedotova, L. N., 77.FehCr, F., 11, 85, 100.Feibush, A. M., 364.Feigl, F., 340, 341.Feingold, D. S., 260.Feld, E. A., 298.Feldman, D., 80.Feldman, I., 77.Feldman, J. A., 372.Feldman, L. I., 224, 316.Felicetta, V. F., 272.Fellenius, O., 333.Fellig, J., 327.Fellowes-Nutting, PUI. D.,295, 296.411.280.Evans, E. -4., 167, 184. F'iniant, S., 18.Fenske, C. S., 380.Fenton, A. J., 369.Ferguson, E. E., 18, 19.Ferigle, S.M., 15.Ferington, T. E., 51.Ferradini, C., 115.Ferreol, G., 180.Ferrero, C., 203.Ferrett, D. J., 358, 360.Fett, E. R., 370.Feuer, H., 88.Fewster, M. E., 282.Fiann, P., 148.Ficini, J., 184.Ficken. G. E., 236.Field, F. H., 34.Field, K., 56, 90.Fields, P. R., 119.Fierens, P. J. C., 134.Fieser, L. F., 190, 219.Figdor, S. K., 209, 242.Figgis, B. N., 123.Fikhtengol'ts, V. S., 359.Fildes, J. E., 357.Filimonov, V. N., 18.Fillet, P., 46.Fillipova, N. A., 350.Finckenor, L. E., 224.Findeis, A. F., 359.Findlay, S. P., 229.Finestone, A. B., 51.Finnegan, M., 253.Firestone, R. F., 37.Fischer, A., 51, 55.Fischer, E., 239.Fischer, E. O., 109, 110,Fischer, F. G., 259.Fischer, H. F., 287.Fischer, H. 0. L., 251.Fischer, J., 104, 374.Fischer, K., 124.Fischer, K.A., 20.Fischer, R. W., 367.Fish, C. A., 307, 309.Fish, M. S., 171.Fish, W. A., 227, 309.Fishbein, L., 160, 250.Fisher, E., 271.Fisher, N. G., 184.Fisher, S., 76, 375.Fisher, W., 111.Fitzgerald, D. B., 281.Fitzgerald, R. J., 281.Fitzgerald, W. E., 231.Flaig, W., 20.Flanagan, T. B., 68.Flaschka, H., 82, 341, 342,347, 350, 351, 372, 375.FleS, D., 179.Fletcher, A. N., 7, 379.Fletcher, H. G., jun., 354,Fletcher, J. M., 120.Flickinger, E., 27 1.Flieschacker, H., 179.111, 197, 198, 397.255428 INDEX OF AUTHORS’ NAMES.Flock, F. H., 199.Flores, H., 224.Flowers, R., 99.Floyd, A. J., 236.Floyd, C. S., 303.Fluck, E., 123.Flynn, E. H., 185.Flynn, J. H., 23.Fodor, G., 239, 240.Fodor, J., 81.Folch, J., 181.Folkers, K., 178, 186, 229,236, 237.Folt, V.L., 54, 57.Fomin, V. V., 77.Fonken, A. E., 167.Fonken, G. F., 202.Fonken, G. J., 217, 220.Ford, D. L., 204, 293.Ford, P. T., 88.Ford, W. G. K., 319.Fornefeld, E. J., 166, 239.Forneris, R., 9, 17.Forrat, F., 393.Forrester, J. S., 366.Forst, W., 32.Fortnum, D., 10.Foss, J., 67.Foss, O., 390.Foster, A. B., 250, 252,255, 257, 260.Foster, T. T., 169.Fotherby, K., 317.Fouarge, J . , 377.Fowler, J . F., 44.Fox, J. J., 260.Fox, M., 42, 59.Fox, R. E., 36.Fraioli, A. V., 65.Fraenkel, G. K., 58.Fraenkel-Conrat. H., 319.Fraenkel-Conrat, J., 319.Francis, E. E., 63.Francis, K. E., 118.Francis, S. A., 63.Franck, B., 234.Francombe, H., 401.Francombe, M.H., 403.Frank, G., 394.Franklin, J. L., 34, 68.Franzen, V., 145.Fraser. M. J., 43.Fraser, R. D. B., 14.Fray, G. I., 179.Frazer, B. C., 401.Fredrickson, D. S., 311.Freedman, R. W., 372.Freeland, M. Q., 367.Freeman, E. S., 95.Freeman, G. R., 32.Freeman, J . H., 102, 395,Freeman, R. D., 114.Freeman, S. K., 379.Freidlin, L. Kh., 66.Freidlina, R. Kh., 113, 168.396.Freiling, E. C., 76.Freitag, W. O., 10.French, C. M.. 62.French, D., 105, 395.French, J. C., 182.Frennet, A., 68.Freudenberg, K., 239, 267,269, 270, 271, 273, 274,276, 277, 278.Freund, H., 77, 114.Freundlich, W., 86.Frevel, L. K., 115, 395.Frey, A. J., 243.Frey, H., 164, 219.Frey, H. M., 26.Fridrichsons, J..414.Fried, J., 221, 222, 224,Fried, M., 264.Fried, S., 119.Friedel, R. A., 10, 20, 108,Friedenwald, J. S., 325.Friedlander, P. H., 412.Friedman, A. M., 119.Friedman, L., 34.Friedmann, S., 142.Friedrich, M., 368.Friedrich, W., 236.Frisch, H. L., 18.Fritz, G., 93.Fritz, J. S., 360, 367.Fromageot, C.. 318.Frost, A. A., 131.Frueh, A. J . , 394.Frush, H. L., 250.Fry, A., 155.Frysinger, G. R., 70, 77, 80.Fuchs, W., 13, 277.Fiichtenbusch, F., 113.Fiirst, A., 218.Fuger, J., 9.Fujii, S., 48, 53.Fujimoto, G. I., 219.Fujinaga. T., 362.Fujino, Y., 181.Fujita, J., 121.Fukazawa. T., 367.Fukui, K., 50.Fukumoto, O., 59.Fukushirna, D. K., 225,306, 307, 311, 316.Fukuto, J . R., 297.Fukuyama, T., 330.Fulmer, R.W., 234.Fulton, J . W., 363.Funaki, T., 325.Funasaka, W., 82, 375.Funk, G. L., 373.Furberg, S., 390.Furman, N. H., 369.Furst, A., 159.Furuichi, J., 74.Fusari, S. A., 182.Fuschillo, N., 64.Fusco, R., 204.315.380.Fuson, N., 13.Futaki, R., 206.Fuzitani, T., 849, 37 1.Gaarde, F., 380.Gable, R. W., 72, 78.Gadamer, J ., 182, 320.Gadient, F., 181.Gadkary, A. D., 53.Gaebler, 0. H., 379.Gaumann, E., 185.Gaumann, T., 130, 198.Gafford, R. D., 280.Gagliardi, E., 337.Gagon, P. E., 168.Gailar, N., 8.Gailis. E. Ya, 364.Galanos, D. S., 181.Galatry, L., 17.Galbraith, A. R., 173, 200.Galdecki, Z., 99.Galijan, T., 183.Gallagher, K. J., 385.Gallagher, T. F., 306, 307,311, 315, 318.Gallai, Z.A., 362.Gallo, U., 373.Gallup, G., 10, 106.Gamlen, G. A., 108.Ganguly, A. K., 39.Ganguly, B. K., 210.Ganguly, J., 177.Gantz, E. St. C., 7, 372,Garber, M., 123.Garbers, C. F., 178.GarciA, S. G., 20.Garcia-Blanco, S., 396.Garden, J . F., 236.Garden, L. A., 61.Gardiner, J . E., 325.Gardner, D. M., 58.Gardner, P. D., 184, 195.Garik, V. L., 24.Garland, R. B., 236.Garn, P. D., 361.Garner, A. Y., 151, 183.Gamer, C. S., 140.Garner, E. F., 257.Garrett, A. B., 56.Garrini, E., 354.Garrison, W. M., 41.Gartaganis, P. A., 32.Garton, G., 90, 394.Garvin, D., 12, 33.Gascoigne, R. M., 215.Gasser, M. M., 186, 236.Gastinger, E., 93.Gates, M., 239, 250.Gaudemar, M., 174.Gaylord, N. G., 60, 162.Gdalia, I., 80.Gedeon, J., 213.Gehrke, G., 276.Geilmmn, W., 335.Gein, L.G., 340.379INDEX OF AUTHORS’ NAMES. 429Geissler, G., 155.Geissman, T. A., 237, 324.Geller, S., 389, 393, 398,Gellerman, J. L., 181.Gellert, H. G., 142.Gemmill, C. L., 46.Gendre, T., 180.Gensler, W., 234.Gensler, W. J., 180, 181.Gent, B. B., 169, 219.Gentile, P. S., 124.Gentles, M. J., 224.Gentsch, L., 86.George, P., 105.Gercke, R. H. J., 38.Gerding, H., 13.Gerhardt, G. E., 369.German, W., 32.Gerold, C., 223.Gerrard, W., 89.Gem, N. J., 25.Gemtsen, H. J., 123.Gersmann, H. R., 304.Gerstacker, H., 61.Gerzon, K., 385.Geske, D. H., 96.Gesser, H., 28.Ghanem, N. A., 53.Ghiorso, A., 119.Ghormley, J. A., 40, 43.Ghosh, A. C., 204.Ghosh, A. K., 356.Ghosh, G.B., 222.Giacomello, G., 406, 409.Gianetto, R., 321, 322.Gianturco, M., 247.Gibbons, D., 350.Gibbs, C. F., 67.Gibbs, D. S., 83.Gibbs, M. H., 1’78, 307.Gibian, H., 329.Gibson, N. A., 346.Giddings, J. C., 21.Giefer, L., 364.Gieren, W., 114.Gierer, J., 272, 273.Gilbert, H., 54.Gilbert, R. E., 386.Gilde, D., 398.Giles, J. A., 179.Gillespie, R. J., 99.Gillis, l3. T., 182.Gillis, J., 378.Gilman, H., 117, 192.Gim6nez-EstellCs, L., 371.Gindler, J. E., 119.Ginetti, Y., 391.Gingrich, N. S., 398.Ginsburg, L. B., 365.Ginsburg, S., 299.Ginsbutg, S. I., 371Gintis, D., 89.Gintz, F. P., 96.Ginzburg, L. B., 375.Girin, 0. P., 20.399.Giuffrida, L. D., 247.Glaser, F. W., 112.Glasner, A., 364.Glasser, L., 99.Glasson, W.A., 17.Glazunova, Z. I., 342.Gleason, E. H., 48.Glemser, O., 19, 101, 117,Glenat, R., 80.Glick, D., 318.Glick, R. E., 140.Glines, A., 39, 55.Glockling, F., 147.Gloss, G. H., 342.Glover, E. E., 234.Gluck, B., 364.Glueckauf, E., 73.Gmelin, R., 182, 32%.Go, S., 301.Goddard, D. R., 96.Godin, G. W., 51.Godsell, 3. A., 187.Godson, D. H., 190, 211.Goedkoop, j. A., 393.Goehring, M., 97, 98, 100,101, 120, 123, 125.Goel, R. N., 237.Goering, H. L., 149, 170.Gijsele, W., 87.Gofton, 3. F., 184.Gokhshtein, Ya. P,., 360.Golay, M. J. E., 20.Gold, J., 161, 184.Goldberg, G., 372.Goldblith, S. A., 36.Goldenson, J., 379.Gol’der, G. A., 411.Goldschmid, O., 273, 274.Goldsmith, G. J., 404.Goldstein, B., 163.Goldstein, D., 340.Goldstein, E.M., 366.Goldstein, J. H., 11, 130.Goldstein, R., 398.Golubtsova. R. B., 365.Gomahr, H., 14.Gomer, R., 60, 69.Gonzalez, 0. D., 65.Good, C. D., 86.Goodall, A. M., 24.Goodman, G., 403.Goodman, L., 131.Goodwin, T. H., 130, 406,Goodwin, T. W., 177,Goossens, J.C., 199.Gopalan, M. R., 51.Gordon, A. S., 25, 28, 31.Gordon, H. T., 377.Gordon, L., 364.Gordon, M., 48, 54.Gordon, S., 95.Gordy, W., 43.Gore, I. Y., 308.123, 126, 364, 392.410.178.Gore, R. C., 378, 379.Gorman, M., 245.Gorsich, R. D., 192.Goryacheva, I. A., 394.Goryushina, V. G., 364.Gosselain, P A., 68.Goto, H., 860, 366.Gottlieb, M. H., 73, 78.Goubeau, J., 9.Gould, D., 223, 224.Gould, R. G., 307, 309.Goulden, J.D. S., 14.Goutarel, M., 246.Goutier, R., 295.Govindachari, T. R., 238,Govindan, K. P., 76.Gowan, J. E., 237.Goyanes, C. B., 344.Grabbe, F., 874.Graber, R. P., 153, 221,Grabmaier, J., 93.Grabowich, P., 224.Gradwell, W. T., 189.Granicher, H., 402, 403.Graf, P., 70, 388.Graf, R., 101.Graham, G. E., 170, 183.Graham, K., 52,Graham, W. A. G., 87.Gralen, N., 273.Gran, G., 336.Grant, A. B., 262.Grant, D. F., 205, 415.Grant, P. M., 260, 267.Grassie, N., 49, 59.Graven, W. M., 34.Gray, B. F., 26.Gray, C. H., 312, 315.Gray, C. W., 217.Gray, P., 94.Gray, P. H. H., 280.Gray, T. J.. 65.Graydon, W. F., 71.GrdeniC, D., 125, 395, 397,Grebenovsk?, E., 369.Green, A. L., 299, 301.Green, B. A., 8.Green, H., 351.Green, J.H. S., 74.Green, M. A. S., 315.Greene, F. D., 150.Greenfield, H., 108.Greenhalgh, E., 65.Greenwoad, N, N., 89.Greer, M. A., 182.Gregor, H. P., 71, 73, 74,Griessbach, R., 374.Grell, A., 204.Grenier, J. W., 359.Grenville-Wells, H. J., 387.Grewe, R., 200.GOSS, F. R., am242.222, 2%.398.76, 78430 INDEX OF AUTHORS’ NAMES.Greyson, M., 66.Gribova, Ye. A., 411.Griessbach, R., 70.Grieveson, B. M., 48, 54.Griffith, E. J., 86, 97.Griffith, J. S., 105.Grigor’eva, N, K., 86.Grimes, M. D., 367.Grimley, T. B., 65.Grimshaw, J., 238, 239.Grinberg, G. P., 78.Grippenberg, J., 234.Grisebach, H., 229.Gritsenko, T. M., 62.Grob, C. A., 135, 154,Grob, R. L., 337.Grone, H., 234.Groeneveld, W.L., 97.Granvold, F., 84.Gross, S. R., 280, 282.Grossman, J., 224.Grossman, R. F., 203.Grossweiner, L. I., 45,Grove, J. F., 210.Grubb, W. T., 43.Grubert, H., 109.Gruen, D. M., 118.Gruen, F., 224.Griine, A., 231.Grunthard, H. H., 15.Grutter, W. F., 70.Gruztner. R., 355.Grunberg-Manago, M., 263.Grundmann, C., 194, 233.Grundon, M. F., 242.Gruntova, Z., 361.Grunze, H., 97.Gruver, J. T., 28.Gubler, K., 186.Guerillot-Vinet, A., 228.Guertin, D. L., 13, 379.Guillet, J. E., 56.Gullikson, C. W., 11.Gundermann, K., 182.Gunderson, K., 292.Gunsalus, C. F., 290.Gunsalus, I. C.. 290.Gunstone, F. D., 181.Gunter, S. E., 290.Gupta, J., 82, 366, 375.Gupta, M. P., 405.Gurdjian, V., 220.Gurev, S. D., 364, 365.Gurin, S..309, 311.Gurvich, I. A., 210Gusev, S. I., 366.Gut, M., 316.Guter, G. A., 87.Gutfreund, H., 302.Gutmann, H., 176.Gutmann, V., 83, 97, 113.Guy, J., 10.Gwilt, J. R., 350.Gyorbiro, K., 360.181.46.H a g , A., 270.Haas, C., 16.Haas, G., 20.Haas, H. J., 159.Haas, M., 16.Haas, W., 337.Habgood, T., 246.Hach, R. J., 105, 395.Hachihama. Y., 51, 53.Hackley, B. E., 300, 301.Hadwick, T., 155.Hadii, D., 13, 91.Hagglund, E., 258. 267,Haggroth, S., 874.Harth, E., 65.Haeseler, H., 101.Haffner, W., 197.Hafner, W., 109, 110, 111.Haggart, C., 169.Hagiwara, Z., 361.Hahn, F. L., 366.Hahn, H., 124,360,394.Hahn, L., 272.Hahn, R. B., 344, 365.Hahn, T., 391.Hahn, W., 51, 55.Haissinsky, M., 41, 115.Hajos, Z., 81.Haldeman, R.G., 66, 67.Halford, J. O., 12.Halford, R. S., 16, 20.Halik, M., 379.Halkerston, I. D. K., 318,328, 329.Hall, D., 406.Hall, D. A., 325.Hall, D. M., 187.Hall, G. G., 131.Hall, H. K., 135.Hall, W. K., 69.Halla. F., 99.Hallam, B. F., 109.Haller, W., 272.Halline, E. W., 361.Hallsworth, A. S., 143, 162.HAlovA, 0.. 9.Halpern, O., 239.Halsall, T. G., 208, 210,212, 213, 215.Ham, G. E., 50.Ham, N. S., 131.Hamano, H., 128.Hamill, W. H., 36, 46.Hamilton, J. K., 259.Hamilton, M. J., 73, 76.Hamilton, W., 212.Hamilton, W. C., 389.Hamm, R. E., 359.Hammick. D. Ll., 230.Hammond, B. R., 302.Hamor, T. A., 410.Hampton, B. L., 209.Hampton, J., 146.Hamrick, A. J., 144.Hsncocli, J. W., 174.273.Hand, J .J., 235.Handschumacher, 13. E.,Hanlos, E., 366.Hannaert, H., 134.Hannan, R. B., jun., 12.Hannerz, K., 38.Hansel, R., 365.Hansen, N., 63, 66.Hanien, R. P., 180.Hansen, R. S., 113.Hanst, 1’. L., 45.Happold, F. C., 279, 282,Haq, S., 258.Hara, K., 364.Hara, R., 369.Hara, S., 354.Hara, Y., 204, 206.Harada, T., 322, 323.Haraldsen, H., 84.Harasawa, S., 376, 377,Harborne, J . B., 237.Hardegger, E., 239.Harder, B., 124.Harding, T. T., 414.Hardt, H. D., 85.Hardy, C. J., 377.Hardy, J . H., 374.Hare, R., 322.Hargreaves, A., 413.Haring, H. C., 13.Harlow, G. A., 372, 373.Harper, E. A., 114.Harper, P. E., 399.Harper, S. H., 161, 184,Harrand, M., 12, 19.Harrington, D. F., 78.Harrington, R.E., 83.Harrington, R. H., 44.Hams, C. M., 122, 124.Harris, E. E., 270.Hams, F. E., 47, 73.Harris, G. M., 35.Harris, G. S., 96.Harris, J. I., 303.Harris, P. M., 85, 392.Harshman, S., 302.Hart, E. J.. 35.Hart, H., 142, 161, 198.Harteck, P., 36, 37.Narter, H. L., 61.Hartert, E., 17, 19.Hartley, A. M., 369.Hartley, B. S., 295, 303,Hartmann, G., 69.Hartung, S., 201.Harukawa, T., 205.Hashimoto, Z . , 285.Hashizume, A., 179, 199.Haskell, T. H., 182.Haslewood, G. A. D., 220,252.283, 284, 285, 290.378.185.303.329INDEX OF AUTHORS’ NAMES. 431Hasner, L., 272.Hass, M., 390.Hassall, C. H., 216, 227.Hassel, O., 104, 413, 414.Hastings, G. W., 55.Hastings, J., 363.Haszeldine, R. N., 153.Hatchard, C.G., 44.Hatt, H. H., 167.Hattori, C., 323, 327.Hattori, K., 230.Hauffe, K., 66.Haul, R. A. W., 60.Hauschild, U., 125, 392.Hauser, A., 116.Hauser, C. R., 144, 152,Hausmann, G., 201.Hausser, K. H., 149.Haven, A. C., 197.Haven, A. C., jun., 159.Havinga, A. E., 319.Havill, J. R., 77.Havinga, E. E., 104, 395.Hawker, F. J., 235.Hawkins, N. J., 9.Hawkinson, D. E., 82.Hawley, D. W., 365.Haworth, R. D., 208, 209,219, 238, 239, 267.Hawthorne, J. N., 181.Hawthorne, M. F., 152.Hay, A. S., 234.Hay, J. E., 189.Hay, R. G., 402.Haya, Y., 128.Hayaishi, O., 285, 286, 290,Hayami, T., 367.Hayano, M., 306.Hayano, S., 378.Hayashi, H.. 325.Hayashi, K., 50.Hayashi, Y., 78.Hayatsu, R., 220, 225.Hayden, A. L., 380.Hayes, D.H., 264.Hayek, E., 100.Hayes, F. N., 225, 229.Hayes, N. F., 236.Haynes, C. G., 238.Haynes, J., 174.Haynes, G. R., 184, 195.Haynes, L. J., 189.Hayward, J. C., 37.Hayward, L. D., 255.Hazel, J. F., 368.Hazen, G. C., 153.Hazen, G. G., 225.Headridge, J . B., 377.Healey, F. H., 61, 65.Healy, E. M., 234.Heaney, F., 192.Heard, R. D. H., 306, 316.Hearon, W. M., 229, 278.Heaton, L., 393, 398.197.291.Hebdon, E. A., 96.Hebling, R., 225.Hecht, K. T., 14.Hechter, O., 305, 306, 307,311, 312.Heck, R., 152.Hedberg, K., 93.Heden, S., 272.Heel, W., 276.Heffernan, M. L., 129, 234.Heffler, M. S., 225.Hegediis, A.. 374.Hegediis, A. J., 116.Hegemann, F., 374.Heiart, R. B., 389.Heidelberger. M., 257, 287.Heikens, D., 59.Heikes, R.R., 84.Heilbron, (Sir) I. M., 171,Heilbronner, E., 130, 196,Heimbuch, A.. 336.Heimburger, G., 303.Hein, F., 111.Hein, T. S., 369.Heine, R. F., 173.Heinle, E., 191.Heinrich, B. J., 367.Heinz, D., 96.Heitmann, H. G., 76.Heitler, W., 131.Helfenstein, A., 178.Helfferich, F., 74, 80.Helg, R., 178, 203.Heller, C. A., 28.Heller, H. J., 54.Heller, M., 222, 224, 316.Hellman, K., 312.Hellman, L., 306, 307, 311.Hellmann, H., 183.Helm, D., 197.Hemala, N., 359.Henbest, H. B., 143, 145,160, 162, 165, 217, 218.Henderson, I>. R., 249.Henderson, H. S., 147.Henderson, M. E. K., 280.Hendriks, H., 90.Hendrickson, J. B., 238.Henglein, A., 39, 48, 55.Henkel, W., 185.Henley, E. J., 36, 41.Henning, G.J., 334.Henrici, G., 53.Henry, J. A., 213.Henry, L., 12.Henry, R., 318, 328.Henseke, G., 253.Henshaw, D. E., 391.Hepler, L. G., 64.Heppel, L. A., 262, 263.Heppolette, R. L., 139.Hepworth, M. A., 396.Herber, R. H.. 77.Herbstein, F. H., 409.174.197.Herissey, H., 276, 320.Herling, F., 217, 226.Herman, M. A., 90.Hernestam, S., 267.Herout, V., 205, 206, 207.Herpin, A., 393.Herr, M. E., 167, 224.Herr, R. R., 233.Herran, J., 209.Herranen, A., 375.Herrington, K., 392.Herrmann, K. W., 388.Herrmann, W., 92.Herron, R. C., 405.Herschbach, D. R., 22.Hershberg, E. B., 223, 224.Hershenson. H. M., 363.Hertoghe, A., 54.Herwig, W., 197.Herz, J. E., 222, 224, 315.Herz, W., 207.Herzberg, G., 46.Herzog, H.L., 223, 224.Herzog, S., 114.Hess, C. L., 268.Hesse, G., 161.Hestrin, S., 299.Hetherington, G., 95, 102,Hettinger, W. P., jun.,Hetzer, H. B., 372.Heusckhel, G., 236.Heusghem, C., 318.Heusler, K., 225.Heusser, H., 186,225.Hewaidy, I. F., 352.Hewel, C. A., 377.Hewitt, E. J., 377.Hewitt, J. J., 157, 185.Hexter, R. M., 11, 16.Heyl, F. W., 167.Heym&s, R., 171.Heyn, A. H. A., 78.Heyndryckx, P., 377.Heyns, K., 184.Hibbert, H., 270, 271.Hickam, W. M., 36.Hickey, F. C., 227, 309.Hickinbottom, W. J., 146,Hickmott, T. W., 63, 64.Hidalgo, A., 20,Hieber, W., 106, 107, 365.Hietala, P. K., 