摘要:

SOIL CHEMICAL ANALYSISBy M. L. Jackson. Med- 8vo. 498 pages. Illustrated.57s. 6d.This book gives the most frequently used soil chemical analysis pro-cedures, useful in instruction and research in soil chemistry, soil fertilityand soil genesis. Because plant growth is essentially related to thesefields, procedures are given for plant inorganic constituents. The authoris Professor of Soils, University of Wisconsin.ELECTROCHEMICAL PROCESSES IN CHEMICALINDUSTRIESBy A. Regner. Translated by K. Kutif, J. Wirner, A. G.Evans. Ex. Cr. 8vo. Paper. 464 pages. 149Jigures.1957. 30s.The theoretical part of this book deals with the basic laws of electro-chemistry and of chemical equilibrium. It then goes on to discuss elec-trolytic conductance and various types of galvanic cells and concludeswith a section on electrolysis and polarization.The second part dealswith industrial applications, beginning with the construction of electro-lytic cells from the general point of view, and the electrolysis of water.Then follows an account of the manufacture of chlorine, hydrogen per-oxide, etc.CHEMICAL ENGINEERING OPERATIONS: An Tntro-By F. Rumford, Ph.D., B.Sc., F.R.I.C., M.1.Chem.E. (De-partment of Chemistry, The Royal Technical College,Glasgow). 2nd Edition. Demy 8110. 387pages. Illus-trated. 1957. 32s. 6d.duction to the Study of Chemical PlantCHEMICAL ENGINEERING MATERIALSBy F. Rumford, Ph.D., B.Sc., F.R.I.C., M.1.Chem.E.Demy 8170. Illustrated. 2nd Edition.AN INTRODUCTION TO THE THEORY AND PRAC-TICE OF SEMICONDUCTORSBy A.A. Shepherd. Ex. Cr. 8vo. 212 pages. Illustrated.1958. 18s. 6d.CONTENTS: Structure of Solids - Conduction in Semiconductors -Minority Carriers - Semiconductor Single Crystals - Rectification bySemiconductors - Transistors - Light Sensitive Semiconductor De-vices - Semiconducting Compounds.Complete catalogue available on requestCONSTABLE & CO. LTD10 ORANGE STREET, LONDON WC2iRecommended B.D.H. Indicatorsfor Calcium TitrationsAmong the many indicators suggested for thecomplexometric titration of calcium three show evident practicaladvantages. We recommend them for laboratory use :o= Cresolphthalein complexoneAnderegg, Flaschka, Sallmann and Schwarzenbach, Helv. Chim. Acta,1954, 37, 1 13.Complexes metal cations and forms deep red chelates with calcium,strontium and barium.The magnesium chelate is pink,Titrations, at pH 10-11, should be carried out in 2550% alcoholsolutions to suppress the faint pink colour of the indicator molecule.lg 6s. 3d. 5g 24s. 3d.Patton & Reeder’s Reagent(2-h ydrox y-l -( 2-h ydrox y-4-sulpho- 1-naph thy1azo)-3-naphthoic acid)Patton & Reeder, Anal. Chem., 1956, 28, 1026.For the complexometric titration of calciumin the presence of magnesium; a verysharp colour change from wine red to pureblue. The indicator may be diluted withsodium sulphate (1 :loo), l g of the mixturegiving a satisfactory end-point.lg 4s. 6d. 5g 15s. 9d.Solochrome dark blue (calcon)Hildebrande and Reilley,Anal.Chem., 1957, 29, 258.For the complexometric titration ofcalcium in the presence of magnesium,giving a sharp colour changefrom pink through purple to blue atpH 12.3 in a diethylamine buffer.25g 3s. Od. lOOg 7s. 6d.THE BRITISH DRUG HOUSES LTDB a D o H o LABORATORY CHEMICALS DIVISION POOLE DOWETSCIENTIFIC & TECHNICAL BOOKSLARGE STOCK OF BOOKS on the Biological, Physical,Chemical and Medical Sciences supplied from stock, or obtained to order.FOREIGN DEPARTMENT. Books not in stock obtained toorder with the least possible delay.LENDING LIBRARYSCIENTIFIC AND TECHNICALAnnual Subscription from f I 17s. 6d.THE LIBRARY CATALOGUE, revised to December, I 956, con-taining a classified Index of Authors and Subjects, to Subscribers,& I 5s.net; to Non-Subscribers, A2 2s. net; postage 2s.Prospectus post free on application.Bi-monthly list of New Books and New Editions added to the Librarysent post free to any address regularly.LONDON: H. K. LEWIS & Co. Ltd.136 GOWER STREET, W.C.1 TELEPHONE: EUSTON 4282F e DARTON & COe LTDeWATFORD HERTS ENGLANDESTABLISHED 1834 IITHERMOGRAPHSHYGROGRAPHSBAROGRAPHSMakers ofKEW PATTERN BAROMETERSFORTIN BAROMETERSHYGROMETERSMAN OM ETERS/ REGISTERED \ I +--- I TRADE MARKALTl METER CALIBRATORS IvBRITISH MADE CRYSTALLINE ENZYMESThe folloming high purity crystalline enzymesare available from British sources(a) partially purified, salt free, lyophilized having 25% activity of crystalline material:(b) highly purified, lyophilized, associated with MgSO,.In sterile vials each of one millionDEOXYRIBONUCLEASE: (in two forms:Dornase Viscosity Units).RIBONUCLEASE: Salt free, 4 x cryst.HYALURONIDASE: ex Bovine Testes.a-CHYMOTRYPSIN, 3 x cryrt. salt free.TRYPSIN (five activities), i.e.:50 Kunitz units per mgm.Salt free, 300 IU per mgm.Trypsin free, 6.0 haemoglobin units per gram.(I) 2 x cryst. + <50% MgSOIactivity 25 Anson units per gram of protein:(a) contains Chymotrypsinactivity 2.5 Anson units per gram of material;(b) activity 3.5 Anson units per gram of material;(c) relatively free of Chymotrypsinactivity 5.0 Anson units per gram of material.PEROXIDASE, ex horse radish, pure.(2) lyophilized, salt free, from f i r s t crystals activity 25 Anson units per gram of material;(3) partially purified + <SO% (NH4)PS0,;Your enquiries for these and other Enzymes and Biochemicalsare invitedL.LIGHT & CO. LTD Colnbrook Bucks EnglandAnnual Reports on theProgress of ChemistryBack Numbers (less certain volumes now out of print)are available-Volumes 1(1904) to LIV (1957)AlsoCollective Index of Volumes I to XLVIItrquiries are invited by:THEC H E M I C A LSOCIETYBurlington House . London, W.lOxford BooksExperimentuZ Techniqtces inLow-Temperature PhjsicsGUY KENDALL WHITE(Monographs on the Plysics and Cbemijtry of Materials)Illustrated 4js netDetermination of MoZectcZar StrmtweP. J. WHEATLEYIllmtrated 3 j~ netThe ChemicaZ Kineticsof Enzyme ActionKEITH J.LAIDLERIkrtrated 60s netA Modern Approuchto Organic ChemistryJ. PACKER A N D J m VAUGHANIlZustrated 8 4 netEZectronic Theoriesof Organic ChemistryA n Introdzrctory TreatmentIlhstrated 3 0s netJ O H N WILLIAM BAKERThe Physics of R&er EZusticityC. R. G. TRELOAR(Monographs on the Ph_ysi< and Chemistry of Materials)Second Edition Illurstrated 40s netOxford University PressxiServing industry.. .Detergents and Wetting Agents: * Delak * Lenka * Lensex * Lensine * Lensitol * LensodelMarinex * Nonidet * Teepex * Teepodol * Teepol * Teepol Anti-foaming agent * Teepol PowderDetergent Intermediates: * Dobane AlkylatesDodecyl BenzeneDry Cleaning Aid: * ElviraInsecticides : * Shelltox with Dieldrin * Shelltox AerosolSolvents and Intermediates:Acetone * Alphanol 79Benzenep-t.Butylbenzoic AcidDiacetone AlcoholI : 2 DichloropropaneDiphenylolpropaneEpichlorhydrinEthyl Amy1 KetoneEthylene Glycol EthersIsopropyl Alcohollsopropyl EtherMethyl Ethyl KetoneMethyl lsobutyl CarbinolMethyl lsobutyl KetoneNonanolPolyethylene Glycols(Liquids and solids)Polypropylene GlycolsSecondary Butyl AlcoholTo I uene(* Oxitol, * Dioxitol and * Trioxito/ solvents)* Shellsol hydrocarbon solventsXyleneTextile Oils: * Besconus * Celconus * ConivaConus * RayconusMothproofing Agent:PI ast i cs :* Dielmoth* Carina (P.V.C.) * Carlona Polyethylene * Carlona Polypropylene * Carinex Polystyrene * Styrocell Expandable andExpanded PolystyreneSynthetic Rubbers: * Cariflex Styrene-butadiene rubbersHighvacuum Oils, Greases and Waxes: * Apiezon gradesCorrosion Inhibitor :Shell V.P.I.260Synthetic Resins: * Epikote ResinsCuring Agents: * Epikure (For * Epikote Resins)General Chemicals:Allyl AlcoholAllyl ChlorideCalcined CokeCE AromaticsDiethanolamineDiethylene GlycolDiisobutyleneOiisopropanolamineDi pro py lene GI ycol * Dutrex ProductsEthaneEthyleneEthylene OxideHexylene Glycol * lonex49MonoethanolamineMonoethylene GlycolMonoisopropanolamineNaphthenic AcidsParaffin WaxPetroleum SulphonatesPitchPropylene GlycolPropylene OxideShell Water Finding Paste * SomilSulphurSynthetic Rubber & Extender OilsTertiary Butyl AlcoholTriethanoiamineTrie t h y lene GI ycolTriisopropanolamine * Registered Trade Marks* Synconus Shell ChemicalsSHELL SHELL CHEMICAL COMPANY LIMITED 0 \!lP In association with Petrochemicals Limited and Styrene Products LimitedDivisional OWces: LONDON: Norman House, 105-9, Strand. W.C.2. Tel: TEMple Bar 4455.MANCHESTER: 144-6. Deansgate. Tel : Deansgate 2411.BIRMINGHAM: 14-20. Corporation Street, 2. Tel: Midland 6954.GLASGOW: 48-54. West Nile Street, C.1. Tel: City 3391.BELFAST: 16-20, Rosemary Street. Tel: Belfast 26094.DUBLIN: 33-34, Westmoreland Street. Tel: Dublin 72114.“SHELL” is a Registered Trade Mark.x

ISSN:0365-6217    

DOI:10.1039/AR95855FP001

出版商:RSC    

年代:1958

数据来源: RSC

摘要:

Vi CONTENTSERRATAVOL. 53, 1956.Page 237, line 17. For synthesis of oxyanin-B read synthesis ofT h e group at position 6 should be HO, not MeO.,oxyayanin-E.formula 61.Page 261, line 2.Page 263, lines 32-34.For pyrazolone read 3-aminopyrazolone.T h i s should read The authors suggest that thismay be because some of the 6-amino- and6-keto-groups form hydrogen bonds withother, unspecifiable, groups.VOL. 54, 1957.Page 36, table, colami% 4, lines 25 and 26.Pages 351 and 352.For 3-6 f 2.0 read 3.6 rf 0.2.T h e scheme near the bottom of p. 351 and formula(XVIII) on p . 352 should be interchanged

ISSN:0365-6217    

DOI:10.1039/AR9585500006

出版商:RSC    

年代:1958

数据来源: RSC

摘要:

