摘要:

ORGANIC CHEMICALSTributylTriamylCITRATESDIETHYLAM I N OETHAN O LHEXYLENE GLYCOLACETATES MethylEthylI sopro DY IBuiyl ' *Amy1 ISOPHORONEACETIC ACID A*R- GradeGlacial B.P. ISOPROPYL MYRISTATEGlacial commercial80% Technical ButylAmy180% Pure LACTATES EthylACETIC ANHYDRIDEMESITYL OXIDEM o n acet i nDiaceti n METHYL ETHYL KETONETriaceti nACETI N SEthyllsopropyland other acetoacetarylidides ButylOLEATES ACETOACETAN l Ll DEMETHYL ACETOACETATEACETONEBisoflex DNABisoflex DOABisoflex 79AAD I PATESALCOHOLS ButylAmy1Diacetone2-Ethyl hexylPentanol-2OXALATES DiethylDibutylCHLOROPHENOXY-ACETIC ESTERSPH TWALATES DimethylDimethyl glycolDiethylDibutylDiamylDioctylDinonylSEBACATES Bisoflex DBS AldolButyraldehyde Bisoflex DESCrotonaldehyde Bisoflex DNSMetaldehyde Bisoflex DOSParaldehyde Bisoflex 79sALDEHYDES AcetaldehydeBRITISH INDUSTRIAL SOLVENTSA Division of The Disti/lers Company LimitedDEVONSHlRE HOUSE, MAYFAIR PLACE, PICCADILLY, LONDON, W.IPHONE: MAYfair 8867 TELEGRAMS & CABLES: BlSOLV LONDON TELEXT.A.3728... a* 11Established 1868ATTWATER& SONS, LTD.PRESTON LANCS.MICA & MICANITEI N A L L FORMS A N D Q U A L I T I E SBAKELITE SHEETSTubes, Bobbins, Varnish and ResinFor O i l Switchgear and TransformersVulcanised Fibre Sheets, Tubes and RodsPeerless L EAT H E R 0 I D InsulationEmpire Cloth and Tapes Cotton and alsoAsbestos Dynamo TapesPresspahn and Fullerboard i n Sheet and RollsEbonite and all Insulating Material for Electrical EngineersPlease indent our goods through your usual agentsvREDIWELDLIMITEDSpecialists in Corrosion-Resistant EquipmentIN PLASTICSWe s u p p l y* EXTRUSIONS in Polythene, Rigid P.V.C., Plasticised P.V.C..k FABRICATIONS in Polythene, Rigid P.V.C., Plasticised P.V.C., Polyisobutylene..k INDUCTION HEATING for Chemical Plant (Mains frequency operated).* INJECTION MOULDINGS in Polythene up to 7 Ibs. in weight.k LABORATORY EQUIPMENT in Polythene or Rigid P.V.C. * PIPE SYSTEMS and FUME DUCTS in Polythene or Rigid P.V.C.j , ‘REDIVI” FILTER CLOTH (P.V.C.).-k PUMPS for C o d v e Liquids.-k TANK LININGS in Polythene, Rigid or Plasticised P.V.C., Polyisobutylene, Asphalt.jc VALVES in Polythene or Rigid P.Y.C..k VENTILATORS in Rigid P.V.C.for Corrosive Fumes. * WELDING EQUIPMENT for Thermoplastic Materials.AGENTS AND REPRESENTATIVES I N THE FOLLOWING COUNTRIES:Belgium * HollandFrance - Switzerland * U.S.A.Denmark * Norway - Sweden * FinlandAustralia.I N CANADA:Rediweld (Canada) Limited, 6301 Park Avenue, Montreal 15.Redweld LIMITED15/17 Crompton Way Crawley - SurrsexPbm CIZAWLEY 127I/2 Cables REDIWELD, CRAWLEYx-MANSFIELD OIL-GAS PLANT-FOR LABORATORIES’ GAS SUPPLYProvides a reliable gas supply for laboratories and indus-t r i a l purposes in localities where a town’s gas Service i s notavailable.Oil-Gas having a calorific value of I350 B.T.U’s per cubicfoot, i s produced in a simple manner from Solar Oil, LightDiesel Oil, or other suitable oils available a t comparativelylow cost.Any of the usual gas burning appliances available for usewith Coal gas are readily adapted t o give equally good resultswith Oil gas.Perfect oxidising o r reducing flames are obtained.Full particulars promptly furnished on receipt of estimatednumber of burners and appliances likely t o be used.MANSFIELD & SONS LTD62 HAMILTON SQUARE, BIRKENHEADENGLANDTelephone: Telegrams:Birkenhead 2250 Gasify Birkenheadour catalogue lists 3,000 organicresearch chemicals and includesamino acids, peptides, purines, pyrimidines,sugars, nucleotides, synthetic drugs, steroids,chromatographic and analytical reagents,alkaloids, hydrides, hormones, enzymes,acet ylenics, fluorines, silanes, vitamins, pyri-dine derivatives, carcinogenic hydrocarbonsWrite foryour copyL. 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About 63s.A practically useful integration of descriptive fact and unifying theoryfor the advanced student, presented in such a manner that he may attaina mature grasp of the subject.The Measurement of Particle Sizein Very Fine PowdersFour Lectures delivered at King’s College, LondonBy H. E. ROSE, Ph.D., M.Sc.Ex. Cr. 8vo. Illustrated. 9s. netElements of Statistical Mechanicsby D.ter HAARDemy 8vo. 468 pages. 45s. netChemical Engineering Materialsby F. RUMFORD, Ph.D., B.Sc., M.1.Chem.E.Demy 8vo. 350 pages. 32s. 6d. netCONSTABLE & COO LTD.10 ORANGE STREET, LONDON, W.C.2 ,-xi- The Techniesl Press Ltd.=A Selection of BooksINDUSTRIAL andMANUFACTURINGCHEMISTRYOriginally compiled by Dr. G . Martin7th Revised Edition published 1952ORGANIC: revised by E. I. Cooke, B.Sc., A.R.I.C.894 pages Illustrated net 90;-Part I.Part II. INORGANIC: revised by W. 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EVERETT, M.B.E., M.A., B.SC., D.PHIL.Professor in the UniversitC Libre de Bruxelles (Faculty of Science)Professor in the UniversitC Libre de Bruxelles (Faculty of Applied Science)A translation i n three volumes of Thermodynamic Chimiquerevised to include work up to 1951 and brought up to date 6yan appendix dealing briefly with developments up toJuly 1953.Contents :-Thermodynamic variables - Principle of conservation of energy- Principle of creation of entropy - Affinity - Average values ofthe affinity - AfTinity and chemical potentials - Ideal systems andreference systems - Standard affinities - The Nernst heat theorem - Perfect gases - Real gases - Thermodynamics of condensedphases - Gibbs’ phase rule and Duhem’s theorem - Phase changes - Thermodynamic stability - Stability and Critical Phenomena -Theorems of moderation - Displacements along an equilibrium line - Equilibrium processes - Relaxation phenomena and transforma-tions of Second Order - Solutions - Solution-vapour equilibrium - Solution-crystal equilibrium: entictecs - Solution-crystal equil-ibrium: mixed crystals and addition compounds - The thermo-dynamic excess functions - Regular solutions and athermal solutions - Associated solutions - Electrolyte solutions - Azeotropes - In-different states.Volume One 63s.netLongmans, Green & Co Ltd., 6 & 7 Clifford St., London, W.I.0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0u New BooksOxine and its DerivativesBy R. 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But ever since the appearance of a paper ofthe author’s in 1917 these ideas have provided valuableworking hypotheses for the organic chemist and will beincreasingly acceptable to the biochemist.1953.By S I R ROBERT R O B I N S O NElementary QualitativeAnalysis on the Small ScaleBY PETER WOODWARD(March 1955) 12s. 6d. netFor university intermediate students and school sixth-formpupils, the author recommends the adoption of a scalenot less than one-tenth of the traditional macro-scale and,apart from using a centrifuge instead of filter paper, retains,as far as possible, both the traditional manipulative tech-niques and the traditional chemical bases of analysis.After a discussion of the arguments for small-scaleworking, teaching methods, apparatus, and techniques,the analytical tables are presented concisely in a separatesection; these are followed by a detailed exposition of theunderlying chemistry, all reactions in solution beingrepresented by ionic equations. A final section and two ofthe appendixes are devoted to more difficult separationsand simple uses of paper chromatography and ion-exchange resins respectively.OXFORD UNIVERSITY PRESSxxiiThe Polytechnic- 309 REGENT STREET, W .I -D e p a r t m e n t of C h e m i s t r y and B i o l o g yHead qf Department : W. DAVEY, B.SC., PH.D., F.R.I.C.DAY A N D EVENING COURSESH.Sc. DEGREE, SPECIAL (Chemistry, Botany, Zoology)B.Sc. DEGREE, GENERAL (Chemistry, Botany, Zoology, Physiology)(University of London, External)ASSOCIATESHIP OF THE ROYAL INSTITUTE OF CHEMISTRY (A.R.I.C.)DIPLOMA DIPLOMA IN BIOLOGYGENERAL CERTIFICATE OF EDUCATION (Advanced Level) and INTER-MEDIATE SCIENCE Courses include Chemistry, Botany, Zoology,and Physics.Prospectuses may be obtained on application to the undersigned.J.C. JONES, Director ofEducationThe latest research onF E RM E N TAT1 0 Nis described in the first English Edition of the Rendiconti dell’lstituroSuperiore di Sanitaof Rome. 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IPrice, post freeOrdinary Edition E2-10-0 per annumEdition printed on one side ofthe paper 23-10-OperannumAir Mail Edition, for countriesoutside Europe E5-0-0 per annumThis new publication of the Chemical Society is amonthly classified world list of new papers in purechemistry.The publication date is mid-month andeach issue normally contains the titles of relevantpapers contained in all the journals received duringthe whole of the previous month. Titles that donot convey adequately the contents of the paper areexpanded and the entries are classified into theprincipal branches of chemistry under some twentydifferent headings. 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ISSN:0365-6217    

DOI:10.1039/AR95451FP001

出版商:RSC    

年代:1954

数据来源: RSC

摘要:

ERRATA.Vol. 49, 1952.Page. Line.55 1 For E, read E,.187 2 For ridellic read riddellic.25 1 1 For riddelline yead riddelliine.Vol. 50, 1953

ISSN:0365-6217    

DOI:10.1039/AR9545100006

出版商:RSC    

年代:1954

数据来源: RSC

摘要:

ANNUAL REPORTSON THEPROGRESS OF CHEMISTRY.GENERAL AND PHYSICAL CHEMISTRY.1. MOLECULAR SPECTRA AND MOLECULAR STRUCTURE.THIS Report aims at presenting some of the salient developments whichappeared during the year ended November 1954. Much significant materialhas had to be omitted, including accounts of valency theory, electronicspectra, X-ray studies, internal rotations, ultrasonics, diamagnetism, etc.Some important general surveys which have appeared may be 1isted.lThe exceptionally valuable reviews and discussions presented at the Parissymposium in 1953 have appeared : they include papers on the theory ofthe chemical bond,ZU electron diffractioqZb the intensity of Raman lines,2cmicrowave spectroscopy,2d the location of hydrogen atoms in crystallinestructures,2e molecular structure studies by neutron diffraction,2-f the per-turbation of X-ray electron levels by chemical bonds,2g nuclear magneticresonance,% and paramagnetic resonance.2i American as well as Europeanauthors contributed to the second Rkunion Intkrnationale de SpectroscopieMol~c~laire,~ with items from the megacycle range to the ultraviolet region.A similar wide survey of the structure and beh‘aviour of water molecules insolids is provided by more then twenty papers4Although almost entirely concerned with theoretical aspects, more par-ticularly with the critique of the resonance treatment of molecular structure(and so not within the topics chosen here), Magat’s review (in French)of Russian developments since 1947 is unusually interesting.Microwave Spectra of Gases.-Microwave spectroscopy provides preciseinformation on the molecular structure of polar gases.The relations necessaryW. Gordy, W. V. Smith, and R. Trambarulo, “ Microwave Spectroscopy,” JohnWiley and Sons, Inc., Xew York, 1953; J,., R. Partington, “ Molecular Spectra andStructure, Dielectrics and Dipole Moments, beiyf Vol. V of a treatise : Longmans,Green and Co., London, 1954; L. J. Bellamy, The Infra-red Spectra of ComplexMolccules,” Methuen, London, 1954 ; 2. G. Pinsker, ‘‘ Electron Diffraction,” translatedby J . A. Spink and E. Feigl, Butterworths Scientific Publications, London, 1954;S. Mizushima, “ Structure of Molecules and Internal Rotation,” Academic Press Inc.,Xew 170rk, 1954 ; (Ed.) W. Klyne, “ Progress in Stereochemistry,” ButterworthsScientific Publications, London, 1954.( a ) H.C . Longuet-Higgins, J . Chim. @hys., 1953, 50, 0 3 ; ( b ) L. E. Sutton, ibid.,0 2 0 ; (c) P. -P. Choruiguine, ibid., 0 3 1 ; ( d ) R. Roubine, ibid., 0 4 2 ; (e) E. Grison,ibid., D59; (f) G. E. Bacon, ibid., 1954, 51, 0 6 5 ; (g) E.. Cauchois, zbid., 074; ( h ) 1’.Grivet, R. Gabillard, Y . Ayant, and A. Bassompierre, zbzd., 089; (2) B. M. Kozyrev,ibid., D 104.Over 100 papers : J . Phys. Radium, 1954, vol. 16 : available as a separate volume.1. Chim. phys, 1953, 50, C1-C119.’M. Magat, Nuova cim. (Supplement), 1953, 10, 4168 GENERAL AND PHYSICAL CHEMISTRY.to analyse the spectra of linear, symmetric top, and asymmetric mole-cules containing one or two quadrupolar nuclei are given in " MicrowaveSpectroscopy." The microwave absorption of the hydroxyl radical hasbeen used to estimate its concentration, showing previous methods to beunreliable.' It is suggested that the microwave absorption by a non-polargas ( e g ., carbon dioxide at a pressure of ca. 60 atm.) is due to dipolesinduced by the quadrupoles of neighbouring molecules.The masses of the stable tellurium isotopes andr(C-S) = 1.557 k are found from the linear compound TeCS.g From astudy lo of SiH,Cl and SiD,Cl it is found that the dimensions of SiH, arechanged in going from SiH, to SiH,Cl as for the methyl group of the analogouscarbon compounds, and r(Si-Cl) is 0.0007 A shorter in SiH3C1. The mole-cular dimensions obtained l1 for SiHF, include r(Si-F) = 1-565 A, or 0.030 Aless than in SiH,F : this may be due to the high electronegativity of fluorinedecreasing the FSiF angle l2 and increasing both the $-character and thelength of the Si-F bonds.In H,C*CiC*CiN the bond-length r(C-CN) is1.379 A, which is shorter than in benzene.13 Antimony trichloride has beenstudied. l4Of asymmetric tops, SO,F, l5 has r(S-F) = 1-57 A, r(S-0) = 1-37 A, andthe angle FSF = 92" 47'; and SOF, l6 has r(S-F) = 1.585 tf, r(S-0) =1.412 A, and the angles FSF = 92" 49' and OSF = 106" 49'. In the thionylcornpound r(S-0) is close to its " normal " double-bond value but 0.020shorter than in sulphur dioxide. For monomeric formic acid the tentativevalues r(C=O) = 1.22 A, r(C-0) = 1-34 A, and the angle OCO = 124.8" aresuggested.l' These agree reasonably with the latest electron diffractionestimates 18 and are within the limits suggested by earlier data.l9 Ethylchloride,20 formaldehyde,21 and nitromethane 22 have been studied.Rota-tional constants have been obtained for vinyl cyanide 23 and vinyl iodide %-the two papers on the iodide showing the tendency to underestimate errorsin microwave studies, a point further illustrated by three papers 25 onMolecdar parameters.W. Gordy, W. V. Smith, and R. Trambarulo, ref. 1.'I T. M. Sanders, A. L. Schawlow, G. C. Dousmanis, and C. H. Townes, J . Chem.(See Linnett, Ann. Reports, 1953, 50, 9.)G. Birnbaum, A. A. Maryott, and P. F. Wacker, J . Chem. Phys., 1954, 22, 1782.W. A. Hardy and G. Silvey, Phys.Rev., 1954, 95, 385.10 B. Bak, J. Bruhn, and J. Rastrup-Andersen, A c t a Chem. Scand., 1954, 8, 367.l1 G. A. Heath, L. F. Thomas, and J. Sheridan, Trans. Faraday Soc., 1954, 50, 7i9.1 2 C. E. Mellish and J. W. Linnett, ibid., p. 657.la J. Sheridan and L. F. Thomas, Nature, 1954, 174, 798.1 4 P. Kisliuk, J . Cheun. Phys., 1954, 22, 86.l6 R. M. Fristrom, ibid.. 1952, 20, 1.l6 R. C. Ferguson, J . Amer. Chem. Sot., 1954, 76, 850.l7 R. Trambarulo and P. M. Moser, J . Chem. I'hys., 1054, 22, 1622.18 I. L. Karle and J. Karle, ibid., p. 43.2O R. S. Wagner and B. P. Dailey, J . Chem. Phys., 1954, 22, 1459.21 A. Okaya, J . Phys. Sot. Japan, 1954, 9, 135.22 E. Tannenbaum, R. D. Johnson, R. J. Myers, and W. D. Gwinn, J . Chem. Phys.,23 W.S. Wilcox, J. H. Goldstein, and J. W. Simmons, ibid., p. 516.24 C. D. Cornwell and R. I,. Poynter, ibid., p. 1257 ; H. W. Morgan and J. H. Gold-stein, ibid., p. 1427.z 5 B. Bak, L. Hansen, and J. Rastrup-Andersen, ibid., p. 565; K. E. McCulloh andG. F. Pollnow, ibid., p, 681; B. B. DeMore, W. S. Wilcox, and J. H. Goldstein, ibid.,p . 876.Phys., 1954, 22, 245.M. Davies and W. J. 0. Thomas, Discuss. Faraduy Sot., 1950, 9, 335.1954, 22, 949DAVIES AND THOMAS : MOLECULAR SPECTRA AND STRUCTURE. 9pyridine. Pyridine is ‘ I slimmer” than benzene, a value for r(C-N) ofCH-O\ about 1.35 being favoured. Studies on cyanobenzene 26 11 c=o indicate a planar symmetrical structure, the ring dimensionsCH-O/ being essentially the same as in benzene. Values for r(C-F) of1.348 A 27 and 1.29 A 28 have been suggested for fluorobenzene.Erlandsson 29 has deduced that cyclopentanone has a non-planar carbon ring,but vinylene carbonate (I), also with a five-membered ring, is planar.30Pentaborane, B,H,, has a tetragonal pyramid of boron atoms.31Recent studies in the millimetre 32 andsubmillimetre 33 wavelength ranges, made possible by development of thetechnique of harmonic generation principally due to Gordy and his collabor-ators, represent an important advance.The first rotational lines of manymolecules of small inertia lie in this region. Burrus and Gordy studiednitric oxide and deuterium iodide,= deuterium bromide,35 tritium chloride,and tritium The tritium species had not previously been investi-gated optically ; whilst yo for deuterium bromide and tritium bromidediffer by 0.0013 A, the re values (calculated by using infrared data) are equal.The ground-state structures of the pairs PH, and PD,,37 ASH, and AsD,,~*and SbH, and SbD, 39 differ by ca.0.004 A in the lengths of the bond betweenthe central atom and the hydrogen atom.An increasingly valuable source of structural information is providedby the effect of centrifugal distortion on the rotational energy levels. Inprinciple, information about the potential functions of molecules is given bythe displacement of the rotational lines.40 For low-lying levels the centri-fugal stretching terms, particularly those in Djj, are too small to be measuredwith high accuracy, but such values may be obtained through the study ofhigher J-transitions occurring in the millimetre region.Using accurateforce constants, Chang and Dennison41 estimated Dii = 18.4 kc./sec. formethyl chloride, which differed by some 40% from the centimetre-wavevalue 42 and that obtained from infrared data.43 A new value, obtained inthe millimetre range, Djj = 18.1 & 0.5 kc./sec., is in excellent agreementwith that of Chang and Dennison. The D,! values for the four methylhalides were in good agreement with those predicted from Kratzer’s formula.44(I)Millimetre-wave spectroscofiy.26 G. Erlandsson, J . Chem. Phys., 1954, 22, 1152; D. R. Lide, ibid., p. 1577.27 G. Erlandsson, Arkzv Fyszk, 1953, 6, 477.28 I<. E. McCulloh and G. F. Pollnow, J , Chew.. Phys., 1954, 22, 1144.29 G.Erlandsson, ibid., p. 563.30 G. R. Slayton, J. W. Simmons, and J. H. Goldstein, ibid., p. 1678.31 H. J. Hrostowski and R. J. Myers, ibid., p. 262.33 A. G. Smith, W. Gordy, J. W. Simmons, and W. V. Smith, Phys. Rev., 1949, 75,260; 0. R. Gilliam, C. M. Johnson, and vli. Gordy, ibid., 1950, 78, 140; W. C. Kingand W. Gordy, ibid., 1953, 90, 319; 93, 407.33 C. A. Burrus and W. Gordy, ibid., 1954, 93, 897.34 Idem, ibid., 1953, 92, 274, 1437.35 W. Gordy and C. A. Burrus, ibid., 1954, 93, 419.36 C. A. Burrus, W. Gordy, B. Benjamin, and R. Livingston (Phys. Rev., in the3 7 C . A. Burrus, A. W. Jache, and W. Gordy, Phys. Rev., 1954, 95, 706.38 G. S. Blevins, A. W. Jache, and W. Gordy (personal communication).39 A. W. Jache, G.S. Blevins, and W. Gordy, Phys. Rev., 1954, 95, 299.40 D. Kivelson and E. B. Wilson, J. Chenz. Phys.,‘1952, 20, 15’75; 1953, 21, 1229.41 T.-S. Chang and D. M. Dennison, ibid., p. 1293.43 J. W. Simmons and W. E. Anderson, Phys. Rev., 1950, 80, 338.43 J. Pickworth and H. W. Thompson, Trans. Faraday SOC., 1954, 50, 218.4 4 W. J. 0. Thomas, J. T. Cox, and W. Gordy, J . Chem. Phys., 1954, 22, 1718.press)10 GENERAL AND PHYSICAL CHEMISTRY.The rotational frequency shifts to be expected in sulphur dioxide were cal-culated from the force constants, the shifts being critically dependent uponthem.45 A precise set of force constants was thus defined by the combinationof infrared and microwave data. This procedure may well solve somevexed questions in the choice of molecular potential functions.Centrifugal distortion constants have been obtained for carbonyl sul-phide,46 ~yridine,~5 and methylmercuric chl0ride.~7Miscellaneous. High-temperature microwave studies have been carriedout on the fluoride, chloride, and bromide of c ~ s i u m , ~ ~ on carbonyl sul-hide,^^ and on potassium and sodium chloride.50 Massey and B i a n ~ e , ~ ~using a flow technique to overcome decomposition, have studied H202,HDO,, and D202.Their analysis indicates the essential correctness of thePenney-Sutherland skew model for hydrogen peroxide. The direct 2-doublettransition of hydrogen cyanide has been measured in the 10 cm. region.52In nitromethane a potential barrier has been estimated 53 which is con-siderably smaller than the value of 800 cal./mole suggested previously.Paramagnetic Resonance.-Molecules sometimes contain at oms, or solidscontain ions, which have unpaired electrons giving rise to molecular orionic magnetic moments.In an appropriate magnetic field these para-magnetic substances absorb microwave radiation with a consequent changein the orientation of the magnetic moment from one allowed position toanother. The actual frequency absorbed depends upon the magnetic fieldand it is by varying the latter that the absorption is detected at some appro-priate frequency (-lo4 Mc./s) of the microwave radiation.54For free radicals 55 with unpaired electrons the absorption is so in-tense that extremely small concentrations can be detected. Thus freeradicals are found in liquid sulphur 56 a t 200" c, their temperature con-centration dependence being consistent with AH = Cid l<cal./mole for S-Sbond rupture in the polymer chain.Free radicals are observed in thegels of vinyl polymers,57 ultraviolet irradiation increasing the intensitywithout changing the form of the absorption. Polymers have also beenused as solid solvents for studies on diphenylpicrylhydrazide 58 and thereare a number of experiments on X-irradiated plastics. The hyperfine45 D. Kivelson, J . Chem. Phys., 1954, 22, 904.*13 W. C. King and W. Gordy, Phys. Rev., 1954, 93, 407.4 7 W. J. 0. Thomas, J . T. Cox, and T. Gaumann (to appear: Discuss. Faraday4 8 A. Honig, M. L. Stitch, and M. Mandel, Phys. nw., 1953, 92, 901.49 H.Feeny, H. Lackner, P. Moser, and W. V. Smith, J . Chenz. Phys., 1954, 22, 79.50 P. A. Tate and M. W. P. Strandberg, ibid., p. 1380.51 J . T. Massey and D. R. Biance, ibid., p. 442.52 R. J . Collier, Phys. Rev., 1954, 95, 1201.53 E. Tannenbaum, R. D. Johnson, R. J. Myers, and W. D. Gwinn, J . Chew.I'lzys., 1954, 22, 949.54 For reviews see B. Rleaney, J . Phys. Chem., 1953, 57, 508; B. Bleaney andK. W. H. Stevens, Reports Progr. Phys., 1953, 16, 108; L. C. van der Marel, Kolloid Z.,1953, 134, 32; B. M. Kozyrev, ref. 2 ( i ) .5 5 J . I?. Lloyd and G. E. Pake, Phys. Rev., 1954, 94, 579; C. Kikuchi and V. W.Cohen, ibid., 1954, 93, 394; H. J. Gerritsen, R. Okker, H. M. Gissman, and J. V. A.Handel, Physica, 1954, 20, 13.5 6 D. RI. Gardner and G.K. Fraenkel, J . Amer. Chem. SOC., 1954, 76, 5891.5 7 G. K. Fraenkel, I. M. Hirshon, and C. Walling, &id. , p. 3606 ; cf. E. E. Schneider,M. J. Dav, and G. Stein, Nutzcre, 1951, 168, 645.68 E. E. Schneider (to appear, Discuss. Faraday Soc., 1955, Cambridge).Soc., April 1955, Cambridge).DAVIES AND THOMAS : MOLECULAR SPECTRA AND STRUCTURE. 11The theory of intermittent illumination has been worked out for the caseof simultaneous monomer and mutual termination.319Bamford and Tompa 320 have obtained molecular weight distributionsfor a number of kinetic schemes of vinyl polymerisation which cannot behandled by simple methods. Their mathematical procedure is somewhatcomplicated but may be more generally useful than other procedures.Radical initiators and rates of initiation.Measurements have been madeon the rates of decomposition of various polymerisation initiators in solu-tion 32l and in various monomers.32293239 324 The small effects of solvent onthe rates of radical decomposition of certain azo-compounds appear to be312 Cornell Univ. Press, 1953.313 I. Murphy and A. Wassermann, J . Polymer Sci., 1954, 14, 477.314 T. Yonezawa, K. Hayashi, C. Nagata, S. Okamura, and K. Fukui, ibid., p. 319.315 I<. L. Herbst and R. E. Martin, ibzd., p. 391.s18 N. Fuhrman and R. B. Mesrobian, .[. Amer. Chem. Soc., 1954, 76, 3281.816Q T. Alfrey and C. C. Price, J . Polymer Sci., 1947, 2, 101.W. I. Bengough and H. W. Melville, Proc. Roy. Soc., 1954, A , 225, 330.G. Goldfinger and C .Heffelfinger, J . Polymer Sci., 1954, 13, 123.319 G. hl. Burnett and W. W. Wright, Proc. Roy. Soc., 1953, A , 221, 37.320 C. H. Bamford and H. Tompa, Trans. Faraduy SOC., 1954, 50, 1097.321 J. C. Bevington, J., 1954, 3707,322 M. F. Shostakovsky, E. P. Gracheva, and V. A. Neterman, Zhur. obshchei Khim.,3z3 M. Takebayashi, T. Shingaki, and Y . Ito, Bull. Chem. Soc. Japan, 1953, 26, 475.324 M. Takebayashi, T. Shingaki, and H. Matsui, ibid., 1954, 27, 371.1953, 23, 54KINETICS OF CHEMICAL. CHANGE. 71somewhat fortuitous since there are large compensating changes with solventin the energies and entropies of activation.325, 326 When a radical catalystis decomposed in solution in the presence of a radical catcher such as 2 : 2-di-phenyl-1-picrylhydrazyl, the rate of removal of the catcher is usually ratherless than twice the rate of decomposition of the catalyst in its absence, evenafter allowance for induced decomp~sition.~~~ In the case of a 1-oxa-4 : 5-dithiacycloheptane the rate of diradical formation by photolysis as measuredby the rate of removal of diphenylpicrylhydrazyl is very considerably lessthan the rate of initiation of polymer radicals.328 All this shows that theonly satisfactory way of measuring rates of initiation of polymer radicals isby estimation of the number of catalyst fragments in the polymer formedafter a given time, under conditions such that transfer to catalyst does notoccur. This has been made possible by the use of labelled azobisisobutyro-nitrile.329 In this way the complications due to solvent cage effects, intra-molecular rearrangements, inefficient radical capture and diradical cyclis-stion are avoided.The main precaution is to ensure that no low polymer islost in the reprecipitation processes which are necessary to remove theunchanged or wasted catalyst. Mayo 330 has studied the thermal polymer-isation of styrene in bromobenzene and has isolated two distinct groups ofproducts. The first consists of low molecular weight, saturated, probablycyclic compounds, while the second consists of higher molecular weightpolystyrene. The two groups of products appear to be formed by inde-pendent reactions, the first from a non-radical or diradical reaction, thesecond by a 512 order reaction which is interpreted in terms of a termolecularinitiation reaction leading to the formation of two monoradicals, which thenpropagate in the usual way.Several methods of initiation, some new, have been described : benzoylperoxide with dimethylaniline 3315 332 a t 0" ; ferrous ions with various per-oxides; 333 photolysis of the ferric-azide ion pair; 334 and the action of lighton dyes in the presence of oxygen and a mild reducing agent.335y336Gamma-radiation has also been used to initiate the polymerisation of anumber of monomers (see p.78).The ability of polymethyl methacrylate to initiate polymerisation of itsown monomer has been interpreted by Szwarc337 in terms of a favourableorientation of adsorbed molecules, but new experimental evidence suggeststhat in fact the polymer becomes peroxidised on exposure to air.338Further velocity constant values or Polymerisation of single monomers.325 M.G. Alder and J. E. LeHer, J . Amer. Chem. SOC., 1954, 76, 1425.326 M. D. Cohen and J. E. Leffler, ibid., p. 4169.327 C. Walling, J . Polymer Sci., 1954, 14, 214.328 K. E. Russell and A. V. Tobolsky, J . Amer. Chem. Soc., 1954, 76, 395.329 J. C. Bevington, J. H. Bradbury, and G. M . Burnett, J . Polymer Sci., 1954, 12,330 F. R. Mayo, J , Amer. Chern. SOC., 1953, 75, 6133.331 T. H. Meltzer and A. V. Tobolsky, ibid., 1954, 76, 5178.332 M. Imoto, H. Kalciuchi, and S. Fusezaki, 3. Chem. SOL. Japaiz, Ind. Chern. Sect.,333 U'. Kern and R. Schulz, &Iakromol. Chenz., 1954, 13, 210.334 M. Santhappa, J . Madras Univ., 1954, 24, B, 91.336 G.Oster, Nature, 1954, 173, 300.336 K. Ueberreiter and G. Sorge, 2. Elektrochem., 1953, 57, 795.337 M . Szwarc, J . Polymer Sci., 1954, 13, 317.338 I. Waltcher, ibid., p. 411.469 ; see also ref. 357.1964, 57, 73672 GENERAL AND PHYSICAL CHEMISTRY.ratios have been obtained for styrene,340 methyl methacrylate,3399 3413 317vinyl acetate,317 and butyl a ~ r y l a t e . ~ ~ ~ For the first two monomers increas-ing conversion has been shown to result in longer radical lifetimes due tothe hindrance of the termination p r o c e ~ s . ~ ~ ~ ~ 341 Burnett and Wright 342have elucidated the kinetics of the polymerisation of vinyl chloride in tetra-hydrofuran solution. In this system the intensity exponent lies between 0.5and 1.0 and increases with temperature, indicating mixed termination.Inthe mercury photosensitised polymerisation of vinyl chloride vapour it isthe lP1 atoms which cause reaction.343 Work on the polymerisation ofacrylonitrile in bulk and in dimethylformamide solution has lent furthersupport to the theory that radicals become buried in polymer when pre-cipitated during formation.344* 345 Thomas and Pellon's 345 kinetic treatmenthas been criticised.346 Other investigations include those on the inhibitingeffect of oxygen in the polymerisation of on the effect of concen-tration and temperature in the polymerisation of sodium a~rylate,3~8 and onthe effect of detergents in the polymerisation of ally1 a ~ e t a t e . ~ 4 ~ Thedetergent was found to have no effect on the rate of initiation or the molecularweight of polymer formed in an initially homogeneous medium.Palit, Nandi, and Saha 350 have discussed methods of obtaining transferconstants from catalysed polymerisation data.Transfer constants havebeen determined for vinyl acetate in a large number of ~olvents.3~~~~52The transfer reactions occurring when styrene is polymerised in the presenceof thiols and d i s ~ l p h i d e s , ~ ~ ~ and of hydroperoxides have been in~estigated.~54With hydroperoxides the O-H bond is broken.354 The transfer of a numberof monomers with carbon tetrabromide 316 and with dihydromyrcene 355has also been studied.Careful determinations of the number of catalyst fragments per polymermolecule have shown that with styrene, mutual termination occurs entirelyby combination, but with methyl methacrylate, the ratio of disproportion-ation to combination increases from 1.5 at 0" to 6 at 60°, corresponding toan activation energy difference of 4 k~al./rnole.~~~, 357 In the copolymeris-ation of methyl methacrylate with styrene, however, the interaction of twodissimilar radicals results only in combination.357Considerable progress has been made in the past few yearsin the quantitative study of branching from the main polymer stem.Poly-Branching.339 13. R. Chinmayanandam and H. W. Melville, Trans. Faraday SOC., 1954, 50, 73.340 S. Fujii, Bull. Chem. SOC. Japan, 1954, 27, 216.341 Idem, ibid., p. 238.342 G. M. Burnett and W. W. Wright, Proc. Roy. Soc., 1953, A , 221, 28, 37, 41.343 M. Koizumi, K.Nakatsuka, and S. Kato, Bull. Chem. SOC. Japan, 1954, 27, 185.344 A. Prkvot-Bernas, Compt. vend., 1953, 237, 1686.345 W. M. Thomas and J. J. Pellon, J . Polymer Sci., 1954, 13, 329.346 C. H. Bamfard and A. D. Jenkins, ibid., 1954, 14, p. 511.347 T. L. Allen, J . AppZ. Chem., 1954, 4, 289.348 S. Suzuki, H. Ito, and S. Shimizu, J . Chem. SOC. Japan, I n d . Chem. Sect., 1954,349 E. J. Meehan, I. M. Kolthoff, and E. M. Carr, J . Polymer Sci., 1954,13, 113.350 S. R. Palit, U. S. Nandi, and N. G. Saha, ibid., 1954, 14, 295.351 S. R. Palit and S. K. Das, Proc. Roy. SOC., 1954, A , 226, 82.352 S. L. Kapur and R. M. Joshi, J . Polymer Sci., 1954, 14, 489.353 V. A. Dinaburg and A. A. Vsnsheydt, Zhur. obshchei Khim., 1954, 24, 840.354 C.Walling and Yu-Wei Chang, J . Amer. Chem. SOC., 1954, 76, 4878.355 J. Scanlan, Trans. Faraday SOC., 1954, 50, 756.356 J. C. Bevington, H. W. Melville, and R. P. Taylor, J . Polymer Sci., 1954, 12,57, 658.449. 3 5 7 Idem, ibid., 1954, 14, 463KINETICS OF CHEMICAL CHANGE. 13(vinyl acetate) contains a considerable number of branches if the percentageconversion of monomer during its formation is at all large.358 This is dueto the high reactivity of the poly(viny1 acetate) radical and hence the easewith which it undergoes transfer with dead polymer. Polystyrene on theother hand, as normally prepared, contains very few branches, owing tothe relatively high stability of the polystyrene Nevertheless,branched polystyrenes can be prepared by the device of first partially bromin-ating the polystyrene and then using this polymer to photo-initiate thepolymerisation of more styrene in the presence of a suitable transfer agentto prevent cross-linking.360 The C-Br bonds are broken by the absorptionof light and provide the necessary branch points.The Iength and numberof branches produced may be found by suitable analytical methods.Studies have also been made on the growth of branches of polymer A on toa main stem of polymer B.36133623363 The branch points may be formed intwo ways ; either by transfer of A radicals with polymer B,361 or by previousintroduction of potential branch points into polymer B, e.g., by brorninationor by per~xidation.~~~? 363 A series of papers from E.I. du Pont de Nemoursand Co. deal with the molecular structure of p~lyethylene.~~ Two types ofbranching during radical polymerisation of ethylene can be distinguished :long chain branching due to intermolecular hydrogen transfer, and shortchain branching due to intramolecular hydrogen transfer. The nature ofthe branching reaction in the radical polperisation of dienes has also beenin~estigated.~"? 366Reactivity ratios have been obtained for thesolution copolymerisations of vinyl chloride with methyl acrylate 367 andof styrene with butyl a ~ r y l a t e . ~ ~ 8 In the latter system, with benzene a ssolvent, the reactivity ratios were found to be constant over a wide rangeof monomer concentration. Effects attributable to the influence of thepenultimate unit on the polymer radical reactivity have been detected inthe copolymerisation of acrylonitrile with styrene, a-methylstyrene, anda-acetoxystyrene respectively and of styrene with f ~ m a r o n i t r i l e .~ ~ ~ Amethod for assessing radical copolymerisation polarity (e) (see p. 70) valuesfrom ionic copolymerisation data has been outlined.369Styrene-fumaronitrile copolymers can be brominated photochemically.The amount of bromine taken up corresponds with that calculated on theassumptions that bromine can only be taken into parts of the chain consist-ing of more than two successive styrene units, and that the distribution ofunits is not random.370 Butadiene has been copolymerised with certainpolynuclear hydrocarbons and the relative reactivities of these hydrocarbonsRadical copolymerisatiort.3G8 J.C. Bevington, G. M. Guzman, and H. W. Melville, Proc. Roy. SOL, 1954, A ,360 M. H. Jones, H. W. Melville, and W. G. P. Robertson, Nature, 1954, 174, 78.361 R. A. Hayes, J . Polymer Sci., 1953, 11, 531.363 T. Saigusa, M. Nozaki, and R. Oda, J , Chenz. SOE. Japan, I n d . Chem. Edn., 1954,57, 243.364 M. J. Roedel, J . Amer. Chem. Soc., 1953, 75, 6110; W. M. D. Bryant and R. C .Voter, ibid., p. 6113; F. W. Billmeyer, ibid., p. 6118; C. A. Sperati, W. A. Franta, andH. W. Starkw-eather, ibid., p. 6127; J. K. Beasley, ibid., p. 6123.365 A. D. Abkin, S. N. Kamenskaya, and S. S. Medvedev, Zhur. $2. Khim., 1953,27, 1064. 366 R. A. Hayes, J . Polymer Sci., 1954, 13, 583.367 Y .Kubouchi, T. Yamamoto, and Y . Sono, J . Chem. SOC. Japan, Ind. Chent.Edn., 1954, 57, 386.369 Idenz, ibid., p. 483.221, 437. 359 Idenz, ibid., p. 453.3e3 Idem, ibid., p. 333.36a G. E. Ham, J . Polymer 5 2 . . 1954, 14, 87.370 L. Rodriguez, Makromol. Chem., 1954, 12, 11074 GENERAL AND PHYSICAL CHEMISTRY.are in the order predicted from their free valency numbers as calculated bythe molecular orbital method.371A method of handling the copolymerisation rate equation so that thecross-termination coefficient $ may be obtained by plotting a linear functionhas been proposed and applied to the styrene-methyl methacrylate system.372Further work has been done on the kinetics of copolymerisation of vinylchloride with vinylidene ~hloride.37~ For the copolymerisation of styrenewith butyl acrylate in benzene solution 45 has been found to be very dependenton the ratio of the two monomer concentrations, while remaining independentof solvent c~ncentration.~~~ The physical interpretation of this effect is notclear.The rates of copolymerisation in the three-component system styrene-$-methoxystyrene-methyl methacrylate have been calculated from thevelocity constants and cross-termination coefficients obtained from thestudy of the three one-component and three two-component systems, andare in good agreement with experimentalA variety of methods for the preparation of block copolymers has beendescribed. Polymer radicals of monomer A may be run in a quickly flowingstream into an excess of monomer B.376 A second method involves the useof transfer agents such as carbon tetrabromide to obtain polymer moleculesof monomer A containing C-Br end groups.377 This polymer may then beused to photosensitise the polymerisation of monomer B.In a third method,monomer A is polymerised with phthaloyl peroxide to yield a polymer withperiodic weak peroxide links3T8 This polymer may then be used toinitiate the polymerisation of monomer B. Another case is that of poly-(methyl vinyl ketone) the main chain of which may be split into tworadicals by the action of light.379 In the presence of acrylonitrile a blockcopolymer may then be formed.Ionic Polymerisation.-This field has been exhaustively reviewed byPepper380 and some recent developments have been summarised by P l e ~ c h .~ ~ The formation of polymethylene from diazomethane, catalysed by copperstearate in toluene, has been shown to proceed a t a rate proportional to bothcatalyst and diazomethane concentration^.^^^ The reaction is also catalysedby boron trifluoride. A cationic chain mechanism has been proposedwhich satisfies the observed kinetics but involves considerable chargeseparation in a non-polar medium. The kinetics of the polymerisation ofn-butyl vinyl ether, catalysed by iodine monochloride and iodine mono-bromide and inhibited by pyridine and by 2-iodopyridine, have been in-v e ~ t i g a t e d . ~ ~ The kinetics are similar to those of the iodine-catalysedreaction and the catalyst efficiency increases in the order : Br,, IBr, IC1, I,.371 C.S. Marvel and W. S. Anderson, J. Amer. Chew. SOC., 1954, 76, 5434.8 i 3 A. D. Abkin, S. S. Medvedev, P. M. Khomikovskiy, and E. V. Zabolotskaya,375 D. C. Blackley, H. W. Melville, and L. Valentine, ibid., 1954, A , 227, 10.376 J. A. Hicks and H. W. Melville, ibid., 1954, A , 226, 314.377 A. S. Dunn, B. D. Stead, and H. W. Melville, Trans. Faraday SOC., 1954, 50, 279.378 G. Sniets and A. E. Woodward, J. Polymer Sci., 1954, 14, 126.379 J . E. Guillet and K. G. W. Norrish, Nature, 1954, 173, 625.38a D. C . Pepper, Quart. Rev., 1964, 8, 88.381 P. H. Plesch, J. Polymer Sci., 1954, 12, 481.382 C. E. H. Bawn and T. B. Rhodes. Trans. Faraduy Soc., 1964, SO, 934.383 D. D. Eley and J . Saunders, J., 1954, 1668, 1672, 1677.S.K. Das and S. R. Palit, Chem. and Ind., 1954, 129.J . H. Bradbury and H. W. Melville, Proc. Boy. SOC., 1954, A , 222, 456.2hur.fiz. Khim., 1953, 27, 1516KINETICS OF CHEMICAL CHANGE. 75The effect of retarders on the molecular weight of polymers formed by ionicmechanisms can be used to measure relative rates of attack of a carboniumion pair on various aromatic compounds which act as retarder^.^^ Thecationic polymerisation of 2 : 3-dihydrofurans proceeds through the doublebond and not by opening of the ring.385 Ferric chloride and stannic chloridehave been compared as catalysts in the polymerisation of styrene,386 and thepolymerisation 3835 3*75 389 and copolymerisation 383y 388 of vinyl ethers havebeen studied.The reactivity ratios for the homogeneous ionic copolymerisation ofstyrene with 9-chlorostyrene in carbon tetrachloride-nitrobenzene mixtureshave been measured with five different catalysts.390 Within the experi-mental error no differences could be detected on changing the solvent ratio,the catalyst concentration, or the catalyst.A quantitative investigation has been made of the polymerisation ofethylene oxide catalysed by the anion of phenol.391Condensation and Ring PoZymerisation.-Continuing interest has beenshown in the kinetics and mechanism of polymerisation of ring compounds,particularly of N-carboxy-a-amino-acid anhydride~,~~~3 393 lac tarn^,^^^^ 395 andethylene sulphide 396 and oxide.391 Work on the kinetics of polycondensationreactions includes investigations on the polyesterification of esters of glyceroland phthalic a ~ i d , ~ ~ 7 and on the condensation of monosilicic acid.398De9oZymerisation.-Charlesby 399 has considered the changes in molecularweight and form of the distribution curve when a polymer chain is subjectedto random fracture.Heat, ultrasonics, mechanical action, and ionising radiations have allbeen used to effect degradation of polymer molecules.The supposedcatalytic effect of hydrogen chloride in the degradation of poly(viny1 chloride)has been proved not to exist*00? 401 The autocatalytic nature of the reactionis due rather to the formation of structures of the type *CH:CH*CH,*CHCl*from which hydrogen chloride is more easily removed than from the originalpolymer. The thermal stability of various olefin polys~lphones,~~~ poly-(tetrafluoroethylene) ,4039 and polymers of fluorinated ethylenes 404 have384 C.G. Overberger and G. F. Endres, J . Amer. Chem. Soc., 1953, 75, 6349.385 D. A. Barr and J. B. Rose, J., 1954, 3766.386 M. F. Shostakovsky and V. A. Gladyshevskaya, livest. Akad. Nauk S.S.S.R.,387 hl. F. Shostakovsky, B. I. Nikhant’ev, and N. N. Ovchimnikova, ibid., p. 1056.388 Idem, ibid., p. 721. 389 A. V. Bogdanovaand M. F. Shostakovsky, ibid., 1954,911.390 C. G. Overberger, R. J. Eyrig, and D. Tanner, J . Amer. Chem. Soc., 1954, 76, 772.391 F. Patat, E. Cremer, and 0. Bobleter, J . Polymer Sci., 1954, 12, 489.392 M. Sela and A. Berger, J . Amer. Chem. SOL, 1953, 75, 6350.a93 D. G. H. Ballard and C. H. Bamford, Proc.Roy. SOG., 1954, -4, 223, 495.394 A. Matthes, Makromol. Chem., 1954, 13, 90.395 S. M. Skuratov, V. V. Voyevodskiy, A. A. Strepikheyev, E. N. Kanarskaya, and396 M. Ohta, A. Kondo, and R. Ohi, J , Chem. SOC. Japan, 1954, 75, 985.397 E. E. Shkolman and I. I. Zeidler, J . AppZ. Chem. (U.S.S.R.), 1953, 26, 689, 763.a9* A. Charlesby, Proc. Roy. SOL, 1954, A , 224, 120.*0° E. J. Arlman, J . Polymer Sci., 1954, 12, 543, 547.401 N. Grassie, Chenz. and Ind., 1954, 161.402 M. ,4. Naylor and A. W. Anderson, J . Amer. Chem. SOC., 1954, 76, 3962.403 R. E. Florin, L. A. Wall, D. W. Brown, L. A. Hymo, and D. J. Michaelsen,404 S. 1,. Madorsky, V. E. Hart, S. Straus, and V. A. Sedlak, ibid., 1953, 51, 327.Otdel. Khim. Nauk, 1953, 319.K. S. Muromova, Doklady Akad.N a u k S.S.S.R., 1954, 95, 591, 829, 1017.G. B. Alexander, J . Amer. Chem. Soc., 1954, 76, 2094.J . Res. Nut. Bur. Stand., 1954, 53, 12176 GENERAL AND PHYSICAL CHEMISTRY.been investigated. Rates and molecular-weight changes , together withmass-spectrographic analyses of volatile products have been obtained in acomparative study of the degradation of polymethylene, polyethylene, andradiation-cross-linked polyethylene.4o5 The degradation of 1 % solutions ofvinyl polymers has been studied at 65-100" by using radicals from benzoylperoxide to initiate the reaction.u6 The relative stability of differentpolymers under these conditions is discussed in terms of the lability of certainatoms in the polymeric chain and of the stability of the intermediate polymerradicals.The thermal degradation of 66 Nylon has been furrther studied 407and the results correlated with other recent work. Diffusion effects whichmay arise in the photochemical degradation of thin films of polymer havebeen considered theoretically.MsIt is now agreed that cavitationis essential if degradation of high polymersis to be brought about by ultrasonic waves.409*410 The major part of thereaction is due to the mechanical forces produced on collapse of the cavities.Dissolved gases have an effect which is an inverse function of their solu-bilities 4*9 and the amount of degradation is also dependent on the length 411and shape410 of the polymer molecules. In aqueous solution secondaryeffects may occur owing to the production of HO,* radicals.410 Themechanical degradation of dissolved polymer molecules on impact withsuspended solids has also been studied.412Increasing interest has been shown in the action of ionising radiation onpolymers. The results are dealt with in the section on radiation chemistryEssex 413 has reviewed themethods available for deciding to what extent gas-phase radiation-chemicalreactions are initiated by each of four primary mechanisms, the argumentsbeing illustrated by previously published and new data.No spectacularadvance has occurred during the past year but two papers merit attention.The first 4l4 presents systematically a large amount of data on the relationbetween molecular structure and the stability of substances towards electronimpact as measured by the mass spectrometer.It will probably be of interestand value to anyone working on the irradiation of organic materials. In thesecond paper Lindholm 415 presents an extension of his previous work on thebombardment of hydrogen sulphide by atomic ions. Carbon dioxide, watervapour, hydrogen sulphide, ammonia, methane, and nitrous oxide werebombarded by sixteen different atomic ions. Water vapour is of specialinterest and it is noteworthy that, whilst with most ions there arises a higherproportion of H,O+ than OH+ (those two always being predominant) never-theless with Kr2+ ions the ratio OH+/H,O* was 5 : 1 and with F+ ions it was1 : 1, adding further point to the comment made last year.415a405 L. A. Wall, S.L. Madorsky, D. W. Brown, S. Straus, and R. Simha. J. Amer.406 G. Tasset and G. Smets, J. Polymer Sci., 1954, 12, 517, 531.407 I. Goodman, ibid., 1954, 13, 175. 40B J . E. Wilson, J . Chem. Phys., 1964,22,334.400 H. W. Brett and H. H. G. Jellinek, J. Polymer Sca., 1954, 13, 441.*lo P. Alexander and M. Fox, ibid., 1954, 12, 533.411 N. Sata and M. Okuyama, 2. Elektrochem., 1954, 58, 196.412 F. Sonntag and E. Jenckel, KoZZoid Z., 1954, 135, 1, 81.413 H. Essex, J. Phys. Chern., 1954, 58, 42.414 M. Pahl, 2. Natu~fo~sch., 1954, Qb, 188.415 E. Lindholm, ibid.. 9a, 535.(P. 79) * Radiation Chernistry.-Primmy pyocesses.Ckem. Soc., 1954, 76, 3430.41sa Ann. Reports, 1953, 50, 63KINETICS OF CHEMICAL CHANGE. 77Actinometry. The enigma of the absolute energy yield (G) of the ferroussulphate actinometer (i.e., the number of moles of ferrous salt producedper 100 ev) for light particle and photon radiations appears to be nearersolution. All the recently published estimates give GF2+ nearer to 15.5than to 20 (see Table).Value of W,,Ref.Measurement used (ev) Radiation G416 I) 32.5 60Co y 15.9 f 0-4417 3, 34.3 1 MevX 15.9 f 0.5418 ,, 35-0 200 kvp X 16.2 f 0.8419 Calorimetric -420 Power input - 1 or 2 Mev electrons 15.6 &- 0-5416 Ionisation 32.6 24-5 Mev X 15.9 & 0.4SOCO y 15.8 f 0-3Nevertheless the situation with regard to the ionisation method stillpresents its anomalies, the agreement between the above values being byno means so good if the same value of W,k (ie., the energy required toproduce an ion pair in air) is used.Criticisms of the first two results in theTable have also been made.417$ 419 Miller and Wilkinson 421 have made a verycareful investigation of the irradiation of the ferrous sulphate system with2lOPo a-rays. Particular attention was given to the absolute energy yieldunder normal actinometric conditions. This was found to be Ga(Fe2+ --PFe2+) = 5-94 This valuecompares favourably with the value Ga(Fe2+ --+ Fe3+) = 6.2 0-2obtained by McDonell and Hart,422 also using 210Po a-rays.Other actinometric methods which have been suggested include the useof ferrous sulphate and cupric sulphate in sulphuric acid to measure“ molecular ” product yields only:= a bromoform-crystal-violet systemcapable of giving a visual colour change with a dose of 5 roentgen^,^^ themeasurement of gas evolution for y,n and a Cellophane-dyesystem.426 Two discussions of physical methods of dosimetry have beenpre~ented.~~7, 428There has been little work donein the vapour phase.The reaction between tritium and oxygen induced bythe p-rays from tritium has been shown429 to proceed by only very shortchains, giving G(H2/02) = 12.7 and G(T,/02) = 9.8. The products of theirradiation of nitrogen dioxide by neutrons do not recombine to nitrogendioxide; some net change to nitrogen, oxygen, and nitrous oxide has beenfound.m0.10, using W,k = 35-6 ev or Wsrgon = 26.3 ev.Non-aqueous vupour and liquid systems.D. V. Cormack, R. W. Hummel, H. E. Johns, and J. W. T. Spinks, J .Chem.Phys., 1954, 22, 6.417 Jerome Weiss, W. Bernstein, and J . B. H. Kuper, ibid., p. 1593.418 F. T. Farmer, T. Rigg, and J. Weiss, J . , 1954, 3248.419 R. M. Lazo, H. A. Dewhurst, and M. Burton, J . Chem. Phys., 1954, 22, 1370.420 J. Saldick and A. 0. Allen, ibid., p. 438.431 N. Miller and J. Wilkinson, Trans. Faraday SOC., 1954, 50, 690.422 W. R. M. McDonell and E. J. Hart, J . Amer. Chem. SOC., 1954, 76, 2121.re3 E. J. Hart and P. D. Walsh, Radiation Res., 1954, 1, 342.4p4 J. F. Suttle, U.S. Atomic Energy Commission Report, 1954, L.A. 1615.425 E. J. Hart and S. Gordon, Nucleonics, 1954, 12 (4), 40.4z6 E. J. HenIey, ibid., (9), 62.4 2 7 L. D. Marinelli, Radiation Res., 1954, 1, 23.449 L. M. Dorfman and B. A. Hemmer, J . Chem. Phys., 1954, 22, 1555.430 P.Harteck and S. Dondes, ibid., p. 953.4z8 U. Fano, ibid., p. 378 GENERAL AND PIIYSIC.41, CHEMISTRY.Paramagnetic resonance absorption measurements have been made onvarious substances irradiated with y-rays. Irradiation of perchloric, sul-phuric, and phosphoric acids, at 77" K, with y-rays gave rise to absorptiontimes attributable to trapped free radicals.431 One of the radicals wasidentified as atomic hydrogen. Various amines, sugars, and plastics havebeen investigated in a similar manner.432 I t is of interest that the amino-acids which did not give positive indication of trapped free radicals containedeither an aromatic ring or a thiol group.The products of bombardment of a series of liquid, air-free alcohols with28 Mev helium ions indicate that the primary act involves breakage of thebonds linking the carbinol carbon atoms to groups other than the hydroxylThere is little indication of a splitting of the C-OH bond to givehydroxyl radicals and this is supported by the results414 of mass spectro-metry. However, an investigation of the irradiation with X-rays of sterolsin various solvents revealed a similarity in the behaviour of methyl alcoholand water, and it was suggested that hydroxyl radicals were produced inboth cases.434The similarity of variation of the radiation and quantum yield in theradiolysis and photolysis of liquid alkyl iodides indicates that the principalreactive species formed is the same in each case,435 despite the fact that theprimary act is not the same.-7-Radiation has been used to bring about the chlorination of variousaromatic compounds.436 Marked differences were found between the resultsof such chlorinations and those induced by ultraviolet light, there being withy-rays a greater tendency to add chlorine to the nucleus.Burton and Patrick have investigated the radiation chemistry of severalmixtures of organic compounds.In mixtures of cyclohexane and hexa-deuterobenzene there is evidence of protection of excited cydohexane mole-cules by energy transfer to the deuterobenzene. There also appears to besome sensitisation, by deuterobenzene excited to a low-lying energy state,437of the decomposition of cydohexane by a rearrangement process. Similarlya rearrangement decomposition of propionaldehyde is sensitised by hexa-deuterobenzene, but in this case the normal decomposition of the excitedaldehyde molecule, as found in the pure state, is unprotected by the deutero-benzene.438 In mixtures of benzene with 9-tcrphenyl, m-terphenyl, oranthracene, only m-terphenyl was effective in protecting benzene fromdecompositi~n.~~An increasing interest is being shown in theaction of ionising radiations in promoting polymerisation and in cross-linkingor degrading polymers.Most of this stems from the potential use of suchreactions in industry.Radiation +oZymerisatioiz.431 R. Livingstone, H. Zeldes, and E. H. Taylor, Phys. Rev., 1954, 94, 725.432 J. Combrisson and J. Uebersfeld, Compt. rend., 1954, 238, 1397.433 W. R. McDonell and A.S. Newton, J . Amer. Chem. SOC., 1954, 76, 4651.434 13. Coleby, M. Keller, and J. Weiss, J., 1954, 66.434a Ann. Reports, 1953, 50, 65.435 E. L. Cochran, W. H. Hamill, and R. R. Williams, J . Amer. Chem. SOC., 1954, 76,436 D. E. Harmer, L. C. Anderson, and J. J. Martin, Chem. Eng. Progv. Symp., 1954,4 3 8 W. N. Patrick and M. Burton, ibid., p . 424.43s M. Btirton and W. N. Patrick, J . Chem. Phys., 1964, 22, 11503145.No. 11, 253. 4 3 7 M. Burton and W. N. Patrick, J . Phys. Chem., 1954, 58, 421I< I N 1c-r I ; s 0 F CII 1; MI C A I, CH AN C E . $9The reactions most commonly studied are those of vinyl compounds butpolymers of other kinds can be produced by radiations. Benzene, forexample, is polymerised by electron irradiation,440 but the structure of thepolymer is unknown and the mechanism not clear cut.Recent work on the radiation polymerisation of vinyl compounds hasincluded the polymerisation of ethylene 441 and vinyl chloride 442 as vapours,the bulk polymerisation of styrene 4439 444 and methyl rnetha~rylate,~~ andthe polymerisation in solution of acrylamide,445 446 methyl meth-acrylate,446 and N-~inylpyrrolidone.~7 The polymerisation of ethylene 441can be induced at much lower pressures than are required in non-radiationpolymerisations and the resultant polymer tends to be somewhat morecrystalline.Sulphur dioxide and ethylene formed an equimolar additionproduct under the same conditions. N-Vinylpyrrolidone was polymerisedin a variety of solvents 447 and it appeared that all the non-aqueous solventswere less efficient than water in promoting polymerisation under y-irradiation.It has been shown that various perfluorinated monomers, which have notpreviously been polymerised, may be polymerised with X-rays.448 How-ever, the rates of polymerisation and molecular weights were very low.Aninteresting development is that of the polymerisation of acrylamide in thesolid state induced by radiation.448, 449, 450 Similar results are also possiblewith other monomers.451 Emulsion polymerisation induced by radiationhas also been reported for the first time.448 With styrene the rates are fasterthan those for polymerisation in bulk.The detailed kinetics of most radiation-induced polymerisations are stilluncertain.The dependence of the overall rate of the polymerisation ofstyrene on the square root of the dose rate has been established for dose ratesbetween 0.3 and 410 r./min.,& and the relation probably holds up to 1150r./min.452 At higher dose rates, however, it is uncertain whether the dose-rate exponent increases to unity451 or falls to zero.444 The rate of thepolymerisation of solid acrylamide is proportional to the 0-75th power ofthe dose rate. This behaviour may indicate some degree of non-uniformityof initial radical production.48Solids. The number of polymers on which the effects of radiation havebeen investigated is now very large. Nevertheless much more informationis required before we have anything like a complete understanding of thedifferent factors involved. Recently an attempt has been made on the basisof known results for vinyl-type straight-chain polymers to correlate effects440 W.N. Patrick and M. Burton, J . Amev. Chem. SOC., 1954, 76, 2626.4 4 1 J. G. Lewis, J. J. Martin, and L. C. Anderson, Chem. Eng. Progv., 1954, 50, 249.442 W. Mund, M. Van Meersche, and J . Momigny, Bull. SOC. chim. bslges, 1953, 62,443 D. S. Ballantine, P. Colombo, A. Glines, and B. Manowitz, Chem. Eng. Progv.444 A. Chapiro, M. Magat, J. Sebban, and P. Wahl, International Conference on4 4 5 R. Schulz, G. Renner, and A. Henglein, Makronzol. Chem., 1954, 12, 20.4 4 6 W. H. Seitzer and A. V. Tobolsky, US. Atomic Energy Commission Report,4 4 a D. S. Ballantine, ibid., 1954, B.N.L. 294.449 R.B. Mesrobian, P. Ander, D. S . Ballantine, and G. J. Dienes, J . Chem. Pliys.,461 D. S. Ballantine-unpublished work.452 A. A. Miller E. J. Lawton. and J . S. Balwit, J . Polymey Sci., 1954, 14, 503,644.Syvlzp., 1954, No. 11, 267.Macromolecular Chemistry, Milan, 1954.1954, N.P. 5306. 4 4 7 D. S. Ballantine and B. Manowitz, ibid., October 1954.1954, 22, 565. 450 A. Henglein and R. Schulz, 2. Maturforsclz., 1954, 9b, 61780 GENERAL AND PHYSICAL CHEMISTRY.with structure.452 It is suggested that cross-linking results if the polymercontains at least one cc-hydrogen atom and that if this is not the casedegradation is predominant. In a polymer of the type (B)the substituents R1 and R2 (which may be anything otherthan hydrogen atoms) will not affect the direction of theradiation effects but will influence the ejiciency and may leadto by-products, i.e., degradation will always be predominantbut the rate of degradation will vary according to R1 andR2.Mechanisms for cross-linking and degradation have also been advancedand many examples supporting the concept are gi~en.45~The polymer which continues to receive the greatest attention is poly-ethylene. In agreement with the above theory the most obvious effect ofirradiation is cross-linking, and this produces marked changes in physicalNevertheless, it has been shown that 70--80% of theevolved hydrogen corresponds to the production of unsaturation in the formof trans-vinylene groups.455, 4669 457 At the same time the number of vinyl-idene groups decreases and the rate of decrease gives evidence of a long-rangemigration of chemically active centres, most probably free radicals.Con-trary to an earlier report and the suggestions therein458 it has been foundthat the evolved gas contains lower hydrocarbons as well asand it has been suggested that cross-linking occurs mainly through sidechains rather than by the main ~ h a i n . ~ 5 ~ A positive demonstration of theoccurrence of chain scission has been given by Baskett460 who has alsoshown how the results of the irradiation of polyethylene may be used toevaluate its molecular weight distribution. Charlesby has shown that theenergy to produce a cross-link is the same for Pz-paraffins between C,H,,C,6H,, as for polyethylene with a chain length of ZOO0.461Other polymers which have been studied in any detail are poly(methy1methacrylate) ,462 poly(ethy1ene terephthalate) ,4631 464 and cellu-10se,*~5 all of which are predominantly degraded, and rubber 466 and sil-oxanes 467 which are predominantly cross-linked.Water and Aqueous Solutions.-As always, investigations of aqueoussystems have accounted for the largest fraction of the published work inradiation chemistry.The major interest continues to centre on the natureof the processes occurring and the values of the " molecular " and " radical "yields. Surveys of these aspects have been made by Allen,468 Hart,a6Q andDewhurst, Samuel, and Magee.470R'-cH~---c- i ( B ) I,i4~ A. Charlesby, Nucleonics, 1954, 12 ( 6 ) , 18.d84 E.J. Lawton, S. Balwit, and A. M. Bueche, I n d . Eng. Chem., 1954, 48, 1703.455 M. Dole, C. D. Keeling, and D. G. Rose, J . Amev. Chem. SOL, 1954, 76, 4304.459 D. S. Ballantine, G. J. Dienes, B. Manowitz, P. Ander, and R. B. Mesrobian,457 M. Dole and C. D. Keeling, J . Amer. Chem. SOC., 1953, '75, 6082.458 A. Charlesby, Proc. Roy. SOG., 1952, A , 215, 187.459 E. J. Lawton, P. D. Zemany, and J. S. Balwit, J . Amer. Chem. SOC., 1954, 76,3437.460 A. C. Baskett, International Symposium on Macromolecular Chemistry, Milan,1954.462 P. Alexander, A. Charlesby, and M. Ross, ibid., 223, 392.463 K. Little, Nature, 1954. 173, 680. 464 A. Todd, ibid., 174, 613.4 6 5 A. Charlesby, Atomic Energy Research Establishment Report, 1954, A.E.R.E.-MIR- 1342.466 Idem, Atomics, 1954, 5 ( l ) , 12.~7 Idem, Nature, 1954. 173, 679. 4~38 A. 0. Allen, Radiation Res., 1854, 1, 85.4~ E. J. Hart, ibid., p. 53.470 H. A. Dewhurst, A. H. Samuel, and J. L. Magee, ibid., p. 62.J . Polymer Sci., 1954, 13, 410.461 A. Charlesby, Proc. Roy. SOL, 1954, A , 222, 60KINETICS OF CHEMICAL CHANGE. 81(i) Processes in the radiation chemistry of water. Laidler 471 has formul-ated a self-consistent scheme of elementary processes in the radiationchemistry of water, based on a combination of theoretical considerations andexperimental observations. The commonly accepted process H,O- ----tH + OH- is considered unlikely to occur and is replaced by H,O--2H + 0-. The proposed fate of the 0- ion (0- + H,O __t OH + OH-)seems rather unsatisfactory in view of an earlier comment.472 A sequencesuggested for the formation of molecular hydrogen is H,O + e-H- + OH, followed by H- + H20 -+ H, + OH-.The ions H+, Of,OH+, and HS+ are also involved.I t has been shown *'3 that the infrared spectroscopic evidence advancedearlier 474 in support of the formation of hydrogen atoms in irradiated wateris ambiguous, but the participation of hydrogen atoms in irradiated water isfar from being disproved. Kelly, Rigg, and Weiss 475 have shown by anelegant method involving the use of deuterated water that some, but byno means all, of the hydrogen evolved from the irradiation of air-free solu-tions of ferrous sulphate is of molecular origin, whilst that from irradiationsof ceric sulphate or oxygenated ferrous solutions is entirely so.They suggestthat " molecular " products are formed by the interaction of excited watermolecules as follows, 2H20* H, + H20,, a concept which has alsoappeared elsewhere.470- 476 In irradiations with a-rays hydrogen may beproduced by a molecular process but hydrogen peroxide appears not to2H20* ---P H2 + 20H477 This has led to two alternative sugge~tions,~7~ viz.,H Oor H20f + H+ + OH followed by H+ H30+ --& H, + OH(ii) The moZecacZar and radical yieZds. The Table summarises recentvalues obtained for these quantities. The work of Hart 481 on the pH-dependence of the measured yields is of particular interest as it is the firstinvestigation with the deliberate aim of ascertaining the effect of pH changeson the yields.The temperature coefficient of the rate ofoxidation of ferrous ions under y-irradiation has been examined 4* andfound to be 0.40 & 0.03% per O c .In the same system the ratioGaerakdlGpir-free has been found to be 1-88 = 0 ~ 0 4 . ~ ~ ~ In the presence ofbenzene a radiation-chemical stationary state is set up with 50--55%of Fe3+ i0n.~86(iii) Other aqueous systems.4 7 1 K. J. Laidler, J . Chem. Phys., 1954, 22, 1740.4 i 3 I;. S. Dainton, Discuss. Favaday SOC., 1952, 18, 245.473 I;. Fiquet and A. Bernas, J . Chint. phys., 1954, 51, 47.4 i 4 E. Collinson and F. S. Dainton, Discuss. Faruduy Soc., 1952, 12, 212.4 i 5 P. Kelly, T. Rigg, and J. Weiss, Nature, 1954, 1'93, 1130.4 i 6 M. Lefort, J . Chinz. phys., 1954, 51, 351.4 i 7 M.Cottin, ibid., p. 404.4 7 8 H. A. Schwarz, J. P. Losee, and A. 0. Allen, J . Amer. Chem. SOL, 1954, 76, 4693.4 i 9 T. J. Sworslii, ibid., p. 4687.480 E. R. Johnson and Jerome Weiss, J . Chem. Phys., 1954, 22, 752.4 s 1 E. J . Hart, J . Amer. Chem. SOC., 1954, 76, 4198.483 M. C. Anta and M. Lefort, J . Chim. phys., 1954, 51, 29.484 H. A. Schwarz, J . Amev. Chem. Soc., 1954, 76, 1587.4a5 N. I;. Barr and C. G. King, ibid., p. 5565.48G C. Vermeil and M. Cottin, J . Chim. Phys., 1954, 51, 24.Idem, ibid., p. 4312Value ofG (Fe3 r )used Radiation15.8 “CO yor 2 BIev X15.6 “CO y60Co y15.8 6 o C ~ y18.5 ‘j0Co y15.5 6 o C ~ y16.2 200 k1.p X12.9 3H ,95.94 ,loPo a8-2 ,loPo a210Po u210Po azlOPo aSystem *D.S.KI, KBr,KNO,, NaAsO,,, KBrD.S. NaPO,4.2 1eB (n, a)’ Li ,, FeSO,Acidityneut., alk.O*4M-I12S041M-HZSO4O*4M-HzSO4O*4M-H,SO,O*4M-H,SO4PH 2neut.pH 0-32 $pH 2.10pH 2.70pH 6.81pH 11.58 -GHlOs ---0.780.75-- -0.860.810.520-480-53-- I0.01N-H2S04 0.54O*4M-H,SO, 0.88 - 9 1-74neut. -GH20.4520.3920.3760.390.420.4330.5180.2650.350.420.410.440.320.430.430.540.3251.561.571.7-1.91.81.81.01-GH---3.702.782-54 - -3.593.473-022-983.10I --3.803.060.700.77 ---0.54* D.S. = Dilute solutions, t G( 1) = G(H,O) for the process H,O --+ H +$ Selected values only.(32) = 9 , I 1 I. H2O- 4H2G(3) = 1 , 3 , ,, H2O- H KINETICS OF CHEMICAL CHANGE.$3Breakdown of polymers both in aqueous and in other solutions has beenBoth chloroform 489 and chloral hydrate 490 decompose by chain mechan-isms when irradiated in aqueous solution. The respective lifetimes of thechains are 1 second and 0.1 second.Stein and Swallow 491 have discussed the reduction by X - and y-irradi-ation of some substances of biological interest.Gas-phase Oxidation Processes.-Gas-phase oxidation processes have notbeen reviewed in these Reports since 1950 ; and then the Review was limitedto the oxidation of hydrocarbons and was necessarily very cursory. Everyyear, however, sees the publication of so large an amount of work on theoxidation of all kinds of fuels that the Reviewer has concentrated on certaintopics.Work on the hydrogen-oxygen reactionwas last reviewed in these Reports in 1948.A general account of the workcarried out up to 1950 is to be found in a book published by Lewis andvon Elbe,492 though it contains little about studies that have been made ofthe lowest pressure limit of explosion. It is notable that the oxidation ofhydrogen is the only gas-phase oxidation system about the “ basic ” mechan-ism of which there is general agreement. This mechanism is accepted to best~died.447,487,488The hydrogen-ozygefi system.. . . . . . H * + O , = * O H + O (1)aOH+H2 =H,O +He (2)O + H 2 = * O H + H * . (3). . . . . .. . . . .together with (i) surface destruction of H, 0, and OH radicals at pressuresnear the first explosion limit; (ii) the reactionand surface reaction of HO, radicals at pressures near and above the secondexplosion limit ; (iii) a “ regeneration ” reaction, such as.. . . H*+O,+M=HO,*+M (4)operative a t pressures above the second and approaching the third explosionlimit. Many other reaction steps are possible, however, and there is nodoubt that some of these are of kinetic importance. Lewis and von Elbe,493for example, give what is described as a “ complete ” reaction mechanism.By 1950, there was a tendency, in some quarters, to regard the completemechanism, especially at pressures near the second explosion limit, as settledand done with. This was premature; for in 1951 Egerton and Warren 494showed that, when the reaction was carried out in a boric oxide-coatedvessel, the plot of partial pressure of hydrogen versus partial pressure of4 8 7 P.Alexander and M: Fox, Trans. Faruduy Soc., 1054, 50, 605.488 A. Chapiro, J. Durup, M. Fox, and M. Magat, International Symposium on489 R. W. Hummel, A. B. Van Cleave, and J. W. T. Spinks, Canad. J . Chem., 1954,491 G. Stein and A. J. Swallow, Eature, 1954, 173, 937.4 g 2 B. Lewis and G. von Elbe, Combustion, Flames and Explosions of Gases,”4B3 Idem, Third Symp. Combustion, Flame and Explosion Phenomena, Williams and*gr (Sir) A. C. Egerton and D. R. Warren, Pvoc. Roy. Soc., 1951, A , 204, 465.Macromolecular Chemistry, Milan, 1954.32, 522. 490 G. 13. Freeman, A. B. Van Cleave, and J. W. T. Spinks, ibid., p. 322.Academic Press, New York, 1951.Wilkins, Baltimore, 194984 GENERAL AND PHYSICAL CHEMISTRY.oxygen at the second explosion limit had a quite different form from whathad always previously been found and on which the above mechanism hadbeen largely founded.The partial pressure plot is now described by theequation[H,] + c[02] = K + b[02]-4 . . . . . (5)which is identical with the usual equation except for the addition of theterm b[02]-4. Subsequently, Dixon-Lewis, Linnett, and Heath 495 havefound that a silica vessel that has been washed with hydrofluoric acid givessimilar results to a vessel coated with boric oxide. Consideration of equation(5) shows that the extra term on the right-hand side must be due to a branch-ing process not hitherto included in reaction schemes.The form of theterm b[O,]-i shows that the new branching process cannot be due to areaction that is first order with respect to chain carrier concentration, but isjust what would be expected if a reaction were included that is of second orderwith respect to chain-carrier concentration. Egerton and Warren 494 veryplausibly propose the reactionto account for this " quadratic branching " process. It is easily seen, fromthe basic mechanism, that if the rate of destruction of HO, radicals isprimarily controlled by the rate of their diffusion to the surface, their con-centration is proportional to the concentration of hydrogen atoms; and sothe rate of (6) is proportional to [HI2. When (6) is included, the conditiondefining the second explosion limit involves the rate of chain-initiation.Now, Lewis and von Elbe 493 have powerfully argued that, once the earlieststages of reaction are over, the effective initiation process in the slow reactiona t pressures well above the second explosion limit isProvided that H,02 reaches a steady concentration independent of chain-carrier Concentration, (7) may fairly be dubbed an " initiation " process.Egerton and Warren494 suppose that (7) is also the main initiation processoperative at the second limit in boric oxide-coated vessels, though theysuppose its rate to be independent of [MI.They follow Lewis and von Elbein supposing H,O, to be mainly destroyed by the reactionand, at the second limit in boric oxide-coated vessels, to be mainly formed bythe surface reaction of HO, radicals.It is thus possible for [H,O,] to beindependent of chain-carrier concentration.With these equations, Egerton and Warren are then able to obtain anequation of the type (5) and so explicitly formulate expressions for K and b.Warren 496 has extended the treatment to obtain general expressions coveringthe behaviour of all three explosion limits over a wide range of temperature,mixture composition, vessel size, and wall coating. At potassium chloride-coated surfaces, Egerton and Warren494 assumed €30, to be destroyedwithout giving rise to H202. This means that, with such surfaces, at thesecond limit no hydrogen peroxide is formed and (7) cannot occur. Since495 G. Dixon-Lewis, J. W. Linnett, and D. F. Heath, Trans.Faraday SOC., 1953,49,766.H*+H02*=20H* . . . . . . (6)H,02+M--r20H*+M . . . . (7)HO,+ H202 =H20+ 02+ OH . . . . (8)496 D. R. Warren, Proc. Roy. SOL., 1952, A , 211, 86KINETICS OF CHEMICAL CHANGE. a5quadratic branching will only be kinetically important when the rate ofchain initiation is sufficiently high, the failure of a quadratic branching effectto be noticed in a KC1-coated vessel is understandable. These assumptionslead to the equations K = Zk,/k, in a potassium chloride-coated vessel andK = 3K,/k, in a boric oxide-coated vessel; whereas, experimentally, K isthe same for both vessels. Warren497 is therefore driven to assume thatHO, gives rise to hydrogen peroxide in both vessels, but that the H,O, isonly released to the gas phase in the boric oxide-coated vessel.(8) is sup-posed to occur in both vessels, but on the surface in a potassium chloride-coated vessel and in the gas phase in a boric oxide-coated vessel. AsWarren himself realised, the complexity of the consequential assumptionslacking independent support is an unsatisfactory feature of his scheme.Dixon-Lewis, Linnett, and Heath495 have attempted to get over thedifficulty by (i), keeping the plausible assumption that HO, is destroyed ata potassium chloride surface without giving rise to hydrogen peroxide;(ii) retaining also steps (6) and (8); (iii) supposing (7) to occur at a ratedependent on [MI, but (iv) postulating that on a boric oxide surface HO,reacts with H, to give rise to H,O, and H which are then liberated to thegas phase. Their scheme leads to more complex expressions than does theEgerton-Warren treatment, but with certain additional assumptions canalso be made to explain the form of equation (5).It seems very probable that Egerton and Warren are correct in theirfundamental assumption that quadratic branching occurs in a boric oxide-coated vessel.The step responsible is not yet established but is veryplausibly taken as (6). Chain-initiation at the second limit by (7) is alsoplausible but not established. There is little doubt that the peculiarbehaviour of the reaction in a boric oxide-coated vessel is somehow con-nected with the formation of hydrogen peroxide from HO, on the surface;while on potassium chloride surfaces the probability is that HO, does notgive rise to hydrogen peroxide.It is readily shown that when quadratic branching is operative theexplosion limits of a chain-isothermal explosion should be widened by anincrease in the rate of initiation.In support of Egerton and Warren'smechanism is the fact that injection of hydrogen and oxygen atoms intohydrogen-oxygen mixtures does produce this eff 499 All earliertheories failed to explain this phenomenon because the proposed branchingmechanisms were linear.The absolute values of the rate constants proposed by Lewis and vonElbe and of which unreserved acceptance has always been difficult, nowrequire revision as a result of the work of Egerton and Warren. Some rateconstants given by Lewis and von Elbe are almost certainly wrong.Thusthey give the value 3-7 x (~rn~/moIecule)~ sec.-l for the rate constant ofreaction (4) when M is H, ; which value implies a rate constant for reaction (1)of ca. 0.87 x cm3/molecule sec.-l at 520" c. Now three independentmethods of estimating k , concur in yielding a value ca. lo3 times as great asLewis and von Elbe's val~e.~W It follows that the true value for k, is also497 D. R. Warren, Proc. Roy. SOL, 1952, A , 211, 96.4s8 F. Haber and F. Oppenheimer, 2. phys. Chem., 1932, B, 16, 443.499 A. Nalbandyan, Phys. 2. Sovietunion, 1933, 4, 747.500 R. R. Baldwin and A. D. Walsh, Discuss. Faraduy SOC., 1954. 17, 9686 GENERAL AND PHYSICAL CHEMISTRY.greater by a factor of ca. lo3 than Lewis and von Elbe's estimate. Therevised value for k4 brings it into line with the known values of the rateconstants for the three-body recombinations of halogen or H atoms, whichare all around (cm3/atom), sec.-l.It has long been known that the carbon dioxide, nitrous oxide, andwater molecules are especially efficient as third bodies in bringing about re-action (4).Walsh 501 has given a theoretical discussion of the efficienciesof third bodies in reaction (4) and show? that the especial efficiency of thesemolecules may be correlated with the magnitudes of the fundamentalvibration frequencies possessed by these molecules.Other recent work on the hydrogen-oxygen reaction has included com-munications by BroidaJm2 Broida and Oldenberg503 and S a y a s ~ v . ~ ~Hydrogen-oxygen-hydrocarbon systems.Many hydrocarbons and theirderivatives inhibit the hydrogen-oxygen reaction at the first ( P I ) and second(Pz) explosion limits.505~ 506' 507 Several pieces of recent work 5°7-512 havebeen devoted to a study of this inhibition. In part, the study has grownout of the war-time problem of reducing exhaust flames from aero-engine~,~~'since the exhaust gases from such engines contain hydrogen, oxygen, andhydrocarbons. The study is also of importance in giving information onthe reaction steps whereby hydrocarbons oxidise at the relevant temper-atures, and on the absolute rates of the reaction steps involved in theoxidation of hydrogen.With ethane and propane,509 an almost linear relation between P, andhydrocarbon mole fraction (i) is obtained.The effectiveness of the inhibitormay, therefore, be conveniently defined by the mole fraction (it) requiredto halve the limit. Study of how it depends on the various variables andalso of the inhibition at P, makes it practically certain that the inhibition isprimarily due to the reactioncompeting with reaction (1) : and that, at ca. 500" c, the fate of the alkylradicals R is, a t least predominantly,From the measurements of i,, it is possible to derive the ratio k,/kl, and SO,from a knowledge of k,, to derive a value for k,. This is one of the waysreferred to above in which k , has been estimated.The characteristics of the inhibition caused by methane are sharplydifferent from those of the inhibition caused by ethane and propane. Thisis not surprising, since when R = CH, reaction (10) cannot occur.Additionsof methane up to a critical mole fraction produce only a very small decreaseof P,; but at a critical mole fraction the explosion suddenly becomes com-. H + R H = H 2 + R . . . . . . (9)R + 0, =olefin + HO, . . . . . (10)501 A. D. Walsh, Fuel, 1954, 33, 247.H. P. Hroida, J . Chem. Phys., 1951, 19, 790.503 H. P. Broida and 0. Oldenberg, ibid., p. 196.504 Yu. S. Sayasov, Zhur.fzz. Khim., 1954, 28, 1043.605 E. Jones, J . Apfil. Chem., 1951, 1, 411.506 L. Seig, Angew. Chenz., 1951, 63, 143. 607 R. R. Ealdwin, Fuel, 1952, 31, 312.508 R. R. Baldwin, N. S. Corney, and R. M. Precious, Nature, 1962, 169, 201.&09 R. R. Baldwin, N. S. Corney, and I?. K. Simmons, Fifth Symp.Combustion,610 A. Levy, Fuel, 1953, 32, 263.511 A. Levy and J. F. Foster, Fifth Symp. Combustion, Williams and Wilkins,Williams and Wilkins, Baltimore, 1955.Raltimore, 1955. 612 A. Levy, J . Chem. Phys., 1953, 21, 2132KINETICS OF CHEMICAL CHANGE. 87pletely s u p p r e s ~ e d . ~ ~ ~ ~ 509, 512 The initial small drop of P, is probably dueto inhibition by water vapour formed from the methane.510, 512 The causeof the sudden suppression of explosion is not altogether clear, but is cer-tainly bound up with the effect of formaldehyde formed from themethane.509, 512 Additions of formaldehyde cause particularly effectiveinhibition. The reason is probably a first step analogous to (9), followedby a reaction of HCO radicals to yield inert products (e.g., HCO + 0, =HO, + CO).Assuming that a first step analogous to (9) occurs, one con-cludes that, a t 500" c and under the conditions used, HCO radicals do notexclusively or largely decompose to H + CO-which is a conclusion ofparticular importance to the theory of the oxidation of formaldehyde,where it has sometimes been supposed that HCO radicals, even a t muchlower temperatures, exclusively decompose to H + CO. Levy 510 andLevy and Foster 511 think that inhibition by water vapour formed from themethane is also partly responsible for the inhibiting effect of methane at P,.Although hydrocarbons inhibit at P, and P,, methane 512 and propane,511a t least, may accelerate the slow reaction of hydrogen-oxygen mixtures atpressures well above P,. Levy and Foster 511 have studied the accelerationcaused by propane and ascribe it partly to the increase of total pressure asthe propane oxidises (which increase reduces the rate of diffusion of chaincarriers to the walls), partly to the production of water vapour from thepropane and partly to other, unspecified, products of the propane-oxygenreaction.It is well known that although water vapour lowers P, it mayaccelerate the slow reaction at pressures well above P,.We have seen that only what maybe described as the basic mechanism of the hydrogen-oxygen reaction canbe regarded as established. The theory of the hydrogen-oxygen reaction,however, is in an advanced stage of development compared with that of thecarbon monoxide-oxygen reaction.Far fewer facts are as yet establishedfor the latter reaction. Nevertheless, the last few years have revealed arevived interest in the oxidation of carbon monoxide and, on the factualfoundation that has now been laid, it is likely that the next few years willsee a rapid erection of further fact and theory.The discovery,513 around 1930, that the carbon monoxide-oxygen systemshows two pressure limits of explosion a t any one temperature led to a spurtof activity in studying the system. Prettre and Laffitte,514 and Topley 515(like Dixon 516 earlier) all showed that small quantities of water vapourcould profoundly affect the system under certain conditions. Garner andhis c o - ~ o r k e r s , ~ ~ ~ ~ 518 however, showed that water vapour did not affect thelower pressure limit of explosion.Hadman, Thompson, and Hinshelwood 519obtained values of the upper pressure limit for the carefully dried gases a tfour different temperatures. It so happened that their values agreed, veryroughly, with values of the upper pressure limit obtained by Kopp, Kowal-sky, Sagulin, and Semenoff 513 for the undried gases. Hadman et al., there-K1a D. Kopp, A. Kowalsky, A. B. Sagulin, and N. Semenoff, Z. phys. Chem., 1930, B,6, 307. 614 M. Prettre and P. Laffitte, Compt. rend., 1929, 189, 177.516 B.Topley, Nature, 1930,125,560. 616 H. B. Dixon, Phil. Trans., 1884, 175, 617.617 V. E. Cosslett and W. E. Garner, Trans. Furaduy Soc., 1930, 26, 190; 1931,518 W. E. Garner and A. S. Gomm, ibid., 1928, 24, 470.61D G.Hadman, €3. W. Thompson, and C. N. Hinshelwood, Pvoc. Roy. SOG., 1932,The carbon monoxide-oxygen system.27, 176.A , 137, 87; 138, 29788 GENERAL AND PHYSICAL CHEMISTRY.fore, concluded that water vapour did not affect the upper pressure limits.This conclusion, reached in 1932, was not well founded, since the considerabledserences in conditions used by the British and Russian authors wereignored and the correspondence of results was neither extensive nor exact.Nevertheless, the statement that water vapour had no effect on the upperexplosion limit was repeated as a fact right through the literature down to1952. For twenty years, no one set of investigators carefully determinedthe upper explosion limit for both wet and dry mixtures under similarconditions.In 1952, however, Gordon 520 and Hoare and Walsh 521 inde-pendently discovered that small quantities of water vapour do in fact havea marked effect in raising the upper explosion limit. Subsequently, thediscovery has been confirmed by other workers.522It has long been known that outside the explosion region a glow mayappear. Only recently, however, have the pressure-temperature limits forthis glow to occur been mapped.523 The glow limits are particularly im-portant for they represent the critical conditions for marked reaction tobegin and are probably to be interpreted as the conditions for the net branch-ing factor of the reaction to be zero, i.e. , they are simpler to treat theoreticallythan are the explosion limits, which probably involve thermal factors.Hoare and Walsh showed that water vapour had no effect on the lower glowlimit, and so lent strong support to the conclusion of Garner and his co-workers that water vapour has no effect on the lower explosion limit.The emitterof the bands in the spectrum is probably the carbon dioxide molecule.Gaydon 524 attempted to interpret the bands on the supposition that thelower state involved was the ground state.It has recently been pointedout 525 that the evidence for this supposition is quite unconvincing ; and thatthe transition responsible for the bands is most probably from an upper,linear, triplet state (perhaps 3D,) of CO, to a lower, strongly bent, tripletstate (probably 3B2) which of course is not the ground state.The prob-ability is that triplet CO, molecules act as chain carriers in the oxidationof carbon monoxide. Hoare and WalshS23 showed the large inhibitingeffect of hydrogen chloride on the oxidation. It is known that many otherchlorine-containing molecules have a similar effect. It is not unlikely thatthe inhibition is due to deactivation of excited, triplet, CO, molecules, forsuch molecules will tend to associate, in " sticky " collisions, with all othermolecules present; and the presence of a chlorine atom in such transientcomplexes would be expected greatly to increase the probability of a triplet-+singlet ground state transition. It is difficult to suggest any other satis-factory explanation of the power of chlorine-containing molecules to inhibitcarbon monoxide combustion.The spectrum of the glow has been.known for some time.The probability is 5223 523 that the reactionsCO2* + o,=co2+20 .. . . . (11)C 0 2 * + 0 2 + M = C 0 2 + 0 , + M . . . . (12)620 A. S. Gordon, J . Chem. Phys., 1952, 20, 340.621 D. E. Hoare and A. D. Walsh, Nature, 1952, 170, 838.522 W. Roth, G. von Elbe, and 13. Lewis, Fifth Symp. Combustion, Williams and523 D. E. Hoare and A. D. Walsh, Trans. Faraday Soc., 1954, 50, 37.524 A. G. Gaydon, Proc. Roy. SOC., 1940, A , 176, 505.6 s 5 A. D. Walsh, J., 1953, 2266.Wilkins, Baltimore, 1955KINETICS OF CHEMICAL CHANGE. 89where CO,* is a triplet CO, molecule, account respectively for chain-branch-ing and for chain-ending at the upper explosion Limit.Hoare and Walsh 523have suggested that the striking fact about the effect of water vapour,namely that it affects the upper but not the lower limits, is due to the H20molecule’s becoming dissociated when it acts as M in reaction (12).A triplet, strongly bent, excited state of carbon dioxide would normallyhave a very low probability of passing to the ground state with emission ofradiation. It would behave almost like a separate chemical species; whichis a conclusion that may clear up the old problem of the “ latent energy ”reported for carbon monoxide flames and may have something to do withthe well-known ‘‘ after-glow ” of such flames.Roth, von Elbe, and Lewis 522 have stressed that adsorbed carbon dioxidemay cause surface chain-ending to occur even at the upper explosion limitand have provided data on the variation of that limit with mixture com-position for the dry gases under conditions where surface chain-ending isabsent.Warren 526 has provided similar data for the undried gases and alsodescribed the effects of certain surface coatings on the limits. Dixon-Lewisand Linnett 5279 5z9 have reported work on the second explosion limits ofhydrogen-oxygen-carbon monoxide mixtures, in which the ratio of hydro-gen : carbon monoxide is varied from high to low values. They disagreewith the values reported earlier by Buckler and Norrish for the activationenergy of the second limit in such mixtures; and find their data can only befitted by supposing that oxygen atoms associate with carbon monoxidemolecules in a reaction that is of the second (and not, as might be expected,third) order.Garvin 528 has studied the oxidation of carbon monoxide in the presenceof ozone.Lewis and von Elbe *g2 had previously postulated the reactionsM + C O + 0 , = C Q 2 + 0 , + M . . . . (13)co+o,=co,+2o . . . . . (14)as the essential competition at the upper explosion limit. Garvin concludes,however, that the upper limit should be reconsidered in terms of reactionsother than these. Hoare and Walsh similarly pointed out that there was noobvious reason why (13) should require a third body.The oxidation of ammoniacatalysed by metal and oxide surfaces has been studied by many workers.The uncatalysed oxidation has been much less well studied, but severalrecent pieces of work m0-533 have been devoted to its study.Several otherrecent papers 534-536 have dealt with the related oxidation of hydrazine.Comparison of the data of Stephens and Pease 530, 531 and of Verwimp andThe ammonia-oxygen and related systems.5 2 6 D. R. Warren, Fuel, 1954, 33, 203.527 G. Dixon-Lewis and J. W. Linnett, Trans. Faraday SOC., 1953, 49, 756.6a8 D. Garvin, J . Amer. Chem. Sot., 1954, 76, 1523.520 G. Dixon-Lewis, Fifth Symp. Combustion, Williams and Wilkins, Baltimore, 1955.530 E. R. Stephens and R. N. Pease, J . Amer. Chem. Soc., 1950, 72, 1188.5s1 Idem, ibid., 1952, 74, 3480.6a2 J. Verwimp and A. van Tiggelen, Bull. SOC. chim. belges, 1953, 62, 205.633 H. Wise and M. F. Frech, J . Chem. Phys., 1953, 81, 948.634 E.J. Bowen and A. W. Birley, Trans. Faraday Soc., 1951, 47, 580.535 P. Gray and J. C. Lee, ibid., 1954, 50, 719; Research, 1954, 7, 5 2 ; Fifth Symp.Combustion, Williams and Wilkins, Baltimore, 1955.W. I. H. Winning, J., 1964, 92690 GENERAL AND PHYSICAL CHEMISTRY.van Tiggelen 532 shows that the rate of ammonia oxidation must be a verycomplex function of total and partial pressures. A particularly interestingresult, first found by Stephens and Pease,530,531 is that ammonia oxidationis subject to self-inhibition. A pressure-time plot has a slope which beginsa t its maximum value and gradually falls off with increasing time. Theplots separate rather sharply into two groups, the rates (for an initial totalpressure of 400 mm.) being relatively low for mixtures richer in ammoniathan stoicheiometric and relatively high for weaker mixtures.Apparently,there is an abrupt change in kinetics as the stoicheiometric ratio is passed,the change occurring over as small a range of mixture strength ratio as 4 : 3to 1 : 1. The existence of such a sharp change in rate as the NH, : 0, ratiois changed has been confirmed by Verwimp and van Tiggelen.532 Thecritical conditions at which the change from low to high rates occurs mayalso be reached by increasing the total initial pressure at any particularmixture strength. The total pressure needed to bring about the changeincreases markedly as the NH, : 0, ratio is increased. Verwimp and vanTiggelen explain the effect by supposing that both NO and NO, are formed,their relative amounts being controlled by the equilibrium 2N0 + 0, +2N0,; and that, according respectively to whether the [NO]/[NO,] ratio ishigher or lower than a critical value, chains are rapidly broken in the gasphase by NO or only slightly broken by NO and increased in number by NO,.This explains why increasing the proportion of oxygen or increasing the totalpressure favours transition from slow to rapid reaction.Wise and Frech 533 have found hydrogen to be a product of partial com-bustion.They suggest that the hydrogen arises by thermal decompositionof the ammonia and that, since such decomposition is known to be retardedby hydrogen adsorbed on the vessel walls, the appearance of hydrogen mayexplain the self-inhibition of ammonia oxidation.The latter suggestion canhardly be correct, however, for (a) more hydrogen was produced from anammonia-lean than from a rich mixture, whereas the self-inhibition ismarked in rich, rather than lean, mixtures; (b) addition of hydrogen causesthe oxidation to proceed at a much more rapid rate than would otherwise bethe case.532A study of the vapour-phase oxidation of hydrazine in a Pyrex vesseland the temperature range 100-160" c led Bowen and Birley 534 to concludethat the oxidation proceeded by short reaction chains. Winning,536 however,using similar temperatures and a quartz vessel, has obtained results whichfit very well the supposition that the oxidation proceeds predominantly by abimolecular surface reaction unretarded by products.Gray and Lee 535have studied the total pressures required for explosion of hydrazine-oxygenmixtures in the temperature range 370-540" c. Under their conditions, itappears that explosion is due to self-heating probably through the operationof a free-radical chain reaction. At temperatures above 420" c and atpressures too low for ordinary explosion a feeble, delayed ignition occursafter a long induction period. For this new type of ignition, lower andupper critical pressure limits exist. The cause has been traced to theignition of hydrogen produced in a side reaction of the hydrazine oxidation.The ignition is inhibited by the hydrazine. Hydrogen accumulates until thehydrazine has gone ; when it has gone, ignition occurs.Several papers on the oxidation of methane The methane-oxygen systemKINETICS OF CHEMICAL CHANGE.91have recently appeared.537-545 Hoare 537 has discussed several differentways in which reproducibility can be attained ; and shown that the oxidationrate and the form of the A$-time curve may differ considerably accordingto the procedure used to secure reproducibility. 542have shown that the kinetic laws governing the rate of pressure rise inmethane oxidation a t ca. 500" in a silica vessel are sharply different accordingto whether, on the one hand, the surface has been treated with hydrofluoricacid or, on the other, has been aged by repeated use without such treatmentor heat-treated or coated with lead oxide. It is not, therefore, sufficient tospecify that work was carried out in a silica vessel; it is necessary also tospecify the previous history of the vessel.In subsequent work, Cheaneyand Walsh 546 have shown that a vessel coated with boric oxide behaves likeone treated with hydrofluoric acid and a vessel coated with potassiumchloride behaves like one coated with lead oxide. The fact that the kineticsof the hydrogen-oxygen reaction (see above) differ according to whether,on the one hand, the vessel has been treated with hydrofluoric acid or coatedwith boric oxide, or, on the other hand, has been coated with, e.g., potassiumchloride, thus has its parallel in the. oxidation of methane. The effect isalmost certainly connected with the conversion of HO, radicals into H,O,molecules on a boric oxide surface but not on potassium chloride.a6 It issignificant that peroxidic substances have been detected 542, 5433 544 duringthe oxidation of methane in an HF-treated vessel.Other papers (especially refs. 539, 541, 545) have dealt with the com-plicated, but interesting, interaction that occurs between the oxidation ofmethane to produce carbon monoxide and the oxidation of the carbonmonoxide so produced.Many recent papers have appeared onthe gas-phase oxidation of various substances (X) by nitrogen dioxide.All the reactions are homogeneous and of the non-chain type.They removenitrogen dioxide at an initial rate which is of the first order with respect tothe concentration of X and, except for the reactions with ethylene, propylene,and ammonia, also of the first order with respect to the concentration ofnitrogen dioxide.In the case of the three exceptions, the initial rate is ofthe second order with respect to the concentration of nitrogen dioxide. Thesubstantial body of data now available on the rate constants of these reactionsis collected in the following Table.One sees that, for the reactions which have a total order of two, the non-exponential factors, A , are all low and do not vary much. For some of thereactions, two different rate-constant expressions are found, according tothe temperature range used. Both non-exponential factor and activation537 D. E. Hoare, Trans. Faraday Soc., 1953, 49, 628.538 M. Vanpde, Ann. Mines Belg., 1948, 47, 111, 1053; ibid., 1049, 48, 44; ibid.,53s M.Vanpde and I?. Grard, Fifth Symp. Combustion, Williams and Wilkins, Balti-540 M. Vanp6e and G. Fally, Bull. SOC. chinz. belges, 1952, 61, 64, 474.541 D. E. Hoare and A, D. Walsh, Fifth Symp. Combustion, Williams and Wilkins,ti42 I d e m , Proc. Roy. Soc. 1952, A , 215, 454.543 G. J. Minkoff and K. C. Salooja, Fuel, 1953, 32, 516 ; and personal communication.544 M. Van Meerssche, Ann. Mines Belg., 1949, 48, 51.645 J. H. Burgoyne and H. Hirsch, Proc. Roy. SOC., 1954, A , 227, 73.646 D. E. Cheaney and ,4. D. Walsh, unpublished work.Hoare and WalshOxidations by nitrogen dioxide.1950, 49, 46, 710.more, 1955.Baltimore, 195592 GENERAL AND PHYSICAL CHEMISTRY.Arrhenius parametersA ESystem Temp. range (1- mole-l sec.-l) (kcal. /mole)CO-NO, .....................2 2 6 5 2 7 " 108.7 27*( 8)CZHZ-NOZ .................. 170-220 107.1 15*(0)CHO*CHO-NOz ............ 160-210 1088 19*(8)160-1 84 109 19*( 0)NOZ-NOZ ..................... 227-552 108'9 25.( 1)CH,.CHO-NOz ............ 118-143 lOs*8(5) 16*(0)118-160 1074 15.( 1){ 160-230 <150 24-( 5)160-220 - 12.(5)220-280 18*(0)1160-260 13.( 6)F2-N0, ..................... 2 7-70 109.2 10.(4)...............- < 24.5HCHO-NO,SOZ-NO, .......................................- 13.6CzH4-N02 {,r (160 ......... CHB*CH:CHz-NOZNHs-N02 .................. 150-200 I - 12*(5)Oa-NO, ..................... 13-29 109.8 7-(0)error.* The original publication gave the non-exponential factor A as 10g*85.Ref.547548549550 *55 1552553554555548553556This was inenergy, E , are higher in the higher temperature range.Walsh 557 haspointed out that, if one takes the higher of the two activation energies forthe HCHO-, SO,-, and C,H4-N0, systems, the order of the activationenergies is commonly the same as the order of the first ionisation potentialsof the molecules concerned. Thus the ionisation energies run in the orderCO > NO, > SO, > CHOCHO > HCHO > C,H, > CH,*CHO > CH,*CH:CH,which is also the order of decreasing activation energy. There are someanomalies to be cleared up (e.g., the negative activation energy reported forammonia), but the correlation is impressive. It suggests that most of therate-determining steps are of the same type and that, in each such step,nitrogen dioxide reacts with the most weakly bound electrons of the moleculebeing oxidised.The exact nature of the rate-determining step, the reasonwhy in some cases two rate-constant expressions in different temperatureranges are found, and the reason why, e.g., the C2H4-NO, system shouldhave third-order kinetics but the C2H,-NO, system second-order kinetics,are not yet certain. One complication is the possibility of reaction withN,04 rather than with NO,.The last Report under this headingappeared in 1951 558 and the intervening years have witnessed a steadilyincreasing literature on the subject. Only those processes which occur onsolid surfaces and result in chemical change will be considered; studies on .physical adsorption and chemisorption where no overall change occurs are14.1 12.3 12-05 11.4 10-88 10.50 10.23 9.8Heterogeneous Catalysis.-General..547 F.B. Brown and R. H. Crist, J . Chem. Phys., 1941, 9, 840.548 J. H. Thomas, Tram. Faraduy SOL, 1952, 48, 1142.54B Idem, ibid., 1953, 49, 630.560 C. A. McDowell and J. H. Thomas, ibid., 1950, 46, 1030.651 F. H. Pollard and R. M. H. Wyatt, ibid., 1949, 45, 760.5 5 2 G. K. Boresky and V. V. Illarionov, Zhur. j i z . Khim., 1940, 14, 1428.555 L. S. Kassel,554 T. L. Cottrell and T. E. Graham, J., 1953, 556.656 Idem, ibid., 1954, 3644.668 C. E. H. Bawn, Ann. Reports, 1951, 48, 64.Kinetics of Homogeneous Gas Reactions," Reinhold, New York,bb6 H. S. Johnston and D. M. Yost, J .Chem. Phys.,1932.1949, 1'4,386. 557 A. D. Walsh, Fuel, 1954, 33, 243KINETICS OF CHEMICAL CHANGE. 93omitted, except where their relevance is obvious and close. Similarly thisSection will not be concerned with purely solid-state aspects of catalysis.The first of a series of volumes on " Catalysis," edited by Emmett, hasappeared ; 559 this contains a valuable and extensive treatment by Laidlerof the kinetics of surface reactions and their interpretation in terms of theabsolute rate theory. The annual publication of " Advances in Catalysis "c0ntinues,5~ and a recent volume contains an especially useful review of theRussian literature.561 A number of general review articles have alsoappeared.56z565 The Fourth Annual Conference of the Soci4tk deChimie physique (June 1954) took as its theme " The Structure and Textureof Catalysts " ; the papers and discussion have beenThe post-war years have been notable for efforts to relate the kineticparameters of a reaction to the bulk properties of the catalytic material.567Variations in the reaction rate over a series of related catalysts may be causedby changes in (i) the activation energy, E , or (ii) the frequency factor, A ,or (iii) changes in both simultaneously; examples of each type of behaviourhave been found.Although correlations between k , A , and E of a reactionand bulk properties have achieved striking success with some systems, thereare others in which the situation is still far from clear, and the picture is oneof considerable and growing complexity.It is noteworthy that in manycases where E and A vary simultaneously over a series of catalysts, thesevariations tend to compensate, E being roughly proportional to log A .It is convenient to divide the remainder of this Report into three principalsections, viz., reactions on (i) metal catalysts, (ii) oxide catalysts, and(iii) acidic catalysts.Reactions 012 Metal Catalysts.-Hydrogenation and exchange reactions.Several specialised and critical reviews have appeared ; 568* 5697 570 attentionis also directed to two thorough but uncritical compilations of literaturereference^.^'^, 572 A number of authors have discussed theoretically themechanism of catalytic reactions involving hydrogen. Winfield 573 indicatesthe probable structures of some chemisorbed molecules and their positionson the metal lattice, and Weyl's monograph 574 contains original suggestionson addition reactions ; Rees's 575 interpretation of reactions of hydrogen,involving migration of lattice defects, is unfortunately only valid at temper-atures exceeding one quarter of the melting point of the catalyst in OK(e.g., 160" c in the case of nickel).Winfield and Weyl consider only a limited66B P. H. Emmett (ed.), " Catalysis," Reinhold Publ. Corp., New York, 1954, Vol. IA.680 Adv. Catalysis, 1948-1954, 1-6.561 J . G. Toplin, G. S. John, and E. Field, ibid., 1953, 5, 217.562 C. Kemball, Ann. Reu. Phys. Chem., 1953, 4, 303.563 G. Jura, ibid., 1954, 5, 375.665 Idem, ibid., 1954, 46, 884.5 E 7 F.C. Tompkins, Ann. Reports, 1950, 47, 54.G68 G. C. Bond, Quart. Rev., 1954, 8, 279.569 B. M. W. Trapnell, ibid., p . 404.670 H. E. Hoelscher, W. G. Poynter, and E. Weger, Chem. Rev., 1954, 54, 575.571 K. Atwood, I n d . Eng. Chem., 1953, 45, 1976.571 W. M. Keeley, ibid., 1954, 46, 1846.673 M. E. Winfield, Austral. J . Sci. Res., 1951, A , 4, 385.674 W. A. Weyl, Penn. State College Bull., 1951, 45, No. 25; Mineral Industries Bxptl.575 A. L. G. Rees, " Chemistry of the Defect Solid State," Methuen, London, 1954,564 M . Boudart, I n d . Eng. Chem., 1953, 45, 898.666 J . Chim. phys., 1954, 51, 409, 625.Stn. Bull., No. 57.p. 11691 GENERAL ANT) I’HYSICAT. CHEMISTRY’.fraction of the available facts, and their treatments should therefore beapproached with caution.Thon and Taylor 576 have listed a number of cases where initial-ratekinetics of surface reactions do not agree with the rate expression governingthe course of reaction ; they advance a general interpretation invoking chainmechanisms, where the chain carrier is an adsorbed radical or a “ chemicallyactive centre.” This idea has been criticised by Laidler.559 Boudart 577has indicated how adsorbed molecules on a plane surface can “ induce ”apparent heterogeneity by setting up an electrical double layer, whichchanges the work function of the metal catalyst (cf. Tompkins 567).Thisheterogeneity would be absent in the filled, reactive surface layer, andSchuit 578 has demonstrated this for a nickel-silica catalyst. Boudart’streatment has been criticised by Kemball 562 and G ~ m e r .~ ~ ~The mechanism of the para-hydrogen conversion and the hydrogen-deuterium equilibration reaction on metal catalysts is still uncertain.Couper and Eley 580 have calculated the rate of para-hydrogen conversionon tungsten which would be expected from the Langmuir (Bonhoeff er-Farkas) mechanism, assuming a fixed interaction energy between adjacenthydrogen atoms (derived from Trapnell’s 581 isotherms). The calculatedrate is lower than the observed rate by a factor of 106, but Kemball 562has pointed that the Peierls equation may not be applicable to this system.The calculation has also been adversely criticised by Laidler,582 who showshow interactions between adjacent atoms affect not only the concentrationbut also the partition function of vacant pairs of sites, the two effects exactlycancelling.He then calculates 583 the rate expected on the Langmuirmechanism ignoring interaction, and finds that the calculated value agreeswell with that observed if there is a small activation energy. Sandler 584criticises Laidler’s use of data obtained from both wires and films, and, inview of the reported 585 difference in their crystal structures, this criticismhas some basis; however, Anderson and Kemball 586 find that tungstenfilms deposited a t 0” c have the usual body-centred cubic form; the tem-perature of deposition may play a decisive role.Couper and Eley 587 have also measured the conversion on tungstenwires treated in various ways; activation energies ranged from 1 to 5kcal./mole, and there was a linear relation between them and the frequencyfactors, of the form E = -I+ 0.6 log A .Kemball 5623 588 has offered ageneral explanation of relations of this type. The conversion is more rapidon tungsten than on palladium,589 and this is chiefly due to the A factor’sbeing larger by about lo3. Cremer and Gerber 590 have measured the rates5 7 6 N. Thon and H. A. Taylor, J . Amer. Chem. SOC., 1953, 75, 2747.6 7 7 M. Boudart, ibid., 1952, 74, 3556.t78 G. C. A. Schuit, Chenz. Abs,, 1954, 48, 11869.57Q R. Gomer, J . Chem. Phys., 1953, 21, 1869.680 A. Couper and D. D. Eley, PYOC. Roy. Soc., 1952, A , 211, 636.581 B. M. W. Trapnell, ibid., 1951, A , 206, 39.582 K. J. Laidler, J .Phys. Chern., 1953, 57, 318.583 Idem, ibid., p. 320.6 8 6 0. Beeck, Discuss. Faraduy SOC., 1950, 8, 118.5 8 6 J. R. Anderson and C. Kemball, Proc. Roy. SOC., 1954, A , 223, 361.587 A. Couper and D. D. Eley, ibid., 1952, A , 211, 544.5 8 8 C. Kernball, ibid., 1953, A , 217, 376.689 A. Couper and I). D. Eley, L)iscuss. Faraduy SOL, 1950, 8, 172.590 E. Cremer and R. Gerber, Z. EZekrochem., 1953, 57, 757.584 1’. L. Sandler, J . Chem. Pliys., 1953, 21, 2243KINETICS OF CIIEMICAI, CIIANGE. 95of the conversion on nickel, cobalt, copper, and some alloys. Mignolet's 591measurements on the contact potentials of hydrogen adsorbed on tungstenand nickel indicate the existence of two types of film.The hydrogen-deuterium exchange reaction has recently been examined onfoils of copper, silver, and gold; 592 these metals are active for the reactionbetween 300 and 450" c.Chemisorption of hydrogen must therefore take placeon them above 300" although it is known not to occur below room temper-ature.593 The authors discuss the possibility that promotion of electronsfrom the filled d-band to the s-band may be responsible for chemisorption,but the activation energies for exchange (Cu, 23; Ag, 16-5; and Au, 14kcal./mole) do not fall in the same sequence as the known energies forelectron promotion (Cu, 2.1 ; Ag, 4.0; and Au, 2.3 ev). However, copper,having the lowest promotion energy, is active at considerably lower tem-peratures than either silver or gold.Two mechanisms for the methane-deuterium exchange can be distin-guished on rhodium, platinum, palladium, and tungsten,588 as with nickel ; 594mechanism (1) produces solely CH,D, while mechanism (2) gives rise toCN,D,, CHD,, and CD,.These two mechanisms result from two differentmodes of zdsorption of the methane, asand* *CH,+D-+CH3+HD . . . . . (1)CH,+ +CH,+H, . . . . . (2)* * * *The hydrogen atoms of the methylene radical are presumed to exchangerapidly with adsorbed deuterium atoms, thus leading to methane moleculescontaining two or more such atoms. Except for tungsten, A , is almostconstant, and El varies only slightly; however, E, and A , are notablygreater than the corresponding values for mechanism (1). Activationenergies and frequency factors for both processes are much lower on tungstenthan on the other metals.An absolute rate theory treatment 595 of theresults for nickel 594 supports the above mechanism if E, is taken as 32kcal./mole ; observed and calculated rates are in excellent agreement.Ethane exchanges with deuterium at much lower temperatures thandoes methane,5g8 and two mechanisms again operate. In this case, multipleexchange proceeds by way of adsorbed ethylene, but product distributionsare independent of temperature, in contrast to the case of methane. Activ-ation energies for a series of transition metals range from 7 to 21 kcal./mole,and high frequency factors accompany high activation energies. Propaneand isobutane 596 behave similarly to ethane, and the secondary and tertiaryhydrogen atoms respectively exchange most readily.With neopentanethe exchange on the four metals studied occurs chiefly by the stepwisereplacement of hydrogen atoms.597Burwell and Briggs 598 have investigated the exchange reaction between591 T . C . P. Mignolet, J . Chem. Phys., 1962, 20, 341.592 k. J. Mikovsky, hl. Boudart, and 13. S. Taylor, J . Amer. Chem. Soc., 1964, 76, 3814.5 9 t 33. M. W. Trapnell, Proc. Roy. Soc., 1953, A , 218, 566594 C. Kemball, i b i d . , 1951, A , 207, 539.5 9 j M. C. Markham, M. C. Wall, and K. J . Laidler, J . Phys. Chcm., 1963, 57, 321.G'6 C. KembaIl, Proc. Roy. Soc., 1954, A , 223, 377.5 9 7 Idem, Trans. Faraduy Soc., 1954, 50, 1344.59: I?. L. Burwell and W. S. Briggs, J . Amer. Chem. Soc., 1952, 74, 509696 GENERAL AND PHYSICAL CHEMISTRY.deuterium and some heptanes and octanes on nickel-kieselguhr between90" and 130" C .3 : 3-Dimethylhexane and 2 : 2 : 3-trimethylbutane ex-change only seven hydrogen atoms, so exchange cannot propagate past aquaternary carbon atom. Under these conditions, (+)-3-methylhexane isracemised at the same rate both by hydrogen and by deuterium, and possiblemechanisms for this process are discussed.The ethylenic products of the reaction between acetylene and deuteriumon nickel-kieselguhr at -80" c are 50% of cis-C,H,D,, 20% of trans-C,H,D,,15% of C,H,D, and 10% of C,HD,, and (presumably) small amounts ofC,H4 and C2D4.599 Only small amounts of C,HD were detected, and so aredistribution reaction similar to that occurring with olefins at low tem-peratures 568 must be taking place.Similar results were found with pallad-ium-kieselguhr, confirming previous work.6oo The use of equilibrated andnon-equilibrated hydrogen-deuterium mixtures showed that hydrogenmolecules dissociate before addition. The hydrogenation of acetylenecatalysed by pumice-supported rhodium, iridium, ruthenium, and osmiumhas been reported by Sheridan and Reid; this reaction has now beenstudied over all the Group VIII elements, and references to previous workare given in this paper. Rhodium is active at 50-100" c and yields 70-80%of ethylene and ethane; iridium was active at 175" c and gave 85% of C,products. Osmium and ruthenium were scarcely active, and this wasattributed to their close-packed hexagonal structure.The authors discussthe variations in activity, selectivity, and extent of hydropolymerisation andconclude that the latter process is chiefly associated with metals of smalleratomic radius, while activity parallels magnetic susceptibility.In order to adduce support for Sheridan's 602 theory of hydropolymeris-ation, the hydrogenation of methylacetylene over pumice-supported nickel,palladium, and platinum has been examined.g03 The presence of the methylgroup should cause steric hindrance in the chemisorbed layer, with the resultthat adsorbed methylacetylene should be less tightly packed than adsorbedacetylene. The expectation that this would reduce the extent of poly-merisation was confirmed except in the case of palladium, where the resultspointed to a process involving physically adsorbed molecules.Acetylene andmethylacetylene in admixture were hydrogenated simultaneously, the formera little more rapidly than the latter.604Keier 605 using 1%-labelled acetylene has deduced that the surface ofRaney nickel is not uniform for acetylene adsorption; he states that hydro-genation occurs only on a small number of sites on which its adsorption isreversible. Acetylene disproportionates and reacts readily with adsorbedhydrogen on the surface of nickel-kieselg~hr.~~~ The reaction C2H2 +C,D, + X,HD has been followed on a nickel-pumice catalyst,606 and theobserved equilibrium constant agrees well with a calculated value. A first-order rate law governs the course of the reaction, but the rate varies as the599 J.E. Douglas and B. S. Rabinovitch, J . Amer. Chem. SOC., 1952, 74, 2486.6oo R. L. Arnett and B. L. Crawford, J. Chem. Phys., 1950, 18, 118.601 J. Sheridan and W. D. Reid, J., 1952, 2962.Oo3 G. C. Bond and J. Sheridan, Trans. Faraday SOC., 1952, 48, 651.6oa Idem, ibid., p. 664.605 N. P. Keier, Izvest. Akad. Nauk S.S.S.X., Ofdel. Khim. Nuuk, 1952, 616; Chent.QoE G. C. Bond and J. Sheridan, Trans. Faraday SOC., 1952, 48, 715.Oat J. Sheridan, J., 1945, 133.Abs., 1952, 46, 10820; 1954, 48, 4927KINETICS OF CHEMICAL CHANGE. 970.65th power of the total pressure; the same paper records the exchangereaction between C2D2 and methylacetylene. The mechanism probablydoes not involve dissociative adsorption. The reaction has also beenobserved on nickel-kieselguhr at temperatures as low as -80°.599The hydrogenation of olefins continues to attract attention.Theposition has recently been reviewed,S6* and the mechanism of ethylenehydrogenation and exchange has been d i s c u s ~ e d . ~ ~ ~ ~ 5733 607 Keii 608 hasshown that the logical development of the Horiuti-Polanyi mechanismaccounts for the varying rates of production of the various isotopic ethylenesand ethanes observed by Schissler et aL609 in the ethylene-deuterium reaction.The absence of exchange between ethylenes in the absence of hydrogen 610has long been quoted as evidence against their dissociative adsorption, butexchange has now been found with nickel-kieselguhr as catalyst.599 Thefinding 611 that the adsorption of hydrogen and ethylene on nickel-kieselguhrreduces its paramagnetism is strong proof that electrons from these moleculesenter the metal's conduction (unfilled d ) band ; the application of the methodto adsorption and kinetic studies is illustrated.The technique has greatpotentialities. The reaction of ethylene with a ten-fold excess of deuteriumhas been examined at -50" and 50' c on a commercial nickel catalyst.s12No deuterated ethylenes were detected at either temperature, but all possibledeuterated ethanes were found, owing to the reaction* * * *t2H4D + C,H, + CIH5 + C2H,DEthane is probably formed at least in part by disproportionation of theadsorbed ethyl radicals. The results of a study of this reaction on variouspreparations of platinum have been briefly r e p ~ r t e d .~ l ~Bond and Turkevich 614 have followed the reactions between propyleneand deuterium on a platinum-pumice catalyst between -18" and 130". Atall temperatures the production of deuterated propylene and HD was low,but all possible isotopic propanes were found, indicating once more a redistri-bution reaction of the above type. [lHsjPropane was the chief product whenpropylene was in large excess. The yield of C,?&D2 decreased with increasingtemperature. Propylene has been hydrogenated over nickel films preparedby decomposition of the carb0nyl.61~In the reaction of cis-but-2-ene with a ten-fold excess of deuterium overa commercial nickel catalyst 612 the yield of the various isotopic butanesremains constant throughout each reaction between -78" and 50°, but theyield of C4H8D2 decreases with increasing temperature.The same authorsrecord that with this catalyst the yield of C,H8D2 is 97%; no reason wasoffered for the small extent of redistribution in this case.607 34. C. Markham, M. C. Wall, and K. J. Laidler, J . Chern. Phys., 1953, 21, 949.60R T. Keii, J . lies. Inst. Catalysis, Hokkaido Univ., 1953, 3, 36; J . Chem. Phys., 1954,6op D. 0. Schissler, J. Turkevich, and A. P. Irsa, J . Phys. Colloid Chcm., 1951, 55,611 P. W. Selwood, T. R. Phillips, and S. Adler, J . Amer. Chem. Soc., 1954, 7G, 2251.612 J. N. Wilson, J. ?V. Otvos, D. P. Stevenson, and C. D. Wagner, I n d . Eng. Chem.,613 G. C. Bond and J. Turkevich, J .Chim. phys., 1954, 51, 473; see also ref. 11.22, 144.1078. 610 G. K. T. Conn and G. H. Twigg, Proc. Roy. SOC., 1939, A , 1'71, 70.1953, 45, 1480.Idem, Tvans. Faraday Sot., 1953, 49, 281.L. J . Baker and R. B. Bernstein, J . A 7 ~ e r . Chem. Soc., 1951, 73, 4434.REP.-VOL. LI 98 GENERAL AND PHYSICAL CHEMISTRY.Allene behaves more as an acetylene than as an olefin in its hydrogen-.ation; 616 it produces small amounts of polymeric products over nickel andplatinum, and considerable amounts over palladium. The expected iso-merisation to methylacetylene was not detected, and a possible explanationfor this was suggested.Racemisation during the hydrogenation of optically active 3-plienyl-but-l-ene is observed over a palladium-CaCO, catalyst, but is much lessover Raney nickel; 617 it was not detected during the reduction of (+)-3-methylhexene over nickel-kieselguhr. 598 Bonner and Collins 618 havefound a 2(7" isotope effect in the hydrogenation of [cd4C]stilbene and a 12%effect with [~c-~*C]acetophenone, using platinum as catalyst.cycloPropane has been found 619 to differ from olefins and acetylenes inthat its initial-rate kinetics are of the form,rate = K[C,H,][H,]*Possible reasons for this were advanced.More recently, the reaction ofcyclopropane with a fifty-fold excess of deuterium has been investigated overa platinum catalyst between -18" and The results were interpretedin terms of differing modes of adsorption of the cyclopropane, on the linesof Kernball's 588 discussion of methane.Hydrogenation of ethylcyclo-propane over platinum-charcoal produces only isopentane. 621 Evaluationof previous work shows that in monoalkyl substituted cyclopropanes, thecarbon-carbon bond opposite the substituted atom almost always breakspreferentially. 1 : 1 : 2-Trimethylcyclopropane yields only 2 : 3-dimethyl-butane over platinum 622 although under more drastic conditions all possibleproducts are By contrast methylenecyclopropane is hydrogenatedto 92-butane, although small amounts of methylcyclopropane have also beendetected. 624 Similarly, vinylcy~lopropane,~~~ isopropenylcyclopropane, 626and 1 -vinylcyclopropane-2 : 2-dicarboxylic acid 627 yield products due toring fission a t the carbon-carbon bond adjacent to the point of vinyl sub-s t itu tion.In the animonia-deuterium exchange reaction on metal films one hydro-gen atom is exchanged at each contact with the surface.628 Frequencyfactors are constant for many transition metals except tungsten, whileactivation energies decrease with increasing work function of the metal 628or with an increasing percentage of d-bond character.569 This reaction hasalso been studied by Gutman 629 using a commercial iron powder.The616 G. C. Bond and J. Sheridan, Trans. Faraday SOC., 1952, 48, 658.617 D. J . Cram, J . Anier. Chem. SOC., 1953, 74, 5518.G I * 11'. .4. Bonner and C. J. Collins, ibid., 1953, 75, 4516.61D C;. C. Bond and J. Sheridan, Trans. Faraday Soc., 1952, 48, 713.620 C;. C. Bond and J. Turkevich, ibid., 1954, 50, 1335.621 BI.Ya. Lukina, 13. A. Kazanski, and V. A. Owdova, L)ok!cidji :Iknri. -\nztk622 I d e m , Izvest. Akad. hTaztk S.S.S.R., Otdel. Khinz. N a u k , 1954, 873.6z3 R. G. Kelso, J. M. Derfer, C. E. Boord, and K. \Ir. Greenlee, J . Airier. Chem. SOC.,624 J . J. Gregson, K Vd. Greenlee, J. M. Derfer, and C . E. Boord, ibid., 1053, 75, 3344.6 2 s V. 13. Slabey and P. Wise, ibid., 1952, 84, 3887.6 2 6 R. van Volkcnburgh, I<. 14'. Greenlee, J. M. Derfer, and C. I<. Eoord, iCitZ ,027 K. W. Kierstead, R. €'. Iinstead, and B. C. 1,. TVeedun, J . , 1952, 3010.G49 J. R. Gutman, J . Phys. Chent., 1953, 57, 309.S.S.S.R., 1954, 98, 783.1952, 74, 287.1949, 71, 172.C. Kernball, Proc. Boy. SOC., 1952, A , 214, 413KINETICS O F CHEMICAL CHANGE. 99Arrhenius plot of the ND3-hydrogen reaction shows a discontinuity a t about40" c.630 Various possible causes of this have been considered and tested.The heats of adsorption of ammonia and hydrogen on evaporated films ofiron, nickel, and tungsten have been measured at room temperature.631Amano and Taylor 632 have recorded the rates of ammonia decompositionon alumina-supported ruthenium, rhodium, and palladium catalysts.Although kinetics and activation energies are similar for each metal there arelarge differences in activity due to variable frequency factors : temperaturesfor an arbitrary rate of decomposition are approximately : Ru, 300";Rh, 360" ; and Pd, 530" c.The most effective metals for ammonia exchangeare the least effective for ammonia synthesis and decomposition.A great volume of material continues to be published on the Fischer-Tropsch and related ~ y n t h e s e s .~ ~ ~ ~ 5723 633 The earlier carbide theory of theFischer-Tropsch reaction has now been replaced by a theory invoking theparticipation of chemisorbed carbon monoxide.634, 635 Gibson and Hall,635using 14C0,, have concluded that carbon dioxide does not take part in thereaction. Stowe and Russell63G have examined the efficiency of iron andcobalt and two of their alloys in the synthesis of hydrocarbons from carbondioxide and hydrogen; iron and the iron-rich alloy yield chiefly carbonmonoxide, while cobalt and the cobalt-rich alloy give chiefly hydrocarbons.Cimino, Boudart, and Taylor 637 have clarified the role played by addedalkali in iron Fischer-Tropsch catalysts.Anomalies in the Arrhenius plot for the decomposition of formic acid intohydrogen and carbon dioxide on nickel and its alloys which are observed nearthe Curie temperature 638 disappear with the nickel-chromium alloy afteruse, owing to coverage of the surface by irreducible oxide.The rate overcopper and silver is a function of the temperature of pretreatment of themetals in hydrogen.639 This reaction has also been studied 011 nickel andcopper ; 640 on evaporated nickel films the rate is independent of their orient-a t i ~ n . ~ ~ l The specific activity of silver powders for fornialdehyde com--position increases with pretreatment temperatures up to 600°, and there is asimultaneous increase of the activation energy (16 to 23 kcal./mole) and ofthe frequency factor.642The hydrogen-oxygen reaction has been investigated over palladiumand platinum 643 and over nickel and these metals.644Oxidation.Orzechowski and MacCormack have carried out a compre-hensive investigation of the oxidation of ethylene and ethylene oxide on ag30 T. Kaneko, Shokubai, 1951, 7, 98; Chem. Abs., 1953, 47, 11924.G31 M. Wahba and C. Kemball, Trans. Faraday SOC., 1953, 49, 1351.G32 A. Amano and H. S. Taylor, J . Amer. Chenz. SOC., 1954, 76, 4201.633 R. Pichler, -4dv. Catalysis, 1962, 4, 272.634 S-. G. Basak and K. K. Bhattacharyya, J . Inst. Fuel, 1964, 27, 195.63.5 $3. J. Gibson and C. C . Hall, J . Appl. Chem., 1954, 4, 464.636 R. A. Stowe and W. W. Russell, J . Amer.Chem. SOG., 1964, 76, 319.637 A. Cimino, M. Boudart, and H. S. Taylor, J . Phys. Chein., 1954, 58, 706.G38 G.-M. Schwab and H. Goetzeler, 2. phys. Chem. (Frankfurt), 1954, 2, 1.639 G. Rienacker and H. Bremer, 2. anorg. Chem., 1953, 272, 126.64n 0. Toyama and Y . Kubokawa, J . CJzem. SOC. Japan, 1953, '94, 876.O g l I d e m , ibid., p. 289; Chenz. Abs., 1953, 47, 11923.G42 G. Rienacker, H. Bremer, and S. Unger, Naturwiss, 1952, 30, 259.633 0. V. Krylov, S. 2. Roginskii, and I. I. Iret'yalrov, Doklady Akad. Nccztk S.S.S.R.,644 G. K. Boreskov, &I. G. Slin'ko, and A. G. Pilippova, ibid., p. 353.963, 92, 75100 GENERAL AND PHYSICAL CHEMISTRY.silver catalyst.645 The products of ethylene oxidation are ethylene oxide,carbon dioxide, and water; the results do not support the hypothesis 646that all the carbon dioxide arises from further oxidation of the ethyleneoxide.At 274" the latter is oxidised without intervening decomposition,and isomerisation to acetaldehyde is also excluded. The mechanism pro-posed is in some respects a t variance with that put forward by Twigg6*'Roginskii and Margolis 648 deduce that the carbon dioxide arises partly fromethylene oxide and partly by another (unspecified) mechanism.Yamada 6499 650 shows that oxidation of carbon monoxide on silverproceeds in different ways depending on whether or not the surface is initiallywholly reduced : the importance of well-defined initial conditions in oxidationreactions is thereby again stressed. Garvin 651 presents evidence for thesilver-catalysed reaction between ozone and carbon monoxide ; ozonedecomposes as 0, -+ 0, + 0, and this is followed by 0 + CO --+ CO,.The oxidation of sulphur dioxide has been investigated over a number ofmetals.652Reactions on Oxide Catalysts.-These have not recently been consideredin these Reports; Garner's review,663 however, covers progress up to 1950.Reactions proceeding on the surface of oxide catalysts are chiefly thoseinvolving hydrogen addition, exchange or elimination , dehydration, andoxidation and oxygen elimination. Adsorption and catalysis on oxidesinvolve electron transfer between the solid and the reacting molecules,654and the interpretation of catalytic activity in terms of defect structureand the electron-band theory of solids has met with general s ~ c c e s s .~ ~ ~ ~ 655, 656In recent years, several groups of workers have used the technique of modify-ing the known electronic properties of a given oxide by small additions offoreign ions (valency induction) to determine reaction mechanisms.Winter et al. have studied the exchange between lS0, andlattice oxygen with magnesium oxide 657 and zinc and Winter hasalso followed the 1S02-1602 equilibrium on both these Theactivation energy, E , for the latter reaction is 22 kcal./mole below 215", theslow step being the adsorption-desorption of oxygen ; above this temper-ature, E is 8.5 kcal./mole, the slow step here being migration of oxygenatoms over the surface. The exchange between lSOz and lattice oxygen hasalso been studied with vanadium pentoxide 6w and manganese dioxide.6619 + xOxidation.1345 A.Orzechowski and K. E. MacCormack, Canad. J . Chem., 1954, 32, 388,415, 432,646 0. M. Todes and I. I. Andrianova, Doklady Akad. Nauk S.S.S.R., 1953, 88, 515.647 G. H. Twigg, Proc. Roy. SOC., 1946, A , 188, 92, 105, 123.648 S. Z. Roginskii and L. Ya. Margolis, Doklady Akad. Nauk S.S.S.R., 1953, 89, 515.649 N. Yamada, J . Chem. SOC. Japan, 1953, 74, 326; Chem. Abs., 1953, 47, 11024.650 Idem, J . Chem. SOC. Japan, 1954, 75, 309; Chem. Abs., 1954, 48, 11895.G 5 1 D. Garvin, J . Amer. Chem. Soc., 1954, 76, 1581.6 5 2 G. K. Boresltov, M. G. Slin'ko, and E. I. Volkova, Doklady Akad. hrauk S.S.S.R.,6 5 4 C. Wagner and K. Hauffe, 2. Elektrochem., 1938, 44, 172.6 5 6 D.A. Dowden, J., 1950, 242.656 RI. Boudart, J . Amer. Chem. Soc., 1952, 74, 1531.6 5 7 G. Houghton and E. R. S. Winter, J . , 1954, 1509.658 J. A. Barnard, E. R. S. Winter, and H. V. A. Briscoe, ibid., p. 1517.659 E. R. S. Winter, ibid., p. 1522.660 W. C. Cameron, A. Farkas, and L. M. Litz, J . PJzys. CJzem., 1953, 57, 229.6 f i 1 S. M. Karpacheva and A. M. Rozen, Zhur fiz. Khim., 1953, 27, 146.443.1953, 98, 109. 653 W. E. Garner, Discuss. Favaday SOL., 1950, 8, 211KINETICS OF CHEMICAL CHANGE. 101Carbon monoxide oxidation should be a suitable reaction for study bythe valency induction method, but grossly differing results have been663 Parravano 662 finds that the reaction on pure nickel oxideshows one kinetic formrate = k[O&CO]I; E = 2.2 kcal./molerate = k[O,]o[CO]; E = 13 kcal./mole, above this temperature.He concludes that the slow steps are surface oxidation in the low-temperaturerange and the reaction CO + 0 --w CO, in the higher range.In supportof his mechanism he reports that added group I oxides increase the activationenergy of the high-temperature reaction, while added tervalent metal oxidesdecrease it ; the low-temperature activation energy is independent ofadditions. Schwab and however, working only in the high-temperature range, find precisely the opposite effect of added uni- and ter-valent metal ions on the activation energy, whence they conclude that theelectron-donating adsorption of the carbon monoxide is the slow step, thesurface reaction being fast.This discrepancy is disturbing and has notapparently been resolved.566 The reaction has also been studied on zincoxide ; $-type semiconductors are in general active for this reaction at lowertemperatures than ~ z - t y p e s . ~ ~ ~ Parravano 664 finds that the Arrhenius plotfor carbon monoxide oxidation on lanthanum strontium manganite shows adiscontinuity near the Curie temperature. The reaction over cuprous oxidea t room temperature does not involve lattice oxygen.665Dell, Stone, and Tiley 666 have examinedthe reaction on cuprous and cupric oxides, and show that $-type oxides areactive in a flow system at 2QO-30O0, while n-type and insulator oxides givereaction only above 400". They conclude that on the $-type oxides thereaction : N20 + e(cata1yst) _.s N, + 0- is rapid, and that the slowstep is the formation of molecular oxygen, as 0- 4 +02 + e(catalyst), orby other possible processes.Engell and Hauffe 667 have shown that thereaction over nickel oxide is accelerated by added univalent metal ions, andSchwab and Block 663 have found that gallium oxide added to zinc oxideincreases the activation energy ; this confirms the view that donation ofelectrons to the solid is involved in the rate-controlling step. Amphlett 668has studied this reaction in the presence of a large excess of oxygen overcobaltous oxide and over asbestos-supported cobaltous, cupric, and nickeloxides.Clark 669 has reviewed the catalytic activityof metal oxides for the hydrogen-deuterium exchange reaction; the rate ofthis reaction on a given oxide is taken as a good measure of its efficiency inhydrogenation and dehydrogenation reactions.The evidence indicates thatbelow 180", and another form, viz.,* *Decomposition of nitrous oxide.Reactions involving hydrogen.6 6 2 G. Parravano, J . Amer. Chertz. SOC., 1953, 75, 1448, 1452.6G3 G.-M. Schwab and J. Block, 2. phys. Chem. (Frankfurt), 1954, 1, 42.6G4 G. Parravano, J . Amer. Chenz. SOG., 1953, 75, 1497.6 G 5 W. E. Garner, F. S. Stone, and P. F. Tiley, Proc. Roy. SOL, 1962, A , 211, 472.G G 6 R. M. Dell, F. S. Stone, and P. F. Tiley, Traws. Faraday SOG., 1953, 49, 201.6G7 H. J. Engell and K. Hauffe, 2. Elehtrochem., 1953, 57, 762, 773.6 6 8 C. B. Rmphlett, Trans. Faraday SOC., 1954, 50, 273.669 A.Clark, Ind. Eng. Chem., 1953, 45, 1476102 GENERAL AND PHYSICAL CHEMISTRY.the excess of metal atoms plays a dominant role, and hydrogenating con-ditions are optimum for their development; they may be present as latticedefects of either the Frenkel or the Schottky type. Molybdenum trioxide(MOO,), chromic oxide, and zinc and nickel oxides, supported on alumina-silica, are considerably more active after reduction than before; MOO, isprobably reduced to the %-type dioxide. Difficultly reducible oxides such asthoria, zirconia, and titania are no more active after reduction than before.Holm and Blue 670 record the hydrogen-deuterium exchange activities of alarge number of oxides, and the reaction has also been followed on pure zincoxide and onzinc oxide with foreign additions.671Irradiation of zinc oxide with y-rays lowers its activity for the hydrogen-ation of ethylene.672Reactions on Acidic Catalysts.-Catalysts of the alumina-silica type. Iso-merisation, polymerisation, and " cracking " reactions can be made to occuron the surface of acidic catalysts, and the I' cracking " of natural oil to givelower molecular weight hydrocarbons of high octane number is the largestcatalytic process now operating.673 The catalysts employed for thesepurposes are principally alumina-silica, magnesia-silica, and y-alumina,promoted with fluorine; 6733 674 the different properties of the first two ofthese have been described.675 Other mixtures of oxides have been tried,but are less widely Briefly, activity is due to the existence ofelectron-accepting (Lewis acid) sites, which are presumably AP+ ions incor-porated isomorphously into the silica structure; 674 when water is adsorbedon them protons become available and the catalyst acts as a Bronsted acid.The processes which these catalysts effect then proceed by a carbonium ionr n e c h a n i ~ m .~ ~ ~ - ~ ~ ~ , 674 There is some difference of opinion as to whetherthe carbonium-ion formation takes place by the reaction RCH, +H+ RCH,+ + H, or by R' = CH, + H+ + RCH,', the olefin R' = CH,being formed in small concentration by a dehydrogenation me~hanism."~Experiments have shown that water is an essential, and there exists anoptimum concentration.680 If deuterium oxide is added to a dry catalystthe deuterons can exchange with a wide variety of hydrocarbons.680 Theactivity of alumina-silica catalysts for the hydrogen-deuterium exchangehas been determined,681 and measurements on their electrical conductivityindicate that they are @type semiconductors with promotion energiesranging from 0.88 to 1.1 ev, depending on the alumina concentration.682The combination of an acidic catalyst witha transition metal produces " platforming " catalysts possessing remarkable" PZatfoyming " catalysts.6 i o V.C. F. Holm and R. W. Blue, Ind. Eng. Chem., 1952, 44, 107.G 7 1 E. Molinari and G. Parravano, J . Amer. Chem. SOC., 1953, 75, 5233.652 E. H. Taylor and J. A. Wetherington, ibid., 1954, '46, 971.673 R. V. Shankland, Adv.Catalysis, 1954, 6, 271.6 7 * G. TV, A. Rijnders and G. C. A. Schuit, in " Cationic Polymerisation and RelatedComplexes," ed. P. H. Plesch, Heffer, Cambridge, 1953.675 E. M. Gladrow, R. W. Krebs, and C. N. Kimberlin, 1 ~ d . Eng. Chem., 1953, 45, 137.6 7 6 R. C. Hansforcl, Adv. Catalysis, 1952, 4, 1.6 7 7 L. Schmerling, I n d . Eng. Chem., 1953, 45, 1447.6 7 8 V. Haensel, Adv. Catalysis, 1951, 3, 179.679 A. G. Oblad, T. H. Milliken, and G. A. Mills, ibid., p. 199.680 R. C. Hansford, P. G. Waldo, L. C. Drake, and R. E. Honig, Ind. Eng. Chem.,6 8 1 V. C. F. Holm and K. Vi7. Blue, ibid., 1951, 43, 501.682 P. B. Weisz, C. D. Prater, and IC. D. Rittenhouse, J . C h e w Phys., 1963, 21, 2236.1962, 44, 1108AGAR AND RANDLES : ELECTROCHEMISTRY.103properties of great technical and chemical interest. Ciapetta and Hunter G83describe in some detail the preparation of alumina-silica catalysts con-taining nickel, cobalt, iron, platinum, or copper, while Mills et aL684 do notspecify the metal they use. The particular value of such catalysts lies intheir ability to effect isomerisation reactions in the presence of hydrogenwith negligible cracking to lower molecular weight species; they are there-fore more selective in producing the desirable isomerisation than is alumina-silica, whose function is primarily cracking. Ciapetta and Hunter G83examined the isomerisation of normal paraffins to iso-paraffins and foundthat nickel, cobalt, and platinum are almost equally active, but that iron andcopper are considerably less so ; molybdena and tungstic oxide show moder-ate activity.The nickel catalysts do not produce the normal reactionsof nickel ( i e . , cracking), and from X-ray diffraction patterns the formationof a hydrous nickel aluminium silicate (“ nickel clay ”) is inferred. Whilethis catalyst isoinerises cyclohexane to methylcyclopentane and vice versa,the unspecified catalyst of Mills et aLGS4 produces benzene from these re-actants. Both groups of workers agree that the reaction is initiated on themetal area or sites by dissociative adsorption of the paraffin; this may bethe slow step.G83 The next is a dehydrogenation step, producing an olefinwhich migrates to the acidic areas where it isomerises by the usual carboniumion mechanism ; desorption of the re-hydrogenated product may then occurfrom the metal areas or sites.The finding 683 that olefins (e.g., pent-l-ene)isomerise at lower temperatures than paraffins accords with the idea that thefirst and slow step is a dehydrogenation.G. C. B.E. C.K. J. I.D. R. S.A. D. W.R. J. W.ELECTROCHEMISTRY.DURING the period under review a second edition of Falkenhagen’s well-known book has appeared; it gives a full account of the theory of theconductance of strong electrolytes, including the Onsager-Fuoss treatment 2of solutions containing more than two kinds of ion, and of the recent theoriesof more concentrated solutions developed by Eigen and Wicke.In “ Ionic Processes in Solution ’’R. W. Gurney discusses and correlates the thermodynamic properties,conductances, and viscosities of ionic solutions, with emphasis on ion-solventinteractions and the “ structure breaking ” and ‘‘ structure forming ’’properties of the ions.Much of the book is original and it develops a highlyinteresting, though tentative and qualitative, point of view. “ ModernTwo other books should be mentioned.683 F. G. Ciapetta and R. F. Hunter, Ind. Eng. Chenz., 1963, 45, 147, 155; 1:. C.6 8 4 H. Heinemann, G. A. Mills, J. B. Hattman, and F. W. Kirsch, ibid., p. 130;Ciapetta, ibid., pp. 159, 162.G. A. Mills, H. Heinemay, T. H. Milliken, and A. G. Oblad, ibid., p. 134.1 H. Falltenhagen,2 L. Onsager and,R. M. Fuoss, J . Phys. Chenz., 1932, 86, 2689.3 R. W. Gurney,Elektrolyte,” Hirzel, Leipzig, 1953.Ionic Processes in Solution,” McGraw-Hill, New York, 1953104 GENERAL AND PHYSICAL CHEMISTRY.Aspects of Electrochemistry ” contains up-to-date accounts of five topicsof current interest by various authors ; the chapter on “ EquilibriumProperties of Electrified Interphases ” is especially valuable.Paperspresented at the Bureau of Standards’ semi-centennial symposium on“ Electrochemical Constants ” in September 1951 have since been pub-lished;The present Report attempts to cover some aspects of recent work onaqueous solutions of electrolytes and on the double layer and electrodereactions. For reasons of space we have had to omit work on polyelectro-lytes,’ ion-exchange resins,8 and the deposition of hydrogen ions.Solutions of Electrolytes.-Experie~t~Z Methods.A. R. Gordon and hisco-workers have studied the conditions under which the concentration ofthe indicator solution in a moving-boundary experiment adjusts itselfspontaneously to the value required by the Kohlrausch relationthey extend over a wider range of subjects than the title implies.and have shown lo that the ratio of the transport numbers in the leadingand indicator solutions can be obtained very accurately from conductometricmeasurements of the concentration in the indicator solution. For infinitelydilute conditions, the transport numbers in both solutions can be cal-culated if this ratio together with the limiting equivalent conductances ofthe electrolytes AX and BX are known.Methods for the investigation of very fast ionic reactions have beendescribed by M. Eigen,ll who gives references to earlier work, especiallyon the ultrasonic absorption method.Results obtained by this method for2 : %salts and certain weak electrolytes have been analysed.l2, 13The preparation and properties of silver-silver halide electrodes havebeen reviewed l4 and an improved form of calomel electrode has been de-veloped. l5 The advantages and general applicability of direct-currentmethods of measuring conductance have been emphasised l6 and a new formof alternating-current conductance cell for non-aqueous solutions has beendescribed.17 Accounts have also been given of the use of the ultracentrifugefor the measurement of activity coefficients (of CdI, and UO,F,),18 of4 “ Modern Aspects of Electrochemistry,” edited by J.O’M. Bockris with theassistance of B. E. Conway, Butterworths Scientific Publications, London, 1954.5 R. Parsons, ref. 4, chap. 3.6 “ Electrochemical Constants,” National Bureau of Standards, Circular 524,Washington, 1953.Reviewed by H. Eisenberg and R. M. Fuoss, ref. 4, chap. 1; R. M. Fuoss andA. S. FLIOSS, An?%. Rev. Phys. Chem., 1953, 4, 64.J. Schubert, zbid., 1954, 5, 413; W. Juda, I. A. Marinsky, and N. W. Rosenberg,ibid., 1953, 4, 373; 2. EEektrochem., 1953, 57, 147 et seq. (Bunsen Gesellschaft sym-posium).A. R. Gordon and R. L. Kay, J . Chem. Phys., 1953, 21, 131.lo D. R. Muir, J. R. Graham, and A. R. Gordon, J . Amer. Chem. SOL, 1954, 16,2157; cf. G. S. Hartley, E.Drew, and B. Collie, Trans. Faraday SOC., 1934, 30, 648.l1 M. Eigen, Biscuss. Faraday SOL, 1954, 17, 194; see also R. G. Pearson, ibid.,p. 1S6.l3 M. Eigen, 2. phys. Chem. (Frankfurt), 1954, 1, 176.14 G. J. Janz and H. Taniguchi, Chem. Rev., 1953, 53, 397.l5 G. J. Hills and D. J. G. Ives, J., 1951, 311.l6 D. J. G. Ives and S. Swaroopa, Trans. Faraday SOL, 1953, 49, 788; see also H. I.l 7 J. C. NichoI and R. M. Fuoss, J . Phys. Chem., 1954, 68, 696.18 J. S. Johnson, K. A. Kraus, and T. F. Young, J . Amer. Ch~.m. SOC., 1954, 76, 1436.l2 M. Eigen, G. Kurtze, and K. Tamm, 2. Elektrochem., 1953, 57, 103.Schiff, ref. 17, p. 699AGAR AND RANDLES : ELECTROCHEMISTRY. 105the determination of the faraday by the oxalate coulometer l9Or and of thecharge-to-mass ratio of the proton and other gaseous ions by the" omegatron." lgbIn 1951 Powell and Latimer20 showed that the con-ventional standard partial molal entropies at 25" c of both positive andnegative monatomic ions could be represented by the empirical formulaIonic entropies.where Mi is the atomic weight, Zg the valency and Yi (A) the Pauling crystalradius of the ion.x = 2.00 A for cations and 1.00 A for anions. Morerecently Powell z1 has given a modified versionin which the In Mi term is omitted, and y = 1.3 for cations and 0.4 Afor anions. Both these formulae fit the observed values remarkably well,including most of those for ter- and quadri-valent ions; they emphasise thefact that the entropy is a linear function of the charge, in contrast to thedependence on 22 predicted by the Born charging process.Severalwriters 33 21* 22 have commented on the high values of ionic entropies for ionsof low charge and large radius as compared, for example, with the entropies ofthe inert gases in aqueous solution.21 Qualitatively, these facts are explicablein terms of some structure-breaking effect (not clearly defined) which counter-acts the expected reduction of entropy due to the ionic field.Analogous empirical formu12 for the entropies of oxy-anions and relatedspecies have also been given. Cobble suggestswhere pi is an effective ionic radius related to the interatomic distancebetween the peripheral oxygen atoms and the central atom by a propor-tionality factor of the order of unity, which varies somewhat according tothe type of ion considered.A simpler formula has been found 24 to fit thedata almost equally well :where a is the number of charge-bearing oxygen atoms in the ion (not count-ing hydroxyl groups). The extensions of such formulze to inorganic complexions has also been con~idered.~~Standard free energies, heats, and entropies of hydration of a largenumber of ions have been tabulated by Benjamin and Gold.26Sio = 43.5 - 46.5( JZil - 0.28n)loo D. N. Craig and J. I. Hoffmann, ref. 6, p. 13,196 H. Sommer and J. A. Hipple, ibid., p. 21.20 R. E. Powell and W. M. Latimer, J . Chem. Phys.. 1951, 19, 1139.21 It. E. Powell, J . Phys. Chem., 1954, 58, 528.e2 H. S. Frank and M. W. Evans, J . Chem. Phys., 1945, 13, 607.23 J.W. Cobble, ibid., 1953, 21, 1443.24 R, E. Connick and R. E. Powell, ibid., p. 2206.25 J: W. Cobble, ibid., pp. 1446, 1451; P. H. George, G. I. H. Hanania, and D. H.*@ L. Benjamin and V. Gold, T v a ~ s . Faraday SOL, 1954, 50, 797.Irvine, zbzd., 22, 16161 OG GENERAL AND PHYSICAL CHEMISTRY.Activity coe$cients and related quantities. Poirier 27 has given numeri-cal tables of the functions required in the calculation of thermodynamicquantities from J. E. Mayer's theory 28 of electrostatic interaction betweenions, and has used them to calculate the activity coefficients of sodiumchloride and zinc sulphate in water at 25". Good agreement with experimentis obtained up to 0 . 2 ~ and 0 . 0 1 ~ respectively by using reasonable values of thedistance of closest approach of the ions, a.This work has been reviewedmore fully by Frank and T ~ a o . ~ ~Poirier's tables have also been used to calculate the relative apparentmolal heat content 4~ and apparent molal volume 4~ of sodium chloride inits aqueous solutions.30 The calculated 4~ and +v agree with experimentup to about 0 . 0 7 ~ and 0.4~ respectively, empirical values being assigned tothe temperature and pressure coefficients of a.Two general accounts 31 of Eigen and Wicke's theory 32 of the thermo-dynamic properties of electrolytes have been published. This theory usesthe Debye-Huckel concept of an ionic atmosphere. A different distributionfunction is, however, obtained by taking account of the fact that the ionstend to exclude one another from the atmosphere by reason of their finitevolumes ; this point has also been discussed by other authors.33$ 34 In Eigenand Wicke's treatment the rather startling assumption is made that onlyions of like sign exclude one another, and behave in this respect like spheresof radius a, the same a being used as the distance of closest approach (i.e.ymean diameter) of two ions of unlike sign.Some justification is provided 31by considering what happens to the water molecules in the hydration spheresof the two ions in the cases of like and unlike charges. The picture is roughlyas follows : In the position of " closest " approach, a positive and a negativeion are separated by one water molecule; any closer approach is treated asion-pair formation and is not dealt with in this part of the theory.Theorientation of the intervening water molecule is such that it may be regardedas part of the hydration spheres of both ions; this cannot occur with twoions of like sign, and it is considered that each ion then retains two layers ofwater molecules when in " contact " with the other.In this form, the theory has only one disposable parameter (a), and forsome 1 : 1 electrolytes (eg., LiC1) gives a reasonable representation of theactivity coefficients, including the minimum values around 1 ~ . In manyother cases, however, it becomes necessary also to introduce a dissociationconstant (i.e.y the experimental activity coefficients are lower than thesimple theory predicts). Correspondingly, in the discussion of heats ofdilution and of heat capacities a contribution arises from the heat of disso-ciation.With these two additional terms (dissociation constant and heat)the concentration dependence of the three quantities, activity coefficient,A short account is given by G. Scatchard,2 7 J. C. Poirier, J , Chenz. Phys., 1963, 21, 965.28 J. E. Mayer, ibid., 1950, 18, 1426.29 H. S . Frank and M.-S. Tsao, Ann. Rev. Phys. Chem., 1954, 5, 43.30 G. C. Benson, Canad. J . Chenz., 1954, 32, 802.3 1 M. Eigen and E. Wicke, J . Phys. Chem., 1954, 58, 702; E. Wicke and M. Eigen,34 Idem, ibid., 1952, 56, 5.51; Naturwiss., 1951, 38, 453; 1952, 39, 645.33 M. Dutta and S. Bagchi, J . Iizdian Chem. SOC., 1950, 97, 4 ; Indian J . Phys.,1950, 24, 2 ; H.Falkenhagen and G. Kelbg, Ann. Physik, 1952, 11, 60; K. Schlogl,2. phys. Chem. (Leipzig), 1954, 202, 370.ref. 6, p. 185.Z. Eleklrochein., 1953, 57, 319.34 E. Schmutzer, ibid., 1954, 203, 292AGAR AND IZANDLES ELECTROCHEMISTRY. 107heat of dilution, and apparent molal heat capacity, can be predicted reason-ably well.Yet another approach to the problem of interaction between ions offinite size has been initiated by Kirkwood and P ~ i r i e r . ~ ~ It is derived froman earlier discussion by Kirk~ood,,~ and attempts to evaluate the potentialof mean force for sets of 12 ions in terms of a charging parameter. Approxim-ate equations are developed for IZ = 2 (taking the radii of the ions intoaccount) and the interesting result emerges that, a t high concentrations, thepotential has oscillating solutions, corresponding to stratification of spacecharges of alternating sign around an ion.Solutions containifzg two electrolytes.Interest in mixed electrolytesolutions has been stimulated by the development of some new thermo-dynamic relations, which can be obtained by making use of equations such aswhere al, a, are the activities of the two solutes and m,, m2 their rnolalitie~.~'In particular, a method has been given for evaluating the activity coefficientsof either solute in a mixture from measurements of the solvent vapourpressure extending over a sufficient range of both concentration^.^^ The studyof activity coefficients by measurement of the E.M.F.s of cells containing twoelectrolytes has also been discussed along similar lines.The types of cellconsidered are exemplified by :in which the activity of one solute (HCI) is measured directly, and(ii) glass electrode I HNO,, AgNO, I Ag 41in which the ratio of the activities of the two solutes is measured. Inprinciple, at least, measurements of this kind can provide more inform-ation about the thermodynamics of the system than had previously beensupposed.Robinson 42 has applied the McKay-Perring formula 38 to isopiesticdata for KC1-NaC1 mixtures; some other salt mixtures have also beenstudied by the isopiestic method.43Recent developments inthe theory of the concentration dependence of conductance and transportnumbers have mainly been concerned with the introduction of a distance ofclosest approach or mean ionic diameter, a, into the Onsager limiting law,As far as the electrophoretic effect is concerned, there is no difficulty in sodoing2 provided that the distribution of charge in the ionic atmosphere isknown and that the macroscopic viscosity can be used to describe the hydro-dynamic interaction of an ion and its atmosphere.The corresponding(i) H, I HC1, BaCl, I AgC1,Ag 39340Conductance, transflort numbers, and difusion.35 J. G. Kirkwood and J. C. Pokier, J . Phys. Chem., 1954, 58, 591.36 J. G. Kirkwood, J . Chenz. Phys., 1934, 2, 767.3 7 H. A. C. McKay, Nature, 1952, 169, 464; E. Glueckauf, H. A. C . McIiay, and3 8 H. A. C. McKay and J. K. Perring, Trans. Faraday SOC., 1953, 49, 163.39 H.S. Named, J . Phys. Chem., 1954, 58, 683.40 H. S. Harned and R. Gary, J . Amer. Chem. SOC., 1954, 76, 5924.4 1 TV. J. Argersinger, jun., J . Phys. Chem., 1954, 58, 792.4 2 R. A. Robinson, Trans. Faraday SOC., 1953, 49, 1411.43 R. A. Robinson, J . Amer. Chem. SOL, 1952, 74, 6035; Trans. Farnday SOL, 1953,A. R. Mathieson, J., 1949, S299.49, 1147; R. A. Robinson and C. K. Lim, ibid., p. 1140108 GENERAL AND PHYSICAL CHEMISTRY.treatment of relaxation effects with a finite value of a has only recently beenpublished. Falkenhagen and his co-workers 44 use Debye-Huckel distri-bution functions modified to take account of the space requirements of theatmospheric ions, following the procedure of Eigen and Wicke. This modi-fication is apparently unimportant except at high concentrations ; byomitting it and making some further approximations valid at low concentra-tions, Falkenhagen’s expression for the equivalent conductance, A, becomes 46where blAo and b, are the coefficients of the relaxation and electrophoreticterms in the limiting Onsager expression and K is the reciprocal of the radiusof the ionic atmosphere.This expression has been found to fit excellentlythe accurate data for hydrochloric acid (up to about O-OSM), sodium chloride,and potassium chloride, bromide, and iodide (up to 0 . 0 1 ~ or above) over arange of temperatures, with temperature-independent a values, close tothose derived from activity ~oefficients.4~Falkenhagen’s original expression is somewhat more complicated , andhe has pointed out that the derivation is not entirely sati~factory.~~ Adifferent treatment of the problem has been given by P i t t ~ , ~ ’ whose finalexpression differs from Falkenhagen’s, but, like it, reproduces the generalform of the conductance curves of several 1 : 1-electrolytes up to 0 .1 ~ orabove. A formula similar to Falkenhagen’s, together with a viscositycorrection, has been shown to give quite good agreement with observedconductances for ammonium chloride up to 5N.4sThe variation of transport numbers with concentration has also beenconsidered; 499 51 in this case the relaxation effect can be neglected and it isfound that good agreement with experiment (up to 0.1 or 0.2M) is obtainedfor 1 : 1 strong electrolytes by subtracting an electrophoretic correction ofthe form b ~ K / [ 2 ( 1 + ~ a ) ] from the mobility of each ion.49 This is a greatimprovement on the limiting law.For unsymmetrical (1 : 2 and 1 : 3) electrolytes the situation is morecomplicated.Spedding and his co-workers 50 have measured the conduct-ances, transport numbers, and activity coefficients of a number of rare-earthsalts ; by using their results for erbium and neodymium chlorides and earlierdata for calcium chloride, Dye and Spedding 5l find that a treatment of thetransport number problem analogous to that described above for 1 : 1electrolytes does not give good agreement with experiment. Much betteragreement is obtained by taking into account contributions to the chargedistribution round an ion arising from the higher terms in the expansion ofthe Boltzmann factors exp( -ei+/kT) which are omitted, more or less justi-fiably, in the treatment of 1 : 1 electrolytes.The value of 4 used, however,is the potential given by the Debye-Huckel theory, in which, of course, thesehigher terms are neglected. Presumably the inconsistency can only be4 4 H. Falkenhagen, ill. Leist, and G. Kelbg, Ann. Physik, 1952, 11, 51 ; H. Falken-4 5 R. A. Robinson and R. H. Stokes, J . Amev. Chem. SOC., 1964, 76, 1991.4 6 Ref. 1, p. 230, footnote.4 8 B. F. Wishaw and R. H. Stokes, J . Amer. Chem. Soc., 1954, 76, 2065.4 9 R. H. Stokes, ibid., p. 1988.50 F. H. Spedding and j. L. Dye, ibid., p. 879; F. H. Spedding and S. Jaffe, ibid.6 1 J. L. Dye and F. H. Spedding, ibid., p.888; cf. ref. 49.liagen and G. Kelbg, Z. phys. Chem. (Leipzig), 1953, 202, 56.4 7 E. Pitts, Proc. Roy. SOL, 1953, A, 217, 43.p. 882, 884AGAR AND RANDLES : ELECTROCHEMISTRY. 109avoided by using more accurate distribution functions than those of theDebye-Hiickel theory.of the electro-phoretic effect in diffusion, except for univalent In this field,Harned and his co-workers have made further measurements of diffusioncoefficients in dilute solutions (mostly in the range 0.001--0-01~) ; the saltsso far studied are as follows : 54 LiC1,55 NaC1,55 KCl, RbC1,56 CsC1; 56 KNO,,AgNO, ; Li,S04, Na,SO,, Cs,SO, ; MgC12,57 CaCl,, SrC12,57 BaCl, ; 57 LaCl, ;MgSO,, ZnSO,; K,Fe(CN),. All the 1 : 1 sdts agree with the Onsager-Fuoss theory, although it should be noted that the calculated electrophoreticcorrection (the main point at issue in this comparison) is often verysma11.39* 553 58 In the case of calcium chloride the observed diffusion co-efficient falls below the theoretical value, but some doubt is cast on thisresult by the later measurements of the other 2 : 1 and 1 : 2 salts, whichagree with the theory.A re-determination of the diffusion coefficient ofcalcium chloride 58a gives values higher than those found earlier, but theystill fall below the theoretical values. The results for zinc sulphate andmagnesium sulphate are very similar to one another, and can be interpretedin terms of ion-pair formation.Accurate measurements of diffusion coefficients of electrolytes at higherconcentrations have been made by use of the Gouy diffusiometer 48, 59-61and the diaphragm cell 62y 63 methods ; neither of these methods is satis-factory at low concentrations.The deviations from the Onsager-Fuosstheory are considerable, as might be expected, but some success has beenachieved in interpreting them as a combined effect of (i) diffusion of thesolvent molecules, (ii) hydration of the ions, and (iii) viscosity change~.~89 60,In the case of ammonium nitrate there is some evidence of ion-pair formation,as is also suggested by conductance studies.48A detailed account of the tracer diffusion of ions and of the self-diffusionof water 65 in ionic solutions cannot be given within the compass of thisReport. Work in this field continues actively 66-69 and some of the con-clusions to be drawn from it have been discussed by Although most52 R.H. Stokes, J , Amer. Chem. SOC., 1953, 75, 4563.63 A. W. Adamson, J . Phys. Chem., 1054, 58, 514.54 References to the earlier papers in this series are given by H. S. Harned, ref. 6,5 5 H. S. Harned and C . L. Hildreth, J . Amer. Chem. SOC., 1951, 73, 650.5 6 H. S. Harned and M. Blander, ibid., 1953, 75, 2853; H. S. Harned, M. Blander,57 H. S. Harned and F. M. Polestra, ibid., 1953, 75, 4168; 1954, 76, 2064.5 8 E. A. Guggenheim, Trans. Faraday SOC., 1954, 50, 1045.ma H. S. Harned and H. W. Parker, J. Amer. Chem. SOC., 1955, 77,265.69 L. J . Gosting, .J. Amer. Chem. SOC., 1950, 72, 4418.6o J . R. Hall, B. F. Wishaw, and R. H. Stokes, ibid., 1953, 75, 1556.61 1’.A. Lyons and J. F. Riley, ibid., 1954, 76, 5216.62 R. H. Stokes, ibid., 1950, 72, 763, 2243; 1951, 73, 3527.63 P. J. Dunlop and R. H. Stokes, ibid., 1951, 73, 5456.64 See also refs. 34 and 53.G 5 J . H. Wang, C. B. Robinson, and I. S. Edelman, .J. Amer. Chem. SOC., 1953, 75,416.6’ J. H. Wang and J. W. Kennedy, ibid., 1950, 72, 2080.6 8 T . H. VC‘ang, ibid., 1051, 73, 510, 4181; 1952, 74, 1182, 1612; 1953, 75, 1769;J. €1. Twang and S. Miller, ibid., 1952, 74, 1611, 6317; R. Mills and J. W. Kennedy, ibid.,1953, 75, 5696.70 J. H. Wang, J . I’hys. Chevn., 1054, 58, 086.Similar difficulties arise in the Onsager-Fuoss theoryp. 69; Ann. Rev. Phys. Chew., 1951, 2, 37; and in refs. 39 and 53.and C. L. Hildreth, ibid., 76, 4219.6 6 J .M. Nielsen, A. W. Adanison, and J. W. Cobble, ibid., 1952, 74, 446.c9 C. J. Kraus and J. W. T. Spinks, Canad. J . Chem., 1954, 32, 71110 GENERAL AND PHYSICAL CHEMISTRY.of the work refers to radioactive ions, tracer diffusion of inactive ions hasalso been studied. 71-73 The agreement between different experimentalmethods is not entirely satisfactory.66Incomplete dissociation in salt solutions was fully discussedin Annual Reports for 1952 ; 74 among the more recent investigations in thisfield, the dissociation constants of some glycollates and lactates 75 and ofsome calcium and thallium salts 76 have been determined. In connectionwith the latter, George, Rolf, and Woodward 77 were unable to detect anyRaman spectrum from the undissociated TlOH in concentrated solutions,which supports the view that the bond is electrostatic. An investigationof the Raman spectrum of concentrated silver nitrate solutions 78 failed toreveal any lines assignable to Ag2++, the existence of which had earlier beensuggested 79 to explain some anomalous properties of solutions of silver salts.Wicke, Eigen, and Ackermann have discussed the nature of thehydrated hydrogen ion.Several lines of evidence lead them to suggest thateach H,O+ ion attaches to itself three water molecules, which form the‘ I inner ” hydration shell, and that the proton can move very freely withinthis H,04+ complex.The Electrical Double Layer at Metal-Electrolyte Interfaces.-During thelast few years there has been an increasing amount of work directed towardsa more exact description of the electrical double layer at metal-electrolyteinterfaces.Apart from its intrinsic interest, a further understanding of thestructure of the double layer is a requisite for a more detailed interpretationof the kinetics of electrode reactions in terms of mechanism. Progress hasbeen made along two complementary main lines. On the one hand thethermodynamics of the “ ideal polarised electrode ” has been clarified anddeveloped, and also used to direct and to interpret experimental work. Inthis way a good deal of fairly exact data on the double layer (at mercury-electrolyte interfaces) has been accumulated. On the other hand there hasbeen some progress in the molecular-kinetic description of the double layerchiefly in the form of modifications to, and refinements of, Stern’s 81 theory.An excellent account of the electrical double layer has recently been pub-lished by parson^.^ In this Report the intention is to indicate briefly theconclusions which may be drawn from recent work and to refer to publicationstoo recent to be included by Parsons.The thermodynamics of the ‘ I ideal polarised electrode,” originally workedout by Gouy s2 and others, was clarified by K0enig,8~ and a concise andthermodynamically rigorous treatment has recently been given by Parsonsand Devanathan 84 (see also reference 5, pp.128-134). I t has also beenOther topics.‘11 R. Suhrmann and I. ’CViedersich, Z. Elektrochem., 1953, 57, 93.72 M.von Stackelbcrg, M. Pilgram, and V. Toome, ibid., p. 342.7 3 C. L. Rulfs, J . Amev. Chew.. SOC., 1954, 76, 2071.74 C. W. Davies and C. B. Monk, Ann. Reports, 1953, 49, 28.75 P. B. Davies and C. B. Monk, Trans. Faraday SOC., 1954, 50, 128, 133.76 R. P. Be11 and J. H. B. George, ibid., 1953, 49, 619.7 7 T. H. B. George, J. A. Rolfe, and L. A. Woodward, ibid., p. 375.78 D. N. Waters and L. A. Woodward, J., 1954, 3260.79 C. W. Davies and D. C. Morgan, Chem. and Ind., 1954, 428.80 E. Wicke, M. Eigen, and Th. Ackermann, 2. Phys. C h m . (Frmzkfzwt), 1964, 1, 340.81 0. Stern, 2. Elektrochem., 1942, 50, 508.82 G. Gouy, Ann. Phys., 1917, 7, 129.83 F. 0. Koenig, J . Phys. Chew., 1934, 38, 111, 339.84 R. Parsons and 11. A. V. Devanathan, Trans. Farnday SOC., 1963, 49, 404AGAR AND RANDLES : ELECTROCHEMISTRY. 111developed by Grahame 85-88 with particular reference to the differential(electrical) capacity of the interface at an ideal polarised electrode.One ofthe most interesting and useful results of the thermodynamic treatment is thedemonstration that the surface excess of any component, whether an un-charged molecule or an individual ionic species, can be calculated preciselyfrom appropriate experimental data. This may be illustrated by a verysimple example, e.g., a mercury-aqueous hydrochloric acid interface, withan auxiliary electrode reversible to chloride ion in the aqueous phase. If E-is the potential of the mercury phase relative to the reference electrode (asmeasured directly by a potentiometer), and y the mercury-solution inter-facial tension, thenHere I?+ is the surface excess of H+ relative to H,O, that is, if rHR+ and rII,orepresent the number of moles of Ht and H,O respectively per cm.2 of thesurface phase 89 and xH+ and XH,O their mole fractions in the bulk of the-((ayppHIa)E- = r+ .. . . . . (1)aqueous phase, then r+ =- ra+ -If the potential E+ relative to an electrode reversible to H i were keptconstant, then,--(ayplJ-HCI)E+ -- rc1- (H,O) * * * (2)Interfacial-tension data for use in equations such as (1) and (2) can onlybe obtained for liquid metals, Le., generally speaking mercury or diluteamalgams. Unfortunately most of the earlier experimental measurements,except some made by Gouy, were made with electrodes involving ill-definedliquid junctions, and so are not adapted to precise calculation.Parsons andDevanathan and Devanathan and Peries 9 1 have recently measuredmercury-electrolyte solution interfacial tensions by a capillary electrometermethod for the specific purpose of calculating surface excesses of ionic,s0, 91and uncharged,w components.Much more extensive and detailed information on the ionic constituentsof the aqueous side of the double layer a t a mercury-aqueous electrolyteinterface has been accumulated by Grahame and co-workers 8 6 y *** 92-96from differential capacity measurements. The preference for mercuryshown by all workers in this field is due t o the ease with which a clean,smooth surface of accurately known area is obtainable.Grahame has useda dropping-mercury electrode throughout. The method by which surfaceexcesses of ionic components are calculated from diflerential capacity datamay be briefly indicated as follows, by using our previous mercury-aqueouse 5 13. 13. IVliitney and D. C. Grahamc, J . Chem. Yhys., l!Ml, 9, 827.p 6 D. C. Graharne, Chent. Hcu., 1947, 41, 441.Idem, J . Chew. Phys., 1948, 16, 1117.D. C. Grahame and B. A. Sorderberg, -1. Chew. Yhys., 1964, 22, 449.R. Parsons and M. -4. V. Devanatlian, Trans. Farada-y SOC., 1953, 49, 673.89 E. A. Guggenheim, Trans. Favaday SOC., 1940, 36, 29s ;9 1 M. A. V. Devanathan and P. Peries, ibid., 1954, 50, 1236.y s D. C. Grahame, .J. Anzev. Chem. SOC., 1949, 71, 2975.y3 Idem, J . Electrochem. SOC., 19.51, 98, 343.y4 Idem, Office of Naval Research Report No.6, 1951.96 D. C. Grahame, M. A. Poth, and J. I. Cummings, ibid., KO. 7, 1961.D 6 D. C Grahame, J . Amer. Chem. SOC., 1954, 76, 4819." Thermodynamics,"Elsevier, 1949, p. 36112 GENERAL AND PHYSICAL CHEMISTRY.HC1 system as example. Assuming that a reference electrode reversible tothe C1- in the solution is used, the Lippman equation for the surface densityof charge on the mercury, qM, isqx = -(ay/aE), where p = p ~ c 1 and E is the previously defined E-,whence the differential capacity per cm.2, C, is given byHence the dependence of C on pH~1 is given bywhence, from (1)( a ~ l a ~ ) ~ = -ap[ay/aE . a,)]( a ~ p ~ ) ~ = +a/aE(ar+ pq = a2r+ /aE2 . . . (3)Thus by double integration of (JC/apHcl)E- with respect to E-, with appro-priate integration constants, r+ can be calculated.Numerical integrationsof this type have been carried out by Grahame (see particularly ref. 88).The conclusions to be drawn from Grahame’s work and their inter-pretation by recent theories are best illustrated with reference to a simplemolecular picture of the electrolyte side of the interface, which forms thebasis of present ideas on the structure of the double layer.I t is generally assumed that the distribution of ions on theelectrolyte side of the interface determines its electricalbehaviour (although Rice’s 97 suggestion that the layer ofcharge on the metal side may be diffuse and limit theelectrical capacity of the interface has never been con-clusively disproved).The closeness of approach of ions inthe electrolyte to the metal surface is determined bywhether or not they lose their hydration shell on the sidenearest to the metal. Ions which do so as they approachthe metal surface enter what is called the inner Helmholtzlayer, and the locus of their centres forms the inner Helm-holtz plane, A in the Figure. Ions which retain at leastthe first layer of their hydration shells cannot approach theelectrode so closely, and the locus of their centres at closestapproach is the outer Helmholtz, or Gouy, plane, B. Thedistribution of these ions, which form the diffuse part ofthe double layer (it?., from the bulk of the solution up to andincluding ions whose centres lie in.the outer Helmholtz plane), is regarded asdetermined by the general electrical field only.On the other hand ionsoccupying the inner Helmholtz layer are regarded as adsorbed to the metalsurface with some degree of “ chemical ” bonding.It appears highly probable from Grahame’s work (see particularlyref. 88) that no monatomic cations enter the inner Helmholtz layer at amercury-aqueous electrolyte interface, except possibly under extremecathodic polarisation.* On the other hand all anions except fluoride ionare adsorbed and enter the inner Helmholtz layer when the mercury is9 7 0. K. Rice, J . Phys. Chem., 1926, 30, 1501. * Although in earlier work 93 i t was argued by Grahame that cations normally losepart of their hydration sheath on approaching the mercury surface, he has since modifiedthis viewAGAR AND RAN DLES ELECTROCHEMISTRY.113positively charged. The readmess with which anions are adsorbed tends toincrease as the solubility of the corresponding mercurous salt decreases.95The more readily adsorbed anions (c.g., iodide) are not completely desorbeduntil the mercury surface carries a considerable negative charge.The fact that fluoride ion appears to be excluded from the inner Helm-holtz layer leads to a rather simple interpretation of the concentrationdependence of the differential capacity of the interface between mercury andfluoride soluti0ns.~6 It is easily understood from the Figure that if there isno charge between the mercury surface and the outer Helmholtz plane B,then the overall capacity should be equal t o the capacity of the diffuse layerin series with the capacity of the condenser represented by the metal and theouter Helmholtz plane.The diffuse layer capacity is easily calculated as afunction of the total charge per cm.2 of interface, if a Boltzmann distributionof ions and a uniform dielectric constant of the medium is assumed (see forinstance refs. 86 and 98).Thus from the measured differential capacity at various potentials ofthe mercury in, say, 1 N-sodium fluoride solution, the corresponding capacitiesof the metal-outer Helmholtz layer system can be calculated. These canthen be combined with the calculated diffuse layer capacities for lowerconcentrations of sodium fluoride to predict the corresponding overalldifferential capacities for these concentrations." The agreement withexperimental measurements is The importance of this result is thatit shows that the various corrections to the simple theory of the diffusedouble layer which have been made (e.g., volume of ions and effect of non-uniform field on the energy of a dipoleJgs, loo saturation of the dielectric in thehigh field near the metal lo1, lo2) are superfluous at the present standard ofaccuracy.The reason for this is that when the field strength or ionic concen-trations in the diffuse layer are high (so that the corrections would beimportant) the diffuse layer capacity is so large that its effect on the overallcapacity is very slight.It is certain that the effective dielectric constant of the water close tothe niercury surface does decrease very greatly.Thus, as pointed out byMcDonald,lo3 the capacity of the charge-free layer in the mercury-aqueoussodium fluoride interface at the null point is about 29 pF/cm.2 (Grahame'sfigure). If the dielectric constant of the medium were 78.5, the distancefrom the metal surface to the outer Helmholtz plane would have to be 24 A,which is most improbable. A separation of about 3 A and an effectivedielectric constant of about 10 is probably nearer the truth. However, itis clear that the ordinary macroscopic concepts of charged surfaces and uni-form dielectrics are not applicable to this problem. Since this low value ofthe capacity refers to the null point it is evident that the hindrance to therotation of the water molecules near the mercury surface is not due to anelectric field caused by a net charge on the mercury, but is probably due to9a J.R. McDonald and M. K. Brachman, J . Clienz. Phys., 1954, 22, 1314.J . J. Bikcrman, Phil. Mag., 1942, 33, 384.l o o V. Frcise, 2. Elektrochem., 1953, 56, 822.I o 1 D. C. Grahamc, J . Chem. Phys., 1950, 18, 903.B. E. Conway, J. 0. M. Bockris, and I . A. Ammar, Tvans. Faraday SOC., 1951,* Frumkin (Traits. Farnday Soc., 1040, 36, 117) made some comparable calculations43, 756.for KCl solutions, but necessarily of a l r s s precisc character.lo3 J. R. McDonald, J . Chem. Phys.. 1954, 22, 763114 GENERAL AND PHYSICAL CHEMISTRY.an interaction between the superficial mercury atoms (or ions) and theadjacent water molecules.There is considerable evidence for the orientationor " freezing " of several layers of water molecules by various solid surfaces.lMNot much progress has been made in the understanding of this problemof the charge distribution and gradient of electrical potential between theouter Helmholtz layer and the surface of the metal. An interesting attemptin this direction has been made by Devanathan.lo5 He postulates that theinner Helmholtz plane is situated a t a distance from the metal surface equalto the crystal radius of the adsorbed ions, and the outer Helmholtz (Gouy)plane at the distance of the centres of the second layer of water molecules.Cation adsorption, when the metal is strongly cathodically polarised, is notexcluded, though it is small.Surface excesses of various ions calculated onthe basis of this model from Graliame's differential capacity data, are infairly good agreement with the values calculated from electrocapillar y dat a,91and the results of the theory are self-consistent. However, it is difficultto tell how sensitive a test of the accuracy of the model these results are,Although, because of the gain in simplicity, the charges in the innerHelmholtz layer are generally regarded as " smeared out " layers of charge,it has been shown by Ershler lo6 (developing some earlier ideas of Esin andShikov lo') that this is not valid for some purposes. In particular the workof introducing a further ion into this layer from the bulk solution, whencalculated on the basis of a layer of discrete charges, may be as small as ahalf of that calculated on the basis of an equivalent " smeared out " layerof charge.On this basis, Ershler explains quantitatively the dependence ofthe potential of the null point on the concentration of salts containing adsorb-able ions (e.g., chloride), which is different from that which is expected if theHelmholtz layer is regarded as a uniform sheet of charge. Ershler's workhas been criticised by Grahame lo8 who has, however, now withdrawn thecriticism in the form originally stated.los@The work so far referred to is all concerned with mercury-electrolyteinterfaces. The capacity of solid electrodes is generally rather ill-definedand only in a very few cases (Tl, Cd, Pb) log, have the capacity-potentialcurves shown any similarity to those of mercury, or any similar dependenceon the concentration of the electrolyte.Electrode Processes-Since the last Report 111 a great deal of work hasbeen published both on the hydrogen-ion discharge reaction and on otherelectrode processes.An extensive review of the subject by Bockris l 1 2 hasrecently appeared. Work on the hydrogen reaction will be omitted fromthis report since the review just mentioned treats this topic in great detail.Of the other electrode reactions investigated, many are much more rapidthan the discharge of hydrogen ions, and therefore special methods are usedto minimise, or to take account of, the effect of limited diffusion rates. Alter-104 J . C.Henniker, Rev. Mod. Phys., 1949, 21, 322.105 M. A. V. Devanathan, Trans. Faraday SOC., 1954, 50, 373.106 B. V. Ershler, Zhur. $2. Khim., 1946, 20, 679.107 0. Esin and V. Shilrov, ibid., 1943, 17, 236.108 D. C. Grahame, Office of Naval Research Report, No. 13, 1954.I d e m , personal communication.109 T. I. Borisova, B. V. Ershler, and A. Frumkin, Zhur. $2. Khin'tn., 1948, 22, 925.110 T. I. Borisova and B. V. Ershler, ibid., 1950, 24, 337.111 A. Hickling, Ann. Reports, 1950, 47, 68.112 J. O'M. Bockris, ref. 4, chap. 4AGAR AND RANDLES : ELECTROCHEMISTRI’. 115nating current, and non-steady state electrolysis, have been used increasinglyand the widespread use of the dropping-mercury electrode for kinetic studiescontinues. Methods of measuring polarisation potentials with particularreference to electrode and cell design are reviewed in recent papers byPiontelli.113The change of potential of an electrode during the initial stages (non-steady state) of constant current polarisation has been investigated byGierst and Juliard 114 and Delahay 115 who have shown that it may be usedin studying the kinetics of electrode reactions and of chemical reactionspreceding an electrode reaction.The theory of the impedance of electrodes to alternating current 116 hasbeen stated in a very general form by D. C. Grahame.l17 I t has been furtherdeveloped by Gerischer and by Vetter both for pure alternating current 11*and for alternating current superimposed on direct current .119 Thetechniques of alternating-current measurements in electrochemistry havebeen reviewed by Gerischer.120 Measurement of the alternating currentimpedance of an electrode at its equilibrium potential leads to an accuratevalue of the “ exchange current ” at the electrode.From the dependenceof the exchange current on the concentration of the reactants and theequilibrium potential of the electrode it is possible to determine the natureof the reactants in the actual charge-transfer reaction.121 By this means,for instance, it has been shown by Gerischer 122 that at a zinc amalgamelectrode in a solution containing zinc largely as zincate ion [Zn(OH),2-] theexchange reaction at the electrode does not involve zincate ion hut Zn(OH), :Zn(Hg) -t 20H- * Zn(OH), 4- 2e-Similarly in a solution containing Zn(0x):- the reacting entity is ZnOx, in asolution of ZII(CN),~- it is Zn(OH),, etc.Similar studies of reaction mech-anisms have been made by Vctter 123 for the Mn(Iv)-Mn(rII), I,--I-,HN0,-HNO,, and quinone-quinol systems, and also by Lewartowicz.The extensive work on the factors determining the degree of reversibilityof metal-ion deposition reactions by Piontelli 125 has been referred to in anearlier report; ll1 this topic has also been discussed by Lyons, Bailar, andLaitinen.126 In the electrodeposition of metals “ addition agents ” (gener-113 R. Piontelli, 2. EZektrochenz., 1954, 58, 54, 86.114 L. Gierst and A. L. Juliard, J . I’hys. Chenz., 1953, 57, 701.115 P. Delahay and C. C. Mattax, J . Anzer. Chenz. Soc., 1954, 70, 874, 5314; P.Also P. Delahay, “hTew Instru-116 J. E. B. Randles, Discztss. Faraday SOC., 1947, 1, 11; B. V. Ershler, Zhur. $2,117 D. C. Grahame, J . Elektrochcrn. Soc., 1952, 99, 3700.15. Gerischer, 2. Elektrochenz., 1951, 55, 98; 2. phys. Chem., 1951, 198, 286;Delahay, C. C. Mattax, and T. Berzins, ibid., p. 5310.mental Methods in Electrochemistry,” Interscience, New York, 1964.Khim., 1948, 22, 683; K. Rosenthal and 13. V. Ershler, ibid., p. 1344.1932, 201, 55; K. J. Vetter, ibid., 1952, 199, 285, 300.1 1 9 H. Gerischer, 2. phys. Chem. (Frankfurt), 1954, 1, 278.12* Idem, 2. Elektrochenz., 1954, 58, 9.1 2 1 K. J. Vetter, 2. phys. Chem., 1950, 194, 284; H. Gerischer, ibid., 1953, 202, 292.la2 H. Gerischer, ibid., 1953, 202, 302; 2. Elektrochem., 1953, 57, 604.123 I<. J. Vetter, 2. Elektrochem., 1951, 55, 121; 1952, 56, 797.l21 E. Lewartowicz, J . Claim. phys., l952, 49, 557, 564, 573; see also idem, ibid.,125 R. Piontelli, J . Insd. i’liletals, 1951--1952, 80, 99 (includes references to earlier126 E. 13. Lyons, jun., .[. Electrochem. SOC., 1954, 101, 363, 376, E. H. Lyons, jun.,1954, 51, 267.work); 1. Chinz. plays,, 1953, 50, 426.J. C. Bailar, and H. A . Laitincn, ibid., p. 410116 GENERAL AND PHYSICAL CHEMISTRY.ally surface-active substances) are frequently added to the electroplatingsolution to improve the texture of the deposited metal. The mode ofaction of such substances continues to be investigated 127 and there is aconsiderable amount of work proceeding, particularly in the U.S.S.R., inwhich the way in which adsorbed substances impede the transit of a metalion between solution and electrode is being specifically studied. Mercuryor amalgam electrodes have been used to study the effect of gelatin andcamphor on Zn2+, Cd2+, or Pb2+ deposition and dissolution12* and theeffect of Ph,NH, thymol, gelatin, etc., on Cd2+, Cu2+, Zn2+, Pb2+, or 8i3+deposition.129 The effect on the A.C. impedance of electrodes has also beeninvestigated.lm Another factor affecting metal-ion deposition is the chargedistribution, or potential gradient, in the electrical double layer at the metal-electrolyte interface. Thus, the anion affects appreciably the deposition ofa metal ion only when the deposition potential is more positive than the nullpoint of the metal.131Some interesting effects in the electro-reduction of anions result fromtheir repulsion from the metal surface. Thus a l0-3~-solution of per-sulphate (S2OS2-) is reduced at a mercury or amalgamated copper cathode,giving a diffusion-limited current at a potential slightly positive to the null-point potential. If the electrode is made progressively more negative thecurrent decreases practically to zero and only increases again as the potentialbecomes extremely negative (>1 v negative to the null point).132 Thiscurrent minimum can be eliminated by adding an indifferent electrolyte suchas N-I<,So,, or a very low (10-4~) concentration of a tervalent cation (e.g.,La3’). Clearly, the current minimum in the very dilute solution is due tothe repulsion of S20g2- from the electrode which is prevented either byeliminating the diffuse double layer (N-I<,SO~) or by forming ion pairs suchas (I,aS,O,)+. Similar results are obtained for the reduction of Fe(CN),3-,PtC142-,133 Cd(CN),2-.134 If electrodes of other metals are used the positionof the current decrease can be used as an indication of the null point.136Interesting correlations between the electronic structure (as determined bythe composition of an alloy) of inert electrodes and the rate of electron-transfer reactions at such electrodes have been demonstrated. 136 The inter-pretation is based on the density of electrons in the various levels in themetals, but it seems possible that changes in null-point potential may alsobe significant.127 L. I,. Shreir and J. W. Smith, Trans. Faraday Soc., 1954, 50, 393; L. I. Antropovand S. Va Popov, Zhur. priklad. Khim., 1954, 27, 55, 206; A. I. Levin, E. A. Ukshe,V. S. Kolevatova, 2hur.fi.z. Khim., 1954, 28, 116.1 z 8 A. G. Stromberg and M. S. Guterman, Zhur. $2. Khim., 1953, 27, 992..lZB M. Dratovsky and M . Ebert, Chem. Listy, 1954, 48, 498; M. A. Loshkarev andA. A. Kryukova, Zhur.$z. Khim., 1952, 26, 731, 737.130 P. J. Hillson, Trans. Faraday SOC., 1954, 50, 385; J. E. B. Randles and K. W.Somerton, ibid., 1952, 48, 937, 951.131 L. I. Antropov, 2hur.fi.z. Khirra., 1951, 25, 1494.132 A. N. Frumkin and G. M. Florianovitch, Doklady Akad. Nauk S.S.S.R., 19Fi1,80, 907.134 S. Siekierski, Roczniki Chem., 1954, 28, 90.N. V. Nikolaeva, N. S. Shapiro, and A. N. Frumkin, Doklady Akad. NaukS.S.S.R., 1952, 86, 581; T. V. Kabsh and A. N. Frumkin, Zhur. $2. Khim., 1054,28, 473, 801.136 W. G. Burgers and M. J. Brabers, PYOC. k . ned. Akad. Weteizsclzap., 1953, 13,56, 1, 12, 439.133 H. A. Laitinen and E. I. Onstott, J . Amer. Chem. SOC., 1950, 72, 4565AGAR AND RANDLES : ELECTROCHEMISTRY. 117Several investigations of anodic processes involving the metal of theelectrode have been reported. The anodic oxidation of mercury in aqueoushydrochloric acid does not result in a straightforward production of calo-mel in the early stages. The anodic reaction of mercury in other halidesol~tions,~~8 and anodic reactions of various other metals, e.g., Cu,139 Ag,140Ta,141, e t ~ . , I * ~ have also been studied.The Reporters thank Dr. R. Parsons for translations of some of the Russianpapers cited.J. N. A.J. E. B. R.J. N. AGAR.G. C. BOND.E. COLLINSON.F. S. DAINTON.MANSEL DAVIES.K. J. IVIN.1. E. B. RANDLES.H. A.D. R.W. J.A. D.R. A.187 R. H. Cousens, D. J. G. Ives, and R. W. Pittman, J.,139 E. H. Boult and H. R. Thirsk, Trans. Faraday Soc., 1954, 50, 404.139 €3. La1 and €3. R. Thirsk, J., 1953, 2638; L. Stephenson and J. H. Rartlett,J . Elektrockem. Soc., 1954, 101, 571; J. S. Ilalliday, Traizs. Fccraday Soc., 1954, 60,171.140 P. Jones and H. R. Thirsk, ibid., p. 732.lg1 L. Young, ibdd., p. 153, 159, 164.1g8 S. E. S. El Wakkad and A. M. Shams El Din, */., 1954, 3094, 3098; S. E. S.H. R. Thirsk, Puoc. Phys. Soc., 1953, B, 66, 129.El Wakkad, ,4. M. Shams El Din, and J. A, El Sayed, ibid., p. 3103.SKINNER.STRANKS.ORVILLE THOMAS.WALSH.WILLIAMS.1953, 3972, 3980, 3938