234.Higashi, S., 364.Higashimura, T., 51, 56.Higashino, T., 363.Higgins, G. H., 119.Higgs, P. W., 387.Highet, P.F., 247.Highet, R. J., 247.Higley, W. S., 103.Higuchi, J., 128.Higuchi, T., 372.Hildahl, G. T., 195.104.171.174432 INDEX OF AUTHORS' NAMES.Hildebrandt, R. A., 117.Hill, D. G., 10.Hillman, J., 328.Hilmer, W., 97, 391.Hilsenrod, A,, 42.Hilz, H., 330.Hinder, M., 203.Hine, G. J., 36.Hine, J., 140.Hine, R., 202, 384.Hinman, J. W., 186, 237.Hinshelwood, (Sir) C. N.,Hinsvark, 0. N., 372.Hintermaier, A., 366.Hirano, H., 14.Hirano, S., 82, 252, 367,Hirokawa, S., 416.Hironaka, J ., 74.Hirsch, D. H., 166, 176.Hirschel, M. I., 241.Hirschmann, E., 92.Hirschmann, F. B., 227.Hirschmann, H., 227.Hirschmann, R., 224.Hirschmann, R. F., 221.Hirshberg, Y., 46.Hirshfeld, F. L., 409.Hirst. E. L., 289.Hirt, R.C., 378.Hisatsune, C., 33.Hiskey, C. F., 174.Hixon, R. M., 266.Hoaglin, R. I., 166, 176.Hoard, J. L., 406.Hobbiger, F., 296,297, 299.Hochanadel, C. J., 36.Hochbrg, J . , 139.Hockenhull, D. J. D., 280.Hodes, M. E., 265.Hodge, N., 96.Hodges. R., 186, 214.Hodgkin, D. C., 236, 414,Hodgson, W. G., 149.HodinAi-, Z., 220.Hodsman, G. F., 232.Hodson, H. F., 246.Htiger, E., 146, 164.HGgfeldt, E., 72.Hoeksema, H., 186, 237.Hoerger, E., 233.Hoey, G. B., 224.Hofbauer. G., 276.Hoffman, C. H., 169, 178.Hoffman, D. C., 81.Hoffman, F., 224.Hoffman, P., 320, 326.Hoffman, W. D., 85.Hoffmann, A. K., 137, 161.Hoffmann, H., 163.Hoffmann, K., 233.Hoffsommer, R. D., 222.Hoffstetter, H., 328.24, 26.376.Hobart, S.R., 3764416.Hofmann, H. J., 10.Hofmann, P., 369, 360.Hogan, J. P., 67.Hogarth, J. W., 120.Hogg, J. A., 166, 224.Hogsed, M. J., 184.Hohlstein, G., 86, 96.Holden, A. N., 403.Holden, J. R., 398.Holden, M., 262.Holden, M. E. T., 143.Holder, B. E., 382.Holfeld, W., 189.Holland, V. F., 72.Holley, C. E., 112, 393.Holley, T. F., 208.Hollingsworth, C. A., 173.Holly, F. W., 169, 186, 229,Hollweg, R. M., 372.Holman, R. T., 13, 379.Holmberg, B., 272, 273,Holme, D., 179.Holmes, J. C., 380.Holmes, R. R., 88.Holness, N. J., 316.Holroyd, A., 77.Holtzapffel, D., 90.Holtzberg, F., 116.Holubek, J ., 361.Honeyman, J., 262, 266.Hooker, D. T., 336.Hooley, J. G., 91.Horiik, J., 340.HorAk, M., 206.Horhammer, L., 366.Horiguchi, Y., 826.Horiuti, J., 66, 67.Horn, H., 369.Home, S.E., jun., 57.Homer, L., 62, 163.Hornig, D. F., 9, 14, 99,Homing, E. C., 171, 241.Horton, D., 262.Horton, W. S., 299.Honvitz, J. P., 230.Hosansky, N. L., 227.Hoshino, S., 400, 402.Hoshino, Y., 364.Hoskin, F. C. G., 303.Hossfeld, R. L., 273.Hough, L., 261, 268, 269.Hough, W. V., 86.Houkanen, E., 234.Hourigan, H. F., 374.House, H. O., 14-4.Houser, T. J., 11.Howard, J. P., 62.Howard-Flanders, P., 40.Howe, P. G., 74.Howe, R., 206.Howell, C. F., 236.Howell, M. G., 160.Howell, P. A.. 80, 393.287.278.394.Hcrwlett, K. E., 24.Howton, D. R., 198.Hoyer, H., 10.Hseu, T. M., 370.Huang, R. L., 149.Hub, D. R., 96.Hubbard, R., 178.Huber, G., 146, 164, 266.Huber, M.L., 183.Huber, P., 37.Hubner, H. H., 277.Huch, A., 67.Huch, C., 67.Hudson, P., 313.Hudson, R. L., 199.Huebner, C. F., 244.Huttel, R., 230.Huttig, G. F., 66.Huff, J. W., 178, 307.Huffman, E. H., 82.Huffman, M., 222.Huggard, A. J., 260.Hughes, E. W., 416.Hughes, G. K., 160,242.Hughes, G. M. K., 260.Hughes, R. B., 379.Hughes, R. E., 67.Huisgen, R., 192.Huisman, H. 0.. 178.Hulanicki, A., 364.Hulet, E. K., 119.Hull, R., 232.Hulm, J. K., 402.Hulme, R., 104, 412.Huls, R., 92.Hultgren, N., 117.Hummel, D., 263.Hunter, G. J., 366.Hunter, J. A,, 375.Huntress, E. H., 229.Hurd, C. D.. 263.Hure, J., 367.Hurlen, E., 266.Hurlen, T., 84.Hurst, R., 118.Hush, N. S., 128.Hussey, A.S., 201.Huston, J. L., 83.Hutchings, B. L., 186.Hutschneker, K., 70, 71.Hutt, H. H., 181.Hutton. T. W., 168.Huyskens. P., 37.Hvoslef, J., 104, 413.lbers, J. A., 91, 391, 396.ldelson, M., 68.Idler, D. R., 227.:do& J. D., jun., 199.Bland, D. C., 148, 168..guchi, A., 77.'guchi, K., 127..'Hay, Y., 130.'kan, R., 160.keda, S., 360, 363, 374.:ball, J-, 408INDEX OF AUTHORS’ NAMES. 433Ikeda, T., 248.Ikemi, T., 196.Illarionov, V. V., 115.Imai, H., 358.Imhof, H. F., 189.Immergut, E. H., 55.Imoto, M., 50, 51, 52.Inayama, S., 13.Ing, H. R., 241.Ingber, N. M., 367.Inge, M., 396.Ingham, R. K., 153, 170.Inghram, M. G., 119.Inglis, J., 357.Ingold, C. K., 105, 180,Ingold, K. U., 30.Ingraham, J. L., 288.Ingram, D.J . E., 149.Ingram, G., 354, 355.Ingri, N., 396.Inhoffen, E., 169, 172.Inhoffen, H. H., 169, 174,177, 178.Inoue, Y., 376.Inouye, Y., 252.Iritani, N., 356.Irmscher, K., 169.Irsa, A. P., 34.Irvine, D. S., 212.Irvine, J . W., 77.Irving, H., 105.Irving, R. J., 106.Isahara, A., 44.Isbell, H. S., 250.Ische, F., 174.Iseda, S., 212.Iselin, B. M., 227.Ishibashi, M., 362, 364.Ishikawa, H., 205.Ishikawa, T., 322.Ishimori, T., 81.Ishimoto, M., 324.Ishutchenko, E. I., 365.Islam, A. M., 200.Isler, O., 166, 171, 174, 175,176, 177, 178.Isono, M., 280.Issa, I. M., 362, 370, 371.Issa, R. M., 371.Isselbacher, K. J., 306.Isshiki, S., 359.Isslieb, K., 197.Ito, F., 375.Ito, K., 11.Ito. T., 364.Itoh, T., 131.Ivanov, Ch., 361.Ivanov-Emin, B.N., 97Ivin, K. J., 29, 50, 58.Iwama, F., 361.Iwamoto, R. T., 369.Iwase, A., 360, 375.Iyer, B. H., 200.Izmailov. N. A,, 76.Izvekov, 1. V., 369.202.Jack, K. H., 396.Jackman, L. M., 130.Jackson, H. G., 119.Jackson, R. W., 165.Jackson, W. G., 186.Jacobi, E., 231.Jacobs, E. S., 337.Jacobs, G., 194.Jacobs, R., 306.Jacobs, T. L., 144, 174.Jacobs, T. M., 196.Jacobs, W. A., 248, 249.Jacobson, E. L., 114.Jacobson, M., 180.Jacquemin, W., 155.Jaffe, H., 403.JaffC, H. H., 132.Jaffe, J. H., 17.Jaffe. M., 280.Jahn, A., 87.Jahn, E. C., 267.Jain, A. C., 237, 238.Jakits, O., 402.Jakubowski, 2. L., 182.Jambregid, I., 168.James, A. T., 181.James, D. R., 220.James, R.W., 387.James, S., 301.James, W. J., 105, 395.Jamieson, R. S. P., 260.Jander, B. J., 294.Jander, G., 83, 114.Jandorf, B. J., 206, 299,Jang, R., 295, 296.Janjid, T., 376, 377.JankoviC, 0. M., 102.Jankovits, L., 351.Jahosi, A., 377.Janot, M.-M., 246.Jansen, E. F., 295, 296.Janson, A., 270.Jansz, H. S., 301.Janz, G. J., 33, 231.Jaquiss, D. B., 209.Jarabin, Z., 341.Jarkovsky, I., 51.Jarrett, A. D., 188.Jarrige, P., 318, 328.Jarvie, A. W., 204.Jarvie, J . M. S., 33, 231.Jaunin, R., 171.Jayko, M. E., 41.Jayle, M. F., 329.Jaynes, E. T., 400.Jean, M., 366.Jefferies, P. R., 204.Jeffrey, G. A., 384, 394.Jefraim, M. I., 160.Jeger, O., 165, 202, 205,Jellinck, P. H., 306.Jellinek, H. H. G., 59.Jenckel, E., 59.JeniEkovB, A., 346.300.212, 223.Jenkins, A. D., 49.Jenkins, F.E., 35.Jenkins, G. I., 66.Jenkins, I. L., 120.Jenkins, W. A., 89.Jennings, K. F., 224.Jenny, E., 192.Jenny, E. F., 198.Jenny, J., 71.Jensen, A., 122.Jensen, E. V., 224.Jensen, H. L., 292.Jensen, K. A., 139.Jensen, R. B., 182.Jentzsch. D., 376.Jette, E. R., 388.Jin, J., 160.Jiu, J., 217.Jockusch, H., 147.Johns, H. E., 36.Johns, R. B., 236.Johnsen, R. H., 174.Johnson, A. H., 368.Johnson, A. R., 251, 252.Johnson, A. W ., 190, 200.Johnson, B. A., 222.Johnson, D. H., 147.Johnson, E. R., 43.Johnson, G. R. A,, 41.Johnson, H. E., 166, 201.Johnson, H. R., 381.Johnson, H. W., 157.Johnson, J. B., 373.Johnson, J. L., 167.Johnson, J.S., 80.Johnson, J . W., jun., 54.Johnson, M., 350.Johnson, N. M., 171.Johnson, P., 43.Johnson, R. G.. 153, 170.Johnson, R. R., 158.Johnson, W. S., 164.Johnston, E. L., 169.Johnston, H. S., 22, 24.Johnston, R., 49.Johnston, W. D., 84.Johnstone, R. A. W., 208.Jolley, J. E., 45, 169.Jona, F., 400, 401, 403,Jonassen, H. B., 110,117.Jones, A. S., 257, 263, 265,Jones, D. N., 219.Jones, E. K., 66.Jones, E. R. H., 159, 171,173, 174, 170, 212, 213.Jones, G., 208, 234.Jones, J. D., 289, 290.Jones, J. I., 229.Jones, J . K. N., 256, 257,Jones, L. A., 380.Jones, L. H., 10, 16, 124.Jones, M., 119.Jones, M. H., 54, 55.404.367.258, 259434 INDEX OF AUTHORS’ NAMES.Jones, N., 56.Jones, P. M. S., 56.Jones, R. E., 221, 223.Jones, R.G., 117, 166, 239.Jones, R. H., 139.Jones, R. M., 312.Jones, R. N., 217.Jones, W. J., 170, 183.Jongen, G. H., 342, 372.Jordan, D. O., 266.Jordan, K., 367.Jargensen, C. K., 105.Jorison, W. J., 138.Josephs, M., 69.Joshi, C. G., 238.Joshi, D. V., 238.Joshi, M. K., 352.Josien, M.-L., 12, 13, 18.Joska, J., 224.Joyce, R. M., 184.Juda, W., 70.Julg, A., 128.Julia, S . , 161, 246.Julian, P. L., 224.Jungreis, E., 368.Just, G., 224.Juza, R., 114, 394.Kabara, J , J ., 309.Kaczka, E. A., 186, 237.KadiC, K., 363.Kaarik, K., 360.Kanzig, W., 403.Kagarise, R. E., 11.Kageyama, M., 341.Kahn, S., 82.Kahnt, F. W., 311.Kaiser, A., 135.Kaiser, F., 322.Kaiser, I. H., 314.Kaiser, R., 20, 44.Kainz, G., 355.Kajiyama, R., 363, 366.Kakihana, H., 71, 73, 354,Kakita, Y., 306.Kakiuti, Y., 13.Kalbas, L., 371.Kalberer, F., 157.Kalidas, C., 351, 353.Kallmann, S., 375.Kalnajs, J., 392, 395.Kalous, V., 361.Kal’pchiev, K.I., 344.Kamio, H., 14.Kamper, J., 236, 415.Kamphenkel, L., 183.Kampmann, F., 9.Kamura, Y., 368.Kanda, F. A., 87.Kanie, T., 375.Kantor, S. W., 152.Kanzelmeyer, J. H., 114.Kaplan, L., 117.Kaplan, L. D., 8, 15.Kapralova, G. A. 36.375, 376.Kapur, S. L., 53.Kapustinskii, A. F., 83, 384.Karandasheva, Y. F., 107.Kargin, V. A., 20.Kariyone, T., 207.Karl-Kroupa, E., 97.Karmas, G., 117.Karpel, W. J., 224.Karpov, V. L., 43.Karrer, P., 177, 178, 218,245.Karstrom, H., 281.Karyakin, A. V., 63.Kashima, J., 372, 373.Kasper, J.S., 399.Kastha, G. S., 18.Kata, H., 230.Katagiri, M., 286.Katayama, M., 406.Katlafsky, B., 9.Kato, T., 351, 367.Kato, Y., 325.Katou, K., 354, 367.Katritzky, A. R., 231.Katsura, T., 324.Katz, J. J., 20, 104.Katz, M., 380.Katz, T. J., 242.Katz, W., 87.Katzman, P. A., 325.Kauffman, G. B., 77.Kaufman, F., 25, 141.Kaufman, J. J., 34.Kaufman, M. H., 231.Kautsky, H.,.80.Kavanagh, K., 269.Kaverin, S. V., 394.Kawabe, H., 75.Kawai, I<., 11.Kawamura, A., 376.Kawase, M., 82, 375.Kay, E. L., 52.Kaye, W., 380.Kazanskii, B. A., 69.Keattch, C. J., 82, 348Kebrle, J., 233.Keegan, P., 309.Keeling, R. O., 403.Keenan, C. W., 89.Kefeli, T. Ya, 271.Kehl, W. L., 402.Keilholtz, G.W., 381.Keilin, D., 298.Kelecsen yi-Dumeonil,Keller. A., 320.Keller, C., 342.Keller, F., 245.Keller. K.. 241.80.E.,Keller; W., 361.Keller-Schierlein, W., 185.Kelley, M. T., 369.Kelly, W., 409.Kemball, C., 68, 69.Kember, N. F., 79, 377.Kemp, A., 298.Kendall, J . D., 231.Kendall, K. K., 374.Kende, A. S., 198, 406.Kennedy, F., 198.Kenner, G. W., 154.Keppler, H. H., 237.Kerckow, A., 164.Kergomard, A., 166.Kerr, L. M. H., 319.Kerr, V. N., 229.Kerridge, D. H., 85.Kertes, S., 82.Ketelaar, J. A. A., 17, 304.Kewitz, H., 299.Key, A., 283.Khadeev, V. A,, 362.KhambBta, S. J., 17.Khan, N. A., 150.Kharasch, M. S., 150, 1‘76.Khastgir, H. N., 185.Khautz, I., 269.Khlopin, N. Ya, 359.Khym, J . X., 260.Kiba, T., 367.Kice, J .L., 53.Kiehl, J . P., 5T.Kierkegaard, P., 399.Kierstead, R. W., 243.Kies, H. L., 369.Kikuchi, Y., 196.Kilby, B. A., 285, 295, 302.Kil’disheva, Y. V., 115.Kilpatrick, M., 102, 136.Kimel, S., 17.Kimura, M., 413.Kincl, F. A., 213.Kindervater, F., 120.King, A. J., 87.King, C., 158, 185.King, C. G., 39.King, F. E., 190, 208, 209,King, F. T., 10, 20.King, T. J., 190, 209, 211,212, 213.King, W., 191.Kington, G. L., 61.Kinnunen, J., 351.Kinsey. J. L., 158.Kipnes, S. M., 361.Kircher, H. W., 269.Kirchner, K., 376.Kirk, D. N., 219, 228.Kirkland, J . J., 357, 380.Kirmse, W., 52.Kirschner, S., 123.Kirsten, W. J., 364.Kir’yalov, N. P., 207.Kistiakowsky, G. R., 30,Kiselova, J.M., 51.Kita, H., 65.Kitagawa, K., 364.Kitagawa, T., 346.Kitahara, K., 196.Kitahara, S., 81.210, 211, 212, 213.31, 45, 152INDEX OF AUTHORS’ NAMES. 435Kitaigorodskii, A. I., 383.Kitaoka, S., 252.Kitchener, J. A., 74.Kitt, G. P., 73.KitteI, C., 400.Kiyota, H., 364.Kjzr, A., 182.Klason, P., 276.Klee, W., 242.Klein, E., 379.Klein, M. P., 382.Klein, R., 24, 32, 45.Kleinberg, J . , 85.Kleinwort, W., 360.Klement, R., 82, 96, 98.Klemer, A., 253.Klemm, W., 105.Klemperer, W., 9, 10.Klimenok, B. V., 68.Klimke, R., 196.Klimova, V. A., 355.Kline, G. B., 166, 239.Klinedinst, P. E., 231.Klink, F., 269, 271.Kloetzel, M. C., 191.Klohs, M. W., 245.Klopper, A., 314.Kloster- Jensen, E., 196,Kluyver, A. J., 280, 281.Klyne, W..201, 202, 205,Knopf, E., 270.Knott, E. B., 231.Knox, J . H., 22.Knox, W. E., 280, 290,291.KO, R., 118.Kobayashi, H., 67.Kobayashi, M., 362.Kober, E., 233.Koberlein, W., 377.Koch, R. C., 233.Koczka, K., 240.Koczor, I., 239.Kodama, K., 376.Kogl, F., 183.Kogler, H. P., 111.Koehler, W. C., 112.Koelle, G. B., 298.Koenig, F. J., 86.Konig, H.-B., 185.Koepsell, H. J . , 256.Korbl, J., 355. 356.Koszegi, D., 353, 354.Kofron, J . T., 174.Kogan, M. B., 73.Kohara, K., 364.Koliler, M., 342.Kohn, E. J., 145.Kojirna, M., 375.Kojima, T., 82, 375.Kokes, R. J . , 68.Kolditz, L., 96.Kolevatova, V. S., 360.Kolka, A. J., 143, 186.Koller, E., 174.197.217, 224, 317, 415.Kolthoff. 1. M., 124, 362.Komandrovskaya, L.V.,Komarewsky, V. I., 66.Komatsu, C., 128.Komiyama, Y., 397.Kondo, T., 78.Kondrashev, Yu. D., 394.Konetza, W. A., 325.Konkoly-Thege, I., 374.Kono, K., 322.Kooyman, E. C., 133.KorbovA, M., 360.Korenman, 1. M., 342.Korn, E. D., 318.Kornblum, N., 158, 160,Kornfeld, E. C., 166, 239.Kornfeld, G., 71.Korshun, M. O., 355.Korst, W. L., 112, 393.Kortum, G., 15.Korzum, B., 244.Kosheleva, G. N., 345.Koski, W. S., 34.Kosower, E. M., 220, 231,Kostic, R. B., 226.Kostiomin, A. I., 362.Kotera, K., 247.Kotlan, J., 148.Koton, M. M., 51.Kotsis, E. A., 352.Kottenhahn, K.-G., 19.Koulkes, M., 136.KovAcs, O., 206.Kovalenko, P. N., 360,Kovafik, M., 346.Kovkts, E., 196, 197.Kozima, K., 20.Kozjireva, L.S., 340, 365.Kradolfer, F., 185.Kraerner, J., 100.Kraffczyk, K., 83.Kraft, L., 147.Krasil’nikova, L. N., 365.Kratzl, K., 269, 271, 272,Krauch, H., 194.Kraus, M., 36.Kraus, K. A., 77, 78, 80, 82.Krebs, H., 394.Kreevoy, M. M., 16, 135.Kreidle, N. J., 36.Kreige, 0. H., 365.Kreiselmeier, H., 263.Kreutzberger, E., 233.Krieve, W. F., 113.Krimm, S., 19, 20.Krinsky, N. I . , 175.Krishnamachari, S. L. N. G.,Krishnamoortliy, C., 74.Krishnamurti, C. R., 322.Krishnamnrti, D., 17.123.170, 183.232.366.275.11.Krishnamurti, K., 376.Krishnan, T. S., 17.Krishnaswamy, N., 77.Kritchevsky, T. H., 225,Kroger, F. A., 84.Krogius, Ye. A., 99.mop, S., 296.Kross, R. D., 12, 13.KrstanoviC, I., 398.Kruck, P., 146, 164.Krueger, R.H., 10.Kruger, G., 294.Kruh, R., 397.Krupp, F., 143.Krylov, E. I., 360.Krylov, 0. V., 68.Kubo, M., 413.Kubokawa, Y., 65.Kubota, S., 159.Kubotera, T., 79.Kudo, K., 20.Kudzin, S. F., 268.Kung, W., 145, 201.Kuhn, A., 82.Kuehne, M. E., 244.Kundig-Hegedus, H., 227.Kuentzel, L. E., 380.Kuffner, F., 242.Kuhn, D. A., 148.Kuhn, L., 10.Kuhn, R., 159, 227.Kuhn, S., 88, 190.Kuhn, W., 48.Kujawa, F. M., 50.Kul’berg, L. M., 333, 336,Kulenok, M. I., 370.Kulka, M., 271.Kulkarni, A. B., 238.Kul’kova; N. V., 65.Kummer, J. T., 69.Kundu, P. C., 334.Kunin, R., 70, 76, 375.Kunkel, E., 335.Kunst, P., 301.Kuo, K., 388.Kuper. S. W. A., 322.Kupriyanov, S. E., 36.Kurbatov, D. I., 114.Kurobe, M., 82, 376.Kuroya, H., 397.Kurzer, F., 230.Kurzovkov, A. D., 542.Kusin, A.M., 42.Kusserow, G. W., 245.Kutschke, K. O., 31.Kuzovkov, A. D., 241.Kuznetsov, V. I . , 340, 345,Kuznetsova, V. K., 363.Kwan, T.. 67.Kyburz, E., 186.Labbe, B. G., 54.Laber, G., 194.306.339, 367.365436 INDEX OF AUTHORS’ NAMES.Labhart, H., 131.Lacey, R. N., 171.Lacourt, A., 377.Lada, Z., 371.Ladam, A., 20.Ladbury, J. E., 187.Ladwig. G., 101.LaFlamme, P., 151, 183Lafont, R., 18.LaForce, R. C., 382.Laforgue, A., 128.Lagally, P., 269.Lago, R. M., 66.Lagowski, J. J., 362.Lagrange, G., 13.Lahey, F. N., 207.Laidler, K. J., 302.k i n g , W., 61.Lakatos, B., 83, 94.Laland, S. G., 265.Lally, M. M., 334.Lamb, B., 361.Lambert, J.L., 348.Lamberton, J. A., 167, 207.Lamp, F. W., 34.Land, D. G., 177.Landa, S., 280.Landesman, H. K., 167,Landor, P. D., 174.Landor, S. R., 174.Lane, E. S., 369.Lane, J. F., 168.Lane, T. J., 10.Laney, D. H., 232.Lange, K. R., 61.Lange, W., 294.Langemann, A., 142.Langer, J., 96.Langford, P. B., 140.Lango, M., 571.Laming, W. C., 57.Lannon, T. J., 287.Lansbury, P. T., 156.Lansdown, A. R., 256.Lapidus, L., 78.Lapin, L. N., 357.Lappert, M. F., 89.Lapporte, S., 152.Lapteva, K. A., 65.Lapworth. A., 319.Lardera, M. R., 338.Lardon, F., 208.Larsen, D. W., 149.Larsen, E. M., 78, 97, 113.Larson, A. C., 391.Larson, H. O., 170, 183.Larson, Q. V., 73.Larssen, P. A., 390.Larsson, R., 117.Lascoimbe, J., 12.Lassettre, E.N.. 85, 392.Latham, H. G., jun., 226.Latimer, P. H., 179.Laubach, G. D.. 220. 