ANNUAL REPORTSON THEPROGRESS OF CHEMUTRYGENERAL AND PHYSICAL CHEMISTRY1. INTRODUCTIONTHIS year's General and Physical Chemistry Section is a collection of reportson separate and limited topics rather than one of general reports on broadfields such as reaction kinetics. Consequently the coverage this year is morespecialised and therefore, in some directions, incomplete. However, it isintended that, over two or three years, all important and interesting physico-chemical subjects will be dealt with in Annual Reports.This year publications on ion association and acid-base equilibria inionic solutions have been surveyed as well as work on electrode processes,particular attention being given to adsorption problems. In the kineticsfield there are sections devoted to transformations occurring in organicmolecules and radicals. Here the Report on ion-molecule reactions willbe of interest to radiation chemists. Related to these is the Report onthe many observations made recently on intermolecular energy transfers.This deals with both liquid and gaseous systems.There is also a recordof the observations that have been made on polymerisations induced byradicals. In the field of molecular structure there is a Report on both theobservations and the theory of the intensities of infrared absorption bands.This deals first with gases and then with the more complicated problem ofliquids and solutions. In addition an account is given of the work that hasbeen done to determine precise shapes and force fields of relatively simplemolecules.J.W. L.2. ACID-BASE EQUILIBRIATHIS Report deals with proton-transfer equilibria in aqueous and non-aqueous solvents. The recently published tables of stability constants ofmetal-ion complexes include values for the proton complexes and so alsoconstitute a valuable collection of acidity constants. Papers of generalinterest report a differential potentiometric titration method in whichhydrogen electrodes are used for comparing the purity of acids to a fewparts in 100,000, new standards for pH measurements3 from 60 to 05",J.,,Bjerrum, G. Schwarzenbach, and L. G. Silldn, " Stability Constants.R. G. Bates and E. Wickers, J . Res. Nat. Bur. Stand., 1957, 59, 9.V. E. Bowers and R. G. Bates, ibid., p. 261.Parts Iand 11, Chem.SOC. Special Publ., 1957, No. 6 ; 1958, No. 78 GENERAL AND PHYSICAL CHEMISTRY.H* + H, __t H, + Ha Hammond gives a qualitative discussion ofappropriate models for the transition complex. The transition-state theoryhas come under fresh fire.93 10111Papers upon the theory of chain reactions have discussed the principleand conditions of applicability of the Semenov-Bodenstein method of quasi-stationary states l2 and an estimate of the accuracy of the method,13 con-secutive reactions and chain reactions,l* catalysis and inhibition of chainreactions,15 and the action of inhibitors upon branched-chain reactions.16In the analysis of experimental results, Wideqvist l7 has emphasised theusefulness of substitutions of the form 8 = f(c)dt, f(c) being a suitablearbitrary function of the coficentration and 8 being obtained graphically.Tobin l8 has indicated methods of treating second-order reactions which areautocatalytic or reversible.The applications of least-square deviations tothe evaluation of rate constants have been discu~sed.1~~ 2O Janz and Wait 21have justified the use of space-time yield as measures of velocities of reaction,provided certain experimental conditions are fulfilled. Other short paperson intramolecular energy transfer,22 methods of calculating collision dia-meters,= revised values of diffusion coefficients of certain hydrocarbons,24rates near eq~ilibrium,,~ kinetics in non-isothermal systems,26 kinetics andthermodynamics of irreversible systems,27 and the concept of rate ofreaction 28 have appeared.Some fresh complexities have been suggested in the kinetics of somereactions previously thought simple.Benson and Srinivasan 29 have arguedthat the high temperature coefficients of the forward and backward velocityconstants in the gaseous reaction H, + I, e- 2HI indicate that the reactionproceeds by concurrent bimolecular and chain processes, but their sugges-tions cannot properly be tested because of the scatter of the available dataon the two velocity constants a t different temperatures. In this connectionPheloux 3O suggests a differential method of analysing Bodenstein's data onthe decomposition reaction which gives more consistent results for thevelocity constant. The oxidation of nitric oxide by oxygen has been studiedG. S.Hammond, J . Amer. Chem. SOL, 1955, 77, 334.N. I. Kobozev, Zhur. $2. Khim., 1954, 28, 2067.lo V. A. Pal'm, ibid., 1955, 29, 1116.l1 V. A. Roiter, Ukrain. khim. Zhur., 1955, 21, 296.12 Yu. S. Sayasov and A. B. Vasil'yeva, Zhur. $2. Khirn., 1956, 29, 802.l3 I. F. Bakhareva, Doklady Akad. Nauk S.S.S.R., 1955, 102, 1151.l4 E. Abel, Osterr. Chem.-Ztg., 1955, 56, 305.l6 2. G. Szabo, P. Huhn, and A. Bergh, Magyar Kem. Folyoimt, 1955, 61, 137,l6 D. G. Knorre, Zhur.$z. Khim., 1955, 29, 1285.17 S. Wideqvist, Arkiv Kemi, 1955, 8, 325.18 M. C. Tobin, J . Phys. Chem., 1955, 59, 799.la S. Huyberechts, A. HalIeux, and P. Kruys, Bull. SOC. chim. belges, 1955, 84, 203.2O D. F. DeTar, J . Amer. Chem. SOL, 1955, "7, 2013.21 G.J. Janz and S. C. Wait, jun., J . Chem. Phys., 1955, 25, 1650.22 H. 0. Pritchard, Rec. Trav. chim., 1955, 74, 779.Zs E. Bauer, J . Chem. Phys., 1955, 23, 1087.24 G. A. McD. Cummings and A. R. Ubbelohde, J., 1955, 2524.25 A. PBneloux, Comfit. vend., 1955, 240, 758.26 H. Gaensslen and H. A. E. Mackenzie, J . Appl. Chem., 1955, 5, 552.27 A. PBneloux, Compt. rend., 1954, 239, 1379.28 J . E. Verschaffelt, Bull. CLasse Sci., Acad. roy. Be&., 1956, 4l, 316.29 S. W. Benson and R. Srinivasan, J . Chem. Phys., 1955, 23, 200.30 A. Peneloux, Compt. rend., 1955, 240, 2142.English summary, 145PRUE : ACID-BASE EQUILIBRIA. 9strength, it is said to have been obtained by " extrapolation to infinitedilution ". This phrase is misleading, for it implies that the pK, valueobtained is necessarily independent of assumptions about the activitycoefficients of the ions, which is only true when measurements can be madein very dilute solutions; small changes in the value assumed for a' canoften be compensated by a change in cp alone because mathematicallyI"(1 + Ba'D) N I* - Ba'I.* The failure of plots of pKa' against I fordifferent choices of a' to converge to a common value of pKa is most seriousfor rather strong acids and bases.loU In these cases, dissociation is only in-complete at high ionic concentrations, and the buffer ratio cannot be setequal to its stoicheiometric value; to calculate the ratio a knowledge of theconcentration of hydrogen or hydroxyl ions is required which in turn necessi-tates assuming a value for fHfcl.Hamerll has drawn attention to thissituation for the bisulphate ion. New measurements on this acid arereported by Nair and Nancollas,12 who, following C. W. Davies, set-logl,fi = xi2A{(I*/(l + 14) - 0.201) throughout. The acidity constantsobtained a t 25", 35", and 45" agree with those obtained by an indicatormethod13 within the outer limit of error (6%) suggested for the latterresults, but there are differences of 15 and 20% a t 15" and 5' respectively.Bates and Schwarzenbach l4 show how in cell measurements the bufferratio can in suitable cases be advantageously measured spectrophoto-metrically. Acidity constants and thermodynamic parameters are reportedfor the second acid dissociation of glycerol l-phosphate l5 and the ion l6H2P0,-, the hydrogen I calomel cell being used for the latter study.Nashand Monk l7 have investigated the effect of up to 0.6 mole 1.-l of carboxylicacids on the E" values of the hydrogen I silver-silver chloride cell, and theextent of acid dimerization. The acidity and basicity constants of $-amino-benzoic acid a t 25" have been measured,l* the glass electrode used beingcarefully calibrated against a hydrogen electrode. The acidity constants ofthe isomeric ephedrinium ions [C,H,*CH(OH)*CHMe-NH,Me] have beenmeasured l9 at 0-60" with hydrogen-electrode concentration cells in whichthe effects of junction potentials due to a potassium chloride salt bridge areeliminated by extrapolation. The thermodynamic parameters are evaluatedand discussed.Purlee and Grunwald 20 have made precision measurements on hydro-loaE.J. King and G. W. King, J . Amer. Chem. SOL, 1952, 74, 1212.l1 W. J. Hamer, Abs. Symp., Structure of Electrolytic Solutions, Washington, 1957,l2 V. S. K. Nair and G. H. Nancollas, J . , 1958, 4144.l3 C. R. Singleterry and I. M. Klotz, Theses, Chicago, 1940; R. A. Robinson andR. H. Stokes, '' Electrolyte Solutions," Butterworths, London, 1955, p. 374.l4 R. G. Bates and G. Schwarzenbach, Helv. Chim. Acta, 1954, 37, 1069.l5 S. P. Datta and A. K. Grzybowski, Biachem. J., 1958, 69, 218.l6 A. K. Grzybowski, J. Phys. Chem., 1958, 63, 550, 555.l7 G. R. Nash and C. B. Monk, J., 1957, 4274.l8 M. L. Deviney, R. C. Anderson, and W. A. Felsing, J . Amer. Chem.Sac., 1957,l9 D. H. Everett and J. B. Hyne, J., 1958, 1636.2O E. L. Purlee and E. Grunwald, J . Amer. Chem. Sac., 1957, 79, 1366, 1372.* Similar comments are relevant concerning the determination of any equilibrium+p. 47.79, 2371.constant in which ions are involved10 GENERAL AND PHYSICAL CHEMISTRY.chloric and carboxylic acids in dioxan-water mixtures with a cell incor-porating glass and silver-silver chloride electrodes; the latter have the silverin mirror form and are reported to reach equilibrium very quickly even invery dilute solutions. The same technique 21 has been used to studycarboxylic acids and anilinium ions in methanol-water mixtures, and theacidity constants for acetic acid over the entire range of composition O-%yOmethanol agree 22 with values found from conductance measurements 23(mean deviation 0.017 in pKa).Measurements with conventionalhydrogen I silver-silver chloride cells of the dissociation of hydrochloric acidare reported in ethanol,= acet0ne,~5 ketone-water mixtures,26 and dioxan-water 27 mixtures. The last paper also reports acidity constants for formic,acetic, and propionic acids in the same solvent. Dunsmore and Speakman 28have measured the dissociation constant of benzoic acid in water and inwater-dioxan by e.m.f. and conductance methods.(b) Spectrophotometric methods. Robinson 29 and his collaborators havedeveloped a spectrophotometric method for determining acidity constantsin which the degree of dissociation of the acid is spectrophotometricallydetermined in a buffer of known pH; it has been applied to a wide rangeof weak organic acids.Kok-Peng Ang30 has tested with isophthalic acida new method for spectrophotometrically determining overlapping acidityconstants of dibasic acids. Other spectrophotometric determinations ofacidity constants are for phenol, cresols, and xylenol~,~~ the hydrogensulphate ion in aqueous methanol,32 2,4-dinitrophenol and chloroacetic andpropionic acids in aqueous ethanol,= hydroxycoumarins,34 and NN-di-methylaniline in water and and ~ater-dioxan.~~(c) Conductance methods. Feates and Ives36 report a determination ofthe acidity constants of cyanoacetic acid at 5" intervals from 5 to 45",accurate to 0.005% in In K. The thermodynamic parameters are discussedin relation to the solvent structure.Shedlovsky reports 37 acidity constantsa t 25" for acetic acid in methanol-water covering the entire range of com-position O - l O O ~ o of methanol. Kortiim and Buck 37a have made measure-ments at 25" on 2,6-dinitrophenol in methanol-water and ethanol-water.21 A. L. Bacarella, E. Grunwald, and G. P. Marshall, J . Org. Chew., 1955, 20, 747.22 A. L. Bacarella, E. Grunwald, G. P. Marshall, and E. L. Purlee, J . Phys. Chew.,23 T. Shedlovsky and R. L. Kay, ibid., 1956, 60, 151.24 H. Taniguchi and G. J. Janz, ibid., 1957, 61, 688.25 D. H. Everett and S. E. Rasmussen, J., 1954, 2812.26 D. Feakins and C . M. French, J., 1957, 2284, 3168.27 S. S. Danyluk, H. Taniguchi, and G. J. Janz, J . Phys. Chenz., 1957, 61, 1679.28 H.S. Dunsmore and J. C. Speakman, Trans. Faraduy Soc., 1954, 50, 236.2s R. A. Robinson, Abs. Symp., Structure of Electrolytic Solutions, Washington,30 Kok-Peng Ang, J . Phys. Chew., 1958, 62, 1109.32 J. I. Evans and C . B. Monk, ibid., 1953, 49, 415.33 W. D. Bale and C. 73. Monk, ibid., 1957, 53, 450.34 B. N. Mattoo, ibid., 1958, 54, 19.35 A. V. Willi, Helv. Claim. A d a , 1957, 40, 2019.313 F. S. Feates and D. J. G. Ives, J . , 1956, 2798.a7 T. Shedlovsky, Abs. Symp., Structure of Electrolytic Solutions, Washington,a7' G. Kortum and M. Buck, 2. Elektrochem., 1958, 62, 1083.1958, 62, 856.1957, p. 90.E. F. G. Herington and W. Kynaston, Trans. Furaday Soc., 1957, 53, 138.1957, p. 94PRUE ACID-BASE EQUILIBRIA. 11Conductometrically-determined acidity constants are reported 38 for sub-stituted benzoic acids and for nitrophenols in water.The Hydrolysis of Cations.-Published data for the acidity constants ofhydrated cations in water have been collected and discussed.39 The simplepicture of aquo-cations as Bronsted acids has been considerably modifiedrecently by the realisation that, even in dilute solutions, polymerization ofthe basic species MOHn+ to form polynuclear species often occurs throughformation of dihydroxyl (or oxygen) bridges.An impressive series of papershas come from Sillen’s school in Stockholm. The equilibria involved areoften complicated, and measurements by e.m.f. cells of hydrogen-ion and,when possible, free metal-ion concentrations have been made in constantionic media (NaC104-HC104) ; the effectiveness of this device in maintainingconstant activity coefficients and eliminating the effects of junction poten-tials has been critically examined.40 The 21st paper in the series,4l whichdeals with the hydrolysis of the stannous ion in 3~-perchlorate medium at25”, illustrates well the methods used in obtaining and analysing the expen-mental results.Stringent precautions were necessary to prevent the form-ation of the stannic ion, which is a stronger acid than the stannous ion. Atstannous concentrations 0~0025-0~040~, the principal hydrolytic equili-brium was 3Sn2+ + 4H20 Sn3(OH)42+ + 4H+, but SnOH+ andSn2(OH)22+ were also formed. Complexes of the general formula M[(OH),M],are formed on hydrolysis of FeIII, CuII, ScIII, InIII, VOII, and U0;I.Thecriterion for the existence of the various species is the constancy of law-of-mass-action expressions involving these species, and when several equilibriaare involved small experimental errors can be seriously misleading. Thus,earlier conclusions about the species present in bismuth(m) solutions arefound to have been vitiated by neglect of the effect that the basicity ofbenzoquinone can exert in sufficiently acid solutions on the behaviour of thequinhydrone electrode. Some recent measurements 42 with glass and bis-muth amalgam electrodes a t bismuth concentrations from 0.0001 to 0.050~show that the main hydrolysis product is Bi6(OH)126+ with some BiOH2+.This conclusion agrees with that of Holmberg, Kraus, and Johnson,43 who,continuing studies of the hydrolysis products of metal ions by ultracentrifugemeasurements, concluded that bismuth( 111) forms a complex containing5 or 6 bismuth atoms.report the main product ofberyllium-ion hydrolysis at concentrations from 0-001 to 0 . 1 0 ~ to beBe3(OH),3+ with some Be20H3+ and Be(OH),. It remains to be examinedto what extent change of the anion of the constant-ionic medium, which inthe Stockholm work is universally perchlorate, changes the nature anddistribution of multiply-charged hydrolysis products.The formation of dimeric Fe2(OH)24+ on hydrolysis of ferric ions has38 J. F. J. Dippy, S. R. C . Hughes, and J. W. Laxton, J., 1956, 2995.39 F. Basolo and R. G. Pearson, “ Mechanisms of Inorganic Reactions,” John Wiley,40 G.Biedermann and L. G. Sillen, A r k i v Kemi, 1953, 5, 425.41 R. S. Tobias, Acta Chem. Scand., 1958, 12, 198.42 A. Olin, ibid., 1957, 11, 1445.43 R. W. Holmberg, K. A. Kraus, and J. S. Johnson, J . Amer. Chem. SOL, 1956,44 H. Kakihana and L. G. Sill& Acta Chem. Scand., 1956, 10, 985.Kakihana and SillenInc., New York, 1958, p. 387.78, 550612 GENERAL AND PHYSICAL CHEMISTRY.recently been studied spectrophotometrically by M i l b ~ r n , ~ ~ who has obtainedthermodynamic quantities for the equilibria. Spectrophotometry of cobalticperchlorate solutions, and kinetic observations of the rate of oxidation ofwater by cobaltic ions, are consistent 46 with the predominance of a dimerichydrolysis product CO,(OH)~~+.Polynuclear complexes are not formed onhydrolysis of mercuric ions ; supersaturated solutions 47 of mercuric hydr-oxide have been prepared and it is found that Hg(OH), is about 25 timesweaker as a base than HgOH+, which means that hydrolysed solutions con-tain very little of the latter ion. Other studies of the hydrolysis of cationshave been recently reported for thorium(~v),~~ plutonium(~v),~~ zir-c o n i u m ( ~ ~ ) , ~ ~ and the uranyl ion; 51 polynuclear complexes are also some-times formed on hydrolysis of chelate c ~ m p l e x e s . ~ ~ ~ ~ ~Oxyacids in Aqueous Solution.-(a) Weak acids. A flow apparatus inwhich the pH of a solution can be measured 10" sec. after mixing potassiumhydrogen carbonate and hydrochloric acid enabled Meier and Schwarzen-bach 54 to measure the acidity constant of H2C0 ( K = 3.58 at 20°, I = 0.1mole 1.-l) ; the value agrees with one rep~rtid!~ earlier from high-fieldconductance measurements.It seems likely that the flow apparatus willbe useful for the study of the initial dissociation of acids whose correspondingbases then polymerize; information has already been obtained about theacid dissociation of molybdic and tungstic acids.56 The infrared absorptionspectra of aqueous solutions of carbon and sulphur dioxides confirm thatthey are present mostly as CO, and SO, re~pectively.~~ A similar conclusionis reached by Falk and G i g ~ & e , ~ ~ who estimate that any H,S03 content iscertainly less than 1/30th of that of SO,, and probably much less.Solutionsof silicates undoubtedly contain polymers, but an estimate of the acidity con-stant of the unstable monomeric silicic acid, prepared by hydrolysis of themethyl ester in situ, has been reported.59 Bunton and Stedman 6o concludefrom ultraviolet spectrophotometry that molecular nitrous acid in aqueousperchloric acid is protonated and dehydrated as the acidity of the mediumincreases. Acidity-constant measurements are also reported for the follow-ing acids : arsenious,61 phosphoric,62 the hydrogen chromate germanic45 R. M. Milburn, J . Auuter. Chem. SOC., 1957, 79, 537.46 J. H. Baxendale and C. F. Wells, 'Trans. Faraday SOC., 1957, 53, 800.47 G. Anderegg, G. Schwarzenbach, M. Padmoyo, and 0. F. Borg, HeZv. Chim. A d a ,48 J.Lefebvre, J . Chim. phys., 1955, 55, 227.49 S. W. Rabideau, J . Amer. Chem. SOC., 1957, 79, 3675.A. J. Zielen and R. E. Connick, ibid., 1956, 78, 5785.51 J. A. Hearne and A. G. White, J., 1957, 2168.52 R. F. Bogucki and A. E. Martell, J . Amer. Chem. SOC., 1958, 80, 4170.53 H. Jonassen and G. J. Strickland, ibid., p. 312.54 J. Meier and G. Schwarzenbach, Helv. Chim. Acta, 1954, 40, 907.55 D. Berg and A. Patterson, J . Amer. Chem. SOC., 1953, 75, 5197, 5731.56 J. Meier and G. Schwarzenbach, J . Inorg. Nuclear Chem., 1958, 8, 302.57 L. H. Jones and E. McLaren, J . Chem. Phys., 1958, 28, 995.58 M. Falk and P. A. Gigdre, Canad. J . Chem.. 1958, 36, 1121.59 R. Schwarz and W. D. Muller, 2. anorg. Chem., 1958, 296, 273.8o C. A. Bunton and G. Stedman, J., 1958, 2440.G.Jander and H. Hofmann, 2. anorg. Chem., 1958, 296, 134.62 J. S. Elliot, R. F. Sharp, and L. Lewis, J . Phys. Chew., 1958, 62, 686.63 J. R. Howard, V. S. K. Nair, and G. H. Nancollas, Trans. Faraday SOC., 1958,1958, 41, 988.54, 1034PRUE : ACID-BASE EQUILIBRIA. 13and t e l l ~ r i c , ~ ~ hypochlor~us,~~ lauric and myristic,66 i s o c i t r i ~ , ~ ~ and a-acetyl-succinic.68 Polymerization to form complex anions has been studied in thecase of borates 69 and vanadium(v); 70 in the last paper the Rossottis haveapplied potentiometry and spectrophotometry to unravelling a complex situ-ation. Heats of neutralization have been measured directly for carboxylicacids by a microcalorimetric method,71 and for ethylenediaminetetra-aceticacid.72 Conclusions about the detailed structures of the various speciesderived from ethylenediaminetetra-acetic acid have been drawn from anexamination of the thermodynamic parameters.In concentrated solutions of the '' strong " acids,e.g., sulphuric, nitric, and perchloric, characteristic Raman lines occur foreach molecular species ; with photoelectric recording instruments, theintegrated intensity of a line can now be accurately determined and seemsto be rather exactly proportional to the concentrations of the species towhich it relates and independent of environmental influences (the height ofthe line is Estimates by Raman studies of the amounts of thevarious species present agree well with those determined from nuclearmagnetic resonance shifts,74 which appear to be influenced only by changesin the immediate environment of the nucleus concerned.In solutions ofsulphuric, perchloric, hydrochloric, and hydrobromic acids, Bascombe andBell 75 conclude from the concentration dependence of Hammett acidityfunctions that the oxonium ion is trihydrated, ie., OH,+(OHJ3, presumablyas a result of the formation of strong hydrogen bonds. The infrared spectraof the ions H,O+ and D30+ have been studied in aqueous solution.76Equilibria in Non-aqueous Solvents-(a) Aprotic solvents. In aproticsolvents proton transfers between uncharged molecules produce ion-pairs.Pearson and Vogelsong 77 have made spectrophotometric measurements ofthe reactions between aliphatic amines and 2,4-dinitrophenol in chloroform,chlorobenzene, ethylene dibromide, n-heptane, benzene, dioxan, and ethylacetate.The solvent has a marked effect on the relative basic strengths ofthe amines; tertiary bases are strongest in the first three solvents, secondarybases in the next three, and primary bases in ethyl acetate. The molecularinterpretation of the results is discussed. Bayles and Chetwyn 78 report athorough study of the equilibria between mono-, di-, and tri-n-butylaminewith 2,4-dinitrophenol in chlorobenzene froin 20 to 60". Continuing earlier(b) Strong acids.72 GENERAL AND PHYSICAL CHEMISTRY.those of silver iodide.72 In the case of silver sulphide this also applies tothe variation of the capacity of the inner region with surface charge(cf. Grahame73) and the structures of the double layers must be closelysimilar.Neutral molecules.Many neutral molecules are strongly adsorbed onmercury a t potentials in the vicinity of the electrocapillary maximum.74The rate of adsorption on a clean mercury surface may be limited by one ormore of the following processes: (a) transport (usually diffusion) to the(b) a preceding chemical reaction in solution, (c) rate of adsorption,(d) adsorption-desorption equilibrium, (e) a succeeding chemical reaction onthe electrode surface. Each of the processes (a), (c), and (d) has beenshown 76 to be rate-controlling in suitable circumstances. Adsorption pro-cesses are usually studied by measuring changes in the differential double-layer capacity77-80y86 and it is assumed that these are related to 8 (thefraction of mercury surface covered at equilibrium).By measuring 0 as afunction of c~ncentration,'~ values of Ci (the bulk concentration needed togive 8 = 8) have been determined for 30 organic compounds; values rangefrom Ci = 6 x 1 0 - 6 ~ for Leucomethylene Blue to C6 = 8 x 1 0 - 2 ~ forpyridine. Processes (a) and (d) were rate-controlling ; equilibration followeda Langmuir isotherm and was complete [for acetophenone pinacol (2,3-di-phenylbutane-2,3-diol)] within 6 seconds only if 0 20.75. The last value isto be compared with 8 0-85 *l obtainable from theoretical data. Similarresults have been obtained with series of lower fatty acids 79 and alcohols,80but with increasing chain length breaks occur in the Langmuir isotherm,which are interpretable in terms of an (e) process, probably a two-dimensionalassociation akin to that found at solution-air interfacess2 Theoreticalstudies of adsorption rates have been made for different transport processes,various rate-controlling steps, and several electrode geometrie~.7~*7~.~*84Information concerning the'relative rates of processes (a), (c), and (e) can beobtained from the effect of frequency v a r i a t i ~ n .~ ~ ~ ~ ~The effect of the distribution ofpotential in the double layer and of the adsorption of anions on the rate ofAdsorPtion and electrode veactions.72 E. L. Mackor, Rec. Trav. chim., 1951, 70, 763.73 D. C. Grahame, J . Amer. Chem. SOC., 1954, 76, 4819.74 A. N. Frumkin, 2. Physik, 1926, 35, 792; 1.A. V. Butler, Proc. Roy. SOL. 1929.A , 122, 399.75 A. N. Frumkin and V. I. Melik-Gaikazyan, Doklady Akad. Nazik S.S.S.R.. 1951.77, 855.76 R. W. Schmid and C. N. Reilley, J . Amer. Chem. Soc., 1958, SO, 2087.77 H. A. Laitinen and B. Mosier, ibid., 1958, 80, 2363.78 R. S. Hansen, R. E. Minturn, and D. A. Hickson, J . Phys. Chem., 1956, 60, 1185;79 W. Lorenz, ibid., 1958, 61, 192.80 Idem, 2. Phys. Chem. (Frankfurt), 1958, 18, 1.81 This inequality is derived from Fig. 3 of Delahay and Fike (ref. 84) which isdependent on a specific value of an unknown parameter. Thus agreement with theexperimental value is within likely errors.8% A. N. Frumkin, 2. phys. Chem., 1925,116,466; D. C. Grahame, Chem. Rev., 1947,4, 441.88 V. I.Melik-Gaikazyan, Zhur.fiz. Khim., 1952.26, 560; T. Berzins and P. Delahay,J . Phys. Chem., 1955, 59, 906; P. Delahay and I. Trachtenberg, J . Amev. Chern. SOC.,1957, 79, 2355.84 P. Delahay and C. T. Fike, ibid., 1958, 80, 2628.1957, 61, 953; W. Lorenz and F. Mockel, 2. Elektrochem., 1956, 60, 507FLEISCHMANN AND OLDHAM : ELECTROCHEMISTRY. 73electrochemical reactions has been frequently considered, particularly forhydrogen evolution. A recent paper 85 contains a bibliography and shows acorrelation between the rates of reduction of the iodate ion and nitromethaneand the potential of the outer and inner Helmholtz planes.67The presence of uncharged surface-active substances may affect theelectroreduction of other substances by one or more of the followingmechanisms: (f) chemical reaction in solution; this will alter both thekinetic parameters of the electron transfer (k and a) and the transportparameters (usually 0) ; (g) the adsorbed substance may physically blockpart of the electrode surface; and (h) the adsorbed material (by changing thedouble-layer structure) may affect the kinetic parameters even on theuncovered fraction of the surface.Three groups of workers in Americahave considered this problem: one 76 discounts (g) and explains its resultsin terms of (f) and ( 1 2 ) ; the second 86 expresses its results in terms of (h) ;while the thirds7 considers (g) and (k) only. The last workers, using a.c.methods to measure k and 8 simultaneously during the occurrence of theTiIV-TiTII exchange reaction at a dropping mercury electrode, found thateffect (h) did not exist for cyclohexanol, but was important for thym01.~~The part played by adsorption of the reacting species itself in the electrodeprocess has been the subject of much theoretical speculation, especially inthe case of hydrogen evolution,88 and recently more direct methods ofdetermining the r61e of adsorption have been u t i l i ~ e d .~ ~ Electrode processesmay be affected both by (i) the adsorption of the reactant and by ( j ) theadsorption of the reaction product. The quantity of adsorbed material canbe determined galvan~statically,~~ by a technique which has been most oftenused in the investigation of oxide 1a~er.s.~~ Where the amount of adsorptionis large compared with the amount of material which can diffuse from thesolution, the transition time will be inversely proportional to the current.The adsorption on mercury of Methylene Blue and eosin has been investigatedin this In the latter case, the reduction product is not adsorbed andconsequently the oxidation rate is small. With Leucomethylene Blue,however, processes (i) and ( j ) are both involved and electron transfer is rapidin either direction.Similarly a comparison of cathodic and anodic transitiontimes in the reaction I, + 2e + 21- shows that I, is rapidly adsorbed.92bThe frequency-dependence of impedance measurements at solid electrodeshas also yielded information concerning the adsorption of reactants in redoxreactions.g& Adsorption of the reactants would also be expected to becharacterised by fractional stoicheiometries a t constant ionic strength, andthis is observed in the growth of PbO, deposits.94$5 M.Breiter, M. Kleinerman, and P. Delahay, J . Anzw. ClLenz. Soc., 1958, 80, 5111.86 H. A. Laitinen and W. J. Subcasky, ibid., p. 2623.87 P. Delahay and I. Trachtenberg, ibid., p. 2094.88 J. O’M. Bockris, “ Modern Aspects of Electrochemistry,” Buttenvorths, London,89 H. Gerischer and W. Mehl, 2. Elektrochem., 1955, 59, 1049.90 W. Lorenz, 2. Elektrochem., 1955, 59, 736.91 K. J. Vetter and D. Berndt, ibid., 1958, 62, 378.92 (a) W. Lorenz and E. 0. Schmalz, ibid., p. 301; (b) W. Lorenz and H. Muhlberg,93 J. Llopis, C.I.T.C.E. Meeting (see ref. 3) ; Andes Fds. Quim., in the press.P4 M.Fleischmann and M . Liler, Trans. Furuday Soc., 1958, 54, 1370.1954.2. phys. Chem. (Frankfurt), 1958, 17, 12974 GENERAL AND PHYSICAL CHEMISTRE’.Hydrogen evolution. The diffusion of hydrogen from one polarised side ofa membrane to the other side, which may also be polarised, has been used toobtain direct evidence on the effect of changes in the surface concentration ofhydrogen atoms on the electrode kinetic^.^^,^^ The change in concentrationproduces a change in potential which is determined by the mechanism of thereaction. For an electrochemical desorption step succeeding a rate-determining discharge,97 a decrease is predicted and observed for a numberof metals. The conclusions are similar to those obtained from current-timetransients at constant potential 89 which are also determined by changes inthe concentration of adsorbed hydrogen. The variation of the concentrationof absorbed hydrogen due to a variation of the surface concentration hasalso been examined by measuring the ionisation of hydrogen.98The variation of the exchange current with the heat of adsorption hasbeen r e - e ~ a r n i n e d .~ ~ - ~ ~ ~ A rough prediction is that the rate of the dischargestep will be increased while the rates of electrochemical desorption and of re-combination will be decreased by an increase in heat of adsorption, the effectbeing greatest with the slow recombination step. For a number of metals thelatter behaviour is observed,lW and an electrochemical desorption step issuggested.An analysis, allowing for a change in the degree of coverage withheat of adsorption lol and for this factor, together with non-ideal behaviourin the adsorbed layer,lo2 shows, however, that for all mechanisms theexchange current will vary in a similar manner, passing through a maximumwith increasing heat of adsorption. Many data fit in with this scheme.The form of the Tafel plots has also been discussed Io2 in relation to themechanisms. The changes in slope observed have received a number ofinterpretation^.