ISSN:0365-6217    

DOI:10.1039/AR9545100007

出版商:RSC    

年代:1954

数据来源: RSC

摘要:

INORGANIC CHEMISTRY.THEORETICAL advances of considerable importance in the interpretation ofthe structures of many types of inorganic compound have been reportedduring the year ; these mainly concern the participation of d-orbitals incovalent bonding, and the nature of the bonding in the higher hydrides ofboron and in the cyczopentadienyls of the transition metals.The recognition over twenty years ago that d orbitals can combine withs and 9 orbitals to form hybridised groups of equivalent orbitals withstrongly directional properties resulted in great advances in the understand-ing of inorganic stereochemistry. This success directed attention mainlyto the angular properties of atomic orbitals, but recently it has been realisedthat d orbitals are likely to participate in bonding in other ways, for exampleby the formation of d,-p, bonds which would account for the double bondingapparent in groups like sulphate,l and by the formation of dn-dT bonds toaccount for the striking difference between co-ordination by oxygen andnitrogen on the one hand and heavier donors such as sulphur, phosphorus,and arsenic on the other.2 Quantitative investigations of these effects havedirected attention more particularly to the radial parts of atomic orbitals.Thus it has been shown that the 3d orbitals of neutral atoms of phosphorusand sulphur are too diffuse to combine effectively with the more compact3s and 3p orbitals, L e ., the radial parts of the d-orbitals diminish with dis-tance from the nucleus much more slowly than those of the s or p orbitals.This prevents effective overlap and the formation, for example, of satis-factory sp3d2 octahedral orbitals, though highly stable octahedral compoundsof these elements are known (e.g., sulphur hexafluoride and the PF,- ion).The difficulty has been largely resolved by considering the relative polaris-abilities of the orbitals concerned.The d orbitals are more polarisablethan s and 1) orbitals, and those of phosphorus and sulphur would contractmore than s or p orbitals if the phosphorus or sulphur acquired a positivecharge due to bonding to more electronegative atoms. This explains whythese elements exert their highest covalencies only when bound to the mostelectronegative atoms, notably fluorine. This is true generally of elementsin which d orbitals available for bonding are of the same principle quantumgroup as the s and p orbitals.Conversely, d orbitals available for bonding, which belong to a lowerprincipal quantum group than the s and p orbitals also involved in bonding,are generally too compact for effective overlap.This occurs with thetransition metals, and in such instances hybridisation involving d orbitalstogether with s and p orbitals is favoured by bonding to the less electro-negative elements. For example, it has been noted that nickel tends toform tetrahedral ( s $ ~ ) complexes with the more electronegative ligands andplanar (as@*) complexes with less electronegative ligands ; likewise copper (11)which normally forms sp2d bonds with the electronegative atoms oxygenand nitrogen uses the 4d and not the 3d orbital.1 G. M.Phillips, J. S. Hunter, and L. E. Sutton, I., 1945, 146.2 U. K. Syrkin, Izvest. Akad. Nauk S.S.S.R., Otdel. Khinz. Nauk, 1948, 75; J .Chatt, Nature, 1950, 165, 637COATES AND GLOCKLING. 119The overlap of d orbitals with 9, or d, orbitals, giving double bonds, hasbeen found to be satisfactory in most cases in which it has been supposed tooccur, and appears to be rather less sensitive to changes in the radial partsof the atomic orbitals. It is mainly in connection with the formation ofG bonds by hybridised orbitals involving d atomic orbitals that the veryimportant influence of electronegativity has to be considered.,Several discussions have appeared concerning the bonding in the higherboron hydrides,* most of the structures now having been determined experi-mentally, including that of the unstable pentaborane, B,H11,5 and thereare preliminary results for hexaborane, B6H10.6The nature of the bonding in the biscyciopentadienyl derivatives of thetransition metals now seems to be fairly well understood, and the magneticproperties of the compounds have been e~plained.~ The extent to which6 bonding, which bears the same relation to x bonding as x to G, takes partis not yet quite clear,,, and the structures of the interesting carbonyl-cyclopentadienyls of vanadium, molybdenum, and tungsten are not yetunderstood.The existence of two more hydrides of boron, octaborane and nonaborane,has been confirmed, and some hydrides and methylated nitrides of berylliumare reported.Subhalides have received considerable attention, particularly that ofboron, B,Cl,, which reacts in an interesting way with ethylene, but the sub-halides of calcium, silicon, germanium, niobium, and tantalum have alsobeen studied.The chemistry of nitrogen has been extended by the addition of numerousazides, e g ., BN,, SiN,,, and Na,SnN,,. Many of these are sensitive to shock.There have been more advances in the chemistry of sulphur, and ofsulphimide (HN-SO,), in particular, and a new oxynitride, S,N205, has beendescribed.The cyclopentadienyl group of compounds has been intensively studiedand now includes several carbonyl-cyclopentadienyls, e.g., C,H,V(CO),, andsome indenyls of which the yellow liquid bistetrahydroindenyliron, (CsH,1)2Feis an example.Some of the most interesting advances during the yearhave again concerned carbonyls and mixed carbonyl-cyanides, particularlythose of cobalt, e g . , the addition of dicobalt octacarbonyl to acetylenes.The series of isocyanide complexes of the transition metals has been extendedand now includes such compounds as [Co(CNR),](ClO,), and W(CNR),.Review articles have been published on co-ordination compounds,8 thesignificance of magnetic measurements in inorganic chemi~try,~ boron tri-fluoride co-ordination compounds, lo the reactions of inorganic iodine com-3 D. P. Craig, A. Maccoll, R. S. Nyholm, L. E. Orgel, and L. E. Sutton, J., 1064, 332.4 W. N. Lipscomb, J .Chem. Phys., 1054, 22, 985; W. H. Eberhardt, 13. Crawford,L. R. Lavine and W. N. Lipscomb, ibid., p. 614.6 K. Eriks, W. N. Lipscomb, and R. Schaeffer, ibid., p. 764.7 W. Moffitt, J . Anzer. Chem. SOC., 1954, 76, 3386; F. Cotton and G. Wilkinson,Z. Naturforsch., 1954, 9b, 453.8 W. Wark, D. P. Craig, R. S. Nyholm, L. N. Short, D. P. Mellor, D. D. Brown,N. 13. Dsvies, E. C. Gyarfas, G. A. Barclay, B. J. Ralph, W, A. Rawlinson, and N. A.Gibons, Rev. Pure Apjd. Clzenz. (Australia), 1954, 4, 110.s R. S . Nyholm, Quart. Rev., 1953, '7, 377.10 N. N. Greenwood and R. L. Martin, ibid., 1954, 8, 1.and W. N. Lipscomb, ibid., p. 989; J . R. Platt, ibid., p. 1033120 INORGANIC CHEMISTRY.pounds,ll isotopic exchange reactions in aqueous solution,12 the alkali-metal amides, 13 the polymeric inorganic phosphates, l4 zirconium,l5 andelements 85 and 87.16Complexes.-Since so many complexes, whose formation constants are ofinterest, are only sparingly soluble in water, quantitative measurementshave frequently been made in alcohols or in mixtures of water with organicsolvents (often dioxan).Activity coefficients commonly depart very farfrom unity in such solvents and the effect of this on the calculation of form-ation constants has continued to receive attention. The difficulty canpartly be overcome by the introduction of correction terms1' An ingeniousprocedure has been devised whereby proton-ligand formation constants(related to ordinary acid-base dissociation constants), which are required inthe calculation of metal-ligand formation constants from experimental(generally pH) data, are not calculated from thermodynamic and accuratedissociation constants but are obtained by a set of experiments closelysimilar to those required to provide the metal-ligand stability data. In thisway errors due to lack of knowledge of activity coefficients can be made tocancel, and accurate stoicheiometric formation constants can be obtained.lsThe method has been applied to the determination of the formation constantsof a number of metal chelates with several derivatives of 8-hydroxyquin-oline. l 9 However, experiments on the stabilities of S-hydroxyquinoline-5-sulphonic acid complexes of eleven bivalent metals, the complexes beingsoluble in water, suggest that the sulphonic acid group has little influence onthe stability of the Formation constants for a variety ofcomplexes have been determined potentiometrically in 75% dioxan-25%water.21 Polarographic methods have also been applied to the measure-ment of formation constants, e.g., of complexes with ethylenediaminetetra-acetic acid (heat and entropy data have also been obtained 22), cyclohexane-1 : 2-diaminetetra-acetic acid,23 and 1 : 3-diaminopropane.24The viewthat the stability of metal chelate complexes decreases with increasing ringsize has been strengthened by a careful study of the complexes formed bycopper, nickel, and cadmium with some diamines, amino-acids, and dibasicacids .2gThe decreased stability constants for NN- and NN'-dialkylethylene-diamine complexes with nickel, copper, and zinc ions (relative to ethylene-diamine complexes) illustrate the effect of steric hindrance on co-ordination,which also accounts for the preferential formation of basic or polynuclearcomplexes when highly substituted ligands are Substitution ofSteric aspects of complex formation continue to be studied.l1 K.J. Morgan, Quart. Rev., 1954, 8, 123.l 3 R. Levine and W. C. Fernelius, Chem. Rev., 1954, 54, 449.l4 C. F. Callis, J. R. Van Wazer, and P. G. Arvan, ibid., p. 777.l5 W. B. Blumenthal, I n d . Eng. Chem., 1954, 46, 528.l6 E. K. Hyde, -1. Phys. Chem., 1954, 58, 21.l7 L. G. Van Uitert and W. C. Fernelius, J . Amer. Cheuvt. SOC., 1954, 76, 5887.H. M. Irving and H. S. Rossotti, J., 1954, 2904.l9 Idem, ibid., p.2910.2o R. Nasanen and E. Uusitalo, A d a Chem. Scand., 1954, 8, 112.21 L. G. Van Uitcrt and W. C. Fernelius, J . Amer. Chem. SOC., 1954, 78, 375.23 R. G. Charles, ibid., p. 5854.23 G. Schwarzenbach, R. Gut, and G. Anderegg, Helu. Chim. Acta, 1954, 37, 937.24 H. M. Irving, R. J. P. Williams, D. J. Ferrett, and A. E. Williams, J., 1954, 3494.2 5 H.M. Irving and J. M. iM. Griffiths, ibid., p. 213.l2 C. B. Rmphlett, ibid., p. 519COATES AND GLOCKLING. 121isopropyl groups (e.g., NHPri CH,*CH,*NHPri) even prevents the formationof the ordinary type of complex with nickel and copper.26 Similar effectshave been observed with N-is~propylglycine.~' Substitution of the C-Hgroups in ethylenediamine has a much smaller effect, as might be expected.However, it is interesting to note that (&)-butylene- and (*)-stilbene-diamines are less strongly chelating than the corresponding meso-compounds,and that C-tetramethylethylenediamine forms a yellow diamagnetic complexwith nickel(=) of the type [Ni diamine2]X2.28An empirical relation has been found between electronegativitiy valuesas calculated by M.Haissinsky 29 and the stabilities of metal complexes ; 30this is essentially in agreement with the Irving-Williams order mentioned inlast year's Reports.31o-Aminobenzaldehyde forms a number of tris-anhydro-complexes some-what analogous to the formation of phthalocyanines from I phthal~nitrile.~~ Kojic acid (I) forms chelated complexeswith a variety of metal ions.These complexes are veryHO.CH,I IFo stable, being comparable with those of tropolone and thep-diketones.=Aquation rate constants have been determined for thereplacement of thiocyanate by water in the complexes Cr(NH,) ,SCN2+,Co(NH,),SCN2+, and trans-Co en,(SCN)2+.34Formation constants have been determined for the complexes of methyl,isopropyl, and other tropolone~,~~ aminothiols leg., NH,*CH,*CH,*SH),and di~ulphides,~~ azomethine and formazyl compounds with the uranylion,37 and with chromium, cobalt, nickel, and copper,38 and hydrazinedzaceticacid with the lanthan~ns.~OGroup 1.-Pure lithium hydrogen sulphide (LiSH) has been preparedfrom lithium n-pentyloxide and hydrogen sulphide in ether solution. It issensitive to hydrolysis and to oxidation, and decomposes to the sulphide andhydrogen sulphide above about 50".Thermal and X-ray data wereobtained .40A further series of ternary phosphides and arsenides of lithium have beenprepared and subjected to X-ray analysis. These compounds, Li,SiP,,Li5SiAs,, Li,GeP,, Li,GeAs,, Li5TiP3, Li,TiAs,, Li,GaP,, and Li,GaAs,, arereadily hydrolysed by water with formation of phosphine and arsine.41A study of the slow formation and decomposition of the compoundsbetween graphite and potassium (and rubidium) has revealed a whole seriesof compounds which differ in the number of graphite sheets between the0 ...--H11(1)2 6 F. Bas020 and R. K. Murmann, J . AuPzer. Chem. SOC., 1954, 76, 211.2 7 F. Basolo and Y . T. Chen, ibid., p. 953.28 F.Basolo, Y . T. Chen, and R. K. Murmann, ibid., p. 956.29 M. Haissinsky, J . Phys. R a d i u m , 1946, 7, 7.30 D. Chapman, Nature, 1954, 174, 887.31 Anw. Reflorts, 1953, 50, 89 ; see also K. J. P. Williams, J . Phys. Chenz., 1954,58, 121.32 G. L. Eichhorn and R. A. Latif, J . Arpzer. Chem. SOL, 1954, 76, 5180.33 B. E. Bryant and W. C. Fernelius, ibid., p. 5351.34 A. W. Adamson and R. G. Wilkins, ibid., p. 3379.35 U. E. Bryant and W. C. Fernelius, ibid., pp. 1696, 3783.3G E. Gonick, W. C. Fernelius, and B. E. Douglas, ibid., p. 4671.3 7 M. Seyhan, B e y . , 1954, $7, 396.38 R. Wizinger, 2. Naturforsch., 1954, 9b, 729.40 R. Juza and P. Laurer, 2. anorg. Chenz., 1954, 275, 79.41 R. Juza and W. Schulz, ;bid., p. 65.30 R. C. Vickery, J., 1954, 385122 INORGANIC CHEMISTRY.layers of alkali-metal atoms.The maximum alkali-metal content, in C,K,is reached when alternate layers are carbon and potassium, but when thereare 2, 3, 4, or 5 graphite layers between each potassium layer the idealformulae are C,,K, C3,K, C4,I<, and C,&. Spacings up to C,,K have beenmeasured by X-ray analysis. All these compounds are weakly para-The reaction between sodium amalgam and carbon dioxide, in whichoxalate is formed, has been studied with particular attention to temperature,stirring, and the effect of gaseous impurities. Other alkali metals, calcium,and barium give similar results, with lower yields in the last two cases.43Mixtures of oxides are generally formed from amalgams and oxygen. Potas-sium and sodium amalgam give mixtures of peroxides and superoxides, whilea mixture of monoxide and peroxide is formed from lithium amalgam.Dithionites (e.g., K2S204) are formed from alkali-metal amalgams and sulphurdioxide, but zinc and lead amalgams give mixtures of dithionite, oxide, andsulphide.@Phase-rule studies are reported for the systems Li2S0,-(NH4),S0,-H,0,45KC1-NaCl-NaF,46 KBr-KC1-H,O, RbBr-RbC1-H,O, and RbBr-KBr-H,O .47Further work has been carried out on the physical properties of KC1-BaCl, 48and NaCl-KC1 49 mixtures.Thermal decomposition of cupric fluoride dihydrate, CuF2,2H20, takesplace in two stages forming Cu(OH)F,CuF, at 132" followed by decom-position into the oxide and fluoride at 420°.50 Manometric measurementshave confirmed that acetylene and cuprous chloride in aqueous hydrochloricacid form the two distinct complexes C,H,(CuCl), and C2H2(C~C1)2.51The precipitate of silver chromate from silver nitrate and chromate ordichromate solutions is of variable composition.A true dichromate resultsonly under strongly acid conditions and at a high silver-ion c~ncentration.~,Silver perchlorate reacts slowly with dioxan in the presence of 0-5y0 of waterto yield a silver-oxygen complex having the composition (C,H,O,),AgClO,from which the dioxan may be quantitatively removed in V ~ C U O . ~ ~The co-ordination number three is quite uncommon among metal coin-plexes, most of which involve metal covalencies of two, four, or six. Severalcopper(1) and silver( I) complexes with tertiary phosphines have been de-scribed, in which the metal atom has a covalency of three.Examples are(C,H5*PMe2),AgI and (P-Me2N*C,H40PEt,)2AgI. The analogous gold(1) com-pounds are ionisecl, [(R,P),Au+]I-, the gold having a covalency of two.Some of the cadmium iodide complexes of the same phosphines dissociate42 W. Riiclorff and E. Schulze, 2. anorg. Chem., 1954, 2'77, 156.43 H. Hohn, E. Fitzer, and H. Nedwed, ibid., 1953, 274, 297 ; see also 1'. A . Hengleinand A. Sontheimer, ibid., 1952, 267, l S l , and C. Porlezza and G. Ginori-Conti, .4nu.Chim. appl., 1925, 13, 53.4 4 H. Hohn, E. Fitzer, H. Chizzola, and H. Nedwed, 2. anorg. Chent., 1954, 275, 32.4 5 A. N. Campbell, W. J. G. McCulloch, and E. M. Kartzmarlc, Cnnnd. J . Chem.,4 6 F.Sauerwald and 13. E. Dombois, 2. anorg. Chem., 1964, 277, 60.4 7 G. S. Durham, E. J . Rock, and J. S. Frayn, J . Amer. Chem. S o r . , 1953, 75, 579'7.4 8 J. S. Peake and M. R. Bothwell, ibid., 1954, 76, 2653, 2656.4 9 \V. T. Bsrrett and W. E. Wallace, ibid., pp. 376, 370.60 C. M. Wheeler and H. M. Haendler, ibid., p. 263.61 K. Vestin, Ada Chem. Scand., 1954, 8, 533.52 K. K. Varma, K. L. Yadava, and S. Ghosh, 2. anorg. Chewz., 1954, 275, 257.63 A. E. Comyns and H. J. Lucas, J . Amer. Chrm. SOC., 1854, 76, 1019.1954, 32, GOGCOATES AND GLOCKLTNG. 123extensively in some solvents, the monomeric units (R,P) CdI, again requiringa metal covalency of three.%Group 11.-Hot-stage microscopy has been used to examine the poly-morphism and transition temperatures of sodium tetrafluoroberyllate,Na,BeF,; there are five solid forms of this salt.55 Lithium sodium tetra-fluoroberyllate, LiNaBeF,, prepared by slow evaporation of the aqueoussolution, has strong crystallographic resemblance to monticellite, CaMgSiO,.56The vapour pressure of beryllium fluoride has been measured, and leads toan extrapolated boiling point 1159" (m. p. -803°).57The complexity of aqueous solutions of beryllium salts has long beenrecognised, though the nature of the polynuclear ions which must be presenthas never been clarified. Recent pH measurements on beryllium perchloratesolutions at constant ionic strength have shown that a description of thesystem by means of only a few ionic species is incomplete; for the twosimplest types (hydration being ignored) 58[BeOH+][Hf]/[Be2'] = (0-3 5 0-1) x[Be,0H3+][H*]/[Be2+]2 = (0-31 & 0.06) xMethods have been developed for interconverting normal and basicSlow sublimation of the normal carboxylic acid derivatives of beryllium.salts leads to the basic derivatives :4Be(O,C*H), = Be,O(O,C*H), + H,O + 2CO~ B ~ ( O A C ) ~ = Be,O(OAc), + Ac,OThe normal salts result when the basic derivatives are heated with a mixtureof acid chloride and acid, e.g.,Be,O(OAc), + 2AcCl+ 2AcOH = 4Be(OAc), + 2HC1 + Ac,Obut the normal formate is obtained simply from anhydrous formic acid andthe oxide or basic acetate.59The chemistry of beryllium has been extended to diisopropylberyllium,m.p. -9.5", which is dimeric in benzene solution and forms a monomericco-ordination compound with trimethylamine (involving a covalency ofthree for the beryllium).On thermal decomposition it affords propyleneand the polymeric half-hydride (Me,CH*BeH),. Reaction with dimethyl-amine gives first dimethylaminoisopropylberyllium, which decomposesthermally to another polymeric half-hydride (Me,N*BeH),, and finally thefully methylat ed beryllium nitride 6o [Be (NMe,) ,I3. Di-tert. -bu tylberyllium,from the chloride and tert.-butylmagnesium chloride, loses isobutene veryreadily, yielding at -210' beryllium hydride containing a small amount(-4 moles yo) of alkyl group :(Me,C),Be = BeH, + 2Me,C:CH,54 R. C . Cass, G. E. Coates, and R. G. Haytcr, Chem. and Itid., 1964, 1485.56 W. Jalin and E.Thilo, 2. anorg. Chem., 1953, 274, 7 2 .56 W. Jahn, ibid., 1954, 276, 113.G 7 K. A. Sense, M. J. Snyder, and J. W. Clegg, .[. Phys. Chew., 1954, 58, 233.58 G. Mattock, .J. Amer. Chem. SOG., 1954, 76, 4835.59 H. Hendus and H. D. Hardt, 2. anorg. Chew., 1954, 277, 127; J. Besson andII. D. Hardt, ibid., p. 188. 6o G. E. Coates and F. Glockling, J . , 1954, 22124 INORGANIC CHEMISTRY,Beryllium hydride thus prepared is stable up to -240-290", and decom-poses rapidly at 300"; it gives the nitride derivative [Be(NMe,),], withdimethylamine. 61Magnesium boride, prepared from the elements a t 800" in a hydrogenatmosphere, has the formula MgB, (not Mg,B,) and is isomorphous withA1B,.62 Three other crystalline phases exist, one being MgB4.63Electrolysis studies using magnesium electrodes in a divided cell con-taining various aqueous salt solutions have provided some evidence for theexistence of Mg+ ions; this is based on measurements of anodic dissolutionrates.64 X-Ray diffraction has shown that the grey subchloride of calcium,CaCl, obtained by heating calcium metal and CaC1, in equivalent proportionsto lOOO", is evidently an individual substance and not a mixture ofCa + CaCl,.In the presence of nitrogen transparent red crystals of thecomposition Ca,NCl are formed when calcium metal and CaCl, are heatedtogether. 65The reaction of calcium with water vapour in the range 177-369"proceeds by three consecutive steps : G62Ca + H20 = CaO + CaH,CaH, + 2H,O = Ca(OH), + ZH,CaO + H,O = Ca(OH),The pH of phosphate and citrate buffer sohtions is markedly reducedby the addition of calcium ions, on account of the formation of associationproducts (ion pairs).Dissociation constants in water a t 25" are reportedfor CaH,PO,+, CaHPO,, CaH,Cit+, and CaHCit.67Solubility studies on calcium phosphate solutions have been recorded,68and the binary systems Sr(ClO,),-H,O, Sr(BrO,),-H,O, and Sr(IO,),-H20have been in~estigated.~~The barium salts of alloxantin, its tetramethyl derivative, and hydr-indantin are coloured deep blue or blue-violet. These compounds have beenconsidered to be free radicals related to the metal ketyls, but magneticexperiments have convincingly shown the absence of radicals. 70The equilibrium constant for the reactionHg(1iquid) + Hg++ = Hg2++; K(25") = 83-4has been measured from 0" to 40" a t various ionic strengths, together withheat and entropy data.71 The composition of the precipitate resulting fromthe addition of ammonia to aqueous mercuric bromide is rather sensitive tothe ammonia concentration.Pure HgNH,Br is formed when the ammoniais between 0.07 and 0 . 0 9 ~ ; at higher concentrations some mercuric bromide61 G. E. Coates and F. Glockling, J., 1954, 2526.62 M. E. Jones and R. E. Marsh, J . Amer. Chem. SOC., 1954, 76, 1434.63 J. Russell, R. Hirst, F. A. Kanda, and A. J. King, Acta Cryst., 1933, 6, 870.64 K. L. Petty, A. W. Davidson, and J. Kleinberg, J . Amer. Chem. Soc., 1854,76, 363.6 5 G. Wehner, 2. anorg. Chem., 1954, 276, 72.6 6 D. S. Gibbs and H.J. Svec, J . Amer. Chem. SOC., 1953, 75, 6052.67 C . W. Davies and B. E. Hoyle, J., 1953, 4134.6 8 J. D'Ans and R. Kniitter, Angew. Chem., 1953, 65, 578.69 W. F. Linke, J . Amer. Chem. SOG., 1953, 75, 5797.7 0 R. W. Asmussen and H. Soling, Acta Chenz. Scand., 1954, 8, 558.7 1 G. Schwarzenbach and G. Anderegg, Helv. Chim. Ada, 1954, 37, 1,089COATES AND GLOCKLING. 125is held in solid solution.72 The nuclear magnetic resonance spectrum ofinfusible white precipitate shows that the protons are arranged in pairs, insupport of the structure HgNH,Cl containing -Hg-NH,-Hg-NH,- chains,and excluding structures such as NHg,Cl,NH,Cl, or xHgO,(l - x)HgCl2,2NH,in which protons are arranged in threes or One of the numerous basicchlorides of mercuryhas been shown, by X-ray analysis, to be an oxoniumsalt [O(HgCl),]Cl.The three O-Hg-C1 bonds are collinear, but the threeO-Hg bonds are apparently in one plane.74Addition of mercurous nitrate solution to dilute potassium ferricyanide pre-cipitates the salt KHg,[Fe(CN),] ; reverse addition gives (Hg,),[Fe(CN),],.75Group 1x1.-The existence of two new hydrides of boron has been con-firmed. The presence of octaborane, B&2, had earlier been suspected inresidues from the decomposition of the unstable pentaborane B5Hl, ; 76 itsexistence, and that of nonaborane," B9H13, have been confirmed by mass-spectrographic methods. 78 Similar methods have been used to investigatethe hydrolysis of stable pentaborane by water bound in silica gel. The firststep appears to be the formation of the tetraborane B,H, by removal of aborine (UH,) fragment and its subsequent hydroly~is.~~A number of metal borohydrides may be conveniently prepared bymetathetical reactions between sodium borohydride and the appropriatemetal chloride in ethanol below Oo,80 e.g.,2NaBH, + MgCl, = Mg(BH,), + 2NaClAlkali-metal borohydrides have also been obtained by the reaction (inmethanol) ,81-t- 4-NaBH, + MOMe = MBH, + NaOMe (M = K, Rb, CS)The preparation of sodium trimethoxyborohydride, from methyl borateand sodium hydride in tetrahydrofuran, has been improved.Its propertiesas a reducing agent for organic compounds have been studied.82Interesting compounds containing arsenic-boron bonds have beendescribed; these are formed from diborane and both arsine and its methylderivatives. The compounds initially formed, e.g., AsMeH,,EH,, are lessstable than the corresponding phosphorus compounds, but in common withthem show an increase in stability with methylation.Diborane and arsineor methylarsine give polymeric products corresponding to the compositions(H,As~BH,). and (MeAsHaBH,),, but the reaction between diborane anddimethylarsine led to the isolation of tri-, tetra-, and poly-meric forms of(M~,AS*BH,),.~ Diborane and dimethyl sulphide form a fairly stablecompound Me,S,BH, in contrast to the low stability of MeSH,BH, and thenon-existence of H,S,BH,. The second compound readily loses hydrogen to72 I<. Brodersen and W. Riidorff, 2. anorg. Chem., 1954, 275, 141.73 C.M. Deeley and R. E. Richards, J., 1954, 3697.74 A. Weiss, G. Nagorsen, and A. Weiss, 2. anoyg. Chern., 1953, 274, 151.7 5 R. S. Saxena and B. I?. Bhsrgava, ibid., 1954, 276, 204.'i6 A. B. Burg and H. I. Schlesinger, J . Atner. Chem. Soc., 1933, 55, 4009.7 7 F. J. Norton, ibid., 1950, 72, 1849.8o J. Kollonitsch, 0. Fuchs, and V. GAbor, Nature, 1954, 178, 126.83 I:. G. -4. Stone and A . 1-3. Burg, ibid., 1054, 78, 386.I. Shapiro and B. Keilin, ibid., 1954, 76, 3864.M. D. Banus, R. W. Bragdon, and A. A. Hinckley, J . Anzer. Chern. Soc., 1954, 76,79 Idewz, ibid., p. 1206.3848. ** H. C. Brown and E. 1. Mead, ibid.. 1953. 75. 6263126 INORGANIC CHEMISTRY.forin polymers (MeS*BH,), which give a liquid adduct (m. p. 14") with tri-methylamine, Me3N,BH,-SMe.s4 Work on boron-sulphur ring compoundshas been extended by the isolation of rnethoxyboron sulphide (MeOBS),from metathioboric acid (HS*BS), and methyl borate.The correspondingdimethylamino-compound has also been described. 85Difficulties involved in the preparation of borazole by reduction of thereadily obtainable B-trichloroborazole have been discussed : B63LiBH4 + B,N,H,CI, = B,N,H, + $B,H, + 3LiC1Reactions of boron trifluoride in which B-F bonds are broken have beenfurther investigated and, at least in certain cases, boron trifluoride adductsare isolable intermediates. Dimethylaminodimethylborine, Me,N*BMe,forms with boron trifluoride the adduct Me,N-BMe,,BF, which at low tem-peratures dissociates into its components in a vacuum.But at 0" or above,reaction occurs to give almost exclusively Me,BF and Me,N*BF,. Thelatter is monomeric and not dimeric as previously reported. With tri-methylamine it forms bisdimethylaminoboron fluoride : g72Me,N*BF2 + Me,N + (Me,N),BF + Me,N,Blt;,Vapour pressure-composition studies on the system BF,,NH3 have shownthat at low temperatures the compounds (NH,),BF,, (NH,),BF,, and(NH,),BF, exist. It is suggested that in the stable compound &H3-EF3the hydrogen atoms are sufficiently acidic to co-ordinate up to three additionalmolecules of ammonia. Dimethylamine only forms the 1 : 1 complexbetween 0" and --64".88Boron trifluoride co-ordinates very strongly with the nitrogen atoms inbisdimethylamine sulphide, giving (Me,N),S,2BF3, and less strongly with( Me2N),S0.The corresponding sulphone, (Me,N),SO,, only co-ordinatesweakly with boron trifluoride. This is the order of stability expected owingto the inductive effect of the oxygen The tetrahydrofuran complexof boron trifluoride forms bi-complexes with ethylenediamine and hexa-methylenediamine, F,B,NH,*[CH,],*NH,,BF, (n = 2 or 6) A numberof 1 : 1 compounds are reported between ethers and boron trifluoride.Dioxan also forms the complex C4H,02,2BF,.91The Raman spectrum of dimethylaminodichloroborine, Cl,B*NMe,,indicates that the B-N bond is essentially a double bond (in the monomer).A more convenient preparative method has been devised, from boron tri-chloride and trisdimethylaminoboron, B(NMe,),.92Tri-ut-propylboron and iodine react above 140" to give mainly di-n-propyliodoboron, which undergoes halogen exchange with antimony chlorideor bromide.g384 A.E. Burg and 13. I. Wagner, J . Amev. Chem. SOC., 1964, 76, 3307.8 6 E. M7iberg and W. Sturm, Z. Naturforsch., 1953, Sb, 689.8 6 R. Schaeffer, M. Steindler, L. Hohnstedt, H. S . Smith, L. B. Eddy, and H. I.Schlesinger, ,I. Amer. Ghcm. SOC., 1954, 76, 3303.A. B. Burg and J. Ranus, ibid., p. 3903.s 8 H. C. Brown and S. Johnson, ibid., p. 197s.89 A. B. Burg and H. W. Woodrow, ibid., p. 219.YO C. -4. Brown, E, L. Muetterties, and E. G. Rochow, ibid., p. 2637.91 J. Grimleyand A. I<. Holliday, J., 1954, 1215.92 J. Goubesu, M. Rahtz, and H. J. Becher, 2. anorg. Chew., 1954, 275, 161.93 L. H. Long and D.Dollimore, J., 1953, 3902, 3906COATES AND GLOCKLING. 127The preparation of diboron tetrachloride has been improved and interest-ing reactions of this compound are reported. Above 0" it partially decom-poses into B,Cl, and rather ill-defined products. With hydrogen a t roomtemperature in the absence of a catalyst diboron tetrachloride forms diboraneand boron trichloride, probably by disproportionation of B,Cl,H,. Theinitial reaction with lithium borohydride is probablyB,Cl, + 4LiBH, = B,H1, + B,H, + 4LiClother boron hydrides being produced by secondary reactions. Ether formsa dietherate, in contrast to trimethylamine which gives a stable tetramer[B2C1,,2NMe,],. Diboron tetrachloride and ethylene form the compoundCl,B*C,H,*BCl, in which the B-B bond has evidently been broken since nohydrogen is produced with sodium hydroxide.The chlorine atoms in theethylene compound can be replaced by methoxy-groups by means of meth-anol, giving (MeO),BC,H,*B(OR!le),, or by methyl groups with dimethyl-zinc, forming Me,B*C,H,*BMe,. Pyrolysis of Me,B-C,H,*BMe, resulted incleavage of methyl groups as trimethylboron, and conditions were estab-lished whereby 75% or 100% of the methyl groups present formed tri-methylboron. Fairly volatile liquids and polymeric products were formedin each case, to which the following structures have been assigned : 94Boron tricyanide, B(CN),, m. p. 146.5", has been isolated by sublimationfroin a mixture of silver cyanide and boron trichloride which had remainedat room temperature for forty years. The reaction is still very slow a t 60"and polymerisation takes place readily a t higher temperatures.Boroncyanide is said to be veryThe presence of polyborate ions in concentrated aqueous solutions ofboric acid is indicated by pH measurements. The observed acidities agreewith calculated values based on the assumption of a singly dissociated trimerand a singly dissociated h e ~ a m e r . ~ ~ Some dialkylboronic acids, R,B*OH,have been prepared by Grignard reaction^.^'Boron acetate, prepared in several different ways, has tlie compositioncorresponding to the " pyroacetate " :2B(OH), + 5Ac20 = (AcO),B*O*B(OAc), + 6AcOHand not the noriiial acetate as sometimes supposedb98The preparation of calcium aluminium hydride, Ca(AlH,),, from alu-minium chloride and finely divided calcium hydride in tetrahydrofuran hasbeen described. The product contains 40-50% of tetrahydrofuran.99Some important reactions between a wide variety of oleiins and the alu-94 G.Urry, T. Wsrtik, 13. E. Bloore, and H. I. Schlesinger, J . Anzer. Chem. SOC.,!Iti 1 . 0. Edwards, J . -'lwei.. CJ~c?tt. SOC., 1953, 75, 6151.n 7 li. Id. I-etsiriger and I. Skoog, zbid., 1054, 16, 4174.W. Gerrard and 31. A. Wheelans, Ghem. apid Iiad., 1954, 758.)IT. Schwab and K. IX'intersberger, Z. ,hTafzufomch., 1963, Sb, 690.19.34, '76, 52'33, 6299. y 5 M. Chaigneau, Coitapt. read., 1954, 239, 1220128 INORGANIC CHEMISTRY.minium hydrides AlH,, LiAlH,, and Et,AlH have been reported. Thediethylaluminium hydride used in this work was obtained from the chlorideEt,AlCl and lithium or sodium hydride.100 Aluminium sulphide and selenideresult from the reaction between trimethylaluminium and hydrogen sulphideor selenide ; the rather less reactive ether complexes give products containingmethyl groups (or ethyl from Et,A1,0Et,).lo1The presence of Al(OH),- ions in sodium aluminate solutions has beensuggested in an investigation on the precipitation of crystalline aluminiumhydroxide.lo2Eight aluminium pentyloxides have been prepared from different pentylalcohols and aluminium isopropoxide. All the aluminium alltoxides appearto be associated, the pentyloxides derived from primary alcohols being tetra-meric and those from secondary alcohols dimeric.The uteopentyloxy-compound is exceptional in being dimeric, and this is attributed to the stericrequirements of the neopentyl group.lo3Conflicting views on the compositions of complexes of aluminium bromidewith various aromatic hydrocarbons have .been somewhat clarified. Vapourpressure-composition studies have revealed solid compounds Al,Br,, ArHwith benzene and toluene, but not with m-xylene or mesitylene. However,both solution colours and molecular weights (in cyclopentane) indicate thatsimilar complexes are formed by m-xylene and mesitylene. The compoundsare formulated as 7;-complexes.104 Of interest in connection with themechanism of Friedel-Crafts reactions, investigations of the complexesformed by the same four hydrocarbons with aluminium bromide and hydro-gen bromide have established the formation of carbonium-ion salts havingthe compositions [ArH,]+ [Al,Br,]- and [ArH,] + [AlBrJ, the former beingthe more stable.The stability of these complexes also increases with thenumber of methyl groups in the hydrocarbon. lo5 Aluminium halide-alkylhalide systems have been examined at temperatures between -78.5" and 0".At -78.5" aluminium bromide is monomeric in methyl bromide and formsa 1 : 1 addition compound in solution. At somewhat higher temperaturestwo solid phases occur, viz., MeBr,AlBr, and MeBr,AbBr,, but only thelatter is present at -31.3". At 0" crystalline aluminium bromide separates.Aluminium chloride is dimeric in methyl or ethyl chloride, but aluminiumiodide is monomeric in methyl iodide.lo6 Dissociation energies have beenobtained for various 1 : 1 complexes between aluminium halides and severalamines.The dissociation energy D(N-A1) is of the order 80 ltcal./molefor most of the complexes, the stability order being AlCl, > AlBr, > Al13,and pyridine > trimethylamine > ammonia.lo7A new sodium aluminium fluoride, NaAlF,, has been obtained by passinga stream of inert gas over a mixture of sodium fluoride and aluminiumfluoride at 1000" ; it is perceptibly volatile above 900°.108100 K. Zieglcr, H. G. Gellert, H. Martin, K. Nagel, and J. Schneider, Annalen, 1954,lol K. Geiersberger and H. Galster, 2. aizorg. Chenz., 1953, 274, 389; see also E.lo3 R. C. Mehrotra, J . Indian Chent. SOL, 1954, 31, 85.Io4 H.C. Brown and W. J . Wallace, J . Amcr. Chenz. SOC., 1953, 75, 6265.lo5 Idem, ibid., p. 6268.lo7 D. D. Eley and H. Watts, J . , 1954, 1319.lo8 E. H. Howard, J . Amev. Chem. Sot., 1954, 76, 2041.589, 91.Wiberg, BEY., 1942, 75, 2003. lo2 E. Herrmann, 2. anovg. Chem., 1053, 274, 81.Io6 Idem, ibid., p. 6279COATES AND GLOCKLING. 129Phase-rule studies have been reported on the systems Al,(S04),-H,0,109Na,SO,-Al,(SO,),-H,O ,110 and Al,O,-P,O,-H,O. ll1 Anion-exchange experi-ments on the last system have indicated the presence of [A1(HP0,),I3- ions.Studies on several oxides in equilibrium with water at high temperaturesand pressures have shown that scandium hydroxide, Sc(OH),, does not exist,but a well-crystallised salt ScO(0H) was obtained.The oxide SC,~, wasthe only other species detected. Thallic oxide afforded no hydrate butchromic oxide gave both CrO(0H) and Cr(OH),.l12Following oxidation of cerium(1rr) and praseodymium(rI1) oxides byX-ray diffraction has shown that the oxides of the types Ce,O, and CeO,cannot depart appreciably from these compositions without the formationof a new phase. However, a phase of intermediate composition can havequite a wide range of oxygen content ; e.g., various oxides such as Ce40,and Pr,OIl, previously considered stoicheiometrically definite compounds,are particular examples of this single phase of variable composition. li3Treatment of terbium and praseodymium oxides with oxygen a t up to 450"and 280 atm. has yielded light brown oxides of compositions TbO,.,, andPrO,.114 Terbium tetrafluoride has been obtained by the action of fluorineon terbium trifluoride at 320".It is monoclinic and structurally similar tothe tetrafluorides of cerium, uranium, and thorium.l15Lanthanons are displaced from their anionic complexes Ln enta- withethylenediaminetetra-acetic acid by addition of cationic lanthanons. Thelanthanon cations of higher atomic number and higher stability constantwill displace from an anionic " enta '' complex a lanthanon of lower atomicnumber and stability constant. This method has been applied with somesuccess to the problem of lanthanon separation.l16The controlled hydrolysis of the trimethylgallium-ether complex leadsto the formation of a trimeric dimethylgallium hydroxide (Me,Ga-OH),,which decomposes thermally to methane and an inert polymeric methyl-gallium oxide.117 An amorphous and polymeric anhydride f (Me,Ga),O), isformed when a deficiency of water is used in the hydrolysis at a low tem-perature, and this is thermally much more stable.ll8The solution phase in the systems gallium chloride-methyl halide (Cl,Rr, I) at low temperatures contains a 1 : 1 addition compound, while thesolid phases (from methyl chloride) have the compositions MeCl,GaCl, andMeCl,Ga,Cl,. Halogen exchange between gallium trichloride and methylbromide is slow (2% in 24 hours a t -80') and it has been suggested that theinitial stage should be formulated RX + GaX, RX,GaX,, which maybe followed by ionisation to R+GaX,-, as has been postulated in connectionwith Friedel-Crafts reactions.119The melting point of indium (156.17" -+ 0.05") has been recomniendedlog N. 0. Smith and P. N. Walsh, 1. Amer. Chem. Soc., 1954, 76, 2054.110 J. A. Skarulis, H. A. Horan, and R. Maleeny, ibid., p. 1450.111 13. F. Jameson and J. E. Salmon, J., 1954, 4013.M. TV. Shafer and R. Roy, 2. anorg. Chem., 1954, 276, 275.113 G. Brauer and H. Gradinger, ibid., 1954, 277, 89.114 TV. Simon and L. Eyring, J . Amer. Chem. SOC., 1954, 76, 5872.115 B. B. Cunningham, D. C. Feay, and M. A. Rollier, ibid., 1954, 76, 3361.116 R. C. Vickery, J., 1954, 1181.117 M. E. Kenney and A. W. Laubengayer, .T. Amer. Chern. SOC., 1954, 78, 4839.118 G. E. Coates and R. G. Hayter, persona1 communication.llS 13.C. Brown, L. P. Eddy, and R. Wong, J . Amer. Chem. SOC., 1953, 75, 6275.REP.-VOL. LI 130 INORGANIC CHEMISTRY.as a useful temperature for thermocouple calibration, since indium can nowbe obtained in a state of high purity.120Group 1V.-Minute concentrations of methyl radicals are apparentlyformed in the decomposition of tetramethylammonium amalgam, as shownby the removal of tellurium mirrors : 121 Me,N --+ Me,N + Me. Thepolymeric and highly stable substance, paracyanogen, results from thedecomposition of oxamide. Its infrared spectrum is compatible with thestructure (11), which involves no great distortion of bond angles.122(11)Cyanogen chloride forms 1 : 1 addition compounds with a number ofmetal chlorides (Au3+, B, Al, Fe3+, Pt4+) and conductivity studies on thesedouble halides dissolved in cyanogen chloride provide evidence for theexistence of a positive cyanogen ion in solution, e.g., CNCl,AlCl, + CN+ +RlCI,-.The conductivities of liquid cyanogen halides are explained interms of dissociation to free halogens and also by self-i0ni~ation.l~~There is some evidence for the formation of free silicon in a particularlyactive form during oxidation of the various calcium silicides. These observ-ations agree with the strong reducing properties of metal silicides even atmoderate temperatures. Thus even titanium(1v) oxide is reduced by CaSibelow 700", forming TiSi, and Ti,Si,.lX If a cold finger is placed above amixture of silicon and silica at 1200-1500" in a vacuum, a new form ofsilica, " fibrous silica," is deposited as well as silica, silicon, and siliconmonoxide.This form of silica (density 1.96-1.98 ;m. p. -1420") has a chain structure similar to that of silicon disulphide.When heated at 200-800" it slowly changes to tridymite, and to cristobalitea t 1390". It is hydrated to amorphous silica by water vapour, and to meta-silicic acid by liquid water.125Of the silylamines SiH,-NMe,, (SiH,),NMe, and (SiH,),N, only SiH,*NMe,co-ordinates with trimethylboron, the heat of dissociation of the complexbeing about 6.5 kcal./mole. The decrease in electron-donor properties inthe above series is attributed to partial double-bond character in the Si-Nbonds.126 Silane and phosphine when heated in a sealed vessel at 450"form the monomeric compound 12' SiH,*PH,.The complex reactions between silane and unsaturated hydrocarbons at450-510" are explicable by assuming the formation of SiH, radicals as theprimary step : From ethylene the main productsare ethyl- and diethyl-silanes.128 Some acetylene derivatives of silicon, tin,and lead of the type exemplified by Et,Sn*CiC*SnEt, have been prepared byThe yield is very small.SiH, _t SiH, + H.120 S.Valentiner, Z. anorg. Chem., 1954, 277, 201.121 G. B. Porter, J . , 1954, 760.122 L. I,. Bircumshaw, F. M. Tayler, and D. H. Whiffen, J., 1954, 931.123 A. A. Woolf, J., 1963, 4121; 1954, 252.124 A. Chrktien, W. Freundlich, and M. Bichara, Cow@. rend., 1954, 239, 1046, 1141.125 A. Weiss and A. Weiss, Z. anorg. Chem., 1954, 276, 96.126 S.Sujishi and S. Witz, J . Amer. Chem. SOC., 1954, 76, 4631.127 G. Fritz, Z . Natzqforsch., 1953, 8b, 776.128 D. G. White and E. G. Rochow, J . Anzer. Chem. SOC., 1954, 76, 389iC0.4TES AND GT,OCKT,ING. 131several methods. Although the silicon compounds are unusually stable, yetthe tin and more particularly the lead compounds are readily hydrolysed andare decomposed by cuprous and silver ions.129Improved methods have been devised for the preparation of mono- anddi-chlorosilanes in about 85 and 1576 yields respectively. Silicon tetra-chloride and formaldehyde are passed over a y-alumina catalyst at 400-450" : 130SiCl, + 3H2C0 = SiH,Cl + 3HC1 + 3COSiCl, + 2H2C0 = SiH2Cl, + 2HCl + 2 C 0Theisothermal dehydration of silicic acid prepared by the action of damp airon silicon disulphide clearly indicates a tetrasilicic acid H8Si,01, to which aring structure is assigned.Dehydration by dioxan and by sulphuryl chlorideprovides less definite evidence for other silicic acids.131 Methyl orthosilicatecannot be obtained by the addition of silicon tetrachloride to methanol sinceit is immediately hydrolysed by water derived from hydrogen chloride andthe excess of methanol. A good yield of the ortho-ester can be obtained bythe reverse addition. The hydrolysis and disproportionation of these estershave been studied, and some di-, tri-, and tetra-silicic acids prepared.1332That silicon can be transported in a stream of silicon tetrachloride hasbeen known for some time,133 but numerous subchlorides might be respon-sible.A quantitative examination of the variation of pressure with temper-ature of silicon tetrachloride in equilibrium with silicon has shown that thereaction is Si + SiCl, _t 2SiC1,. Thermodynamic data have been obtainedfor this reaction, which becomes appreciable only above about 1100". Thethermal decomposition of SKI, into SiC1, and chlorine takes place to a muchsmaller extent. l34An interesting series of compounds is reported containing alternate Si-SiandSi-0-Si linkages formed by partial hydrolysis of Si,Cl, at -78". So far, threepure compounds have been isolated : 135 Si40C1,,( Cl3Si*SiC1,*0*SiC1,*SiC1,),Si,O,Cl,, , and Sis03Clls. Ammonolysis of hexachlorodisiloxane, Si,OCl,,leads to the formation of (Si,ON,H,) which, on pyrolysis, forms silicon oxy-nitride, (SiON,),, slightly contaminated with ~ i 1 i c a .l ~ ~ Silicon tetrahalidesform a variety of complexes with pyridine and related compounds. Thesegenerally are of the type SiX,,Bpy, but silicon tetraiodide adds four moles ofbase. The formation of these complexes was followed by a simple methodof calorimetric titration. The complexes are all water-sensitive, and decom-pose without melting when heated. 13' Chlorosilanes and trimethylamineform very weak 1 : 1 complexes. A comparison of the stabilities of theseadducts indicates that the steric effect of the chlorine atoms predominatesThe existence of definite silicic acids has been a matter of dispute.129 C. Beermann and H. Hartmann, Z. anorg.Ckem., 1954, 276, 20.I3O 0. Glemser and W. Lohmann, ibid., 1954, 275, 260.lJ1 R. Schwarz, ibid., 1954, 276, 33.132 R. Schwarz and K. G. Knauff, ibid., 1954, 275, 176.lJ3 L. Troost and P. Hautefeuille, Ann. Cham. phys., 1876, 7, 469.p. 265 ; P. F. Antipin and V. I-. Sergeyev, Zhztr. priklad. Khinz., 1954, 27, 784.135 W. C. Schumb and R. A. Lefever, J . Amer. Chenz. Sor., 1954, 76, 2091.136 Idem, ibid., p. 6882.lS7 U. Wannagat, R. Schwarz, H. Voss, and K. G. Knauff, Z. anorg. Chevz., 1954,H. Schafer and J. Nickl, 2. anorg. ChenL., 1953, 274, 250; H. Schiifer, ibid.,277, 73132 INORGANIC CHEMISTRY.over its electronegativity effect, which should increase the strength of theN-Si bonding. 138Silicon tetrachloride and ammonia, a t high temperatures (825"), yieldtwo volatile products : a liquid iminochloride, Si,(NH)Cl,, and a crystallinecompound which is probably a cyclic tetramer, Si,N,C1,0.139 Dimethyl-formamide co-ordinates by its nitrogen atom with silicon tetrafluoride, form-ing SiF,,H*CO*NMe,, which shows the characteristic CO absorption in theinfrared. 140Several new biscyclopentadienyl salts of titanium-(111) and -(Iv) and of zir-conium(1v) have been described.The zirconium(1v) bromide, (C5H5)?,ZrBr2,which is colourless and diamagnetic, could not be reduced to a zirconium(rr1)compound.141If tetrapropoxytitanium in propyl alcohol is added to potassium aprecipitate having the composition (PrO),Ti is formed. In the presence ofair this forms the dialkoxytitanium oxide (PrO),TiO.Analogous butylcompounds are reported. 142 Tetra-tert.-butyl titanate complexes with severaldiols have been examined by cryoscopic measurements in tert.-butanol. Aproduct having a titanium : glycol ratio of 2 : 3 is strongly suggested, andevidence for other complexes having 2 : 2, 2 : 4, and 3 : 6 ratios has beenobtained.I&TitaRium trifluoride has been prepared by various methods, but mostsatisfactorily from titanium hydride and hydrogen fluoride at 700". Itforms a blue solid which can be purified by sublimation in a vacuum at 950°,and is remarkably stable to air, water, and even concentrated sulphuric acid.Its magnetic susceptibility (1.75 B.M.) is appropriate for the Ti3+ ion.144The well-known yellow colour obtained when hydrogen peroxide is added toacidified Ti(Iv) solutions was for some time thought to be H,[TiO,(SO,),].The test, however, is equally sensitive in acids other than sulphuric, andanions have been shown to be absent from the complex, Ti02+-H,02, whichis positively charged (dissociation constant 5 xDecomposition studies on M,TiCl, have led to heats of formation for thereaction 2MC1 4- TiCl, + M,TiCl, of 35 and 27 kcal. per mole for therubidium and the potassium compound respectively.146Vapour-pressure measurements on zirconium dioxide give A HVaP. =153-6 3: 1 kcal./mole. The heat of dissociation of ZrO,(g) into gaseousatoms is 365 rf 5 k~al./mole.l~~Zirconium and hafnium tetrachlorides form complexes with diethylphthalate and other esters.143 The amidochloride ZrNH,Cl, is obtainedfrom ZrC14 and ammonia in contrast to the behaviour of thorium tetra-chloride which only forms an unstable addition complex.1491451 3 8 A. B. Burg, J . Amer. Chem. SOL, 1954, 76, 2674.139 W. C. Schurnb and L. H. Towle, ibid., 1953, 75, 6085.140 T. S. Piper and E. G. Rochow, ibid., 1954, 76, 4318.1 4 1 G. Wilkinson and J. M. Birmingham, ibid., p. 4281.142 A. N. Nesmeyanov, 0. V. Nogina, and R. K. Freidlina, Doklady Akad. Xuuk143 R. E. Reeves and L. W. Mazzeno, J . Amer. Cltem. SOC., 1954, 76, 2533.1 4 4 P. Ehrlich and G. Pietzka, 2. anorg. Chenz., 1954, 275, 121.145 E. Gastinger, ibid., p. 331 ; see also R. Schwarz, ibid., 1933, 210, 303.1 4 6 P. Ehrlich and E. Framm, 2. Naturforsch., 1954, gb, 326.1 4 7 M.Hoch, M. Nakata, and H. L. Johnston, J . Amer. Chem. SOC., 1954, 70, 2661.148 R. V. Moore and S. Y . Tyree, ibid., p. 5253.3 4 9 G. W. A. Fowles and F. H. Pollard, ,I., 1953, 4128.S.S.S.R., 1954, 95, 813COATES AND GLOCKLING. 133An improved method for the purification of zirconium and hafniumoxides has been described involving crystallisation of the sulphate tetra-hydrate.150The hafnium silicides HfSi and HfSi, have been prepared by directcombination of the elements.151In contrast to the other group IVA metals thorium tetrachloride reactswith the lower alcohols to form tetra-alcoholates of the type ThC1,,4ROH.152Investigations of the alkoxides of group IVA metals have now been extendedto the hitherto-unknown thorium alkoxides. The isopropoxide, obtainedfrom ThC1,,4PriOH and sodium isopropoxide, had a degree of association of3.8 and 1.8 in benzene and isopropyl alcohol, respectively, and could be sub-limed at 200" in vacuo.The methoxide and ethoxide were obtained fromthe isopropoxide by alcohol-exchange reactions ; both were involatile andinsoluble in benzene. Those tetra-alkoxides Th(OR), having more complexalkoxy-groups (e.g., R = CMe,, CEt,) are liquids of low volatility. Theirmolecular weights in boiling benzene show degrees of association varyingfrom unity (R = CEt,, CMeEtPr') to 3.4 when R = CMe,. This behaviouragrees with that found for other group IV metal alkoxides for which themolecular complexity is determined essentially by the size and shape of thealkyl group.153Thorium nitrate forms stable tetra- and penta-hydrates at 25", and ananhydrous solid, isolated from the low water region,l= had the compositionTh(N0J4,2HNO3. Thorium nitrate and sodium citrate at pH 3 form thesoluble complexes Th,Cit, in aqueous solution and ThCit, in 50% ethanol.An insoluble product had the composition (ThCit),, and was soluble in excessof sodium citrate.155Dimethyl- and triphenyl-germanes, Me,GeH, and Ph,GeH, have beenobtained from Me,GeS and Ph,GeBr by reduction with zinc amalgam andhydrochloric acid.156 Tetramethoxygermane, (MeO),Ge, b. p. 146", hasbeen prepared by the action of germanium tetrachloride on sodium methoxidein methanol (the corresponding reaction with SiC1, does not occur). Tetra-isopropoxygermane was obtained by alcohol exchange : (MeO),Ge +4PriOH + (PriO),Ge + 4MeOH.Several poly-esters of germanic acidhave also been prepared.15'Further work on the acid reduction of germanium dioxide using theminimum amount of hypophosphorous acid has led to the isolationof germanous hydrogen phosphite, GeHPO,, and the two complexes3Ge(H,PO,),,GeI, and Ge,(P0,),,2GeHP04.158When germanium tetrachloride vapour, mixed with an inert carrier gas,is heated to 900-1000" and suddenly cooled, a brown subchloride, (GeCl),,is formed. This is insoluble in all solvents, but is decomposed by alkali withevolution of hydrogen :2GeCl+ 6KOH = 2K,GeO, -t 2KC1+ 3H,lS0 A. W. Henderson and K. B. Higbie, J . Amer. Chem. SOL., 1954, 78, 5878.151 B. Post, F. W. Glaser, and D.Moskowitz, J . Chem. Phys., 1954, 22, 1264.152 D. C. Bradley, M. A. Saad, and W. Wardlaw, J., 1954, 2002.163 Idem, ibid., pp. 1091, 3488.15* J. R. Ferraro, L. I. Katzin, and G. Gibson, J . Amer. Chew. SOC., 1954, 76, 90'3.156 M. Bobtelsky and B. Graus, ibid., p. 1536. lSa R, West, ibid., 1953, 75, 6080.lS7 R. Schwarz and K. G. Knauff, 2. anorg. Chem., 1954, 275, 193.15* D. A. Everest, J., 1953, 4117132 INORGANIC CHEMISTRY.Heating in a vacuum causes disproportionation :500"6GeC1-+ GeCl, + 4Ge f- GeCl,whereas only Ge and GeC1, result at a higher pressure. Small amounts ofGe,Cl, (m. p. 32") have been obtained by thermal decomposition of GeCl-GeC1, mixtures. The hexachloride is soluble in benzene, and dissolves inalkali with evolution of hydrogen.159 Germanium iodide, GeI,, and diethyl-mercury react exothermically in benzene solution , forming ethane and butaneas gaseous products. Mercurous iodide, Hg,I,, EtHgI, and GeEt, were alsoisolated from the reaction mixture. Germanium iodide and di-n-butyl-mercury in acetone gave butylmercuric iodide and an oil considered to beBu,IGe*GeIBu,. 160Stannane is obtainable in 84% yield by the reduction of stannous chloridewith sodium borohydride in acid solution.161 Tetrabutylstannane andstannic chloride disproportionate on warming, the main product beingBu,SnCl, which, with sodium ethoxide in ethanol, yields tetrabutyldichloro-dist annane, Bu,ClSn*SnClBu,. 162Stannous oxide is more volatile than tin metal or stannic oxide; this isalso true of GeO and SiO.The vapour pressure of SnO has been measured,and the condensate from SnO vapour consists of Sn, SnO, and Sn0,.163A spectrophotometric and electromigration study on stannic ions insulphuric acid has shown the following equilibria : Sn4+ + Sn(S04), __LH,Sn(SO,),. That involving H,Sn(SO,), only becomes appreciable in veryconcentrated sulphuric acid.164 Complex tartrates of tin, germanium, andtitanium have been re-examined. Metal : tartrate ratios of 1 : 1 and 1 : 2occur in each case.165The lead-sodium compounds, K,PbNa, can be obtained by any of thefollowing reactions in liquid ammonia :R,PbPbR, + 2Na __t 2R3PbNaR3PbC1 + 2Na+ R,PbNa 4- NaClR4Pb + 2Na + R,PbNa + RH + NaNH,The relative merits of these methods have been discussed and the thirdreaction has been used to obtain Et,PbNa and Ph,PbNa.The reactivitiesof these two compounds towards alkyl halides have been studied. 166A study of the basic lead azides has revealed the existence of five differentspecies; in this connection the hydrolysis and solubility product (2.3 x loA9a t 25") of lead azide itself has been investigated.16'Addition of sodium hydroxide to lead nitrate gives precipitates havingthe compositions Pb(NO,),,Pb(OH), and Pb(N0J2,5Pb(OH),. Lead hydr-oxide, Pb(OH),, is not precipitated.168 Normal and basic lead styphnate159 R. Schwarz and E. Baronetzky, 2. anorg. Chenz., 1954, 275, 1.160 G. Jacobs, Compt. rend., 1954, 238, 1825.161 G. W. Schaeffer and M. Emilius, J . Amer. Chem. SOC., 1954, 76, 1203.162 0.H. Johnson and H. E. Fritz, J . Org. Ckewz., 1954, 19, 74.lti3 H. Spandau and T. Ullricli, 2. nnorg. Chern., 1953, 274, 271.1 6 4 C. H. Brubaker, J . Amw. Chenz. SOC., 1954, 76, 4269.165 G. Mattock, J., 1954, 989.166 H. Gilman and E. Bindschadler, J . Org. Chern., 1953, 18, 1675.167 W. Feitknecht and M. Sahli, Helv. Chim. A d a , 1954, 37, 1423, 1431.J . L. l'auley and M. R. Testerman, J . d m w . Chew. Sac., 1954, 76, 4220COATES AND GLOCKLLNG. 135(2 : 4 : 6-trinitroresorcinol) have been prepared in a pure state, and theirinfra-red spectra examined.169Group V.-From vapour-pressure measurements over a wide temperaturerange the maximum sublimation point of ammonium hydrogen carbonatehas been estimated as 19.5".170The reactions between chlorine and ammonia leading to the formationof hydrazine have received further extensive st~dy.17~ tert.-Butyl hypo-chlorite, like the alkali-metal hypochlorites, reacts with aqueous ammonia togive hydrazine.It has been suggested that the chloramine, formed as anintermediate, reacts with added base to give the chloramide ion NHC1- andimide as reactive intermediates :NHCL- NH + C1-; NH + NH3 = N2H4Hydrazine is also formed from urea and tert.-butyl h y p ~ c h l o r i t e , ~ ~ ~ and goodyields of alkylhydrazines have been obtained by application of the Raschigsynthesis to primary aliphatic a m i n e ~ . l ~ ~ . There is some evidence thathydroxylamine is formed as an intermediate in the decomposition of chlor-amine by sodium h y d r 0 ~ i d e .l ~ ~ More salts of hydrazine, e.g. , with antimonyand bismuth halides, have been de~cribed.~'~Improved laboratory preparations of several oxides of nitrogen in a stateof high purity have been described.177Anhydrous nitrates of weakly basic metals are difficult to prepare.Several of these, and some other salts, have been obtained by the electro-lysis of silver or copper nitrate solutions in methyl cyanide, anodes of theappropriate metal being used. Substances prepared by this generalmethod include Co(N03),,3MeCN, Ni(NO,),,ZMeCN, Zn(N03),,2MeCN,Cd (NO,),,ZMeCN, and Sn( C10,) ,,ZMeCN. 178Liquid dinitrogen tetroxide containing a tetra-alkylammonium nitratedissolves zinc, giving a solution which contains the ions [Zn(N0,)4]2-, R4N+,and NO k.This is explained by the equilibrium : 179(K4N) 2+ [Zn (NO,) 4]2- + 2N20, t;l (NO) ,+ [ Zn + 2 R4N*N0,The crystalline complex nitrate (EtNH,),,[Zn(NO,),] is formed when zincdissolves in a solution of ethylammonium nitrate in dinitrogen tetroxide.lsOThe ion-radical K,(SO,),NO acts as an oxidising agent to hydrazine,4K,(SO,),NO + N2H4 = N, + 4K,(SO3)2NOHas well as to a variety of organic compounds. The reaction, which can beused for analytical purposes, is practically quantitative in alkaline solutionand is, of course, accompanied by the disappearance of the deep violetIG9 R. A. Zingaro, J . A m e r . Chem. SOG., 1954, 76, 816.l i 0 J. Zernke, Rec. Trav. chim., 1954, 73, 95.171 H. H. Sisler, F. T. Neth, R. S. Drago, and D. Yaney, J .Amer. Chenz. Soc., 1954,76, 3906, 3909, 3912, 3914.172 L. F. Audrieth, E. Colton, and M. M. Jones, ibid., p. 1428.1 7 3 I d e m , ibid., p. 2672.1 7 5 R. E. McCoy, ibid., p. 144'7.l i 7 R. E. Nightingale, A. K. Downie, D. L. Rotenberg, B. Crawford, and R. A. Ogg,J . Pliys. Chenz., 1954. 58, 1047.1 7 8 H. Schmidt, 2. anorg. Chem., 1953, 271, 305; see also i d e m , ibid., 1952, 270, 188.17Q C . C. Addison, N. Hodge, and R. Thompson, J., 1954, 1143.180 C. C. Addison and N. Hodge, ibid., p. 1138.174 I,. F. Audrieth and L. H. Diamond, ibid., p. 4868.W. Pugh, J . , 1954, 1385136 INORGANIC CHEMISTRY.colour of the radical.lSl I n a similar way hydroxylamine is oxidised tonitrous oxide in alkaline solution. During this investigation solutions ofhydroxylamine hydrochloride were observed to decompose slowly onboiling.ls2A detailed kinetic study indicates that the nitrite-azide reaction proceedsthrough the formation of nitrosyl cations : 183NO,- + 2H,O+ = NO+ + 2H20NO+ + N,- __t [NO-N,] __t N, + N,OThe range of nitrosyl salts has been considerably extended, mainly bypreparations carried out in anhydrous liquid sulphur dioxide solution.Forexample, nitrosyl methosulphate has been prepared by the two reactions :(a) NO*SbCI, + Me,N*MeSO, = NO*MeSO, + Me,N*SbC16Fluorides react in liquid sulphur dioxide as if present as fluorosulphinate,S02F-, which gives nitrosyl fiuorosulphinate with a suitable nitrosyl salt :Me,NF -1 SO, + NO-HSO, = NO*S02F + Me,N*HS04Many of the reactions studied have a bearing on the lead-chamber processand the Rctschig hydroxylamine synthesis.184 The tendency for nitrosylchloride to ionise in the sense NO' + C1- is well known, and it has beenfound that complete and rapid exchange takes place between chloride ionsand nitrosyl chloride : 185Me,NS6C1 f- NOCl + Me4NC1 + N03%lA highly interesting series of metal azides is reported.The main pre-parative method involved the reaction between a metal hydride or alkyl andhydrazoic acid in ethcr or tetrahydrofuran, e.g.,( b ) MeONO + SO, = NO-MeSO,AlH, + 3HN3 = A1(N& + 3H2A12Me, + 4HN3 = 2MeA1(N3), + 4CH4Similarly, beryllium azide, Be(N,)2, and magnesium azide were preparedfrom dimethyl-beryllium and -magnesium, and Ga(N3), and B(N3), fromGa,H, and B,H6.In certain cases, by controlling the temperature, thereaction could be made to proceed in two stages; e g . , with lithium boro-hydride at -80" one mole of hydrogen is evolved corresponding to thereactionLiBH, + HN, = LiN, + 4B2H6 + H,and at 0" 3 moles of hydrogen are produced4B2H6 + 3HN3 == B(N3)3 + 3H2the overall reaction beingLiBH, + 4HN, = LiB(N,), + 4H2181 H. Gehlen, H. Elchlepp, and J. Cermak, 2. anorg. Chem., 1953, 274, 293.182 H. Gehlen and G. Dase, i t i d . , 1954, 275, 327.183 F. Seel and R. Schwaebel, zbid., 1953, 274, 169.184 F. Seel and H. Meier, ibid., p. 190, 197.185 J. Lewis and R. G. Wilkins, Chem. and Ind., 1964, 634COATES AND GLOCKLING. 137Aluminium a i d e and silicon azide were also obtained from the halide andsodium azide.Stannic azide, Sn( N,),, resulted from stannic chloride andsodium azide, but excess of the latter gave the salt Na,Sn(N,),.When the trirnethylamine compounds of aluminium hydride were allowedto react with hydrazoic acid, complex azides were obtained, e.g.,[ Me,NH] + [ Al( N3) 4]- and [Me,N H I,+ [Al( N,) J2-All these azides are white solids and as might be expected are shock-sensitive and readily hydrolysed.ls6The monolithium derivative of phosphine, LiPH,, has been prepared ingood yield by adding phenyl-lithium to ether through which phosphine ispassing. It is precipitated as a white powder, which has found use in thepreparation of primary organic phosphines.The primary product of the reaction between sodium and yellow phos-phorus in liquid ammonia appears to be Na,H,P, + 2NaNH,, and notNa,P,. Filtration from insoluble sodamide gives, on concentration, anorange-yellow solid whose composition is nearly Na,H,P,.lS8Phosphorus(v) oxide reacts slowly with isopropyl ether at room temper-ature (also with boiling ethyl ether), forming mainly isopropyl esters oftetraphosphoric acids. These esters are very much more easily hydrolysedto lower phosphoric acids than the salts of the higher polyphosphoric acids.lsDTetraphosphoric acid is a major product of the controlled hydrolysis ofphosphorus(v) oxide, e.g., with damp ether. 190A new phosphorus(v) oxychloride, P,04C11,, has been described. lglThe triamide of orthophosphoric acid, OP(NH,),, and its thio-analogue,SP(NH,),, have been prepared from phosphorus oxychloride (or PSC1,) andammonia, both in chloroform solution :POCl, + 6NH3 = OP(NH,), + 3NH,ClThey are both crystalline solids, easily soluble in water with gradual hydro-lysis, and are monomeric in aqueous solution.192Esters of hypophosphoric acid have been prepared by the action ofpowdered sodium on esters of phosphorochloridic acid : lse2(RO),P(O)Cl + 2Na = (RO),(O)P*Y(O)(OR), + 2NaClAmmonia dissociation-pressure measurements have shown that sesqui-ammonium orthophosphate, (NH4),H,(P04),, does not exist lS4 as previouslyclaimed.lS5Solubility relations in the system NaP03-H,O up to the melting point ofNaPO, have been determined,196 and two new sodium phosphates have beenE. Wiberg and H.Michaud, 2. Naturforsch., 1954, 9b, 495-503.113’ N. Kreutzkamp, Chem. Ber., 1954, 87, 919.188 P. Royen and W. Zschaage, 2. Naturforsch., 1953, 8b, 777.laB E. Thilo and H. Woggon, 2. anorg. Chent., 1954, 277, 17.loo E. Thilo and W. Wieker, zbzd., p. 27.191 R. Klement, 0. Koch, and K. H. Wolf, Naturwiss., 1954, 41, 139.lB2 R. Klement and 0. Koch, B e y . , 1954, 87, 333.193 M. Baudler, 2. Naturforsch., 1954, 9b, 447.194 J. A. A. Ketelaar, H. J. Rundervoort, J. L. Lobatto, and F. N. Hooge, Rec. Trav.1Q6 G. W. Morey, J . Amev. Cbem. Soc., 1953, 75, 5794.chim., 1954, 73, 662.A. de Passillk, Compt. rend., 1934, 199, 356; 1935, 201, 344138 INORGANIC CHEMISTRY.isolated from the reaction between sodium dihydrogen phosphate andort hophosphoric acid.lg7The system PC1,-AlCl, shows a sharp eutectic corresponding to PCl,,AlCl,.Ion-transport experiments indicate that the complex is likely to be[PCl,]+[AlCl,]-. Ferric chloride behaves similarly, giving [PCl,]+ [FeC1,]-.lg8Addition compounds are reported between the tri- and penta-chlorides ofphosphorus, arsenic, antimony, and bismuth (trichloride) and triethylamine.All the halides form 1 : 1 addition compounds, but some interesting com-plexes having more than one mole of amine per mole of halide were alsoobtained. Of these,, the most definite were (Et,N),,PCl, and (Et,N),,AsCl,,which are stable white powders. No molecular weight, solubility, or con-ductivity data were reported. lg9Tetramethylammonium chloride dissolves readily in arsenic trichloride,and a crystalline solvate [Me,N]+[AsCl4]-,2AsC1, can be isolated, whichreadily loses arsenic trichloride to give the previously known compound 2oo[Me,N] +[AsCl,]-. Ultraviolet absorption spectra have been used toidentify the complexes present in solutions of antimony(v) in hydrochloricacid of varying concentration. The extent to which hydroxy-groups arereplaced by chlorine in the series Sb(OH),Cl,-, increases with hydrochloricacid concentration.201 A number of ammines of bismuth(rI1) have beenprepared, e.g., with quinoline and dimethylaniline.202The hydrides and deuterides of niobium and tantalum have been prepareddirectly from the elements, and examined by X-ray diffraction.Themaximum hydrogen uptake corresponds to the formulae NbH,.,, andTaHo..s.203BiscycZopentadienylvanadium, (C,H,),V, has been prepared as a violet,paramagnetic solid.One of its most interesting reactions is with carbonmonoxide, when the orange monomeric and diamagnetic compoundC,H,V(CO), is formed.2a Several halides of biscyclopentadienyl-vanadium(m), -vanadium(Iv), -niobium(v), and -tantalum(v) have also beeninvestigated. 141Niobium and tantalum pentoxides, which form solid solutions, havedifferent crystal lattices. The change of lattice form of the solid solutionshas been measured in terms of temperature and composition.205 A numberof borovanadites, or double oxides of boron and vanadium(m), have beenobtained by electrolysis of fused salt mixtures at 900" ; these include MgBVO,,Fe,BVO,, and CO,BVO,.~~~The Raman spectrum of vanadium oxychloride (VOCl,) indicates thepresence of a double bond (VZO) ; similarly Re0,Cl contains ReZO bonds.207There has recently been considerable interest in the electrical conductivityof anhydrous halides.The conductivities of niobium and tantalum penta-lg7 E. J . Griffith, J . Amer. Chem. SOC., 1954, 76, 5892.lo* Y. A. Fialkov and Y . B. Bur'yanov, Doklady Akad. Nauk S.S.S.R., 1953, 92, 585.lgO IV. R. Trost, Canad. j. Chenz., 1954, 32, 356.2oo I. Lindqvist and L. H. Anderson, Acta Chem. Scand., 1964, 8, 128.201 14. M. Neumann, J . Awier. Chem. Soc., 1954, 76, 3611.202 N. hI. Turkevich, Zhur. obshchei Khim., 1954, 24, 978.203 G. Erauer and K. Hermann, 2. anorg. Chent., 1053, 274, 11.204 E.0. Fischer and W. Hafner, 2. Nalurforsch., 1954, gb, 503.f06 P. Blum and H. Bozon, Complpt. rend., 1954, 239, 811.207 H. J . Eichhoff and F. Weigel, 2. anorg. Chem., 1954, 275, 267.H. Schafer, A. Durkop, and M. Jori, Z . anorg. Chem., 1964, 275, 289COATES AND GLOCKLING. 139fluorides, which have positive temperature coefficients, are consistent withpartial ionisation,208 e.g., 2NbF, __ NbF,+ + NbF,-.The vapour pressure of niobium(1v) chloride, from the metal and thepentachloride, has been measured between 300" and 370". The extra-polated sublimation point is 456", but above about 420" disproportionationoccurs : 209 2NbC1, = NbCl, + NbCl,. The preparation and properties ofthe lower chlorides of tantalum, from tantalum pentachloride and aluminium,have been investigated more closely than previously.210 The tetrachloride,TaCl,, is deposited from the vapour as black crystals isomorphous withNbC1, ; it gives a brown solution in water, which evolves hydrogen. Readilyoxidised, it is a stronger reducing agent than niobium tetrachloride. Atabout 280" it disproportionates into gaseous tantalum pentachloride andsolid trichloride ; at higher temperatures the dichloride TaC1, is formed.211Group V1.-The trioxides, M203, of the alkali metals have sometimesbeen believed to contain 0,2- ions, and sometimes been regarded as latticecompounds containing 0 2 2 - and 0,- ions.The absence of any infraredabsorption by K203 excludes the presence of a bent triatomic ion 03,- andsupports the view that it consists of a mixture of K20, and K20,.212 Amixed peroxide-superoxide of potassium and barium ( K2Ba06) has beenisolated from the reaction between barium salts and potassium superoxide inliquid ammonia.213It should be noted that violent explosions can occur when activatedalumina is used to dry oxygen, if the alumina has previously been used todry hydrogen.The paramagnetic resonance absorption spectrum of liquid sulphursupports the view that chain-type polymers rather than large rings arepresent in theA study of the potassium sulphides.has confirmed the existence of all thesulphides from K,S to K2S,.216 Potassium thus differs from sodium in thatneither Na2S3 nor Na,S, could be prepared.217 Potassium hexasulphide (redcrystals) does not give a clear solution in water, but is partly decomposedwith the precipitation of sulphur.The pentasulphide appears to be themost stable member of the series. Measurement of the densities of thesesulphides indicates that the " chain " sulphur atoms are smaller than thoseat the ends of the chains, which is to be expected since the latter should carrythe greater part of the negative charge.218 Polysulphides of several amineshave been obtained by reaction of hydrogen sulphide with solutions of theamine and sulphur in organic (preferably non-polar) solvents. Compoundsprepared in this way include (Me,N),H,S, and (Et3N),H,Sg; both formorange-coloured crystals. 219The reaction between sulphur trioxide and ammonia has been investig-This can happen at room temperature.214208 I?.Fairbrother, W. C. Frith, and A. A. Woolf, J., 1954, 1031.2oB H. Schafer and L. Bayer, 2. anorg. Chem., 1954, 277, 140.310 0. Ruff and F. Thomas, ibid., 1925, 148, 1.211 H. Schafer and L. Grau, ibid., 1954, 275, 198.412 P. A. GiguZ?re and K. B. Harvey, J . Amer. Chem. Soc., 1964, 76, 6891.213 D. L. Schechter and J. Kleinberg, ibid., p. 3297.214 D. J. C. Bailey, Chem. a9ad I n d . , 1954, 492.215 D. M. Gardner and G. K. Fraenkel, J . Amer. Chem. SOC., 1954, 76, 5891.217 Idem, ibid., p. 144.219 H. Krebs, E. F. Weber, and 11. Balters, ibid., p. 147.F . F6her and H. J. Berthold, 2. anorg. Chem., 1953, 274, 223.21s Idem, ibid., 1954, 275, 241140 INORGANIC CHEMISTRY.ated several times and is not a t all simple.The previously supposed 220intermediate formation of sulphamic acid, NH,*SO,H, and iminodisulphonicacid, NH(SO,H),, has been disproved. The reaction appears to consist ofthe formation of sulphimide, SO,:NH, which partly polymerises to ringcompounds, and partly forms polymeric chains,221 H0,S-(-NH-SO,-),-OH.Trisulphuryl chloride, S,O,Cl,, has been isolated from the reaction be-tween sulphur trioxide and carbon tetrachloride. Pyrosulphuryl chloride,S,O,Cl,, which is well known, is also formed.222The preparation of thionyl bromide, which now becomes a reagent ofvalue for the substitution of bromine for hydroxy-groups in organic com-pounds,223 has been much improved. It is formed when thionyl chloride isadded to a solution of potassium bromide in sulphur dioxide.224A mixture of sulphur bromides, S,Br, (n varies from 4 to ll), has beenobtained by the action of hydrogen on sulphur monobromide, S,Br, ; hydro-gen bromide is eliminated.Higher sulphur chlorides have also beenprepared.225A new oxysulphide of nitrogen, S,N,O,, has been prepared by the reactionbetween nitrogen sulphide and sulphur trioxide ; it is colourless, crystalline,easily sublimed, and soluble without reaction in nitrobenzene.The oxysulphide is very sensitive to moisture, and a study of thehydrolysis products has shown that two of the sulphur atoms arePyridine vapour isabsorbed, with formation of two moles of the betaine C,H,N*SO,-,which, together with the fact that the sulphur dioxide obtainedby the hydrolysis of samples prepared from radioactive sulphur trioxide andnormal nitrogen sulphide is inactive, suggests the constitution (111) .226Addition of potassium amide to a liquid ammonia solution of sulphurnitride gives a yellow precipitate, K3N,S2, which takes fire in the air and isvery reactive to water and alcohols.The reaction is thought to take thecourse N4S, + GKNH, = 2KNS + 2(KN),S + 4NH,. The substance issoluble in formamide, and the molecular weight in this solvent agrees withdissociation into 3K+, NS-, and N,S2- ions.227The preparation of ammonium sulphimide, (NH4*NS02),, by the thermalrearrangement of sulphamide has been improved, and a variety of other saltsobtained. The silver salt Ag3(NS02).,,3H,0 can be dehydrated and convertedinto the free acid by hydrogen chloride in dry ether.Sulphimide (HN*SO,),polymerises readily, and is rapidly hydrolysed. Dilute solutions, however,are relatively stable and can be titrated electro- or conducto-metrically ; thefirst two dissociation constants are fairly large, the third being much smaller,but sulphimide can be titrated as a tribasic acid with 0-IN-sodium hydroxide(phenolphthalein) .228fs\\sT(111)Oas\ /SO2 in the +6 oxidation level, the other +a.0 +s20 P. Baumgarten and A. H. Krummacher, Ber., 1934, 67, 1257.aal R. Appel and W. Huber, 2. anorg. Chem., 1954, 275, 338.22a H. A. Lehmann and G. Ladwig, Chem. Tech., 1953, 5, 455.223 M. J. Frazer, W. Gerrard, G. Machell, and B. D. Shepherd, Claem. and Ind., 1954,226 F. FCher and G.Rempe, 2. Naturforsch., 1953, Sb, 688; F. FCher and J. Kraemer,226 M. Goehring, H. Hohenschutz, and J. Ebert, 2. anorg. Chem., 1954, 276, 47.227 W. Berg and M. Goehring, tbid., 1954, 275, 273.228 G. Heinze and A. Meuwsen, ibid., p. 49.931.ibid., p. 687.224 M. J. Frazer and W. Gerrard, ibid., p. 280COATES AND GLOCKLING. 141Dithio-acids combine readily with many heavy metals giving colouredcompounds, some of which are useful analytically. There is evidence thatthe four-membered rings considered to be present in these compounds openeasily in the presence of electron donors : 229PYis\ J. R.C\ 7M, ,C*R + 2 py e- R*CS.S*M-S*CS*Rs s + PYTetrapyridinecopper(11) tetrathionate is very much less soluble than thetri- or penta-thionate, and is suitable both for the separation of tetrathionatefrom other polythionates, and for the gravimetric analysis of copper.Tri-and penta-thionate ions can be precipitated as salts of the hexammino-cobalt(II1) ion.230The yellow dioxide of polonium, PoO,, formed by decomposition of thenitrate or oxidation of the metal a t 300°, provides further evidence (byX-ray analysis) for the existence of quadrivalent Po4+ ions.231Chromium and molybdenum cyclopentadienyls have been prepared bynew methods. Tetrahydrofuran has been found an excellent reactionmedium for the interaction of cyclopentadienylsodium with anhydrous metalchlorides, and the red, exceedingly air-sensitive chromium compound/C,H,),Cr, reported last year, has been obtained in 70% yield by this method.Compounds containing cyclopent adienyl-molybdenum and -tun@ en ionswere similarly obtained.232 The other method involves the interaction ofcyclopentadiene itself with the hexacarbonyls of these elements at 280-340".Chromium hexacarbonyl [as well as Fe(CO),, Co,(CO),, and Ni(CO),]afforded normal biscyclopentadienyl derivatives of the metals, but the hexa-carbonyls of molybdenum and tungsten under similar conditions gave theremarkable mixed cyclopentadienyl-carbonyls C,H,Mo(CO) ,MoC,H, andC,H,W(CO)6WC,H,. Both are quite stable and have molecular weightscorresponding to the formulze given above, and they are diamagnetic. Thestructures of these compounds are formulated as three-tiered sandwiches,each metal atom being bonded to a cyclopentadienyl ring, with carbonylgroups bridging the atoms. Preliminary X-ray data are consistent with thisinterpretation .%In its reactions with transition metals the isocyanide molecule RNC isremarkably similar to carbon monoxide, and a series of hexaisocyanide deriv-atives of chromium,234 molybdenum,235 and tungsten 236 has been obtained,e g ., Cr(CN*C,H5) 6 from chromous acetate and W(CN*C,H,) g from tungstenhexachloride and phenyl isocyanide. These are closely analogous to thecarbonyls M (CO) 6.Many oxides of chromium of compositions between Cr203 and CrO,have been described at various times, but there has been much doubt aboutthe identity of many of them. The slow decomposition of both chromium(v1)229 H. Krebs, E. F. Weber, and H. Fassbender, 2.anorg. Chem., 1954, 276, 128.230 G. Heinze, ibid., p. 146.232 F. A. Cotton and G. Wilkinson, 2. Naturforsch., 1954, 9b, 417.233 G. Wilkinson, J . Amer. Chem. SOC., 1954, 76, 209.z34 L. Malatesta, A. Sacco, and S. Ghielmi, Gazzetta, 1952, 82, 516.235 L. Malatesta, A. Sacco, and M. Gabaglio, ibid., p. 548.2a6 L. Malatesta and A. Sacco, A?m. Chim. (Italy), 1953, 43, 622.asl A. W. Martin, J . Phys. Chem., 1954, 58, 911142 INORGANTC CHEMISTRY.trioxide and chromyl chloride in a stream of oxygen has been followed byX-ray analyses and magnetic measurements. The first oxide formed isCr02.6(Cr5013) which is followed by an oxide of continuously variable com-position Cr02.38-2.48. The ferromagnetic dioxide CrO, is formed in smallamounts and is best obtained from chromyl chloride; it has a rutile-typestructure, the radius of the W+ ion being 0.55 A.Similar oxides are formedby the cautious thermal decomposition of ammonium dichromate, but thedioxide is not produced in this reaction. Chromium dioxide has also beenprepared by the decomposition of the trioxide at 420-450" under an oxygenpressure of 200-300 atm.237 Spectrophotometric examination of the de-composition of blue " perchromic acid " has shown that chromium(II1)dichromate appears to be the main product, rather than chromium(v1) tri-oxide or chromium(r1r) chromate as had earlier been supposed.238The exchange between the green chromium(1n) chloride and chloride ions,examined by means of radioactive chlorine, is extremely slow, so the complex[CrC1,(H20)4]+ is essentially covalently bound.239Solutions of molybdenum(v) change colour from green to brown as theacidity changes from 8 to 2~ (HCl).240 Magnetic evidence shows that athydrochloric acid concentrations greater than 7 ~ , molybdenum(v) ions existas monomers (one unpaired electron).A t lower concentrations of hydro-chloric acid the magnetic susceptibility falls as electron pairing takes place,and below 26~-hydrochloric acid all the molybdenum(v) ions are present asdimers linked by an electron-pair bond, Mo(v)-Mo(v) .241y 242A number of fluoromolybdates have been prepared by the action ofaqueous potassium fluoride on molybdenum(vr) trioxide. These includeK,MoO,F,, K2Mo0,F,,H,0, K3Mo,O,,F,3H2O, and K,Mo02F4,H20 ; thefluorotungstate K2W0,F2,H20 was also obtained.243 More data on tungstenbronzes (Na,WO,) have been reported.2MUranium and the Transuranic Elements.-Published work on the in-organic chemistry of uranium has mainly concerned its complexes in aqueoussolution or in mixtures of water with organic solvents. Visible and ultra-violet spectra of uranyl complexes with p-diketones in anhydrous andaqueous organic solvents provide evidence for the existence of strongcovalent bonds between the metal and the ligands.The high degree ofhydration and solvation supports the view that the U(VI) atom in suchcomplexes has a co-ordination number greater than ~ i x . ~ 5 The conduc-tivity of the uranyl nitrate complex with benzoylpicolinoylmethane suggeststhe presence of covalent U-N bonds.246 Uranyl nitrate combines with citric,malic, and tartaric acids a t pH 3.5 to form binuclear complexes by tridentatechelation involving oxygen or hydroxy-bridges between uranium atoms.Inslightly alkaline solution similar trinuclear complexes are formed.=' Data237 0. Glemser, U. Hauschild, and F. Triipel, 2. anorg. Chem., 1954, 277, 113;S. M. Ariya, S. A. Shchukarev, and V. B. Glushkova, J . Gen. Chem. (U.S.S.R.), 1953, 23,1107 (U.S. trans.).239 H. van der Straaten and A. H. W. Aten, Rec. Trav. chim., 1954, 73, 157.240 I. M. Issa and H. Khalifa, J. Indian Chem. SOC., 1964, 31, 91.241 M. M. Jones, J. Amer. Chem. SOC., 1954, 76, 4233.242 L. Sacconi and R. Cini, ibid., p. 4239.243 0. Schmitz-Dumont and P.Opgenhoff, Z . anorg. Chem., 1954, 275, 21.944 B. W. Brown and E. Banks, J . Amer. Chem. SOC., 1954, 76, 963.245 L. Sacconi and G. Giannoni, J., 1954, 2751.247 I Feldman, J. R. Havill, and W. F. Neumann, J . Asner. Chem. SOC., 1954, '96,4726.238 R. C. Rai and S. Prakash, 2. anorg. Chem., 1954, 275, 94.246 Idem, ibid., p. 2368on the stability of uranyl complexes with 2-thenoyltrifluoroacetone havebeen obtained and related to the use of that complexing agent for the solventextraction of uranium.24sUranium selenide and the tellurides, Use, UTe (both with the NaClstructure), U,Te4, and UTe,, have been prepared by heating the elementstogether, and their structures have been determined. The oxyselenideUOSe results when potassium cyanide, selenium, and uranium oxide aremelted together : 249SKCN + U,O, + 3Se = 3UOSe + FiKCNOThree solid phases have been identified from solubility studies on uran-ium(v1) orthophosphate in phosphoric acid.These are (UO2),(P0,),,6H,O,U0,HP04,4H,0, and U0,(H,P0,),,3H,0.250Five allotropes of plutonium are reported having densities between 16.4and 19. The negative temperature coefficient of expansion of &plutoniumis of interest as possibly being unique for a polycrystalline pureThe hydrates of uranium and plutonium tetrafluorides have been re-investigated : both form salts MF4,2-5H,O, and a lower hydrate with 2H20or less.,S2 Plutonium dioxide or oxalate and anhydrous hydrogen fluoridegive the tetrafluoride (PuF,) in the presence of oxygen and the trifluoride inits absence.The tetrafluoride is readily reduced to the trifluoride by hydro-gen. The hydrate PuF4,26H,O decomposes to the trifluoride when heated.253The direct fluorination at 500' of americium-(Irr), -(Iv), and -(v) compoundshas led to the isolation of AmF, and KAmF,.254Evidence that actinides form complex ions with chloride to a greaterextent than the lanthanides has been obtained from cation-exchange studiesat high hydrochloric acid concentration. The actinide complex ions areconsidered as partly covalent, with hybridisation involving the 5f orbitals.255Group VI1.-The heat of atomisation of fluorine, which has been indispute, has been measured by an effusion method; AH0298 = 37.6 & 0.8kcal. /mole.256The possible ability of fluorine to exert a covalency of two is of consider-able interest.A compound H2F*CI04, m. p. 56-58', prepared from an-hydrous hydrogen fluoride and anhydrous perchloric acid was described in1930.257 Recent experiments, however, conducted with carefully driedmaterials indicate that this compound does notFluorine converts dry sodium nitrite almost quantitatively into nitrylfluoride, N0,F :2NaN0, + F, + 2NaF + 2N0,Nitryl fluoride reacts with most metals below 300" to yield either the fluorideZNO, + F, -ID- 2N0,F248 R. A. Day and R. M. Powers, J . Amer. Chem. SOC., 1954, 76, 3895.21y R. Ferro, 2. anorg. Chem., 1954, 275, 320.260 J . M. Schreyer and C. F. Baes, J . Awser. Chem. SOL-., 1954, 76, 354.z61 W. B. H. Lord, ,Valure, 1954, 173, 534.Z52 J.K. Dawson, R. W. M. D'Eye, and A. E. Truswell, J., 1954, 3922.253 J. K. Dawson, R. M. Elliott, R. Hurst, and A. E. Truswell, J . , 1954, 555.z54 L. 13. Asprey, J . ,4mer. Chem. SOC., 1954, 76, 2019.2 5 5 M. Diamond, K. Street, and G. T. Seaborg, ibid., p. 1461.2 j s €1. Wise, J . Phys. Chem., 1954, 58, 389.2 5 8 G. Rrauer and €I. Distler, 2. atlorg. Chem., 1954. 275. 157z 6 7 A. Hantzsch, Ber., 1930, 63, 1789144 TNORGANIC CHEMISTRY.and oxide or the oxyfluoride. Non-metals, with the exception of bromineand tellurium, form nitronium salts : e.g., (N0,)SeF,.259A number of fluorosulphonyl complexes have been formed by reactionsbetween metal halides and fluorosulphonic acid in the complete absence ofwater. Those characterised include TiCl,(SO,F),, ZrF,(SO,F), TaCI,(SO,F),,and SF,(S0,F).260Oxidative hydrolysis of di-iodo( trifluoromethy1)arsine with aqueoushydrogen peroxide readily yields trifluoromethylarsonic acid, which under-goes progressive dehydration in uucuo forming first a pyro-acid and then ananhydride :3 5'1 1 0-* 73'1 lo-*m.mm .CF,*AsI, _t CF,*ASO(OH)~ + (CF,*AsO*OH*),O + CF,*AsO,Both trifluoromethylarsonic acid and the previously described bistrifluoro-methylarsinic acid, (CF,),AsO(OH), are almost completely ionised in aqueoussolution and are therefore much stronger acids than methylarsonic andcacodylic. Interesting use is made of infrared spectra for characterisationpurposes.261Trifluoromethyl-phosphonous and -phosphonic acids, CF,*P(OH), andCF,*PO(OH),, have also been prepared and studied.Like the correspondingarsenic compounds they are remarkably strong acids. The phosphonousacid was obtained by hydrolysis of the halides CF,*PX, or (CF,),PX (X = C1or I) or by controlled hydrolysis of (CF,),P, and the phosphonic acid byoxidative hydrolysis ( H202-H,O) of these three compounds. Oxidation ofthe phosphonous acid yields trifluoromethylphosphonic acid. Trifluoro-methylphosphonous acid is monobasic and the structure, CF,*PH(:O)*OH, isalso indicated by its infrared spectrum; i.e., it is really trifluoromethyl-phosphinic acid. In contrast to CF,*P(O)(OH), the phosphonous acid isvolatile in water vapour at reduced pressure. Bistrifluoromethylphos-phinous acid, (CF,),P*OH was also prepared. I t is unstable in water,yielding fluoroform and CF3*PH(0)*OH.262 Compounds containing fluoro-carbon radicals were reviewed in the Liversidge Lecture.a6aReactions of fluorine with various metals and their oxides are reported.Titanium, zirconium, tin, and their oxides react at moderately low tem-peratures forming the tetrafluorides.Vanadium(v) oxide, V205, yields theoxyfluoride VOF, at 475". Copper and a number of its compounds formcupricAredcrystallineoxy-sulphateof chlorine, dichloryl trisulphate (ClO,),S,O,,,has been prepared from potassium chlorate (or chlorite) and sulphur trioxide.It is perceptibly volatile in a vacuum and is formulated as a salt of thechloryl ion C102+ .265 Chloryl fluoride C10,F has been further studied.26625Q E. E. Aynsley, G.Hetherington, and P. L. Robinson, J., 1954, 1119.260 E. Hayek, J. Puschmann, and A. Czaloun, Monatsh., 1954, 85, 359.*61 H. J . Emelhs, R. N. Haszeldine, and R. C. Paul, J . , 1954, 881.262 F. W. Bennett, H. J. Emelkus, and R. N. Haszeldine, ibid., p. 3598.263 H. J. EmelCus, ibid., p. 2979.264 H. M. Haendler, S. F. Bartram, R. S. Becker, W. J. Bernard, and S. W. Bukata,J . Amer. Chew. SOG., 1954, 76, 2177; H. M. Haendler, L. H. Towle, E. F. Bennett, andW. L. Patterson, ibid., p. 2178; H. M. Haendler, S. F. Bartram, IV. J . Bernard, andD. Kippax, ibid., p. 2179.265 H. A. Lehmann and G. Kriiger, 2. anorg. Chent., 1953, 274, 141; see also A . .4.Woolf, Chewz. and Ind., 1954, 346.266 M. Schmeisser and F. L. Ebenhoch, Angew. Chem., 1954, 66, 230COATES AND GLOCKLTNG.145Several physical properties of iodine pentafluoride have been measured 267including the dielectric constant 268 which is surprisingly high (41.1 a t 0").Experimental procedures are given for the preparation of metallic chlorides[Co, Ni, Mn, Zn, and C~(III)] by chlorination of the metal in the presence ofa donor solvent such as ethanol or ether.269The bright yellow substance formed when 100% nitric acid acts oniodine is iodyl nitrate, IONO,, not neutral iodine nitrate I(NOJ,, as oftenPhase studies on the ternary system BaBr,-WgBr,-H,O at 25", 10*4",and 4.5" are reported. At the lower two temperatures a solid phase con-taining all three components is present.271Manganese carbonyl, Mn,(CO),,, has been obtained from manganeseiodide, magnesium, and carbon monoxide in ether under high pressure.Itforms volatile golden-yellow crystals (m. p. 155" in sealed tube) which aresoluble in organic solvents. With iodine it forms Mn(CO),I as ruby-redcrystals, m. p. 115". X-Ray and infrared data were obtained for Mn,(CO),,.The absence of an absorption band in the 5.5 p region (see ref. 287) suggeststhat manganese carbonyl, like Re,(CO),, but unlike Fez( CO),, dimerisesthrough the formation of metal-metal bonds rather than bridging carbonylgroups .272From the reaction between manganese chloride and cyclopentadienyl-magnesium bromide both biscyclopentadienyl-manganese and -magnesiumcan be separately isolated. Biscyclopentadienylmanganese forms a mixedcyclopen tadien yl-carbonyl, C,H,-Mn( CO),, m.p. 77 ", with carbon monoxideunder pressure, which is monomeric in benzene solution. At normaltemperatures it is diamagnetic, but is remarkable in that it becomes para-magnetic at low temperatures.273Biscyclopentadienylmanganese, from cyclopentadienylsodium and man-ganese(r1) bromide in tetrahydrofuran, presents an interesting case of isomer-ism since the brown paramagnetic form (three unpaired electrons) stable atroom temperature becomes white sharply a t 158-159", and then melts a tthe characteristic temperature 172-173". The white form, which hasonly one unpaired electron, reverts to the brown form on slow cooling, butthe process can be halted by sudden cooling. It has been suggested that thebonding in the brown form, which is highly reactive, is similar to that whichobtains in, for example, an alkyl derivative of an electropositive metal, thewhite form on the other hand having the typical biscyclopentadienylstructure.274Salts of the univalent ion containing manganese(I), e.g., [Mn(CNR),]+I-,have been obtained by reaction of aromatic isocyanides with manganese(I1)iodide.Treatment with iodine does not oxidise the stable (diamagnetic)hexaisocyanidemanganese(1) ion, but gives the periodide [Mn(CNR)6]+13-.275267 M. T. Rogers, J. L. Speirs, H. B. Thompson, and M. B. Panish, J . Amer. Chem.SOL., 1954, 76, 4843.2 6 8 31. T. Kogers, H. B. Thompson, and J. L. Speirs, ibid., p. 4841.203 R. C. Osthoff and R. C. West, ibid., p. 4732.270 T. Kikindai, Compt.rend., 1954, 288, 1229.271 H. J. V. Tyrrell and J. Richards, J . , 1953, 3812.2 7 2 E. 0. Brimm, M. A. Lynch, and W. J. Sesny, J . Amer. Chewz. SOC., 1954,76, 3831.273 E. 0. Fischer and R. Jim, 2. Naturforsch., 1954, 9b, 618.2 7 4 G. Wilkinson and F. Cotton, Chem. and Ind., 1954, 307.2 7 5 A. Sacco, Atti Accad. naz. Lincei, Rend. Classe Sci.fis. mat. nat., 1953, 15, 421.. stated.27146 INORGANTC CHEMISTRY.Potassium manganate is not readily obtained in a pure state, but hasrecently been purified to 9943%. Its thermal decomposition is complex, butproceeds mainly by the reaction 3K,Mn04 = 2K3Mn0, .+ MnO, + 0,.A certain amount of K2Mn0, is also formed together with oxides of variableThe highly reactive fluorides of permanganic and per-rhenic acids,MnO,F and ReO,F, have now been isolated in a pure state and characterised.The former was obtained from potassium permanganate and hydrogenfluoride or fluorosulphonic acid :KMnO, + 2HF = Mn0,F + KF + H,OKMnO, + 2F*SO,H = Mn0,F + KS03F + H,SO,It forms dark green crystals, m.p. -38", b. p. (extrap.) -60"; the vapouris an intense green. The rheniumoxyfluoride, ReO,F, was prepared from the corresponding chloride andanhydrous hydrogen fluoride. It formed a yellow solid melting (at 147') toa very viscousReduction of potassium per-rhenate, KReO,, with potassium in aqueousethylenediamine leads to the isolation of potassium rhenide KRe in an impurestate as a grey hydrated solid. Its paramagnetism was less than is requiredfor an atom with one unpaired electron.Since rhenium contains five un-paired electrons this magnetic evidence suggests that the Re- ion exists as ahydrated complex having four water molecules co-ordinated at the cornersof a ~quare.~78 Rhenium and germanium are shown by X-ray and vapour-pressure measurements to form only the highly inert compound, ReGe,(AH = -2 & 10 kcal.).,,,Group VII1.-The extensive work reported last year on cyclopent adienyl-metal complexes is now being extended to indene, which forms metal com-plexes, at least with iron and cobalt, which are analogous to the cyclopenta-dienyl complexes. Bisindenyliron( 11) , Fe(C,H,),, has been prepared fromferric chloride and indenyl-lithium or indenylmagnesium bromide as a deeppurple diamagnetic solid soluble in organic solvents.It sublimes in avacuum at go", sinters in nitrogen at 160", and melts a t 179-181". Unlikebiscyclopentadienyliron, Fe(C5H,),, it is not oxidised to the correspondingwater-soluble cation, Fe(C,H,),+, because of decomposition.280 Catalyticreduction 281 gives bistetrahydroindenyliron, Fe(C,H,,),, as a diamagneticoil, m. p. 18.5-19", which can be distilled in V ~ C U O at 125". Bisindenyl-cobalt, Co(C,H7),, has been prepared from indenyl potassium andCO(NH,)~(SCN), in liquid ammonia solution. The initially formed complex,[CO(NH,)~][C,H,], loses all its ammonia in a vacuum. Bisindenylcobaltforms black paramagnetic crystals, and is monomeric in benzene solution.It sublimes in a high vacuum at 100" and sinters about 160".Oxidationwith hydrogen peroxide or potassium persulphate gives the correspondingcomposition, M1101.75-1.8~. 276Above 0" it decomposes explosively.2 7 6 R. Scholder and H. Waterstradt, 2. anorg. Chem., 1964, 277, 172.2 7 7 A. Engelbrecht and A. V. Grosse, J . Amer. Chem. SOC., 1954, 76, 2043.2 7 8 J . B. Bravo, E. Griswold, and J. Kleinberg, J . Phys. Chem., 1954, 58, 18.27e A. W. Searcy, R. A, McNees, and J. M. Criscione, J . Amer. Chem. SOC., 1954, 76,280 E. 0. Fischer, D. Seus, and R. Jira, 2. Natwforsch., 1953, 8b, 693, 694: 1'. I.5287.Pauson and G. Wilkinson, J . Amer. Chem. SOG., 1954, 76, 2024.E. 0. Fischer and D. Sew, 2. A'aturforsch., 1954, 9b, 386COATES AND GLOCKLTNG. 117cation [Co(C,K,) 2]+, which also results from treatment of indenylmagnesiumbromide with cobalt(1r)-acetylacetone. Bisindenylnickel has been mentionedas a deep red-brown solid.280Further reports have appeared on biscyclopentadienyl compounds of iron,cobalt, and nickel.They are obtained in poor yields from the metalcarbonyls and cyclopentadiene. The heat of formation of Ni(C,H,), fromthe elements is 62.8 & 0.5 kcal./mole [compare AH” for Fe(C5H5)2, 33.8kcal. /mole]. Magnetic-susceptibility measurements on Ni(C5H5)2 and[Ni(C,H,),]+ show the presence of two and one unpaired electrons, respec-tively.282 Ferrocene and n-butyl-lithium form a mixture of mono- and di-metallated products, indicating that the hydrogen atoms are more acidic thanin benzene.283 Small yields of ferrocene and of (C5H5)2TiC12 have beenobtained by the interaction of cyclopentadiene and the metal chloride in thepresence of a hydrogen halide acceptor such as an amine : 2842C,H, + FeC1, + 2Base - Fe(C,H,), + 2Base, HC1Phase-diagram studies on the system Fe2O3-P,O5-H2O have revealedthe four stable solid phases : Fe20,,P20,,5H20 ; Fe20,,2P205,8H20 ;Fe203,3P20,,10H20 ; Fe203,3P20,,6H20, the last probably beingH3[Fe(HP0,),].Diferric tetraphosphate was found as a metastable solidphase.285 Equimolar mixtures of citric acid and ferrous or ferric perchlorate0 0 Ill Ill111 111 0 0Reproduced, by permission, fromJ. W. Cable, R. S. Nyholm, andR. K. Sheline, J . Amer. Chern. Sor.,1954, 76, 3373.(IV)form a variety of complexes depending onthe pH of the solution, and formationconstants have been calculated.Thespecies identified from ferrous are FeHCit,(FeCit)-, and (FeOHCit)2-, and fromferric, (FeHCit)+, FeCit, (Fe0HCit)-, and[ Fe (OH) ,CitI2- .286Further important advances have beenmade in the chemistry of carbonyl com-pounds, A spectral examination of dicobaltoctacarbonyl has revealed absorption inthe 5.5-p region of the spectrum, stronglyindicating the presence of bridged carbonylgroups in the molecule, in addition tocarbon monoxide-type carbonyl groups.Of various possible structures a trigonalbipyramidal configuration (IV) about eachcobalt atom is favoured. The bridged carbonyls are considered to be similarto those in strained cyclic ketones.287With acetylene and a number of substituted acetylenes, dicobalt octa-carbonyl undergoes a remarkable reaction, quantitative at room temperature,whereby the two bridge carbonyl groups are replaced by one molecule of theacetylene :R-CiC-R’ + CO~(CO), _t C~RR’CO~(CO), -1 2COa82 G.Wilkinson, P. L. Pauson, and F. A. Cotton, J , Amer. Chem. SOC., 1954, 76,1970.283 R. A. Benkeser, D. Goggin, and G. Schroll, ibid., p. 4025.285 R. F. Jameson and J. E. Salmon, r., 1954, 28.288 R. E. Hamm, C. M. Shull, and D. M. Grant, J . Amer. Chem. Soc., 1954, 76, 2111.287 J. W. Cable, R. S. Nyholm, and R. I<. Sheline, ibid., p. 3373.J. M. Birmingham, D. Seyferth, and G. Wilkinson, ibid., p. 4179148 INORGANIC CHEMISTRY.The diphenylacetylene compound (R = R' = Ph) formed deep purplecrystals, m.p. 110", which sublimed at 90" under 1 mm. pressure. It isdiamagnetic and monomeric in cyclohexane, and its dipole moment is re-ported as 2.1 D. Examination of the infrared spectrum of this and relatedcompounds showed bands corresponding to the terminal carbonyl groups indicobalt octacarbonyl. The characteristic bridge carbonyl frequency wasabsent, as also were bands corresponding to acetylene groups. Certain ofthe derivatives such as that from ethylene itself showed a band a t 3096 cm.-l,characteristic of an ethylenic or aromatic C-H bond. This evidence leadsto two types of possible structure (V and VI). In (VI), which cannot be0 R 0 \\ I 2o=c=co:;- j -;;g=c=oHC\c Rc\\ ,c.. 0=c=co=c \ I R0\o// \ RC1, Ncc=co=c=o // 'F' "..,R' 0flC0(V) (VI)represented by localised bonds, the C-C and Co-Co bonds may be coplanaror perpendicular.28Further investigations on the reactions of cobalt carbonyls with a varietyof bases have shown that the tricarbonyl [Co(CO),], is quantitatively trans-formed into a [Co(CO),] derivative :~[CO(CO),], + 24C5H5N = ~[CO(C,H,N),][CO(CO),], + 4CODicobalt octacarbonyl not only reacts with pyridine and amines in the mannerreported last year, but also with such weak bases as acetone :~[CO(CO)~], + 12COMe, = ~[CO(COM~,),][CO(CO)~]~ + 8COThe ions [Co(COMe2),l2+, [CO(M~-CN),]~+, and [c~(hfe*NH,),]~+ have beenobtained in this way.The reaction with methylamine is of particularinterest : 289~[CO(CO),]~ + 20Me*NH2 = ~[CO(M~=NH,),][CO(C~)~], + 8Me*CO*NH,A solution of cobalt (11) chloride in aqueous potassium cyanide absorbscarbon monoxide in the presence of much hydroxide ion, the cobalt beingreduced by part of the carbon monoxide with formation of carbonate andthe [Co(CN),C0I2- ion containing cobalt(1).The only solid salt of this ionwas formed with tris-o-phenanthroline-iron(xr), [Fe phenan,][Co(CN),CO],as a bright red precipitate.2wCompounds of cobalt(0) have been prepared by the reduction ofK,Co(CN), suspended in liquid ammonia containing potassium, K,Co(CN) 6 +3K = K4Co(CN), + 2KCN. The potassium tetracyanocobalt(0) is obtainedas a brown-violet hygroscopic powder, very sensitive to air (in which it ispyrophoric) and moisture. It immediately liberates hydrogen on additionto water.The ion CO(CN),~- would contain an odd number of electrons,288 R. A. Friedel, H. Greenfield, R. Markby, H. W. Sternberg, I. Wender, and J. Wotiz,J . Amer. Chem. SOC., 1954. 76, 1457.290 W. Hieber and C. Bartenstein, 2. anorg. Chem., 1954, 276, 1 .W. Hieber and J. Sedlmeier, Chern. Ber., 1954, 87, 25, 789COATES AND GLOCKLING. 149but the weak paramagnetism (043 B.M.) of the potassium salt, which isdifficult to keep pure, indicates a dimeric structure analogous to that ofdicobalt octacarbonyl, viz., K,[Co,(CN),]. This compound, when suspendedin ammonia, absorbs carbon monoxide :K,[Co,(CN),] + CO = K,[Co,(CN),CO] + KCNDicobalt octacarbonyl similarly reacts with potassium cyanide with partialdisplacement of carbon monoxide and formation of a mixture ofK,[Co,(CN),(CO),] and K,[CO,(CN),(CO)~].Of particular interest is thereaction between sodium tetracarbonyl cobalt and sodium cyanide in liquidammonia, which results in the partial formation of sodium tricarbonylcyanocobalt(-I) : NaCo(CO), + NaCN = N~,[COCN(CO),].~~~There have been considerable advances in the chemistry of the isocyanidederivatives of the transition elements (see also Cr, Mo, W, and Mn). Addi-tion of $-tolyl isocyanide to an alcoholic solution of ferrous chloride givestwo isomeric compounds, Fe(CNR),Cl,, one deep blue-violet, the other brown ;both are diamagnetic.292 These compounds are evidently octahedrally co-ordinated and non-electrolytes. Pentaisocyanide derivatives of cobalt (I),[Co(CNR),]+X-, were reported last year.Several derivatives of cobalt(11)have now been described; addition of an aromatic isocyanide to cobalt(I1)iodide affords two isomeric compounds Co(CNR),12, one metastable, greenor blue, and diamagnetic, the other stable, reddish , and paramagnetic.With silver perchlorate a 1 : 1 electrolyte is formed, [Co(CNR),I]C104, in adisproportionation reaction. In this compound the unusual five co-ordin-ation of the CO(I) complexes disappears but is present again in[Co(CNR),] (ClO,),, obtained from the isocyanide and cobalt(@ perchlorate.The pentaisocyanidecobalt (11) complexes are paramagnetic to an extentcorresponding to the presence of one unpaired electr0n.~~3Mixed isocyanide-carbonyls of cobalt have been described, and are cobaltcarbonyl salts of the pentaisocyanidecobalt (I) cation, e.g.,,*CO,(CO)~ + SRNC = [CO(CNR),][CO(CO)~] + 4CONaCo(CO), + [Co(CNR),]ClO, = [Co(CNR),][Co(CO),] + NaC10,by several methods, viz., (1) the displacement of carbonyl by isocyanide,Fe(NO),(CO), + 2RNC = Fe(NO),(RNC), + 2CO(2) reaction between isocyanides and other nitroso-compounds (q., Roussin’ssalt),K,Fez(NO)4S, + 4RNC = 2Fe(N0)2(RNC), + K,S,[CO(NO)(NH~)~]C~~ + SRNC + *N2H4 = Co(NO)(RNC), + 2NH4C1(3) the reaction between isocyanide complexes and hydroxylamine in alkalinesolution,isocyanide-nitrosyl derivatives of both iron and cobalt have been obtained(black form) + 2NH, + p 2Co(CNR),X + 2NH2*OH = Co(CNR),NO + 2RNC + H,O + NH4X2s1 W. Hieber and C. Bartenstein, 2. araorg. Chem., 1954, 276, 12.2s2 L.Malatesta, A. Sacco, and G. Padoa, Ann. China. (Italy), 1953, 43, 617.ag4 A. Sacco, ibid., 1953, 83, 632.L. Malatesta and A. Sacco, Gazzetta, 1953, 83, 499; L. Malatesta, ibid., p. 958;A. Sacco, ibid., 1954, 84, 3701 ti0 INORGANIC CHEMISTRY.The last reaction may well involve the disproportionation of hydroxylamine,2NH2-OH = NH, + NOH + H,O. Many of the isocyanide-nitrosyls arequite stable compounds ; they are diamagnetic, monomeric, and soluble inorganic solvents. The dipole moments of several derivatives containingfiara-substituted phenyl isocyanides have been measured ; the positive endof the dipole is in the direction of the phenyl isocyanideNickel carbonyl and sodium in liquid ammonia give the dimeric carbonylhydride [NiH(CO),],.The reaction involves also the formation of sodiumcarbonyl :BNi(CO), + 3Na -1- ZNH, = [NiH(CO),], -$- CO + NaCO -1- 2Na-NH2Sodium carbonyl and sodamide separate from the reaction mixture, leavingthe carbonyl hydride in solution. The hydrogen atoms in nickel carbonylhydride appear to be non-a~idic.,~~The reaction between nickel carbonyl and phosphorus trihalides givingcomplexes of nickel(O), Ni(PX,),, has now been extended to phosphorus tri-isocyanate and triisothiocyanate (X = NCO and NCS). The crystallineproducts are quite stable and A variety of nickel carbonylsin which one to four carbonyl groups have been replaced by phosphorus(rr1)has been described. These include such compounds as[ ($-MeO*C6H,*O),P],NiC0, [ (fi-N0,*C,H4*O),P],NiC0, and Ni(C,H,*PC&),,which are all prepared from the appropriate phosphorus(II1) compounds andnickel c a r b ~ n y l .~ ~ ~Attempts have been made to separate racemates by chromatographicadsorption. Several octahedral cobalt (111) complexes have now beenseparated on columns of ordinary potato starch. The separation is facilitatedif the complexes contain hydroxyl or other groups which can associate withthe hydroxyl groups of starch. Complexes such as cobalt(m) tris(amino-acetate) and trisethylenediaminecobalt (111) chloride were separated intooptical isomers, as well as several ~anthates.,~g Trisethylenediamine-cobalt (111) salts are racemised in the presence of decolorisingThe compound previously believed to be N~,[CO(NO,)~NO],ZH,O, is nowconsidered to be N~,[CO(NO,),,NO,H,O].~~~A potentiometric investigation of the reduction of potassium nickel@)cyanide by potassium in liquid ammonia shows that, with excess of salt pre-sent, two single-electron reactions occur : [Ni(CN)J2- -++ [Ni(CN),I3-[Ni(CN),I4-, whereas in the presence of excess of potassium a two-electronreaction occurs.3o2Some quadridentate cobalt(I1) complexes and the 1 : 10-phenanthrolinecomplex undergo isotopic exchange with labelled cobalt (11) ions, indicatingionic or weakly covalent bonding.I n contrast bistripyridylcobalt (11) showsZg5 L. Malatesta and A. Sacco, 2. anorg. Chem., 1953, 274, 341.z96 H. Behrens and F. Lohofer, 2. Naturforsch., 1953, 8b, 691.2g7 G. Willrinson, ibid., 1954, 9b, 446.298 L. Malatesta and A.Sacco, Ann. Chim. (Italy), 1954, 44, 134.z9* H. Krcbs and R. Rasche, Z. anorg. Chem., 1954, 270, 236.300 €3. E. Douglas, J . Amer. Chem. SOC., 1954, 70, 1020.301 R. Nast and M. Rohmer, 2. anorg. Chem., 1954, 275, 162; see also J. 12. Frazer302 G. W. Watt, J , L. Hall, G. R. Choppin, and P. S. Gentile, J . Amer. Chent. SOC.,and N. 0. Long, J . Chem. Phys., 1938, 6, 462.1954, 76, 373WATES AND GLOCKLlNG. 151a very slow rate of exchange.303 Cobalt inner complexes with salicylidene-anilines are suggested to possess a tetrahedral structure in contrast to theestablished planar configuration of the copper c o m p l e ~ e s . ~ ~ Sexadentatechelate compounds between cobalt (111) and various complex Schiff's basessuch as the salicylidene derivative of (VII) have been investigated.3o5If oxygen is bubbled through sodium or lithium hydroxide contained innickel tubes a t 800°, the alkali-metal nickelates result, MNi0,.306N=F-Ph--I-/ -N, 2- / ONickel forms red-to-brown diamagnetic complexes with acylhydrazonesof a number of diketones and related compounds, some of which are mono-nuclear (e.g., VIII), and others polymeric, polynuclear complexes.307A preliminary communication has appeared on certain bis-salicylaldiminecomplexes of nickel which are apparently solvated in pyridine, alcohol, ordioxan, and acquire an octahedral structure.The same complexes inchloroform, benzene, toluene, or xylene give interesting equilibria betweenplanar diamagnetic and tetrahedral paramagnetic forms .308The Platinum Metals.-The complex fluorides of ruthenium have beenfurther investigated. Ruthenium and bromide trifluoride react vigorouslya t room temperature forming RuBrF,, i.e., (BrF,)+(RuF,)-, from whichruthenium pentafluoride is readily obtained by heating at 120" in a vacuum.Mixtures of potassium bromide and ruthenium react with bromine trifluorideto form the new complex, potassium hexaffuororuthenate(v), KRuF,.With water, these complex salts of quinquevalent ruthenium evolve oxy-gen and form a hexafluororuthenate(1v) : ~ R u F , ~ - + 6H,O = 4RuFG2- +4H30+ + 0,. The simultaneous formation of some ruthenium tetroxide isaccounted for by the disproportionation reaction : 309 4Ru(v) _t Ru(vi1r) +3Ru(1v).What appears to be a remarkable co-ordination compound ofpalladium(1) has been obtained from 2-phenylisophosph-A4 indoline (IX) and potassium palladochloride, having the j\/j/r..nl composition (C1,HI3P),,PdC1. Under different conditions the( 1x1 normal complex ( Cl4HI3P),PdCl, is formed. The colourlesscomplex of palladium@), which is dimorphic, melts to a scarletliquid. Its solutions in warm ethanol or acetone are bright yellow, and onboiling become bright red. These colour changes are reversible and suggestdissociation, but molecular-weight determinations in boiling solvents indicatea six-fold association to [(Cl,H13P),PdC1],.310Two series of isocyanide complexes of palladium, Pd(CNR),X, andPd(CNR)4X2, have been obtained. Compounds of the first type, which are303 R. 0. West, J , , 1954, 395, 678.305 F. 1'. Dwyer, N. S. Gill, E. C. Gyarfas, and I;. Lions, J . ,4?ner. Chem. SOL., 1964,307 L. Sacconi, Gazzetta, 1953, 83, 884, 894; Z. anorg. Cheni., 1954, 275, 449.308 H. C. Clark and A . L. Odell, Chew. and Iwd., 1954, 1510.30D M. A. Hepworth, R. D. Peacock, and P. L. Robinson, J . , 1954, 1197.310 F. G. Rlann, I. T. Millar, and F. H. C. Stewart, ibid., p. 2833.304 I d e m , Naiurr, 1964, 173, 1187.76, 383. 30G L. D. Dyer, H. S. Borie, and G. 1'. Smith, ibid., p. 1499152 INORGANIC CHEMISTRY.soluble in chloroform, have been reduced to derivatives of palladium(O),Pd(CNR),. These are probably polymeric, and are insoluble in solventsother than pyridine and nitrobenzene, in which they are decomposed to themetal ; with iodine, Pd(CNR),I, is formed.311Reduction of pentamminoiridium bromide, (NH3)&Br, and of tetr-amminoplatinum dibromide, (NH,),PtBr,, with potassium in liquid ammoniagives pentamminoiridium (0) which is insoluble in ammonia, and tetr-amminoplatinum(0) , respectively. Decomposition results in formation ofthe metal and ammonia.312Dichlorodicarbonylplatinum(11) can be obtained readily from platinum(rr1)chloride and carbon monoxide at 125" under high pressure. The pure com-pound, PtCl,(CO), loses carbon monoxide irreversibly in a vacuum. Furtherevidence in favour of the cis-configuration has been obtained.313cycZoPropane appears to form compounds with platinum analogous to thenormal olefin compounds. Thus chloroplatinic acid in acetic anhydrideabsorbs cyclopropane rapidly, forming (PtC1,,C3H6), and probablyHPtC13,C3H,,H20, from which cyclopropane is evolved on treatment withpotassium cyanide.Potassium bromoplatinite, K2PtBr4, and potassium nitritoplatinite,K,Pt(NO,),, form mixed cis- and trans-forms of the complex K,[Pt(NO,),Br,]which were found to undergo the following reactions :Pyridine forms the stable complex PtC1,1C,H6,2py.314NH3 3C.IK2[Pt (NO,),Br,] _t trans-Pt (NO,),(NH,), -+ trans-Pt (NH,),T,Radioactive tracer techniques have been used to investigate exchangereactions between chloroplatinite and chloroplatinate ions. The catalysedexchange reactions are interpreted in terms of a chloro-complex of Pt (111) .31GThere is some evidence for the existence of a perceptibly volatile platinumsilicide, which may be responsible for attack on platinum in some high-temperature experiments in which both silica and platinum are used.317G. E. COATES.F. GLOCKLING.311 L. Malatesta, Atti Accad. naz. Lincei, Rend. Classe Sci.fis. mat. nat., 1954, 16, 364.312 G. W. Watt, M. T. Walling, and P. I. Mayfield, J . Amer. Chem. Soc., 1953, 75,313 J. M. Lutton and R. W. Parry, ibid., 1954, 76, 4271.314 C. F. H. Tipper, personal communication.315 A. I. Dobroborskaya and G. A. Shagisultanova, Izzvest. Akad. Nauk S.S.S.R.,316 R. L. Rich and H. Taube, J . Amer. Chem. Soc., 1954, 76, 2608.317 R. E. Carter and F. D. Richardson, Research, 1954, 7, S3.6175; G. W. Watt and P. I. Mayfield, zbid., p. 6178.Odtel. Khim. Nauk, 1953, 968