324.Lauchenauer, A., 178, 203.200.Laudise, R. A., ll7.h u e , W., 100.Lauer, J. L., 9.Laughland, 0. H., 319.Laughlin, B. D., 85.Laughlin, R. G., 151, 183.Laurie, W., 212.Lautsch, W., 269, 272.Lavine, L. R., 415.Law, j. T., 63.Law, M. J. D., 64.Lawrence, E. P., 171.Lawrence, H. C., 869.Lawton, E. J., 43, 44.Layton, E. M., jun., 12.Lazarus, A. K., 153.Lazo, R. M., 91.Lazo-Wasem, E. A., 314.Leaback, D. H., 252.Leaf, R. L., 268.Leake, P. H., 187.Leavitt, F., 131.LeBail, H., 40.LeBaron, F. N., 181.Lebas, J.-M., 13.Lebedeva, N. V., 336.Lebedeva, S. V., 370.Lebedinskii, V. V., 121.Le Boulch, N., 228.Leclerc, E., 76.Lecomte, J., 7, 12.Leden, I., 124.Lederer, E., €80, 203, 205,Lederer, M., 40,82,376,377.Lednicer, D., 188.Lee, C.C., 144.Lee, E., 258.Lee, T. B., ’246.Lee, T. S., 355.Lee, W. A., 2W.Lee, W. H., 95.Leeming, P. R., 173.Lees, H., 283.Leete, E., 239.Lefebvre, R., 128.Leffler, J. E., 152.Lefkovits, H. C., 128.Lefort, M., 35, 40, 41, 47.Legrand, M.. 13.Lehmann, H.-A., 101.Lehr, J . R., 390.Leitch, L. C., 140.Lemal, D., 110.Lemieux, R. U., 164, 254,Lemin, A. J., 213.Lemon, H. M., 316.Lenhard, R. H., 221, 224,Lenormant, H., 14.Lenskaya. V. I., 376.Leo, A., 146.Leoffler, L. J., 349.Leonard, N. J . , 13, 163,234,208.255, 256.316.412.Leopold, B., 268, 269, 270.Lepoutre, G., 94.Lerner, M.W., 386.LeRoy, D. J., 30, 62.Le Roy, G. V., 307, 309.Lesslie, M. S., 187.Lesslie, T. E., 229.Lester, C. T., 224.Lester, G. R., 132.Lestyan, J., 240.Letham, D. S., 266, 367.Letort, M., 46.Letsinger, R. L., 141, 156.Letters, R., 283.Leung, Y. C., 389, 394.Levenson, T., 138.Lever, F. M., 12Q.Levin, A. P., 299.Levin, R. H., 224.Levine, P., 233.Levitt, B. P., 25, 33.Levit’skii, I. Ya., 72.Levitz, H., 316.Levitz, M., 317.Levy, E. J.. 10.Levy, H. A., 385, 403.Levy, J. B., 27.Levy, L. K., 139.Levy, M., 55.Levy, S., 192.Lewbart, M. L., 330.Lewinsky, H., 107.Lewis, B., 402.Lewis, E. S., 158.Lewis, H. F., 269.Lewis, j., 85, 96, 126.Lewis, J. 1. M., 328.Lewis, P. R., 366.Lewis, T. J., 102.Lewycka, C., 330.Ley, J. B., 155.Ley, K., 148.Li, K.C., 237.Liang, C. Y., 19, 20.Lichter, J. W., 237.Liddel, U., 18.Lide, D. R., 103.Lide, D. R., jun., 378.Liebau, F., 97, 391.Lieber, E., 230.Lieberman, S., 305.Liebhafsky, H. A., 348,Liehr, A. D., 130.Lien, A. P.. 103.Liener, I. E., 303.Lies, T. A., 300.Lightfoot, E. N., 220.Liimatainen, R., 104.Lincoln, F. A., 165.Lind, S. C., 35.Lindberg, B., 258.Lindeman, L., 10.Lindeman, L. P.. 9, 11.Linden, C. E., 224.Lindgren, B. O., 272.378INDEX OF AUTHORS’ NAMES. 437Lindlar, H., 166, 174, 176,Lindquist, R. H., 26.Lindqvist, I., 93, 389, 394.Lindsay, J. K.. 197.Lindsay, W. S., 187.Lindsey, J . M., 414.Lingane, J. J., 333, 369.Lingens, F., 183.Lingren, W. E., 379.Linke, W.F., 120.Linker, A., 320, 326.Linner, E., 177.Linnett, J. W., 8, 108,411.Linstead, R. P., 145, 163,181, 229, 236, 285, 286.Lionetti, F., 322.Lipkin, D., 66, 263.Lipmann, A. E., 202.Lipmann, F., 300, 330.Lippert, E., 18.Lippert, E. L., 87, 389.Lippert, M., 177.Lippincott, E. R., 10, 20,Lippincott, W. T., 160.Lippmaa, E. T., 369, 373.Lippman, A. E., 209, 224.Lipscomb, W. N., 86, 87,89, 389, 393.Lipsky, S., 37.Liquori, A. M., 406, 409.Lisanti, V. F., 322.Lisicki, N. M., 366.Liss, T. A., 166, 200.Lister, B. A., 80.Lister, J. H., 235.Litt, M., 50.Littell, R., 224, 316.Little, E. D., 188.Little, J . S., 249.Littman, F. E., 380.Litvin, K. I., 343.Livingston, R., 47.Livingstone, R., 238.Livingstone, S.E., 122.Llacer, A. J., 341.Llewellyn, D. R., 155.Llewellyn, P. J., 406.Lloyd, A. G., 320, 321.Lloyd, D., 198.Lloyd, G., 237.Lloyd, P. F., 260.Locke, D. M., 227.Locksley, H. D., 204.Loder, 3. W., 144, 107.Uken, B., 223.Lijmker, F., 165.Loew, G., 18.6.Low, I., 227.Lohman, F. H., 98.Loke, K. C., 317.Long, D. A., 15.Long, G., 118.Longone, D. T., 187, 199.176, 178.131.Longuet-Higgins, H. C., 10,Lonsdale, K., 386.Lonsdale, M., 354.Looney, F. S., 26.Lopatina, 2. P., 360.Lord, R. C., 7, 11, 12, 93.Loreasen, R. E., 400.Lornitzo, F., 195.Losev, I. P., 80.Losinger, S., 231.Lossing, P. P., 31, 147.Lothe, J. J . , 367.Lotspeich, F. J., 233.Lott, M. H., 222.Loudon, D. J.. 188.Louw, P. G.J., 214.Love, D. L., 360.Lovell, B. J., 217.Lovell, C. H., 249.Lovett, W. E., 138.Lowe, E. J., 379.Lowe, G., 184.Lowen, J., 375.Lowey, P. H., 353.Lucchesi, P. J., 17.Lucius, G., 203.Luck, C. F., 43.Luckhaus, R., 366.Ludwig, R., 192.Liittringhaus, A., 192.Lukina, M. Yu., 69.Lundberg, R. D., 58.Lundeen, A. J., 182.Lundgren, G., 392, 399.Lundy, R., 64.Lunnon, J. B., 312, 316.Lunts, L. H. C., 219.Lupien, Y., 103.Lure, Yu. Yu., 77.Lutchenko, N. N., 365.Luther, H., 15.Luthy, N. G., 361.Lyalikov, Yu. S.. 360.Lykos, P. G., 128.Lyle, R. E., 161.Lynn, W. S., jun., 311.Lyntaya, M. D., 342.Lynton, H., 392, 411.Lyons, E., 336.Lysenko, Yu. A., 113.McAuliffe, C., 81.McBee, E. T., 199.McBride, W. R., 9%McBryde, W.A. E., 82.McCall, E. B., 293.McCarley, R. E., 344.McCarron, F. H., 170.McCarthy, J . L., 272.McCaulay, D. A., 103.McCauley, D. J.. 73.McClure, D. S., 12, 106.Maccoll, A., 137.McCollum, J. D., 144.McCombie, J. T., 171.108, 132, 159, 192.McConnell. H. M., 128. 384.McConnell, J. D. M., 120.McConnell, W. B., 380.McCorkingdale, N. J,, 242.McCormick, C. G., 43.McCoy, T. C., 340.McCullough, J. D., 407.McCurdy, 0. L., 246.McCutcheon, T. P., 116,McDaniel, D. H., 23.MacDiarmid, A. G., 93,Macdonald, A., 349, 352.McDonald, D. L., 251, 288.Macdonald, D. L., 282.McDonald, L. A., 80.Macdonald, P. J., 79.McDonell, W. R., 40.MacDougall, D., 369.McDowell, C. A., 36, 147.McDowell, W. J., 89.McElcheran, D. E., 31.McElhill, E.A., 137.McElroy, A. D., 86.McElvain, S. M., 204.McEntee, M. E., 174.McEwan, W. S., 231.McEwen, K. L., 132.McEwen, W. E., 85.McFarlin, R. F., 161.McGarvey, F., 70, 76.McGhie, J . F., 181.McGilvery, R. W., 319.McGookin, A., 189, 216.MacGregor, W. S., 278.McGregor, W. S., 270.McHale, A. P., 33.McInteer, B. B.. 393.MacIntyre, I., 374.MacIver, D. S., 60.Mackay, M., 236,414,415.McKean, D. C., 14.McKenna, J., 169, 210.Mackenaie. N., 68.Mackk, J . S,, 72. 75.McKinley, J . D., 33.McKinley, J. D., jun., 20.McKusick, B. C., 161, 246.Mackworth, J . F., 295.McLafferty, j. j., 334.McLean, J., 180.MacLmnan, A. P.. 260.MacLennan, G., 391.McMahon, G. H., 237.McManimie, R. J., 173.McMillan, I. D., 48, 64.MacMillan, J ., 210.McMillan, R. K., 90.McMurry, T. B. H., 206,McNab, A. S., 2l2.McNabb, W. M., 368.McNaughton, G. S., 49.McNesby, J. R., 25, 28, 31.McNeill, I. C., 69.354, 369.101.206438 INDEX OF AUTHORS’ NAMES.MacNevin, W. M., 365.MacNulty, B. J., 365.McOmie, J . F. W., 198,232, 236, 377, 408.McPherson, J., 258.McPherson, J. F., 236.McQuillin, F. J., 206.McWeeny, R., 128.MacWood, G. E., 113.Madden, R. P.. 8, 103.Maddock, A. G., 118.Mader, C., 82, 375.Madera, J., 363.Madorsky, S. L., 59.Madras, G. W., 54.Magat, M., 49.Magee, C., 10, 106.Magee, J . L., 30.Magee, R. J., 377.Magnano, G., 392.Magndi, A., 84, 117, 393.Magnusson, L. B., 119.Magoon, E. F., 231.Magrath, D. I., 262.Mahadevan, A.P., 180.Mahon, B. H., 30, 45.Maier, H., 15.Mair-Waldburg, H., 377.Maitte, P., 184.Majer, H., 48.Major, A., 253.Makarov, S. Z., 86.Maki, M., 378.Maki, N., 359.Makuklia, M. P., 339, 365.MalAt, M., 346.Malatesta, L., 107, 122.Malatesta, M., 107.Malcolm, B. R., 14.Malinek, M., 362.Malinovskii, T. I., 121,Malkin, T., 181.Mallik, A. K., 344.Malm, J . G., 9, 118.Malmstadt, H. V., 370.Malmstrom, B. G., 14.Malmstrom, 1.-L., 269.Malowan, L. S., 345.Malz, H., 101.Mamalis, P., 137.Mamlock, L., 169.Mancera, O., 167, 222, 224.Mandell, L., 217.Mandleberg, C. J., 118.Manecke, G., 375.Mangani, A., 231.Mangin, C., 18.Mangini, A., 224.Mann, C. K., 365.Mann, D. E., 11, 103.Mann, F. G., 192.Mann, G., 370.Mann, M.J., 166, 239.Mann, R. L., 186.Mann, T., 298.397.Mannhardt, H.-J., 179.Manning, D. L., 366, 866.Manning, L. C., 190.Manning, P. P., 131.Manning, W. M., 119.Mansfield, R. C., 231.Manson, A. J., 224.Manson, D., 148, 319, 324.Mantica, E., 57.Marcali, K., 356.March, N. H., 408.Marcus, R. A., 73.Marek, J., 359.Margoshes, M., 13, 19, 374,Mariani, E., 81.Marin-Malumbres, J. L.,Marinsky, J. A., 70.Marion, F., 84.Marion, L., 165, 209, 246,248, 414.Mark, H., 55.Mark, V., 142.Markby, R., 106, 108.Marker, R. E., 226.Markham, A. E., 272.Markham, R., 262, 264.Markley, F. X., 242.Markova, G. S., 20.Markovskii, L. Ya., 394.Marktscheffel, F., 146, 164.Markunas, P. C., 373.Markus, R. A.. 34.Marrian, G.F., 317.Marsden, D. G. H., 31.Marsh, G. E., 263.Marsh, R. R., 297.Marsh, R. E., 411.Marshall, D., 179.Marshall, H. S. B., 24.Marszak, I., 173.Martin, A. E., 7.Martin, A. F., 104.Martin, A. J. P., 181.Martin, D. S., 124.Martin, E. C., 376.Martin, F. S., 120.Martin, G. A., 117.Martin, H., 12.Martin, J. V., 377.Martin, R. H., 13, 134.Martin, R. L., 122, 123.Martinez, J. B., 116.Martinez, S., 396.Maruichi, N., 71.Maruta, S.. 361.Marvel, C. S., 54.Marynowski, C. W., 380.Mason, D. M., 113.Mason, E. A., 16.Mason, J., 12.Mason, R., 406.Mason, S. F., 233, 235.Mason. W. P., 400.Masson, C. R., 2%.379.366.Massonne, J ., 11 1.Massy-Beresford, P. N.,Mastagli, P., 13, 81.Masters, B. J., 40.Materova, E.A.. 78.Mathers. A. P., 374.Mathers, M. P., 357.Matheson, M. S., 39, 46.Matheson, N. K., 259.Mathieson, A. McL., 384,Mathieson, A. R., 266.Mathieu, J.-P., 12, 17.Mathur, K. B. L., 149, 184.Mathys, F., 246.Matic, M., 180.Matlow, S. L., 130.Matoush, W. R., 105.Matrovsova, T. V., 365.Matsen, F. A., 128, 131.Matsuda, M., 50.Matsuda, Y., 82, 375.Matsumura, S., 196.Matsuo, H., 359. 362, 364.Matsuo, S., 365.Matsuo, T., 375.Matsuura, T., 73.Matthews, R. J. S., 54.Matthias, B. T., 398, 402,Mattox, V. R., 317.Mattraw, H. C., 9.Matty, S., 266.Maurodineann, R., 368.Maxon, M., 297.Maxted, E. B., 69.May, S. C., 301.Mayer, R., 196, 199.Mayer, S. W., 389.Mayer, W., 189,190,237.Mayo, F. R., 53.Mazur, A., 295, 303.Mazur, Y., 207.Mazzanti, G., 57.Mazzi, F., 396.Mead, E.J., 87, 90.Meakins, G. D., 212, 217,Meal, H. C., 134.Meal, J. H.. 11.Mean, E. J., 162.Meares, P., 72, 75.Mecarelli, E., 373.Mech, J . F., 119.Mecke, R., 12, 19.Medalia. A. I., 333.Meddings, B., 122.Medvedev, S. S., 52.Medvedeva, A. M., 375.Mee, L. K., 43.Meek, E. G., 258.Meeker, T. R., 87.Megaw, H. D., 16,400,402.Meggers, W. F., 378.Meggy, -4. H., 59.226.407, 414.403, 404.219INDEX OF AUTHORS’ NAMES. 439Meguro, K., 78.Mehlig, J. P., 345.Meier, J., 119, 225.Meier, W. M., 403.Meine, W., 374.Meinwald, J., 144, 156,Meinwald, Y. C., 187, 199.Meisels, A., 207.Meisels, G. G., 36.Meislich, E. K., 299.Meissner, H. P., 100.Meissner, J., 377.Meister, A.G., 11.Meites, L., 359, 360.Melera, A., 213.Meller, F., 394.Mellish, C. E., 411.Mel’nik, G. A., 345.Meloche, V. W., 371.Meluch, W. C., 181, 229.Melville, H., 54.Melville, H. W., 28, 32, 50,Melville, T. H., 322.Menary, J. W., 359.Mendel, H., 414.Menefee, A., 19.Menkes, J. H., 191.Mercer, E. R., 81.Merchant, J. R., 161, 238,Mercier, D., 203, 208.MQiel, P., 393.Merikanto, B., 351.Merrill, S. H., 135.Merritt, L. L., jun., 410.Merz, W. J., 400, 403.Meschino, J. A., 227.Mesrobian, R. B., 39, 43,Mester, L., 253, 254.Metcalf, R. L., 297.Metlesics, W., 148.Metz, C. F., 293.Metz, D. J., 39, 43, 51, 55.Metz, K., 185.Metzinger, L., 51.Meuwsen, A., 99.Meyer, A. S., 317, 366.Meyer, H. J., 398.Meyer, K., 320, 326.Meyer, L., 100.Meyer, R., 355.Meyer, R.J., 366.Meyers, E. A., 389.Meystre, C., 164, 219.Mezhennyi, Ya. F., 99.Michalski, J., 12.Micheel, F., 252, 253.Michel, H. O., 296.Micheli, R. A., 160, 217.Michels, A., 17.Michelson, A. M., 261, 262,Michie, E. A., 314.195, 203.55.246.51, 55.264.Mickley, H. S., 100.Miedreich, W., 14.Miekka, R. G., 11.Mierzecki, R., 12.Migeon, C. J., 313.Mikaya, M., 325.Mikhailov, G. I., 345.Mikheyeva, V. I., 87.Miki, T., 204, 205.Milas, N. A., 179.Mildner, P., 177.Miles, J . W., 368.Milkovich, K., 55.Milks, J . E., 258.Millar, I. T., 192.hlillen, D. J., 17, 95, 99.Miller, A. A., 44, 53.Miller, C. C., 375.Miller, C. D., 379.Miller, C. O., 235.Miller, F.A., 7, 12.Miller, F. F., 54.Miller, J . , 139.Miller, J. G., 93.Miller, J. N. B., 259.Miller, L. A., 163, 234.Miller, L. P., 280.Miller, N., 40.Miller, R., 221.Milligan, B., 204.Milligan, D. E., 9.Millner, T., 116.Mills, J. S., 211.Milner, D. C., 15.Milner, G. W. C., 350, 358,Milner, I., 82, 375.Milner, 0. I., 365.Milstrey, R., 236.Minckler, L. S., 201.Minczewski, J ., 371.Mirone, P., 18.Misaki, T., 363, 366.Mishima, H., 241.Mislow, K., 153, 181, 229.Misumi, S., 360.Mitchell, L. C., 378.Mitoma, C., 286.Mitra, G. N., 335.Mitteldorf, R., 216.Miyahara, K., 68.Miyai, M., 196.Miyasaka, R., 131.Miyama, H., 47, 48, 51.Miyazawa, T., 11, 13.Mizushima, S., 10, 11, 13.Mizutani, Y., 47, 55.Mlinko, A., 190.Moacanin, J., 272.Rlochizuki, H., 363, 366.MbczBr, E., 253, 254.Modest, E.J., 233.Mogling, H., 99.Moeller, T., 364.Moffitt, W., 127.Moffitt, W. E., 128.360.Mole, T., 132, 133, 159,Molinari, E., 32, 67.Moll, H., 212.Molot, L. A,, 336, 339.Molyneux, P., 55.Momigny, J., 36.Monaci, A., 56.Monahan, R., 185.Mondon, A., 246.Mondy, L., 366.Monnot, G. A., 20.Monod, J., 281.Monod-Herzen, G., 368.Montavon, M., 166, 174,175, 176, 178.Montegudet, G., 80.Montgomery, R., 257, 259,Mooberry, D. D., 170,Moody, D. P., 208.Mooi, J., 355.Mooney, R. C. L., 391.Moore, B., 144, 167.Moore, B. P., 209.Moore, C. E., 334.Moore, D., 40.Moore, E. B., 89, 389.Moore, J . A., 227.Moore, L. E., 62.Moore, M., 227.Moosath, S.S., 112.Morawetz, H., 43, 48, 51,Morawietz, W., 125.Moreland, W. T., 135.Morero, D., 57.Morgan, H. W., 11, 381.Morgan, J. W. W., 255.Mori, A., 338.Mori, M., 82.Mori, N., 14.Mori, Y., 128, 376.Morice, I. M., 180.Moriconi, E. J., 188.Morikawa, H., 363, 374.Morino, Y., 11.Morozov, V. A., 365.Morozov, V. P., 9.Morozova, Yu. A., 75.Morris, C. J., 182.Moms, C. J. 0. R., 361.Morrison, A. L., 297, 298.Morrison, A. R.. 322.Morrison, D. E., 166, 239.Morrison, G. A., 193.Morrison, S. R., 60.Morrisson, M. H., 224.Morrow, J . C., 23.Morse, J. G., 136.blortensen, E. M., 136.Morthland, F. W., 59.Morton, A. A., 143.Morton, M., 54.Morton, R. A., 178.191.320.183.55440 INDEX OF AUTHORS’ NAMES.MMMMMMMMMMMMMMMMMMMMMMMMMMMMoser, C.M., 128.osettig, E., 209, 226.osher, H. S., 380.oskowitz, D., 112.oss, J. H., 99.oss, P., 293.oss, R. L., 69.ostyn. K. M. C., 206.otojima, K., 344.otorina, N. N., 76.ouEka, M., 346.oulton, C. W., 93.ounter, L. A., 303,304.ousseron, M., 201.ovchan, N. T., 359.oyer, H. V., 343.oyle, M., 171.iihlrod, E., 370.uller, A., 37, 242.ueller, C. R., 131.iiller, E., 92, 142, 148.ueller, G. C., 375.iiller, H., 169, 173.U e r , J., 51.uller, K.-H., 394.uir, B. L., 224.ukherjee, A. K., 364.ukherii. S. M.. 204.MulcahG,- M. F.-R., 148.Mulford, R. N. R., 112,Mulhaupt, J. T., 9, 99.Mulholland, T. P. C., 210.Muller. N., 130.Muller, Y.M. F., 242.Mulliken, R. S., 130, 132.Mund, W., 37.Mundy, R. J., 366.Munemori, M., 363.Munk-Weinert, M., 181.Mura, S. I., 241.Muraca, R. F., 337.Murakami, H., 18.Muraki, I., 371.Murata, A., 378.Murata, H., 11.Murmann, R. K., 105.Murphy, W. A., 136.Murray, A. W., 310.Murray, J . , 190.Murray, M. F., 222.Murrell, J. N., 132.Murtazinova, G. F., 362.Murthy, T. K. S.. 366.Musha, S., 346, 363.Mushinskaya, S. Kh., 76.Musina, T. K., 361.MUSSO, H., 19.Mustafin, I. S., 333.Mutaguchi, M., 373.Muto, S., 377.Muxfeldt, H., 234.Myasnikov, I. A., 37.Myers, D. K., 295. 298.Myers, G. E., 72, 73.Myrback, K., 318.118, 393.Nachmansohn, D., 296,Nachod, F. C., 70, 378,379.NAdler, 2.. 345.Nagai, H., 376, 378.Nagao, H., 59.Nagarajan, K., 238, 242.Nagata, C., 50.Nagazaki, M., 162.Nagy, Z ., 367, 377.Naik, A. R., 218.Naito, S., 207.Naito, T., 377.Nakagawa, I., 10.Nakagawa, Y., 247.Nakahara, A., 121.Nakahara, K., 230.Nakajima, M., 179.Nakajima, N., 199.Nakakura, S., 19.Nakamoto, K., 16, 396.Nakamoto, N., 19.Nakamura, M., 412.Nakamura, N., 368.Nakanishi, K., 14, 321.Nakano, K., 368.Nakatsu, K., 397.Nakazawa, H., 79.Naldini. L., 119.Nall, W. R., 339.Nandi, U. S., 51.Napier, D. R., 187.Nara, A., 357.Nara, K., 159.Narasimhan, A., 1 1.Narasimhan, N. S., 242.Narath, A., 98.Narayan, V. A., 377.Nardelli, M., 391.Narita. K., 365.Nast, R., 106, 107.Nath, B., 180.Nathansohn. G., 220.Natta. G., 57, 69.Named, K., 85.Naves, Y.