^^*^^^*^^^ It is of interest to discuss some of the recentobservations on platinum. The ionisation of hydrogen, a useful cri-terion,10*,105 has been measured and on electrodes of low activity is of thefirst order with respect to H,.lO4 It is therefore suggested that the desorptionof H, must be included in the reaction scheme.On electrodes of higheractivity the reaction is of zero order lo5 and this suggests slow surface diffusionor slow ionisation. These experiments have shown a correlation betweenthe “ poisoning’’ for the ionisation and the adsorption of anions.69 Atlower stirring rates the reaction is diffusion-controlled.lo6 A re-examin-ation 106 of the a.c. impedance lo7 of active platinum electrodes suggests afast discharge and a large contribution to the overpotential by diffusion of95 A. N. Frumkin, 2. phys. Chem. (Leipzig), 1957, 207,321; I. Bagozkaya, DokladyAkad. Nauk S.S.S.R., 1956,107, 843; 1956, 110, 397.96 S. Schuldiner and J. P. Hoare, J . Electrochem. Soc., 1957, 104, 564; 1958, 105,278.97 A.N. Frumkin, Zhur.fiz. Khim., 1957, 31, 1875.98 M. Fleischmann, J. Sowerby, and H. R. Thirsk, Trans. Faraday SOC., 1957,53, 91.99 P. Riietschi and P. Delahay, J . Chem. Phys., 1955, 23, 195.100 B. E. Conway and J. O’M. Bockris, ibid., 1957, 26, 532.101 H. Gerischer, Bull. SOC. chim. belges, 1958, 67, 506.102 R. Parsons, Trans. Faraday SOC., 1958, 54, 1053.103 J. O’M. Bockris, I. A. Ammar, and A. K. M. S. Huq, J . Phys. Chem, 1957, 61,104 K. J. Vetter and D. Otto, 2. EZektrochem., 1956, 60, 1072.105 A. N. Frumkin and E. Aikazyan, Doklady Akad. Nauk S.S.S.R., 1955, 100, 315.106 M. Breiter, H. Kammermaier, and C . A. Knorr, 2. Elektrochem., 1956, 60, 37.107 p. Dolin and B. V. Ershler, Acla Physicochim. U.R.S.S., 1940, 13, 747.879FLEISCHMANN AND OLDHAM ELECTROCHEMISTRY. 75hydrogen through the solution.In common with other metalslo8 someauthors conclude lo3 that the electrochemical desorption step is rate-determining in acid solutions. The exact nature of the metal surface isclearly important.There has been a general treatment of the stoicheiometric number,lm thenumber of times the rate-determining step takes place in unit reaction. Theelectrochemical desorption step has been considered in detail.llO*lll It hasbeen shown 110 that, with increasing overpotential, on electrodes with lowcoverages the discharge must become rate-determining even if electro-chemical desorption is slow at the reversible potential. As the exchangecurrent used in the calculation is obtained by extrapolation from highoverpotentials the stoicheiometric number will only be unity provided thedischarge step is slow in the reaction sequence at all overpotentials.Theconclusion that this is generally true ll2s1O8 is unjustified. This treatmenthas been generalised for constant surface coverage.lll If both stages havecomparable rates the stoicheiometric number is 2.1113109In recent years many examples 113-12*have been reported of the occurrence of minima in cathodic current-voltagecurves in regions of potential where a diffusion plateau would be expected.32These minima are not related in any way to polarographic m a ~ i m a . l l ~ ~ ~ ~ Most attention has been devoted to those minima found on the electro-reduction of the large multivalent anions s2082-, Fe(CN)63-, and PtC142- onmercury at negative potentials: the current within such minima iskinetically controlled l 1 5 p 1 1 6 and is often very sensitive to foreign ions.Thus5 x 10-3~-KC1 11’ or 10-2~-Na2S04 is sufficient to eliminate the minimumof K,Fe(CN), completely and it has been suggested 117 that trace quantitiesof cations of high valency may have prevented Kivalo and Laitinen 118,115Minima in current-voltage cwves.108 N. Pentland, J. O’M. Bockris, and E. Sheldon, J . Electrochem. SOC., 1957, 104,109 A. C. Makrides, ibid., p. 677.110 K. J. Vetter, 2. Elektrochem., 1955, 59, 435.111 A. N. Frumkin, Doklady Akad. Nauk S.S.S.R., 1958, 119, 318.112 J. O’M. Bockris and E. C. Potter, J . Res. Inst. Catalysis, 1956, 4, 50; 1956, 4, 256.113 A.N. Frumkin and G. M. Florianovich, Doklady Akad. Nauk S.S.S.R., 1951, 80,114 N. V. Nikolajeva, N. S. Shapiro, and A. N. Frumkin, ibid., 1952, 86, 681.115 P. Kivalo and H. A. Laitinen, J . Amer. Chem. Soc., 1955, 77, 5205.116 G. M. Florianovich and A. N. Frumkin, Zhur. fiz. Khim., 1955, 29, 1827.117 A. N. Frumkin, Birmingham Meeting (see ref. 6).118 P. Kivalo, J . Phys. Chem., 1957, 61, 1126.118 T. A. Kryukova, Doklady Akad. Nauk S.S.S.R., 1949, 65, 517.120 H. A. Laitinen and E. I. Onstott, J . Amer. Chem. SOL, 1950, ‘92, 4565.122 P. Kivalo, Suomen Kern., 1957, B, 30, 208.123 A. N. Frumkin, 2. Elektrochem., 1955, 59, 807.124 Idem, ‘‘ Va Prosy khimicheskoi kinetiki, kataliza i reaktsionnoi sposobnosti,”Akad, Nauk S.S.S.R., Moscow, 1955, p.402.125 N. V. Nikolajeva-Fedorovich, L. A. Fokina, and 0. A. Petry, Doklady Akad. NaztkS.S.S.R., 1958, 122, 639.126 T. V. Kalish and A. N. Frumkin, Zhur. fiz. Khim.. 1954, 28, 473.127 A. N. Frumkin and N. V. Nikolajeva-Fedorovich, Vestnik Moscow Univ. Chem.Ser., 1957, 169; A. N. Frumkin, B. Damaskin, and N. V. Nikolajeva-Fedorovich,Doklady Akad. Nauk S.S.S.R., 1957, 115, 751.12* A. N. Frumkin, N. V. Nikolajeva-Fedorovich, and R. Ivanova, Paper 16a,Toronto Symposium (see ref. 1).182.907.A. N. Frumkin and N. V. Nikolajeva, J . Chem. Phys., 1957, 26, 155276 GENERAL AND PHYSICAL CHEMISTRY.from reproducing the curves obtained by other workers 1133116 with ferri-cyanide solutions. Two early theories 119*120 have been superseded by twonewer ones: the first of these 113*1263129~130 seeks to explain minima in termsof electrostatic principles, while the second ll5s1l8 is based on kinetic effects.In their present forms, neither theory is entirely satisfactory.121J22The effect of added salts in suppressing minima (increasing the rate ofelectroreduction) has been studied most thoroughly for the reduction ofK2S20, at a dropping mercury electrode.The efficiencies of salts insuppressing the persulphate minimum follow the sequences Th(SO,), >BaCl, > KC1,lI6 La,(SO,), > Na,-$O, = NaBr = NaOH, 1 1 3 9 1 1 9 and CsCl >RbCl > KCl > NaCl > LiC1,123 demonstrating the importance of the chargeand size of the cation in determining the efficacy of the suppressor. Frumkinoriginally12, explained this effect in terms of the electrostatic theory, thecations affecting the potential distribution in the double layer, but he now 121shares with Schmid and Reilley131 the opinion that the cation exerts itsinfluence by forming a bridge between the reducible anion and the mercurysurface.The tetrabutylammonium ion is effective in suppressing minimaonly at potentials more positive than the desorption potential of thei0n,117J~~ showing that the adsorbed Bu,N+ cation is the effective suppress-ing agent. It is therefore somewhat surprising to find126 that the I- ion(which is adsorbed on Hg even at negative potentials32) is also capable ofsuppressing the persulphate minimum. However, the nature of the addedcation is also important 12’ and the order of efficacy for certain alkali-metalhalides is 128 CsI > CsCl > KI > KBr > KC1 > NaCl = NaF = NaI.Itis suggested128 that adsorption of iodide ion depends on the formation ofcationic bridges and that the bridging capacity of a large cation is greaterthan that of a smaller ion such as Na+. The localisation of cations on theelectrode surface may then serve to accelerate the electroreduction of theS20,2- anion. The formation of a trinsition complex involving both thepersulphate and the iodide ion at the electrode surface does not appear tohave been considered, though the homogeneous reaction between thesetwo anions is well known.132Electyocry stallisation. The formation of a layer of adsorbed molecules oratoms has been frequently postulated to be an intermediate stage in thegrowthof crystals.It is suggested that the lattice is built up from these adatoms atsteps on the crystal faces such as those formed by screw dislocations.133The growth of deposits on electrodes has been examined in a number ofways. As these are frequently fast reactions some workers have used a.c.impedance measurement^.^^,^^^ The separation of the faradaic componentdue to the electrode process is more difficult than in the case of mercury136as “ perfectly ” polarised solid surfaces always show a resistive component129 J. Koryta, 2. Elektrochem., 1957, 61, 423.130 A brief account of the principles is given by Delahay et al. (see ref. 85).131 R.W. Schmid and C. N. Reilley, J . Amer. Chem. SOC., 1958, 80, 2101.132 T. S. Price, 2. phys. Chem., 1898, 27, 474.133 W. K. Burton, N. Cabrera, and F. C. Frank, Phil. Trans., 1951, A , 243, 299.134 W. Lorenz, 2. phys. Chem. (Frunkfuvt), 1958, 17, 136; 2. Naturforsch., 1954,186 J. O’M. Bockris and B. E. Conway, J. Cheun. Phys., 1958, 28, 707.136 J. E. B. Randles, Discuss. Furaduy Soc., 1947, 1, 11.9a, 716FLEISCHMANN AND OLDHAM ELECTROCHEMISTRY. 77as well as the double-layer capacity. Bockris and Conway, in examiningthe growth of copper, assume that the frequency-dependent values areindependent of potential and subtract (vectorially) the impedance ap-propriate to that frequency.135 Lorenz has examined the deposition ofsilver from a complex so that a value of the non-faradaic component in theabsence of the depositing ion could be obtained a t the deposition potential.The electrode impedance consists of a frequency-dependent resistance andcapacitance in paralle1.lM From the limiting values at low and highfrequencies and from the dispersion frequency the following quantities canbe obtained in the event of slow surface diffusion: the exchange current forthe formation of adatoms and the lifetime of adatoms; the ratio of the meandiffusion path-length and the mean separation of the step lines; the densityof the adatoms. Some of these quantities are naturally not independent.In the case of copper,135 the deduced faradaic impedance has been found tovary in the same way with frequency as that observed for discharge atarnalgams,l36 so that deposition is evidently a normal transfer step with nosubsequent slow stages. The slope of the plot of faradaic resistance againstI/& is greater than that corresponding to unit surface and it is suggestedthat deposition only takes place on part of the surface.Thc concentration polarisation a t an electrode is equal to the over-potential a t which no current would flow a t the concentration established inthe steady state.This principle has been used137 to measure the totalconcentration overpotential by changing the potential to the correct valuewith a potentiostat. The total concentration polarisation is larger than thatcalculated for the solution and it is concluded that this is due to the adatoms.A measure of the concentration of adatoms on silver a t the reversiblepotential has been obtained by measuring the initial rate of change ofpotential a t constant current and equating the anomalously high capacityto the concentration of a d a t ~ m s .l ~ * ? ~ ~ ~ The interpretation also leads to ameasure of the rate of crystal growth. It is found that this is much smallerthan the exchange current for adatoms and this is consistent with anappreciable activation polarisation for lattice formation. An interestingcomparison has been made of the rate of growth of solid and liquid mercury 42near the melting point. As there is very little difference in the kinetics, theprocesses must be similar. This may well be related to the formation ofatomically rough surfaces near the melting point.140A feature of these investigations is that they are restricted to the initialperiod of deposition and it could be argued that they are not related to thecrystal growth process.In the limit, adatoms could be deposited butgrowth take place by direct deposition on step lines or kinks from thesolution, as was originally suggested.l= The steady rate of growth of silverchloride 141 and of lead dioxide 94 has been examined at constant potential157 H. Gerischer and R. P. Tischer, 2. EZeRtrochern., 1957, 61, 1159.138 H. Gerischer, ibid., 1958, 62, 256.139 W. Mehl and J. O’M. Bockris, J . Chem. Phys., 1957, 27, 818; J. O’M. Bockris140 W. I<. Burton and N. Cabrera, Discuss. Faraday Soc., 1948, 5, 33.141 ni.FIeischmann and H. R. Thirsk, C.I.T.C.E. Meeting (see ref. 3) ; EZectrocJLi+nicaand W. Mehl, Paper 8, Toronto Symposium (see ref. 1).L 4 ~ i n , 1959, 178 GENERAL AND PHYSICAL CHEMISTRY.and with use of a sequence of two constant potentials to separate nucleationand growth constants. The growth of a solid such as silver chloride onsilver is a favourable case for observing the effects of lattice formation due tostep lines, owing to the short diffusion path. In this case a transition froma second- to a first-order reaction is observed with increasing potential,which would be characteristic of growth at the steps produced by screwdis10cations.l~~ For such a mechanism an inductive component would, how-ever, be predicted for the electrode impedance whereas a capacitative com-ponent is found.141 The generation of step lines 142 would always beexpected to lead to an inductive component, particularly in the experimentsnear the reversible potential.This will apply even in the event of com-petition for adatoms between adjacent lines (i.e.J in the first order region)and must complicate the interpretation of the impedance and galvanostaticmeasurements. In view of this inductive component it can be stated thathitherto no evidence has been found of the participation of step lines in theoverall growth mechanism. (See however, earlier observations of super-polarisation.143)The formation of oxides, and passivation. The effect of corrosioninhibitors 144 and the pH of the solution 145 in the region where iron dissolvesfreely and the action of passivating inhibitors 146 has recently been consideredin the way first followed by Wagner and Traud. The papers given at acolloquium on passivity have been publi~hed.~The anodic polarisation of several metals 1479148 and alloys 149 in acidsolutions follows a well-defined pattern.If the current-voltage plot isdetermined under controlled-potential conditions 150 it is found that thecurrent first increases owing to dissolution (corrosion) and then reaches alimiting value. On further increase of the potential the current decreasesrapidly to a much lower value. At this " Flade " potential 151 the metalbecomes passive, and when the polarisation is switched off, becomes activeagain. The current remains constant in the passive region and finallyincreases owing to further dissolution and evolution of oxygen.This behaviour is frequently interpreted as being due to the formation ofa film of oxide which dissolves at a slow constant rate in the acid.In thecase of transition metals, ions of the lowest stable valency are formed in theregion of active dissolution and ions of a higher valency in the passive142 D. A. Vermilyea, J . Chem. Phys., 1956, 25, 1254.148 V. A. Roiter, V. A. Juza, and E. S. Polhyan, Acta Physicochim. U.R.S.S., 1939,144 H. Kaesche and N. Hackerman, J . Electrochem. SOL, 1958, 105, 191.145 I. A. Ammar and S. Riad, J . Phys. Chem., 1958, 62, 150.146 M. Stern and A. Geary, J . Electrochem. Soc., 1957, 104, 56; M.Stern, ibid., 1958,147 U. F, Franck, 2. Elektrochem., 1958, 62, 649; Nickel: G. Okamoto, H. Koba-10, 399, 845.105, 638.yashi, M. Nagayama, and N. Sato, ibid., 1958, 62, 775; Chromium: T. Heumann, ibid.,p. 745; Iron: J. H. Bartlett and L. Stephenson, J . Electrochem. Soc., 1952, 99, 504;Iron: U. F. Franck, 2. phys. Chem. (Frankfurt), 1955, 3, 183.148 Chromium: Ya. M. Kolotyrkin, 2. Elektrochem., 1958, 62, 664.149 Iron-Chromium: R. Olivier, Thesis, Leiden, 1955; M. Prazak and V1. Cihal,2. Elektrochem., 1958, 62, 739; Austenitic steel: N. Ya. Bune and Ya. M. Kolotyrkin,Doklady Akad. NUZ& S.S.S.R., 1956, 111; 1050.150 H. J. Bartlett, Tram. Electrochem. SOC., 1945, 87, 521.161 F. Flade, 2. PJqrs. Chem., 1911, 76, 513FLEISCHMANN AND OLDHAM ELECTROCHEMISTRT.79region.l@~ 1529 153 Appreciable quantities of charge are stored and released onincreasing and decreasing the potential 152~1549155 and the potential drop isestablished solely across the oxide layer,lM which grows by high fieldc o n d ~ c t i o n . ~ ~ ~ ~ ~ ~ ~ As the passive electrode responds to redox systems theoxide is electron-c~nducting.~~~~ 154 This electronic conductivity explainsthe onset of passivity due to the oxidation Fe304 ---t y-Fe,O, lS,l5* and alsoother phase changes such as Ag,O + In the absence of a redoxequilibrium in solution there must be a gradient in chemical potential ofelectrons across the layer so as to maintain a constant electrochemicalpotential. This is equivalent to a change of activity of the metal atoms and,at the appropriate potential, a disproportionation or further oxidation setsin.The field strength is simultaneously reduced and prevents the furthergrowth of the lower oxide. Certain aspects of the passivation of metalssuch as the effect of adsorbed carbon monoxide are more easily interpretedby assuming an adsorbed film.160 Electrodes may be passivated for theionisation of hydrogen by the adsorption of anions lo4 and the similarity ofthis process to the curves of anodic dissolution has been emphasised.lM Itis inferred that passivation is due to a similar cause.Othermetals such as zinc 162-164 and cadmium show active and passive regionsin neutral and alkaline solutions which are similar to those observed foriron. The different regions are due to the formation of oxide and hydroxidephases.164 The film in the passive region grows by high field conducti-~ity,~~~and a similar mechanism has been suggested for their inter~onversion.1~However, since the layers on zinc 163~165 and cadmium 166 dissolve in saturatedsolutions, the oxide solution interface cannot be in equilibrium and a dualprocess must operate.The Reporters thank Dr.R. Parsons and their colleagues for helpful dis-cussions and for assistance in translation.The behaviour of iron in alkaline solutions is less certain.161M. F.K. B. 0.152 U. F. Franck and I<. Weil, Z. Elektrochem., 1952, 56, 814.153 N. M. Knasheva and Ya. M. Kolotyrkin, Doklady Akad. Nauk S.S.S.R., 1957,154 K. J. Vetter, 2. phys.Chem. (Leipzig), 1953, 202, 1.15j K. J. Vetter, 2. Elektrochem., 1958, 62, 642.156 Idem, ibid., 1954, 58, 230.157 K. G. Weil, ibid., 1955, 59, 711.15* K. J. Vetter, 2. phys. Chem. (Frankfurt), 1955, 4, 165; H. Gohr and E. Lange,loo For example H. H. Uhlig, 2. Elektrochem., 1958, 62, 626.161 K. G. Weil and K. F. Bonhoeffer, 2. phys. Chem. (Frankfurt), 1955, 4, 175; K.Heussler, K. G. Weil, and K. F. Bonhoeffer, ibid., 1958, 15, 149.lo2 H. Liidering, Thesis, Gottingen, quoted by U. F. Franck, 2. Elektrochem., 1958,62, 652.1G3 I. Sanghi, Thesis, University of Durham, 1955.lo4 K. Huber, Z. Elektrochem., 1958, 62, 675.l o 5 T. P. Dirkse, J . Electrochem. SOC., 1954, 101, 328; 1955, 102, 497.166 P. E. Lake and E. J. Casey, ibid., 1958, 105, 52.114, 1265.hTatztrwiss., 1956, 43, 12; 2.Elektrochem., 1957, 61, 1291.H. Gohr and E. Lange, 2. phys. Chern. (Frankfurt), 1958, 17, 10080 GENERAL AND PHYSICAL CHEMISTRY.8. ENERGY TRANSFER IN LIQUIDS AND GASESA STABLE molecule requires considerably more than its average energy if itsnuclear configuration is to undergo a permanent change. This energy maybe acquired by the nuclei directly in collisional processes, or be communi-cated to the electrons by the absorption of radiation of the appropriatefrequency; in the latter case vibrational activation or change in nuclearconfiguration follows the crossing of two or more potential-energy surfaces.Processes involving one, and more than one such surface, respectivelyclassified as adiabatic and diabatic in the Ehrenfest sense,l form a con-venient subdivision for the report of recent work on energy transfer.Electron transfer processes are not included.Excellent accounts of the various aspects of this subject were presentedat the American Chemical Society’s symposium on “ Intermolecular EnergyTransfer ” held in Atlantic City in September 1956; more recent discussionsinclude those on ‘‘ The Structure and Reactivity of Electronically ExcitedSpecies ” (Ottawa, September 1957 3, and on “ Transfer of the Energy ofLuminescence and Photosensitisation ” (Paris, May 1958 4).Energy Transfer in Adiabatic Processes.-A collision between twomolecules may result in the excitation of translational, rotational, orvibrational energy of one of the colliding partners at the expense of theother.Since the primary process usually involves bond rupture it isevident that thermal reactions proceed by vibrational activation, althoughrotational activation is also important in the dissociation of the simplestmolecules.5 A knowledge of the probability and extent of vibrationalactivation and de-excitation on collision is therefore required for a completeunderstanding of reaction rates. Careri has discussed the various stagesof refinement of the molecular model used to calculate these probabilities,assuming that the energy conditions are met, In a series of importanttheoretical papers Shuler and his collaborators7 have provided a firmtheoretical basis for the treatment of relaxation data under non-equilibriumconditions which obtain in shock waves and chemical reactions.Applicationof their findings for a system of harmonic oscillators to the relaxation ofthe 8th vibrational level of the 0, molecule produced in the flash photolysisof C10,8 leads these authors to the conclusion that the collisional efficiencyof the N, molecules used as a heat bath is too small to account for theobserved rate of depopulation to the 7th vibrational level, and that C10with an estimated efficiency of 1 collision in 200 must be largely responsible1 S. Glasstone, K. J. Laidler, and H. Eyring, “The Theory of Rate Processes,”2 Published in J. Phys. Chenz., 1957, 61, 833-878.a Most of the papers presented have appeared in Canad. J. Chem., 1958, 36, 1-146.4 Published in J .Chim. phys., 1958, 55, 607-712.6 0. K. Rice, J . Chem. Phys., 1953, 21, 749; G. Careri, ibid., p. 749.7 E. W. Montroll and K. E. Shuler. J. Chem. Plzys., 1957, 26, 454; K. E. Shuler,J . Phys. Chem., 1957, 81, 849; N. W. Bazley, E. W. Montroll, R. J. Rubin, and K. E.Shuler, J . Chem. Phys., 1958, 28, 700; 1958, H, 1185; R. Herman and K. E. Shuler,ibid., p. 366; E. W. hlontroll and K. E. Shuler, Adv. Chem. Phys., 1958, 1, 361.8 F. J. Lipscomb, R. G. W. Norrish, and B. A. Thrush, Proc. Roy. SOG., 1956, A , 233,455.McGraw-Hill, New York, 1941. See also ref. 78.G. Careri, Adv. Chem. Phys., 1958, 1, 119STEVENS: ENERGY TRANSFER I N LIQUIDS AND GASES. 81for the effect observed. The consequences of the remarkable stability ofthe vibrationally excited 0, molecule are reported below in connection withthe decomposition of 0,.Some further conclusions of Shuler et al. are:(a) the analysis of relaxation data in terms of half-lives has no significancewhen more than two energy levels are involved; (b) insofar as translational-vibrational transition probabilities are independent of the vibrational levelinvolved, i.e. , for low vibrational levels, the relaxation behaviour of a systemof anharmonic oscillators can be represented by that of a system of harmonicoscillators ; in higher vibrational levels where the vibrational amplitude is nolonger small compared with the interaction range of colliding molecules, someuncertainty attaches to translational-vibrational transit ion probabilities andthe effects of anharmonicity which increase the vibrational excursion maybe pronounced; (c) a system of rigid rotator-harmonic oscillators relaxesas two independent systems of harmonic oscillators and rigid rotators ;rotational relaxation times calculated on the assumption that AJ = &lare some 100 times longer than experimental values, which suggests thatwhere AE < kT, AJ is not so restricted and multiquantum transfers areimportant ; (d) the rate of stepwise activation in a unimolecular dissociationreaction, i.e., A V = 1, calculated on the basis of a harmonic oscillator modelis some l o 5 times smaller than the observed value in the case of I, in thepresence of inert gases, implying that the restriction AV = *l must alsobe relaxed (as for an anharmonic oscillator) when AE( V , ---t Vn+l) < kTat higher vibrational levels.Hornig9 has also pointed out the legalityof multiquantum excitation when the relative kinetic energy of the collidingmolecules is many times the separation of vibrational levels, and states thatthere is no reason why violent collisions should not produce direct dissociationfrom lower vibrational levels. Thus it appears that in addition to allowingdissociation to take place, the anharmonic perturbation of vibrationsaccelerates the rate of activation necessary to produce it, and it is perhapsnot unlikely that this rate is directly related to the anharmonicity constantof the excited vibration.The Lindemann mechanism assumes that collisional deactivation ofvibrationally excited molecules proceeds with unit efficiency.If this is aone-quantum process the assumption is difficult to justify in view of thelarge number of collisions required to deactivate the lowest vibrationallevels.10 Mahan l1 has shown that the efficiency of collisional deactivationis considerably increased if this involves simultaneous excitation of a secondvibration of lower frequency; thus he calculates a collisional probabilityof 10-2 for simultaneous deactivation of v1 (926 cm.-l) and activation ofv3 (830 cm.-l) in the case of F20 whereas deactivation of v1 (V = 1) alonerequires some lo5 collisions. The removal of smaller " difference quanta "from higher vibrational states should be even more efficient and a treatmentof the effect of various gases on nitryl chloride decomposition leads to avalue of 12 cm.-I for the energy removed in the deactivating collision.Since vibrational transfer probabilities vary enormously with the9 D.F. Hornig, J . Phys. Chem., 1957, 61, 856.10 J. C. McCoubrey and W. D. McGrath, Qaart. Rev., 1957, 11, 87,11 B. H. Xlahan, J . Phys. Chem., 1958, 62, 10082 GENERAL AND PHYSICAL CHEMISTRY.vibrational level concerned, recent results will be reported for low, inter-mediate, and high vibrational levels independently along the lines of thevaluable review by McCoubrey and McGrath.lOTranslation-vibration relaxation involvingone or two quanta above the zero-point half-quantum involves smallchanges in translational temperature encountered in sound propagation.The origin of ultrasonic absorption and dispersion in terms of translation-vibration relaxation, together with the results of various workers, and theirsignificance in chemical kinetics has been discussed by Herzfeld andGriffing,lz whilst a review of molecular dispersion in liquids contains a shortaccount of vibrational relaxation in this phase.13 More recently, ultrasonicabsorption data for liquid CO,, SF,, N,O, CH3C1, and cyclopropane in therange 0-50" have been treated in terms of vibrational relaxation, the totalspecific heat relaxing with a single relaxation time, and it is concluded thatvibrational transitions in unassociated liquids occur in binary c0llisions.~4For non-polar liquids the collisional efficiency has a positive temperaturecoefficient whilst for polar ones it is virtually independent of temperatureover the range measured.Bass and Lamb l4 have also observed doubledispersion in liquid SO, which is a feature of this molecule in the gas phase.15The different ratios of the two relaxation times in the liquid (65) and gas (10)are attributed to the effect of environment on the collision frequenciesproducing the transitions. The multiple relaxation of sulphur dioxide gashas been treated theoretically by Dickens and Linnett ,16 their results beingin fairly good agreement with the experimental values; these authorsdiscuss the close resemblance in behaviour of sulphur dioxide and methylenechloride and suggest a number of other molecules in which multiple dispersionmay be expected on the basis of their relaxation mechanism for SO,.As yet, relaxation times cannot be calculated reliably from molecularproperties, although under certain conditions the predicted temperature-dependence is observed.These conditions have been studied by Lambert 17and his school in the past year, who present data for C2H4, CF,, CH,Cl,CH,Br, and cyclopropane over a wide temperature range (290-588') andcorrelate them with data for CH3F and SO, previously obtained.18 Thepredicted T-i dependence of logl, P is observed for non-polar gases overthe whole range studied, and for polar molecules at the higher temperatureswhere they acquire spherically-symmetrical force fields by rotation ; howeverthe exponential temperature coefficients require a much steeper repulsionthan that afforded by the Lennard- Jones and Krieger potentials.A similarstate of affairs exists for a large number of pure and mixed gases and has ledUbbelohde's school to suggest l9 the introduction of a " steric " factor intoLow-Zying vibrational levels.12 K. F. Herzfeld and V. Griffing, J. Phys. Chem., 1957, 61, 844.13 R. 0. Davies and J. Lamb, Quart. Rev., 1957, 11, 134.14 R. Bass and J. Lamb, Proc. Roy. Soc., 1968, A , 247, 168; 1957, A , 243, 94.15 J. D, Lambert and R. Salter, ibid., p. 78.16 P. G. Dickens and J. W. Linnett, ibid., p. 84.17 P. G. Corran, J. D. Lambert, R. Salter, and B. Warburton, ibid., 1968, A, 244, 212.18 P. G. T. Fogg, P. A. Hanks, and J. D. Lambert, ibid., 1953, A , 219, 490; J.Lam-19 J. W. Arnold, J. C . McCoubrey, and A. R. Ubbelohde, Trans. Faraday SOC.,bert and R. Salter, ibid., 1955, A , 232, 537.1957, 53, 738STEVENS: Eh’ERGY THANSFEK I S LIQUIDS AKU GASES. $3the theoretical expressions 2o to allow €or the inefficiency of certain collisionalorientations. At lower temperatures where the dipole interaction energybetween polar molecules is less than kT, the predominance of particularlyefficient oriented collisions leads to a negative temperature coefficient oftransfer probability, and the comparatively small temperature Coefficientof relaxation observed for CH,Br is attributed to the mutual compensationof collisional orientation and factors contributing to normal temperature-dependence. The high catalytic effect of H,O on relaxation in C2H4 andN,O 21 is similarly ascribed to a favourable collisional orientation, compoundformation, as with CO,, being less likely with C2H4 and N,O.Methane andbenzene are also found to be more efficient in heterocollisions than in self-transfer, whilst the catalytic effect of the paraffins on relaxation in C,H,and N,O increases with the number of carbon atoms which may be due torepeated (wrestling) collision involving different parts of the paraffin mole-cule which effectively steepens the repulsion curve, or to vibration-vibrationtransfer.Excitation of low vibrational levels by the absorption of infrared radiationis followed by a slight pressure pulse in the gas as the system relaxes. Jacosand Bauer 22 describe the application of the spectrophone based on thisoptico-acoustical effect to the vibrational relaxation of CO, in whichdifferent vibrations are excited exclusively. The results do not permit thedrawing of quantitative conclusions but it appears that hydrogen selectivelydeactivates the asymmetric CO, stretching frequency. This paper includesa valuable discussion of the problems encountered in this field together witha critical survey of the methods available for the examination of vibrationalrelaxation.One of the major difficulties in theoretical interpretation is thechoice of a satisfactory intermolecular potential to which the calculatedcross-section for excitation of the first vibrational level is extremely sensitiveeven in the collision between two H, molecules.23 has examinedthe feasibility of obtaining vibrational deactivation times from the intensityof radiation emitted by a heated gas; this may be regarded as a quenchingof infrared luminescence which competes with emission, the vibrationaldeactivation time being in principle determined from the half-intensitypressure. In this respect Cashion and Polanyi’s interesting observations 25on the infrared chemiluminescence of HC1 may be mentioned.The reactionbetween atomic H and C1, produces HC1 almost exclusively in the secondvibrational level although the energy of reaction is sufficient to excite 6vibrational quanta; the recombination of H atoms in HC1 alone on theother hand produces emission from the first vibrational level only, indicatingthat further excitation of HC1 is not easily achieved once it is formed.Recombination of 0 atoms produced by a vacuum-ultraviolet flash alsoexcites undissociated 0, molecules to the first vibrational level ; 26 howeLTer,20 E.g., see T.L. Cottrell and N. Ream, Trans. Faraduy SOC., 1955, 51, 150, 1453.21 J . W. Arnold, J . C. McCoubrey, and A. R. Ubbelohde, Proc. Roy. SOC., 1958,22 M. E. Jacox and S. H. Bauer, J. Phys. Chem., 1957, 61, 833.23 M. Salkoff and E. Bauer, J. Chem. Phys., 1958, 29, 26.24 D. A. Dows, ibid., 1957, 27, 1430.25 J . Ii. Cashion and J . C. Polanyi, ibid., 1958, 29, 466.26 J . A. Golden and ‘\. L. RIycrson, zbid., 1968, 28, 978.DowsA , 248, 44584 GENERAL AND PHYSICAL CHEMISTRY.the addition of 7 mm. of argon to the oxygen at 3 mm.pressure produced nosuch excitation, which seems to show either that Ar * is much more effectivethan 0, as third body or that it quenches the excited 0, (V = 1) with greatefficiency.In order to study vibrational relaxationit is desirable to excite a particular vibrational level selectively; althoughthis is not difficult for the lowest levels or for the dissociation region ifstudied from the recombination angle, selection rules forbid the directphotoexcitation of intermediate levels and their collisional population is nolonger selective. However, reactions between atoms and simple moleculescan produce radicals or molecules in more or less well-defined vibrationalstates as in the case of HC1 quoted above. Examples of such chemicalactivation are the production of vibrationally excited oxygen in the flashphotolysis of NO, and ClO, discovered by Norrish and his co-workers,* andthe detection of OH radicals in vibrational levels up to the 9th in the reactionproducts of H atoms with 0, by McKinley, Garvin, and B~udart.,~Collisional efficiencies for the one-quantum deactivation of 0, from the sixthvibrational level are of the order of those found for the lowest levels andrange from one in lo7 for Ar and N, to one in 500 for NO,.The remarkablestability of vibrationally excited 0, has led McGrath and Norrish2* toresuscitate the energy chain theory of 0, decomposition, the propagatingprocesses beingIntermediate vibrational levels.o(3q + o,(~A) --+ o2*(3xO-, v = 12 - 16) + o~(~A,J02* + 0, -+ 20,(3c,-) + o(3qOther excited radicals are formed in the reaction between halogen atomsand ozone 29 thusC1+ 0, ClO(V < 5) + 0,Br + O,+BrO(V< 4) + 0,As Norrish has pointed out in his Liversidge lecture,30 there is a strongtendency for most of the energy of reaction to remain unequilibrated inthe newly formed bond in the exothermic reactionA + BCD-AB + CDThe reader cannot do better than refer to this lecture for an authoritativcand comprehensive account of this work.It is now generally recognised31 that the emitter of the first positivebands in the nitrogen afterglow is the B311, state of N, formed with from7 to 11 vibrational quanta by preassociation of N atoms in the ground (4s)27 J.D. McKinley, jun., D.Garvin, and M. J. Boudart, J. Chem. Phys., 1955, 23,784.28 W. D. McGrath and R. G. W. Norrish, Nature, 1957, 180, 1272; Proc. Roy. SOC.,1957, A, 242, 265.29 Idem, 2. phys. Chem. (Frankfurt), 1958, 15, 245.30 R. G. W. Norrish, Proc. Chem. Soc., 1958, 247.31 K. R. Jennings and J. W. Linnett, Quart. Rev., 1958, 12, 116.