ISSN:0365-6217    

DOI:10.1039/AR9545100118

出版商:RSC    

年代:1954

数据来源: RSC

摘要:

ORGANIC CHEMISTRY.1. INTRODUCTION.THIS Report covers only the advances in organic chemistry of 1954, exceptthose of 1953 which were published in periodicals not readily available toworkers in general.The theory of the effect of structure on reaction rate and equilibrium isintimately concerned with (a) the change of steric interaction effected bychange in conformation in passing from reactants to transition state andfrom reactants to products respectively, and (b) the geometry of reactions.This year’s publications show that these generally recognised factors arebeing vigorously investigated and widely illustrated.*Details of the work on hydrogen transfer have been published and arereported in sections 3 and 5. The latter is also concerned with advances inthe chemistry of aphis pigments.Extensive progress has been made in thefield of polynucleotides since it was previously reported in Annual Re;Sortsfor 1952, Vol. 49; consideration of other natural macromolecules is post-poned.Terpene chemistry has advanced at a rapid rate and it has been founddifficult to keep the report within the bounds of space allotted. The year’swork in the field of sesquiterpene chemistry has been characterised by thesynthesis, by a group of Japanese workers, of naturally occurring a- andP-santonin, racemic a- and P-santonin, and four of the other six racemicmodifications, an outstanding achievement. This year it has been deemedmore logical to include the C,, compounds, of the lanosterol group, whichare reduced cyclopentenophenanthrenes, with the steroids.In the steroidfield the elucidation of the structure of the cortical steroid aldosterone byReichstein and his school is noteworthy for its relevation of the uniquehemiacetal grouping in this compound. Special mention must also be madeof the clarification of the structure of the hypotensive steroid alkaloids of thecevine group, by Woodward, Jeger, and Barton.In the non-steroidal alkaloid field two brilliant pieces of synthetic workhave emerged from Woodward’s school. Lysergic acid and strychnine havebeen synthesised. The synthesis of the former is notable for its simplicityand that of the latter reveals a characteristically elegant approach to acomplicated molecule.G. B. w. c.2. THEORETICAL ORGANIC CHEMISTRY.Excited States.-This year’s Presidential Address to the Society intro-duced the field of the stereochemistry of excited states.Change of form andconstitution seems to be the rule in valency-shell excitation. Analysis ofthe absorption spectrum of acetylene 1¶ shows the first excited electronic* See especially W. Klyne, “ Progress in Stereochemistry,” Butterworths ScientificC. K. Ingold, J., 1954, 2991. K. K. Innes, J . Chem. Phys., 1954, 22, 863.Publ., London, 1954154 0 RGAN IC CHEMISTRY.state to be planar, trans-bent, and centro-symmetrical. In the excitationthe C-C and C-H bonds become elongated, easier to stretch but harder tobend. The molecule achieves its energetically lowest electronic excitationby breaking of one of the x-orbitals of the original triple bond into twounshared-electron orbitals which accommodate the two electrons of thebroken orbital and an electron excited out of the remaining x-orbital (see 1).q/ HThe nature of the excited states determines the " general polarisability " ofthe normal states and thereby those properties which are of main importancein determining the steric and electronic mechanism of organic reactions.Thus the formation of (1) may be connected with the general importance oftrans-addition to acetylenic compounds. Appropriate extension of the cis-form of (1) provides structure (2) which may describe the product of dehydro-chlorination of chl~robenzene.~Bimolecular Elimination.-An interesting illustration of the effectof (a) intramolecular interaction and ( b ) the stereospecificity of trans-elimination is provided by the action of potassium tert.-butoxide on the2 : 4 : 6-trimethylbenzoates of (&)-" erythro "- and (&)-" tkreo "-2-deutero-1 : 2-diphenylethanol (3 and 4 respectively) ; (a) ensures the formation oftrans-stilbenes and, in combination with ( b ) , determines whether proton ordeuteron is eliminated.The products are ( 5 ) and (6) re~pectively.~HO .Ph \ ;'>HHofmann elimination is subject to the same stereochemical requirement,and an equatorial rather than an axial p-hydrogen atom should therefore bepreferentially displaced in the Hofmann decomposition of reduced hetero-cyclic amines. This view is compatible with (i) ring fission between N andin trans-decahydroquinoline and between N and the cycZohexane ring incis-octahydroindole and (ii) the easier ring fission of piperidinium hydroxidesthan of the corresponding pyrrolidinium hydroxides5 It is unsafe, however,to assume that these differences are caused wholly by difference in conform-1.D. Roberts, H. E. Simmons, jun., L. A . Carlsmith, and C . IV. Vaughan, J . Airier.C/W~F?: Soc., 1953, 75, 3290; H. Gilman, H. W. Melvin, and J. J. Goodman, ibid., 1954,76, 3219. D. Y. Curtin and D. B. Kellorn, ibid., 1953, 15, 6011.J. McKenna, Chem. and Ind., 1954, 406; B. Bailey, R. D. Haworth, and J.McIienna, J., 1954, 967; 1:. E. King and H. Booth, ibid., p. 3798BAUDELEY : THEORETICAL ORGANIC CHEMISTRY. 155ation of 8-hydrogen atoms in these quaternary ammonium hydroxides (seep. 170).The transition states of base-catalysed eliminations may be representedas a hybrid of structures (7-10) :B-J3-HB-s-l4' (11)There is general agreement that a planar and anti-relation of C(d-H toC(,)-X provides a " concerted " process ; its transition state (21) can bederived from combination of appropriate amounts of (7), (S), and (10).Onthe other hand, there is considerable uncertainty about the amount of (9)to be introduced when (a) the ad-relation cannot be attained, ( b ) neigh-bouring substituents augment the acid strength of the @-hydrogen atom,and (c) a less basic is replaced by a more basic reagent, e.g., of the seriesBu- > Ph- > Me- > Ph-CH,- > Ph,C- > NH,- > OAlkyl- > OH-.6trans-Dehydrochlorination of menthyl chloride (12) is compelled to gothrough the form (13) which, having axially bound cis-1 : 3-substituents, isvery strained.Reaction is comparatively slow but, as shown by the ex-clusive formation of menth-2-ene, follows this course none the less,'H Pri(12) (13)The base-catalysed dehydrochlorination of 8-hexachlorocyclohexane, inwhich all vicinal pairs of hydrogen and chlorine atoms are cis, is a moredifficult reaction. The Arrhenius energy of activation is ca. 12 kcal./molemore than for the other isomers and it is suggested 8 that the additionalenergy is employed in part to force the relevant portions of the moleculemore nearly into the desirable trans-conformation and in part to force themechanism against the still imperfect orientation of the bonds involved." Forcing the mechanism " may involve inclusion of resonance structure (9)in the transition state of the elimination, but there is little justification(<1% of hydrogen exchange) for the extreme view that the rate-determiningstep involves removal only of a proton and that a carbanion intermediateis formed which inverts before decomposition to olefin and chloride ion canO C C U ~ .~In the base-catalysed dehydrobromination of the cis- and tram-isomersG. Wittig, Angew. Chem., 1964, 66, 10.E. D. Hughes, C. K. Ingold, and J . B. Rose, J . , 1963, 3830. * E. D. Hughes, C. K. Ingold, and K. Pasternak, ibid., p. 3832.H. D. Orloff and A . J . Kolka, J. Amer. Chcnz. SOC., 1954, 76, 5484; S .J . Crisioi,ibid., 1947, 69, 338; S. J. Cristol and D. D. Fix, ibid., 1953, 75, 2647156 ORGANIC CHEMISTRY.of p-bromostyrene and its $-nitro-derivative, the increase in rate effected bythe presence of the nitro-group is significantly greater in the elimination ofcis- than of trans-elements. The data support the view lo that the transitionstate of cis-elimination resembles the carbanionic structure analogous to (9)more closely than does that of the concerted process of trans-elimination,and that the nitro-group, by dispersing the charge of the carbanion, exerts agreater stabilising effect in the former transition state (14) (10 kcal./mole)than in the latter (15) (4 kcal./mole).s-Ar\s-- /H ..Brs - *'\,(y A; _. . -H.e**c\Br Ho---H.*' \H(14) (15)Formation of only the +unsaturated sulphone in the base-catalysedelimination reaction of cis- and trans-2-tolyl-~-sulphonylcycZohexyl toluene-$-sulphonate and the corresponding cis- and trans-compounds in the cyclo-pentane series is offered l1 as an indication that the structure of the transitionstate and the direction of elimination are determined by the difference in acidstrength of the hydrogen atoms on the p-carbon atoms.The conformational requirement of Hofmann decompositions seems to beeffective in preventing vinylogous Hofmann decomposition of 2 : Z-dimethyl-isoindoliniuin cation (16) in the presence of phenyl-lithium.Reactionaffords 2-methylisoindole (19) and methane l2 and probably takes the courseindicated. l3 The reaction brings to mind the paraffinic decomposition ofphosphonium salts : R,P+OH- RH + R,P0.14 The structure (17),in which the delocalised electrons afforded by removal of a proton from (16)are oriented " axially," is conformationally suitable for the formation of (18)and hence of (19), but not for that of (20).Ring opening corresponding to(17 ----P 20) occurs in 2 : 2-dimethyl-4 : 5-benzoisoindolinium bromide, and/ H\&*e,\Jl,NMe or I\ \ck (A,NM% - I ) CHCI-I, CH Li+ CH /v \ + /\/ \ + /\/ \ +CIS, CH2 LA /NMe2 - CH2(16) (17) + LiMe (18) + LiHI1 I v Ithe action of phenyl-lithium on the product affords the base (21) in 47%yield. Ring opening in this instance is apparently related to the stabilityof the 1 : 2-naphthaquinone system for it does not occur in 2 : 2-dimethyl-5 : 6-benzoisoindolinium bromide.13lo S.J. Cristol and W. P. Norris, J . Amer. Chem. SOC., 1954, 76, 3005.J. Weinstock, R. G. Pearson, and F. G. Bordwell, ibid., p. 4748.l2 G. Wittig, H. Tenhaeff, W. Schoch, and G. Koenig, Annalen, 1951, 572, 8 .l3 G. Wittig and H. Ludwig, ibid., 1954, 589, 55.14 Cf. E. Rothstein, J., 1953, 3991BADDELEY : THEORETICAL ORGANIC CHEMISTRY. 157When one of the methyl groups of the ion (16) is replaced by a benzylgroup the intermediate corresponding to (17) rearranges as in the Sommeletor, at higher temperatures, as in the Stevens isomerisation ; .i.e., the productis (22 ; R = o-tolyl or benzyl).15 Similarly, the trimethyl-l-phenylethyl-ammonium cation (23) affords 2-ethylbenzyldimethylamine together withsome styrene polymer, the product of p-elimination.16 The mechanism ofthese rearrangements resembles that of the isomerisation of azoxybenzene(24 --P 25).17CHMe CHMeThe action of magnesium on Z-alkoxymethyl- or 2-aryloxymethyl-benzylchlorides, whereby o-xylylene l8 is obtained, is vinologously related to trans-elimination and must be expected to occur while the ether group is not inthe plane of the benzene ring.The reaction of o-methoxymethylaniline withphenylmagnesium bromide is similarly interpreted : elimination of mag-nesium bromide methoxide from the Grignard derivative of the amine affordsan imine which, with phenylmagnesium bromide, gives o-benzylaniline. l9Pyrolysis of the " threo "- and I ' erythro "-racemates of the amine oxides(26 and 27) affords a mixture of the three olefins (28-30) in the amountstabulated.These results make it clear that this reaction belongs to thefamily of pyrolytic reactions which assume a predominantly cis-course.21These reactions, like trans-eliminations, are subject to steric hindrance :decomposition of the threo "-amine oxide is readier and more stereospecificthan that of the " erythro "-isomer; the difference can be correlated withthe fact that steric repulsions associated with eclipsing of phenyl by methylare greater than those associated with eclipsing of methyl by methyl. Sincethe decomposition of amine oxide affords more conjugated olefin than doesthe corresponding Tschugaeff reaction, the olefinic linkage which is formedseems to be more fully developed in the transition state of the former reactionthan in that of the latter.The ready cis-elimination of the elements of methyl alcohol by inter-action of methyl trans-2-phenylcyclohexyl ether and butyl-lithium is evidencefor a cyclic mechanism involving a complex in which lithium is attached tooxygen atom of the methoxyl group.238 ORGAISIC CHEMISTRY.yielded on treatment with base a phenol [isolated as its methyl ether acetate(93)] and formaldehyde.For further discussion see ref. 143.Trimethy1steroids.-The past year has seen rigid proof by synthesis 144, 145that the lanosterol group of tetracyclic triterpenoids are steroids with threeadditional methyl groups (two at position 4 and one at position 14).Ittherefore seems appropriate to include these C,, (and related C31) compoundsin the steroid section of the Report.The total synthesis of lanost-7-en-3p-01 was achieved jointly by theschools of Woodward and Barton. Lanostan-3p-01 (94) was converted into14-1nethylcholestan-3~-01 (95) 146 by known methods for indirect removalof the gem-dimethyl group.147 The same compound (95) was subsequentlyobtained from cholesterol (96) as follows : 144 15-Oxocholest-8( 14)-en-3p-o1(97) (as benzoate) was methylated with a large excess of methyl iodide andpotassium tert . -bu t oxide in tert.-bu t anol, to give 14-methyl- 15-oxocholest -7-en-3p-01 (98). The 15-oxo-group was removed by Wolff-Kishner reductionin special conditions, to give (99).Removal of the 7 : 8-double bond in thiswas achieved by a four-stage process [-+ 7 : 9(11)-diene ---t 8-ene-7 : 11-dione + saturated 7 : ll-dioneIn the total synthesis,145 cholest-4-en-3-one (100) or its A5-isomer wasmethylated (methyl iodide and potassium tert.-butoxide) to give 4 : 4-di-methylcholest-5-en-3-one, which on reduction with lithium aluminiumhydride yielded 4 : 4-dimethylcholestero1 (101). Transformation of this viathe 5 : 7-diene and the 7 : 14-diene into the 8(14)-en-15-one (102) followed theroutes previously used in the cholesterol and ergosterol series. Methylationat position 14 and removal of the 15-oxo-group gave lanost-7-en-3p-01 (103).Two groups of workers have independently proved the constitution ofcycloart enol as 9 : 19-cycZolanost-24(2 8) -en-3 8-01.Polyporenic acid A [3a : 12a-dihydroxyeburico-8 : 24(28)-dien-26-oic acid] *has been converted into a derivative of lanosterol.14* Polyporenic acid B isa mixture of 3p : 16a-dihydroxyeburico-8 : 24(28)-dien-21-oic acid and thecorresponding 7 : 9(11) : 24(28)-t1-iene.l~~ Polyporenic acid C [16-hydroxy-saturated deoxo-compound (95)].143 I.I<. Florey and hL. Ehrenstein, J . Org. Chmz., 1954, 19, lli4; C. Djerassi andR, Ehrlich, ibid., p. 1351.144 D. H. R. Barton, D. A. J . Ives, R. B. Kelly, R. B. Woodward, and A. A. Yatchett,Chenz. and Iizd., 1954, 605.145 R. B. Woodward, A. A. Patchett, D. H. R. Barton, D. A. J. Ives, and R. B. Kelly,J . Amer. Chenz. SOC., 1954, 76, 2852.146 D. H. R. Barton, D.A. J. Ives, and B. R. Thomas, J . , 1054, 903.147 W. Voser, M. Montavon, H. H. Giinthard, 0. Jeger, and L. Ruzicka, Helv. Chim.Acta, 1950, 33, 1893; W. Voser, D. E. White, H. Heusser, 0. Jeger, and L. Ruzicka, ibid.,1962, 35, 830.149 J. M. Guider, T. G. Halsall, R. Hodges, and E. K. H. Jones, J . , 1054, 3234.* Eburicane is 24-methyl-lanostane.14* T. G. Halsall and R. Hodges, J . , 1954, 2385KLYNE : STEROIDS. 2393-oxoeburico-7 : 9(11) : 24(28)-trien-Zl-oic acid] is a 16~-hydroxy-coni-pound,150 and the configuration at C(,,,) is the same as that in eburicoic acidand therefore (most probably) in lanoster01.l~~ Interesting stereochemicalstudies on the related 21+16-lactones have been made.150R RR REuphol (euphadienol) has been shown independently by two schools l % l 5 3to be a stereoisomer of lanostadienol, differing from the latter in configurationat positions 13,14, and 17 (formula 104 with a doublebond a t positions 2 6 2 5 ) .Euphenol acetate (104) on treatment with mineral acid is transformed intoan isomer isoeuphenol acetate (105).The double bond of the latter is notat position 7 : 8 (as in the lanosterol series). The proof that this doublebond is in ring D, and the suggestion that its wandering involves two 1 : 2-methyl shifts in a concerted reaction have given the essential clues to thestructure and stereochemistry of euphol. Key compounds are the 1 : 5-diketone (106), obtained by cleavage of the double bond, and the a@-unsatur-ated ketone (107) which on further oxidation yields the tricyclic keto-acid(108) and (-)-2 : 6-dimethylheptanoic acid (109) ; the last-named compoundproves the stereochemistry at position 20.The different behaviours oflanostenol and euphenol must be ascribed to stereochemical causes. Ifeuphenol is epimeric with lanostenol at all the three centres 13, 14, and 17,its isomerisation to isoeuphenol may be represented as in (110).150 A. Bowers, T. G. Halsall, and G. C. Sayer, J , , 1954, 3070.151 J. S. E. Holker, A. D. G. Powell, A. Robertson, J. J. H. Simes, R. S. Wright, andR. M. Gascoigne, J., 1953, 2422.1 5 2 D. H. R. Barton, J . F. McGhie, M. K. Pradhan, and S. A. Knight, Chew. and Id.,1954, 1325; J., 1955, 876.153 D. Arigoni, R. Viterbo, M. Dunnenberger, 0. Jeger, and L. Ruzicka, Helv.Clzinz.A d a , 1954, 37, 2306; cf. K. Christen, M. Dunnenberger, C. B. Roth, H. Heusser, and0. Jeger, ibid., 1952, 35, 1756240 ORGANIC CHEMISTRY.Another group of trimethylsteroids which have been related to oneanother includes elemadienolic acid, tirucalladienol, and euphorbadienol.RIH+ +H dThese have been named as derivatives of elemane * (111). Workrecently reported indicates that elemane is 13% : 149 : 17% : 20-isolanostane 155(cf. ref. 153, footnote on p. 2315).156 The 2 : 6-dimethyheptanoic esterobtained by degradation is the (+)-form [enantiomer of (log)].XHV (111)W. K.8. HETEROCYCLIC COMPOUNDS.Small Rings.-Bromination of 1 : l-dimethylallyl alcohol (2-methylbut-3-en-2-01) in alkaline solution affords 1-bromo-2 : 3-epoxy-3-methylbutane, whileunder the same conditions ally1 alcohol affords no epoxide: the effect ofthe methyl groups in facilitating cyclisation may be electronic or steric.2154 D.Arigoni, H. Wyler, and 0. Jeger, Helv. Chim. A d a , 1954, 37, 15.53.155 D. Arigoni, 0. Jeger, and L. Ruzicka, ibid., 1955, 38, 222.156 J. 33. Barbour, W. A. Lourens, F. L. Warren, and K. H. Watling, Chem. and I n d .1955, 226.1 S. Winstein and L. Goodman, J . Anzer. Cheiqt. SOC., 1954, 70, 4368, 4373.2 Ann. Reports, 1922, 19, 114. * This name is open to the objection that it has already been used for a sesquiterpene(F. W. Semmler and Futung Liao, Ber., 1916, 49, 704; H. Jansch and P. Fantl, Bey.,1923, 56, 1363)EDWARD : HETEROCYCLIC COMPOUNDS. 241The trans-formula (1) is assigned to the a-form of the o-nitrobenzylidene-acetophenone oxide on the basis of ultraviolet absorption and chemicalreactions ; this necessitates, contrary to the general rule, a cis-configurationfor the thermodynamically more stable @-form produced by isomerisation byalkali.The a- and the p-form of the halogenodiphenacyls, prepared byalkaline self-condensation of phenacyl chloride or bromide, are representedas (2) and (3) respectively (X = C1 or Br), in line with their stereospecificconversions into a variety of heterocyclic compounds; 5a here too the P-com-pounds (3) are the more stable.5*Substituted trimethylene oxides have been made by ultraviolet irradi-ation of mixtures of aldehydes and olefins and by the action of alkali on3-chloroalkanols.7 3-Hydroxypropyl derivatives are furnished by the re-action of trimethylene oxide with alcohols and phenols,8 with amines andaminomagnesium derivative^,^ and with benzene and mesitylene underFriedel-Crafts conditions.lo The alftaline hydrolysis of mono- and di-acetylderivatives of 2-mercaptoalkanols gives alkylene sulphides in 25-90%yield. l1 Lithium alkyls and aryls remove the sulphur from thiacyclopropaneto yield lithium derivatives of thiols and ethylene. Thiacyclopentane givesno reaction, and thiacyclobutane gives a mixture of products which can beformulated as coming from the initial substance RS*[CH,],*Li.12A new syntheticroute, especially suited to give 3-substituted pyrroles (e.g., 5), proceeds viathe 1 : 2-thiazine derivative (4) obtained from the reaction of a suitable dieneFive-membered Ring Systems.-Pyrrcle derivativas.(4) ( 5 ) (6)with a thionylamine, OS:NR.13 tert.-Butyl acetoacetate is advantageouslyused in the Knorr synthesis of various substituted pyrroles, the tert.-butylgroup being subsequently selectively removed as isobutylene by the action3 S.Bodforss, Ber., 1918, 51, 192.4 N. H. Cromwell and R. A. Setterquist, J . Amer. Chenz. Soc., 1954, 76, 5752;cf. Ann. Reports, 1951,48,140, for a discussion of the isomerism of the analogous ethylene-imines.5 ( a ) H. H. Wasserman and J. B. Brous, J . Org. Chem., 1954, 19, 515; J . Anter.Chent. Soc., 1954, 76, 5811; C. L. Stevens, R. J. Church, and V. J. Traynelis, J . Org.Chem., 1964, 19, 522; C.L. Stevens and V. J . Traynelis, ibid., p. 533. ( b ) J. A. Berson,J . Amer. Chem. Soc., 1952, 7 4 , 5175.6 G. Buchi, C. G. Inman, and E. S. Lipinsky, ibid., 1054, 76, 4327; cf. E. Paternoand G. Chieffi, Gazzetta, 1909, 39, 341.7 N. G. Gaylord, J . H. Crowdle, W. A. Himmler, and H. J. Pepe, J . Amer. Chem.SOC., 1954, 70, 59. S. Searles and C. F. Butler, ibicl., p. 56.9 S. Searles and V. P. Gregory, ibid., p. 2789. lo S. Searles, ibid., p. 2313.1 1 J. S. Harding and L. N. Owen, J., 1954, 1528; cf. Ann. Reports, 1952, 49, 203.12 E’. G. Bordwell, H. M. Anderson, and B.M. Pitt, J . Awzer. Chem. SOC., 1954, 76, 1082.13 0. Wichterle and J. Rdek, Coll. Czech. Chem. Comm., 1954, 19, 282; J. RoEek,ibid., p. 275242 ORGANIC CHEMISTRY.of a trace of acid under conditions which leave other ester groups unaffected.l42 : 3 : 4 : 5-Tetramethylpyrrole gives positive Ehrlich and diazo-couplingreactions, although these are generally considered diagnostic of a free 01- or@-position.l5 Infrared measurements on various 2-aminopyrroles show thatthey do not exist as 2-iminopyrrolines, l6 although 2- and 3-hydroxypyrrolesexist as the oxopyrroline forms; l 7 these differences are to be expected ontheoretical grounds.ls The action of dimethylformamide and phosphorusoxychloride, widely used for introducing the formyl group into the yyrrolenucleus, 1 9 9 2oy 21 involves the prior formation of the mesomeric ammoniumion (6) which decomposes readily in water to the formyl derivative.lgFormyl 21 and other acyl pyrroles 22 can be reduced to hydroxyalkylpyrroleswith sodium borohydride, or with lithium aluminium hydride if the hydrideis added to the pyrrole during the reaction and not vice versa (cf. ref.23).Vinylene homologues (7) of pyrrole aldehydes, inaccessible by aldol-typecondensations, have been made by the reaction shown.=Succinonitrile reacts with ammonia to give succinimidine (8), in which theimino-groups can be replaced stepwise by oxo-, hydroxyimino-, or phenyl-imino-groups to give a variety of corn pound^.^^ Light-absorption measure-ments exclude an alternative formulation (9a) for succinimidine, whichaccords with current views on the superior stability of exo- over endo-cyclicdouble bonds in five-membered rings; 26 however, a third possibility (9b) isnot yet excluded.cycZoHexanone in the presence of sodamide undergoes aStobbe-like condensation with succinonitrile, affording the iminopyrrolidones(10) and (11).25a1 4 A. Treibs and K. Hinternieier, Clzem. B e y . , 1954, 87, 1167.15 A. Treibs and H. Derra-Scherer, Annulen, 1954, 589, 196.l 6 C. A. Grob and H. Utzinger, Helv. Chim. A d a , 1954, 37, 1256.l7 Awn.. Repovts, 1953, 50, 234.l8 S. J. Angyal and C. L. Angyal, J . , 1952, 1461. lo G. F. Smith, J., 1954, 3842.2o E. J.-H. Chu and T. C. Chu, J . Org. Chem., 1954, 18, 266.21 K. M. Silverstein, E. E. Ryskiewicz, and S. W. Chaikin, .I. A w e r . Chew. Soc.,22 W. Herz and C. F. Courtney, ibid., p . 576.24 &I. Strell and F. Kreis, Clzem. Ber., 1954, 87, 1011.2 5 J , A.Elvidge and R. P. Linstead, J., 1954, 442.2- P. E. Fanta and S. Smith, J . Amer. Chenz. SOC., 1954, 76, 2916.g 6 H. C. Brown, J . H. Brewster, and H. Schechter, ibid., p. 467.1954, 76, 4485 ; E. E. Ryskiewicz and R. M. Silverstein, ibid., p. 5802.23 Ann. Reports, 1952, 49, 206EDWARD HETEROCYCLIC COMI’OUKDS. 2434-Hydroxy-A3-pyrroline-2-carboxylic acid has been suggested as a pre-cursor of the pyrrole-2-carboxylic acid, isolated after the alkaline hydrolysisof various mucoproteins, and its possible function in the linkage of proteinand polysaccharide moieties has been disc~ssed.~’The ring of tetrahydro-l-furylalkanols such as (12) isopened by alkali-fusion, to afford ma’-dicarboxylic acids (e.g., 13).28 Avariety of furans has been isolated from sweet potatoes infected with Cerato-stomella Jimbriata Elliott, including furan-3-carboxylic acid, batatic acid(14),29 ipomeanine (15),30 and ipomeamarone (16) ; 319 32 the compounds (14)and (16) are isoprenoid.Ngaione, from Eremophila Eatrobei, is a diastereo-isomer of ipomeamarone.32Furan derivatives.l(--CO*[CH,] ,.XC --(;-JMe‘O/ (15) Boi! CH2CO-CH,*CHMe2(16)Thiophen derivatives. Thiophen I : l-dioxide 33 exists in solution largelyas the monomer, as shown by its bromination to 1 : 2-dibromo-1 : 2-dihydro-thiophen dioxide ; its reactions with dienes and dienophiles have beenstudied.34 The base-catalysed reaction of methyl mercaptoacetate withmethyl fumarate furnishes 4 : 5-dimethoxycarbonyl-3-oxothiophan ; withmethyl acetylenedicarboxylate it furnishes 3-hydroxy-2 : 5-dimethoxy-~arbonylthiophen.~~ The alkaline hydrolysis of partly or fully acetylated3 : 4-dimercaptobutanol affords 3-mercaptothiophan ; 36 the dithiol groupingis necessary for ring formation, as shown by the failure of the acetates of4-mercaptobutanol to ~yclise.~’ The 3 : 5-dimethyl derivative (17) ofof thiopheno(2’ : 3’-3 : 4)thiophen, a new thiophthen, has been made by theroute shown.38Me Me Me /” (1) C1-SO,H=_ S / \ ~ ~ (1) BraCH2-CH(Oble), s/\,/ \S - \/ (2) Zn-H+ \/ (‘4 HF \/\/ Me Me Me(17)Miscellaneous.Nitropyrazolines of the general structure (18), preparedby reaction of nitro-olefins with diazoalkanes, undergo a double Wagner shift2 7 A. Gottschalk, Nature, 1954, 174, 652; cf. ibid., 1953, 172, 808; N.I-Iiyama,* 8 F. Runge, R. Hueter, and H.-D. Wulf, Chem. Ber., 1954, 87, 1430.29 T. Kubota and I<. Naya, Cherit. and Ind., 1954, 1427.30 T. Kubota and N. Ichikawa, ibid., p. 902.32 A. J. Birch, R. A. Massy-Westropp, S. E. Wright, T. Kubota, T. Matsuura, and34 W. J . Bailey and E. W. Cummins, J. .4mer. Chem. Soc., 1954, 76, 1932, 1936, 1940 ;3 5 H. Fiesselmann and P. Schipprak, Cltem. Ber., 1954, 87, 835.36 L. W. C. Miles and L. N. Owen, ,/., 1952, 817.37 J . S. Harding and L. N. Owen, J , , 1954, 1536.3 8 0. Dann and W. Dimmling, Chem. Bey., 1954, 87, 373.7’ohoku J . exp. Med., 1948, 51, 317.31 Ann. Beports, 1952, 49, 530.M. D. Sutherland, Chem. and Ind., 1954, 902.cf. W. Davies and F. C. James, ,I., 1954, 15.33 Ann Reports, 1953, 50, 236244 ORGANIC CHEMISTRY.when treated with acid or base and afford 3 : 4 : 5-trisubstituted pyrazoles(19).39RHC-CH.NO2 -HNO, R / R I f - Rfdl 11‘NC (19)R’R’’C N(18) \Iq/A theoretical investigation by the molecular-orbital approximation showsthat nitration, bromination, and sulphonation of glyoxaline, which occur inacidic media and give 4-substitution, involve the free glyoxaline molecule orits cation ; diazonium coupling and probably iodination, which occur inalkaline solution and give 2-substitution, involve the glyoxaline anion.40The chemistry of dihydro- and tetrahydro-glyoxaIines has been re~iewed.4~Diazomethane reacts with some benzylideneanilines to give 1 : 5-diaryl-1 : 2 : 3-tria~olines.~~ The structures of the products from the methylationof 1 : 2 : 4-triazoles and 5-aminotetrazoles 43b have been studied, the latteraffording l-alkyl-5-imino-4-methyltetrazoles and the mesoionic l-alkyl-5-imino-3-methyltetrazoles (20).NHSeveral syntheses of a-lipoic acid (6-thioctic acid) 44 have been reported.It has been suggested that the primary chemical change in photosynthesis isthe homolytic fission of the disulphide linkage in lipoic acid, brought aboutby energy transferred from c h l ~ r o p h y l l .~ ~ 1 : 2-Dithiolan (trimethylenedisulphide) has been studied as a model ; 46 this compound is highly unstable,with a strong tendency to form a linear polymer, and has been isolated onlyin solution ; the ring strain, made evident by the shift in absorption maximumto 3300 from the 2500 A usual for straight-chain aliphatic disulphides, leadsto ready photolysis, which from chemical and spectroscopic evidence takesthe course (21) + (22) __p (23).The manner in which a mercapto-sulphenic acid such as (23) might initiate the various photosynthetic processesis discussed.5-Amino-l-thia-2 : 4-diazoles (24), prepared by the reaction of N-bromo-amidines and potassium thi~cyanate,~’ yield with methyl iodide the imino-thiadiazolines (25), the imino-structure of which is shown by a different39 W. E. Parham and W. R. Hasek, J . Awzev. Chenz. SOC., 1954, 76, 7!N.4 0 I. M. Basset and R. D. Brown, J . , 1954, 2701.4 1 R. J . Ferm and J. L. Riebsomer, Chenz. Rev., 1954, 54, 593.42 G. D. Buckley, J . , 1954, 1850; cf.A. Mustafa, J . , 1949, 234.43 ( a ) M. R. Atkinson and J. B. Polya, J . , 1954, 141, 3319; Chem. alzd Ind., 1954,462; G. F. Duffin, J. D. Kendall, and H. R. J. Waddington, ibid., p. 1458. ( b ) R. A.Henry, W. G. Finnegan, and E. Lieber, .I. Amel.. C h e w Soc., 1954, 76, %894.4 4 Ann. Reports, 1953, 50, 238; M. ?V. Bullock, J. A. Brockmsn, E. L. Patterson,J. V. Pierce, M. H. von Saltza, F. Sanders, and E. L. R. Stokstad, J . Awzer. C h n t . Sor.,1954, 76, 1828; Q. F. Soper, W. E. Buting, J . E. Cochran, and A. Pohland, ibid., p.4109; E. IValton, A. I?. Wagnei-, L. H. Peterson, F. W. Holley, and K. Folkers, ibid.,p. 4748. 4 5 M. Calvin and J. A. Barltrop, ibid., 1952, 74, 6153.4 6 J . A. Barltrop, P. M. Hayes, and M. Calvin, ibid., 1954, 76, 4348.47 J.Goerdeler, Chem. B e y . , 1954, 87, 57EDWARD HETEROCYCLIC COMPOUNDS. 245ultraviolet absorption ; 48 this serves to eliminate a possible imino-formul-ation for (24).RC-N RC- NhleII II I/ I(24) yS/CNH2 (25 1Six-membered Ring Systerns.-Ppidine. Commercial 2 : 6-lutidine isreadily purified by addition of boron trifluoride and distillation. The borontrifluoride forms complexes with most pyridines but, for steric reasons, notwith 2 : 6-disubstituted p y r i d i n e ~ . ~ ~ In the O-benzoylation of ethyl benzoyl-acetate (26) to ethyl p-benzoyloxycinnamate (28) by benzoyl chloride inpyridine, it is suggested that the substituted 1 : 2-dihydropyridine (27) isinvolved as an intermediate so that in fact the primary reaction gives C-/\ CHC0,Etrather than O-substitution.” The N-oxides of 2- and 4-picoline condensewith ethyl oxalate, showing the enhancement of the reactivity of the methylgroups by oxide f ~ r m a t i o n , ~ ~ and rearrange in hot acetic anhydride to theacetates of 2- and 4-hydroxymethylpyridine.52 The Willgerodt reaction hasbeen applied to 2- and 4-alkylpyridines. 53 The leaf-wilting toxin isolatedfrom the culture fluid of Fusarium Zycopersici Sacc. has been identified as5-butylpicolinic acid. 64 Many enzymic reactions for which pyridoxal is thecoenzyme can be duplicated by pyridoxal alone in the presence of the ionof a suitable metal ; the mechanism of these reactions and the importance ofthe specific structure of pyridoxal have been discussed.55Pyridaxines ; pyrimidin.es.The synthesis of pyridazines (e.g., 29) viathe reaction of dienes with azodicarboxylic esters has been further ex-p10red.~~~ 57 The double bond of the tetrahydropyridazine (29) migratesduring alkaline hydrolysis so that the tetrahydropyridazine (30) is formed ;Ph Ph Ph Ph(30) (29) (31) (32)similarly the double bonds migrate in the hydrolysis and subsequent de-carboxylation of (31) to (32).66 New syntheses have been described in4 ~ 3 J . Goerdeler, A. Huppertz, and K. Wember, Chem. Bey., 1954, 87, 68.4 9 H. C. Brown, S. Johnson, and H. Podall, J . Amer. Clzem. SOC., 1954, 76, 5556.6o W. R. Gilkerson, W. J. Argersinger, and W. E. McEwen, ibid., p. 41 ; cf. W. von E.Doering and W. E. McEwen, ibid., 1951, 73, 2104.51 R.Adams and S. Miysno. ibid., p. 3168.53 V. Boekelheide and W. J. Linn, ibid., p. 1286.54 P. A. Plattner, W. Keller, and A. Boller, Helv. Clzim. Acta, 1954, 37, 1379.55 D. E. Metzler, M. Ikawa, and E. E. Snell, J . Amer. Chem. SOG., 1954, 76, 648.56 K. Alder and H. Niklas, Annulen, 1954, 585, 81.5 7 J. Levisalles and P. Baranger, Compt. rend., 1954, 238, 692.c3 H. D. Porter, ibid., p. 127246 ORGANIC CHEMISTRY.which 6-pyridazinones are formed by condensation of hydrazine, an a-di-carbonyl compound, and an ester having an active a-methylenicSeveral convenient syntheses of pyrimidines utilise the reaction of diketenwith thioureas or arnidine~.~~The “ dimer ” of hydrogen cyanide 60 is in fact the long-sought 1 : 3 : 5-triazine. It is easily hydrolysed.61 X-Ray diffractionstudies show that 1 : 4-dithiacyclohexadiene (33), related to cyclooctatetraeneas thiophen is to benzene, exists in boat rather than a planar form.62 Thisaccords with the failure of the system to show aromatic properties.At-tempted formylation of the dithian (34) leads to the extrusion of an atom ofsulphur and formation of the thiophen (35).63 Reaction of N-bromobenz-Miscellaneozts.amidine with sodium ethyl sulphide affords a compound formulated ashaving the new ring system (36) [an alternative mesoionic formulation(37) is possible]. It yields on acid hydrolysis a variety of products, includingethanesulphinic acid and N-benzoylbenzamidine.Skat oleand 3-benzylindole rearrange to the 2-substituted compounds in an alu-minium chloride-sodium chloride melt .65 The reaction of indole with nitro-ethylene affords 3-2’-nitroethylindole.66 N- (3-Indolylmethyl) -N-met hyl-aniline is obtained from the reaction of gramine methosulphate with methyl-aniline in alkaline solution ; in acetic acid this changes to $-(3-indolylmethyl)-N-methylaniline. This Hofmann-Martius type of rearrangement is anintermolecular reaction, as shown by the fact that N-(3-indolylmethyl)-N-methylaniline reacts with excess of dimethylaniline under these conditionsSimple Condensed Ring Systems-Indole and related compounds.to give 9- (3-indolylmethyl) -NN-dimethylaniline. The structures (38) and(39; R = 3-indolyl) are advanced for the dimer and the trimer produced bythe action of acid on indole; the presence of a primary amino-group in thetrimer has been shown.6scycZoHexanone 2-chloro-5-methylphenylhydrazone under conditions of58 P.Schmidt and J. Druey, Helv. Chim. Acta, 1964, 37, 134, 1467.58 R. N. Lacey, J., 1954, 839, 845. 6o J. U. Nef, Annalen, 1895, 287, 366.81 C. Grundmann and A. Kreutzberger, J . Amer. Chem. SOC., 1954, 78, 5646.62 W. E. Parham, H. Wynberg, W. R. Hasek, P. A. Howell, R. hl. Curtis, and6s W. E. Parham and V. J. Traynelis, ibid., p. 4960.64 J. Goerdeler and D. L. Loevenitch, Chem. B e y . , 1954, 87, 1079.6 j G. R. Clemo and J . C. Seaton, J . , 1954, 2582.e 8 W. E. Noland and P. J. Hartman, J . Amer. Chem. SOC., 1964, 78, 3227.6 7 J . Thesing, H. Mayer, and S. Klussendorf, Chem. Bey., 1954, 87, 901 : J.Thesing88 G. F. Smith, Chem. and Ind., 1954, 1451.W. N. Lipscomb, ibid., p. 4957.and H. Mayer, ibid., p. 1084EIjU'ARD : HETEROCYCLIC COMPOUNDS. 247the Fischer indole synthesis affords, besides the expected 8-chloro-1 : 2 : 3 : 4-tetrahydro-5-methylcarbazole, 1 : 2 : 3 : 4-tetrahydro-6-hydroxy-7-methyl-carbazole; 69 in the latter case ring closure at the position occupied by thechlorine leads to its expulsion and the introduction of a hydroxyl group metaThe action of phenyl-lithium on NN-dibenzylisoindoliniumvariety of products, including N-benzylisoindole (40) ; theisolated, except as its adduct with maleic anhydride (41;to this position.bromide yields alatter cannot beR = CH2Ph).70coQuinoline and isoquinoline. Cyclopenin,7l isolated from the culturefiltrates of Penicillium cycZoPium Westling, affords on acid hydrolysis methyl-amine, carbon dioxide, and viridicatin ; the last compound has been isolatedfrom P.viridicatum Westling 72 and has been shown to have the structure(42).'l The structures (43, 44) which have been suggested for cyclopenin,7lare dihydrohydroxyquinolines ; 73 the structure (45), in which completearomatisation is blocked and for which a plausible biogenesis from phenyl-(42) (43) (44) (45)alanine and hydroxyanthranilic acid can be devised, appears also worthy ofconsideration. l-Vinylisoquinoline has been prepared, and thence, by theMichael addition of ethyl malonate, diethyl 2-l'-isoquinolylethylmalonate.7~The Birch reduction of 1 : 2 : 3 : 4-tetrahydro-6-methoxy-2-methyliso-quinoline yields the ap-unsaturated ketone (46) ; 75 the abnormally lowwave-length of its absorption maximum has been attributed to the electroniceffects of the dipoles associated with the nitrogen atom.76fY\, a/:\/ (46) O b m L e (47)Other Polycyclic Heterocycles containing Nitrogem-The simple dehydro-quinolizinium system (47) has been synthesised 77 for the first time, and con-venient syntheses of its 2-methyl-3-ethyl derivative 78 and of benzo[b]quinol-izinium salts 79 have been described.O9 J.A. Cummins, B. F. Kaye, and M. L. Tomlinson, J., 1954, 1414; cf. K. H.70 G. Wittig and H. Ludwig, Annalen, 1954, 589, 55.71 A. Bracken, A. Pocker, and H. Raistrick, Biockem. J., 1954, 57, 587.72 K. G. Cunningham and G.F. Freeman, ibid., 1953, 53, 328.73 Cf. Ann. Re$orts, 1950, 47, 183, for examples of dihydrodihydroxy-aromatic75 A. Marchant and A. R. Pinder, Chem. and Ind., 1953, 1366; 1954, 1261.7 6 V. Georgian, ibid., p. 930.7 7 V. Boekelheide and W. G. Gall, J . Amer. Chem. SOC., 1954, 76, 1832.7 8 A. R. Richards and T. S. Stevens, Chem. and Ind., 1954, 905.79 C. K. Bradsher and L. E. Beavers, ibid., p. 1394.Pausacker and (Sir) Robert Robinson, J., 1947, 1557.compounds. 74 V. Boekelheide and A. L. Sieg, J . Org. Chem., 1954, 19, 587248 ORGANIC CHEMISTRY.Condensation of 2-aminotropone and ethyl malonate in the presence ofsodium ethoxide affords the ester (48; R = CO,Et), from which 1 : 2-di-hydro-2-oxo-l-aza-azulene (48; R = H) is obtained by hydrolysis and de-carboxylation.m In its ultraviolet absorption this compound resembles2-oxo-l-oxa-azulene (51), differs from the methyl ether of (as), and mustexist chiefly in the form (48) (cf.ref. 18). The oxygen can be removed from(52) (53) (54)the ketone (48 or 49; R = H) to give l-aza-azulene (50) by successivereaction with phosphoryl chloride, replacement of chlorine with hydrazine,and oxidation of the hydrazino-compound with a cupric salt.80 l-Aza-azulene can be brominated, and its 2-dimethylamino-derivative undergoesdiazo-coupling and nitrosation at the 3-position. The reaction of tropolonemethyl ether with thiourea in the presence of sodium ethoxide affords thethiol (52) from which 1 : 3-diaza-azulene (53) is obtained by the action of hotdilute nitric acid.The failure of the diaza-compound (53) to undergo diazo-coupling, nitration, or sulphonation is attributed to the high contribution ofthe hybrid (54).81Oxygen-containing Ring Systems-Evidence accumulates that “ tannins ”and Zeucoanthocyanins are probably identical 82 and are flavan-3 : 4-diols.A flavan-3 : 4-diol (melacacidin) (55; R = H) has been isolated from Acaciamelanoxylon. 83 I t is uncrystallisable but gives a crystalline tetramethylether (55; R = Me) and other crystalline derivatives. A racemate of oneof the diastereoisomers of the ether (55; R = Me) is produced by hydrogen-ation over Raney nickel of the tetramethyl ether (56; R = Me) ; anotherracemate is obtained by the reduction of 3-hydroxy-3’ : 4’ : 7 : S-tetra-met hoxyflavanone with lithium aluminium hydride.85 Melacacidin com-bines the properties of a Zeucoanthocyanidin and a phlobotannin, giving ontreatment with hot hydrochloric acid a red-brown amorphous materialT. Nozoe, S. Seto, S.Matsumara, and T.Terasawa, Chem. and Ind., 1954, 1356,1357.T. Nozoe, T. Mukai, and I . Murata, J . Amer. Chem. Soc., 1964, 76, 3352.82 E. C. Bate-Smith and T. C. Swain, Chem. and Iizd., 1053, 377 ; E. C . Bate-Smith83 F. E. King and W. Bottomley, J., 1954, 1399.84 F. E. King and J. W . Clark-Lewis, Chem. and Ind., 1954, 757.e 5 A, B. Kulkarni and C. G. Joshi, ibid., p. 1456.and N. H. Lerner, Biochem. J . , 1954, 58, 126EDWARD HETEROCYCLIC COMPOUNDS. 219(" phlobaphene ") and 3 : 3' : 4' : 7 : 8-pentahydroxyflavylium chloride.83* 86The chloride has partition characteristics very similar to those of cyanidinchloride, and may have been overlooked in surveys of plant material.Otherflavan-3 : 4-diols, all uncrystallisable but capable of characterisation bychromatographic behaviour,*' have been prepared by reduction of theappropriate flavone 88 or flavan~ne.~' Anthocyanidins such as cyanidin andpelargonidin 873 88 have been prepared by the action of hot hydrochloric acidon such flavan-3 : 4-diols in the presence of air.The addition of aluminium chloride to alcoholic solutions of compoundshaving a hydroxy-group ortho to a carbonyl group, as in the flavanols, leadsto a bathochromic shift of 40-75 mp in the absorption maximum. Anovtho-dihydroxy-grouping in aromatic compounds, as in 3 : 4-dihydroxy-flavone, is shown by a hypsochromic shift in borate sol~tion.~g The basici-ties of flavones in sulphuric acid have been measured by a spectrophotometricmethod, and the effect of substitution in the 2-phenyl ring has been in-ves tigatedThe hydroxyfuranotropolone (58) has been prepared from 8-2-furyl-valeric acid (57).g1 The structures of verbenalin (59; G1 = glucosyl), theglucoside from Verbena o$i~ianZis,~~ and of gentiopicrin (60 ; G1 = glucosyl),the bitter principle of Gentiana ZuteaYg3 have been determined; both areisoprenoid.HOZC-H-0 (58)(57)(59) (60) (61)Purines and Pteridines.-a-Met hyladenine, not previously observed inNature, has been isolated as the crystalline picrate after the hydrolysis of$sezidovitamin BI2d and identified by its X-ray diffraction pattern.94 6-Di-methylaminopurine has been synthesised by several routes and shown to beidentical with the purine moiety of the antibiotic puromycin ; 95 spectroscopicevidence shows the sugar moiety to be joined to the 9-po~ition.~~ A carefulstudy has been made of the ultraviolet absorption of mono- and poly-substituted purines.Absorption bands have been assigned to the various8 6 W. Bottomley, Chem. and Ind., 1954, 516.88 L. Bauer, ,4. J. Birch, and W. E. Hillis, ibid., p. 433.s9 J . B. Harborne, ibid., p. 1142; T. Swain, ibid., p. 1480.90 C. T. Davis and T. A. Geissman, J . Amer. Chcm. SOC., 1954, 76, 3507.91 W. Treibs and W. Heyer, Chem. Ber., 1954, 87, 1197.02 M.Cohn, E. Vis, and P. Karrer, Helv. Chim. A d a , 1954, 37, 790.'JJ 13. W. Dion, D . G. Calkins, and J . J . Pfiffner, J . Amer. Chern. SOC., 1964, 76, 948.95 G. B. Elion, E. Burgi, and G. H. Hitchings, ibid., 1952, 74, 411; B. R. Baker,96 Idem, zbzd., p. 635.T. Swain, ibid., p. 1144.F. Korte, Chenz. Bey., 1954, 87, 512, 769.J. P. Joseph, and R. E. Schaub, J . Org. Chcnz., 1954, 19, 631250 OKGANIC CHEMISTKY.structural elements, and the effect of substitution discussed.Q7 A spectro-scopic study of xanthine (61) and of various substituted xanthines supportsthe keto-formulation shown, and indicates that the acidic centres, in order ofdecreasing strength, are the 3-, 7-, and l - p o s i t i ~ n . ~ ~ The ionisation constantsof 34 purines have been measured and discussed; 99 and the mechanism ofthe oxidation of uric acid has been studied with isotopically labelledinat erial,“ Active methionine ” lol has been synthesised by the reaction of 5-deoxy-5-methylthioadenosine with a-aminoy-bromobutyric acid hydrobromide ina mixture of formic and acetic acid, and its structure thereby confirmed.lo2Purines are in general more stable than pteridines to acid and alkalinehydrolysis.This is attributed to a more even x-electron distribution, withfew centres strongly positive.99 Several methylpteridines have been found,contrary to expectation, to be weaker bases than the parent substance, andare possibly exo-methy’lene tautomers. The introduction of one amino- orone methoxy-group also weakens the basicity ; the results may imply thatpteridine lacks a true aromatic structure.lo3 The yellow pigment from thesepia mutant of Droso@kiZa melanogaster has been shown to be probably (62)or (63) .lo4 Convenient syntheses of xanthopterin lo6 and of various pteridinesand derived heterocycles lo6 have been described.CO-CHMe-OH COCHMe*OH I INuc1eotides.-Adenosine-5’ tetraphosphate has been isolated fromcommercial adenosine-5’ triphosphate.lo7 A one-step synthesis of adenosinediphosphate and triphosphate has been accomplished by treatment of amixture of adenosine monophosphate and 85% phosphoric acid in aqueouspyridine with dicyclohexylcarbodi-imide.Adenosine monophosphate aloneunder similar conditions gave P1P2-diadenosine-5’ pyrophosphate in excellentyield. lo8 Two cytidine derivatives having unidentified residues attached tothe phosphate group of cytidine-5’ phosphate have been found in rapidlykilled cells of Lactobacillus arabinosus.logMedium and Large Rings.-o-Cyanoanilium toluene-P-sulphonate, onbeing heated, affords 6 : 12-diaminophenhomazine (64) and tricycloquin-azoline (66), the latter presumably being formed via (65; R = NH,).l1°9 7 S. F. Mason, J., 1954, 2071.9 8 L. I;. Cavalieri, J. J. Fox, A. Stone, and N. Chang, J . Amer. Chenz. SOC., 1954, 76,9g A. Albert and D. J. Brown, J . , 1954, 2060.100 C. E. Dalgliesh and A. Neuberger, J., 1954, 3407; H. Brandenberger, Helv.lol Ann. Refiorts, 1953, 50, 244.102 J. Baddiley and G. A. Jsmieson, Chem. and Ind., 1954, 375.103 A.Albert, D. J. Brown, and H. C. S. Wood, J., 1954, 3832.104 1%. S. Forrest and H. K. Mitchell, J . Amcr. Chem. Soc., 1954, 76, 5658.106 F. Korte, Chem. Bey., 1954, 87, 1062.lo6 T. S. Osdene and G. M. Timmis, Chem. a d Ind., 1954, 404, 405: D. G. I. FeItonand G. NI. Timmis, J . , 1954, 2881; R. G. W. Spickett and G. M. Timmis, ibid., p. 3887;D. G. I. Felton, T. S. Osdene, and G. M. Timmis, ibid., p. 2895.10’ D. H. Marrian, Biochim. Biophys. Ada, 1954, 13, 278.l o 8 H. G. Khorana, J . Amer. Chem. SOC., 1954, 76, 3517.109 J. Baddiley and A. P. Mathias, J., 1954, 2723.110 I?. C. Cooper and M. W. Partridge, J., 1954, 3429.1119.Chim. Acta, 1954, 37, 641Benzo-lactams of the general formula (67; n = 1, 2, 3, 4, and 5) have beenmade, in most instances by application of the Schmidt orothe Beckmannreaction to the appropriate kktones.lll As the size of the lactam ringincreases, the planar amide group Il2 is progressively forced out of the planeof the benzene ring; this is reflected in a shift of light absorption to shorterwavelengths, a lower reactivity of the aromatic nucleus towards substitutionby bromine, and a greater basicity of the amide linkage.Transannular inter-action of the type previously found in the ten-membered ring of cryptopineRand the nine-membered ring of N-methyl-sec.-$seudostrychnine 113 is foundalso in the nine-membered amino-acyloin (68), shown by measurements ofbasicity and infrared absorption to exist under certain conditions chiefly inthe form (69).l14 The effect seems to be limited to eight-, nine-, and ten-membered rings, as would be expected from considerations of the stabilitiesof the bicyclic compounds formed.For the form (68) the transannular inter-action is decreased by increasing bulk of the R group, which must be axialin (69).l15 The tetra-imine (70) has been made in good yield by the routeshown (Tos = toluene-p-sulphonyl) .SCHWARZ : CARBOHYDRATES. 265previous observations that primary toluene-9-sulphonic esters derived fromaldoses are reduced to deoxy-compounds (route a) while secondary esters aresplit according to route b. However, deoxy-compounds have been isolatedfrom the products obtained when methyl 4 : 6-0-benzylidene-2 : 3-di-0-tosyl-a-D-glucoside (3) 38 or methyl 2-O-tosyl-p-~-arabinoside 37 reacts withlithium aluminium hydride.2 : 3-Anhydro-compounds may be involved asintermediates, although the observation that these give different proportionsof the 2- and the 3-deoxy-compound with lithium aluminium hydride suggeststhat direct reduction of the secondary esters may also occur.The chemistry of 2-deoxy-sugars has been reviewed.39 2-Deoxyriboseand related compounds can be conveniently prepared from metasaccharinicacids obtained by alkaline degradation of appropriate glucose derivative^.^^Corchsularose, a sugar produced by the hydrolysis of a bitter principle fromjute seeds, is believed to be a 2-deo~y-3-0-methylpentose.~~Amino-sugars and Other Nitrogen Compounds.-The reaction of D-fructose with cyclohexylamine and isopropylamine gives 2-amino-aldosederivatives rather than the expected AT-subst itu t ed fruc t osylamines ,42 andD-glucosamine can be obtained in small yield by the action of ammonia onD-fructose.a 6-O-Methyl- and 4 : 6-di-O-methyl-~-glucosamine,~ and 3-0-methyl-, 4-O-methyl-, and 4 : 6-di-O-methyl-~-galactosamine have been~ynthesised.~~ Glucosamine 6-phosphate can be prepared by the directphosp horylation of glucosamine with met aphosphoric acid .46P i ~ r o c i n e , ~ ~ an interesting aminodeoxy-sugar produced by hydrolysis ofthe antibiotic picromycin, has been identified with desosamine 48 (amine A 49),a degradation product of erythromycin. The compound reduces Fehling's Ti::::CHO CHOI---w I1ICH,CH - LH-OH CHOL {;;NMe' 0 1 r x::::~~ CH, I+ i F H 2 CH ICH3ICH,(4) ( 5 )TH CH,solution, gives the iodoform test, and splits off dimethylamine under alkalineconditions.The structure (4) has been established by degradation. Oxid-ation with 1 mol. of periodate gives the amino-pentose (5), which on furtheroxidation with periodate loses dimethylamine and yields crotonaldehyde.38 E. Vis and P. Karrer, Helv. Chim. Acta, 1954, 37, 378.39 W. G. Overend and M. Stacey, Adv. Carbohydrate Chem., 1953, 8, 45.40 G. N. Richards, J., 1964, 3638; J. Kenner and G. N. Richards, ibid., p. 3277;41 M. A. Khalique and M.-D. Ahrned, J . Org. Ckem., 1964, 19, 1623.4 2 J. F. Carson, Amer. Chem. SOC. Meeting, New York, Sept., 1954, Abs. Papers, 1 7 ~ .43 K. Heyns and K.-H. Meinecke, Chem.Bev., 1963, 86, 1463.44 R. W. Jeanloz, J . Amer. Chem. SOL, 1964, 76, 665, 558.4 5 P. J. Stoffyn and R. W. Jeanloz, ibid., pp. 561, 563, 5682.Q6 J. M. Anderson and E. Percival, Chem. and Ind., 1954, 1018.4 7 H. Brockrnann, H.-B. Konig, and R. Oster, Chem. Ber., 1954, 87, 856.4 8 E. H. Flynn, M. V. Sigal, P. F. Wiley, and K. Gerzon, J . Amel.. Chem. Soc., 1954,J. C. Sowden, J . Amer. Chem. SOL, 1954, 76, 3541.76, 3121. 4 0 R. K. Clark, Antibiotics and Chemotherapy, 1953, 3, 663266 ORGANIC CHEMISTRY.The stereochemistry has not yet been elucidated. Hydrolysis of erythro-mycin also gives cladinose, C8H1,0,, a deoxy-sugar whose structure has beenonly partially e~tablished.~~, 50 The total synthesis of puromycin has beenreported.61 The 3-aminoribofuranose portion of this compound was pre-pared from a 3-aminoarabofuranose derivative (6) by inversion at C(,l usinga neighbouring-group reaction well known in cyclohexane chemistry ; 52another example of this ingenious method was given in last year’s Report.34, 53A re-investigation of substituted hydrazones derived from osones sug-gests that the hydrazine residue is attached at C(l).54 Anhydro-compoundsderived from osazones and osotriazoles have also been studied. 55 ACetyl-ation of fructose oxime gives two hexa-acetates, one of which has an open-chain structure.56Ascent and Descent of Sugar Series-New procedures for the preparationof a number of l-W-labelled sugars and aldonic acids from Na14CN havebeen described.57 The reaction of primary toluene-@-sulphonic esters withpotassium cyanide can be used to yield deoxy-aldonic 59 Thus2-deoxy-~-galactonic acid has been obtained from 1 : 3-0-benzylidene-5-0-tosyl-L-arabi tol.58A new method of descent, depending on the oxidation of the diethylmercaptal of an aldose acetate to an unsaturated disulphone (7), which isthen degraded to the lower aldose, was described in last year’s Report.34Further examples of this degradation, which may be regarded as a reverscdCH,*OAc IIICH,(SO,Et), C( S0,Et) ,[CH-OAc]CH,*OAc__jp CHO I K R( 7 ) ( 8 )Knoevenagel reaction, have been described and two new types of disulphonehave been encountered. Oxidation of penta-0-acetyl-keto-D-fructose diethyl50 R. B. Hasbrouck and F. C. Garven, Arztibiotics and Chemotherapy, 1953, 3, 1040.61 B.R. Baker, R. E. Schaub, J. P. Joseph, and J. H. Williams, J . Amer. Chem.Soc., 1955, 77, 12; see also B. R. Baker, R. E. Schaub, and J. H. Williams, ibid., p. 7.52 G. E. McCasland, R. K. Clark, and H. E. Carter, ibid., 1949, 71, 637.6s B. R. Baker and R. E. Schaub, J . Org. Chem., 1954.19, 646.64 G. Henseke and H. Hantschel, Chem. Bey., 1954, 87, 477; G. Henseke and W.5 5 E. Schreier, G. Stohr, and E. Hardegger, Helv. Chim. A d a , 1954, 37, 35, 574.5 6 H. Bredereck, G. Hoschele, and T. Heinkel, Chem. Bey., 1954, 87, 531.5 7 A. C. Neish, Canad. J . Chem., 1954, 32, 334; H. G. Hers, J. Edelman, and V.Ginsburg, J . Amev. Ckem. SOC., 1954, ‘76, 5160; H. L. Frush, and H. S. Isbell, . J . Rcs.Nut.Bur. Stand., 1953, 51, 307; see also idem, Ann. Rev. Biochem., 1953, 22, 111.5 a R. Grewe and H. Pachaly, Chem. Ber.. 1954, 87, 46.69 R. Grewe and G. Rockstroh, ibid., 1953, 86, 536.Liebenow, ibid., p. 1068SCHWARZ : CARBOHYDRATES. 267mercaptal with monoperphthalic acid gave the saturated disulphone (8),which was degraded to D-erythrose bisacetamide (9) with alcoholic ammonia.60The procedure has also been applied to unacetylated mercaptals ; thus,oxidation of D-fructose diethyl mercaptal with perpropionic acid gave D-ery-throse directly.61 D-Threose and D-erythrose can be obtained from D-xyloseand D-arabinose via the corresponding unsaturated disulphones.62” Thedisulphone derived from D-galactose has been reported to have the cyclicstructure (10) .62b Oxidation of D-mannose diethyl mercaptal gives anCHOH.C*OH CH(NHAc),H* *OH ’i @:-:>, CH (S02Et) HC*OH H*C*OHCHO CH,.OHIIIIHH0C.H 11 H 1-1H H(9) ( 10) (11)analogous cyclic compound as well as a saturated acyclic disulphone ; theformer is identical with the disulphone obtained from D-glucose diethylmercaptal.All these disulphones can be degraded to the lower aldose byammonia.G2 xyZoTrihydroxyglutardialdehyde (1 1) is produced when thedisulphone degradation is applied to scylloinosose. 61 The preparation oflower aldoses by oxidation of sugars with a limited quantity of lead tetra-acetate G3 or sodium periodate 64 has also been investigated.Miscellaneous.-A paper reporting the isolation of D( +)-apiose fromPosidonia amtralis contains suggestions regarding the nomenclature ofcertain branched-chain sugars.65The interpretation of infrared spectra of glucopyranose derivatives 66was discussed in last year’s Report.34 Results obtained with other hexo-pyranosides and with pentapyranosides are more c0mplicated,6~ but serve toconfirm the structural assignment of some characteristic frequencies.Deoxy-compounds and furanose derivatives have also been studied.68 Cautionmust be exercised in the interpretation of the spectra of syrups 67 and in theuse of potassium bromide films.69Recent work on the degradation of reducing sugars under alkaline con-ditions shows that the course of the reaction is profoundly influenced by sub-stitution. Thus 3-alkyl ethers and 1 : 3-linked disaccharides derived fromglucose and fructose are much more sensitive than the parent sugars.70ao E.J. Bourne and R. Stephens, J., 1954, 4009.61 D. L. MacDonald and H. 0. L. Fischer, Amer. Chem. SOC. Meeting, New York,63 L. Hough and T. J. Taylor, Chem. and Ind., 1954, (a) 575, ( b ) 1018.63 A. S. Perlin, J , Amer. Chem. SOC., 1954, 76, 2595.64 C. Schopf and H. Wild, Chem. Ber., 1954, 87, 1571.6 5 D. J. Bell, F. A. Isherwood, and N. E. Hardwick, with a note by R. S. Cahn,6 6 S. A. Barker, E. J. Bourne, M. Stacey, and D. H. Whiffen, J., 1954, 171.67 S. A. Barker, E. J. Bourne, R. Stephens, and D. H. Whiffen, J., 1954, 3468.6 8 Idem, J . , 1954, 4211 ; S. A. Barker and R. Stephens, J., 1954, 4550.S. A. Barker, E. J - Bourne, W.B. Neely, and D. H. Whiffen, Chem. and Ind.,‘O ( a ) J. Kenner and G. N. Richards, J., 1954, 278; W. M. Corbett and J. Kenner,Sept.. 1954, Abs. Papers, 9 ~ .J., 1954, 3702.1954, 1418.J., 1054, 3274; ( b ) R. Kuhn, H. H. Baer, and A. Gauhe, Chem. Ber., 1954, 87, 1553268 ORGANIC CHEMISTRY.The group attached at Cb) is eliminated and the remainder of the molecule isconverted into acidic products in which the metasaccharinic acids appear topredominate. ~-Acetyl-3-~-galactosido-~-glucosamine is reported to beeven more sensitive to alkali than the corresponding galactosides of glucoseand fructose.70b 1 : 4-Linked aldoses (lactose and maltose) are degradedmore slowly than the 1 : 3-linked compounds.71 The corresponding ketoses(lactulose and maltulose) are probably involved as intermediates ; thesereadily lose the glycosyl group attached at CQ~, the main acidic productbeing a mixture of isosaccharinic acids.l-0-Methyl-D-fructose yieldsD-glucosaccharinic acid and lactic acid.72 These results are in harmony withthe view that the first step in the formation of the saccharinic acids is theelimination of an anion from a p-alkyloxy- or p-glycosyloxy-carbonyl com-pound. It is evident that degradation by alkali may become a useful tool inthe structural investigation of oligo- and poly-saccharides. 73The chemistry of the methyl ethers of D-mannose has been reviewed.74In a powerful, new methylation te~hnique,7~ the sodio-derivative of apartially methylated product is treated with dimethyl sulphate in ether ;this method makes the preparation of fully methylated glucose and sucrosemuch less tedious.Two independent syntheses of 2 : 4-di-O-methyl-~-rhamnose have been 76 and 2 : 4-di-O-methyl-~-glucose has beenprepared by the methylation and hydrolysis of 6-O-triphenylmethyl-laminarin. 77 Reduction of glycosides of D-glucuronolactone or its derivativeswith lithium aluminium hydride or sodium borohydride provides a con-venient route to glucofuranosides ; methyl a-D-glucofuranoside 78 and its2 : 5-di-O-methyl derivative 79 have been prepared by this method.Experiments using l80-enriched water show that hydrolysis of a- andp-methyl glucopyranosides by acid or enzymes proceeds by fission of theglucosyl-oxygen b0nd.w The hydrolysis of sucrose in the presence of in-vertase is said to involve fructosyl-oxygen fission.810ligosaccharides.-The number of oligosaccharides isolated from partialhydrolysates of polysaccharides, and from enzymic transglycosylationsystems, is rapidly increasing.Methylation studies show that the inulobioseobtained by partial hydrolysis of inulin is l-p-D-fructofuranosyl-D-fructose.82A crystalline 1 : 4-linked galactobiose has been isolated from the acid hydro-lysate of okra mucilage,s3 and 3-f3-~-arabopyranosyl-~-arabinose has beenobtained from several polysaccharides. Partial hydrolysis of lemongum7172757475767 77879801954,818283841953,gave 4-0-(4-O-methyl-&-~-glucuronosyl)-~-arabinose and other oligo-( a ) W.M. Corbett and J. Kenner, J., 1954, 1789; ( b ) idem, J . , 1953, 2245.J. Kenner and G. N. Richards, J., 1954, 1784.Idem, Chem. and Ind., 1954, 1483.G. 0. Aspinall, Adv. Carbohydrate Chem., 1953, 8, 217.H. Bredereck, G. Hagelloch, and E. Hambsch, Chem. Ber., 1954, 87, 35.K. Butler, P. F. Lloyd, and M. Stacey, Chem. and Id., 1954, 107.D. J. Bell and D. J. Manners, J., 1954, 1145.D. D. Phillips, J . Amer. Chem. Sac., 1954, 76, 3598.R. E. Reeves, ibid., p. 934.C. A. Bunton, T. A. Lewis, D. R. Llewellyn, H. Tristram, and C. A. Vernon, Natuve,174, 560.D. E. Koshland and S. S . Stein, J . Biol. Chem., 1964, 208, 139.H. H. Schlubach and A. Scheffler, Annalen, 1954, 588, 192.R. L. Whistler and H. E. Conrad, J . Amer. Chem. SOC., 1954, 76, 1673.J.K. N. Jones, J., 1953, 1672; P. Andrews, D. H. Ball, and J. K. N. Jones, J.,4090SCHWARZ : CARBOHYDRATES. 269saccharide^.^^ Investigations of the di- and tri-galacturonic acids producedby the partial hydrolysis of pectic acid confirm that this substance containspyranose galacturonic acid units. 86 The oligogalacturonic acids can becharacterised as their crystalline brucine salts.No less than six disaccharides have been isolated as crystalline acetatesfrom the mixture of " reversion " products obtained when glucose is heatedwith mineral acid.88 The formation of isomaltose has been studied indetaiLa9 Gentiobiose is among the products formed when glucose is heatedwith a cation-exchange resin.90 Higher oligosaccharides and even poly-saccharides are also produced by the action of acid on monosaccharides underappropriate c0nditions.9~ These results emphasise the importance ofapplying tests for reversion before interpreting the results of partial hydro-lysis of polysaccharides.An excellent review on enzymic transglycosylation reactions appearedrecently,92 and it seems advisable to postpone further discussion until theresults of detailed structural investigations become available.At presentmuch of the work relies on characterisation by chromatographic mobilityalone, and the number of systematic studies 93 using methylation techniquesis still small. Paper-electrophoresis has proved useful in the separation ofthe oligosaccharides produced from sucrose by yeast i n ~ e r t a s e . ~ ~The seaweed glycoside, floridoside, has been shown to be 2-glycerola-D-galactopyranoside 95 and a mannosylfloridoside has recently beenisolated.96 The 3-~-arabitol p-D-galactoside, umbilicin, is reported to havea furanose stru~ture.~' Di- and tri-saccharides obtained from the alkaloidstomatin and solanin have been in~estigated.~~ The revised structure (12)for stachyose is supported by methylation studies 99 and periodate oxid-a-D-Galp 1----6cr-~-Galp l-Ba-~-Gp l---2j?-~-Fruf ( 12)ation.loO A series of oligosaccharides, related to stachyose but containing alarger number of galactose units, has recently been isolated from naturalsources.lo18 5 P. Andrews and J . K. N. Jones, J . , 1954, 1724.86 J. K. N. Jones and W. W. Reid, J., 1954, 1361; H.Altermatt and H. Deuel,8 7 R. M. McCready, E. A. McComb, and D. R. Black, J . Amer. Chem. Soc., 1954,*e A. Thompson, K. Anno, M. L. Wolfrom, and M. Inatome, J . Amer. Chsm. SOL,89 E . E. Bacon and J. S. D. Bacon, Biochem. J., 1954, 58, 396.91 C. R. Ricketts, J., 1964, 4031.98 J. S. D. Bacon, Ann. Reports, 1953, 50, 281; see also R. L. Whistler and D. I.93 D. Gross, P. H. Blanchard, and D. J. Bell, J., 1954, 1727; S. A. Barker, E. J.94 D. Gross, Nature, 1954, 173, 487.8 5 E. W. Putman and W. 2. Hassid, J . Amer. Chem. SOC., 1954, 76, 2221.9 6 B. Lindberg, Actu Chena. Scand., 1954, 8, 869.O 7 B. Lindberg and B. Wickberg, ibid., p. 821.98 R. Kuhn and I . Low, Angew. Chsm., 1954, 66, 639; Chem. Bev., 1953, 86, 1027.O9 R. A. Laidlaw and C. B.Wylam, J., 1953, 567.loo J. E. Courtois, A. Wickstrom, and P. Le Dizet, Bd1. Soc. Chim. biol., 1953,101 H. Herissey, P. Fleury, A. Wickstrom, J. E. Courtois, and P. Le Dizet, Compt.Helv. Chim. Acta, 1954, 3'9, 770.76, 3035.1954, 76, 1309.G. Zemplh and L. Kisfaludy, Acta Chim. Acud. Sci. Hung., 1954, 4, 79.McGilvray, Ann. Rev. Biochem., 1954, 23, 82.Bourne, and T. R. Carrington, J., 1954, 2125.35, 1117.rend., 1954, 239, 824270 ORGANIC CHEMISTRY.The order of the sugar units in a nitrogenous tetrasaccharide from humanmilk has been deduced from a study of the di- and tri-saccharides producedby partial hydrolysis. 7 0 b 9 lo2 This investigation also indicates that theMorgan-Elson p-dimethylaminobenzaldehyde reaction is not infallible as adiagnostic test for reducing N-acetylglucosamine residues.lo3 It appearsthat certain compounds containing this system fail to give the reaction,while some alkali-sensitive N-acetylglucosaminides give positive tests. Theformer class includes ~-acety~-4-~-~-ga~actosido-D-g~ucosamine (“ Z-acet-amidolactose ”). This disaccharide, which can be obtained from severalnatural sources, has recently been synthesised.lM l-Acetamidola~tose,~~~l-acetamidolactulose, lMb and two 1 : 6-linked nitrogenous disaccharides lo6have also been prepared. The method employed in the recent synthesis oflaminaribiose l o 7 has been applied to the preparation of other 1 : 3-linkeddisaccharides. lo8J. C. P. S.11. POLYNUCLEOTIDES.Structural Components.-(a) Carbohydrates.The carbohydrate com-ponent of the purine nucleosides of the deoxyribonucleic acid of Myco-bacterium phlei has been identified as 2-deoxy-~-ribose.l Owing to thestability of pyrimidine nucleosides to hydrolysis, the nature of the carbo-hydrate residues of pyrimidine deoxypentosides has been assumed only byanalogy with the purine nucleosides. However, thymidine has now beensynthesised enzymically from S-deoxy-~-ribose l-phosphate,2 and it hasbeen found possible, after reduction of pyrimidine nucleosides with sodiumand ethanol, to hydrolyse the reduced product without destruction of thesugar. In this way, thymidine and deoxycytidine yielded 2-deoxy-D-r i b ~ s e . ~ A modified colour reaction has been developed which is suitablefor the determination of both purine- and pyrimidine-bound deoxyribose.*The preparation of the sugar from deoxypentose nucleic acids is facilitatedby using an acidic ion-exchange resin,5 and new syntheses of this sugar arealso available.6*Confirmation of the structure of deoxyadenosine hasbeen provided by the formation of a cyclonucleoside salt from 3’-0-acetyl-2’-deoxy-5’-toluene-~-sulphonyladenosine.~ 2’-Deoxy-5’-toluene-~-sulphonyl-(b) Nucleosides.lo* R.Kuhn, A. Gauhe, and H. H. Baer, Chem. Ber., 1954, 87, 289.lo3 I d e m , ibid., p. 1138; see also D. Aminoff, W. T. J. Morgan, and W. M. Watkins,104 R. Kuhn and W. Kirschenlohr, Chem. Ber., 1954, 87, ( a ) 560, ( b ) 1547.Io5 R. Kuhn and G. Kruger, ibid., p. 1544.186 R. Kuhn and W. Kirschenlohr, ibid., p.384.107 P. Bachli and E. G. V. Percival, J . , 1952, 1243.188 R. Kuhn and H. H. Baer, Chem. Bey., 1954, 87, 1560.Biochem. J . , 1952, 51, 379.1 A. S. Jones and S. G. Laland, Acta Chem. Scand., 1954, 8, 603.M. Friedkin and Dew. Roberts, J . Biol. Chem.. 1954, 807, 257.3 D. C. Burke, Chem. and i n d . , 1954, 1393.4 L. A. Manson, Nature, 1954, 174, 967.5 S. G. Laland and W. G. Overend, Acta Chem. Scand., 1954, 8, 192.G. N. Richards, J., 1954, 3638.7 J. C. Sowden, J . Amer. Chem. SOC., 1954, 76, 3541.W. Andersen, D. H. Hayes, A. M. Michelson, and A. R. Todd, J . , 1954, 1888BARKER : POLI’NUC1,EOTIDES. 27 1cytidine also appears to give a cyclonucleoside salt, but this compound is toounstable to allow of its isolation. The formulation of the cations of thesecyclonucleoside salts respectively as (1) and (2) is consistent only with thepresence of p-furanoside structures in the parent nucleosides.that chloromercuri-derivatives are convenient forthe synthesis of pyrimidine nucleosides as well as of purine nucleosides.Thymidine has been isolated by use of the chromatopile,1° and both naturaland synthetic nucleosides have been separated from each other and from thecorresponding bases by ionophoresis in presence of borate.l1It has been reportedOAc(c) Nucleotides. The pairs of isomeric nucleotides first separated byion-exchange chromatography of hydrolysates of ribonucleic acids have nowbeen resolved by paper electrophoresis.12 That they differ in the locationof the phosphoryl residues has been confirmed by the demonstration that theisomeric adenylic, guanylic, and cytidylic acids yield respectively the sameadenosine, guanosine, and cytidine on enzymic dephosphorylation.135 l4 Itfollows also that uridylic acids a and b differ in the position of the phosphorylresidue. Differentiation between the isomeric uridylic acids by methylationis not possible,15 and the designation of the pyrimidine a and b nucleotides as2’- and 3’-phosphates respectively is dependent partly on physical studies l6and partly on a comparison with pyrimidine deoxyribonucleotides. l7 Rapiddesorption of the products of hydrolysis of adenylic and guanylic acids on asulphonated polystyrene resin minimises phosphoryl migration. Chromato-graphy of the hydrolysate on a basic resin yielded a greater proportion ofribose-2 phosphate from a-isomers and a higher proportion of ribose-3 phos-phate from b-isomers.l8 Conclusive evidence for the formulation of adenylicacid n as adenosine-2’ phosphate has been provided by synthesis.lg Acetyl-ation of 5’-0-acetyladenosine yielded a crystalline di-0-acetyladenosinewhich was converted into adenylic acid a by phosphorylation and removal ofthe protective groups.Phosphoryl migration was excluded by the fact thatJ. J. Fox, N. Chang, and J. Davoll, Fed. Proc., 1954, 13, 211.lo W. Drell, J . Amer. Chem. SOC., 1953, ‘45, 2506.l1 D. C. Burke, Chem. aPtd I n d . , 1954, 1510.l2 A. M. Crestfield and F. W. Allen, Fed. Proc., 1954, 13, 195.1s H. Z. Sable, Biochim.Bio$hys. Ada, 1953, 12, 522.la P. Reichard, Y . Takenaka, and H. S. Loring, J . Biol. Chem., 1952, 198, 509.l5 D. M. Brown, D. I. Magrath, and A. R. Todd, J - , 1954, 1442.l6 Cf. Anm. Reports, 1953, 50, 245.1’ A. M. Michelson and A. R. Todd, .J., 1954, 34.ID D. M. Brown G, D. Fasman, D. I. Magrath, and A. R. Todd, J . , 1954, 1448,J. X. Khym and W. E. Cohn, J . Amer. CFem. Soc., 1954, 76, 1818, 5523272 ORGANIC CHEMISTRY.the product was uncontaminated by other isomers. Toluenesulphonation ofthe above di-O-acetyladenosine, followed by methanolysis, gave a methylO-toluene-9-sulphonylriboside which, after methylation, removal of the acylgroup, and hydrolysis, gave 3 : 5-di-O-methyl-~-ribose. These react ions aretherefore correctly represented as follows :AcO OH AcO O-~I-I.OCH,Ph0 +MeO-H, /O\MeogH2C/o‘HO.H,C /’\ 1 >H,OMe + k, ,>H,OH IK,-?H*OMe - HO OTs Me0 \I-I OTs Me0 OH(Ts = p-C,H,Me*SO,-)A synthesis of adenosine-2’ and adenosine-3’ [32P]phosphates has beendescribed,2o and a new method for the synthesis of cyclic phosphates fromnucleoside-2’ or nucleoside-3‘ phosphates using carbodi-imides is alsoavailable. 21Ion-exchange chromatography of hydrolysates of the deoxyribonucleicacid of herring sperm has yielded thymidine diphosphate and deoxycytidinediphosphate identical with materials obtained by phosphorylation of thym-idine and deoxycytidine.22 A further compound which is probably 2’-deoxy-5-methylcytidine diphosphate was also obtained.This confirms the originalclaim by Levene et aZ.for the existence of pyrimidine deoxyriboside diphos-phates23 which had been disputed by Bredereck and Care.% 2’-Deoxy-cytidine-3’ and 2’-deoxycytidine-5’ phosphates have been synthesised , thelatter being identical with the deoxycytidylic acid derived from deoxy-ribonucleic acids. l7 The 5’-phosphates of ribo- and deoxyribo-nucleosideshave been separated by ion-exchange chromatography in presence ofborate 25 and it is interesting that 2’-deoxyadenosine-5’ phosphate can actin vitro as an acceptor of ‘‘ high-energy phosphate.” 262o G. R. Barker, J., 1954, 3396.21 C. A. Dekker and H. G. Khorana. J . Amer. Chem. SOC., 1954, 76, 3522.22 C. A. Dekker, A. M. Michelson, and A. R. Todd, J., 1953, 947.23 P. A. Levene and W.A. Jacobs, J . Biol. Chem., 1912, 12, 411; P. A. Levene,24 H. Bredereck and G. Caro, 2. physiol. Chem., 1938, 253, 170.25 J. X. Khym and W. E. Cohn, Biochim. Biophys. Ada, 1954, 15, 139.2 G H. 2. Sable, P. B. Wilber, A. E. Cohn, and M. R. Kane, ibid., 1954, 13, 156.ibid., 1921, 48, 119; 1938, 126, 63BARKER : POLYNUCLEOTIDES. 273Isolation of Polynuc1eotides.-The isolation of polynucleot ides has notbeen reviewed in these Reports in recent years. The more refined techniquesnow available are capable of distinguishing chemically between differentpreparations of polynucleotides from the same tissue, and even betweennucleic acids from different parts of the same cell.27 For this reason, moreattention is being given to methods of isolation and their effects on thecomposition and detailed structures of the materials.Methods for the isolation of ribopolynucleotidesare determined partly by the nature of the tissue concerned, but there hasbeen a tendency to avoid the use of alkaline reagents such as sodium hydr-oxide 28 or ammonia.29 However, it is claimed 30 that a brief treatment ofyeast with sodium hydroxide at low temperature causes less degradationof the ribonucleic acid than prolonged heating with milder reagents.31Ribonucleic acids extracted from yeast under alkaline conditions are not,however, homogene~us.~~ On the other hand, extraction with " Duponol "at 100" is the best method for preparing certain virus ribonucleic acids.33More commonly, nucleoproteins are first extracted with isotonic sodiumchloride,34, 3 5 ~ 3G and may be isolated by complex formation with cetyltri-methylammonium bromide.37 Recent methods for the dissociation of thenucleic acid and protein include hydrolysis with t r y p ~ i n , ~ ~ or treatment withsodium dodecyl s ~ l p h a t e , ~ ~ strontium nitrate,39 or Guanidinehydrochloride has also been used for the extraction of ribonucleic acidsand has the advantage of combining a chemically mild reagent withone which denatures proteins, thus minimising enzymic degradation duringisolation.41542The three commonest methods for thepreparation of deoxyribopolynucleotides involve : extraction with 10%sodium chloride solution followed by deproteinisation ; 43, 44 direct isolationof the sodium nucleate by use of saturated sodium chloride ; 45, 46,47 andextraction with detergenk489 40j 50 Direct comparison of these methods 51(a) Ribopolynucleotides.(b) Deoxyribopolynuchotides.2 7 G.W. Crosbie, R. M. S. Smellie, and J. N. Davidson, Biochem. J., 1953, 54, 2S7.28 T. B. Johnson and H. H. Harkins, J . Amer. Chem. SOC., 1929, 51, 1779.29 W. Diemair and G. Schwindling-Manderscheid, 2. analyt. Chem., 1951, 132, 104.3O G. Jungner and L. G. AIIgkn, Acta Chem. Scand., 1950, 4, 1300.31 G. Clark and S. 33. Schryver, Biochem. J., 1917, 11, 319.32 M. F. Mallette and C. Lamanna, Avck. Biochem. Biophys., 1953, 47, 174.33 R. W. Dorner and C. A. Knight, J . Biol. Chem., 1953, 205, 959.34 S. E. Kerr and K. Seraidarian, ibid., 1949, 180, 1203.35 R. N. Beale, R.3 . C. Harris, and E. M. F. Roe. J . , 1950, 1397.3G Y . Khouvine and Y . Wysmann, Compt. rend., 1954, 289, 834.37 A. S. Jones, Chem. and Ind., 1961, 1067; Biochim. Biophys. A d a , 1053, 10, 607.38 E. R. M. Kay and A. L. Dounce, J . Amer. Chem. Soc., 1963, 75, 4041.38 N. W. Pirie, Biochem. J., 1954, 56, 83.40 R. Markham and J. D. Smith, ibid., 1951, 49, 401.41 E. Volkin and C. E. Carter, J . Amer. Chem. Soc., 1951, 73, 1516.4 2 E. L. Grinnan and W. A. Mosher, J . Biol Chem., 1951, 191, 719.43 Y . Khouvine, Compt. vend., 1954, 239, 782.4 4 Cf. J. M. Gulland, D. 0. Jordan, and C. J. Threlfall, J., 1947, 1129.4 5 13. Schwander and R. Signer, Helv. Chim. Acta, 1950, 33, 1521.4 6 C. F. Emanuel and I. L. Chaikoff, J . Bid. Chem., 1953, 203, 167.4 7 R.Signer, R. Butler, and P. Reist, Makvomol. Chem., 1954, 13, 5.4 8 A. M. Marko and G. C. Butler, J . Biol. Chem., 1951, 190, 165.49 E. R. M. Kay, N. S. Simmons, and A. L. Dounce, J . Amer. Chem. SOL, 1952, 74,61 G. Frick, Biochim. Biophys. Acta, 1954, 13, 41, 374.1724. 50 V. L. Mayers and J. Spizizen, J . Bid. Chem., 1954, 210, 877274 ORGANIC CHEMISTRY.reveals that the use of detergents causes some degradation of the materialduring the processes of washing and drying, and that, although degradationis avoided by using 10% sodium chloride solution, subsequent removal ofprotein is incomplete. For complete removal of protein a combination ofseveral methods is necessary.52 A study has been made of the precipitationof deoxyribonucleic acids by increasing concentrations of acid,53 and inten-sive drying of sodium deoxyribonucleate at 110" is claimed to cause ruptureof some internucleotide linkages.54(c) Separation of ribo- and deoxyribo-polynucleotides. Although byextraction of cytoplasmic material only, ribonucleic acids can be obtainedrelatively free from deoxyribonucleic acids, extraction of nuclear materialor whole tissue usually results in contamination of one type of nucleic acidwith the other. Separation of the two types has been achieved by adsorptionof ribonucleic acids on to activated charcoal 55 and elution with 15y henolsolution. 56 Purification has also been carried out by electrophores?~ i7 andthis technique has been used successfully for the purification of the trans-forming factor from Haemophilzcs infE~enzae.~~Analysis of Polynuc1eotides.-( a) Methods.Determination of theproportions of the constituent nucleotides in polynucleotides of differentorigin has been carried out in the past largely by hydrolysis in a one- or atwo-stage process to mixtures of the constituent bases. Hydrolysis to purinebases and pyrimidine nucleotides has been extensively used recently for theanalysis of ribopolynucleotides and is claimed to give reproducible results. 59Probably the most convenient method is to hydrolyse ribonucleic acids tomixtures of nucleotides which are separated by paper electrophoresis. 6oDeoxyribopolynucleotides have been degraded quantitatively by deoxyribo-nuclease and snake-venom diphosphoesterase to nucleotides which wereseparated by ion-exchange chromatography.6l -4 new method is availablefor the determination of purines in deoxyribonucleic acids.62 It is clearthat in the quantitative analysis of polynucleotides, experimental erroris likely to vary according to the method of analysis and, for this reason,caution is necessary in correlating analytical results obtained by differentprocedures.(b) ComfJosition of deoxyribopolynucleotides. Analyses of large numbersof deoxyribopolynucleotides of human,63 mammalian,@ and microbial 65origin have been found to conform to the pattern previously suggested.6662 A.S. Jones and G. E. Marsh, Biochim. Biophys. Acta, 1954, 14, 559.53 A. R. athieson and M. R. Porter, Nature, 1954, 173, 1190.54 A.R. Peacocke, Biochim. Biophys. Acta, 1954, 14, 157.5 5 S. Zamenhof and E. Chargaff, Nature, 1951, 168, 604.5 6 S. K. Dutta, A. S. Jones, and M. Stacey, Biochim. B i q h y s . Acta, 1953, 10, 613.5 7 M. Deimel, Biochem. Z., 1954, 325, 358.5* S. Zamenhof, G. Leidy, H. E. Alexander, P. L. Fitzgerald, and E. Chargaff, Arch.59 C. A. Knight, J . Biol. Chem., 1952, 197, 241.6" J. N. Davidson and R. M. S. Smellie, Biochem. J . , 1952, 52, 594.62 S. G. Laland, Acta Chem. Scand., 1964, 8, 449.63 L. L. Uzman and C. Desoer, Arch. Biochem. Biophys., 1954, 48, 63.64 E. Chargaff and R. Lipshitz, J . Amer. Chem. SOC., 1953, 75, 3658.6 5 S. Zamenhof, G. Brawerman, and E. Chargaff, Biochim, Biophys, A c f a , 1952, 9,6 6 Cf. Ann. Reports, 1950, 47, 257.Biochem. Biophys., 1952, 40, 50.R.0. Hurst, A. M. Marko, and G. C. Butler, J . Biol. Chem., 1953, 204, 847.402BARKER : P0LYNUCLEOTJI)ES. 275Deoxyribopolynucleotides of viruses vary in composition in a similar way,67and differ in composition from those of the host.68, 6D 5-Hydroxymethyl-cytosine is present in the deoxyribonucleic acids of bacteriophages of Esche-richia C O Z ~ and a nucleotide derived from this base has also been obtainedfrom this source. 71 The deoxyribonucleic acids of various bacteriophageshave been found to contain a component which is believed to be 2'-deoxy-5-hydroxymethylcytidylic acid linked glycosidically to glucose at the5-hydroxymethyl group. 729 73 No significant differences have been observedbetween the compositions of deoxyribopolynucleotides of tumours andhomologous normal tissue.74Generalisations regarding the composition of 'deoxyribonucleic acids ofdifferent tissues must be accepted with caution in view of the probableheterogeneity of the materials analysed.Thus deoxyribopolynucleotidefractions of varying composition have been obtained by adsorption on histoneimmobilised on a kieselguhr support , 75 by selective precipitation with sodium77 and by extraction of a nucleohistone with sodium chloridesolutions of varying concentration.78,79 On the other hand, it is possiblethat such fractions of different composition are artefacts since the com-position of deoxyribonucleic acids has been found to vary according to theprevious treatment of the materiaLS0The claim has been made that,provided the material analysed is undegraded, ribopolynucleotides revealregularities in composition similar to those exhibited by deoxyribopoly-nucleotides.sl It is suggested that uracil takes the place of thymine inthe deoxyribopolynucleotides and that the ratios adenine : uracil andguanine : cytosine are approximately unity.No detail has been given asyet concerning the criteria used for assessing the integrity of the nucleic acidsanalysed.Internucleotide Linkages in Ribonuc1eotides.-The most importantadvances in the knowledge of internucleotide linkages have resulted fromstudies of partial breakdown products. Complex fission products have beenreported in alkaline hydrolysates,82 but their nature has not yet been deter-mined.Evidence has been presented which suggests that during the fissionof ribonucleic acids according to Brown and Todd's scheme (see Ann. Re$orts,1952,49, 246) the C(,)-O bond is split, and not the 0-P bond as is normallythe case in the alkaline hydrolysis of phosphoric esters,@ and the following(c) Composition of ribopoZynucZeotides.6 7 G. R. Wyatt, J . Gen. Physiol., 1952-3, 36, 201.6 8 J. D. Smith and M. G. P. Stoker, Brit. J . Exp. Path., 1951, 33, 433.69 G. R. Wyatt and S. S. Cohen, Nature, 1952, 170, 846.7O Idem, Biochem. J., 1953, 55, 774.71 L. L. Weed and T. A. Courtenay, J . Biol. Chem., 1954, 206, 735.7 2 E. Volkin, J . Amer. Chem. Soc., 1954, 76, 5892.73 R. Sinsheimer, Science, 1954, 120, 551.74 D. L. Woodhouse, Biochem.J., 1954, 56, 349.7 5 G. L. Brown and L. Watson, Nature, 1953, 172, 339.7 6 A. Bendich and P. J. Russell, Fed. Proc., 1953, 12, 176.7 7 A. Bendich, P. J. Russell, and G. B. Brown, J . B i d . Chem., 1953, 203, 305.'ia E. Chargaff, C. F. Crampton, and R. Lipshitz, Nature, 1953, 172, 289.79 C. F. Crampton, R. Lipshitz, and E. Chargaff, J . Bid. Chem., 1954, 211. 125.81 D. Elson and E. Chargaff, ibid., 1954, 173, 1037.a J K. C. Smith and F. W. Allen, J . Anaer. Chem. Soc., 1953, 75, 2131.J. A. Lucy and J. A. V. Butler, Nature, 1954, 174, 32.E. Blumenthal and J. B. M. Herbert, Trpns, Faraday Soc., 1945, 41, 611276 ORGANIC CHEMISTRY.mechanism is put forward to explain the course of the hydrolysis with[lgO]water : 84H O * H 2 7 / ' v e\pq/I\Y/T\ -o/ \o-- _I_t0 0 -0 0RO-P+-0-0-II RO 0-0-+ + H O + H ~ T < ~ > ~-1-O 9 -*-pf-180-0-7 O- P -0- t-180-I 0-Further examination of the dinucleotides produced by ribonuclease actionconfirms the view that the nucleosides are linked through phosphoric acid byesterification at the 3'- and the $-position as in (3) rather than the alternative2' : Y-lir~kage.~~ Thus the dinucleotide (4) was dephosphorylated by prostatephosphomonoesterase to yield the dinucleoside monophosphate (5), which wasP - O HCc29-0H I(jrs,,-O\p/OH ~,.,-O\IJO* (3)-q5') OH \0-q5., OR \o-converted by sodium metaperiodate into the dialdehyde (6).underwent fission at pH 10 to yield cytosine and guanosine-3' phosphate :This aldehydeOHO\?OHO\?/p\OHON?__t /p\ 0 OHP ---+ 9/ 'OH 9 OHHztc/O\Cytoiine1' OHC CHO0 OH €30 OH( 6 )IPO(OH2) (4) ( 5 )84 D.Lipkin, P. T. Talbert, and M. Cohn, J . Amer. Chem. Soc., 1954, 78, 2871.85 P. R. Whitfield and R. Markham, Nature, 1953, 171, 1151BARKER : POLYNUCLEOTIDES. 277Additional evidence for a 3’ : 5’-diester linkage has been obtained by fissionof the ribonuclease-resistant core with a spleen enzyme which liberates3’-phosphonucleosides without the intermediate formation of cyclic phos-phates.85Q Furthermore, it appears probable that a unifonn 3’ : 5’-diesterlinkage is present throughout the polynucleotide chain since the combinedactions of ribonuclease and spleen enzymes convert nucleoside-3’ alkylphosphates, but not nucleoside-2‘ alkyl phosphates, into cyclic phosphateswhich are further hydrolysed back to nucleoside-3’ 87 Sinceribonucleic acids are also broken down to nucleoside-3’ phosphates by theseenzymes, it is concluded that the same type of diester linkage is present asin the synthetic substrates.There is also evidence that a 3’ : 5’-diesterlinkage is produced by the reverse of the above type of enzymic reaction.88It has been pointed out that a polynucleotide chain containing 3’ : 5’-diester linkages may be terminated in two ways (7 and 8).sg According t oBrown and Todd’s theory (Zoc. cit.), (8) should yield a nucleoside diphosphate,- 4- -1( 7 )P-I- I- -Inand a nucleoside from the two end groups respectively, whereas (7) shouldyield only nucleoside-2’ and nucleoside-3’ phosphates on alkaline hydrolysis.It is found that nucleoside diphosphates and nucleosides are formed to aconsiderable extent during the alkaline fission of the ribonucleic acids oftobacco mosaic virus and potato virus X, and accordingly, these nucleicacids are believed to be of the type represented by (8).Methods have been developed for the determination of the sequence ofnucleotides in ribonucleic acids,90, 91 but only experiments with small mole-cules have so far been reported.Internucleotide Linkages in Deoxyribopo1ynucleotides.-Examination ofdinucleotides produced by the action of deoxyribonuclease had previouslysuggested that the nucleotides were joined through 3’ : 5’-linkages and this issupported by studies of apurinic acids which have now been prepared byhydrolysis of deoxyribonucleic acids by an ion-exchange resin.62 Polaro-graphic studies indicate the presence of aldehyde groups in apurinic acids,92and since they are resistant to oxidation by p e r i ~ d a t e , ~ ~ it is concluded thatthe carbohydrate residues are doubly esterified.A further consequence ofthe aldehyde nature of apurinic acids is that both the 3’- and 5’-phosphoesterresidues are situated adjacent to a free hydroxyl group at the 4’-position of85a L. A. Heppel, R. Markham, and R. J. Hilmoe, Nature, 1953, 1’71, 1152.8 6 D. M. Brown and A. R. Todd, J., 1953, 2040.8 7 D. M. Brown, L. A. Heppel, and R. J. Hilmoe, J., 1954, 40.8 8 L. A. Heppel, P. R. Whitfield, and R. Markham, Biochem.J., 1954, 56, iii.8g R. Markham, R. E. F. Matthews, and J. D. Smith, Nature, 1954, 173, 537.B1 P. R. Whitfield, Biochem. J., 1954, 58, 390.92 J. A. Lucy and P. W. Kent, Reseavch, 1953, 6, 49s.D. M. Brown, M. Fried, and A. R. Todd, Chem. and Ind., 1953, 352.C. Tamm and E. Chargaff, J . BioE. C k m . , 1953, 2303, 689278 ORGANIC CHEMISTRY.what were the purine nucleotides of the original polynucleotide. As a result,such phosphoester residues are labile to alkali.94 Simultaneous hydrolysisof deoxyribonucleic acids and condensation of the free reducing groups withthioglycollic acid yield a mercaptal (9 _+ 10) in which some of the carbo-hydrate residues are fixed in the open-chain form : 95IO=P-OHIO=P-OH I0O=P-OH1H2I,/'>'yrimidine\;-I 1/"O=P-OH IiP ' O=P-OH IBy an argument similar to that developed above, the ester (10) shouldbe, and is, readily split by alkali at a and b.Both the above investigationssuggest that there are regions of the polynucleotide chain composed ex-clusively of pyrimidine nucleotides.Miscellaneous.-The molecular size and shape of both ribo- and deoxy-ribo-polynucleotides still continue to receive much attention and , during theperiod covered by this Report , studies based on light-scattering, viscometry,flow birefringence, and sedimentation behaviour 96-100 have been described.The most important advance of recent years in knowledge of the macro-g4 C. Tamm, H. s. Shapiro, R. Lipshitz, and E. Chargaff, J . Bid. Chem., 1953, 203,95 A.S. Jones and D. S. Letham, Biochim. Bioph-ys. Acfa, 1954, 14, 438.g 6 A. R. Mathieson and M. R. Porter, ibid., p. 288.9 7 M. E. Reichmann, S. A. Rice, C. A. Thomas, and P. Doty, J . Amev. Chem. Soc.,g* T. G. Northrop and R. L. Sinsheimer, J . Chem. Phys., 1954, 22, 703.99 M. Goldstein and M. E. Reichmann, J . Amev. Chew SOL, 1954, 76, 3337.loo A. R. Peacocke and H. K. Schachman, Biochim. Biophys. Acta, 1964, 15, 198.673.1954, '76, 3047HASZELDINE : PERFLUOROALKYL COMPOUNDS. 279molecular properties of deoxyribopolynucleotides has resulted from X-raystudies. On the basis of a polynucleotide chain consisting of phospho-diester groups linking the 3‘- and the 5’-position, a molecular model has beenconstructed 101 in which two helical chains are coiled round the same axis.The bases are on the inside of the helix and the phosphoryl residues on theoutside.The model is in agreement with X-ray diffraction measurementsof sodium deoxyribonucleate,102-1M and also with studies of infrareds p e ~ t r a . ~ 0 ~ > ~ ~ 6 It has been pointed out lo7 that this structure requires thepairing of adenine with thymine and guanine with cytosine, a fact which mayaccount for the regularities in composition observed by Chargaff and others(see above). A mechanism for the self-duplication of the structure inbiological systems has also been suggested.lo7Other recent studies have concerned the reaction of formaldehyde withribopolynucleotides,los the ultraviolet absorption spectra of intact anddegraded deoxyribonucleic acid~,~O~-ll~ and the actions of X-rays 113 andultraviolet radiation 114 on polynucleotides.G.R. B.12. PERFLUOROALKYL COMPOUNDS.Great progress has been made since the last Report 1 on fluorine compoundsand their study is becoming more of a science and less of an art. Detailedliterature surveys,2 reviews,3- and textbooks 5 should amplify the follow-ing review, which concerns only major advances of the past seven years.The main trends have been away from the preparation of perfluorocarbons101 J. D. Watson and F. H. C. Crick, Nature, 1953, 171, 737.102 M. H. F. Wilkins, A. R. Stokes, and H. R. Wilson, ibid., p. 738.103 R. E. Franklin and R. G. Gosling, ibid., p. 740.104 M. H. F. Wilkins, W. E. Seeds, A. R. Stokes, and H.R. Wilson, ibid., 1953, 172,lo5 G. Frick and A. Rosenberg, Biochim. Biophys. A d a , 1954, 13, 455.106 Cf. E. K. Blout and H. Lenormant, ibid., 1954, 15, 303.lo‘ J. D. Watson and F. H. C. Crick, Nature, 1953, 172, 964.lo8 H. Fraenkel-Conrat, Biochinz. Biofihys. Acta, 1954, 15, 307.log E. R. Blout and A. Asadourian, ibid., 1954, 13, 161.1lo R. Thomas, ibid., 1954, 14, 231.111 S. G. Laland, W. A. Lee, W. G. Overend, and A. R. Peacocke, ibid.. p. 356.112 E. Christensen and A. C. Giese, Avch. Biochem. Biophys., 1954, 51, 208.113 G. Scholes and J. Weiss, Biochem. J . , 1954, 56, 65.114 R. Setlow and B. Doyle, Biochim. Bio$hys. Acta, 1954, 15, 117.2 0. R. Pierce and E. T. McBee, Ind. Eng. Chewz., 1949, 41, 1882; 1950, 42, 1696;1951, 43, 1976; 1952, 44, 2015; 1953, 45, 1971; 1954, 46, 1835.a H.R. Leech, Research, 1952, 5, 449; Quart. Rev., 1949, 3, 22; A. Roc, ‘ I ThePreparation of Aromatic Fluorine Compounds from Diazonium Fluoborates,” in OrganicReactions, John Wiley and Sons, New York, 1949, Vol. V, p. 193 ; W. Bockemuller jnI ‘ Newer Methods of Preparative Organic Chemistry,” Interscience Publ., New York,1948, p. 229; K. Wiechert, op. cit., p. 315; R. N. Haszeldine, Angew. Chem., 1954, 66,693 ; M. Stacey, Roy. Inst. Chem. Monograph, 1948 ; Progr. Org. Chem., 1953, 2, 29 ; 1%’.Kwasnik and P. Schercr, “ Recent German Research Work on Fluorine and FluorineCompounds,” F.I.A.T. Report No. 11 14, London, H.M.S.O.W. K. R. Musgrave, Qfavt. Rev., 1954, 8, 331.J. H. Simons, Editor, Fluorine Chemistry,” VoI.1, Academic Press Inc., NewYork, 1950, Vol. 11, 1954; R. K. Haszeldine and A. G. Sharpe, “ Fluorine and Its Com-pounds,” Methuen and Co. Ltd., London, 1951 ; Slesser and Schramm, Editors, “ Pre-paration, Properties, and Technology of Fluorine and Organic Fluoro-compounds,”McGraw-Hill Book Co. Inc., New York, 1951 ; G. Schienann, “ Die Organischen Fluor-verbindungen,” D. Steinkopff, Darmstadt, 1951.759.F. Smith, Ann. Reports, 1947, 44, 86280 ORGANIC CHEMISTRY.(which are not reviewed) and towards the development of new generalmethods and of fluorine compounds containing functional groups.6Fluorination of Compounds containing Oxygen, Nitrogen, or Sulphur.-The electrochemical method of fluorination 7-10 utilises the fact that manyorganic compounds containing oxygen, nitrogen, or sulphur are soluble inanhydrous hydrogen fluoride to give conducting solutions.For any givensolution there is a minimum voltage, often 5-6 v, below which free fluorineis not formed on electrolysis, and under such conditions the organic com-pound is converted, by an anodic process which is not clearly understood,into a perfluoro-compound; this is often volatile and is swept out of thecell by the cathodic hydrogen, or is insoluble in hydrogen fluoride andforms a lower layer which can be drained off periodically. Fluorinationproceeds until all hydrogen has been replaced by fluorine, and partly fluorin-ated compounds are seldom obtained. The main advantage of the methodis that fluorination occurs, if only in poor yield, without loss of functionalgroups or of potential functional groups.The compounds prepared in this way have been mainly perfluoro-acids,CF,-[CF2],*C02H, -ethers,g and -amines.lo Electrolysis of solutions of anacid, its anhydride, or acyl fluoride in anhydrous hydrogen fluoride is saidto give good yields of the corresponding perfluoroacyl fluoride, althoughdetails have not been disclosed ; much breakdown occurs with longer-chaincompounds, but trifluoroacetic acid is a t present best prepared by this route.Perfluoro-ethers such as (CF3),0 (b. p. -60.5") and (C,F,),O (b. p. O"), havebeen described; they are also obtained, though less conveniently, byvapour-phase fluorination of hydrocarbon ethers. The b.p. of a fluoro-ether ROR' is remarkably close to that of the fluorocarbon RR'. Thecompounds are thermally and chemically stable, are not cleaved by hydrogeniodide, do not form stable addition products with boron trifluoride, and infact show few properties normally associated with ethers. l1Vapour-phase fluorination of tertiary amines l2 with cobalt trifluoride givesonly low yields of the corresponding perfluoro-compounds [e.g., (C,F,),N,b. p. 70.3'1; trimethylamine gives (CF3),NF (b. p. -37") and CF3*NF,(b. p. -75"), as well as (CF3),N (b. p. -6"). Electrochemical fluorinationof the tert.-amines gives better yields of the perfluoro-compounds. lo Thereplacement of carbon by nitrogen in a fluorocarbon does not alter the b. p.appreciably even though the resultant compound contains a smaller numberof fluorine atoms. 2 : 6-Lutidine,13 pyridine,lo, l3 and aniline lo, l3 similarlyyield peduoro-2 : 6-dimethylpiperidine, perfluoropiperidine (b.p. 49"), andperfluorocyclohexylamine (b. p. 75") respectively. The perfluoroamines arenon-basic and inert to chemical attack, and are better regarded as derivativesof nitrogen trifluoride rather than as derivatives of ammonia ; the perfluoro-6 See J., 1952, 5059, for editorial notes on nomenclature.7 T. J. Brice, R. D. Dresdner, H. T. Francis, W. I. Harland, J. A. Hogg, W. H.Pearlson, J. H. Simons, and W. A. Wilson, J . Electrochem. SOC., 1949, 95, 47; J. H.Simons, U.S.P. 2,5 19,983 1 1950.E. A. Kauck and A. R. Diesslin, U.S.P. 2,593,73711951; Ind. Eng.Chew., 1951,43, 2332.Q J. H. Simons, U.S.P. 2,500,388/1950; E. A. Kauck and J. H. Simons, U.S.P.2,644,823/1953 ; U.S.P. 2,594,27211952.lo Idem, U.S.P. 2,616,92711952; J. H. Simons, U.S.P. 2,490,098/1949,2,490,099/1949.11 R. N. Haszeldine. Besearch. 1951. 4. 338HASZELDINE : PERFLUOROALKYL COMPOUNDS. 281tertiary amines form perfluoroazomethines when pyrolysed at 700°, e.g.,Fluorination of CH,*CN, CF,CN, Et*NH,, or CF,CH,*NH, gives C,F,*NF,(b. p. -35-5"), and C,F,CH,-NH, or C,F,-CN yields C,F,*NF,.ll Trifluoro-methyleneimide, CF,:NF, b. p. -95", is a by-product from acetonitrilefluorination ; it liberates iodine from aqueous potassium iodide, attacksmercury, and has been considered as a route to polymers of typeElectrochemical fluorination of carbon disulphide yields SF,, CF4, andCF,*SF, l 6 with small amounts l7 of CF,(SF,), (b.p. 60-5"), CF,(SF,), (b. p.35"), and CF,(SF),, whereas CF,(SF,),, SF,CF,*SF, (b. p. 26") , CF,*SF,(b. p. -7"), and S,F,, (b. p. 25") are the by-products of vapour-phasefluorination.18 The tendency for sulphur to be oxidised to its highestvalency state is also shown by electrochemical fluorination of dimethylsulphide 1 7 which gives mainly CF,*SF, and (CF,),SF,, but no CF,*SFor (CF,) ,S.Fluoro-acids and their Derivatives.-Four new general methods havebeen developed for the preparation of perfluoro-acids : (a) Electrochemicalfluorination of the hydrocarbon acid or a suitable derivative, e.g., CH,-COF__SF CF3-CQF.8y l9 (b) Conversion of a perfluoroalkyl iodide into theGrignard reagent followed by carboxylation [e.g., C,F,I + C,F,*MgI__jc C,F,-C02H].19a (c) Reaction of a perfluoroalkyl iodide with acetylene,followed by oxidation,,O e.g., C3F71 + C,F,*CH:CHI I__) C,F,*CO,H.(d) Photochemical halogen-sensitised oxidation of certain polyfluoro-com-pounds,21 e.g., C,F,-CFClI --+ C,F,*COF ; C,HF7 __t C,F,*COF.Thefirst of these is the most versatile, the others are suitable for laboratorysyntheses, particularly of long-chain acids. The properties of pentafluoro-propionic, heptafluorobutyric, and perfhorocyclohexanecarboxylic acid, andof longer-chain acids obtained by routes (a) and (c), have been described ; *, 2obranched-chain acids, e.g., (C,F,) (CF,)CF*CQ,H, can be obtained similarly.2oAcids with properties very similar to those of the perfluoro-acids areobtained by the peroxide-initiated polymerisation of tetraffuoroethylene inpresence of methanol to give H*[C,F,],CH,*QH, followed by permanganateoxidation to H*[C,F4],*C02H (n = 1-9).,,(C,F,)3N __t C,F,N:CF,, b.p. -13".14-CF,*NF.CF,*hTF*CF2.NF-.11i l5co2CZH, KMnO,l4 W. H. Pearlson and L. J. Hals, U.S.P. 2,643,267/1953.l5 J. A . Cuculo and L. A. Bigelow, J . Amer. Chem. SOC., 1952, 74, 710.G. A. Silvey and G. H. Cady, i b i d . , p. 5792.l7 A. F. Clifford, H. K. El-Shamy, H. J. Emeli.us, and R. N. Haszeldine, J., 1953,2372.G. A. Silvey and G. H. Cady, J . Amer. Chem. SOG., 1950, 72, 3624; E. A. Tycz-kowski and L. A. Bigelow, ibid., 1953, 85, 3523.R. N. Haszeldine, Nature, 1951, 167, 139; 168, 1028; Abs.Amer. Chem. Soc.Meeting, New York, 1951, p. 6 ~ ; Atlantic City, 1963, p. 1 3 ~ ; J . , 1952, 3423; 1953,1748; 1954, 1273; A. L. Heme and W. C. Francis, J . Amer. Chern. Sac., 1951, 73,3518; 1953, '45, 992; 0. R. Pierce and M. Levine, ibid., 1953, 75, 1254; 0. R. Pierce,A. F. Meiners, and E. T. McBee, ibid., p. 2516.*O R. N. Haszeldine and K. Leedham, J . , 1953, 1548; R. N. Haszeldine, J . , 1950,2789, 3037; 1953, 3559; Natuve, 1950, 166, 192; 1951, 168, 1028.*l W. C. Francis and R. N. Haszeldine, J., 1955, in the press.R. M. Joyce, U.S.P. 2,559,62811951; K. L. Berry, U.S.P. 2,559,629/1951,2,559,752/1951; K. L. Berry and J. A. Bittles, U.S.P. 2,559,751/1951; J. F. Carnahanand H. J. Sampson, U.S.P. 2,646,44911953.l9 T.J. Brice and J. H. Simons, ibid., 1951, 73, 4017282 ORGANIC CHEMISTRY.Perfluoromalonic acid has been isolated as its methyl ester.23 Theoriginal synthesis of perfluorosuccinic acid 24 by the route :2000 CF2-CXC1 Zn-EtOH CFZ-CX I<iLlnO, CF,.CO,HCFz:CXC1 __t 1 1 - 1 1 X = F or C1has been confirmed ; 257 26 the anhydrous acid melts at 116",26, 27 and theearlier 25 m. p. of 87" is actually that of the monohydrate. The fluoro-aw-di-iodoalkanes, I*[CF,],,-I, have been converted into perfluoro-dicarboxylicacids by routes (b) and (c) above.28Trifluoroacetic, pentafluoropropionic, and heptafluorobutyric acid havebeen converted 20, 29 into compounds RFX, where RF = CF,, C,F,, or C,F,,and X = CO,Na, CO,K, CO,Ag, CO,Me, CO,Et, CO-NH,, COC1, COBr, COI,C0,-CH:CH2, CH,*OH, CHO, CH(OH),, CH,-NH,, CH,-NCO, CO*O*RBT, orCON,.Diesters (RO,C*[CF,],*CO,R ; RF*CH,*O*CO*[CF,],~C0,-CH2R~~ ;Rp*C02;[CH,],*O*CO*RF; R =Me, Et,etc. ; RF = CF,, C,F,, etc. ; x = 2,3, or4),aromatic t h i o l e ~ t e r s , ~ ~ and vinyl esters 329 2o (C,F2, + I*CO,*CH:CH, ;n = 1-7) have been prepared by conventional routes; the vinylesters yield thermally stable homopolymers .32 The fluoroacrylat es,CaF2?, + 1*CH,*O*CO*CH:CH2, prepared from the fluoro-alcohol and acryloylchloride, undergo peroxide-polymerisation to " fluoro-rubbers " which arenon-inflammable and retain their elasticity at low temperature^.^^Except for the action of heat on the ammonium salts, the amides of theperfluoro-acids are prepared in the usual way.8, 2o They do not undergo theHofrnann reaction with alkali hypohalite to give the primary arnines RF*NH,,which are still unknown ; CF,*CO*NH, is said to give C,F, when heated withsodium hypobromite,33 whereas perfluoropropionamide and amides oflonger-chain acids yield CF3*[CF2],*Cl, CF,*[CF,].*Br, or CF,*[CF,];H whentreated with sodium hypochlorite, hypobromite, or hypoiodite, re~pectively.,~The N-chloro- or N-bromo-amide is believed to be the intermediate in thefirst two reactions [e.g., C,F7*CO-NHBr __a GF,Br + CO, + NH,],whereas the hypoiodite merely converts the amide into the sodium salt [e.g.,C,F,*CO*NH2 ---+ C,F,*CO,Na 3 C,F,H].CFz-CXC1 CFz-CX CF,*CO,HNaOHNaOI NaOH23 A.L. Hennf,and E. G. Dell'itt, J . Amer. Chenz.Soc., 1948, 70, 1548.24 0. Scherer, Fluoroderivate des Propans und Eutans," I.G. Research Laboratories,25 A. L. Henne and R . P. Ruh, J . Amer. Chenz. SOC., 1947, 69, 279.26 &I. W. Buxton, D. W. Ingram, F. Smith, M. Stacey, and J. C. Tatlow, J . , 1952,2 7 I<. N. Haszeldine, J . , 1954, 4026.21 D. R. Husted and A. H. Ahlbrecht, J . Amer. Chem. SOC., 1953, 75, 1605; J . 0.I<endricks, I n d . Eng. Chem., 1953, 45, 99.30 R. Filler, I n d . Eng. Chem., 1954, 46, 544; M. Hauptschein, C. S. Stokes, and E. A.Nodiff, J . Arner. Chem. SOC., 1952, 74, 4005; M. Hauptschein, J. F. O'Brien, C. S.Stokes, and R. Filler, ibid., 1953, 75, 87; R. Filler, J. F. O'Brien, J. V. Fenner, andM. Hauptschein, ibid., p. 966; R. Filler, J. V. Fenner, C. S. Stokes, J .F . O'Brien, andM. Hauptschein, ibid., p. 2693; R. Filler, ibid., p. 3016; A. D. Kirshenbaum, A. G.Streng, and M. Hauptschein, ibid., p. 3141.31 R. F. Clark and J . H. Simons, ibid., 1953, 75, 6305.32 T. S. Reid, U.S.P. 2,592,069/1951; A. H. Ahlbrecht, T. S. Reid, and D. K. Husted,33 E. Gryszkiewicz-Trochimowski, A. Sporzynski, and J . U'nuk, Rec. Trav. chim.,D. R. Hustedand W. L. Kohlhase, J.,4mer. Chem. SOC., 1954, 76, 5141.U.S. Dept. of Commerce, Office of Technical Services, PB 776.3830; J . J . Padbury and E. L. Kropa, U.S.P. 2,502,478/1950.28 Idem, Nature, 1951, 168, 1028.U.S.P. 2,642,41611953.1947,66,419HASZELDINE : PERFLUOROALKYL COMPOUNDS. 283Keduction of perfluoro-amides by lithium aluminium hydride givesthe ainines Rv*CH,*NH,.8y 20, 32 Trifluoroethylamine, also obtained fromCF,*CH,Br and ammonia in presence of sodium iodide, reacts withtrifluoroacetamide a t 250" to give CF,*CH,-NH*CO=CF,, which lithiumaluminium hydride reduces to the weak base (CF3*CH,)2NH.35Perfluoro-nitriles (e.g., C,F,.CN, b.p. -35"), obtained from the amides,201 32are readily hydrolysed and react with lithium aluminium hydride to givethe amine ; they yield amidines + 1*C(:NH)*NH2 when treated withliquid ammonia.36The perfluoroacyl chlorides with sodium azide in xylene giveC11F2,L + ICON, ; C,F,*CON,, like CF,*CON,, is explosive, whereas the longer-chain compounds undergo smooth rearrangement to CnFzn + 10NCO (n. = 3-9)when heated.,' The isocyanates show some unusual reactions, since systemscontaining -CF,*NH, or -CF,*NH- groups usually break down with loss offluoride, e.g.:H2O I I 0C,F,*NCO + C,F,CF,-NH*CO,H C,F,*CO.NH, + 2F- + CO,A perfluoro-aldehyde such as CF,*CHO cannot be obtained from trifluoro-acetonitrile by the Stephen reduction, from trifluoroacetyl chloride by treat-ment with sodium hydride or sodium borohydride, or from trifluoroethanolby reaction with acetone and aluminium isopropo~ide.~~ The earlier state-ment 38 that Rosenmund reduction of trifluoroacetyl chloride gave only thealcohol has been corrected, and in absence of impurities the acyl halide isconverted into trifluoroacetaldehyde in high yield.39 The aldehyde is alsoproduced by oxidative nitration of CF,*CH,*CH,,4° but is best prepared, asare its homologues, by reaction of the perfluoro-acid, or its esters, acylchloride, or nitrile, with lithium aluminium h ~ d r i d e , ~ ~ ? 387 2o particularly ifthe inverse-addition technique is used to prevent further reduction to theTrifluoroacetaldehyde (b.p. -18') forms a solid polymer fromwhich the monomer may be regenerated by heat. The perfluoro-aldehydehydrates [e.g., C,F,*CH(OH),, m. p. 54-56', b. p. 92-94'] can be recon-verted into the aldehydes by treatment with phosphoric anhydride ; 41$ 389 2odiacyl esters are obtained by reaction with anhydride^.^^ Trifluoroacet-aldehyde yields fluoroform and a formate with strong aqueous base, andshows reducing action, Schiff coloration, etc. Hemiacetals are readilyobtained by reaction with an anhydrous alcohol.41Thc alcohols C,F2, + I*CH,*OH are obtained (a) by lithium aluminiumhydride reduction of perfluoro-acids, -amides, or -acyl chlorides, or of alkylesters of perfluoro-acids,42> 293 20 (b) by catalytic (copper-chromium oxide)reduction of esters, acid chlorides, or anhydride^,^, and (c) by reaction of the35 12.H. Meen and G. I?. Wright, J . Urg. Chem., 1954, 19, 301.36 D. ii. Husted, U.S.P. 2,676,985/1954.37 A. H. Ahlbrecht and D. R. Husted, U.S.P. 2,617,817/1952.A. L. Henne, R. L. Pelley, and R. M. Alm, J . Amev. Chem. SOL, 1950, 72, 3370.39 F. Brown and W. K. R. Musgrave, J . , 1952, 5049.H. Schechter and F. Conrad, J . Amer. Chem. SOG., 1950, 72, 3371.41 D. R. Husted and A. H. Ahlbrecht, ibid., 1952, 74, 5422; B.P. 705,714/1954;4 2 0. R.Pierce and J. G. Kane, J . Amer. Chem. SOL, 1954, 76, 300; M. Braid,43 D. R. Husted and A. H. Ahlbrecht, Abs. hmer. Chem. SOC. Meeting, New York,U.S.P. 2,681,370/1954.H. Iserson, and F. E. Law-lor, ibid., p. 4027.1954, 2 7 ~ ; U.S.P. 2,666,799/1954284 ORGANIC CHEMISTRY.perfluoroalkyl Grignard derivative with formaldehyde. lQa Unlike trifluoro-ethanol, the longer-chain compounds do not give mixed ethers on reac-tion with ethanol and sulphuric acid (cf. CF3*CH,*OH __t CF,*CH,-OEt),and do not yield esters with perfluoro-acids (cf. CF,*CH,*OH - CF,CO,*CH,-CF,). Conversion into CF,*[CF,].-CH,X (X = C1, Br, or I) isbest effected by reaction of toluene-P-sulphonates of the fluoro-alcoholswith a metal halide, e.g., LiC1, LiBr, NaI.@Secondary 45, 46 and tertiary 45 poly- and per-fluoro-alcohols have beenprepared by use of alkyl or perfluoroalkyl Grignard reagents [e.g., CF,-CHO - (CF,) (C,F,)CH*OH ; CF,*CO*CF, + (CF,),C-OH], or by reduction ofpoly- or per-fluoro-ketones.Heptafluorobutyraldeliyde is obtained in goodyield by the chlorination of the alcohol C3F,*CHz*0H (cf. the preparation ofchloral from ethanol), and C,F,*CHMe-OH similarly yields the ketoneC3F7*CO*CH3.47The primary perfluoro-alcohols have ionisation constants 457 4 8 9 49 somelo4 times those of their hydrocarbon analogues (thus correcting Swarts'searlier value 50 of K = lo-'), and the secondary alcohols (CnFzn+ 4,CH*OHshow a further 10-fold increase in acidity; 459 46 the tertiary alcohols are asacidic as phenols.4510'ZK 1 012 KCH,*[CH,],*CH,-OH ............0.0003 CF,*CH,*OH ..................... 4-5CF,.[CH,],*OH .................. 0.1 (CH 3) ,CH *OH .................. 0.000 1CF,.[CH,],*OI-I .................. 0.2 C,F,.CHMe.OH ............... 4.2CHF2CH2*OH .................. 1.0 CF,.CHMe.OH .................. 5.2CCI,*CH,.OH.. ................... 1.6 (C3F,),CH*OH .................. 30CF,-CO,HCF2ClCH2*OH .................. 2.4 (CF,)(CIF,)CHoOH ............ 35CF,~[CF,],*CR,*O€I ............ 4.5Perfluoro-diols [CF,],(CH,.OH), have first and second dissociation con-stants48 ca. 1 x Infrared spectroscopic studies45show that intermolecular hydrogen bonding is much reduced in the per-fluoro-alcohols, in accord with the low b.p. of these compounds;(C,F7)3C*OH, for example, boils a t a lower temperature than the fluoro-carbon C,F,,.Application of the Arndt-Eistert reaction converts trifluoroacetyl chlorideinto trifluorodiazoacetone and thence into the ester CF,*CH,-C0,Et ; 51the acid CF,*CH,*CO,H, kept slightly basic with sodium hydroxide,slowly yields CF,:CH-CO,H as a mon~hydrate.~~ yyy-Trifluorocrotonicacid is prepared by hydrolysis of its nitrile made by reaction of thealkyne CF,*CfCH with hydrogen cyanide or of trifl uoroiodomethanewith acrylonitrile followed by dehydroiodination 53 (CF,I ____aand 4 x 10-1,.CH,XH.CN44 G.V. D. Tiers, H . A. Brown, and T. S. Reid, J. Ameu. Chem. SOC., 1953, 75,5978; L. 0. Krogh, T. S. Reid, and H. A. Brown, J . Org. Chem., 1954, 19, 1124.4 5 R.N. Haszeldine, J . , 1952, 3423; 1953, 1748, 1757.4 6 W. C . Francis and A. L. Henne, J . Amer. Chem. SOC., 1953, 75, 991.4 7 E. T. McBee, 0. R. Pierce, and W. F. Marzluff, ibid., p. 1609.18 E. T. McBee, W. F. Marzluff, and 0. R. Pierce, ibid., 1952, 74, 444; A. L. Henne49 A. L. Henne and R. L. Pelley, ibid., p. 1426. and S. Richter, p. 5420.F. Swarts, Bull. SOG. chim. Belg., 1929, 38, 99.51 F. Brown and W. K. €2. Musgrave, J., 1953, 2087.62 A. L. Henne and C. J. Fox, J . Amer. Chem. SOG., 1953, 75, 6750; 1954, 76, 479.63 R. N. Haszeldine, J., 1952, 3490; 1953, 922HASZELDIKE PERFLUOROALKYL COMPOUNDS. 285CF3*CH,-CHI*CN CF,.CH:CH.CN - CF,*CH:CH*CO,H). Later syn-theses 53 involve hydrolysis of the allylic CCl, group of CF,*CH:CH*CCl, withconcentrated sulphuric acid.Ethyl yyy-trifluorocrotonate is obtained bydehydration (boric or phosphoric anhydride) of CF,*CH(OH)*CH,*CO,Et,prepared by reduction of ethyl trifluoroacetoacetate or from trifluoroacet-aldehyde by a Reformatsky reaction.54 Chlorine-sensitised photochemicaloxidation of CF,Cl*CX:CCl, (X = F or Cl) yields CF,Cl*CXCl*COCl, withCF,Cl*CX=CCl,-O as postulated intermediate ; 55 the nitrile CF,:CF.CN (b. p.18') is obtained from CF,Cl.CFCl.CN and zinc but the acidCF2:CF*C0,H is unstable in aqueous solution and is thus best preparedby dechlorination of the acid CF,C1*CFC1-C02H rather than by hydrolysisof CF,:CF*CN.52The dissociation constants ( x lo5) shown in the annexed Table 52-547 56show that the perfluoro-acids are almost completely dissociated in aqueoussolution ; CF,*CH,*CO,H and CF,*[CH,],*CO,H are relatively weak electro-lytes, but incomplete shielding of the inductive effect of the CF, group is stilldetectable even when two CH, groups separate it from the carboxyl group.If it is assumed that a CF, group can exert no inductive effect through threeCH, groups, the fact that the dissociation constant of CF,*[CH,],*CO,H ishigher than the expected 1-5-1-7 x PO-5 may be attributed to hydrogenr-----l1G6KCH,.CO,T-T ........................1.8C,H,-CO,H ..................... 1.5C,H ,*CO,H ..................... 1.5C,H,*CO,H ..................... 1-3CII,:CHCO,H .................. 5.6- -- -7 -- ICCl,:CCl.CO,H .................. 6200 - -CH,CH:CHCO,H ............2.0CH,FCO,H .....................CF,CO,H ........................CF,.CH,CO,H ..................CF,.[CH,],*CO,H ...............CHF,*CO,H .....................CF,*[CH,],*CO,H ...............C,F,CO,H .....................CH,:CF.CO,H ..................CF,:CHCO,H ..................CF,:CF*CO,H ..................CF,.CH:CH*CO,H ............-1 0 5 ~220570059,00010076 8,0003.22 8068I55070-bonding in a 6-membered ring, rendered possible by the increased acidity ofthe hydrogen atoms a to the CF, group. The fluorine atom in CH,:CF*CO,Hexerts its influence mainly by induction (cf. CH,F*CO,H), whereas the lowvalue for CF,:CH*CO,H indicates that back-co-ordination [CF,:CH*CO,H&CF*CH*CO,H ++ &CF*CH:C (@*OH] successfully opposes the inductiveeffect ; the further introduction of fluorine to give CF,:CF*CO,H increases thedissociation constant, but the acid is still appreciably weaker thanCC1,:CCl*C02H.52 The influence of the CF, group is relayed through thevinylic system in CF,-CH:CH*CO,H by induction and hyperconjugation 53(5 CF,:CR-~H*CO,H) so that this acid is approximately as strong asCF,*CH,*CO,H.B4 H.&I. Walborsky and 34. Schwarz, J . Amer. Chena. SOC., 1953, 75, 3241; E. T.55 D. W. Chaney, U.S.P. 2,439,505/1948 ; 2,443,024/1948 ; 2,456,76811948 ;6 6 F. Swarts, Bull. Acad. ~ o y . Belg., 1896, 6S1; 1903, 624; 1922, 353; J. F. J . Dippy,McBec, 0. R. Pierce, and D. D. Smith, ibid., 1954, 76, 3722, 3725.2,s 14,473/ 1950.Chew. Rev., 1939, 25, 151286, ORGANIC CHEMISTRT;.In 70y0 aqueous acetone the hydrolysis of ethyl trifluoroacetate is rapid,as expected, and unaffected by acid concentration during the early stages,whereas the uncatalysed hydrolysis of ethyl acetate is extremely slow; 57fluorine substitution facilitates nucleophilic attack by water on ethoxy-carbonyl carbon.Measurement of the relative acid strength of trifluoro-acetic acid by comparison of the extent of catalysis of the hydrolysis of ethylacetate in water or 70% aqueous acetone shows that it is approximately halfas efficient as hydrochloric acid.57 Conductivity measurements in a non-aqueous solvent such as anhydrous acetic acid show that the perfluoro-carboxylic acids are only as strong as nitric acid.58 Fluorine-containing oxy-acids of groups v and VI are much stronger, the order of decreasing strength,with approximate relative strengths shown in parentheses, being HC10,(350) and CF,*SO,H > (CF,),PO,H (250) > HBr (180) > H,SO, (32) >CF3*P03H2, HC1 (9) > (CF,),AsO,H (3.5) > CF,*AsO,H, (2.5) > CF,*CO,H,HNO,, C,F,.CO,H (l).58Trifluorolactic acid has been resolved.59 Attempted dehydration ofCF,*CMe(oH).CN 60 by concentrated sulphuric acid yields the amide,61 notthe fluoroacrylonitrile claimed earlier,60 but pyrolysis of the acetate at 500"gives CF3-C(CN):CH2.60s 61CHF,*CO*CF,*CO,Et can be obtained by Claisen condensation only in pres-ence of a strong base such as sodium hydride; even ethyl difluoroacetatewill then condense with ethyl trifluoroacetate to give CF,*CO-CF,*CO,Et .62The esters yield the expected ketones only with 40% sulphuric acid underreflux.Hexafluoroacetone has been prepared by oxidation of ( CF,),C:CCl,,(CF,),C:CH,, or (CF3),C:CHBr,63 but is best made by permanganate oxidationof perfluoroi~obutene.~~ Ketones, e.g., C,F,*COR (R = Me, Et, CF,, C2F5,or C,F,) have been synthesised by reaction of perfluoroalkyl Grignard com-pounds such as C3F,*MgI or CF,*MgI with esters or acyl halides.65 Theyreact only slowly with alkyl or perfluoroalkyl Grignard compounds togive tertiary alcohols, undergo the haloform reaction, and are reducedto the secondary alcohols by lithium aluminium hydride; chromic acidoxidises a perfluoro-secondary alcohol to the ketone, which forms a stablehydrate.Tri-fluoroiodomethane (b.p. -22.5") and pentafluoroiodoethane (b. p. 13") werefirst prepared by the action of iodine pentafluoride on carbon tetraiodide orPolyfluoroacetoacetic esters such as CF,*CO*CHF*CO,Et andF1uoroiodoalkanes.-These compounds have found widespread use.5 7 G. Gorin, 0. R. Pierce, and E. T. McBee, J . Anzer. Chewz. SOC., 1953, 75, 5622;6 * H. J. Emelhs, R. N. Haszeldine, and R. C. Paul, J . , 1954, 881.Go J. B. Dickey, U.S.P. 2,472,81211949, 2,541,465/1951.G2 E. T. McBee, 0. R. Pierce, 13. W. Kilbourne, and E. R. Wilson, J . ,?wzer. Chew.SOC., 1953, 75, 3152.63 A. L. Henne, J . W. Shepard, and E. J. Young, i b i d . , 1950, 72, 3577; R. N. Has-zeldine, J . , 1953, 3565.64 J.D. LaZerte, L. J. Hals, T. S. Reid, and G. H. Smith, J . Awer. Chem. Sor.,1953, 75, 4525; T. J. Brice, J. D. LaZerte, L. J . Hals, and W. H. Pearlson, i b i d . ,p . 2698.G6 R . N. Haszeldine, J . , 1953, 1748.0. R. Pierce and G. Gorin, ibid., p. 1749.R. Darrall, F. Smith, M. Stacey, and J. C. Tatlow, J . , 1951, 2329.M. W. Buxton, M. Stacey, and J. C. Tatlow, J . , 1954, 366tetraiodoetliyIcne,GC and a more convenient and general synthesis was laterdeveloped : 67-71CF3fCF2],i*C02Ag + X, __t CF,fCF,],*X + CO, + AgX(X = C1, Br, or I) with CF,*[CF,],;CO,X as the unstable intermediate.71Iodine and bromine trifluoroacetates, 71, 72 like N-bromoperfluorosuccinimideand N-bromotrifluor~acetamide,~~ are powerful iodinating or brominatingagents, and halogenate the nucleus in aromatic compounds in the positionexpected for at tack by an electrophilic reagent .7 1 Silver fluorohalogeno-acetates react with halogen to give fluorohalogenomethanes 67 (CFYZ*CO,Ag--G CFYZX ; X = C1, Br, or I ; Y and 2 = H, F, C1, or Br). Silver saltsof the dicarboxylic acids [CF,],(CO,H), similarly yield aw-dihalides, but whenn = 3 or 4, perfluoro-lactones, e.g., O*CF,*CF,*CF,*dO are simultaneouslyproduced.67* 70 Free-radical mechanisms have been suggested for thesesilver salt reactions.67 Treatment of the lactones with aqueous reagentsopens the ring to give transient compounds containing the -CF,*OHgroup, which decomposes by loss of two fluoride ions to give -CO,H, e.g.,HO2C*[CF2].,*CF2*OH --+ H0,C*[CF,]2*C02H.67, 70Pyrolysis of acyl iodides 67 (e.g., C,F,-COI) and of acid anhydrides 67[e.g., (CF,*CO),O] in presence of iodine provides other routes to the fluoro-iodoalkanes.Free-radical, short-chain polymerisation of tetrafluoroethylenein presence of trifluoroiodomethane or pentafluoroiodoethane gives thepolymers CF,*[CF2],*I in good yield, whence the complete homologous series(n = 2-20) has been isolated. Tetrafluorodi-iodoethane, prepared fromtetrafluoroethylene and iodine, undergoes a similar reaction to givethe cto-di-iodides I*[CF,],*I (n = 6 - 2 4 ) which may be converted intoCF,*[CF,];I, Br*[CF,],*Br, Cl*[CF,].*Cl, and F*[CF,],-F each containing aneven number of carbon atoms by suitable halogen-replacement reactions.67, 73Nucleophilic substitution of iodine in trifl uoroiodomethane by OH, NH,,CN, NO,, etc., has so far proved impossible.Reaction with alcoholic potas-sium hydroxide, for example, yields fluoroform, not CF,*OH, since nucleo-philic attack is on the relatively positive iodine, not on carbon 6 7 9 73* 74(OH- I-CF, + HOI + CF,- ____t CHF,) ; ffuoroiodomethanes whichalso contain chlorine or hydrogen are usually decomposed by aqueous base (eg.,OH- CHClFq -+- HO-CHCIF + HoCO,K).~~ Complex formations,In o Solventcsc6 6 A. A. Banks, H. J. Emeleus, R. N. Haszeldine, and V. Kerrigan, J . , 1948, 2188;15’ R. N. Haszeldine, Natwe, 1950, 166, 192; 1951, 168, 1028; J . , 1951, 585; 1052,6 8 A. L. Henne and W. G. Finnegan, J . Amer. Chem. SOC., 1950, 72, 3506.6s J. H.Simons and T. J. Brice, ibid., 1951, 73, 4016; U.S.P. 2,554,210/1951.i o M. Hauptschein and A. V. Grosse, J . Amer. Chem. Soc., 1951, 73, 2461; M.Hauptschein, C. S. Stokes, and A. V. Grosse, ibid., 1952, 74, 848; M. Hauptschein,li. L. Kinsman, and A. V. Grosse, ibid., p. 549; M. Hauptschcin, E. A. Nocliff, andA. V. Grosse, ibid., p. 1347.72 A. L. Henne and W. F. Zimmer, J . Amer. Chem. SOC., 1951, 73, 1103, 1362;J . D. Park, H . J. Gerjovich, W. R. Lycan, and J . R. Lacher, ibid., 1952, 74, 2189.73 K. N. Haszeldine, Naluve, 1951, 167, 139; J : . 1949, 2856; 1953, 3761,H. J. Emelkus and R. N. Haszeldine, J . , 1949, 2953.4259, 3490.R. N. Haszeldine and A. G. Sharpe, J., 1952, 993.J. Banus, H. J . Erne1C.u~. and R. N. Haszeldine, J . , 1951, 60288 ORGANIC CHEMISTRY.between polyhalogenoiodo-compounds and neutral-molecule bases such asalcohols, ethers, and amines has been detected by ultraviolet spectroscopy.75Homolytic fission of the carbon-iodine bond in the polyfluoroiodoalkanesis readily achieved by ultraviolet light or heat, and the ultraviolet spectra ofthe iodo-compounds have been used to indicate the relative stabilities of thepolyfluoroalkyl radicals so produced.75Fluoro-olefins and -acetylenes.-Terminally unsaturated perfluoro-olefinsCF3-[CF2],*CF:CF, (n.= 1-6) are conveniently prepared in high yield bypyrolysis at 250-300" of the anhydrous sodium salts of the perfluoro-acids.64* 76 Fluoride elimination from a ff uorocarbanion has been postulatedto explain this unusual reaction,76 e.g.:C,F,CO,Na ---t C3F,*C0,- + C,F,- + CO, ; F-CF-CF,- --+ F- + CF,CF:CF, 0 ur>ICF,In marked contrast is the pyrolytic decomposition of silver salts, which yieldfluorocarbons, probably by free-radicalC,F,*CO,* 4 C,F,* + C,F1,. Pyrolysis of the salt C,F9*C02K yieldsC,F,*CF:CF2 (b. p. 1") and, by fluorine migration, CF,-CF:CF*CF, (b. p. 0')in a ratio of 1 : 4.64 Disodium octafluoroadigate produces perfluorobut-adiene when heated : 7730 e.g., C3F,*C02Ag-F--O,C.[CF2],*CFz- -O,CCF,*CF,CF:CF, __t-F--CF,CF,*CF:CF, __P. CF,:CF*CF:CF,Perfluoroisobutene, (CF,),C:CF, (b. p. 6.5"), is toxic and readily preparedby uncatalysed pyrolysis of octafluorocyclobutane a t 720" ; it is easilyoxidised to he~afluoroacetone.~4 Partial fluorination of benzene with cobalttrifluoride gives a mixture from which undecafluorocyclohexane, C,HF,,(m.p. 49", b. p. 63") can be separated and converted into perfluorocyclo-hexene by concentrated aqueous potassium hydroxide. Similar reactionswith 1H : 2H- and 1H : 3H-decafluorocycZohexane (b. p. 92" and 78") haveproduced perfluorocyclohexa-1 : 3- and -1 : 4-diene (b, p. 68" and 57°).78The coupling of an alkyl group containing fluorine and another halogen canbe effected if the compound contains a -CFClX group (X = Br, or preferablyI), and is not readily dehalogenated to give an 0lefin.7~ Perfluorobutadienehas thus been prepared from chlorotrifluoroethylene : 79CF,CICFCl*H g , h / \IC1 Zn-dioxan < 60' Zn-EtOHCF,:CFCI CF,CICFClI -* ( CF2ClCFC1) , ___t CF,:CF*CF:CF,This technique has been applied to C,F5*CFC11 to give C,F,*CFCl*CFCl*C,F,and thence peduorohex-3-ene,79 and, by use of acetic anhydride instead ofdioxan, to the compound CC13CF2CFC1Br to give (CCl,*CF,CFCl)2. 8o75 R.N. Haszeldine, J . , 1953, 2525, 2622.7o Idem, Nature, 1951, 168, 1028; J., 1952, 4269.'13 A. K. Barbour, H. D. Mackenzie, M. Stacey, and J. C. Tatlow, J . A$$. Chenz.,79 R. N. Haszeldine, J., 1952, 4423 ; R. N. Haszeldine and B. R. Steele, J., 1853,1592.8o A. L. Henne, J . Amer. Chem. Soc., 1953, 75, 5750.7 7 Idem, J., 1954, 4026.1954, 4, 347; D. E. M. Evans and J. C. Tatlow, J., 1954, 3779HASZELDINE : PERFLUOROALKYL COMPOUNDS. 289Convenient syntheses for 1- and 2-trifluoromethylbutadiene and for1 : 1-difluorobutadiene 82 have been described.Pyrolysis of chlorotrifluoroethylene a t 550" yields, amongst other pro-ducts, 1 : 2-dichlorohexafluorocyclobutane and the olefins CF2:CF*CFC1CF2C1(used to prepare hexafluorobutadiene) and CF,:CF*CF,Cl.The allylicchlorine in the last compound is readily lost during nucleophilic attack on theolefin : 83n(4Xn CF2=CF-CF2-C1 CF,XCF:CF, + C1-; X = MeO, I, Br, or CNWhen heated at 150-180", hexafluorobutadiene is converted into hexa-fluorocyclobutene, and mixed dimers C,F,, and trimers C,,F18. The dimerfraction probably contains the diene (l), since when heated a t higher tem-CF2-CF--CF CF, CF,-CF-CF-CF, CF2-CF I l l I II CF,-CH I I I t CF,-CF-CF-CF, CF,-CF-CF=CF,( 1 ) (2) (3)perature it is converted into the fused-ring isomer (2).Lithium aluminiumhydride reduction of 1 : 2-dichlorohexafluorocyclobutane followed by treat-ment with aqueous potassium hydroxide gives the cyclobutene (3) .aTrifluoromethylacetylene, CF,*CiCH, was first prepared by the route 85CF,I 4- C2H2 __t CF,*CH:CHI - CF,-CiCH, and alternative syntheses(e.g., CF,*CH:CH, + CF,*CHBr*CH,Br __t CF3-CBr:CH2 --+CF3-CBr,*CH2Br CF,-CBr:CHBr CF,-CiCH) are now available.85, 86It is better to form a triple bond by dehalogenation of a compoundCF,*CX:CHX (X = C1 or preferably Br) than by dehydrohalogenation ofCF,*CX:CH,. Dehydrohalogenation of CF,*CH,*CH,X or CF,*CH:CHX isrelatively easy, since the hydrogen atom adjacent to a perfluoroalkyl groupis readily removed as a proton; conversely, halogen adjacent to a perfluoro-alkyl group is difficult t o remove as halide.85Hexafluorobut-2-yne is similarly prepared from CF,*CCl:CCI*CF, orCF3-CH:CHCF3,S7 and CF,*CiC*CH, from CF3*CH:CI*CH3.88The addition reactions of fluoro-defins and -acetylenes, convenientlyconsidered under (a) electrophilic addition, (6) nucleophilic addition, and(c) polymerisation and free-radical reactions, have been summarised in arecent review ; 89 only additional, more recent, or amplified results are there-fore considered in the rest of this section.Addition of hydrogen halides to perfluoro-H.M. Hill and E. B. Towne, U.S.P. 2,490,753/1949; A. L. Hcnnc and P. E.010" KOH(a) EZectrophiZic addition.Hinkamp, J . Anzer. Chem. SOC., 1954, 76, 5147.82 1'.Tarrant, M. R. Lilyquist, and J. A. Rttaway, ibid., p. 044.83 W. T. Miller, U.S.P. 2,671,799/1954, 2,668,182/1054; M. Prober and \V. '1. hlillcr,84 &I. W. Buxton and J. C. Tatlow, J . , 1954, 1177.8 5 R. N. Haszeldine, Natztre, 1950, 165, 152; J . , 1951, 588, 3495; R, K. Haszeldineand I<. Leedham, J., 1952, 3483.8 G A. L. Henne and M. Nager, J . Amer. Clzeiia. SOC., 1951, 73, 1042.8 7 C. I. Gochenour, E. A. Belmore, and 13. H. Wojcik, Abs. Amer. Chem. SOC.Meeting, Kew York, 1947, p. 1 3 ~ ; A. L. Henne and W. G. Finnegan, J . Anzer. Chern.SOC., 1949, 71, 208; R. N. Haszeldine, J . , 1952, 3490.a9 \V. I<. R. Miusgrsvc, Quart. Rev., 1954, 8, 331.J . Anzcr. Cheiii. SOC., 1949, 71, 59s.R. N. Haszeldine and I<. Leedham, J., 1954, 1261.RISP.-\'OL.LI 290 ORGANIC CHEMISTRY.olefins is dificult, since the double bond is deactivated to attack by a positiveentity by the fluorine atoms attached to the CX group and particularly byadjacent perfluoroalkyl groups. Tetrafluoroethylene and chlorotrifluoro-ethylene each yield the 1 : 1 adduct when treated with chloroform or carbontetrachloride in presence of aluminium trichloride ; the adduct fromchlorotrifluoroethylene and carbon tetrachloride was originally thought to beCC13*CF,*CFCl,,gQ but that electrophilic attack is on the CFCl group ofCF,=CFCl to give CC13CFC1*CF,C1 as expected, has since been proved.g1The inductive and hyperconjugative effects 92 (F-CF,:CH*CH,) of thetrifluoromethyl group in trifluoropropylene and trifluoromethylacetylenedeactivate the double or triple bonds, and polarise them 92p 93 as CF3*C-C ;addition of HX to the last compound thus yields CF3*CH:CHX (X = F,C1, Br, I, or CN).92 Addition to the alkyne CF3*CiC*CF3 is particularlydifficult, and use of Friedel-Crafts catalysts is advantageous or nece~sary.~,Deactivation to electrophilic attack usuallymeans activation to nucleophilic attack, particularly with fluoro-olefinscontaining fluorine attached to the C:C group.Thus perfluorohept-1-ene iscompletely decomposed by solid (but not anhydrous) potassium hydroxidea t 135°.94s+ s-f1- 8+(b) Nucleophilic addition.Aq. KOHC,I~,~CFZ.CF:CFz - j ~ C4Fg*CF2CHF*CF2*OH +- HFC,F,CF,*CHF*COF __t C,F,*CF:CF.COFC,F,CF:CFCOF C4FgCF:CHF 4 etc.Most fluoro-olefins need alkoxide ion to initiate the ready addition of analcohol to the double bondROH(e.g., RO- + C,F, RO*CF,CF2- ___t RO*CF,*CHF, + RO-)but perfluoroisobutene 64 and trifluoroacrylonitrile 55* 95 are so sensitive tonucleophilic attack that they react with alcohols in absence of catalyst togive (CF,!,CH*CF,*OR and ROCF,CHF.CN.Reaction of trifluoromethylacetylene or hexafluorobut-2-yne with diethyl-amine, or with methanol or ethanol in presence of sodium alkoxide, readilyyields CF,*CH:CHX, or CF3*CH:CX*CF3, and under more vigorous conditionsCF,*CH,*CHX, or CF3*CH,*CX,*CF3 (X = NEt,, OMe, or OEt) .92 Duringthese reactions, during that of trifluoropropylene with ethanol and sodiumethoxide to give CF3*CHz*CH2-OEt,96 and during that of hexafluorobut-2-ynewith acetic acid in a basic medium to give CF,*CH:C(OAc)-CF3,96 loss of90 D.D. Coffman, R. Cramer, and G. W. Rigby, J . Arne+. Chcnz. SOC., 1949, 71, 979.9 1 A. L. Henne and D. W. Kraus, zbid., 1951, 73, 5303.92 R. N. Haszeldine, J., 1952, 2504, 3490; R. N. Haszeldine and 1C. Leedham, J . ,93 A. L. Henne and S. Kaye, J . Anaer. Chena. SOC., 1950, 72, 3369; A. L. Henne and94 D. Grafstein, Aizalyf. Chem., 1964, 26, 523.95 J. D. LaZerte, R. J. Koshar, W. H. Pearlson, J. D. Park, B. A. Rauscli, and J. 13.9 6 A. L. I-Ienne, M. A. Smook, and R. L. Pelley, J . Amer. Chewz. SOC., 1950, 72,1952, 3483.M. Nag-er, ibid., 1952, 74, 650.Lacher, Abs. Amer. Chem. SOC. Meeting, New York, 1954, p. 2 6 ~ .4'756; A. L.Henne, J. V. Schmitz, and W. G. Finnegan, ibid., p. 4195HASZELDINE : PERFLUOROALKYL COMPOUNDS. 291fluoride occurs from the allylic perfluoroalkyl groups. It has been sug-gested 92 that the extreme negativity of fluorine makes hyperconjugativestructures such as F CF,:C:bH, F CF,:CH-bH,, and $ CF,:C:?*CF, foracetylenes and olefins more important than hyperconjugative structures inhydrocarbon compounds (e.g., H CH,:C:CH), so that fluorine atoms attachedto a carbon atom adjacent to a double bond (F*CC:C) are labile and readilylost during nucleophilic attack, e.g. :+ -F- + [CF,:C:CH.OR] etc.It will be noted that the inductive and the hyperconjugative effect act in thesame sense as far as direction of ionic addition to an unsaturated link isconcerned. In 1 : 1 : 3 : 3 : 3-pentafluoro-2-methylpropene the inductive(F,C+CMe:CF,) and the hyperconjugative (F CF,:CMe*EF,) effect of thcCF, group, and the inductive and the back-co-ordination effect of fluorinein F C C act in the same direction to give the overall polarisationCF,CMe=CF, ; in 1 : l-difluoropropene, however, the methyl group(CH,+-CHXF,; I? CH,:CH*CF,) opposes the effects of the fluorine atoms(CW,*CH=C’” ; CH3*CH*CF:6), but the overall polarisation, determinedby experiment, is CH,*CH=CF,.g7 In general, the simple inductive effectof fluorine in F C C can be used to predict empirically the direction of ionicaddition in compounds CF,=CXY (X or Y = F, C1, H, CH,, or CF,).Inabsence of “ vinylic ” halogen the inductive effect of the perfluoroalkylgroups attached to the double bond determines direction of addition [e.g.,s- 6+ 6- s+ 6- s+CF,*CH=CH, ; (CF,),CYCH2 ; CF,*C=CH].Recent reviews 9 8 3 99 covermost of the salient features of the polymerisation of fluoro-olefins to long-and short-chain polymers.A recently fluorocarbon elastomer loo is a saturated copolymer of chloro-trifluoroethylene, which shows excellent elasticity and resists chemical attack.Perfluoroiodoalkanes readily react by a free-radical mechanism with anolefin CRR’:CR”R”’ :CV31 -- CF,. -1- 1.s- 6+NF 6- s-i-s+ s-(c) Polymerisation and free-radical reactions.h v or heatCF,.-1- CRR’:CR”R”’ __t CF,*CRR’*CR”R”’ InitiationCI;,*Cl<i<’*~R”K”’ + CRR’:CR’’R”’ __tCF,.CRR’.CR“R”/.CKR’.~R//~~///, ctc.l’ropagationCF,CRR’CR”R”’I + CF,. __t etc. Chain transferCI;,-CRR’.~R//R~// + CF,I __t9 7 13. N. Haszeldine, J., 1953, 3665.9 8 G. Bier, K. Schaff, and EC. H. Kalirs, Angew. C h e w , 1964, 66, 285.99 1. I. G. Cadogan and D. H. Hey, (&art. Rev., 1954, 8, 308.100 %I. E. Conroy, L. E. Robb, D. R. Wolf, and F. J. Honn, Abs. Amer. Chem. SOC.Meeting, Kew York 1954, p. 5 ~ 292 ORGANIC CHEMISTRY.Iodo-compounds are thus produced, e.g., CF,*CH,*CH,I from ethylene,CF,*CH:CHI from acetylene.lo1 Tetrafluoroethylene yields CF,fCF2]n*I,and the value of n can be substantially controlled, and in particular madesmall, by choice of reactant ratio and by ensuring that reaction occursmainly in the liquid phase. Attack of a CF, radical on a variety offluorine-containing olefins and acetylenes has been studied to determinethe ease of attack and in particular the direction of addition ; trifluoroiodo-methane is used as source of the radical, since heat or light breaks thecarbon-iodine bond homolytically and addition proceeds smoothly to giveCF,*CRR'*CR"R"'I with few side-reactions.The point of attack, indicatedby an asterisk in the series : CHJHX (X = C1 or F), RCHXH, (R = CF,,CH,, CO,Me, CH,Cl, or CN), CF,*CF?F,, tF,:CFCl, CH,*~H:CF,,(CF,),C:?H,, (CF3) (CF,Cl)C:EH,, ?H,:CF,, CF3&HJ CH,*CiCH, andCH,:C:CH,, enables one to conclude that the direction of addition dependsupon the relative stability of the two possible intermediate radicalsCF3-CRR'kRt'Rt'' or CF,*CR"R"'*tRR', rather than on the polarisation ofthe double bond, steric effects, etc., though these undoubtedly affect the ratePolymerisation of CF,:CFCl, CH,:CHF, and CH2:CF2 occurs by head-to-tail addition.lo2 The conclfision that radical attack on chlorotrifluoro-ethylene was on the CFCl group lo4 has been criticised lo2 and withdrawn.lo5Free-radical reaction of hydrogen bromide with chlorotrifluoroethylene givesBr*[CF,=CFCl];H (n = 1, 2, 3, etc.) and the bromine atom, like a CF,radical, thus attacks the CF, group in this olefin.lo2Reaction of CF,Br*CI;ClBr with ethylene initiated by benzoyl peroxidegives CF,Br-CFCl*CH,*CH,Br, from which CF,:CF-CH:CH, has been prepared ;substituted butadienes CF,:CF=CH:CHR are similarly obtained from com-pounds CH,:CHR.136 Dibromodifluoromethane reacts with ethylene,propylene, etc., to give CF,Br*CH,*CRRBr (R = H, Me, C,Hll; R' = H,Me, etc.), dehydrobromination of which yields 1 : 1-difluorobutadienes.lo6Reaction of but-2-ene with bromochlorodifluoromethane or dibromodi-fluoromethane, followed by dehydrohalogenation, has been used to yield thediene CF2:CMe*CH:CH,.107Compounds containing Sulphur or Nitrogen.-Bistrifluoromet hyl di-sulphide is conveniently synthesised by the reaction of iodine pentafluoridewith carbon disulphide : loS* *.K.*of reaction.999 101,102,1031, IF, HeatCS, [CI,*SI] 4 CF,*SI + CF,.S,*CF,1°1 R. N. Haszeldine, J., 1949, 2856; 1950, 2789, 3037; 1953, 3761.102 Idem, J., 1952, 2504; 1953, 922, 3559, 3665; R. N. Haszeldine and B. R. Steele,Chew. and I n d . , 1051, 32, 684; J., 1953, 1199; 1954, 923, 3747; R.. N. Haszeldine andK. Leedham, J., 1953, 1548; 1954, 1261, 1634; R. N. Haszeldine, K. Leedham, and13. R. Steele, J., 1954, 2040.103 A. L. Henne and M. Nager, J . Amer. Chem. SOC., 1951, 73, 5627.1°4 A. L. Henne and D. W. Kraus, ibid., 1951, 73, 1791.lo5 I d e m , ibid., 1954, 76, 1175.P. Tarrant and E. G. Gillman, ibid., p. 5423; P. Tarrant and A. M. Lovelace,107 G. Crane and W. S. Barnhart, U.S.P. 2,686,20711954.108 R. N. Haszeldinc and J. M. Kidd, J., 1953, 3210; 1954, 4228.ibid., p. 3466HASZELDINE : PERFLUOROALKYL COMPOUNDS. 293or by interaction of trifluoroiodomethane and sulphur a t 250".109 Photo-chemical fission of the S-S bond in presence of mercury gives bis(trifluoro-methylthio)mercury, Hg(S*CF,),, which chlorine converts into the sulphenylchloride CF3.SC1 (b. p. -0.7"), also obtained quantitatively by direct chlorin-ation of the disulphide.lo8. log The thiol, CF,*SH (b. p. -37"), which is thesulphur analogue of the still unknown trifluoromethanol, is formed quantit-atively when the mercurial reacts with anhydrous hydrogen chloride.Trifluoromethanesulphonic acid, CF,*SO,H (b. p. 162") (cf. Me-SO,H,b. p. 165"/8-5 mm.), is the first member of a new series of acids, and is syn-thesised by oxidation of bis(trifluoromethy1thio)mercury with hydrogenperoxide.lo8 It liberates hydrogen chloride from alkali chlorides, and, likeits salts, shows high thermal stability. Conductivity studies in anhydrousacetic acid show that the acid is stronger than hydrochloric acid, sulphuricacid, or the perfluoro-carboxylic acids ; it is in fact one of the strongest acidsknown. Perfluoroalkanesulphonic acids have recently been obtained byelectrochemical fluorination. l10Fluoro-olefins combine with dinitrogen tetroxide,lll, 112 nitrosylchloride,l12 or nitryl chloride 112 to give compounds such as NO2*CF2*CF2*NO,and CF2C1*CF2*N02, but the perfluoroalkyl compounds are best preparedfrom the corresponding nitroso-compounds. The latter are intensely blue,monomeric, volatile compounds which result from combination of nitricoxide with a polyfluoroalkyl radical derived photochemically from a poly-fluoroalkyl iodide; the series CF,fCF,];NO with n = 1 4 or 6, and variouschloro- and bromo-compounds (e.g., CF2Br*NO) have thus been prepared. 112Synthesis from perfluoro-acids has also been achieved [e.g., CF3*C02Ag &CF,*CO*O*NO ___t CF,*NO, CF3*N0,, C02].112 Oxidation of the nitroso-compounds by oxygen or hydrogen peroxide yields trifluoronitromethane(b. p. -31"), etc. Trifluoronitrosomethane is not converted into the colour-less, stable trifluoroformamide, F*CO*NF,, as claimed earlier,l13 but intotrifluoronitromethane and hexafluoroazoxymethane, CF,*N+ (0-) :N*CF, (b. p.7"; cf. azoxymethane, b. p. 97"), by aqueous base or active carbon.ll2 Onexposure to ultraviolet light free-radical addition to an N=O bond occurs, thefirst reported :NOClHeatCF,*NO __t CF,. + NONOCF,. + CF,.N:O __t CF,-~~~OCI;, or (cF,),N.o. __tCF,*N(NO)-O.CF, or (CF,),N.O*NOInsuficient evidence is yet available to make a firm decision between thetwo possible dimers, although there is a slight preference for the fonner.114109 G. R. A. Brandt, H. J. Emelkus, and R. N. Haszeldine, J., 1952, 2198, 2549;Nature, 1950, 166, 225.110 P. W. Trott, T. J. Brice, R. A. Guenthner, W. A. Severson, R. I. Coon, J. D.LaZerte, A. M. Nirschl, R. D. Danielson, D. E. Morin, and W. H. Pearlson, Abs. Amer.Chem. SOC. Meeting, New York, 1954, p. 4 2 ~ ; T. Gramstad and R. N. Haszeldine,unpublished work.111 D. D. Coffman, M. S. Raasch, G. W. Rigby, P. L. Barrick, and W. E. Hanford,J. Org. Chcm., 1949, 14, 747.112 R. N. Haszeldine, Nature, 1951, 168, 1028; .T., 1963, 2075; J. Jander and R. N.Haszeldine, Natuvwiss., 1953, 22, 579; J., 1964, 912, 919; 1953, 4172; J. Banus, J.,1953, 3755. 113 0. Ruff and M. Giese, Rev., 1936, 69, 598, 654.114 J. Jander and R. N. Haszeldine, J., 1964, 696294 ORGANIC CHEMISTRY.Organometallic and Organometalloidal Compounds.-Perfluoroalkylderivatives (usually CF, or C3F7) of the following elements are nowknown: l15s116 Li, Mg, Zn, Cd, Hg, Al, Ga, C, Si, N, P, As, Sb, 0, S, Se, F,C1, Br, and I. The difficulties involved in the preparation of the Grignardcompounds, and their re'actions to produce primary, secondary, and tertiaryalcohols [including perfluoro-alcohols such as (C,F,),CH*OH, (C,F,),C*OH] ,ketones (including perfluoro-ketones), perfluoro-carboxylic acids, and per-fluoroalkyl derivatives of silicon [e.g. ,- (CF,),SiCl,], have been reviewed. llGR. N. H.G. BADDELEY.G. R. BARKER.W. COCKER.J. T. EDWARD.R. N. HASZELDINE.G. W. KENNELW. KLYNE.J. D. LOUDON.A. R. PINDER.M. C. WHITING.J. C. P. SCHWARZ.115 (Li, Cd, Si) : R. N. Haszeldine, Nature, 1951, 168, 1028; 0. R. Pierce, E. T.McBee, and G. F. Judd, J . Anaer. Claenz. SOL, 1954, '96, 474. (Zn) : R. N. Haszeldineand E. G. Walaschewski, J., 1953, 3607; W. T. Miller, Amer. Chem. SOC. Meeting,Atlantic City, 1952. (Hg) : H. J. Emelkus and R. N. Haszeldine, J., 1949, 2948, 2963;J. Banus, H. J. Emelkus, and R. N. Haszeldine, J . , 1950, 3041. (P) : F. W. Bennett,H. J. EmelCus, and R. N. Haszeldine, J . , 1953, 1565; 1954, 3598, 3896. (As) : G. R. A.Brandt, H. J. Emelkus, and K. N. Haszeldine, J . , 1952, 2652; H. J. Emelkus, R. N.Haszeldine, and E. G. Walaschewski, J., 1953, 1552; H. J. Emelhs, R. N. Haszeldine,and R. C. Paul, J., 1954, 881.ll6 W. K. R. Musgrave, Quart. Rev., 1954, 8, 333; R. N. Haszeldine, Angew. Cheni.,1954, 66, 693; H. J. Emelkus, J., 1954, 2979; H. J. EmelPus and R. N. Haszeldine,Science, 1953, 117, 311.For Mg, see ref. 19a

ISSN:0365-6217    

DOI:10.1039/AR9545100153

出版商:RSC    

年代:1954

数据来源: RSC

摘要:

BIOCHEMISTRY.1. INTRODUCTION.THE Annual Review of Biochemistry, 1954, 23, contains 636 pages and biblio-graphies of over 4200 publications ; nevertheless, the whole field of biologicalchemistry is not covered by one year's issue. The present Reporterstherefore make no apologies for omissions but express the hope that" Thermodynamical Data and their Applications," " The Chemical Natureof Active Centres of Enzymes," " Porphyrin Metabolism," and " BiologicalSyntheses and Interconversions of some Monosaccharides " will prove asufficiently catholic selection of topics to interest chemists in general.The following abbreviations are used, without further explanation, in thetext : A = adenosine ; AMP = adenosine monophosphate ; ATP = adenosinetriphosphate ; DPN = " diphosphopyridine nucleotide " {coenzyme I) ;TPN = " triphosphopyridine nucleotide " (coenzyme 11).D.J. B.2. THERMODYNAMIC DATA AND THEIR APPLICATION.In reporting this subject within a limited space one has the choice be-tween a cursory survey of data for the energy changes in the whole arrayof biochemical reactions or the more detailed treatment of a limited numberof these reactions. Here the latter approach is used and the topics chosenfor detailed discussion are selected on a purely personal basis and not fortheir relative importance in the general scheme. Reference is also made toa number of reviews and essays on thermodynamic considerations of bio-chemical systems, which are not otherwise treated.Concepts.-Some of the definitions and concepts which have been used indiscussions of the energy balance of biochemical reactions have been criticisedrecently.l, 2 The terms " high energy bonds " and " energy rich bonds ''introduced by Lipmann3 and elaborated by Kalckar4 are very useful forthe description of different energy levels of phosphate and other esters in-volved in the storage and passage of energy for endergonic syntheticalprocesses.However, the terms, if taken too literally, conflict with somewell-established concepts of chemical thermodynamics. First , bond energyis defined as the endothermicity of the separation of two bonded atoms.Hence the stronger the bond the more energy is required for its dissociation,while the biochemical " high energy bond " is defined as one which requiresmore than the standard amount of free energy for its formation.This maylead to confusion since covalent-bond energies are of the order of 150kcals./mole while the " energy rich " phosphate bond energies are about8 kcals./mole and of opposite sign. This leads to the second point of1 T. L. Hill and M. F. Morales, J. Amer. Chem. Soc., 1951, 73, 1656.2 R. J. Gillespie, G. A. Maw, and C. A. Vernon, Nature, 1953, 171, 1147.3 F. Lipmann, Adv. En,~pt~oZ., 1941, 1, 99.4 H. M. Kalckar, Clzem. Rev., 1941, 28, 111296 BIOCHEMISTRY.conflict,ll2 namely that free-energy values attributed to the various bondsinvolved in biochemical transfer reactions do not describe the energy storedin any one bond. They describe the overall free-energy change of a hydro-lysis or transfer reaction involving a number of consecutive chemical stepsof both the cleavage and formation of chemical bonds, quite apart fromchanges in electronic configuration, ionisation, and hydration which have amarked influence on the overall free-energy change of a reaction.Suchdiscussions about terminology must not be allowed to overshadow thebiochemical significance of the concepts and as long as they are alwaysclearly defined it is probably no worse to talk about the energy stored ina phosphate bond than it is to talk about the energy of an electron. Forthe time being the term " bond energy " as used in biochemical literature isequivalent to and interchangeable with the free-energy change associatedwith the hydrolysis of the particular ester.The use of one further concept, the efficiency of free-energy transferduring a series of consecutive reactions, is worthy of review.The criticismsof the terms used in this connection are again only justified because theyhave been interpreted sometimes too literally. The explanation of theenergetically unfavourable (endergonic) synthesis or reduction coupled withan exergonic hydrolysis or oxidation is of course not a thermodynamic onebut is found in the study of the intermediary compounds. Most biochemicalreactions involve enzyme catalysis. Catalysts, by definition, do not affectthe final equilibrium of a reaction but they do affect the efficient use ofenergy in two ways. First, by forming intermediary compounds 59 6 withradicals which are being transferred from a donor to an acceptor without thedissipation of free energy which would occur if this radical were to be setfree in solution. A simple example, which indicates the principle probablyapplicable to much more complicated multistage mechanisms, is the trans-phosphorylation described by M ~ r t o n .~ The phosphate-enzyme bond hasan energy which is higher than that of the phosphate bond in the reactionproduct. Since the enzyme concentration is very small compared with thatof the original phosphate donor the enzyme-phosphate bond can and prob-ably must have a larger energy than the phosphate bond in either reactantor product. The course of the transfer can only be explained by consider-ations of reaction mechanisms.Purely thermodynamical concepts can onlypredict the final equilibrium situation and give some information aboutenergetically possible intermediary compounds.The second important role played by enzymes and other catalysts in theefficient use of chemical energy is due to their specificity and resulting highyield of single intermediaries and products. Thus free-energy transfer canbe highly efficient in any scheme in which no other divergent reaction takesplace at an appreciable rate at any stage; it could be theoretically verynearly 100% efficient and it is therefore misleading to judge the efficiency ofsuch isothermal processes by the usual criteria for heat engines. It is outof place here to discuss such " chemical engines" in any detail.Beforediscussing thermodynamic data some obvious remarks about their applicationhave to be repeated and a further reminder given that such data cannotreadily be used for the prediction of reactions in vim unless full considerationis given to the complex concentration gradients and mechanical surroundings6 R. K. Morton, Nature, 1953, 172, 65. E. Racker, J . Bid. Chem., 1951, 190, 685GUTFREUND : THERMODYNAMIC DATA AND THEIR APPLICATION. 297of intracellular reactions. Nevertheless, with due care thermodynamicdata can be used more widely than just for the prediction of equilibria. Thedivision between the application of thermodynamical data and of modelsof physical and chemical mechanisms is described very clearly by Dixon.7Methods.-There are two general methods for the determination ofAGO, the standard free-energy change of a reaction.First it can be cal-culated from the difference in the free energy of the reactants and thereaction products in their standard states in solution. This can be done if datafor the heat of combustion, specific heat or spectroscopic energy levels, andfree energy of solution are available for all the components of the reaction.Though reliable thermal data are available for a number of amino-acids andpeptides 8s9 they are very scanty for other metabolites, and no new measure-ments have been reported for substances of biochemical interest since theoutbreak of the last war. Burton and Krebs lo have collected availablethermal data and the present interest has stimulated new programmeswhich should, in due course, provide more complete coverage.The second method for the calculation of free-energy changes rests uponthe interpretation of equilibria, by means of the equation AGO = -RT In K,,where K , is the thermodynamic equilibrium constant, based on activities.Most of the new data now reviewed come from this source, but in many casesan uncertainty is introduced because only the equilibrium constant K,,based on concentrations, is known, This method is applicable only if allcomponents are present in such quantities that their equilibrium concen-trations can be accurately determined.Furthermore one has to rely on AGOvalues calculated from thermal data for one standard reference reaction, asshown in the calculations for reactions involving ATP (p. 295).Thestandard free-energy change and the free-energy change a t any arbitraryactivity of the reactants can be calculated from the relation AG = AGO +RT In [product of activities of reactants on right-hand sidelproduct ofactivities of reactants on left-hand side]. If the system is in equilibrium theterm in brackets is K,, and AG = 0.The standard heat changes AHo of reactions have been determinedeither by use of the effect of temperature upon the equilibrium constant- AHo = R[d In Ka/d(l/T)]or from direct calorimetric measurements of the reactions. The heatchange during a chemical reaction does of course not give information aboutits direction or equilibrium position. However, the division of the free-energy change into its two components, heat and entropy, is often instructivefor an understanding of the mechanism of a reaction.llAcid- and Base-linked Equilibria.-Various mechanisms have recentlybeen clarified in which the concentration of hydrogen and other ions affectsthe equilibrium position of a reaction, which is in some way linked to anionising group.7 M.Dixon, “ Multi-Enzyme Systems,” Cambridge University Press, Cambridge,H. Borsook and H. M. Huffman, in ‘‘ Chemistry of Amino Acids and Proteins,”H. Borsook, Adv. Protein Chew., 1953, 8, 127.1949.Ed. C. C . Thomas, Springfield, 1938.10 K. Burton and H. A. Krebs, Biochm. J., 1963, 54, 94.11 H. Gutfreund, Adv. Enzymol., 1951, 11, 26298 BIOCHEMISTRY.Krebs l2 describes the effect of the hydrogen-ion concentration on theequilibrium ratio L-malic : fumaric acid.This system is a good example ofan enzyme-catalysed equilibrium reaction with associated changes of ionis -ation constants. The two ionisation constants of malic acid are K, =3-3 x 10-4 and K, = 7.7 x lov6 while those for fumaric are K,’ = 9.6 x 10-4and K,‘ = 4.0 x The following equation is derived :where T and T‘ are the concentrations of all forms of malic and fumaricacid, respectively, and Y = [M=]/[F’], the ratio of the concentrations of thefully ionised species. Clearly Y can be evaluated experimentally ; when [H+]is considerably smaller than any of the four ionisation constants TIT’ =[M=]/[F‘] = r. For equilibria between two monobasic acids A and B theexpression becomes :TA [A-] .KB{[H+] + KA)TB = [m KA([H+] + KB)Krebs points out that this problem is analogous to that of the effect ofpH on oxidation-reduction potentials, treated by Borsook and Schott,13and he also applies the above equation to the equilibrium ratio [total inorganicphosphate]/[total glucose-1 phosphate] in the phosphorylase system betweenpH 5 and 7.3; there is a fourfold change of equilibrium constant over thispH range. Similar calculations were also carried out by Trevelyan, Mann,and Harrison,14 who also take into consideration the effect of ionic strengthon this equilibrium.Alberty l5 treated similar problems and analysed the effect of pH onthe equilibrium K = [aldehyde][DPNH]/[alcohol][DPN] over the range pH7.0-10.0 in which there is a 1000-fold change in the value of K.For ananalysis of the effect of pH on oxidation-reduction equilibria see also Dixon.’resolve the dephosphorylation of ATP into threeionisations and one hydrolytic step under neutral conditions.Hill and MoralesH20 + ATP4- ADP2- + HPOd2- + +H’ 11 H+r 11 ADP8- +ATP3 - Hf H,PO,-From these examples it can be seen that the ionisation constants of all thereactants and products are an essential part of the thermodynamic datadescribing such systems. Alberty, Smith, and Bock l6 have determined theapparent (non-thermodynamic) dissociation constants of adenosine mono-,di-, and tri-phosphates, adenosine, and adenine, and described the contri-12 H. A. Krebs, Biochern.J . , 1953, 54, 78.13 H. Borsook and H. F. Schott, J . Biok. Chem., 1931, 98, 535.14 W. E. Trevelyan, P. F. E. Mann, and J. S. Harrison, Arch. Biochem. Biophys.,16 R. A. Alberty, R. M. Smith, and R. M. Bock, J . Biol. Chem., 1951, 193, 425.1952, 39, 419. 1 5 R. A. Alberty, J . Amer. Chem. Soc., 1953, 75, 1928GUTFREUND : TITERMODYNAMTC DATA AND THEIR APPIJCATION. 299bution of the ionising groups to the free energy of the three hydrolysisreactions :A M P - - t A + PADP -+ AMP + PATP-ADP + Pover the range pH 3-10 in 0.15~-sodiurn chloride solutions.Ashby, Crook, and Datta l7 have dealt with theoretical and experimentalaspects of the determination of thermodynamic dissociation constants ofbiologically important compounds. They stress the importance of suchthermodynamic constants and of a knowledge of the activities of the ions inthe systems for which calculations of thermodynamic quantities are at-tempted.They applied their procedure to the determination of the thermo-dynamic pK's of glycerol 2-phosphate; l8 at 25" pK, = 1.335, pK, = 6.650.Trevelyan et aZ. l4 determined the second dissociation constant for glucosel-phosphoric acid at 30" to be pK = 6-51. A comparison with pK, = 2-148and pK, = 7.198 for inorganic orthophosphate at 25" demonstrates theincrease in acidity on esterification.The effect of biologically present bivalent ions, e.g., Mg2+, on equilibriainvolving bivalent acids has been discussed by Trevelyan et aZ.19 and Burtonand Krebs.20 Clarke, Cusworth, and Datta 21 have determined the thermo-dynamic quantities for the dissociation equilibria of the magnesium salts ofphosphoric acid, glucose l-phosphoric acid, and glycerol 2-phosphoric acid.As their programme l7 progresses one will be able to calculate the effect ofthe concentration of various ionic species on the hydrolysis equilibrium ofmany of the important phosphate esters.The effect of the concentration of Mg2+ on the equilibrium[ATP] [creatine]/ [ADP] [creatine phosphate]has been investigated 22, 23 but only the results obtained from extrapolationto zero concentration of Mg2+ can be interpreted a t present.Ionisation equilibria also have to be considered in connection with free-energy changes during the synthesis of amino-acid amides, esters, andpeptides.This subject has been reviewed recently by Borsook and somecalculations of the effect of pH on the hydrolysis equilibrium of the peptidebond in benzoyl-L-tyrosylglycinamide have been carried out by Dobry,Fruton, and S t ~ r t e v a n t . ~ ~ Their equation (14) showing the relation betweenthe apparent equilibrium constant and the hydrogen-ion activity aH+ shouldreadKapparent == Khydrolgsis - (1 + a€I+/KA)(l KB/&T+)KA and KB are the dissociation constants of the acid and base formed onhydrolysis and Khydrolysis is the pH-independent equilibrium constant for theformation of the fully ionised hydrolysis products.1 7 J. H. Ashby, E. M. Crook, and S. P. Datta, Biochem. J., 1954, 56, 190.Is W. E. Trevelyan, P. F. E. Mann, and J.S. Harrison, Arch. Biochem. Biophys.,20 K. Burton and H. A. Krebs, Biochem. J.. 1953, 54, 94.21 H. B. Clarke, D. C. Cusworth, and S . P. Datta, ibid., 1954, 58, 146.Z2 B. Asconas, Dissertation, Cambridge, 1951.23 S. A. Kuby, L. Noda, and H. A. Lardy, J. Biol. Chem.. 1954, 210, 83.24 A . Dobry, J . S. Fruton, and J. M. Sturtevant, ibid., 1952, 195, 149.Idem, ibid., p. 198.1962, 39, 440300 BIOCHEMISTRY.The ionisation constants of amino-acids and their derivatives listed byCohn and Edsall 25 are still generally used though some new programmes forobtaining thermodynamic ionisation constants are under way.26% 27In the subsequent discussions AGO is taken strictly as the standard free-energy change calculated for’ specified ionic species (see for instance ref.24),while AG is a pH-dependent quantity calculated from the apparent equili-brium constant which takes into account the sums of all ionic species of eachreactant. A very clear description of the effect of pH on a number ofequilibrium systems is given by Dixon.‘Phosphate Esters.-In a previous Report 28 “ the part played byphosphate in storage and transfer of energy” was surveyed. Apart fromthe properties of phosphate esters already described in the preceding pagesa number of revised estimates of the standard free energy of hydrolysis ofthese compounds under specified conditions as well as analyses of the variouscontributions to such energies have appeared recently.The problem of drawing up a table of values of AG of hydrolysis forthese compounds can be reduced to establishing reliable values for the freeenergy for one compound from calorimetric data and for others from equili-brium constants for phosphate transfer between them.Morales, Botts, Blum, and Hill 2Dj30 calculate AG = -7000 cal./mole forthe hydrolysis of the third phosphate of ATP.Their value is based on acombination of the equilibrium measurements of Levintow and Meister 31for the reaction :Glutamate + ATP + Ammonia + Glutamate + ADP + Phosphatewith an estimate for the standard free energy of the formation of glutaminefrom glutamate and ammonia. The value for the latter reaction is obtainedby correcting Borsook’s data for AGO for the formation of asparagine bytaking into account the difference in the pK of the two carboxyl groups tobe aminated.It is difficult to assess the accuracy of the resulting value,AG = -2700 cals./mole, and calorimetric work which is being carried outunder the direction of Dr. J. 0. Hutchens at the University of Chicago willgive a direct determination of AGO for the formation of glutamine. Theequilibrium constantK = [ADP] [glutamine] [orthophosphate]/[ATP] [glutamate] [NH,+]was found 31 to be 1.2 x at 37” and pH 7.0. The difference between AGfor the hydrolysis of ATP and for the synthesis of glutamine is -4300cals./mole which, together with the above value for the synthesis of glutamine,gives AG = -7000 cals./mole for the hydrolysis of ATP to ADP and ortho-phosphate. The pH and temperature dependence of the above equilibriumconstant have also been discussed.25 E.J. Cohn and J. T. Edsall, “ Proteins, Amino Acids, and Peptides,” Reinhold2 6 E. J. King, J , Amer. Chem. SOC., 1954, 76, 1006.27 E. Ellenbogen, ibid., 1952, 74, 5198.28 D. M. Needham, Ann. Re$orts, 1952, 40, 276.29 M. F. Morales, J. Botts, J. J. Blum, and T. L. Hill, “ The Elementary Process inMuscle Action ” in “ Currents in Biochemical Research,” 2nd Ed., 1955, IntersciencePublishers, New York.31 L. Levintow and A. Meister, J . BioE. Chem., 1954, ROO, 265.Publishing Corp., New York, 1943.so M. F. Morales, Appdx. t o Ref. 31GUTFREUND THERMODYNAMIC DATA AND THEIR APPLICATION, 301Burton32 adduced a value AG = -8900 cals./mole for the hydrolysisof ATP to ADP and orthophosphate at pH 7.5 and discusses reasons forthe revision of the value, AG = -9400 cals./mole, previously used byBurton and Krebs.20 Wurmser 33 has also suggested a revision from Lip-mann’s 3 value of -11,800 to about -8800 cals./mole to bring the resultsof calculations from equilibrium measurements into line with the free energiesof formation of glucose and lactate determined calorimetrically by Parksand Huffman.34 We are thus left with an estimate for the free energy ofhydrolysis of ATP of -8000 & 800 cals./mole at pH 7.However, this valueis subject to refinement when some of the calorimetric data which have beenpromised become available.The following two recent equilibrium determinations give examples ofthe use which can be made of a reliable value for the free energy of hydrolysisof ATP.Eggleston and Hems 35 measured the equilibrium[ATP4-] [AMP2-]/[ADP3-I2 = 0.444at pH 7.4 and 25”, and one can write :ADP + ADP __+ ATP + AMP + 480 cal.to indicate the difference in the free energy of hydrolysis of the two pyro-phosphate bonds.The equilibrium [ATP] [creatine]/[ADP][creatine phosphate] = 1.5 wascalculated by Asconas 22 from an extrapolation to zero concentration ofMg2+ ions a t pH 8.5.The difference between the free energies of the twohydrolysis reactions under these conditions is :ADP + Creatine phosphate ATP + Creatine -240 cals.The combination of the result obtained by Stadtman 36 for the reaction :Acetyl phosphate + Coenzyme A +Acetylcoenzyme A + Phosphate -2400 cals.(at pH 8.0) with Burton’s32 value for the hydrolysis of acetylcoenzyme Agives AG = -10,500 cals./mole as an approximate value for the hydrolysisof acetyl phosphate.The free-energy data for steps involving the phosphorylation of glucose,glycerate, and pyruvate have been summarised recently37 and have beendiscussed very critically. This paper by Burton and Krebs 10 and theprogramme of obtaining ionisation constants for various phosphates 179 18922has set a new standard for experimental accuracy and rigorous thenno-dynamic analysis in this field.There is no further need to draw attentionto data which ought to be obtained, because the work referred to clearlydraws attention to the weak links in the calculations and this does not seemto be the time to discuss doubtful data.32 K.Burton, Bioclaem. J., 1955, 59, 44.33 R. Wurmser, Ann. Rev. Biochem;, 1951, 20, 1.34 G. S. Parks and H. M. Huffman,35 L. V. Eggleston and R. Hems, Biochem. J., 1952, 5&, 156,36 E. R. Stadtman, J . Biol. Chem., 1952, 196, 535.The Free Energies of Some Organic Compounds,”1932, Reinhold Publishing Corp., New York.37 Ref. 10, Table 7302 BIOCHEMISTRY.Sturtevant and his colleagues have recently redetermined and discussedthe heats of hydrolysis of three phosphates :Compounds pH AH (cals. /mole) Ref.lnorganic pyrophosphate ............... 7-3 6800 38 ....................................... 5800 39 ATP -pNitropheny1 phosphate ............... 3.6-5.8 6280 40These values are considerably lower than those previously reported.Greatcare has been taken to obtain accurate data for the heat of neutralisationby the buffers present in the reaction mixture and to correct for them.Other Labile Esters.-Earlier data for the free-energy change associatedwith the hydrolysis of acetylcoenzyme A have been reviewed by Burton32and he gives a revised value of AG = -8200 cals./mole for this reaction atpH 7. This is an approximate value since he describes the results of cal-culations for three different equilibrium reactions which give AG = -7380,-8700, and -8250 cals./mole. These values can be compared with thoseobtained by Faber and Reid 41 for the esterification of acetic and propionicacid by various thiols, and it is likely that thermodynamic data for a numberof thiol esters will be obtained soon.This group of compounds may playan important role as the catalytic centre of enzymes during group-transferreactions in various systems and may be responsible for “ energy-rich ”enzyrne-substrate bonds. Acylglyoxalines may play a similar role ; theyhave been suggested as labile intermediaries during enzymatic ester hydro-lysis by trypsin 42 and may also occur during other hydrolytic reaction^.*^^ *The equilibrium reaction :was studied by Stadtman.45 The standard free-energy change, AGO =-3200 cals./mole for the hydrolysis of acetylcholine is discussed by H e ~ t r i n . ~ ~Peptides and Amides.-Thermodynamic information about amino-acidsand peptides was obtained by Borsook, Huffman, and their collaborators.This calorimetric work a t the California Institute of Technology was dis-continued during the early part of the last war but a new collaborative effortto obtain data for the free energy and heat of formation, as well as thethermodynamic solution properties, of compounds concerned in proteinsynthesis is being organised by Dr.Hutchens of the University of Chicago.A feature of this programme will be that all the constants will be determinedon the same, highly purified preparations.Borsook and Dubnoff 47 obtained the following values for the standardfree energy of hydrolysis of peptide bonds in an acid and a zwitterionrespectively :Acetylcoenzyme A + Glyoxaline Acetylglyoxaline + Coenzyme AHippurate- (1 M) -+ H2Oliq. --+ Benzoate- (1 M) -+ Glycine -2640 cals.Alanylglycine+ (1 M) + H20liq._I) Glycine* + Alanine* -4000 cals.38 N. S. Ging and J. M. Sturtevant, J . Amer. Chem. SOG., 1954, ’76, 2087.39 R. J. Podolsky, C. Kitzinger, T. H. Benzinger, J. M. Sturtevant, andM. F. Morales,41 E. M. Faber and E. E. Reid, ibid., 1917, 39, 1930.42 H. Gutfreund, Trans. Faraday Soc., 1956, 51, 441.43 I. B. Wilson, “ The Mechanism of Enzyme Action,” 1954, Johns Hopliins Univer-45 E. R. Stadtman, “ The Mechanism of Enzyme Action,” 1954, Johns Hopkins4 7 H. Borsoolr and J. W. Dubnoff, J . BioZ. Chent., 1940, 132, 307.Fed. Pyoc., 1954, 13, 112. 40 J. M. Sturtevant, J . Amer. Chem. Soc., 1955, 7’9, 255.sity Press, p. 642.University Press, p. 581.4 4 P. Desnuelle, Ann. Rev. Biochem., 1954, 23, 56.4* S.Hestrin, Biochem. Biophys. A d a , 1950, 4, 310HARTLEY CHEMICAL NATURE OF “ ACTIVE CENTRES ” OF ENZYMES. 303These were calculated from calorimetric data including solution properties ;Huffman 48,49 gives values for the free energy of peptide bonds in a widerrange of compounds which were calculated from thennal data for the freeenergy of formation of the solid compounds without considerations of thefree energy of solution.Dobry, Fruton, and SturtevantK = [benzoyl-~-tyrosine~[glycinamide]~[benzoyl-~-tryosylglycinamide]in the presence of chymotrypsin by an isotopic-tracer method and calculatedthe standard free energy for the reaction AGO = -420 & 50 cals./mole.It is not easy to say whether this value can be compared with those obtainedby Borsook et al.Thermodynamic data for the solid crystalline materialswould correspond to those for fully ionised zwitterions.The heat of hydrolysis of various peptides and amides has been deter-mined by Sturtevant and his colleagues by his calorimetric te~hnique.5~In each case the contribution from ionisation of the products and from thebuffer present has been taken into account and the data given below referto the formation of fully charged products at 25”. The bond hydrolysed isindicated by a broken line.studied the equilibriumCompound AH (cals./mole) Ref.Benzoyl-L-tyrosiniamide ........................... 5840 & 220 52Glycyl-L-phenylarialyllamide ..................... 6220 f 150 51Benzoyl-~-tyrosyllglyc‘inamide .................. 1557 100 34Carbobenzoyloxyglycyli-L-leucine ...............21 10 -J= 50 51Carbobenzoyloxyglycyli-L-phenylalanine ...... 2550 & 50 5 2Polylysine(. . . lysyljlysyl . . .) .................. 1240 53In connection with studies on the heat of hydrolysis of polylysine,Sturtevant 53 has also determined the heat of ionisation of aminotrishydroxy-methylmethane, a useful buffer for many enzyme experiments :C(CH,*OH),*NH, + H+ -+ C(CH,*OH),*NH,+ -10,900 cals. (AH)H. G.3. THE CHEMICAL NATURE OF THE “ACTIVE CENTRES” OF ENZYMES.The concept of active centres in enzymes arose from the discovery oftheir high substrate specificity. Fischer’s “ lock and key ” analogy for theenzyme-substrate reaction is still largely accepted, but should be interpretedwith caution as a definition of an active centre.Early attempts at suchdefinition (e.g., Willstatter l) suggested a specific catalytic molecule attachedto a non-specific inactive colloid. Much of the work on respiratory enzymeand other conjugated proteins tended to favour this hypothesis. However,all attempts to separate activity from the protein fraction were unsuccessful.The necessity for an intact protein structure was emphasised by the prepar-ation of crystalline homogeneous enzymes such as urease or pepsin, which4 8 H. M. Huffman, J . Anzer. Che.nz. SOC., 1940, 62, 1009.4 9 H. M. Huffman, J . Phys. Chem., 1942, 46, 885.50 A. Ruzzell and J. 14. Sturtevant, J . Amer. Chem. SOC., 1951, 73, 2454.51 J. M. Sturtevant, ibid., 1953, ‘95, 2016.52 A. Dobry and J.M. Sturtevant, J . Biol. Chew., 1962, 195, 141.53 J. M. Sturtevant, Abs. Meeting Amer. Chem. SOC., Sept., 1954.1 R. Willstatter, J., 1927, 1359304 BIOCHEMISTRY.appeared to be entirely protein in character. The increasing reliability ofamino-acid analysis confirms this conclusion.2Nevertheless, there is considerable evidence that the substrate reacts a ta very limited number of specific sites in the protein. Conjugated enzymesinvariably possess a small fixed number of prosthetic or bound coenzymegroups per molecule, e.g., two DPN groups in Liver alcohol dehydrogenase.3Myrback showed that invertase is completely inhibited by a concentrationof silver ions amounting to 7-8 ions per molecule of enzyme. Unless grosschanges of structure occur, not more than 7-8 active centres can exist inthe molecule.Urease is completely inhibited when about 4 silver ionsare bound. Many other workers have observed reversible inhibition ofenzymes by reaction with a small number of thiol groups.6 The moleculesof chymotrypsin contain only one active centre, as is shownby their reaction with organophosphorus inhibitors. Similarly acetyl-cholinesterase can contain only a limited number of active sites9 Dialysisequilibrium methods, which estimate the number of molecules of competitiveinhibitor lo or of substrate l1 bound to chymotrypsin, support the hypothesisof a single active centre in this enzyme.In the absence of adequate information about protein structure or mech-anism of enzyme action, it may be desirable to include in a definition of the“ active centre” any groups in the enzyme which affect its activity.Afurther classification of such groups may, however, be useful. “ Activatinggroups ” may combine covalently with the substrate in one of the catalyticsteps, or provide the electrostatic field which weakens susceptible bonds.“ Specificity groups ” would play their major part in the initial formation ofthe enzyme-substrate complex, and would therefore contribute largely tosubstrate specificity. A high degree of organisation is presumed in theremainder of the enzyme molecule. Other chemical structures may there-fore play an essential part in maintaining structural rigidity in the protein,or influence ionisation in the active centre.Such classification of essentialgroups may prove illusory. Smith l2 points out that substrate specificitymay reflect the relative contribution of various ‘‘ activating groups.” Never-theless, distinctions of this nature have been of value in formulating catalyticmechanisms for enzymes, e.g., acetylch~linesterase.~~The structure of prosthetic groups of conjugated enzymes such as flavo-proteins or cytochromes explains a great deal of their catalytic activity.This subject has been extensively reviewed elsewhere l4 and must be omittedor trypsina G. R. Tristram, Adv. Protein Chem., 1949, 5, 83; “The Proteins,” Academic3 H. Theorell and R. Bonnichsen, Acta Chem. Scand., 1951, 5, 1105.4 K. Myrback, 2. physiol. Chem., 1926, 158, 160.5 J .F. Ambrose, G. B. Kistiakowsky, and A. G. Kridl, J . Amer. Chein. SOC., 1951,E. S. G. Barron, Adv. EnzymoZ., 1951, 11, 201.7 E. I;. Jansen, M. D. F. Nutting, and A. K. Balls, J . Bzol. Chem., 1949, 179, 189, 201. * B. A. Kilby and G. Youatt. Biochem. J., 1954, 5’7, 303.Press, New York, 1953, Vol. lA, p. 181.‘73, 1232.J. A. Cohen and M. G. P. J. Warringa, Biochim. Biophys. Acta, 1953, 11, 310.10 M. W. Loewus and D. R. Briggs, J. Biol. Chem., 1952, 199, 857.11 D. 0. Doherty and F. Vaslow, J . Amer. Chem. Soc., 1952, 74, 931,12 E. L. Smith, Adu;.EnzymoZ., 1951, 12, 191.13 I. B. Wilson, in Mechanism of Enzyme Action,” Johns Hopkins Press, Balti-14 H. Theorell, Adv. Enzymol., 19$,7, 7 , 265; J. Wyman, Adv. Protein Chem., 1948, 4,The Enzymes,” Academic Press, New York, 1951.more, 1954, p.042.407; J. B. Summer and K. MyrbackHARTLEY : CHEMICAL NATURE OF “ ACTIVE CENTRES ” OF ENZYMES. 305from this Report. Less is known about tihe protein environment of theseprosthetic groups, or about the active site in non-conjugated enzymes.Emphasis is therefore placed, in this Report, on methods by which muchuseful information has been obtained.Metal ions must be considered part of the active centre of many enzymes.Iron in the haem enzymes and copper in many oxidases play a central rolein the catalysis. Lehninger distinguishes cases in which the metal servesto bind the substrate to the enzyme. Thus the role of magnesium in manyphosphokinases, e.g. , fructokinase,16 may be to form a magnesium-ATPchelate complex which is the optimal substrate. Chelate complexes betweenmetal, substrate, and enzyme have been postulated by Smith l7 to explainthe activity of some peptidases, or by Hellerman for arginase.Klotz l9doubts whether such complexes would have the appropriate properties.He suggests that the metal, chelated at the active centre, may increase thelocal concentration of Bydroxyl ions, or stabilise the transition state.Substrate and Inhibitor Specificity.-The “ lock and key ” analogy ofenzyme action implies that the active centre has a configuration comple-mentary to that of the substrate. Hence systematic variation of structuralelements in the substrate can help to define this complementaTy configur-ation. Enzymes of moderate specificity have yielded most fruitful results,since considerable variations can be tolerated in the substrates.On theother hand, the criteria for specificity must be sufficiently rigid to permitreasonable speculation about structures in the active centre. Neurath andhis co-workers have suggested structural requirements for substrates of pan-creatic proteolytic enzymes.20 Thus chymotrypsin acts most efficiently onamides, esters, hydroxyamides, or peptides of aromatic L-a-amino-acids inwhich the a-amino-group is acylated.21 The aromatic ring, the carbonylgroup adjoining the susceptible bond, and possibly the “ secondary peptidebond,” reflect complementary structures in the enzyme. Similarly the sub-strate specificity of acetylcholinesterase 22 indicates a negatively charged“ specificity group ” in the eneyme close to the “ activating site.”Unfortunately many specificity studies are conducted a t a single arbitrarysubstrate concentration.If a range of substrate concentrations is used,kinetic constants can be calculated.hi k3k ,E + S e E S - E + Products . . . . (1)E, S, and ES represent enzyme, substrate, and enzyme-substrate complex,respectively : K,, k,, and k, are velocity constants and K , the Michaelisconstant = ( k , + h,)/k,. In a series of substrates, variations in K , whichare not due to changes in k, can be ascribed to structures involved in formingthe enzyme-substrate complex. For example, with the substrates for1 5 A. L. Lehninger, Physiol. Rev., 1950, 30, 393.1 4 H.G. Hers, Biochim. Biophys. A d a , 1952, 8, 424.1 7 E. L. Smith, in “ Enzymes and Enzyme Systems,” Harvard, 1951, p. 47.18 I,. Hellerman, Physiol. Rev., 1937, 17, 454.19 I. M. Klotz, in ” Mechanism of Enzyme Action,” Johns Hopkins Press, Baltimore,1954, p. 257.21 S. Kaufman and H. Neurath, Arch. Biochem., 1949, 21, 437; S. Kaufman, H.Neurath, and G. W. Schwert, J . Biol. Chem., 1949, 177, 793; €3. M. Iselin, H. T. Huang,R. V. McAllister, and C. Niemann, J . Amer. Chem. Soc., 1950, 72, 1739.*O H. Neurath and G. ?V. Schwert, Chem. Rev., 1950, 46, 69.22 V. 1’. JVhittaker, Physiol. Rev., 1951, 31, 312306 BIOCHEMISTRY.chymotrypsin N-acetyl-L-tyrosine ethyl ester 23 and N-acetyl-L-tyrosin-amide,= the values for Km are practically identical, while the values for k3are 2.0 and 0.003, respectively.Hence the ester or amide group plays littlepart in the initial formation of the enzyme-substrate complex.Structural analogues of substrates will often act as competitive inhibitorsof the enzyme. They are presumably bound at the active centre, but theirstructural requirements are often simpler than those for substrates. Sincethere is no catalytic reaction, the only groups involved are those concernedin complex formation with the enzyme. Structures which decrease thestability of the susceptible bonds in the substrate are here excluded.The structural requirements for competitive inhibitors of chymotrypsinare very similar to those for substrate^.^^ A secondary peptide bond in theinhibitor has little effect, and the susceptible ester or amide group can bereplaced by carboxyl or acetyl.An aromatic ring separated by twomethylene groups from a carbonyl group appears to be involved in bindingthese compounds to the active centre.26Efects of pH.-The effects of pH on enzyme activity have often beenascribed to the ionisation of groups in the active centre.27 A suitableanalysis of the pH-activity curves might therefore yield the dissociationconstants of these groups. Their identity can be inferred if it is assumedthat the values correspond to those of similar groups in amino-acids orpeptides. In general, this is a reasonable assumption, since variations indissociation constants of a particular group are fairly small in a large seriesof peptides2* Furthermore, such dissociation constants correlate thetitration curve of proteins such as serum albumin with their amino-acidcompo~ition.2~ However, considerable reservation must be made in apply-ing this argument to the active centre of enzymes, since unusual electrostaticfields may exist in these areas. Indeed many theories of enzyme actionimply such unusual ionising pFoperties, e.g., chelation with metal ions.lgThe interpretation of variations in enzyme activity with pH is by nomeans easy.Dixon 30 has analysed the effect of pH on K , in the case wherethis approximates to k 2 / k , [see equation (l)]. Dissociation constants ofgroups in enzyme, substrate, or complex appear as discontinuities in a plotof - log Km against pH. This analysis was applied to f ~ m a r a s e , ~ ~ andextended to allow for the effect of pH on k3.32 Two dissociation constantsobtained were ascribed to groups in the enzyme-substrate complex, since thevalues differ according to whether maleate or fumarate is the substrate.33Moreover, the values depend on the concentration of phosphate present 34or on the presence of other anions.35 This exhaustive study demonstrates23 J.E. Snoke and H. Neurath, J . Biol. Chem., 1950, 183, 577.24 G. W. Schwert and S . Kaufman, ibid., 1949, 180, 517.2 5 S. Kaufman and H. Neurath, ibid., 181, 623.26 H. Neurath and J.,P. Gladner:,ibid., 1950, 188, 407.2 7 J. B. S. Haldane, Enzymes, Monographs on Biochemistry, London and New28 E. J. Cohn and J. T. Edsall, ‘‘ Proteins, Amino-acids, and Peptides,” Reinhold28 C.Tanford, J . Amer. Chem. Soc., 1950, 72, 441.30 M. Dixon, Biochem. J., 1953, 55, 161.. 81 V. Massey, ibid., p. 172.32 R. A. Alberty and V. Massey, Biocham. Biophys. Acla, 1954, 13, 347.33 V. Massev and R. A. Alberty, ibid., p. 354.34 R. A. Alberty, V. Massey, C. Frieden, and A. R. Fuhlbrigge, J. Amer. Chem. SOC.,York, 1930.Publishing Corp., New York, 1943.1964, 76, 2485. 3 5 V. Massey, Biochem. J., 1953, 53, 67HARTLEY : CHEMICAL NATURE OF “ ACTIVE CENTRES ” OF ENZYMES. 307the care required in interpreting effects of pH on enzyme activity. Conse-quent conclusions about the nature of the groups in the active centre musttherefore necessarily be tentative.Additional evidence is available from the effect of pH on competitiveinhibition of the enzyme.With acetylcholinesterase the most effectiveinhibitors contain a positively charged trimethylammonium structure 36at a critical distance from an electrophilic carbon atom.37 The authorssuggest that these requirements correspond to “ anionic ” and “ esteratic ”sites, respectively, in the active centre, and have derived dissociation con-stants for groups in these sites.38 A later interpretation of their results l3ascribes pK 6.3 to the anionic and esteratic sites and pK 10.4 to a group inthe enzyme-substrate complex. Histidine has been suggested as a possiblegroup in the ‘‘ esteratic ” site.13 Histidine has also been suggested as anactive group in t r y p ~ i n , ~ ~ from a study of the effect of pH on the tryptichydrolysis of N-benzoyl-L-arginine methyl ester.Chemical Modification of Enzymes.-Chemical modification of specificgroups in the protein can indicate what types of structure are essential foractivity,40 but many conditions must be satisfied.The reagents and con-ditions must be specific for a limited number of groups, and must not causedenaturation of the protein. Both reagents and the protein groups involvedshould be estimated quantitatively. Ideally the inhibition should be capableof reversal. If modification of a particular group causes loss of activityunder these conditions, this group may be part of the active centre. Alter-natively the substituent may prevent access to the active centre by sterichindrance. Another possibility is that the modified group is an essentialstructural unit in the protein, e.g., a disulphide bridge linking peptide chains.Such distinctions have been made by Singer,41 who found that the inhibitionproduced in pancreatic lipase after reaction with various thiolic reagentsdepended on the substrate used for assay.With D-amino-acid oxidase theinhibition was the same whatever substrate was employed. In the formercase, the essential group involved may be a “ specificity’’ group, or theinhibition may be due to steric hindrance by the substituent. In D-amino-acid oxidase the essential thiol group is probably part of the substrate-activating mechanism.Although there is a considerable literature for this type of experiment,the conclusions are often ambiguous.Very few reagents show appropriatespecificity, and complete balance sheets for the reaction are often not available.In many cases the conditions used cause inactivation in control solutions.Some of the most satisfactory results have been obtained with reagentsattacking thiol groups in 18, 42 Few “ thiol-reagents ” are abso-lutely specific, but use of several with overlapping specificities can yieldsuggestive evidence. Oxidising agents, e.g., ferricyanide, porphyrindenc,iodosobenzoate, or iodine, and alkylating agents such as iodoacetate or iodo-36 I. B. Wilson and F. Bergmann, J . Biol. Chew., 1950, 185, 479.37 F. Bergmann, I. B. Wilson, and D. Nachmansohn, ibid., 1950, 186, 693.38 I. 33. Wilson and F. Bergmann, ibid., p.683.39 H. Gutfreund, l r a n s . Faraday SOC., in press.4 0 Reviews : R. M. Herriot, A d z . Proteiiz Claem., 1947, 3, l69;, H. S. Olcott and H.Fraenliel-Conrat, Chenz. Rev., 1947, 41, 151; F. W. Putnam in The Proteins,” Aca-demic Press, New York, ’1953, Vol. IB, p. 893.4 1 T. P. Singcr, J . Biol. Clzent., 1948, 174, 11. 42 Idem, Brewed Digest, 1946, 20, 8 5 ~ 308 BIOCHEMISTRY.acetamide are commonly employed. Mercaptide-forrning reagents are morespecific. Boyer 43 has developed a spectrophotometric method for deter-mining the amount of j5-chloromercuribenzoate bound to the protein. Heavymetals and organic arsenicals also form mercaptides with protein thiol groups.Inhibition by these reagents can frequently be reversed by addition ofreducing agents or thiols such as glutathione, cysteine, or B.A.L.Barron gives a list of enzymes in which essential thiol groups are claimed.More recent additions include aconitase,44 cytochrome red~ctase:~ isocitricdehydr~genase,~~ pyropho~phatase,4~ ribon~clease,~~ and p r ~ l i d a s e .~ ~ Thiolgroups vary greatly in reactivity in these enzymes. Thus only some of theless reactive thiol groups in urease are essential for activity.50 In certaincases, substrates 51 or coenzymes 52 protect an essential thiol group againstthe inhibiting reagent. In these cases, the thiol group must be part of theactive centre. Various functions have been ascribed to these essential thiolgroups, e.g. , as initiators of free-radical mechanisms in oxidative enzymes,6as binding sites for coenzyme or ATP,s3s 54 or as carriers of “ high-energy ”acyl groups.Cystine disulphide bridges probably preserve the structural configurationof many enzymes.In pepsin,55 one of the three disulphide bonds can bereduced with loss in activity, but further reduction causes inactivation ,probably by denaturation. Inactivation of lysozyme by periodate oxidationmay involve S-S bonds.56Essential amino-groups in enzymes have been investigated by deaminationwith nitrous acid or acetylation with keten or acetic anhydride. Tyrosineresidues also react with these reagents, but often more slowly.67 Thespecificity of other reagents, such as formaldehyde or phenyl isocyanate, iseven less satisfactory. Free amino-groups are probably not essential forthe activity of pepsin,58 t r y p ~ i n , ~ ~ chymotrypsin,60 or p-amylase.61 Theymay be involved in the activity of pancreatic amylase,62 alkalinepho~phatase,~~ and l y ~ o z y m e .~ ~The phenolic groups of tyrosine residues have been claimed as essential43 P. D. Boyer, J . Amer. Chem. SOC., 1954, 76, 4331.44 S. R. Dickman and A. A. Cloutier, J . Biol. Chem., 1951, 188, 379.4 5 L. P. Vernon, H. R. Mahler, and N. K. Sarkar, ibid., 1952, 199, 599.4 6 W. D. Lotspeich and R. A. Peters, Biochem. J., 1951, 49, 704.4 7 B. Naganna, Current Sci., 1951, 20, 101.4 8 L. Ledoux, Biochim. Biophys. Acta, 1953, 11, 517.4 9 E. Adams and E. L. Smith, J - Biol. Chem., 1952, 198, 671.50 L. Hellerman, F. R. Chinard, and V. R. Deitz, ibid., 1943, 147, 443.5 1 F.G. Hopkins and C. Lutwak-Mann, Biochew. J., 1938, 32, 1829.52 L. Rapkine, ibid., p. 1729; L. Hellerman, A. Lindsay, and M. R. Bovarnick, J .53 K. Bailey and S. V. Perry, Biochim. Biophys. Acta, 1947, 1, 506.54 E. Racker and I. Krimsky, J . Biol. Chem;; 1952, 198, 731.5 5 H. L. Kern, mentioned by R. M. Herriot, Mechanism of Enzyme Action,” JohnsHoykins Press, Baltimore, 1954, p. 24.5 6 H. Fraenkel-Conrat, Arch. Biochem., 1950, 27, 109.5 7 J. St.-L. Philpot and P. A. Small, Biochem. J., 1938, 32, 542; K. G. Stern andA. White, J . Biol. Chem., 1938, 122, 371; R. M. Herriot and J. H. Northrop, J . Gen.Physiol., 1934, 18, 35.59 13. Fraenkel-Conrat, R. S. Bean, and H. Lineweaver, J . Biol. Chem., 1949, 177, 385.60 I. W. Sizer, ibid., 1945, 160, 547.6 1 C .E. Weill and M. L. Caldwell. J. Amev. Cham. SOL, 1945, 67, 212.62 J. E. Little and M. L. Caldwell, J . Bd. Chew., 1942, 142, 585; 1943, 147, 229.63 33. S. Gould. ibid.. 1944, 16S, 365.Biol. Chem., 1946, 163, 533; H. L. Segal and P. D. Boyer, ibid., 1953, 204, 265.5 8 R. M. Herriot, ibid., 1935, 19, 283HARTLEY : CHEMICAL NATURE OF " ACTIVE CENTRES " OF ENZYMES. 309for the activity of many enzymes. Under appropriate conditions, iodinewill substitute specifically in the phenyl ring of these residues.64 However,thiol groups also react with iodine, and in some cases histidine is probablyiodinated.65 Complete iodination inactivates pepsin 66 when twelve of theseventeen tyrosine residues are s~bstituted."~ Acetylation with keten oracetic anhydride has been used to detect essential phenolic groups.Thethree free amino-groups of pepsin can be acetylated without loss of activity.58The inactivation after further acetylation is paralleled by the loss of freetyrosine groups. These acetylated tyrosine groups can be hydrolysed inacid, and the enzyme can be fully reactivated. Hence the active centre ofpepsin contains at least one tyrosine group. However, amino-groups arenot necessarily acetylated before tyrosine groups in all proteins.68 Nitrousacid often reacts with tyrosine residues more slowly than with amino-groups,57 but the specificity is doubtful.Carboxyl groups of proteins can be esterified by using methanol con-taining 0-1N-hydrochloric acid. This procedure caused inactivation oftryp~in,~Q but the conditions may cause denaturation.Diazoacetic ester ordiazoacetamide 69 may prove useful reagents for this purpose.Histidine and tryptophan have seldom been investigated as essentialgroups in enzymes. Fraenkel-Conrat 56 observed that the inactivation oflysozyme by iodination was reversed by treatment with sodium sulphite.This behaviour resembles that of iodinated histidine. Photo-oxidation ofproteins in the presence of methylene-blue has been studied by Weil andBuchert .'O With lysozyme, 71 70% inactivation occurred when one histidineand 1.2 tryptophan residues had been destroyed. With chymotrypsin 72complete inactivation corresponded with the destruction of one histidine andthree tryptophan residues.No detectable denaturation occurred, and theproduct no longer reacted with diisopropyl phosphorofluoridate (DFP) .Chymotrypsinogen similarly treated was no longer activated by trypsin.Fluorodinitrobenzene seems a promising reagent for detection of essentialgroups. Although not specific, the reaction products can be identified afteracid hydrolysis of the enzyme.73 Van Vunakis 74 has shown that bothglyoxaline residues of chymotrypsin and chymotrypsinogen react withfluorodinitrobenzene. However, Hartley and Massey 75 find that onehistidine residue in chymotrypsin is protected by a competitive inhibitorof the enzyme from reaction with fluorodinitrobenzene. Hence histidine ispart of the active centre of chymotrypsin.Organo@hos@zorus Compoumk-Certain organophosphorus compounds,e.g., diisopropyl phosphorofluoridate (DFP) or diethyl 9-nitrophenyl phos-phate, are powerful inhibitors of a group of hydrolytic enzymes.A crystalline64 C. R. Harington and A. Neuberger, Biochem. J., 1936, 30, 809.65 H. Bauer and E. Strauss, Biochem. Z., 1936, 284, 197, 231.g6 R. M. Herriot, J . Gen. Physiol., 1937, 20, 335.137 C. H. Li, J . Amer. Chem. SOC., 1945, 67, 1065.g8 C. H. Li and A. Kalman, ibid., 1946, 68, 285.69 P. E. Wilcox, Compt. rend. X I l t h Intern. Congr. of Pure and A$$L Chem., New7 1 L. Weil, A. R. Buchert, and J. Maher, ibid., 1952, 40, 245.i2 L. Weil, S. James, and A. R. Buchert, ibid., 1953, 46, 266.(4 H. van Vunakis, mentioned by R. M. Herriot (ref. 56).75 B. S. Hartley and V.Massey, unpublished results.York, 1951, p. 60. 70 L. Weil and A. R. Buchert, Arch. Biochem., 1951, 34, 1.F. Sanger, Biochem. J., 1945, 39, 507310 BIOCHEMISTRY.inhibited enzyme containing one atom of phosphorus per molecule can beisolated after reaction of chymotrypsin with DFP, while reaction with diethyl9-nitrophenyl phosphate results in liberation of one mole of nitrophenol permole of enzyme. 76 There is little doubt that these inhibitors react specificallyat the active centres of these enzymes, since DFP will not react appreciablywith the constituent amino-acids or the zymogen precursor of chymo-trypsin.7 Substrates or competitive inhibitors protect the active centres ofchymotrypsin 77 or cholinesterase 78 against these reagents. Sedimentationstudies indicate no denaturation after inhibition 79 and the inhibited enzymesare slowly reactivated by hydrolysis of the attached dialkyl phosphorylgroup.80The mechanism of action of these hydrolases is believed to involveacylation of a group in the active centre : - -E-H + R-CO-X E-CO-R + HX -% E-H + RCO,Hwhere E-H is the enzyme and RCO-X the substrate.81,82 Organophos-phorus inhibitors may react similarly, but hydrolysis of the dialkylphos-phorylated active centre would be very slow.Attempts have been made to identify the site of reaction of DFP inchymotrypsin or acetylcholinesterase by acid or enzymic hydrolysis of theinhibited enzyme containing 32P tracer.83 In this way O-phosphorylserineand O-phosphorylserylglycine have been obtained as hydrolysis products.The authors point out that these products may have arisen by transfer of alabile phosphoryl residue from its original site in the active centre.Mild enzymic hydrolysis of DFP-inhibited chymotrypsin has yielded apeptide which contains proline, leucine, aspartic acid, serine, and two orthree glycine residues, and has most of the added 32P tracer present in adiisopropylphosphorylsuggests that histidine is the primary siteof reaction of these organophosphorus inhibitors but intramolecular transferof the phosphate residue to another group in the enzyme, possibly a serinehydroxyl, may occur.Model Systems.-Model systems which imitate enzyme activity canoccasionally clarify the mechanism of enzyme action.Langenbeck 85 hasreviewed some such systems.Reactions catalysed by pyridoxal phosphateplus metal salts have been compared by Snell et aLS6 with those catalysed byenzymes containing this prosthetic group. Calvin 87 has considered theproperties of metal-chelate complexes as analogues of enzymes.The available evidence 729 75*7 6 B. S. Hartley and B. A. Kilby, Biochem. J., 1952, 50, 672.7 7 L. W. Cunningham, J. Biol. Chem., 1954, 207, 443.7 8 K. B. Augustinsson and D. Nachmansohn, J . Biol. Chem., 1949, 179, 643.79 E. L. Smith and D. M. Brown, J . Biol. Chem., 1952, 195, 525.80 I. B. Wilson, J. Biol. Chem., 1952, 199, 113; L. W. Cunningham and H. Neurath,82 B. S. Hartley and B. A. Kilby, Biochem. J., 1954, 56, 288.83 N. K. Schaffer, S. C. May, and W.H. Summerson, J . Biol. Chem., 1953, 202, 67;1954, 206, 201 ; N. K. Schaffer, S. Harshmann, and R. K. Engle, Fed. P ~ o c . , 1954,18,289.83a R. A. Oosterbaan, P. Kunst, and J. A. Cohen, Biochirn. Biofihys. Acta, 1955,16,299.84 T. Wagner-Jauregg and B. E. Hackley, J . Amer. Chem. Soc., 1953, 75, 2126.85 W. Langenbeck, Adv. Enzymol., 1953, 14, 163.8 6 D. E. Metzler, M. Ikawa, and E. E. Snell, J . Amer. Chem. Soc., 1954, 76, 649.87 M. Calvin, in “ Mechanism of Enzyme Action,” Johns Hoplrins Press, Baltimore,Biochim. Biophys. Acta, 1953, 11, 310. 81 I. B. Wilson, ibid., 1951, 7, 466, 520.1954, p. 221RIMINGTON : PORPHYRTN METABOLISM 31 1Labile acyl-enzyme intermediates have been postulated in substratecatalysis by cholinesterase 81 or chymotrypsin.82 Acyl derivatives ofglyoxaline satisfy many of the requirements of such an intermediate. Anacyl group attached to a glyoxaline ring is rapidly hydrolysed * 8 and willtransfer to a free a-amino-group (tran~peptidation),~~ or to thiol, alcohol, orphosphate groups.90 Histidine inpeptide form, e.g., N-benzoyl-L-histidine methyl ester, will catalyse thehydrolysis of 9-nitrophenyl acetate, which is a substrate for chym~trypsin.~~A corresponding low catalytic activity in insulin is probably also due tohistidine. 82 Derivatives of glyoxaline will catalyse the hydrolysis of organo-phosphorus inhibitors such as DFP. 84 However, these model systems explainonly a few of the properties of the enzyme. Much work remains to be doneon the chemical nature of active centres.It is a “ high-energy ” acyl d e r i v a t i ~ e .~ ~B. S. H.4. PORPHYRIN METABOLISM.Porphyrin chemistry was surveyed in these Reports in 1950. At thattime the location in the porphyrin ring of those carbon atoms contributedduring biosynthesis by glycine had been ascertained and also the origin ofthe nitrogen atoms from glycine, but all that was known of the remainingcarbon atoms was that the use of radioactively labelled acetate resulted inradioactively labelled protoporphyrin or hzem. So rapid has progress beenduring the last four years that this Report will be devoted almost entirely tothe subject of porphyrin biosynthesis and metabolism. Outstanding dis-coveries have been the structure of porphobilinogen, the fact that this sub-stance is an intermediate in porphyrin biosynthesis-it being, in fact, theprimary pyrrolic material from which hzem and chlorophyll are derived,and the role played by 8-aminolzevulic acid in the biosynthesis of porpho-bilinogen itself. Methods for the production of an experimental “ por-phyria ” accompanied by porphobilinogen excretion in animals may proveto be of great eventual value in elucidating the biochemical defects in acuteand congenital porphyria in man.The past year has seen the appearance of a book on porphyrins and ofseveral review articles dealing with one or other aspect of porphyrin bio-chemistry; attention may be drawn to “ Porphyrins in Nature,” “ Meta-bolism of haem and chlorophyll,” “ Drugs and porphyrinmetabolism,” “ Normal and pathological metabolism of porphyrins,” 7“ Patterns of porphyrin excretion,” Pathology of acute porphyria :experimental porphyria in animals.”“ Porphyria,”and8 8 0.Gerngross, 2. physiol. Chem., 1919, 50, 108.a9 M. Bergmann and L. Zervas, ibid., 1928, 175, 145.91 B. S. Hartley and V. Massey, unpublished results.E. R. Stadtman and F. H. White, J . Amer. Chem. Soc., 1953, 75, 2022.J. E. Falk and C. Rimington, A m . Reports, 1950, 47, 271.A. Vannotti (Translated by C. Rimington), “ Porphyrins,” Hilger and Watts,S. Granick, Cheun. Pathways of Metabol., 1954, 2, 287.C. J. Watson, Adu. Intern. Med., 1954, 6, 235.M. Weatherall, Pharunacol. Rev., 1954, 6, 133.H. M. Muir, “ Chemical Pathology of Pigments,” Biochenz. Soc.Sywzp., 1954, 12, 4.J. E. Falk, ibid., p. 17.London, 1954. R. Lemberg, Fortschr. Chem. oyg. Naturstofle, 1964, 11, 299.A. Goldberg, ibid., p. 27312 BIOCHEMISTRY,Methods.-The separation of porphyrins or their methyl esters bychromatography on adsorbent columns or on paper has been reviewed byFalkJlo and there have been subsequent contribution^.^^-^^ Paper chromato-graphy has been applied to the separation of the chlorophyll^,^^ and thepurification of 2 : 6-lutidine has been described.15 Two studies 16-17 haveappeared recently of the separation of porphyrins by counter-current distri-bution. Brugsch and Kubowitz l8 give data concerning the spectrophoto-metric determination of coproporphyrin I. An improved technique for thedecarboxylation of uroporphyrins has been described.19Uroporphyrins.-Uroporphyrin I has been synt hesised by MacDonaldand Stedman,20 thus confirming the structure proposed by Fischer.Itsextractability by ethyl acetate from dilute aqueous solutions a t suitable pHhas been demonstrated.21 Uroporphyrin occurs in normal human urine,22 thequantity being probably about 20 pg. per diem. With and Petersen 23 havedescribed cases of symptomatic uroporphyrinuria, some of which eliminatedup to 500 pg. per diem of uroporphyrin. Treibs and Ott 24 obtained uropor-phyrin I11 as the principal product in a synthesis depending on the self-con-densation of a suitably substituted pyrrolylmethanol to p ~ r p h y r i n . ~ ~ Theirproduct has an octamethyl ester, m. p. 252", compared with m.p. 264" fornatural uroporphyrin I11 from turachZ6Agreement has not yet been reached concerning the nature of the'' Waldenstrom porphyrin " of acute porphyria urines, 1 y 5p 26ay 279 28 butCookson and Rimington 29 give reasons for regarding it as a chemical artefactand show that the isomer composition varies according to the conditions ofits formation. An ether-insoluble porphyrin having physical propertiessimilar to those of a uroporphyrin, except for slightly higher Rf and a methylester, m. p. 211-216", has been found 30 accompanying uroporphyrin in theurines of several cases of cutaneous porphyria.Source of the Carbon Atoms of Protoporphyrh-Shemin and Witten-berg 3 l incubated duck blood with either [methyZ-14C]acetate or [carboxy-lo J.E. Falk, Brit. Med. Bzcll., 1954, 10, No. 3, 211.l 1 T. 0. Cliu and E. J.-H. Chu, J . Biol. Chew., 1954, 208, 537; J . Amer. Chem. SOC.,l2 J. Lucas, G. L. Vassilaros, and L. Petraites, Fed. Proc., 1954, 13, 256.l3 R. Kehl and R. B. Gunter, 2. physiol. Chem., 1954, 297, 254.l4 A. H. Sporer, S. Freed, and K. M. Sancier, Science, 1954, 119, 68.l5 H. C. Brown, S. Johnson, and H. Podall, J . Amer. Chem. SOC., 1954, 76, 5556.l6 K. G. Paul, Scand. J . Clin. Lab. Invest., 1953, 5, 212.S. Granick and L. Bogorad, J . Biol. Chem., 1953, 202, 781.I s J. Brugsch and F. Kubowitz, 2. ges. inn. Med., 1953, 8, 749.l9 P. R. Edmonson and S. Schwartz, J . Biol. Chem., 1953, 205, 605.*O S. F. MacDonald and R. J. Stedman, J . Amer. Chem. Soc., 1953, 75, 3040; Canad.J .Claem., 1954, 32, 812. 21 E. I. B. Dresel and B. E. Tooth, Nature, 1954, 1'74, 271.22 R. E. H. Nicholas and C. Rimington, Scand. J . Clin. Lab. Invest., 1949, 1, 12;A. Comfort, H. Moore, and hl. Weatherall, Biochem. J . , 1954, 58, 177; S. Schwartz,Veterans' Admin. Tech. Bull., 1953, TB 10-94; W. H. Lockwood, Austral. J . Exp.Biol. Aged. Sci., 1953, 31, 453.1953, 75, 3021.23 T. K. With and H. C. A. Petersen, Lancet, 1954, ii, 1148.24 A. Treibs and W. Ott, Naturwiss., 1953, 40, 476.25 W. Siedel and F. Winkler, Annalen, 1943, 554, 162.26 R. E. H. Nicholas and C . Rimington, Biochem. J . , 1981, 50, 194.26a Idem, ibid., 1953, 55, 109 ; 0. Kennard and C. Rimington, ibid., p. 105.2 7 C. J. Watson and M. Berg, Fed. Proc., 1954, 13, 316.28 J.E. Falk and A. Benson, Arch. Biochem. Biophys., 1954, 51, 528.29 G. H. Cookson and C. Rimington, Biochenz. J., 1954, 57, 476.30 J . Canivet and C. Rimington, ibid., 1953, 65, 867.31 D. Shemin and J . Wittenberg, J . Biol. Chem., 1951, 192, 315RIMINGTON : PORPHYRIN METABOLISM. 318l*C]acetate, and isolated the haems formed. These were degraded stepwiseas already described 1 and the labelling of the individual carbon atoms fromthe two pairs of similar pyrrole rings thus ascertained. It was shown thatacetate could serve as a source for all the carbon atoms of protoporphyrinnot contributed by glycine and that certain relationships among differentparts of the molecule were evident. Thus, when there is used the numberingand scheme of classification of individual atoms proposed by Wittenberg andShemin 32 (see Fig.(Az. + A3 . . . A, + B, +- B, . . . B,) = (C, +C, . . . C, + D, + D, . . . D,) which indicates that all four pyrrole ringsalmost certainly have the same precursor, modification of their side-chainsapparently occurring after formation of the macrocycle. Degradation ofmesoporphyrin, prepared from the protoporphyrin (Fig. l b ) of haem byreduction of its vinyl side-chains, results, under the conditions usuallyobserved, in two molecules of hzmatinic acid derived from the " acidic "l a ) ,FIG. la FIG. l b .C0,H C0,H101 10 110 ICO,H C0,I-IUroporphyrin 11110 I 10 IProtoporphyrinCO,H CO,Hpyrrole rings C and D and two molecules of ethylmethylmaleinimide derivedfrom the " basic " pyrroles A and B.Stepwise degradation being appliedto the porphyrin synthesised by duck blood in the presence of [carboxy-Wlacetate, the highest activity is found in the two carboxylic acid groupsTABLE 1. Total activity (c.9.m.) of each ojthe carbon atoms of protoporphyrifibiosynth,esised from [methyl-14C]acefate and [carboxy-14C]acetate, respectively.Carbonnumber2346G8910[methyl- 14C]acetaterings A + I3 rings C + D0 0776 767973 811770 8331210 1010854 8691190 113080 -[cnvboxy- 14C]acetate0 095 880 0109 1060 00 00 01260rings A + R rings C + DIC<lol and D(lol. of the porphyrin, although some is present in carbon atoms 3and 5 of all rings. When [~nethyZ-~~CIacetate is used, the highest activity is52 J.Wittenberg and D. Shemin, J . Bid. Chem., 1950, 185, 103314 BIOCHEMISTRY.found in carbon atoms 6 and 9 of all rings but a great deal is found also inpositions 4, 8, 5, and 3 and a little in C(lo) and D(,,) (see Table 1). Evidencethat the two halves of the pyrrole rings which give rise to pyruvic acid anda-oxoglutaric acid, respectively, on degradation are derived from the sameprecursor is forthcoming from equal labelling, each to each, of the positionpairs 6 and 9, 4 and 8, 5 and 3, respectively (see Fig. 2).FIG. 2 .-Average activities, in parentheses, of comparable carbon atoms in all pywote units.The pyrrole unit represented contains a carboxyl group, only found an rings c and Dof the porphyrin (after Shemin and Wittenberg 31).(80) CO,H CO,H CO,H (1170)I CH, IICH,&?Q?.* CHZ*' II --' I11 q?F,+* 11 11: tll I/ q?Y I jlo I CH,91"376 8(iHZ H3'i I/%&A /c\/\H~C-+;:.-.CH,C T C c-c c-cH H HWith [ynethy2-1*C]acetate With [carboxy-W]acetateShemin and Wittenberg postulated from these findings that in the courseof porphyrin biosynthesis a single precursor pyrrolic substance was firstformed from union of two unsymmetrical four-carbon units and one glycineunit. The four-carbon unit could be a derivative of succinic acid arisingfrom acetate via the tricarboxylic acid cycle.If this were so the precursorpyrrole of all four rings A to D would carry acetic acid and propionic acidside chains in its p positions. Union in some way of 4 units of this pyrroleand 4 units representing the a carbon atoms of glycine could yield a uro-porphyrin. Postulated loss of carbon dioxide from 6 carboxyl groups andof 4'hydrogen atoms could then lead to protoporphyrin.The scheme issummarised below (compiled after Shemin) :Acetate~ Tricarboxylic acida-OxoglutarateSuccinyl derivativecvcle' \Succinic acid+ Glycine i Common pyrrolic precursor+ Derivative of glycine 1 Uroporphyrin-6C02, -4H i ProtoporphyriR'TMTNGTON : PORPHYRIN METABOLISM. 315Certain difficulties were clearly obvious. The structure of the pyrrolicprecursor was unknown as was also that of the fragment derived from glycineand the method of their union. Further, biosynthesis leads, as far as weknow, to only one isomer of protoporphyrin, namely protoporphyrin 9belonging to the ztioporphyrin series I11 and such a scheme as the abovewould have been expected to lead either to a mixture of isomeric porphyrinsor to series I derivatives only.Participation of Succinate.-Shemin and Kumin 33 have obtained powerfulevidence in favour of the participation of a succinyl derivative in porphyrinbiosynthesis by performing experiments based on the following consider-ations.Succinate could be utilised for porphyrin synthesis either afterpassing through the tricarboxylic acid cycle in its oxidative direction or bydirect transformation. In the former case, 14C-labelling of the carboxylgroups of added succinate would disappear during a revolution of the cycle,but such labelling would be retained in the latter eventuality.The additionof malonate, which blocks the oxidative pathway, should therefore havelittle, if any, effect upon the degree of incorporation of [~arboxy-~~C]succinateinto protoporphyrin. [~t-~~C]Succinate could be incorporated to give a radio-active porphyrin either by following the cycle or directly, and malonateFIG. 3.--The distribution paitem of I4C in protoporphyrin synthesised from [carboxy-l4C]-Structure in brackets is that of the intermediate postulated by Shemin succinate.and Kumin.33.CO,HI.bQR kH,-CO,H' / 'NH2I.CO,H4.CO,H10 IH+ 6 .CO,(Frompositions7 and 10)Radioactive carbon atoms.would therefore be expected to depress substantially the degree of labellingachieved from this substrate.Both these expectations were realised experi-mentally. Furthermore, if succinate is utilised as a unit, the distributionshown in Fig. 3 would be expected, namely 40% of the 14C-activity should33 D. Shemin and S. Kumin, J . Biol. Chem., 1952, 198, 827316 BIOCHEMISTRY.reside in rings A and B and 60% in rings C and D, since 2 carboxyl groupshave been lost during formation of the vinyl side chains at A, and B,.Further, C,, and D,, should together contain one-fifth of the whole 1%-activity of the porphyrin, one-third of the activity present in rings C and Dand one-half of that present in rings A and B. How nearly these predictionswere borne out in experiment can be seen from Shemin and Kumin’s results(Table 2).The fact that addition of a coenzyme A concentrate to the duck-TABLE 2. Distribation of 14C activity in protoporphyvin biosynthesised from[~arboxy-~~C]sztccinate. Absence of efect by malonate (0.02~).Compound analysedphyrinHaemin or mesopor-EthylmethylmaleinimideHzematinic acidEthylmethylmaleinimidefrom aboveBarium carbonate fromabove decarboxylationPosition inporphyrinTotalPyrrole rings A and B, 9 ,, C and D,, C and Dless carboxyl groupsCarboxyl groupsMolar activity (mean c.p.m.)(no inhibitor) (with malonate)Found Theory Found TheoryIA\9340 - 9920 -3670 3740 3710 39705570 5600 6210 59503800 3740 4050 39701920 1870 2040 1990blood system increased the utilisation of succinate for porphyrin formationsuggested to Shemin and Kumin that the unsymmetrical succinyl derivativemight be succinyl-coenzyme A but no more direct evidence in support ofthis possibility has as yet been forthcoming.The existence of the tricarb-oxylic acid cycle of reactions has been demonstrated in avian erythrocytesby Rubinstein and Denstedt 34 whilst Wriston, Lack, and Shemin 35 havefound radioactive citric acid and a-oxoglutarate to produce the expecteddistribution of labelling of protoporphyrin in the duck-bIood system.Porphobilinogen.-The occurrence in the urines of patients with acuteporphyria of porphobilinogen, a substance giving a red chloroform-insolubleproduct with Ehrlich’s reagent, was first observed by S a ~ h s . ~ ~ Until recently,it was believed that porphobilinogen in the urine was pathognomonic ofacute porphyria but it is now known to occur in animals after poisoningwith Sedormid,,’ allylisopropylacetamide,38 or diallylbarbituric acid.39Watson 40 has also reported a positive colour test (Watson-Schwartz) incertain human cases of liver disease, malignant disease, and infectious ornervous diseases but confirmation by isolation or by chromatography thatthis was in fact due to porphobilinogen has not yet been presented.Thepossibility that the individuals concerned might have had latent porphyriahas not been excluded. The existence is also suggested by Watson 40 of twoforms of porphobilinogen in urine. An intensive study of porphobilinogenby Waldenstrom and Vahlquist 41 revealed many of its properties but attempts34 D.Rubinstein and D. F. Denstedt, J . Bid. Chem., 1953, 204, 623.3 5 J. C. Wriston, L. Lack, and D. Shemin, Fed. Proc., 1953, 12, 294.3 6 P. Sachs, KZin. Wochenschr., 1931, 10, 1123.3 7 R. Schmid and S. Schwartz, Proc. Soc. Exp. Biol. Med., 1952, 31,685 ; R. F. Labbe,E. L. Talman, and R. A. Aldrich, Biochim. Bio9hys. Acfa, 1254, 15, 590.3 8 A. Goldberg, Abs. IF‘ Congr. Europ. SOC. Haemalol., 1953, p. 27; A. Goldberg andC. Rimington, Pruc. Roy. Soc., B, in the press.39 A. Goldberg, Biochern. J . , 1954, 5’9, 55.40 C. J. Watson, Arch. Intern. Med., 1954, 93, 643.4 1 J. Waldenstrom and B. Vahlquist, 2. fihysiol. Chem., 1939, 260, 189RIMINGTON : PORPHYRIN METABOLISM. 317at isolation were not successful. The authors believed from diffusion-velocity measurements that it was a dipyrrolylrnethane.Its isolation wasachieved by Westall 42 who used ion-exchange resins after a preliminaryprecipitation of porphobilinogen from the urine with mercuric acetate. Histransformation of the crystalline material into uroporphyrin left no doubt401 43that porphobilinogen was one of the uroporphyrin precursors present inacute porphyria urine. Using at first Westall's method of isolation andlater an improved technique which dispenses with ion-exchange columns andaffords much better yields, Cookson and Rimington prepared sufficientporphobilinogen to establish its chemical structure 453 z9 as (l), confirmedby Kennard's 46 X-ray diffraction studies and the preparation by Granickand Bogorad 47 of an iodo-derivative.The existence of an amino-group inporphobilinogen had been suggested by Westall's42 finding that half itsnitrogen was lost as N, on treatment with nitrous acid, or as ammonia onboiling it with buffer of pH 8.5. The course of reaction with acylating agentswas found by Cookson and Rimington 44 to depend upon the solvent; insodium hydroxide solution an N-acetyl derivative is formed exclusively, butin aqueous pyridine a lactam (2) is the principal product. This lactam couldbe isolated easily and proved to be a key compound. Had the position ofthe @-substituents in porphobilinogen been reversed, such a lactam wouldhave possessed a seven-membered ring but this alternative structure wasexcluded45 by cyclisation of (2) by means of polyphosphoric acid to (3).Comparison of the ultraviolet absorption spectra of these compounds withthose of model compounds afforded further support for the structuresassigned.29Formation of Uroporphyrins from Porphobi1inogen.-The optimal acidconcentration for formation of porphyrin from porphobilinogen is about0-5~-hydrochloric acid at 100" for 20 min.Cookson and Rimington29observed that the colourless porphyrinogen is first formed, and obtaineduroporphyrin in a yield of 77.5% when this was oxidised, by drawing astream of air through the solution. The uroporphyrin mixture yieldedan octamethyl ester, m. p. 258-260", which ran to the uroporphyrin I11position (with tailing) on chromatography in dioxan. Decarboxylationshowed, however, that a mixture of coproporphyrins resulted, in whichcoproporphyrin I11 appeared to predominate. When porphyrin formationfrom porphobilinogen took place at 20" and at different pH, the proportionof isomers varied; in the presence of sodium carbonate in urine, the series Iisomer predominated.As described later in this Report, porphobilinogen is converted intoporphyrins by biological systems also. The course of these reactions is4 2 R.G. Westall, Nature, 1952, 170, 614.43 V. Hawlunson and C. J. Watson, Scieme, 1952, 115, 496.44 G. H. Cookson and C. Rimington, Nature, 1953, 171, 875.4 5 G. H. Cookson, ibid., 1953, 172, 457.4 6 0. Kennard, ibid., 1953, 171, 876.4 7 S. Granick and L. Bogorad, J . Amer. Chew. SUG., 1353, 75, 3610318 BIOCHEMISTRY.unknown ; it seem likely, however, that reactions siniilar to those discussedbelow are involved, although the proportions in which the isomeric por-phyrins are formed would be influenced by enzymic catalysis.In the past,schemes for porphyrin biosynthesis 483 51 have understandably laid greatemphasis on the fact that naturally occurring porphyrins appear to belongonly to isomer types I and I11 with a great predominance of the latter.In order to explain this situation differently substituted pairs of dipyrrolyl-methanes have been postulated as intermediates, these in turn being picturedas being formed from at least two different monopyrroles. A purely chemicalconsideration 29 provides an acceptable explanation of uroporphyrin form-ation from porphobilinogen in vitro and indicates, moreover, that isomer I11may be expected, in certain circumstances, to predominate in the possiblemixture of all four uroporphyrins.The existence of more than one porpho-bilinogen need not be assumed.Electrophilic attack on a pyrrole will tend to take place at the point ofhighest negative charge, but the reaction rate, being controlled by the energyof activation, will be favoured by a transition complex of low energy. Thereaction, therefore, normally takes place by direct displacement so that thepyrrole ring system may be retained (i.e., pyrrolenines are not formed).The group replaced must be able to give up an electron pair and separate asa cation or a combination of neutral and positive fragments; such groupsinclude H, CH,*OH, CH,*NH2, or pyrrolylmethylene, but not alkyl orCH,*NH,+.The term " free position " is customarily given only to onebearing a hydrogen atom, but it must be remembered that positions are not" blocked " if substituted by other groups which are readily replaceable.Although there is no fundamental difference between condensations involvingdisplacement of hydrogen or of a larger group, it will be convenient for thefollowing discussion to call these two reactions of the nucleophilic com-ponent schemes A 1 and A2, respectively.SCHEME -411SCHEME ,42H R+L - +CH2=OHA compound such as porphobilinogen which contains two replaceablegroups can react in several ways so that the product of each individual step,let alone of the condensation of four molecules into a porphyrin, cannot bepredicted in the absence of data on reaction rates, etc.Moreover, these andthe reaction mechanism, itself, are doubtless dependent on pH and manyother factors (e.g., the CH,*NH, group can react according to scheme A2only as a iree base). Only the condensation in acid solution will be dis-48 I<. Dobriner and c. P. Rhoads, J. CZin. Immt., 1928, 17, 9 5 ; R. Leniberg andJ. W. Legge, " Haematin Compounds and Bile Pigments," Interscience, h'ew York,1040; A. Neuberger, H. &I. BInir, and C. H. Gray, Natuve, 1050, 165, 948RIMINGTON : PORPHYRIN METABOLISM. 319cussed, although obviously a parallel scheme would apply for base catalysis,where the initial step would be removal of a proton from the pyrrole nitrogen.The acid-catalysed reaction is illustrated by the S x l reaction in whichporphobilinogen first loses ammonia and the resulting carbonium ion eitherattacks another pyrrole acting as an electrophilic component or reacts withwater (scheme B).SCHEME BH HHIf the a-hydrogen atom is more easily displaced than aminomethyl orhydroxymethyl, reactions according to B and A 1 will lead to uroporphyrinogenI and after oxidation to uroporphyrin I.If the aminomethyl or hydroxymethyl side-chain is displaced in preferenceto the a-hydrogen atom (AZ), but the latter in preference to a-pyrrolyl-methylene ( A l ) , the product will be a mixture of uroporphyrins I11 and IVwith a small amount of I1 (equal speeds of reaction being assumed).Theintermediate steps are outlined in scheme C in which the porphobilinogenSCHEME C PA-AF-A€’-,U? + Uroporphyrin I I1 7\r PA-PA-AP-AP __t Uroporphyrin 1V1’A- __P PL4-AP .”rp PA-AP- PA-AI’-PA-AY + Uroporphyrin I1unit is abbreviated to PA- (P indicating the propionic acid and A the aceticacid residue in the PP’-positions and the rule the link between units). Rin A1 or A2 is an a-pyrrolylmethylene or a cation formed by the addition ofa proton to formaldehyde but that possibility of R being H (see below) isnot considered in scheme C.Actual examples of a similar order of ease of substitution of groups byelectrophilic reagents have been observed in phenols (which owing to theoperation of similar electronic displacements are analogous to pyrroles) .For example, Ziegler and Zigeuner and Ziegler,49 investigating the react ionbetween diazonium salts and hydroxybenzyl alcohols, found cases in whichthe ease of replacement of groups was in the order CH,*OH > H ortko tophenolic OH > o-hydroxybenzyl.A proton could also act as the substituting reagent, and although reaction,41 (R = H) would cause no change, reaction A2 would yield formaldehydeand 3-2’-carboxyethyl-4-carboxyinethylpyrrole. The reactivities of thea-positions of this compound are probably very similar, so that the equili-4 9 E.Ziegler and G. Zigeuner, Sitrungsber. A kad. Wzss. Wien, fiIath.-Naturwiss. K l . ,Abt. l l b , 1049, 158, 295; E. Zicglcr, Scz. Pharm., 1951, 19, 10320 BIOCHEMISTRY.brium mixture obtained by this mechanism would contain comparableamaunts of the isomeric or-hydroxymethylpyrroles.If such isomerisation ismuch more rapid than the condensation between pyrroles, the pairs of sidechains in the final gorphyrin will be arranged at random, and a mixture ofisomeric uroporphyrins in the proportions &I, QII, 4111, and $IV will beobtained, irrespective of the details of condensation.The discovery by Corwin and Andrews 50 of the formation of tripyrrolyl-methanes during the synthesis of dipyrrolylmethencs from aldehydes andpyrroles with a free a-position, which can then split into any of severaldifferent dipyrrolylmethenes is often quoted *3 51 as a mechanism which couldlead to the production of isomers. Redistribution of the charge on the saltof the dipyrrolylmethene may be postulated to enable the bridge carbonatom to acquire a positive charge; reaction according to A1 where thiscation is represented by R+ would lead to the formation of the intermediatetripyrrolylmethane. It is obvious that a dipyrrolylmethane could not takepart in such a reaction as the substituting reagent, and that therefore thisniechanism does not concern the lower state of oxidation considered through-out the foregoing discussion.Utilisation of PorphobiIinogen by Tissue Systems.-That porphobilinogencan serve as a precursor of uroporphyrin, coproporphyrin, and protoporphyrinwhen incubated aerobically with a chicken red-cell ha3moIyzate system 52was demonstrated by Falk, Dresel, and Rimington; 53 in the absence ofoxygen or when the supernatant liquid resulting from centrifugation of thel~~molyzate is used (aerobically), the formation of protoporphyrin is greatlyreduced.Direct demonstration of the interconversion of these porphyrinsin the red-cell system was also sought. On addition of pure uroporphyrinIII,26 there was a 52% conversion into protoporphyrin, thus affording con-firmation of Salomon, Richmond, and Altman’s 54 demonstration of thesame conversion in a bone-marrow system by an isotope-tracer method, butadded coproporphyrin I11 gave no significant increase in protoporphyrin andwas recovered largely unchanged. The conversions which have been shownto take place in the red-cell hzmolyzate system may be suminarised asi’ollows :PorphobilinogenUroporpliyrin Coproporph y rin ProtoporphyrinUroporphyrin __t ProtoporphyrinWhilst this is suggestive it does not prove that these substances areintermediate stages in the biosynthesls of hzm.That they do in fact arisei r m radioactive glycine added to the system was proved by the isolation,in the presence of “ carrier,” of radioactive porphobilinogen, uroporphyrin,and coproporphyrin, respectively.%Schwartz 55 Other tissues are capable of utilising porphobilinogen.50 A. H. Corwin and J. S. Andrews, J . Amer. Chegn. SOC., 1937, 59, 1973.5 1 W. J . Turner, J . Lab. Cliit. Med., 1940, 26, 323.52 E. I. €3. Dresel and J. E. Falk, Biochem. J., 1954, 58, 156.53 J. E. Falk, E. I. B. Dresel, and C . Rimington, Nature, 1053, 172, 292.54 li.Salomon, J. E. Richmond, and K. I. Altman, J . Biol. Chem., 1953, 196, 463.65 S. Schwartz, 1;d. I’Yoc., 1084, 13, 393RTMTNGTON PORPHYRTN METAROT,TSM. 32 1found that rat-liver homogenate converted it into copro- and proto-porphyrinsin 50-600/, yield. He failed, however, to detect conversion of radioactiveuroporphyrin into coproporphyrin, protoporphyrin, or hzm by bone-marrow or liver preparations or by perfusion of rats' liver. Radioactivecoproporphyrin gave only doubtful results. Bogorad and Granick 56obtained very efficient conversion of porphobilinogen by extracts of ChZoreZZainto uroporphyrins, coproporphyrins, protoporphyrins, and also porphyrinshaving six and five carboxyl groups. The effect of vitamins and antagonistsadded to erythrocyte systems has been studied by Dresel and Falk,52 Londonand Yama~aki,~' Abbott and D o d ~ o n , ~ ~ and the effect upon bone-marrowpreparations by Richmond, Altman, and Sa10rnon.~*~8-Aminolaevulic Acid-Once the structure of porphobilinogen was knownand it had been shown that this substance is formed in tissue systems fromglycine and might therefore be an intermediate step in the biosynthesis ofhzm, it became possible to speculate upon the steps lying between glycineand succinate and porphobilinogen itself.Some possible precursors wereunder consideration by Neuberger and Scott 59 when Shemin and Russellannounced that 8-aminolzvulic acid could replace " active " succinate andglycine for porphyrin synthesis in duck blood. The first product of con-densation of succinate and glycine may be a-amino-@-oxoadipic acid whichcould readily lose carbon dioxide.The activity of 6-aminolzvulic acid inhzem and porphyrin production was confirmed by Neuberger and Scott 59whilst Dresel and Falk 61 were able to show its conversion into porpho-bilinogen as well as porphyrins in their chicken red-cell hzemolyzate system.52The formation of porphobilinogen may therefore be summarised as follows :2 " Active " succinate2 Glycine-I- ___)c 2[H0,CCH,CH,CO-CH(NH,)C02~ i co,H CO,H II I1 + IICH, C0,HCH, CH,C H, coI cEr, COJT I II 1 CH, CH,c-c/I II H2C\NH20C-CH2- I NH213 c\N,C-C H,-NH,PorphobilinogenHIn confirmation of these findings, Shemin, Abramsky, and Russell 62incubated 8-amin0[8-~~C]l~vulic acid with a duck-blood system and foundthe expected distribution of radioactivity on degradation of the hEmsynthesised.5 6 L.Bogorad and S. Granick, PYOG. Nut. Acad. Sci. Washington, 1953, 39, 1176.5 7 I. M. London and M. Yamasaki, Fed. PYOC., 1952, 11, 250.5 8 L. D. Abbott and M. J. Dodson, Proc. SOC. Exp. Biol. Med., 1954, 86, 476.GEa J. E. Richmond, K. I. Altman, and K. Salomon, J . Biol. Chem., 1954, 211, 981.59 A. Neuberger and J . J. Scott, Nature, 1953, 172, 1093.6u D. Shemin and C. S. Russell, J . Amer. Chem. SOC., 1953, 75, 4873.G 1 E. I. 13. Drcsel and J. E. Falk, Nature, 1953, 172, 1185.G 2 D. Shemin, T. Abramsky, and C. S. Russell, J . Amer. Chem. SOL, 1954, 76, 1204.REP.-VOL. LI 323 RIOCHEMISTRT.8-Aminolaevulic Acid Dehydrase.-An enzyme in liver, kidney, andavian erythrocytes and some micro-organisms which brings about the con-version of 8-aminolzvulic acid into porphobilinogen has been purified andstudied by Gibson, Neuberger, and It is a sulphydryl enzymeactivated by reduced glutathione and appears to be rather specific for itssubstrate. Further study of this enzyme will be interesting, a condensationof this type being apparently without precedent in biochemistry.Metabolism of 8-Aminolzvulic Acid in the Whole Organism.-ThelSN-labelled substance administered to rats or man 64 was largely excretedunchanged but was converted to some extent into porphobilinogen, porpho-bilin, and ammonia; the incorporation into blood hzmin was very slight.In a human experiment with 8-amin0[~~C]laevulic acid, incorporation intohzem was again low but the faeces contained large quantities of labelledprotoporphyrin and stercobilin, and labelled porphobilinogen was againfound in the urine.The investigators state that “ the relative specificactivities of 8-aminolzvulic acid, porphobilinogen, porphyrin, and sterco-bilin were in accord with the theory that each of these compounds is theprecursor of the succeeding one ” and “ that it is likely that porphyrin isconvertible into bile pigment outside the hzmopoietic system.” The lowincorporation of 8-aminolzevulic acid into hEm may be due to its rapidelimination by the kidney. It has been shown e5 that in the rat and in manporphobilinogen is excreted promptly in the urine as a non-threshold sub-stance.Of obvious interest was a comparison of the metabolism of &amino-laevulic acid in acute porphyria with that in normal man. The experiment hasbeen performed 66 and shows that the percentage of 8-aminolaevulic acid con-verted into urinary porphobilinogen is many times greater in the diseased state.Overall Picture of Porphyrin Biosynthesis.-As the result of research todate it is possible to draw up a tentative scheme to illustrate the probablecourse of porphyrin synthesis in the tissues which have so far been studied.It must be emphasised, however, that many questions are still unanswered,as, for example, whether or not porphyrins with more than two carboxylgroups, including coproporphyrin, are direct precursors of protoporphyrin 9.At the moment, evidence for or against is only circumstantial.Thus Granickand his collaborators 67 have isolated from a mutant of the alga Chlorelln,hzmatoporphyrin 9 and a monovinylmonohydroxyethyl-deuteroporphyrin 9,both of which could be intermediate stages in the transformation of copro-porphyrin I11 into protoporphyrin 9 ; the investigators take the view thatthey are, in fact, such direct precursors. The occurrence in various situationsof porphyrins probably containing from 8 to 1 carboxyl groups has now beenreported several times 22,30, 68 and would suggest that they are serially83 K. D. Gibson, A. Neuberger, and J. J. Scott, Biochem. J., 1964, 58, xli.84 N. I. Berlin, C. H. Gray, A. Neuberger, and J .J. Scott, ibid., p. xxx.6 5 A. Goldberg and C. Rimington, Lancet, 1954, ii, 172 ; A. Goldberg, ibid., p. 1095.6 8 -4. Xeuberger, J. J. Scott, and C. H. Gray, Biochem. J., 1954, 58, xli.6 1 L. Bogorad and S. Granick, J . Bio2. Chem., 1953, 202, 703; ’3. Granick, L. Bogorad,and H. Jaffe, ibid., 1953, 202, 801.R. E. H. Nicholafi and C. Rimington, Biochem. .I., 1951, 48, 306 ; A. G. Macgregor,R. E. H. Nicholas, and C. Rimington, Arch. Intern. Med., 1952, 90, 483; C . Rimingtonand P. A. Miles, Biochem. J., 1951, 50, 202; L. Bogorad and S. Granick, Xature, 1052,170, 321; M. Weatherall and A. Comfort, ibid., 1952, 169, 5 8 7 ; E. G. Larsen, C. R l .Glafkides, and J. M. Of:en, Fed. Proc., 1953, 12, 236.139 C . Rimington in Handbuch der gesamten Haernatologie,” TJrban and Schwarzen-berg, Munich, 2nd Ed., 2RThITNGTON PORPFTI'RTN bIET4BOLTShl.323related, although all attempts to demonstrate the direct conversion of oneporphyrin into another in the living animal have so far failed; lack ofsuccess may perhaps be explained by permeability considerations.The early stages by which glycine and succinate or a-oxoglutarate areunited to form 6-aminolzvulic acid are as yet unknown but certain specula-tions may perhaps be permitted. From work on micro-organisms, it appearsthat lipothiamide (or diphosphothiamine and lipoic acid acting in conjunc-tion) and coenzyme A can bring about the formation of " acetyl " for bio-FIG. 4.DPNHDPNSuccinyl-CoA CoA SHGlycyl Co A 5-4 a-Amino-$3-ketoadrpyl - Co AGlycine / .. - r o A - S ! 4 d A C Q 2 8.Arninolsvubc acidI Tentative scheme of biosynthesis of porphobilinogen Porphobilinoqenchemical synthesis from pyruvic acid by a sequence,'* in which a lipo-thiamide-pyruvate compound loses carbon dioxide, the acetyl group thenbeing transferred to coenzyme A by a transferase, and the lipoic cofactorbeing regenerated in its reduced form.An analogous sequence of events might be imagined to take place with7* I. C . Gunsalus, Fed. Proc., 1954, 13, 715; L. J. Reed and B. G. De Busk, ibid.,1954, 13, 723324 BIOCHEMISTRY.a-oxoglutarate, from Krebs's cycle or other sources, as the keto-acid in placeof pyruvate, and would lead theoretically to succinyl-coenzyme A. Succinyl-coenzyme A may possibly arise more directly from succinate and the co-enzyme, just as the acetyl derivative is known to do so from acetate, and soaccount for the malonate-insensitive fraction of porphyrin synthesis,33 butin any case the formation of a-amino-p-oxoadipic acid (and therefrom, bydecarboxylation, of 6-aminolzvulic acid) is regarded by Lipmann 7l as apossible step in porphyrin synthesis through a " head-tail " condensationbetween succinyl-coenzyme A and glycyl-coenzyme A in analogy with theformation of acetoacetic acid from two molecules of acetyl-coenzyme A.Should it proveto have any basis in fact, it will be seen that there are several points vulner-able to attack, or to pathological and pharmacological disturbances, in thevery early stages of porphyrin biosynthesis.This purely speculative scheme is illustrated in Fig.4.C. R.5. BIOLOGICAL SYNTHESES AND INTERCONVERSIONS OF SOMEMONOSACCHARIDES.The obscurity attending the origins of the biologically known mono-saccharides (and their phosphates) is now being dispelled, though by nomeans completely. Recent studies, with catalysts ranging from crystallineenzymes to crude tissue preparations and aided by chromatography and14C-labelling, are affording evidence that fundamental and reversible mech-anisms of monosaccharide synthesis are possessed in common by cells ofdiverse origin. Furthermore, it seems probable that more than one routeof production, including both aerobic and anaerobic systems, may be availablefor the same compound; indeed it appears that cells can possess a pool ofenzymes and substrates out of which may be produced one or more mono-saccharides when the occasion demands.In such reactions the sugarsappear to react in their open-chain forms. The interconversion of D-galac-tose and D-glucose is not dealt with here since the Reporter considers that thisapparent Walden inversion cannot, at present, be logically attributed to anyknown single chemical mechanism likely to occur in a biological environment.Anaerobic Systems.-A number of enzyme-types will be considered whichcan synthesise (or break) a carbon-carbon linkage without gain or loss ofatoms within the system :These specifically require dihydroxyacetone phosphate (1)and a variety of aldehydes (2) and carry out a condensation of the mixed(a) AZdoZases.C;H,.O.PO,H,I coICHO H a ' -0iH 7 *------(3)I( 3 ) Raldol type to produce a ketose l-phosphate (3).The synthetical reactionmay be regarded as involving an intermolecular hydrogen transfer havingF. Lipmann, Science, 1954, 120, 855BELL : BIOLOGICAL SYNTHESES OF SOME MONOSACCHARIDES. 325the hydroxyl groups on C(,l and Cf,) respectively “ left ”- and (‘ right ”-handed in the conventional Fischer projection formulz. It is puzzling thataldolases from different sources possess markedly different activation require-ments although they catalyse the s m e thermodynamic reaction.Not a great deal is known about this, but at presentit may be regarded as specifically linking acetaldehyde (4) with D-glycer-aldehyde 3-phosphate (5) to give 2-deoxy-~-ribose 5-phosphate (6), an aldose.This type of mechanism may account for the origin of other deoxy-sugars,e.g., digitoxose and cymarose.(b) “ DR-aldolase.”CHOL -- H*’*OiH ’i I - - - - - - 7 H* *OH 7”” HC-OHCH,*O*PO,H, (6) I (5) C€I,*O*€’03H,(c) Tramketolases.These enzymes transfer, from a donor molecule,HXCO*CH,OH (7), to an aldehydic acceptor (8), a hydrogen atom and thehydroxyacetyl group (together, the elements of glycollaldehyde) . The pro-ducts are a ketose (9) and a carbonyl-containing molecule (10). (R’ andusually X are esterified by phosphate.)CH,*OH CH,.OHco I ‘ 0 ,-!f ---.-- *..----I--,( 7 ) X*iH - H;-’~-oH 4- xco(10) 13‘ -t-CHO(9) I(8) R’The C(,>-hydroxyl group in (9) is “ right-handed ” in distinction to the“ left-handed )’ configuration produced by aldolases.( d ) Transaldolases.Here the enzyme transfers, from a suitable ketosew-phosphate (11) to an aldose w-phosphate (12), the dihydroxyacetonylradical of (11) and a hydrogen atom (the elements of dihydroxyacetone).CH,*OHco II1 ____-_I--; ,1 .---ICH2*O€IcoC(H,OH) 4- CHO CHO + C(H,OH)1I( ,--.IC(iHi,OH) R ---.‘..-I.-. I C(iH!,OH) K’(13) (’*) R’ (13)R = R’ = PO,H,(11) RThe products are a ketose a-phosphate (13) having three carbon atoms morethan (12), and an aldose a-phosphate (14) with three carbons less than (11).The work reported arises from the early observations byP. K. Stumpf, ‘‘ Chemical Pathways of Metabolism,” Academic Press, New York,Aldolases.1954, 1, 82326 BIOCHEMISTRY.Meyerhof, Lohmann, and Schuster that extracts of yeast and animaltissues, especially rabbit muscle, are capable of causing the condensation ofdihydroxyacetone phosphate with various aldehydes (2) to give ketosel-phosphates (3) having a D-threo-configuration of the 3 : 4-diol system, asfollows :Aldehyde (2) used Product (3) Reaction..................D-Glyceraldehyde 3-phosphate u-Fructose 1 : 6-diphosphate (1)D-Glyceraldeh yde D-Fructose l-phosphate (2)L-Glyceraldeh yde L-Sorbose l-phosphate (3)Acetaldehyde ( ?) 5-Deoxy-~-xylulose l-phosphate (4).....................................................................Propaldehyde S-C-Methyl-5-deoxy-~-xylulose l-phosphate (5)Reaction (1) has long been known.to be readily reversible; reactions (2)and (3) on the other hand were considered to proceed only in the directionof synthesis2,3 but this was challenged by Hers and Ja~ques.~ Lardyet al. ,5 using crystallised rabbit-muscle aldolase , have shown that reactions(2) and (3) are, in fact, reversible. Moreover, the enzyme is not so specificstereochemically as was originally thought; it will cleave D-tagatose 1 : 6-diphosphate which possesses a cis-3 : 4-diol structure, but at a much slowerrate than when attacking D-fructose and L-sorbose 1 : 6-diphosphates. Thelatter is produced by this aldolase from L-glyceraldehyde 3-phosphate ; thiscondensation is effected at a much slower rate than that with the D-enantio-morph. Although D-tagatose has been detected only once in a biologicalproduct (I synthetic D-tagatose 6-phosphate can be phosphorylated bypurified hexokinase.8Using chromatographic separations, J.K. N. Jones et al. have extendedaldolase studies to the green plant. Pea extracts (containing isomeraseand phosphatase as well as aldolase) were catalytically active towards (1)and a number of added aldehydes (2). The products, detected and isolatedas the free ketoses (being enzymically de-esterified by the accompanyingphosphatase), were as follows :Aldehyde (2) used Product (3)Glycollaldehyde l o u-Xylulose (15)Acetaldehyde l1 5-Deoxy-~-xylulose (1 6)n-Threo se l2 D-Idoheptulose (1 7)u-Erythrose l3 n-Altroheptulose (Sedoheptulose) (1 8)m-Lactaldehyde I* 6-Deoxy-~-fructose and 6-deoxy-~-sorboseIn each case, a ~-threo-3 : 4-diol was formed, with the hydroxyl groupsshowing the configuration formed by yeast and animal aldolases.2 0.Meyerhof, K. Lohmann, and P. Schuster, Biochem. Z . , 1936, 286, 301, 319.3 F. Leuthardt, E. Teste, and H. P. Wolf, Helv. Chim. Acta, 1953, 36, 227.4 H. G. Hers and P. Jacques, Amh. int. Physiol. SOC. belge Biochem., 1953, 61, 260.5 Ta-cheng Tung, Kuo Huang Ling, W. L. Bryne, and H. A. Lardy, Biochim.6 E. L. Hirst, L. Hough, and J. K. N. Jones, J., 1949, 3145.7 E. L. Totton End H. A. Lardy, J . Biol. $hem., 1949, 181, 701.8 H. A. Lardy, Phosphorus Metabolism,9 P. K. Stumpf, J . Biol. Chem., 1948, 176, 233.10 L. Hough and J. K. N. Jones, J., 1952, 4047.11 P.A. J. Gorin, L. Hough, and J. K. N. Jones, J . , 1953, 2140.12 P. A. J. Gorin and J. K. N. Jones, J., 1953, 1537.13 L. Hough and J. K. N. Jones, J . , 1953, 342.Siofihys Acta, 1954, 14, 488.1951, Johns Hopkins Press, Baltimore,Vol. I, 116.14 Idem, J . , 1952, 4052BELL : BIOLOGICAL SYNTHESES OF SOME MONOSACCHARIDES. 327Marmur and Schlenck,15 using an aldolase from Esch. coli and glycoll-aldehyde phosphate, have likewise demonstrated a synthesis of u-xylulose(15) (as its 1 : 5-diphosphate).Charalampous and Mueller l6 have found that [14C]formaldehyde acts asaldehyde substrate in a condensation with (l), the productCH2'O'P*3Hz being L-erythulose 1-phosphate (19).CO I This system was found in various animal tissues;Charalampous 16a has obtained evidence that this reactionis not catalysed by the ordinary adolases of the tissue.CH,.OH I The above reactions suggest likely biological pathwaysfor syntheses of 2-keto-sugars based on four to seven (19) carbon atoms; they depend, it must be noted, on theavailability of the necessary components.That a particular synthesiswill take place, when the appropriate substrates are presented to anenzyme, does not prove it to be an actual process in vivo. Evidencemust be obtained of the presence in the cells, as normal metabolites, howevertransitory, of the chemical components of the reactions. Acetaldehyde isknown as an intermediary in the alcoholic fermentations of micro-organismsand green plants ; mammalian liver possesses an aldehyde oxidase which,acting in reverse, reduces acetate.Glycollaldehyde is less well known as abiological component either free or as its phosphate. (It could of coursearise by aldolase cleavage of D-XyhlOSe phosphate.) Walker et al. l7 haveisolated glycollaldehyde as its 2 : 4-dinitrophenylhydrazone from culture mediaof A cetobacter acelzgenuwz when fermenting ethylene glycol, D-xylose, or L-arabinose. It is also possible that glycollic acid phosphate might undergoreduction to the aldehyde in a manner analogous to the reduction of D-glyceric acid 3-phosphate ; the acid is found in plants, and oxidising enzymesfor which it is a substrate are known.l* The occurrence of tetroses is obscure,except as transitory fission products of higher sugars. The reductionproduct of erythrose, erythritol,l9 is known in a l p .The synthetic tetrulose1-phosphate (19) belongs to the L-series.L-Glyceraldehyde 3-phosphate has not been found in Nature ; it is a well-I €1 0 * C -Hl5 J. Marmur and F. Schlenck, Arch. Biochem., 1951, 31, 154.l 6 F. C. Charalampous and C. C. Mueller, J. Bid. Chem., 1953, 201, 161.lea F. C. Charalampous, ibid., 1954, 211, 249.l 7 R. Kaushal and T. K. Walker, Biochem. J., 1951, 48, 618; R. Kaushal, 1'. Jowett,I. Zelitch and S. Ochoa, J . Bid. Chem., 1953, 201, 707; I. Zelitch, ibid., p. 719.l9 S. A. Barker, " Modern Methods of Plant Analysis," Springer, Berlin, 1955, Vol. 11,and T. I<. Walker, Nature, 1951, 167, 949.60BIOCHEMISTRY. 328known inhibitor of the D-glycerddehyde 3-phosphate dehydrogenase system.It could arise by aldolase cleavage of L-sorbose 1 : 6-diphosphate, if thatsubstance is a natural product.Similarly L-glyceraldehyde could be formedfrom L-sorbose l-phosphate. The Reporter is not aware that L-sorbose orits derivatives have been found in Nature ; none the less, the parent hexitolis well known. Since D-arabitol and ribitol are of phytochemical occur-rence 2o and enzymes of Acetobacter are known to oxidise them to the corre-sponding ketoses 21 similar systems oxidising sorbitol (D-glucitol) to L-sorbosemay await discovery.Tyansketolases. In 1952 Horecker and Smyrniotis 22 reported an im-portant observation on the enzymic behaviour of a rat-liver preparation.They recalled that extracts prepared from erythrocytes,22u bacteria, yeasts, 22band livers22 were known to produce " triose phosphate " and a " two-carbon fragment " when presented with '' pentose phosphate." (" Triosephosphate " is the isomerase-equilibrated mixture ofCHz*oH D-glyceraldehyde 3-phosphate and dihydroxyacetonephosphate, the latter greatly predominating." Pentosephosphate" is an analogous mixture of D-ribose andD-ribulose 5-pho~phates.~~~) The authors' preparation wasinert towards pentose phosphate, unless an " acceptor "(produced by the simultaneous addition of muscle aldolaseand D-fructose 1 : 6-diphosphate) was present. Then,sedoheptulose 7-phosphate (20), hitherto known only as thefree sugar 23 or phosphate 24 in plants and yeast,25 wasFurther work showed that spinach leaves,26 yeast,27and rat liver 28 contained a hydroxyacetyl radical-transferring enzyme whichthe authors termed " transketolase." Horecker et aZ.Z6? 2 8 y 29 have elucidatedits mechanism by using two differently marked [14C]-preparations of D-ribulose &phosphate (21) (ketol donor) and D-ribose 5-phosphate (22) (ketolacceptor). inthe other at Cb) and C o ) . The following scheme illustrates the mechanismwhere *C indicates labelled C(,), and C** labelled C(2) and C@>.In the reverse reaction (5) served as acceptor for the ketol radical of (20).Racker et aZ.275 30 have shown that crystalline yeast transketolase will cleave21 R. M. Hann, E. B. Tilden, and C. S. Hudson, J . Amer. Chew. Suc., 1938,60,1207;z z B. L. Horecker and P.2. Smyrniotis, J . Amev. Chem. Soc., 1952, 74, 2123.22@ 2. Dische, Abs. 1st Int. Congr. Biochem., 1949, p. 572.22b F. Schlenk and M. J. Waldvogel, Amh. Biochem., 1947, 14, 484 ; 1949, 22, 185.22c G. E. Glock, Biochem. J., 1952, 52, 575.23 K. T. Williams, E. I?. Potter, A. Bevenue, J . Assoc. O ~ G . Agric. Chemisls, 1962,35, 483; A. Nordal and R. Klevstrand, Acta Chem. Sccand.. 1951, 5, 85, 898.24 A. Nordal and D. Oiserth, ibid., p. 1289; ibid., 1952, 6. 476; A. A. Benson, J. A.Bassham, and M. Calvin, J . Amer. Chem. Soc., 1951, 73, 2970; A. A. Benson, J. A.Bassham, M. Calvin, A. G. Hall, H. E. Hirsch, S. Kawaguchi, V. Lynch, and N. E.Tolbert, J . B i d . Chem., 1952, 196, 703.I 7" '""'P"'iH*C*OH I H. *OHHa -OH 7CHz'o.Po3H2 an observed product.(20)In one series of experiments the sugars were labelled atR.H. Hockman and V. M. Trikojus, Biochem. J., 1953, 51, 653.T. Reichstein, Helv. Chim. Acta, 1934, 17, 996.a5 R. Robison, M. G. Macfarlane, and A. Tazelaar, Nature, 1938, 142, 114.as B. L. Horecker and P. 2. Smyrniotis, J . Amer. Chem. Suc., 1953, '95, 1009.2 7 E. Racker, G. de la Haba, and I. G. Leder, ibid., p. 1010.28 B. L. Horecker, M. Gibbs, H. Klenow, and P. 2. Srnyrniotis, J , Bid. Chem., 2954,3O E. Racker, G. de la Haba, and I. G. Leder, Arch. Biochewt. Biuphys., 1954, 48, 238.207, 293. ee M. Gibbs and B. L. Horecker, ibid., 208, 213BELL : BIOLOGICAL SYNTHESES OF SOME MONOSACCHARIDES. 329I **COH- *OH c. H- -OH 'i H. .OH 7 pi) CH,O.PO,H~ bH,.O*PO,H, ( 5 ) or eH,*O*PO,H,*(;HO *7H,.OH+ L + - +I**HC-OHH-C,*OH IIICH ,.O.PO,H,I H-C-OH ICI~,.O-PO,H, (20) or CH,.O.PO,H,D-fructose 6-phosphate (23), but only in presence of a suitable aldehydicacceptor, i.e., with (22) it yields (20) and with (5), (21).These authors termthe ketol radical " active glycollic aldehyde " ; it ispresumably associated with the enzyme during transfer.The " two-carbon fragment " postulated in the earlierwork does not seem to have an independent existence.31Transketolase will also use hydroxypyruvic acid 27as ketol donor, with accompanying liberation of carbondioxide [i.e., in (10; X = O)].Thiamine diphosphate is an obligatory coenzyme forCH,.O.po,H, the rea~tion.~l It seems to the Reporter that trans-ketolation (transhydroxyacetylation with transhydrogen-ation) may have some enzymic similarity with transacetyl- (23)ation.It also seems possible that glycollic acid itself might be introduced intotransketolation along lines parallel to the generation of acetylccenzyme A.32While dihydroxyacetone phosphate (1) and D-erythrose (25) will reactto give sedoheptulose l-phosphate, and while DL-glycerddehyde and L-ery-thulose will react in vitro to give D- and L-heptulose phosphates, Horeckeret aL31 consider that these are improbable routes in vivo for sedoheptulosesynthesis and, conversely, for pentose synthesis.Horecker et aZ.339 =,35 have discovered yet another widelydistributed synthesising mechanism in preparations from liver,32 yeast ,33various animal and spinach leaves,35 through " transaldolases."It is now possible to elucidate the hitherto baffling observation that numeroustissues appeared to generate D-glucose 6-phosphate (24) at the expense of" pentose phosphate." By using ~-[~~C]glyceraldehyde 3-phosphate (5) asacceptor and unlabelled sedoheptulose 7-phosphate (20) as donor of a81 B.L. Horecker, P. 2. Smyrniotis, and H. Klenow, J . BioE. Chem., 1953, 306,661.32 A.tz?z. Reports, 1953, 50, 301.33 B. L. Horecker and P. 2. Smyrniotis, J . Amer. Chem. SOC., 1953, 7'6, 2021.84 T. E. Seegmiller and B. L. Horecker, J . Biol. Chem., 1952, 194, 261.36 B. L. Horecker, M, Gibbs, H. Klenow, and P. 2. Smyrniotis, ibid., 1954, 207, 398.- - .-_--- 7-0HOG~H 1 I---...HC-OHH* *OH I 'iTransaldolase330 BIOCHEMISTRY.HOCH,CO*C(OH)* group the following disproportionation was demon-strated (* indicates labelled carbon atoms).CH,*OHco CHO II - *IICH,*OHcoIIHexme H'C'oH1I-.-*.*IIIIIphosphatesisonierase HO.C.EILH0.C.H --I _________HI C.OH H0C.HHC-OH ~ i .c . 0 ~ HC-OHHC-OH-we.-- I ,--I _-.__ +_.-H4.01-X HC*OH II *CH,*O.PO,H, (24) *CH,*O*PO,H, (23) (20) CH,.O.PO,H,I-*CHO CHOH&OH H-C-OHHC-OH- + -I *CII,.O*PO,H,CH,.O-PO,H, (25)Gibbs and H ~ r e c k e r , ~ ~ using two separately 14C-labelled " pentose phos-phate " preparations [(a) C(l) labelled; (b) C(z> and C(!l both labelled], haveexamined the transaldolase and transketolase systems in the leaves and rootsof pea plants.Since the proportions of the relevant labelled atoms in the final productswere not identical, it was concluded that, while the system in the rootsappears identical with that of rat liver, in the leaves an additional unknownmechanism can function whereby of pentose phosphate becomes incorpor-ated into and C(5? of sedoheptulose 7-phosphate.The following schemeillustrates these findings [ * indicates Co) original labelling, * * indicatesC(,) and original labelling, and strongly labelled atoms in the products.Weakly, but significantly labelled atoms in the products are indicated( 5 )by ! (leaf)] : -*C *YH0 I c** **co*'i**V0 *C***C**GOII .---I-+ Transketolase .--L. 7** + **c 1 - F C T CTransaldolase I . .I. +1 sF** +**CHo 1 *F** + **CHo IIF** 7 $.!'i F CCI I(22) (21) c (20) ( 5 ) !C (23) C (25)With [ l-14C]pentose, root preparations gave hexose phosphate having 700/,of C(l) labelled ; leaf preparations, on the other hand, gave hexose phosphate63% labelled at 19% at C(,), and significant labelling at C(*>, C(5), and C(s>.With C(2)-C(3) labelled pentose, both root and leaf extracts gave 14C-contentsas follows : C(d, 50% ;Aerobic Pentose Formation.-It is now clear that there exists a widelydistributed natural pathway for the production of D-ribose 5-phosphateIand Ch), 25% eachDELL BIOLOGICAL SYNTHESES OF SOME MONOSACCHAlIlI>ES. 331which commences with the dehydrogenation of D-glucopyranose 6-phosphate(26) through TPN.36-41 Cori and Lipmann42 showed the initial productto be almost certainly D-glucono( 1 -+ 5)lactone 6-phosphate (27) ; this, ofcourse, undergoes hydrolysis to the acid (28) but whether spontaneously orenzymically is not known (cf.Meister 43). While reversible hydrogenationof the lactone by reduced TPN will take place in vitro 44 it is not knownwhether, at physiological pH, sufficient of the acid can undergo lactonisationto make this a genuine process in vivo. Oxidation and decarboxylation ofthe gluconic acid 6-phosphate then produce D-ribose 5-phosphate (29) whichbecomes, in turn, enzymically equilibrated with D-ribose Ci-phosphate, andthe latter with p-D-ribofuranose l-phosphate. The ester-glycoside inter-conversion is catalysed through D-ribofuranose 1 : 5-diphosphate ; 45 the wholeseries of pentose interconversions is thus exactly analogous to the series ofreactions linking D-fructose 6-phosphate and a-D-glUCOSe l-phosphate.1$0IIH*C*OHH*C.OH Ii CH2*0.P0,H, (28) I CH2*0.1’03H, (27)-CO,+co,L - ?I3C.OH I CH2*O*I’03H, (29)The nature of the substance intermediate between (28) and (29) hasbeen a matter of speculation; Dickens and Glock 46 postulated a 3 : 4-dienolstructure while Horecker 47 suggested that a 3-oxo-derivative might equallywell give rise to P-decarboxylation.Using cell-free extracts of Pseudomonassaccharophzila, Entner and Doudoroff 48 found that ~-[l-~~C]gluconic acid36 0. Warburg and W. Christian, Biochent. Z., 1931, 298, 131 ; 1936, 287, 440; 1937,292, 287. 37 F. Lipmann, Nature, 1936, 138, 588.F.Dickens, itrid., p. 1057; Biochem. J . , 1938, 32, 1626, 1645.S. S. Cohen and D. B. M. Scott, Science, 1950, 111, 543; D. B. M. Scott andS . S. Cohen, J . Biol. Chem., 1951, 188, 609.383; B. L. Horecker, ibid., 1952, 194, 261.202, 619.40 €3. L. Horecker and P. 2. Smyrniotis, Arch. Biochem., 1960, 29, 232.40a B. L. Horecker, P. 2. Smyrniotis, and J. E. Seegmiller, J . Biol. Chem., 1951, 193,4 1 B. Axelrod, R. S. Bandurski, C. M. Greiner, and R. Tang, J . Biol. C h e w , 1953,42 0. Cori and F. Lipmann, J . Biol. Chew.. 1952, 194, 417.43 A. Meister, Science, 1952, 11-5, 521.j4 R. L. Horecker and P. 2. Smyrniotis, Biochim. Biophys. Acta, 1953, 12, 98.4 5 H. M. Kalckar, ibid., 1963, 12, 350; H. Klenow and B. Larson, ibid., 1952, 37,488; A.Kornberg and W. Price, ibid., 1953, 203, 583; M. Saffron and E. Scarano,Nature, 1953, 1’42, 949.4 7 B. L. Horecker, “ Phosphorus Metabolism,” Johns Hopkins Press, Baltimore,1951, Vol. I, 117.4 6 F. Dickens and G. E. Glock, Bicchem. J . , 1951, 50, 81.4 8 N. Entner and M. Doudoroff, J . Bid. Chem., 1952, 196, 853332 BIOCHEMISTRY.6-phosphate was converted into pyruvate and glyceraldehyde 3-phosphatewhich could be fixed with hydrazine. The precursor of this pyruvate wasneither glyceraldehyde nor glyceric acid. Entner and Doudoroff suggestedthat it might be 3-deoxy-2-oxogluconic acid 6-phosphate (30). McGee andDoudoroff 49 have now isolated the intermediate substance and have strongevidence for their proposed structure.Whether this substance is the generalintermediary in the conversion of glucose into ribose remains to be seen. Itis not obvious how its decarboxylation could lead to D-xylulose 5-phosphate ;direct a-decarboxylation would, however, give 2-deoxy-D-ribose 5-phos-phate (6).Several additions to the above interconversion of glucose and ribose havecome to light. D-Gluconic acid, a frequent product of aerobic oxidation ofglucose by micro-organisms (it can be produced by a liver enzyme 50), can betransphosphorylated at C(6) through ATP to give (28) by strains of Esch.coli 51 and yeast.52 The carboxylation of D-ribulose 5-phosphate (29) to thehexonic acid stage (28) has been demonstrated in yeast, by using 14C0, 53(and the reaction, D-ribose 5-phosphate _t glucose, has been shown totake place in Corynebacterium creatinovorans =).Cohen 51 has shown thatstrains of Esch. coli adapted to D-arabinose (known only in some bacteria)possess an enzyme of a new type, one which catalyses an aldose ketoseisomerisation of the free sugars : D-arabinose __L D-ribulose. The lattercan be transphosphorylated through ATP and thus introduced into theribulose-ribose, etc., system. (It should be noted that D-arabinose isreported to be metabolisable by mammals.50, 5 5 ) The origin of L-arabinoseremains quite unknown, although in plants it is widely distributed.To what extent the aerobic degradation of D-glucose or its 6-phosphatetakes place in animals is not yet solved. Bloom and Stetten 56 and Bloom,Stetten, and Stetten,5' using isotope techniques, found that liver and kidneyslices, but not rat diaphragm, would oxidise the carbon of glucose by a routethat did not involve preliminary anaerobic glycolyses.They believe, how-ever, that intact animals do effect their carbon dioxide production viaglycolysis coupled to the citric acid cycle. Chaikoff et aZ.,57a while obtaininganalytical data in agreement with the previous authors, interpret their resultsto mean that the liver preparations do, in fact, degrade SO--SO% of theglucose oxidised via an initial anaerobic glycolysis. On the other hand,Abraham, Hirsch, and Chaikoff 57b believe that about 60% of glucose addedto rat mammary tissue is attacked by direct aerobic oxidation. Kinoshitaand Masurat 58 have demonstrated an " oxidative cycle " in preparationsof bovine corneal epithelium : (a) decarboxylative oxidation of D-glucose6-phosphate to D-ribose 5-phosphate, (b) conversion of pentose phosphate4 9 J.McGee and M. Doudoroff, J . Bid. Chem., 1054, 210, 617.50 W. W. Wainio, ibid., 1947, 168, 569.52 V. A. Engel'hart and A. P. Barkash, Biokhimiya, 1938, 3, 520; H. 2. Sable andA. J. Guarino, J . Bid. Chem., 1952, 196, 395.53 B. L. Horecker and P. 2. Smyrniotis, ibid., p. 135.64 F. G. Liretti and E. S. G. Barron, Biochim. Biophys. Acta, 1954, 15, 445.55 E.g., F. L. Breusch, Biochem. Z., 1951, 321, -354; E. W. Rice and J. H. Roe,5 0 B. Bloom and D. Stetten, J . Amer. Chem. Soc., 1953, 75, 5446.57 B. Bloom, M. R. Stetten, and D. Stetten, J .BioZ. Chern., 1953, 204, 681.570 J. Katz, S. Abraham, R. Hill, and I. L. Chaikoff, J . Amer. Chem. Soc., 1954, 76,576 S. Abraham, P. F. Hirsch, and I. L. Chaikoff, J . Bid. Chem., 1954, 211, 31.58 J. Kinoshita and T. Masurat, Arch. Biochem. Biophys., 1954, 53, 9.61 S. S. Cohen, ibid., 1953, 201, 71.J . Biol. Chem., 1951, 188, 463.2277BELT. : BIOLOGICAL SYNTHESES OF SOME MONOSACCHARIDES. 333into sedoheptulose phosphate, and (c) production of hexose phosphate at theexpense of the heptose derivative.D-Xylose and D- and L-Xylu1oses.-While derivatives of D-xylose and L-arabinose are abundant in higher plants, there is no evidence of the occur-rence of these sugars in animals. Cryptococcus neofQYmans (formerly Tor*lopsis histolyticum) appears to produce an exocellular xylose-containingpolysa~charide.5~ L-Xylulose is the sugar excreted by man in the curious“ inborn error of metabolism,” pentosuria.60 There is no evidence regardingthe origin of this sugar although its concentration in urine of pentasurics(but not of normal subjects) is increased by feeding D-glucuronic acid.61McGeowan and rvllalpress,62 investigating the action of a guinea-pig liverextract on added D-fructose diphosphate and glycollaldehyde, obtainedchromotographic evidence of xylulose formation 22c at an early stage in thereaction.If this should prove to be the D-isomer, its synthesis could beattributed to the ordinary aldolase reaction, but whether or not D-xyluloseis a normal animal component remains to be proved.A slower productionof ribulose in this system could be attributed to transketolation and not toa Walden inversion as suggested by the authors. Ashwell and Hickman 63have isolated crystalline D-xylose phenylosazone from D-xylulose phosphateformed from D-ribose phosphate in presence of mouse-spleen extracts. Theynote that the orcinol-trichloroacetic spray of Klevstrand and Nordalserves to differentiate the pentulose from the pentose. While the spleenhomogenate had strong transketolase activity, the extract did not possessenough to be dete~ted.~l Byrne and Lardy 65 have shown that crystallinemuscle aldolase (see aldolase section) is capable of synt hesising D-XylUlOS~l-phosphate and D-XylUlOSe ( ?) 1 : 5-diphosphate from dihydroxyacetonephosphate and glycollaldehyde or its phosphate.Hochster and Watson G6 have shown the transphosphorylation (ATP) ofD-xylose, probably at in extracts of Pseudomonns hydrophila and alsothat this organism possesses an isomerase equilibrating D-xylose withD-xylulose 67 (cf. ref. 51). A possible pathway thus exists to link D-xylosewith the interconversions discussed in this and previous sections. Since ithas been shown repeatedly that an enzymic system initially detected in onetype of organism is later found to be of general distribution it would seem tobe only a matter of iurther investigation before chemically acceptable routesfor the interconversion of natural monosaccharides are established.While not strictly within the scope of this report, attention is drawn torecent work on fixations of carbon dioxide involving D-ribdose diphos-phate.68, 69, 705g E. E. Evans and R. J. Theriault, J. Bacteriol., 1953, 65, 571.6o Cf. H. W. Larson, W. H. Chambers, N. R. Blatherwick, M. Ewing, and S. D.61 M. Enklewitz and M. Lasker, J. Biol. Chem., 1935, 110, 443.62 M. G. McGeowan and F. Malpress, Nature, 1954, 173, 312.G3 G. Ashwell and J. Hickman, J . Amer. Chem. SOC., 1954, 76, 5889.64 R. Klevstrand and A. Nordal, Acta Chem. Scand., 1950, 4, 1320.6 5 W. Byrne and H. A. Lardy, Biochim. Biophys. Acta, 1954, 13, 255.b6 R. M. Hochster and R. W. Watson, Nature, 1952, 170, 357.Sawyer, J . Biol. Chem., 1939, 129, 701.Idem, J . Autzer. Chem. SOG., 1953, 75, 3284; Arch. Bauhena. Biophys., 1954, 48, 120.J. A. Bassham, A. A. Benson, L. D. Kay, A. 2. Harris, A. T. Wilson, and M.Calvin, J . Amer. Chem. SOG., 1954, 76, 1760.69 A. Weissbach, P. Z. Smyrniotis, and B. L. Horecker, ibid., p. 3611, 5572.70 3. R. Quayle, R. C. Fuller, A. A. Benson, and M. Calvin, ibid., p. 3610334 BIOCHEMISTRY.Some Apparent Hexose Interconversions not involving Six-carbon ChainCleavage : D-Glucosone.-~-[ 1J4C]Mannose 71 was injected intrapentoneallyinto rats and the glycogen later analysed. 80-90% of the radioactivity wasfound a t C(l) of the resulting glucose. A similar result was obtained withyeast 72 with respect to its mannan as well as its glycogen.The origin of D-glucuronic acid in animals has long been one of speculation.There is now evidence for two pathways : ( a ) direct oxidation of ofD-glucose and (b) synthesis by reversed glycolysis from smaller precursors.In support of ( a ) , Eisenberg and Gurin 73 found C<,>-labelling predominating inthe menthyl P-D-glucuronide isolated after feeding menthol and [1-14C]glucoseto rats. Roseman et aZ.,74 after feeding [1-14C]- and [6-14C]-glucoses toGroup A Streptococcus, found correspondingly labelled glucuronic acidmolecules derived from the hyaluronic acid fractions synt hesised.In support of ( b ) , however, Doerschuk 75 found that bornyl @-[14C]glucu-ronide resulted after administration of labelled glycerol. Bidder 76 haslikewise found labelled menthyl glucuronide to be synthesised by liver slicesof fasted guinea pigs in presence of added menthol and [3-14C]lactate.The D-glucosamine moieties of the hyaluronic acid synthesised by Group AStreptococcus have been found to be derived by direct transformation of[1-14C]- and [6-14C]-glucose.74’ 77 Interesting experiments on the rat byBecker and Day 78 showed that ~-[l-~~C]glucosone gave a higher transform-ation into serum ~-[l-~~C]glucosamine than did glucose, and suggest thetransformation : Glucose _L. Glucosone + Glucosamine.Interest in D-glucosone has been revived by the work of Bayne and hiscolleagues. Mitchell and Bayne 79 and Johnstone and Mitchell 8o haveshown that D-glucosone inhibits the transphosphorylation of D-fructose,D-fructose, D-glUCOSe, D-mannose, and D-glucosamine by yeast hexokinaseand ATP by acting as a competitive acceptor for phosphate-L-glucosone isnot phosphorylated by this system. D-Glucosone has been found in plasmo-lysed preparations of Aspergillus spp. acting on D-glucose.sl I t has also beenbelieved to be formed from D-glucose by a system present in the crystallinestyle of the mollusc Saxidomis giganteus. 82D. J. R.D. J. BELL.H. GUTFREUND.C. RIMINGTON.B. s. HARTLEY.7 * M. Cook and V. Lorber, J . Bid. Chem., 1952, 199, 1 .72 C. Gilvarg, ibid., p. 57.7s F. Eisenberg and S. Gurin, ibid., p. 1.74 S. Roseman, J . Ludoweig, F. Moses, and A. Dorfman, Arch.. Biochewz. Siophys..7 5 A. P. Doerschuk, J . Biol. Chem., 1952, 195, 855.7 6 T. G. Bidder, Fed. Proc., 1952, 11, 323.i7 Y. J . Topper and M. M. Lipton, J . Bid. Chem., 1953, 203, 135.79 I. L. S. Mitchell and S. Bayne, Biochem. J . , 1952, 50, xxvii.eo J. H. Johnstone and I. L. S. Mitchell, ibid., 1953, 55, xvii.81 T. K. Walker, Nature, 1932, 130, 582; C. R. Bond, E. C. Knight, and T. I(.82 C. Berkeley, ibid., 1933, 27, 1367.1953, 42, 472; J . Rid. Chem., 1953, 203, 213; ibid., 1954, 206, 665.C. E. Becker and H. G. Day, ibid., 1953, 201, 795.Walker, Biochem. J . , 1937, 31, 1033

ISSN:0365-6217    

DOI:10.1039/AR9545100295

出版商:RSC    

年代:1954

数据来源: RSC

摘要:

ANALYTICAL CHEMISTRY.THIS Report is restricted to a limited number of topics-perhaps those mostinteresting to the Reporters. Those omitted, e.g., radiochemical methodsand absorptiometry, will be dealt with in subsequent years.The outstanding event of interest to analytical chemists during 1954 wasthe Symposium on Analytical Chemistry held by the Midlands Society forAnalytical Chemistry at Birmingham during the later summer. About350 delegates attended, of whom about 50 were from abroad. A total of 56papers was read during the eight days the Symposium continued.The opening Plenary lecture was given by Professor Fritz Feigl whodealt with new organic spot-tests which he demonstrated. It was moststimulating to listen to this great analytical chemist, both to the youngerchemists who had never before experienced his impeccable lecturing technique,and to the older chemists to whom, before the war, a lecture by Feigl was anoutstanding event.Plenary lectures were also given by Professor M.K. Zacherl, ProfessorM. Stacey, and Dr. G. F. Hodsman, and summaries have appeared in variousjournals.A further notable event during 1954 was the lectures given at the RoyalInstitution by Professor H. Burton and Dr. P. F. G. Praill, and by ProfessorG. F. Smith, and organised by the Society for Analytical Chemistry. Thesepapers did much to dispel the fears many chemists have of using perchloricacid, and showed that danger only arose from ignorance or gross carelessness.Amongst his many demonstrations, Professor Smith showed how rapidlyand smoothly a cigar could be wet-ashed by using perchloric acid.GENERAL.A review of progress in analytical chemistry under 25 different headingshas been dealt with by a group of authors.2 West has described the applic-ation of microchemistry in chemical analysis and makes particular referenceto ultramicro-techniques.The development, present state, and prospectsof organic spot analysis and the problems encountered have been reviewedby Feigl.4The principles concerning the preparation of dry reagents for analyticalwork have been discussed by DannenbergJ5 and a classification presentedbased on stability and application. Amongst the reagents proposed are dryforms of the Folin-Wu reagent, Benedict’s reagent, and Rothera’s reagent.has used a phase-rule method for determining purity invarious compounds, and has applied it to a series of amino-acids.has described a neat and convenient apparatus for conductingwet ashing on the semimicro-scale.Anon., Chem. Age, 1954, 51, 821 ; Ind.Chemist, 1954, 30, 545.Anon., Analyt. Chem., 1954, 26, 1.T. S . West, Research, 1954, 7 , 00.F. Feigl, Mikrochim. Acta, 1953, 157.E. Dannenberg, Analyt. Chim. A d a , 1954, 10, 101.H. A. Frediani, Rendiconti 1st Sup. Sanit., 1953, 18, 502,FredianiBethge7 P. 0. Bethge, Analyt. Chim. Acta, 1954, 10, 317336 ANALYTICAL CHEMISTRY.Some attention has been devoted to error in analytical chemistry.Linnig, Mandel, and Peterson describe the titration of a fatty acid and thestatistical examination of the results.They offer this as an example of thegeneral procedure to be adopted in such examinations. Carbon and nitrogendeterminations have been carried out in different laboratories, the figuresobtained have been examined statistically, and a working estimate of thereliability of the method and operator has been d e d ~ c e d . ~ Gysel lo reportsthat errors arise in reading microanalytical balances owing to an unconsciouspreference for certain numbers and rejection of others. This psychologicalfactor can cause errors of 0.25%. It is considered that improvements inbalance design may eliminate these errors Livingston l1 has indicated thatthe rotating field produced by magnetic stirrers can induce fluctuations inpH meters.The effect was not eliminated by earthing either the stirrer orthe meter, and it is recommended that the stirrer be stopped before valuesare recorded. In the reduction of permanganate solution at glass surfacesit has been shown that surface area plays an important part, and the possi-bility of 8 quantitative relationship between extent of reduction and surfaceis being examined. l2The most outstanding new technique described during 1954 is probablythat using the device known as the “ ring oven.” 13. This enables severalions or groups of ions to be cleanly separated on a single drop of solution,1.5 pl. being sufficient. A semi-quantitative colorimetric procedure has alsobeen developed.The relation between “ weighting effect ” and sensitivity has beenstudied.l4 Changes in solubility can be charactetised for each group by aconstant.Krauss and Grund l5 have discussed the theory of absorptionspectra of what they term “primary complexes,” i.e., those formed bydirect birnolecular reaction between the reagent and test substance. Deter-minations involving indirect reactions are considered to be less suitable ;they should be used with caution. The effect of different groups on thereactions of organic reagents has been discussed; those other than thefunctional group, which cause changes in the product and sensitivity of thereaction are termed “ analytico-active ” groups. The reactions of 17rhodanine derivatives with 8 ions were examined to study the effect of suchgroups.l6Freiser and his co-workers have continued their interesting and importantstudies concerning the structure and behaviour of organic analytical reagents.Metal complexes formed by 2-o-hydroxyphenyl-benzoxazole, -benzothiazole,and -benzothiazoline which form 6-membered rings containing the metalare less stable than the 5-membered 8-hydroxyquinoline complexes.Allthree compounds are more selective than 8-hydroxyquinoline. The aciddissociation constants and some chelate stability constants of these l7 andF. J. Linnig, J. Mandel, and J. M. Peterson, AnaZyt. Chem., 1954, 26, 1102.D. S. McArthur, E. L. Baldeschweiler, W. H. White, and J. S. Anderson, ibid.,p. 1012. lo H. Gysel. Mikvochim. Acta, 1953, 266.l 1 G. E. Livingston, Chemist-Analyst, 1964, 43, 106.l2 M. J.Cotter, Chem. and Ind., 1954, 433.l3 H. Weisz, Mikrochim. Acta. 1954, 140, 276, 460.l4 K. B. Yatsimirsky, Zhur. analit. Khim., 1953, 8, 314.Is W. Krauss and H. Grund, 2. analyt. Chem., 1954, 142, 173,l6 L. M. Kulberg, A. A. Ponomarev, and N. 1. Davydova, Zhu9. analit. Khim., 1954,9, 85. l 7 R. G. Charles and H. Freiser, Analyt. Chim. Acta, 1954, 11, 1BELCHER : GENERAL. 337some substituted benziminazoles 18 have been determined. The formationcmstants for several metal complexes of 8-hydroxy-2- and -4-methyl-quinoline l9 and of dimethylglyoxime and its monomethyl ether 2o have alsobeen determined. Since nickel dimethylglyoxime is not except ionallystable, the selectivity of the reagent must be due to other causes.The ionisation constants and oil-water partition coefficients of thirteenanalogues of 8-hydroxyquinoline have been determined and correlated withtheir structure. The stability constants of certain metal complexes withthese compounds have been determined.Acidic ionisation constants of themonohydroxypyridines have been discussed in relation to the variations inacidic strength of nitrogenous heteroaromatic substances. 21The reaction of cyclohexane-1 : 2-dione dioxime with iron(I1) has beenstudied to throw light on the interference of the latter in the nickel deter-mination.22 Christopherson and Sandell 23 have determined the molecularsolubilities, the solubility product constants, and the ionisation constants ofdimethylglyoxime and its nickel compound.The reactions of 2-2’-pyridyl-benziminazole and -benziminazoline withvarious metals have been Coloured complexes were formedwith copper-(I) and -\II), and with cobalt- and iron-(II) and -(III), the reactionwith iron( 11) being particularly suitable for colorimetric measurements.The complex can be extracted with isopentyl alcohol, and the reaction thusrendered more sensitive.2,In his Fisher Award lecture, Professor G.F. Smith 2g has reviewed theproperties and reactions of 1 : 10-phenanthroline, 2 : 2’-dipyridyl, 2 : 6-di-(2-pyridy1)pyridine (2 : 2’ : 2”-tripyridyl), 2 : 2’-diquinolyl, and some sub-stituted derivatives. Some trifluoromethyl-substituted benziminazoles havebeen synthesised and their reactions with certain metals have been studied.26Although some metal ions formed precipitates, no outstanding propertieswere noted. Those with triffuoromethyl groups in both the glyoxaline andthe benzene ring were appreciably acid.The reactions of 5-fluoro-8-hydr-oxyquinoline have been found to resemble closely those of S-hydroxy-q~inoline.~’0-, m-, and +-Fluoromandelic acid and the corresponding trifluoro-met hyl-acids have been prepared and their reactions with zirconium havebeen examined.28 The para-derivatives are satisfactory as precipitants buthave no advantage over mandelic acid for this purpose.Lutwick and Ryan29 examined the reactions of 9 aromatic phenyl-liydroxylamines with metals. Their selectivity increases with increase inacidity of the oxime group, and in acid solutions only vanadium, tin, titanium,and zirconium are precipitated.The only noteworthy property was exhibitedby N-furoylphenylhydroxylamine which forms a water-soluble ammoniumsalt, whereas all the other reagents have to be used in alcoholic solution.I s W. D. Jolinston and H. Freiser, Aizarlyt. Chim. Ada, 1954, 11, 301.l9 Idem, ibid., p. 201.2 1 A. Albert and A. Hampton, J., 1954, 505.22 C. V. Banks and E. K. Byrd, Analyt. Chim. Ada, 1954, 10, 129.23 1%. Christopherson and E. B. Sandell, ibid., p. 1.24 H. Freiser, Analyt. Chem., 1954, 26, 217.26 R. Belcher, A. Sykes, and J. C. Tatlow, J., 1954, 4159.27 R. G. W. Hollingshead, Chem. and Ind., 1954, 344.2 B R. Belcher, A. Sykes, and J. C . Tatlow, Analyt. Chim. Acta, 1954, 10, 34.29 G. D. 1-utwick and D. E. Ryan, Canad. J .Chem., 1954, S2, 949.20 R. G. Charles and €3. Freiser, ibid., p. 101.G. F. Smith, ibid., p. 1534338 ANALYTICAL CHEMISTRY.REAGENTS.Colorimetric.-Rush and Yoe 30 have recommended 5-(2-~arboxyphenyl)-1 -(2-liydroxy-5-sulphophenyl)-3-phenylformazon as a reagent for zinc andcopper. Zinc is measured at pH 9 and 620 mp, and copper at pH 5.2 and600 mp. NN-Dimethyl-P-nitrosoaniline can be used to determine platinumand palladium alone or in admixture. The colour due to platinum onlydevelops on heating, but that due to palladium develops also in the4 : 4’-Dimethyl-2 : 2’-diquinolyl(2 : 2‘-di-lepidine) has been examinedas a reagent for copper. The extinction coefficient of the complex, likethat of the parent 2 : 2’-diquinolyl, is lower than those of 1 : 10-phen-anthroline and its derivatives, but it has the advantage of being stabletowards atmospheric oxygen.32 4 : 4’-Diphenyl-2 : 2’-diquinolyl has beenshown to be the most sensitive of 10 substituted quinolyls examined ascopper reagents by Smith and Wilkins.33 Tetrabromochrysazin has beenrecommended as a particularly sensitive reagent for boron : the inter-ference of other ions is eliminated by distilling the boron as trimethylborate.34Mannelli and Biffoli 35 have examined meconic acid as a reagent for ferriciron. The reaction is quite sensitive but the effect of the other ions does notappear to have been investigated.Precipitants.-Cobalt has been determined gravimetrically after precipit-ation with isonitrosodimedone (hydroxyiminodirnedone) ; few of the commonions interfere.36 Adipic acid has been proposed as a selective reagent formercury.The main interferences are from tin(Iv), antimony(v), man-ganese(II), iron(m), and tellurate. A gravimetric and a less attractive titri-metric procedure are de~cribed.~’Phenylacetic acid has been advanced as a very sensitive reagent for thedetermination of thorium. Very few ions interfere. Cerium earths arewithout influence, unless present in large excess. In such a case reprecipit-ation gives a clean s e p a r a t i ~ n . ~ ~Cheng 39 has studied the reactions of benzo-1 : 2 : 3-triazole in the presenceof excess of complexone. Only the silver complex was precipitated out ofseveral metals examined; hence the reagent appears to be highly selective.The precipitate can be weighed, or titrated cyanometrically.Barium in small amounts may be determined by precipitation with3-ethyl-5-methyl picrate. The precipitate is dissolved, and the absorbencymeasured at 390Byrn and Robertson 41 have shown that at a pH of 11 in the presenceof ethylenediaminetetra-acetic acid, copper is precipitated quantitatively by2-o-hydroxyphenylbenzoxazole. Only metals which are precipitated from30 R.M. Rush and J. H. Yoe, AnaZyt. Chem., 1954, 26, 1345.31 J. H. Yoe and J. J. Kirkland, ibid., p. 1335.32 J. Gillis, J. Hoste, and Y. Van Moffaert, Mededel vlaam. chem. Yev., 1953, 15, 12.33 G. F. Smith and D. H. Wilkins, Analyt. Chim. Acta, 1954, 10, 139.34 J. H. Yoe and R. L. Grob, Analyt.Chem., 1954, 26, 1465.35 G. Mannelli and B. H. Wilkins, Analyt. Chim. Ada, 1954, 11, 168.36 J. Gillis, J. Hoste, and J. Pijck, Mikrochim. Acta, 1953, 244.37 D. R. Idler, Chemist-Analyst, 1954, 43, 9.38 A. Puroshottam and B. S. V. R. Rao, 2. analyt. Chem., 1954, 141, 97.39 K. L. Cheng, Analyt. Chem., 1954, 26, 1038.40 E. R. Caley and C. E. Moore, ibid., p. 939.d 1 E. E. Byrn and J. H, Robertson, ibid., p, 1606the medium interfere, and these can be filtered off before addition of thereagent. Procedures for the determination of copper in various alloys havebeen worked out. This reagent, originally introduced for the determinationof cadmium, appears to be one of the most outstanding of recent years. I tmay be useful for the separation of copper and cadmium in qualitativeanalysis.Withincreasing acidity, interference by other ions is reduced, but precipitation isthen incomplete unless an increased amount of reagent is added.As withall reagents of this type, it is necessary to ignite to the oxide, for a formula-pure precipitate cannot be obtained. The method is recommended particu-larly for small amounts of z i r ~ o n i u m . ~ ~Benzilic acid has been examined as a reagent for zirconium.R. B.INORGANIC QUALITATIVE ANALYSIS.Goldberg43 has evolved a selective test for cobalt as a result of hisstudies of the reaction between thiourea and cobalt salts. The cobalt saltin the solid state is diluted with sodium nitrate and ground with thiourea,and a blue or green colour is obtained.The limit of detection is 0-31 pg.of cobalt at a limiting concentration of 1 : 460,000. A more elegant butsomewhat less sensitive test for cobalt is obtained by soaking strips offilter-paper in a boiling solution consisting of 1 part of cobalt test solutionand 1 part of a saturated aqueous thiourea solution, and drying the paper.A green colour is obtained. Here the limit of detection is 2-5 pg. of cobaltat a limiting concentration of 1 : 20,000. A disadvantage of the method is.the interference of nickel. Less serious is the interference of bismuth,chromium, and copper.Sierra and Monllor 44 have examined the qualitative reactions of zincwith ferricyanide and various organic bases such as o-dianisidine, dimethyl-$-phenylenediamine, l-naphthylamine, and o-toluidine.A coloured pre-cipitate is obtained in dilute sulphuric acid solution with concentrations ofzinc greater than 10 p.p.m., whilst as little as 1 p.p.m. of zinc can be detectedcolorimetrically. The reactions are less sensitive than that using 3 : 3'-di-methylnaphthidine as the organic b a ~ e . ~ 5 Cations which form sparinglysoluble ferrocyanides and ferricyanides will interfere.A critical survey of the wet methods available for the detection andseparation of potassium, rubidium, and caesium has been made by Geilmannand G e b a ~ h r . ~ ~ Their examination , which included the use of radioactivetracer techniques, has indicated what has been known for some years,vix., that many of the methods are unreliable for the qualitative analysis ofmixtures of alkali salts where the concentration of one is much greater thanthat of the others, and that it is possible to detect traces of rubidium andczesium in sodium and potassium, but difficult to detect potassium in presenceof large amounts of rubidium and cEsium.Nickel can be characterised by formation of nickel ferrocyanide ammine,*'4 2 J.J. Klingenberg, N. Vlannes, and M. G. Mendel, Analyt. Chem., 1954, 28, T54.43 G. S. Goldberg, Zhur. analit. Khim., 1954, 9, 56.4 4 F. Sierra and E. Monllor, Aiaales Fis. Quim., B, 1954, 50, 63.4 5 R. Belcher, A. J. Nutten, and W. I. Stephen, Analyst, 1951, 76, 378.4 0 W. Geilmann and W. Gebauhr, 2. analyt. Chem., 1954, 142, 241.Q 7 A. S. Kozlov, Izvest. Akad. Nauk S.S.S.R., Otdel.Khim. Nauk, 1954, 94, 705340 ANALYTICAL CHEMISTRY.which crystallises from a solution of green nickel ferrocyanide in concentratedammonia solution as pale violet, slender prisms, which can attain a lengthof about 100 p. The ammine decomposes in air, losing ammonia and re-forming the original ferrocyanide, which aids in the identification of thenickel. The procedure suggested is to evaporate almost to dryness a dropof the nickel test solution and to treat it with a drop of a 20% solution ofpotassium ferrocyanide in concentrated ammonia solution. Cobalt does notinterfere unless present in greater than two-fold excess, but cadmium,manganese, silver, and zinc must be absent. The test appears to have apractical value only when the conventional and more selective reagents fornickel are not available.In the field of anion analysis, the need still exists for a comprehensiveand systematic scheme. Little progress has been made towards solvingthis long-standing problem, and at present recourse must necessarily be madeto schemes which involve either the use of separate portions of solutions andprecipitation of groups of anions, or a combination of this with the systematicqualitative analysis of a few of the more common anions.Any compre-hensive scheme of anion detection should include the important salts of thesulphur acids, and in this respect the work of Jacquinot 48 is noteworthy.She has developed a method for the detection (and determination) of thetetrathionate ion either alone or in admixture with sulphate, sulphide,sulphite, bisulphite, metabisulphite, thiosulphate, dithionate, and per-sulphate.The method is based on the reaction a t about pH 10 with anti-mony trichloride to give the orange-coloured antimony trisulphide, the limitof identification being 8 pg. of tetrathionate. The author does not discussthe behaviour of the remaining 3 polythionates under the conditions of thetest.Cole and Wilson 49 have investigated the effectiveness of the removal ofthe orthophosphate ion by precipitation with zirconium salts, with particularreference to semimicro-analysis. They also examined the extent of co-precipitation by various cations and other factors influencing the precipit-ation. In the procedure finally recommended, the filtrate from the Group I1precipitation is adjusted to less than 1~ with respect to hydrochloric acid,and about 0.2 g .of ammonium chloride is added per ml. of solution. Addi-tion of a 10% solution of zirconyl nitrate is made until precipitation is com-plete, the precipitate is centrifuged and the supernatant liquid examinedfor the cations of the other Groups. The excess of zirconium is precipitatedalong with iron and does not interfere in the usual confirmatory tests for it.INORGANIC GRAVIMETRIC ANALYSIS.A feature of recent developments in inorganic gravimetric analysis hasbeen the attention given to precipitation from homogeneous solution.The advantages and applications of this method of precipitation are perhapsnot as well known as they deserve to be. As the precipitant is generateduniformly throughout the entire reaction region, the concentration gradientswhich characterise the ordinary methods of precipitation are avoided.Precipitates obtained by the homogeneous method are less prone to co-precipitation than those obtained by conventional methods and are more4 8 hf.Jacquinot, Chirn. analyt., 1953, 35, 277.4 9 D. J. Cole and D. W. Wilson, Analyst, 1954, 79, 174NUTTEN : INOKGANIC GKAVIMETRIC ANALYSIS. 341readily filtered and washed. L. Gordon, one of the pioneer workers in thisfield, has continued his studies and has made several notable contributionsduring the past year. In conjunction with Reimer and B ~ r t t , ~ * he has useda radiochemical technique to examine the distribution of strontium inbarium sulphate precipitates obtained by heterogeneous and homogeneousmethods. The homogeneous method (hydrolysis of methyl sulphate) givesa precipitate of barium sulphate that has the smaller proportion of strontium.Using the same technique, these workers have shown, rather unexpectedly,that the coprecipitation of strontium with heterogeneously precipitatedbarium sulphate is greater with increased digestion time.Precipitation of barium as barium chromate from homogeneous solutionhas minimised interference from calcium and ~trontium.~l The precipitationis effected from hot solution containing ammonium acetate, the addition ofurea resulting in a slow increase in pH to the value required for the pre-cipitation.In this way 0.1 g.of barium can be separated from calcium andstrontium. If the quantity of strontium present is more than half that ofbarium, a double precipitation is necessary, but when calcium is present asingle precipitation is sufficient for complete separation, and strict controlof pH is not necessary.Washizuka 52 has separated amounts of copper between 10 and 100 mg.from large amounts of calcium and magnesium by precipitation from homo-geneous solution. The copper is precipitated at a final pH of greater than 8as sulphide by thiourea in presence of urea. The solution is boiled for 40-60minutes after the first appearance of a precipitate. If a separation fromcobalt, manganese, and zinc is desired, ammonium chloride must be addedto limit the final pH to not greater than 8.The precipitate is ignited andweighed as cupric oxide.It is well known that thorium cannot be separated from bismuth, titan-ium, and zirconium by precipitation as the iodate, but in presence of oxalicacid Tillu and Athavale 53 have obtained a complete separation from thesemetals and from the rare earths. The precipitation is carried out in 40%v/v nitric acid solution, under which conditions phosphate does not interfere.The separated thorium iodate is redissolved in hydrochloric acid containingsulphurous acid, and the thorium is determined gravimetrically as thoria inthe usual way.An overdue investigation has been made into the solubility losses ofthorium oxalate in dilute acid so1utions.H The results of this investigation,which include the effects of pH, time of digestion, and the thorium andoxalate concentrations, indicate that the oxalate method for the determin-ation of thorium is of little value, but may be used to separate thorium fromtitanium, zirconium, and phosphate in the absence of ammonium salts.Ifammonium salts are present, rare earths should be present as carriers. Theauthors also find that hexamethylenetetramine will precipitate thoriumquantitatively in the presence of ammonium salts or the rare earths, buttitanium, zirconium, and phosphate interfere.The development of the tetraphenylboron method for the determination50 L. Gordon, C . C. Reimer, and B. P. Burtt, Analyt. Chew., 1954, 26, 842.51 L. Gordon and F. H. Firsching, ibid., p.759.t2 S. U'ashizuka, Bull. Chem. SOC. Japan, 1954, 27, 76.53 M. Tillu and V. T. Athavale, Analyt. Chim. Acfa, 1964, 11, 62.54 H. I. Kall and L. Gordon, Analyt. Chem., 1953, 25, 1256342 ANALYTICAL CHEMISTRY.of potassium continues. The method, which has solved one of the long-standing problems of analytical chemistry, is finding widespread use. Itsgravimetric applications have been reviewed 55 and a rapid method for thedetermination of potassium in coal ash has been proposed.56 In the latterthe ash is opened-out according to the well-known Lawrence Smith pro-cedure. Potassium is precipitated from an aliquot part of the leachings aspotassium tetraphenylboron and weighed in this form.Erdey and Paulilc 57 have added to the extensive and sometimes confusingliterature on the precipitation of barium sulphate by publishing the resultsof an investigation into the composition of barium sulphate precipitatedunder different conditions.As is known, the composition of the precipitatedepends to a large extent on the conditions of precipitation and on the amountand nature of the anions and cations present. The concentration of hydrogenions greatly affects the crystal form and the composition of the bariumsulyhate precipitate. When the weight of the ignited precipitate is correctedby a given value, results close to theoretical are obtained, evidence beinggiven that variations in the composition of precipitated barium sulphate arechiefly due to the escape of volatile ingredients. According to the authors,high concentrations of hydrogen ions are favourable for the precipitation ofbarium sulphate, the composition of which approaches the theoretical valuebetween pH 0 to 1.The crystal structure of the precipitate varies withvariation in chemical composition. Some of the findings of this investigationcontradict what has been hitherto been regarded as established practice,whilst several important factors, e.g., the rate and temperature of precipit-ation, do not appear to have been examined.The effect of various amounts of certain compounds on barium sulphate,silver chloride, and nickel dimethylglyoxime precipitates has been studied byFischer and Rhi~~eharnrner.~~ It has been established for many years thatsmall amounts of certain compounds (known as addition agents) added to amedium of precipitation may exert a profound effect on the physical char-acteristics of the substance, particularly on the size, shape, degree of per-fection, and adsorptive properties of the crystal.The results of this in-vestigation involving three widely different precipitation processes indicatethat the morphology of barium sulphate is affected by several of the additionagents which have no effect on the organo-nickel salt. Naphthol-yellowprevents the photolytic decomposition of silver chloride precipitates, one ofthe common sources of error in this determination. None of the additionagents influences coprecipitation with the three precipitates either beneficiallyor adversely.INORGANIC TITRIMETRIC ANALYSIS.Indicators.-Basic ferric sulphate has been suggested as a convenientindicator for the titrations of strong inorganic acids 59 at dilutions as lowas 0 .0 1 ~ and of strong organic acids (e.g., the lower fatty acids) at dilutionsof 0 . 1 ~ . The indicator is easily prepared by treating a solution of ferroussulphate with hydrogen peroxide, a yellow basic ferric sulphate being$ 5 A. J. Nutten, Ind. Chemist, 1954, 30, 25.56 R. Belcher, A. J. Nutten, and H. Thomas, Analyt. CMm. Acta, 1954, 11, 120.j7 L. Erdey and F. Paulik, Acta Chim. Acad. Sci. Hung., 1954, 4, 97.5 8 R. R. Fischer and T. B. Rhinehammer, -4naZyt. Chem., 1954, 26, 244.5@ A. Krause and M. J. Daleszyhska, Roczniki Chem., 1954, 28, 134K UTTEN : INORGANIC TITRIMETRIC ANALYSIS. 343precipitated.The precipitate is converted by hydroxyl ions into the redzsoorthoferrihydroxide. The coagulation of the precipitate is most suitablyachieved at pH 8. Accurate results are obtained in the titration of sulphuricacid owing to the common-ion effect, but in the titration of hydrochloric acid,some potassium sulphate must be added to suppress the peptising influenceof the hydrochloric acid. Citric, phosphoric, and tartaric acids cannot betitrated in this way, as they form complexes with the indicator ; the indicatorcannot be used in the titration of bases with acids. Comparison with phenol-phthalein and methyl-orange indicators showed agreement to within 1 yofor inorganic acids and about 4% for organic acids.Karabash 6o has extended the use of dithizone as an extraction indicator.Titrations are based on reactions involving the metal complexes of dithizone.The solution of the metal containing dithizone and a non-miscible organicsolvent is titrated with a suitable solution until the organic layer changescolour.By this technique, silver may be titrated with bromide, iodide, andthiocyanate. The reverse titrations are also possible. Methods are alsodescribed for the determination of chloride, cyanide, sulphide, bismuth,cadmium, gold, lead, and mercury(rr). The indicator is of little practicalvalue owing to the large number of interferences, but is of considerableinterest academically.Frey 61 considers that methyl-purple can be used with advantage in placeof methyl-orange in the determination of the alkalinity of sewage and non-potable waters.Methyl-orange does not stand comparison, however, withmany of the newer mixed and screened indicators which change over asimilar pH interval. Accordingly, the properties of any proposed newindicator should surely be compared with those of a recent rather than anoutdated one.Saling 62 has stabilised the methyl-orange-indigo-carmine indicator byimpregnating filter-paper with freshly prepared solution of the mixture anddrying it. A strip of the indicator paper is immersed in the test solution, theindicator being leached from the paper. End-points are sharp and of thesame colour as that obtained with freshly prepared indicator solution. Thepaper shows no change in properties after storage for more than 6 months.Standardisation.-Desjobert and Petek 63 have critically reviewed theprincipal methods used for standardising solutions of acids and have proposedthe use of potassium carbonate for the preparation of standard alkali solutions.The potassium carbonate is obtained by calcining pure commercial potassiumhydrogen carbonate, the results quoted indicating a precision of about$0.2%.Because of its hygroscopic nature, potassium carbonate itselfcannot be recommended as a primary standard substance.Standard solutions of sulphuric acid can be prepared by means of specific-gravity determinations.6q Concentrated solutions of sulphuric acid arehygroscopic, and special precautions must be observed in weighing it. Acidof concentration between 32 and 39% by weight is not hygroscopic andcan be kept for at least 6 months without change.Standard solutions ofsulphuric acid can be made by direct weighing of sulphuric acid whose specific6o A. G. Karabash, Zhur. analit. Khinz., 1953, 8, 140.61 R. W. Frey, Water and Sewage Wks., 1954, 101, ~ . 1 4 0 .63 A. Desjobert and F. Petek, Analyt. Chim. Ada, 1954, 10, 10.64 R. E. Essery, ibid., 1954, 11, 501.H. J. Saling, Chernist-Analyst, 1953, 48, 87344 ANALYTICAL CHEMISTRY.gravity lies in this range : by means of a simple equation the normality canbe readily calculated.Methods.-During the past year, the applications of ethylenediamine-tetra-acetic acid have been considerably extended. There is a need for newand better indicators for titrations involving the use of this reagent, moreparticularly for the benefit of the routine worker who often experiencesdifficulty in detecting end-points, which are denoted by the disappearance orappearance of a particular colour in a solution which is already coloured.This aspect apart, it is always desirable to have a range of indicators availablewith colour changes covering different parts of the spectrum.Blaedel and Knight 6s have shown that a single recrystallisation fromethanol suffices for the purification of reagent-grade disodium ethylene-diaminetetra-acetate dihydrate (E.D.T.A.) to primary standard specific-ations. The optimum temperature for safe drying is 80" at a relative humid-ity of 50%.Solutions of primary standard E.D.T.A.show a negligiblechange in titre after 5 months' storage in borosilicate glass or Polythenebottles .Flaschka and his colleagues have again been active in the developmentof E.D.T.A. methods. They have described microtitrimetric methods forthe determination of aluminium,66 iron,67 and palladium.68 Milner andWoodhead 69 have determined aluminium in non-ferrous alloys by usingE.D.T.A. as titrant. The aluminium is first separated as its sparinglysoluble benzoate, which is then dissolved in hydrochloric acid. An excess ofE.D.T.A. is added and the excess is determined by titration with a standardsolution of ferric chloride, with salicylic acid as indicator. When iron ispresent, thioglycollic acid is added to keep it in the non-interfering ferrousstate.The method is applicable to amounts of aluminium up to 60 mg.with an accuracy of better than &1%.Sijderius 70 has shown that, in the direct titration of barium with E.D.T.A.,the indistinct end-point normally obtained can be improved by the additionof a magnesium salt. The same author 7 1 has applied his method to theindirect determination of sulphate. The sulphate (10-200 mg.) is firstprecipitated as barium sulphate by an excess of barium chloride, and theexcess is determined by titration with E.D.T.A. The method is not rapid,as it includes an overnight standing period. Calcium and magnesiuminterfere and a correction has to be applied or the sample must be treatedbeforehand with a cation exchanger.Belcher, Gibbons, and West 72 earlier proposed a complexometric pro-cedure for the evaluation of barium sulphate precipitates.The method con-sists essentially in dissolving the precipitate in an excess of E.D.T.A. solutionand titrating the excess with a standard solution of magnesium chloride.These workers 73 have now indirectly determined the sulphate ion by usingthis procedure. They have described more rapid methods for the precipit-ation of barium sulphate and have shown that for 1-2 mg. amounts of66 W. J. Blaedel and €2. T. Knight, Analyt. Chem., 1964, 26, 741.66 K. ter Haar and J. Bazen, Analyt. Chim. Acta, 1954, 10, 23.6 7 H. Flaschka, Mikrochim. Acta, 1954, 361.6g G. W. C. Milner and J. L. Woodhead, Analyst, 1954, 79, 363.i o R. Sijderius, Analyt.Chim. Acta, 1954, 10, 617.i 2 R. Belcher, D. Gibbons, and T. S . West, Chem. and Ind., 1964, 127.6 8 Idem, ibid., 1953, 226.7 1 Idem, ibid., 1954, 11, 28.Idem, ibid., p. 850NUTTEN : 1NORGANIC TITRIMETRIC ANALYSIS. 345sulphur a standing time of 1-2 hours is adequate, whilst for 30-50 mg.amounts of sulphur a standing time of 10-15 minutes suffices. The methodmay be applied to the determination of sulphur in steel and organic compounds.Kinnunen and Wennerstrand 74 have determined cadmium in cadmium-copper alloys by E.D.T.A. titration after precipitation as cadmium sulphidewith thiourea, complexing with thiocyanate, and extraction with a mixtureof ethyl methyl ketone and Pt-butyl phosphate. The method is applicableto the determination of cadmium in zinc spelter.A similar procedure hasbeen developed for the determination of zinc in zinc concentrate^.^^ Herethe interference of copper, iron, and silver can be masked, and when fluorideis present the interference of calcium and lead can also be overcome. Cad-mium interferes in the determination, but small amounts may be neglectedin routine work.The simultaneous determination of cadmium and magnesium has beendescribed by Brown and Hayes,76 a solution of E.D.T.A. containing zincsulphate being used as titrant. The cadmium is first titrated selectively atpH 6.8, the magnesium being titrated subsequently at pH 10. The titrationsare successful only when the molecular ratio of cadmium to magnesium isgreater than 1. Rio andTodardo 77 have proposed alternative methods for the determination ofcalcium and strontium both singly and when present together.The firstmethod depends on determination of the hydrogen ions liberated whenE.D.T.A. is added to the test solution. In the second method the totalcalcium and strontium is determined by titration with E.D.T.A. at pH 8.6.The calcium is then determined at pH 6-5 and the strontium is obtained bydifference.Important applications of the complexometric method to the determin-ation of nickel 78 and of cadmium and zinc 79 have been reported, and Fritzand Fulda have determined zirconium by direct and indirect methods.In this last paper, the interferences of 47 ions are discussed. Under theconditions of the determination, antimony(II1) , bismuth, hafnium, molyb-denum(III), thorium, tin(II), titanium(m), fluoride, molybdate, sulphate, andtungst at e interfere.New titrants proposed during the year are sodium metavanadateand chloramine-B.82 A solution of sodium metavanadate will oxidise mostof the common reducing agents in presence of iodine monochloride in acidsolution.The test solution contains chloroform in which the end-pointcolour change (pale violet to pale yellow) is seen. An advantage of thismethod over, say, the conventional iodate procedure is that it does notinvolve the liberation of large quantities of iodine with the subsequent riskof loss.Chloramine-B used for the determination of bisulphide, sulphide, sul-phite, tetrathionate, thiocyanate, and thiosulphate appears to have no74 J.Kinnunen and B. Wennerstrand, Chemist-Analyst, 1954, 43, 34.76 Idem, ibid., 1953, 42, 80.76 E. G. Brown and T. G. Hayes, Analyst, 1954, '79, 220.7 7 A. Rio and M. Todardo, Ann. Chim. (Italy), 1954, 44, 139.7a K. E. Langford, Electroplatiuag, 1954, 7 , 46.79 J. P. Leftin, Metal FinishiBg, 1954, 52, 74.8o J. S. Fritz and M. 0. Fulda, Analyt. Chem., 1954, $26, 1206.82 A. Singh, J . Indian Chem. SOL, 1954, 31, 327.Calcium and lead are titrated with the cadmium.B. Singh and R. Singh, Analyd. Chim. Acta, 1954, 10, 408346 ANALYTICAL CHEMISTRY.advantages over chloramine-'r, nor, indeed, has it been established whatadvantages accrue from the use of chloramine-?. in place of the hypochloritereagents.The behaviour of quadrivalent uranium as a reducing titrant has beenexamined by Belcher, Gibbons, and West.= The reagent will effect thereduction of cerate, iron(rrr), perrnanganate, and vanadate a t 60".It isstable but has no advantages over available reducing titrants. Pierson &2has devised a convenient procedure for the determination of nitrite andthiosulphate in aqueous ammonia solution. The solution is treated withsilver nitrate at a carefully controlled pH. The nitrite is not affected butthe thiosulphate affords silver sulphide in quantitative yield. The silver inthe precipitate is determined by the classical Volhard procedure, thus givinga measure of the thiosulphate present. The nitrite in the filtrate from thesilver nitrate treatment is then determined titrimetrically with ceric ammon-ium sulphate.F.Burriel-Marti and his colleagues have continued their studies on thereducing properties of mercury and its salts. They have shown 85, 86 thatthe reducing power of mercury is greatly enhanced by the presence of thio-cyanate. Ferric iron, for example, is readily reduced, and conditions aredescribed for its determination. In alkaline solution and in presence ofcyanide, atmospheric oxygen is reduced to hydrogen peroxide and then towater, and ferricyanide is reduced to ferrocyanide. Ferricyanide can bedetermined by using this reaction. In presence of iodide, ferricyanide isreduced by mercurous salts to ferrocyanide. 87 In strongly alkaline solution(pH {la), not less than 0 . 2 ~ with respect to iodide and at a temperaturenot greater than 30°, ferricyanide can be determined by titration with astandard solution of mercurous perchlorate, barium diphenylaminesulphonatebeing used as indicator.Alternatively, the titration can be done potentio-metrically.Recoveries of 99-101~o are claimed for both anions.Chloride, nitrate, and sulphate do not interfere.A. J. N.CLASSICAL ORGANIC ANALYSIS.Qualitative.-A semimicro-scheme for the qualitative and quantitativeanalysis of 32 elements has been described.88 The sample is decomposed ina sodium peroxide bomb; the water leachings and the residue are thenexamined systematically.A modified Lassaigne test for nitrogen on the microscale has been de-scribed in which the cyanide ion formed is detected by Feigl's benzidine-bluereaction.The Lassaigne fusion has been adapted to the micro-scale and appliedto the detection of the halogens, sulphur, arsenic, phosphorus, and carbon.s0Each element can be detected in the presence of all the others except thatphosphorus cannot be detected when arsenic is present.Widmark alsodescribes a modified Emich method s1 (fusion with lime-zinc metal mixture).As little as 0.5 pg of nitrogen can be detected.8983 R. Belcher, D. Gibbons, and T. S. West, Analyt. Chem., 1954, 26, 1205.84 R. H. Pierson, ibid., p. 315.a s F. Burriel-Marti, F. Lucena-Cond6, and S. Bolle, Anales Fis. Quim., 1953, B, 49,693.8 6 F. Burriel-Marti, F. Lucena-Cond6, and S. Arribas- Jimeno, Analyt. Clzzm. Acfa,1954, 10, 301. Idem, Anales Fis.Quim., 1954, B, 50, 289.E. H. Swift and C. Niemann, Autalyt. C h e w , 1954, 26, 538.G. Kainz and F. Scholler, Mikrochim. Acta, 1954, 327.O 1 Idem, ibid., 1954, 8, 246. O0 G. Widmark, Acta Chem. Scand., 1953, 7, 1395BELCHER : CLASSlCAL ORGANIC ANALYSIS. 347He states that it is better to carry out simultaneously tests with the twodifferent procedures rather than to perform duplicate tests by one only.Quantitative.-Carbon and hydrogen have been determined volu-metrically by absorbing the water formed in pyridine-methanol and titratingit with Karl Fischer reagent, and by absorbing carbon dioxide in sodiumhydroxide-barium chloride, converting the barium carbonate into iodate,and determining this iodometrically. This method does not appear to haveany special advantages-except perhaps for smaller samples than are usuallytaken-for the operations after the combustion appear to be more trouble-some than those of the conventional method.92When fluorine is present, Ghel’man and Korshun 93 add magnesium oxideto the sample. Carbon and hydrogen can then be determined in the usualway, and fluorine can be determined in the residue.Presumably this methodis only applicable to relatively non-volatile compounds.The formation of silicon carbide in the combustion of organo-siliconcompounds can be avoided by adding vanadium pentoxide or chromicoxide, supported on asbestos. Silica can be determined simultaneously withcarbon and hydrogen.94Kirsten 95 has described a novel procedure for the simultaneous deter-mination of carbon, hydrogen, and nitrogen. The compound is decomposedin a sealed quartz tube containing metallic copper and pure oxygen.Thecombustion products are then analysed in a special gas-analysis apparatus.Another unusual procedure makes use of the calorimetric bomb to effectcornbu~tion.~~Cropper 97 has suggested a test for measuring the efficiency and capacityof batches of lead dioxide used for the removal of nitrogen oxides. He con-siders the variability of different batches is due to differences in primaryparticle size, and claims that an efficient product can be obtained by ball-milling or by the action of sodium hypochlorite on lead acetate.Some further alternative reagents to lead dioxide have been examined.Diphenylamine-sulphuric acid absorbed on alumina is recommended as anexternal absorbent .98 Cross and Wright 99 find trishydroxylamine phosphateand sulphamic acid, also used externally, to be superior to lead dioxide.Results are more accurate and replacement is less frequent.A semimicro-wet combustion method for the determination of carbonhas been recommended.lO0 Dry sucrose gave low results owing to rapidformation of carbon monoxide (this might possibly be overcome by includinga packing of Hopcalite).Volatile hydrocarbons were not completelyoxidised, and a heated silica tube had to be incorporated after the decom-position flask. The process of wet combustion has been reviewed.lolFor the determination of deuterium, combustion over a catalyst at9 2 A.Johansson, Analyt. Chem., 1954, 26, 1183.O3 N. S. Ghel’man and M. 0. Korshun, Izvest. A k a d . Nauk S.S.S.R., Otdel. h’hznz.94 V. A. Klimova, M. 0. Korshun, and E. G. Bereznitskaya, ibid., 1954, 96, 81.96 W. Kirsten, Analyt. Chem., 1954, 26, 1097.96 R. K. S. Mehta, J . S c i . I n d . Res. I n d i a , 1954, 13, 195.97 I;. R. Cropper, Mikrochim. Acta, 1954, 25.9 8 E. Abramson and A. Brochet, Bull. SOC. chim. France, 1954, 21, 367.gs C. K. Cross and G. F. Wright, Analyt. Chem., 1954, 26, 886., Nauk, 1953, 89, 685.loo E. E. Archer, Analyst, 1954, 79, 30.lol Van Slyke, Fisher Award address, Analyt. Chem., 1954, 26, 1706348 ANALYTICAL CHEMISTRY.400-420" is used. Water is condensed in carbon dioxide snow and laterdistilled into a known volume of water.Deuterium is finally evaluated bymeasuring the density of the solution.102Tritium is determined after combustion and condensation of water byreduction with magnesium turnings at 480". The 6-particle emission of thehydrogen evolved is then measured by Geiger counters.103The Schutze-Unterzaucher method for oxygen has been modified toovercome sources of error due to the high temperature and su1ph~r.l~~Instead of heating carbon to 1120", 50% platinised carbon is used at 900".Sulphur compounds are decomposed by passage over copper at 900". Theformer modification at least appears to be a notable contribution, and accord-irig to private communications which have been received, works extremelysatisfactorily .Four modifications of the Unterzaucher method have been examined bya Sub-committee of the American Petroleum Institute.105 All are claimedto give satisfactory results over the range O.Ol-l.O~o of oxygen and eliminatethe hydrogen effect on iodine pentoxide.The excessive blank value foundin the conventional method may be eliminated by careful conditioning of thecarbon-filled tube. lo6Improved apparatus for the Dumas method has been described, butentails nothing entirely new apart from incorporating refinements based onearlier procedures. lo8Kuck and Altieri log have devised a small nitrometer of 0.2 ml. capacitywhich will measure 0.1 pl. Samples between 0.1 and 0.4 mg. were analysed.At 0.4 mg. the error was &0.28% and at 0-1 mg. & 0.96%. Modifications tothe conventional microazotometer have been described by Cropper 110 andby Stehr.lll In the former the upper tap is replaced by a mercury-sealedlevelling device and the zero reading calibration is eliminated.The secondmodification consists of a ball-and-socket joint with an integral levellingdevice.The applications of the Kjeldahl method to organic analysis since 1939have been reviewed by Bradstreet.l12 He also recommends a 1 : 1 mixtureof l-naphthol and pyrogallol for converting nitro-compounds into a moretractable form for Kjeldahl decompo~ition.~~3 This reagent gives betterrecoveries than reagents of a similar kind. The problem still remains incom-pletely solved, however, for in certain cases the results are unacceptably low.In an interesting and important study of the Kjeldahl method, it hasbeen shown that coals and various organic compounds can be rapidly andsafely decomposed, without the addition of catalyst or potassium ~u1phate.l~~Permanganate crystals are added at suitable intervals to the boiling sulphuricacid digest and the end of the reaction is indicated by a colour change.Itlo2 M. Corval and R. Viallard, Mikrochim. Acta, 1954, 231.lo3 R. Viallard, M. Corval, B. Dreyfus-Alain. M. Grenon, and J. Herrmann, Chirn.104 I. J. Oita and H. S. Conway, Analyt. Chem., 1954, 26, 600.Io5 W. H. Jones, ibid., 1953, 25, 1449. lo6 A. F. Colson, Analyst, 1954, '79, 784.lo' T. D. Parks, E. L. Bastin, E. J. Agazzi, and F. R. Brooks, Analyt. Cham., 1954,lo* H. Swift, Analyst, 1954, 79, 718.log J.A. Kuck and P. L. Altieri, Mikvochim. Acta, 1954, 17.110 F. R. Cropper, Analyst, 1954, 19, 178.E. Stehr, Mikrochim. Acta, 1954, 213.112 R. B. Bradstreet, Analyt. Cham., 1954, 26, 185.113 Idem, ibid., p. 235.analyt., 1954, 36, 102.26, 229.1l4 A. E. Beet, J . A+pl. Chem., 1954, 4, 373WEST : INSTRUMENTAL METHODS OF ANALYSIS. 349is noteworthy that this procedure is much more akin to the original Kjeldahlmethod than any other of the host of modifications which have been practisedfor the last four or five decades.Liggett has proposed diphenylylsodium in 1 : 2-dimethoxyethanesolution for decomposing organic compounds in the determination of halogen.Conventional methods are used for completing the determination. In afurther new decomposition procedure, chlorine or bromine and sulphur canbe determined simultaneously.ll6 The compound is decomposed by heatingwith magnesium..Sulphur is determined by evolution of hydrogen sulphideand iodometric titration, and the halide in the residual solution by a modifiedVolhard titration. This procedure appears to be an advance over previousfusion methods which use metallic potassium.Chlorine, bromine, and iodine can be determined in compounds contain-ing fluorine by decomposition with metallic sodium in a nickel bomb, fol-lowed by various titrimetric procedures. 117 Any combination of these threeand fluorine may be determined on the same sample by suitable adaption.Potentiometric titration has been applied to the determination of chlorineafter combustion of decirnilligram samples by Pregl's method.Satisfactoryresults were obtained a t the 0.2 mg. level, but below this a positive errorbegins to develop and the results are unacceptable a t the 0.1 mg. level.llsA sealed-tube method for chlorine, bromine, or iodine has been recom-mended in which the compound is decomposed with nitric acid in the presenceof silver nitrate.ll9 The silver halides are eventually reduced with hydrazineand the precipitated silver metal is weighed, or the halide in solution isti tratedLevy 120 determines arsenic by precipitation as silver arsenate and back-titration of the excess silver with potassium chloride after decomposition ofthe organic compound.R. B.INSTRUMENTAL METHODS OF ANALYSIS.Electrodegosition.-The optimum conditions for the removal by niercury-cathode electrolysis of large amounts of elements such as iron, nickel, andchromium from alloys, having a wide range of compositions, have beenestablished.121 Mercury-cathode separation has also been used in thedetermination of impurities in vanadium salts,122 and of sulphur in insoluble~u1phides.l~~ In the latter case the evolved hydrogen sulphide was trappedby means of cadmium, and was determined iodometrically.A previouslydescribed method for the electrolytic determination of lead in steel has beenmodified and improved.1x The electrodeposition of iron 125 and that of tinfrom solutions of its chloride 126 have been examined.115 L. M. Liggett, Analyt. Chem., 1954, 26, 748.ll0 W.Schoniger, Mikrochim. Acta, 1954, 74.1 1 7 R. Belcher, A. J. Nutten, and A. M. G. Macdonald, Mikrochim. A d a , 1954, 104.118 J. A. Kuck, M. Daugherty, and D. K. Batdorf, ibid., p. 297.119 S. J. Pirt and E. B. Chain, Bendiconti 1st Sup. Sanit., 1953, 18, 363.120 E. Lkvy, Compt. rend., 1954, 238, 2320.121 Methods of Analysis Committee of B.I.S.R.A., J . Iron Steel Inst., 1964, 176, 29.122 W. E. Schmidt, Diss. Abs., 1954, 14, 756.123 7. Bertelli, Ann. Chim. (Italy), 1953, 43. 167.120 H. A. Nicolas, Chim. analyt., 1954, 38, 8.lZ5 J. 0. Lay, Metallurgia, 1953, 58, 313.A. Foschini, Z. analyt. Chem., 1953, 139, 408350 AN .-I 1.Y TI C AT, C H E hi I STR J-,Po1arography.-Inorganic. The relationship between voltammetry andpotentiometric and amperometric titrations has been discussed by Kolt-hoff,12' and Charlot 128 has stressed the importance of a thorough under-standing of the polarisation curves involved in a number of potentiometricand amperometric titrations.The use of unstirred diaphragm cells in thedetermination of polarographic diffusion coefficients has been advocated 129and the relationship between half-wave potential and temperature in somereversible and irreversible processes has been examined. 130 Others 131 havediscussed the " minimum error " polarographic analysis of binary mixtures,lead and thallium(1) being chosen as a practical example. The resultsobtained showed an average relative error of only 3%. The applications ofthe cathode-ray polarograph to rotating platinum electrodes,l32 the uses ofmercury-plated platinum micro-ele~trodes,~~~ and the residual current-voltage curves and dissolution patterns in supporting electrolytes, obtainedwith rotating and stationary platinum wire electrodes,134 have been examined.Polarographic studies with gold, graphite, and platinum electrodes havebeen reported,135 and the use of a rotating nickel micro-electrode for polaro-graphy in hydrofluoric acid solution has been illustrated.136 Further workon the polarography of various elements in concentrated calcium chloridesolution has been p ~ b 1 i s h e d . l ~ ~ ~ 13*Lead has been studied polarographically in a supporting electrolyte ofpotassium thiocyanate and has been determined in lead-plating so1utions,lMin petroleum products,141 in plasma along with copper and zinc,142 and bysquare wave polarographic technique.143 Zinc has been determined ampero-metrically with ferrocyanide 144 similarly with a rotated platinum anode,145and by conventional methods in plating solutions,146 plant materials, 147plasma,142 and metallic gold? Uranium(vr) has been determined polaro-graphically in a salicylic acid-thymol supporting electrolyte 149 and in oxalicacid-sulphuric acid solution after separation from other materials on acellulose column.l5* Niobium has been determined in the presence oftantalum in materials such as niobites and tantalites in l0N-hydrochloric12' I. M. Kolthoff, Analyt. Chem., 1954, 26, 1685.128 G. Charlot, Chim. analyt., 1954, 36, 63.12$ C.L. Rulfs, J . Amer. Chem. Soc., 1954, 76, 2071.130 J. Kamecki and L. Suski, Bull. Acad. polon. Sci., 1954, 2, 143.131 A. Frisque, V. W. Meloche, and I. Shain, Analyt. Chem., 1954, 26, 471.132 I. Shain and A. L. Crittenden, ibid., p. 281.133 T. L. Marple and L. B. Rogers, ibid., 1953, 25, 1351.134 I. M. Kolthoff and N. Tanaka, ibid., 1954, 26, 632.135 S. Lord and L. B. Rogers, ibid., p. 284.136 J. W. Sargent, A. L. Clifford, and W. R. Lemmon, ibid., 1953, 25, 1727.137 G. F. Reynolds, H. I. Shalgosky, and T. J. Webber, Amlyt. Chim. Ada, 1954, 10,la* G. F. Reynolds and H. I. Shalgosky. ibid., p. 273.13$ J. 0. Hibbits and S. S. Cooper, Analyt. Chem., 1954, 26, 1119.140 R. Diaz, Plating, 1953, 40, 261.141 Anon., PYOC. A.S.T.M., 1952, 52, 365.142 G.Kahle and E. Reif, Biochem. Z . , 1954, 325, 380.143 D. J. Ferrett, G. W. C. Milner, and A. A. Smales, Analyst, 1954, 78, 731.144 B. Khosla and H. C. Gaur, J . Indian Chem. SOC., 1953, 30, 637.145 T. D. Parks, 0. D. Smith, and S. B. Radding, Analyt. Chim. Acta, 1954, 10, 485.146 R. Diaz and E. H. Lindemann, Plating, 1953, 40, 762.0. N. Hinsvark, W. H. Houff, S. H. Wittwer, and H. M. Sell, Analyt. Chem.,148 S. B. Deal, ibid., p. 1459.149 V. B. Vouk, M. Branica, and 0. A. Weber, Arkiv Kemi, 1953, 25, 225.150 D. I . Legge, Awlyt. Chem., 1954, Z6, 1617.192.1954, 26, 1202IVEST : INSTRUMENTAL METHODS OF ANALYSIS. 35 Iacid containing 20% v/v of ethylene glyc01.l~~ Vanadium(v) has beenpolarographed in oxalate solution in the presence of iron(m) and copper,152and the anodic wave of the quadrivalent form, aged in alkaline solution, hasbeen studied.lS3 Titanium has been determined by reduction of its complexwith E.D.T.A.a t the dropping electrode.lM A new polarographic wave fortungsten in a hydrochloric acid-tartrate solution has been used for deter-mination of this metal in rocks.l659 l56 Molybdenum has been determined inplant materials by application of polarography after separation from otherinterfering ions by use of a-benzoin oxime and chloroform e~tracti0n.l~’Tartaric acid was used as supporting electrolyte in the same determinationby others. 158 Arsenic and antimony have been determined polarographic-ally.159and the former in natural waters.161The amperometric titration of calcium with the disodium salt of E.D.T.A.has been described.lc2 High results were obtained by others in titrating thealkaline earths amperometrically with the same titrant, but a differenttechnique was employed.l63 Normal curves were obtained for manganese,cobalt, nickel, zinc, and mercury by the same authors, however. Theamperometric titration of selenious acid with mercurous nitrate in thepresence of sulphuric acid, using a rotated platinum micro-electrode, hasbeen accomplished. l G 4 Valenta and Zuman 165 have criticised earlier workon the polarographic reduction of germanium, proving that the secondreduction wave is catalytic in nature. The polarographic determination ofsoluble silicate has been described.lc6All the known micro-methods for the polarographic determination ofchloride in biological fluids have been examined, preference being found forthe original direct method.l67 Chlorine in vinyl chloride copolymers hasbeen determined similarly.l68 Depression of the wave given by the alumin-ium-Solochrome Violet R.S.complex in the presence of fluoride ion has beenutilised by others for the determination of the latter, using cathode-raypolarography. l G 9 7 170 Phosphate has been determined amperometricallyby titration with ferric chloride,l‘l and phosphonium salts polarographicallywith tetraethylammonium iodide as supporting electrolyte. 172 Free sulphurlS1 S. Vivarelli and D. Cozzi, Chinzie et Indzkstrie, 1953, 35, 637.lS2 G. de Angelis and N. Carugno, Bicerca sci., 1953, 23, 1593.153 I.M. Kolthoff and P. T. Toren, Analyt. Chem., 1954, 26, 1361.154 S. I. Sinyakova, Zhur. apzalit. Khim., 1953, 8, 333.lSG Idem, Analyt. Chem., 1954, 26, 1302.1 5 7 G. 13. Jones, Analyt. Chim. Acta, 1954, 10, 584.16* E. P. Parry and M. G. Yakubiak, Analyt. Chem., 1954, 26, 1294.lG9 G. P. Haight, ibid., p. 593.160 H. F. Hourigan and J. W. Robinson, Analyt. Chim. Ada, 1954, 10, 281.161 H. R. Olivier, Bull. Soc. Chim. biol., 1954, 36, 695.162 H. A. Laitinen and R. F. Sympson, Analyt. Chew., 1954, 26, 556.163 G. Michel, Analyt. Chinz. A d a , 1954, 10, 87.164 W. Hubicki and M. Dabkowska, Ann. Univ. M . Curie-Sklodowska, Sect. A A .165 P. VaIenta and P. Zuman, Analyt. Chinz. Acta, 1954, 10, 591.16G M. A. De Sesa and L. B.Rogers, Analyt. Chem., 1954, 26, 1278.lG7 0. T~lupilov6-Krest);.nov6 and F. Santavq, Mihrochim. Acta, 1954, 64.168 M. Prai6k, J. Benc, and 2. PartuSek, Chem. PrGmysl., 1953, 3, 297.171 W. Hubicki, K. Wiacek, and J. Wysocka, Ann. Univ. M . Curie-Sklodowska, Sect.The latter element has been determined in lead-antimony alloysL. E. Reichen, Science, 1954, 119, 355.1951, 6, 161.B. J. MacNutty, G. F. Reynolds, and E. A. Terry, Analyst, 1954, 79, 1901.Idem, with J. S. Beveridge, p. 267.A A , 1951, 6, 169. 173 E. L. Colichman, Analyt. Chem., 1954, 26, 1204352 ANALYTICAL CHEMISTRY.in petroleum products has been determined polarographically by use of asolvent-electrolyte medium of ammonium acetate in glacial acetic acid. 173Sulphide ion has been determined amperometrically.174The behaviour of organic compounds a t the mercury-poolelectrode has been studied,175 and the use of the polarograph in identifyingnarcotics l 7 6 and in the petroleum industry 177 has been reviewed. Thetechnique of determining traces of metals in organic compounds 178 and thedetermination of the total cation-exchange capacity of soils have also beenreviewed. 179 The polarography of various organic compounds has beenexamined : thiourea,180 monochlorinated cyclanones,lsl mixed nitrochloro-benzenes,ls2 2 : 4 : 6-trinitrotoluene, and cyclotrimethylenetrinitramine lS3all having received attention.Polarographic determinations of the following acids have been reported :citric,l@ maleic and fumari~,l8~? ls8 amino-acids,ls6 picolinic and iso-nicotinic,ls7 succinic,188 salicylic,1sg and a-oxoglutaric acid.lW Others havedevised methods for chlor~acetaldehyde,~~~ phthalaldehyde, lg2 and aldehydesand ketones ls3 in semicarbazide base solutions.Very many procedures havebeen described for the polarographic determination of y-benzene hexa-ch1oride.lg4-l98 Thiol groups have been determined in proteins 199 and atthe rotating 201 Polysulphides,202 3 : 3' : 5-tri-i0dothyronine,~~~and cephaeline 2049 205 have been determined polarographically, and alsosaccharin in foods.206 The amperometric titration of oxine with potassiumbromate has been examined.2o7 Sulphate has been determined indirectly inOrgafinic.17s S. Harrison and D. Harvey, Analyst, 1954, 79, 640.174 R.E. Press and K. A. Murray, J . S. African Chem. Inst., 1952, 5, 45.176 C. A. Streuli and W. D. Cooke, Analyt. Chem., 1954, 26, 963.176 C. G. Farmilo and L. Levi, Bull. Narcotics (United Nations), 1953, 5, 20.17' A. Poussin, Rev. Inst. franc. Pe'trole, 1953, 8, 504.17* E. Wahlin, Acta Chem. Scand., 1953, 7, 956.179 K. R. Holtzinger, J. R. McHenry, and D. W. Rhodes, Soil Sci., 1954, 77,180 R. L. Edsberg, Analyt. Chem., 1954, 26, 724.lS2 W. Kemula and H. Buchowski, RoczniRi Chem., 1954, 28, 303.lX3 D. T. Lewis, Analyst, 1954, 79, 644.lX4 P. J. Elving and R. E. van Atta, Analyt. Chem., 1954, 28, 396.lX5 P. J. Elving and I. Rosenthal, ibid., p. 1454.1 8 6 D. R. Norton and N. H. Furman, ibid., p. 1116.18' H. H. G. Jellinek and J. R. Urwin, J . Phys.Chem,, 1954, 58, 168.lS8 N. Lemjakov, Analyt. Chem., 1954, 26, 2227.lB9 C. H. Hale and M. N. Hale, ibid., p. 1078.lgo J. K. Palmer and C. 0. Jensen, ibid., p. 1049.lS1 P. J. Elving and C. E. Bennett, ibid., p. 1572.lg2 N. H. Furman and D. R. Norton, ibid., p. 1111.lg3 P. Souchay and M. Graizon, Chinz. analyt., 1954, 36, 85.lg4 S. Wolf, C. Miinster, and E. Sarfort, 2. analyt. Chem.. 1953, 140, 25.lS5 S. Wolf, ibid., 1954, 142, 189.lg6 C. A. Streuli and W. D. Cooke. Analyt. Chem:, 1954, 26, 970.lg7 G. W. Walker, Nature, 1954, 174, 44.lg8 J. Watt, Analyst, 1954, 79, 735.lsg L. MatouSek and 0. LauEikovA, Chem. Listy, 1953, 47, 1062.201 W. Stricks, I. M. Kolthoff, and N. Tanaka. ibid., p. 299.202 J. H. Karchmer and M. T. Walker, ibid..p. 271.203 H. E. Evert, Arch. Biochem. Biophys., 1954, 49, 93.205 A. Jindra, V. Jangr, and J. Zyka, Ada Pharm. I n d . , 1953, 2, 397.205 0. Gry, ibid., p. 383.206 D. E. Pratt and J. J. Powers, J . Assoc. Ofic. Agric, Chem., 1954, 37, 486.207 Q. Fernando, AnaZyst, 1954, 79, 713.J. C. Pariaud and C. Perruche. Corn$& rend., 1954, 238, 1514.I. M. Kolthoff, W. Stricks, and L. Morren, Analyt. Chem., 1954, 26, 366.137WEST : INSTRUMENTAL METHODS OF ANALYSIS. 353glacial acetic acid by polarographing the excess of lead after addition ofethanol to depress the solubility of the lead sulphate.208Botentiometric Titrations-In a study of the rates of processes occurringduring potentiometric titrationsY2O9 it has been shown that the slowness oftitrations in the ferri-ferro-cyanide system is due to the slow chemicalreaction in solution rather than the rate of establishment of potential, whichis rapid.Study of the mechanism of the reaction also revealed that instrongly acid solution, hydrogen and potassium ions expedited the titration,whilst the retarding action of aluminium was shown to be due to the form-ation of slightly ionised aluminium ferrocyanide rather than desensitis-ation of the platinum electrode as is commonly supposed. The predictionof curves of potentiometric titrations, and in particular those of iodine-thiosulphate, arsenic( 111)-iodine and iron(n)-permanganate,210 and theprediction of bimetallic potentiometric determination curves by means ofpolarisation curves has been examined once more by Coursier.211 Thepotentiometric differentiation of certain inorganic cations by titration innon-aqueous media has been discussed under the heading of non-aqueoustitrations, but in this connection it is of interest to note the reference electrodefor potentiometric titrations in glacial acetic acid devised by Glenn.212Studies of the formation of complexes of lead and cadmium with malonates 213and of silver citrate and lead acetate 214 have been reported. Potentiometrictitrations of lead 215 and formate ions 216 with alkaline permanganate andalso of thallium(1rr) 217 and tellurium218 with the same reagent have beendescribed.Various potentiometric titrations-of halide ions,219-223 ofarsenic in organic compounds via silver nitrate precipitation and chloridetitration of the excess,2% and of silver in solution containing E.D.T.A. *ithferrous sulphate-have been described.225 The indirect determination ofphosphorus in phosphates by precipitation as magnesium ammonium phos-phate and solution of this in a measured amount of standard hydrochloricacid has been reported 226 but the method appears open to several sources oferror. Copper has been titrated potentiometrically with potassium ferro-cyanide,227 and, after precipitation with oxine, by bromometric titration.228Uranium has also been determined potentiometrically in the presence of ironby titration with dichromate, permanganate, or ceric sulphate.The reduc-tion was effected with chromous sulphate and the titration of ferrous iron208 W.Kernula and A. Kxzeminska, Rocznilzi CJaenz., 1954, 28, 125.20g L. Ya. Polyak and B. N. Kabanov, Zhur. analit. Khinz., 1953, 8, 253.210 J. Coursier, Analyt. Chim. Acta, 1954, 10, 182.211 Idem, ibid., p. 265. 212 R. A. Glenn, Anakyt. Chenz., 1953, 25, 1916.213 S. Suzuki, Sci. Refiovts Tohoku Univ., A . , 1953, 5, 147,214 Idem, ibid., p. 153.215 I. M. Issa, R. M. Issa, and A. A. Abdul-Azim, Anakyt. Chim. Acta, 1064, 10, 474.21G I. M. Issa and R. M. Ism, ibid., 1954, 11, 192.217 Idem, AnaZyst, 1954, 79, 771.219 C. Mahr and 0. Otterbein, 2. analyt. Ghem., 1953, 140, 261.220 P. Deschamps, Compt. rend., 1954, 238, 100.221 M. L. Masten and M. G. Stone, Analyt. Chern., 1954, 26, 1076.222 J. M. Bather and J. P. Riley, J.’Cons.Int. ExPZor. Mer., 1954, 18, 277.223 G. K. Helrnkamp, F. A. Gunther, J. P. Wolf, and J. E. Leonard, J . Agric. Food225 R. Pfibil, J. Dolefal, and V. Simon, Chewa. Listy, 1953, 47, 1007.226 A. Margara, Ann. Chim. (Italy), 1954, 44, 321.227 I. L. Teodorovich and I. K. Leushina, Zhur. andit. Khinz., 1953, 8, 340.228 A. I. Busev, ibid., p. 299.218 Idem, Chenaist-Analyst, 1954, 43, 61.Cheiit., 1954, 2, 836. 224 R. Lhy, Compt. rend., 1954, 238, 2320.REP.-VOL. LI 351 ANALYTICAL CHEMISTRY.by the oxidant was prevented by complexing with 1 : lO-phenanthr0line.~29Fritzsche 230 has reported on the potentiometric titration of cobalt throughaddition of excess of ferrocyanide and back-titration with a standard cobaltsolution using a dead-stop end-point technique.Various phenolic antioxidants 231 have been titrated potentiometricallywith ceric sulphate, and organic sulphides with potassium iodate.232 Mix-tures of benzoic and perbenzoic acids have been titrated potentiometricallywith sodium hydroxide, two inflections being observed on the titration curve.233The technique of potentiometric titrations on the ultramicro-scale hasbeen discussed 23g and the potentiometric determination of cations and anionswith permselective collodion and protaniine collodion membrane electrodes.235Conductometric Titrations-The conductometric standardisation of solu-tions of common bivalent metals using ethylenediaminetetra-acetic acid astitrant has been examined and its accuracy has been shown to comparefavourably with the best previously described meth0ds.~~6 Sulphate hasbeen determined conductometrically with barium nitrate solution by the" overshot end-point I' technique with an accuracy which agrees well withtedious gravimetric methods,237 and it has been determined similarly withbarium acetate in diluted ~ i n e s .~ ~ 8Conductometric titrations in 50% aqueous alcohol have shown thatmandelic acid may be used for the determination of lead and smallamounts of the latter have also been determined conductometrically bytitration with a solution of hydrogen sulphide.2ao The latter method doesnot appear to be a very practicable one, however, and in the former methodthe use ol a 50% alcoholic medium for the determination of lead is anobvious limitation in the presence of other ions.A conductometric methodwith silver nitrate was used by American workers 241 for the determinationof chloride ion in sucrose solutions.Measurement of the conductance of barium solutions was used for thedetermination of carbon in metals after oxidation to carbon dioxide in astream of 0xygen.~4~>High-frequency Titrations-The use of high-frequency oscillators inchemical analysis has been reviewed.24a Applications to organic and in-organic compounds in aqueous and non-aqueous solutions are discussed andthe theoretical concepts of the techniques and of instrument design are out-lined. Titration methods have been reviewed by Russian a ~ t h o r s , 2 ~ ~ andJapanese authors have investigated the mechanism of high-frequency229 R.B. Hahn and M. T. KelIey, Anulyt. Chim. Acta, 1954, 10, 178.Z3O H. Fritzsche, Brennstoff-Chem., 1954, 35, 49.z31 F. Wenger, Mitteil. Gebiete Hyg., 1954, 45, 185.z32 V. G. Lukyanitsa and A. S. Nakrasov, Izvest. Akad. Nauk S.S.S.R., Otdel, Khirn.234 I. P. Alimarin and M. N. Petrikova, Zhur. analit. Khim., 1954, 9, 127.235 H. P. Gregor and K. Sollner, J . Phys. Chem., 1954, 58, 409.2313 J. L. Hall, J. A. Gibson, P. R. Wilkinson, and H. 0. Phillips, Analyt. Chem.,Z3* I. M. Cortks, Inform. Quiin. analht. (Spai*z), 1954, 8, 86.Z39 W. Waksmundzki and B. Szucki, Ann. Univ. M. Curie-Sklodowska, Sect. A A ,241 A. Gee, L. P. Domingues, and V. R. Deitz, Analyt. Chem., 1954, 26, 1487.242 J. E. Still, L. A. Dauncey, and R. C. Chirnside, Analyst, 1954, 79, 4.243 Idem, ibid., p.308.245 0. L. Kaptsan and V. A. Teplyakov, Zhuv. analit. Khinz., 1953, 8, 184.N a u k , 1053, 90, 1043. 233 R. Wolf, Bull. SOC. chim. France, 1964, 21, 644.1954, 26, 1484.1961. 6, 63.237 F. Spillner and I T . Voigt, Angew. Chewz., 1954, 66, 198.240 A. Schneider and B. Beisken, 2. analyt. Chem., 1954, 141, 326.244 P. W. West, Selecta Chim. (Bmzil), 1953, [lZ], 19w x r : INSTRUMENTAL METHODS OF ANALYSIS. 355titrations of simple acids and b a ~ e s . ~ ~ 6 Apparatus 247 and technique havebeen discussed, and a resistance-type instrument 248 and a submerged-chokemethod 249 have been investigated for use in various titrations. A criticalevaluation has been made 250 of high-frequency titration methods and hasshown that for selected ranges of concentration and frequency, the H.F.instruments compare favourably with the usual conductance instruments.An interesting comparison of experimental results is given for potentio-metric, conventional conductometric, and high-frequency conductometricmethods for two non-aqueous titrations.During the period covered by this Report, few new practical methodsemploying H.F.technique have been advanced. Two methods whichdeserve mention are those due to Blaedel and Knight 251 and to Bie11.25~The former concerns the stoicheiometry of titration of copper, zinc, calcium,and magnesium ions with the disodium salt of E.D.T.A. at various valuesof pH, and the latter deals with the titration of sulphate and chloride withbarium acetate and silver acetate respectively.Coulometric Titrations-Recent applications of coulometry have beenrevie~ed,25~9 254 and various authors have published papers on apparatus :for current supply at constant intensity for the coulometric titration ofhydrochloric acid solutions ; 255 a coulometric coulometer 256 measuring0.01 coulomb within O*lyo.An automatic titrimeter dispensing withstabilisation of the electrolysis current, but recording the quantity of electri-city by integration, has been developed and used for titrations with iodine.25'Leisey 25* has developed an automatic titrator for the coulometric deter-mination of thiols. Photometric determination of the end-point in coulo-metric titrations of acids and bases is complicated by the generation ofbubbles during the course of the titration which the photometric detector isunable to distinguish from a decrease in optical density.Wise, Gilles, andReynolds 259 overcame this by using a differential or ratio-detecting photo-meter.A photometric end-point was used in the coulometric titration of arsenicwith iodine.260 Arsenic has also been determined with externally generatedchlorine, bromine, and iodine ; 261 thiosulphate with iodine ; 262 iodide withsilver ion 263 using a dead stop end-point technique; iodide, bromide, andchloride with silver Small quantities of sulphanilamides 265 have2d6 S. Fujiwara and S. Hayashi, Analyt. Chem., 1954, 26, 239.247 V. A. Zarinsky and D. I. Koshkin, Zhur. analit. Khim., 1954, 9, 943.248 K.Nakano, R. Hara, and K. Yashiro, Analyt. Chem., 1954, $36, 636.249 G. G. Blake, Analyst, 1954, 79, 108.250 J. L. Hall, J. A. Gibson, H. 0. Phillips, and F. E. Critchfield, Analyt. Chenz.,252 G. S. Bien, ibid., p. 909.254 N. H. Furman, J . Electrochem. Soc., 1954, 101, 19c.2 5 5 J. Badoz-Lambling, Analyt. Chim. Acta, 1953, 9, 455.z 5 6 V. B. Ehlers and J. W. Sease, Analyt. Chem., 1954, 26, 513.257 N. Bett, W. Nock, and G. Morris, Analyst, 1954, 79, 607.258 F. A. Leisey, Analyt. Chem., 1954, 26, 1607.259 E. N. Wise, P. W. Gilles, and C. A. Reynolds, ibid., p. 779.260 G. E. Everett and C . N. Reilley, ibid., p. 1750.2G1 J. N. Pitts, D. D. De Ford, T. W. Martin, and E. A. Schmall, ibid., p. 628.262 K. Rowley and E. H. Swift, ibid., p.373.2G3 R. L. Kowalkowski, J. H. Kennedy, and P. S. Farrington, ibid., p. 626.264 J. J . Lingane, ibid., p. 622.266 K. Sykut, Ann. Univ. M . Curie-Sklodowska, Sect. A A , 1951, 6, 47.1954, 26, 1539. 261 W. J. Blaedel and H. T. Knight, ibid., p. 743.253 R. Gauguin, Chim. analyt., 1954, 36, 92356 ANALYTICAL CHEMISTRY.been determined by coulometric bromination with a platinum-siliconcarbide electrode pair. Reynolds and Shalgosky 266 have used a micro-coulometric technique to determine the number of electrons involved inirreversible reductions.Photometric Titrations-There has been a considerable increase in thevolume of literature in which titrimetric methods with photometric detectionof the end-point have been used. Titrations with ethylenediaminetetra-acetic acid have been used in this way for the determination of ferric ironand copper,267 for magnesium, calcium, zinc, cadmium, titanium, andzirconium,268 for bismuth,269 for calcium,270 for thorium and c o p p ~ r , ~ ~ and for iron, copper, nickel, and cobalt.272 The methods generally possessaccuracy and a fair degree of specificity, because of the substantial differencesin the stability constants of the various metal complexes.A theoreticaltreatment of the spectrophotometric titration of bivalent cations withcomplexone I11 and metal specific indicators has been published.273Bobtelsky and his co-workers have used the photometric (or hetero-metric) method for the determination of magnesium with S-hydroxy-quin~line,~~* aluminium,275 and copper 2 7 6 9 277 with the same reagent, anduranium(v1) with ferrocyanide 278 and phosphate.279Photometric titrations for the determination of weak acids (or bases),which differ in light-absorption powers in the ionised and un-ionised states,have been studied theoretically and experimentally.280 Satisfactory end-points were obtained where the product of ionisation constant and concen-tration was There is little doubtthat the photometric method holds considerable promise for this type ofdetermination.The same authors 281 have reviewed the principles of photo-metric titration, and previous work in this field. Apparatus and the advan-tages and disadvantages of the method were discussed. Photometrictitrations of various bases in glacial acetic acid have been carried out 282with perchloric acid as titrant.There is little doubt that the technique willprove valuable for non-aqueous titrations in general and for many othercomplexometric and precipitation titrations.Titrations in Non-aqueous Media.-A review of the theoretical andpractical considerations involved in the titration of acids and bases in non-aqueous media has been published,283 and the determination of many basespotentiometrically in glacial acetic acid, conductometrically in thionylchloride, and by means of indicators has been discussed.2a Sodium andpotassium acetates have been differentiated by titration in glacial aceticacid-chloroform with 0-1x-perchloric acid in dioxan. Potassium andat concentrations of lod5 or greater.2 6 6 G.F. Reynolds and H . I. Shalgosky, Analyt. Chim. Acta, 1954, 10, 386.2 6 7 A. L. Underwood, Analyt. Chem., 1953, 25, 1910.2 6 8 P. B. Sweetser and C. E. Bricker, ibid., 1954, 26, 195.269 A. L. Underwood, ibid., p. 1322.2 7 1 H. V. Malmstadt and E. C. Gohrbrandt, Analyt. Chem., 1954, 28, 442.2 7 2 D. C. Burtner, Diss. Abs., 1954, 14, 755.273 J. M. H. Fortuin, P. Karsten, and H. L. Kies, Analyt. Chim. Ada, 1954, 10, 356.274 M. Bobtelsky and Y . Welwart, ibid., p. 156.2 7 6 Idem, ibid., p. 459.278 M. Bobtelsky and 15. Halpern, ibid., 1954, 11, 84.280 R. F. Goddu and D. N. Hume, Analyt. Chenz., 1954, 26, 1679.281 B i d . , p. 1740.2S3 H. Ballczo, Mitteil. chem. Forsch. Wirtsch. Inst. Osterr., 1953, 7, 104.284 Idem, ibid., p.126.270 R. A. Chalmers, Analyst, 1954, 79, 510.a75 Idem, ibid., p. 151.2 7 7 Idem, ibid., p. 464.a79 I d e m , ibid., p. 188.28a C. N. Reilley and B. Schweizer, ibid., p. 1124WEST : CHROMATOGRAPHY. 357ammonium acetates are the strongest bases in the solvent system used, butmany other ions, including the alkaline earths, the other alkali metals, zinc,silver, nickel, and cadmium, are in a class having a basicity comparable to thatof .Pz-butylamine, but stronger than p ~ r i d i n e . ~ ~ ~ Potentiometric titrationsof bromine, chromium(v1) , manganese( VII), iodine monochloride, bromate,iodate, and chloramine-?. with sodium thiosulphate in glacial acetic acid, andother reductometric titrations with vanadyl acetate, arsenic tricbloride, andcatechol in the same solvent have been described.286 Neutralisation titra-tions in various solvents have been re~iewed.~s’ Substituted fatty acidshave been titrated potentiometrically with sodium methoxide in benzene-methanol (3 : l), calomel and antimony electrodes being used.288 Variousweak and strong acids and bases present in tobacco smoke289 have beendetermined in glacial acetic acid by means of a glass electrode and a calomelelectrode in the first case with perchloric acid as the titrant, and by usingsodium methoxide to determine the acids in butylamine solution with anantimony-glass electrode system.The titration of aliphatic and aromaticamine picrates in acetic acid by use of perchloric acid as titrant has beendescribed. Methyl-violet was found to be a suitable indicator.290 Neutral-isation titrations in anhydrous formic acid with perchloric acid as titrant havebeen reported.291 Potentiometric titrations were carried out with a quin-hydrone or hydrogen electrode, and visual titrations with indicators such asgentian-violet, neutral-violet, safranine, or malachite-green.Formic acid isa more troublesome medium than acetic acid since the removal of water byrepeated distillation and freezing out is a tedious process. A report ofneutralisation titrations in anhydrous pyridine of perchloric acid, formicacid, benzoic acid, etc., with piperidine, diethanolamine, etc., by using aglass electrode or bromothymol-blue as visual indicator has also been pub-l i ~ h e d . ~ ~ ~ The applicability of non-aqueous titration methods for the analysisof pharmaceuticals 293 and, in particular, for the titration of aspirin andphenacetin in the presence of caffeine 294 has been reviewed.The determin-ation of barbiturates and other weak acids by means of alkali methoxide 295and the titration of sulphonamide and similar derivatives in pyridine andbenzene-methanol with sodium methoxide has also received attention.29GThe selection of the medium for any particular t i t r a t i ~ n , ~ ~ ’ and the inter-pretation of data obtained in non-aqueous media 298 havc been discussed.CHROMATOGRAPHY.Inorganic.-The technique of paper chromatography has been used tostudy some poly- and meta-phosphates, the existence and constitution of2 8 5 C.W. Pifer, E. G. Woolish, and M. Schmall, Analyt. Chew., 1954, 26, 215.286 0. TomiCek, 0. Stodolova, and M. Herman, Chem. Listy, 1953, 47, 516.287 12. Ballczo, Mitteil. chem. Forsch. Wirtsch. Inst. Osterr., 1954, 8, 37.288 J. Raclell and E. T. Donahue, Analyt. Chew., 1954, 26, 590.289 B. R. Warner and W. W. Haskell, ibid., p. 770.290 J. R. Clark and S. M. Wang, ibid., p. 1230.291 0. TomiEek and P. Vidner, Chem. Listy, 1953, 47, 521.292 0. TomiCek and S. Krepelka, ibid., p. 626.293 E. G. Wollish, C. W. Pifer, and M. Schmall, Analyt. Chenz., 1954, 26, 1704.294 E. G. Wollish, R. J. Colarusso, C. W. Pifer, and M. Schmall, ibid., p. 1753.a85 P. Ekeblad and K. Erne, J . Pharm. Pharmcol., 1954, 6, 433.286 J. S. Faber, ibid., p- 187.297 J. S.Fritz, Analyl. CAem., 1954, 26, 1701.298 E. Grunwald, ibid., p. 1696358 ANALYTICAL CHEMISTRY.which is in dispute; 299 and particular attention has been paid to the acidcorresponding to Graham’s salt.300 Crowther 3019 302 has improved Westmanand Scott’s method so as to enable any mixture of ortho-, pyro-, trimeta-,or tetrameta-phosphates to be separated into bands on filter-paper chromato-grams. Cobaltinitrite has been used for the identification of potassium,lead, caesium, and ammonium after their separation on paper chromato-grams.303 Barium and strontium have been separated by selective enrich-ment on an aluminium oxide column,304 and beryllium has been separatedfrom iron and aluminium on a paper-pulp column by elution with butyricacid in ethyl acetate.305 Aluminium in mineral waters has been determinedby ascending chromatography using aluminon or morin, the spot beingcompared with standards similarly treated.30G Nickel has been determineddirectly in microgram amounts by quantitative paper chromatography,the impurities being eluted with acetylacetone and the nickel detected withdit hio-~xamide.~~~ Nydahl 308 has evolved a method for determiningsulphur in steels in which sulphuric acid is separated on an alumina columnfrom ferric iron, etc.The sulphur is then determined conventionally bythe barium sulphate method. The chromatographic separation of molyb-denum(v1) and rhenium(vI1) has been described.309 A shortened chromato-graphic method (on cellulose) for the determination of niobium and tantalumin minerals and ores based on earlier work in this field has been described.310Another rapid method for determining niobium in low-grade ores by paper-strip chromatography has recently been reported.311 Ethyl methyl ketoneand hydrofluoric acid are used as the eluant in both methods.The concen-tration and purification of uranium by paper chromatography using nitricacid in admixture with Iz-butanol, cyclohexanol, etc., for the purpose ofdetermining this metal in deep-sea sediments has been investigated.312Ether and nitric acid were used, on a special apparatus, for the separation ofuranium from copper and aluminium by elution chromatography with thickfilter-paper.313 Separation of uranium from copper and iron(Ir1) on paperchromatogranis by pre-treatment with sodium carbonate and the use offerrocyanide has been described for the determination of this metal in rock~amples.~14 On alumina columns and on paper strips, cobalt (11) has beenseparated from nickel and iron by use of thiocyanate as developer, andmercury( 11) from iron(m), chromium, copper, and lead with potassium iodideas devel0per.3~~ Swiss workers 31G have described the paper chromato-J.P. Crowther, Nature, 1954, 173, 486.299 J. P. Ebel, Bull. SOC. chim. France, 1953, 20, 1089.300 Idem, ibid., p. 1096.308 Idem, Analyt. Chem., 1954, 26, 1383.303 A. E. Steel, Nature, 1954, 173, 315.305 S. Banerjee, A. K. Sundaram, and H. D. Sharma, Analyt. Clzim. Acla, 1954,10, 256.306 K. E. Quentin, 2. analyt. Chem., 1953, 140, 92.307 S.V. Vaeck, Analyt. Chim. Acta, 1954, 10, 48.308 F. Nydahl, Analyt. Chem., 1954, 26, 580.309 D. I. Ryabchikov and A. I. Lazarev, Izvest. Akad. Nauk S.S.S.R., Otdel. Khinz.310 R. A. Mercer and R. A. Wells, Analyst, 1954, 79, 339.311 E. C. Hunt and R. A. Wells, ibid., p. 351.312 E. Hahofer and F. Hecht, Mikrochim. Ada, 1954, 417.313 W. J. Frierson, P. F. Thomason, and H. P. Raaen, Analyt. Chem., 1954, 26, 1210.314 H. Seiler, M. Schuster, and H. Erlenmeyer, Helv. Chim. Ada, 1954, 37, 1252.315 0. I. Khokhlova, Aptechnoe Delo, 1954, 3, 17.3 1 6 A. Weiss and S, Fallab, Helv. Chim. Acta, 1954, 37, 1253.H. Ballczo and W. Schenk, Mikrochim. Acta, 1954, 163.Nazak, 1953, 92, 777WEST : CHROMATOGRAPHI'. 359graphic separation of copper, silver, and mercury and discussed the use ofvioluric acid and quercetin for identifying and determining (semiquantit-atively) microgram amounts of these metals.The solvent system n-butanol-pyridine-water was used for the separation of mercury, silver, and lead oncircular paper 317 after an examination of the factors affecting paperchromatographic separation of the three metals.The paper chromatography of germanium and its separation fromarsenic and other metals by means of butanol saturated with N-hydrochloricacid has been investigated."* Several developers were used, e.g., ammoniummolybdate-sodium stannate, oxine (in the ultraviolet region of the spectrum),and also hydrogen sulphide; Rp values of 0.26, 0.84, and 0.52 were reportedfor Ge(Iv), As(v), and AS(III), respectively.Hecht and his co-workers 3199 320have also studied the paper chromatography of germanium, using phenyl-fluorone as the reagent. The paper-chromatographic separation of scandiumfrom metals such as zirconium, titanium, and thorium, by use of methylacetate-nitric acid with quinalizarin as the developing agent has beenrep0rted.3~~ What is claimed to be the first separation by paper-chromato-graphic methods of tin, iron, and molybdenum in the analysis of titaniumand its alloys has recently been reported.322 The use of various developerssuch as iodide, sulphide, hydroxide, thiourea, and sodium stannite for detect-ing the heavy metals on various absorbents in chromatography has beenreviewed.323 A new conductometric method for detection of the alkalimetals on paper chromatograms has been put forward.32* A chromato-graphic type of separation of various cations by diffusing them over paperimpregnated with various precipitants such as silicate, antimonate, arsenate,and borax, with subsequent development by immersion in distilled water, hasbeen described.325 The paper chromatography of dithizone complexes 326has been investigated, and also that of various azo-derivatives of o ~ i n e .~ ~ 'The main events in the evolution of paper chromatography have 'beenreviewed,328 and a modification for improving detection and identification ofinorganic ions on paper strips has been advanced.329 Infrared radiation hasbeen used for detecting colourless ions on paper.330' 331' 337 A modifiedtechnique for paper-circle chromatography has been used for amino-acids 332and for various inorganic ions.333 Multiple colour development has beenused for amino-acids, organic acids, and sugars on paper strips,334 and aninteresting study of solvents used in adsorption chromatography has been317 S.N. Tewari, Z. analyt. Chem., 1954, 141, 401.3 1 8 M. Lederer, Analyt. Chim. Acta, 1954, 11, 132.31Q I. M. Ladenbauer, L. K. Bradacs, and F. Hecht, Mikrochim. Acta, 1954, 388.320 I. M. Ladenbauer and F. Hecht, ibid., p. 397.321 0. H. Johnson and H. H. Krause, Analyt. Chim. Acta, 1954, 11, 128.322 I. Kolier and C. Ribaudo, Analyt. Chem., 1954, 26, 1546.323 K. M. Olshanova and K. V. Chmutov, ZAur. analit. Khim., 1954, 9, 67.324 G.de Vries, Nature, 1954, 173, 735.325 M. Milone, G. Cetini, and F. Ricca, Ann. Chim. (Italy), 1953, 43, 652.326 G. Venture110 and A. M. Ghe, Analyt. Chirn. Acta, 1954, 10, 336.327 Q. Fernando and M. de Silva, Analyst, 1954, '99, 711.328 H. Weil, Canad. Chem. Processing, 1954, 38, 68.329 S. N. Tewari, Kolloid Z., 1953, 133, 132.330 D. R. Kalkwarf and A. A. Frost, Analyt. Chem., 1954, 26, 191.331 J. D. S. Goulden, Nature, 1954, 173, 646.332 E. Schwerdtfeger, Naturwiss., 1953, 40, 201.333 R. J. LeStrange and R. H. Muller, Analyt. Chem., 1954, 26, 953.334 C. C. Woodward and G. S. Rabideau, ibid., p. 248360 ANALYTICAL CHEMISTRY.made.335 Aspects of chromatography in organic analysis have been re-viewed.336 The effect of side chains on the chromatographic adsorption ofketones on carbon was investigated.338 Elution methods have been examinedfor the separation of substances such as lubricating-oil components,339 andvarious devices for use in this type of technique have been described.340Organic-The chromatography of many organic acids has beend e ~ c r i b e d ~ ~ l - ~ ~ ~ Methods have been worked out for fatty acids ingeneral : 344- 3459 351 for C,,-C,, and C5-C1, 347 straight-chain fatty acids ;for bile acids 348 and keto-acids; 349 for separating the isomeric pyridine-carboxylic acids ; 350 and pyruvic acid, oxaloacetic acid and a-ketoglutaricMalic acid has beendetermined chromatographically in wine 354 and the acids from the oxidationof a-pinene have been separated and identified.355Nine non-nitrogenous acids have been identified and determined bypartition chromatography in sugar-cane A reversed-phasechromatographic procedure for the determination of oleic and lineoleic acidsin the presence of straight-chain saturated fatty acids (C8-C20> has alsobeen ev0lved.~~7 A separation has been evolved for choline e~ters.3~8Amino-acids have been separated chromatographically by various tech-n i q ~ e s .~ ~ ~ - ~ 6 ~ These cannot oi course all be dealt with here, but meremention of some of them should be made; e g . , lysine and hi~tidine.36~The colorimetric determination or detection of various amino-acids on paperchromatograms has been the concern of various auth0rs.~709 37l335 P. B. Moseley, A. L. LeRosen, and J.K. Carlton, Analyt. Chem., 1954, 26, 1563.336 M. Servigne, Chim. analyt., 1954, 36, 3.337 T. Y. Toribara and V. Di Stefano, Analyt. Chem., 1954, 26, 1519.338 E. D. Smith and A. L. LeRosen, ibid., p. 928.339 G. E. Irish and A. C. Karbum, ibid., p. 1445.340 R. M. Bock and N. S. Ling, ibid., p. 1543.341 V. K. M. Rao, J . Sci. I n d . Res. India, 1954, B, 13, 280.343 F. Smith and D. Spriestersbach, Nature, 1954, 174, 466.343 E. R. Reichl and J. E. Loffler, Mikrochim. Acta, 1954, 226.344 P. Savaray, Bull. SOC. Chim. biol., 1954, 36, 927.345 W. J. Harper, J . Dairy Sci., 1953, 36, 808.346 H. J. Nijkamp, Analyt. Chim. Acta, 1954, 10, 448.347 F. Micheel and H. Schweppe, Angew. Chem., 1954, 66, 136.348 A. Norman, Acta Chem. Scand., 1953, 7, 1413.349 D.Cavallini and N. Frontali, Biochim. Biophys. Acta, 1954, 13, 439.350 T. Hashizume, Nature, 1954, 173, 645.352 F. A. Isherwood and D. H. Cruickshank, ibid., p. 121.353 S. Markees, Biochem. J., 1964, 56, 703.354 P. R. Gayon, Ann. FaZtif., 1954, 47, 3.356 D. E. Baldwin, V. M. Loeblich, and R. V. Lawrence, A~zalyt. Chem., 1954, 26, 760.356 E. J. Roberts and L. F. Martin, ibid., p. 815.3 5 7 W. M. L. Crombie, R. Comber, and S. G. Boatman, Nature, 1954, 174, 181.358 I<. B. Augustinsson and M. Grahn, Acta Chern. Scand., 1953, 7, 906.359 J. de Wael and R. Diaz Cadavieco, Rec. Trav. chim., 1954, 73, 333.360 A. L. Levy, Nature, 1954, 174, 126.361 R. A. Clayton and F. M. Strong, Analyt. Chem., 1954, 26, 1302.362 V. K. M. Rao, J .Sci. I n d . Res. India, 1954, B, 13, 342.363 K. Lakshminarayanan, Arch. Biochem. Biophys., 1954, 41, 367.364 J. C. Underwood and L. B. Rockland, Analyt. Chem., 1954, 26, 1553.365 Idem, ibid., p. 1557.367 P. N. Wahi and R. G. Nigam, Indzan J . Med. Res., 1953, 41, 461.368 D. M. Waldron-Edward, Chem. and Ind., 1954, 4, 104.369 I<. Dakshmamurti, Current Sci., 1954, 23, 89.370 F. A. Isherwood and D. H. Cruickshank. Nature, 1954, 174, 123.371 G. Curzon and J. Gittrow, ibid., 1954, 173, 314.and also pyruvic acid from acetoaceticssl H. S. Burton, ibid.. p. 127.366 J. F. Roland and A. M. Gross, ibid., p. 502WEST CHROMATOGRAPHY. 361Many aspects of the chromatography of the alkaloids have been dealtwith.376-378 Codeine has been determined in opium and other complexmixture^,^'^ codeine, morphine, papaverine, and narcotine in papavereturn,373and atropine and hyoscyamine in the presence of each other.374 Theseparation of 17 alkaloids as their reineckates by paper chromatographicmethods has been de~cribed.~~5 The use of chromatography for the separ-ation and determination of sugars and allied substances has been the subjectof very many Spray reagents have been Qroposed for ketoses,e t ~ .~ ~ , 385 The separation of glucose and sorbit01,~86 methylatedsugar~,~87> 388 and sugars and oligosaccharides 389 was readily effected bypaper-chromatographic methods. Volatile amines were dealt with by thesame techniq~e.~m, 391 Similarly, the quantitative chromatographic separ-ation of o- and p-nitroaniline and their monosubstituted derivatives,3gzpyridine ba~es,3~~9 3~ substituted naphthaquinones and benzoquin~nes,~~~2 : 4-dinitrophenylhydra~ones.~~~~ 397 9-phenylazophenacyl esters,3g8 ( 3.)-threonine and ( +)-nllothreonine 399 have been described.Chromatographic methods have been proposed for vitamin D, in thepresence of vitamin A,4001401 for vitamin A,402 group B vitamins,403 andascorbic 405 and also for the analysis of various ~teroids.~O~-~l~ The372 G.C. McEtheny, G. De La Mater, and R. D. Rands, Analyt. Chem., 1954, 26, 819.373 C. G. Lindblad and A. Agren, Farm. Revy. (Sweden), 1954, 53, 69.374 B. Kamiehski and EC. Puchalka, Bull. Acad. polon. Sci., 1953, 1, 305.375 M. Milletti and G. Ademri, Sperimentale, 1954, 4, 99.376 A.Resplandy, Compt. rend., 1954, 238, 2527.377 G. Thomas and P. Roland, Ann. pharm. franc., 1954, 12, 318.3 7 8 H. Bohme, Dewt. Apoth.-Ztg., 1954, 94, 365.379 T, Griffith and J. A. Johnson, Cereal Chem., 1954, 31, 130.380 R. Williams, J . Med. Lab. Technol., 1954, 12, 43.381 J . D. Geerdes, B. A. Lewis, R. Montgomery, and I;. Smith, Analyt. Chern., 1954,383 S. Baar, Biochenz. J., 1954, 58, 175.385 R. U. Lemieux and H. F. Bauer, Annlyt. Chem., 1954, 28, 920.386 S. N. Parikh, J. M. Parikh, and A. N. Godbole, Current Sci., 1954, 23, 53.3a7 W. J. Whelan and K. Morgan, Chem. and Ind., 1954, 78.388 G. R. Barker and D. C. C. Smith, ibid., p. 19.389 I<. V. Giri and V. N. Nigram, J . Indian Inst. Sci., 1954, A , 36, 49.390 W. Dililmann, Biochem.Z . , 1954, 325, 295.391 R. A. Clayton and F. M. Strong, Analyt. Chem., 1954, 26, 579.392 J. E. Larson and S. H. Harvey, C h e w and Ind., 1954, 45.393 D. Jerchel and W. Jacobs, Angew. Chem., 1954, 66, 298.394 A. Waksmundzki and J. OsCik, Roczniki Chem., 1954, 28, 239.395 T. Sproston and E. G. Bassett, Analyt. Chem., 1954, 26, 552.3g6 H. S. Burton, Chem. and Ind., 1954, 576.3g7 G. A. Howard and A. R. Tatchell, ibid., p. 219.398 R. M. Ikeda, A. D. Webb, and R. E. Kepner, Analyt. Chem., 1954, 26, 1228.399 T. L. Hardy and D. 0. Holland, Chem. and Ind., 1954, 517.400 T. D. Schlabach, Diss. A h . , 1954, 14, 456.4O1 J. B. Burnett, ibid., p. 452.402 J. Green and D. 0. Singleton, Analyst, 1954, 79, 431.403 A. Jones, M. P. Taylor, and D. N.Gore, Chem. and Ind., 1954, 461.4O4 M. Ulmann, Pharmazie, 1954, 9, 523.4O5 L. C. Mitchell and W. I. Patterson, J . Assoc. Ofic. Agric. Chem., 1953, 36, 1127.406 M. M. Pechett, J . Clin. Endocrinol., 1953, 13, 1542.4O7 E. Heftmann and D. F. Johnson, Analyt. Ckem., 1954, $6, 519.408 E. R. Katzenellenbogen, K. Dobriner, and T. H. Kritchevsky, J . Biol. Chem.,410 L. R. Axelrod and M. Goldstein, J . Biol. Chem., 1953, 205, 173.4 1 1 F. L. Mitchell and R. E. Davies, Biochem. J.. 1954, '56, 690.412 G. Arroyave and L. R. Axelrod, J . Biol. Chem., 1954, 208, 579.26, 264. 382 M. M. Chollet, I n d . Agric. Alim., 1954, 71, 205.3a4 P. Godin, Nature, 1954, 174, 134.1954, 207, 315. 409 S. McDonough, Nature, 1954, 173, 645362 ANALYTICAL CHEMISTRY.separation of normal aliphatic aldehydes and methyl ketones 413 on silicagel, nitromethane being used as the immobile phase and petroleum as themobile phase, has been described, and various methods for the chromato-graphic separation of 415 yhexachlorocycZohexane,4”6 chloro-p h y l l ~ , ~ ~ ’ pesticides,41s barbiturates,419 and essential oils 420 have beenproposed.The paper chromatography of periodate-oxidisable compo~nds,~21N-(4-~hlorodiphenyl)-N’N’-dimethylurea,~~~ indole thiouracilderivative^,^^ and oT digitoxin and gitoxin 425 has been studied.Hydrocarbons have been classified by chromatography on silica gel withvisual and fluorescent indicators 426 and hydrogenation reactions have beenstudied by use of paper chr~matography.~~~ The adsorption chromato-graphy of high polymers has been treated 428 and the rBle of paper chromato-graphy in the qualitative and quantitative analysis of organic flavouringcompounds has been reviewed.429ELECTROPHORESIS.A technique for electrophoresis combined with paper chromatographyhas been applied to the analysis of amino-acids and ba~es.~30 A methodfor the detection of proteins on paper in paper electrophoresis has beenproposed.This depends on reaction of the separated protein band withsilver bromide paper and development of the bromide paper to make theimage visible.431 The electrophoretic separation of proteins on paper andtheir automatic photometric evaluation 432 has been the concern of others.The electrophoretic separation of serum proteins on filter-paper has beene ~ a m i n e d .~ ~ ~ j 434 A continuous scanning device for electrophoresis and paperchromatography has also been de~cribed.~~5ION EXCHANGE.The use of ion-exchange methods in water analysis has been reviewedLow results have been reported in determining total sodium re~ently.~367 437413 P. J. G. Kramer and H. van Duin, Rec. Trav. chim., 1954, 73, 63.414 G. Panopoulos and J. Mi.galdoikonomos, Chim. analyt., 1954, 36, 68.415 G. G. McKeown, J . Assoc. OBc. Agric. Chenz., 1954, 37, 527.416 A. Germano, R. Fazan, and I. Lossius, Helv. Chim. A d a , 1954, 37, 1332.417 A. H. Sporer, S. Freed, and K. M. Sancier, Science, 1964, 119, 68.41s L. C. Mitchell, J . Assoc. OBc. Agric. Chem., 1954, 37, 216.419 J. T. Wright, J. Clin. Path., 1954, 7, 61.420 R.H. Reitsema, Analyt. Chem., 1954, 26, 960.4 2 1 R. L. Metzenberg and H. K. Mitchell, J . Amer. Chem. Soc., 1954, 76, 4187.422 W. E. Bleidner, .J. Agric. Food Chew., 1954, 2, 682.423 L. F. Weller, S. H. Wittwer, and H. M. Sell, J . Amer. Chem. Soc., 1954, 76, 629.424 F. Reinhardt, Mikrochim. Acta, 1954, 2, 219.425 C. Giinzel and F. Weiss, 2. analyt. Chem., 1953, 140, 89.426 P. G. Harvey and R. M. Pearson, Analyst, 1954, 79, 158.427 W. Irion and E. Moosmuller, 2. analyt. Chem., 1953, 140, 416.428 D. W. Bannister, C. S. G. Phillips, and R. J. P. Williams, Analyt. Chem., 1954,429 R. ter Heide and J. F. Lemmens, Perfumery Essen2. Oil Record, 1954, 45, 21.430 J. Blass, 0. Lecomte, and J. Polonovski, Bull. Soc. Chim. biol., 1954, 36, 627.4 3 1 W.F. Bon, Chem. Weekblad, 1954, 50, 131.432 W. Kemula and W. Bartosiewicz, Roczniki Chem., 1954, 28, 100.433 J. Hardwicke, Biochem. J . , 1954, 57, 166.434 M. Martinette, J . Chem. Educ., 1954, 31, 18.435 0. Bassir, Chem. and Ind., 1954, 709.436 C. Calmon, J . Amer. Water Works Assoc., 1954, 46 (470.437 M. V. Tovbin and F. G. Dyatlovitskaya, Uhrain. khim. Zhur., 1952, 18, 647.26, 1451\VEST : TON BXC€T:\NGE. 363and potassium in natural waters by cation-exchange methods 438 and anindirect method for the same determination has been reported.439 Separ-ation of the alkaline earths on a colloidal Dowex 50 column by elution with1-2M-ammonium lactate has been described.440 The ions are eluted in theorder calcium, strontium, barium.Separation of the last two on a basic ion-exchange column with ethylenediaminetetra-acetic acid as eluant has alsobeen described.&l The same eluant has also been used both to wash outmagnesium from a cation column, thus achieving a separation from calcium,442and to separate adjacent rare earths by elution from an ion-exchange resin,443and quantitative data have been published for the elution of neodymiumwith citric acid-ammonium citrate.444 A theory was also advanced by thesame authors445 to deal with the mechanism involved in elution by dilutecitrate solutions. The relative elution positions of the lanthanide andactinide elements with lactic acid as eluant a t 87" have been reported byother workers in this field.446 Palladium has been separated from iridium 447by passage of an ammoniacal solution of their chlorides through a columnof Amberlite 1R-100.The palladium is retained as its positively chargedamine complex whilst the iridium is washed through in anionic form asII-C~,~- or IrC163-. The separation of the platinum metals by means ofstrongly basic anion-exchange resins has recently been described.448 Theseparation of metal cations by alginic acid exchange was described withparticular reference to the separation of sulphate ion and its gravimetricdetermination. Binary separations of copper and magnesium, copper andnickel, etc., and some ternary separations of iron, nickel, and copper andiron, copper, and magnesium were effected on the same column.@gThe behaviour of the various condensed phosphates in anion-exchangechromatography has been examined,450 and the separation of halide mixturesby ion-exchange chr~matography.~~~ An excellent method for the separationof zinc from many other elements by means of anion exchange has beendescribed.452The application of ioii-exchange resins to organic analysis has beenreviewed.453 Ion exchangers have proved useful for the determination ofsugars in honey,454 for the hydrolysis of polysa~charides,~~~ and for theseparation and identification of several amino-acid~.~~63 45'438 31.V. Tobin and F. G. Dyatlovitskaya, Ukrain. khinz. Zhur., 1953, 26, 657.459 R. Navone, J . Amer. Water Works Assoc., 1954, 46, 479.440 M. Lerner and W. Rieman, Analyt. Chem., 1954, 26, 610.4 4 1 R.Bouy and G. Duyckaerts, Analyt. Chim. Acta, 1954, 11, 134.4 4 2 D. N. Campbell and C. T. Kenner, Analyt. Chem., 1954, 26, 560.443 F. H. Spedding, J. E. Powell, and E. J. Wheelwright, J . Anzer. Chem. Soc., 1954,4 4 4 Idem, ibid., p. 2545.4 4 6 L. Wish, E. C. Freiling, and L. R. Bunney, ibid., p. 3444.4 4 7 W. M. MacNevin and W. B. Crummett, Analyt. Chim. Acta, 1954, 10, 323.4 4 8 E. Blasius and U. Wachtel, Z. analyt. Chem., 1954, 142, 341.449 H. Specker, M. Kuchtner, and H. Hartkamp, ibid., p. 33,450 J. Beukenkamp, W. Rieman, and S. Lindenbaum, Analyt. Chem., 1954, 26, 505.451 R. C. DeGeiso, W. Rieman, and S. Lindenbaum, ibid., p. 1840.4 5 2 C. C. Miller and J. A. Hunter, Analyst, 1954, 79, 483.453 B. S. Miller and J. A. Johnson, Trans.Amer. Assoc. Cereal Chem., 1954, 12, 29.454 J. W. White and J. Maher, J . Assoc. Ofic. Agric. Chem., 1954, 37, 466.4 5 6 R. E. Glegg and D. Eidinger, Analyt. Chem., 1954, 26, 1365.4 5 6 B. Bergeret and F. Chatagner, Biochim. Biophys. Ada, 1954, 14, 543.4 5 7 P. C. van der Schaaf and T. H. J. Huisman, Chew. Weekblad, 1954, 50, 273.76, 612.445 Ibid., p. 2550364 ANALYTICAL CHEMISTRY.FLAME PHOTOMETRY.Factors influencing the applications of flame photometry and in particularthe determination of the minimum amounts of Mn, Cu, Co, B, and Fe deter-minable within a standard deviation of *lo% have been reviewed,458 andvariations in flame feed, strong background interference, and perturbationscaused by molecular interactions have been discussed.459 The influence ofviscosity and particle size with particular reference to sucrose solutions hasbeen examined,460 and methods for the determination of the alkali metals,magnesium, and calcium have been 0utlined.~6l Aluminium interferes withthe determination of calcium.Removal of the aluminium as its insolublebenzoate has been used to overcome the interferenceJ4G2 but use has alsobeen made of this interference to determine aluminium by measuring theeffect on the calcium flame.463 Flame-photometric methods have beenproposed for determination of the alkali metals in many different types ofmaterial, e.g., lithium in magnesium-lithium alloys,464 and in spodumene ; 465sodium and potassium in plant extracts; 466 in cast iron with the alkalineearth metals ; 467 in zinc cadmium sulphide phosphors ; 468 in Portlandcement ; 469 distilled water and sulphuric acid,470 and with calcium in serum471(with particular reference to the effect of organic solvents on the determin-ation). Calcium has been determined similarly in deproteinised wholein in coal ash and coke ash,474 and the interference ofphosphate ions in its determination has been examined.475 Phosphate itselfhas been determined in powdered rock samples by use of the calcium flamemeth0d.~76 Flame photometry with the oxy-hydrogen flame has been usedfor determining indium in aluminium bronze alloys,47 copper and aluminiumbeing added to the standards to cover interference from these two metals.Nitric and hydrochloric acids do not interfere up to l ~ , but N-sulphuric acidconsiderably depresses the flame intensity. The determination of iron ,chromium, and manganese in the presence of considerable amounts of thealkali metals has been described in a flame-spectral investigation of theferrite composition of In conclusion, an ingenious method for thedetermination of rubber solids in f a b r i ~ s , ~ 7 ~ based on the flame photometric4 5 8 W.G. Schrenk, Trans. Anaer. Assoc. Cereal Chem., 1954, 12, 64.459 M. Pinta, Chim. analyt., 1954, 36, 126.460 R. D. Caton and R. W. Bremner, Analyt. Chem., 1954, 26, 806.4151 A. Gee, L. P. Domingues, and V. R. Deitz, ibid., p. 1487.462 0. Gjems and D. Lydersen, 2. Pfiant Erniihr. Dung., 1954, 64, 36.463 M. Servigne and P. G. de Montgareuil, Chim.analyt., 1954, 36, 115.464 A. M. Robinson and T. C. J. Ovenston, Analyst, 1954, 79, 47.4 8 5 R. J. Brumbaugh and W. E. Fanus, Analyt. Chern., 1954, 26, 463.4 6 6 H. M. Bauserman and R. R. Cerney, ibid., 1953, 25, 1821.4 6 7 D. F. Kuemmel and H. L. Karl, &id., 1984, 26, 386.4 6 8 S. B. Deal, ibid., p. 598.469 C. L. Ford, ibid., p. 1578.470 P. Mazzamaro and G. Tatoian, ibid., p. 1512.4 7 1 G. R. Kingsley and R. R. Schaffert, J . Biol. Chem., 1954, 206, 807.472 G. 0. Schiiltz, Schweiz. med. Wochenschr., 1953, 83, 452.473 J. R. Denson, J . Biol. Chem., 1954, ZO9, 233.474 L. J. Edgcombe and D. R. Hewett, Analyst, 1954, 79, 755.4 7 5 L. Leyton, ibid., p. 497.4 7 6 W. A. Dippel, C . E. Bricker, and N. H. Furman, Awalyt. Chem., 1954, 86, 5534 7 7 V. W.Meloche, J. B. Ramsay, D. J. Mack, and T. V. Philip, ibid., p. 1387,4 7 8 F. Wever, W. Koch, and G. Wiethoff, Arch. Eisenhiittenwesen, 1953, 84, 383.478 H. E. Todd and H. M. Tramutt, Analyt. Chem., 1954, 26, 1137WHIFFEN : SPECTROSCOPIC METHODS OF ANALYSIS. 365determination of the sodium contained in the latex formulation, is note-worthy. The method was applied to cotton, rayon, Nylon, Fiberglas, andDacron.T. S. W.SPECTROSCOPIC METHODS OF ANALYSIS.A special section is being devoted to spectroscopic methods this year inview of their importance and because the emphasis lies on the apparatus,spectral region, etc., rather than on the analytical reagents which play suchan important part in the other sections. For this reason colorimetricmethods in the visible region in which no dispersing agent, such as a prism,is used, and in which the search for coloured complexing agents or indicatorsis all-important, are not included in this section.It isnot easy to make a rigid distinction between qualitative and quantitativeanalysis, since in most cases some idea of quantity to &20% is given by themore qualitative studies, and the same method can normally be made togive a more accurate quantitative estimate with greater precautions andaccurate calibration procedures.X-Ray Methods.-Although some use of X-rays in analysis has beenmade in the past, there has been increased interest in recent years and thematter has been reviewed.480 There are three distinct methods, of whichthe oldest is the identification of crystals through the positions of diffractedspots, or more commonly rings, when powder techniques are used.Theindividual crystalline forms are detected although the accuracy is notspecially high, and typical is the result of K l ~ g , ~ ~ ~ who reports an analysisof quartz in silicates of 59.7 & 1.0%. Amorphous materials would beunsuitable and many component mixtures would be difficult, but singlecrystals can be identified with considerable certainty.Secondly, there is an X-ray absorption method which measures the totalabsorption of the material, commonly a petrol or an oil. Since heavy ele-ments absorb more strongly than carbon or hydrogen, analysis can bemade for one of them by obtaining the excess absorption compared to thepure petrol, and some specificity can be obtained by working at an absorp-tion edge of the element concerned.No information is obtained about thestate of combination of the element in question, and the material must befree from other heavy elements. Levine and Okamato have shown themethod to be capable of determining sulphur in petrolsgs2 to 0.02% in15 minutes, and lead alkyls 483 at 0.02 ml. ,per gallon (ca. 2 p.p.m.), again in15 minutes.Thirdly, there is a fluorescence method4&47455 whereby the material isirradiated with X-rays, and the X-ray fluorescence spectrum is analyseclinto its constituent wavelengths with a rock-salt analyser and then detectedquantitatively with a Geiger counter. The method is specific since eachelement has a different fluorescence frequency and the method has been usedfor iron in blood and for chromium, cobalt, iron, and molybdenum in steelsThe field is best divided according to the wavelength region used.480 >I.A. Liebhafsky, Amlyt. Chem., 1953, 25, 689; 1954, 26, 26.481 H. P. Klug, ibid., 1963, 25, 704.482 S. W. Levine and A. H. Okamato, ibid., 1951, 23, 699.484 L. S . Birks, E. J. Brooks, and H. Friedman, ibid., 1953, 25, 692.4 8 5 H. J. Beattie and R. M. Brissey, ibid., 1954, 26, 980.483 Idem, ibid., p. 1293366 ANALYTICAL CHEMISTKY.to an accuracy of 1% or better with only one minute’s counting time,Kokatailo and Damon 486 prefer to use an internal standard added in knownamount to correct for internal absorption, geometrical factors, etc., and theyadd selenium to a hydrocarbon to be analysed for bromine and the analysisis then obtained from the ratio of the fluorescence intensities at 1.039 and1.105 A due to the selenium and bromine respectively.In the range 0-0.4%of bromine the accuracy is O - O l ~ o . A comparison with chemical analysisfor niobium and tantalum in ores has been made,487 and the X-ray fluor-escence method is found to be cheaper, very much more rapid, and quite asaccurate.Ultraviolet Methods.-The application of ultraviolet spectra down to2200 A for the identification and analysis of organic molecules is widespreadin organic chemistry laboratories. The advantages and disadvantages rela-tive to other regions are related to the fact that only materials with at leasttwo conjugated double bonds are likely to absorb at all strongly in thisrange.Consequently, only a limited range of compounds can be investi-gated, but they can be detected in small quantities in solution in non-absorb-ing media. This comment does not apply to the shorter wavelengths of thevacuum ultraviolet beyond 2000 A, where even saturated aliphatic com-pounds absorb strongly, but unfortunately the practical difficulties of thisregion are much greater. Many designs of near ultraviolet spectrometer areavailable commercially. Although normally solutions are studied, this maynot always be convenient, and for use with pure liquids a cell thickness assmall as 0.34 micron has been obtained488 with spacers of evaporatedaluminium.and a useful up-to-date andcomprehensive book has been written by Gillam and Stern.490 Thiscontains information on all the commoner applications, and a list of sub-headings gives some idea of the range of materials for which ultravioletspectra are used : carbonyl compounds, thione grouping, conjugatedpolyene series, polyacetylenes, semicarbazones, benzenoid absorption,tropolones, azulenes, pyrimidines, alkaloids, carotenoids, anthocyanins,sterols, chlorophyll, vitamin A, tyrosine and tryptophan, ionones, pyrethrins,cis-trans-isomerism, etc.In many cases a complete analysis into individualcompounds is not possible and several molecules differing slightly in theplacement of methyl groups or the length of an aliphatic chain are foundtogether.Recently, it has become apparent that the ultraviolet is not withoutinterest for inorganic analysis,491.and analyses which have been suggestedinclude those of niobium as the reduced t h i ~ c y a n a t e , ~ ~ ~ mercury as thio-cya1iate,4~3 thorium as the ~ e r s e n a t e , ~ ~ * telluric acid,495 and vanadium asRecent applications have been486 G. T. Kokatailo and G. F. Damon, Analyt. Chem., 1953, 25, 1185.4 8 7 W. J. Campbell and H. F. Carl, ibid., 1954, 26, 800.488 V. von Keussler, Spectrochim. A d a , 1954, 6, 185.4a9 E. J. Rosenbaum, Analyt. Chem., !?54, 26, 20.480 A. E. Gillam and E. S. Stern, Electronic Absorption Spectra in Organic491 R. P. Buck, S. Siqghadeja, and L. B. Rodgers, Analyt. Chem., 1954, 26, 1240.492 A.E. 0. Marzys, dnalyst, 1954, 79, 327.4g3 G. E. Markle and D. F. Boltz, Analyt. Chern., 1954, 26, 447.49% H. V. Malmstadt and E. C. Gohrbrandt, ibid., p. 442.495 L. W. Scott and G. W. Leonard, jun., ibid., p. 445.Chemistry,” Arnold Ltd., London, 1954WIIIFFEN : SPECTROSCOPIC METHODS OF ANALYSIS. 367sodium vanadate after an oxine extraction.496 Also with a sensitive Geigercounter detector it has been possible to observe the bands on a paperchromat gram.^^Emission Spectrography .-Although often extending into the ultra-violet from the visible, spectrographic methods using atomic emission linesfor detection of elements are of an essentially different character. Theirsensitivity may be very high, but owing to the destructive nature of theexcitation conditions, no indication is given of the nature of the compoundin which any element may be.Again, the instruments and basic techniquesare by now well known and recently much useful information has beenbrought under one cover in a book 498 and the subject has been reviewed.499Instrumental developments mostly concern the replacement of the photo-graphic plate by one or more photoelectric cells, it being quite common tohave one detector cell for each element required. Hasler 500 has a direct-reading instrument which records 19 elements in 57 seconds including thepre-sparking period ; the standard deviations are 0~4---0-0004% of thesample according to the element concerned and the amount present. Inmany cases chemical enrichment precedes the spectrographic analysis, andthis method has been used for the rare earths,501 and for trace elements inwater,502 where the sensitivity may reach 0.001 p.p.m.; electrolytic separ-ation is useful for rare earths in Other recent analyses includecopper alloys 504 to O-OOl% in Pb, Sn, Fe, Ni, Si, Bi, and Al, and rather lesssensitivity for Te, As, P, and Zn; aluminium; 505 coal ash 506 for Na andK ; and several applications to silicate rocks and slags; 507-511 and alsoimpurities in manganese dioxide.512New cathode designs to obtain more even sampling techniques are becom-ing popular. Friederickson and Churchill 513 use molten electrodes foraluminium samples. A hollow stainless-steel cathode enables halogendeterminations 514 to be made in the microgram range.The porous graphitecup technique 515 is much used and has proved successful for brass analysis.516In this connection a survey 517 has been made of all the lines due to N, 0,H, C, etc., which inevitably arise in this technique from air, electrodematerial, and water, as well as the lines from diatomic radicals such as CN,4g6 I. M. Gottlieb. T. F. Hazel, and W. M. McNabb, Analyt. Chinz. Acta, 1954, 11, 376.4s7 T. D. Price and P. B. Hudson, Analyt. Chem., 1954, 26, 1127.4s8 T. A. Cutting, “ Practical Spectroscopy,” Heinemann, London, 1952.4gQ W. F. Meggers, Analyt. Chew., 1954, 26, 54.500 M. F. Hasler, Spectrochim. Acta, 1953, 6, 19.501 H. J. Rose, jun., J. K. Marata, and M. K. Carron, ibid., 1954, 6, 161.502 F. Pohl, ibid., 1953, 6, 19.508 E. W.Spitz, J. R. Simmler, B. D. Field, K. H. Roberts, and S. M. Tuthil1,AnaZyt.505 J. Orsag, ibid., 1953, 6, 80.506 C. H. Anderson and C. D. Beatty, Analyt. Cheia., 1954, 26, 1369.507 P. G. Harris, ibid., p. 737.509 F. Raldi, ibid., p. 39.511 G. A. Monnot, ibid., 1954, 6, 153.512 J. W. Mellichamp, Analyt. Chem., 1954, 26, 977.613 2. D. Frederickson, jun., and J. R. Churchill, ibid., p. 795.514 F. T. Birks, Spectrochim. Acta, 1954, 6, 169.515 C. Feldman, Analyt. Chem., 1949, 21, 1041.516 L. G. Young, J. M. Berriman, and B. E. J. Spreadborough, Analyst, 1954, 79, 551.517 L. G. Young, B. E. J. Spreadborough, and P. M. Reed, Spactrochim. Acta, 1954,Chem., 1954, 26, 304. 504 F. V. Schatz, Sfiectrochim. Acta, 1954, 6, 198.W.J. Price, Spectrochim. Acta, 1953, 6, 26.510 W. Muld, ibid., p. 53.6, 144368 ANALYTICAL CHEMISTRY.C,, OH, NH, etc., which may also give sharp spectra simulating the desiredmetallic atoms and must therefore be guarded against.Raman Spectra in Analysis.-Analysis by means of the Raman scatteringspectrum has several disadvantages compared with ultraviolet or infraredabsorption methods, but i t has been found useful for special purposes,especially in the petroleum industry, and has been the subject of a book 618and a review.519 One of the difficulties is the comparatively large amountsof liquid or concentrated solution required (20 ml. is not unusual with mostsources), and another is the trouble required to get satisfactory quantitativemeasurements when using photographic plates, although in favourablecases 06y0 accuracy 520 may be obtained.However, the latter difficulty isovercome by modem recording with photoelectric cells, and a commercialinstrument of this type has been described,521 and among the more recenthome-built recording spectrometers is that of Robert ,522 which has provedsatisfactory for petrols and for water-acetone-alcohol mixtures. At leastwith photographic detection Raman spectrometers are less costly than thosefor the infrared, and a second advantage is that the received radiation isdirectly proportional to the concentration , as opposed to the logarithmicnature of the Beer-Lambert absorption law. Those interested in a furthercomparison might take the analysis for y-hexachlorocyclohexane, for whichboth Raman 523 and infrared methods 524 have proved satisfactory.Infrared Absorption in Analysis.-A general review of recent work hasbeen made by G0re.52~ Greater interest is now being shown in the nearinfrared region, which has hitherto been largely neglected.This neglect ispartly because fundamental work is difficult since the absorption is due toovertones and combination bands which are not easy to interpret, but thisis unimportant for analysis, The advantages arise from the use of com-paratively long path lengths, from 0.1 t o 10 cm. for liquids, of quartz orglass cell windows, of comparatively cheap gratings, and of rapid sensitivephotoconducting detectors of lead sulphide. A general review of thisregion 526 includes analytical applications and shows that in favourable cases,such as water or acids in hydrocarbons, the sensitivity may reach as littleas 0404~0.A similar sensitivity is obtained for H,O in D20 in the rangeabove 99.6% D,O by using the HOD absorption near 3 microns.527For general analytical work at longer wavelengths several authors 528-530have stressed the advantages of double-beam operation, where it is possiblet o balance out the absorption of solvents, unwanted interfering componentsand the like, all of which may be introduced into the comparison beam. Ithas even proved possible 528 to use a special rag paper for a paper chromato-gram, which is thin enough to transmit considerable infrared radiation , and5 1 8 W.Otting, ‘ I Der Raman-Effekt und seine analytische Anwendung,” Springer-620 G. Michel, Spectrochinz. Acta, 1952, 5, 218.5 2 1 J. Skinner, ibid., 1953, $, 110.623 A. Simon and D. Jentzsch, 2. anorg. Chem., 1951, 266, 193.524 D. H. Whiffen and H. W. Thompson, J., 1948, 1420.625 R. C. Gore, Analyt. Chem., 1954, 26, 11.626 W. Kaye, Spectrochim. Acta, 1954, 6, 257.527 J. Gaunt, Analyst, 1054, 79, 580: J . Sci. Instr., 1954, 31, 315.6 2 8 L. J. Bellamy, J . A$@. Chem., 1953, 3, 421.52Q I. R, C. McDonald, Nutuve, 1954, 174, 703.690 R. Schnurmann and E. Kendrick, Analyt. Chem., 1954, 26, 1263.Verlag, Berlin, 1952. 519 R. I?. Stamm, AnaZyt. Chem., 1954, 26, 40.622 L. Robert, ibid., p. 115WHIFFEN : SPECTROSCOPIC METHODS OF ANALYSIS. 389so the materials in the different bands of the chromatogram may be identifiedfrom their spectra by using blank paper in the comparison beam.Othernew techniques include a simple variable silver chIoride cell 531 and the useof the pressed-disc technique 532- 533 to remove scattering errors. For this,the material is weighed and mixed with finely ground potassium chloride orbromide, and the whole is evacuated and pressed under a pressure of some20 tons per square inch, whereupon a transparent plate results. In thesecircumstances advantage may easily be taken of the smallness of the samplewhich is sufficient to show infrared absorption, and with the assistance ofsilver chloride lenses Anderson and Woodall 534 obtain good spectra withonly 10 pg. of material.In many laboratories infrared absorption spectra are widely used for theidentification of unknown materials, but often, being a once-only problem,this type of work is not published.The first stage in such a quest is theidentification of the chemical groupings which are probably present. Thistask has been made much easier by the publication of a book 535 which isa compilation of known characteristic group frequencies ; a selection fromchapter headings will indicate the range of groups for which information isnow available : alkanes, alkenes, alkynes, aromatic compounds, alcohols,ethers, ketones, carboxylic acids, esters, amides, proteins, amino-acids,amines, heterocyclic compounds, organo-silicon compounds, organo-phos-phorus compounds, organic sulphur compounds, inorganic ions, etc.Several quantitative analyses by infrared methods have been publishedrecently, most of which only aim at a limited accuracy (1-5%), if judged byother analytical standards, but the compounds to be differentiated are oftenso similar that no other method is likely to prove nearly so satisfactory,unless the materials are sufficiently volatile for a mass spectrometer or forgas-phase chromatography.These analyses include a four-component boronhydride nitric and nitrous diphenyl in lemons andoranges,538 steroidal pseudo-sap~genins,~~~ polyalcohol mixtures,540 chloral,carbon tetrachloride and chloroform mixtures,541 polymerised esters,542and 00-dimethyl O-P-nitrophenyl thiophosphate. 543 One case which ismore favourable as regards sensitivity is the detection and analysis ofchloroform, methylene chloride, etc., as impurities in liquid c h l o r i r ~ e , ~ ~where cells up to 5 cm.long can be used down to a t least 1150 cm.-l since themajor component is completely transparent ; consequently the sensitivityreaches 5 p.p.m.There are also non-dispersive instruments which often have advantages531 B. M. Mitzner and S. 2. Lewin, J . Opt. SOC. Amer., 1954, 44, 425.632 R. 0. French, M. E. Wadsworth, M. A. Cook, and I . B. Cutter, J . Phys. Chenz.,534 D. H. Anderson and N. B. Woodall, Analyt. Chem., 1953, 25, 1906.535 L. J. Bellamy, " The Infra-red Spectra of Complex Molecules,'' Methuen, London,s36 L. V. hlccarty, G. C. Smith, and R. S. McDonald, Analyt.Chem., 1954, M, 1027.537 E. L. Saier and A. Pozefskjr, ibid., p. 1079.538 W. F. Newhall, E. J. Elvin, and L. R. Knodel, ibid., p. 1234.539 A. L. Hayderi, P. B. Smeltzer, and I . Scheer, ibid., p. 550.~0 T. F. Shay, S. Skilling, and R. W. Stafford, ibid., p. 652.541 L. Breitman and E. \V. R. Steacie, Canad. J . Ckem., 1953, 21, 328.542 N. H. E. Ahlets and N. G, McTaggart, A?zaZyst, 1954, 79, 70.543 J. Derkosch, H. Jansch, R. Leutner, and F. X. Mayer, Monatsh., 1954, 85, 684.544 A. W. Pross, Nature, 1954, 174, 467.1954, 58, 805. 533 M. A. Ford and G. R. Wilkinson, J . Sci. Instr., 1954, 31, 338.1854370 ANALYTICAL CHEMISTRY.of cheapness and of robustness for plant-control applications. The bestknown is the gas analyser which has been discussed by Martin,545 whogives several analytical examples of its use including measurement ofcarbon dioxide, sulphur dioxide, hydrogen cyanide, acetone, and watervapour.Full scale deflection of the indicating meter or recorder may becaused by as little as o-25-@10~0 of the required material in the gas flowstream. It has also proved useful 546 for estimating 13C in carbon dioxideto o.005~0 near its natural 1% abundance. Luft 5c7 has introduced a ratherdifferent non-dispersive scheme, whereby a wedge-shaped absorption cell,filled with the liquid component to be detected, is made to vary in effectivethickness with time by mechanical movement and so to modulate the radiationbeam passing through it. But only the frequencies absorbed are modulated,and so a detector tuned to the modulation frequency is far more sensitive inits output to the same compound in the analysis cell, since this componentnecessarily absorbs at the modulated frequencies, than to other materials.The original instrument was sensitive to 0.001% of cyclohexane in otherwisepure liquid benzene.Kalkwarf and Frost 548 have introduced a simple arrangement for detect-ing, though not identifying, colourless bands on paper chromatograms.The total radiation from a hot filament received through the paper by athermistor bolometer is measured and found to diminish at places where thepaper carries a chromatographically formed band of material.Microwave Methods-Since the experimental technique is relativelynovel and no commercial microwave spectrographs are available, the use ofthis frequency range for analysis has been little studied. However, thepotentialities have been d i s c u s ~ e d . ~ ~ - ~ ~ ~ Among the advantages are thesmall quantities, about 5 pg., and the wide spectral range available which isable to accommodate 4,000,000 distinct bands as opposed it 3000 for theinfrared with normal resolution. A consequence of this wide range is thatthe certainty of qualitative identification is very high even if only one or twobands are observed, since overlapping is so improbable. Among the require-ments for the material to be analysed are a permanent and preferably largedipole moment, a vapour pressure of mm., and preferably not too largea moment of inertia, since this multiplies the number of bands a t the expenseof their intensities. Unfortunately for quantitative analysis, there isdifficulty since the peak intensity for any one component depends markedlyon the amount and nature of other components present; consequently,careful calibration in this respect will be required or else band areas must bemeasured which introduces further experimental difficulties. Analysessatisfactorily made by microwave gas methods are deuterated ammonia inammonia, 15N in ammonia to 3% of the 15N c~ncentration,~~~ and 13C incyanogen chloride 552 to 2% of the amount present in the range l-lOyo.545 A. E. Martin, Research, 1953, 6, 172.546 J . C. Kluyver and J . M. W. Milatz, Physica, 1953, 19, 401.5 4 7 K. F. Luft, Comfit. rend., 1954, 238, 1651.548 D. R. Kalkwarf and A. A. Frost, Azalyt. Chem., 1954, 26, 191.549 R. H. Hughes, Ann. N.Y. Acad. Sci., 1952, 55, 872.550 J. Sheridan, Chew and Ind., 1953, 648.551 J. Weber and K. J. Laidler, J. Chem. Phys., 1951, 19, 1089.552 A. L. Southern, H. W. Morgan, G. W. Keilholtz, and W. V. Smith, Analyt. Chem.,1951, 23, 1000WHIFFEN : SPECTROSCOPIC METHODS OF ANALYSIS. 37 1The microwave absorption of solids and liquids consists of very broad absorp-tion regions whose centres are sensitive to environment and temperature,and there is little promise for analysis unless it be the detection of polarimpurities in non-polar solvents.Radiofrequency Spectra.-The even newer topic of radio frequency ornuclear resonance spectra 553 shows some promise for analytical purposes.In these spectra the atomic nuclei are transferred from one spin orientationt o another in a strong magnetic field; the associated absorption irequencyfor a given field strength depends on the nucleus involved and may be usedspecifically to detect such nuclei. A promising case might be to detecthydrogen in fluorinated hydrocarbons. The analysis would require a fewml. of material which is not destroyed and would have the advantage forsome purposes that the sensitivity per hydrogen atom is independent of thecompound and calibration would be possible without using the particularmaterial involved. Recently, with more homogeneous magnetic fields,improved resolution has been obtained, and each compound shown to havea spectrum of some dozen absorption lines for each type of nucleus, exceptthose without spin which do not give rise to any absorption. These spectracould be used to identify individual compounds and also to help characteriseunknown structures, since, for example, the exact frequency of a hydrogenresonance depends on whether it is part of a CH,, CH,, or CH group, etc.Though the possible troubles are not yet known, the method has proved itsusefulness in estimating the keto-enol ratio of pentane-2 : 4-di0ne,~5~ forwhich the self-calibrating feature is especially valuable since neither com-ponent can be obtained separately. In another application the muchdiminished line width in the liquid as opposcd to the solid state has madepossible the non-destructive determination of free liquid water in solids suchas agricultural products and clays. 555D. H. W.R. BELCHER.A. J. NUTTEN.T. S. WEST.D. H. WHIFFEN.5 5 3 J . A. S. Smith, Quart. Rev., 1953, 7, 379.564 H. S. Jarrett, M. S. Sadler, and J. N. Shoolery, J . Chew. Phys., 1953, 21, 2092.5 5 5 J. N. Shoolery, Analyt. Chem., 1954, 26, 1400

ISSN:0365-6217    

DOI:10.1039/AR9545100335

出版商:RSC    

年代:1954

数据来源: RSC

摘要:

CRYSTALLOGRAPHY.Introduction.-THE Annual Reports for 1949,1950, and 1951 gave accountsof crystallographic work since 1946 in the inorganic, organic, and protein fields,respectively; and a section of the 1952 volume covered the whole subject upto the end of that year. The Society’s policy now is to report Crystallographybiennially. A cta Crystallographica printed over 400 communications during1953-1954, and the number of titles of possible crystallographic importincluded in Current Chemical Papers for 1954 alone was of the order of 1000.Thus, were it the intention of the Reports to be comprehensive, the availablespace could be filled merely by listing the references. Emphasis has had tobe restricted to structure analysis and to some of the results obtainedthereby, though many other branches of crystallography may be of actual,or potential, importance to chemists, and of greater inherent interest to manycrystallographers.The Third Congress of the International Union of Crystallography met inParis in July, 1954.A short report on the meeting has been given,l andabstracts of most of the 600 communications offered have been reprinted asPart 10, Vol. 7, of Acta Cryst. Amongst the special symposia arranged, oneon the training of crystallographers attracted unexpected attention and ledto the appointment of a Commission under the chairmanship of N. F. M.Henry. Hitherto nearly all workers in the field have been primarily trainedas physicists, chemists, mineralogists, or metallurgists, and have subse-quently acquired an amateur’s knowledge of such branches of crystallographyas have seemed useful in the pursuit of their respective interests.Opinionis divided as to whether this situation is desirable-or at any rate unavoid-able2-or whether the intending worker should in future be required toundergo a thorough discipline in the ‘‘ study of the solid state, with all thatthat implies.”Amongst important books to be mentioned, first place belongs to theStructure ReportsJ4 of which Vols. 10 and 13 (covering work published in1945-1946 and 1950) appeared during the period under review. Thiscompilation contains a critical summary of all structure determinations byX-ray and electron-diffraction , and by certain other physical methods.Vols. 8 and 9 (1940-1944) are now in preparation, and when published theywill link up with Vol.7 of Strztkturbericht, so that all work up to 1950 willthen have been dealt with. Also issued under the auspices of the Unionare the new Interrcational Tables for X-Ray C~ystallography,~ which are tosupersede the Internationale TabeZlen of 1935; Vol. 1 appeared towards theend of 1952 and deals with symmetry-groups, and two other volumes arebeing prepared. Vol. I11 of Bragg’s “ Crystalline State ” has appeared as“ The Determination of Crystal Structures,” and the authors give anadmirably clear and authoritative account of the subject up to the end of1952. was mentioned in Robertson’s “ Organic Crystals and Molecules ”1 H. Lipson, Nature, 1954, 174, 378.K. Lonsdale, ibid., 1963, 6, 874.5 Kynoch Press, Birmingham.7 J.M. Robertson, Cornell Univ. Press, 1953.R. Pepinsky, Acfn Cryst., 1964, 7, 620.Oosthoek’s Uitgevers, Utrecht.H. Lipson and W. Cochran, Bell, London, 1953SPEAKMAN. 373last year’s Reports. During 1953 was issued Vol. I11 of Wyckoff’s “ CrystalStructures,” covering organic compounds. ‘‘ Crystal Data ’’ is valuablebecause of its wide coverage; its intention is explained in the sub-title :“ Classification of Substances by Space-groups and their Identification fromCell Dimensions.” Vol. I11 of Partington’s “ Treatise on PhysicalChemistry ”-on “ The Properties of Solids ’’ l*-though its author is nota crystallographer, contains valuable information on many aspects of thesubject not accessible elsewhere and includes a wealth of references to theearlier literature.An English translation of “ Electron Diffraction ” hasbeen produced,ll summarising the important, and little known, Russianwork in this field. The Russian delegates to the International Congressdistributed copies of a volume l2 containing French translations of 19 im-portant papers on crystallographic subjects. There has also appeared areview in English l3 of recent Russian work in crystallography.Zeitschrift fiir Kristallographie suspended publication in 1945 after theappearance of Vol. 106, No. 1. Publication was resumed in October, 1954,with No. 2, under the joint editorship of an American, a Swiss, and twoGermans. Paul Niggli-a former editor of the Zeitschrift-died in January,1953.A general review of crystallographic work published in 1953 has beengiven.l4Dislocations and Crystal Growth.-The theory that crystals grow by useof screw-dislocations continues to receive support, and it can now be takenas generally accepted as a possible-though not necessarily the only-mechanism of growth. Meantime, interest in dislocations and their move-ments develops over a wider field ; l5 for they play a part in many importantmechanical properties of metals in particular. Mention should also be madeof three important books on this subject.16 Orientated crystalline over-growths (epitaxy) and related topics have been extensively reviewed byNeuhaus,17 over 200 references being appended.The central diffi-culty in structure analysis by diffraction methods is that of determining theexperimentally inaccessible phase constant associated with each observedreflexion.For centrosymmetric systems this reduces to the simpler, butstill formidable, task of attributing the correct signs to the observed structureamplitudes. Hitherto, the problem has almost always been solved by trial-and-error, by taking advantage of the presence of a heavy atom, or, morerecently, by study of the three-dimensional Patterson synthesis. All suchMethods of Structure Analysis.-The phase problem.* R. W. G. Wyckoff, Interscience Publishers, New York.J. D. H. Donnay, W. Nowacki, and G. Donnay, Geological Society of America,Memoir 60, 1954.l1 2 . G. Pinsker, transl. by J. A. Spink and E.Feigl, Butterworths Scientific Pub-lications, London, 1953.la hcad6mie des Sciences de l’U.R.S.S., Travaux de L’Institut de Cristallographie,Livraison 10, Communications au 111 Congrks International de Cristallographie, Moscou,1954.lo J. R. Partington, Longmans, London, 1952.l3 A. L. Mackay, Nuovo Cimento, 1953, 10 Suppl., 387.E. G. Cox, Ann. Rev. Phys. Chem., 1954, 5, 367.l5 A valuable review has been given by A. J. Forty, Adv. i.tz Plays., 1954, 3, 1.l 6 A. H. Cottrell, “ Dislocations and Plastic Flow in Crystals,” Oxford, 1953 ; W. T.A. 13. Verma,Crystal Growth and Dislocations,” Butterworths Scientific Publications, London,p d , “ Dislocations in Crystals,” McGraw-Hill, New York, 1953 ;1953. 17 A. Neuhaus, Fortschr. Min.. 1950-1951, 29-30, 13G-296374 CRYSTALI.OGRAFHY.methods become very difficult, and ultimately impracticable, as morecomplex substances come to be investigated.Given a reliable and generallyapplicable method of phase determination, the way would be open for analmost unlimited advance in structure analysis. Great importance thereforeattaches to the search for new “ direct ” methods, and indeed to the questionof whether a general method is possible. In a strictly mathematical senseno unique solution of the problem exists; but, since the electron-density ina crystal cannot be negative, and must be concentrated around discreteatoms arranged in a chemically acceptable way, a Physical solution is con-sidered to be attainable. This approach to the phase problem was coveredin some detail in the 1952 Report (pp.345-350).The principal subsequent development has been the appearance of aseries of papers l 8 and a monograph l9 in which the authors claim to haveestablished a general solution for any centrosymmetric crystal. They firstsuppose the atoms to be allowed to move at random over all positions in theunit cell. In this situation a given structure factor, F , might have anyvalue within recognised limits, and the probability of its having a particularvalue has a distribution which is symmetrical about zero, so that positiveand negative values are equally likely. However, as soon as the experimentalmagnitudes for a number of structure factors are known, a severe limitationis placed upon the possible positions of the atoms; and this affects theprobability distribution, rendering positive and negative values no longerequally likely.On this basis the authors derive a number of equationsgiving the probability that the sign of a given F is positive. These equationscan be divided into two groups : (a) those giving the probability in termsof the magnitudes only of certain other F’s, and (b) those giving it in termsof magnitudes and signs. Equations of group (a) only can be used initially;but, once some signs have been deduced, those of group (b) come into usealso.The mathematical treatment is difficult, though its validity does notseem to be in question. What is doubtful is whether the probabilities arehigh enough to be useful. Karle and Hauptman20 believe that they are,provided that enough observed F-terms are available.In evidence theyshow a successful estimation of some signs for the known structure ofnaphthalene, and-much more significantly-they cite the analysis of theunknown structure of coleinanite [CaB,0,(OH)3,H,0],21 for which over 2000observed values of F were known. The general validity of their claim hasbeen severely criticised,22 chiefly on the grounds that equations of group (a)are not powerful enough to yield reliable results in the early stages. (Whena sufficient number of signs has once been correctly decided, it is compara-tively simple to find others by well-recognised methods.) It has also beenargued that some of the equations may guide the analysis towards an in-correct structure; that, in any case, most of them are equivalent to-andno more powerful than-existing methods of sign-determination ; and,Is J.Karle and H. Hauptman, Acla Cvyst., 1952, 5, 48 : 1953, 6, 131, 136; 1954, 7, 369.l9 I d e m , American Crystallographic Association Monograph, No. 3, Wilmington,Delaware, Sept., 1953. 2o Idem, Acfa Cryst., 1954, 7, 452.21 C. L. Christ, J. R. Clark, and H. T. Evans, ibid., 1954, 7, 453.22 W. Cochran and M. M. Woolfson, ibid., p. 450; V. Vand and R. Pepinsky, ibid.,p. 45: ; R. K. Bullough and D. W. J. Cruickshank, ibid., p. 598; V. Vand and R. Pepin-sky, The Statistical Approach to X-Ray Analysis,” Pennsylvania State Univ., 1953SPEAKMAN. 375incidentally, that the structure of colmanite could have been solved by thesemethods.A structure product has been introduced,23Xn,K, defined as gB.$=. SH + K,where Sn is the unitary * structure factor for a triple of indices representedfor short by H. The maximum value of XH, g is +1, whilst its minimum isshown to be -& (somewhat higher minima obtain in special circumstances).It follows that, if the magnitude of XH, K is greater than Q, its sign must bepositive, so that Cochran's rule 24 (that the product of the signs of FH and Fg:equals the sign of F H + K) then holds. Except with very simple structures,the chance of finding an X-value exceeding 4 is very small ; but it is possibleto investigate the probability that X H , K has a positive sign, and along theselines a procedure for attacking the phase problem is developed.A general account of the " optical transform " method of studying crystalstructure has been given.25Meantime, the vast majority of structures continue to be solved bytraditional methods.Classification is not easy since two methods are oftenused in collaboration; but a rough survey of the analyses covered in thisreport suggests that about 30% were based on each of, the heavy-atommethod, some (other) version of the Patterson method, and the trial-and-errormethod. Only a small proportion of the remaining 10% depended on thesuccessful use of the newer direct methods.The 1952 Report mentioned the development oftechniques for studying crystal structures a t temperatures down to that ofliquid nitrogen. This is important not only because it enables simple sub-stances which are liquid or gaseous at room temperatures to /\/%\ be studied, but also because, as thermal motion is diminished,I I I the electron-density peak corresponding to an atom becomes "%"' much sharper.26 This effect is strikingly shown in Fig.1,which compares projections of the a-phenazine molecule (I) atroom temperature and a t 90" K.27 B. Post and I. Fankuchen are issuing fromBrooklyn Polytechnic Institute an informal bulletin listing substances that havebeen studied a t low temperatures or that are known to be under investigation.ReJinement and Signi$cance of Parameters.-There is a valuable surveyof modern trends in crystal structure analysis by the X-ray method.28Although observed structure factors are always liable to considerable errors,their number nearly always greatly exceeds the number of co-ordinates tobe determined.In the past crystallographers have not generally taken fulladvantage of this situation. Therefore the survey pays special attentionto the refinement of atomic co-ordinates and to the statistical methods forassessing the accuracy of, and the significance to be attached to, the finalresults. What can be accomplished by these methods, when applied togood experimental data, is well illustrated by a recalculation z9 of the mole-Low-temperature work.(I)2s A. I. Kitaigorodski, ref. 12, p. 42.2 5 A. W. Hanson, H. Lipson, and C . A. Taylor. Proc. Roy. Soc., 1953, A , 218, 371.28 R. D. Burbank, Acta Cryst., 1953, 6.55.2 7 F. H. Herbstein and G. R I . J. Schmidt, n'alure, 1952, 169, 323 ; F. L. Hirshfeld and(In a personal communication the authors24 w. Cochran, Acta Cryst., 1952, 5, 66.G. M. J. Schmidt, Acta Cryst., 1954, 7, 129.state that there is an error in the contour-line scale in the second paper.)28 G. A. Jeffrey and D. W. J. Cruickshank, Quavt. Rev., 1953, 7, 335.m F. R. Ahmed and D. W. J. Cruickshank, Acta Cryst., 1953, 6, 385. * I.e., so scaled that the maximum value is always unity376 CRYSTALLOGRAPHY.cular parameters of oxalic acid dihydrate from the early measurements oftwo groups of authors.30In this Report use will be made of the convenient abbreviation of allow-ing r(X-Y)[or r(X - * - Y)] to stand for the distance between the bonded [ordr;:not directly bonded] atoms X and Y.Limits of error (-&I) following adiffraction result imply the estimated standard deviation based on thestatistical considerations mentioned above.The Location of Hydrogen Atoms.-X-Rays are scattered by the electronsin a crystal, and, since the electron-density is mainly concentrated round30 J. 11. Robertson and I. Woodward, J., 1936, 1817; R. Brill, C. Hermann, andA. Peters, Ann. Physik, 1942, 42, 357SPEAKMAN. 377the heavier nuclei and is not much affected by the presence of protons, it hasbeen held as a general principle that hydrogen atoms cannot be located byX-ray analysis. This is not strictly true when the analysis is an accurateone. In a number of favourable cases the hydrogen atoms show themselvesas minor peaks or as buttresses to the major peaks representing heavieratoms,31 and especially at low temperatures, as is well seen in Fig.l ( b ) . Theybecome more evident when the electron-density due to the heavier atomshas been s ~ b t r a c t e d . ~ ~ For locating hydrogen atoms there are some othermethods-usually best applied after the rest of the structure has been deter-mined by a conventional X-ray analysis-and the subject was dealt with ina special symposium at the Paris Congress.33Although electron diffraction has long provided astandard method for the study of molecular structure in the gaseous state,it has only recently, and notably in the U.S.S.R., been applied to the studyof the (bulk) structures of crystalline solids.Electrons are scattered by theelectrostatic potential field in the crystal lattice, and the scattering power ofan atom depends on (2 -fx), where 2 is the atomic number and jx thescattering factor for X-rays. Sincefx falls further below 2 for lighter atomsthan for heavier, it follows that lighter atoms are relatively better scatterersof electrons than of X-rays. The scattering power of the hydrogen atom,compared with those of carbon or oxygen, is relatively larger for electrons bya factor of about 3. On the other hand, the necessity for using very smallcrystals (thickness -500 A), and for exposing them in a high vacuum, leadsto experimental difficulties. Powders are simplest to use, but, to take fulladvantage oi the diffraction method, single crystals are needed, or, a t least,a preparation of minute crystals all with one axis parallel.Short exposuretimes suffice, and, provided adequate intensity data can be obtained, theFourier method can then be used to yield a map showing, not the electron-density, but the distribution of potential in the unit cell. The first suchsynthesis seems to have been carried out in and Cowley 35 has alsoCH, developed a technique for producing such projections. The/\NH possibilities of electron diffraction are impressively shown in '7 1 Fig. 2, which represents the structure of diketopiperazine (11),1<NvCO which had been previously studied by X-rays in 1939.36 FewCH, details of the Russian work are yet available but it is stated 37that 250 reflexions were recorded, and that these were usedto compute a three-dimensional synthesis, sections of which, runningthrough each atom, have been combined in the figure.Brief reports havealso been given of the location of hydrogen in a straight-chain hydrocarbon 38and in he~amethylenetetramine.~~This was dealt with in an earlier Report.40 As thesevere experimental difficulties are overcome, and as suitably powerfulsources of thermal neutrons become available, this method will be widely31 E.g., J. D. Morrison and J. M. Robertson, J . , 1949, 981 : see also Robertson, ActaCryst., 1964, 7, 689.32 W. Cocliran and B. R. Penfold, ibid., 1952, 5, 649.34 R. I<. Vainshtein (Weinstein ; Vajngtejn) and 2. G. Pinsker, DokEady Akad. Nauk,S.S.S.K., 1949, 84, 49.35 J. M. Cowley, Acta Cryst., 1953, 6, 516, 846.30 R. B. Corey, J . Amer. Chem. Soc., 1938, 60, 1598.37 Ref. 12, p. 135. 38 Ref. 12, p. 154.4 O J. Thewlis, Ann. Reports, 1950, 47, 420; see also G. E. Bacon. Research, 1954, 7,Electron difraction.(11)Neutron difraction.33 Ibid., 1954, 7, 6S9.39 Ref. 12, p. 172.257, 312378 CRI'STAL1,OGRAPIIY.used. For the present purpose it has the great advantage that the scatteringpower of hydrogen is not generally inferior to those of other atoms. Thescattering factor is a property of the nucleus, and for hydrogen it has aboutthe same magnitude as those for carbon and oxygen but an opposite sign(i.e., there is a different change-of-phase on scattering). By contrast,deuterium scatters with a positive sign.As has been pointed thisFIG. 2. Electrostatic-potential map of the di-ket@iperarine molecule, obtained by a tizree-dimensional synthesis based on electron-diflraction data. (Sections through theatoms are shown.)Isuggests a novel way of solving the phase problem; crystals of a hydrogencompound and of its deuterium analogue differ only in that certain positionsare occupied by atoms whose neutron-scattering powers differ, not only inmagnitude, but in sign; if these positions can be found, a form of the iso-morphous replacement method becomes possible, with a wide range ofpotential applicability.Potassium dihydrogen phosphate has been studied by neutrondiffra~tion.~~ The Fourier projection shows the hydrogen atoms as (negative)peaks elongated in the directions of the hydrogen bonds (Fig.3n) at roomtemperature : at -196", where the crystals have changed to a ferro-electricform of lower symmetry, and with the crystal constrained to act as a singledomain by application of an electrostatic field, the protons appear in un-symmetrical positions, 0-21 fi from the centre of each bond (Fig. 3b).43 Anumber of exact analyses by neutron diffraction have been briefly reported.44Nuclear magnetic resonance. This subject has been reviewed.45 Themethod for locating the proton (and certain other nuclei, notably that offluorine) depends upon the particle's possessing a magnetic moment, or spin.Very small in magnitude and heavily shielded by the surrounding electron-4 1 R.Pepinsky, Acta Cryst., 1954, 7, 690.42 G. E. Bacon and R. S . Pease, Proc. Roy. Soc., 1953, A , 220, 397; see also B. C.43 R. S. Pease and G. E. Bacon, Nature, 1954, 173, 443; Proc. Roy Soc. (in the press).4 4 H. A. Levy, Acta Cryst., 1964, 7, 690.45 J . A. S. Smith, Quart. Rev., 1953, 7, 279; see also H. S. Gutowsky, Ann. Rev.Frazer and R. Pepinsky, Acta Cryst., 1953, 6, 273.Phys. Chem., 1954, 5, 333FIG. 3. Projections of the neutron-scattering powev i n the crystal of KH,temperature, and (b) at - 196' with an applied electrostatic field.lines (bvoken lines) coyyespoiid to hydrogen nuclei.The P and K atomsi n this projection.aReprinted, by permission, from ( a ) G. E. Bacon and R. S. Pease, Proc.A , 220, 397; ( b ) G. E. Bacon, personal communication380 CRYSTALLOGRAPHY.different energy levels, transitions between which can be detected, for in-stance, as a magnetic resonance when the substance is exposed to mutuallyperpendicular static and alternating (radio-frequency) fields, of suitablyadjusted strength and frequency, respectively.The proximity of othernuclear spins will cause a perturbation of the effective (static) field at thefirst nucleus. This effect cancels out in the liquid or gaseous state becausethe times of relaxation for molecular movements are usually low comparedwith the period of the alternating field. The resonance absorption line is thenextremely sharp. In the solid state, on the other hand, relative orientationsof neighbouring molecules are more rigidly fixed, so that perturbation doesoccur and the line may be greatly broadened.Detailed consideration ofline-broadening shows the effect to be complex, but in suitable cases thepattern and degree of broadening can be quantitatively related to the sum ofall internuclear distances involving spins. The broadening depends on ahigh inverse power of the distances, with the important consequences thatonly near neighbours make appreciable contributions and that accurate estim-ates of distance can be derived from less accurate measurements of line-width.However, it is the inter-protonic vector that is obtained, not the position ofeither proton directly; and, when a number of hydrogen atoms are involved,every pair contributes to the broadening, which may be difficult to dis-entangle.Materials have generally been examined in powder form, and thenthe observed effect is one averaged over all possible orientations of thecrystal. When a single crystal can be examined, the dependence of line-width on crystal setting yields fuller information (cf. the section on MolecularSpectra and Molecular Structure).A comparison of the methods for locating hydrogen atoms has beenmade with special reference to the degrees of accuracy attainable.46 WithX-ray diffraction it should be possible to place the atom to within 0.1 ora little better; as the experimental difficulties are overcome, electron diffrac-tion should be rather more accurate; neutron diffraction could be muchmore accurate, but perhaps h0.03 A might be a reasonable estimate atpresent ; nuclear magnetic resonance is probably the most accurate method,giving relative positions within &O-Ol A in favourable cases.Whilst theresults given by the last three methods agree satisfactorily, slight differencesoften appear in those given by the first. In individual cases the differencehardly exceeds the standard deviation; but, considering the results as awhole, there can be no doubt that C-H or O-H is found to be about 0.1 Ashorter by X-rays. The obvious explanation-though not necessarily thecorrect one-is that the electron-density peak for a bonded hydrogen atomdoes not coincide with the proton, but is somewhat displaced towards thenucleus of the heavier atom.Hydrogen Bonds.-The rBle of hydrogen atoms in crystals , with specialemphasis on the hydrogen bond, was discussed in lectures delivered to theParis Congress.47~48 Levy4* considered the relationship between the distancesO-H and O - .. O in a bond O-H.--O. In a very weak bond, withr ( 0 - . .O) near to 3.0 A, 0-H will not differ appreciably from its unperturbedvalue of about 0.95 A ; in a strong and symmetrical bond, expected 49 to haver ( 0 - - 0) = 2.30 A, r ( 0 - H ) would be 1-15 A. The experimental data46 M7. Cochran, Acfa Cryst., 1954, 7, 689.48 M. Magat, ibid., p. 689.*' J. D. Bernal, ibid., p. 689.40 J. Donohue, J . Phys. Chew., 1052, 56, 502SPEAKMAN. 381assembled by Levy suggest the tentative conclusion that, as 0 - - - 0increases, the bond at first remains symmetrical until r(O-H) reaches about1.22 A, after which O-H diminishes and the bond becomes unsymmetrical.A nuclear resonance study of potassium hydrogen difluoride 50 supportsthe conclusion 5l that the proton is centrally placed in HF,-.In solidhydrogen fluoride, which has been studied at -l25",52 r(F - - - F) is 2-49 &0.01, A, and the proton is almost certainly not centrally situated. Thecrystal consists of infinite planar, zig-zag chains of fluorine atoms, with theangle 120" at each fluorine. This angle-and the rather larger one foundby a less exact electron-diffraction study of the vapour 53-suggests thatsomething more than the simplest form of electrostatic mechanism is neededto account for the bonding. The infrared evidence makes it appear possiblethat the intramolecular hydrogen bond in the hydrogen maleate ion may bethough the detailed structure is not yet known.In the remainder of this report the results of some structure determin-ations are presented; they are roughly classified as inorganic and organic,with subdivisions in each class.The short section on proteins is unavoidablyheld over until next year.Inorganic Structures.-Elements and simple compounds. With a suitablycrystalline substance, determinations of the bulk density and of the unit cellvolume furnish a very accurate value for the formula weight. This '' pykno-X-ray method " can therefore be used for determining atomic weights; andresults obtained in this way have been reviewed.56 A hypothesis has beenadvanced to account for the different types of diamond.56 Though thevarious experimental criteria do not always lead to a consistent classification,those based on infrared and ultraviolet spectra usually agree.Type I1diamonds, thus diagnosed, are taken to be more normal in texture; andtype I to contain varying concentrations of " anomalies," which may beeither foreign atoms at certain lattice sites, or carbon atoms in a different(e.g., graphitic) state, or both. The structural parameters of orthorhombicsulphur have been redetermined with high pre~ision.~' In the puckered%membered ring, r(S-S) = 2-037 & 0.005 A, which is shorter than would beexpected for a pure single bond. The possibility of a slight " aromatic "resonance in the ring is tentatively considered.The " open-ring " structureproposed 58 for the Se, molecule in p-selenium has been proved incorrect bya recalculation 59 which is remarkable in that some of the data used werederived from an X-ray photograph reproduced in the original paper. A fulleraccount 6o of the X-ray study of nitric oxide at -175" confirms the impres-sion that the NO molecules are loosely dimerised in the solid; the precisestructure of the dimer remains uncertain, since there is disorder, with nitrogenand oxygen atoms occurring randomly, so that it is impossible to distinguish50 J. S. Waugh, F. B. Humphrey, and D. M. Yost, J. Phys. Chew., 1953, 57, 486.51 E. I;. Westrum and I<. S. Pitzer, J . Amer. Chew. SOC., 1949, 71, 1940.52 M. Atoji and W.N. Lipscomb, Acta Cvyst., 1954, 7, 173.53 S. H. Bauer, J. Ti. Beach, and J. H. Simons, J . Amer. Chew. Soc., 1939, 61, 19.54 H. M. E. Cardwell, J. D. Dunitz, and L. E. Orgel, J., 1953, 3740.5 5 T. Batuecas, Nature, 1954, 173, 345.G 7 S. C. Abrahams, M.I.T. Technical Report No. 83, 1954.59 K. E. Marsh, L. Pauling, and J. D. McCullough, ibid., 1953, 6, 71.6o W. J. Dulmage, E. A. Meyers, and W. N. Lipscomb, ibid., p. 760.G. B. B. M. Sutherland, D. E. Blaclcwell, and m7. G. Simeral, ibid., 1954, 174, 901.(To be published inActn Cryst.) 58 R. D. Burbank, Acia Cvyst., 1952, 5, 236382 CRYSTALLOGKAPH I’.between alternative structures. The infrared spectrum 6 l of dinitrogenpentoxide supports the earlier X-ray finding that the crystal is composedof NO,’ and NO,- ions.The ammonium halides show a number of phasetransitions which have been explained as due to the onset-in varyingdegrees with rising temperature-either of rotation of the NH,+ ion 62 or ofits orientational di~ordering.~~ A neutron-diffraction study of ND,Br inits four successive solid phases has been described.64 Models are proposedfor the phases; and a discussion of the data for these and the other ammon-ium halides leads to the conclusion that disorder is more important thanrotation in causing polymorphism because of the potentially strong attractionbetween a halide ion and the hydrogen (or deuterium) atom. I t is estimatedthat r(N-H) or r(N-D) = 1.03 & 0.02 A. This value accords well withthose found in several proton magnetic-resonance studies-in particularwith the 1.035 It 0.01 A found in ammonium chl0ride.6~Hydrates, oxides, and oxy-acids.A symposium on the r81e of water incrystals has been reported,66 the introductory paper by Bernal including ageneral survey of the types of crystalline hydrates. The structures of salthydrates have been reviewed.67 Ammonium oxide 68 has been studied withX-rays at -95°.69 It would be more correctly called ammonia hemi-hydrate, in accordance with its formula, BNH,,H,O, for it consists of analternation of H,O and NH, molecules, linked by rather weak hydrogenbonds into an array not unlike that in ice; an additional NH, is then ap-pended to each H20 molecule, which thus becomes 5-co-ordinated. Thereseems to be no randomness in the ordering of the two species of molecules.Unlike the other ammonium halides, limited proportions of NH,F can formsolid solutions with ice; 70 no doubt the fact that NH,+ and F- are iso-electronic with H,O is significant.Sodium superoxide, NaO,, crystallises in the cubic system, with Na+ and0,- centred on positions corresponding to those of the ions in rock-salt.The orientation of the anion is disordered at room temperature (I, or p-form),to give effectively spherical symmetry according to one in~estigation,~~ butaccording to another 72 to give a disordered pyrites structure.At lowertemperatures other phases of lower symmetry become stable. a-Potassiumsuperoxide is free from disorder, and a careful X-ray analysis 73 showsr(0-0) to be 1.28 It 0.02 A.This value for 0,- falls into a satisfactorysequence with those in molecular oxygen, 0, (1.207, & 0*0001 A 74), and inthe peroxide ion, 02- (1.49 It 0.04 A 75). The structure of Sr(OH),,8H20 7661 R. Teranishi and J . C. Decius, J . Chem. Phys., 1954, 22, 896.62 L. Pauling, Phys. Rev., 1930, 36, 480.63 J . Frenkcl, Acta Physicochem. U.S.S.R., 1935, 3, 23.84 H. A. Levy and S. W. Peterson, J . Amer. Chena. SOC., 1953, 75, 1536.6 5 H. S. Gutowsky, G. E. Pake, and R. Bersohn, J . Chem. Phys., 1954, 22, 643.6 6 J . D. Bernal, J . China. fihys., 1953, 50, cl.6 7 A. F. Wells, Quart. Rev., 1964, 8, 380; see also Acta Cryst., 1954, 7, 545, 842.6 8 Atzit. Reports, 1953, 50, 105.69 W. J. Siemons and D. H. Templeton, Acta Cryst., 1954, 7, 194.70 R.Brill and S. Zaromb, ibid., p. 677.71 G. S. Zhdanov and 2. V. Zvonkova, Doklady Akad. Nauk S.S.S.R., 1952, 82, 743.72 G. F. Carter and D. 33. Templeton, J . Amer. Chem. Soc., 1953, 75, 5247.73 S. C. Abrahams and J. Kalnajs, M.I.T. Technical Report, No. 84, 1954. (To be74 G. Herzberg, (Value for equili-7 6 H. G. Smith, ibid., 19353, 6, 604.published in Acta C;Tst.)brium position.)Molecular Spectra,” Vol. I (New York, 1950).S. C. Abrahams and J. Kalnajs, Actu Cryst., 1954, 7, 838SPEAKMAN. 383is of interest because alternative sets of positions are possible for Sr2+ andcannot be distinguished by X-rays-a Patterson ambiguity.Boric oxide has a curiously complicated structure 77 consisting of twokinds of irregular BO, tetrahedra sharing corners.Cowley has studiedsingle crystals of orthoboric acid by electron diffraction 78 and has deriveda map showing the distribution of potential in the layers of which the struc-ture consists. In addition to the larger peaks clearly representing boron andoxygen atoms, there are smaller ones supposed to represent hydrogen atoms.These lie well off the direct lines between pairs of oxygen atoms expected tobe hydrogen-bonded. He therefore suggests that diagonal bonding (ie., fourcanonical forms typified by IV) is involved as well as direct bonding ( i e . ,four forms typified by 111), and that a similar “ resonance ” might occurbetween linked carboxyl groups. Cowley’s final map was obtained after an(111) (IV)elaborate process of correction, needed because of random stacking of successivelayers in the very small crystals used, and is therefore open to question so faras the hydrogen peaks are concerned.Moreover, Zachariasen 79 has done acareful repetition of his X-ray analysis of 1934, and finds the hydrogen atomsto be in the positions expected (111). To observe these atoms, the electrondensity due to boron and oxygen was first subtracted, and then one of thetwo layers of atoms superposed in the unit cell was eliminated by an in-genious use of the generalised projection : r ( 0 - - * 0) = 2.72 and r ( 0 - H ) =0.88 A. The latter value may well be low in accordance with the effectmentioned earlier.The “ asbestos-like,” @-form of sulphur trioxide consists of SO, tetrahedrasharing two corners so as to give infinite helical chains : -O-SO2-0-SO2-.81A careful X-ray analysis 82 of nitric acid trihydrate shows the hydrogenatoms to be located in accordance with the formulation, (H30) +NO3-,2H,O.Somewhat earlier work on the monohydrate 83 was not refined to the pointwhere the hydrogen positions could be firmly established; but protonmagnetic-resonance measurements indicate the structure (H,O) +NO,-,with corresponding structures for the monohydrate of perchloric acid, andthe dihydrates of sulphuric and chloroplatinic acids.A brief survey of N-0distances in nitrate units 82 shows them to be more nearly equal when theNO3- ion is involved, as in these oxonium salts, than in anhydrous nitricacid-a situation paralleling that in the carboxyl group and ion.Mostother acid hydrates are probably not oxonium salts (see p. 389). Only thevery strongest acids are able to transfer their proton to a water molecule in7 i S. V-. Rerger, Actu Chem. Scand., 1953, 7, 611.7 8 J. M. Cowley, Actu Cryst., 1953, 6, 522.7s W. H. Zachariasen, ibid., 1954, 7, 305.6o W. Cochran, ibid., 1952, 5, 634.61 R. Westrik and C. H. MacGillavry, ibid., 1954, 7, 764.82 V. Luzzati, ibid., 1953, 6, 152, 157.O3 Idem, ibid., 1962, 5, 802.84 R. E. Richards and J . A. S. Smith, Trans. Faraduy SOC., 1951, 47, 1261384 CRYSTALLOGRAPHY.the solid state-in understandable contrast to what happens in aqueoussolution. 84a That the hydrated compounds of boron trifluoride probably 85have structures such as (H,O) + (BF,*OH)- illustrates a similar phenomenonoccurring with a very strong " Lewis acid "; and a similar interpretationcan be placed on the facts that the substance of composition HN03,2S0,proves, on X-ray analysis,s6 to be (N0,)+(HS207)-, and N205,3SO3 to be2(NOz)+(S,010)2-.87 A preliminary report 88 of work on anhydrous sulphuricacid at 0" c shows it to consist of SO, tetrahedra linked into infinite chainsby pairs of hydrogen bonds-a contrast to selenic acid.89 Sodium phosphor-amidate has the '' zwitter-anion " of structure (O&NH,)-.A seriousdiscrepancy between two careful analyses of sodium nitrite has now beenresolved in a paper 91 which gives r(N-0) = 1.247 & 0.035 A and the angleO-N-0 = 114" &- 4", and which incidentally deals with the tactical problemsinvolved in refining a non-centric structure.Polyszdphides and related compounds.X-Ray studies have been made ofa number of compounds-mainly inorganic, but some organic-whosemolecules contain chains of sulphur atoms, one or more of which has in somecases been replaced by selenium or tellurium. Such compounds are Cs2S6,g2BaS4,H20,93 BaS,06,2H,0,94 BaS506,2H20,g5 Ba[Se(S*S0,),],2H20,96Se(SCN)2,97 Se( SeCN)2,g8 Se( S0,Ph)2,99 Te( S*S02CH3)2,100 and[Te(S*S03),]2-2(NH,)t.fOl In allcases the chains are unbranched, non-linear, and, if comprising more thanthree atoms, non-planar ; the bond-angles (S-S-S, etc.) differ little from 106"(range 100-109") ; and the dihedral angles made between next-but-onebonds, with respect to rotation about the intervening bond, are usually nearto go", as predicted,lo2 though they show a tendency to be less *--not more-than go", which is perhaps contrary to priwza facie expectation.In many ofthese compounds there is an alternation of S--S lengths along the chain ( e g . ,in S62-, 1.99/Z.10/2-03/2-12/2-03 _t 0.03 A). When the chain comprises anodd number of atoms and has symmetry about the centre one, an alternation,as distinct from a variation, of lengths is of course no longer possible (e.g.,in S50G2-, which is bisected by a plane of symmetry, r(S-S) ==2.14/2.04/2.04/2-14 A). When a significant alternation of this kind can beestablished, it can hardly be closely related to that which has been supposed84a For a discussion of the influence of acidic and basic strengths on the formation ofhydrogen bonds in crystals see A.R. Ubbelohde and I<. J. Gallagher, Acta Cryst., 1055,8, 71.86 J. W. M. Steeman and C. H. MacGillavry, Acta Cryst., 1954, 7, 402.87 K. Eriks and C. H. MacGillavry, ibid., p. 430.8 8 R. Pascard, ibid., p. 638.90 E. Hobbs, D. E. C. Corbridge, and B. Raistrick, Acta Cvyst., 1853, 6, 621.91 M. R. Truter, ibid., 1954, 7, 73.9 2 S. C. Abrahams and E. Grison, ibid., 1953, 6, 200.93 S. C. Abrahams, ibid., 1954, 7, 423.9 4 0. Foss, S. Furberg, and H. Zachariasen, Acta Chon. Scald., 1864, 8, 450.9 5 0. Foss and H. Zachariasen, ibid., p. 473.g6 0. Foss and 0. Tjomsland, ibid., p. 1701.97 S. M. Ohlberg and P. V. Vaughan, J . Amer. Chenz.SOC., 1954, 76, 2619.9 8 0. Aksnes and 0. Foss, Acta Chenz. Scand.. 1954, 8, 702.99 S. Furberg and P. Oyum, ibid., p. 42.loo 0. Foss and E. H. Vihovde, zbid., p. 1032.101 0. Foss and P. A. Larssen, zbid., p. 1042.102 L. Pauling, Proc. Nut. Acad. Sci., 1949, 35, 495.- +(S, could also be added to this series.57)85 N. N. Greenwood and R. L. Martin, Quart. Rev., 1954, 8, 9.M. Bailey and A. F. Wells, J., 1951, 968.* See footnote on p. 423 of Ref. 93SPEAKMAN, 385to occur in certain polymethylene chains (see p. 388), conditions in the twokinds of chains being so dissimilar. 0. Foss lo3 has discussed the stereo-chemistry of molecules containing polysulphidebond-order-bond-length curve for S-S 93 andS-C104 bonds have been considered.According to a preliminary report lo5 solidP,S,, has a tetrahedral cage-structure like thatof the P,Ol0 molecule in the gaseous and the(rhomboliedral) solid state, whilst P,S, probablyhas the new form of cage-structure shown at (V).The crystal structure of czesium tetraiodide lo6 accords betterwith the formula CS,I,.~ The anion is 2-shaped, and the bond lengths, shown(in A) at (VI), make it justifiable to regard the horizontal strokes as composedof I,- ions (possibly slightly bent), with the perturbed iodide ions at thecorners, weakly linked to an I, molecule lying along the diagonal stroke.There is an obvious relationship to the structure of the I,- ion.lo7 Themolecule of B,C1,108 has the boron atoms a t the corners of a tetrahedronwhich does not deviate appreciably from the regular figure with edge1.70 0.04 A; the order of the B-B bonds is thus less than unity. Thechlorine atoms are attached radially to the borons, so as to maintain tetra-licdral symmetry, with r(B-Cl) = 1-70 & 0.03 A.Yttrium trifluoride logand trichloride each have ionic structures, the latter like that of alu-minium chloride. The fluorides and chlorides of a number of rare-earthelements prove to be respectively isostructural with the correspondingyttrium halide. The simple structure of SiF, a t -145" lends itself toaccurate analysis,lll which indicates a tetrahedral molecule with r(Si-F) =1-56 & 0-01 A. Unlike solid phosphorus pentachloride, antimony penta-chloride is not ionic, but contains bipyramidal molecules similar to thosefound in the vapour.l12 The low-temperature form of chlorine trifluoridehas also been studied with X-rays a t -120°.11~ The molecule is strictlyplanar and roughly T-shaped. The F-Cl-F angles are, however, slightlyIess than right angles (87") ; along the top of the T, r(C1-F) = 1.72 & 0.004 A(at both sides), whilst in the downstroke, r(C1-F) = 1-62 $1 0.006 A.Theselengths differ very slightly from those derived from the microwave spectrumof the gas; 114 but the claim that the difference may be significant is difficultto accept, though given a statistical justification. Despite difficulties due tocomplex twinning, the crystal structure of iodine trichloride has beene1~cidated.l~~ There are present planar 12C16 molecules with the shapeindicated (VII) ; r(1-C1) = 2-38 and 2.39 k at the ends, and 2-68 and 2.72S chains.The possibilities of constructing a useful(IT)Halides.Io3 0. Foss, Acta Chew. Scand., 1954, 8, 469.P. J . Wheatley, Acta Cryst., 1953, 6, 369.A. Vos and E. H. Wiebenga, PYOC. k . ned. Akad. Wetensch., 1954, B, 57, 497.E. E. Havinga, I<. H. Boswijk, and E. H. Wiebenga, Acta Cryst., 1954, 7, 487.li. J. Hach and R. E. Rundle, J . Amer. Chem. Soc., 1951, 73, 4321.lo8 M. Atoji and W. N. Lipscomb, Acta Cryst., 1953, 6, 547.loa A. Zalkin and D. H. Templeton, J . Amer. Chem. SOL, 1953, 75, 2453.I 1 O D. H. Templeton and G. F. Carter, J . Phys. Chem., 1954, 58, 940.M. Atoji and W. N. Lipscomb, Acta Cryst., 1954, 7, 597.' I 2 S. Ohlberg, ibid., p.640.l i 3 R. D. Rurbank and F. N. Bensey, J . Chew. Phys., 1953, 21, 602.l i d D. F. Smith, ibid., p. 609.j 1 5 K. H. Boswijk and E. H. \%'iebenga, Acfa Cryst., 1954, 7, 417.REP.-VOL. LI 386 CRYSTALLOGRAPHY.in the middle.ance hybrid, VII representing one of the two canonical forms.This structure, which is %on-ionic, is interpreted as a reson-Cl\-/Ch,s+/C1 CH,\ ,XH,*-, /CH32.8yI'' I ::A13.42,,'1 Cl/ \CI,**''r\Cl CH3/A1::' CH,/ \CH3(VII) (VIII) ,' 0. I-+---I(VI, o! = 80")Hydrides and related compounds. The hydride of thorium, supposed tobe ThH,, has been examined by X-ray methods.l16 The hydrogen atomsdo not contribute appreciably to the scattering, but, on the reasonableassumption that the X-ray symmetry must apply to the whole structure aswell as to the heavy atoms, the compound is shown to have the compositionTh4Hl,, and the arrangement of the hydrogen atoms is determined.Thepeculiar resemblances between the structures of B,H, and BloH14 and thoseof other boron compounds were set out in the 1952 Report. X-Ray analyses(mostly at low temperatures) of B ~ H ~ o , ~ ~ ' E5H11,118 and B6H1, 119 show thatthese molecules also have similar structures. The structures of the boronhydrides have been surveyed,120 and the bonding has been discussed.121Anomalous bonding also occurs in trimethylaluminium dimer, whose moleculehas the form shown in (VIII) ; 122 r(A1-C) = 1-99 A to the terminal, and2-24 Al) = 2-24 A, corre-sponding to a fractional bond. This structure has obvious resemblances tothat of Be(CH,),,123 which, however, consists of infinite chains.Co-ordination Compounds.-An X-ray study of Zeise's salt,I<[PtCl3(C,H,)],H,O, supports the spectroscopic deductions as to the structureof the anion.lZ5 The chlorine atoms occupy three corners of a slightlyirregular square, at the centre of which lies the platinum atom; weakerelectron-density peaks occur at positions suggesting that the centre of theethylene molecule occupies the fourth corner, with C=C perpendicular to theplane of the square.A study of the double co-ordination compound[CU(~~),][H~(SCN)~] 126 shows it to have four amino-nitrogen atoms in squareco-ordination round the copper atom with two rather more distant thio-cyaiiate nitrogen atoms completing an irregular octahedron, and foursulphur atoms in tetrahedral co-ordination round the mercury atom.Anaccurate analysis of nickel dimethylglyoxime l 2 7 finds the molecule to beplanar, with a very short intramolecular hydrogen bond (2.44 & 0.02 A),which might possibly be symmetrical (see p. 381). This structure is also ofinterest because it involves a short Ni . * Ni (= 3.24 A) approach betweenparallel molecules; this is taken to imply weak bonding, and may be ofsignificance in relation to the absence of such an approach in the copperto the bridge, methyl groups, whilst r(A1.TV. H. Zachariasen, Actu Cryst., 1953, 6, 393.117 C. E. Nordman and W. N. Lipscomb, J . Chem. Phys., 1953, 21, 1856.118 L. R. Lavine and W. N. Lipscomb, ibid., 1954, 22, 614.110 K.Eriks, W. N. Lipscomb, and R. Schaeffer, ibid., p. 754.l 2 O W. N. Lipscomb, ibid., p. 985.121 W. H . Eberhardt, B. Crawford, jun., and W. N. Lipscomb, ibid., p. 989.lZ2 P. H. Lewis and R. E. Rundle, ibid., 1953, 21, 986.lZ3 A. I. Snow and R. E. Rundle, Actu Cryst., 1951, 4, 348.124 J. A. Wunderlich and D. P. Mellor, ibid., 1954, '9, 130.125 Ann. Refiorts, 1953, 50, 122.127 L. E. Godycki and R. E. Rundle,ibid., p. 487 ; see also J . Chem. Phys., 1952,20,1487.lZ6 H. Scouloudi, Acta Cryst., 1953, 6, 651SPEAKMAN. 387derivative and to the fact that the latter does not tend to be co-precipitatedwith the nickel compound. The absolute configuration of the ion [Co(en),13+in an enantiomorph of 2[Co(en),]C1,,NaC1,6H20 has been determined bya version of Bijvoet's method.129A.Magn6li has further discussed 130structures of the R0,-type with recurrent dislocations such that the com-position is of the form Rn03fL.-1. Mg,Mn08 is cubic with a new type ofstructure.131 Importance attaches to the first X-ray analysis of the salt ofa 9(or 18)-heteropolyacid : K,[P,W,,0,2],14H,0.132 The anion, of sym-metry 31992, consists of two PO, tetrahedra surrounded by two rings of six,and two of three, WO, octahedra, many oxygens being held in commonbetween different units. The anion in (NH4),[MnMo90,,],8H20 has lowersymmetry (32) and consists of nine MOO, octahedra clustered round anMn0,.133 The structure of the polyniobate, 7Na20,6Nb,0,,32H,0, has beenpartially solved; the anion, [Nb,0,,]8-, consists of six NbO, octahedra,themselves in an octahedral arrangement.Psilomelane, (Ba,H20),Mn,0,0,135contains ribbons of linked MnO, octahedra, interspersed with Ba2+ and H20,which cannot be distinguished from one another, indicating some random-ness of arrangement. Structural work has been done on a number of silicates :e. g . , epidot e, 136 nepheline,13 tilleyit e,13, and magnesium-vermiculit e. 139The data on A1-0 and Si-0 distances have been reviewed,140 with specialreference to intermediate structures where aluminium and silicon atomsoccupy sites randomly in known proportions ; a linear relationship obtainsbetween length and proportion of silicon, and its use is suggested in decidingthe (average) occupancy of a given site.Magnetic measurements,l4l neutrondiffraction,142 and even careful X-ray work 143 have enabled the distributionof different cations amongst the tetrahedral and octahedral sites in spinelsto be elucidated. Ferro-electric substances attract increasing attention, andwere discussed in several of the symposia a t the Paris Congress.lU Megaw 145has stressed the necessity of considering the whole structure, rather thanone species of atoms only, in studying the mechanism of a ferro-electrictransition.Organic Structures.-Parajin hydrocarbons and related substances. Apreliminary report of work on n-C2,H4, gives a precise value for r(C - - C)between alternate atoms of a planar zig-zag chain, viz., 2.549 & 0-004 A.The unit-cell dimensions in a series of even, straight-chain acids (in theirComplex oxides and their salts.12* Y .Saito, K. Nakatsu, M. Shiro, and H. Kuroya, Acta Cryst., 1954, 7, 636.Iz9 D. C . Hodgkin, Ann. Reports, 1951, 48, 361.I 3 O A. Magndli, Acda Cryst., 1953, 6, 495; see also Research, 1952, 5, 394.131 J. S. Kasper and J. S. Prener, Acta Cryst., 1954, 7, 246.132 B. Dawson, ibid., 1953, 6, 113.133 J. L. T. Waugh, D. P. Shoemaker, and L. Pauling, ibid., 1954, 7, 438.134 I . Lindqvist, Arkiv Kerni, 1953, 5, 247.I 3 j A. D. Wadsley, Acta Cryst., 1953, 6, 433.136 T. Ito, N. Morimoto, and R. Sadanaga, ibid., 1954, 7, 53.1 3 i M. J. Buerger and T. Hahn, ibid., p. 632; see also N. 'v. Rklov, ref. 12, p. 19.13* J. V. Smith, Acta Cryst., 1953, 6, 9.lZ9 A. McL. Mathieson and G.F. Walker, Amer. M i n . , 1954, 39, 231.J. V. Smith, Acta Cryst., 1954, 7, 479.G. E. Bacon and F. F. Roberts, Acta Cryst., 1953, 6, 57.1 4 1 E. W. Gorter, Nature, 1954, 173, 123.la3 G. E. Bacon and A. J. E. Welch, ibid., 1954, 7, 361.114 E.g., ibid., p. 689, 696; see also C. F. Oxbrow, Nature, 1954, 174, 1092.I4; H. D. MegaTT, Acta Cryst., 1952, 5, 739; 1954, 7, 157.l l 6 A . E. Smith, J . Chew. Phys., 1953, 21, 2229388 CRYSTALLOGRAPHY.C-forms) have been accurately measured, pure materials being used.147 Thec-axis, almost exactly along which lies extended the double molecule of theacid, increases linearly with the number of atoms in the chain, the incrementper atom being 2.538 rt 0-004 A. These two quantities should not neces-sarily be exactly equal, but the agreement is noteworthy. A striking differ-ence between a hydrocarbon chain and that in a fluorocarbon is revealed bya single-crystal study of perfluorocetane, n-C,,F,,, and by diffractionmeasurements on drawn fibres of poly(tetrafluoroethy1ene).14* The fluorin-ated chain is a twisted zig-zag, which turns through 180" after thirteen carbonatoms; and the twisting is well accounted for in terms of the steric effectsbetween the fluorine atoms of alternate CF,-groups.There continues to be a conflict of evidence 149 on the supposition thatthe C-C length may alternate along a polymethylene chain carrying polarsubstituents at one end, or at both. In no case has a significant alternationappeared in an exact three-dimensional analysis.When it has appeared,the analysis has been one based on two-dimensional projections. Theprojection of a planar zig-zag of atoms will in general show successive pairsof atoms more, than less, overlapping. When the electron-density concen-trations of two atoms overlap, the distance between the two maxima is lessthan the true projected internuclear distance; but it is shown how thiserror can be corrected.lM It seems unlikely that much of the presentevidence for alternation would survive this correction.One celebrated anomaly has now been eliminated : a recalculation 151of the structure of geranylamine hydrochloride (individual atomic temper-ature factors being used to take account of the fact that thermal vibrationbecomes more vigorous the further the atom is from the polar end of thechain) shows the central T(C-C) to be 1.537 &- 0-045 A, not 1.44 A as wasonce supposed.The neutral carboxyl group (IX)would be expected to have C(1)-O(1) shorter than C(1)-0(2), and the angleCarboxylic acids and related compounds.(IX) (X)C(2)-C( 1)-0(1) greater than C(Z)-C(l)-O(2).A consideration of the accuratemeasurements available 162 confirms these expectations, though in nocrystal has C(1)-O(2) been found with a length appropriate to a single bond(-1.44 A). In terms of valency-bond theory, this implies some resonancewith the form (X). In the carboxylate ion (e.g., in a zwitterion) these formsbecome equivalent, so that greatly enhanced resonance should occur, and theC-0 lengths should be equal.This expectation is also borne out, exceptperhaps when one of the oxygen atoms is more heavily involved than theother in the formation of strong hydrogen bonds.153 When C(2) forms part147 S. Abrahamsson and E. von Sydow, Acta Cryst., 1954, 7, 591.14* C. W. Bunn and E. R. Howells, Nature, 1954, 174, 549.E.g., A. McL. Mathieson, Acta Cryst., 1953, 6, 399; S. Hirokawa, T. Ohashi, andD. 3%. Burns and J. Iball, Proc. Roy. Soc., 1954-1955, A , 227, 200.I. Nitta, ibid., 1954, 7, 87.151 D. W. J. Cruickshanlc and G. A. Jeffrey, Acta Cryst., 1954, 7, 646.lS2 E. G. Cox, M. W. Dougill, and G. A. Jeffrey, J., 1952, 4854; see also ref. 29.lZ3 E.g., R. A. Pasternak, L. Katz, and R. B. Corey, Acta Cryst., 1954, 7, 225SPEAKMAN. 389of a conjugated system (e.g., a benzene ring) , some interaction with C( 1)=0(1)should take place, with shortening of C(2)-C(1). This effect is seen in sali-cylic It should be less marked in thecorresponding salts.156Oxalic acid, once thought to exemplify this conjugation, is now knownto be exceptional. A reconsideration29 of earlier X-ray data on the di-hydrate, and a careful redetermination of part of the data,157 show that thecentral C-C bond length does not deviate significantly from 1.54A. Thisconfirms the findings for the anhydrous a-form of the acid,ls2 and forammonium,l58 and dimethyl l6O oxalates. By this criterion thecentral bond has no double-bond character, and the planarity of the oxalateunit (except in the ammonium salt) must be explained in some otherway.The possibility that the dihydrate is really a hydroxonium salt,2(H,0)+(C,04)2-, is now excluded by an X-ray study which enabled thehydrogen atoms to be located,157 by neutron diffraction,161 by nuclearmagnetic-resonance measurements both on the powder &i and on a singlecrystal,162 and perhaps by spectroscopic observations. lG3 A precise analysisof oxamide 16* reveals planar molecules with C-C = 1-542 & 0.006 A,hydrogen bonded into infinite layers, which presumably explains the highmelting point, though the bonds do not seem particularly strong ones[r(N - - H-0) = 2-94 A]. A preliminary report on dithio-oxamide 165 alsoshows a planar molecule with a normal, single C-C bond.Cochran's work on salicylic acid was mentioned in the 1952 Report,which reproduced an important electron-density map (p.352). The fullaccount of this work has now been published,lM and it constitutes the mostthorough X-ray analysis yet achieved for a compound of this type. Mostof the intensities were measured by Geiger counter, and the enhanced accur-acy justified unusual refinements in the computational work. The " differ-ence map," referred to above, shows all the hydrogen atoms very clearly;moreover, the density peaks for the hydroxylic hydrogens are lower thanthose for atoms attached to carbon-as would be expected from consider-ations of electronegativity. Furthermore, when the effects of the non-hydroxylic hydrogens have also been subtracted, small, but apparentlysignificant, concentrations of electron-density are left a t the centres of thecovalent bonds.These may possibly betoken the bonding electrons, thoughnot certainly.A brief preliminary report has been made of a three-dimensional refine-ment of the structure of @-succinic acid.l66 An account has been published lG7lb4 W. Cochran, Acta Cvyst., 1953, 6, 360.155 G. A. Sim, J. M. Robertson, and T. 13. Goodwin, ibid., 1956, S, 157.lS6 ,411 effect of this kind, though of uncertain significance, has been found i nammonium hydrogen disalicylate hydrate (T. C. Downie and J. C. Spealtman, I . , 1954,787) and in the potassium salt of 2 : 6-dihydroxybenzoic acid (E. M. Cant, unpublishedwork). 15' G. E. Pringle, A c f a Cryst., 1954, 7, 716.and benzoic 155 acids for instance.15* G.A. Jeffrey and G. S. Parry, J . , 1962, 4864.lb9 Idem, J . Anzev. Chem. SOG., 1954, '76, 5283.16* M. W. Dougilland G. A. Jeffrey, Acta Cryst., 1953, 6, 831.161 IS. A. Levy, ibid., 1954, 7, 690.18* J . Itoh, R. Kusaka, Ii. Kiriyama, and S. Yabumoto, ,i. Chem. Phys., 1953, 21,16s A. Wed, Conapt. rend., 1954, 238, 576.164 E. M. Ayerst and J. R. C. Duke, Acta Cryst., 1954, '7, 688; see also C. Romers,165 B. Long, P. Markey, and P. J, Wheatley, ibid., 1954, '7, 140.lG6 J . M. Robertson, H. M. M. Shearer, and J. S. Broadley, ibid., 1954, 7, 645.167 T. H. Goodwin and C. M. Thomson, ibid., p. 166.1895.ibid., 1953, 6, 429390 CRYSTALLOGRAPHY.of the structure of furoic acid, the planar molecules of which are dimerisedby pairs of short (2.53 A) hydrogen bonds. This is the commonest form ofassociation of carboxylic acids ; exceptions to it are illustrated by nicotinicand formic acids.The former structure proves 168 to consist of chains ofmolecules linked by N * H-0 bonds (2.66 A) between the carboxyl groupof one molecule and the nitrogen atom of the next. The latter acid, studiedat -50°J169 also has a chain structure. The C-0 lengths are given as 1.23and 1.26 (each -&0.03) A. The estimated errors would allow a considerabledifference between these lengths, but not enough for r[C-O(2)] to come intoagreement with the values-1.36 and 1.34 (1.41) A-found by electrondiffraction l 7 O and spectroscopically 171 in the vapour. Possibly a correctionfor overlap of these atoms [C and 0(2)] would reduce the discrepancy.Formamide 172 consists of dimeric molecules, further linked to give layers.A note 173 on an X-ray study of Feist's acid confirms the suggestion 174 thatthe acid is trans-l-methylenecyclopropane-2 : 3-dicarboxylic acid, rather thanthe met hylcy clopropene compound.The previous Report mentioned the unusual situation in cupric acetatehydrate, where a pair of copper atoms only 2.64 k apart would seem to beunited by a (metallic?) bond.A fuller account of this structure has nowappeared 175 and also of that of hydrated chromous acetate, which has asimilar pe~u1iarity.l~~ Low-temperature magnetic measurements 1 7 7 oncupric laurate may hint a t a pairing of copper atoms here too. On the otherhand, no pairing occurs in cupric f ~ r r n a t e , l ~ ~ nickel a~etate,l'~ or zincacetate 180 (all hydrated).An analysis of potassium hydrogen dibenzoate 181shows it to be another example of the group of acid salts which possess ashort hydrogen bond lying across a crystallographic centre of symmetry.In contrast, potassium (and ammonium) hydrogen disalicylate hydrate 156has a different kind of structure without such bonds. Acareful study of dipotassium nitroacetate has been de-scribed.ls2 The anion has an interesting structure, shownin one possible form at (XI). The whole ion is planar,including the hydrogen atom; the C-N and C-C lengthsare sensibly equal (1.38, 1-39 A), as also are those of N-0(1.26, 1.28 A) ; for r(C-0), 1-33 and 1.26 A are found, butA study of p-nitropropionic acidA mino-acids and related compomds.-Two more precision analyses have1 6 8 W.B. Wright and G. S. D. King, Acta Cryst., 1953, 6, 305. (For the correspond-169 F. Holtzberg, B. Post, and I. Fankuchen, ibid., 1953, 6, 127.170 I. L. Karle and J. Karle, J . Chem. Phys., 1954, 22, 43.171 V. 2. Williams, ibid., 1947, 15, 232; see also R. Trambarulo and P. M. Moser,17a J. Ladell and B. Post, Acta Cryst., 1954, 7, 559.173 D. Lloyd, T. C. Downie, and J. C. Speakman, Chem. and I n d . , 1954, 222, 492.174 M. G. Ettlinger, J . Amer. Chem. Soc., 1952, 74, 5805.1 7 5 J. N. van Niekerk and F. R. L. Schoening, Acla Cryst., 1953, 6, 227.176 I d e m (with J. F. de Wet), ibid., p. 501.1 7 7 A. Gilmour and R. C. Pink, J ., 1953, 2198.1 7 8 R. Kiriyama, H. Ibamoto, and K. Matsuo, Acta Cvyst., 1954, 7, 482.179 J. N. van Niekerk and F. R. L. Schoening, ibid., 1953, 6, 609.1*0 J. 3. van Niekerk, F. R. L. Schoening, and J. H. Talbot, ibid., p. 720.1 8 1 T. M. Skinner, G. M. D. Stewart, and J. C. Speakman, J., 1954, 180.I R 2 D. J . Sutor, F. J. Llewellyn, and H. S . Maslen, Acta Cryst., 1954, 7, 145.1e3 D. J. Sutor, L. D. Calvert, and F. J. Llewellyn, ibid., p. 767.HC0--YH \C=o\'I - 01()(I)the difference is probably not significant.has been carried out in the same 1aborat0ry.l~~ing amide, see idem, ibid., 1954, 7, 283.)ibid., 1964, 22, 1622SPEAKMAN. 391been described : of DL-Serine and of glycyl-L-asparaghe; 153 and a fulleraccount of the work on NN'-diglycyl-L-cystine dihydrate has appeared.ls5Careful, though rather less exact, studies have been made of glycyl-L-tyrosine hydrochloride,ls6 of DL-glutamic acid hydr~chloride,~~~ and of DL-norleucine.188 Preliminary accounts have been given of work on glycyl-L-alanine hydrobromide 189 and on a new crystalline form of L-glutamicacid.lgO The results of these investigations are generally in line with thestructural principles established for other amino-acids and peptides.J.Trommel and J. M. Bijvoet l91 have studied D-(-)-isoleucine in the forms ofits hydrated hydrochloride and hydrobromide ; though very similar, thesecrystals are not isomorphous because of a difference in the orientations ofthe sec.-butyl chains. The absolute configuration of this amino-acid mole-cule was shown to be in accord with chemical convention by the methodoriginally applied to rubidium sodium tartrate 129 H2N\ H. Mendel and D.C. Hodgkin 192 have1 & 4 analysed the structure of creatine hydrate [(XII),(XI11 not creatinine]. The virtual equality of r(C-0)(1.25 A) and guanidyl (amidino-)r(N-C) (1-33 A) lengths shows the moleculet o be a zwitterion, and the positive charge to be shared between the threenitrogen atoms by resonance. It has been known for some time that theheavy atoms in the urea molecule are co-planar. It has now been shownby proton magnetic-resonance absorption 193 that the hydrogen atoms alsolie in the same plane. A neutron-diffraction analysis44 suggests that thetwo types of N-H bonds differ in length (0.98 and 1.04 A).Cruickshank and A.P. Robertson lg4 have appliedstatistical methods to the comparison of molecular parameters obtainedexperimentally with those derived from theory. In illustration of theirtreatment they consider the bond lengths in naphthalene and anthracene,which have been the subject of accurate X-ray studies lg5 and of elaboratemolecular-orbital treatment .lg6 The comparison shows significant discrepan-cies for naphthalene, though not for anthracene.The C-C distance in the benzene molecule is an important datum intheoretical chemistry. It has been taken as 1-39-1.40 A, and values withinthis range have been found in many benzene derivatives, and in particularfor the vapour of benzene itself by electron-diffraction lg7 and Ramanspectrum (1.397 A).198 For the solid a t -195" Andrew and Eades lg9have measured the line-broadening in the protonic magnetic-resonanceabsorption; and, by an ingenious comparison of measurements on C6H,,6, 241.c.N(cH,~cH,.&,,H,o in 1951.Aromatic systems.ls4 D.P. Shoemaker, R. E. Barieau, J. Donohue, and Chia-Si Lu, Acta Cryst., 1953,ls6 D. W. Smits and E. H. Wiebenga, ibid., 1953, 6, 531.lS7 B. Dawson, ibid., p. 81.lBR T. C. Tranter, Nature, 1954, 1'93, 221.loo T. H. Doyne, S. Hirokawa, and T, Watanabt5, Acta Cryst., 1954, 7, 652.lgl J. Trommel and J. M. Bijvoet, ibid., 1954, 7, 703.lg2 H. Mendel and D. C. Hodgkin, ibid., p. 443.lS3 E. R. Andrew and D. Hyndman, Proc. Phys. Soc., 1953, 66, A , 1187.lg4 D.W. J. Cruickshank and A. P. Robertson, Acta Cryst., 1953, 6, 698.lg5 F. R. Ahmed and D. W. J. Cruickshank, ibid., 1952, 5, 852.ly(i C . A. Coulson, R. Daudel, and J. M. Robertson, Proc. Roy. Soc., 1951, -4, 207, 306.lg7 0. Hassel and H. Viervoll, Acta Chem. Scand., 1947, 1, 149.198 B. P. Stoicheff, J . Chem. Phys., 1953, 21, 1410; see also Nature, 1955, 175, 79.Ig9 E. R. Andrew and R. G. Eades, Proc. Roy. Soc., 1953, A , 218, 537.lS5 H. L. Yakel, jun., and E. W. Hughes, ibid., 1954, 7, 291.la* A. McL. Matliieson, ibid., p. 399392 CRYSTALLOGRAPHY.C,H,D, and 1 : 3 : 5-C6H3D3, were able to eliminate the effects of inter-molecular proton-proton coupling, and to fix the distance between neigh-bouring hydrogens of the same molecule as 2.495 -& 0-018 A.Takingr(C-€3) to have the reasonable value of 1-085 A, they find r(C-C) = 1.41 &0.03 A. On the other hand, Cox and Smith have undertaken arepetition and refinement of the early X-ray work of the former on solidbenzene. About 300 structure factors have been measured at -5", and ina preliminary report 2oo r(C-C) was estimated to be 1.378 & 0.0033 A.(Though no details are yet available, it is understood that a similar resulthas been obtained at Brooklyn Polytechnic Institute.) At least a partialexplanation 201 of this discrepancy may be found in the circumstance thatthe benzene molecule undergoes considerable torsional oscillation about itssix-fold axis. The heat capacity curve shows no anomaly up to the meltingpoint, but Andrew and Eades estimate that the molecule can reorientateitself by surmounting an energy barrier of no more than 3.7 kcal.The effectof allowing for this peculiar type of anisotropic thermal motion is likely tobe a small increase in the X-ray value found for r(C-C).Hitherto there has been little or no reliable evidence that the ring ofcarbon atoms in any simple benzene derivative deviates significantly froma regular hexagon; but in salicylic acid 15* and in acetanilide-recently thesubject of a very accurate analysis 202-differences in r(C-C) up to about0.04 A can now be regarded as well established.A study of the structure of ovalene (XIII) has been described.2o3 Theunit cell has a short axis and the molecule proves to be planar, and thesecircumstances allowed accurate bond lengths to be derived from a projection.Individual Y(C-C) values differ by 0-08 A, and in a sense in good generalagreement with the predictions of wave-mechanical calculations.The outer(" exposed ") bonds are significantly shorter than the inner ones, whoseaverage length approaches the 1.42 A found in graphite. Perylene (XIV)/\/ \/AII ICH, (A /\//I / , A \ \ > p.i.,v.:l II ( I 1 ;a f)TT\,\ \pp i'\/\d \A/ (XV) (XVI)I II I \n./ CH,(XIII) W V )proved to be less suited for accurate analysis,2@3 but the C-C bonds betweenthe naphthalene residues are abnormally long (-1.50 A). Fluorene (XV)was a t one time thought to have a non-planar molecule, but two recentanalyses205 show it to be planar within close limits, According to theformer, and probably more exact, analysis, the formally single bonds bywhich the benzenoid rings are joined have lengths of 1.465 A (to CH,) and1.482 A.On the other hand, the homologous 9 : 10-dihydroanthracerieE. G. Cox and J. A. S. Smith, Nature, 1954, 173, 75.201 Personal communication from Prof. E. G. Cox.202 C . J. Brown and D. E. C. Corbridge, Acta Cryst., 1954, 7, 711.a03 D. M. Donaldson and J. M. Robertson, Proc. Roy. SOC., 1953, A , 220, 157.a04 D. M. Donaldson, J. M. Robertson, and J. G. White, ibid., p. 311.206 D. M. Burns and J. Iball, Nature, 1954, 173, 635 (fuller account now appe;trsin Proc. Roy. Soc., 1954-1955, A , 327, 220); G. M. Brown and M. H. Bortner, ActaCryst., 1954, 7, 139SPEAKMAN. 393(XVI) has a non-planar mo1ecule,206 the two halves of which lie in planesintersecting at an angle of 145" along the line of the methylene carbon atoms.The adjective " overcrowded " has been applied 207 to those aromaticcompounds whose molecules would, in first approximation, be expected tobe planar, but which are forced to become non-planar by steric interactions.The molecular distortion of 3 : 4-5 : 6-dibenzanthracene was mentioned inthe previous Report, and a fuller account of this structure has now beenpublished.208 Were it strictly planar, the octamethylnaphthalene moleculewould involve an approach to within about 2.4A between pairs of methylcarbons in the peri-positions.In fact,209 these methyl groups are forced outof the mean molecular plane by about 0-73 A, so that r(C - C) rises to nearly3.0 A.The p-methyl groups are also forced slightly out of the plane in theopposite directions, and a general slight distortion of the naphthalene nucleusis probable.The occurrence of overcrowding has been discussed,210 and illustrated byX-ray studies of a number of complex polycyclic systems.211 As a firstprinciple the authors suggest that distortion may be expected when the planarstructure would bring non-bonded carbon atoms within 3-0 A of one another,though they point out some exceptions. Thus the planarity of the hexa-methylbenzene molecule appears to be well established,212 though Y(C * C)between adjacent methyl groups is only 2-9 A, and although the repulsionbetween corresponding pairs of groups in durene (XVII) causes the anglebetween the C-CH, directions to exceed 120".It is possible that crystalforces may tend to maintain a planar molecule in the solid state when thesteric repulsions are just sufficient to cause distortion in the vapour, or insolution. Thus the X-ray measurements show perylene to be planar,whilst dipole-moment and spectroscopic evidence suggests non-planarity.204A more definite apparent discrepancy is shown by hexachlorobenzene ;I<. Lonsdale's classical study z13 seems to preclude the degree of distortionof the C-C1 bonds, in the solid, indicated by a careful electron-diffractionstudy of the v a p ~ u r . ~ ~ ~ It is suggested 210 that part of this discrepancy maybe due to an out-of-phase bending of the C-C1 bonds.The second principlesuggested by Schmidt et al. is that, when distortion is imposed by over-crowding, it tends to be shared by all the benzenoid rings concerned. Thisis illustrated in 3 : 4-benzophenanthrene (XVIII), the simplest of the over-crowded compounds examined by this group of workers. The distortion,which enables the neighbouring non-bonded carbon atoms to elude oneanother by 3.0 A, has the effect of forcing some of the other carbon atoms toadopt an almost tetrahedral arrangement of valencies-with pronouncedeffect on physical and chemical properties.The molecule of 1 : 3 : 5-triphenylbenzene was shown to be non-planarby magnetic measurements.215 The structure has now been examined by?06 \V. G. Ferrier and J. Iball, Chem.and Ind., 1954, 1296.207 I;. Bell and D. H. Waring, J . , 1949, 2689.208 A. 0. McIntosh, J. M. Robertson, and V. Vand, J., 1954, 1661.2oe D. M. Donaldson and J. M. Robertson, J., 1953, 17.210 E. Harnik, F. H. Herbstein, G. M. J. Schmidt, and F. L. Hirshfeld, J . , 1954, 3288.211 Idem., ibid., pp. 3295, 3302, 3314.212 L. 0. Brockway and J. M. Robertson, J., 1039, 1324.214 0. Bastiansen and 0. Hassel, Acta Chew. Scand., 1947, 1, 489.215 E.g., K. Lonsdale, 2. Krist., 1937, 97, 91.K. Lonsdale, Proc. Roy. SOC., 1931, A , 133, 536394 CRYSTALLOGRAPHY.X-ray diffraction; 216 the twisting of the phenyl groups (also found byelectron-diffraction in the vapour 217) is confirmed, though the twisting is notall in the same direction; i.e., the molecule does not have the shape of a" three-bladed propeller." Overcrowding may also be involved in causingthe free radical, di-j5-anisyl-nitric oxide, (CH,*OmC6H,),N0, to be non-planar; the angle C-N-C is about 124", and the planes of the benzenoidrings are twisted through -33" about the directions of the N-C bonds.21s(XVIII) H2C- CH,(XIX)Much more extreme steric repulsions occur in two remarkable substances,9- and m-xylylenes (XIX and XX).219 In neither case was the structuralformula known until it was revealed by the X-ray analysis. Both structureswere refined by three-dimensional methods and are determined with con-siderable accuracy.The molecule of (XIX) has three mutually perpendicularplanes of symmetry (nzmm) ; the benzene rings face each other, 3.1 A apartso far as eight of their carbon atoms are concerned; the p-carbons are, how-ever, pulled to within 2.8 A of one another, so that the rings become distortedinto " boat " shapes.The molecule of (XX) has only a centre of symmetry :the benzene rings are parallel to each other but laterally displaced so as tobring their meta-carbon atoms nearly opposite one another; each ring isagain " boat " shaped, but now the distortion causes the boats to lie '' keel-to-keel." In both these compounds the lengths of the single bonds to themethylene groups are substantially normal (1.54-166 A)-a good illus-tration of the principle that it is easier to bend molecules than to stretchbonds.f), /NH-CH2I I \NH-CH, s=c I H,c/\/\cH,HzC\/\/CH2II I (XXI)\/ (XX)The structure derived for triphenylene,220 implying an anomalouslyclose approach (2.58 A) between non-bonded carbon atoms, has been shownto be incorrect.221 Work has been reported on the structures of diphenylene-naphthacene,222 1 : 1 : 6 : 6-tetraphenylhe~apentaene,~~~ fla~anthrone,~~~acedian throne, 225 and diant hronylidene.226216 M. S. Farag, Acta Cryst., 1954, 7, 117.219 C. J. Brown, J . , 1953, 3265, 3278.221 V. Vand and R. Pepinsky, ibid., 1964, 7, 595. (A similar conclusion appears t ohave Peen reached independently by workers at the Manchester College of Technology.)828 A. Bennett and A. W. Hanson, ibid., 1953, 6, 736.223 M. M. Woolfson, ibid., p. 838.22*i P. 13. Friedlander, T. H. Goodwin, and J . &I.Robertson, ibid., 1954, 7, 127.2 2 6 S. C. Nyburg, ibid., p. 779.0. Bastiansen and 0. Hassel, Acta Cltem. Scand., 1952, 6, 205.A. W. Hanson, Acta Cryst., 1953, 6, 32.220 A. Klug, Acta Cryst., 1950, 3, 165.3z4 H. P. Stadler, ibid., p. 540SPEAKMAN. 395Heterocyclic Compounds.-A precise X-ray study of ethylenethiourea(XXI) has been described.227 The two types of C-N bonds differ very sig-nificantly in length, r(N-CH,) being 1.471, and r(SC-N) 1.322, each &0408 A.All the hydrogen atoms were located, and a slight bending (*lo) of the S=Cbond out of the plane of the ring was established as probably significant, andattributed to lattice forces. A corresponding difference has been found 228between the cyclic C-0 lengths in ethylene carbonate (1.40 and 1-33 A), butthe shortness (1.16 fi) of the exocyclic G O bond is not paralleled by r(C=S)in ethylenethiourea (1-708 A careful analysis 229 of 2-pyridone(XXII) indicates-not only by the accurate definition of bond lengths, butalso by location of the hydrogen atoms-that the molecule has indeed thisstructure and is not the hydroxypyridine. The corresponding sulphur com-pound has also been studied 230 and proved to be 2-thiopyridone, as expected.The structure of 6-amino-3-pyridazone has been investigated.%l Uracil0.007 A).NH/\ oc/ \co coHN/ \NH I I (JL HC\ I I /NWoc-co CH I H(XXII) (XXIII) (XXIV)(XXIII) has a planar molecule,232 which shows small but apparently signi-ficant differences between C-N lengths a t the two nitrogen atoms ; the bondsare shorter at the atom which is deduced to have a small positive charge.Two intermolecular (0 - H-N) hydrogen bonds are carried by one oxygenatom, and none by the other.A study of parabanic acid (XXIV) hasbeen briefly reported.233 A preliminary note 234 rules out the possibility ofa bridge structure in the cation of the " mesoionic" compound (XXV),5-imino-1 : 3-dimethyltetrazole hydrochloride, but the work has not yetreached the stage where bond lengths can be stated. The two halves ofthe molecule of 1 : 4-dithiin (XXVI) are planar, their planes intersectingat an angle of about 137" along the line S-S.235 By contrast 1 : 4-dithianhas a centrosymmetric, '' chair "-shaped molecule.236 As with the corre-HC/~\CH HZ /S-CH,/N-NMe 7 CH-HC 1\S-CH,II II Mel" f I +\N-C=NH, w HC\ S /HC H2C-S/(XXV) (XXVI) (XXVII)sponding oxygen the compound C,H,,S,, produced by theaction of 2 : 3-dichloro-1 : 4-dioxan on ethylenedithiol, has been shown byX-ray analysis to be bis-2-1 : 3-dithiacyclopentyl (XXVII) .238 The nickel227 P.J. Wheatley, Acta Cryst., 1953, 6, 369.229 B. R. Penfold, ibid., 1953, 6, 591.231 P. Cucka and R. W. H. Small, ibid., 1954, '7, 199.232 G. S. Parry, ibid., p. 313.233 D. R. Davies and J. J. Blum, Nature, 1954, 173, 993.234 J. H. Bryden, R. A. Henry, W. G. Finnegan, R. H. Boschan, W. S. McEwan,236 P. A. Howell, R. M. Curtis, and W. N. Lipscomb, Acta Cryst., 1954, 7, 498.236 H. J. Dothie, ibid., 1953, 6, 804.z37 S. Furberg and 0. Hassel, Acta Ckem..%and., 1950, 4, 1584.238 L. B. Brahde, ibid., 1954, 8, 1145.228 C. J. Brown, ibid., 1984, 7, 92.230 Idem, ibid., p. 707.and R. W. van Dolah, J . Anzer. Claevn. Soc., 1953, 75, 4863396 CRYSTALLOGRAPHY.derivative of a macrocyclic compound analogous to phthalocyanine-one ofa series discovered by Linstead and his co-workers239-proves to have anon-planar molecule in the solid state.240 Thio- and seleno-indigo , thoughnot isomorphous in the forms examined,=l have similar crystal structures,with centro-symmetric, and approximately planar, molecules ; and thestructure of indigo itself has also been studied by the same authoress.242H. M. Powell’s Tilden Lecture 243 gives a valuablesurvey of the whole field of intermolecular compounds , with special referenceto the clathrates.A number of crystalline, binary, aromatic molecularcompounds have been studied by X-ray methods.244 Thus in phenoquinonea molecule of quinone is sandwiched between pairs of molecules of phenol;and in the 1 : 1 compound between anthracene and s-trinitrobenzene themolecules are packed in parallel, alternate arrangement. Though the per-pendicular distances between the aromatic rings are not abnormally low, thecombination is thought to be principally due to “ polarisation bonding ”between a polarising and a polarisable molecule.245 The well-known ureaadducts with straight-chain hydrocarbons, etc. ,246 are paralleled withthiourea.=’ By itself, thiourea crystallises in the orthorhombic system ;but in its adducts the system is hexagonal: the thiourea molecules arehydrogen-bonded so as to constitute the “ walls of the honeycomb,” leavingchannels along which lie the molecules of the second constituent-usually ahydrocarbon.On account of the greater width of the channels, branchedchains can be accommodated, or even cyclohexyl groups. This cyclic groupshows a preference for locating itself along the channel in a region wheresulphur atoms occur in the walls; some distortion of the hydrocarbon chaincan be tolerated to ensure this fit.Miscellaneom organic compomds. Wheatley has made an accurateanalysis of a vinylideneamine derivative (XXVIII) .248 The molecule has aCH,*S<, two-fold (crystallographic) axis, and the C-C-N-C,C:C:NCH, chain is therefore strictly linear.The values of r(C=C)CH,.SO, and r(C=N) are respectively 1.342 and 1.l54A (each&O.OOS); if bond orders are derived from these lengthsby conventional means, the intermediate carbon atom acquires a totalvalency of five, an extreme example of an effect observed in othermolecules such as dimethyltriacetylene and dicyan~acetylene.~~~ Theresults of an X-ray study of the disodium salt of ethylenedinitramine,N0,~NH*C,H4-NH-N0,,250 can be compared with an earlier study of theparent sub~tance.~5~ The chief point of difference appears to be a lengthen-Moleczdar compozmds.(xxvlll)239 See R. P. Linstead, Pedler Lecture, J., 1953, 2873.240 J . C. Speakman, Acta Cryst., 1953, 6, 784.241 H. von Eller, Compt. rend., 1954, 239, 1137, 1043.242 Idem, Acta Cryst., 1954, ‘7, 650.243 H.M. Powell, Tilden Lecture, J . , 1954, 2658 ; see also a survey by L. J. Andrews,244 S. C. Wallwork et al., Acta Cryst., 1953, 6, 791; 1954, 7, 648.245 See also R. S. Mulliken, J . Amer. Chern. Soc., 1952, 14, 81 1 ; K. Nakamoto, ibid.,246 W. Schlenk, jun., Annalen, 1949, 565, 204; Acta Cryst., 1953, 6, 670; A. E. Smith,247 H.-U. LennC, z’bid., 1954, 7, 1. 248 P. J. Wheatley, ibid., p. 68.249 G. A. Jeffrey and J. S. Rollett, Proc. Roy. SOC., 1952, A , 213, 86; R. B. Hannanand R. L. Collin, Acta Cryst., 1953, 6, 350. 250 N. Allentoff and G. F. Wright, ibid., p. 1.251 F. J. Llewellyn and F. E. Whitmore, J., 1948, 1316.Chem. Rev., 1954, 54, 713.p. 1739.ibid., 1952, 5, 224SPEAKMAN. 397ing of N-0 in the salt.The sodium ions are environed by the oxygen,rather than by the amino-nitrogen, atoms.Nitta and his co-workers have determined the structures of tropolonehydrochloride 252 and of sodium t r ~ p o l o n e . ~ ~ ~ Both are salts and showsignificant points of difference from copper tropolone,264 which is a co-ordination compound. In the hydrochloride, not only are the C-O lengthsapproximately equal and of a value (1.41 A) appropriate to a single bond,but the structure is not unlike that of rock-salt, with some quite short valuesfor r(C - - - Cl) (-3.5 A), which suggests that the positive charge is distri-buted over the whole cation. A full account of the " tropolonate " structureis not yet available. The copper compound of nootkatin has also beenexamined by X-rays and shown to be a tropolone derivative,255 as indicatedby the chemical evidence.Other natwal $Yoduck.In the Third G. G. Henderson MemorialLecture 256 J. M. Robertson has revietved.recent X-ray work on triterpenesand some related compounds : viz., p-caryophyllene derivatives,257 longi-folene hydr~chloride,~~~ lanostenyl i o d o a ~ e t a t e , ~ ~ ~ and methyl oleanateiodoacetate.260A striking X-ray analysis 261 has led to the elucidation of the structure,hitherto quite unknown (and of a novel type), of the alkaloid cryptopleurine.The presence of the heavy atom in the cryptopleurine derivative (XXIX)made the analysis practicable. As the unit cell did not possess a short axis,an unobstructed view of the molecule could not be had by conventionalprojections. The problem was solved by making full use of the generalizedproj ection,sO so that overlapping molecules could be separately recognised, asshown in Fig.4. This constitutes an absolute structure determination, andit can be regarded as a logical extension to a non-planar molecule in threedimensions of the classical studies of the planar phthalocyanines.M. Przybylska and W. H. Barnesae2 have determined the structure ofa-isosparteine hydrate with an accuracy surprising in a compound of thistype. Their results confirm the structure-and the stereochemical relation-ship between the various C,,-lupin alkaloids-proposed by L. Marion andN. J. This structure is remarkable in a minor detail : althoughthe anhydrous form is very hygroscopic, the water molecule in the hydratedoes not appear to be bonded in any way to the rest of the structure.InL-ephedrine hydrochloride, Ph*CH(OH)*CH(CH3)*&H2*CH3)C1,264 the con-figuration of the cation is such that -OH and -NH2*CH3 adopt a " gauche ''relationship to one another about the C-C bond-not surprisingly different+252 Y . Sasada, K. Osalii, and I. Nitta, Acta Cryst., 1954, 7, 113.253 Y. Sasada and I. Nitta, ibid., p. 652.z54 J. M. Robertson, J., 1951, 1222.255 R. B. Campbell and J. M. Robertson, Chem. and Ind., 1952, 1266.z 5 6 Royal Institute of Chemistry, Lectures, Monographs, and Reports, 1954, No. 6.258 R. H. Moffett and D. Rogers, ibid., p. 916.259 J . Fridrichsons and A. McL. Mathieson, J., 1953, 2159.t 6 0 A.M. Abd El Rahim and C. H. Carlisle, Chem. and Ind., 1954, 279.261 J . Fridrichsons and A. McL. Mathieson, Natztre, 1964, 173, 732.262 M. Przybylska and W. H. Barnes, Acta Cryst., 1953, 6, 377.263 L. Marion and N. J. Leonard, Canad. J . Res., 1951, 29, 355.264 D. C . Phillips, Acta Cryst., 1954, 7, 159.J. M. Robertson and G. Todd, Chem. and Ind., 1953, 437398 C. RY STAT.LOGR APH \-.from the “trans” arrangement (of -OH and -NH*CH,) suggested by thechemical behaviour of the free base. An X-ray study of tropine hydro-bromide (XXX) 265 confirms the structural relationship between tropine andFIG. 4. Generalised projection of the crystal struc-ture of a cryptopleurine derivative (XkIX). Thetwo superposed molecules are distinguishable i r rthis type of projection, and one of them i s repre-sented by broken contour-lines.L’ (XXIS)0 80 N C o i a 3 AReprinted, by permission, from J.Fridrichsons and A.McL. Mathieson, Nafure, 1954, 173, 732.+tropine deduced from chemical considerations and outlined in last year’sReports (p. 165). The same conclusion has been reached independently byPepinsky and his co-workers,266 who have also shown evidence in support ofMe-&H}Br-(XXX) d-”MeOH\ H o~,)--cH~-+HM~‘\ ,Nhle,+) I-(XXXI)Sir Robert Robinson’s formula for a-methyldihydrothebaine methiodideThe most remarkable achievement in structure analysis during the period2 6 5 J. W. Visser, J. Manassen, and J. L. de Vries, Acta Cryst., 1954, 7, 288.268 R. Pepinsky and P. F. Eiland, ibid., p. 652: D. W. Smits and R, Pepinsky, ibid.,653.(XXXI)SPEAKMAW. 399under review has been the progress made by the group of workers (mostlyat Oxford) who have been studying vitamin B,, for a number of years.With a molecule of largely unknown structure containing about 100 atoms(other than hydrogen), the problem has rightly been described as being of adifferent order of magnitude from those hitherto solved by X-ray analysis.The molecule possesses a cobalt atom, which is moderately “ heavy,” thoughby itself totally inadequate to surmount the phase problem in a non-centricstructure of such complexity. However, there is also a CN group attachedto the cobalt atom, and it has proved possible to prepare derivatives, inwhich this group was replaced by SCN and by SeCN, and which had verysimilar crystal structures to that of the original B,,, though not strictlyisomorphous ones. The positions of the various heavy atoms in theseFIG. 5. Electrou-demity map, showingsections taken through the atoms,of part of the crystal of vitamin B,,(SeCN derivafive) in the region ofthe cobnlt atom.Reprinted, by permission, from D. C.Hodgkin et al., Nature, 1954,174, 1169.related systems could be found ; and three-dimensional electron-densitysyntheses were computed, using the phase-angles (necessarily inaccurate)required by these atoms alone. Individually these syntheses were too im-perfect to be very useful ; but, by comparing them point-by-point and notingdetails of agreement, it became possible to piece together the structure in theregions of the heavy atoms, and thus, in particular, to obtain a striking map(Fig. 5 ) of the environment of the cobalt atom.267 Co-ordinated round thecobalt are four atoms (possibly nitrogens) which form part of a porphyrin-like system with the startling difference that two of the five-membered ringsare directly linked. (The genuineness of this feature has been confirmed byfinding it independently in the crystal of a degradation product.26s) Per-pendicular to the general plane of this ring-system the cobalt atom is co-ordinated to the CN (or SCN or SeCN) group in one direction, and in the otherto a benziminazole residue, attached to which can be recognised a ribose2 6 7 C. Brink, D. C. Hodgkin, J. Lindsey, J . Pickworth, J. H. Robertson, and J. G.White, Nature, 1954, 174, 1169; see also D. C. Hodgkin, lecture to International Con-gress, briefly reported in A c f a Cryst., 1954, 7, 616, and to be reproduced a t length in B d .Soc. min.2 6 8 J. R. Cannon, A. W. Johnson, and A. R. Todd, Nature, 1954, 174, 1168400 CRYSTALLOGRAPHY.molecule, itself linked to a phosphate group in an unorthodox way. Sincethese details were announced, further progress has been made, particularlyin following up the side-chains attached to the " pseudoporphyrin '' ring-system; and it now seems certain that the complete structure must bedetermined in due course.The fortieth anniversary of the discovery of X-ray diffraction was cele-brated in 1952, and reports of the celebrations have been given.269 In theevolution of structural crystallography from that discovery, the analysis ofvitamin B,, will be recognised as a major land-mark.J. C. SPEAKMAN.2G9 J. Thewlis, ibid., 1953, 171, 106; see also Brit. J . Appl. Physics, 1963, 4, 33

ISSN:0365-6217    

DOI:10.1039/AR9545100372

出版商:RSC    

年代:1954

数据来源: RSC

摘要:

INDEX OF AUTHORS’ NAMES.Abbott L. n., 331.Abe, H., 11.Abe, Y., 209.Abel, E., 58, 64.Abdel-Akher, M., 176.Abd el Rahim, A. M., 397.Abdul-Azim, A. A., 353.Abkin, A. D., 73, 74.Abraham, S., 332.Abrahams, S. C., 381, 382,Abrahamsson, S., 388.Abramsky, T., 321.Abramson, E., 347.Ackermann, Th., 110.Acquista, N., 16.Adams, E., 308.Adams, R., 194, 245, 260.Adams, W. J., 227, 233.Adamson, A. W., 57, 109,Addison, C. C., 135.Adelberg, E. A., 188.Ademri, G., 361.Adler, S., 97.Aebi, A., 215.Agazzi, E. J., 348.Agren, A., 361.Ahlbrecht, A. H., 282, 283.Alders, IS. H. E., 186, 369.Ahmad, R., 175.Ahmed, F. R., 375, 391.Ahmed, M.-D., 265.Airola, A., 30.Alrabori, S., 68.Alrimoto, Y., 22.-4lciyoshi, S., 191.Akroyd, P., 199.Aksnes, O., 384.Albert, A., 250, 337.Alberti, C.G., 236.Alberty, R. A,, 298, 306.Alder, B. J., 28, 29.Alder, K., 204, 245, 255.Alder, M. G., 71.Aldrich, R. A., 316.Alexander, G. R., 75.Alexander, H. E., 274.iilexander, 0. R., 69.Alexander, P., 76, 80, 83.A41frey, T., jun., 70.Alfthan, M., 188.Alimarin, I. P., 354.,411an, G. G., 222.Allen, A. O., 77, 80, 81.384.121.Allen, F. W., 271, 275.Allen, G., 16, 20, 21.Allen, H. C., 15.Allen, T. L., 72.Allentoff, N., 396.Allerton, R., 264.Allinger, A. L., 203.Allinger, N. L., 203.Allgdn, L. G., 273.A h , R. M., 283.Alt, G. II., 223, 231.Altermatt, H., 269.Altieri, P. L., 348.Altman, K. I., 320, 321.Altshuller, A. P., 30.Amano, A., 99.Ambrose, J. F., 304.Ames, T.R., 165.Amiel, Y., 202.Aminoff, D., 270.Amis, E. S., 59.Ammar, I. A., 113.Amphlett, C. B., 53, 101,Anagnostopoulos, C. E.,Ander, P., 79, 80.Anderegg, G., 120, 124.Andersen, F. A., 16, 17.Andersen, W., 270.Anderson, A., 54.Anderson, A. G., 202.Anderson, A. W., 75.Anderson, C. H., 367.Anderson, D. H., 369.Anderson, H. C., 45.Anderson, H. M., 192, 241.Anderson, H. R., jun., 48.Anderson, H. V., 234, 235.Anderson, J. M., 265.Anderson, J. R., 94.Anderson, J. S., 336.Anderson, L. C., 78, 79.Anderson, W. E., 9.Anderson, W. S., 74.Anderson, L. H., 138.Andrew, E. R., 24, 391.Andrews, J. S., 320.Andrews, L. J., 396.Andrews, P., 268, 269.Andrianova, I. I., 100.Anet, F. A. L., 251, 256.Angyal, C.L., 242.Angyal, S. J., 173, 242,40 1120.230.253.Anner, G., 231.Anno, K., 269.Ansell, M. F., 193.Anta, M. C., 81.Antia, N. J., 237.Antipin, P. F., 131.Antropov, L. I., 116.Appel, R., 140.Arai, T., 199.Arakawa, M., 215.Archer, E. E., 347.Archer, S., 193, 232, 254.Arens, J . F., 182.Argersinger, W. J., 107,Arigoni, D., 207, 208, 322,Arima, K., 230.Ariya, S. M., 142.Arlman, E. J., 75.Armitage, J. B., 182.Arnett, R. L., 96.Arnold, I$., 200.Arnold, J. R., 27.Arnold, R. T., 203.Aroeste, H., 27.Arribas- Jimeno, S., 346.Arroyave, G., 361.Arth, G. E., 160, 177.Arvan, P. G., 120.Asadourian, A., 279.Aschenbrand, L. &I., 64.Asconas, B., 299.A4skani, V., 193.Asker, W., 194.Ashby, J. H., 299.Ashwell, G., 333.Asmussen, R.W., 124.Aspinall, G. O., 265.Asprey, L. B., 143.Assony, S. J., 201.Aston, J. G., 17.Aten, A. H. W., jun., 54,55, 56, 142.Atkinson, M. R., 244.Athavale, V. T. 341.Atoji, M., 381, 385.Attaway, J. A., 289.Attree, R. W., 61.Atwood, K., 93.Audrieth, L. F., 135.Augestad, I., 263.Augustinsson, K. B., 310,Ausloos, P., 62, 63.245.239, 240.360402 INDEX OF AUTHORS' NAMES.Aust, H., 21.hutenrieth, W., 252.Axelrod, B., 331,Axelrod, L. R., 361.Ayant, Y., 7.Aycock, B. F., 189.Ayer, W. A., 195.Ayerst, E. M., 389.Aymonino, P. J., 50..4ynsley, E. E., 144.Ayscough, P. B., 53.Baar, S., 263, 361.Bab3, T., 236.Babcock, J., 235.Bachmann, W. E., 253.Back, R. A., 63.Backer, H. J., 181, 182.Bacon, E.E., 269.Bacon, G. E., 7, 377, 378,Bacon, J. S. D., 269.Baddeley, G., 166, 169, 190.Baddiley, J., 250.Badger, G. M., 157, 189,Badger, R. M., 19.Badgley, G. R., 23.Badoz-Lambling, J., 356.Bachli, P., 270.Baer, D. R., 166.Baer, H. H., 267, 270.Baes, C. F., 143.Bagchi, S., 106.Bailar, J. C., 115.Bailey, A, S., 251.Bailey, B., 154, 253.Bailey, D. J. C., 139.Bailey, K., 308.Bailey, M., 384.Bailey, W. J., 202, 243.Rak, B., 8, 16, 17.Baker, B. R., 249, 266.Baker, B. ?V., 187.Baker, L. J., 97.Baldeschweiler, E. L., 336.Baldi, F., 367.Baldwin, D. E., 360.Baldwin, R. R., 85, 86.Ball, D. H. 268.Ballard, D. G. H., 76.Ballantine, D. S., 80.Ballczo, H., 356, 357, 358.Balls, A. K., 304.Balters, H., 139.Balwit, J .S., 79, 80.Balwit, S., 80.Bamford, C . H., 70, 72, 75.Bandurski, R. S., 331.Banerjee, S . , 358.Banerjee, S. B., 20.Banfi, D., 186.Banks, A. A., 287.Banks, C . V., 22.Banks, E., 142.Bannister, B., 160.Bannister, D. W., 362387.190, 192.Banus, J., 126, 287, 293,Banus, M. D., 125.Baranger, P., 245.Baranov, S. N., 53.Barber, G. W., 230.Barbier, M., 186.Barbour, A. K., 288.Barbour, J. B., 240.Barclay, G. A., 119.Barger, G., 261.Barieau, R. E., 391.Baril, A., 68.Rarkash, A. P., 332.Barker, G. E., 272.Barker, G. R., 263, 361.Barker, S. A., 19, 267, 269,Barkley, L. B., 178.Barlin, G. B., 191.Barltrop, J. A., 195, 244.Barnard, J. A., 100.Barnes, R. B., 17.Barnes, R. G., 25.Barnes, W.H., 397.Barnhart, W. S., 292.Baronetzky, E., 134.Barr, D. A., 75.Barr, N. F., 81.Barrett, TV. T., 122.Barrick, P. L., 293.Barriol, J., 30.Barron, E. S. G., 304, 332.Barrow, R. F., 21, 41, 45.Barry, V. C., 264.Bartenstein, C., 148.Barth, G., 30.Bartholomew, R. M., 61.Bartlett, J. H., 117.Barton, A. D., 188.Barton, D. H. R., 157, 159,160, 168, 172, 176, 207,208, 211, 216, 217, 218,219, 220, 222, 223, 224,225, 226, 231, 233, 238,239.294.327.Bartosiewicz, W., 362.Bartram, S. F., 144.Bartz, Q. R., 188.Basak, N. G., 99.Baskett, A. C., 80.Basolo, F., 57, 121.Basset, I. M., 244.Bassett, E. G., 361.Bassham, J. A., 328, 333.Bassir, O., 362.Bassompierre, A., 7.Bastiansen, O., 393, 394.Bastin, E. I,., 348.Batdorf, D.K., 349.Bateman, L., 92, 162.Bates, E. B., 167, 175, 183.Bate-Smith, E. C., 248.Bather, J . M., 353.Batres, E., 176, 228, 236.Batuecas, T., 381.Baudler, M., 137.Bauer, E., 32,Bauer, H., 309.Bauer, H. F., 262, R G I .Dauer, L., 249Bauer, S. H., 22, 27, 28, 45,Baumann, R. P., 16.Baumgarten, H. E., 159.Baumgarten, P., 140.Bauserman, H. M., 364.Rawn, C. E. II., $4, 92.Baxendale, J. H., 5 s .Bayer, L., 139.Bayer, O., 180.Bayne, S., 334,Bazen, J., 344.Beach, J. Y., 381.Beachell, H. C., 20.Beale, R. N., 273.Beames, A. N., 194Bean, R. S., 308.Beasley, J . K., 73.Beaton, J. M., 222.Beattie, H. J., 365.Beatty, C. D., 367.Beavers, D. J., 193.Beavers, E. M., 193.Beavers, L. E., 247.Becher, H.J., 126.Beck, P. W., 68.Becker, C. E., 334.Becker, G., 35.Becker, R. S., 144.Bedard, F. D., 12.Beech, W. F., 181, 192.Beeck, O., 94.Beereboom, J . J., 230.Beermann, C., 131.Beet, A. E., 348.Behr, L. C., 192.Behrens, H., 55, 150.Beisken, B., 354.Belcher, R., 264, 337, 339,Belford, R. L., 61.Bell, D. J,, 237, 267, 268,Bell, F., 194, 393.Bell, K. P., 47, 110.Bell, W. E., 65.Bellamy, L. J., 7, 19, 368,Belniore, E. A . , 289.BGlov, N. V., 387.Benc, J., 351.Bender, M. L., 56.Bendich, A , , 275.Bengough, W. I., 70.Benjamin, L., 105.Renltescr, R. A., 147.Bennett, A., 394.Bennett, C. E., 352.Bennett, E. F., 144.Bennett, F. \IT., 144, 294.Benning, A., 199.Benoit, H., 25.Bensey, F. N., 385.47, 50, 381.342, 344, 346, 349.269.369INDEX OF AUTHORS' NAMES. 403Benson, A., 312.Benson, A.A., 328, 333.Renson, G. C., 106.Benson, S. W., 48.Bentley, K. W., 253.Benzinger, T. H., 302.BerAnek, J., 252.Rereznitskaya, E. G., 347.Berg, A.-M., 188.Berg, M., 312.Berg, N., 163Berg, W., 140.Berger, A, 75.Berger, S . V., 383.Bergeret, B., 363.Bergmann, F., 307.Bergmann, J. S., 57.Bergmann, M., 311.Beriger, E., 235.Berlie, M. R., 62.Berlinguet, L., 176.Berkeley, C., 334.Berman, A. M., 193.Rernal, J. D., 380, 382.Bernard, W. J., 144.Bernas, A., 81.Bernatek, E., 175.Berner, E., 203, 263.Bernstein, H. J., 15, 16,Bernstein, R. R., 16, 62, 61,Bernstein, S., 233, 234.Bernstein, W., 77.Bernt, E., 263.Berriman, J.M., 367.Berry, K. L., 281.Berry, M. G., 62.Bersohn, R., 24, 382.Berson, J . A., 241.Bertelli, J., 349.Berthold, H. J., 139.Berzins, T., 115.Besson, J. 133.Bethell, D. E., 18.Bethge, P. O., 335.Ueton, J. L., 165.13ett, N., 355.Beukenkamp, J ., 363.Beutell, F., 252.Bevenue, A., 328.Beveridge, J. S., 361.Bevington, J. C., 70, 71,Beyerman, H, C., 255.Bhargava, B. P., 125.Bhat, G., 204.Bhattacharyya, K. K., 99.Biance, D. R., 10.Richara, M., 130.Bichowsky, F., 42.Bidder, T. G., 334.Bien, G. S., 355.Bier, A,, 55.Bier, G., 291.Bigeleisen, J., 55, 61.Bigelow, L. A, 281,20, 21.97.72, 73.Bigol, J. A., 56.Biilman, E., 163.Bijl, D., 11.Bikerman, J. J., 113.Billmeyer, I;. W., 73.Bindschadler, E., 134.Birch, A.J., 177, 192, 195,214, 230, 243, 249.Bircumshaw, L. L., 130.Bird, G. R., 26.Bird, M. L., 161.Bird, R. B., 14.Birks, F. T., 367.Rirks, L. S., 365.Birley, A. W., 89.Birmingham, J. M., 132,Birnbaum, G., 8.Birnbaum, P. P., 68.Bissell, E. R., 254.Bittles, J. A., 281.Bjellerup, L., 36.Blacet, F. E., 64, 65.Black, D. R., 369.Black, H. K., 182.Blackie, J. J., 261.Blackley, D. C., 74.Blackwell, D. E., 381.Blades, A. T., 48, 51.Blades, H., 48.Bladon, P., 231.Blaedel, W. J., 344, 355.Blair, J., 192.Blake, G. G., 355.Blance, R. E., 175.Blanchard, J . P., 203.Blanchard, P. H., 269.Blander, M., 109.Blasius, E., 363.Blass, J., 362.Blatherwick, K. R., 333.Bleaney, B., 10, 11.Bleicher, S., 187.Bleidner, W.E., 362.Blevins, G. S., 9.Hloch, F., 23.Bloch, K., 218.Block, J., 101.Blomeyer, F., 236.Bloom, B., 332.Bloom, B. M., 160.Blount, B. K., 256.Blout, E. R., 17, 279.Blue, R. W., 102.Blum, J. J., 300, 396.Blum, P., 138.Blumann, A., 206, 214.Blumenthal, E., 275.Blumenthal, W. B., 120.Boatman, S. G., 360.Boaz, H. E., 257.Bobinska, J., 37.Bobka, E. J., 157.Bobleter, O., 76.Bobtelsky, M., 133, 356.Bock, R. M., 298, 360.Bockemiiller, W., 279,147.Bockris, J . O'M., 113, 114.Bodelos, L. J., 47.Bodforss, S., 241.Boeseken, J., 203.Bohme, H., 189, 361.Boekelheide, V., 245, 247.Bogdanova, A. V., 75.Bogle, G. S., 11.Bogorad, L., 312, 317, 321,Bohlmann, F., 183.Bohme, H., 158.Bolland, J. L., 67.Bolle, S., 346.Boller, A., 245.Bolliger, H.K., 264.Bolton, H. C., 31.Boltz, D. I?., 366.Bon, W. F., 362.Bond, A. C., 23.Bond, C. R., 334.Bond, G. C., 93, 96, 97, 98.Boimer, N. A., 64.Bonner, W. A., 98.Bonnichsen, R., 304.Boord, C. E., 98, 201,Boozer, C. E., 60, 169.Boozer, G. E., 67.Bordeaux, J. J., 162.Bordwell, F. G., 156, 192,Boreskov, G. K., 92, 99,Borie, B. S., 151.Borisova, T. I., 114.Borkowski, M., 170.Borkotvsky, F., 205.Borsook, H., 297, 298, 302.Bortner, M. H., 392.Boschan, R. H., 395.Bose, A. K., 258, 262.Bose, S., 256.Boswijk, K. H., 385.Bothwell, M. R., 122.Bottomley, W., 248, 249.Botts, J., 300.Roudart, M., 93, 94, 95, 99,Boult, E. H., 117.Bounds, D. G., 187.Bourne, E. J., 19, 267, 269.Bourns, A.M., 61.Bouy, R., 363.Bovarnick, 1cI. R., 308.Bowen, E. J., 69, 89.Bowen, H. J. M., 22.Bower, F. A., 159.Bowers, A., 165, 239.Boyd, D. R. J., 14.Boyd, V., 196.Boyer, P. D., 308.Boyland, E., 191.Boyle, B. J., 40.Boynton, C . F., 66.Bozon, H., 138.Brabers, M. J., 116.Brachman, M. K., 113.322.241.100.100404 INDEX OF AUTHORS’ NAMES.Bracken, A., 247.Bradacs, L. K., 359.Bradbury, J. H., 71, 74.Bradbury, R. B., 261.Brade, H., 251.Bradfield, A. E., 216.Bradley, D. C., 133.Bradley, W., 191, 195.Bradsher, C. K., 193, 247.Bradstreet, K. B., 348.Bragdon, R. W., 125.Brahde, L. B., 395.Braid, M., 283.Branch, R. F., 19.Brand, K., 263.Brandenberger, H., 250.Brandt, C. W., 217.Rrandt, G.R. A., 293,294.Brandt, J. L., 22.Branica, &I., 360.Bratoi, S., 18.Braude, E. A., 174, 177,Brauer, G., 129, 138, 143.Braun, T., 183.Bravo, J. B., 146.Brawerman, G., 274.Bray, P. J., 25.Bredereck, H., 189, 283,266, 268, 272.Breil, G., 41.Rreitman, L., 63, 369.Bremer, H., 99.Bremner, R. W., 364.Breslow, R., 216.Brett, H. W., 76.Breusch, F. L., 332.Brewer, L., 42, 44, 45.Brewster, J. H., 170, 242.Brice, T. J., 280, 281, 287,Bricker, C. E., 356, 364.Bridgwater, R. J., 236.Briggs, D. R., 304.Briggs, W. S., 95.Bright, R. D., 206.Brill, R., 376, 382.Brill, W. F., 183.Brimm, E. O., 145.Briner, E., 20, 40.Brink, C., 399.Brink, N. G., 224.Brinton, 13. K., 63.Briscoe, H. V. A., 56, 100.Brissey, R. M., 365.Britton, D., 50.Britton, R.D., 50.Broach, W. G., 59.Broadley, J. S., 389.Brochet, A., 347.Brockman, J. A., 244.Brockmann, H., 265.Brockway, L. O., 23, 393.Brodersen, K., 125.Brodskiy, A. I., 55, 56.Broida, H. P., 86.Brook, A. G., 178, 194.178, 194, 195.293.Brooks, C. J. W., 222, 225,Brooks, E. J., 365.Brooks, F. R., 348.Brot, C., 31, 32.Brous, J. B., 241.Brown, B. R., 196, 197.Brown, €3. W., 142.Brown, C. A., 126.Brown, C. J., 392, 394, 395.Brown, D. D., 119.Brown, D. J., 250.Brown, D. M., 271, 277,Brown, D. W., 75, 76.Brown, E. G., 345.Brown, F., 61, 283, 284.Brown, F. B., 92.Brown, G. B., 275.Brown, G. L., 275.Brown, G. M., 392.Brown, H. A.. 284.Brown, H. C., 28, 125, 126,128, 129, 165, 166, 170,173, 242, 245, 312.Brown, J.J., 192.Brown, J. K., 16, 17.Brown, M., 17.Brown, R. D., 244.Brown, W. G., 176.Brubaker, C. H., 134.Bruce, D. R., 195.Hriicltner, K., 171, 236.Brugger, W., 166.Brugsch, J., 312.Bruhn, J., 8.Brumbaugh, R. J., 364.Bruns, L., 204.Bryant, B. E., 121.Bryant, W. M. D., 73.Bryce, W. A., 53.Bryden, J. H., 395.Bryne, W. L., 326.Buchanan, G. L., 198.Buchanan, J. G., 262, 264.Buchanan, T. J., 33.Buchert, A. R., 309.Buchi, G., 218, 241.Buchman, E. R., 205.Buchowski, H., 352.Buck, R. P., 366.Buckingham, A. D., 29, 30.Buckles, R. E., 29, 179.Buckley, G. D., 244.Buckley, S. M., 188.Bueche, A. M., 80.Buerger, M. J., 387.Butler, R., 273.Bukata, S. W., 144.Bull, T. H., 47.Bullock, M.W., 244.Bullough, R. K., 374.Bu’Lock, J. D., 183.Bunce, S. C., 201.Bunn, C. W., 31, 388.Bunnett, J. F., 199.Bunney, L. R., 363.226.310.Bunton, C. A., 161, 268.Burawoy, A,, 159.Burbank, R. D., 375, 381,Burg, A. B., 125, 126, 133.Burgers, W. G., 116.Burgi, E., 249.Burgoyne, J. H., 91.Burke, D. C., 270, 271.Bumett, G. M.. 48, 61, 69-Burnett, J. B., 361.Burns, D. M., 388, 392.Bums, J. F., 45.Burr, J. G., 167.Burriel-Marti, F., 346.Burrus, C. A., 9.Burtner, D. C., 356.Burton, H. S., 360, 361.Burton, K., 297, 299, 301.Burton, M., 77-79.Burtt, B. P., 341.Bunvell, R. L., 95.Bur’yanov, Y. B., 138.Busev, A. I., 353.Buting, W. E., 244.Butler, C. F., 241.Butler, G. C., 273, 274.Butler, J.A. V., 275.Butler, K., 268.Buttery, R. G., 157, 192.Buxton, M. W., 282, 286,Buyle-Bodin, M., 25.Buzzell, A., 303.Bykova, E. V., 55.Byrd, E. K., 337.Bym, E. E., 338.Byrne, W., 333.Cable, J . W., 18, 147.Cadogan, J. I. G., 61, 291.Cady, G. *I., 281.Cahn, R. S., 237, 267.Calderbank, A., 196, 197.Caldin, E. F., 48, 55.Caldwell, M. L., 308.Caley, E. R., 338.Caliezi, A., 217.Calkins, D. G., 249.Callear, A. B., 47.Callis, C. F., 120.Callomon, H. J., 14.Callow, R. K., 236.Calmon, C., 362.Calvert, J. G., 65, 66, 68.Calvert, L. D., 390.Calvert, E., 43.Calvin, M., 244, 310, 328,Camerino, B., 236.Cameron, W. C., 100.Campbell, A. D., 193, 194.Campbell, A. N., 122.Campbell, C. S., 41.Campbell, D. N., 363.Campbell, D.O., 59.385.72.289.333INDEX OF AUTHORS’ NAMES. 405Campbell, J. E., 193.Campbell, R. B., 200, 397.Campbell, W. J., 366.Canham, P. A. S., 237.Canivet, J., 312.Cannon, J. R., 399.Cant, E. M., 389.Cardwell, H. M. E., 159,Carini, F. F., 43.Carl, H. F., 366.Carlisle, C. H., 397.Carlsmith, L. A., 154.Carlton, J. K., 360.Carlton, N., 56.Carnahan, J. F., 281.Caro, G., 272.Carr, E. M., 72.Carrington, T. R., 269.Carron, &/I. K., 367.Carson, J. F., 265.Carter, C. E., 273.Carter, G. F., 382, 385.Carter, H. E., 266.Carter, R. E., 152.Carugno, N., 351.Case, L. C., 58.Cashion, J. K., 69.Cass, R. C., 27, 34, 123.Cassis, F. A., 162.Catchpole, A. G., 171.Caton, R. D., 364.Cauchois, E., 7.Cava, M.P., 260.Cavalieri, L. F., 250.Cavallini, D., 360.Cavill, G. W. K., 179,Cekan, H., 201.Cekan, Z., 214.Cerato, C. C., 20.Cermak, J., 136.Cerney, R. R., 364.tern?, J., 207.Cerny, V., 230.Cetini, G., 359.Chaigneau, M., 127.Chaikin, S. W., 176, 242.Chaikoff, I. L., 273, 332.Chain, E. B., 349.Chakravarti, D., 256.Challenger, F., 188.Challoner, A. R., 34, 35.Chalmers, R. A., 356.Chambers, W. H., 333.Champier, G., 21.Chance, B., 48.Chaney, D. W., 286.Chang, N., 250, 271.Chang, T.-S., 9.Chanley, J. D., 187.Chapiro, A., 79, 83.Chapman, D., 121.Charalambous, G., 264.Charalampous, F. C., 327.Chargaff, E., 274, 275, 277,237, 381.191.278.Charles, R. G., 43, 120, 336,Charlesby, A., 75, 80.Charlot, G., 350.Charnley, T., 41.Chatagner, F., 363.Chatt, J., 118.Chatterjee, A., 256, 258,Chaykin, A.M., 51.Checkland, P. B., 14.Chen, Y. T., 121.Cheng, K. L., 338.Chiavarelli, S., 251.Chibnall, A. C., 185.Chieffi, G., 241.Chilton, H. T. J., 46, 51.Chinard, F. R., 308.Chinmayanandam, B. R.,Chipman, J., 45.Chirnside, R. C., 354.Chisholm, D. A., 13.Chizzola, H., 122.Chmutov, K. V., 359.Chollet, M. l’v‘l., 361.Choppin, G. R., 150.Chopra, N. M., 211, 212.Choruiguine, P. P., 7.Chouteau, J., 19.ChrCtien, A,, 130.Christ, C. L., 374.Christen, K., 239.Christensen, E., 279.Christensen, M. T., 14.Christian, W., 331.Christiansen, J. A., 49.Christie, M. I., 50, 67.Christol, H., 166.Christopherson, H., 337.Chu, T. C., 242.Chu, T.O., 312.Chupka, W. A., 43.Church, R. J., 241.Ciapetta, F. G., 103.Cifonelli, J. A., 262.Cimino, A., 99.Cini, R., 142.Claassen, H. H., 16, 18, 20.Clark, A., 101.Clark, G., 273.Clark, H. C., 57, 151.Clark, J. R., 357, 374.Clark, R. F., 282.Clark, R. I<., 365, 266.Clarke, D. A., 188.Clarke, F. II., 254.Clarke, H. B., 299.Clarke, P., 189.Clark-Lewis, J. W., 248.Clausinger, R., 162.Clayton, R. A., 360, 361.CIegg, J. W., 123.Clemo, G. R., 192, 213,Cleveland, F. F., 16.337.260.72.Chu, E. J.-H., 242, 312.215, 246.Clifford, A. F., 281.Clifford, A. L., 350.Clingman, A. L., 186.Clippinger, E., 164.Cloutier, A. A., 308.Coates, G. E., 123.Cobble, J. W., 105, 109.Cochran, E. L., 66, 78.Cochran, J.E., 244.Cochran, W., 372, 374, 375,377, 380, 383, 389.Cocker, W., 210-213,218.Coderre, R. A,, 234.Coe, D. G., 180.Coffey, S., 196.Coffin, K. P., 22.Coflman, D. D., 290, 293.Cohen, D., 54.Cohen, J. A., 304, 310.Cohen, M. D., 71.Cohen, S. S., 275, 331, 332.Cohen, V. W., 10.Cohen, TV. V., 163.Cohn, A. E., 272.Cohn, E. J., 300, 306.Cohn, M., 11, 249, 276.Cohn, W. E., 271, 272.Colarusso, R. J., 357.Cole, A. R. H., 16, 201,Cole, D. J., 340.Cole, R. H., 29, 32, 33.Cole, W., 177, 234.Coleby, B., 78.Colichman, E. L., 351.Collie, B., 104.Collie, J. N., 181.Collier, R. J., 10.Collin, R. L., 396.Collins, C. J., 98.Collins, J. C., 221.Collins, J. R., 264.Collinson, E., 81.Colombo, P., 79.Colson, A.F., 348.Colthup, N. B., 19.Colton, E., 135.Comber, R., 360.Combrisson, J., 11, 78.Comfort, A., 312, 322.Comyns, A. E., 122. .Conbere, J. P., 235.Conia, M. J. M., 206.Conn, G. K. T., 97.Connick, R. E., 105.Conrad, H. E., 268.Conrad, F., 283.Conroy, M. E., 291.Considine, W. J., 179, 236.Constam, E. J., 35.Constantin, J. M., 227.Conway, B. E., 113.Conway, H. S., 348.Conway, K. C., 40.Cook, J. W., 193, 198, 200,Cook, M., 334.214.261406 INDEX OF AUTHORS’ NAMES.Cook, M. A., 369.Cooke, N. J., 185, 186.Cooke, R. G., 265.Cooke, W. D., 352.Coolrson, G. H., 312, 317.Cookson, R. C., 167, 172,Coon, R. I., 293.Coope, J. A. R., 53.Cooper, F. C., 250Cooper, G. D., 60.Cooper, H. R., 67.Cooper, S. S., 350.Coops, J., 34.Cope, A.C., 204.Coppinger, G. M., 60, 169.Corbett, R. E., 208.Corbett, W. M., 158, 267,Corbridge, D. E. C., 18,384.Cordes, H. F., 49.Cordon, M., 204.Corey, E. J., 160, 171, 210,Corey, R. B., 377, 388.Cori, O., 331.Cormack, D. V., 77.Corney, N. S., 86.Cornforth, J. W., 159, 223,Cornubert, R., 175, 203.Cornwell, C. D., 8.Corrodi, H., 258.Corth, I. M., 354.Corval, M., 348.Corwin, A. H., 163, 320.Cosslett, V. E., 87.Cotter, M. J., 336.Cottin, M., 81.Cotton, F., 119, 145.Cotton, F. A., 141, 147.Cottrell, A. H., 373.Cottrell, T. L., 33, 50, 92.Coulson, C. A., 391.Couper, A., 94.Coursier, J., 353.Courtenay, T. A., 275.Courtney, C. F., 242.Courtois, J. E., 269.Courtoy, C., 15.Cousens, R.H., 117.Couture-Mathieu, L., 21.Coward, N. A., 69.Cowley, J. M., 377, 383.Cox, E. G., 373, 388, 392.Cox, J. D.. 35.Cox, J. T., 9, 10.Cozzi, D., 351.Craig, D. N., 105.Craig, D. P., 27, 119.Craig, L. C., 225.Cram, D. J., 98, 157, 161,Cramer, R., 290.Crampton, C. F., 275.Crane, C. W., 158.Crane, G., 392.173.268.228.227, 232.167, 175, 203-205.Crane, R. A., 64.Crawford, B., 119, 135.Crawford, B., jun., 27, 386.Crawford, B. L., 96.Crawshaw, A., 172, 233.Cremer, E., 75, 94.Cremlyn, R. J. W., 230.Crestfield, A. M., 271.Crew, M. C., 166.Crick, F. H. C., 27, 279.Criscione, J. M., 146.Crist, J, G., 263.Crist, R. H., 92.Cristol, S. J., 155, 156.Critchfield, F. E., 355.Crittenden, A. L., 350.Crombie, L., 182, 186, 187,Crombie, W.M. L., 360.Cromwell, N. H., 241.Cronyn, M. W., 29.Crook, E. M., 299.Cropper, F. R., 347, 348.Crosbie, G. W., 273.Crosby, G. A., 30.Crosby, H. J., 50.Cross, B. E., 211, 212.Cross, C. K., 347.Crowder, D. A., 60.Crowder, J. P., 59.Crowdle, J. H., 241.Crowther, J. P., 358.Croy, V. D., 19.Cruickshank, D. H., 189,Cruickshank, D. W. J., 374,Cruickshank, P. A., 234.Crummett, W. B., 363.Cucka, P., 395.Cuculo, J. A., 281.Cullis, C. F., 52.Culvenor, C. C. J., 260,261.Cumming, C., 15.Cummings, J. I., 111.Cummins, E. W., 243.Cummins, J. A., 247.Cunningham, B. B., 42,129.Cunningham, K. G., 247.Cunningham, L. W., 310.Curran, C., 30.Curtin, D. Y., 154,166,252.Curtis, N. F., 57.Curtis, R.M., 246, 395.Curzon, G., 360.Cusworth, D. C., 299.Cutter, I. B., 369.Cutting, T. A., 367.Cutton, J. M., 152.Cvetanovic, R. J., 62.Cymerman-Craig, J., 177,Czaloun, A., 144.Daasch, L. W., 16, 17.Dabkowska, M., 351.Daeniker, H. U., 203.202.360.375, 388, 391.183, 192.Daeniker, I-l. V., 260.Daglish, A. F., 236.Dailey, B. P., 8, 25, 26.Dainton, F. S., 53, 81.Dakshmamurti, K., 360.Dalbert, R., 32.Daleszynska, M. J., 342.Dalgliesh, C. E., 250.Dalziel, K., 48.Damon, G. F., 366.Danaher, M. G., 160.Danby, C. J., 51.Danielson, R. D., 293.Dann, O., 243.Dannenberg, E., 336.D’Ans, J., 124.Darrall, R., 286.Darwent, B. de B., 46, 53,Das, S. K., 72, 74.Dase, G., 136.Date, M., 11.Datta, S. P., 299.Dauben, H.J., 181.Dauben, H. J., jun., 227.Dauben, W. G., 205.Daubeny, R. de P., 31.Daudel, R., 391.Daugherty, M., 349.Dauncey, L. A., 354.David, H. G., 49.Davidsen, H., 181.Davidson, A. W., 124.Davidson, D. W., 15, 32.Davidson, F. G., 37.Davidson, J. N., 273, 274.Davidson, N., 50, 66.Davies, A. G., 166.Davies, C. W., 110, 124.Davies, D. N., 395.Davies, J. E., 195.Davies, M., 8, 16, 19, 23,Davies, N. R., 57, 119.Davies, P. B., 110.Davies, R. E., 361.Davies, R. O., 29.Davies, T., 43.Davies, W., 243.Davis, C. T., 249.Davis, E. G., 183.Davis, T. W., 63, 67.Davoll, J., 271.Davydova, N. I., 336.Dawson, B., 387, 391.Dawson, C. R., 192.Dawson, J. K., 143.Dawson, T. L., 215.Day, H. G., 334.Day, M. J., 10.Day, R.A., 143.Deal, S. B., 350, 364.Dean, D. J. A., 41.de Angelis, G., 351.DeAngelis, L., 52.Deas, P. J., 48.Debiais, L., 67.69.31, 45INDEX OF AUTHORS’ NAMES. 407de Boer, T. J., 181.De Busk, B. G., 323.de Chastonay, Ph., 20, 40.Decius, J. C., 17, 382.Deck, 0. F., 54.Deeley, C. M., 24, 125.De Ford, D. D., 355.de Hemptinne, M., 15, 20.Dehmelt, H. G., 24, 25,Deimel, M., 274.Deitz, V. R., 308, 354, 364.Deltker, C. A., 262, 272.de la Ilaba, G., 328.Delahay, P., 48, 115.de la Mare, P. B. D., 167.De La Mater, G., 361.Delhpine, M., 35, 175.Dell, R. &I., 101.Demaecker, J., 230.Demarteau-Ginsburg, H.,de Mayo, P., 218, 219, 220,de Montgareuil, P. G., 364.DeMore, B. B., 8.Denbigh, K. G., 48.Dennison, A.C., 186.Dennison, D. M., 9.Denny, G. €I., 189.Denson, J. R., 364.Denstedt, D. F., 316.Dent, C. E., 188.de PassillE, A., 137.Derbyshire, D. H., 66.Derevenskikh, L. V., 51.Derfer, J. M., 98, 201.Derkosch, J., 389.Derra-Scherer, H., 242.de Ruggieri, P., 236.Derungs, R., 263.Deschamps, P., 353.De Sesa, M. A., 351.de Silva, M., 359.Desjobert, A., 343.Desnuelle, P., 302.Desoer, C., 274.Deuel, H., 263, 269.Deutsch, A. S., 228.Deutsch, D. H., 205.Dev, S., 201.Devanathan, M. A. V., 110,111, 114.de Vries, G., 359.de Vries, J. L., 398.de Wael, J., 360.Dewar, M. J . S., 167.Dewhurst, H. A., 77, 80.De?Vitt, E. G., 282.de Wet, J. F., 390.D’Eye, R. W. M., 143.DeYoung, J. J., 224.Diamond, L. H., 135.Diamond, R.M., 143.Diassi, P. A., 257.Diaz, R., 350.Diaz Cadavieco, R., 360.26.187.226.Dicltens, F., 331.Dickey, J. B., 286.Dickman, S. R., 308.Dickson, D. 13. W., 236.Diemair, W., 273.Dienes, G. J., 79, 80.Dienske, J. W., 34.Diesslin, A. R., 280.Dietrich, P., 217.Dihlmann, W., 361.Dimmling, W., 243.Dimroth, O., 195.Dinaburg, V. A., 72.Dion, H. W., 249.Dippel, W. A,, 364.Dippy, J. F. J., 285.Dische, Z., 328.Di Stefano, V., 360.Distler, H., 143.Dixon, H. B., 87.Dixon, J. S., 263.Dixon, M., 297, 306.Dixon, R. N., 15.Dixon-Lewis, G., 84, 89.Djerassi, C., 179, 213, 220,221, 229, 230, 231, 232,235, 237, 238.Dobriner, K., 167, 179, 223,318, 361.Dobroborskaya, A. I., 152.Dobry, A., 299, 303.Dodd, R.E., 62.Dodson, M. J., 321.Dodson, R. W., 56.DoebeI, I<., 195.Doehaerd, T., 44.Dorfel, H., 263.Doering, W. von E., 198,190, 245.Doerschuk, A. P., 334.Doherty, D. O., 304.Dole, M., 80.DolejS, L., 206, 215.Doleial, J., 353.Dollimore, D., 126.Dombois, H. E., 122.Domingues, L. P., 354, 364.Donahue, E. T., 185, 357.Donaldson, D. M., 392, 393.Dondes, S., 50, 77.Donnay, G., 373.Donnay, J. D. H., 373.Donohue, J., 380, 391.Donovan, F. W., 195.Dorfman, A., 334.Dorfman, L. M., 77.Dorner, R. W., 273.Dornow, A., 180.Dorsey, C. L., 35.Dortmann, H. A., 204, 255.Dostrovsky, I., 166.Dothie, H. J., 395.Doty, P., 278.Doudoroff, &I., 331, 332.Dougill, M. W., 388, 389.Douglas, A. E., 15, 45.Douglas, B. E., 121, 150.Douglas, J.E., 96.Douglas, P. E., 44.Dounce, A. L., 273.Dousmanis, G. C., 8.Dowden, D. A., 100.Dowell, A. M., jun., 159.Dowling, J. M., 16.Downie, A. R., 135.Downie, T. C., 389, 390.Downs, J., 55.Doyle, B., 2‘79.Drago, R. S., 135.Drake, L. C., 102.Draper, M. D., 257, 258.Dratovsky, M., 116.Dreiding, A. S., 173, 188222, 233.Drell, W., 271.Dresdner, R. D., 280.Dresel, E. I. B., 312, 320,Drew, E., 104.Dreyfus-Alain, B., 348.Druey, J., 246.Drummond, A. Y., 58.Drummoncl, L. J., 260.Dubnoff, J. W., 302.Dubois, F. W., 30.Duchesne, J., 24, 25, 26.Dunnenberger, M., 239.Durkop, A., 138.Diirr, H., 263.Duewell, H., 196.du Feu, E. C., 205.Duff, S. R., 159, 200.Duffin, G. F., 244.Duke, H. R., 58.Duke, J.R. C., 389.Dulmage, W. J., 381.Dulou, R., 215.Dunn, A. S., 74.Dunn, G. E., 61.Dunn, J. R., 65.Dunitz, J. D., 18, 381.Dunlop, P. J., 109.Dupont, G., 215.Durham, G. S., 122.Durup, J., 83.Dutta, M., 106.Dutta, S. I<., 274.Dutton, G. G. S., 262.Duval, Cl., 18.Duyckaerts, G., 363.Dworkin, A. S., 40.Dwyer, F. P., 57, 151.Dyatlovitskaya, F. G., 362.Dye, J. L., 108.Dyer, L. D., 151.Dykhno, N. M., 55.Eades, R. G., 391.Eager, R. L., 59.Eastham, J. F., 22s.Eastman, R. H., 201, 502.Eastwood, I;. W., 255.Ebel, J. P., 368.Ebenhoch, F. L., 144.321408 INDEX OF AUTHORS’ NAMEEberhardt, W. H., 27, 119,Ebert, J., 140.Ebert, M., 116.Eckstein, B. H., 45, 64.Ecollan, J.-F., 21.Ecollan, M., 21.Eddy, C.R., 236.Eddy, L. B., 126.Eddy, L. P., 129.Edelman, I. S., 109.Edelman, J., 266.Edgcombe, L. J., 364.Edmonson, P. R., 312.Edsall, J. T., 300, 306.Edsberg, R. L., 352.Edward, J. T., 191, 211,Edwards, J. O., 127.Edwards, 0. E., 254.Edwards, R. K., 42.Ege, S. N., 166.Egerton, (Sir) A. C., 83.Eggers, D. F., jun., 30.Eggert, H. G.. 175.Eggleston, L. V., 301.Eglington, G., 182.Ehlers, V. B., 355.Ehrenstein, M., 229, 230,Ehrlich, G., 17.Ehrlich, P., 132.Ehrlich, R., 238.Eichhoff, H. J., 138.Eichhorn, E. L., 47.Eichorn, G. L., 28, 121.Eidinger, D., 363.Eigen, M., 23, 47, 59, 104,Eiland, P. F., 398.Eilbracht, IS., 222.Eisenberg, F., 334.Eisenbraun, E. J., 189.Eisner, A., 185.Ekeblad, P., 357.Ekstrand, T., 196.Elad, D., 200, 262.Elchlepp, H., 136.Elder, C.C., 188.Elderfield, R. C., 258.Eleuterio, H. S., 162.Eley, D. D., 41, 74, 94, 128.Eliel, E. L., 222.Elion, G. B., 249.Elisberg, E., 228.Elkeles, H., 56.Elks, J., 223, 232, 236.Ellenbogen, E., 300.Elliott, A., 19.Elliott, R. M., 143.Ellis, A. J., 158.Ellis, B., 230.Ellis, E. L., 36.El Mangouri, H. A., 185.Els, H., 229.El Sabeh, S. H. M., 32.El Sayed, J. h., 117.386.212, 218.238.106, 110.El-Shamy, H. K., 281.Elson, D., 275.Elvidge, J. A, 242.Elvin, E. J., 369.Elving, P. J., 47, 352.El Wakkad, S. E. S., 117.Emanuel, C. F., 273.Emelkus, H. J., 53, 144,281, 286, 287, 293, 294.Emilius, M., 134.Emmons, W. D., 191.Endres, G. F., 75.Endres, H., 176.Engel, C.R., 235.Engelbrecht, A.. 146.Engel’hart, V. A., 332.Engell, 13. J., 101.Engle, R. R., 310.Enklewitz, M. , 333.Enomoto, S., 49.Enthoven, R. H., 255.Entner, N., 331.Entwistle, N., 182.Ercoli, A., 236.Erdey, L., 342.Erdtman, H., 200.Eriks, E., 384.Eriks, K., 29, 119, 386.Eriksen, W. T., 34, 206.Erkut, H., 58.Erlandsson, G., 9.Erlanger, B. F., 181.Erlenmeyer, H. , 358.Erne, K., 357.Ershler, B. V., 114, 115.Eschenmoser, A., 197, 208,216, 230.Esin, O., 114.Essery, R. E., 343.Essex, H., 76.Esteva, E., 25.Ettlinger, M. G., 390.Evans, D. E., 230.Evans, D. E. M., 258.Evans, E. E., 333.Evans, H. T., 374.Evans, J. C.. 19.Evans, M. W., 105.Evans, R. F., 193.Evans, R. M., 232, 233,Evans, W.H., 38.Everest, D. A., 133.Everett, G. E., 355.Evert, H. E., 352.Ewing, M., 333.Eyrig, R. J., 75.Eyring, H., 49, 53.Eyring, L., 129.Faber, A. C., 34.Faber, E. M., 302.Faber, J. S., 357.Fagley, T. F.. 48.Fahrenfort, J., 13.Fainberg, A. H., 164.Fairbrother, D. M., 38.236.Fairbrother, F., 139.FajkoS, J., 234.Falk, F., 49.Falk, J. E., 311, 312, 320,Falkenhagen, € I . , 103, lU6,Fallab, S., 358.Fally, G., 91.Fankuchen, I., 390.Fano, U., 77.Fanta, P. E., 242.Fantl, P., 240.Fanus, W. E., 364.Farag, M. S., 394.Farkas, A., 100.Farkas, E., 221.Farkas, L., 60.Farmer, F. T., 77.Farmer, J. B., 45.Farmilo, C. G., 352.Farrands, J . L., 33.Farrar, M. W., 178.Farrington, P. S., 355.Fasman, G. D., 371.Fassbender, H., 141.Fava, A., 56.Fawcett, J.S., 195, 225.Fawcett, R. W., 215.Fazan, R., 362.Feay, D. C., 129.Feeny, H., 10.Fdher, F., 139, 140.Feigl, F., 335.Feit, P., 232.Feitknecht, W., 134.Feldman, C., 367,Feldman, I., 142.Felton, D. G. I., 250.Fknkant-Eymard, F., 29.Fenner, J. V., 282.Ferguson, J., 20.Ferguson, R. C., 8.Ferm, R. J., 244.Fernando, Q., 352, 359.Fernelius, W. C., 120, 121.Ferrante, G. R., 263.Ferraro, J. R., 133.Ferrett, D. J., 120, 171,Ferrier, W. G., 393.Ferrin, J. P., 190.Ferro, K., 143.Feurer, M., 160, 177, 180.Fialkov, Y. A., 138.Ficken, G. E., 253.Field, B. D., 367.Field, E., 93.Field, F. H., 46.Fieser, L. F., 193, 227, 229,Fieser, M., 227.Fiesselmann, H.. 243.Filbert, R.B., 45.Filippova, A. G., 99.Filler, R., 282.Findlay, S. P., 254.321.108.350.230INDEX OF AUTHORS' NAMES. 409Finke, H. L., 36.Finnegan, W. G., 244, 287,289, 290, 395.Fiquet, F., 81.Firsching, F. H., 341.Fischer, E. O., 138, 145,Fischer, F. G., 263.Fischer, H. 0. L., 267.Fischer, R., 264.Fischer, R. R., 342.Fishman, J., 237.Fitzer, E., 122.Fitzgerald, P. L., 274.Fix, D. D., 155.Flaschlra, H., 344.Fleury, P., 269.Florentine, F. P., 170.Florey, I. K., 238.Florey, K., 229.Florianovitch, G. M., 116.Florin, R. E., 75.Flynn, E. H., 265.Flynn, J. P., 41.Fodor, G., 186, 254, 260.Follrers, K., 188, 244.Fonken, G. S., 232.Forbes, J. W., 257.Forchheimer, 0. L., 56.Ford, C. L., 364.Ford, M. A,, 369.Fornefeld, E.J., 256.Forneris, R., 21.Forrest, H. S., 250.Forrest, J., 158.Fortuin, J. M. H., 356.Forty, A. J., 373.Foschini, A., 349.Foss, O., 384, 385.Foster, A. B., 172, 264.Foster, J. F., 86.Foster, R. V., 166.Fowden, L., 188.Fowler, D. I., 188.Fowles, G. W. A., 138.Fox, C. J., 284.Fox, J. J., 250, 271.Fox, M., 76, 83.Fox, R. C., 251.Fraenkel, G., 61.Fraenkel, G. J., 62.Fraenkel, G. K., 10, 139.Fraenkel-Conrat, H., 279,Framm, E., 132.France, H., 253.Francesconi, L., 209.Francis, E. M., 216.Francis, H. T., 280.Francis, W. C., 281, 284.Frank, H. S., 105, 106.Frankel, 31., 192.Franklin, J. L., 46.Franklin, R. E., 279.Franzen, V., 182.Fraser, F. M., 34.Fraser, R. D., 19.146.307, 308.Frayn, J.S., 122.Frazer, B. C., 378.Frazer, J. H., 150.Frazer, hl. J., 140, 180.Frech, M. F., 53, 89.Frederickson, L. D., jun.,Fredga, A., 202.Frediani, H. A., 335.Freed, S., 68, 312, 362.Freedman, A. J., 55.Freeman, G. F., 247.Freeman, G. R., 83.Freeman, R. D., 44.Freidlina, R. K., 132.Freiling, E. C., 363.Freise, V., 113.Freiser, H., 336, 337.Frejacques, C., 49.French, R. O., 369.Frenkel, J., 382.Freundlich, W., 130.Frey, R. W., 343.Fricli, G., 273, 279.Fridrichsons, J., 397.Fried, J., 227, 233.Fried, M., 277.Friedel, R. A., 148.Frieden, C., 306.Friedkin, M., 270.Friedlander, P. H., 394.Friedman, H., 365.Frierson, W. J., 358.Frigimote, G. I., 205.Frisque, A., 350.Fristrom, R. M., 8.Frith, W.C., 139.Fritz, G., 130, 180.Fritz, H. E., 134.Fritz, J. S., 345, 357.Fritzsche, H., 354.Froitzheim-Kiihlhorn, H.,Frohardt, R. P., 188.Frontali, N., 360.Frost, A. A., 26, 359,Fruhstorfer, W., 222.Frumkin, A., 114.Frumkin, A. N., 116.Frush, H. L., 266.Fruton, J. S., 299.Fry, C. E., 202.Fuchs, O., 125.Fudge, A. J., 230.Fiirst, A., 178, 200, 207,Fuhlbrigge, A. R., 306.Fuhrman, N., 70.Fujii, S., 72.Fujiwara. S., 23, 355.Fukui, K., 70.Fukushima, D. K., 179,233, 235.Fulda, M. O., 345.Fuller, R. C., 333.FUOSS, A. S., 104.367.204.370.216, 229.Fuoss, R. M., 103, 104.Furberg, S., 384, 395.Furman, N. H., 352, 355,Furrer, M., 229.Fusari, S. A., 188.Fusezaki, Y., 71.Fuson, N., 20, 29.Futung Liao, 240.Gabaglio, M., 141.Gabillard, R., 7.GAbor, V., 125, 179.Gadsby, J., 49.Galatry, L., 14.Galik, V., 253.Galinovsky, F., 254, 255.Gall, W.G., 247.Gallagher, J . J . , 12.Gallagher, K. J., 384.Gallagher, T. F., 179, 228,Galloway, W. L., 197.Galster, II., 128.Galy, A., 21.Ganio, I., 26.Gandini-Kezstler, F., 213.Garden, J., 195.Gardner, D., 192.Gardner, D. M., 10, 139.Gardner, P. D., 192.Garg, S. N., 27.Garner, C. S., 56, 57.Garner, W. E., 87, 100,101.Garrett, E. R., 235.Garven, F. C., 266.Garvin, D., 47, 89, 100.Gary, R., 107.Gascoigne, R. M., 239.Gash, V. W., 20.Gastinger, E., 132.Gates, M. D., 193.Gattow, G., 40.Gaudemar, M., 189.Gauguin, R., 355.Gauhe, A., 267, 270.Gaumann, T., 10, 30.Gaunt, J., 17, 368.Gaur, H.C., 350.Gautschi, F., 224, 226.Gaydon, A. G., 88.Gaylord, N. G., 241.Gayon, P. R., 360.Gebauhr, W., 339.Gee, A., 354, 364.Geerdes, J. D., 263, 361.Gehlen, I-I., 136.Geiersberger, K., 128.Geilmann, W., 339.Geissman, T. A., 249.Geistlich, P., 231, 232.Geller, L. E., 220.Gelled, H. G., 128.Gelles, E., 160.Genaux, C. T., 52.Gent, W. L. G., 31.Gentile, P. S., 150.364.233, 235410 INDEX OF AUTHORS’ NAMES.George, J., 47.George, J. H. B., 110.George, P. H., 105.Georgian, V., 236, 247.Gerber, R., 94.Gerding, H., 21.Gerischer, H., 115.Gerjovich, H. ’J., 287.Germano, A., 362.Gerngross, O., 311.Gernstein, M., 173.Gerold, C., 228, 233.Gerrard, W., 127, 140, 180.Gerritsen, H. J., 10.Gerzon, K., 265.Ghe, A.M., 359.Ghel’man, N. S., 347.Ghielmi, S., 141.Ghosh, B. N., 46.Ghosh, S., 122.Ghosh, S. N., 11.Giannoni, G., 142.Gibbins, B. J., 28.Gibbons, D., 344, 346.Gibbs, D. S., 124.Gibbs, J. H., 27.Gibbs, M., 328, 329.Gibons, N. A., 119.Gibson, D. T., 175.Gibson, E. J., 99.Gibson, G., 133.Gibson, J. A., 354, 355.Gibson, I<. D., 322.Gibson, Q. H., 48.Giddings, J. C., 49.Gierst, L., 115.Giese, A. C., 279.Giese, M., 293.Gigukre, P. A., 139.Gilby, R. F., 34.Gilkerson, W. R., 245.Gill, N. S., 151,Gillam, A. E., 366.Gilles, P. W., 355.Gillespie, R. J., 295.Gillian, 0. R., 9.Gillis, J., 338.Gillman, E. G., 292.Gilman, H., 134, 154.Gilmour, A., 390.Gilvarg, C., 334.Ging, N. S., 302.Ginori-Conti, G., 122.Ginsburg, A., 187.Ginsburg, D., 200, 202, 262.Ginsburg, V., 266.Giri, K.V., 361.Gissman, H. M., 10.Gittrow, J., 360.Gjems, O., 364.Gladner, J. A., 306.Gladrow, E. M., 102.Gladyshevskaya, V. A., 75.Glafkides, C. M., 322.Glaser, I;. IT., 133.Glazener, M. R., 188.Glegg, R. E., 363.Glemser, O., 131, 142Glenn, A. L., 256.Glenn, R. A., 353.Clines, A., 79.Glock, G. E., 328, 331.Glockling, F., 123.Glueckauf, E., 107.Glushkova, V. B., 142.Gochenour, C. I., 289.Godbole, A. N., 361.Goddu, R. F., 356.Godin, P., 361.Godycki, L. E., 386.Goehring, M., 140.Goerdeler, J., 244, 245, 246.Goering, H. L., 59, 203.Goetzler, H., 99.Goggin, D., 147.Gohrbrandt, E. C., 356,Gold, A. M., 207.Gold, V., 47, 105.Goldberg, A., 312, 316.Goldberg, G.S., 339.Golden, S., 49.Goldfinger, G., 70.Goldfinger, P., 44.Goldstein, J. H., 8, 9.Goldstein, M., 278, 361.Gomer, R., 94.Gomm, A. S., 87.Gonick, E., 121.Good, W. D., 36, 37.Goodall, A. M., 48, 52.Goodman, I., 76.Goodman, J. J., 154.Goodman, L., 168, 240.Goodwin, T. H., 389, 394.Gordon, A, R., 104.Gordon, A. S., 63, 88.Gordon, L., 341.Gordon, M., 169, 171.Gordon, S., 77.Gordy, W., 7-11, 25, 26.Gore, D. N., 361.Gore, R. C., 17, 368.Gorin, G., 59, 286.Gorin, P. A. J., 326.Gorter, E. W., 387.Gosling, R. G., 279.Gosting, L. J., 109.Gottlieb, I. &I., 367.Gottschalk, A., 243.Goubeau, J., 126.Gould, B. S., 308.Goulden, J. D. S., 20, 359.Goutarel, R., 257, 258.Gouy, G., 110.Govindachari, T.R., 255,Gowenlock, B. G., 46, 51.Gracheva, E. P., 70.Gradinger, H., 129.Granicher, H., 32.Graftstein, D., 290.Graham, J. R., 104.Graham, T. E., 50, 93.366.261.Grahame, D. C., 111, 113,Grahn, M., 360.Grsizon, M., 352.Gramstad, T., 293.Granick, S., 311, 312, 317,Grant, D. M., 147.Grant, F. W., jun., 218.Grard, F., 91.Grassie, N., 75.Grassmann, W., 176.Grau, L., 139.Graus, B., 133.Graven, W. M., 50.Gray, C. H., 318, 322.Gray, P., 35, 52, 89.Green, J., 236, 361.Greene, E. F., 47.Greenfield, H., 148.Greenlee, K. W., 98.Greenstreet, C. H., 161.Greenwood, N. N., 119,Gregor, H. P., 354.Gregory, V. P., 241.Gregson, J. J., 98.Greiner, C. M., 331.Grenon, M., 348.Grewe, R., 266.Grey, T.F., 189.Griffith, E. J., 138.Griffith, T., 361.Griffiths, J. H. E., 11.Griffiths, J. 141. M., 120.Grigor, J., 187, 231.Grimley, J., 126.Grimmer, G., 237.Grinngn, E. L., 273.Grisenthwaite, R. J., 14.Grison, E., 7, 384.Griswold, E., 146.Grivet, P., 7.Grob, C. A., 171, 242, 252.Grob, R. L., 338.Gross, A. M., 360.Gross, D., 269.Gross, M. E., 36.Gross, P., 41.Grosse, A. V., 146, 287.Grosslinsky, O., 192.Grossnickle, T. T., 237.Groth, W. E., 64.Grove, J. F., 192, 195.Griindel, R., 171.Grund, H., 336.Grundmann, C., 246.Grundy, J., 162.Grunwald, E., 357.Gry, O., 352.Gryszkiewicz-Trochimow-Guarino, A. J., 332.Gunter, R. B., 312.Gunthard, H. H., 30, 200,Gunthard, 13. S., 178.114, 115.321, 322.384.ski, E., 282.238INDEX OF AUTHORS’ NAMES.41 1Guenthner, R. h., 293.Giinzel, C., 362,Guggenheim, E. A., 109,Guider, J. M., 238.Guillet, J. E., 74.Guinn, V. P., 47.Gulland, J. M., 273.Gundry, H. A., 34.Gunn, S. R., 43.Gunning, H. E., 64, 68.Gunsalus, I. C., 323.Gunstone, F. D., 186, 187,Gunther, F. A., 353.Gurin, S., 334.Gurney, R. W., 103.Gur’yanova, E. N., 56.Gustavson, M. R., 47.Gut, R., 120.Guterman, M. S., 116.Gutfreund, H., 297, 302,Guthrie, G. B., jun., 44.Gutman, J. R., 98.Gutowsky, H. S., 17, 23,24, 174, 378, 382.Gutsche, C. D., 163.Gutsell, E. S., 232.Guzman, G. M., 73.Gwinn, W. D., 8, 10.Gyarfas, E. C., 119, 152.Gysel, H., 336.Haack, E., 257.Haber, F., 85.Hach, R.J., 385.Hacklcy, B. E., 310.Hadman, G., 87.Hadni, A., 16.Hadii, D., 18, 196.Haendler, H. M., 122, 144.Haensel, V., 102.Hafner, W., 138.Hagelloch, G., 268.Hahn, H. H., 186.Hahn, R. B., 354.Hahn, T., 387.Hahofer, E., 358.Haight, G. P., 351.Haissinsky, M., 121.Hajek, J., 28.Hajbs, A., 179.Haldane, J. B. S., 306.Hale, C. H., 352.Hale, M. N., 352.Hales, J. L., 162.Haliord, J. O., 28.Hall, A. G., 328.Hall, C. C., 99.Hall, D. M., 194.Hall, G. R., 11.Hall, J. A., 187.Hall, J. L., 150, 354, 355.Hall, J. R., 109.Hall, M. I?., 59.Hall, N. F., 56.111.210.307.Hall, R. M., 181.Hallam, H. E., 21.Halliday, J. S., 117.Halpern, M., 356.Hals, L. J., 281, 286.Halsall, T. G., 165, 238,Ham, E. A., 224.Ham, G.E., 73.Ham, J., 28.Hamann, S. D., 49.Hambel, F., 32.Hambsch, E., 268.Hamill, W. H., 66, 78.Hamilton, J. K., 176.Hamilton, L. A., 190.Hamlet, J. C., 233.Hamm, R. E., 147.Hammer, I., 180.Hammond, G. S., 67, 171.Hampel, B., 21.Hampton, A., 337.Hamuro, M., 209.Hanaria, G. I. H., 105.Hanby, W. E., 19.Hancock, C. K., 34.Handel, J. V. A., 10.Hanford, W. E., 293Hanger, W. G., 208.Hann, R. M., 328.Hannan, R. B., 396.Hansen, J. H., 158.Hansen, L., 8.Hansen, R. P., 185, 186.Hansen, W. W., 23.Hansford, R. C., 102.Hanson, A. W., 375, 394.Hantschel, H., 266.Hantzsch, A., 143.Hanze, A. R., 232.Hara, K., 355.Harborne, J. B., 249.Hardegger, E., 254, 266.Harding, J. S., 241, 243.Hardwick, N. E., 237, 267.Hardwicke, J., 362.Hardy, C.J., 52.Hardy, H. R., 58.Hardy, T. L., 361.Hardy, W. A,, 8.Hardt, H. D., 123.Hargrave, K. R., 162.Harington, C. R., 309.Harkins, H. H., 273.Harland, W. I., 280.Harley-Mason, J., 253, 255.Harman, R. E., 224.Harmer, D. E., 78.Harned, H. S., 107, 109.Harnik, E., 393.Harper, S. H., 202.Harper, W. J., 360.Harris, A. Z., 333.Harris, F. E., 28, 29, 30.Harris, G., 262.Harris, G. M., 63.Harris, J. O., 215.239.Harris, J. T., jun., 29.Harris, P. G., 367.Harris, R. J. C., 273.Harrison, J. S., 298, 299.Harrison, S., 352.Harshmann, S., 310.Hart, E. J., 77, 80, 81.Hart, H., 162.Hart, V. E., 75.Harteck, P., 50, 77.Hartkamp, H., 363.Hartley, B. S., 309, 310.Hartley, G. S., 104.Hartman, L., 186.Hartman, P.J., 246.Hartmann, H., 131.Harty, W. E., 60.Harultawa, T., 209.Harvey, D., 362.Harvey, K. B., 139.Harvey, P. G., 362.Harvey, R. B., 22.Harvey, S. I<., 361.Hasbrouck, R. B., 266.Hase, H., 32.Hasek, W. R., 244, 246.Hashizume, T., 360.TIaskell, T. H., 188.Haskell, W. W., 357.Hasler, M. F., 367.Haslewood, G. A. D., 236.Hassel, O., 391, 393, 394,Hassid, W. Z., 269.Hassion, F. X., 32.Hasted, J. B., 32.Haszeldine, K. N., 20, 144,279, 280, 281, 282, 284,286, 287, 288, 289, 291,292, 293, 294.395.Hattman, J. R., 103.Hatton, J., 26.Hauffe, K., 100, 191.Hauptschein, M., 282, 287.Hauptman, H., 374.Hauschild, U., 142.Hayser, C. R., 157, 158,Hautefeuille, P., 131.Haven, A.C., jun., 227.Havill, J. R., 142.Havinga, E., 30, 203.Havinga, E. E., 385.Hawkins, J. E., 34, 206.Hawkinson, V., 317.Haworth, R. D., 154, 199,Hawthorne, M. F., 161.Hayashi, I., 11.Hayashi, K., 70.Hayashi, S., 355.Hayatsu, R., 230.Haycock, E. W., 30.Hayden, A. L., 369.Hayek, E., 144.Hayes, D. H., 212, 270.Hayes, J. C., 57.191.25341 2 INDEX OF AUTHORS’ NAMES.Hayes, P. M., 244.Hayes, R. A., 73.Hayes, T. G., 345.Hayman, C., 41.Haynes, H. F., 255.Hayter, R. G., 123.Hayward, B. J., 188.Hazel, T. F., 367.Head, F. S. H., 263.Heath, D. F., 84.Heath, G. A., 8.Hecht, F., 368, 359.Heffelfinger, C., 70.Heftmann, E., 361.Heggie, R. M., 210.Heidt, L. J., 68.Heilbronner, E., 197, 201Heine, V., 11.Heinemann, H., 103.Ileinkel, T., 266,Heinze, G., 140, 141.Helbling, R., 231.Helfferich, F., 181.Heller, M., 234.Hellerman, L., 305, 308.Hellmann, H., 188.Helmkamp, G.K., 353.Hemmer, B. A., 77.Hems, B. A., 231.Hems, R., 301.Henbest, H. B., 172, 223,Henderson, A. W., 133.Henderson, I. H. S., 45, 46,Henderson, W. G., jun., 61.Hendricks, J. O., 282.Hendrie, J. M., 45.Hendus, H., 123.Henglein, A., 79.Henglein, F. A., 122.Henley, E. J., 77.Henne, A. L., 281,282, 284,286, 287, 288, 289, 290,292.Henniker, J. C., 114.Henry, R. A., 244, 395.Henseke, G., 266.Hepler, L. G., 43.Heppel, L. A., 277.Hepworth, M. A., 151.Herbert, J. B. M., 275.Herbert, R. H., 56.Herbky, J., 254.Herbst, R. L., 70.Herbstein, F. IS., 375, 393.Herissey, H., 269.HerIing, F., 167, 223.Herman, M., 357.Hermann, C., 367.Hermann, E., 128.Hermann, R., 138.Heron, S., 69.Herout, V., 201, 206, 207,Herr, M.E., 181, 227.Herran, J., 213.231, 233.62.208, 213, 214, 215.Herriot, R. M., 307, 308,Herrmann, J., 348.Hers, H. G., 266, 305, 326.Hershberg, E. B., 228, 233,Herz, J. E., 227.Herz, W., 200, 242.Herzberg, G., 382.Herzberg, H., 212.Herzog, H. L., 233.Heslop, R. B., 191.Hesse, G., 192, 222.Hestrin, S., 302.Hetherington, G., 144.Heusler, K., 207, 236.Heusner, A., 254.Heusser, H., 230, 231, 232,235, 236, 238, 239.Hewett, D. R., 364.Hewgill, I;. R., 203.Hextall, P., 230.Hey, D. H., 61, 193, 236,Heyer, W., 249.Heyl, F. W., 181, 227.Heyns, K., 265.Hibbits, J.O., 350.Hickling, A., 114.Hickman, J., 333.Hicks, J. A., 74.Hieber, W., 148.Higbie, K. B., 133.Ilildreth, C. L., 109.Hill, D. G., 11, 18, 158.Hill, H. M., 289.Hill, N. E., 32.Hill, R., 332.Hill, R. M., 12.Hill, T. L., 296, 300.Hillis, W. E., 249.Hillman, M., 163.Hills, G. J., 104.Hillson, P. J., 116.Hilmoe, R. J., 277.Hilton, J., 47.Himmler, W. A., 241.Hinckley, A. A., 125.Hindman, J. C., 54.Hine, J., 55, 159.Hinkamp, P. E., 289.Hinshelwood, (Sir) C. N.,Hinsvark, 0. N., 350.Hintermeier, K., 242.Hipple, J. A., 44, 105.Hirokawa, S., 388, 391.Hirota, E., 29,Hirsch, H., 91.Hirsch, H. E., 328.Hirsch, P. F., 332.Hirschmann, R., 195, 223.Hirschmann, R. F., 223.Hirshfeld, I;. J., 376.Hirshfeld, F.L., 393.Hirshon, I. M., 10.Hirshon, J. M., 62.309.234.291.49, 51, 87.Hirst, E. L., 326.Hirst, R., 124.Hisatsune, I. C., 30.Hiskey, C. F., 223.Hitchings, G. H., 249.Hiyama, N., 243.Hoare, D. E., 88, 91.Hobbs, E., 384.Hobbs, M. E., 29, 31.Hoch, M., 45, 132.Hochster, R. M., 333.Hockman, R. H., 328.Hodge, N., 135.Hodges, R., 238.Hodgkin, D. C., 391, 399.Hoelscher, H. E., 93.Hormann, H., 176.Hoschele, G., 266.Hofer, L. J. E., 40.Hoffman, J. D., 32.Hoffman, N. E., 206.Hoffmann, J. I., 105.Hofmann, A., 256, 257.Hogg, J. A., 236, 280.Hoh, J., 25.Hohenscliutz. H.. 140.Hohn, H., 122. .Hohnstedt, L., 126.Hoijtink, G. J., 34.Holcomb, D. E., 3.5.Holker, J. S. E., 239.Holland, D.O., 361.Hollenberg, J. L., 16.Holley, C. E., jun., 40.Holley, F. W., 244.Holley, T. F., 218.Holliday, A. K., 126.Hollinger, R., 255.Hollingshead, R. G. W.,Holm, V. C. F., 102.Holrnan, R. T., 186.Holme, D., 183.Holroyd, R. A., 66.Holtermann, H., 159.Holtzberg, F., 390.Holtzinger, K. R., 352.Ilolub, M., 213.Honeyman, J., 236.Honig, A., 10.Honig, R. E., 42, 43, 102.Honn, F. J., 291.Hooge, F. N., 137.Hopkins, F. G., 308.Horan, H. A., 129.Horeau, A,, 1’75.Horecker, B. L., 328, 329,331, 332, 333.Iloriuti, J., 49.Horn, D. H. S., 182, 185,Horner, E. C. A., 49, 67.Hosking, J, R., 218.Hossenlopp, I. A., 35.Hoste, J., 338.Houff, W. H., 350.Hougen, F. W., 185.337.187IIough, L., 262, 267, 326.Houghton, G., 100.Hourigan, H.F., 351.Houtgraaf, H., 21.Howard, E. €I., 128.Howard, G. A., 361.Howell, P. A., 246, 395.Howells, E. R., 388.Howlett, K. E., 48, 52.Hoyle, B. E., 124.Hrostowski, 33. J., 9, 17.I-Iuang, H. T., 305.Hua,ng, l3. L., 194.Huang-Minlon, 211, 235.Hubbard, W. N., 36, 37.Huber, E. J., jun., 40.Huber, W., 140.Hubicki, TV., 351.Hudgell, A. W. D., 232.Hudson, C. S., 325.Hudson, P. B., 367.Hudson, R. F., 161.Hiickel, E., 107.Huckel, W., 216.Hueter, R., 243.Huffmann, H. ill., 36, 37,297, 301, 303.Hughes, E. D., 155, 160,161, 168, 171, 203.Hughes, E. W., 391.Hughes, G. H., 255.Hughes, R. H., 370.Hugus, 2. z., 43.Iluisgen, R., 251.Iluisman, T. H. J., 363.Huldt, L., 45.Human, J. P. E., 196.Humber, L.G., 195, 261.Hume, D. N., 356.Ilummel, R. W., 77, 83.Humphrey, F. B., 381.Humphrey, G. L., 40.Hunger, A., 237, 260.Hunt, E. C., 358.Hunter, D., 199.Hur,ter, J. A., 363.Hunter, J. S., 118.Hunter, R. I?., 103.Huppertz, A., 245.Ilurst, R., 143.Hurst, R. O., 274.Hurtubise, F. G., 69,Husted, D. R., 282, 283.Huston, J. L., 56.Hutchison, C. A., 11.Hutchison, H. P., 212.Huuskonen, T., 30.Hyde, E. K., 120.Hymo, L. A., 75.Hyndman, D., 24, 391.Iball, J., 388, 392, 393.Ibamoto, H., 11, 33, 300.Ichikawa, N., 243.Idler, D. R., 338.Igarashi, M., 22.Ikawa, M., 245, 310.TNDEX OF AIJTHORS' NAMES.Ikeda, R. M., 361.Ikenaka, T., 68.Illarionov, V. V., 92.Imaeda, Y., 25.Imoto, M., 71.Inatome, M., 269.Inghram, M.G., 43.Ingold, C. K., 153, 160,161, 168, 171, 203.Ingold, K. U., 45, 46, 62.Ingram, D. W., 282.Inhoffen, H. H., 171, 185,Inman, C. G., 241.Innes, K. K., 153.Inokuchi, T., 55.Inone, N., 25.Ipatieff, V. N., 202, 206.Iret'yakov, I. I., 99.Irion, W., 362.Irish, G. E., 360.Irsa, A. P., 97.Irvine, D. H., 105.Irving, H. M., 120, 171.Isbell, H. S., 266.Iselin, B., 180.Iselin, B. M., 227, 305.Iserson, H., 283.Isherwood, F. A4., 189, 237,2G7, 360.Ishikawa, $I., 209.Isler, O., 195.Isrnay, D., 192.Issa, I. M., 142, 353.Issa, R. M., 353.Ito, H., 72.Ito, M., 21.Ito, T., 387.Ito, Y., 70.Ttoli, J., 389.Ives, D. A. J., 238.Ives, D. J. G., 104, 117,Iwasalri, M., 22.Izrailevich, E. A., 54.Jaarma, M., 263.Jache, A.W., 9.Jach, J., 51.Jaclrlin, A. G., 187.Jackman, J., 193.Jackman, L. M., 177, 194.Jackman M., 232.Jackson, A. H., 255.Jackson, W. J., 193.Jacobs, G., 134.Jacobs, T. L., 183.Jacobs, W., 361.Jacobs, W, A., 224, 225,Jacobson, M., 186.Jacques, P., 326.Jacquest, J. A. T., 45.Jacquier, K., 166.Jacquinot, M., 340.Jaeger, R. H., 173.Jaffe, H., 322.232, 236.169.272.41 3affk, H. H., 60.affe, S., 108.ahn, W., 123.ames, F. C., 243.ames, S., 309.ames, V. H. T., 236.ameson, R. F., 129, 147.amieson, G. A., 250.ander, J., 20, 293.angr, V., 352.anot, M.-M., 257, 259.ansch, H., 240, 369.ansen, E. I?., 304.anz, G. J., 104.arolixn, V., 215.arrett, H. S . , 11, 371.eanes, A., 263.eanloz, R.W., 265.efferies, P. R., 199, 203.effes, J. H. E., 42.effrey, G. A., 375, 388,Jeffreys, J. A. D., 195.Jeger, O., 207, 205, 220-Jellinek, H. H. G., 76, 352.Jenckel, E., 76.Jenkin, D. G., 16.Jenkins, A. D., 72.Jensen, C. O., 352.Jentzsch, D., 368.Jerchel, D., 361.Jessup, 33. S., 34, 37.Jindra, A., 352.Jira, R., 145, 146.Johannessen, D. W., 188.Johanson, R., 264.Johansson, A., 347.John, G. S., 93.Johns, 13. E., 77.Johns, R. B., 198, 200.Johns, W. I?., 160, 177.Johnson, A. W., 196, 197,Johnson, C. M., 9, 12.Johnson, D. F., 361.Johnson, E. R., 81.Johnson, F., 236.Johnston, H. L., 132.Johnston, €I. S., 49, 50.Johnson, J . A., 361, 363.Johnson, J. S., 104.Johnson, 0. H., 134, 359.Johnson, P. R., 206.Johnson, R., 206.Johnson, R.D., 8, 10.Johnson, R. E., 55.Johson, S., 28, 126, 245,Johnson, T. B., 273.Johnson, W. H., 34, 41.Johnson, W. S., 160.Johnston, H. L., 45.Johnston, H. S., 47, 50, 92.Johnston, J . D., 222.Johnston, W. D., 337.389, 396.222,224-227,232,238-240.198, 200, 399.312414 INDEX OF AUTHORS’ NAMES.Johnstone, J. H., 331.Jona, F., 32.Jordan, D. O., 273.Jorgensen, H. E., 233.Jori, M., 138.Jones, A., 361.Jones, A. S., 270, 273, 274,Jones, E., 86.Jones, E. R. FI., 165, 167,172, 175, 182, 183, 231,233, 238.Jones, G., 218.Jones, G. B., 361.Jones, J. I., 45, 162.Jones, J. K. N., 262, 263,268, 269, 326.Jones, Ll. H., 17, 18.Jones, M. E., 124.Jones, M. H., 73.Jones, M. M., 135, 142.Jones, P., 117.Jones, P.G., 233.Jones, R. E., 228.Jones, R. G., 256.Jones, R. L., 19.Jones, R. N., 167, 223.Jones, W. H., 348.Joseph, J. P., 249, 266.Joshi, B. S., 197.Joshi, C. G., 248.Joshi, R. M., 72.Josien, M.-L., 20, 29.Joska, J., 230.Jowett, P., 327.Joyce, R. M., 281.Jucker, E., 254.Juda, W., 104.Judd, G. F., 294.Judge, W. A., 158.Julia, S. A., 230.Julian, P. L., 177, 234.Juliard, A. L., 115.Jungner, G., 273.Jura, G., 29, 93.Just, G., 236.Juza, K., 121.Kabanov, B. N., 353.Kabsh, T. V., 116.Kaclalia, P. K., 32.Kahan, J . , 2 64.Kahle, G., 350.Kahn, A., 64.Kahn, M., 55.Kahrs, K. H., 291.Kainer, H., 11.Kainz, G., 346.Kaiser, F., 257.Kakiuchi, H., 71.Kalckar, H. M., 296, 331.Kalkwarf, D.R., 359, 370.Kall, H. I., 341.Kalman, A., 300.Kalnajs, J., 382.Kalvoda, J., 207.Kamecki, J., 350.278.Kamenskaya, S. N., 73.Kamienski, B., 361.Kamiya, T., 254.Kanarskaya, E. N., 75.Kanda, F. A., 124.Kandel, R. I., 46.Kane, J. G., 283.Kane, M. R., 272.Kaneko, Y., 99.Kantor, S. W., 158.Kaplan, L., 20, 55, 60, 69.Kapur, S. L., 72.Kaptsan, 0. L., 354.Karabash, A. G., 343.Karbum, A. C., 360.Karchmer, J. H., 352.Karl, H. L., 364.Karle, J., 8, 22, 374, 390.Karle, I . L., 8, 22, 390.Karpacheva, S. M., 100Karrer, P., 249, 265.Karsten, P., 356.Kartzmark, E. M., 122.Kasaka, R., 25.Kashima, M., 22.Kasper, J. S., 387.Kassel, L. S., 92.Kato, M., 67.Kato, S., 72.Katsura, H., 261.Katz, A., 235.Katz, C., 36.Katz, G.I., 51.Katz, J., 332.Katz, L., 388.Katzenellenbogen, E. R.,179, 223, 361.Katzin, L. I., 133.Kauck, E. A., 280.Kaufman, S., 305, 306.Kaushal, R., 327.Kawaguchi, S., 328.Kawatani, T., 213.Kay, E. R. M., 273.Kay, L. D., 333.Kay, R. L., 104.Kaye, B. F., 247.Kaye, S., 20, 38, 290.Kaye, W., 368.Kazanski, B. A., 98.Kazuno, T., 236.Keeley, W. M., 93.Keeling, C. D., 80.Kehl, R., 312.Keier, N. P., 96.Keii, T., 97.Keilholtz, G. W., 370.Keilin, B., 125.Kelbg, G., 106, 108.Keller, A., 16.Keller, F., 257, 268.Keller, F. L., 1.5.Keller. M., 78.Keller, R. T., 204.Keller, W., 200, 216, 245.Kelley, M, T., 354.Kellom, D. B., 154.Kelly, P., 81.Kelly, R. B., 238.Kelso, R. G., 98..Kernball, C., 93, 94, 95, 98,Kemp, A.D., 160.Kemp, K. C., 56.Kemula, W., 21, 67, 352,Kendall, J. D., 244.Kendall, V. G., 187.Kendrick, E., 368.Kennard, O., 312, 317.Kennedy, J. H., 356.Kennedy, J. W., 109.Kenner, C. T., 363.Kenner, J., 158, 190, 265,Kenney, M. E., 129.Kent, P. J. C., 41.Kent, P. W., 277.Kepner, R. E., 361.Kerlogue, R. II., 169.Kern, F., 52.Kern, H. L., 308.Kern, W., 71.Kerr, S. E., 273.Kerrigan, V., 287.Ketelaar, J. A. A., 13, 14,Khalifa, H., 142.Khalique, M. A.; 265.Khan, N. A., 186.Kharasch, N., 192, 201.Khokhlova, 0. I., 358.Khomikovskiy, P. M., 74.Khorana, H. G., 250, 272.Khosla, B., 350.Khouvine, Y., 273.Khym, J. X., 271, 272.Kianpour, A., 19.Kidd, J. M., 292.Kierstead, R. WT., 98, 187.Kies, H.L., 356.Kieslich, K., 183.Kikindai, T., 145.Kibuchi, C., 10.Kikuchi, J., 32.Kilbourne, H. W., 286.Kilby, 13. A,, 304, 310.Kilgour, G. L., 262.Kilpatrick, M. L., 59.Kimberlin, C. N., 102.Kimla, A., 28.Kimura, K., 22, 23.Kimura, M., 22.King, A. J., 124.King, C. G., 81.King, E. G., 40.King, E. J., 300.King, E. L., 47, 64.King, F. E., 195, 217, 218,King, G. S. D., 390.King, T. J., 217, 221.King, W. C., 9, 10.King, W. R., jun., 57,99.353, 362.267, 268.55, 137.221, 248INDEX OF AUTHORS' NAMES. 425Iiingsley, G. R., 364.Kinkel, K. G., 67.Kinney, R. E., 190.Kinnunen, J., 345.Kinoshita, J., 332.Kinter, &I. I<., 204.Kippax, D., 144.Kirby, A. F., 189.Kiriyama, R., 33, 389, 390.Kirk, D.N., 227.Kirkbride, F. W., 37.Kirkland, J. J., 338.Kirkwood, J. G., 107.Kirsch, F. TV., 103.Kirschenbaum, A. D., 282.Kirschenlohr, W., 270.Kirschner, H. G., 216.Kirsten, W., 347.Kisfaludy, L., 269.Kisliuk, P., 8, 26.Kiss, J., 186.Kistiakowsky, G. E., 47,G6, 304.Kitagawa, M., 213.Kitahara, Y., 199.Kitaigorodski, A. I., 375.Kitamura, S., 209.Kitzinger, C., 302.Kivelson, D., 9, 10.Kliiui, H., 216.Klein, E., 48.Kleinberg, J., 124, 139,Klement, R., 137.Klempcrer, W., 18, 29.Klenow, H., 328, 329, 331.Klevstrand, R., 328, 333.Klimke, R., 200.Klimova, V. A., 347.Kline, G. B., 256.Klingenberg, J. J., 339.Klohs, M. W., 257, 258.Klotz, I. M., 306.'Klug, A,, 394.Klug, H. P., 365.Klussendorf, S., 246.Kluyver, J.C., 370.Klyne, W., 153, 172, 205,206, 228, 223.Knauff, K. G., 131, 133.Kniebes, D. V., 68.Knight, C. A., 273, 274.Knight, E. C., 334.Knight, H. T., 344, 355.Knight, J. D., 204.Knight, S. A., 239.Knight, W. D., 23.Knodel, L. R., 369.Knoth, P., 254.Knowles, W. S., 178.Knowlton, J. W., 37.Knox, L. H., 198.Kniitter, R., 124.Kobayahi, T., 256.Koch, C. TV., 42.Koch, E., 67.Koch, O., 137,146.Koch, W., 205, 364.Kocher, F. W., 228.Kocor, M., 260.Koe, B. K., 185.Koenig, F. O., 110.Koenig, G., 156.Konig, H.-B., 265.Kohlhase, W. L., 282.Kohn, D. H., 193.Kohno, K., 68.Koizumj, M., 72.Kojima, R., 22.Kokatailo, G. T., 366.Kolevatova, V. S., 116.Kolier, I., 359.Kolka, A. J., 155.Kollonitsch, J., 125, 179.Kolthoff, I.M., 48, 72, 350,351, 352.Koltzenburg, G., 68.Komatsubara, T., 236.Kondo, A., 75.Kondo, H., 214, 261.Kondo, M., 30.Kopp, D., 87.Kornberg, A., 331.Kornblum, R. B., 165.Kornfeld, E. C., 256.Korshun, M. O., 347.Korte, F., 249, 250.Koryta, J., 58.Koshar, R. J., 290.Koshkin, D. I., 355.Koshland, D. E., 268.Kosolapoff, G. M., 30.Kotgsek, Z., 230.Kotera, K., 261.KovA.cs, o., 254.KovAts, E., 178, 200.Kowalkowski, K. L., 355.Kowalsky, A., 87.Kozima, K., 30.Kozlov, A. S., 339.Kozyrev, B. M., 7, 10.Kraemer, J., 140.Kraitchman, J., 26.Kramer, P. J. G., 362.Kramer, T. J. E., 34.Kraus, C. J., 109.Kraus, D. W., 290, 295.Kraus, K. A., 104.Krause, A., 342.Krause, H. H., 359.Krause, W., 158.Krauss, W., 336.Krebs, H., 139, 141, 150.Krebs, H.A., 297, 298, 299.Krebs, R. W., 102.Kreis, F., 242.Kreiter, V. P., 55.Kremmling, G., 32.Krepelka, S., 357.Kretschmer, C. N., 28.Kreutzberger, A,, 246.Kreutzkamp, W., 137.Kridl, A. G., 304.Krimm, S., 16.Krimsky, I., 308.Krishnaji, 33.Krishnan, T. S., 21.Kritchevsky, T. H., 179,Icrohnke, F., 180.Krogh, L. O., 284.Krook, S . , 36.Kropa, E. L., 282.Kriiger, G., 144, 270.Kriiger, H., 23, 24, 25.Krug, 13. C., 208.Kruh, R., 28.Krummacher, A. H., 140.Krylov, 0. V., 99.Kryukova, A. A., 116.Krzeminska, A., 353.Kubo, M., 22, 30.Kubobawa, Y., 99.Kubota, T., 243.Kubouchi, Y., 73.Kubowitz, F., 312.Kuboyama, A., 30.ICuby, S. A., 299.Kuchitsu, K., 23.Kuchtner, M., 363.Kuck, J.A., 348, 349.Kuemmel, D. F., 364.Kuhn, L. P., 29, 52.Kuhn, K., 84, 180, 267,Kuivila, H. S., 58.Kulberg, L. M., 336.Kulka, M., 191ICulkarni, A. B., 248.Kumagasi, H., 11.Kumazai, H., 11.Kumin, S., 315.Kumler, W. D., 19.Kundu, N., 236.Kunst, P., 310.Kuo Hxang Ling, 326.Kupchan, S. hl., 226, 227.Kuper, J. B. H., 77.Kuratani, K., 19.Kurita, Y., 22, 30.Kurosaki, S., 33.Kuroya, H., 387.Kurtze, G., 59, 104.Kury, J. W., 43.Kusaka, R., 389.Knshida, R., 25.Kutschke, K. Q., 65.Kwasnik, W., 279.Kwestroo, W., 30, 308.Kyburz, E., 227.Labbe, R. F., 316.Labes, M. M., 55.Ljbler, L., 230.Lacey, R. N., 189, 246.Lacher, J. R., 19, 287, 290.Lack, L., 316.Lackner, H., 10.Lacroix, R., 11.Ladacki, M., 46.Ladell, J., 390.361.269, 270416 INDEX OF AUTHORS’ NAMES.Ladenbauer, I.M., 359.Ladwig, G., 140.Laffitte, P., 87.Lagemann, R. T., 15, 17.Lagerquist, A., 45.Lahey, E. N., 214.Laidlaw, R. A., 269.Laidler, K. J., 81, 94, 95,Laird, W., 231.Laitinen, H. A., 115, 116,Lake, J. S., 183.Lakshmanan, B. R., 21.Laltshminarayanan, K.,Lal, H., 117.Laland, S. G., 270, 274,Lamanna, C., 273.Lampe, F. W., 66.Lancaster, 3 . E., 19.Landauer, S. N., 180.Landauer, S. R., 180.Langenbeck, W., 310.Langer, A., 44.Langford, K. E., 345.Lanka, W. A., 183.Lardon, A., 228.Lardy, H. A., 299,326,333.Lark, P. D., 19, 172.Larnaudie, M., 17, 10.Larsen, E. G., 322.Larsen, L. L., 56.Larson, B., 331.Larson, 11.W., 333.Larson, J. E., 361.Larssen, P. A., 384.Lascombe, J., 29.Lasker, M., 333.Latif, R. h., 121.Latimer, W. M., 43, 105,Latourette, H. K., 193.Laubengayer, A. W., 129.LanEikovA, O., 352.Lauer, J. L., 20.Laurer, P., 121.La.ves, F., 218.Lavignc, R., 254.Lavine, L. R., 27, 119, 386.Lawlor, F. E., 283.Lawrence, R. V., 360.Laws, G. F., 222, 230, 233.Lawton, E. J., 79, 80.Lay, J. O., 349.Lazarev, A. I., 358.LaZerte, J . D., 286, 290,Lazo, R. M., 77.Leach, R. O., 65.Leanza, W. J., 235.Lecomte, J., 12, 18.Lecomte, O., 362.Leder, I. G., 328.Lederer, E., 186, 187, 217.Lederer, M., 359.Le Dizet, P., 269.97, 370.351.360.279.293.Ledoux, L., 308.Lee, C. C., 60, 166.Lee, D. A., 56.Lee, J. C., 89.Lee, T.B., 192.Lee, W. A., 279.Leech, H. R., 279.Leedham, K., 279,281,289,290, 292.Leeds, N. S., 179, 233.Leete, E., 253.Lefever, R. A., 131.Le F h r e , C. G., 31.Le F h r e , R. 3. W., 20,30-Leffler, J. E., 71.Lefort, M., 81.Leftin, J. P., 345.Legallis, V., 48.Legge, D. I., 350.Legge, J. W., 318.Le Hir, A., 257, 258.Lehmann, H. A., 140, 144.Lehninger, A. L., 305.Leidy. G., 274.Leisey, F. A., 355.Leist, M., 108.Lemay, L., 254.Lemberg, R., 311, 318.Lemieux, R. U., 262, 361.Lemin, A. J., 220, 221, 232.Lemjakov, N., 352.Lemmens, J. F., 362.Lemmon, W. R., 350.Lenhard, R. H., 233.Lenk, C . T., 179, 235.LennC, EL-U., 396.Lenormant, H., 17, 279.Leonard, G. W., jun., 366.Leonard, J. E., 353.Leonard, N.J., 20, 251,Lerner, M., 363.Lerner, N. H., 248.LeRosen, A. L., 360.LeRoy, D. J., 62, 69.Leskinen, E., 202.LeStrange, R. J., 359.Letham, D. S., 278.Letort, M., 67.Letsinger, R. L., 127, 157.Leuchs, H., 260.Leushina, I. K., 353.Leuthardt, F., 326.Leutner, K., 369.Levene, P. A., 272.Levering, D. R., 175.Levi, D. L., 41, 352.Levin, A. I., 116.Levin, R. H., 232.Levine, M., 281.Levine, R., 120.Levine, S. W., 365.Levintow, L., 300.Levisalles, J., 245.Levitt, L. S., 69.Levy, A., 86.32.254, 307.Levy, A. L., 3GO.LCvy, E., 349.Levy, H. A., 378, 352, 389.Levy, J. B., 51, 52.Levy, M., 46, 63, 64.LCvy, R., 353.Lewartowicz, E., 1 15.Lewenz, G. F., 38.Lewin, S. Z., 369.Lewis, B., 83, 88.Lewis, B. A., 263, 361.Lewis, D.T., 352.Lewis, E. S., GO, 169.Lewis, J., 55, 136.Lewis, J. G., 79.Lewis, J. R., 229.Lewis, M. S., 185.Lewis, P., 24.Lewis, P. H., 386.Lewis, T. A., 265.Lewis, T. li., 232, 254.Lewis, W. E., 11.Leyton, L., 364.Li, C. €I., 309.Liang, C. Y., 16.Liddicoct, T. H., 183.Lide, D. R., 9.Liebenow, W., 266.Lieber, E., 175, 244.Liebhafsky, H. A, 365.Lien, A. P., 190.Liggett, L. M., 349.Ligthelm, S. P., lS2.Lilyquist, M. Ti., 289.Lim, C. K., 107.Limberg, G., 263.Lincoln, F. H., jun., 235.Lindberg, B., 262, 263, 269.Lindblad, C. G., 361.Lindeman, L. P., 16.Lindemann, E. H., 350.Lindenbaum, S., 363.Lindholm, E., 76.Lindqvist, I., 13S, 387.Lindsay, A., 305.Lindsey, A. S., 162, 215.Lindsey, J., 399.Lineweaver, II., 308.Ling, N.S., 360.Lingane, J. J., 355.Lingens, F., 188.Linlce, W. F., 124.Linker, A., 263.Linn, W. J., 245.Linnell, W. H., 193.Linnett, J. IV., 8, 25, 27,Linnig, F. J., 336.Linschitz, H., 62.Linstead, R. P., 98, 174,175, 177, 178, 187, 194,242, 253, 396.84, 89.Lions, F., 151.Lipinsky, E. S., 241.Lipkin, D., 263, 276.Lipman, C., 211.Lipmann, F,, 295, 324, 331INDEX OF AUTHORS’ NAMES. 417Lippincott, E. R., 38.Lippman, A. E., 220.Lipschitz, R., 274, 275,Lipscomb, F. J., 67.Lipscomb, W. N., 27, 119,Lipson, H., 372, 375.Lipton, M. M., 334.Liretti, F. G., 332.Little, E. D., 193.Little, J. E., 308.Little, K., 80.Litz, L. M., 100.Livermore, A. H., 188.Livingston, G. E., 336.Livingston, R., 11.Livingston, R.L., 21-23,Livingstone, R., 78.Llewellyn, D. R., 268.Llewellyn, I[;. J.. 390, 396.Llewellyn, P. M., 11.Lloyd, D., 199, 390.Lloyd, J. P., 10.Lloyd, P. F., 268.Lobatto, J . L., 137.Lockwood, W. H., 312.Loeblich, V. B., 360.Loffler, A., 202.Lofler, J . E., 360.Loken, B., 181, 227.Loevenitch, D. L., 246.Low, I., 269.Loewus, M. W., 304.Lohmann, K., 326.Lohmann, W., 131.Lohofer, F., 150.Lombard, R., 218.Loncrini, D. F., 204.London, I. M., 321.Long, A. G., 232, 236, 262.Long, B., 389.Long, D. A., 16, 21.Long, F. A., 59.Long, F. J., 50.Long, G., 55.Long, J. J., 48.Long, L. H., 38, 126.Long, N. O., 150.Longuet-Higgins, H. C., 7.Lonsdale, K., 372, 393.Lopez-Quiros, J. A., 51.Lorber, V., 334.Lord, G., 40.Lord, R .C., 15, 19.Lord, S., 350.Lord, W. B. H., 143.Loring, H. S., 271.Los, J . N., 59.Losee, J. P., 81.Loshkarev, M. A., 116.Lossing, F. P., 45, 46, 62.Lossius, I., 362.Lotspeich, W. D., 308.Loudon. J. D., 190, 191,278.246, 381, 385, 386, 395.25.198, 200, 261.REP.-VOL. LILounsbury, M., 61.Lourens, W. A., 240.Louw, P. G. J., 220.Lovelace, A. M., 292.Lovell, B. J., 231.Lowe, E. J , , 18.Lowrie, H. S., 253.Lucas, H. J., 122.Lucas, J., 312.Lucena-Condk, F., 346.Lucy, J. A., 275, 277.Ludoweig, J., 334.Ludwig, H., 156, 246.Ludtke, M., 264.Luetscher, J . A., jun., 224.Luttke, W., 19.Luft, K. I?., 370.Luft, N. W., 16.LukeS, R., 253.Lukes, R. M., 160, 177.Lukina, M.Ya., 98.Lukyanitsa, V. G., 354.Lumb, P. B., 187.Lundberg, W. O., 186.Lunde, K., 184.Lundin, B., 36.Luther, H., 21.Lutwak-Mann, C., 308.Lutwick, G. D., 337.Lutze, E., 11.Luzzati, V., 383.Lycan, W. R., 287.Lydersen, D., 364.Lynch, B. M., 192.Lynch, M. A , , 145.Lynch, V., 328.Lyons, E. H., 115.Lyons, P. A., 109.McAllister, R. V., 305.McArthur, D. S., 336.McBee, E. J., 59.McBee, E. T., 279, 281,284, 286, 294.Macbeth, A. K., 203.McCallum, K. J., 59.McCarthy, R. L., 62.McCarty, J . E., 157, 175.McCarty, L. V., 369.McCasland, G. E., 266.McCauley, D. A., 190.McCloskey, P., 261.Maccoll, A., 119.McComb, E. A,, 263, 269.MacCormack, K. E., 100.McCormick, J. E., 264.McCosky, R. E., 37.McCoy, R.E., 135.McCready, R. M., 263, 269.McCulloch, W. J . G., 122.McCulloh, K. E., 8, 9.McCullough, J. D., 381.McCullough, J. P., 35, 36.McCusker, P. A., 30.Macdiarmid, A. G., 56.Macdonald, A. M. G., 349.Lu, C.-S., 390.McDonald, C. C., 64.Macdonald, C. G., 253.MacDonald, D. L., 267.McDonald, I. R. C., 186,McDonald, J. R., 113.McDonald, R. M., 220.McDonald, R . S., 369.MacDonald, S. F., 196, 197,McDonnell, W. R., 78.McDonnell, W. R. M., 77.McDonough, S., 361.McDowell, C. A., 45, 92.McElvain, S. M., 189, 206.McEtheny, G. C., 361.McEwan, W. S., 42, 395.McEwen, W. E., 245.Macfarlane, M. G., 328.McFarren, E. F., 263.McGee, J., 332.McGee, M. A,, 187.McGeowan, M. G., 333.McGhie, J . F., 189, 239.MacGillavry, C.H., 383,Macgregor, A. G., 322.Machell, G., 140, 180.McHenry, J. R., 352.MacInnes, D., 187.McIntosh, A. O., 194, 393.McIntosh, A. V., jun., 232.McIntyre, D., 59.Mack, D. J., 364.Mackay, A. L., 373.McKay, H. A. C., 107.McKenna, J., 154, 253.McKenna, J. M., 230.Maclienzie, H. D., 288.McKeown, G. G., 362.McKinley, J. D., jun., 44.McKnight, J. T., 55.McLamore, W. M., 207.Maclean, D., 231.Mclean, J., 187.McMillan, A. F., 68.McMurry, T. B. H., 210.McNabb, W. M., 367.McNees, R. A., 146.McNesby, J. R., 63, 67.MacNevin, W. M., 68, 363.MacNutty, B. J., 351.McQuillin, F. J., 205, 208.McRorie, R. A., 188.McTaggart, N. G., 369.MacWilliam, I. C., 262,McWhirter, R. W. P., 69.Maddock, A. S., 55.Madejski, M., 203.Madorsky, S.L., 75, 76.Magat, M., 7, 31, 32, 79, 83,Magee, J. L., 80.Magerlein, B. J., 232.MagnCli, A,, 387.Magrath, D. I., 271.Mah, A. D., 40.368.312.384.380.418 INDEX OF AUTHORS NAMES.Maher, J., 309, 363.Mahler, H. R., 308.Mahr, C., 353.Maier, W., 30.Maisey, R. F., 195.Majumdar, S. G., 260.Maki, A. H., 29.Malatesta, L., 141, 149,Malcolm, B. R., 19.Maleeny, R., 129.Malesh, W.. 257, 258.Malherbe, F. E., 16.Malinovskiy, M. S., 53.Maller, W., 29.Mallette, M. F., 273.Malmstadt, H. V., 365,366.Malpress, F., 333.Manassen, J. , 398.Mancera, O., 229, 233.Mandel, J., 336.Mandel, M., 10.Mandelcorn, L., 63, 65.Manes, M., 49.Mann, D. E., 16, 17.Mann, F. G., 151, 157.Mann, M. J., 256.Mann, P. F. E., 298, 299.Manneback, C., 27.Mannelli, G., 338.Manners, D.J.. 268.Mannich, C., 181, 205.Manowitz, B., 79, 80.Mansfield; G. H., 182.Manson, L. A., 270.Marata, J. K., 367.Marchant, A., 247.Marcus, R. J., 49, 53.Margara, A., 353.Margolis, L. Ya., 100.Margoshes, M., 27.Marion, L., 253, 254, 397.Marinelli, L. D., 77.Marinetti, G., 186.Marinsky, I. A., 104.Markby, R., 148.Markees, S., 189, 360.Markey, P., 389.Markham, M. C., 95, 97.Markham, R., 273, 276,Markle, G. E., 366.Marko, A. M., 273, 274.Marmur, J., 327.Marple, T. L., 350.Marrian, D. H., 250.Marsh, G. E., 274.Marsh, R. E., 124, 381.Marshall, D., 184, 199.Marshall, R., 66.Martell, A. E., 43.Marti, L., 178.Martin, A. E., 370.Martin, A. W., 141.Martin, L. F., 360.Martin, H., 128.Martin, J.J., 78, 79.150, 152,277.Martin, R. E., 70.Martin, R. H., 230.Martin, R. L., 119, 384.Martin, T. W., 66, 355.Martinette, M., 362.Martini, C. M., 232.Martz, D. E., 17.Marvel, C. S., 74, 251.Maryott, A. A., 8.Marzluff, W. F., 284.Marzys, A. E. O., 366.Masamune, S., 199.Maschka, A., 21.Maschka, H., 19.Maslen, H. S., 390.Mason, S. F., 250.Mason, S. G., 33.Massey, J. T., 10.Massey, V., 306.Masten, M. L., 353.Masumoto, H., 64.Masurat, T., 332.Massy-Westropp, R. A.,Mathias, A. P., 250.Mathieson, A. McL., 387,388, 391, 397.Mathieson, A. R., 107, 274,278.Mathieu, J., 218.Mathieu, J.-P., 21.Matikkala, E. J., 188.Matossi, F., 31.Matougek, L., 352.Matsen, F.A., 49.Matsui, H., 70.Matsui, M., 209.Matsumara, S., 248.Matsuo, K., 390.Matsuura, T., 243.Mattax, C. C., 115.Matterson, A. H. S., 21.Matthes, A., 75.Matthews, R. E. F., 277.Mattock, G., 123, 134,Mattrow, H. C., 17.Mattson, R. H., 194Maw, G. A., 295.May, S. C., 310.Mayer, F. X., 369.Mayer, H., 246.Mayer, J. E., 106.Mayer, R., 203.Mayers, V. L., 273.Mayfield, P. I., 152.Mayo, F. R., 71.Mazumder, M., 20.Mazur, Y., 237.Mazzamaro, P., 364.Mazzeno, L. W., 132.Mead, E. J., 125.Meadow, M., 181.Meakins, G. D., 20, 172,Meakins, R. J., 33.Meal, H. C., 25.Mebane, A. D., 185.243.223.Mecke, R., 29.Medvedev, S. S., 73, 74.Meehan, E. J., 72.Meen, R. H., 283.Meesils, A., 213.Meetham, A. R., 34, 35.MCgaldoikonomos, J., 362.Megaw, H.D., 387.Meggers, W. F., 367.Mehrotra, R. C., 128.Mehta, R. K. S., 347.Meier, H., 136.Meijer, F. A., 30, 203.Meinecke, K.-H., 265.Meiners, A. F., 281.Meinwald, J., 206.Meister, A., 300, 331.Meister, A. G., 16.Mel, H., 43.Melander, L., 55.Mellichamp, J. W., 367.Mellish, C. E., 8, 27.Mellor, D. P., 119, 386.Meloche, V. W., 350, 364.Meltzer, T. H., 71.Melville, H. W., 48, 61, 67,69, 70, 72, 73, 74.Melvin, H. W., L54.Mendel, H., 391.Mendel, M. G., 339.Mengel, W., 232.Menzies, M., 63.Mercer, R. A., 358.Merling, G., 198.Mertz, E. C., 59.Mesrobian, R. B., 70, 79,Messerly, J. F., 36.Metcalf, W. S., 69.Metzenberg, R. L., 262,362.Metzler, D. E., 245, 310.Meuwsen, A., 140.Meyer, K., 263.Meyer, S., 216.Meyerhof, O., 326.Meyers, E.A., 381.Michael, M., 214.Michaelsen, D. J., 75.Michaud, H., 137.Micheel, F., 360.Michel, G., 351, 368.Michelson, A. M., 270-272.Micka, K., 48.Mignolet, J. C. P., 95.MijoviC, M. V., 227.Mikhant’ev, B. I., 75.Miki, T., 209.Mikovsky, R. J., 95.Milatz, J. M. W., 370.Milburn, A. H., 187.Miles, L. W. C., 243.Miles, P. A., 322.Millar, I. T., 151.Miller, A. A., 79.Miller, B. S., 363.Miller, C. C., 363.Miller, E., 160, 168.80INDEX OF AUTHORS’ NAMES. 419Miller, F. A., 16.Miller, N., 77.Miller, 0. B., 25.Miller, R., 195.Miller, R. E., 38.Miller, S., 109.Miller, W. T., 289, 294.Milletti, M., 361.Milliken, T. H., 102, 103.Mills, G. A., 59, 102, 103.Mills, I.M., 14.Mills, J. A., 208, 262.Mills, J. F., 29.Mills, R., 109.Milner, G. W. C., 344, 350.Milone, M., 359.Minkoff, G. J., 17, 20, 91.Miramontes, L., 230.Mirza, R., 225.Misiorny, A., 263.Mislow, K., 187.Mitchell, F. L., 361.Mitchell, H. K., 250, 262,Mitchell, I. L. S., 334.Mitchell, L. C., 361, 362.Mitchell, P. W. D., 174, 175,Mitchell, W., 254.Mitra, S. S., 26.Mitzner, B. M., 369.Miyagawa, I., 30.Miyano, S., 245.Miyazaki, M., 200.Miyazaki, S., 67.Mizano, T., 30.Mizushima, M., 12.Mizushima, S., 7, 16, 19.Modderman, P., 182.Moller, C. K., 15, 20.Moffett, R. B., 234, 235.Moffett, R. H., 397.Moffitt, W., 119.Mokrasch, L. C., 264.Molera, M. J., 51.Molinari, E., 102.Momigny, J., 79.Monfils, A., 24.Monk, C.B., 110.Monllor, E., 339.Monnot, G. A., 367.Montavon, M., 238.Montgomery, R., 263, 361.Moon, K. A., 68.Moon, P. B., 47.Moore, C. E., 338.Moore, H., 312.Moore, J. A., 237.Moore, M., 227, 257.Moore, R. E., 127.Moore, R. V., 132.Moosmuller, E., 362.Morales, M. F., 295, 300,Morey, G. W., 137.Morgan, D. C., 110.Morgan, H. W., 8, 370.362.194, 264.302.Morgan, K., 262, 361.Morgan, K. J., 120.Morgan, W. H. D., 194.Morgan, W. T. J., 270.Mori, A., 236.Morimoto, N., 387.Morin, D. E., 293.Morino, Y., 23, 30.Morren, L., 352.Morris, G., 355.Morrison, J. D., 377.Morritz, F. L., 175.Morton, R. K., 296.Moseley, P. B., 360.Moser, P. M., 8, 10, 390.Moses, F., 334.Mosher, W. A., 273.Moskowitz, D., 133.Mousseron, M., 203.Mousseron-Canet, M., 203.Mowery, D.F., 263.Muecke, E. C., 188.Muller, A., 200.Mueller, C. C., 327.Muller, F. H., 31.Mueller, G. P., 236.Mueller, K. H., 53.Muller, R. H., 359.Munster, C., 352.Muetterties, E. L., 126.Muhr, H., 237.Muir, D. R., 104.Muir, H. M., 311, 318.Mukai, T., 30, 248.Mulcahy, M. F. R., 67.Muld, W., 367.Mulder, D., 34.Muller, G., 218.Muller, J. M., 257.Mulliken, R. S., 29, 396.Mund, W., 79.Munson, T. R., 38.Rlurata, I., 248.Murfin, I;. S., 16.Murmann, R. K., 121.Muromova, R. S., 75.Murphy, G. M., 18.Murphy, I., 70.Murray, J., 200.Murray, K. A., 352.Musgrave, W. K. R., 279,283, 284, 289, 294.Mustafa, A., 194, 244.Musulin, B., 26.Myers, C.E., 44.Myers, H., 54.Myers, R. J., 8, 9, 10.Myrback, K., 304.Nachmansohn, D., 307.Nasanen, R., 120.Naffa, P., 215.Nagakura, S., 30.Naganna, B., 308.Nagase, S., 22.Nagata, C., 70.Nagdy, K. A., 193.Nagel, K., 128.Nager, M., 289, 290, 292.Nagorsen, G., 125.Nakagawa, I., 16.Nakamoto, K., 396.Nakano, K., 355.Nakata, M., 132.Nakatsu, K., 387.Nakatsuka, K., 72.Nakrasov, A. S., 354.Nalbandyan, A., 85.Nandi, U. S., 72.Narasimhan, N. S., 255.Narayanan, C. R., 227.Narriman, H. J., 20, 21.Nast, R., 150.Nathan, A. H., 235.Navone, R., 363.Nawkins, N. J., 17.Naya, K., 243.Nayler, P., 184.Naylor, M. A., 75.Nazarova, L. M., 30.Neale, E., 41.Kedwed, H., 122.Needham, D. M., 300.Neely, W. B., 267.Nef, J.U., 246.Negita, H., 32.Neher, A., 224.Neher, R., 223.Neish, A. C., 266.Nelson, K. L., 166.Nelson, R. A., 37.Nelson, R. E., 41.Nery, R., 166.Nesmeyanov, A. N., 132.Neterman, V. A., 70.Neth, F. T., 135.Neubauer, L. G., 217.Neuberger, A., 250, 309,318, 321, 322.Neuhaus, A., 373.Neuilly, M., 29.Neumann, H. M., 138.Neumann, H. N., 57.Neumann, M. S., 60.Neumann, W. F., 142.Neurath, H., 305, 306, 310.Neuss, N., 257.Nevitt, T. D., 171.Newbold, G. T., 192, 231,Newhall, W. F., 369.Newman, F. C., 202.Newman, M. S., 59, 212,Newth, F. H., 262.Newton, A. S., 78.Nichol, J. C., 104.Nicholas, R. E. H., 312,Nicholson, A. J. C., 65.Nicholson, G. R., 34.N!ckl, J., 42, 131.Niclause, M., 67.Nicolaides, N., 218.236.252, 253.322420 INDEX OF AUTHORS’ NAMES.Nicolas, H.A., 349.Nielsen, A. H., 15.Nielsen, J. M., 109.Nielsen, J. R., 16.Niemann, C., 305, 346.Nigam, R. G., 360.Nightingale, D. V., 190.Nightingale, R. E., 17,Nigram, V. N., 361.Nijkamp, H. J., 360.Niklas, H., 245.Nikolaeva, N. V., 116.Nikuradse, A., 21.Nirschl, A. M., 293.Nitta, I., 198, 388, 397.Nock, W., 355.Noda. L., 299.Nodiff, E., 287.Nodiff, E. A., 282.Nogina, 0. V., 132.Noland, W. E., 246.Noller, C. R., 220.Nordal, A., 328, 333.Nordman, C. E., 386.Norman, A., 360.Norman, I., 62, 6.5.Normant, H., 189.Norris, J. H., 56.Norris, W. P., 156.Norrish, R. G. W., 47, 60,Northrop, J. H., 308.Northrop, T. G., 278.Norton, D. R., 352.Norton, F. J., 125.Norymberski, J.K., 221,Novotnp, L., 206.Novotnq, N., 215.Nowacki, W., 373.Noyes, R. M., 48, 66.Noyes, W. A., 65, 66, 69.Nozaki, M., 73.Nozoe, T., 199, 248.Nukata, M., 45.Nunn, J. R., 203.Nutten, A. J., 264, 339,Nutting, M. D. F., 304.Nyburg, S. C., 394.Nvdahl. F.. 358.135.67, 74.228, 230.342, 349.Nyholm, K. S., 18, 119,147.NyGrom, R. F., 61.Oberly, J. J., 18.Oblad, A. G., 102, 103.O’Brien, J. F., 282.Ochoa, S., 327.Oda, R., 73.O’Dea, J. F., 263.Odell, A. L., 57, 151.O’Dwyer, M. F., 20.oiserth, D., 328.oyum, P., 384.Ogg, R. A., 23, 63, 135.Ogg, R. A., jun., 48.Ohashi, T., 388.Ohi, R., 75.Ohlberg, S., 385.Ohlberg, S. M., 384.Ohta, M., 75.Oita, I. J., 348.Okada, Y., 68.Okamoto, A.H., 365.Okamura, S., 70.Okamura, T., 11.Okaya, A,, 8.Oki, M., 251.Okker, R., 10.Okuda, M., 68.Okuyama, M., 76.Olcott, H. S., 307.Oldenberg, O., 86.Oliveto, E. P., 228, 233,Olivier, H. R., 351.Ollis, W. D., 260.Olshanova, K. M., 359.Olson, A. R., 60.Olson, S., 55.Onat, E., 58.Ono, K., 11.Onsager, L., 29, 103.Onstott, E. I., 116.Onyszchuk, M., 63.Oosask, H., 22.Oosterbaan, R. A., 310.Opgenhoff, P., 142.Oppenheimer, F., 85.Orgel, L. E., 18, 29, 119,Orloff, H. D., 155.Oroshnik, W., 185.Orsag, J,, 367.Orten, J. M., 322.Orzechowski, A., 100.Osaki, K., 198, 397.Osbond, J. M., 232.OsCik, J., 361.Osdene, T. S., 250.Oshida, H., 29.Oshida, I., 29.Oster, G., 68, 71.Oster, R., 265.Osthoff, R. C., 146.Ott, H., 254.Ott, W., 312.Otterbein, O., 353.Otting, W., 368.Otvos, J.W., 97.Oughton, J . F., 232, 236.Ourisson, G., 215.Ovchimnikova, N. N., 75.Ovenston, T. C. J., 364.Overberger, C. G., 75.Overend, J., 14.Overend, W. G., 172, 264,265, 270, 279.Ovodova, V. A,, 98.Owen, J., 11,Owen, L. N., 243.Oxbrow, C. F., 387.234.381.Pachaly, H., 266.Pachucki, C. F., 17.Packard, M., 23.Padbury, J. J., 282.Padoa, G., 149.Page, F. M., 48.Page, J. E., 218, 236.Page, M., 51.Pahl, M., 76.Pahls, K., 200.Pai, B. R., 255.Pajaro, G., 56.Pake, G. E., 10, 24, 382.Pakrashi, S., 258.Palit, S. R., 72, 74.Palmer, J. K., 352.Panish, M. B., 145.Panopoulos, G., 362.Pappas, J. J., 218.Pappo, R., 160.Parham, W.E., 244, 246.Pariaud, J. C., 352.Parikh, S. N. 361.L’ark, J . D., 19, 287,Parker, C. A, 65.Parker, H. W., 109.Parks, A. G., 58.Parks, G. S., 301.Parks, T. D., 348, 350.Parravano, G., 101, 102.Parry, E. P. 351.Parry, G. S., 389, 395.Parry, R. W., 152.Parsons, R., 104, 110, 311.Partington, J., 373.Partington, J . R., 7.Partridge, M. W., 250.PartuSek, Z., 351.Pascard, R., 384.Passer, M., 251.Pasternalr, R., 155, 203.Pasternak, R. A., 388.Patat, F., 75.Patchett, A. A., 238.Patel, D. K., 227, 233.Paterno, E., 241.Patrick, W. N., 75, 79.Patterson, E. L., 244.Patterson, W. I., 361.Paul, K. G., 312.Paul, €2. C., 144, 286, 294.Paul, V. J., 51.Psuley, J. L., 134.Paulik, F., 342.Pauling, L., 36, 381, 382,Pausacker, K.H., 191, 192,Pauson, P. L., 146, 147,Payne, C. C., 233.Peacock, R. D., 151.Peacocke, A. R., 274, 278,Peake, J. S., 122.Peal, W. J., 236.290.384, 387.247.198.279INDEX OF AUTHORS’ NAMES. 