-R., 7, 201.Nayler, P., 175, 179.Naylor, B. F..402.Nazarenko, V. A., 336.Nazarov, I. N., 210.Neapolitano, J. P., 143.NCel, L., 393.Neher, K., 311, 312.Neill, K. G., 193.Neilson, A. H., 262.Neipp, L., 185.Neish, A. C., 276, 276.Nelson, F., 77, 78, 81, 82.Nelson, J. A., 197.Nelson, K. L., 133.Nelson, L. S.. 45.Nelson, R. A., 374.Nenitzescu, C. D.. 57.Neptune, W. E., 358.Nervik, W. E., 76, 81, 375.Nes, W. R., 209.298.Nesbet, R. K., 128.Nesmeyanov, A. N.. 113,141, 168.Ness, R. K., 264.Neu. J. T., 20.Neuberg, C., 318, 320, 324,325, 327.Neugebauer, J., 116.Neuman, W. F., 77.Neumann, R., 369.Neunhoeffer, O., 293.Neurath, H., 299,301,302.Neven, L., 8.Newcombe, A. G.. 182.Newcomer, J.S.. 199.Newhall, W. F., 169.Newman, A. S., 292.Newman, C., 11.Newman, F. C., 185.Newman, M. S., 135, 162.Newnham, R., 401.Newnham, R. E., 391.Newth, F. H., 254, 255.Newton, E. B., 57.Newton-Hem, P. A., 267.Nezu, H., 369.Nicholas, L., 157, 185.Nicholson, B. J., 401.Nicholson, D. E., 68.Nicholson, I., 232.Nicholson, M. M., 358.Nicholson, W. H., 258.Niclause, M., 46.Nieciecki, L., 74.Niedenzu, K., 97, 98.Nielsch, W., 363, 364, 366.Nielsen, J. P., 82.Nielsen, J. R.. 11.Niemann, K. E., 111.Niemic, J., 398.Nietzel, 0. A., 367.Nigam, S. S., 180.Niggli, A., 394.Nightingale, R. E., 33.Nikelly, J. G., 361.Nikitin, E. E., 26.Nikitin, V. A., 63.Nikitina, T. S., 39.NikoliC, K., 369.Nisel’son, L.A., 97.Nisizawa, K.. 321.Nitta, I., 389, 413.Nixon, E. R., 10.Nobel, D., 73, 78.Nobis, J. F., 117.Noble, C. M., 372, 373.Noth, H., 87.Nolin, B., 12.Nolte, E., 200.Nomitsu. T., 74.Nord, A. A., 90.Nord, F. F., 268.Norman, I., 149.Norman, J. M.. 408.Norman, R. 0. C., 190.168, 188Normant, H., 184.Norrish, R. G. W., 46, 65.Norymberski, J., 222.Novk, V., 371.Novak, A., 91.Novak, I. I., 20.Novak, I. J., 15.Novgk, J. V. A., 358.Novikova, E. N., 361.Novoselova, A. V., 85.Novotng, B., 361.Novotny, J., 372.Novotn9, L., 207.Novozhenyuk, 2. M., 121.Nowacki, W., 247, 411.Noyce, D. S., 202, 217.Noyes, W. A., 45, 169.Nozaki, T., 364, 365.Nozoe, S., 196.Nozoe, T., 192, 196.Nudenberg, W., 160.Numanoi, H., 327.Nunn, J.R., 259.Nutman, P. S., 292.Nyholm, R. S., 120, 122,124, 137, 397.Ochoa. S., 203.Ockenden, H. M., 118, 394.O’Cleirigh, S., 837.O’Colla, P. S., 258.O’Connor, R. T., 13, 379.O’Connor, W. F., 188.Oda, T., 412.Oda, Y., 290.Oda, Z., 64.O’Donnell, T. A., 117.O’Donnell, V. J., 306, 316.O’Driscoll, K. F., 52.O’Farrell, B. R., 237.Ogarkova, N, F., 335.Ogg, R. A., 87, 95.Ogston, A. G., 287.Ohara, E., 378.Ohloff, G., 204.Ohta, M., 230.Oi, N., 364.Oka, Y., 365.OkAE, A., 340.Okada, Y., 52.Okamoto, H., 44.Okamura, H., 876.Okamura, S., 50, 51, 56.Okaya, Y.. 412.Okinaka, Y., 367.Okita, G. T., 309.Okuda, M., 128.Okuda, S., 241.Okumura, F. S., 236.OlAh, G., 88, 190.Oliveto, E. P., 170, 183,Olleman, E.D., 272.Olley, J., 181.O’Loane, J. K., 11.Ol’shanova, K. M., 377.223.INDEX OF AUTHORS’ NAMEOlson, B., 342.Olson, E. C., 362.Olszewski, S., 131.O’Neill, J. J., 301.Onishi, H., 364.Onishi, S., 159.Onodera., K., 252.Onshuus, I., 234.Onstott, E. I., 111.Onyon, P. F., 48, 50.Ooshika, Y., 131.Oosterbaan, R. A., 301.Opp, K., 394.Oranskaya, M. A., 123.Orekhov, V. D., 40, 41, 42.Orgel, L. E., 105, 107, 108,109, 128, 132, 137, 159,192.Orkin, B. A., 285.Orlemann, E. F., 122.Oroshnik, W., 172.O’Kourke, C. E., 228.Orr, J., 214.Orr, S. F. D., 16, 148.Ortegui, B., 365.Orth, A., 60.Ortiz, P. J., 263.Orville-Thomas, W. J ., 11.Osaki, K., 389, 413.Osborn, A. R., 234.Osborn, G. H., 70.Osdene, T. S., 235.Osgan, M., 5’7.Oshchapovskii, V.V., 376.Oshida, I., 131.Osipov, 0. A., 113.Osipova, V. F., 375.Oster, G., 47, 55.Oster, R., 185.Oswalt, R. L., 82.Ota, K., 363.Ota, T., 50, 62.Otero, C., 9.Otsu, T., 60, 52.Ott, A. C., 222.Ott, D. G., 229.Ottawa, N., 240.Ottmann, G., 194.Otvos, J. W., 26.Oubridge, J. V., 99.Ourisson, G., 211, 214.Overberger, C. G., 48, 51,Overend, J., 8.Overend, W. G., 252.Overton, K. H., 214.Ovsepyan, E. N., 353.Owen, B. D. R., 76, 78.Owen, J., 106, 403.Owen, L. N., 184, 189.Owens, K. E., 47.Owens, 0. O., 300.Owston. P. G., 121, 397.Oyum, P., 390.Oza, R. J., 73.Oza, T. M., 94.56.441Oza, V. T., 94.Ozerov, R. P., 115.Pace, E. L., 60, 81.Packhurst, R. M., 360.Packman, G., 360.Pacquot, C., 147.Paech, K., 267.Page, J.E., 14, 217.Pahls, K., 197.Pai. B. R., 238.Pailer, M., 189.Pain, R. H., 42, 267.Painter, T. J., 258.Pake, G. E., 134.Pakrashi, S. C., 239, 246.Palik, E. D., 8.Palit, S. R., 51, 64.Pallaud, R., 80, 81.Palmer, A., 218.Palmer, F. S., 190.Palmer, L. C., 48.Pan, K., 370.Panattoni, M., 317.Panova, G. D., 361.Pantlitschko, M., 322.Pantony, D. A., 377.Paoloni, L., 129.Pappo, R., 164.Parham, W. E., 232.Parihar, D. B., 205.Pariser, R., 47, 127, 128.Parish, R. V., 120.Parke, A. V. M., 158.Parke, D. V., 280.Parker, C. A., 44, 149.Parker, C. O., 184.Parker, L. F. J., 378.Parker, R. E., 361.Parks, T. D., 355.Parr, R. G., 127, 128.Parr, W. H., 287.Parravano, G., 60, 65.Parrish, J.R., 79.Panish, M. B., 104.Parry, G. S., 394.Parry, R. W., 87.Parsons, J., 379.Parsons, J. L., 59.Parsons, J. S., 369.Parsons, M. A., 262.Parts, L., 8.Pascale, D. A., 25.Pascard, R. 390.Pasky. J. Z., 187.Passerini, R. C., 99, 231.Passynsky, A. G., 42.Pasternak, R. A., 406, 416.Patel, C. C., 364.Patel, D. K., 219, 222, 224,Patel, M. D., ego.Patelli, B., 224.Patoharju, O., 234.Patrick, J. B., 186.Patrovsky,V., 351,364,367.228442 INDEX OF AIJTHORS, NAMES.Patterson, E. L., 236, 236.Patton, J.. 347.Pats, R. G., 359, 360.Paul, D. E., 56.Paul, R., 229.Pauling, L., 385.I’ausacker, K. H., 146.Pauson, P. L., 109, 397.Pavan, M., 204.PavlAth, A., 88.Pavlov, D., 361.Pavlovic, A., 401.Pavone, D., 393.Pawlik, I., 375.Payne, D. S., 96, 97.Payza, A.N., 318.Peach, S. M., 336.Peacock, R. D., 120.Peacocke, A. R., 263, 265,Pearl, I., 267, 269.Pearlman, W. H., 314.Pearson, 0. H., 316.Pearson, R. G., 105.Pearson, R. W., 44.Pease, R. S., 387.Peat, S., 256, 259.Pecsok, R. L., 360.Pedersen, C., 235.Pedersen, D. R., 198.Pederson, R. L., 222.Pedler, A. E., 24.Peerdeman, A. F., 239, 384.Pelc, B., 220.Pelczar, M. J., 325.Pelikan, J., 346.Pel’kis, P. S., 334.Pelletier, G. E., 256.Pelletier, S., 125.Pelletier, S. W., 227, 248,Pellon, J. J., 48.Peltier, J., 129.Pemsler, J. P., 9.Penfold, A., 128.Penfold, A. R., 196.Penfold, B. R., 407.Peniston, Q. P., 272.Penkova, L. I., 376.Penneman, R.A., 10, 124.Pennington, D., 267.Pennington, D. E., 272.Penot, D., 17.Pentland, R. B., 10.Pepinsky, R., 400, 401,403, 404, 408, 411.Pepler. W. J.. 325.Pepper, J. M., 269, 270.Peraldo, M., 67.Percival, E. G. V., 267.Peremyslova, E. S., 77.Periam, J. D., 191.Perila, O., 181.Perkins, P. E., 94.Perlin, A. S., 251, 256.266, 267.249.Peshkova, V. M., 362.Petch, H. E., 16.Petek, F., 349.Peters, D., 146.Peters, T. V., 82, 375.Petersen, D. R., 406.Petersen, J. C., 254.Petersen, H. I., 292.Peterson, S. W., 385, 403.Petit, J., 80.Peto, A. G., 184.Petracek, F. J., 177.Petropolous, C. C., 152.Petrova, E. I., 351.Petrova, L. N., 361.Petrow, V., 219, 222, 224,l’etry, R. C., 38.Petter, W., 403.Pettit, R., 193, 194.Petzold, A., 352.Peuschel, G., 123.Pew, J .C., 268, 269, 270,Pfab, B., 374.Pfeiffenschneider, K., 94.Pfeiffer, H. G., 348.Pfeil, E., 155.Philbin, E. M., 237, 238.Phillips, D. C., 388, 410.Phillips, D. D., 188, 200,Phillips, G. H., 162.Phillips, H. O., 80.Phillips, J. B., 369.Phillips, J. N., 232.Phillips, P. C., 212.Phillips, T. R., 62.Phokas, G.. 241.T’hotaki. I., 169.Piaux, L., 12.Piazolo, G., 269, 272.Pickard, P. L., 358.Pickett, L. C., 130.Pickett, 0. A., jun., 53.Pickworth, J., 236, 416.Piera, J. M., 374.Pierce, L., 8.F’ierotti, R. A., 355.Pierpoint, W. S., 262.Pierson, R. H., 7, 379.Pietsch, R., 341.Pietzka, G.. 115.Piffko, H., 196.Pignataro, E., 412.Piirma, I., 54.Pikayeva, V.L., 33, 361.Pike, R. A., 169.T’ilte, R. M., 54.Pill, -4. L., 343.Pillai, K. S. M., 213.Pimentel, G. C., 9, 19, 20.Pinchas, S., 379.Pinckard, J. H., 177.f’incus, G., 306. 307, 319,228.274.212.Peron, F. G., 306. 313.Pincus, R., 325.Pinder, A. R., 174, 240.Pinder, J. A., 30.Pines, H., 142.Pink, R. C., 405.Pino, P., 57.Pinsker, 2. G., 394, 396.I’inson, R., jun., 220.Piper, T. S., 109, 110.Pirenne, J ., 400.l’irie, N. W., 262.Pirrenne, J., 19.Pitman, D. T., 410.Pitzer, K. S., 22, 134, 385.Plack, P. A., 178.Plager, J. E., 313.Plaget, W. G., jun., 9.Plantin, L. 0.. 306.Plapinger, P., 301.Plass, R., 90, 395.Platonova, T. F., 241, 242.Platt, J. R., 132.Plattner, P. A.. 218.Platzer, R., 367.PleSek, J., 184.Pleva, M., 359.I’lieninger, H., 229.Plieth, K., 396.Pliskin, W.A., 63.l’liva, J., 207.Ploger, F., 115.Plotz, E. J., 314.Plumb, R. C., 394.Plyler, E. K., 8, 11, 20.Pocker, Y., 155.Podall, H., 89.Pode, J. S., 146.Phgrund, R. S., 324.Pohl, F. A., 367.Pohl, H., 363.Poirier, P., 13.Polanyi, J . C., 28.Polgar, N., 179.Polglase, W. J., 258.Polissar, J., 385.Pollard, F. H., 24, 37’7.Pollock, J. B., 366.Pollock, M. R., 281.Polo, S. R., 11, 17.Polonsky, J., 180, 203.Polster, R., 170, 183.Polton, D. J., 181.Pommer, H., 174.Pon, G., 260.Ponder, B. W., 150.Pondy, P. R., 10.Ponomarev, A. I., 367.Ponsold, K., 190.Poos, G. I., 224.Poos, L., 360.Pope. G., 236.Popel’, A. A., 361.Popiel, W. J.. 77.PopjAk, G., 307, 308.Pople, J.A., 128, 131,1.1IN im s OF A u TH o K s NAMES. 413Popov, A. I., 96.Popov, M. A., 343.Popov, N. I., 38.Poppe, E. J., 196.Popplewell, D. S., 122.pom, L.. 57.Porro, T. J., 379.Port, w. s., 54.Porte, A. L., 405, 410.Porter, C. R., 155.Porter, G., 149.Porter, G. B., 45, 159.Porterfield, W. W., 369.Posey, F. A., 121.Posner, H. S., 286.Post, B., 112, 378, 402, 411,Posthumus, T. A. P., 164,Potter, J. L., 264.Potter, R. M., 10, 393.Potter, V. R., 287.Potts, W. J., 380.Potts, W. J., jun., 379.Ponlet, H., 16.Poutasse, E., 313.Powell, A. R., 120.Powell, D. B., 10, 107, 258.Powell, H. M., 90.Powell, J. E., 81, 111.Powell, R. E., 22.Powers, D. H., 153.Pozdnyakova, A. A., 360.Prakash, S., 46.Prange, I., 311.Prater, C.D., 66.Pratt, J. W., 266.Pratt, R. J., 224.Pravednikov, A. N., 60.Preisler, E., 364.Prelog, V., 145, 161, 186,Prentice, N., 250.Prescott, J. F., 252.Previc, E. P., 229.Prevot-Bernas, A., 38, 42,Pfibil, R., 356.Price, C. C., 67.Price, J. R., 167, 184, 239.Price, S. J. W., 24.Prichard, W. W., 187.Primas, H.. 16.Pring, J. N., 367.Prins, H. J., 199.Pristera, F., 379, 380.Pritchard, G. 0.. 28.Pritchard, H. O., 21, 22,Privilova, K. P., 369.Pro, M. J., 357, 374.Proctor, B. E., 36.Prokof’eva. I. V., 349.Proper, R., 300.Prophet, H., 90.l’rosen, R. J., 124.412.219.186, 201, 202, 246.49.25, 28, 129.Proskurnin, M. A., 40, 41,Proskurnina, N. F., 242.Prosser, T. J., 154.ProStenik, M., 181, 182.Proszt, J., 360.Protzer, W., 253.Pruett, R.D., 103, 104.Prunty, F. T. G., 306.Pruss, M. P., 229.Prydz, H., 84.Przheval’skii, E. S., 335.Przybylowicz, E. P., 369.Przybylska, M., 209, 248,Pshenitsyn, N. K., 349,Pshezhetsky, S. Y., 37.Pucheault, J., 35, 41.Puckett, J. E., 367.Pullman, A., 128.Pullman, B., 128, 129.Pulpan, R., 370.Pungor, E., 345, 374.Pupko, L. S., 334.Purdy, W. C., 371.Purves, C. B., 255, 258,Puschel, R., 351.Pyle, G. L., 119.Quackenbush, F. W., 177.Quagliano, J. V., 10.Quarck, U. C., 185.Quarg, M., 196.Quarterman, L. A., 228.Quastel, J . H., 283, 292.Queiser, J. A., 20, 380.Quimby, 0. T., 98.Quintin, M., 125.Raabe, B., 93.Rabideau, S. W., 118.Rabindran, K., 207.Rabinovitch, B.S., 26, 68.Rabinowitz, J. L., 309,316.Rabourn, W. J., 177.Rachin’skii, V. V., 75.Radakrishnamurti, C., 352.RBdy, G., 351.Rae, H. K., 118.Raeuchle, R. F., 399.Rafailoff, R., 368.Raff, R. A. V., 57.Raijola, E., 90.Raistrick, H., 193.Raitt, J . S., 79.Rajadurai, S., 242.Rajan, I<. S., 82, 375.Rajappa, S., 242.RBkosi, M., 238.Ramachandran, L. K., 380.Raman, K., 209.Ramirez, F., 192, 226.Ramirez-Muiioz, J., 373.Ramler, W. J., 35.42.414.371.267, 273.Ramsay, D. A., 45, 46.Ramsey, W. J., 398.Rand, L., 184, 195.Randles. J. E. B., 338.Ranganathan, S., 233.Rank, B., 147.Rao, B. C. S., 143, 162.Rao, B. G., 306.Rao, B. R. L., 364.Rao, G. G., 349, 353, 353.Rao, K. B., 363.Rao, K.N., 8.Rao, M. R. A., 97, 112.Rao, U. V., 349.Rao. V. N., 349.Rao, V. P., 352.Raoul, Y., 228.Rapala, R. T., 222.Raper, H. S., 284.Raper, R., 240.Raphael, R. A., 171, 192,Rapoport, H., 187, 242,Rapport, M. M., 320.Ray, J. D., 87.Ray, J. R., 95.Rasin-Streden, R., 366.RaspC, G., 177.Rastadter, K., 183.Rastrup-Andersen, J ., 129.Rathje, A. O., 373.Ratina, L. L., 367.Rausser, R., 223.Read, D. E., 267.Recordati, M., 177.Redman, M. J., 80.Reed, D. H., 193.Reed, H. W. B., 157.Reed, L. J., 229.Reed, R. I., 203.Reeder, W., 347.Rees, H. L., 379.Rees, W. T., 149.Reeves, C. M., 22.Regan, B. M., 225.Reggianini, O., 325.Rehak, B., 362.Reich, F., 374.Reich, H., 223.Reichenberg, D., 73. 74, 76.Reichstein, C., 227.Reid, J.J., 292.Reiff, H. E., 152.Reigert, A. L., 36.Reilley, C. N., 116, 362,Reiner, E., 7 1.Reinhart, M. A., 57.Reinhart, R. C., 371.Reisman, A., 115.Reist, H. N., 249.Reitz, H. C., 286.Relyea, D. I., 149.Rembaum, A., 56.Hemeika, J. P., 403, 404.200.249.369444 INDEX OF AUTHORS’ NAMES.Remers, W. A., 194, 200.Rempe, G., 100.Remschneider, R., 197.Renier, J. J., 124.Renk, E., 135.Renson, M., 92.Restaino, A. J., 39, 43, 61,Reusser, P., 185.Reuter, A., 14.Reuter, G., 183.Reyerson, L. H., 60.Reyle, K., 227.Reynolds, G. F., 359, 360.Reynolds, L. T., 110.Reynolds, T. M., 76.RezA,C, Z., 363, 369.Rhem, C. R., 372.Ricciuti, C., 181.Rice, F. A. H., 170, 250,251, 252, 258.Rice, R.G., 145.Rice, S. A., 72.Rich, A., 109, 263.Richards, E. G., 267.Richards, H. C., 160, 219.Richards, J. H., 212.Richards, N. E., 125.Richards, R. E., 88, 383.Richardson, J. H., 197.Richardson, J. W., 16, 396.Richman, D., 36, 74.Richter, J. W., 186.Richtmyer, N. K., 266.Richtzenhain, H., 270.Rider, P. R., 61.Ridgley. D., 84.Riding, F., 32.Riedl, W., 189, 216.Riehl, L., 100.Rieman, W., 82, 356, 376.Rienacker, G., 63, 66, 67.Rigby, W., 165, 208.Ringe, J. P., 169, 250.Ringold, H. J., 164, 219,Riniker, B., 185, 202.Riniker, R., 202.Rinn, H. W., 115, 395.Riogh, S. P. M., 237.Riolo, C. B., 354.Rios, T., 213.Rist, C. E., 268.Rist, H., 192.Ritchie, C. F., 210.Ritchie, E., 242.Ritchie, P. F., 267.Rittenhouse, K.D., 66.Ritter, D. M., 267, 272.Rivoir, L., 396.Roadhouse, F. E., 269.Robb, J. C., 28, 32.Robbins, P. W., 330.Robert, G.. 225.Robert, N., 173.Roberts, C. W., 199.55.223, 224.Roberts, G., 12.Roberts, H. L., 9, 90, 121,394.Roberts, J. D., 130, 136,137, 144, 159, 180, 192,198.Roberts, J. G., 256.Roberts, L. R., 389.Roberts, S., 305.Robertson, A., 209, 216,Robertson, D. M., 361.Robertson, E. R., 50.Robertson, J. H., 387.Robertson, J. M., 389, 405,406, 407, 408, 409, 410,412, 415.Robins, P. A., 212.Robinson, C. H., 213.Robinson, D., 319.Robinson, D. W., 11, 93.Robinson, F. M., 159, 236.Robinson, G. M., 136.Robinson, J. W., 351, 374.Robinson, P. L., 95, 102,Robinson, R., 136.Robinson, R. E., 139.Robinson, S.A., 223.Rockett, J., 181.Rocklin, S. R., 35.Rodig, O., 219.Rodin, J. O., 186, 237.Roeder, A., 125.Rosch, G., 236.Rogers, D., 202, 205, 384,Rogers, G. T., 45.Rogers, J. L., 125.Rogers, L. B., 369, 371.Rogers, M. A. T., 147.Rogers, M. T., 103, 104.Rogers, W., 361.Rogoff, M., 292.Rohmer, M., 106.Rohrer, K. L., 364.Rohrmann, E., 226.Rolfe, J. A., 10, 96.Rollefson, G. K., 25.Rollett, J. S., 406, 407, 416.Romanoff, E., 307.Romanoff, E. B., 312, 313.Romahk, M., 207.Rommell, 0.. 10.Remming, C., 104, 414.Romo, J., 225.Romo de Vivar, A., 226.Rondestvedt, C. S., 149.Roof, B. S., 287.Roof, R. B., 396, 397.Roothaan, C. C. J., 127.Rose, F. A., 319, 321.Rose, F. L., 233.Rose, J. B., 58, 228.Rosemberg, E..311.Rosen, C., 402.238.104, 122.416.Rosenbaum, D. M., 119.Rosenbaum, E. J., 378.Rosenberg, A., 14.Rosenberg, A. F., 10.Rosenberg, A. J., 60.Rosenberg, B. H., 260.Rosenberg, N. W., 70.Rosenfeld, G., 311.Rosenfeld, R. S., 307,311.Rosengren, K., 117.Rosenkilde, H., 306.Rosenkrantz, H., 217, 380.Rosenkranz, G., 164, 167,219, 222, 223, 224.Rosenthal, D., 174, 207.Rosenthaler, L., 350, 366.Rosenwald, R. H., 154.Rosie, D. J., 358.Rosoff, M., 266.Ross, J. M., 213.Ross, J. W., 370.Ross, W. A., 181.Rosser, W. A., 26,Rossmann, K., 8.Rossmann, M. G., 409.Rossmy, G., 19.Rossotti, F. J. C., 114.Rossotti, H., 105, 114.Rotenburg, D. L., 38.Roth, W. L., 392. *Rothaupt, R. K., 183.Rothberg, S., 286.Rothe, C.F., 374.Rothenberg, M. A., 298.Rothman, E. S., 224.Rothmund, V., 71.ROUSSOS, G. G., 234.Rowe, I., 411.Rowe, R. A., 94.Rowland, B. I., 153.Rowland, R. L., 179.Rowlands, J. R., 128.Roy, A. B., 318, 319, 320,321, 322, 328, 330.Roy, A. C., 227.Roy, M., 72.Roy, N., 374.Roychaudhuri, D. K., 163.Royen, P., 60.Ruben, H., 388.Rubin, L. J., 220.Rubin, 0.. 326.Rubinshtein, A. M., 66.Rubisch. O., 91.Rudner, B., 232.Rudnev, N. A., 338.Riickert, A., 145.Riickert, H., 76.Ruedenberg, K., 131.Riidorff, W., 91, 125.Riiegg, R., 166, 174, 175,Rukhadze, E. G., 343.Rulfs, C. L., 363, 368.Rummert, G., 174.Rotzoll, R.-H., 200.176, 178Runck, R. J., 119.Rundel, W., 142.Rundle, R. E., 16, 19, 105,Runner, M.E., 102.Runnstrom, J., 327.Rurarz, E., 12.Russell, G. A., 51, 53.Russell, R. A., 14, 16.Russell, V. A., 87.Ruths, K., 60.Rutland, J. P., 299.Rutrnan, V. M., 340.RuiiEka, E., 340.Ruzicka, L., 202, 208, 213,Ryabov, A. V., 361.Ryan, J., 77. 