* Attention is directed to the recent alteration of the symbol for argon from A to Arby I.U.P.A.C. This change is now adopted for publications of the Chemical Society,but care should be taken to avoid confusion with the standard usage of Ar for aryl.-EDSTEVENS: ENEICGY TRANSFER IN LIQUIDS AND GASES. 85state. By measuring the relative band intensities of this system as a functionof nitrogen pressure, Stanley 32 has obtained the probabilities of collision-induced transition from the 11th vibrational level relative to the spon-taneous radiative transition probability from this level.This ratio for allvibrational transitions is 1.37 x per cm. pressure of nitrogen, for whichone-quantum relaxation is 76% responsible , two- and three-quantarelaxations are 13% and 9% responsible, and single-quantum excitationcontributes 2%. The relative efficiencies of multiquantum relaxation areinteresting but the results are inconveniently expressed for purposes ofcomparison; from Kistiakowsky and Volpi’s 33 NH, quenching data a valueof 1-6 x for the radiative lifetime of N2(B3II,)which, combined with Stanley’s results, provides a collision efficiency of2 x 10” for vibrational transfer from the 11th vibrational level; this orderof magnitude is predicted by Zener’s theoretical e~pression.~~~35 Chartonand Gaydon 36 have attributed the strengthening of OH emission bands withV’ = 2 and 3 observed in hydrogen flames to formation of these vibrationallevels by preassociation of 0 and H, the overall scheme beingsec.can be calculated0 + H __t OH(’C-) + OH(’Z+, V = 2,3) _+ OH(,II) + hvIn electronic transitions AV is not restricted, and intermediate levels ofexcited molecules can be produced selectively by the absorption of mono-chromatic radiation; thus the Hg 5461 A line excites I, to the 26th vibra-tional level of the 3rZ state. Polanyi, and Arnot and McDowell,37 haveseparately investigated vibrational transfer from this level by measuringthe intensity dependence of transfer bands in the emission spectrum atvarious pressures of added gases.Transfer probabilities some 10-15 timesgreater than unity are obtained based on an adopted value of 10-8 secondfor the lifetime of 12(3n); it is indeed remarkable that, in this age ofelectronics, it is necessary to assume a value for the radiative transitionprobability of such a simple and important molecule. From the fluorescenceself-quenching data of these workers Stevens has calculated the muchlonger lifetime of 1.6 x lo* seconds for the excited I, molecule whichreduces the vibrational transfer probabilities to digestible values in therange 10-1-10-2. An interesting feature of the transfer bands in this caseis the comparable intensity of transitions from vibrational levels higher thanthe 26th; for higher levels of lower separation it appears that not only isthe vibrational transfer probability increased but that further excitationis almost as probable as collisional deactivation.High vibrational levels.When the vibrational energy of a molecule is ofthe order of that required for its dissociation, the vibrational separation isoften so small that individual levels are not easily resolved. In simple32 C. R. Stanley, Proc. Roy. SOL. 1957, A , 241, 180.33 G. B. Kistiakowsky and G. G. Volpi, J . Chem. Phys., 1958, 28, 665.34 Calculated from the half-quenching pressure of 0.16 mm. NH,, with the assump-35 C. Zener, Phys. Rev., 1931, 37, 556.36 M. Charton and A.G. Gaydon, Proc. Roy. SOC., 1958, A , 245, 84.37 J. C. Polanyi, Canad. J . Chem., 1958, 36, 121; C. Arnot and C . A. McDowell,38 B. Stevens, ibid., in the press.tion of a quenching collisional efficiency of unity and a quenching diameter of 7.0 A.ibid., pp. 114, 132286 GENERAL AND PHYSICAL CHEMISTRY.molecules this is largely due to vibrational anharmonicity, but in morecomplex systems, additional combination of the various vibrational modesin different levels may be such as to produce a virtual vibrational continuumin this region and the transfer of energy, both internally and externally, ismore amenable to a classical than to a quantum treatment.39 Thus althoughthese levels can be readily excited by collision, recombination, or atom orradical addition and by diabatic processes following electronic excitation,absolute efficiencies of vibrational transitions involving them can only beevaluated insofar as the transitions themselves are defined.Much attention has been given recently to the experimental verificationof one or other of the theories of unimolecular reactions which stand or fallby their ability to account for the pressure variation of the rate constant a tlow pressures.Accurate measurements made in this region by Hinshelwoodand his co-w~rkers~~ have shown that the form of k-p curves is more complexthan was a t first thought. In addition to the inflexion observed whencollisional activation is sufficient to sustain decomposition, other changesof slope are revealed at lower pressures depending on the nature of reactingand foreign gases; indeed the high-pressure rate constant itself shows asimilar dependence.These results, which are of sufficient importance tomerit discussion in the Anniversary Address to the Royal Society by itsPresident,41 require the introduction of additional steps to the Lindemannmechanism such thatNormal - Energised Activatedmoiecu tes - molecules - molecules - Productswith the provisions that any one of the 3 stages may be rate-determining,depending on the total pressure, and that the effect of different gases on eachis specific. That the activated molecule in the case of N20 is in allprobability a triplet has led these authors40 to suggest that a change inmultiplicity may be the rate-determining step for saturated molecules inwhich all electrons are bonding.Gill and Laidler 42 find that with twooscillators contributing to the activation of N,O, the theories of Hinshelwood,Kassel, Rice, and Ramsperger account satisfactorily for the observed de-composition rate in the low-pressure region, whereas the Slater theorypredicts a lower value owing to its more stringent activation requirements.Forst 43 has extended previous work on the unimolecular decompositionof hydrogen peroxide vapour, obtaining frequency factors of 1016 and1013.2 for activation by H20 and He respectively. These require that 5classical oscillators contribute to the activation by peroxide as comparedwith 3 for activation by He; relative efficiencies of the foreign gases in-39 M.J . Boudart and J. T. Dubois, J . Chem. Phys., 1965, 23, 223; B. Stevens,Canad. J . Chem., 1958, 36, 96.40 J . Lindars and Sir C. N. Hinshelwood, PYOC. Roy. SOL, 1957, A , 231, 162, 178;J. Jach and Sir C. N. Hinshelwood, ibid., 1957, A , 229, 143; 1957, A , 231, 145; F. W.Birss, ibid., 1958, A , 247, 281; G. R. Freeman, C. J. Danby, and Sir C. N.HinsheluTood,ibid., 1958, A , 245, 28.4 1 Sir C. N. Hinshelwood, ibid., 1957, A , 243, v.42 E. K. Gill and K. J. Laidler, Canad. J . Chem., 1958, 36, 1570.43 W. Forst, ibid., 1958, 36, 1308; cf. P. A. Gigukre and I. D. Lin, ibid., 1957, 35283; C. N. Satterfield and T. W. Stein, J . Phys. Chem., 1957, 61, 537; D. C. Conway:ibid., p. 1578STEVENS: ENERGY TRANSFER IN LIQUIDS AND GASES.87vestigated are H,O, = 1, H,O = 0.75, 0, = 0.15, He = 0.11. From astudy of the isotope effect on the low-pressure pyrolysis of ethyl bromideand [,H,]ethyl bromide, Blades 44 finds that if the higher activation energyof the deuterated molecule (AE = 2600 cal./mole) is to be explained interms of zero-point energy differences, it is necessary to assume that morethan one vibration is involved in activation. The rate-determining stepin the simple isomerisation of cyclopropane may require some revision inview of the reported geometrical isomerisation of [2H,]cyclopr~pane byRabinovitch and his co-workers ; 45 cis- and trans-isomers undergo reversiblegeometrical isomerisation in addition to a simultaneous structural isomeris-ation, the first-order rate constants beingkgeom = 1016'o exp (-64,20O/RT) sec.-lkseruct = exp (-65,50O/RT) sec.?The pressure variation of kgeom requires that at least 10 oscillatorscontribute, but ring rupture is preferred to the initial hydrogen-migrationmechanism.Cowperthwaite and Warhurst 46 have catalogued the uni-molecular decomposition of phenylmercuric iodide as second-class, with afrequency factor of 1015.7; the activation energy (63 2 kcal./mole)satisfies the criterion that it should be close to the energy sum of the bondsbroken, In this respect an interesting discussion of simultaneous bondrupture in terms of potential-energy surfaces by Szwarc and Herk47 ispertinent; they point out that the primary production of an unstableradical requiring zero activation energy for decomposition can lower theoverall activation energy by an amount equal to its dissociation energy if,and only if, both bonds break simultaneously, i.e., exothermicity of theradical decomposition contributes to the overall activation.An excellentdescription of the application of shock tubes to the study of dissociationrelaxation is provided by Hornig; 48 measurement 49 of the rate of dissoci-ation of Br, in this way shows that rotational energy contributes to activationin the temperature range 1200-2225"~, whilst the dissociation relaxation 50of 0, at higher Mach numbers is consistent with the 0 atom concentrationrequired for a chain mechanism in the N,-0, reaction at 2000-3000"~.As Hoare and Walsh 51 point out, all recombination processes will exhibitthird-order characteristics a t pressures below which the lifetime of theadduct is exceeded by the reciprocal of the collision frequency; this lifetime isshortest for the diatomic case where, since stabilisation requires the removalof small vibrational quanta, all third bodies should behave with perfectefficiency.Collisional stabilisation of larger systems, in which the recom-bination energy is transferred internally to lower levels of greater separation,should be more specific.51 Statistical theories of atom recombination rates44 A. T. Blades, Canad. J . Chem., 1958, 36, 1043.45 B. S. Rabinovitch, E. W. Schlag, and K. B. Wiberg, J . Chem. Phys., 1958, 28, 504.413 M. Cowperthwaite and E. Warhurst, J., 1958, 2429.47 M.Szwarc and L. Herk, J . Chem. Phys., 1958, 29, 438.48 D. F. Hornig, J . Phys. Chem., 1957, 61, 856.49 H. B. Palmer and D. F. Hornig, J . Chem. Phys., 1957, 26, 98.50 H. S. Glick and W. H. Wurster, ibid., 1957, 27, 1224.51 D. E. Hoare and A. D. Walsh, Chem. SOC. Special Publ., 1957, No. 9, 1788 GENERAL AND PHYSICAL CHEMISTRY.have been presented by Keck and by Bunker and David~on,~, and testedon I atom recombination data; Keck's calculated rate constant varies as That lower temperatures and as 1/T above 700"c and is much lower than theobserved value, although the predicted relative efficiencies of third bodiesagree well with less recent data. The latter authors account for the higherobserved rates in terms of a collision complex between the atom and thethird body, the concentration of which is calculated from intermolecularpotentials] and obtain good agreement with experimental relative efficienciesfor heavier non-polar third bodies.Atom recombination produces a steadyincrease in flame temperature above the reaction zone; with sodium atomsas a third-body " thermometer,'] Padley and Sugden 53 obtain rate constantsfor the reactionsH + H + Na--+H, + Na*H+OH+Na-H,O+Na*of the order of molecule-2 cm.6 sec.-l. The chemiluminescence of Nain the presence of H atoms has also been examined by McKinley andPolanyi at lower temperatures, the responsible reactions being eitherNa + Na + H d N a H + Na*with a collision yield of ca. 0.4 x lod3 orNa + H + H+H,(V = 5,J = 3) + Na*with a yield of ca.A convenient method55 of measuring concen-trations of nitrogen atoms in the nitrogen afterglow by titration with nitricoxide led to independent determinations of N atom recombination ratesby Harteck and his co-worker~,~~ who obtaink = 1.72 x molecules-2 cm.6 sec.-lwith argon and nitrogen equally efficient, and by Herron et aZ.,57 who findk = 1-52 x molecules-2 cm.6 sec.-lindependent of temperature in the range 2 7 3 4 5 3 " ~ ~ and with relativethird-body efficiencies, N, = 1, Ar = 0.61, and He = 0.15. Wentink,Sullivan, and Wray58 present a higher value of 3.31 x molecules-2cm.6 sec.-l at room temperature. Kaufman 59 has related the air afterglowintensity to the concentration of oxygen atoms and finds that CO, and N,Oare twice as effective as Ar or N, in the recombination of 0 and NO.Theextremely high efficiency of C1, in oxygen-atom recombination is attributedto a chemical mechanism involving C1 atoms and the C10 radical.52 J. C . Keck, J . Chem. Phys., 1958, 29, 410; P. L. Bunker and N. Davidson, J .53 P. J. Padley and T. M. Sugden, Proc. Roy. SOL, 1958. A , 248, 248.54 J. D. McKinley and J. C . Polanyi, Canad. J . Chem., 1958, 36, 107.55 F. Kaufman and J. R. Kelso, J . Chem. Phys., 1957, 27, 1209; G. B. IGstiakowsky66 P. Harteck, R. R. Reeves, and G. Manella, ibid., 1958, 29, 608.57 J. T. Herron, J. L. Franklin, P. Brandt, and V. H. Dibeler, ibid., p. 230.68 T. Wentink, J. 0. Sullivan, and K. L. Wray, ibid., p. 231.s9 F. Kaufrnan, ibid., 1958, 28, 352; Proc.Roy. Soc., 1958, A , 247, 123,Amer. Chem. Soc., 1958, 80, 5090.and G. G. Volpi, ibid., p. 1141STEVENS: ENERGY TRANSFER I N LIQUIDS AND GASES. 89The longer lifetime of vibrationally excited polyatomic species formedby combination is due to intramolecular energy transfer which may leadto the rupture of a different bond from that initially formed. Possibly thesimplest example is the HO,* radical for which Burgess and Robb 6o havemeasured the rates of both decompositionsH- + 0, + H02* __t He + 0,; k = 2 x lo1, exp (-7100/BT) sec.-l.__)I 0 + *OH; k = 2 x 1013 exp (-21,50O/RT) sec.-l.The beautiful work of Berisford and LeRoy 61 has produced a value of lo*sec. for the lifetime of the methane molecule formed by combination ofCH, + H; although ethane formed in the same way is more complex itcontains a weaker bond and is much less stable.Processes following theaddition of 0 atoms to olefins, and H atoms to alkylamine radicals have beenstudied by the schools of Cvetanovic 62 and Winkler 63 respectively, whilstSteacie and his co-workers suggest that CN abstraction proceeds via a‘‘ cracking mechanism,” and the addition of CH, to but-l-ene results in theformation of propene in similar fashion.65 Vibrational activation of mole-cules by CH, intrusion also affords a means of studying vibrational-energytransfer by analysis of products. This domain is now shared betweenKistiakowsky 66 and Trotman-Dicken~on,~~ who find that the limitingstabilising pressure decreases with increasing complexity of the adduct andthat relative efficiencies for stabilisation of keten formed from CO are:keten = 1, SF6 = 0-8, and N, = 0.1.Frey 68 has suggested that a moreenergetic CH, radical is produced in the photolysis of keten than in thephotolysis of diazomethane. Acetone and methyl iodide have been foundto be some 10 times as efficient as CO, in the third-body combination ofCH,. and 0,,G9 whilst the cyclic structure suggested for the pentylperoxy-radical may form a variety of products depending on the bonds subsequentlybroken.70The removal of vibrational energy from electronically excited fluorescentmolecules has been reviewed recently; 71 the large amounts of energy trans-ferred by more complex molecules suggest a vibration-vibration transfermechanism.Okabe and Steacie 72 have measured the fluorescence stabilis-ation of hexafluoroacetone as a function of inert-gas pressure and find thesame order of efficiency as that obtained from inert-gas effects on the yield60 R. H. Burgess and J. C. Robb, Trans. Faraduy SOC., 1958, 54, 1008.61 R. Berisford and D. J. LeRoy, Canad. J . Chern., 1958, 36, 983.62 R. J. Cvetanovic, ibid., p. 623; S . Sat0 and R. J. Cvetanovic, ibid., p. 970.63 2. M. George, A. N. Wright, and C. A. Winkler, ibid., p. 1171; A. N. Wright,J. W. S. Jamieson, and C. A. Winkler, J . Phys. Chewz., 1958, 62, 657.64 D. E. McElcheran, M. H. J. Wijnen, and E. W. R. Steacie, Canad. J . Chew.,1958, 36. 321.66 W. A. Bryce and P. Kebarle, Trans. Faraday SOL, 1958, 54, 1660.66 T.B. Wilson and G. B. Kistiakowsky, J . Amer. Chem. Soc., 1958, 80, 2934;G. B. Kistiakowsky and K. Sauer, ibid., p. 1066.67 J. H. Knox, A. F. Trotman-Dickenson, and C. H. J. Wells, J., 1958, 2897.68 H. M. Frey, J . Amer. Chem. SOC., 1957, 19, 1259; 1958, 80, 5005.6s M. I. Christie, Proc. Roy. SOL, 1958, A , 244, 411.70 I. R. McGowan and C. F. H. Tipper, ibid., 1958, A , 246, 64.7 1 B. Stevens, Chem. Rev., 1957,57,439; B. Stevens and M. Boudart, Ann. New Yovk72 H. Okabe and E. W. R. Steacie, Canad. J . Chem., 1958, 36, 137.Acad. Sci., 1957, 67, 57090 GENERAL AND PHYSICAL CHEMISTRY.of products of photolysis ; however the collisional reactivation process isomitted from the previous scheme 73 and the doubtful assumption is impliedthat higher vibrational levels of the fluorescent molecule do not emit.Asimilar investigation of the Hg-photosensitised decomposition of cyclo-octatetraene by Yamazaki and Shida 74 shows that this is inhibited by inertgases with the relative efficiencies cyclo-C,H, = 1, He = 0.13, Ar = 0.19,Kr = 0.17. The quantum yield of photolysis of azoethane at 3660 A provesto be pre~sure-dependent,~~ the excited molecule decomposing with anactivation energy of 2.4 kcal./mole. A surprising slow component of thefluorescence of organic vapours is attributed by Williams 76 to the formationof a dimer by excited and unexcited molecules which can be stabilised ordissociated by collision to produce the original fluorescent molecule, thelifetime of which is increased by the duration of the dimer.Rapid removalof excess of vibrational energy of fluorescent molecules by collision withsolvent molecules is admirably demonstrated by the work of Weber andTeale,77 who show that the excitation spectra of 26 compounds coincide withtheir absorption spectra down to 2100 A.Energy Transfer in Diabatic Reactions.-The fundamentals of processesinvolving radiative or radiationless transitions between potential-energysurfaces have recently been reviewed by Eyring, Stewart, and Parlin; 78 thetransmission coefficient is resolved into a diabatic factor based on theLandau-Zener approximation which gives the chance of a transition’soccurring per vibration, and a correcting or recruitment factor which allowsthe equilibrium expressions of absolute rate theory to be applied to the non-equilibrium conditions in chemical reactions.Electronic relaxation maybe a uni- or a bi-molecular process.Radiative transitions will not be reportedexcept insofar as they are involved in the photon theory of energy transfer;the coincidence of excitation and absorption spectra of a large number offluorescent organic molecules in solution over wide frequency ranges 77strongly challenges this theory’s interpretation of the “ cascade ” process bywhich higher electronic states revert to the lowest excited singlet. A strongresemblance between the phosphorescence spectra of naphthyl- and diphenyl-substituted aldehydes and ketones and the spectra of the parent compoundshas led Ermolaev and Terenin 79 to suggest an intramolecular energytransfer between the triplet states of the carbonyl group and of the sub-stituents mentioned.Crosby and Kasha *O have noted the intense emissionby the chelated ytterbium ion a t 9710 A produced by excitation in thelowest X,X* absorption band (3660 A) of the chelating molecule with aquantum yield in the range 0-2-1.0; this extraordinarily efficient transferbetween such widely separated energy states is attributed to vibrationalinteraction. A further interesting case of transfer between the adenine andIlztramoZecuZar processes.7 3 P. B. Ayscough and E. W. R. Steacie, Proc. Roy. Soc., 1956, A, 234, 476.74 H. Yamazaki and S. Shida, J . Chem. Phys., 1956, 24, 1278; 1958, 28, 737.75 H. Cerfontain and K. 0.Kutschke, Canad. J . Chem., 1958, 36, 344.76 R. Williams, J . Chem. Phys., 1958, 28, 577.77 G. Weber and F. W. J. Teale, Trans. Faraday Soc., 1958, 54, 640.78 H. Eyring, G. Stewart, and R. B. Parlin, Canad. J . Chem., 1958, 36, 72.79 V. Ermolaev and A. Terenin, J . Chzm. phys., 1958, 55, 698.80 G. A. Crosby and M. Kasha, Spectrochim. Acta, 1958, 10, 377STEVENS: ENERGY TRANSFER IN LIQUIDS AND GASES. 91nicotinamide groups insulated by a long saturated chain in dihydrodi-phosphopyridine nucleotide is described by Weber ; 81 since no transfer isobserved when the chain is broken, this author suggests a coupled-oscillatormechanism with high (30%) efficiency due to the formation of an intra-molecular complex between the groups concerned.The mechanism of p-bond fission following n,n* excitation in aromaticmolecules has been enterprisingly tackled by Porter 82 in terms of an internalsensitisation of a repulsive state in the side-chain by the In* state of theconjugated system.This problem is of general importance in photo-chemistry where it is becoming increasingly apparent that more than oneprimary dissociation can occur simultaneously; 83 a similar diversity hasbeen suggested to account for the photosensitised decomposition productsof ethyleneimine s4 and the radiation decomposition products of isopropylether.85 The explanation will probably require transitions to differentelectronic states as observed in the case of the simpler N2(5Cg+) system 31which now has three progeny, alll,, B311,, and a new Y state 86 which LeBlancet al.designate 3Au.87 A viscosity dependence of the limiting first-orderrate of naphthalene and anthracene triplet decay in solution seems toindicate a critical nuclear configuration requirement 88 which is suggestedby Bowen and SahuS9 in connection with the internal quenching offluorescence of acridine and acridone in the same phase. Should differentprimary photochemical processes proceed from states of different multi-plicity with possibly different nuclear configurations, these processes mayalso be controlled by the viscosity of the medium and differ from those inthe gas phase.g0An admirable concise review of the circum-stances in which electronic energy is transferred between atoms andmolecules and of the theories put forward to account for these observationshas been given by Livingst~n.~~ Gunning 92 has analysed the products ofHg-photosensitised reactions in which the 202Hg isotope is preferentiallyexcited and finds no enrichment in the case of N20 and 02, which thereforeexcludes primary reaction between these molecules and 202Hg(63.P,) ; fromenergy considerations Gill and Laidler 93 conclude that the sensitised 0,molecule is 3C+u.The pressure-dependence of H, formation in the Hg-photo-sensitised polymerisation of acetylene also suggests the primary formationof an excited C2H2 moleculeg4 which should be in the triplet state; spinIntermolecular pyocesscs.81 G. Weber, Nature, 1957, 180, 1409.82 G. Porter, Chem. SOC. Special Publ., 1957, No.9, 143.8 3 M. H. J. Wijnen, J . Amer. Chem. SOC., 1958, 80, 2394; P. Ausloos, Canad. J .84 C. Luner and H. Gesser, J . Arner. Chem. Soc., 1958, 80, 1148.85 A. S. Newton, J . Phys. Chem., 1957, 61, 1490.86 G. B. Kistiakowsky and P. Warneck, J . Chem. Phys., 1957, 27, 1417.87 F. LeBlanc, Y . Tanaka, and A. Jursa, ibid., 1958, 28, 979.BE G. Porter and M. W. Windsor, PYOG. Roy. Soc., 1958, A , 245, 238.89 E. J. Bowen and J. Sahu, J , , 1958, 3716.90 P. Ausloos, Canad. J . Chem., 1958, 36, 383.91 R. Livingston, J . Phys. Chem., 1957, 61, 860.92 H. E. Gunning, Canad. J . Chem., 1958, 36, 89.93 E. K. Gill and K. J. Laidler, ibid., p. 79.94 S. Shida, 2. Kuri, and T. Furuoya, J . Chem. Phys., 1958, 28, 131.Chem., 1958, 36, 40092 GENERAL AND PHYSICAL CHEMISTRY.conservation also requires that triplet NH, should be a product whenNZ(B3ng) is strongly quenched by this molecule in the nitrogen afterglowalthough Kistiakowsky and Volpi 33 detect no products of its subsequentdecomposition.Birks 95 has challenged Weinreb’s attempt 96 to discriminate betweenradiative and non-radiative transfer of excitation energy in liquid systemson the grounds that use of the technical fluorescence yield of the donor,arbitrarily assigned a value of 33%’ enables the observed transfer to becompletely accounted for by the photon theory.In reply, Weinreb givesfive reasons why secondary donor fluorescence cannot seriously affect hisoriginal interpretation in which photon transfer has a considerable but notexclusive role.Solvent-solute transfer has been treated by Brown, Furst,and Kallmann 97 from the point of view of emission intensities produced by’y- and ultraviolet irradiation; the last two authors 98 find that concentration“ cross-quenching ” between different molecules can take place if thedifference in their energy levels is close to their average vibrational energy.A different approach has been used by Knaqg9 who measures the fluorescencedecay time of anthracene in benzene solution excited directly by ultravioletlight (4 x lo* sec.), and indirectly following transfer from the solventexcited by electrons (9 x sec.) ; the difference in decay time is a measureof the “ transfer time ” which decreases with increasing solute concentrationand thus rules out the photon-transfer theory.Both this theory and theForster dipole interaction theory predict increasing transfer efficiency withincreasing overlap of the donor emission and acceptor absorption spectraand with decreasing separation of the molecules concerned and should nottherefore be considered as mutually exclusive. However from his measuredtransfer efficiencies of carotenoid-sensitised chlorophyll fluorescence in vitrowhich range from 0 to lOOyo for acceptors exhibiting comparable emission-absorption overlap a t the same concentrations, Teale loo concludes thatproximity and overlap are not the only factors controlling transfer. Calvin 101and his coworkers find that a similar sensitisation in ChZoreZZa and spinachchloroplasts is considerably more efficient than in Nostoc, which suggests thata critical orientation is necessary.A valuable account of the roles playedby homogeneous and heterogeneous energy transfer in photosynthesis isgiven by Rabinowitch,lo2 who emphasises the difference in conditionsobtaining in the chloroplast and under experimental conditions in solution ;the delayed onset of sensitised chlorophyll fluorescence by pigments(-15 mp sec.) is that expected from measurements of excitation time andof sensitiser quenching in vitro.100 GENERAL AND PHYSICAL CHEMISTRY.Interesting bridged structures of the electron-deficient compoundsB6H1() and InMe, have been determined57,58 by X-ray studies. Halogenbridges are met in niobium 59a and tungsten 59b derivatives : in the niobiumpentachloride dimer two chlorine atoms link the two NbCl, units, while inthe ion W,Clg3- three chlorine atoms link the two WCl, units; in both theconfiguration about the metal atoms is octahedral. Chlorine atoms also formthe bridge in the molecule 6o (C,H,),TiCl~lEt,, while two carbon monoxidemolecules join the two halves of the dicyclopentadienyldi-iron tetracarbonylmolecule.61A microwave determination 62 of cyclopentadienylnickel nitrosyl showsCsV symmetry with the Ni, N, and 0 atoms lying on the %fold symmetryaxis of the carbon ring.Polyatomic molecules: organic compounds.Most structural determin-ations on simple organic molecules are concerned with increased precisionand small but significant variations. In the microwave field, structuraldeterminations have recently taken second place to measurements ofrotational barriers discussed in the third section of this Report.The organicmolecules considered here are grouped into (a) substituted methanes (in-cluding a number of t-butyl derivatives), (b) substituted acetylenes andolefins, and (c) cyclic compounds.(a) Substituted methanes. Methane itself and [,H&nethane have beenexamined 63 by infrared and Raman spectroscopy, and new rotational con-stants have also been obtained for methyl chloride and for chloroform.65Electron-diffraction measurements have been made on a number offluoro-derivatives: dichlorodifluoromethane,66 trifluoromethyl bromide,67i ~ d i d e , ~ '168 and cyanide:' and trifluoromet hylsulphur pent afluoride .67 Theredetermination 68 of the structure of CF,I by use of complex atomic scatter-ing factors and incorporation of the microwave determination of IB (momentof inertia) leads to C-I = 2.135, C-F = 1.340 A, and LFCF = 108.4", bothbond distances being 0.012 fi longer than Bowen's 69 values.Otherwise,C-F distances fit into the established patterns for CF, groups: the CNdistance 67 of CF,.CN is 1.495 fi, significantly longer than the 1.458 & 0.005of methyl ~yanide.~Another cyanide investigated by electron diffraction is t-butyl cyanide;its isomer t-butyl isocyanide has been investigated '0 by microwave methods :57 F. L. Hirshfeld, K. Eriks, R. E. Dickerson, E. L. Lippert, and W. N. Lipscomb,J . Chem. Phys., 1958, 28, 56.68 E.L. Amma and R. E. Rundle, J . Amer. Chem. Soc., 1958, 80, 4141.69 (a) A. Zalkin and D. E. Sands, Acta Cryst., 1958,11, 615; (b) W. €3. Watson, jun.,and J. Waser, ibid., p . 