42 1Pearlson, W. H., 280, 281,286, 290, 293.Pearson, J., 42.Pearson, L., 48.Pearson, R. G., 47, 48, 57,Pearson, R. M., 362.Pease, R. N., 49, 53, 89.Pease, R. S., 378.Pechett, M. M., 361.Peek, A. E. J.. 203.Pedlar, A. E., 52.Pelletier, S. A,, 224.Pelley, R. L., 283, 284, 290.Pellon, J . J., 72.Penfold, B. R., 377, 395.Penneman, R. A., 17.Pennington, R. E., 35, 36.Pepe, H. J., 241.Pepinsky, R., 372, 374, 378,Pepper, D. C., 74.Percival, E., 264, 265.Percival, E. G. V., 270.Peries, P., 111.Perlin, A.S., 263, 267.Perlmutter, P., 60.Perold, G. W., 220.Perrine, R. L., 50.Perring, J. K., 107.Perruche, C., 352.Perry, S. V., 308.Pesez, RI., 179.Pestemer, M., 68.Petek, F.. 343.Peters, A., 376.Peters, R. A., 308.Petersen, E. M., 17.Petersen, H. C. A., 312.Peterson, J . M., 336.Peterson, L. H., 244.Peterson, S. W., 382.Petit, A., 218.Petracek, F. J., 257.Petraites, L., 312.Petrikova, M. N., 354.Petrow, V., 227, 230, 233.Pettebone, R. H., 234.Petty, R. L., 124.Pfeiffer, G., 41.Pfeiffer, H. G., 32.Pfeiffer, M., 207.Pfiffner, J . J., 249.Pfister, K., tert., 236.Phibbs, M. K., 69.Philip, T. V., 364.Phillipps, G. H., 223, 232.Phillips, C. S. G., 362.Phillips, D. C., 397.Phillips, D. D., 163, 268.Phillips, G.M., 118.Phillips, G. O., 262.Phillips, H. O., 354, 355.Phillips, T. R., 97.Philpot, J . St.-L., 308.Pichler, H., 99.Pickett, E. E., 201.104, 156.394, 398.Pickworth, J., 9, 14, 399.Pierce, J. V., 244.Pierce, 0. K., 59, 279, 281,283-286, 294.Pierson, R. H., 346.Piette, L. H., 47.Pietzka, G., 132.Pifer, C. W., 357.Pijck, J., 338.Pilgram, M., 110.Pillar, C . , 222.Pimentel, G. C., 17, 18, 29.Pinchas, S., 19.Pinckard, J . H., 184.Pinder, A. R., 177, 247.Pines, H., 202, 206.Pink, R. C., 390.Pinkus, A. G., 252.Pinsent, B. R. W., 48.Pinsker, 2. G., 7, 373, 377.Pinta, M., 364.Piontelli, R., 115.Piper, S. H., 185.l’iper, T. S., 28, 132.Pirie, N. W., 273.Pirt, S. J., 349.Pitt, B. M., 192, 241.Pittman, R.W., 117.Pitts, E., 108.Pitts, J . N., 65, 66, 355.Pitzer, K. S., 16, 381.Plattner, P. A., 178, 200,216, 229, 245.Plesch, P. H., 74.Plint, C. A., 20.Pliva, J., 26, 207, 215.Plummer, A. J . , 256.Plyler, E. K., 15, 16.Pocker, A , , 247.Podall, H., 246, 312.Podolsky, R. J., 302.Pohl, F., 367.Pohland, A., 175, 244.Poirier, J. C., 106, 107.Poisson, J., 257.Pokrovsky, 1:. I., 21.Polestra, F. M., 109.I’oley, J. P., 32.Polgar, N., 187.Pollard, F. H., 52, 92, 132.I’ollnow, G. F., 8, 9.Polo, S . R., 15, 17.Polonovski, J . , 362,Polya, J. B., 244.Polyak, L. Ya., 353.Ponomarev, A. A., 336.Ponticorvo, L., 56.Poole, V. D., 236.I’oos, G. I., 160, 177.Popelak, A., 257.PopjAk, G., 222.Porlezza, C., 122.Porter, G., 46, 47, 50, 62,Porter, G.R., 130.Porter, H. D., 245.Porter, M. R., 274, 278.67, 69.Porter, R. F., 44, 45.Post, 133, 390.Poth, M. A,, 111.Potter, E. F., 328.Pound, R. V., 23, 24.Poussin, A., 352.Powell, A. D. G., 239.Powell, H. M., 396.Powell, J. E., 363.Powell, R. E., 105.Powers, J. J.. 352.Powers, R. M., 143.Powles, J . G., 32.Poynter, R. L., 8.Poynter, W. G., 93.E’ozefsky, A., 369.Pradhan, M. K., 189, 239.Prakash, S., 142.Prater, C. D., 102.Pratt, D. E., 352.Pratt, L., 24.Pratt, R. J., 188.Praidk, M., 351.Precious, R. M., 86.Prelog, V., 163, 224, 225-227, 258, 260.Prener, J . S., 387.Press, R. E., 352.Pretorius, Y. Y., 187.Prettre, Rf., 87.Prkvost, C., 179, 189.Prkvot-Bernas, A., 72.I’Fibil, R., 363.Price, C.C., 59, 70Price, D., 199.Price, J . R., 260.Price, T. D., 367.Price, T. J., 286.Price, W., 331.Price, JV. C., 13, 19.Price, W. J., 367.l’riday, K., 52.I’ridham, J . B., 263.Pringle, G. E., 389.Pritchard, G. O., 63.Pritchard, H. O., 51, 52, 63.Pritchard, J. G., 167.Prober, M., 60, 289.ProchBzka, Z., 230.Promislow, A. L., 61.Proops, W. R., 252.Proost, W. C., 205.Prosen, E. J., 34, 38, 39,Pross, A. W., 369.Pryce, M. H. L., 11.Przybylska, M., 397.Puchalka, K., 361.Pugh, W., 135.Pullin, A. D. E., 19.Purcell, E. M., 23.Purlee, E. L., 55.Puroshottam, A., 338.Puschmann, J., 144.Putman, E. W., 269.Putnam, F. W., 307.Pyke, J . B., 63.41422 INDEX OF AUTHORS’ NAMES.Quartey, J.A. K., 230.Quayle, J. R., 196, 197,Quentin, K. E., 358.Quin, J. I., 219.Quinney, P. R., 58.Quynn, R. G., 19.Raaen, H. P., 358.Raaen, V. F., 60.Raasch, M. S., 293.Rabideau, G. S., 359.Rabinovitch, B. S., 96.Racker, E., 296, 308, 328.Radding, S. B., 350.Radell, J., 185, 357.Ramisch, F., 192.Raffelson, H., 178.Rahman, A., 27.Rahtz, M., 126.Rai, R. C., 142.Raistrick, B., 384.Raistrick, H., 247.Ralls, J. W., 227.Ralph, B. J., 119.Ramage, G. R., 215.Ramirez, F., 189.Ramsay, D. A., 167.Ramsay, J. B., 364.Rand, M. H., 47.Randles, J. E. B., 115, 116.Rands, R. D., 361.Rank, D. H., 15, 17.Rankin, G. T., 68:Rankin, J. C., 263.Rao, B. S. V. R., 338.Rao, D. A. A. S. N., 31.Rao, V. K. M., 360.Rapkine, L., 308.Rapson, W.S., 203.Rasche, R., 150.Rasp& G., 185.Rastrup-Andersen, J., 8.Rauenbusch, E., 251. .Rauh, E. G., 44.Rausch, B. A., 290.Rausser, R., 233.Rawlinson, W. A., 119.Razdan, R. K., 200.Read, J., 206.Read, W. T., 373.RCal, M., 175.Rebbert, R. E., 63.Reber, F., 228.Reed, I;. J., 323.Reed, P. M., 367.Reed, R. I., 202.Rees, A. G., 56.Rees, A. L. G., 93.Reeves, R. E., 132, 268.Regenass, F. A., 180.R&gnier, J., 30.Reich, H., 236.Reichard, P., 271.Reichen, L. E., 351.Reicheneder, F., 222.Reichl, E. R., 360.333.Reichmann, M. E., 278.Reichstein, T., 223, 228,237, 264, 328.Rcid, C., 29.Reid, D. H., 197.Reid, E. B., 176, 189.Reid, E. E., 302.Reid, T. S., 282, 284, 286.Reid, W. D., 96.Reid, W.W., 269.Reif, E., 350.Reilley, C. N., 355, 356.Reilly, E. L., 30.Reilly, H. C., 188.Reimer, C. C., 341.Reinhardt, F., 362.Reinisch, L., 31, 32.Reiser, A., 28.Reist, P., 273.Reitmann, J., 254.Reitsema, R. H., 362.Rempe, G., 140.Renk, E., 252.Renner, G., 79.Resplandy, A., 361.Reynolds, C. A., 355.Reynolds, G. F., 350, 351,Reynolds, W. L., 48.Rhinehammer, T. B., 342.Rhoads, C. P., 188, 318.Rhoderick, E. H., 69.Rhodes, D. W., 352.Rhodes, T. B., 74.Ribaudo, C., 359.Ricca, F., 359.Rice, E. W., 332.Rice, F. O., 47.Rice, 0. K., 112.Rice, S. A., 49, 278.Rich, R. L., 57, 152.Richards, A. R., 247.Richards, G. N., 265, 267,Richards, J., 145.Richards, R. E., 23, 24,Richards, S., 67.Richardson, F.D., 42, 152.Richardson, P. N., 203.Richau, W., 182.Richmond, J. E., 320, 321.Richter, R., 237.Richter, S., 284.Ricketts, C. R., 269.Ridgwell, S., 194.Riebsomer, J. L., 55, 244.Riegel, B., 227, 236.Rieman, W., 363.Riemschneider, R., 30.Rienacker, G., 99.Rigby, G. W., 290, 293.Rigg, T., 58, 77, 81.Riggs, N. V., 191.Rijnders, G. W. A., 102.Riley, J. F., 109.Riley, J. P., 353.356.268, 270.125, 383.Rimington, C., 219, 311,312, 316, 317, 320, 322.Ringold, H. J., 181, 227,230, 232.Riniker, B., 207, 222.Rink, M., 254.Rio, A., 203, 345.Ritchie, E., 255.Riteris, G., 39.Rittenberg, D., 56,Rittenhouse, K. D., 102.Rivett, D. E. A., 186.Rix, H. D., 16.Rix, T. R., 182.Robb, J. C., 47.Robb, L. E., 291.Robert, L., 368.Roberts, Dew., 270.Roberts, E.J., 360.Roberts, F. F., 387,Roberts, G., 159, 228.Roberts, J. C., 195.Roberts, J. D., 154 166.Roberts, K. H., 367.Robertson, A., 239.Robertson, A. P., 391.Robertson, J. D., 194.Robertson, J. H., 338, 399.Robertson, J. M., 23, 200,394, 397.Robertson, W. G. P., 73.Robin, S., 14.Robinson, A. M., 364.Robinson, C. B., 109.Robinson, C. H., 159, 176.Robinson, C. N., 251.Robinson, F. M., 160, 177.Robinson, G. C., 164.Robinson, H. G., 25.Robinson, J. W., 351.Robinson, P. L., 144, 151,191.Robinson, (Sir) R., 159,181,205, 230, 247, 251, 256,258.372, 376, 377, 389, 391-Robinson, R. A., 107.Robinson, S. J. Q., 45.Robinson, T. S., 13, 196.Robison, R., 328.Robson, A.C., 196.RoEek, J., 241.Rochow, E. G., 28, 126,Rock, E. J., 122.Rockland, L. B., 360.Rockstroh, G., 266.Rodda, H. J., 189.Rodenburg, H. G., 202.Rodgers, L. B., 366.Rodriguez. L., 73.Roe, A., 279.Roe, E. M. F., 273.Roe, J. H., 264, 332.Roedel, M. J., 73.Roets, G. C. S., 219.Rogers, D., 397.130, 132INDEX OF AUTHORS’ NAMES. 423Rogers, E. F., 235.Rogers, G. T., 52.Rogers, L. B., 350, 351.Rogers, M. T., 28, 145.Rogier, E. G., 160.Roginskii, S. Z., 99, 100.Rohmer, M., 150.Roland, J. F., 360.Roland, P., 361.Rolfe, J. A., 20, 110.Rollefson, G. K., 60.Rollett, J. S., 396.Rollier, M. A., 129.Rollin, 13. V., 25.Romero, M. A., 229.Romers, C., 389.Romo, J., 229.Roos, E. E., 251.Roos, H., 195.Ropp, G.A., 60.Rose, D. G., 80.Rose, H. J., jun., 367.Rose, J. B., 75, 155.Rose-Innes, A. C., 11.Roseman, S., 334.Rosen, D. B., 227.Rosen, W. E., 227, 236.Rosenbaum, E. J., 366.Rosenberg, A., 279.Rosenberg, A. F., 18.Rosenberg, N. W., 104.Rosenblum, E. I., 254.Rosenkranz, G., 176, 227-Rosenmund, K. W., 212.Rosenthal, I., 352.Rosenthal, I<., 115.Rosner, M., 216.Ross, A,, 253.Ross, J. M., 221.Ross, M., 80.Ross, W. A,, 189.Rossini, F. D., 34, 41, 42.Rossotti, H. S., 120.Rotenberg, D. L., 135.Roth, C. B., 239.Roth, W., 88.Roth, W.. A., 35.Rothstein, E., 156, 193.Roubine, R., 7.Roughton, F. J. W., 48.Rowe, F., 199.Rowley, K., 355.Rowlinson, H. C., 41.Roy, J. K., 208.Roy, R., 129.Royen, P., 137.Rozen, A.M., 100.Rubalcava, H., 19.Rubin, T., 59, 65.Rubinstein, D., 316.Ruck, K., 263.Rudorff, W., 122, 125.Ruff, O., 139, 293.Ruh, R. P., 282.Rulfs, C. L., 110, 350.Rumpf, 3. A., 171.233, 236.Rundervoort, H. J., 137.Rundle, R. E., 385, 386.Runge, F., 243.Rush, R. M., 338.Russell, C. S., 321.Russell, J., 124.Russell, K. E., 50, 64, 71.Russell, P. B., 203.Russell, P. J., 275.Russell, W. W., 99.Rutkowski, H. R., 263.Rutledge, R. L., 160, 174.Ruzicka, L., 166, 206, 207,218, 221, 229, 238-240.Ryabchikov, D. I., 358.Ryan, D. E., 337.Ryder, A . , 188.Rydon, Y . N., 180.Ryskiewicz, E. E., 176,242.Saad, M. A., 133.Sable, H. Z., 271, 272,Sabo, E. F., 233.Sacco, A., 141, 145, 149,Sacconi, L., 142, 151.Sachs, P., 316.Sackman, J.I?., 38.Sadanaga, R., 387.Sadler, M. S., 371.Saffron, M., 331.Sagulin, A. B., 88.Saha, N. G., 72.Sahli, &I., 134.Saier, E. L., 369.Saigusa, T., 73.St. Pierre, G., 45.Saito, T., 22.Saito, Y., 387.Sakashita, K., 30.Saldick, J., 77.Saling, H. J., 343.Salmon, J. E., 129, 147.Salomon, K., 320, 321.Salooja, I<. C., 91.Sambrook, C. M., 264.Sampson, H. J., 281.Sampson, P., 263.Samuel, A. H., 80.Samuel, D., 19, 165.Samuels, B. K., 236.Sancier, K. M., 68, 312,Sandell, E. B., 337.Sandeman, I., 16.Sanders, F., 244.Sanders, T. M., 8.Sanderson, T. F., 218.Sandler, Y. L., 94.Sanger, F., 309.Santav?, F., 208, 351.Santhamma, V., 26.Santhappa. M.. 71.Sarett, L. H., 160, 177, 224,332.150.362.227.Sarfort, E., 352.Sargent, J.W., 350.Sarkar, N. K., 308.Sasada, Y., 198, 397.Sasmor, D. J., 40.Sasse, W. H. F., 189.Sata, N., 76.Sato, S., 49.Sat6, T., 199.Satterfield, C. N., 58.Saucy, G., 231.Sauer, H., 204, 257.Sauerwald, F., 122.Saunders, D. R., 204.Saunders, J., 74.Saunders, W. H., jun., 166.Savaray, P., 360.Sawyer, S. D., 333.Saxena, R. S., 125.Sayasov, Yu. S., 86.Sayer, G. C., 239.Sayigh, A..A., 199.Scaife, B. K., 29.Scanlan, J., 72.Scarano, E., 331.Scatchard, G., 106.Schachman, H. K., 278.Schachter, O., 60.Schafer, H., 131, 138, 139.Schaff, R., 291.Schaeffer, G. W., 134.Schaeffer, R., 27, 119, 126,Schafer, H., 41, 42.Schaffer, N. K., 310.Schaffert, R. R., 364.Schatz, F.Y., 367.Schaub, R. E., 249, 266,Schawlow, A. L., 8.Schechter, D. L., 139.Schechter, H., 170, 242,Scheer, I., 369.Scheffler, A., 268.Schenk, G. O., 67, 68.Schenk, W., 358.Schenker, K., 260.Scheraga, H. A., 48, 64.Scherager, H. A., 45.Scherer, O., 282.Scherer, P., 279.Scheri, M. A., 232.Scherrer, P., 32.Schiemann, G., 279.Schiff, H. I., 104.Schilling, E. D., 188.Schindler, O., 223, 237.Schinz, H., 206, 208, 217.Schipprak, P., 243.Schissler, D. O., 45, 97.Schlabach, T. D., 361.Schlatter, M. J., 190.Schlenck, F., 327.Schlenk, F., 328.Schlenk, W., jun., 396.Schlesinger, H. I., 125, 126,386.283.127424 INDEX OF AUTHORS’ NAMES.Schlittler, E., 256, 257.Schlogl, R., 106.Schlubach, H. H., 268.Schmall, E.A., 355.Schmall, M., 357.Schmeisser, M., 144.Schmerling, L., 102, 190.Schmid, R., 316.Schmid, R. W., 201.Schmidlin, J., 234.Schmidt, G. M. J., 375,Schmidt, H., 135, 206.Schmidt, P., 246.Schmidt, W. E., 349.Schmitz, J. V., 290.Schmitz-Dumont, O., 142.Schmutzer, E., 106.Schneider, A., 40, 354.Schneider, B., 26.Schneider, E. E., 10.Schneider, J., 204, 128.Schneider, J. A., 256.Schnurmann, R., 368.Schoch, W., 156.Schdler, F., 346.Schollkopf, U., 181.Schonberg, A., 194.Schoniger, W., 349.Schoening, F. R. L., 390.Schopf, C., 267.Scholder, R., 146.Scholes, G., 279.Scholler, K. L., 184.Schoolery, J. N., 23.Schott, H. F., 298.Schreiber, K., 227.Schreier, E., 266.Schrenk, W. G., 364.Schreyer, J.M., 143.Schroll, G., 147.Schroth, W., 200.Schryver, S. B., 273.Schubert, J., 104.Schubert, W. M., 170, 183,Schultz, G. O., 364.Schuit, G. C. A., 94,Schuler, D. E., 29.Schuler, R. H., 29.Schulte, H., 260.Schulz, A. I<., 32.Schulz, R., 71, 79.Schulz, W., 121.Schulze, E., 122.Schumacher, H. J., 50.Schumb, W. C., 131, 132.Schuster, M., 358.Schuster, P., 326.Schwab, G.-M., 99, 101.Schwab, W., 127.Schwaebel, R., 136.Schwander, H., 273.Schwartz, S., 312, 316, 320.Schwarz, H. A,, 81.Schwarz, J. C. P., 263.393.193.102.Schwas-z, M., 285.Schwarz, R., 131, 132, 133,Schwarzenbach, G., 120,Schweiter, U., 185.Schweitzer, D., 62.Schweizer, B., 356.Schweppe, H., 360.Schwerdtfeger, E., 359.Schwert, G.W., 305, 306.Schwindling-Manderscheid,Schwyzer, R., 180.Scott, D. B. M., 331.Scott, D. W., 35, 36, 37, 44.Scott, G. P., 190.Scott, J. J., 321, 322.Scott, L. W., 366.Scouloudi, H., 386.Scovil, H. E. D., 11.Scroggie, J . G., 191.Seaborg, G. T., 143.Searcy, A. M., 232.Searcy, A. W., 44, 146.Searles, S., 174, 241.Sease, J. W., 355.Seaton, J. C., 246.Sebban, J., 79.Sedlak, V. A., 75.Sedlmeier, J., 148.Seeds, W. E., 279.Seegmiller, J. E., 329, 331.Seel, F., 136.Seelbeck, E., 226.Segal, H. L., 308.Seher, A., 182.Sehon, A. H., 46, 52.Seidman, R., 33.Seig, L., 86.Seiler, H., 358.Seitzer, W. H., 79.Sekine, H., 22.Sela, M., 75.Sell, H. M., 350, 362.Selover, J . C., 202.Selwood, P. W., 97.Semeluk, G.P., 52.Semenoff, N., 87.Semmler, F. W., 240.Sengupta, P., 213.Sense, K. A., 45, 123.Seraidarian, K., 273.Sergeyev, V. V., 131.Sermin, T., 230.Serota, S., 236.Servigne, M., 360, 364.Sesny, W. J., 145.Setkina, V. A., 55.Setlow, R., 279.Seto, S., 30, 199, 200, 248.Setterquist, R. A., 241.Seus, D., 146.Severson, W. A., 293.Seyferth, D., 147.Seyhan, M., 121.Shabica, A. C., 236.134.124, 171.G., 273.Shackelford, J . M., 190.Shafer, M. W., 129.Shagisultanova, G. A., 152.Shain, I., 350.Shalgosky, H. I., 350, 356.Shams El Din, A. M., 117.Shankland, R. V., 102.Shapiro, H. S., 278.Shapiro, I., 125.Shapiro, N. S., 116.Shapp, A., 27.Sharma, H. D., 358.Sharpe, A. G., 279, 287.Shatenshteyn, A. I., 55.Shatz, P.N., 26.Shaw, 13. L., 182, 184.Shaw, J. T., 180.Shawlow, A, L., 25.Shay, T. F., 369.Shchukarev, S. A., 142.Shearer, H. M. M., 389.Shearer, J. N., 15.Sheehan, J . C., 234, 254.Sheline, R. K., 18, 147.Shelton, E. M., 20.Shemin, D., 312, 313, 315,Shepard, J. W., 286.Shepherd, B. D., 140, 180.Sheppard, N., 15, 16, 17Sheppard, W. A., 61.Sheridan, J., 8, 26, 96, 98,Shibata, S., 23.Shikov, V., 114.Shilov, A. Y., 52.Shimada, J., 11.Shimanouchi, T., 19.Shimizu, S., 72.Shimomura, K., 25.Shiner, V. J., jun., 60, 168,Shingaki, T., 70.Shiro, M., 387.Shive, W., 188.Shkolman, E. E., 75.Shoemaker, D. P., 387,391.Shoolery, J. N., 371.Shoppee, C. W., 159, 172,Shorland, F. B., 185, 186.Short, L. N., 18, 119.Shostakovsky, M.F., 70,Shott, G., 50.Shreir, L. L., 116.Shull, C. M., 147.Shull, E. R., 15, 17.Shver, E. S., 51.Sicre, J . E., 50.Siedel, W., 179, 312.Sieg, A. L., 247.Siegel, J. R., 176.Sieger, R. A., 66.Siekierski, S., 116.Siemons, W. J., 382.316, 321.18, 20, 196.370.169.228, 229, 230.75INDEX OF AUTHORS’ NAMES. 425Sienicki, E. A., 251.Sierra, F., 339.Sigal, M. V., 265.Sigiura, M., 23.Signer, R., 273.Sihlbom, L. , 180.Sijderius, R., 344.Silberstein, 3 1.Silcocks, C. G., 51.Silk, M. H., 186.Silverman, J. C., 54.Silverstein, R. M., 176, 242.Silvey, G., 8.Silvey, G. A., 281.Sim, G. A., 389.Simeral, W. G., 381.Simes, J. J. H., 239.Simha, R., 76.Simmler, J. R., 367.Simmons, F. R., 86.Simmons, H.E., jun., 154.Simmons, J. W., 8, 9.Simmons, N. S., 273.Simon, A., 21, 368.Simon, V., 353.Simon, W., 129.Simonetta, M., 167, 230.jimons, J. H., 280, 281,?imonsen, (Sir) J., 207, 215,Simonson, T. R., GO.Simpson, D. M., 16.Simpson, S. A., 223Sims, P., 191.Singer, R. B., 56.Singer, S. S., 43.Singer, T. P., 307.Singh, A., 345.Singh, B., 345.Singh, I<., 27.Singh, K., 345.Singhadeja, S., 366.Singleton, D. O., 361.Sinsheimer, R. L., 275,Sinyakova, S. I., 351.Sisler, H. H., 28, 135.Sizer, I. W., 308.Sjohander, J. R., 188.Skarulis, J. A., 129.Skell, P. S., 158, 263.Skilling, S., 369.Skinner, G. S., 170.Skinner, H. A., 39, 40, 41.Skinner, J., 368.Skinner, J. M., 390.Skoog, I., 127.Skuratov, S. M., 75.Slabey, V.A., 19, 98, 201,Slater, N. B., 26.Slates, H. L., 223.Slator, M., 192.Slayton, G. R., 9.Slaytor, M., 177.Slin’ko, M. G., 99, 100.282, 287, 381.216.278.202.REP.-VOL LISloan, G. J., 11.Slomp, G., 235.Slutsky, L., 28, 45.Smales, A. A., 350.Small, P. A., 308.Small, R. M. B., 20.Small, R. W. H., 395.Smellie, R. M. S., 273, 274.Smeltzer, P. B., 369.Smets, G., 74, 76.Smith, A. E., 387, 396.Smith, A. G., 9.Smith, D. C. C., 263, 361.Smith, D. D., 285.Smith, D. F., 385.Smith, E. D., 360.Smith, E. L., 304, 305, 308.Smith, F., 176, 262, 263,279, 282, 286, 360, 361.Smith, G. B. L., 175.Smith, G. C., 369.Smith, G. F., 180, 242, 246,Smith, G. H., 286.Smith, G. P., 151.Smith, H., 173, 177.Smith, H.G., 382.Smith, H. S., 126.Smith, J. A. S., 371, 378,Smith, J. C., 187, 193.Smith, J. D., 273, 275, 277.Smith, J. V., 387.Smith, J. W., 116.Smith, K. C., 275.Smith, L., 36.Smith, L. W., 202.Smith, N. B., 39, 41.Smith, N. O., 129.Smith, 0. D., 350.Smith, P. A. S., 166, 253.Smith, P. L., 35.Smith, R. M., 298.Smith, S., 237, 242.Smith, W. M., 69.Smith, W. V., 7, 8, 9, 10,Smits, D. W., 391, 398.Smittenberg, J., 34.Smook, M. A., 290.Smyrniotis, P. Z., 328, 329,331, 332, 333.Smyth, C. P., 32.Sneeden, R. P. A., 237.Sneen, R. A., 160, 228.Snell, E. E., 245, 310.Snoddy, C. S., jun., 223.Snoke, J. E., 306.Snow, A. I., 386.Snyder, M. J., 45, 123.Soling, H., 124.Sollner, K., 354.Solomon, D. H., 179, 191.Soloway, A.H., 179, 228,Somerton, K. W., 116.Sommer, H., 105.337, 338.383, 392.370.235.Sondheimer, F., 176, 207,227, 228, 229, 230, 231,232, 233, 236.Sonntag, F., 76.Sono, Y., 73.Sontheimer, A., 122.Soper, F. G., 158.Soper, Q. F., 244,Sorderberg, B. A., 11 1.Sorensen, J. S., 184.Sorensen, N. A., 183, 184.Sorenson, W. R., 202.Sorge, G., 71.Sorm, F., 201, 206, 207,213, 214, 215, 230, 234,252.Souchay, P., 352.Southern, A. L., 370.Sowden, J. C., 265, 270.Sowden, R. G., 52.Spath, E., 213.Spall, B. C., 51.Spandau, H., 134.Speakman, J. C., 389, 390,Specker, H., 363.Spedding, F. H., 41, 108,Speirs, J. L., 28, 145.Sperati, C. A., 73.Spickett, R. G. W., 250.Spillner, F., 354.Spingler, H., 257.Spinks, J.W. T., 60, 77,Spinner, B., 159.Spitz, E. W., 367.Spizizen, J., 273.Spliethoff, W. L., 162.Sporer, A. H., 312, 362.Sporzynski, A., 282.Spreadborough, B. E. G.,Spriestersbach, D., 263,Spring, F. S., 222, 231, 236,Springall, H. D., 27, 34.Sproston, T., 361.Srinivasan, R., 51.Staab, H. A., 184.Stacey, M., 19, 172, 264,265, 267, 268, 274, 279,282, 286, 288.Stackelberg, M. von, 110.Stadler, H. P., 394.Stadtman, E. R., 301, 303,Stafford, R. W., 369.Stafford, W. H., 197.Stahl, E., 201, 214.Stamm, K. F., 368.Stammreich, H., 21.Standing, H. A., 263.Stanek, J., 254.Starkweather, H. W., 73.Stauffacher, D., 206.396.363.83.367.360.237.311.426 1Staveley, L. A. K., 43.Steacie, E. W. R., 48, 62,63, 65, 66, 369.Stead, B.D., 74.Stedman, R. J., 312.Steel, A. E., 358.Steel, D. K. V., 190, 198.Steel, R., 19.Steele, B. R., 288, 292.Steeman, J. W. M., 384.Steese, C. M., 15.Steffensen, O., 203.Steger, E., 21.Stehr, E., 348.Stein, G., 10, 83.Stein, S. S., 268.Steinacker, K. H., 252.Steinberg, H., 167, 205.Steindler, M., 126.Steinemann, A., 32.Stejskal, E. O., 17.Stephen, W. I., 339.Stephens, E. R., 89.Stephens, R., 267.Stephenson, L., 11 7.Stephenson, O., 158.Stephenson, R. J., 228.Stepukhovich, A. D., 51.Stern, E. S., 366.Stern, K. G., 308.Stern, O., 110.Sternberg, H. W., 148.Sternberg, J. C., 66.Stetten, D., 332.Stetter, H., 251, 252.Stevens, C. G., 42.Stevens, C. L., 241.Stevens, K.W. H., 10.Stevens, T. S., 247.Stevens, W. H., 60.Stevenson, D. P., 44, 45,Stevenson, R., 222, 229.Steward, F. C., 188.Stewart, F. H. C., 151, 157.Stewart, G. M. D., 390.Stewart, €3. B., 189.Stewart, J. A., 69.Stewart, J. L., 222.Still, J. E., 354.Stitch, M. L., 10.Stock, C. C., 188.StodolovA, O., 357.Stohr, G., 266.Stoffyn, P. J., 265.Stoicheff, B. P., 15, 20,391.Stoker, M. G. P., 275.Stokes, A. R., 279.Stokes, C. S., 282, 287.Stokes, R. I I . , 108, 109.Stokes, W. M., 223.Stolrstad, E. L. R., 244.Stolar, S. M., 234.Stoll, A., 226, 264, 256.Stone, A,, 250.Stone, F. G. A., 125.Stone, F. S., 101.97.DEX OF AUTHORS’ NAMES.Stone, K. G., 353.Stork, G., 181, 216.Stotz, E., 186.Stowe, R. H., 99.Strachan, A.N., 65.Strandberg, M. W. I?., 10.Strange, II., 38.Stranks, D. R., 61.Strating, J., 182.Straus, S., 75.Strauss, E., 309.Street, K., 143.Streib, H., 157.Streibel, P., 229.Streibl, M., 215.Strell, M., 242.Streng, A. G., 282.Strepikheyev, A. A., 75.Streuli, C. A., 252, 352.Stricks, W., 352.Stromberg. A. G., 116.Strong, Fi M., 188, 360,Stuart-Webb. I. A., 227.361.233.Stubbs, F. J., 51.Stumpf, P. K., 325, 386.Sturm, W., 126.Sturtevant, J. M., 299, 302,Style, D. W. G., 49, 67,Subluskey, L. A., 218.Suess, R., 178.Sugasawa, S., 254.Sugihara, J. M., 262.Sugita, T., 19.Suhrmann, R., 110.Sujishi, S., 130.Sulima, L. V., 56.Sullivan, E. P. A., 32.Sullivan, H. R., 175.Sullivan, J. C., 54.Suma, K., 55.Sumi, M., 209.Summer, J.B., 304.Summers, D., 49.Summers, G. H. R., ,230.Summers, L. A., 191.Summerson, W. H., 310.Sundaram, A. K., 358.Sundstrom, K. V. Y., 194.Sundt, E., 227.Sunner, S., 36.Sunthankar, S . V., 192.Surdut, A,, 32.Suski, L., 350.Sutherland, G. B. B. M.,17, 19, 381.Sutherland, G. L., 188.Sutherland, M. D., 243.Sutor, D. J., 390.Sutphen, W. T., 63.Suttle, J. F., 77.Sutton, D. A., 185, 186.Sutton, L. E., 7, 21, 22,303.68.118, 119.Suzuki, M., 67.Suzuki, S., 72, 353.Suzuki, Y., 209.Svec, H. J., 124.Sverdlov, L. N., 26.Swain, C. G., 55, 160.Swain, T. C., 248, 249.Swallow, A. J., 83.Swaroopa, S., 14.Swarts, F., 37, 254, 285.Swarup, P., 33.Sweeney, W. A., 170, 193.Sweetser, P.B., 356.Swenson, R. W., 33.Swick, D. A., 22.Swidler, R., 192.Swientoslawski, W., 35, 37.Swift, E. H., 346, 355.Swift, H., 348.Swingle, S. M., 23.Sworski, T. J., 81.Sykes, A., 337.Sykes, K. W., 49.S9kora, V., 207.Sykut, K., 355.Symes, W. F., 193.Symons, M. C. K., 58, 5.9.Syrnpson, R. F., 351.Syrkin, Ya. K., 30, 118.Szmuszkovicz, J., 160, 181.Szuclri, B., 354.Szwarc, M., 34, 45, 46, 52,63, 64, 71.Ta-cheng Tung, 326.Tachimori, S., 11.Tait, J. F., 223.Takagi, S., 261.Takebayashi, M., 70.Takeda, K., 214, 261.Takeishi, Y., 30.Takenaka, Y., 271.Takeuchj, C., 51.Takeuchi, T., 55, 213.Takezaki, Y., 51, 64.Talbert, P. T., 276.Talbot, J . T., 390.Talman, E. L., 316.Tamm, C., 229, 277, 378.Tamm, K., 59, 104.Tamres, M., 174.Tanaka, I., 68.Tanaka, N., 350, 362.Tanake, T., 38.Tanford, C., 306.Tang, R., 331.Taniguchi, H., 104.Tannenbaum, E., 8, 10.Tannenbaurn, S., 20, 38.Tanner, D., 75.Tanner, K.N., 19.Tarkoy, N., 230.Tarlton, E. J., 208.Tarrant, P., 289, 292.Tasset. G., 76.Tatchell, A. K., 361.Tate, P. A., 10Tatlow, J. C., 282, 286,288, 289, 337.Tatoian, G., 364.Tatsuno, T., 254.Tatum, E. L., 188.Taub, D., 207, 234.Taube, H., 54, 56, 57, 61,Tayler, F. M., 130.Tayler, J. L., 186.Taylor, B. R., 158.Taylor, C. A., 375.Taylor, D. A. H., 173, 223,Taylor, E. H., 11, 78,Taylor, G. W., 69.Taylor, H. A., 66, 94.Taylor, H. S., 95, 99.Taylor, J. W., 34, 46.Taylor, M. P., 361.Taylor, R. C., 20.Taylor, R.P., 72.Taylor, T. J., 267.Taylor, W., 58.Taylor, W. I., 158, 195,260,Taylor, W. S., 254.Tazelaar, A., 328.Tees, T. F. S., 39.T6lupilov6-KrestYnov6, O.,Templeton, D. €I., 382, 385.Teodorovich, I. L., 353.Teplyakov, V. A., 354.Teranishi, R., 17, 382.Terasawa, T., 199, 248.ter Haar, K., 344.ter Heide, R., 362.Terrell, R., 181.Terry, E. A., 351.Teste, E., 326.Testerman, M. K., 134.Tewari, S. N., 359.Thcander, O., 263.Theidel, H., 180.Theorell, H., 304.Theriault, R. J., 333.Thesing, J., 176, 180, 246.Theurer, K., 68.Thewlis, J . , 377, 400.Thieberg, K. J. L., 214.Thilo, E., 123, 137.Thirsk, H. R., 117.Thomas, A. F., 258.Thomas, B. R., 238, 261.Thomas, C. A., 278.Thomas, C. H., 55.Thomas, F., 139.Thomas, G., 361.Thomas, G.H., 221, 230,Thomas, H., 342.Thomas, J . H., 92.Thomas, 1,. F., 8.Thomas, P., 175.Thomas, R., 279.152.236.102.261.351.232.DEX OF AUTHORS’ NAMES. 427Thomas, W. J. O., 8, 9, 19,Thomas, W. M., 72.Thomason, P. F., 358.Thompson, A., 269.Thompson, E. W., 45.Thompson, H. B., 28, 145.Thompson, H. W., 9, 14,Thompson, J. L., 232.Thompson, J. M., 183.Thompson, Q. E., 178.Thompson, R., 38, 135.Thomson, C. M., 389.Thomson, R. H., 195.Thon, N., 94.Thorn, R. J., 44.Thornley, M. B., 202.Thornton, C. G., 22.Threlfall, C. J., 273.Throssell, J., 46, 64.Thyagarajan, B. S., 261.Tiers, G. V. D., 284.Tilden, E. B., 328.Tiley, P. F., 101.Tillu, M., 341.Timmis, G. M., 250.Tishler, M., 234.TiSler, M., 198.Tjomsland, O., 384.Tobin, M.C., 38.Tobolsky, A. V., 71, 79.Todardo, M., 345.Todd, A., 80.Todd, (Sir) A. R., 196, 197,Todd, G., 397.Todd, H. E., 364.Todes, 0. M., 100.Toga, T., 209.Toki, K., 209.Tolberg, R. S., 66.Tolbert, N. E., 328.TomiEek, O., 357.Tomlin, D. H., 44.Tomlinson, M. L., 247.Tompa, H., 70.Tompkins, F. C., 93.Toome, V., 110.Tooth, 13. E., 312.Topless, J. G., 217.Topley, B., 87.Toplin, J. G., 93.Topper, Y. J., 334.Toren, P. T., 351.Toribara, T. Y., 360.Torrey, H. C., 23.T6th, J., 254.Totton, E. L., 326.Tovbin, M. V., 362.Towers, G. H. N.. 188.Towle, L. H., 132, 144.Towne, E. B., 289.Townes, C. H., 8, 25, 26.Townsend, J., 11.Toyama, O., 99.Trachtenberg, I.&I., 47.26, 27, 49.87, 368.270-272, 277, 399.Trambarulo, R., 7, 8, 390.Tramer, A., 21.Tramutt, H. M., 364.Tranter, T. C., 391.Trapnell, B. M. W., 93.Travers, M. W., 51.Traynelis, V. J., 241, 246.Treibs, A., 180, 242, 312.Treibs, W., 183, 200, 203,Trenan, R. S., 11.Trevelyan, W. E., 298, 299.Trikojus, V. M., 328.Tristram, G. R., 304.Tristram, H., 268.Troost, L., 131.Trost, W. R., 138.Trotman-Dickenson, A. V.,51, 52, 63.Trott, P. W., 293.Trowse, I;. W., 48, 56.Triipel, F., 142.Truswell, A. E., 143.Truter, E. V., 187.Truter, M. R., 384.Tsao, M.-S., 106.Tschesche, Ti., 237.Tsuboi, M., 19, 29.Tsubomura, H., 29.Tsuda, K., 230.Tsuda, Y., 261.Tsukamoto, K., 261.Tull, R., 235.Tuomikoski, P., 29, 30.Turkdogan, E.T., 42.Turkevich, J., 97, 98.Turkevich, N. &I., 138.Turnbull, J. H., 230, 232.Turner, E. E., 194.Turner, 13. B., 230, 237.Turner, T?i. J., 320.Tuthill, S. M., 367.Tweit, R. C., 205.Twigg, G. H., 97, 100.Tyczkowski, E. A., 281.Tyree, S. Y., 132.Tyrrell, H. J. V., 145.Tyson, F. T., 180.Ubbelohde, A. R., 384.Ueberreiter, K., 7 1.Uebersfeld, J., 11, 78.Ueno, K., 191.Ugi, I., 251.Uhlig, F., 181.Ukita, T., 200.Ukshe, E. h., 116.Uksila, E., 188.Ulbrich, R., 21.Ullrich, T., 134.Ulmann, M., 361.Underwood, A. L., 356.Underwood, J. C., 360.Unger, S., 99.Uphaus, R. A,, 64.Urban, R. S., 193.UrbAnek, L., 213.249428 INDEX OF AUTHORS’ NAMES.Urry, G., 127.Urwin, J. R., 352.Utzinger, G. E., 180.Utzinger, H., 242.Uusitalo, E., 120.Uyeo, S., 158, 261.Uzman, L.L., 274.Vaeck, S. V., 358.Vahlquist, B., 316.Vainshtein, B. K., 377.Valenta, P., 351.Valentine, L., 74.Valentiner, S., 130.van Artsdalen, E. R., 40,van Atta, R. E., 352.Vance, J. E., 44.Van Cleave, A. B., 83.Vand, V., 194, 374, 393,Vanderhaeghe, I€., 179,van der Marel, L. C., 10.van der Schaaf, P. C., 363.van der Straaten, H., 54,van Dolah, R. W., 395.van Duin, H., 189, 362.Van Duuren, B. L., 260.Van Kranendonk, J., 14.van Maurik, D., 34.Van Meersche, M., 79, 91.Van Moffaert, Y., 338.van Niekerk, J. N., 390.Vannotti, A,, 311.Vanpde, M., 91.Van Riet, R., 15, 20.Van Rysselberghe, P., 49.Vansheydt, A. A., 72.Van Slyke, 347.van Tamelen, E.E., 205,van Tiggelen, A., 89.Van Uitert, L. G., 120.van Veen, A. G., 207.van Volkenburgh, R., 98.van Vunakis, H., 309.Van Wazer, J. R., 120.Va Popov, S., 116.Varma, K. K., 122.Varnerin, R. E., 47.Varshavski, Ya. M., 55.Varshni, Y. P., 26.Vaslow, F., 304.Vassilaros, G. L., 312.Vaughan, C. W., 154.Vaughan, G., 172, 264.Vaughan, P. V., 384.Velasco, M., 176, 227, 228.Velluz, L., 218.Venturello, G., 359.Vercellone, A., 236.Vergnoux, A. M., 18.Verma, A. R., 373.Vermeil, C., 81.Vernon, C. A., 268, 296.45, 48, 64.394.228.55, 142.253.Vernon, L. P., 308.Venvimp, J., 89.Vestin, R., 122.Vetter, K. J., 115.Viallard, R., 348.Vickery R. C., 121, 129.Vidner, P., 357.Viehe, H. G., 183.Viervoll, H., 391.Vihovde, E.H., 384.Vincent-Geisse, J., 17.Vineze, I., 254.Virtanen, A. I,., 188.Vis, E., 249, 265.Vischer, E., 234.Visser, J. W., 398.Viterbo, R., 239.Vivarelli, S., 351.Vlaar, H. T., 55.Vlannes, N., 339.Vodar, B., 13, 14.Voelz, F. L., 16.Vogel, C., 225.Voigt, U., 354.Volkenstein, M. V., 21.Volkein, E., 273, 275.Volkova, E. I., 100.Volman, D. H., 63.Voltz, S. E., 30.von Elbe, G., 83, 88.von Eller, H., 396.von Euw, J., 223.von Keussler, V., 29, 366.von Rudloff, E., 185.von Saltza, M. H., 244.von Sydow, E., 388.von Wartenberg, H., 39.Vorob’eva, G. P., 51.Vos, A., 385.Voser, W., 238.Voss, H., 131.Voter, R. C., 73.Vouk, V. B., 350.Voyevodskiy, V. V., 75.Vriens, G. N., 48.Vyes, S., 261.Wachtel, U., 363.Wacker, P.F., 8.Wada, E., 254.Waddington, G., 35-37,Waddington, H. R. J., 244.Wadman, W. H., 262.Wadsley, A. D., 27, 387.Wadswortb, M. E., 369.Waelbrock, F., 44.Wager, H. G., 264.Wagland, A. A., 231.Wagman, D. D., 38.Wagner, A. F., 244.Wagner, C., 100.Wagner, C. D., 97.Wagner, E. L., 17.Wagner, R. I., 126.Wagner, R. S., 8.Wagner- Jauregg, T., 310.44.Wahba, M., 99.Wahba, N., 236.Wahi, P. N., 360.Wahl, A. C., 54.Wahl, P., 79.Wahlin, E., 352.Wailes, P. C., 188.Wainio, W. W., 332.Waksmundzki, A., 361.Waksmundzki, W., 354.Walaschewski, E. G., 294.Walborsky, H. M., 204,Waldenstrom, J., 316.Waldo, P. G., 102.Waldron-Edward, D. M.,Waldvogel, M. J., 328.Walker, G. F., 387.Walker, G.W., 352.Walker, M. T., 352.Walker, R. W., 19, 223.Walker, T., 233.Walker, T. K., 327, 334.Wall, L. A., 75, 76.Wall, M. C., 95, 97.Wall, M. E., 236.Wallace, W. E., 122.Wallace, W. J., 128.Wallenfels, K., 263.Wallenstein, M. B., 39.Walling, C., 10, 62, 71, 72.Walling, M. T., 152.Walls, F., 213, 221.Wallwork, S. C., 396.Walser, M., 47.Walsh, A. D., 50, 85, 86, 88,Walsh, P. D., 77, 129.Waltcher, I., 71.Walters, P. M., 206.Walters, W. R., 52.Walters, W. D., 53.Walton, E., 244.Wang, J. H., 109.Wang, S. M., 357.Wang, S. Y., 201.Wannagat, U., 131.Warburg, O., 331.Wardlaw, W., 133.Waring, D. H., 393.Wark, W., 119.Warner, B. R., 357.Warnhoff, E. W., 218, 220.Warren, D. R., 83, 84, 85,Warren, F. L., 237, 240.Warringa, M.G. P. J., 304.Wartik, T., 127.Washizuka, S., 341.Wasserman, H. H., 241.Wassermann, A., 70.Waszeciak, P., 38.Watanabe, H., 200.Watanabd, T., 391.Watase, T., 38.Waters, D. N., 21, 110.205, 285.360.91, 92.89INDEX OF AUTHORS’ NAMES. 429Waters, W. A., 58, 158.Waterstradt, H., 146.Watkins, W. M., 270.Watling, K. H., 240.Watson, C. J., 311, 312,Watson, G. M., 34.Watson, J. D., 279.Watson, L., 275.Watson, R. W., 333.Watt, G. W., 150, 152.Watt, I. C., 67.Watt, J., 352.Watts, H., 41, 128.Waugh, J. L. T., 387.Waugh, J. S., 381.Weatherall, M., 311, 312,Weatherly, T. L., 25.Webb, A. A., 195.Webb, A. D., 361.Webb, J. A., 188.Webber, T. J., 350.Weber, E. F., 139, 141.Weber, H., 195.Weber, J., 370.Weber, L., 233.Weber, 0.A., 350.Weed, L. L., 275.Weedon, B. C. L., 98, 175,182, 187.Weger, E.. 93.Wehner, G., 124.Weigel F., 138.Weil, A., 21, 389.Weil, H., 359.Weil, L., 309.Weill, C. E., 308.Weiner, G., 18.Weinheimer, A. J., 157,191.Weinstock, J., 156.Weisenborn, F. L., 257.Weisener, K., 59.Weiss, A., 125, 130, 358.Weiss, F., 362.Weiss, J., 53, 58, 77, 78, 81,Weissbach, A., 333.Weissmann, B., 263.Weisz, H., 336.Weisz, I., 254.Weisz, P. B., 102.Weizmann, A., 213.Welch, A. J. E., 387.Weller, L. F., 362.Weller, S., 49.Wells, A. F., 382, 384.Wells, R. A., 358.Welsh, H. L., 13, 20.Welwart, Y., 356.Wember, K., 245.Wender, I., 148.Wendler, N. L., 223, 234.Wendles, N. L., 195.Wenger, F., 354.Wenkert, E., 158, 253, 261.Wennerstrand, B., 345.316, 317.322.279.Werner, R.L., 19, 20, 172.West, B. O., 57, 151.West, J. P., 190.West, P. W., 354.West, R., 133.West, R. C., 145.West, T. S., 335, 344, 346.Westall, R. G., 317.Westermark, H., 36.Westman, A. R., 59.Weston, R. E., jun., 55,Westrik, R., 383.Westrum, E. F., 381.Wetherington, J. A., 102.Wettstein, A., 223, 224,231, 234, 236.Wever, F., 364.Weygand, F., 195.Weyl, W. A., 93.Whaley, W. M., 181.Wheatley, A. T., 53.Wheatley, N., 59.Wheatley, P. J., 385, 389,Wheelans, M. A., 127.Wheeler, C. M., 122.Wheeler, 0. H., 171, 206.Wheelwright, E. J., 363.Whelan, W. J., 262, 361.Whiffen, D. H., 19, 130,Whistler, R. L., 268.White, A., 308.White, D.E., 214, 238.White, D. G., 130.White, F. H., 311.White, J., 35.White, J. G., 392, 399.White, J. W., 363.White, T. R., 27, 34.White, W. H., 336.White, W. R., 220.Whitfield, P. R., 276, 277.Whitham, G., 167.Whitham, G. H., 182.Whiting, M. C., 167, 175,182, 183, 184, 185, 188.Whitmore, F. E., 396.Whitney, R. B., 111.Whittaker, V. P., 305.Whittle, E., 62.Wiacek, K., 351.Wibaut, J. P., 255.Wiberg, E., 126, 128, 137.Wiberg, H. B., 60.Wiberley, S. E., 201.Wichterle, O., 241.Wickberg, B., 262, 269.Wicke, E., 106, 110.Wickstrom, A., 269.Widmark, G., 346.Wiebe, R., 28.Wiebenga, E. H., 385, 391.Wiechert, K., 279.Wiedersich, I., 110.WiehJ, H. E., 30.159.395, 396.267, 368.Wieker, W., 137.Wieland, T., 180.Wierzchowski, K. L., 67.Wiethoff, G., 364.Wiggins, T. A., 15.Wijnen, M. H. J., 62, 63.Wilber, P. B., 272.Wilcox, P. E., 309.Wilcox, W. S., 8.Wild, H., 267.Wildman, W. C., 204.Wiley, P. F., 265.Wilhelm, M., 163.Wilkins, B. H., 338.Wilkins, C. J., 22,Wilkins, D. H., 338.Wilkins, M. H. F., 279.Wilkins R. G., 55, 57, 136.Wilkinson, G., 18, 119, 132,141, 145-147, 150.Wilkinson, G. R., 369.Wilkinson, J., 77.Wilkinson, P. R., 354.Willard, J. E., 63.Williams, A. E., 120, 171.Williams, J. H., 233, 266.Williams, K. T., 328.Williams, L. T. D., 41.Williams, M. M., 42.Williams, Q., 25.Williams, R., 361.Williams, R. J. P., 120, 121,Williams, K. L., 14, 16.Williams, R. R., 66, 78.Williams, V. Z., 390.Willis, A. J., 264.Willstatter, R., 303.Wilson, A. T., 333.Wilson, D. W., 340.Wilson, E. B., 9, 286.Wilson, 1%. K., 279.Wilson, I. B., 302, 304, 307,Wilson, J., 59.Wilson, J. E., 76.Wilson, J. N., 97.Wilson, M. K., 15-17.Wilson, R. R., 237.Wilson, W., 230, 233.Wilson, W. A., 280.Wilzbach, K. E., 55.Windsor, M. W., 69.Winfield, M. E., 93.Winkler, C. A,, 59, 63.Winkler, F., 179, 312.Winkler, R. E., 237.Winning, W. I. H., 89.Winstein, S., 164, 167, 168,Winter, E. R. S., 56, 100.Winternitz, F., 236. ’Wintersberger, K., 127.Wintersteiner, O., 227.Wise, E. N., 355.Wise, H., 53, 89, 143.Wise, P., 98.171, 362.310.179, 230, 240430 INDEX OF AUTHORS’ NAMES.Wish, L., 363.Wishaw, B. F., 108, 109.With, T. K., 312.Witkop, B., 255.Wittenberg. J., 312, 313.Wittig, G., 155, 156, 157,162, 181, 247,Wittwer, S. H., 350, 362.Witz, S., 130.Wizinger, R., 121.Wnuk, J., 282.Woggon, H., 137.Wojcik, B. H., 289.Wolf, D. R., 291.Wolf, H. P., 326.Wolf, J. P., 353.Wolf, K. H., 137.Wolf, R., 354.Wolf, S., 352.Wolff, R. E., 217.Wolffenstein, R., 254.Wolfgang, R. L., 56.Wolfrom, M. L., 269.Wolfsberg, M., 61.Wollish, E. G., 357.Wollrak, F., 19.Wolovsky, R., 192.Wong, R., 129.Wood, D. L., 19.Wood, G. W., 172, 223.Wood, H. C. S., 250.Wood, J. L., 17.Wood, W. R., 206.Woodall, N. B., 369.Woodhead, J. L., 344.Woodhouse, D. L., 275.Woodrow, H. W., 126.Woods, G. F., 228, 231.Woods, R. J., 175.Woodward, A. E., 74.Woodward, C. C., 359.Woodward, I., 376.Woodward, L. A., 20, 110.Woodward, R. B., 207,209,218, 224, 225, 226, 227,238, 256, 260.Wooldridge, K. R. H., 174,175, 194.Woolf, A. A., 40, 130, 139,144.Woolfson, M. M., 374, 394.Wooten, F. O., 25.Worsham, J. E., jun., 31.Wotherspoon, N., 68.Wotiz, J., 148.Wright, G. F., 283,347,396.Wright, J. T., 362.Wright, R. H., 21.Wright, R. S., 239.Wright, S. E., 243.Wright, W. B., 390.Wright, W. W., 70, 72.Wriston, J. C., 316.Wurstlin, F., 33.Wulf, H.-D., 243.Wunderlich, J. A., 386.Wurmser, R., 301.Wyatt, G. R., 275.Wyatt, R. M. H., 92.Wyckoff, R. W. G., 373.Wylam, C. B., 269.Wyler, H., 240.Wyman, J., 304.Wyman, L. J., 223.Wynberg, H., 246.Wysmann, Y., 273.Wysocka, J., 351.Wythe, S. L., 258.Yabumoto, S., 389.Yadava, K. L., 122.Yajima, H., 261.Yakel, H. L., jun., 391.Yakubiak, M. G., 351.Yamada, N., 55, 100.Yamaguchi, S., 199.Yamaha, M., 22.Yamamoto, T., 73.Yamamura, H., 32.Yamasaki, K., 254.Yamasaki, M., 321.Yanaihara, N., 261.Yaney, D., 135.Yankwich, P. E., 61.Yashimoto, T., 19.Yashiro, K., 355.Yasumori, I., 49,Yates, P., 204, 209.Yatsimirsky, K. R., 336.Yeddanapalli, L. M., 51.Yemm, E. W., 264.Yoe, J. H., 338.Yoffe, A. D., 52.Yonezawa, T., 70.Yoshida, Z., 67.Yost, D. M., 92, 381.Youatt, G., 304.Youhotsky, I., 222.Young, E. J., 286.Young, H. T., 168.Young, L., 117.Young, L. G., 367.Young, R. L., 160.Young, T. F., 104.Yu-Wei Chang, 72.Yuzawa, T., 22.Yvernault, T., 48.Zabolotskaya, E. V., 74.Zachariasen, H., 384.Zachariasen, W. €I., 383,Zaffaroni, A., 230.Zahler, K. E., 199.ZaIkin, A., 385.Zamenhof, S., 274.Zarinsky, V. A., 355.Zaromb, S., 382.Zechmeister, L., 184, 185.Zeidler, I. I., 7 5 .Zeiss, H. H., 215, 218.Zeldes, H., 11, 78.Zelikoff, M., 64.Zelitch, I., 327.Zeltmann, A. H., 55.Zemany, P. D., 80.Zempl6n, G., 269.Zernke, J., 135.Zervas, L., 311.Zhdanov, G. S., 382.Ziegenbein, W., 200.Ziegler, E., 319.Ziegler, J. B., 236.Ziegler, K., 128, 204.Zielen, A. J., 18, 43.Zigeuner, G., 319.Zirnmer, W. F., 287.Zingaro, R. A., 135.Zinner, G., 189.Zschaage, W., 137.Ziircher, A., 232.Zuman, P., 351.Zverina, V., 254.Zvonkova, 2. V., 382.Zwolinski, €3. J., 49, 63.Zylra, J., 352.386

ISSN:0365-6217    

DOI:10.1039/AR9545100401

出版商:RSC    

年代:1954

数据来源: RSC

摘要:

INDEX O F SUBJECTS.(“ detn.” = determination)Acetic acid, trans-2-phenylcycZopentyl-,Acetone, photo-oxidation of, 67.Acetone, hexafluoro-, preparation of,[a-l4C]Acetophenone, isotope effect inAcetylene, complexes of, with copper(1)diphenyl-, dimerisation of, 201.methyl-, catalytic hydrogenation of,96.Acetylenes, alkoxy-, preparation andproperties of, 182.Acetylenic acids, prototropic rearrange-ments of, 182.Acid- and base-linked equilibria in bio-chemical studies, 297.Acids, amino-, 187.crystallography of, 390.fatty, synthesis of, 187.Actinometry, 77.‘‘ Active centres ” of enzymes, 303.Activity coefficients, 106.Acylation of amines, 180.Adenine, 2-methyl-, occurrence of, 249.Adenosine, deoxy-, structure of, 270.Adenylic acid a, formulation of, 271.Affinin, configuration of, 186.Agrocybin, structure and synthesis of,Ajmaline and isoajmaline, structures of,Akuammigine, probable structure of,Akuammigol, 258.Alcohols, acetylenic, reduction of, 175.Aldehydes, aromatic, preparation of,photolysis of, 65.Aldolases, 324.Aldosterone, structure of, 222.Alicyclic compounds, 201.Alkali metals, detection and separationof, 339.reduction by, 176.Alkali-metal nickelates, 151.Alkaloids, 253.Alkanes, fluoroiodo-, 286.Alkenylmagnesium bromides, formationof, 189.Allene, catalytic hydrogenation of, 98.Allenes, 183.Alstoniline chloride, structure of, 258.Aluminium, trimethyl-, bond lengths inreaction of, with hydrogen sulphide203.286.hydrogenation of, 98.chloride, 122.183.257, 258.258.192.bond distances in, 15.dimer of, 386.or selenide, 128.Aluminium bromide, complexes of, 128.chloride, complexity of, 128.fluoride, heat of formation of, 41.halides, complexes of, with amines, 128.hydride, diethyl-, 128.iodide, complexity of, 128.pentyl oxides, 128.Amalgams, reaction of, with oxygen, 122.Ambreinolide, 2 17.Americium fluorides, 143.Amines, alkylaryl-, preparation of, 180.acylation of, 180.reaction of, with nitrous acid, 165.Aminomercuric bromide, 124.Ammonia, kinetics of catalytic decom-oxidation of, by oxygen, 89.proton resonance between liquid andreaction of, with nitric oxide, 53.position of, 99.vapour state of, 23.with nitrogen dioxide, 49.composition of, 130.382.of, 135.Ammonium amalgam, tetramethyl-, de-Ammonium halides, crystal structure of,hydrogen carbonate, sublimation pointion, hindered rotation in, 24.oxide, crystal structure of, 382.phosphate, “ sesqui-”, non-existence of,137.Anacycline, structure of, 182.Analytical chemistry, 335.Anhydro-sugars, ring opening of, 173.Anilides, deacetylation of, 180.ZeucoAnthocyanins, structure of, 248.Anthraquinone, amination of, 195.Anthraquinones, reduction of, 196.Antimony pentachloride, crystal structureAphis pigments, 196.Aphylline, configuration of, 254.Arborine, identity of, with glycosine, 260.Aricine, structure of, 258.Arjunolic acid, 220.Aromatic compounds, 190.Arsenic, detn.of, in organic compounds,Arsenic-boron compounds, 126.Arsonic acid, trifluoromethyl-, 144.Artemazulene, 214.cycZoArteno1, structure of, 238.Association of reactants, 160.Atomic reactions, 61.1-Aza-adamantane, synthesis of, 262.l-Aza-azulene, formation of, 248.l-Aza-azulene, 1 : 2-dihydro-2-oxo-, form-ation of, 248.Aza-azulenes, 199.of, 385.349.43432 INDEX OF SUBJECTS.Azasereine, natural occurrence of, 188.Azides, preparation of, 136.Azoimide.See Hydrazoic acid.Azomethane, kinetics of decompositionof, 51.Azulene, preparation of, 178.Azulenes, 200.perhydro-, 213.Barium, colorimetric detn. of, 338.direct titration of, 344.separation of, 341.Barium salts of alloxantin, its tetramethylderivative, and hydrindantin, 124.sulphate, pptn. of, 342.Benzene, C-C distance in, 391.C-H bond-dissociation energy in, 46.cyano-, structure of, 9.fluoro-, heat of combustion of, 37.hexachloro-, C-C1 bonds in, 393.hexamethyl-, planarity of, 393.internuclear distances in, 20.1 : 3 : 5-triphenyl-, structure of, 393.Benzenes, azoxy-, rearrangement of, 192.Benziminazole, 2-2’-pyridyl-, as analyticalreagent, 337.Benziminazoline, 2-2’-pyridyl-, as ana-lytical reagent, 337.4 : 5-Benzoisoindolinium bromide, 2 : 2-dimethyl-, ring opening of, 156.Benzonitrile.See Benzene, cyano-.3 : 4-Benzophenanthrene, non-planarityof, 393.p-Benzoquinone, C-0 bond length invapour of, 23.Benzoyl radical, heat of formation of, 46.Benzyl ion, bond-dissociation energy of,45.Beryllium fluoride, vapour pressure of,123.salts, complexity of, in aqueous solution,123.diisopropyl-, 123.di-tert.-butyl-, 123.hydride, 124.Biochemistry, 295.Biological syntheses, 324.Bis-2-1 : 3-dithiacyclopentyl, 395.Bond-dissociation energies, 45.Bond energies in chloro-dimethylamino-and -ethoxy-borines, 39.Bond properties, 26.Boron, detection of, 338.di-n-propyliodo-, 126.Boron acetate, 127.sulphide, methoxy-, 126.tricyanide, 127.trifluoride, 126.Boric acid, ortho-, crystal structure of,Boric oxide, crystal structure of, 383.Borine, dimethylaminodichloro-, 126.Borohydrides, preparation of, 125.Diborane, compound of, with dimethylreaction of, with ethylene, 53.reactions of, with nitrites, 136.383.sulphide, 125.Boron.Diboron tetrachloride, 127.Nonaborane, 125.Octaborane, 125.Pentaborane, unstable, 125.Polyborate ions, 127.Te traboron tetrachloride, crystal s tru c-B,H,, structure of, 9.ture of, 385.Boron-arsenic compounds, 125.Branching in polymers, 72.Bridged-ring systems, 252.cycZoButane, bromomethyl-, preparationisoButane, Me&-H bond-dissociationterl.-Butyl titanate, complexes of, withn-Butyl vinyl ether, kinetics of poly-But-2-ynoic nitrile, C-CN bond lengthCadinene, S- and E-, structures of, 208.Cadmium, volumetric detn.of, 345.Czsium tetraiodide, crystal structure of,CaIcium, reaction of, with water vapour,Calcium monochloride, 124.Carbanions as intermediates, 159.Carbazole,Carbohydrates, 262.of, 202.synthesis of, 202.energy in, 46.glycols, 132.merisation of, 74.in, 8.385.124.1 : 2 : 3 : 4-tetrahydro-6-hydr-oxy-7-methyl-, 247.detection and separation of, 262.detn.of, 263.See also under Sugars.Carbon, detn. of, in metals, 354.heat of sublimation of, 43.volumetric detn. of, 347.Carbon dioxide-hydrogen or -oxygen’mixtures, infra-red absorption of,14.Carbon monoxide, adsorbed, infra-redcatalysis of reaction of, with ozone,catalytic oxidation of, 100, 101.reaction of, with oxygen, 87.388.spectrum of, 14.100.Carbonium ions, reactions of, 164.Carboxylic acids, crystal structure of,Cardiac aglycones and glycosides, 237.Carissone, structure of, 208.( f )-a-Carotene, synthesis of, 185.Carpaine and $-carpahe, relationshipp-Caryophyllene, structure of, 215.Catalysis, heterogeneous, 92.Catalysts of alumina-silica type, 102.‘‘ platforming,” 102.Cedrene, 216.Cerium, oxides of, 129.Cetane, perfluoro-, configuration of, 388,Cevine alkaloids, 224.Chloral hydrate, decomposition of, byirradiation in aqueous solution, 83.between, 255INDEX OF SUBJECTS, 433Chlorine atoms, reaction of, with hydro-dioxide, reaction of, with fluorine, 50.trifluoride, crystal structure of, 385.Dichloryl trisulphate, 144.carbons, 63.liquid, association of, 28.combustion of, 36.aqueous solution, 83.Chlorine-containing compounds, heats ofChloroform, basic hydrolysis of, 159.decomposition of, by irradiation inChlorohydrocarbons, pyrolysis of, 52.Cholegenin, 237.Cholestane, 5-chloro-, reduction of, 160.Cholestan- l-one, 229.Cholestanyl bromide, carboxylation of,Cholesteryl toluene-p-sulphonate, re-Chromatography, inorganic, 357.Chromium, biscyclopentadienyl-, 141.Chromium(I1) chloride, use of, in reductionof epoxy-ketones, 177.Chromium oxides, 141." Perchromic acid " (peroxychromicacid), 142.Chrysanthemic acids, configuration of, 202.Cobalt, bisindenyl-, 146.detn.of, 338.selective test for, 339.Cobalt isocyanide-carbonyls, 149.diphenylacetylene hexacarbonyl, 148.tricarbonyl, 148.Cobalt(1) complex, 148.Cobalt(m) complexes, separation of race-mates of, 150.Cochalic acid, 221.Colorimetry, 338.Complexes, inorganic, 120.steric aspects of, 120.Conductance, electrolytic, 107.Conductometric titration, 354.Co-ordination compounds, crystal struc-Copper, colorimetric detn.of, 338.pptn. of, as sulphide, 341.separation of, 338.Copper(I), tercovalency of, 122.Copper( I ) chloride, complexes of, withacetylene, 122.Copper( :I), tetrapyridine-, . polythionatesof, 141.Copper(I1) acetate, structure of, 390.Copper(1r) fluoride dihydrate, 122.Coprostane, 5 : 6-cc-dibromo-, reduction of,Corchsularose, 265.Cortisalin, synthesis of, 184.Cosmene, structure and synthesis of, 184.Coulometric titrations, 355.Creatine hydrate, structure of, 391.Cryptopleurine, structure of, 397.Crystallography, 372.Cumulenes, 183.Cyanogen halides, conductivities of, 130.160.duction of, 160.organic, 360.Dicobalt octacarbonyl, 147.ture of, 386.160.Cyanogen ion, positive, 130.Cyanide ions, complex, infra-red spectraof, 17.isocyanides, complexes of, with m?tals,141.with transition elements, 149.isocyanide-nitrosyl derivatives of ironand cobalt, 149,Paracyanogen, 130.Cyclic structures, effects of, 170.Cyclopenin, structure of, 247.p-Cyperone, structure of, 208.tram-Decalin, chlorination of, 205.Decal-2-one, cis- and trans-, formationDehydrogenation, 177.by quinones, 194.Desosamine, 265.Deuterium, detn.of, 347.exchanges of, with organic molecules, 54.Deuterium-acetylene exchange on metal-ammonia exchange on metal catalysts,-cis-but-2-ene exchange on metal cat--ethane exchange on metal catalysts,-hydrogen exchange on metal catalysts,-methane exchange on metal catalysts,-propylene exchange on metal catalysts,Diatretyne I, structure and synthesis of,1 : 3-Diaza-azulene, formation of, 248.Diazomethane, new preparation of, 181.tautomeric form of, 15.Dibenzyl, pyrolysis of, 62.Dielectric constants, 29.Diffusion, electrolytic, 107.Diffusion-controlled reactions, theory of,Digitogenin, 237.Diketen, formation of unsaturated ketonesDimethyl ether, infrared spectra of vapour2 : 4-Dinitrophenylhydrazones, existenceDipole moments, 30.Diterpenes, 217.1 : 4-Dithian, structure of, 395.1 : 4-Dithionin, structure of, 395.Dithizone as extraction indicator, 343.Double layer, electrical, a t metal-electro-lyte interfaces, 110.Dumortierigenin, 22 1,Durene, bond angles in, 393.isoDurene, formation of, 194.Dyes, photo-bleaching of, 68.Electric polarisation, 29.Electrochemistry, 103.of, 205.catalysts, 96.27, 98.alysts, 97.95.95.95.97.183.dispersion, 31.48.from, 189.of, 16.of, as geometrical isomers, 189434 INDEX OF SUBJECTS.Electrode processes, 114.Electrodeposition, in analysis, 349.Electrolytes, mixed, thermodynamics of,Electron diffraction, 21.Electrophoresis in analysis, 362.Elemane (alicyclic), synthesis of, 207.Elements, crystal structures of, 381.Elemol (alicyclic), structure of, 207.Elimination, bimolecular, 154.Emission spectrography, 367.Entropies, ionic, 105.Enzymes, “ active centres I’ of, 303.Eperuic acid, 218.L-Ephedrine hydrochloride, structure of,Ergonovine, synthesis of, 256.Erythroaphin-fb and -sZ, 196.Ethane, C-C bond-dissociation energyEthane formed from methyl radicals,hexachloro-, potential barrier in, 22.Ethyl formate, kinetics of decompositionnitrate, heat of formation of, 35.nitrite, reaction of, with nitrogenEthylene, branching during radical poly-107.use of, in crystallography, 377.(steroidal), 240.Hofmann, 154.chemical modification of, 307.397.in, 46.stabilisation of, 62.of, 51.dioxide, 52.merisation of, 73.catalytic oxidation of, 99.photobromination of, 66.reaction of, with diborane, 53.sensitised decomposition of, 69.trichloro-, inhibited decomposition of,48.Ethylene oxide, catalytic oxidation of, 99.rings, Walden inversion in fission of,264.Ethylenediaminetetra-acetic acid, uses of,344, 354.Ethylenethiourea, bond lengths in, 395.Euphenol, 239.Euphol (euphadienol), 239.Evolitrine, structure of, 255.Evoxine, structure of, 255.Exchange reactions on metal catalysts,Excited states, 153.Fischer-Tropsch syntheses, theories of, 99.Flame photometry, 364.Flaviolin, structure of, 195.Floridoside, 269.Fluorene, planarity of, 392.Fluorescence and excited states, 69.Fluorine, heat of atomisation of, 143.93.quenching of, 60.reaction of, with chlorine dioxide,50.with nitrogen dioxide, 50.Fluoride, polarographic detn.of, 351.Fluorination, 280.Fluoro-acetylenes, 288.Fluoro-acids and derivatives, 281.Fluoro-compounds containing sulphur ornitrogen, 292.Fluoromolybdates, 142.Fluoro-olefins, 288.Fluorosilicate ion, reversible dissociationof, 56.Fluorosulphonyl complexes, 144.Formaldehyde, photo-oxidation of, 67.Formazan, 5 - (2 - carboxyphenyl) - 1 - ( 2 -hydroxy- 5 - sulphophenyl) .3- phenyl-,as colorimetric reagent, 338.Formic acid, crystal structure of, 390.monomeric, molecular dimensions of, 8.peaks in infrared spectra of vapour of,heats of combustion of, 37.18.Free-radical reactions, 61.Friedel-Crafts alkylation, 190.Fructose oxime, acetylation of, 266.Furan derivatives, 243.Fusarubin, structure of, 195.Gallium chloride-methyl halide complexes,hydroxide, dimethyl-, 129.Gas-phase oxidation processes, 83.Gas reactions, bimolecular, 50.129.termolecular, 49.unimolecular, 51.General and physical chemistry, 7.Gentiopicrin, structure of, 249.Geranylamine hydrochloride, bond lengthsGermanium, heat of atomization of, 44.in, 388.hydrogen phosphite, 133.subchloride, 134.Digermanium hexachloride, 134.Germane, dimethyl- and triphenyl-,formation of, 133.tetramethoxy-, 133.tetraisopropoxy-, 133.Globulol, 214.Glutamic acid, ,!I-hydroxy-, non-occurrenceof, among natural amino-acids, 188.DL-y-methylene-, synthesis of, 188.synthesis of, 188.Glutamine, y-methylene-, synthesis of, 188.Glycosine, identity of, with arborine, 260.Glyoxaline, reactions of, 244.Granatoline, N-methyl-, configuration of,#-Granatoline, N-methyl-, configurationGraphite, compounds of, with potassiumGuaianolides, 201.Guaiazulene, 214.Guaiazulenic acid, 214.255.of, 255.and rubidium, 121.Hafnium oxide, purification of, 133.Halides, preparation of, from alcohols,silicides, preparation of, 133.180.Halogens, detn.of, in organic compounds,349INDEX OEHeats of combustion of inorganic com-of organic compounds, 33.reaction of inorganic compounds, 40.Helium atoms, excited, lifetimes of, 69.bicycZo[2 : 2 : 11Heptane - 2 : 7 - diol, form-neoHerculin, configuration of, 186.Heterocyclic compounds, 240.Hexadeca-6 : 9 : 12 : 15-tetraenoic acid,cycZoHexane, 8-hexachloro-, dehydro-cycZoHexanes, dihalogeno-, conformation1 : 3-disubstituted, configuration of, 203.cycZoHexylamine, ( 3 )-trans-3-methyl-,High-frequency titrations, 354.Homophthalimide, hexahydro-, cis- andHumulane, 214.Humulene, 214.Hydrazine, formation of, 135.Hydrazine sulphate, line-width transitionHydrazoic acid (azoimide), bond orders ofHydrides, crystal structure of, 386.Hydrocarbons, effect of, on the hydrogen-pounds, 40.ation of, 204.isolation of, 186.chlorination of, 155.of, 203.203.tram-forms of, 253.vapour-phase oxidation of, 90.in, 24.links in, 27.oxygen system, 86.heats of combustion of, 34.reaction of, with chlorine atoms, 63.Hydrogen, atomic, identification of, incertain frozen acids irradiated withy-rays, 11.pounds, 347.reaction of, with oxygen, 83.volumetric detn.of, 'in organic com-Hydrogen atoms, abstraction of, by alkylradicals : frequency factors andenergies of activation of, 62.location of, in crystals, 376.bonds in crystals, 380.fluoride, crystal structure of, 381.peroxide, reaction of, with ferrousHydrogen-deuterium exchange, catalysisHydrogenation, catalytic, 174.Hyperconjugation, 168.Ice crystals, anisotropy in, 32.Icterogenin, 219.cycZoIndeny1 compounds of iron, cobalt,and nickel, 147.Indicators in volumetric analysis, 342.Indium, m.p. of, 129.Indole derivatives, 246.isoIndolinium cation, 2 : 2-dimethyl-, de-Infrared absorption in analysis, 368.ion, 58.of, 101.on metal catalysts, 93." transfer," 174.See also under separate metals.composition of, 156.spectra, 12.SUBJECTS. 435Infrared studies, high-resolution, 14." Infusible white precipitate," formula of,Inhibitor specificity, 305.Inorganic chemistry, 118.24, 125.complex ions, racemisation of, 57.gravimetric analysis, 340.qualitative analysis, 339.Interaction across a saturated carbonInternucleotide linkages, 275.Ion exchange in analysis, 362.Iodine, dissociation of, in solution, primaryquantum yield of, 66.thermal exchange of, with methyliodide, 55.Iodine pentafluoride, dielectric propertiesof, 145.trichloride, crystal structure of, 385.Iodyl nitrate, 145.Ions in solution, thermodynamic pro-perties of, 43.Iridium, separation of, by ion exchange,363.Iridium(O), pentammino-, 152.Iron(II), bisindenyl-, 146.bistetrahydroindenyl-, 146.ion, reaction of, with hydrogen peroxide,sulphate actinometer, 77.Iron(m), sulphate, basic, as indicator,Iron-citrate complexes, 147.Isotope effect, in catalytic hydrogenationof [a-14C]acetophenone and [a-14C]-stilbene, 98.exchanges, involving inorganic complexatom, 167.liquid, association, of 28.58.342.Ferricyanide, detn.of, 346.on reaction rates, 60.ions, 56.Jacobine, structure of, 261.Jaconine, structure of, 261.Javanicin (solanione), structure of, 19.".Kamlolenic acsp, 186." Kayser unitKetones, a-acylation of, 181.a-alkylation of, 181.conversion of, into olefins, 181.epoxy-, reduction of, 177.photolysis of, 65.@-unsaturated, alkylation of, 206.Kinetics, chemical, theory of, 47.Kjeldahl's method, modification in, 348.Lactaroviolin, 201.Lactone rule, Hudson's, reinterpretationisolactucerol, 222.Laevulic acid, &amino-, in porphyrin( K ) as term for cm.-l, 12.of, 205.synthesis, 321.dehydrase, 322.metabolism of, 322.hnost-7-en-3&01, total synthesis of, 238.Lanosterol triterpenoids, 238436 INDEX OF SUBJECTS.Lantadene A and B, 220.Laserol, 213.Laserpitine, 213.Latent heats, 43.Lead azide, solubility product of, 134.nitrate, basic, 134.tetra-acetate, acetoxylation of toluenederivatives by, 179.Lead-sodium compounds, 134.Linderazulene, 2 14.Lipids, 185.a-Lipoic acid (6-thioctic acid) in photo-Lithium aluminium hydride, use of, 175.synthesis, 244.arsenides and phosphides, 12 1.derivative of phosphine, 137.hydrogen sulphide, 12 1.hydroxide, stretching and bendingOH frequencies in, 18.Longidione, 216.Longifolene, 215.Longifolic acids, 216.Longispinogenin, 220.Low temperatures, use of, in crystallo-graphy, 375.Lupinane alkaloids, 254.Lycopene, 185.Lycorine, structure of, 261.(&)-Lysergic acid, synthesis of, 266.Machaeric acid, structure of, 220.Magnesium, volumetric detn.of, 345.Magnesium, biscyclopentadienyl-, 145.Manganese, univalent, 145.Manganese, biscyclopentadienyl-, 145.carbonyl of, 145.Dimanganese decacarbonyl, 145.Permanganate, mechanism of oxidationby, 58.Permanganic fluoride, 146.Marrubin, 217.Melacacidin, structure of, 248.Menthyl chloride, dehydrochlorination of,Mercury, detn. of, 338.Mercury, use of, as reducing agent, 346.Mercury, dimethyl-, photolysis of, 66.di-n-propyl-, decomposition of, 51.See also under “ Infusible white pre-boride, 124.155.cipitate.’’Metal catalysts, reactions on, 93.Meteloidine, 254.Methane, heat of atomization of, 44.nitro-, heat of formation of, 35.oxidation of, 90.tetrafluoro-, heat of combustion of,Methionine, “ active,” synthesis of, 250.Methyl bromide, photolysis of, effect of37, 39.mercury on, 66.chloride, value of Djj in, 9.fluoride, infrared spectrum of, 14.formate, kinetics of decomposition of,iodide, thermal exchange of, with51.iodine, 55.Methyl orthosilicate, formation of, 131.Irans-2-phenylcyclohexyl ether, de-hydration of, 157.radicals, addition of, to unsaturatedaliphatic hydrocarbons, 63.a- and 8-Methyl glucopyranosides, mechan-ism of hydrolysis of, 268,Methyl-purple as indicator, 343.Metrosiderene, composition of, 208.Microwave methods of analysis, 370.Millimetre-wave spectroscopy, 9.Molecular compounds, crystal structure of,spectra and molecular structure, 7.Molybdenum, polarographic detn.of,Molybdenum, cyclopentadienyl-, 141.Molybdenum(v) ions, 142.Monosaccharides, interconversion of, 324.Mycolic acids, 186.Mycomycin, structure of, 183.Naphthalene, octamethyl-, non-planarityl-Naphthoic acid, trans-decahydro-, pre-Nepetalactone, structure of, 206.Neptunium(v), dismutation of, 54.Neutron diffraction, use of, in crystallo-graphy, 377.New species, formation of, in electron-transfer reactions, 57.Nickel, detection of, 339.Nickel, Raney, nature of surface of, 96.Nickel carbonyl complexes, 150.spectra of gases, 7.396.351.of, 393.paration of, 205.hydride, 150.386.dimethylglyoxime, crystal structure of,Nicotinic acid, crystal structure of, 390.Niobium, polarographic detn.of, 350.Niobium hydrides and deuterides, 138.Nitrogen, active, 63.Nitrogen, bond-dissociation energy of,modified Lassaigne test for, 346.Nitrogen dioxide, oxidations by, 91.reaction of, with ammonia, 49.with ethyl nitrite, 52.with fluorine, 50.45.oxysulphide, 140.Dinitrogen tetroxide, formation ofpentoxide, crystal structure of, 382.Nitrate units, N-0 distance in, 383.Nitrates, anhydrous, preparation of,135.Nitric acid trihydrate, crystal structureof, 383.Nitric oxide, crystal structure of, 381.reaction of, with ammonia, 53.Nitrite, detn.of, in presence of thio-sulphate, 346.Nitrites, reaction of, with azides, 136.Nitrosyl salts, 136.Nitrous acid, reaction of, with amines,complex ions from, 135.165INDEX OF SUBJECTS. 437Nitrogen. Nitrous oxide, catalytic decom-position of, 101.infrared spectrum of, 15.Nitryl fluoride, 143.o-Nitrobenzylideneacetophenone oxide,Nitro-compounds in KjeIdahl decomposi-Nitrones, preparation of, 180.Spir0[4 : 4lNonanedio1, 205.Nootkatin, structure of, 200.Nuclear magnetic resonance, 23.quadrupole resonance, 24.Nucleosides, 270.Nucleotides, 250, 271.241.tion, 348.use of, in crystallography, 378.Octadecan-ynoic and octadecenediynoicl-Octalin, cis- and trans-, stability of, 173.cycZoOctane, 1 : 3-diphenyl-, formationcycZoOcta-1 : 3 : 5-triene, 205.bicycZo[2 : 2 : ZIOct-Z-ene, formation of,bicycZo[4 : 2 : O]Oct-3-ene, 204.bicycZo[3 : 2 : 110ct-3-en-2-01, formation of,Oestriol, preparation of, 234.Olefins, catalytic hydrogenation of, 97.cis-cycEoOlefins, rates of addition ofdiethylaluminium hydride to, 204.Oligosaccharides, 268.Organic analysis, qualitative, 346.quantitative, 347.Organic chemistry, 153.Organometallic compounds, heats of com-bustion of, 38.Organophosphorus compound as inhibitorsof enzymes, 309.Ouabagenin, formula of, 237.Ovalene, planarity of, 392.“ Overcrowded ” molecules, 393.1-Oxa-4 : 5-dithiacycZoheptane, diradical of,Oxalic acid dihydrate, C-C bond lengthOxamide, planarity of, 389.Oxidation in organic chemistry, 178.Oxidation reactions in aromatic com-Oxides, complex, crystal structure of,Oximes, aromatic, preparation of, fromOxygen, detn.of, in organic compounds,acids in seed oils, 182.of cis- and trans-, 204.204.204.oxidation of, to glycols, 178.formed by photolysis, 71.in, 389.pounds, 191.387.diazonium salts, 181.348.reaction of, with ammonia, 89.with carbon monoxide, 87.with hydrogen, 83.with tritium, 77.monoxide, 100.Ozone, catalysed reaction of, with carbonPalladium, colorimetric detn. of, 338.separation of, by ion exchange, 363.Palladium, isocyanide complexes of,Palladium( I), co-ordination compound of,Paracyclophanes, 203.Paraffin hydrocarbons, crystal structure of,Paramagnetic resonance, 10.Pelletierine, identity of, with iso-rt-Pentane, kinetics of decomposition of,cyclopentane, 1 : 2-dimethylene-, formationcyclopentadienyls, 141.cycZoPentadieny1-carbonyls, 141.cycZoPentanone, non-planar structure oi,cycZoPent-2-enone, 2-hydroxy-3-2’-hydr-Pentose formation, aerobic, 330.Peptides, thermodynamics of, 302.Perbenzoic acid, heat of formation of,Perfluoroalkyl compounds, 279.Perylene, bond distances in, 392.Phase problem, in structure analysis,Phenhomazine, 6 : 12-diamino-, 250.Phenylglyoxylate ion, rate of protonationisoPhorone, reactions of, 190.Phosphine, derivatives of, with lithiumPhosphorus pentachloride, exchange of,sulphides, crystal structure of, 385.Hypophosphoric acid, esters of, 137.Orthophosphoric triamide, 137.Phosphate, amperometric detn.of,351.Phosphate esters, function of, in bio-chemistry, 300.ion, removal of, 340.Phosphonium ion, P-H distance in,24.salts, polarographic detn. of, 351.Phosphonous and phosphonic acids,trifluoromethyl-, 144.Pyrophosphates, hydrolysis of, 59.151.151.387.pelletierine, 254.51.of, 202.9.oxycyclopentyl-, 204.2-phenyl-, 202.40.planarity of, 393.373.of, 59.and sodium, 137.with 3Tl,, 55.Photochemistry, 64.Photometric titrations, 356.Photo-oxidation, 67.Phthalimides, hexahydro-, cis-form of,Phthiocerol, structure of, 187.Phyllanthane, 219.Phyllanthol, 218.Picolines, heats of formation of, 35.Picolinic acid, 5-butyl-, 245.Picrocine, 265.Pimelic acid, a-amino- and a-amino-y-Pinene, a- and p-, heats of combustion of,253.hydroxy-, occurrence of, 187.206438 INDEX OF SUBJECTS.Platinum, colorimetric detn.of, 338.dichlorodicarbonyl-, 152.Platinum(O), tetrammino-, 152.Plutonium, allotropes of, 143.tri- and tetra-fluoride, 143.Polarisabilities, molecular, 31.Polarography, inorganic, 350.organic, 352.Polycyclic compounds, 193.Polyenes, 184.Polyethylene, irradiation of, 80.Polymer radicals, measurement of rates ofPolymerisation of radicals, 69.Poly(methy1 vinyl ketone), scission of,by light, 74.Polymethylene, rate of formation of,from diazomethane, 74.Polynucleotides, 270.analysis of, 274.deoxyribo- and ribo-, composition of,isolation of, 273.formation of by intramolecular acyl-ation, 193.initiation of, 7 1.274, 275.Polyporenic acids, 238.Polystyrenes, branched, preparation of,Polysulphides, crystal structure of, 384.Polythene, infrared spectrum of, 13.Poly(viny1 chloride), degradation of, 75.Porphobilinogen, 316.utilisation of, by tissue systems, 320.Porphyrin biosynthesis, 322.metabolism, 3 1 1.Potassium, compounds of, with graphite,73.121.detn. of, 342.dibromodinitritoplatinite, 152.dihydrogen phosphate, structure of,hesafluororuthenate(v), 151.hydrogen difluoride, crystal structureof, 381.manganate, 146.rhenide, 146.sulphides, 139.superoxide, a-, crystal structure of,tetracyanocobalt(O), 148.-Dipotassium nitroacetate, structure of,Dipotassium trioxide, composition of,378.382.390.139.Potentiometric titration, 353.Praseodymium, oxides of, 120Precipitants, analytical, 338.Precipitation in homogeneous solution,Pregnane side chain, 233.Prochamazulene, 214.Prochamazulenogen, 214.Propane, C-C bond-dissociation energycycZoPropane, ethyl-, catalytic hydrogen-340.in, 48.ation of, 98.kinetics of hydrogenation of, 98.cycZoPropane, methylene-, catalytic liydro-monosubstituted, spectra of, 201.1 : 1 : 2-trimethyl-, catalytic hydrogen-Propene, oxidation of, by nitrogen di-isoPropy1 tetraphosphates, 137.Prop-2-ynyl chloride, 1 : l-dimethyl-, re-Proteins, electrophoretic detection of,Protoporphyrin, source of various carbonPurine, derivatives of, 249.6-dimethylamino-, 249.Pyrazoles, 3 : 4 : 6-trisubstituted, form-Pyrazolines, nitro-, formation and re-Pyrethrolone B-2, constitution of, 202.Pyridazines, 245.Pyridine, derivatives of, 245.resonance energy of, 35.Pyrid-2-one, structure of, 395.Pyrimidine, derivatives of, 349.Pyrimidines, 246.Pyrocin, 202.Pyrrole, derivatives of, 241.Pyrroles, 3-substituted, synthcsis of,241.Pyrrolidone, AT-vinyl-, polymerisation of,79.Pyrrolidones, imino-, formation of, 242.A3-Pyrroline-2-carboxylic acid, Chydroxy- ,Pyrrolizidine alkaloids, 260.Quadrupole coupling and bond character,tricycloQuinazoline, 250.Quinones, use of, in hydrogen transfer,genation of, 98.ation of, 98.oxide, 50.action of, with alkali, 159.362.atoms of, 312.ation of, 244.actions of, 243.243.25.194.y-Radiation, use of, in chlorination, 78.Radiation chemistry, 76.Radicals, production and detection of,Radiofrequency spectra in analysis, 37 1.Raman spectra, 20.in analysis, 368.Reaction calorimetry, 39Reactions, in solution, 53.photosensitised, 68.Reduction in organic chemistry, 174.Rehmannic acid, structure of, 219.Rescinnamine, probable structure of, 258.Reserpiline, structure of, 258.Reserpine, structure of, 257.Reserpinine, structure of, 257.Rhenium oxychloride, 13 8.Per-rhenate ion, tetrahedral structure of,Per-rhenic fluoride, 146.polymerisation, 78.62.18.D-Ribose, 2-deoxy-, in deoxyribonucleicacid of Mycobacterium phlei, 270INDEX OE( f )-Iiicinoleic acid, syntheses of, 187.Rmg systems, medium and large, 250.Ruthenium fluorides, 151.Santonins and their derivatives, 208.Sapogenins, 236.Selective and protective reactions inmultifunctional compounds, 227.Selenium, /3-, structure of, 381.Selenious acid, amperometric titrationof, 351.Semiquinone ion, stabilisation of, 11.Sesquiterpenes, 207.Silicon, active, 130.Silicon, dichloride, 131.detn.of, in organic compounds, 347.heat of atomization of, 42, 44.heat of formation of, 42.monoxide, heat of formation of, 42.oxynitride, 13 1.tetrachloride, crystal structure of, 385.tetrafluoride, complex of, with dimethyl-tetrahalides, complexes of, 132.Disiloxane, hexachloro-, 13 1.Silane, reactions of with unsaturatedhydrocarbons, 130.Silanes, mono- and di-chloro-, 131.Silica, “ fibrous,” 130.Silicic acids, 131.Silylamines, 130.Silyl halides, bond lengths in, 8.reaction of, with ammonia, 132.formamide, 132.Silicon-containing compounds, heats ofcombustion of, 37.Silver, separation of, 338.Silver chromate, variable compositionof, 122.Silver(r), tercovalency of, 122.Sodium amalgam, reaction of, withcarbon dioxide, 122.borohydride, use of, 176.metavanadate as titrant, 345.nitrite, crystal structure of, 384.phosphoramidate, structure of, 384.sulphides, 139.superoxide, crystal structure of, 382.tetrafluoroberyllate, forms of, 123.tricarbonyl cyanocobalt(r), 149.Solutions, infra-red spectra of, 17.Sparteine, dehydro-, position of doublea-isoSparteine hydrate, structure of, 397.Spectroscopic methods of analysis, 365.Sphingomyelin, configuration of, 186.Stability constants for dialkylethylene-Stachyose, structure of, 269.Standardisation of acids, 343.Steroids, 222.stereochemistry of, 222.trimethyl-, 238.ation of, 98.bond in, 254.oxo-, configuration of, 2.54.diamine complexes with metals, 120.[~t-*~C]Stilbene, isotope effect in hydrogen-Strontium, volumetric detn.of, 345.Strychnine, total synthesis of, 260.Styrene, /3-bromo-, dehydrobrominationof, 156.8-bromo-+nitro-, dehydrobrominationof, 156.Substrate specificity, 305.Succinate, participation of, in porphyrinbiosynthesis, 315.Succinimidine, 242.Sugar series, ascent and descent of, 266.Sugars, amino-, 265.anhydro- and deoxy-, 264.reducing, degradation of, 267.Sulphanilamides, detn.of, 355.Sulphimide, 140.ammonium salt of, 140.Sulphur, detn. of, in organic compounds,349.free, polarographic detn. of, 351.liquid, free radicals in, 10.orthorhombic, crystal structure of, 381.Sulphur ( S2), bond-dissociation energySulphur (S8), heat of formation of, 44.Sulphur compounds, organic, heats oftrioxide, Is-, crystal structure of, 383.Disulphur decafluorodioxide, structureSulphate, conductometric detn. of,structure of, 139.of, 45.combustion of, 35.of, 22.354.detn. of, in acetic acid, 352.indirect volumetric detn. of, 344.polarographic detn. of, 352.alkyl hydroperoxides, 162.384.340.Sulphides, organic, oxidation of, bySulphuric acid, crystal structure of,Tetrathionate, detection and detn.of,Thionyl bromide, 140.Thiosulphate, detn. of, in presence ofnitrite, 346.ion, thermodynamic properties of, 43.Trisulphuryl chloride, 140.Synthesis in anaerobic systems, 324.“ Tannins,” structure of, 248.Tantalum hydrides and deuterides, 139.Taraxerol (skimmiol), corrected formulaTerbium, oxides of, 129.Tercovalency of copper(1) and silver(I),Terebic acid, 208.Terpenes, short notation for, 206.Thallium azide, heat of formation of, 42.Thermochemistry, 33.Thermochromism, 194.Thermodynamic data, application of, toThiadiazolines, imino-, formation of,Thiols, w-, C-S bond-dissociation energytetrachloride, 139.of, 222.tetrafluoride, 129.122.biochemical reactions, 295.244.in, 46440 INDEX OF SUBJECTS.Thiophen derivatives, desulphurisationThiophen 1 : l-dioxide, 243.Thiophenols, preparation of, 192.Thiopheno(2’ : 3’-3 : 4)thiophen,methyl-, 243.Thorium, detn.of, 338.separation of, as iodate, 341.Thorium alkoxides, 133.citrates, 133.hydride, 386.nitrate, hydrates of, 133.of, 189.2 : 6-di-Thujaplicin, transformation of #3- intoThymidine, enzymic synthesis of, 270.Tin, vapour pressure of, 44.y-, 199.Stannane, 134.Stannic ions in sulphuric acid solution,Stannous oxide, 134.tripropoxy-, 132.!Tifluoride, 132.134.Titanium, polarographic detn. of, 351.Titanium tri- and tetra-chloride, heats offormation of, 41.Peroxytitanates,” structure of, 132.in, 46.Titrations in non-aqueous media, 356.Toluene, C-Me bond-dissociation energya-phenylazoxy-, 192.Transaldolases, 325, 329.Transketolases, 325, 328.Transport numbers, 107.1 : 3 : 5-Triazine as polymer of hydrogen1 : 2 : 3-Triazolines, 1 : 5-diaryl-, formationTrifluoromethyl halides, bond lengths in,Trimethylene oxides, formation and re-Triterpenes, 218.Tritium, detn. of, 348.cyanide, 246.of, 244.22.actions of, 241.exchanges of, with organic molecules,induced reaction of, with oxygen,Tropolone hydrochloride, bond lengths in,Tropolones, 197.isoTropolones, 198.Tropones, 198.54.77.397.Ultraviolet methods of analysis, 366.Umbilicin, 269.Uracil, configuration of, 395.Uranium, heat of sublimation of, 44.(ortho)phosphate, 143.selenide, 143.telluride, 143.Uranyl complexes, 142.Uranium(1v) as titrant, 346.Uranium(vx), polarographic detn. of, 350.Urea, planarity of, 391.Uridylic acids a and b, difference between,Uroporphyrins, 3 12.formation of, from porphobilinogen, 317.Vanadium, biscyclopentadienyl-, 138.oxychloride, 138.oxyfluoride, 144.Vanadium(v), polarographic detn. of, 351.Verbenalin, structure of, 249.Vernolic acid, structure of, 186.Vinyl chloride, kinetics of polymerisationVinylene carbonate, planarity of, 9.Viridicatin, structure of, 247.a-Vitamin A methyl ether, synthesis of, 186.Vitamin B,,, structure of, 399.Walden inversion in fission of ethyleneWater, ion exchange in analysis of, 362.radiation chemistry of, 81.X-Kay methods of analysis, 365.Ximerynic (santalbic) acid, 187.D-Xylose, biological formation of, 333.Xylulose, D- and L-, biological formationo-Xylylene, formation of, 157.Xylylenes, m- and p - , structure of, 394.Zinc, colorimetric detection of, 330.271.of, 72.oxide rings, 264.of, 333.colorimetric detn. of, 338.heat of sublimation of, 44.volumetric detn. of, 345.Zingiberene, configuration of, 208.Zirconium, detn. of, 339.pptn. of, 337.Zirconium amidochloride, 132.dioxide, purification of, 133.thermodynamic properties of, 132

ISSN:0365-6217    

DOI:10.1039/AR9545100431

出版商:RSC    

年代:1954

数据来源: RSC