114.Ryazanov, I. P., 334, 363.Rybachikov, D. I., 375.Rydon, H. N., 137, 301.Ryser, G., 176.h r , W. S., 203.Saba, N., 306, 307,311, 312.Sabatka, J. A,, 66.Sabbioni, F., 51.Sabo, E. F., 221, 222, 224,Sabol, W. W., 9.Sato, A., 81.Sacco, A., 119.Sadek, E. H., 100.Sadek, F., 82, 341, 351,Sadovskaya, G. K., 20.Saeki, S., 241.Saffran, J. C., 306.Sager, W. F., 146.Saha, N. G., 61.Saha, N. N., 210.Saito, Y., 397.Saj6, I., 347, 350.Sakai, K., 367.Sakamoto, T., 376, 377.Sakashita, K., 12, 20.Sakharov, M.M.. 68.Salamon, M.. 370.Salaria, G. B. S., 337, 338.Saldadze, K. M., 76.Saldick, J., 52.Salee, E. M., 380.Salg6, I?., 853, 354.Sallo, J. S., 160.Salmon, J. E., 77, 81.Salvetti, 0.. 10.Sampson, R. J., 133.Samuel, I., 130.Samuel, T., 76.Samuels, B. K., 223.Samuels, L. T., 313.Samuelson, O., 70, 76, 81,Sanborn, R. H., 122.Sandberg, A. A., 317.Sandell, E. B., 364.395, 396.309.315.375.376.INDEX OF AUTHORS’ NAMESander, H., 240.Sanderson, B. S., 113.Sandi, E., 348.Sandorfy, G., 130.Sandri, J. M., 142, 198.Sandstrom, W. M., 273.Sankar-Das, M., 365.Sant. B. R., 348.Santhappa, M., 51, 52.Sanyal, A. K., 255.Saperstein, L. A., 374.Saraeva, V. V., 38.Sara€, J.R., 10.Sarayeva, N. F., 371.Sarda, L., 304.Sargeant, K., 166, 246.Sarkanen, K., 267, 272,Sarma, B., 366.Sarma, L. S., 351.Sarma, R. N. S., 344.Sarmousakis, J. N., 64.Sarro, S. D., 316.Sarudi, I., 344.Sas, F.-E., R., 352.Sasada, Y., 413.Sastri, M. N., 351, 352,353.SasvBri, K., 116.Sato, S., 22.Sato, T., 330.Sato, Y., 19,226,241.Satterfield, C. N., 392.Saucy, G., 176, 178.Sauer, J. C., 167.Sauer, K., 30, 152.Saulnier, J., 82, 375.Saumagne, P., 18.Sauve, D. M., 139.Savage, A. W., 117.Savard, H., 328.Savard, K., 307, 313, 316.Savige, W. E., 209.Saville, B., 301, 357.Savur, G. R., 259.Sawaguchi, E., 402.Saxton, J. E., 239.Scaffone, E., 377.Scanlan, J., 32, 127.SCavniEar, S., 392, 395.Schachman, H.K., 267.Schade, G., 204.Schafer, H., 366.Schafer, K., 61.Schafer, O., 230.Schaefer, W. C., 258.Schaeffer, G. W., 86, 87.Schaeffer, W. D., 160.Schaeppi, W. H., 193.Schaffer, N. K., 296, 301,Schaffner, K., 212.Schairer, J. F., 86.Schalkwyk, T. G. D., 412.Schall, E. D., 367.Schawhw, A. L., 381, 388.Schecliter, M. S., 239.273.302.445Scheer, I., 226.Scheer, M. D., 21, 32.Scheiber, D. H., 173.Scheibler, U., 94.Schellenberger, H., 146.Schenk, G. O., 195.Schenk, J., 388.Scherp, H. D., 323.Scherp, H. W., 325.Schier, 0.. 378.Schiff, S., 372.Schiff, H. I., 28.Schiffries, W. P., 41.Schildknecht, C. E., 57.Schilt, A. A., 334, 336.Schindler, O., 227.Schinz, H., 178, 179, 203.Schinzel, E., 148.Schissler, D.O., 34, 36.Schlatter, M. J., 50.Schlein, H. N., 181.Schlenk, H., 181.Schleppinghoff, B., 253.Schlesinger, H., 177.Schlittler, E., 244.Schluter, H.. 278.Schmeisser, M., 92.Schmid, E., 12.Schmid, H., 157, 245.Schmid, K., 157.Schmid, R. W., 116, 130,Schmidhuber, W., 148.Schmidle, C. J., 231.Schmidt, C. H., 229.Schmidt, G., 327.Schmidt, G. M., J., 409.Schmidt, H., 239.Schmidt, J., 191.Schmidt, K. R., 76.Schmidt, N. 0.. 362.Schmidt, O., 23.Schmidt, 0. T., 190, 237.Schmidt, R. F.. 54.Schmitt, W. J., 188.Schmitz-Dumont, O., 04,Schmorak, J., 256.Schnable, G. L., 368.SchnZderman, S. Ya., 338.Schneider, J. J., 330.Schneider, W., 249, 341.Schneider, W. G., 19, 103.Schneider, W. P., 165.Schnell, W.-D., 99.Schnellenberger, H., 164.Schoen, L.J., 24, 32, 45.Schoenbeck, O., 324.Scholler, F., 355.Schoniger, W., 354, 357.Schopf, C., 241.Schofield, K.. 234.Schofield, P., 134.Scholder, R., 120.Scholes, G., 41, 42, 267.Scholey, R., 339.196, 369.113, 396446 INDEX OF AUTHORS’ NAMES.Schott, G., 32, 92.Schotte, A., 295.Schraube, H., 277.Schreiber, E. C., 220.Schreiber, J., 147.Schreiber, K. C., 137.Schreiber, R., 369.Schreibman, I., 330.Schrodel, R., 161.Schroeder, E. D., 410.Schroder, H., 101.Schroeder, H. E., 190.Schroeder, W., 305.Schrumb, W. C., 11.Schubert, C., 12.Schubert, J., 70, 74, 77,Schubert, K., 306.Schubert, W. J., 268, 276.Schuerch, C., 48, 267, 270,272, 273, 370.Schufle, J. A., 53.Schulek, E., 345.Schuler, R.A., 35.Schuler, R. H., 35, 38.Schulte, F., 366.Schultz, G. R., 138.Schultz, 0. E., 81, 320, 375.Schultz-Handt, S. D., 323,Schulz, G. V., 63.Schulz, I., 116.Schulz, K., 62, 63.Schulz, K. F., 71.Schulze, W., 91.Schumacher, H. J., 103.Schumaker, V. N., 267.Schuman, R. P., 119.Schumb, W. C., 93, 392.Schuster, L., 106.Schwab, G.-M., 46, 69, 93.Schwabe, K., 272.Schwarz, H. P., 14.Schwarz, J. C . P., 253, 264,Schwarzmann, M., 92.Schweers, W., 272.Schwenk, E., 307, 309, 316.Schwenkler, T. A.. 360.Schwieter, U., 178.Scipioni, A., 80.Scott, C. B., 19.Scott, D. W., 11.Scott, E. M., 300.Scott, G. P., 54.Scott, J. E., 257.Scott, N., 90.Scott., W. E., 45.Scribner, W. G., 362.Seaborg, G.T., 119.Seaman, W., 369.Searcy, A. W., 114.Searles, S., 228.Seaton, J. C., 240.Sebban-Danon, J., 49.Sederholm, C. 1-I., 19.80.325.255.Seel, F., 92, 94, 95, 96, 100,Seemann, H., 391.Sefton, V. B., 52.Segal, H. L., 330.Segal, K., 302.Segaloff, A., 224.Segar, G. A., 350.Sehnert, M. F., 124.Seibold, E. A., 109.Seidel, C. F., 203.Seiler, H., 268.Sekiguchi, K., 73, 375.Seligrnan, R. B., 380.Selwood, P. W., 62, 64, 66.Semechkina, A. F., 271.Semenenko, K. N., 85.Semenov, D. A., 130, 192,Semenov, N. N., 26.Sen, B., 340.Senio, P., 388.Seoane, E., 212.Sergeev, G. B., 26.Serratosa, J. M., 20.Serre, J., 128.Servigne, Y., 348.Seshadri, T. R., 237, 238.Seubold, F. H., 143.Seubold, F. H., jun., 13.Seus, D., 111, 198.Shah, H.A., 76.Shah, J. D., 180.Shah, R. C., 238.Shain, I., 370.Shalgosky, H. I., 359.Shambelan, C., 57.Shamma, H., 242.Shapiro, E., 223.Shapiro, E. L., 224.Sharma, T. R.. 204.Sharp, D. W. A., 117, 124.Sharpe, A. G., 117, 124.Sharpe, E. S., 256.Shatunina, A. N., 86.Shavitt, I., 22.Shavrova, N. N., 114.Shaw, J. I., 213.Shaw, R., 24.Shchukarev, S. A., 123.Sheard, D. R., 50.Shearer, D. A., 270.Shearer, H. M. M., 408,Sheehan, J. C., 233.Sheft, I., 104.Sheinker, Yu. N., 242.Sheka, I. A., 91, 97.Sheldon, J. C., 94, 95.Sheline, R. K., 10, 122.Shemyakina, T. S., 123.Shenderetskaya, Ye. V.,Shepp, A., 28.Sheppard, N., 10, 13, 16.Sheyanova, F. R., 343.116.198.412.121.Shiba, ‘J., 69.Shibarenkova, A.P., 366.Shibata, M., 82.Shida, S., 45.Shigorin, D. N., 19.Shikata, S., 321.Shimada, A., 412.Shimanouchi, T., 13.Shimizu, K., 9.Shimoe, D., 357.Shimoni, A., 302.Shinagawa, M., 358, 359,Shiner, V. J., 371.Shinozawa, R., 351.Shipman, G. E., 365.Shipman, J. J., 57.Shirane, G., 400, 401, 402,403, 404.Shiro, M., 397.Shishkin, N. V., 99.Shiuchi, Y., 372.Shkodin, A. M., 361.Shkrobot, E. P., 375.Shlenskaya, V. I., 335.Shmonina, L. I., 210.Shnaiderman, S. Ya., 366.Shoaf, C. J., 87, 90, 162.Shoemaker, D. Y., 109, 399.Shoolery, J. N., 103, 381,Shooter, K. V., 42, 267.Shoppee, C. W., 14, 160,170, 216, 219, 220.Shore, S. G., 87.Shore, V. G., 380.Shorland, F. B., 180.Short, L. N., 234.Short, R.V., 314.Shorygin, P. P., 12.Shorygina, N. N., 271.Shpanov, V. V., 242.Shreve, 0. D., 379.Shriner, R. C., 138.Shrivastava, G. C., 322.Shryne, T. M., 152.Shufler, S. L., 10.Shulenberg, J, W., 210.Shull, H., 128, 131.Shults, W. D., 369.Shultz, J. F., 69.Shunk, C . H., 186,236,237.Shyluk, W. P., 256.Sicha, M., 369.Sicre, J. E., 103.Siddhanter, S. K., 334,Sidhu, S. S., 393.Sidisunthorn, P., 238.Sidman, J. W., 12, 193.Sidorov, A. N., 63.Sieber, R., 183.Siebert, A. R., 60, 61.Siegel, S., 104, 393, 394,Siewers, I. J., 379.Sigal, XI. V., jun., 186.362, 364.382.396, 399INDEX OF AUTHORS’ NAMES. 447Sigg, H. P., 227.Siggia, S., 371.Siliprandi, L., 51.Sils, V., 91.Silver, H. B., 89.Silverman, L., 365, 366.Silversmith, E.F., 199.Silverton, J . V., 412.Sim, G. A., 406, 412.Simet, L., 302.Simha, R., 59.Simionescu, C., 80.Simmler, W., 93.Simmons, C. R., 113.Simmons, H. E., jun,, 192.Simms, J. A., 173.Simon, E., 318.Simon, V.. 349.Simonitsch, E., 189.Simonsen, (Sir) J., 206.Simpson, C. J . S. M., 8.Simpson, J . D., 236.Simpson, J. R., 292.Simpson, S. A., 311.Simpson, T. H., 216, 235.Simpson, W. S., 407.Simpson, W. T., 134.Sims, C. M., 283.Sims, P., 148, 285, 319,Sinclair, V. C., 407.Singer, K., 95.Singh, B., 348.Singh, S., 348.Singleton, E., 319.Singley, J . E., 140.Sin’kovskii, V. V., 77.Sinozaka, H., 362.Siperstein, M. D., 310.Sircar, S. S. G., 335.Sirkar, S. C., 18.Sisler, H. H., 94.Sissins, M.E., 177.Sistrom, W. R., 286.Sivertz, C., 52.Sixma, F. L. J., 90.Sizeland, M. L., 81.Sjoblom, R., 119.Sjonberg, B., 375.SkariC, V., 183.Skeggs, H. R., 178.Skell, P. S., 151, 152, 183.Skoblionok, R. F., 78, 79.Skogstrom, P., 217, 380.Skoog, F., 235.Slack, N., 65.Slater, A., 357.Slater, C. A., 232.Slater, J. C., 400.Slater, N. B., 21.Slates, H. L., 170, 174, 218.Slaunwhite, W. R . , jun.,Slaytor, M., 161, 162.Sleeper, B. P., 282, 287.Slin’ko, ill. G., G5.324.313, 317.Sloan, J. W., 258.Small, G., 136.Small, P. A., 58.Smets, G., 54.Smiley, R. A., 138, 183.Smit, A., 178.Smith, B., 171.Smith, B. S. W., 285, 286,Smith, C. L., 43.Smith, C. R., 209.Smith, D. C. C., 256, 268.Smith, D. R., 144.Smith, E., 199.Smith, F., 250, 357, 259,Smith, G.F., 246, 334, 336.Smith, H., 162, 174.Smith, H. A., 357.Smith, H. E., 204.Smith, H. L., 81.Smith, H. Q., 223.Smith, J., 356.Smith, J. A. S., 386.Smith, J. C., 180.Smith, J. N., 319.Smith, J. P., 390.Smith, L. L., 72.Smith, M. J., 30.Smith, M. L., 371.Smith, P., 48.Smith, R. J. D., 185.Smith, R. M., 28.Smith, R. N., 355.Smith, R. P., 136.Smith, S., 8.Smith, S. R., 28.Smith, W. T., 119.Smith, W. V., 382.Smissman, E. E., 174.Smithies, D., 42.Smoot, C. R., 33.Smutny, E. J., 198.Sneen, R. A., 160.Snoddy, C . S., jun., 221.Snog-Kjaer, A., 311.Sobczyk, L., 79.Sobek, A., 271.Sobel, A. E., 319.Sobue, H., 73.Soda, T., 318, 320, 321,324, 326, 327, 328.Sorensen, J.S., 172.Sorensen, N. A., 172.Sogani, N. C., 335.Sohngen, N. L., 284.Soldano, B. A., 73.Soling, H., 122.Solomon, D. H., 148.Solomon, S. S., 306.Solontsev, N. I., 360.Somasundaram, K. Al.,Somasundarum, I(. M.,Sly, J. C. P., 219.289, 290, 292, 293.260.362.333.Sommer, ti., 376, 377.Sondheimer, F., 164, 167,173, 174, 200, 210, 219,222, 223, 224.Songina, 0. A., 343, 361,362.Sonnerskog, S., 229.Sood, S. P., 56.Sorm, F., 205, 206, 607,208, 220, 224.Souchay, P., 116.SouEkovA, M., 363.Souffie, R. D., 45.Sourisseau, G., 18.Southern, A. L., 381.Southwick, P. L., 229.Sowards, D. M., 92, 344.Sowden, J. C., 256.Sowden, R. G., 46.Sowerby. D. B., 95, 125.Soye, C., 377.Spaulding, G. H., 356.Spector, M., 24.Spedding, F. H., 81, 111,Speirs, J.L., 103, 104.Spencer, B., 318, 319, 320,321, 322, 323, 324, 328.Spencer, C. F., 186, 237.Spenser, C. F., 169.Spicher, G., 292.Spiegelman, S., 281, 282.Spiesecke, H., 12.Spinelli, F., 81.Spinks, J. W. T., 36.Spinner, E., 134.Spitsyn, V. I., 114.Spitzer, J. R., 317.Spoerri, P. E., 319.Spoors, J. W., 257.Sporek, K. F., 342.Spriggs, A. S., 256.Spring, F. S., 212, 213, 614,Springer, M. J., 315.Sprinzak, Y., 144, 232.Sreenivasan. K. R., 237.Srinivasan, R., 34.Srivastava, H. C., 259.Srivastava, M. C., 259.Staab, H. A., 229.Staats, P. A., 11.Stacey, A. B., 252.Stacey, M., 37, 42, 158, 1 8 i ,257, 260, 265.Stallbergstenhagen, S.,180.Stafford. C., 367.Stafford, J.E., 167.Stafiej, S., 225.Stahl, H. O., 109, 111Stammer, C. H., 186, 837.Stammreich, H., 9, 17.StanaCev, N. z., 182.Standen, C. W., 374.388.215.198448 INDEX OF AUTHORS, NAMES.Stanier, R. Y., 279, 281,282, 285, 286, 287, 288,290, 291.Stannett, V., 61, 56.Staple, E., 311.Stapp, C., 292.Staritzky, E., 124, 393.Stark, C., 341.Starkanen, K., 370.Starkweather, H. W., 50.Staskun, B., 164.Stauffacher, D., 178, 203.Staveley, F. W., 67.Steacie, E. W. R., 28, 29,Steenson, T. I., 292.Steel, G., 15.Steele, C. G., 375.Steeple, H., 388.Stefanac, Z., 182, 183.StefanoviC, G., 376, 377.Stein, G. , 43, 1 12, 116.Steinberg, G. M., 301.Steinberg, M., 364.Stehegger, E., 241.Steiner, H., 66.Steinfink, H., 411.Stekhanov, A.I., 17.Stender, W., 247.Stenhagen, E., 180, 406.Stening, T. C., 255.Stephen, A. M., 259.Stephen, H., 164, 236.Stephen, T., 227.Stephen, W. I., 337, 339.Stephens, E. R., 45.Stephenson, J. E., 235.Stephenson, J. S., 156, 201.Stephenson, N. A., 124.Stephenson, N. C., 122.Stepukhovich, A. D., 22,Sternberg, H. W., 10, 106,Stetter, H., 180.Steuer, F., 366.Stevens, B., 26.Stevens, C. L., 182.Stevens, C. M., 119.Stevens, D., 307.Stevens, H. M., 377.Stevens, I. D. R., 150.Stevens, T. E., 210.Stevenson, D. P., 26, 34,Stevenson, R., 213, 214,Stewart, A. C., 43.Stewart, A. T., 144.Stewart, D. K. R., 209,Stewart, F. D., 54.Stewart, J. E., 10,15.Stewart, J. L., 216.Stewart, R. J., 71.Stiles, M., 142, 155.30.26.108.36.215, 219.248.Stilmar, F.B., 190.Stilz, W., 187.Stitch, S. R., 318, 328, 329.Stock, J. T., 124, 362.Stoddart, C. T. H., 69.Stodola, F. H., 256.Stoicheff, B. P., 8.Stokem, M., 306.Stokes, B. J., 161, 184.Stokes, R. H., 77.Stokes, W. M., 227, 309.Stokr, J., 361.Stokstad, E. L. R., 235,Stolar, S. M., 316.Stolberg, M., 301.Stoll, M., 203.Stone, A. L., 266.Stone, B. R,, 233.Stone, D., 307.Stone, F. G. A., 87.Stone, J. E., 268, 269, 275.Stone, K. G., 372.Stone, R. W., 293.Stoner, G. A., 365.Stonner, F. W., 249.Stork, G., 156, 167, 200,Stoudt, T. H., 307, 309.Strachan, W. S., 214.Straley, J. W., 8.Strandberg, M. W. P., 381.Strange, R. E., 260.Strassner, J. E., 377.Straub, J., 377.Straus, S., 59.Strause, S.F., 63.Straws, F. B., 20.Strawinski, R. J., 293.Streibel, P., 218.Streitweiser, A., jun., 158,Streuli, C. A., 369, 372.Struck, H. C., 138.Strufe, R., 185.Struthers, G. W., 379.Stroebel, H. A., 72, 78.Stroechi, P. M., 72.Strominger, J. L., 326, 331.Strong, F. M., 235.Stuart, E. R., 206.Stuart, W. I., 61.Stuart-Webb, I. A., 222,Studier, M. H., 119.Stuetz, D. E., 251.Stumpf, W., 232.Sturdy, G. E., 112, 118.Sturgeon, B., 224.Sturtevant, J. M.. 302.Subbaraman, P. R., 344.Subrahmanya, R. S., 358.Subramian, R. V., 52.Suda, M., 289, 290.Sudo, F., 357.Suling, C. H., 234.236.210.160.224.Suetaka, W., 18.Sugai, S., 74.Sugihara, J. M., 254.Sugihara, M., 81.Sugimoto, S., 75.Suhnnann, R., 60, 62, 63.Suk, V., 346.Sulcek, Z., 351.Suld, G., 139.Sulfata, A.D., 75.Sumi, M., 205.Sumimoto, H., 61, 63.Summers, G. H. R., 160,170, 219, 220.Summerson, W. H., 296,301.Sumner, F. H., 129.Sumner, J. B., 318.Sun, S. C., 360.Sunahara, H., 359.Sundaram, S., 9.Sunderasan, M., 365.Sundralingam, A., 147.Sunko, D. E., 181.Suryanarayana, B., 233.Suryanarayana, C. V., 333,Surber, W., 179.Suseela, B., 363.Sussman, M., 282.Sutani, S., 53.Sutcliffe, L. H., 112.Sutherland, G. B. B. M.,16, 19, 20, 390.Sutton, D. A., 180.Sutton, J., 40.Sutton, L. E., 109, 137,Suzuki, K., 376, 402.Suzuki, S., 321.Suzuki, T., 330.Svach, M., 337, 364, 365.Svach, V., 363.Svasta, J., 351.Svec, H.J., 81, 83.Svehla, G., 349.Sverdlov, L. M., 12.Svitok, P., 370.Swain, C. G., 139.Swallow, A. J., 37, 38, 168.Swaminathan, S., 233.Swan, E. P., 255.Swan, G. A., 245.Sweeney, D. M., 10.Sweenley, C. C., 171.Sweet, T. R., 336.Swern, D., 181.Swidler, R., 301.Swift, E. H., 337, 369.Sworski, T. J., 40, 41.Sykes, A., 342.Sykora, V., 205, 207.Syme, A. C., 356.Symons, G. E., 284.Symons, M. C. R., 119.Syzganova, 0. P., 343.352.412INDEX OF AUTHORS’ NAMES. 