689.60 G. Natta, P. Corradini, and I. W. Bassi, J . Amer. Chem. SOC., 1958, 80, 755.61 0. S, Mills, Acta Cryst., 1958, 11, 620.63 A. P. Cox, L. F. Thomas, and J. Sheridan, Nature, 1958, 181. 1157.63 D. E. Brown, Diss. Abs., 1958, 18, 2172; G. G. Shepherd and H. L. Welsh, J .64 R. G. Brown and T. H. Edwards, J . Chew. Phys., 1958, 28, 384.65 T. L. Weatherley, Diss. Abs., 1958, 18, 1469.66 J. J. Kristoff, ibid., p. 1997.67 R. E. Andersen, ibid., p. 50.68 C. H. Wong and V. Schomaker, J . Chem. Phys., 1958, 28, 1010.a9 H. J. M. Bowen, Trans. Faraday Soc., 1954, 50, 444.70 B.Bak, L. H. Nygaard, and J. R. Andersen, J . MoZ. Sfiectroscopy, 1958, 2, 54.Mol. Spectroscopy, 1957, 1, 277GRAY : MOLECULAR STRUCTURE AND MOLECULAR VIBRATIONS. 101bond lengths in these molecules are similar to those4 in the methyl com-pounds. Other t-butyl derivatives examined * are isobutane and t-butylfluoride; the C-F distance in the latter, 1.43 rf 0.2 A, is markedly longerthan in methyl fluoride. However, the molecules were studied40 with theaim of determining rotational barriers and this length (and that of the C-Cbond, 1.516 A) depend on assumed dimensions for the methyl groups.Notable determinations of thedimensions of ethylene and allene have been made by fine-structure analysisof vibration-rotation spectra. Allen and Plyler 71 find for ethylenero(C=C) = 1.337, r,(C-H) = 1.086 A, and LHCH = 117" 22'.There areno inconsistencies although four experimental quantities are available todetermine these three parameters : previous electron-diffraction and Ramanwork led to the results 1.334 and 1.3MA respectively for yo. For allene,Stoicheff's Raman work fixes ro(C=C) at 1.309 & 0.001 A and provides arelation between LHCH and r(C-H). Overend and Crawford's 72 newrotational analysis supplies the second relation fixing LHCH at 116" & 0-5"and r,(C-H) at 1.061 & 0.004; this bond length is significantly shorter(0.025 A) than in ethylene. Cyvin 72 has calculated vibration amplitudes forallene and [2H,]allene.Electron-diffraction studies have been made of the isomers cis-l,2-&-chloroethylene and 1, l-dichloroethylene and of the conjugated olefinsbuta-1 J3-diene,7* ~hloroprene,~~ and acryloyl ~hloride.'~ In the two di-chloroethylenes the experimental value of 1-33A for r(C=C) is markedlyshorter than that (1.38 A) assumed hitherto.The LClCCl in vinylidenedichloride, 114.5" &;lo, does not differ significantly from that in tetrachloro-ethylene.Acetylenic molecules are represented by propargyl chloride 77 and di-methyldia~etylene.~~ The single-bond length in propargyl chloride is1.458 A; in butadiene 74 it is 1.483 & 0.01 A, and in chloroprene 76 1.46 A.In dimethyldiacetylene an X-ray study of the solid leads to the bond dis-tances C-c, 1.199 A; CH,-C 1.466 A; and EC-G 1.375 A. A list of carbon-carbon triple bond lengths has been compiled by G~odwin.~~A vibrational analysis of 1,3,5-hexatriene is in accords0 with a planarstructure with the double bonds trans to one another, giving the molecule acentre of symmetry.(c) Cyclic compounds. A complete determination of the structure ofpyridine 81 has been made by microwave spectroscopy, isotopic substitution71 H.C. Allen and E. K. Plyler, J . Amer. Chem. SOC., 1958, 80, 2673.72 J. Overend and B. Crawford, J . Chem. Phys., 1958, 29, 1002; S. C. Cyvin, A d a73 C. C . W. Hoffman, Diss. Abs., 1958, 18, 420.74 A. Almenningen, 0. Bastiansen, and M . Tratteberg, Acta Chem. Scand., 1958, 12,76 P. A. Akishin, L. V. Vilkov, and V. M . Tatevskii, Doklady Akad. Nauk S.S.S.R.,76 T.Ukaji, Bzcll. Chem. SOC. Japan, 1957, 30, 737.77 E. Hirota, T. Oka, and Y . Morino, J . Chem. Phys., 1958, 29, 444.'13 R. C. Himes, Diss. Abs., 1958, 18, 1619.7s T. H. Goodwin, J., 1958, 3893.8o E. R. Lippincott, C. E. White, and J. P. Sibilia, J . Amer. Chem. Soc., 1968,80,2926.B. Bak, L. H. Nygaard, and J. R. Andersen, J. Mol. S@ectroscopy, 1958, 2, 361.(b) Substituted olefins and acetylenes.Chem. Scand., 1958, 12, 233; J . Chem. Phys., 1958, 29, 583.1221.1958, 118, 117102 GENERAL AND PHYSICAL CHEMISTRY.being used for both C and H in every position to derive accurately the tengeometrical parameters of the molecule. The carbon-carbon bond lengthsare identical at 1.3944 or 1.3945 A; the carbon-nitrogen distance is 1.3402 Aand the nitrogen angle 116' 50'.The bond lengths so found had been pre-viously predicted by Cumper 82 on the basis of a correlation between lengthsand angles dependent on hybridization: the errors of the prediction areconcentrated in the region of the nitrogen atom.A new, precise electron-diffraction study 83 of 1,3,5,7-cyclo-octatetraeneconfims Hedberg and Schomaker's results and disagrees with Bastiansen'sprevious work: the D 2 d (tub) form is satisfactory in all respects.84 The bondlengths (A) and angles measured 83 are: C=C, 1.334 & 0.001; C-C,1.462 0.001 ; C-H, 1.090 & 0.005 A; LGC-C, 126.46 & 0.23"; LCzC-H,118.3" & 5.9". An empirical relation 85 between the length of the singlecarbon-carbon bond joining two trigonally hybridized carbon atoms and theinterplanar angle of the linked groups has been suggested.The newestvalues from cyclo-octatetraenes3 and butadiene74 do not appear to fit itperfectly.Bond lengths and angles in cyclopropyl chloride and cyanide have beenderived by Friend and Dailey 86 on the basis of an equilateral triangle withall C-H bonds equal. They find a carbon-chlorine distance (1.7780A)similar to that in unsaturated halides and they ascribe to this bond 4%double-bond and 23% ionic character. Other lengths (A) are: C-C in ring,1*5131A; LHCH, 114'36' in chloride and 115'35' in cyanide; C-CN,1.4679; E N , 1.1574 A.Hexaphenylbenzene has been examined 87 by electron diffraction. Asin 1,3,5-triphenylbenzene the peripheral rings are not coplanar. Theyoscillate to a rather limited extent (&lo") from the orthogonal.(a) Miscellaneous.Bond lengths have been obtained in the course ofdeterminations of rotational barriers in a number of species discussed inthe last section of this Report. Configurations of propene,88 n-propylchloride,sg and of the two substituted ethanes CF,Br.CHFCl andCFCl,CHCl, 91 have also been established. In propyl chloride the greaterstability of the gauche-form (azimuthal angle 59") is in accord with an electro-static attraction between the chlorine atom and the methyl group.Molecular Vibrations and Force Constants.-The arrangement followed issimilar to that of the previous section with the emphasis again on simplesystems. Torsional oscillations are considered in the next section.Allstretching force constants quoted are in lo5 dynes/cm. (millidyneslA) unlessotherwise stated.82 C. W. N. Cumper, Trans. Faraday Soc., 1958, 54, 1261, 1266.8* 0. Bastiansen, L. Hedberg, and K. Hedberg, J . Chem. Phys., 1957, 27, 1311.B4 I. J. Lawrenson and F. A. Rushworth, Nature, 1958, 182, 391.86 J. P. Friend and B. P. Dailey, J . Chem. Phys., 1958, 29, 577.87 A. Almenningen, 0. Bastiansen, and P. N. Skancke, Acta Chem. Scand., 1958,88 D. R. Herschbach and L. C. Krisher, J . Chem. Phys., 1968, 28, 728.88 Y. Morino and K. Kuchitsu, J . Chem. Phys., 1958, 28, 175.n1 R. E. Kagarise, J . Chem. Phys., 1958, 29, 680.D. Cook, J . Chem. Phys., 1958, 28, 1001.12, 1215.J. Lee and L. H. Sutcliffe, Trans. Faraday Soc., 1958, 54, 308GRAY : MOLECULAR STRUCTURE AND MOLECULAR VIBRATIONS.103Pistorius 92993 has carried out normalco-ordinate analyses for a number of species and derived expressions for theforce constants of the valence-force field in terms of the general force con-stants. The species examined are: square-planar X4 (D4h) ; pyramidalXYa (C4J; planar XY4 (Ddh); planar xY6 (&); octahedral xY6 (Oh);and tetrahedral Xq (Td) previously treated by Slater.93 Other species whichhave been treated recently are the square-pyramidal 94 M(XY)S (C,,) ;octahedral 95 M(XY)6 (Oh) ; and pentagonal-bipyramidal 96 M(XY)lo ( D 5 d ) .Apart from their formal value these treatments are of the greatest help incomparing the force fields in different molecules. Basically, two modes ofcomparison commend themselves: one based on general force constants ofthe same symmetry type and the other on, e.g., valence-force field constantsfor a particular bond.The first has the advantage of exactness : the secondthat these are the force constants which are successfully transferred frommolecule to molecule.A second-order sum rule, involving fourth powers of frequencies inisotopic molecules, has been deduced by Bigelei~en.~~ A freqency rule fornon-isotopic species has been applied 98 to CO,, COS, and CS, and to C2F4and C,Cl,; the rule corresponds to transferred general force constants ratherthan valence-force constants which are commonly used (see, e.g., prediction ggof v3 in CTe,).Wilson loo has described a method of determining the order of atoms in alinear molecule and isotopically substituted species from vibration frequenciesonly.Diatomic molecules.The influence of anharmonicity on vibrationalprobability density and mean amplitudes of vibration has been examined byReitan.lol Experimental work has been done on the vibration frequenciesin the Cl,+ ion l6 and in the isoelectronic radicals l7 C10, BrO, and 10. Inall these species, excitation leads to the expected decrease in the firmness ofbinding. Excited states of Cl,, Br,, and I, have also been examined l5 andnew bands of the P, molecule located.18 A comprehensive investigation ofhydrogen, deuterium, and tritium electronic-vibration spectra has beenpublished by Diecke: lo2 all six isotopic pairs have been examined and acatalogue of 100,000 lines compiled and analysed.A number of empirical correlations have been explored.Varshni lo3has made a full investigation of the correlations arising from Sutherland'sNormal co-ordinate analyses.C . W. F. T. Pistorius, 2. phys. Chem. (Frankfurt), 1958,16, 126; ibid., 17, 292;Mol. Phys., 1958, 1, 295; J . MoZ. Spectroscopy, 1958, 2, 287; J . Chem. Phys., 1958,29, 1328.9a N. B. Slater, Trans. Faraday SOC., 1954, 50, 207; C. W. F. T. Pistorius, J. Chem.Phys., 1958, 29, 1421.94 M. F. O'Dwyer, J. Mol. Spectroscopy, 1958, 2, 144.96 H. Murata and K. Kawai, J. Chem. Phys., 1957, 2'7, 605.96 E. R. Lippincott and R. D. Nelson, Spectrochim. Acta, 1958, 10, 307.97 J. Bigeleisen, J. Chem. Phys., 1958, 28, 694.S. Brodersen and A.Langseth, Acta Chem. Scand., 1958, 12, 1111.99 T. Wentinck, J. Chem. Phys., 1958, 29, 188.loo E. B. Wilson, Spectrochim. Acta, 1958, 12, 1.lol A. Reitan, Acta Chem. Scand., 1958, 12, 131.loa G. H. Diecke, J. Mol. Spectroscopy, 1958, 2, 494.lo* Y. P. Varshni, J . Chem. Phys., 1968, 28, 1078104 GENERAL AND PHYSICAL CHEMISTRY.potential formula u = a(r - d)" - b(r - d)* especially of the relationk&, - d), = A , where d and A are constants for each molecular group.A most interesting simple potential function has been suggested by Keyes 104for excited states of diatomic molecules. It requires knowledge only of(I) the Morse function for the ground state and (2) the fraction of valenceelectrons in the excited state occupying bonding orbitals.Agreement withexperimental values of a,' and r,' is very good but estimates of anharmoni-city and dissociation energies are cruder. In certain circumstances thefunction is itself a Morse curve and the relation to the bond order is plain (acorrelation which has been explored lo4 by Stevens).Triatomic molecules. (a) Linear molecules. Zero-order frequencies andthe four general force constants have been derived lo5 for N,O. In valence-force field terms, f" = 17-33, very similar to its value in the similarHN,; fN0 = 12.53; the interaction constant is 0.733 and the bending con-stant 0.66 x erg per radian. For carbon disulphide, Stoicheff'svibrational Raman work 22 leads to accurate zero-order frequencies (there isno Fermi resonance) and anharmonicity corrections.Absolute infraredintensities have been measured lo6 for v3 of CS, in both the gas and the liquidstate: the band in the liquid is twice as intense. In the ion CS2+ themeasured 25 vibration frequencies v1 = 617 or 631 cm.-l and v2 = 409.5 cm.-lare very little changed from the neutral molecule. Fundamental frequenciesin the higher members of the CS, family have been measuredg9 for CSe,,SCSe, and SCTe, and estimates made on the basis of uniform potential-energy functions of the v3 frequency in OCTe, SeCTe, and CTe,.In BeF,, BeCl,, and MgC1, bending and asymmetric stretching forceconstants have been located; lo7 the stretching force constants are close tothose in the corresponding diatomic BeX radicals.The ions NCO- and NCS- have been studied in the solid state.There isFermi resonance between v1 and 2v2 in the cyanate; lo* for the thiocyanate logfundamental frequencies and anharmonicity constants are derived. An in-teresting simplified treatment l1* of the vibrations of the UO, group in uranylcomplexes has been given : the assumption of a free linear group is a good one.Precise work on nitrogen dioxide continues :with a new determination of x , ~ all the zero-order frequencies and an-harmonicity constants of the general force field are determined.lll Invalency-force field terms, fd = 10.927 f J d 2 = 1-125, f & = 2.038, andfdCL/d = 0.390.Among partial vibrational assignments are the identification of two ofthe fundamentals of SiF, 27 and of HNO in its ground and excited 29 states.(b) Angular molecules.The high value of the interaction constant fa is notable.104 R.W. Keyes, J . Chem. Phys., 1958, 29, 523; B. Stevens, Spectrochim. Acta,lo5 G. &I. Begun and W. H. Fletcher, J . Chem. Phys., 1958, 28, 414.Io6 P. N. Schatz, ibid., 1958, 29, 959.lo7 A. Biichler and W. Klemperer, ibid., p. 121.lo* A. Maki and J. C. Decins, ibid., 1958, 28, 1003.Io9 L. H. Jones, ibid., p. 1234.1958, 12, 154.L. H. Jones, Spectrochim. Acta, 1958, 10, 395.E. T. Arakawa and A. H. Nielsen, J. Mol. Spectroscopy, 1958, 2, 413; J. W.Keller and A. H. Nielsen, J . Chem. Phys., 1958, 29, 252; G. R. Bird, A. Danti, andR. C. Lord, Spectrochim. A d a , 1968, 12, 247GRAY: MOLECULAR STRUCTURE AND MOLECULAR VIBRATIONS. 105The Renner effect 112 in the NH, radical has been further discussed.Aspeculative identification of the bending vibration (at 1114 or 1362 cm?)the iong-sought methylene radical has been suggested113 on the basis of a studyof the photolysis of diazomethane at low temperatures in a rigid medium.Vibrational assignments 32 have been made tofour excited states of acetylene: the v5 (nu) vibration of cyanogen has beenmore precisely located 11* at 235.0 cm.-l.Existing data on seven planar AX, (D3h) molecules (BF,, BCl,, BBr,,B033-, C0,2-, NO,-, SO,) have been used115 to evaluate all five forceconstants of the general quadratic force field. All comparisons show thestriking similarities of COZ2- and NO,-; although BO,,- is also isoelectronic,differences are apparent between it and the other two.New measurementsare reported 116 on boron tri-bromide and -iodide. The frequencies of car-bony1 chloride (planar AXY,) have been reassigned 117 and previous third-law entropy discrepancy reduced from 1.6 to 0.36 cal. deg.-l mole-l; forceconstants in nitryl fluoride and chloride have been discussed.llsAmong pyramidal AX, ((4 molecules, ammonia continues to receive 119detailed attention. Further work has also been done120 on the inversionspectrum of ND,. Thefundamental frequencies of the pyramidal trihalides PCl,, AsCl,, SbCl,, PBr,,and SbBr, have been measured122 (they lie in the 85-550 cm.-l range)and used to evaluate four of the general force constants. The expectedregularities are found in the series of chlorides, resistance to both stretchingand bending falling in the order P > As > Sb.A six-constant potentialfunction (valency-force field) has been derived for nitrogen trifluorideby combining experimental distortion constants with the four fundamentalfrequencies. In these terms,fd = 4.36 andfa/d2 = 1.92. The low permanentdipole moment of this interesting molecule owes its origin to opposing factors:these are differently affected123 by different vibrational modes and in fact&/&(D/A) takes the value 1.75 for class A, and 4.5 for class E vibration.The infrared and Raman spectra of chlorine trifluoride and brominetrifluoride have been investigated.124 All six fundamentals of ClF, havebeen assigned on the basis of CBU symmetry. The low-lying lA2 excitedstate of formaldehyde shows 39 sharply changed frequencies (except for C-Hstretching and CH, bending) from the ground state: bonding similar to thatin formic acid has been suggested.Tetratomic molecules.The v2 frequency 121 of PD, has been newly located.J.A. Pople and H. C. Longuet-Higgins, MoZ. Phys., 1958, 1, 372.113 G. C. Pimentel, J . Chem. Phys., 1958, 29, 1405.114 T. Miyazawa, ibid., p. 421.116 C. W. F. T. Pistorius, ibid., p. 1174.116 T. Wentinck and V. H. Tiensun, ibid., 1958, 28, 827.117 E. Catalan0 and K. S. Pitzer, J . Amer. Chem. SOC., 1958, 80, 1054.11s T. A. Hariharan, Proc. Indian Acad. Sci., 1958, 48, 49; L. Burnelle and J.11s W. S. Benedict, E. K. Plyler, and E. D. Tidwell, J . Res. Nut.Bur Stand., 1958,120 G. Hermann, J . Chem. Phys., 1958, 29, 875.121 W. M. Ward, Diss. Abs., 1958, 18, 1823.122 P. TV. Davies and R. A. Oetjen, J . Mol. Spectroscopy, 1958, 2, 253.123 P. N. Schatz, J . Chem. Phys., 1958, 29, 475, 481.lZ4 H. H. Claassen, B. Weinstock, and J. G. Malm, ibid., 1958, 28, 285.Duchesne, Nature, 1958, 182, 653.61, 123; J . Chem. Phys., 1958, 29, 829106 GENERAL AND PHYSICAL CHEMISTRY.Tetrahedral molecules. Methane (as CT, and CHT,) has been investi-gated 125 and the observations combined with existing data for CH, andCD, to calculate all the valence-force constants for the methanes. In thesetermsfd = 5.3985 andfdd = 0.0171. General force constants have also beenobtained 126 for the borohydride ion from a study of its Raman spectrum inliquid ammonia.Interest is added to these measurements by two theoreticalpapers 127 in which hydride vibration frequencies are calculated in speciessuch as NH,+, CH,, and BH,-. For the class E frequency the simple relation~ x ~ v , ~ = 92/6e2/32mrO3 (yo is length of bond) predicts frequencies with about5% error. In the two isoelectronic triads BH,-, CH,, NH,+, and AlH,-,SiH,, PH,+ the force constants of the A , mode have been compared.128There is a steady increase with increasing nuclear charge which is correlatedwith the simultaneous change in bond length.Fundamental frequencies of twenty-two tetrahedral species (mainlyhalides and oxyanions) have been collated 129 and used to derive five of thegeneral valence-force constants.A similar collection of data, together withsome new determination^,^^^ has been made by Woodward 128 and used toinvestigate the systematic variations in the force constant of the A , mode.Among the halides the following six isoelectronic families have been in-vestigated: AlCl,-, SiCl,, PC14+; ZnX,,-, GaX,-, GeX, where X = C1, Br,or I ; CdX,2-, InX,-, and SnX, where X = Br or I. Whether the valence-force constant or the symmetry-force constant of the A , mode is used thesame generalization emerges that there is an increase in force constant withincreasing nuclear charge and a simultaneous shortening in bond length.When the two oxides families: PO:-, SO:-, ClO,-, and WO,2-, ReO,-,OsO, are examined the correlation is not found. In the former triad,phosphate and sulphate are closely similar to one another; perchlorate isless tightly bound. A re-identification 131 of the fundamentals of the chro-mate ion CrO,,- ( T d ) has been made and used to derive two sets of four outof five possible general force constants.Molecules of similar arrangement but lower symmetry which have beenexamined are SiD,I for which a complete assignment 132 has been made,CH,F and CH,Cl (all C,); chromyl fluoride and bromide (C2J for whichall nine fundamentals are assigned; and sulphuryl bromofluoride 135 (CJ.Complete vibrational assignments and force-constant calculations have alsobeen made 138 for CHC1,F and CHF,Cl and their deuterium derivatives (CJ.Pistorius 137 has collected data for fifteen fluorides Octahedral molecuules.125 L.H. Jones and M. Goldblatt, J . M d . Spectroscopy, 1958, 2, 103.126 A. R. Emery and R. C. Taylor, J . Chem. Phys., 1958, 28, 1029.lZ7 H. Hartmann and G. Gliemann, 2. phys. Chem. (Frankjwt), 1958, 15, 108;12s C. W. F. T. Pistorius, J . Chem. Phys., 1958, 28, 514.130 L. A. Woodward and G. H. Singer, J.. 1958, 716.131 H. Stammreich, D. Bassi, and 0. Sala, Spectrochim. Acta, 1958, 12, 403.la2 H. R. Linton and E. R. Nixon, Sfiectrochim. Acta, 1958, 12, 41.133 C. Tanaka, J . Chem. SOC. Japan, 1958, 79, 686.13* W. E. Hobbs, J . Chem. Phys., 1958, 28, 1220.T. I. Crow and R. I. Lagemann, Spectrochim. Acta, 1958, 12, 143.136 H. B. Weissman, A. G. Meister, and P. C. Cleveland, ibid., p. 72.13' C. W. F. T. Pistorius, J .Chem. Phys., 1968, 29, 1328.D. A. Brown, J . Chem. Phys., 1958, 29, 451.L. A. Woodward, Trans. Faraday SOC., 1958, 54, 1217GRAY: MOLECULAR STRUCTURE AND MOLECULAR VIBRATIONS. 107and chlorides of formula MX, (Oh) and calculated six of the seven generalforce constants. In the triad SF, (775), SeF, (710), TeF, (697) the frequen-cies (cm.-l) of the Al, mode show a uniform decrease in force constant;similar trends are present in the data for WF, (770), ReF, (753), OsF, (notgiven), IrF, (696), and for UF, (666), NpF, (648), PuF, (626), though all thechanges are relatively small.The carbonyls and cyanides share thegeneral formula M(AB),: representatives of the classes n = 4, 5, and 6 havebeen investigated this year. Vibrational assignments have been made 138~139for the isoelectronic tetrahedral group Ni(CO),, Ni(CN),4-, and CU(CN)*~-and force constants evaluated.The numerical values13* accord with anormal single nickel-carbon bond in nickel carbonyl.Alternative assignments and force constants, based on square-pyra-midal 94 (C4 or trigonal-bipyramidal95 ( D 4 structures for iron penta-carbonyl, have been suggested : the structure remains 94,95~140 in dispute.Fairly complete Raman spectral investigation has been made 141 of thehexacarbonyls of chromium, molybdenum, and tungsten ; the analogouscyanides of chromium and ruthenium have been studied142 by infraredtechniques, and the force constants of Cr(CN)z- and Cr(CO), compared. Allthese have symmetry Oh.Ferrocene and ruthenocene can be represented as M(AB),, with sym-metry D5d: a detailed account 143 of their spectra has been published.Anexamination of frequencies in thallium and magnesium cyclopen tadien ylshas been interpretedIn the set of tetramethyls [M(AB,),, Td] of carbon, silicon, germanium,tin, and lead 145 the metal-carbon force constants fall regularly from carbonto lead. The nickel derivative, Ni(PF3)4, has a nickel-phosphorus forceconstant consonant with a normal single bond.146Complex molecules lie outside the scope of thisReport but attention is drawn here to some isolated examples, to the fieldsof amide derivatives 14' and silicon compounds148 in which a number ofMetal carbonyls and cyanides.as favouring ionic bonding: Tl+(C,H5-).Polyatomic molecules.la8 L.H. Jones, J. Chem. Phys., 1958, 28, 1215; 1958, 29, 463.la* M. F. El Sayed and R. K. Sheline, J. Amer. Chem. SOC., 1958, 80, 2047.140 W. G. Fateley and E. R. Lippincott, Spectrochim. Acta, 1957, 10, 8 ; F. A.Cotton, A. Danti, J. S. Waugh, and R. W. Fessenden, J. Chem. Phys., 1958, 29, 1427.141 A. Danti and F. A. Cotton, ibid., 1958, 28, 736.142 V. Caglioti, G. Sartori, and M. Scrocco, A t t i Accad. naz. Lincei, 1957, 23, 359;G. B. Borino and G. Fabbri, ibid., p. 191.14a E. R. Lippincott and R. D. Nelson, Spectrochim. A c f a , 1958, 10, 307.144 F. A. Cotton and L. T. Reynolds, J. Amer. Chenz. SOC., 1958, 80, 269.146 D. N. Waters and L. A. Woodward, Proc. Roy. SOC., 1958, A , 246, 119.146 L. A. Woodward and J . R. Hall, Nature, 1958, 181, 831.A.Yamaguchi, T. Miyazawa, T. Shimanouchi, and S. Mizushima, S$ectrochim.Acta, 1957, 10, 170; T. Shimanouchi and S. Mizushima, ibid., 1958, 12, 253; T. Miya-zawa, T. Shimanouchi, and S. Mizushima, J. Chem. Phys., 1958, 29, 611; A. E. Parsons,J. Molec. Spectroscopy, 1958, 2, 566; W. J . 0. Thomas and A. E. Parsons, ibid.. 1958,2, 203; Trans. Faraday SOC., 1958, 54, 460; M. Davies and W. J. Jones, ibid., 1958, 54,1454; J., 1958, 955; M. Davies and N. Jonathan, Trans. Faraday SOC., 1958, 54, 469.14* R. C. Lord, D. W. Mayo, H. E. Opitz, and J . S. Peake, Spectrochim. A d a , 1958,12, 147; H. R. Linton and E. R. Nixon, ibid., 1957, 10, 299; J . Chem. Phys., 1958, 28,990; 1958, 29, 921; R. F. Curl and K. S. Pitzer, J. Amer. Chem. SOC., 1958, 80, 2371;J.Goubeau and J. Reyhling, 2. anorg. Chem., 1958, 294, 92, 96; H. Kriegsmann, ibid.,1958, 294, 113108 GENERAL AND PHYSICAL CHEMISTRY.complete or nearly complete assignments have been made, and to a review 149of valence bonding in nitrogen compounds.Among the most remarkable vibrational assignments are those made byFateley et al. in work 150 on the nitrogen oxides; by condensing the freshlyformed molecules in a matrix on a cold surface they have been able to isolateand identify nitric oxide dimer, nitrous anhydride as ON-NO, and ON-0-NO,dinitrogen tetroxide as 02N*N02 and ON*O*NO,, and covalent dinitrogenpentoxide 02N*O*N02. A tentative identification is made of the D 2 d formof N20,.Vinyl fluoride and its seven deuterated derivatives have been studied 151and eight of the twelve vibrations assigned.Diborane has been investi-gated 152 as 1°B2H6, 11B2H6, "B2D6, and 11B2D6 and as B2H,D and B2D,H.Incompletely deuterated mixtures contain all twenty-one possible forms anddata thus require disentanglement. Assignments 152 on the basis of D2ksymmetry together with non-crossing and product and sum rules are satis-factory .For the isoelectronic molecules BF,*NH, and SO,*NH, (the zwitterionof sulphamic acid) complete vibrational assignments have been made.In SO,*NH,, force constants of the Urey-Bradley potential are 2.2 forsulphur-nitrogen and 7.5 for sulphur-oxygen stretching. The correction lMof an error completes the assignment for the similar molecule c2F6.Potential-energy Barriers to Internal Rotations.-Methods of measuringthe size of the energy barrier to internal rotation have become more diverseand more precise.The original '' entropy deficit " method has been supple-mented by measurements of specific heat, of torsional frequencies by spectro-scopy, of torsional amplitudes by electron diffraction, of nuclear magneticresonance spectra, of the dispersion and absorption of ultrasonics, and ofline splittings and intensities. The cosine form of the potential-energybarrier remains the basis of all estimates of barrier size: so far as the originsof the barriers axe concerned theory has not kept pace with experiment.Some general aspects of the origins of barriers and some values of barriersmeasured by various techniques6 have been recently published.In thisReport barrier heights are given in cal./mole.Lide156 has re-viewed the spectroscopic data for torsional frequencies in ethane: thebarrier which they imply (3030 & 300) is less precise than that from calori-metry which remains the " best " value at 2875 & 125. In propene theRotation of methyl groups abozzt carbon-carbon bonds.149 W. J. 0. Thomas, Chem. Rev., 1957, 51, 1179.150 W. G. Fateley, H. A. Bent, and B. L. Crawford, Symposium on Free Radicals,151 B. Bak and D. Christensen, Spectrochim. Acta, 1958, 12, 355.152 R. C. Taylor and A. R. Emery, ibid., 1958, 10, 419; W. J. Lehmann, J. F.Ditter, and I. Shapiro, J . Chem. Phys., 1958, 29, 1248.153 J. Goubeau and H. Mitschelen, 2. phys. Chem. (Frankfurt), 1958, 14, 61; I.Nakagawa, S. Mizushima, A. J. Sarceno, T. J. Lane, and J. V. Quagliano, Spectrochim.Acta, 1958, 12, 239.154 I. M. Mills, W. B. Person, J. R. Scherer, and B. Crawford, J . Chem. Phys., 1958,28, 851.L. Pauling, PYOC. Nut. Acad. Sci. U.S.A., 1958, 44, 211; H. Eyring, G. H.Stewart, and R. P. Smyth, ibzd., p. 259.San Francisco, 1958.15* D. R. Lide, J . Chem. Phys., 1958, 29, 1426GRAY MOLECULAR STRUCTURE AND MOLECULAR VIBRATIONS. 109barrier is 2000 cal./mole; when, in acetaldehyde,157 the CH, group is re-placed by an 0 atom, the barrier (now determined by three methods) has avalue of 1130 cal./mole.Substitution of halogen atoms on the carbon atom attached to therotating methyl group does not alter the barrier vastly from its value inethane. Thus, in ethyl fluoride values found by three spectroscopicmethods 157~159 are all close to 3300 cal./mole; in ethyl chloride and bromidethey are 3400 and 2800. Even in the triply-substituted molecules160l,l,l-trifluoro- and -trichloro-ethane the barriers remain at 3000 and 2900cal./mole respectively. In isobutane and in t-butyl fluoride the barriers *Oare higher : 3900 and 4300 cal./mole respectively.In theseries CF3*CH,C1, CF,-CHCl,, and CF3*CCl, study 160 of torsional oscillationfrequencies leads to barrier heights of about 6000 cal./mole. In hexa-chloroethane electron diffraction 161 suggests a high barrier, 10,800 cal./mole.These figures are in sharp distinction to those suggested by Lamb andKrebs,lG2 who studied symmetrical tetrabromoethane and reported barrierheights of only 1800 cal./mole above the more stable (gauche) form. In1,2-dibromoethane the torsional frequency has been located at 188 ~ m . - ~ . ~ Rotation of methyl (and substituted methyL) groufis about other bonds. Inthe molecules CH3*SiHF2 and CH,*SiH2F barriers derived 164 from micro-wave measurements are 1255 and 1560 cal./mole; the barrier in methylsilaneitself is 1700 cal./mole, and increasing fluorination clearly lowers the resist-ance to rotation. All these barriers are lower than in the ethanes and thesame is true of the fully chlorinated derivatives. In the series C,Cl,,CCl,SiCl,, Si,C1, barriers are 10,800, 4300, and only 1000 cal./mole re-spectively.161A similar relation exists between trimethylamine 4O with its barrier of4400 (from microwave measurements) or 4270 (from specific heats), similarto that in isobutane40 and trimethylphosphine40 with a barrier of 2600cal./mole. In tri-n-butylamine, ultrasonic measurements 162 lead to abarrier height of 5200 cal./mole. Torsional oscillation frequencies of di-methyl ether have been located 165 at 164 cm.-l (A,) and 265 cm.-l (&);implied barriers are not given.In hydrogen peroxide an assumed potentialZv(0) = vl(l + cos 0) + v,(l + cos 20) has been used to interpret the infra-red absorption spectrum.166 The double-minimum potential corresponds toa barrier 1290 cal./mole above the cis-form and 590 cal./mole above trans.In propylene oxide it is 2560 cal./mole.Rotation of substituted methyl groups about carbon-carbon bonds.Rotation of other groups.15' P. H. Verdier and E. B. Wilson, J . Chem. Phys., 1958, 29, 340.168 D. R. Herschbach and J. D. Swalen, ibid., p. 761.15s E. Catalano and K. S. Pitzer, J. Phys. Chem., 1958, 62, 873.160 E. Catalano and K. S. Pitzer, ibid., p. 838; K. S. Pitzer and J. L. Hollenberg,161 Y. Morino and E. Hirota, J . Chem. Phys., 1958, 28, 185.162 K. Krebs and J. Lamb, Proc. Roy. SOC., 1958, A , 244, 558.I. Ichishima, H. Kamiyama, T. Shimanouchi, and S. Mizushima, J. Chem. Phys.,164 J . D. Swalen and B. P. Stoicheff, ibid., 1958, 28, 671; L. Pierce, ibid., 1958, 29,166 Y. Mashiko and K. S. Pitzer, J. Phys. Chem., 1958, 62, 367.lB6 E. Hirota, J. Chem. PhysJ . Amer. Chem. Soc., 1953, 75, 2219.1958, 29, 1190.383.1958 28, 839110 GENERAL AND PHYSICAL CHEMISTRY.In methyl nitrite, the nitrosyl group rotates about the C-0 bond.Entropy measurements correspond l67 to a barrier height of 7800 cal./molein the gas phase where the cis-form is more stable; in the liquid trans pre-dominates. An interpretation in terms of double-bond character is con-sistent with the absence of a barrier in methyl nitrate.In ethyl formate 168 measurements of sound absorption and dispersionlead to barriers 3380 cal./mole above the higher state.P. G.J. C. BEVINGTON.M. FLEISCHMANN.P. GRAY.J. W. LINNETT.I. M. MILLS.K. R. OLDHAM.J. E. PRUE.B. STEVENS.A. F. TROTMAN-DICKENSON.167 P. Gray and M. W. T. Pratt, J . , 1958, 3403.168 D. Tabuchi, J . Chem. Phys., 1958, 28, 1014

ISSN:0365-6217    

DOI:10.1039/AR9585500007

出版商:RSC    

年代:1958

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INORGANIC CHEMISTRY1. INTRODUCTIONTHE Report follows the pattern adopted in the last two years. The elementsare subdivided into main groups and transition elements, according to thelong form of the Periodic Table. Section 2 deals systematically with thechemistry of the elements in the main groups, and Section 3 is concernedwith the chemistry of the transition elements. Co-ordination chemistryis reviewed at the beginning of Section 3.The report of the International Commission on Atomic Weights has beenpublished. The Commission met in July 1957 and agreed that no changeswould be recommended in the values for atomic weights approved byI.U.P.A.C. in 1955 (see Annual Reports for 1956, p. 83). However, thereare four anisotopic elements for which values derived from physical measure-ments are regarded by the Commission as more accurate than the valuesgiven in the 1955 table.These elements, with atomic weight values fromphysical measurements, are arsenic (74.92), yttrium (88*91), praseodymium(140.91), and bismuth (208.99). Differences are small, but should be takeninto account in work of high accuracy. Serious consideration was also givento the choice of a unified scale for atomic weights, to replace the two oxygenscales. A scale based on the exact number 12 as the assigned mass ofcarbon-12 appears to offer the best promise of acceptance.l The I.U.P.A.C.Commission on Inorganic Nomenclature at its 1957 meeting adopted thesymbol Ar * for argon and Md for mendelevium. The Commission alsoadopted the names proposed by the discoverers for einsteinium (Es), fermium(Fm), and nobelium NO).^ A table (320 pp.) has been published listing allthe radioactive and stable isotopes of the elements, together with a numberof their salient features, and is complete to February, 1958.2Reviews have been published on “ stereochemistry of inorganic mole-cules and complex ions,” “ high-temperature chemistry,” * “ polarographyin non-aqueous solutions,” ‘‘ ortho-salts and maximum oxygen co-ordination,” ‘‘ inorganic high polymers,” and ‘‘ vibrational spectroscopyand its application in structural inorganic chemistry.’’ Other reviews ofa more specific character will be mentioned in context.The quantity of published work in inorganic chemistry has continuedto increase.In particular, there have been significant advances in the study12a227.4E. Wichers, J . Amer. Chem. Soc., 1958, 80, 4121; J. Mattauch, ibid., p. 4125.D. Strominger, J. M. Hollander, and G. T. Seaborg, Rev. Mod. Phys., 1958,80,585.R. J. Gillespie and R. S. Nyholm, Progr. Stereochem., 1958, 2,.261.L. Brewer, X V I Internat. Congr. Pure Appl. Chem., Experaentaa Suppl. VII, 1967,V. Gutmann and G. Schiiber, Angew. Chem., 1958, 70, 98.R. Scholder, ibid., p. 583.H. Krebs, ibid., p. 615.J. B. Willis, Rev. Pure Appl. Chem. (Australia), 1958, 8, 101.* The Chemical Society has accepted this recommendation, and the symbol A forargon will no longer be used in its publications,-ED112 INORGANIC CHEMISTRY.of the organic derivatives of boron, silicon, and phosphorus which are notincluded in the Report.2.THE MAIN GROUPSGroup 1.-A monograph has been published on the occurrence and manu-facture of lithium and the uses of this metal, its alloys, and compound^.^The freezing point-composition curve of the system lithium-lithium hydrideresembles that of metal-metal halide systems. The f. p. of lithium hydrideis 668" & 1" and there is a monotectic at 685" & 1" between 26 and 98 molesyo of the hydride.1° Accurate values for the heats of formation of thecrystalline hydrides of lithium, sodium, and potassium have been measuredand compared with the corresponding values for the deuterides, the slightdifferences between the hydrides and deuterides being discussed on the basisof terms involved in the classical calculation of electrostatic lattice energies.llThe complex Na[PhLiPh] has been known for some years; others arenow reported in which sodium is replaced by potassium or czesium and theorganic radical is a methyl, n-butyl, phenyl, or para-substituted phenylgroup.The preparations, carried out in ether, follow the sequence R,Hg +Li __t RLi; RLi + R,Hg + Na -+ Na[R,Li]. Of the compounds in-vestigated, (di-n-butyl-1ithium)sodium proved to be the strongest metallat-ing agent.12There is continued interest in the molecular composition of alkali halidevapours (see last year's Report, p. 96) and work has been extended to thehydroxides. The relative abundance of polymeric species in the vapourabove alkali fluorides was determined by an analysis of the velocitydistribution of the molecules effusing from an isothermal enclosure. Theabundance of dimers at a given pressure decreased from lithium fluoride tocaesium fluoride, and the dissociation energies of the dimers decreased in thesame direction (LiF 58.9, NaF 54.3, KF 47.6, RbF 42.0, CsF 37.8 kcal. mole-l).The trimer of lithium fluoride was observed and had l3 a dissociation energyof 38.3 kcal.mole-l. Similar results were obtained for the alkali-metalchlorides by mass-spectrometric analysis,14 and theoretical calculationsagree substantially with experimental results for all the gaseous alkali-metalhalides15 Sodium and potassium hydroxides vaporize mainly as dimersin the temperature range 300--450", and energies of dimerization l6 in thegas are 54 and 49 kcal.molew1, close to those obtained for the fluorides. The10 C. E. Messer, E. B. Damon, P. C. Maybury, J. Mellor, and R. A. Searles, J . Phys.Chem., 1958, 62, 220.11 S. R. Gunn and L. G. Green, J . Amer. Chew. Soc., 1958, 80, 4782; see alsoA. F. le C. Holding and W. A. Ross, J . APpZ. Chem., 1958, 8,321. *12 G. Wittig and F. Bickelhaupt, Chem. Ber., 1958, 91, 865; see also G. Wittig andE. Benz, ibid., p. 873.M. Eisenstadt, G. M. Rothberg. and P. Kusch, J . Chem. Phys., 1958, 29, 797;see also A. C. P. Pugh and R. F. Barrow, Trans. Faraday Soc., 1958, 54, 671.14 T. A. Milne, H. M. Klein, and D. Cubicciotti, J . Chem. Phys., 1958, 28, 718;J. Berkowitz and W. A. Chupka, ibid., 1958, 29, 653.16 T.A. Milne and D. Cubicciotti, ibid., p. 846.16 R. F. Porter and R. C. Schoonmaker, ibid., 1958, 28, 168; idem, ibid., p. 454;idem, J . Phys. Chem., 1958, 62, 234; see also L. H. Spinar and J. L. Margrave, Spectro-chim. Actu, 1958, 12, 244.D. S. Laidler, Roy. Inst. Chem. Monogvaphs, 1957, No. 6ADDISON AND GREENWOOD: MAIN GROUPS. 113vapour above a fused mixture of sodium and potassium hydroxides containsthe species NaK(OH), in addition to monomers and dimers of the individualhydroxides. The stability of the mixed dimer is intermediate betweenthose of its component dimes1'Finely divided casium reacts with carbon dioxide at 0" to give a blue-black compound of empirical formula Cs2C0,. The compound hydrolysesto an equimolar mixture of cEsium fonnate and caesium hydroxide andevidence is adduced in favour of its formulation as the czsium salt ofcaesioformic acid, Cs*CO,H.lsGroup 11.-Beryllium oxyacetate, Be,O(OAc) 6, in boiling methanol splitsout acetic anhydride intermolecularly to form the methanol adduct of anon-stoicheiometric polymer of approximate composition [Be,O,(OAc)~,-,,~],where m > 2.4 and n > rn.Other aliphatic and cyclic alcohols and alsopyridine induce a similar reaction and heterogeneous, often gelatinousmixtures of beryllium oxyacetate and the alcohol or pyridine adduct of thehigher basic acetates are slowly precipitated on co01ing.l~ Berylliumoxypropionat e , oxychloroacet ate, and oxybromoacetate, Be,O (RCO,) ,(R = Et, CH,Cl, CH2Br) behave analogously.20 An independent study ofthe reaction of beryllium oxyacetate with methanol and ethanol claims thatalcoholysis occurs to give the compounds Be(0R)OAc ; with butanol therewas also a polymeric product, formulated as ~B~(OH)OAC,B~(OBU)OAC.~~Basic beryllium pivalate, acrylate, phenylacetate, and pentapropionatehave been prepared and characterized.22 When two monobasic carboxylgroups are replaced by carboxyl groups of dibasic acids, chain polymers oflow molecular weight are obtained.nBe,O(OCO*R), + nR'(COCI), __jc 2nReCOCI + -[Be40(0*C0.R)aX]n-The monobasic groups RCO, were acetate, propionate, and benzoate, andthe dibasic acyl chlorides R'(COCl), were sebacoyl, adipoyl, terephthaloyl,and isophthaloyl.The compounds were thermally stable-0 at 400" and did not hydrolyse but there was a tendency/'- for the linear polymers to disproportionate into mono-\ meric basic beryllium carboxylates and cross-linkedpolymers -[(Be,0)X3J-.22 -0(1) x The compound formed between magnesium andacetylene in liquid ammonia has been shown to betriammineacetylenemagnesium carbide, MgC2,C2H2,3NH,.23 At 2600-2750'silica and calcium metasilicate both react with fused calcium carbide togive silicon carbide, and alumina gives aluminium carbide A&; above2850" calcium sulphide reacts with carbon to give calcium carbide.%Dimethyl-calcium, -strontium, and -barium have been prepared froml7 R.F. Porter and R. C. Schoonmaker, J. Phys. Chem., 1958, 62, 486.I* H. D. Hardt, 2. anorg. Chem., 1957, 292, 53, 224 257.2o Idem, ibid., 1957, 293, 47.21 A.I. Grigor'yev, A. V. Novoselova, and K. N. Semenenko, Zhur. neorg. Khim.,22 C . S . Marvel and M. M. Martin, J. Amer. Chem. SOC., 1958, 80, 619.2p R. Juza and K. Biinzen, 2. anorg. Chem., 1958, 295, 334.\,C- RLCL. Hackspill and R. Setton, Compt. rend., 1958, 246, 2430.1957, 2 2067.E. L. Lippert and M. R. Truter, J., 1958, 2636114 INORGANIC CHEMISTRY.the metals and methyl iodide under an atmosphere of helium followed byrepeated extraction of the iodine with pyridine. The compounds areunchanged in a vacuum up to 400" but hydrolyse readily and becomeincandescent when exposed to oxygen or carbon dioxide.25Barium chloride nitride, Ba2NCl, was obtained by fusing an equimolarmixture of barium chloride and barium nitride.On a phase diagram thecompound is seen as a melting-point maximum at 965". The correspondingcalcium compound was prepared similarly but strontium chloride and nitridefailed to react. Barium chloride nitride was decomposed by cold water butthe calcium compound required hot mineral acid for noticeable hydrolysis.26Group 111.-The chemistry of Group I11 continues to expand rapidly andconsiderable advances have been reported in the preparation of new com-pounds of boron and in the determination of structures and stabilityrelations of several compounds of boron, gallium, and indium. Recentlines of development in the chemistry of boron have been reviewed.27A study of the thermodynamic data for the chlorides of Groups I11 andIV suggests that it is misleading to interpret the instability of thallium(II1)and lead(1v) on the basis of the so-called inert-pair effect and that thcdecreasing stability of the group valency is more correctly attributed to aprogressive decrease in the covalent bond strength with increasing atomicnumber in each group.% Stability relations among analogous molecularaddition compounds of the Group I11 elements have been extensivelyreviewed,29 and the stability of complexes of a series of boron esters withpyridine, ammonia, and the ethylamines has been qualitatively related toback co-ordination from oxygen to boron in the acceptor moiety.30Boron.A new crystalline modification of boron is obtained by pyrolysisof boron tri-iodide on a surface at 800-1000".The rhombohedral crystalsare red and have 12 atoms (one icosahedron) in the unit cell, the icosahedrabeing held in slightly deformed cubic close packing by two types of bond:half of the boron atoms in one icosahedron form conventional single bondswith atoms of other icosahedra and the other kind of bonding involvesequilateral triangles of boron atoms, each boron coming from a differenticosahedron. This new boron structure is therefore essentially that of theboron framework in the carbide B,&, with the difference that the omissionof the chain of three carbon atoms from the octahedral holes results in thecloser approach of the icosahedra and the formation of the new triangularb0nds.3~ This is structurally the simplest modification of boron yet prepared.Above 1500" it is transformed into the normal rhombohedral which,though it is the most easily prepared allotrope of this element, has by farthe most complicated structure and contains 108 atoms (9 icosahedra) in25 D.A. Payne and R. T. Sanderson, J . Amer. Chem. SOL, 1958, 80, 5324.26 P. Ehrlich and W. Deissmann, Angew. Chem., 1958, 70, 656.27 E. Wiberg, XVI Internat. Congr. Pure Appl. Chem., Experientia Supfil. VII,28 R. S. Drago, J . Phys. Chem., 1958, 62, 353.29 F. G. A. Stone, Chem. Rev., 1958, 58, 101; see also A. P. Kochetkova and V. G.SO E. W. Abel, W. Gerrard, M. F. Lappert, and R. Shafferman, J., 1958, 2895.31 L, V. McCarty, J. S. Kasper, F. H. Horn, B. F. Decker, and A. E. Newkirk, J .1957, 183.Tronev, Zhur. neorg.Khim., 1957, 2, 2043.Amer. Chem. SOL, 1958, 80, 2592ADDISON AND GREENWOOD: MAIN GROUPS. 115the unit cell.32 The structure of tetragonal boron has also been elucidated.The 50 boron atoms in each unit cell comprise 4 icosahedra and two individualboron atoms. Each icosahedral boron forms six bonds directed towardsthe comers of a pentagonal pyramid, five within the same icosahedron andthe sixth to an adjacent icosahedron or to an individual boron atom. Theresulting framework is continuous in threeA complete single crystal structure of hexaborane, B6H10, shows themolecule to have an approximately pentagonal pyramidal arrangement ofboron atoms [shown in planar projection in (2)]. There are four basalbridge hydrogen atoms and, like B5Hg and BloH14, the molecule has noBH, groups.%01Bt I0(3)01The topological theory of boron hydrides has been extended to includeions and it is predicted that, besides the known ions BH4- and B3H8-, themore stable polyborohydride ions 34 will be Bl2Hl,2-, B,oH142- (cf.BloH1,),BloHl,-, B&ll+, B,H,-, B6H62-, B5Hl0-, and B3H6'. In particular, theclose analogy of the filled molecular orbitals of B5H, with those of benzenesuggests the possible occurrence of B4H7- and B6Hll+ analogous to thecyclopentadienyl and tropylium ions C,H5- and C,H7+, the BH, group beingisoelectronic with the CH group. The expected structure of B,H,- is atrigonal pyramid (3), and B6H11+ is formed simply by adding a proton, H+,to the unoccupied basal bridge position of B6H10 (2).35A new polyhedron of boron atoms (4) has been found in octaboronoctachloride, B,C18, and each boron is joined by a single bond to a chlorineatom as in B,C14.36 Nuclear magnetic resonance establishes that themonoiodide, m.p. 53", and the monobromide, m. p. 34", of pentaborane,B5Hg, are substituted at the apex boron atom and that the monoiodide,m. p. 116" and monobromide, m. p. 105", of decaborane, B10H14, are alsoapex-substituted. A second monoiodide, m. p. 72", of decaborane, isprobably substituted at the B, position.37An ingenious semicontinuous process for preparing boron and siliconhydrides has been devised.= Applied to the preparation of diborane it32 J. L. Hoard, R. E. Hughes, and D. E. Sands, J . Amer. Chem. Soc., 1958,80,4507.s8 F.L. Hirshfeld, K. Eriks, R. E. Dickerson, E. L. Lippert, and W. N. Lipscomb,s4 W. N. Lipscomb, J . Phys. Chem., 1958, 62, 381.s5 Idem, J . Chem. Phys., 1958, 28, 170.s6 R. A. Jacobson and W. N. Lipscomb, J . Amer. Chem. SOL, 1958, 80, 5571.37 R. Schaeffer, J. N. Shoolery, and R. Jones, ibid., p. 2670.38 W. Sundermeyer and 0. Glemser, Angew. Chem., 1958, 70, 625.J . Chem. Phys., 1958, 28, 56116 INORGANIC CHEMISTRY.involves electrolysis of the molten lithium chloride-potassium chlorideeutectic (359") for 10 minutes a t 32 A followed by passage of hydrogenthrough the catholyte for 30 minutes to convert the liberated lithium metalinto lithium hydride. Boron trichloride is then passed through and givesdiborane in 40% yield. The cycle can be repeated indefinitely.Silicontetrachloride was quantitatively converted into silane, SiH,, and dimethyl-silicon dichloride gives dimethylsilane Me2SiH2.38 Sodium borohydride,though insoluble in diethyl ether, is readily soluble in diethylene glycoldimethyl ether (" diglyme ") and this solution, when dropped into a slightexcess of boron trifluoride-ether complex in the same solvent, gives aquantitative yield of diborane. This is the most convenient laboratorypreparation of diborane yet reported.39 Boron trichloride reacts in a flowsystem with hydrogen during 30 seconds' contact with an aluminium-coppercatalyst at 450" to give a 54% yield of diborane. Both boron trichlorideand diborane were conveniently stored by adsorption on to activatedcharcoal a t 0" but desorption by pumping was not quantitative.40Several high-yield interconversions of the boranes have been reported.A hot-cold tube technique has been developed for quantitatively convertingdiborane into a mixture of tetraborane and B,H,,.Under appropriateconditions either a 95% yield of tetraborane or a 70% yield of B5H11 can beobtained, these yields being higher than any previously reported for thesecompounds.41 Decomposition of diborane in a silent discharge at 15 kv inthe presence of helium produces 40% of B,H,,, 20% of B5H,, 30% of B5H11,and smaller amounts of B6H10 and B9H15. About half the diborane usedwas transformed after three cycles.42 B5H,! has been converted intotetraborane, B5Hg and hexaborane. Hydrolysis for one minute at 0" gavetetraborane almost quantitatively: B5H11 + 3H,O --t 2H2 + B(OH), +B,H,,.Treatment with bisdimethylaminoborine, (Me,N),BH, at lowtemperatures gave 50% conversion into B5Hg and also 3.6% of B6Hlo; thisrepresents the most efficient preparation of the rare hexaborane yet reported.Tetraborane a t -78" formed a 1 : 1 adduct with bisdimethylaminoborine,which, when held at -15", gave 25% conversion into B5H,,& Decaboranehas less thermal stability than was previously supposed and is rapidlypyrolysed at 200" to a non-volatile polymer of approximate compositionIn a closely reasoned set of papers, the diborane diammoniate has beenshown not to contain the ammonium ion, as implied by the formulationNH,+[(BH,),NH,]-, but to contain the borohydride ion; its structure 45(BH10)X.3O H.C. Brown and P. A. Tierney, J . Amer. Chem. SOC., 1958, 80, 1552.40 V. I. Mikheyeva and T. N. Dymova, Zhur. neorg. Khim., 1957, 2, 2530, 2539.dl M. J. Klein, B. C. Harrison, and I. J. Solomon, J. Amer. Chem. SOL, 1958, 80.42 W. V. Kotlensky and R. Schaeffer, ibid., p. 4517.43 J. L. Boone and A. B. Burg, ibid., p. 1519.44 B. Siege1 and J . L. Mack, J. Phys. Chem., 1958, 62, 373.45 D. R. Schultz and R. W. Parry, J . Amer. Chem. SOC., 1958, 80, 4; S. G. Shoreand R. W. Parry, ibid., pp. 8, 12; R. W. Parry and S. G. Shore, ibid., p. 15; S . G.Shore, P. R. Giradot, and R. W. Parry, ibid., p. 20; R. W. Parry, G. Kodama, andD. R. Schultz, ibid., p. 24; see also R. W. Parry, D. R. Schultz, and P. R.Giradot,ibid., p. 1; J. R. Weaver, S. G. Shore, and R. W. Parry, J. Chem. Phys., 1958, 29, 1.4149ADDISON AND GREENWOOD: MAIN GROUPS. 117is [(NH,),BH,] +BH,-. Reaction of diborane with ammonia thereforeresults in unsymmetrical cleavage (BH2+ + BH,-) in contrast to thesymmetrical cleavage (BH, + BH,) which results from reactions withamines. The monomer BH,-NH, was made by reaction of an ammoniumhalide with a borohydride (including diborane diammoniate) : MBH, +NH,X _+ MX + BH,*NH, + H,. The reactions of these and relatedcompounds have been studied extensively45 and the Raman spectrum ofdiborane diammoniate in liquid ammonia furnishes further evidence for thepresence of the borohydride i0n.46 Phase diagrams show that diethyl etherforms two complexes with diborane, the expected BH,,Et,O, m.p. -124",and also (BH,),,Et,O, m. p. -1126". Ethyl methyl ether forms only a 2 : 1complex (BH,),,MeOEt, m. p. - 139", whereas dimethyl ether, tetrahydro-furan, and tetrahydropyran form 1 : 1 c~mplexes.*~ Pressure-compositionisotherms indicate that lithium borohydride forms a 1 : 1 adduct withdimethyl, diethyl, and di-isopropyl ethers, and in addition the compoundsLiBH4,2Me,0, (LiBH,),,Me,O, and (LiBH,),,Et,O were established and theheats of dissociation of all six compounds determined.48Diborane reacts with the fluoro-derivatives of ethylene to give complexmixtures of products; fluorine is replaced by hydrogen in the ethylenes andboron appears mainly as BF,, EtBF,, Et,BF, and Et,B.49 Sodium boro-hydride dissolved in tetraethylene glycol dimethyl ether reacts with vinyland ally1 bromides to give dialkyldiboranes in 70--80~0 e l d ; e.g., NaBH, +CH,=CHBr + NaBr + +Et,B,H,.Diborane and triphenylboron reactat 2 - 4 atm. and 40-100" to give diphenyldiborane, Ph,B,H,, and the samecompound can also be obtained by reducing phenylboron dichloride withlithium borohydride: PhBCl, + 2LiBH4 + 2LiC1+ QPh,B,H4 + B?H6.Diphenyldiborane and phenyl-lithium afford lithium phenylborohydride,Li[PhBH,], m. p. 5-9", and this forms 1 : 2 adducts with diethyl ether anddioxax6lDiborane forms 1 : 1 adducts with O-methylhydroxylamine, MeOeNH,,and its N-methyl derivatives MeOONHMe and MeOoNMe, ; their stabilityincreases with increasing methylation but all evolve hydrogen and formpolymers above their m.p., the decomposition being explosive at highertemperatures. The 1 : 1 addition compound between diborane and NN-di-methylhydroxylamine was also prepared by analogous compounds withhydroxylamine itself and N-methylhydroxylamine gave impure productswhich lost hydrogen explosively even at low temperature^.^^ The complexB2H,,P,H4 formed by the addition of diborane to diphosphine at -78" ismore stable to decomposition by elimination of phosphine than is diphosphine46 R. C. Taylor, D. R. Schultz. and A. R. Emery, J . Amer. Chem. Soc., 1958, 80, 27.47 H. E. Wirth, F. E. Massoth, and D. X. Gilbert, J . Phys. Chem., 1958, 62, 870.48 G. W. Schaeffer, T. L. Kolski, and D. L. Ekstedt, J . Amer.Chem. Soc.. 1957, 79,6912; T. L. Kolski, H. B. Moore, L. E. Roth, K. J. Martin, and G. W. Schaeffer, ibid.,1958,80, 549; J. J. Bums and G. W. Schaeffer, J . Phys. Chem., 1958,62, 380.49 B. Bartocha, W. A. G. Graham, and F. G. A. Stone, J . Inorg. Nuclear Chem.,1958, 6, 119.6o T. Wartik and R. K. Pearson, ibid., 1958, 5, 250.s1 E. Wiberg, J. E. F. Evans, and H. Noth, 2. Naturforsch., 1958, 13b, 263, 265.6r4 D. H. Campbell, T. C. Bissot, and R. W. Parry. J . Amer. Chem. Soc., 1958, 80,1649, 1868118 INORGANIC CHEMISTRY.itself, but when the reaction is carried out at room temperature both phos-phine and hydrogen are evolved, leaving a defective solid containing boron,phosphorus, and hydrogen. The analogous compIex with boron trifluoride,(BF3),,P2H4, eliminates 53 phosphine above -118".Pentaborane forms a series of non-volatile, liquid complexesB,H,,%R,NH (n = 2-45) with dimethylamine and diethylamine, andsolid complexes B,H,,BR,N with trimethylamine and triethylamine.Whenthese complexes are warmed above 0" a series of reactions occurs withevolution of hydrogen and the breakdown of the pentaborane molecule toform polymers.54 An inorganic Grignard reagent, BloH13MgI, is formedwhen decaborane reacts with magnesium iodide in ether. The compoundhydrolyses to decaborane and yields benzyldecaborane, m. p. 64.6", whentreated with benzyl chloride. The compound B,H,,(MgI), was alsoprepared.65B10H14 + MeMglB10H13Mg1 f HZoB1oH13Mgl + 2PhCHzCICH4 + B10H13Mg1BIOHIO $. Mgl*oHPhCH,*B,oH13 + MgCIz + PhCHZIBioH13Mgl f MeMgl + BioHiz(Mgl)Z + CH4The diphenylboronium cation Ph,B+ has been identified in a solutionof diphenylboron chloride in ethyl methyl ketone containing one equivalentof aluminium chloride: Ph,BCl + AlCl, + Ph,B+(solv.) + AlC14-.Thesolution was bright yellow and the ion is the boron analogue of the diphenyl-carbonium ion Ph,CH+.56 The vapour-phase reactions of trimethylboronwith water, hydrogen sulphide, ethylene glycol, and several ortho-substitutedphenols were investigated 57 at 200-340". A series of acyloxy-derivativesof boron have been preparedm and their infrared spectra reported.59 Auseful review of the infrared spectra of a large number of organoboroncompounds has been published and the frequencies of some characteristicgroups listed.60 The possible use of arylboronic acids in brain-tumourtherapy has stimulated renewed interest in the synthesis of thesecompounds.61Tri-N-alkyl-tri-B-chloroborazoles (Alkyl = Me, Et, Bun) were preparedsmoothly in 80% yield by the following sequence of reactions (illustratedG.J. Beichl and E. C. Even, J . Amer. Chem. SOC., 1958, 80, 5344.64 A. F. Zhigach, Ye. B. Kazakova, and I. S. Antonov, Zhur. obshchei Khim., 1957,65 B. Siegel, J. L. Mack, J. U. Lowe, and J. Gallaghan, J . Amer. Chem. SOC., 1958,66 J. M. Davidson and C. M. French, J., 1958, 114.57 D. Ulmschneider and J. Goubeau, Chem. Ber., 1957, 90, 2733.58 W. Gerrard, M. F. Lappert, and R. Shafferman, J., 1958, 3648; L. A. Duncanson,W. Gerrard, M.F. Lappert. H. F'yszora, and R. Shafferman, ibid., p. 3652; see alsoB. M. Mikhailov and N. S. Fedotov, Izvest. Akad. Nauk S.S.S.R., Otdel. khim. Nauk,1958, 857; B. M. Mikhailov and T. A. Shchegoleva, ibid., p. 860.60 M. F. Lappert, J., 1958, 2790, 3256; see also T. P. Povlock and W. T. Lippincott,J . Amer. Chem. SOL, 1958,80,5409.60 L. J. Bellamy, W. Gerrard, M. F. Lappert, and R. L. Williams, J.. 1958, 2412;see also H. R. Snyder, M. S. Konecky, and W. J. Lennarz, J . Amer. Chem. SOC., 1958,80, 3611.6 1 H. R. Snyder, A. J. Reedy, and W. J. Lennarz, ibid., 1958, 80, 835; L. Santucciand H. Gilman, ibid., p. 193; H. Gilman and L. 0. Moore, ibid., p. 3609.27, 1655.80, 4523ADDISON AND GREENWOOD MAIN GROUPS. 119by the methyl derivative) : MeNH, + BCl, + BCl,,MeNH, (m.p.126-128') in boiling chlorobenzene; BCl,,MeNH, + 2Me3N +2Me3NHC1 + *Me,N,B,Cl, (m. p. 153-156') in toluene suspension.The triethyl derivative melts at 55-57' and the tributyl at about 30'.62The three chlorine atoms in the trimethyl derivative can be successivelyreplaced by a variety of alkyl groups by use of the Grignard reaction.63Diboron tetrafluoride, B2F4, which (unlike B2C14) cannot be made byelectrical discharge through the trihalide, has now been prepared in excellentyield by fluorination of diboron tetrachloride with antimony trifluoride.It is a stable gas, m. p. -56", b. p. -34", which decomposes slowly at 200"and is chemically very similar to the chloride.@ The molecule 66 is planar,F,B-BF,. Yields of diboron tetrachloride were improved more thantenfold when a d.c.rather than an a.c. discharge was employed in thepreparationF6 and microwave excitation has also been suggested67 as ameans of stimulating the decomposition of the trichloride : 2BC13 _tB2C14 + Cl,. When a silent electric discharge was passed through borontribromide at low pressures, free bromine and a red solid (BBr), wereobtained, and when a glow discharge was used with argon as carrier theproducts were an amorphous powder BBT,,.,-~.~, the known liquid B,Br4,and the previously mentioned red solid (BBr),. The latter on ammonolysisgave @ the new white substance (B,NH),.The 1 : 1 and 1 : 2 addition compounds of boron trifluoride with heavywater have been prepared, and their properties compared with those of themono- and di-hydrates.Deuterium substitution raises the m. p.s by 5.0"and 5.1" respectively, this increase being greater than for any other isotopicpair of compounds yet reported. The influence of deuteration on electricalconductivity and viscosity is consistent with the view that the fused com-pounds are considerably ionized as D+[BF,*OD]- and D,O+[BF,*OD]- andconduct electricity by normal ionic migration rather than by a chainmechanism.68 Phase studies indicate that boron trifluoride not only formsthe familiar 1 : 1 ether complex but also a 3 : 1 adduct (BF,),,Et,O, m. p.-71'. Dimethyl and di-isopropyl ethers form only the known 1 : 1 com-plexes but ethyl methyl ether and methyl propyl ether form complexes withboth 1 and 2 mol.of boron trifluoride. The 2 : 1 and 3 : 1 complexes areless stable than the 1 : 1 but all melt congruently above the b. p. of borontrifl~oride.~~ Boron trifluoride forms a stable, white, solid complex with di-nitrogen pentoxide which decomposes in inert solvents above 75", is an excel-lent nitrating agent, and has been formulated 71 as N02+[0,N0 + BF,]-.hailov and T. K. Kozminskaya, Doklady ARad. Nauk S.S.S.R., 1958,121, 656.80, 4515.62 H. S. Turner and R. J. Warne, Chem. and Ind., 1958, 526; see also B. M. Mik-6a G. E. Ryschkewitsch, J. J. Harris, and H. H. Sisler, J . Amer. Chern. SOC., 1958,65 L. Trefonas and W. N. Lipscomb, J . Chem. Phys., 1958, 28, 54.66 A. K. Holliday and A. G. Massey, J . Amer. Chem. SOC., 1958, 80, 4744.67 J.W.. Frazer and R. T. Holzmann, ibid., p. 2907; see also R. T. Holzmann and68 A. Pflugmacher and W. Diener, Angew. Chem., 1957, 69, 777.6s N. N. Greenwood, J . Inorg. Nuclear Chem., 1958, 5, 224, 236.'O H. E. Wirth, M. J. Jackson, and H. W. Griffiths, J . Phys. Chem., 1968,62, 871.71 G. B. Bachman and J. K. Dever, J . AMY. Chem. SOL, 1968, 80, 5871.A. Finch and H. I. Schlesinger, ibid., p. 3573.W. F. Morris, J . Chem. Phys., 1958, 29, 677120 INORGANIC CHEMISTRY.The preparation, thermal stability, and physical properties of complexesof boron trifluoride with numerous ketones have been reported.72 Anunusual preparation of boron trifluoride dialcoholates involves thequantitative conversion of trialkyl borates with hydrogen fluoride at 30" :B(OR), + 3HF -+ BF3,2ROH + ROH.The complex RF,,AcOH waslikewise formed in good yield when hydrogen fluoride reacted with boricoxide in acetic anhydride.73The infrared spectra of complexes between aliphatic and aromaticketones and such electron acceptors as BF,, AlCl,, FeCl,, and ZnC1, showa characteristic lowering of the C=O vibration frequency and this, togetherwith some dipole-moment measurements, is considered 74 to favour thestructure R2C=O+BF, rather than [ (R2C=O)2BF2]+ BF4-. Infrared andRaman data on pyridine, quinoline, and isoquinoline complexes of borontrifluoride and aluminium trichloride are also rec0rded.7~ Dipole momentsof pyridine and trimethylamine complexes indicate that electron-acceptorpower increases 75 in the order BF, < BH, < BCl, < BBr,, the sequencefor the halides being the same as that previously obtained from the heatsof formation of the complexes.Consistently with this, diphenyl etherforms a 1 : 1 addition compound with boron trichloride but not with borontrifl~oride.~~ Dioxan forms a 1 : 1 complex when mixed with boron trichloridein methylene dichloride; addition of excess of boron trichloride formed theinsoluble 3 : 2 complex (BC1,),,2C4H,0, from which the 1 : 1 complex couldbe recovered by addition of dioxan. Both complexes hydrolyse immediatelyto boric acid, hydrochloric acid, and dioxan. Boron tribromide formed onlythe 1 : 1 complex, a white solid less stable than the chloro-compound.77The electron-acceptor properties of boron trichloride have been reviewedand findings suggesting the presence of the tetrachloroborate ion in somecomplexes discussed; infrared bands at 670 and 800 cm.-l were assigned tothis Alkali-metal tetrachloroborates MBCl, have been prepared bydirect addition of boron trichloride to metal chlorides under pressure at hightemperatures.Stability increases from potassium through rubidium toc~esium.7~ Alkyl-substituted ammonium tetrachloroborates were formedwhen boron trichloride was added to an alkylammonium chloride in boilingchloroform, the preparation differing from that of the tri-N-alkyl-tri-B-chloroborazoles (see p. 118) only in the choice of solvent. The five tetra-chloroborates investigated all had strong peaks in the region 660-700cm.-l of the spectrum.80 Tetrachloroborates were also formed when72 R.Lombard and J. P. StBphan, Bull. SOC. chim. France, 1957, 1369.7a E. L. Muetterties, J . Amer. Chem. SOC., 1958, 80, 4526.74 B. P. Susz and P. Chalandon, Helv. Chim. Actu, 1958, 41, 697, 1332; H. Luther,D. Mootz, and F. Radwitz, J . grakt. Chem., 1957, 5, 242.76 C. M. Bax, A. R. Katritzky, and L. E. Sutton, J., 1958, 1258; see also idem, ibid.,p. 1254.76 R. M. Healy and A. A. Palko, J. Chem. Phys., 1958, 28, 211; see also A. A. Palko,R. M. Healy, and L. Landau, ibid., p. 214.77 M. J. Frazer, W. Gerrard, and S. N. Mistry, Chem. and Ind., 1958, 1263.78 N. N. Greenwood, K. Wade, and P. G. Perkins, XVI Internat. Congr. Pure Afipl.Chem. (Sect. Chim. min.), Paris, 1957, 491; see also R.H. Herber, J . Amer. Chem. SOC.,1958, 80, 5080, for kinetic evidence.79 E. L. Muetterties, J . Amer. Chem. SOC., 1957, 79, 6563.80 W. Kynaston and H. S. Turner, Proc. Chem. Soc., 1958, 304ADDISON AND GREENWOOD: MAIN GROUPS. 121cyclohexylamine or benzylamine reacted with boron trichloride in methylenedichloride a t -78", the simultaneously formed substituted aminoborondichloride also being isolated: 81 SRNH, + 2BC13 + 2(BC13,RNH,) _tRNH3+ BC1,- + RNH*BCl,.A study of the dehydration of the metaborates Ca(B0,),,2H20 andCa(B0,),,6H20 has led to a re-formulation of these salts as dihydrogenborates, Ca(H,BO,), and Ca(H2B0,),,4H,O, in which boric acid behaves asa monobasic acid. Calcium monohydrogen borate CaHBO, was alsoprepared and thermally dehydrated to the diborate C S B , ~ ~ .~ ~ Reactionof " boron acetate " with glycerol does not give the highly strained glycerolborate (5A) as previously thought but a white, amorphous powder formulatedas (5B) on the basis of molecular weight, infrared spectra, and the presenceof hydroxyl groups.*,H2C.O O.CH2IH2C. 0H0.C.H 'f3-0- B' H-k-OH'O-CH, (58)I I /Aluminium, gallium, indium, and thallium. The physicochemicalstudy of complexes formed between aluminium tribromide and variousethers continues and the conductivity, viscosity, and density of severalternary systems are reported.84 The infrared spectra of many additioncompounds of the aluminium trihalides with a variety of ligands have beenreviewed,85 and the infrared spectra of 1 : 1 complexes of aluminium tri-chloride and tribromide with methyl nitrate, nitrobenzene, and severalpara-substituted nitrobenzenes are interpreted as showing that only oneoxygen atom in the nitro-group is involved in bonding to aluminium.86Ultraviolet absorption spectra and solubility studies indicate weak complexformation between Al,Br6 and pent-2-ene in solution but no solid complexwas found down to -23", in contrast to the behaviour in benzene which is abetter solvent for A1,Br6 and which forms an incongruently melting complexwith it.*'The existence of univalent gallium in gallium dibromide has beenestablished by Raman spectroscopy, the structure of the (diamagnetic)compound being Ga+GaBr,-, analogous to the dichloride.88 Consistentwith this, gallium dichloride, m.p. 172~4"~ and dibromide, m. p. 166-7", aretypical molten salts with conductivities similar to that of fused silver nitrate;the physical properties of both compounds were measured over a range oftemperat~re.~~ The dibromide is dimorphic and can be partly reduced to81 W. Gerrard and E. F. Mooney, Chem. and Ind., 1958, 1259.s2 H. A. Lehmann, A. Zielfelder, and G. Herzog, 2. anorg. Chew., 1958, 296, 199;83 W. Gerrard and E. F. Mooney, Chem. and Ind., 1958, 227.84 Ye. Ya. Gorenbein and V. L. Yivnutel, Zhur. obshchei Khim., 1957,27,20; Ye. Ya.85 A. Terenin, W. Filimonow, and D. Bystrow, 2. Elektrochem., 1958, 62, 180.86 P. Gagnaux, D. Janjic, and B. P. Susz, Helv. Chim. Ada, 1958, 41, 1322; see alsosee also J. Krogh-Moe, Arkiv Kemi, 1958, 12, 277.Gorenbein and V.N. Danilova, ibid., p. 858; idem, ibid., 1958, 28, 1387.idem, ibid., p. 1023, for dipole moments.F. Fairbrother and J. F. Nixon, J., 1958, 3224.L. A. Woodward, N. N. Greenwood, J. R. Hall, and I. J. Worrall, ibid., p. 1505.8s N. N. Greenwood and I : J. Worrall, ibid.. p . 