449SzabadvAry, F., 336, 367.Szabb, L., 261.Szabb, 2. G., 94.Szamt, H. H., 139.Szarvas, P., 366.Szasz, G. J., 16.Szego, C. M., 305.Szmant, L. H., 232.Szonntagh, J., 877.Szpilfogel, S. A., 164, 219.Szucki, B., 334.Szumer, A. Z., 215.Szwarc, M., 24, 48, 51, 55,56, 131.Tabota, Y., 73.Tadokoro, H., 389.Taft, R.W., jun., 135.’raft, W. K., 64.Tahara, A., 206.Taimni, I. K., 337, 338.Tait, J. F., 311.Tajika, Y., 372.Takagi, Y., 402.Takahashi, N., 14,320,321,Takahashi, T., 211, 214.Takahasi, M., 149.Takamoto, S., 351.Takasu, K., 377.Takatsugi, H., 60, 52.Takayama, Y., 361.Takeda, A., 402.Takeda, K., 247.Takeda, Y., 289.Takei, S., 179, 199.Takemoto, K., 51, 52.Taketatsu, T., 82.Takeuchi, T., 361.Takeuchi, Y., 408.Takino, Y., 373.Takiura, K., 373.Tal, E. M., 360.Talat-Erben, M., 23.Talbert, P. T., 263.Talipov, Sh. T., 343, 375.Tallent, W. H., 241, 379.Tamm, C., 218, 227.Tamres, M., 228.Tanaka, I., 128.Tanaka, M., 363, 374.Tanaka, S., 48, 53.Tanaka, Y., 356.Tani, H., 357.’rankb, B., 327.Tannenbaum, E., 129.Tannenberger, H., 113.Tanner, K.G., 275.Tannhauser, P., 224.Tarayan, V. M., 353.Tarbell, D. S., 138, 153,Tarkoy, N., 196.Tarsey, A. R., 117.Tashkhodzhayer, A. T.,377.167, 184.343.REP,-VOL. LIITTasman, H. A., 395.Tate, B. E., 170, 204.Tatlow, J. C., 187.Tattersfield, F., 293.Tatum. E. L., 280, 282.Taub, D., 222, 225.Taube, H., 105, 121.Taube, R., 114.Taussig, P. R., 158, 201.Tausson, W. O., 285.Tavares, Y., 9.Tavormina, P. A., 178,307.Tawney, P. O., 176.Taylor, B., 282.Taylor, C. B., 309.Taylor, D., 158.Taylor, E. C., 235.Taylor, E. H., 65.Taylor, H. A., 31.Taylor, J. W., 24.Taylor, R. C., 18, 87.Taylor, R. P., 45.Taylor, T. J., 251.Taylor, W., 314.Taylor, W.H., 399.Taylor, W. I., 248.Tazuma, J. J., 197.Tchen, T. T., 203.Teach, E. G., 144.Tecotzky, M., 364.Teese, C. M. S., 94.Teich, S., 306.Teicher, H., 343.Teichert, A., 79.Temkin, M. I., 65.Temple, C., 362.Templeton, D. H., 388,394, 398.Ten’kovtsev, V. V., 332,Tennant, C. B., 374.Terenin, A., 46.Terenin, A. N., 18.Teresa, J. de P., 137.Teresaki, H., 327.Terent’ev, A. P., 343.ter Haar, K., 351.Terin, S. I., 362.Tetaz, J. R., 234.Tetenbaum, M., 74.Teter, J. W.. 171.Teufer, G., 396.Tevlina, A. S., 80.Tezak, B., 71.Thakur, R. S., 149, 184.Thannhauser, S. J., 327.Tharp, A. G., 114.Theander, O., 270.Thesing, J., 242.Theus, V., 179.Thevenet, M., 318.Thewlis, J., 388.Thieberg, K.J. L., 214.Thiec, J., 128.Thilo, E., 96, 97.Thirtle, J. R., 117.366.Thomas, A., 165.Thomas, A. G., 15.Thomas, C. A., 266.Thomas, D. B., 213, 215.Thomas, G. H., 213.Thomas, G. J., 259.Thomas, H. C., 70, 74, 77,Thomas, J., 321.Thomas, J. C., 110.Thomas, J. H., 56.Thomas, J. K., 42, 59.Thomas, J. R., 59, 292.Thomas, L. C., 16.Thomas, P. D., 163, 234.Thomas, R., 182, 266.Thomas, R. C., 229.Thomas, W. M., 48.Thomason, P. F., 369.Thompson, A., 259, 260.Thompson, B. R., 64.Thompson, D., 185.Thompson, H. B., 104.Thompson, H. W., 8, 14,Thompson, J. F., 182.Thompson, J. M., 173.Thompson, L. M., 306.Thompson, N. S., 259.Thompson, R. H., 189.Thompson, S. G., 119.Thomson, R. H., 236.Thorne, N., 155.Thornton, D.W., 213.Thornton, H. G., 280, 292.Thornton, R. E., 162, 174.Thorpe, J. F., 180.Throssell, J. J., 56.Thrush, B. A., 33, 45.Tidwell, E. D., 8.Tikhomirov, M. V., 36.Tikhomirova, G. P., 361.Tillotson, A., 222.Tillu, M. M., 366.Timell, T. E., 256.Timmons, C. J., 210.Timnick, A., 368.Tinley, E. H., 371.Tishchenko, G. N., 396.Tjomsland, O., 390.Tkacz, L., 330.Tobbin, M. V., 75.Tobin, H., jun., 68.Tobin, M. C., 19.Tobolsky, A. V., 51, 52.Todd, (Sir) A. R., 154, 190,260, 261, 262, 264.Todd, G., 416.Todd, S. S., 400.Todes, 0. M., 75.Toei, K., 335.Toga, T., 205.Tolmacheva, T. A., 123.Tolbert, B. M., 382.Tolbert, N. E., 256.Tomirek, O., 370.P80.15450 INDEX OF AUTHORS’ NAMES.Tomida, I., 179, 199.Tomkins, G.M., 306.Toms, D., 44.Tongue, K., 77.Topliss, J. G., 209.Topp, N. E., 81.Toribasa, T. Y., 77.Torii, T., 363, 364.T6th, J., 239.Toubiana, R., 180.Tourky, A. R., 370.Townes, C. H., 381.Towle, P. H., 169.Townsend, J., 134.Toyama, O., 65.Tracey, M. V., 267.Tramer, A., 18.Tranter, T. C., 415.Trapnell, B. M. W., 65, 68.Trappe, G., 147.Trave, R., 204.Traylor, T. G., 140, 141.Traynelis, V. J., 232.Traynham, J. G., 124.Treadwell, W. D.. 119.Treibs, W., 196, 206.Trevett, M. E., 165, 209,Trevorrow, LaV., E., 113.Trick, G. S., 303.Tridot, G., 116.Triebwasser, S., 400.Trifan, D. S., 53.Trifonova, As., 361.Trippett, S., 178.Trischmann, H., 227.Trisler, J. C., 150.Trivedi. A. H., 177.Troitskaya, M.I., 371.Tronieri, A., 325.Troscianiea, H. J., 161.Trostyanskaya, E. P., 80.Trotman-Dickenson, A. F.,Truce, W. E., 173,233.Trueblood, K. N., 124, 236,389, 414, 415.Triipel, F., 392.Trumbore, C. N., 40.Trumbull, H. L., 54.Truter, M. R., 123, 398,Trzebiatowski, W., 398.Tsai, K.-R., 85, 392.Tsapiv, I. I., 358.Tschesche, R., 227, 236.Tschudi, G.. 239.Tse, R. L., 152, 233.Tseitlin, R. T., 362.Tsubomura, H., 18, 19.Tsuchida, M., 282, 290.Tsuchida, R., 121.Tsuda, K., 220, 225, 241.Tsuda, Y., 248.Tsuji, K., 341.Tsujii, T., 357.248, 249.22, 24, 28.412.Tsutsui, M., 198.Tsuzuki, Y., 14.Tucker, C. W., 388.Tuffly, B. L., 366.Tuites, D. E., 212.Tullen, P., 206.Tully, M. E., 223.Tulub, T.P., 20.Tunit’skii, N. N., 36, 75.Tuppy, H., 242.Turiyan, Ya. I., 359.Turner, A. H., 238.Turner, J. C., 287.Turner, L., 168, 187, 188.Turner, R. B., 219, 225,Turvey, J . R., 259.Tuttle, L. C., 300.Tuttle, T. R., 134.Twigg, G. H., 69.Twombly, G. H., 317.Twort, D. N., 322.Tyrrell, H. J. V., 10.Ubbelohde, A. R., 385.Uchida, M., 59.Udaka, K., 325.Udenfriend, S., 286.Udovenko, V. V., 370.Uffer, A., 227.Uhle, F. C., 227.Ujhelyi, C., 366.Ulko, N. V., 364.Ulrich, P., 231.Umland, F., 376.Umland, J. B., 160.Ungar, F., 306, 307, 311.Ungnade, H. E., 183.Updegraff, I. H., 80.Ura, M., 367.Urban, F., 107.Urban, R. S., 155.Urch, D. S.. 191.Urone, P. F., 364.Ursprung, J. J., 166, 212,Urwin, J. R., 55.Usanovich, M.I., 370.Usatenko, Yu. I., 362.Usol’tseva, V. A., 99.Uson, R., 87.Uyeo, S., 247.Vaal, E. G., 17, 99.Valasek, J., 399.Valcikova, Z., 359.Valee, B. L., 374.Valenta, Z., 209, 248, 249.Vallarino, L., 107.Vamplew, P. A., 96.Van Allan, J. A., 230.Van Artsdalen, E. R., 9,Van Atta, R. E., 361.Vance, E., 49.Van Cleve, J . W., 268.227.214.35.Vand, V., 412.van Dalen, E., 378.Vandekar, M., 300.van Dorp, D. A., 164, 219.van Duuren, B. L., 247.van der Heide, J., 104, 388.van der Heijde, H. B., 371.van der Kelen, G. P., 90.Vango, S. P., 113.van Houten, S., 389.van Itallie, L., 211.van Leeuwen, P. H., 178.Van Nechel, R., 13.Vannerberg, N.-G., 86.van Rij, J. H., 178.Van Rysselberge, J., 134.van Tamelen, E.E., 195,van Tassel, R., 99.van Vucht, J. H. N., 399.Van Wazer, J. R., 97, 382.van Zijp, J . C. M., 280.Varadarajan, S., 261.Varma, J. P., 180.Varnerin, R. E., 27, 34.Vasil’ev, S. S., 23.Vasudeva-Murthy, A. R.,Vaughan, C. W., 192.Vaughan, G., 37, 42, 158.Vaughan, P. A., 392, 396.Vaughan, W. R., 187.Veerkamp. T. A., 337.Veloric, H. S., 61.Venanzi, L. M., 107, 108,Venkatamma, N. C.. 352.Venkateswarlu, K., 9.Vennesland, B., 287.Vercellone. A., 204, 224.Verdier, E. T., 359.Verdol, J. A., 198.Vergnoux, A,-M., 16.Verina, A. D., 38.Verly, W., 318.Verma, M. R., 345.Vermeulen, A., 315.Vernon, C. A., 155.Vert, Zh. L., 78.Viala, R., 321, 322.Vick, K., 193.Vickery, R. C., 111.Vidale, G. L., 18.Vig, 0. P., 204.VigvBri, M., 377.Ville, J., 183.Vincze, I., 239.Vining, L.C., 234.Viola, A., 179.Virasoro, E., 80.Virtanen, A. I., 234.Vis, E., 255.Viswanatha, T., 303.Viterbo, R., 212.Vittimberga, B., 203.Vlgck, A. A., 9.241, 242.377.123INDEX OF AUTHORS’ NAMES. 451Vlitos, A. J., 318.Voaden, D. J., 230.Vodar, B., 17.Volz, H. G., 117.Vogel, E., 157.Vogel, W., 18.Vogl, O., 149.Vogt, C. M., 88.Voigt, D., 101.Voigt, G., 100.Voiloshnikova, A. R., 362.Voitovich, B. A., 97.Volcheck, E. J., 242.Volger, J., 400.Volkenan, N. A., 141.Vol’kenshtein, F. F., 67.Vol’kenshtein, M. V., 15.Vollmann, H., 236.Volman, D. H., 45.Volnov, I. I., 86.Volpe, M., 24.Volpi, G. G., 32.von Batcheldor, F. W., 399.von Bunsen, H., 120.von der Bey, G., 177.Vonderwahl, R., 194.von Dohlen, W.C., 389.von Eller, H., 411.von Holdt, M. M., 259.Von Keussler, V., 19.von Philipsborn, W., 245.von Pigenot, D., 107.von Rudloff, E., 164.Von Saltza, M. H., 235.von Sydow, E., 405.Vormum, G., 67.Vorobeichikov, V. A., 345.Vorres, K., 395.Vos, A., 104, 388, 389.Voser, W., 164, 219.Voter, R. C., 335.Vousden, P., 401.Vuillard, G., 100, 103.Vulterin, J., 353.Vvedmskaya, L. L., 370.Vyakozina, 0. K., 362.Wacek, A. V., 269.Wachtmeister, C. A., 238.Wada, K., 376.Wade, K., 89.Wadier, C., 348.Wadsley, A. D., 84, 392,Wagener, S., 64.Wagenknecht, A. C., 237.Wagner, A., 19, 253.Wagner, A. F., 229.Wagner, C. D., 26.Wagner, F., 119.Wagner, H., 171, 178.Wagner, J., 324.Wagner- Jauregg, T., 300,Wahl, D., 402.Wahlroos.O., 234,396.301.Wahrhaftig, A. L., 36.Waight, E. S., 184.Wailes, P. C., 159, 173.Wain, A. G., 120.Wait, E., 117.Waksmundzki, A., 334.Walch, H., 273.Wald, G., 172.Walker, A. D., 280.Walker, I. G., 264.Walker, I. S., 233.Walker, N., 287, 292, 293.Walker, P. G., 252.Walker, R., 224.Wall, M. E., 224.Wall, R. F., 380.Wall, W. J., 76.Waller, C. W., 186.Waller, I., 387.Wallis, E. S., 168.Wallmann, J. C., 388.Walls, F., 213.Wallwork, S. C., 414.Walton, E., 159, 186, 229,Walton, H. F., 71, 77, 367.Walton, W. L., 379.Wang, P., 78.Wang, S. Y., 233.Wannagat, U., 85, 94, 95.Ward, C. H., 9.Ward, I. M., 15.Ward, M., 118.Ward, R., 84.Ward, R. L., 134.Wardlaw, W., 112, 113,Warf, J.C., 112, 393.Warford, E. W. T., 132,Warhurst, E., 22, 32.Waring. C. E., 24.Warner, R. C., 263.Warnhoff, E. W., 247.Warren, B. E., 388.Warringa, M. G. P. J., 296,Waser, J., 389, 394.Wasif, S., 99.Wasserman, H. H., 233.Watanabe, H., 374.Watanabe, S., 360.Waters, W. A., 146, 148,Waterstrat, R. M., 399.Watkins, J. C., 190, 215.Watkins, N., 54.Watson, E. J. D., 317.Watson, H. S., 212.Watson, R. B., 238.Watson, W. F., 55.Watt, G. W., 92, 124, 344.Watts, D. W., 95.Weaver, H. E., 382.Weaver, 0.. 186.Weaving, A. S., 236.237.115.191.301.190, 238.Webb, E. C., 295.Webb, J . L., 306.Webb, R. F., 154.Weber, A., 15.Weber, H. H., 394.Weber, J. R., 112.Weber, L., 223, 365.Weber, W., 11.Webster, M.S., 413.Weedon, B. C. L., 177, 180.Weeks, B. M., 41.Weeks, J. L., 39.Wehber, P., 347, 350.Wehrli, H., 178.Weil, L., 301.Weill-Marchand, A., 17.Weiner, J. S., 312.Weinreb, A., 46.Weinstock, B., 9, 118.Weise, E., 120.Weise, W., 240.Weisenborn, F. L., 163,243, 244.Weiss. A., 80, 90, 124, 395.Weiss, D., 144.Weiss, E., 109, 111. 198,Weiss, F., 361.Weiss, J., 39, 41, 42, 123,Weiss, R., 189.Weissberger, A., 168.Weissman, S. I., 56, 134.Weisz, H., 339.Weisz, P. B., 66.Welch, G. A., 118, 394.Weller, S., 67.Weller, S. W., 66.Wells, C. F., 47.Wells, R. A., 79, 377.Welzel, G., 230.Wender, I., 106, 108.Wendlandt, W. W., 111,342, 344.Wendler, N. L., 153, 170,174, 218, 221, 222, 225.Wenkert, E., 163,210.Mrentworth, R.L., 392.Werner, A. E. A., 211.Werner. G., 239.Werthessen, N. T., 316.Wesemann, D., 118.Wesseley, F., 148.Wesslau, H., 80.West, C. D., 316.West, P. W., 340, 369.West, T. S., 346, 350.Westheimer. F. H., 136,Westland, A. D., 344, 365.Westland, G. J., 122, 396.Westman, A. E. R., 23.Wettstein. A., 164, 178,185, 219, 226. 311, 312.Weygand, F., 168, 264.Whalley, W. B., 237.397.267.146, 287452 INDEX OF AUTHORS’ NAMES.Wheatley, P. J., 86, 389,Wheatley, V. R., 181.Wheeler, C. M., 267.Wheeler, D. M. S., 208.Wheeler, T. S., 237, 238.Wheelwright, E. J., 111.Whelan, W. J., 256, 258,Wheland, G. W., 131, 132,Whiffen, D. H., 11, 13, 202,Whisman, M., 374.Whistler, R.L., 258, 259.Whitaker, J. W., 356.Whitcombe, R. A., 91.Whitcutt, J. M., 180.White, D. E., 209, 213, 214,White, E. A. D., 402.White, E. F. T., 54.White, J. C., 365, 366, 372.White, J. G., 236, 408, 415.White, L., jun., 379.White, N. E., 410.White, R. A., 171, 346.White, R. R., 73, 75.White, W. N., 156.Whitecombe, J. A., 73.Whitehead, J. E. M., 322.Whiteway, S. G., 28.Whitfield, P. R., 262.Whiting, M. C., 159, 171,175, 178, 179, 238.Whitley, A., 115.Whitman, G. M., 94.Whittaker, A. G., 94.Wibaut, J. P., 241.Wiberg, E.. 87, 93.Wiberg, K. B., 152, 153,Wiberley, S. E., 13, 379.Wichers, E., 83.Wicker, R. J., 145, 160.Wideqvist, S., 23.Wiebenga, E. H., 104, 388,389, 395, 409.Wiegers, G. A., 389.Wieland, T., 183.Wiemann, J., 128.Wiesner, K., 209, 248,Wightman, C.E., 150.Wijnen, M. H. J., 45.Wilde, K. A., 24.Wilder, P., jun., 201.Wildman, W. C.. 247.Wildy, P., 322.Wiley, P. F., 185.Wilhelm, M., 161, 246.Wilke, G., 169, 173.Wilkie, K. C. B., 259.Wilkin, G. D., 280.Wilkins, D. H., 334.Wilkins, R. G.. 122, 123.393, 409.259.150.378.215.168.249.Wilkinson, G., 10, 106, 109,Wilkinson, J. F., 2W.Willenz, J., 168.Willhalm, B., 203.Williams, D. C., 324.Williams, D. F., 220.Williams, H. R., 380.Williams, J. P., 360.Williams, K., 322, 323.Williams, L. A., 82.Williams, M., 349.Williams, R. B., 194.Williams, R. E., 245.Williams, R. J. P., 105,Williams, R. J. W., 220.Williams, R. L., 11, 16.Williams, R. P., 186.Williams, R. R., 36, 45.Williams, R. T.. 280, 319.Williams, T. R., 347.Williams, V. Z., 380.Williamson, H. G., 367.Williamson, P. M., 61.Williamson, R., 190.Willis, H. H., 81.Willis, J. B., 247.Willoughby, H., 306.Willson, E. A., 57.Wilmshurst, J. K., 11.Wilmshurst, K. J.. 11.Wiloth, F., 58.Wilson, A. J. C., 383.Wilson, A. N., 159, 186,Wilson, C. L., 150, 234.Wilson, E. B., jun., 378.Wilson, F. C., 109.Wilson, I. B., 296, 298, 299,Wilson, L. G., 330.Wilson, M. K., 9, 11, 17.Wilson, R. A. L., 160,Wilson, S., 78.Wilson, W., 216.Wiltshire, G. H., 293.Winder, F. G., 280.Winer, R. A., 322.Wingfield, H. C., 336, 341.Winkler, C. A., 32, 158.Winkler, C. E., 24.Winnick, T., 300.Winogradsky, S., 283.Winslow, E. H., 378,Winstein, S., 140, 141, 152,Winston, A., 201.Winter, G., 138.Winter, M., 253.Winter, S. S., 70.Wintcrsteiner, O., 227.Wirth, F., 254.Wirtsman, J., 368.Wise, H., 25.110.236.237.302.218.154, 220.Wise, L. E., 267.Wise, R. M., 188.Wise, W. M., 367.Wise, W. S., 362.Wisniewski, W., 79.Withrow, C. D., 359.Witkop, B., 153.Witnauer, L. P., 54.Wittenberg, L. J., 97.Wittig, G., 145, 169, 170,183, 187, 192.Wizerkaniuk, M., 330.Wizinger, R., 231.Wolfel, E., 398.Wolf, D. E., 178.Wolf, F. J., 186.Wolf, K. H.. 96.Wolf, L., 111.Wolf, W., 236.Wolff, I. A., 258.Wolff, R. E., 205.Wolffenstein, R., 169.Wolfrom, H. L., 320.Wolfrom, M. L., 166, 255,Wolfsberg, M., 128.Wolinsky, J., 187, 199.Wong, R., 90.Wood, D. G. M., 146.Wood, D. L., 14.Wood, E. A., 393, 402, 403.Wood, G. A., 77.Wood, G. W., 156, 201.Wood, H., 319.Wood, H. B., jun., 264.Wood, H. C. S., 235.Wood, H. N., 302.Wood, H. W., 378.Woods, G. F., 179.Woodward, L. A., 7, 9, 10,83, 90, 95, 121, 394.Woodward, R. B., 136,166,185, 205, 239, 243, 245,308.Woodworth, R. C., 151,183.Woolard, L. D., 365.Wooldridge, K. R., 145,Wooldridge, K. R. H., 181,Woolett, A. H., 11.Woolf, D. O., 186.Worrell, €3. E., jun., 53.Worthing, C. R., 248.Wortman, R., 64.Wortmann, J., 281.Wotiz, I-I. H., 316.Wotiz, J. €3.. 108, 173.Wotring, A. W., 380.Wright, L. D., 178.Wright, N., 380.Wright, W. B., 415.Wrigley, T. I., 143, 162.Wiirsch, J., 178.259, 260.Wood, J., 221.163.229INDEX OF AUTHORS’ NAMES. 463Wulff, H., 262.Wurzel, M., 302.Wyatt., P. A. H., 99.Wyld, G. E. A., 372, 373.Wyman, L. J., 162.Wynn, C. H., 321.Xavier, J., 335.Yagashita, K., 212.Yagi, K., 322.Yajima, H., 247, 248.Yakubov, A. M., 362.Yakusheva, 2. P., 370.Yale, H. L., 117.Yamabe, T., 71, 72.Yamada, M., 330.Yamada, T., 377.Yamagita, M., 75.Yamaguchi, T., 69.Yamaji, I., 369.Yamamoto, T., 364.Yamasaki, K., 71, 376.Yamashina, J., 324, 327.Yamashita, T., 51.Yamazaki, H., 46.Yamazaki, Y., 128, 327.Yan, M. M., 273.Yana, M., 363, 366.Yanagita, M., 206.Yang, J. Y., 85.Yasuda, S. K., 348.Yates, C. H., 306.Yates, P. , 206.Yatsimirskii, K. B., 350.Yazyka, S. M., 15.Yoda, O., 324.Yoe, J. H., 336, 337, 341,Yoeman, F. A., 117.Yoffe, A. D., 94.Yohizumi, H., 131.365.Yokosuka, S., 363, 374.Yokouchi, N., 361.Yonemoto, H., 14.Yonezawa, T., 60.Yoshida, A., 328.Yoshikawa, H., 330.Yoshikawa, S., 79.Yoshimine, M., 187.Yoshimura, C., 333, 349,Yoshino, T., 18, 20.Yoshino, Y., 376.Yoshioka, T., 180.Youatt, G., 295.Young, D. W., 408.Young, G. J., 61.Young, J. P., 368.Young, L., 294, 319, 322.Young, R. C., 117.Young, R. L., 160.Young, W. G., 156.Yung, N., 260.Zachariasen, W. H., 112,388, 393, 399.Ziihner, H., 186.Zahradnik, R., 23.Zaichikova, L. B., 366.Zakharkin, L. I., 168, 173.Zalkin, A., 394, 398.Zamanov, R. K., 367.Zamith, A. A. L., 102.Zand, R., 61.Zapp, E. g., 374.Zarza, M. A. H., 129.Zarrow, M. X., 314.Zauberis, D. D., 393.Zavyalov, S. I., 210.Zderic, J. A., 186.Zechmeister, L., 177, 231.Zehden, W., 20.Zehner, J. M., 336.363, 371.Zeile, K., 236.Zeiss, H. H., 146, 197, 198,Zeiss, W., 120.Zeitlow, J. P., 11.Zelikoff, M., 45.Zeller, P., 166, 174, 175,176, 177, 178.Zeller, R., 91.Zemek, O., 366.Zervas, L., 260.Zhdanov, A. K., 362.Zhdmv, G. S., 411.Zhivopistsev. V. P., 340.Ziegler, K., 57, 142, 143.Ziegler, M., 364.Ziegler, P., 220.Zill, L. P., 256.Zimin, A. V., 38.Zimmer, H., 94.Zimmerman, H. E., 162.Zimmermann, W., 306.Zinke, H., 164.Zinn, T. L., 380.Zinner, H., 261, 252.Zioudrou, C., 250.Zirker, G., 125.Zobell, C. E., 279.Zobrist, F., 178, 203.Zolotavin, V. L., 341, 363.Zolotukhin, V. K., 360.Zora, J. G., 182.Zosel, K., 143.Ziirn, G., 394.Zvonkova, 2. V., 88.Zvyagintsev, 0. Y., 107.Zwanzig, F. R., 146, 204.Zweifel, E., 178, 203.Zweifel, G., 252.Zwerdling, S. 2.. 16, 20.Zfka, J., 337,349,363,363.Zyryanova, N. G., 360.204

ISSN:0365-6217    

DOI:10.1039/AR9565300419

出版商:RSC    

年代:1956

数据来源: RSC

摘要:

INDEX OF SUBJECTS.Absolute configuration, 384.Absorptiometric methods in analysis, 363.Acepleiadylene, formation of, 193.Acetone, activation energy of decompos-ition of, 24.Acetyl groups, detmn. of, 367.17-Acetylandrostan-l7-01~, rearrangementof, 225.Acetylenes, 171.Acids, carboxylic, crystal structure of,fatty, 179.long-chain, crystal structure of, 405.Acorone, structure of, 207.Acridine, crystal structure of, 410.Acrylonitrile, y-induced polymerisation of,polymerisation of, by azoisobutyro-Actinomycin, depeptido-, structure of,Actinomycins, structure of, 235.Adsorption, 60.Agapanthagenin, structure of, 227.Aglycones, cardiac, 227.Ajmalidine, structure of, 245.Ajmaline, structure of, 245.Aldohexoses, reaction of, with sulphuricAldonolactones, reduction of, 250.Aldopentoses, reaction of, with sulphuricAlicyclic compounds, 198.Aliphatic compounds, 171.Aliphatic SE reactions, 140.Alkali metals, reduction by, 162.Alkaloids, 239.Alkoxides of vanadium-group elements,115.Allene, dimensation of, 198.Allenes, 17 1.Ally1 acetate, catalysed bulk polymeris-Alstoniline oxide, structure of, 245, 246.Alstyrine.synthesis of, 246.Aluminium, detmn. of, 336.405.42.nitrile, 50.236.thermodynamics of, 60.acid, 250.acid, 250.ation of, 60.test for, 339.unipositive, 90.Aluminium borohydride, dissociation of,87.structure of, 88.phosphate, structure of, 390.“ Ambident,” definition of, 168.Amides, infrared spectra of, 13.Amides, structure of, 406.Amine oxides in organic reactions, 170.Amino-acids, oxidation of, by micro-Aminoboranes, reactions of, 88.9-Aminosalicylic acid, structure of, 406.1 l-Aminoundecanoic acid, hydrobromide,crystal structure of, 412.Ammonia, liquid, electrochemical proper-ties of, 94.Ammonia synthesis, stoicheiometric num-ber for, 67.Ammonia-diborane, structure of, 389.Ammonium imidoperchlorate, formationof, 103.kmperometric titrttion, 361.l-a- Amyradiene, 21 3.u-Amyrin, structure of, 212.Anacyclin, 172.(+)-Anagyrine, total synthesis of, 241.Analytical chemistry, 332.ion-exchangers in, 8 1.Anatase, crystal structure of, 392.Angustione, structure of, 216.Aniline, photo-excited, decomposition of,Annotinine, structure of, 249.Anthracene, crystal structure of, 407.Antibiotics, 185.Anti-esterase action, mechanism of, 295.Antimony, concentration of traces of, 332.Antimony(m), detmn.of, 336.Antimony as reducing agent, 333.Antimonybromide, formation of Rb,SbBr,and Rb,Sb,Br,, from, 99.Ants, compounds isolated from, 204.Apurinic acids, 266.D-kabinose, preparation of D-erythrosefrom, 251.Argon. heat of sorption of, in chabazite, 61.Aristolochic acid, structure of, 189.Amdt-Eistert homologation, 168.Aromatic compounds, 186.Arsenic, detmn. of, 344.Arylsulphatases, 321.Ascorbic acid as titrimetric reagent, 349.Aspidin, structure of, 216.Atisine, diacetyl-, pyrolysis of, 248.Atoms, reactions involving, 31.Aurocyanic(1) acid, preparation of, 124.Azulene, crystal structure of, 408.Azulenes, 196.organisms, 289.26.nng-cleavage of, biochemical, 280.Barbaloin, structure of, 189.Barium, detmn.of, 350.test for, 341.46INDEX OF SUBJECTS. 455Barium hydride chloride, 86.Barium sulphate, precipitation of, 343.Bamngtogenic acid, structure of, 213.Barringtogenol, structure of, 213.Beckmann rearrangement, the, 154.Bellaradine, identity of, with cuscohy-Benzene iodochloride, crystal structure of,Benzeneseleninic acid, crystal structure of,p-chloro-, crystal structure of, 407.Benzil + benzilic acid change, 154.Benziminazole, reactions of, 234.Benzocyclobutene, formation of, 187.2 : 1 3-BenzofluorantheneJ configuration of,Benzoic acids, oxidation of, by micro-Benzo[c]phenanthryl-6-acetic acid, 1 : 12-3 : 4-BenzopyreneJ structure of, 408.Benzo(a1pyrene-3 : 12-quinoneJ synthesisBenzoxazolone, 6-methoxy-, occurrenceBenzoyl groups, detmn.of, 357.Benzoyl peroxide, oxidation of phenols by,Benzyne intermediates, 192.Berkelium-248 isotope, formation of, 118.Beryllium, detmn. of, 344, 360, 353.Beryllium bride, crystal structure of, 394.Beryllium oxyacetates, 85.Biological chemistry, 279.Biopterin, 236.Bis- (NN-dimethy1dithiocarbamato)-nitrosylcobalt(rI), 121.Bisdiphenylchromium(1) iodide, 111 , 198.Bismuth, concentration of traces of, 332.grine, 241.413.407.409.organisms, 287.dimethyl-, optical resolution of, 188.of, 190.and synthesis of, 234.148.test for, 340.unipositive, 85.detmn. of, 346.test for, 339.univalent , 90.Bixbyite, crystal structure of, 393.Borate, detmn.of, 337.Borides of lanthanides, 112.Borohydrides, preparation of, 87.Boron, detmn. of, 337.Boron hydrides, 86.Boron trichloride, addition compounds of,trifluoride, addition compounds of, 88.trihalides, heats of solution of, 88.fi-Boswellic acid, stereochemistry of ringBranching in polymerisation, 55.Bromine complexes, crystal structure of,88.A Of, 213.413.pentafluoride, structure of, 104.trifluoride, structure of, 103.Browning of foods, non-enzymic, 253.Butadiene-trifluoroacetonitrile reaction,cycZoButanone, formation of, 198.33.tevt.-Butyl phenyl ketone, fission of, byn-Butyl radicals, decomposition of, 31.Butyrospermol, structure of, 212.Cadmium, detmn.of, 343,360.Cadmium chloride, anhydrous, 125.Caesium oxides, structure of, 85.Cafestol, structure of, 208.“ Calcium ” as a substitute for murexideas indicator, 346.Calcium, detmn. of, 346.Calcium hydride chloride, 86.Calcium sulphate. See Gypsum.Carbanions, 140.‘ I Carbenes,” 147, 150.Carbon, detmn. of, 354.Carbon monoxide, adsorption of, on nickelCarbon tetraiodide, reactions of, 91.Carbonyl compounds, 166.Carbonyls, reaction of, with isocyanides,Carboxylic acids, 168.fl-Carotene, 175.Carotenoids, 174.fi-Caryophyllene chloride, crystal structureof, 415.Catalysis, 66.heterogeneous, 60.Catechol-violet, uses of, 346.Cerimetric titrations, indicators for, 345.Cerium(Iv), test for, 341.Cerium(1v) iodate, crystal structure of,chromic acid, 146.test for, 340.films, 64.107.391.sulphate, titration of, 363.Charge transfer complexes,” 231.Chemisorption, 62.Chitose, structure of, 252.p-Chlorobenzene iododichloride, structureof, 104.Chlorocarbon, C,,CI,,, structure of, 199.Chlorophenoxyacetic acid herbicides,oxidation of, by micro-organisms, 292.Chlorotungstates, complex, 117.Chloryl fluoride, preparation of, 103.Cholesta-1 : 3 : 5-trien-7-one, 219.Cholest-l-ene, pure, 218.Cholesterol, biosynthesis of, 307.catabolism of, 310.Cholesterol balance, 309.Chondrosulphatase, 325.Chromate, detmn.of, 337.Chromatography in analysis, 376.Chromium(I1) salts, use of, in KjeldahlChromium(III), detmn. of, 347.Chromone derivatives, sulphonation of,Chrysene, structure of, 408.Circumanthracene, configuration of, 409.Claisen rearrangement, the, 157.Cobalt, detmn.of, 338, 346.procedure, 356.238.syntheses of, 188.tests for, 340, 341466 INDEX OF SUBJECTS.Cobalt(rrr), detmn. of, 354.Cobalt(II1) as oxidising titrant, 349.Cobalt carbnyl hydride, position ofhydrogen atom in, 106.Cobalt selenides and tellurides, 84.Codeine, crystal structure of, 414.Coefficients, activity, in ion-exchangeselectivity, in ion-exchange resins, 72.Colorimetric reagents, 336.Columbin, structure of, 209.Complexes of transition elements, 106.Complexometnc titrations, 360.indicators for, 346.Condensed ring systems, 233.Conductometric titration, 370.Co-ordination compounds, crystal struc-ture of, 397.Copolymers, block, 66.Copolymerisation, 64.Copper, concentration of traces of, 332.Copper(Ir), reduction of, on resin, 364.Copper(I1) acetate, Cu-Cu distance in,“ Cord factor,” identity of, 180.“ Corticosteroidogenesis,” 31 1.Corynantheidine, configuration of, 243.Corynantheine, configuration of, 243.Coulometric titration, 369.Coumarones, 3-aroyl-.237.Crinine, structure of, 247.Cross-linking, degree of, 72.Crucibles, porcelain, cooling of, 333.Crystallography, 383.Crystals, infrared spectra of, 10.Cumulenes, 171.isoCyanic acid, structure of, 389.Cyanogen chloride, structure of, 389.(-)-Cytisine, synthesis of, 240.Dammar resin, triterpenes from, 211.Dead-stop end-point titrations, 369.Decaborane, reactions of, 87.Dehydroangustione, structure of, 216.Dehydrogenation, 163.Dehydronorcamphor, preparation of, 204.Delpheline, structure of, 249.Delphinine, structure of, 249.Deoxyribonucleic acid, 204.Depolymerisation, 69.“ Desmosterol,” structure of, 227.Deuterides, crystal structure of, 393.Deuterium-hydrogen exchange reaction,Dianin’s compound, inclusion products of,Dibasic acids, ratio of dissociation con-Dibenzenechromium(O), 110, 197.Dibenzenemolybdenum(O), 110, 198.resins, 72.graft, 66.detmn.of, 334.sexaco-ordinated, 123.test for, 340.123.by halogenated quinoaes, 145.32.236.structure of, 230.stants of, 136.1 : 2-3 : 4-DibenzocycZooctatetraene, 5 : 8-Dibenzyl hydrogen phosphate, crystalDiborane-ammonia, structure of, 369.Diboron tetrachloride, structure of, 389.2 : 4-Dichloro-3-phenylcycZobutenone, race-misation of, 198.Diethyl ether-nitrogen dioxide reaction,33.NN‘-Dicyclohexylcarbodi-imide, use of,171.Di(hydroxyduryl)methane, crystal struc-ture of, 413.Dihydrohydroxyeremophilone, structureof, 206.Dihydroxy-fumaric and -maleic acid,nature of, 406.3 : Il-Dihydroxytestan-l-one as normalconstituent of urine, 306.Dimethylacetylene, crystal structure of,412.NN-Dimethylaniline, use of, as promoter,60.1 : 2-Dimethylenecy~Zobutane~ formationof, 198.Dimethylketen dimer, crystal structure of,412.Dimethylphosphinoborine, structure of,389.NN‘-Dimethylsulphamidedisulphonicanhydride, ammonolysis of, 101.Dinitrogen pentoxide-nitric oxide reac-tion, 33.Dinitrogen tetroxide, properties of, 94.Dinitrosyl pyrosulphate, 06.Dioscorine, tentative structure of, 240.Diphenyl ether, crystal structure of, 412.Diphenyloctatetraene, structure of, 409.Diplospartyrines, a- and 8- structure of,Dipole moments of meso-ionic tetrazoles,2 : 2‘-Dipyridyl, crystal structure of, 410.Dioxan, complexes, crystal structure of,Disiloxane, structure of, 93.Disulphur dinitride, 101.Diterpenes, 208.1 : 4-Dithian, structure of, 411.1 : 4-Dithiins, 232.Di-p-tolyl sulphide, etc., crystal structureDivicine, structure of, 232.Donnan equilibrium in ion-exchangeDosimetry in radiation chemistry, 36.Double bond in steroids, location of, 217.Dumortierigenin, structure of, 213.Elaiomycin, structure of, 182.8-Elemene, structure of, 206.Enzymes, inhibited, degradation of, 301.Eperuic acid, structure of, 208.Eremophilone, hydroxydihydro-, crystaldiphenyl-, preparation of, 187.structure of, 407.241.230.413.of, 412.equilibria, 7 1.structure of, 416INDEX OF SUBJECTS. 467Erysotrine, dihydro-, degradation of, 246.Erythraline, structure of, 247.Erythromycin, structure of, 1sS.Ester sulphptes, bioqmthesis of, 329.Esters of sugars, %4.Esterases, 294.Ethyl radicals, decomposition of, 28, 29.Ethylene, deuteration of, 68.polymerisation of, by y-radiation, 37.thermal decomposition of, 26.Feist's acid, structure of, 198.Femtes, crysbl structure of, 393.Ferrocene, crystal sttnoture of, 109.Ferrocenes, 197..Ferrotlectrics, S O .Film diihsion in ion exchange, 74.Flame-photometry, 373.Flavaspidic acid, structure of, 216.Flavogallol, structure of, 239.Flavonok, synthesis of, 237.Fluoride, test for, 341.Fluorine fluorosulphopate (fiuorosulphate) ,9 a - F l u o l .o a e t s of 1 l-oxygenatedFolicanthine, degradation of, 246.Fom wfastanfs, 9.Formaldehyde, pyrolysis of, 25.Formsmidcdme, struclz-e of, 406.Formazans, 253.Free radicals, 147.D-ErythrOSa, prepaI'atiOn Of, 261.preparation of, 197.103.hormones, 221.-it-, loo.Gadolinium hybrides, 'I 12.Gallium, detmn. of, 336.Gallimn dichkoride, stiucture of, 90.Gases, radiation chemistry of, 36.Geatelal and physical chemistry, 7.Germanium, detmn. of, 344.Germanium monohde, 93.Gibberellic acid, 210.Gibberic acid, 210.albGibberic acid, 210.Glabric acid, structure of, 214.Glass-fibre sheets, use of, in ionophoresis,D-GlUcOSamhe, derivatives of, 262.Glucosinalbate ion, structure of, 182.GMakhione, crystal structure of, 416.Glutinone, structure of, 216.1 : 2-GlycolsS oxidation of, by lead tetra-acetate, 164.Glyco)s, rates of oxidation of, by lead tetra-acetate, 146, 164.Glycosulphatase, 827.Glycyl-L-alanine hydrochloride hydrate,crystal structure of, 416.Gl yoxaline, 2.carboxymethylthiodihydro-,rearrangement of, 230.Gold, detmn.of, 364.Gold(1) iodide, structure of, 124.unipositive, 90.260.test for, 340.Graphite, intercalated compounds of, 91.Group I1 metals in analysis, precipitationGuaianolides, 207.Gypsum, infrared spectrum of, 17.Halides, crystal structure of, 394.Halides in organic reactions, 170.Halogens, detmn.of, in organic analysis,Hector's bases, structure of, 230.Helvolic acid, structure of, 229.Heptafulvalene, formation of, 196.Heptafulvene, formation of, 195.cycEoHeptatnenes, 194.Heterocyclic compounds, 228.Heteropolytungstates containing anionicHexachloroceric acid-dioxan complex, 1 12.Hexadeuterodibmane-pentaborane reac-6-Hexanolactam, polymerisation of, 68.n-Hexatriacontane, configuration of, 412.Hexoses, oxidation of, with lead tetra-acetate, 261.cycEoHexylammonium chloride, crystalstructure of, 412.High-frequency titration, 388.Histidine hydrochloride hydrate, crystalstructure of, 416.Holarrhenin, structure of, 227.D-Homosteroids, 226.Hormones, modified, table of, 223.Hydrates, cqstal structure of, 396.3ydrazine sulphate as reductometric3ydrides, crystal structure of, 393.3ydride ion, transference of, 144.3ydrocarbons, aromatic, crystal structuregaseous, thermal decomposition of, 26.infrared spectra of, 13.-Iydrogen, detmn.of, in organic com-3ydrogen atoms, addition of, 32.3ydrogen bonding, infrared study of,lydrogen bonds, 385.lydrogen-deuterium exchange reaction,lydrogen-nitrogen dioxide reaction, 33.Iydrogen chloride hexahydrate, 103.lydrogen fluoride, pure, conductivity of,Iydrogen peroxide, crystal structure of,formation of, by radiation, 40.Iydrogen sulphide-mesitylene complex,18.1-Hydroxycinnamyl alcohols, dehydro-genation of, 276.lydroxylamine, structure of, 389.3ydroxylamine-O-sulphonic acid ( '' sul-phoperamidic acid "), 94.of, 338.structure of, 390.357.systems, crystallography of, 409.cobalt, 116.tion, 34.titrant, 353.of, 407.pounds, 364.18.32.102.392458 INDEX 01Hygromycin, structure of, 186.Hyocholic acid, structure of, 220.Hypobromite, detmn.of, 353.Hypochlorite as oxidimetric titrant, 352.isoHypophosphate salt, new, 96.Hypophosphites, detmn. of, 360,363.Hypophosphite as reducing titrant, 352.Ibogaine, structure of, 246.Iboluteine, structure of, 246.Ice, effects of irradiation on, 43.Indeno[2, 1-alperinaphthene, synthesis of,Indicators in titrimetric analysis, 345.Indigo, crystal structure of, 411.Indium, detmn.of, 347.Inductive effect, the, 135.Infrared methods of analysis, 379.Inorganic chemistry, 83.Inorganic compounds, infrared spectra of,Inorganic electrophoresis in analysis, 378.Inorganic gravimetric analysis, 342.Inorganic qualitative analysis, 337.Inorganic structures, crystallography of,Inorganic titrimetric analysis, 346.Intensity measurements, infrared, 14.Intermetallic compounds, crystal struc-‘ I Intrinsic carbanion stability,’’ 142.a-Iodine monochloride, structure of, 104,addition compounds of, 104.Iodine pentafluoride, structure of, 104.Iodoform, infrared spectrum of, 16.p-Iodonitrosobenzene, crystal structure of,Ion exchange, 70.equilibria in, 71.in non-aqueous systems, 78.kinetics of, 74.193.9.388.ture of, 398.388.413.Ion-exchange methods of analysis, 374.Ion-exchange resins, exchange capacitiessorption of neutral molecules by,use of, in volumetric analysis, 348.of, 76.76.Ion-exchangers as catalysts, 80.in analytical chemistry, 81.new and modified, 79.Ions, nature of, in ion exchange, 77.Iridium(Iv), detmn.of, 349.Iridium fluorides, 121.Iron(rr), detmn. of, 336.Iron(m), detmn. of, 336, 351.reduction of, on resin, 364.Iron(Iv), preparation of a compound of,Iron carbide, crystal structure of, 394.Iron(1rr) chloride decahydrate, 120.Iron pentacarbonyl, structure of, 105.Isomerism, rotational, 15.Isopolytantalate ion, 114.Isopolyvanadate ions, 114.Isoprenoids, unconjugated, 178.120.SUBJECTS.Keten, photolysis of, 30.‘ I Ketone 250,” structure of, 228.Kinetics, gas-phase, 20.Kinetics in ion-exchange columns, 75.Ketones, infrared spectra of, 12.a-Kosin, structure of, 216.Krypton, adsorption of, 60.Labdanolic acid, structure of, 208.Lactaroviolin, structure of, 130.Lantadene A, identity of, with rehmannicacid, 214.Lanthanides, 11 1.Lapochenole, structure of, 238.Lead, detmn.of, 360.Lead carbonate, basic, crystal structure of,391. 0Lead dioxide, thermal decomposition of,84.Ledol, structure of, 207.Leucrose, structure of, 126.Lignin, biosynthesis of, 275.Lignins, 267.degradation of, 268.reactive groups in, 273.a-Lipoic acid, polymers from, 229.(+)-a-Lipoic acid, configuration of, 181.Liquids, infrared spectra of, 17.non-aqueous, radiation chemistry of, 37.Lithium, test for, 339.Lithium aluminium hydride, reduction by,Lithium metasilicate, crystal structure of,Lithium niobate, crystal structure of,Lithium tri-tert.