1680122 INORGANIC CHEMISTRY.the monobromide, a reaction which goes to completion in the presence ofaluminium tribromide : Ga+GaBr,- + 2Ga + ZA12Br6 + 4Ga+AlBr4-.90The corresponding chloro-complex was prepared similarly and also by directreduction 91 of molten gallium trichloride with aluminium a t 190" : 2Ga2C1, +3A1- 3Ga+A1C14- + Ga. The dihalides of gallium are usually preparedby direct reduction of the trihalides with gallium; a new method involvesheating gallium metal a t 150" with mercurous or mercuric halides.In thepresence of benzene the complexes Ga+GaCl,-,C,H, and Ga+GaBr,-,C,H,were obtained. Addition of hydrogen sulphide to such benzene solutionsprecipitated only the univalent gallium; hydrogen halide was evolved andgallium trihalide remained in solution : e.g., 2Ga+GaCl,- + H2S _+G+S + 2HC1+ Ga2Cl,. The sulphide precipitate could not be characterizedand contained up to 20% by weight of chlorine.92 The thermal stabilityof phases occurring in the system Ga-S were re-investigated up to 1300".Digallium disulphide melts at 970" and then decomposes: 3Ga,S2 -FGa,S, + Ga2S. Crystalline digallium monosulphide disproportionates above950" (2GsS + Ga,S, + Ga) and a t the same temperature the sesquisulphideloses sulphur: 2GsS, + Ga,S, + QS,.The compound Ga,S, (ie.,Gas,.,,) is stable up to 1200" and variesg3 in composition from Gas,.,to Gastw.Phase studies indicate that gallium trichloride forms two complexes withpyridine, GaCl,,py, m. p. 126", and GaC13,2py, m. p. 113"; the 1 : 2 complexreverts to the 1 : 1 compound when evacuated. Both complexes form ionicmelts and their physical properties, measured over a range of temperatures,have been interpreted on the basis of the formulz [py2GaC1,]+GaC1,- andCpy2GaC12] +C1-. The piperidine complexes GaCl,,pip, m. p. 134", andGaC13,2pip, m. p. 112", are analogous.94 The heats of formation of piperidinecomplexes of gallium trichloride and tribromide are greater than those ofthe pyridine complexes and the first mol.of ligand is added with considerablymore evolution of heat than the second. Heats of formation of severalother addition compounds of the trichloride were studied and it was alsoshown that the heats of formation of crystalline complexes of the tribromidewere greater than the corresponding heats for complexes of the tri~hloride.~~An important study of the lower halides of indium has been published.The mono- and di-halides (X = C1, Br, I) were prepared from indium andappropriate amounts of mercurous or mercuric halides at 325400". Phasestudies show that indium dichloride does not exist as a compound, andpreparations having this stoicheiometry are equimolar mixtures of In2C13and InCl,. The latter is extracted by a small amount of ether to leave thesolid In2Cl,, which is the most stable species in the system and is formulatedas (111+)~1nCl~,-, i.e., InC13,31nC1.Further continuous ether extraction ofthis compound leaves a residue approaching InCl in composition, theO0 J. D. Corbett and A. Hershaft, J . Amer. Chem. SOL, 1958, 80, 1530.O1 R. K. McMullan and J . D. Corbett, ibid., p. 4761.92 R. C. Carlston, E. Griswold, and J. Kleinberg, ibid., p. 1532.g3 H. Spandau and F. Klanberg, 2. anorg. Chem., 1958, 295, 300; see also idem,9* N. N . Greenwood and K. Wade, J., 1968, 1663, 1671.Naturwiss., 1958, 45, 209, for thallium sulphide.N. N. Greenwood, J. Inorg. Nuclear Chem., 1958, 8, 234ADDISON AND GREENWOOD : MAIN GROUPS. 123solution phase again containing InCl,.The complex In+AlC14- was preparedby chlorinating a mixture of indium and aluminium with mercury chloride.96In contrast to gallium, indium didsnot form fluoro-complexes with 13 of aseries of 15 cations investigated. However, the known complex (NH4),InF,was formed, and cobaltous fluoride reacted with indium trifluoride in dilutehydrofluoric acid to give the red complex [CO(H,~),]~+[I~F,,H,~]~-.Thermal analysis of the system LiF-InF, showedg7 that the only stablecomplex was Li,InF,, m. p. 867". Trimethylindium (unlike Al,Me,) is atetramer and the elucidation of its structure by X-ray analysis revealsthe presence of both inter- and intra-molecular methyl bridges of newtype?8The 1 : 1 and 1 : 2 complexes of thallic halides with bidentate ligandsB (B = 2,2'-dipyridyl, 1 ,lo-phenanthroline, and ethylenediamine) areuni-univalent electrolytes of the type [B,T1X2] +TlX,- and [B,TlX2] +X-where X = C1, Br, I; gQ cf.the complexes of gallium trihalides with pyridineand piperidine (p. 122). Thallous t-pentyloxide is a tetramer like thelower homologues, implying that these tetramers are structures which canaccommodate bulky alkyl groups.l0O The infrared spectrum of cyclo-pentadienylthallium, TlC,H,, indicates a " half-sandwich " configurationof C,, symmetry. Chemical reactions and molecular-orbital calculationssuggest lol that the bonding is essentially ionic.Group IV.-A new scale of electronegativity based on electrostatic forcehas been proposed and applied in detail lo2 to the study of analogous com-pounds of C, Si, Ge, Sn, and Pb.The preparation of graphitic oxide by methods described in the literatureis time-consuming and hazardous.A rapid and relatively safe method hasbeen developed in which the graphite is oxidized below 45" with an anhydrousmixture of sulphuric acid, sodium nitrate, and potassium permanganate forless than 2 hour.lo3 Graphitic oxide has the constant overall compositionC,04H2 independent of the type of graphite used, and the tentative assign-ment of functional groups mentioned in last year's Report (p. 104) has beenconfirmed and extended.la Graphite reacts with chlorine at -78" during500 days; the total uptake is 42% by weight and the anomalous dia-magnetism of graphite is completely removed.Finely ground graphitereacts more rapidly than coarsely ground graphite, for which the speed ofreaction is strongly dependent on temperature with a maximum at -12".Above 0" absorption of chlorine cannot be detected magnetochemically.lMThe system is thus very similar to the graphite-bromine system. Bromine-graphite " compounds " react with chlorine or iodine more rapidly than96 R. J . Clark, E. Griswold, and J. Kleinberg, J. Amer. Chem. SOC., 1968, 80, 4764.97 J . E. Roberts and A. W. Laubengayer, ibid., 1967, 79, 5895.98 E. L. Amma and R. E. Rundle, ibid., 1968, 80, 4141.9e G. J. Sutton, Austral. J. Chem., 1968, 11, 120.loo D. C. Bradley, J., 1958, 4780.lol F. A. Cotton and L. T. Reynolds, J. Amer. Chem. Soc., 1958, 80, 269.Io2 A.L. Allred and E. G. Rochow. J. Inorg. Nuclear Chem., 1958, 5, 264, 269.W. S. Hummers and R. E. Offeman, J. Amer. Chem. SOL, 1958,80, 1339.Io4 J. H. de Boer and A. B. C. van Doom, Proc. k. ned. Akad. Wetenschap., 1968, 61,R. Juza, P. Janck, and A. Schmeckenbecher, 2. anorg. Chem., 1957, 292, 34.B, 12, 17, 160124 INORGANIC CHEMISTRY.does graphite itself, apparently because of the formation of interhalogencompounds, such as iodine bromide.lO6 Sodium, unlike its heavier congeners,has previously been thought not to form a lamellar compound with graphite.The compound C,,Na has now been prepared by heating graphite with 3%by weight of sodium in an atmosphere of helium at 200-500" for about1 hour, and its probable structure deduced on stoicheiometric and X-rayevidence.lo7 Several intercalation compounds of graphite with galliumtrichloride and indium trichloride in the presence of chlorine have beenstudied and compared with analogous compounds formed by aluminiumchloride and ferric chloride.The gallium compounds always appeared tohave a ratio C1: Ga between 3-2 and 3.4 whereas 108 the ratio for the indiumcompounds was more nearly 3.0. Established procedures being used, thewhole series of graphite-rare earth chloride systems was re-investigated andonly yttrium trichloride and gadolinium trichloride found to intercalateconsistently and in appreciable quantities.lOg" Red carbon," prepared by the anhydrous pyrolysis of carbon suboxide,has the composition (C30Jn. X-Ray analysis, paramagnetic resonanceabsorption, and the nature of the hydrolysis products indicate that itconsists of small graphite-like layers about 10 A across in which some of thecarbon atoms are replaced by oxygen atoms.The edges of the layers carryfunctional groupsllo such as -OH, =O, and -CO,H. Some properties ofexplosive, solid carbon monosulphide have been reported.lllA stable, dipositive carbonium ion formed by the loss of two chlorideions from a single carbon atom, is produced when trichloromethylpenta-methylbenzene is dissolved in anhydrous sulphuric acid : C,Me5*CC1, +2H,S04 _+ C,Me5*CC12f + 2HS04- + 2HC1. In accordance with thisequation the solution is intensely red, has a van't Hoff i-factor of 5-0, andevolves two mol. of hydrogen chloride when nitrogen is bubbled through,leaving a solution of identical spectrum but having an i-factor of 3.Bothsolutions on hydrolysis gave quantitative yields of pentamethylbenzoicacid C,Me,*CO,H and the presence of the two highly conducting bi-sulphate ions was demonstrated by measurement of the equivalent con-duc tivi ty.l12When silver cyanide is electrolysed between silver electrodes in liquidammonia the cyano-radicals formed dissolve silver quantitatively. Withan antimony anode and pyridine as solvent, the new compound antimonytricyanide was formed almost quantitatively. Bismuth behaves similarly,but with arsenic some paracyanogen was f0rmed.1~3 Electrolysis of silvercyanide in liquid ammonia between inert electrodes yields cyano-radicalswhich react with the solvent to give ammonium cyanide and nitrogen inlo* R.Juza and A. Schmeckenbecher, 2. anorg. Chem., 1957, 292, 46; see alsoG. Colin and A. Herold, Compt. rend., 1957, 245, 2294.I07 R. C. Asher and S. A. Wilson, Nature, 1958, 181, 409.lo8 W. Rudorff and A. Landel, 2. anorg. Chem., 1958, 293, 327.Io9 R. C. Vickery and N. L. Campbell, J . Anzer. Chem. SOC., 1957, 79, 5897.L. Schmidt, H. P. Boehm, and U. Hofmann, 2. anorg. Chem., 1958, 296, 246.ll1 M. A. P. Hogg and J. E. Spice, J., 1958,4196; see also H. Schafer and H. Wiede-112 H. Hart and R. W. Fish, J . Amer. Chem. SOC., 1958, 80, 5894.11* H. Schmidt and H. Meinert, 2. anorg. Chem., 1958, 295, 156, 173.meier, 2. anorg. Chem., 1958, 296, 241AIIDISON AND GREENWOOD : MAIN GROUPS.125addition to small amounts of cyanogen which react with more ammonia togive 113 the dark red 2,3,5,6-tetraiminopiperazine (6) :HNN r C CEN HN=C C=NH HlN- C- C E N / \NEC CEN HN=C, ,C=NH H,N-C-C=NHH-NH-HI I - I I I(6) 17)H-NH-H' NFurther evidence from the physical and chemical properties of the hydrogencyanide tetramer is adduced 114 to support the diaminomalonodinitrilestructure (7). Commercial cyanuric chloride has been fluorinated withmixed antimony chlorofluorides under various conditions to give 115 a 71%yield of (CNF),, m. p. -38", b. p. 74"; a 24% yield of C3N3F,C1, m. p. 23",b. p. 113"; or a 20% yield of C3N,FC1,, m. p. 2", b. p. 155". Thiocyanogentrichloride, formed by reaction of thiocyanogen with excess of chlorine, isconsidered on the basis of chemical and spectroscopic evidence to be thesulphenyl chloride C1N=CC1*SC1.ll6 Equimolar portions of thiocyanogenand chlorine in an inert solvent give monomeric thiocyanogen mono-chloride, ClSCN, rather than the previously reported inert polymericspecies.The monomer adds immediately to olefins giving 2-chloroalkylthiocyanates.ll7A quadrivalent silicon complex with acetylacetone [Si(acac),]Cl,HCl hasbeen shown conclusively to be hexaco-ordinated and octahedral by its resolu-tion into optical enantiomers.lls The acid SiMeEtPh*C,H,*CO,H-$ (m. p.99.5") has also been resolved and this is the first reported resolution of aquadricovalent silicon compound containing a single asymmetric siliconatom. Despite the apparent accessibility of 3d-orbitals on the silicon atom,the acid did not racemize either at 100" in the molten state or in 5% aqueousmethanolic potassium hydroxide at room temperature.llg Hydrolysis of themethyl ester of silicic acid in conductivity water has given solutions of purewater-soluble orthosilicic acid H,SiO, ; the conductimetrically determineddissociation constant 120 u7as 1-24 xDisiloxane, (SiH,),O, reacts with Me,Al,Br, to give the volatile electron-deficient compound Me,Al,(O*SiH,),, m.p. 42", which slowly decomposeswith loss of silane at room temperature. Corresponding reactions withthe aluminium trihalides give polymeric products (SiH,-OA1X,)n.121 Chloro-methoxytrichlorosilane ClCH,*O-SiCl, has been prepared both by directchlorination of methoxytrichlorosilane and by reaction of silicon tetra-chloride with formaldehyde, and its physical properties and chemicalat 25".11* P.S. Robertson and J. Vaughan, J . Amer. Chem. SOC., 1958, 80, 2691.115 A. F. Maxwell, J. S. Fry, and L. A. Bigelow, ibid., p. 548.116 R. G. R. Bacon, R. S. Irwin, J. McC. Pollock, and A. D. E. Pullin, J., 1958, 764.117 A. B. Angus and R. G. R. Bacon, ibid., p. 774; R. G. R. Bacon and R .S. Irwin,11* S. K. Dhar, V. Doron, and S. Kirschner, J . Amer. Chem. SOC., 1958, 80, 753.llS C. Eaborn and C. Pitt, Chem. and Ind., 1958, 830.120 R. Schwarz and W. D. Miiller, 2. anorc. Chem., 1958, 296. 273.ibid., p. 778.lZ1 W. A. Kriner, A. G. MacDiarmid, an&E. C. Evers, J. Amer. Chem. SOC., 1958,80, 1546126 INORGANIC CHEMISTRY.reactions reported.122 In an attempt to increase the electron-donor proper-ties of the oxygen atom in disiloxane its methyl derivatives were prepared.Boron trifluoride and trichloride do not form stable complexes with thesecompounds even at -78" but cleave the Si*O*Si group, e.g., (MeSiH,),O +BF, _+ MeSiH,F + MeSiH,*O*BF,. The latter compound then decom-poses spontaneously : 3MeSiH2*O*BF, __t 3MeSiH,F + BF, + B,O,.Boron tri-iodide and trimethylboron do not react but hydriodic acid alsocleaves the Si*O*Si group.No donor properties were exhibited lZ3 by1,l'-dimethyldisilthiane (MeSiH,),S. Reaction of boron trichloride withcyclosiloxanes (R,SiO), results initially in ring opening (a) followed by rapiddisproportionation on attempted distillation (b).The tris(dialky1chloro-siloxy)boranes further disproportionate (c) into products which, though morestable, can in turn be disproportionated by distillation (a) into the originalcyclosiloxane and dialkyldichlorosilanes : 124 e.g. :a bC d(R,SiO), + 3BC13 __t 3RZSiCI*O.BCI, __t 2BC13 + (R,SiCI.O),B2(R,SiCI*O),B _I_t BzOs + 3(RzSiCI),O (R,SiO), + 3R,SiCI,The effect of methyl-substitution in the silyl group on the donorproperties of nitrogen in the silylamines has been studied and many newcompounds prepared. The Si-methylated silylamines are comparativelyweak ligands but the NN-dimethylsilylamines are much stronger and formadducts such as BMe,,Me,N*SiMe, and BMe,,Me,N*SiH,Me. In somesystems the Si-N bonds were ~1eaved.l~~ NN'-Bis(trialkylsily1) hydrazinecompounds, R,Si-NH*NH*SiR,, and silyl esters of perchloric acids,R,Si*O*ClO,, have been reported.126The synthesis and properties of inorganic compounds of germanium havebeen reviewed.12' Germanium cyanides have formerly only been knownwith one cyano-group in the molecule; germanium tetracyanide has nowbeen made by reaction of the tetraiodide with silver cyanide in benzene.It is yellow, decomposes above 80°, and is rapidly solvolysed by water oralcohols.128 A stable complex GeC1,,2py, m.p. 207-214" (decomp.), isreported but the corresponding adduct with diethylaniline could not bemade.129 Germane was obtained in 80% yield by reducing the tetra-chloride with lithium tri-t-butoxyaluminium hydride Li[(ButO),AIH], butlithium aluminium hydride itself, which reduces stannic chloride smoothlyto stannane, gave unsatisfactory results owing to the preferential formationof germanium d i ~ h l o r i d e .~ ~ ~ (Reduction of lead tetrachloride with lithium122 R. E. Frost and E. G. Rochow, J . Inorg. Nuclear Chem., 1958, 5, 201, 207.123 H. J. EmelCus and M. Onyszchuk, J., 1958, 604; H. J. EmelCus and L. E.Smythe, ibid., p. 609.124 P. A. McCusker and T. Ostdick, J . Amer. Chem. SOC., 1958, 80, 1103; see alsoW. Gerrard and J. A. Strickson, Chem. and Ind., 1958, 860.125 E. A. V. Ebsworth and H. J. EmelCus, J., 1958, 2150; see also M. Becke-Goehring and G. Wunsch, Annalen, 1958, 618, 43.126 U. Wannagat and W. Liehr, Angew. Chem., 1957, 69, 783, 783.127 H.Nowotny and A. Wittman, X V I Internat. Congr. Pure APPl. Chem.,Experientia Suppl. V I I , 1957, 239.12* W. Menzer, Angew. Chem.. 1958, 70, 656.lZ0 E. W. Abel, J., 1958, 3746.130 S. Sujishi and J. N. Keith, J . Amer. Chem. SOC., 1958, 80, 4138ADDISON AND GREENWOOD: MAIN GROUPS. 127aluminium hydride yielded only metallic lead.131) The new compoundhexamethyldigermane Me3Ge*GeMe3 has been prepared in 74% yield byreducing trimethylgermanium bromide with molten potassium, and thereactions of this compound and its silicon and tin analogues ~tudied.1~~Conductimetric titration of sodium in liquid ammonia with stannanedemonstrates the formation of the mono- and di-sodio-derivatives, SnH3Naand SnH,Na,. The former decomposes at -63" in the absence of ammoniabut reacts in solution with alkyl iodides to give alkylstannanes, RSnH,.The disodio-derivative is fairly stable at 0" in the absence of ammonia, doesnot react with methyl iodide, and regenerates stannane when treated withammonium chloride in ammonia: SnH,Na, + 2NH,C1 __t SnH, +2NH, + 2NaC1.131 Tin tetrahalides react with ammonia to give the corre-sponding ammonium halide and ammonobasic tin ( IV) halides SnX (NH,),,where X = C1, Br, I.The complex (NH,),[SnCl,(NH,)J was also isolatedand the thermal decomposition of these compounds studied.133 Heats offormation and physical properties of 1 : 2 complexes of stannic chloride withorganic ligands containing oxygen or nitrogen are reported.laThe recent chemistry of organotin compounds has been re~iewed.l3~The alkoxides of tin were prepared by adding ammonia to a mixed solutionof stannic chloride and the appropriate alcohol in benzene: SnCl, +4ROH + 4NH3 + Sn(OR), + 4NH4C1.l3, However, an independentinvestigation found this reaction unsuitable for the preparation of the purealkoxides and the preferred method was by alcohol interchange involvingthe isopropoxide isopropyl alcoholate, Sn2(OPri)8,2PriOH, which was itselfobtained by a 4-stage synthesis involving the double alkoxide NaSn,(OEt),and t-pentyl alcohol as intermediates.137 The properties of the alkoxidesprepared in this way differ somewhat from those obtained by the ammoniamethod.The hexafluoroplumbates of the alkali metals are well known.Thoseof the alkaline-earth metals have now been prepared, e.g., by direct fluorin-ation of the corresponding plumbates MPbO,.The compound BaPbF, hasthe hexagonal, BaGeF,-type lattice with discrete PbFG2- anions. Thestrontium compound is tetragonal and has one-dimensional chains of linkedPbF,- octahedra and individual fluoride ions. CaPbF, has the cubicRe0,-type structure with an ordered distribution of Ca2+ and Pb4+ on thecation sites.138 In an attempt to prepare covalent borohydrides of tin andlead it was found that tetramethyl-tin and -lead do not react with diboranebut do so vigorously with lithium aluminium hydride to give solid inter-mediates of the type Me,Sn(BH,), and Me,Pb*BH, which rapidly decomposelal H. J. EmelBus and S. F. A. Kettle, J., 1958, 2444.133 M.P. Brown and G. W. A. Fowles, J., 1958, 2811.133 E. Bannister and G. W. A. Fowles, J., 1958, 751, 4374.ls4 S. T. Zenchelsky and P. R. Segatto, J . Amer. Chem. Soc., 1958, 80, 4796; T.la5 G. J. M. van der Kerk, J. G. A. Luijten, and J. G. Noltes, Angew. Chem., 1958,ls6 A. Maillard, A. R. J. Deluzarche, and J. C . Maire, Bull. SOC. chim. France, 1958,13' D . C. Bradley, E. V. Caldwell, and W. Wardlaw, J . , 1957, 4775.Sumarakova and I. Litvyak, Zhur. obshchei Khim., 1957, 27, 837, 1125.70, 298.853, 855.R. Hoppe and K . Blinne, 2. anorg. Chem., 1958, 293, 251128 INORGANIC CHEMISTRY.in the presence of lithium aluminium hydride to the metals, hydrogen, and amixture of methylboranes and MeA1(BH4)2.139 The reactions of tetra-methyl-lead and trimethyl-lead chloride with alkali metals in liquid ammoniahave been investigated.The anion PbMe,- is first formed; this reacts withsodium and lithium to give dimethyl-lead but with potassium all threemethyl groups are removed and lead imide, PbNH, is obtained, the differencein behaviour being ascribed to solubility effects.140Group V.-Nitrogen. Thirteen papers were read at a Symposium on'' recent aspects of the inorganic chemistry of nitrogen," 141 and reviewshave appeared on the orbitals used in valency bonding in nitrogen com-pounds,l& and the spectroscopic and chemical properties of active nitrogen.lGThermal analysis has established the existence of the compoundSiC14,2NOCl.144 Nitrosyl azide, NO-N,, m. p. --57', is obtained as anunstable, volatile yellow compound by the low-temperature reaction ofsodium azide or hydrazoic acid with nitric acid or nitrosyl compounds suchas nitrosyl chloride or nitrosylsulphuric acid.It decomposes even at -50"into nitrous oxide and nitrogen.145 The history of " violet-blue sulphuric "acid formed in the nitric oxide catalysed synthesis of sulphuric acid isreviewed. The colour is ascribed to a nitric oxide addition compound ofnitrosylsulphuric acid, N2O2+HSO4-, and the chemistry of the ion N,02+ isdeveloped. It has two interconvertible isomeric forms, one blue and onecarmine red. I' Blue phosphoric " and " violet hydrofluoric " acids can beobtained similarly by adding nitric oxide under pressure to nitrosylphos-phoric and nitrosylhydrofluoric acids.lMThe chemistry of nitryl fluoride, NO,F, and nitronium compounds hasbeen reviewed,l*' and the microwave spectrum of nitryl chloride establishesthat it is a planar molecule like the fluoride with chlorine and oxygen atomsat the comers of an isosceles triangle ClN0,.14* The physical and chemicalproperties of nitryl chloride have been re-investigated and its reaction as achlorinating agent was shown to be due to small amounts of water presentin the organic solvents used.149 In the presence of nitrogen dioxide, chlorinedioxide and nitrosyl chloride react completely according to the equation2NOC1+ ClO, + N02C1 + NO, + CI,, and the reaction has been thesubject of a detailed kinetic study.lW The formation of nitryloxy chloride,NO,Cl, by the reaction of chlorine dioxide or dichlorine oxide with nitrogendioxide or pentoxide has been investigated under a variety of conditions.Pure NO,Cl is a white solid, melting at 107' to a pale yellow liquid which boils13s A.K. Holliday and W. Jeffers, J . Inorg. Nuclear Chem., 1958, 6, 134.140 A. K. Holliday and G. Pass, J., 1958, 3485.141 Chem. SOC. Special Publ., 1957, No. 10.142 W. J. Orville-Thomas, Chem. Rev., 1957, 57, 1179.143 K. R. Jennings and J . W. Linnett, Quart. Rev., 1958, 12, 116.144 C. Devin and R. Perrot, Comfit. rend., 1958, 248, 950.146 H. W. Lucien, J . Amer. Chem. SOC., 1958, 80, 4458.146 F. Seel and H. Sauer, 2. anorg. Chem., 1957, 292, 1; F. Seel, ref. 141, p. 7.14' G. Hetherington and P. L. Robinson, ref.141, p. 23.14* D. J. Millen and IC. M. Sinnott, J., 1958, 350,llS M. J. Collis, F. P. Gintz, D. R. Goddard, E. A. Hebdon, and (in part) G. J.Minkoff, ibid., p. 438; F. P. Gintz, D. R. Goddard, and (in part) M. J. Collis, ibid., p.445.150 H. Martin and E. Kohnlein, 2. phys. Chem. (Franhfwt), 1958, 17, 375ADDISON AND GREENWOOD : MAIN GROUPS. 129at 18". It is hydrolysed 151 quantitatively by sodium hydroxide to sodiumnitrate and hypochlorous acid: NO,Cl + NaOH + NaNO, + HOC1.The chemistry of dinitrogen tetroxide has been reviewed 15, and arigorous evaluation of existing data on the NO,-N,O, equilibrium hasshown that dissociation is far less in the liquid than in the gas, so that theliquid can be regarded153 as a dilute solution of NO, in N204.The ultra-violet spectra of N,04 in hexane or cyclohexane closely resemble the spectrumof the vapour. With non-aromatic solvents the extinction coefficientdecreases with increase in dipole moment of the solvent and there is adecrease in the wavelength of maximum absorption determined largely bythe donor properties of the solvent, suggesting that partial electron-transferoccurs rather than the formation of discrete molecules of complex. Inaromatic solvents, where the type of electron interaction is different, lmX. isunchanged but the extinction coefficient increases with increasing x-donorstrength.lm The occurrence 155 of multibanded spectra in solutions ofdinitrogen tetroxide is due to the presence of moisture in the solvents. Thevolume changes on mixing dinitrogen tetroxide with eleven organic liquidshave been correlated with the electron-donor properties of these liquids andcompared with corresponding data for mixtures of sulphur dioxide withorganic liquids.lM The explosive oxidation of acetonitrile by dinitrogentetroxide in the presence of indium is reported.16' The fact that thetetroxide in ether reacts with olefins in the presence of iodine to give 2-nitro-alkyl iodides is taken as further evidence for the radical mechanism ofaddition of dinitrogen .tetroxide to double bonds. Acetylenes (e.g. ,PhGCH) yield l-iodo-2-nitroethylenes (e.g., PhCI=CH*NO,)Vapour pressures at 0" for the system D20-N,05 have been measured,the total vapour-pressure curve being similar to the one obtained withwater.The vapour pressure of pure liquid deuterium nitrate (15.03 mm.at 0.) is 7% higher than that for nitric acid but the heats of vaporizationof the two liquids and the extent of their self-dissociation are similar.159Conductivity and transport numbers of alkali-metal nitrates in anhydrousnitric acid have been determined. Electrode reactions occurring duringelectrolysis of these solutions are NO2+ + e- __t NO, and NO,- -+,NO,+ + +02 + 2e-. The transport numbers of NO,+, NO,-, and waterin nitric acid are normal, showing that there is no significant contri-bution by chain conductance in this solvent.lW Studies of the ultravioletspectra of nitrous acid in aqueous perchloric acid continue and have led toequilibrium constants for reactions involving the formation of NO+ and161 H.Martin, Angew. Chem., 1958, 70, 97.152 C. C. Addison and B. J. Hathaway, ref. 141, p. 33; P. Gray, Roy. Inst. Chem.153 P. Gray and P. Rathbone, J., 1958, 3550.154 C. C. Addison and J. C. Sheldon, J., 1958, 3142.155 A. I?. Altshuller, D. Stephens, and C. M. Schwab, J . Phys. Chem., 1958, 62, 607;156 C. C. Addison and B. C. Smith, J., 1958, 3664.157 C. C. Addison, J. C. Sheldon, and B. C . Smith, Chem. aBd Ind., 1958, 1004.l5* T. E. Stevens and W. D. Emmons, J . Amer. Chem. SOC., 1958, 80, 338.168 J. G. Dawber and P. A. H. Wyatt, J., 1958, 3636.160 W. H. Lee and D. J. Millen, J.. 1958, 2348.Monographs, 1958, No. 4.see also A. P. Altshuller, I. Cohen, and C. M. Schwab, ibid., p. 621.REP.-VOL.LV 130 INORGANIC CHEMISTRY.N202.161 Nitroxyl, H-N=O, has been detected for the first time by itsinfrared spectrum; it is formed during the photolysis of methyl nitritein solid argon at -2253°.162The halogen derivatives of ammonia have been reviewed.16, A re-investigation of the reaction between liquid ammonia and bromine at -78"has shown that there is an equilibrium between the yellow brornamine,which could be isolated pure, and a violet compound NBr3,6NH3. Nitrogentri-iodide forms an adduct with silver amide in liquid ammonia, NH,,AgNH,,but with sodium or potassium amide it reacts with liberation of nitrogen:NI, + 3MNH, + N, + 3MI + 2NH3.1mThe oxidation of hydrazine in aqueous solutions has been reviewedand a monograph covering the manufacture and organic chemistry ofhydrazine and its use as a reducing agent has also been p~b1ished.l~~Direct reduction of nitrogen trifluoride by metals a t 375" leads to tetra-fluorohydrazine, N,F,; it boils at -73", has a critical temperature of 36",and has been characterized by analysis and molecular weight.165 Theinfrared spectrum of the unusual hydrazine derivative (N2H4)3(HI)2 indicatesthat it is best formulated as (N,H,+I-),,N2H4.Attempts to prepareanhydrous hydrazonium di-iodide were unsuccessful but led to the newhydrate N2H612,2H20.166 The hydrazine-NN-disulphonate (9) and -trisul-phonate (10) were prepared by treating potassium imidodisulphonate (8) withhydroxylamine-0-sulphonic acid and then with pyridine-sulphur trioxide :HPN.0.SO.H PY-SOaHN(SO3K)Z ___l_t H,N0N(SO3K)2 ____t KO3S*NH0N(SO3K)z(8) (9) (10)The hydrazinetetrasulphonate (13) was prepared from the NN'-disulphonate(ll), via the unstable azodisulphonate (12) :ClSOjK NaOClN,H, -+ KO,S*NH*NH*SO,K ____t [KO3S*N:N*SO3K] __+ (KO&)zN*N(S03K)z( 1 1) (12) (13)The hydrolysis and redox reactions of these compounds and others preparedby cation exchange were investigated.16' Hydrazinedisulphamide,H,N*SO,*NH*NH*SO,*NH,, was prepared by reaction of hydrazine withsulphamyl chloride (NH,*SO,Cl) in acetonitrile; it melts at 111" withdecomposition.16*Phosphorus.Work on the lower hydrides of phosphorus mentioned inlast year's Report (p. 108) has been extended to a study of the decompositionof diphosphine in liquid ammonia.169161 C.A. Bunton and G. Stedman, J., 1958, 2440; T. A. Turney and G. A. Wright,J., 1958, 2415.162 H. W. Brown and G. C. Pimentel, J. Chew. Phys., 1958, 29, 883.163 J. Jander, E. Kurzbach. and E. Schmid, ref. 141, p. 65; J. Jander and E. Kurz-bach, 2. anorg. Chem., 1958, 296, 117; J. Jander and E. Schmid, ibid., 1957, 292, 178.164 W. C. E. Higginson, ref. 141, p. 95; R. A. Reed, Roy. Inst. Chem. Monographs,1957, No. 5.165 C. B. Colburn and A. Kennedy, J . Amer. Chem. SOC., 1958, 80, 5004.166 E. C. Gilbert and J. C. Decius, ibid., p. 3871.167 A. Meuwsen and H. Tischer, 2. anorg. Chem., 1958, 294, 282.168 R. Appel and G. Berger, Chem. Bey., 1958, 91. 1339.169 E. H. Street, D. M. Gardner, and E. C. Evers, J . Amer. Chem., SOC., 1958, 80,1819ADDISON AND GREENWOOD: MAIN GROUPS.131Transport measurements in anhydrous phosphoric acid (m. p. 42.35")have established that the abnormally high electrical conductivity of thiscompound (4.68 x ohm-1 cm.-l at 25") is due to a proton-switchmechanism involving the (dihydrogen phosphate) ion H2P04-. Additionof boron trifluoride to form the complex BF3,H3P04 decreases the amountof hydrogen bonding in the liquid and lowers the viscosity of the systemfourfold. The conductivity simultaneously diminishes to an even greaterextent owing to the elimination of the chain mechanism. Trideutero-phosphoric acid, m. p. 46.0", behaves ~imi1arly.l~~The structural chemistry of condensed phosphates has been reviewedand the properties of each group of salts described in detail.171 There isalso a review on the paper chromatography of inorganic phosphorus com-p o u n d ~ .~ ~ ~ The two forms of sodium triphosphate Na5P301, are enantio-morphic, with a transition temperature of 417" & The crystalstructure of the low-temperature form has been determined; the P3OlO5-ions have a twofold axis of symmetry (14) and the Na+ ions are co-ordinatedby oxygen atoms in distorted octahedral arrangements which form channelsparallel to the b axis and sheets parallel to the (101) plane.17* The Ramanspectrum of fused sodium diphosphite, Na3HP205,12H20, at 65" differs fromthat of sodium pyrophosphite and contains lines ascribable to P-P and P-Hvibrations. The structure of the anion is 175 therefore (15).The cyclictrimetaphosphate anion reacts with aqueous ammonia at pH 12to give the monoamidotriphosphate ion (16) which was isolated as itsdibariuin salt. High-resolution nuclear magnetic resonance confirms thethree chemically different environments of the phosphorus atoms in theion ,176O*PO,*O-PO,*O~PO, 4- 2NH3 = NH2 -t [P03.0*P02*O*P0,*NH,]4--[ I I 1 3 - (16)Keaction of phosphoryl chloride with phosphorus pentoxide at 200"gives pyrophosphoryl tetrachloride, P203Cl,, m. p. - 16.5", and trimeta-phosphoryl chloride, P306c13 (17). Small amounts of polyphosphorylchlorides PnO(2n-llCl(r8,. 2) (n = 4,5,6) are also formed.177 Pure dichloro-phosphoric acid, m. p. -28", has been prepared by the controlled170 N. N. Greenwood and A. Thompson, Proc.Chem. SOC., 1958, 352.171 E. Thilo, Acta Chim. Acad. Sci. Hung., 1957, 12, 221; &err. Chem.-Ztg., 1958,172 H. Hettler, J . Chromatog., 1958, 1, 389.173 G. W. Morey, J . Amer. Chem. Soc., 1958, 80, 775.174 D. R. Davies and D. E. C . Corbridge, Acta Cryst., 1958, 11, 315.175 M. Baudler, 2. anorg. Chem., 1957, 292, 325.176 0. T. Quimby and T. J. Flautt, ibid., 1958, 296, 220.l7' H. Grunzc, ibid., p. 63.59, 1132 INORGANIC CHEMISTRY.hydrolysis l78 of pyrophosphoryl tetrachloride at - 60" : Cl,PO*O*POCl, +H20 + 2HP0,C12. The structure of the compound P40&110 (see AnnualReports, 1956, 53, 96) has been investigated by chemical and spectroscopicmethods; these indicate the presence of ac1 CI CI CI CI P-P bond, and the linear formulation (18) I \ I I I o=p-o-~-P-o--~=o is preferred 179 to a cyclic structure.CI I CI CI / \ CI CI (I8) The addition compound GaBr3,POBr3,m.p. 154", is less stable than the corre-sponding chloro-complex, POCl,+GaCI,-, but otherwise has similar pro-perties and is considered to contain the new non-metal cation POBr2+.Physical properties of the two compounds digallium hexabromide andphosphoryl bromide are also reported.180 The infrared spectra of severaladdition compounds of phosphoryl halides and triphenylphosphine oxidewith metal halides have been interpreted in terms of co-ordinationthrough the oxygen atorn.ls1 A single-crystal analysis of the complexSbC1,,POC13 indicates that the antimony atom is surrounded by asquare pyramid of chlorine atoms, the sixth octahedral position beingoccupied by the oxygen of the tetrahedral POC13 molecule.ls2 It seemsprobable therefore that, depending on the electron acceptor involved, thephosphoryl halides can form addition compounds either by halide-iontransfer or by co-ordination through the oxygen atom.Tetramethyl- andtetraethyl-ammonium chloride form solvates with arsenic trichloride butnot with phosphoryl chloride, suggesting that the latter is the weakerchloride-ion acceptor. Solvates with SeOC1, were reported a t the sametime.ls3Vapour-density measurements between 65" and 180" show that gaseousphosphorus pentabromide is completely dissociated, the heat of dissociationls*of the solid into gaseous tribromide and bromine being 26-5 kcal. mole-1.Bond isomerization between ionic and covalent forms of the mixed phos-phorus halides is reviewed.The activation energy 185 for the transformationof covalent PC1,F into ionic PCl,+F- is 10.6 kcal. mole-l. The compoundPBr4+PF6- was prepared by fluorination of phosphorus pentabromide witharsenic trifluoride and its properties compared with those of the analogouscomplex PC1,+PF6- (Ann. Reports, 1956, 53, 96); both sublime a t 135" andare isomeric with gaseous PX,F, (see also Ann. Reports, 1957, 54, 114, forAsC14+PF6-) Addition of bromine to phosphorus trichloride in arsenictrichloride yields PCl,+ [PCl,Br]- and arsenic tribromide. The constitutionof the complex was established by fluorination with arsenic trifluoride ;this reacts only with the hexa-co-ordinated phosphorus anion, yielding178 H.Grunze and E. Thilo, Angew. Chem., 1958, 70, 73.179 R. Klement and E. Rother, Naturwiss., 1958, 45, 489.I80 N. N. Greenwood and I. J. Worrall, J . Inorg. Nuclear Chem., 1958, 6, 34.181 J C. Sheldon and S. Y. Tyree, J. Amer. Chem. SOC., 1958, 80, 4775.182 I. Lindqvist and C. I. BrandCn, Acta Chem. Scand., 1958, 12, 134.183 M. Agerman, L. H. Anderson, I. Lindqvist, and M. Zackrisson, ibid., p. 477;184 G. S. Harris and D. S. Payne, J., 1958, 3732.186 L. Kolditz, 2. anorg. Chem., 1957, 298, 147.186 L. Kolditz and A. Feltz. ibid., p. 155.see also I. Lindqvist, ibid., p, 135ADDISON AND GREENWOOD: MAIN GROUPS. 