-butoxyaluminium hy-dride, uses of, 161.Loganin, structure of, 199.(+)-Lupanine, total synthesis of, 240.Lycoctonine, structure of, 248.Lycopene, synthesis of, 176.Lycorine, structure of, 247.I ‘ Macrolides,” 186.Macromolecules, natural, 267.Magnamycin, structure of, 186.Magnesium, detmn.of, 343.Magnesium hydride, 86.Mammals in ring-cleavage of aromaticcompounds, 280.Manganese, detmn. of, 350, 352.Manganese(I1). oxidation of, to perman-Manganese dioxide, oxidation by, 165.Marrubiin, 208.Masticodienonic acid, structure of, 212.isoMasticodienonic acid, structure of, 212.Melacacidin tetramethyl ether, oxidationMelaleucic acid, structure of, 214.Melamine, structure of, 129.160.391.402.de(oxymethy1ene)-, structure of, 248.6 : 7 : 6‘ : 7’-tetrahydro-, 177.dihydro-, stereochemistry of, 247.univalent, 119.ganate, 354.of, 238INUJLA UEMercury, detmn.of, in organic compounds,Mercury(I), detmn. of, 334.Mercury(II), detmn. of, 344.Mercury(11) amidofluoride, constitution of,Mercury(1) fluoride, Hg-Hg distance in,367.125.126.nitrate, Hg-Hg distance in, 126.perchlorate as reducing titrant, 363.Mercury(I1) oxide, crystal structure of,Mesitylene-hydrogen sulphide complex, 18.Meso-ionic compounds, 230.Metabolic pathways, intermediates in, 281.Metal acetylide complexes, 107.Metallic complexes of aromatic hydro-carbons, 197.Metallo-organic compounds, infrared spec-tra of, 9.Methoxyl determination, 367.Methyl acrylate, transfer constants inpolymerisation of, 53.N-Methyl, determination of, 367.Methyl radicals, reaction of, with nitricoxide, 30.Methylaluminium halides, structure of, 90.3-Methylcholestan-3-ols, stereochemistryof, 218.( +)-S-Methyl-L-cysteine sulphoxide, oc-currence of, 182.Methylene radical, the, 161.24-Methylenecholesterol, occurrence of,l-Methyl-a-fenchene, pure, 204.Methylguanidinium nitrate, crystal struc-4-Methylcyclohexane-1 : 2-dione, use of, inMethymicin, structure of, 185.Meyerhoff ente, crystal structure of, 384.Micro-organisms, oxidative metabolismby, 284.Micro-organisms in ringcleavage of aro-matic compounds, 280.Microwave methods of analysis, 381.Mo lecule-mo lecule reactions, 3 3.Molecular thermal decompositions, dataMolybdenum(1v) oxides, double (ternary),Molybdenum(v1) fluorides, complex, 117.phosphates, 116.Monoterpenes, 204.Morphine, crystal structure of, 414.Morphine alkaloids, biogenesis of, 250.Muscarhe, structure of, 182, 239.Mycolipenic acid, configuration of, 179.Myrosulphatase, 324." Naphthalyne " intermediates, 192.Nemotin A, 172.*isoNemotinic acid, 172.392.227.ture of, 415.analysis, 335.for, 24.116.Nickel, spongy, use of, in organic analysis,Nickel, detmn. of, 334, 336, 346.365.Nickel, test for, 341.Nickel as reducing agent, 333.Niobium-strontium bronzes, 84.Niobium chlorides, basic, 114.Niobium oxfluorides, 115.Niobium trifluoride, 116.Nitrate, test for, 341.Nitrate esters of sugars, 255.Nitration of polycyclic hydrocarbons, 191.Nitratoaquonitrosyhthenium complexes,Nitric acid, anhydrous, 95.Nitric oxide, reaction of, with methylNitric oxide-dinitrogen pentoxide reac-Nitrites, crystal structure of, 391.+-Nitroandine, crystal structure of, 414.Nitro-compounds in organic reactions,Nitrogen, adsorption of, on tungsten, 63.afterglow of, 31.detmn.of, in organic compounds, 354.Nitrogen dioxide, bimolecular decompos-- tion of, 25.Nitrogen dioxide-diethyl ether reaction,Nitroguanidine, crystal structure of, 415.Nitronium tetrafluoroborate as nitratingagent, 190.Nitrophenols, oxidation of, by micro-organisms, 292.4-Nitropyridine 1-oxide, crystal structureof, 410.Nitrosyl carbonyls, 107.Nitrosyl reineckate, 115.Nitrous acidium ion, 95.Nitryl chloride, chlorination by, 96, 96.Nitryl fluoride, structure of, 95.Non-aqueous titrations, 371.cycZoNovobiocic acid, structure of, 237.Novobiocin, structure of, 186, 236.Nuclear magnetic-resonance methods ofanalysis, 381.Nucleic acids, 260.Nuclides, new, 119.120.radicals, 30.tion, 33.detmn.of, 337.170.33.-hydrogen reaction, 33.cycZoOcta-1 : 3-dienes1 formation of, 200.cycZoOcta-1 : 5-diene, reaction of, withOlefins, 169.Oligosaccharides, 255.a-Onocerin, absolute configuration of, 212.&Orbital resonance, 137.Organic analysis, 364.Organic chemistry, 126.the0 re t ical , 134.Organic compounds, radiation-inducedoxidation of, 41.Organic structures, crystallography of,405.Organophosphorus compounds, 294.hydrolysis of, by enzymes, 303,Organosilicon compounds, cyclic, 93.rhodium trichloride, 108460 INDEX OF SUBJECTS.Osazones of sugars, structure of, 263.Osmium (IV), ethylenediamine complexesof, 120.Osmium(vr), detmn.of, 336.test for, 341.Oxazirines, 229.Oxidation in organic chemistry, 164.Oxidation of organic compounds, 144.Oxides, crystal structure of, 392.ferroelectric properties of, 401.16-Oxotestosterone, formation of, 222.Oxy-acids, structure of, 390.Oxyanin-B, synthesis of, 237.Oxygen, detmn. of, in organic compounds,Ozonides, reduction of, by triphenylphos-Palladium, detmn.of, 336.Palladium(n), detmn. of, 344.Palladium( 11) complexes with o-phenylene-Parkeol, structure of, 212.Particle diffusion in ion exchange, 74.Patchouly alcohol, structure of, 206.“ Pelletierine,” natural, identity of, withPentaborane-hexadeuterodiborane reac-Pentacene, configuration of, 409.cycZoPentadienerneta1 complexes, 108.Pentafluorosulphur hypofluorite, 103.Peptides, infrared spectra of, 13.Perchloric acid, catalytic action of, incertain organic reactions, 141.Perchloric acid monohydrate, Ramanbands in spectrum of, 10.Perchloryl fluoride, preparation and struc-ture of, 103.Perinaphthenylium salts, 193.Periodic acid, detmn.of, 364.Permanganate titration, substitutes forZimmermann-Reinhardt reagent in,333.” Permolybdic acid,” 116.Peroxychromates, double, 116.Phenanthrenes, synthesis of, 187.Phenazine, crystal structure of, 409.Phenol, oxidative metabolism of, byPhenols, 189.monohydric, oxidation of, 238.Phenyl isocyanate dimer, crystal structurePhenylpropiolic acid, dimeric, 406.Phloroglucid? structure c~f, 189.Phosphates, condensed, 97.366.phine, 163.bisdimethylarsine, 122.isopelletierine, 241.tion, 34.micro-organisms, 294.of, 413.detmn. of, 361.structures of, 391.97.Metaphosphates, colloidal, structure of,Phosphides, crystal structure of, 394.Phosphite, detmn. of, 363.Phospholipids, 181.Phosphoric acid, structure of, 390.triamide, 97.Phosphoronitrile fluorides, 96.Phosphorous acid, detmn.of, 350.Phosphorus oxychloride, addition com-pounds of, 97.pentahalides, mixed, 96.sulphides, structure of, 389.Phosphorylated entymes, re-activation of,Photochemistry, 44.Photometric titration, 368.Physalien, 176.Pilocereine, structure of, 242.Finacol+ pinacolone change, 166.Pinidine, structure of, 241.Plants in ring-cleavage of aromatic com-Platinous complexes, trans-directing effectPleiadene, synthesis of, 193.Plutonium, structures of allotropes of, 388.Plutonium hexafluoride.- 118.298.pounds, 280.in, 107.hydrides, 118.nitrate, 118.nitride, 118.Polarography, 368.Polonium(Iv), extraction of, into ethers,Polonium, various derivatives of, 102.Polyarsenates, lithium and sodium, struc-Polycyclic compounds, aromatic, 187.Polymerisation, initiation constants in, 61.102.tures of, 391.ionic, 66.kinetics of, 48.radiation-induced, 38.radical, 47.retardation and inhibition of, 62.ring, 68.stereo specific, 6 7.Polymers, degradation of, 69.irradiation of, 43.Polynucleotide phosphorylase, 263.Polysaccharides, 257.Polystictin, 234.Porphyrilic acid, structure of, 238.Porphyrins, 236.Potassium detmn. of, 335.as tetraphenylboron salt, 342.in natural salt deposits, 342.Potassium carbonate as acidimetric stan-dard, 349.Potassium fluororuthenate (111), 120.Potassium glucose 6-sulphate, impure,320.Potassium metavanadate, crystal struc-ture of, 391.Potassium nitrosohydroxylaminesulpho-nate, 94.Potassium vanadates, 115.Potential functions, 7.Potentiometric titration, 370.Precipitation from homogeneous solution,F’regnane side chain, reactions involving,Progoitrin, 182.343.222INDEX 01cycZoPropane, isomerisation of, 25.polymerisation of, 58.Propyl radicals, n- and iso-, decompos-ition of, 28, 29.Proteins, infrared spectra of, 13.Pteridine, crystal structure of, 410.Pteridine and its simple derivatives, pro-Pteridines, synthesis of, 235.Pulcherrimic acid, structure of, 232.Pummerer’s ketone, 238.Purines, 235.a-6-Purinylaminosuccinic acid, structurePyrazole, chlorination of, 229.Pyridine, 4-phenyl-.preparation of, 231.2-trifluorornethyl-, preparation of, 231.Pyridine-sulphur dioxide complex, 18.Pyrimidines, 5-hydroxy-, synthesis of, 232.Pyrochlores, crystal structure of, 403.Pyrophosphoryl chloride, 96.Pyrosulphuryl chloride, ammonolysis of,Pyrroles, N-aryl-, preparation of, 229.Pyrrolidines, 2 : 3-dioxo-, preparation of,Pyrrolones, preparation of, 229.Pyrylium salts, formation of, 231.Quantum organic chemistry, 126.Queretaroic acid, structure of, 213.Quinol as reductometric reagent, 349.Quinones, 190.Radiation chemistry, 35.Radicals, data for reactions of, 27.Rauvomitine, structure of, 245.SN Reactions, 168.Reactions involving radicals, 27.Rearrangements in organic chemistry, 152.Reduction in organic chemistry, 159.Reductor methods, 353.Rehmannic acid, identity of, with lanta-dene A, 214.Reserpine, total synthesis of, 243.PseudoReserpine, 244.Rhenium, preparation of, in a state of highRhodium trichloride, reaction of, withcyczoocta-1 : 5-diene, 108.Ribonuclease action, reversibility of, 262.Ribonucleic acid, hydrolysis of, 263.Ribonucleic acids, 260.D-Ribose 1 : 3 : 5-tribenzoate, 254.Ring-oven technique, applications of, 339.“ Rivanol,” name of and use of, 337.“ Rongal,i;e C,” crystal structure of, 412.Rubber, natural,” synthesis of, 57.Rutile, crystal structure of, 392.Samarium(1r) oxide, 112.Sanshool I, non-identity of, with spil-anthol, 180.Santonins, 205, 206.Scandium, detmn.of, 347.Scandium group, 11 1.perties of, 235.of, 235.100.229.purity, 119.SUBJECTS.461Scopolamine, total synthesis of, 239.(+)-Sedridine, structure of, 241.Selenic acid, hydrates of, 100.Selenium, detmn. of, 352.Selenoindigo, crystal structure of, 41 1.Selenosemicarbazide, 92.“ Sequential induction,’’ enzymic, 281.“ Serposterol,” 222.Sesquiethylenediaminetrimeth ylplatiniciodide, 123.Sesquiterpenes, 205.Silicon, adsorption of gases by, 63.Silicon-thorium system, 114.Silicon dibromide, 92.detmn. of, in organic compounds, 355.oxyhydride, 92.sesquioxide, 92.subhydride, 92.tetrachloride-ammonia, true compos-ition of, 93.Silver, test for, 340.Silver iodide ions, complex, 124.Silver(r1) oxide, use of, as oxidant, 333.Silver perchlorate-dioxan, structure of,Silver perfluorobutyrate, crystal structureSilver permanganate as combustion cata-Silyl compounds, 93.Sinigrin ion, structure of, 182.Small rings, heterocyclic, 228.Sodamide, crystal structure of, 394.Sodium, detmn.of, 336.Sodium atoms, reaction of, with aromaticSodium-naphthalene complex as initiatorSodium amidophosphate, thermal de-124.of, 406.lyst, 355.halides, 32.in anionic polymerisation, 56.composition of, 98.borohydrides, 87.borohydride, uses of, 162.carbonate as acidimetric standard, 348.diamidophosphate, thermal decompos-dithionite, structure of, 100.hexafluororhodate (11) , 12 1.“ metabismuthate,” structure of, 99.metagermanate, structure of, 391.metaperiodate, oxidation by, 164.nitrilotriphosphate, 98.sesquicarbonate, crystal structure of,triethoxyaluminium hydride, uses of,triisopropoxyborohydride, uses of, 162.tropolonate, crystal structure of, 413.ition of, 98.385.161.Solanesol, occurrence of, 179.Solanidol, configuration of, 227.Solasodine, configuration of, 226.Solids, radiation chemistry of, 43.Solutions, aqueous, radiation chemistry of,Spectra vibration-rotation, 8.Spectroscopic methods of analysis, 378.39.infrared spectra of, 17462 INDEX OF SUBJECTS.Spectroscopy, infrared and Raman, 7.Sphingosine, configuration of, 181.Spilanthol, non-identity of, with sansho61,Squalene, biological cyclisation of, 203.syntheses of, 178.Standards for volumetric analysis, 348.Sterculic acid, structure of, 180.Stereochemistry, 201.Steroid alkaloids, 226.Steroid sapogens, 226.Steroid-sulphatase, 328.Steroids, 216.metabolism of, 305.C,,, C,,, C,,, biosynthesis and cata-180.bolism of, 311, 313, 316.Streptonivicin, structure of, 236.Strontium, detmn.of, 342.Strontium-niobium bronzes, 84.Strontium hydride chloride, 86.Subercolic acid, formation of, 184.Substitutions, electrophilic, 190.“ 6-Succinaminopurine,” structure of, 235.Sugars, 250.compounds obtained fkom, with amines,hydrazines, etc., 252.Sulphamic acid, structure of, 389.Sulphamide, structure of, 389.Sulphatases, 318.Sulphate, detmn. of, 350.Sulphates, ferroelectric properties of, 403.Sulphate esters, preparation of, 398.Sulphides, crystal structure of, 394.Sulphites, detmn. of, 350, 354.“ Sulphoperamidic acid.” See Hydroxyl-Sulphur, crystallography of allotropes of,detmn.of, in organic compounds, 356.elementary, test for, 341.test for, 341.amjne-O-sulphonic acid.388.in steels, 343.Sulphur di-imide, derivatives of, 107.Sulphur dioxide-pyridine complex, 18.Sulphuric acid, structure of, 390.Sulphuric acid system, 99.Sydnones, halogenation of, 230.Tasmanone, structure of, 216.Taspine, structure of, 242.Tazettine, structure of, 247.Technetium, valency states of, 119.Tellurium, detmn. of, 343.Terminolic acid, 213.Terpenes, 202.Tetraethylammonium heptaiodide, struc-ture of, 104.Tetramethylammoniumenneaiodide, struc-tureof, 104.cycZoTetramethylenetetranitramine, crys-tal structure of, 411.3 : 7 : 12 : 16-Tetramethyloctadeca-3 : 7 : 9 : 11 : 15-pentaene-5 : 13-diyne-1 : 18-dicarboxylic acid, synthesis of,177.Tetraphosphoryl chloride, 96.Tetraphyllicine, structure of, 245.Tetrathionitrosyl compounds of palladiums-Tetrazine, crystal structure of, 409.Tetrazole, 5-imino-1 : 3-dimethyl-, dipoleThermal vibrations in crystals, 385.( A)-Thermopsine, 241.Thianthren, configuration of, 411.Thioacetamide, use of, in analysis, 337.(-J-)-5 : 8-Thioctic acid, 229.Thioctic acid.See (+)-a-Lipoic acid.Thioindigo, crystal structure of, 41 1.Thionyl tetrafluoride, 103.Thiosulphate as oxidimetric titrant, 352.Thiourea, detmn. of, 350.Thorium, detmn. of, 335, 336, 346, 347.Thorium, tests for, 340.Thorium-silicon system, 114.Thymidine, structure of, 264.Tiglic acid, configuration of, 405.Tigogenin, 226.neoTigogenin, 226.Tin(rr), test for, 340.Tin(Iv), detmn.of, 336.Titanium, alkoxy-derivatives of, 113.Titanium chlorides, lower, thermodynamicTitanyl amide, 113.Titrimetric reagents, 349.Tomatidine, configuration of, 226.Transfer in polymerisation, 53.Transfer constants in polymerisation ofmethyl acrylate, 53.Transition elements, 105.Transuranic elements, 115.crystal structure of, 399.s-Triazine, crystal structure of, 409.s-Triazines, 233.Trifluoroacetonitrile-butadiene reaction,Trifluoromethyl radical, decomposition of,Trimethylindium, 90.2 : 4 : 6-Trinitrophenols, use of, in analy-sis, 333.Triphenylphosphine, use of, in reduction ofozonides, 163.Triplienylphosphonium cyclopentadienyl-ide, 192.Tristrifluoromethylantimonic acid, 99.Triterpenes, 21 1.TricycZovetivene, structure of, 206.Tropolones, 195.Tropone system, resonance energy of, 196.“ Tropylidene,” structure of, 194.Tropylium salts, 194.Tryptophan, oxidation of, by micro-organisms, 290.Tungsten(v1) fluorides, complex, 117.Uranium, detmn. of, 344.Uranium, organic compounds of, 117.Uranium(Iv), detmn. of, 352, 353.and platinum, 123.moment of, 230.oxides of, 84.salts of,’ 113.properties of, 113.33.28INDEX OF SUBJECTS. 463Uranium(vI), detmn. of, 352, 353.Uranium(1v) halides, mixed, 117.Uranium(v1) oxide, hydrates of, 117Vanadium, dipyridyl complexes of, 114.Vanadium(v), detmn. of, 352.Vinylideneamine, configuration of, 412.Visamminol, structure of, 239.Vitamin A, 174.Vitamin B,,, crystal structure of, 415.Water vapour, p-irradiation of, 37.Wittig reaction, the, 169.Xanthates of D-glucose, 255.tests for, 341.Xanthazole, crystal structure of, 41 1.Xanthostemone, structure of, 216.(&)-Yohimbane, synthesis of, 242.18methyl-, synthesis of, 243.Zeaxanthin, 176.isazeaxanthin, 175.Zerumbone, structure of, 205.Zierazulene, structure of, 196.Zinc, test for, 340.Zinc chloride, anhydrous, m. p. of, 124.terpyridyl complex of, 125.Zirconium, detmn. of, 344,347.Zirconium, test for, 340,341.Zirconium tetrafluoride hydrates, 114

ISSN:0365-6217    

DOI:10.1039/AR9565300454

出版商:RSC    

年代:1956

数据来源: RSC