133PCl,+PF,--, whereas the complex [PCl,Br] +PF6- would have resultedhad the complex been [PC13Br] +PC16-.The polymeric compound (HN=P-NH,), which can be regarded as theimide-amide of metaphosphorous acid (O=P-OH), has been prepared by thereaction of ammonia with an ether solution of phosphorus trichlorideat -20": PCl, + 5NH, __t NH=P*NH, + 3NH4C1.Other reactionsoccurring in the system are reviewed and various derivatives of the imide-amide prepared.188 Bistrifluoromethylphosphorus chloride reacts similarlyin both the vapour and the liquid phase: (CF,),PCl + 2NH,-(CF,),P*NH, + NH,C1. With primary and secondary amines, analogouslow-melting, volatile liquids are obtained, e.g., (CF,),P*NHMe, (CF,),P*NMe,,and (CF,),P*NHPh. Hydrolysis and other reactions of these compoundswere studied, and their infrared spectra measured for characterization.lsSThe tendencies of phosphorus and antimony trichlorides and pentachloridesto form complexes were examined by using trimethylamine, triethylamine,and trimethylphosphine as reference ligands.Various 1 : 1 and 1 : 2complexes were formed ; phosphorus pentachloride was reduced'b y trimethyl-and triethyl-amine and there was no reaction between triethylamine andphosphorus t richloride or be tween t rimet hylphosphine and phosphoruspentachloride. Phosphorus trichloride and antimony trichloride alsoformed 1 : 1 complexes with trimethylarsine but the pentachlorides werereduced to the trichlorides with simultaneous formation of trimethylarsenicdichloride, Me,AsCl,. Trimethylstibine reduced both the tri- and the penta-chloride to the elements with formation of Me,SbCl, in each case, e.g.,lgo2SbC1, + 3SbMe, __t 3Me3SbC1, + 2Sb.A review has appeared on the chemistry of compounds which containthe C-P bond.lgl A series of unexpectedly stable triphenylphosphoniumsalts Ph,PH+X- have been prepared and characterized by their spectra(X = C1, ClO,, I, SbCl,, FeCl,, FeBr,, +SnCl,, 4SnBr,).lg2 Several dimethyl-arsinophosphonium salts such as [Me,As*PEtJ+Cl- and related compoundshave been synthesized.lg3 The reaction between phenylphosphine, PhPH,,and phenylphosphorus dichloride, PhPCl,, which was formerly consideredto give the phosphorus analogue of azobenzene, PhP=PPh, is now shown togive a tetrameric product, tetraphenylcyclotetraphosphine (PhP),. Thethermal decomposition and chemical reactions of this novel compound arereported.lM Vinyl and tris(trimethylsilylmethy1) derivatives of phosphorus,arsenic, antimony, and bismuth have been prepared and studied.195A theory of the aromatic character of cyclic phosphoronitrile chlorides(PNCl,), has been developed in which the concept of an aromatic sextet187 L.Kolditz and A. Feltz, 2. anorg. Chem., 1957, 293, 286; see also L. Kolditz and188 M. Becke-Goehring and J. Schulze, Chem. Ber., 1958, 91, 1188.189 G. S. Harris, J., 1958, 512.190 R. R. Holmes and E. F. Bertaut, J . Amer. Chem. SOL, 1958, 80, 2980, 2983.191 P. C. Crofts, Quart. Rev., 1958, 12, 34.192 J. C. Sheldon and S. Y . Tyree, J . Amer. Chem. SOC., 1958, 80, 2117.19s G. E. Coates and J. G. Livingstone, Chem. and Ind., 1958, 1366.194 W.Kuchen and H. Buchwald, Chem. Ber., 1958, 91, 2296.196 L. Maier, D. Seyferth, F. G. A. Stone, and E. G. Rochow, J . Amer. Chem. SOL,D. Hass, ibid., 1958, 294, 191.1957, 79, 5884; D. Seyferth, ibid., 1958, 80, 1336134 INORGANIC CHEMISTRY.of electrons is merely incidental; both the trimeric and tetrameric rings(containing 6 and 8 electrons, respectively) are aromatic, in contrast tobenzene and cyclo-octatetrene for which only the six-membered ring isaromatic.lg6 The X-ray single-crystal structure of (PNCl,), confirms thepresence of a planar six-membered ring of alternate phosphorus and nitrogenatoms, with two chlorine atoms attached to each phosphorus atom in aplane perpendicular to the ring.lg7 Three new mixed phosphoronitrilehalides have been prepared by the reaction of bromine-containing phos-phorus halides with ammonium chloride or bromide. They are P,N,Cl,Br,m.p. 123", P,N,Cl,Br,, m. p. 135", and P,N,Cl,Br,, m. p. 169".lg8 Trimericphosphoronitrile chloride and hydrazine in ether afford the white, crystallinehexahydrazide P3N3(N,H3)6.199 The chlorine atoms can also be replacedby isothiocyanate groups; thus reaction with potassium thiocyanate inacetone200 gives P,N,(NCS),, m. p. 42". Reaction of the trimer withphosphorus pentachloride yields a new compound P,NCl, which was alsoobtained by direct addition of phosphorus trichloride to N,S,. Thesuggested structure is PCl,+PNCl,- and it is noteworthy that, since N- isisoelectronic with 0 and C1+, the new anion PNC1,- is isoelectronic with theknown 201 species POCl, and PC1,+.201Arsenic, antimony, and bismuth.The confusion regarding the formul-ation of alkali-metal arsenites has been resolved. Sodium arsenite isNaAsO,, not Na,HAsO,, and a single-crystal X-ray analysis shows thateach arsenic atom is at the apex of a triangular pyramid having three oxygenatoms as a base, the AsO, units being linked in chains by shared oxygenatoms (19). The compound is therefore correctly called sodium polymeta-arsenite and is structurally related to the monoclinic form of arsenious oxide(20) which is also polymeric.202 The structure of arsenious acid in aqueoussolution between pH 2 and pH 14 has been investigated by ultravioletspectroscopy, diffusion, cryoscopy, potentiometric and conductimetrictitration, and paper chromatography. It is concluded that there is anequilibrium between monomeric HAsO, and small amounts of H,AsO,which is independent of the type of arsenious oxide or arsenite disso1ved.mThe first well-defined oxyhalide of arsenic has been reported; arsenylfluoride, AsOF,, was made by direct fluorination of an equimolar mixture196 D.P. Craig and N. L. Paddock, Nature, 1958, 181, 1052; see also M. Becke-Goehring and K. John, Angew. Chem., 1958,70, 657, for reactions.197 A. Wilson and D. F. Carroll, Chem. arzd Ind., 1958, 1558.198 R. G. Rice, L. W. Daasch, J. R. Holden, and E. J. Kohn, J. Inorg. Nuclear Chem.,198 R. J . A. Otto and L. F. Audrieth, J. Amer. Chem. Soc., 1958, 80, 3575.200 Idem, ibid., p.5894.201 W. L. Groeneveld, J. H. Visser, and A. M. J. H. Seuter, J. Inorg. Nuclear Chem.,2Oe J . W. Menary, Acta Cryst., 1958, 11, 742.20s G. Jander and H. Hofmann, 2. anorg. Chem., 1958, 296, 134.1958, 5, 190.1958, 8, 245ADDISOX AND GREENWOOD: XIAIS GROUPS. 135of arsenious oxide and arsenic trichloride; it melts at -68.3", boils at-25.6", is readily hydrolysed, and its constitution was confirmed by analysis,molecular weight, mass spectrum, and infrared spectrum.204The chemistry of fluoroarsenates, hydroxyfluoroarsenates , and hydroxy-fluoroantimonates has been extensively studied,205 and several complexescontaining the cation AsCl,+ have been synthesized, e.g., AsCl,+MCl,-, whereM = Al, Ga, Fe, A u . ~ ~ The addition compounds of arsenic trichlorideand tribromide with copper and silver which are described in the olderliterature have been shown by X-ray diffraction to be mixtures of CU(I)or Ag(1) halides with amorphous arsenic.207A nuclear magnetic resonance study of liquid antimony pentafluorideindicates three non-equivalent sets of fluorine atoms in the ratio 1 : 2 : 2.A model which explains the spectra and also interprets the extraordinarilyhigh viscosity of the liquid envisages the compound as a mixture of longchains of SbF, groups, each sharing two fluorine atoms with two neighbours.The three types of fluorine atoms are then (a) bridging fluorine atoms, (b)fluorine atoms trans to these, and (c) non-bridging fluorine atoms trans toeach other.At 80" only a single broad line is obtained in the spectrum, theloss of detail being due to rapid fluorine-atom exchange.2o8 The use ofantimony trichloride 209 and antimony tribromide as ionizing solventshas been extended.Literature on the lower halides of bismuth was reviewed and the prepar-ation and properties of the monochloride BiCl were studied in some detail.It is a black, diamagnetic solid formed by reaction of the trichloride withbismuth below 323".Cryoscopic and vapour-pressure data have beeninterpreted in terms of a cyclic tetramer Bi,Cl,. The compound is stablein air at room temperature but disproportionates into bismuth and thetrichloride above 323". With aluminium chloride it gives the previouslyreported BiAlCl,. There is no evidence for a dichloride.,llGroup VI.-It is claimed that a 67% yield of the peroxide H,O, isobtained by bombarding a film of pure ozone with atomic hydrogen a t- 196°.212 Proton resonance spectra indicate that alkali metal perboratesare true peroxy-salts with water of crystallization.On the other hand, theso-called perpyrophosphates and percarbonates of sodium containedhydrogen peroxide of crystallization ; the pyrophosphates should thereforebe formulated as Na,P,O,,nH,O, rather than Na4P,08,nH20 and thestructure Na2C0,,2H,O is probably also incorrect, the spectrum beingconsistent with the more normal formulation 2Na2CO3,3H20,.2f3z04 G. Mitra, J . Amer. Chem. SOC., 1958, 80, 5639.205 L. Kolditz and D. Sarrach, 2. anorg. Chem., 1957, 293, 132; L. Kolditz and2O6 L.Kolditz and W. Schmidt, 2. anorg. Chem., 1958, 296, 188.207 W. Rudorff and J. Gelinek, Chem. Ber., 1957, 90, 2654.208 C. J. Hoffman, B. E. Holder, and W. L. Jolly, J . Phys. Chew., 1958, 62, 364.209 G. B. Porter and E. C. Baughan, J., 1958, 744.21* G. Jander and J. Weis, 2. Elektrochem., 1957, 61, 1275; 1958, 62, 850.e l l J. D. Corbett, J . Amer. Chem. SOC., 1958, 80, 4757; J . Phys. Chem., 1958, 62,212 N. I. Kobozev, I. I. Skorokhodov, L. I. Nekrasov, and Y e . I. Makarova, Zhur.219 T. M. Connor and R. E. Richards, J., 1957, 289.W. Rohnsch, ibid., p. 168.1149.fiz. Khim., 1957, 31, 1843136 INORGANIC CHEMISTRY.Recent work 011 the inorganic chemistry of sulphur was the subject of aChemical Society Symposium.214 A contribution to the optical crystallo-graphy of the various allotropes of sulphur has been published.215The first direct synthesis of the pure sulphanes H2S, and H2S4 has beenachieved by reaction of the appropriate chlorosulphane S,C12 with excess ofliquid hydrogen sulphide. The viscosities of the sulphanes from H2S2 toH2S, when expressed as log r) increase linearly with chain length, and theactivation energy increases concurrently.The heats of formation andevaporation, the critical temperatures, and other physical properties ofthese compounds are also reported.216 Further methods have been devisedfor the synthesis of chloro-, bromo-, and cyano-sulphanes Sax2 (n = 1-8) 217and the preparation of bisdialkylaminosulphanes is described : R2N*S;NR2,where R = Me, Et ; n = 2,3, 4.218The chemistry of the sulphur nitrides and their derivatives has beenre~iewed.2~~ From the relation between S-S bond length and bond orderin a variety of compounds it is concluded that the S-S distance of 2.58 Ain tetrasulphur tetranitride implies pure $-bonding (21) .220 An analogousbut inverse structure has been suggested for realgar, As,S,, in which theAs-As distance is 2.47 A.Normally, oxidizing agents convert tetrasulphurtetraimide into the tetrasulphide but when the former is heated in air at120°, especially in the presence of powdered sulphur, tetrathionyl tetraimide,(OSNH), (22), is obtained as an orange-red solid.221 An improved prepar-ation of the imide S,NH is described which involves the reaction of ammoniawith sulphur dichloride in dimethylformamide at Oo.222 Reaction of theimides S7NH and S,(NH), with triphenylmethylsodium gave the sodiumderivatives Na[NS,] and NaJNS], which are more unstable and reactivethan the imides themselves.Treatment of the tetranitride with ammoniagave the imide-amide HN=S=N*S*NH, which afforded the brown sodio-derivative Na[--N=S=N*S*NH,] and the yellow, explosive trisodio-derivative214 Chem. SOC. Special Publ., 1958, No. 12, 247.21s 0. Erametsa, Suomen Kern., 1958, 31, B , 237, 241, 246; see also G. Gee, ref.214, p. 247, and N. H. Hartshorne, ref. 214, p. 253.216 F. FCher and W. Kruse, 2. anorg. Chem., 1958, 293, 302; F. FCher, W. Kruse,and W. Laue, ibid., 1957, 292, 203; F. FCher and G. Winkhaus, ibid., p. 210; F. FCherand G.Hitzemann, ibid., 1958, 294, 50.F. F6her and S. RistiE, ibid., 1958, 293, 307, 311; F. FCher and H. Weber, Chem.Ber., 1958, 91, 642; see also F. FCher, ref. 214, p. 305.M. Becke-Goehring, ref. 214, p. 45; H. Garcia-Fernandez, Bull. SOC. chim. France,218 H. Jenne and M. Becke-Goehring, Chem. Ber., 1958, 91, 1950.220 I. Lindqvist, J . Inorg. Nuclear Chem., 1958, 6, 159.221 E. Fluck and M. Becke-Goehring, 2. anorg. Chem., 1957, 292, 229.222 M. Becke-Goehring, H. Jenne, and E. Fluck, Chem. Ber., 1958, 91, 1947.1958, 265ADDISON AXD GREENWOOD : MAIK GROIJPS. 137Na.J-N=S=N*S-N=] .,23 Boron trifluoride is absorbed at room temperatureby solid tetrasulphur tetranitride to form the carmine-red adduct BF3,4S,N,which sublimes at 95" in an atmosphere of boron trifluoride.The structuresof this compound and the green complex BF3,S4N4F, are being studied byX-ray diffraction.,=The system SO,-D,O has been investigated and the m. p. of D,SO,found to be 14.35" (cf. 10.37' for H,S04). Cryoscopic and conductivitymeasurements indicate that the extent of self-dissociation is less in thedeutero-compound and that dideuterodisulphuric acid, D,S,O,, is a weakeracid in D,S04 than is H,S,O, in H,S0,.225 Work mentioned in last year'sReport (p. 116) on the oxyacids of sulphur has been extended226 and thewhole subject reviewed.,,' The solvate of barium pentathionate with acetone,BaS(S,O,),,Me,CO,H,O, has the same internal structure as the dihydrate,one water molecule being replaced by acetone. The middle S-S bonds ofthe pentathionate ion (23) are 4% shorter than the outermost S-S bondsand contain some double-bond character.,,* The telluropentathionate ion,Te(S,0,),2-, has the same structure.,% The configuration of the sulphur2-chain in the hexathionate ion in K,Ba(S,O,), is &cis (24) as in the penta-thionate ion (23) and the S, ring of orthorhombic sulphur.(The trans-trans-chain, such as occurs in the helical chains of fibrous sulphur, is known inczesium hexa~ulphide.~~~) The reactivities of penta- and hexa-thionateswith nucleophilic reagents have been reviewed. Normally, cleavage involvesthe formation of thiosulphate but other modes lead to the formation ofsulphate and of thiosulphate and sulphur.230The chemistry of compounds containing sulphur and fluorine has beenreviewed.231 Sulphamyl fluoride, H,N*SO,F, m.p. 8O, was made by fluorin-ation of the chloride with potassium fluoride in acetonitrile; it reacts ex-plosively with water to give sulphamic and hydrofluoric Sulphuryl223 M. Becke-Goehring and R. Schwarz, 2. anorg. Chem., 1958, 296, 3; see also0. Westphal, H. H. Brauchle, and H. Hurni, Pharm. Acfa HeZv., 1958, 33, 429.224 0. Glemser and H. Ludemann, Angew. Chem., 1958, 70, 190.225 R. H. Flower. R. J. Gillespie, J. V. Oubridge, and C. Solomons, J., 1958, 667;see also B. J. Kirkbride and P. A. H. Wyatt, ibid., p. 2100; Trans. Faraday SOC.,1958, 54, 483.226 M. Schmidt and G. Talsky, Angew. Chem., 1958, 80, 312; M. Schmidt, B. Wir-woll, and E. Fliege, ibid., p.506; M. Schmidt and R. R. Wagerle, ibid., pp. 572, 572,594; F. FCher, J. Schotten, and B. Thomas, 2. Naturforsch., 1958,13b, 624.227 F. H. Pollard and D. J. Jones, ref. 214, p. 363.228 0. Foss and 0. Tjomsland, Acta Chem. Scand., 1958, 12, 44, 52.229 0. Foss, A. Hardvik, and K. H. Palmork, ibid., p. 1339.230 0. Foss, ibid., p. 959; see also V. A. Lunenok-Burmakina, Zhur. obshchei Khim.,231 R. N. Haszeldine. ref. 214, p. 317.232 R. Appel and W. Senkpiel, Angew. Chem., 1958, 70, 572.1957, 27, 311, for studies with radioactive sulphur138 IN ORGANIC CHEMISTRY.di-isocyanate, O,S(NCO),, m. p. -4", b. p. 139", and disulphuryl di-iso-cyanate, S,O,(NCO),, m. p. 26", have also been prepared.= Alkali-metalazides when warmed with excess of sulphur trioxide give as one of theproducts disulphuryl diazide, S205(N3),, m.p. 7", which hydrolyses slowlyin dilute alkali to SO,N,-, SOZ-, and N,-.234 The reaction between thionylchloride and ammonia usually gives the volatile, colourless, thionyl imide,OS=NH, which polymerizes at higher temperatures to a yellow or brownsolid. However, when the reaction is carried out in chloroform in whichcalcium oxide is suspended, a deep red isomer is obtained: OSCl, + NH, +CaO - CaCl, + H,O + HOSN. With excess of thionyl chloride, tris-(thiazyl chloride), (NSCl),, is obtained and with excess of ammonia, thereaction affords imidodisulphinamide HN (SO*NH,),. The red hydroxylisomer can be metallated with triphenylsodiomethane to give NaOSN, whichis much more stable than the hydrogen c o m p o ~ n d .~ ~ The orange-redtetramer (22) was mentioned on p. 136.Thionyl chloride is a useful reagent for preparing anhydrous inorganicchlorides from their hydrat es.236The addition compound SeO,,C,H,N was prepared by direct reactionof selenium trioxide with pyridine; it reacts with liquid ammonia to giveammonium amidoselenate, NH,(SeO,*NH,), and also ammonium selenateand selenite.237 Selenium trioxide gives potassium diselenate when heatedwith potassium chloride: 3Se0, + 2KC1 _t K,Se,O, + SeO, + Cl,.Potassium bromide gives the ele en ate.,,^ The previously unknown SeO,F,was prepared in good yield by warming barium selenate with excess offluorosulphuric acid at 50": BaSeO, + 2HS0,F __t SeO,F, + Ba(HSO,),.The compound melts at -99.5", boils at -8*4", is hydrolysed to selenic andhydrofluoric acids, and is more reactive than SO,F,.Its physical propertiesare also reported.239 A number of ammonia and amine complexes ofselenium and tellurium tetrachlorides have been prepared and characterized,and their stabilities investigated by differential thermal analysis.240Trifluoromethyl derivatives of selenium have been investigated in somedetail. The reaction between trifluoromethyl iodide and selenium at260-280" yields the selenide, (CF,),Se, b. p. -2", and the diselenide,(CF,),Se,, b. p. 73", in a ratio of about 4 : 1. The diselenide decomposes tothe monoselenide and selenium in ultraviolet light. Chlorination of bothcompounds under appropriate conditions gives CF,*SeCl or CF,*SeCl,.Bromine reacts similarly.Nitric acid oxidation of the diselenide orhydrolysis of the trichloride affords trifluoromethylseleninic acid, CF,*SeO,H,m. p. 119". The diselenide and the monochloride both give bistrifluoro-methylmercury with mercury and this compound reacts with anhydroushydrogen chloride to give CF,*SeH, b. p. -14.5". It appears that the2.38 R. Appel and H. Gerber, Chem. Ber., 1958, 91, 1200; Angew. Chem., 1958, 70271.234 H. A. Lehmann and W. Holznagel, 2. anorg. Chem., 1958, 293, 314.235 M. Becke-Goehring, R. Schwarz, and W. Spiess, ibid., p. 294.236 J. H. Freeman and M. L. Smith, J. Inorg. Nuclear Chem., 1958, 7 , 224, 287.237 K. DostAl and K. KrejEi, Z . anorg. Chem., 1958, 296, 29.238 J. FrkQii, Chem.Zvesti, 1958, 12, 330.239 A. Engelbrecht and B. Stoll, 2. anorg. Chem., 1957, 292, 20.240 V. G. Tronev and A. H. Grigorovich, Zhur. neorg. Khim., 1957, 2, 2400ADDISOK AND GREENWOOD: MAIN GROUPS. 130trifluoromethyl derivatives of selenium are more reactive than the analogoussulphur compounds owing to the relative weakness of the C-Se and Se-Sebonds. The ability to form quadrivalent selenium compounds involvinghalogens (not readily formed by the sulphur analogues) and the formationof CF,*SeO,H as the most stable acid (in contrast to the sulphonic acidCF,*SO,H) are also trends which accord with the general chemistry ofselenium and sulphur.=lThiourea forms four types of complex with tellurium tetrahalides (X =C1, Br), the products depending on the solvent used and the relativeconcentration of the reactants; the compounds are (CSN,H,),TeX,,(CSN,HJ2TeX,, (CSN,H,),TeX6,2CSN,H,X, and disubstitution productsof the form (CSN2H,),TeX,.242New methods of preparing polonium metal have been developed.Liquid ammonia reduces the hydroxide Po(OH), and other compounds, andalkaline reduction can also be effected by hydrazine, hydroxylamine, orsodium dithionite; PoCl, is reduced in hydrochloric acid solution bystannous chloride, titanium trichloride, or dithionite.2a Polonium tetra-nitrate, which was prepared by the action of dinitrogen tetroxide on PoO,or PoCl,, slowly decomposes in air at room temperature to give a basic salt;this, in turn, decomposes at higher temperatures to give a second basic salt.Both compounds appear to have dimeric or polymeric oxygen-bridgedstructures and possible formulations are discussed. Evidence for a polon-ium nitrite is also presented.M Partition of molar polonium(1v)between aqueous acids and isobutyl methyl ketone has been studied.Addition of strong oxidants such as Ce4+ or Cr0,2- displaces the equilibriumtowards the aqueous phase but addition of hydrogen peroxide re-establishesthe original equilibrium.The effect confirms the existence of polonium(vI),the potential of the couple polonium(1v)-(vI) being about 1-5 v.245 Thevolatility of polonium compounds extractable with organic solvents in thepresence of organic complexing reagents is greater than the volatility ofspecies extracted in the absence of such reagents.246Group VI1.-The physical and chemical properties of the halogen fluoridesand other covalent fluorides have been reviewed.247 Values for surfacetension and viscosity of bromine trifluoride and pentafluoride and of iodinepentafluoride over a range of temperature are reported.These, in con-junction with published data on chlorine trifluoride and the energies ofvaporization, suggest that chlorine trifluoride and bromine pentafluoride areprobably normal liquids whilst bromine trifluoride and iodine pentafluorideare associated.w Raman and infrared spectra of chlorine and bromine tri-fluorides confirm the planar T-shaped structure of these molecules and leadto values of their thennodynamic properties between 250" and 1000" ~ .2 4 9241 J. W. Dale, H. J. EmelBus, and R. N. Haszeldine, J., 1958, 2939.242 E. E. Aynsley and W. A. Campbell, J., 1958, 3290.24s K. W. Bagnall, P. S. Robinson, and M. A. A. Stewart, J., 1958, 3426.244 K. W. Bagnall, D. S. Robertson, and M. A. A. Stewart, J., 1958, 3633.245 N. Matsuura and M. Haissinsky, J. Chim. phys., 1958, 55, 475.246 H. Mabuchi, Bull. Chem. SOC. Japan, 1958, 31, 245.a4' H. C. Clark, Chem. Rev., 1958, 58, 869.248 M. T. Rogers and E. E. Garver, J. Phys. Chem., 1958, 62, 952.349 H. H. Claassen, B. Weinstock, and J. G. Malm, J. Chem. Phys., 1958, 28, 286140 INORGANIC CHEMISTRY.Nitrosonium tetrafluorobromate, NO+BrF4-, has been prepared by directreaction of nitrosy1 fluoride and bromine trifluoride and by passing nitricoxide through bromine trifluoride: 3N0 + 4BrF3 --+ 3NOBrF, + 4Br2.The bromine trifluoride is readily displaced from the compound to givecomplexes (NO),MF, where M = Si, Ge, Sn, Ti.250 Experimental details aregiven for the simple laboratory preparation of iodine pentafluoride in goodyield from the pentoxide and either bromine or chlorine trifluoride as thefluorinating agent: 61,05 + 20XF3 _+ 121F5 + 150, + 10X2.251A systematic study has been made of the changes in the infrared spectrumof the iodine monochloride stretching vibration as the interhalogen formscomplexes of increasing stability. The frequency decreases regularly from375 cm.-l for uncomplexed IC1 in carbon tetrachloride to 275 cm.-l for thestrongest complex, ICl,C5H5N.The intensity of the band increases con-currently.252 The formation constants of 1 : 1 complexes of acetonitrilewith iodine monochloride, iodine monobromide and iodine have been deter-mined spectroscopically, and the slow increase in electrical conductivity ofthe acetonitrile solutions of these complexes is attributed to a slow ionizationprocess.= The voltametric behaviour of the solutions is also reported.254Potassium dichloroiodide has been prepared by wet and by dry methods andanalytical deficiencies in the product obtained by the wet method havebeen shown to be due to the formation of the hydrate, KIC1,,H20, despiteprevious (inconclusive) arguments that this hydrate did not exist. Thedissociation pressure of this monohydrate agrees with earlier values onmaterial thought to be anhydrous and the true anhydrous compound has,in fact, a much lower dissociation pressure.Powder photographs are alsorecorded.255An X-ray single-crystal analysis of the complex Br2,C6H6, m. p. -14",indicates a structure comprising straight chains of alternating benzene andbromine molecules, the benzene rings being parallel to each other andperpendicular to the chains, whilst the bromine molecules lie along the chainsperpendicular to the benzene rings and on their common principal axis. Itappears that the x-electrons of all six carbon atoms are involved equally inthe bonding.256 The 1 : 1 complex of bromine with acetone also has infinitechains, both non-bonding pairs of electrons on the oxygen atom beinginvolved (25).The keto-carbon, oxygen, and bromine atoms are coplanarand the methyl groups slightly out of the plane. The Br-Br bond distancein this complex and the benzene complex is 2.28 A, very close to the value infree bromine itself .257The infrared absorption of hydrogen fluoride vapour between -70" and+73" is strongly dependent on pressure and temperature. In special250 A. Chrdtien and P. Bouy, Compt. rend., 1958, 246, 2493.251 G. A. Olah, A. E. Pavlath, and S. J. Kuhn, J . Inorg. Nuclear Chem., 1958, 7,301.252 w. B. Person, R. D. Humphrey, W. A. Deskin, and A. I. Popov, J . Amer. Chent.sot., 1958, 80, 2049; see also S. Nagakura, ibid., p. 520.253 A. I. Popov and W. A. Deskin, ibid., p. 2976.254 A. I. Popov and D. H. Geske, ibid., p. 5346.255 G.F. Allison and G. H. Cheesman, J., 1958, 1177.256 0. Hassel and K. 0. Strarmme, Acla Chem. S c ~ n d . , 1958, 12, 1146.257 Idem, Nature, 1958, 182, 1155ADDISON AND GREENWOOD: MAIN GROUPS. 141circumstances absorption varies either as the 4th or the 6th power of thepressure but normally the absorption corresponds to the overlapping spectraof the tetramer and hexamer. Heats of polymerization are estimatedto be 19 and 40 kcal. mole-l, respectively. Deuterium fluoride behavessimilarly.2m An infrared study of hydrogen bonding and molecular-complex formation has been carried out on solutions of anhydrous hydrogenI\Me/"Me ; (25) Me' 'Mefluoride (and sometimes deuterium fluoride) in a selection of ten represent-ative organic s0lvents.25~ Tetramethylammonium hydrogen dichloride ,Me,N+HCl,-, has been prepared, its X-ray powder photograph indexed,and the infrared spectrum of the HC1,- ion shown to be similar to that ofthe more familiar HF,- ion.260The reaction of ammonium fluoride with metal bromides in methanolhas been established as a general method for synthesizing ammoniumfluorometallates.Typical examples of the 17 complexes prepared areNH,MnF,, NH,BiF,, (NH,),TiF,, and (NH,)31nF6.261 Fluorine nitrate,N03F, decomposes explosively into NOF and oxygen when sparked, but theslow first-order thermal decomposition can be studied kinetically at temper-atures between 80" and 110°.262Viscosity and specific gravity isotherms of aqueous solutions of perchloricacid establish the following hydrates: 1, 2, 2*, 3, and 3$.263 The exo-thermic reaction between dichlorine hexaoxide and fluorine yields 70-75y0of C102F, 20-%y0 of Cl,O,, 1-3y0 of Cl,, and small amounts of a morevolatile product C10,F.The mechanism of the reaction is discussed.264Further methods for preparing chloryl fluoride, ClO,F, have been developed;these involve the fluorination of chlorine dioxide with argentic fluoride orbromine trifluoride and the reaction of dichlorine hexaoxide with nitrylfluoride. Improved syntheses of bromyl fluoride are also reported. Theseuse bromine pentafluoride to fluorinate bromine dioxide, potassium bromate,or a mixture of bromine and ozone. The compound melts at -9"258 D. F. Smith, J . Chem. Phys., 1958,28, 1040; see also P. A. Giguhre and N.Zengin,259 R. M. Adams and J. J. Katz, J . Mol. Spectroscopy, 1957, 1, 306; see also M. L.260 T. C. Waddington, J . , 1958, 1708.261 H. M. Haendler, F. A. Johnson, and D. S. Crocket, J . Amer. Chem. SOC., 1958,262 W. E. Skiens and G. H. Cady, ibid., p. 5640.263 A. A. Zinov'yev and V. P. Babayeva, Zhuv. neorg. Khim., 1957, 2, 2188.264 IV. H. Basualdo DQvila, Rev. Fac. Cienc. qztinz., Univ. jzac. L a Plata, 1957, 29, 27.Canad. J . Chem., 1958, 36, 1013, for spectrum of solid.Josien, P. Grange, and J. Lascombe, Compt. rend., 1958, 246, 3339.80, 2662142 INORGANIC CHEMISTRY.and decomposes at 56” according to the equation 3Br02F + BrF, +Br2 + 302.2653. THE TRANSITION ELEMENTSMUCH of the work published during the year on the chemistry of the transitionelements has again been concerned with the chemistry of complexes.Thoseaspects which illustrate the general properties of complexes or ligands, andwhich are not necessarily characteristic of any single transition metal, arediscussed first under the heading “ complexes ”. The chemistry of theelements is then discussed systematically in the ten transition groups.The proceedings of the International Symposium on Co-ordinationCompounds, held in Rome in September 1957, have now been published.266The field was fully reviewed, and the various section headings are givenbelow, with the titles of introductory lectures to each section. 1. Thechemical bond : ultraviolet, infrared and Raman spectroscopy; introductorylectures on “ theory of bonding in metal complexes,” 267 “ vibrational spectraand structure of co-ordination compounds,” 268 and ‘ I absorption spectra ofcomplexes in the visible and ultraviolet range.” 269 2.Stereochemistry,reactivity, and stability constants; introductory lectures on “ someproblems in the stereochemistry of co-ordination compounds,” 270 “ stabilityconstants,” 271 and “ polarography of metal complexes.” 272 3. Magneticand structural properties, with introductory lectures on “ magneto-chemistry,” 273 “ nuclear magnetic resonance,” 274 and “ paramagneticresonance.” 275 4. Valency stabilization and unusual compounds, withintroductory lectures on “ the stabilization of low-valency states of thetransition metals,” 276 “ stabilization of high valency states,” 277 and“ unusual types of co-ordination compounds.” 278 5.Catalytically activecomplexes, with an introductory lecture on “ stereospecific polymerizationsby means of co-ordinated anionic catalysis.” 279 Complex formation isdiscussed in a review on “ aqueous metal salt solutions.” 280 The proceed-ings of a symposium on non-stoicheiometric compounds have been pub-lished,B1 and a paper on the ‘‘ chalcogenides of transition elements ” isalso concerned with non-stoicheiometry.282265 M. Schmeisser and W. Fink, Angew. Chew., 1957, 69, 780; M. Schmeisser and266 J . Inorg. Nuclear Chem., 1958, 8.267 L. E. Sutton, ibid., p. 23.268 J . P. Mathieu, ibid., p. 33.26s H. Hartmann, ibid., p. 64.270 J . C. Bailar, ibid., p. 165.271 L. G.SillCn, ibid., p. 176.272 G. Sartori, ibid., p. 196.273 R. S. Nyholm, ibid., p. 401.274 R. E. Richards, ibid., p. 423.276 J. Owen, ibid., p. 430.276 J . Chatt, ibid.. p. 515.277 W. Klemm, ibid., p. 532.278 H. M. Powell, ibid., p. 546.279 G. Natta, ibid.. p. 589.280 G. Schwarzenbach, Angew. Chem., 1958, 70, 451.281 Trans. Brit. Ceram. SOC., 1957, 58, 553.282 H. Haraldsen, X V I Infernat. Congr. Pure Appl. Chem., Experientia Szifipl. V I I ,1957, 165.E. Pammer, ibid., p. 781ADDISON AND GREENWOOD : THE TRANSITION ELEMENTS. 143An attractive theory for polymerization of metal alkoxide polymers hasbeen developed. These polymers are normally small, and much data canbe correlated by assuming that the metal alkoxide adopts the smalleststructural unit consistent with all the metal atoms’ attaining a higher CO-ordination number.283 Methods for the preparation of trialkylsiloxy-derivatives of transition metals involve reaction between the appropriatesilanol and the metal alk0xide.mComplexes.-(a) GeneraZ.Magnetic data on the magnetically dilute com-plexes of the second and the third transition series have been summarized;much of the data can be explained on the basis of large spin-orbit couplingconstants, and the possibility of co-ordination numbers greater than six.285The significance of various factors which influence the stereochemistry ofcomplex halides of the transition metals has been compared. It isemphasized that when crystal field forces are opposed by others they maybe swamped, and the structure may be that determined by bond and latticeinteractions.28s Magnetic properties of some binuclear complexes of chrom-ium and iron have been studied.These include the chloro-bridged complex[Cl,FeC13FeC13]3-, the 1 , 10-phenanthroline complex [phen,Fe(OH),FephenJ4+,and corresponding chromium complexes. In the ion [C1,CrC1,CrC13]3-,the metal-metal distance is large, and the magnetic moment 3.82 B.M.Data for this and for the iron compound show that the metal-metaldistance in the latter should also be long, which is in contrast tothe shortening of the iron-iron distance in the iron ennea~arbonyl.~~’ Highpressure on a complex (up to 130,000 atm.) has been shown to influencethe ligand field, and thus the splitting of the 3d levels. This is interpretedin terms of change in metal-ligand distance, by reference to Cr, Fe, Ni andCo complexes.mA second form of the complex [Co(NH,),(NO,),] (for which onlythe trans-isomer is known) has been isolated.Infrared spectraindicate that it is the cis-i~omer.~~ Only one form of the related complex[Co(NH,),(NO,),Br] is known and X-ray analysis shows it to be the trans-isomer, with a nitro-group in the trans-position to the bromine atom.290cis- and tram-Isomers of [Rh py3Cl,] have also been chara~terized.~~~Further attention has been given to oxidation-reduction reactionsinvolving the metal ion in complexes, the influence on reaction rates exertedby added ions, and the mechanisms concerned. Spontaneous reaction ofthe ion [Cr(NH,),C1I2+ in acid solution yields [Cr(NH,)5H20]3+ and C1-, butwhen the chromous ion is present, CrC12+ and NH4+ are formed; halidesprobably act as bridge groups for electron transfer.292 The exchange rates2E3 D.C. Bradley, Nature. 1958, 182, 1211.284 D. C. Bradley and I. M. Thomas, Chem. and Ind., 1958, 17, 1231.Za5 B. Figgis, J , Inorg. Nuclear Chem., 1958, 8, 476.2a8 N. S. Gill, R. S. Nyholm, and P. Pauling, Nature, 1958, 183, 168.za7 A. Earnshaw and J . Lewis, ibid.. 1958, 181, 1262.288 R. W. Parsons and H. G . Drikamer, J. Chem. Phys., 1958, 29, 930.290 Y. Komiyama, Bull. Chem. SOC., Japan, 1958, 31, 26.291 J . P. Collman and H. F. Holtzclaw, J. Amer. Chem. Sot., 1958, 80, 2054; see also292 A. E. Ogard and H. Taube, J. Amer. Chem. SOC., 1958, 80, 1084.A. K.Majumdar, C. Duval, and J. Lecomte, Compt. rend., 1958, 247, 302.V. Carassiti and 0. Salvetti, Ann. Chim. (Italy), 1958, 48, 844144 INORGANIC CHEMISTRY.of Cr2+ with CrX2+ (X = F, C1, Br, NCS, or N3) support this mechanism.293Isotope exchange between platinum(r1) and platinum(1v) has been studiedwith the compounds [PtenBr,] and [PtenBr,]. In the solid compound[Pt enBr,] no exchange occurs, so that the platinum(I1) and platinum(1v)complexes of which [Pt enBr,] is composed in the solid retain their identity.In dimethylformamide solution, exchange is strongly catalysed by bromideions, which may act as bridging atoms.294 The very slow exchange ofchloride ion with [Pt en,C1,I2+ is catalysed by the presence of [Pt en,],+; thisis explained in terms of the mechanism [Pt en,],+ + C1- +, [Pt en2C1]+,in which case the rate of platinum exchange between the platinum(I1)and platinum(1v) species should equal the rate of chlorine exchange.Thishas been confirmed for the related reaction[Pt en2I2+ + [Pt pn2C12]2+ + [Pt en2Ct2]2+ -t [Pt pn2]2+in which the change was followed by optical rotation difference of (-)-propylenediamine (pn) in the two complexes.295 Other exchanges studiedinclude those between the tetracyanonickelate ion and certain amino-acidcomplexes of nickel(11) ,296 and between the nickel(I1) and the nickel ethylene-diaminetetra-acetate ions.297 Chromatographic analysis has been used tostudy the aquation of hexa-, penta-, and tetra-amminechromium(II1) ions inacidic and basic solutions; the monoammine [Cr(NH,) (H20)5]3+ wasisolated as a czsium alum.This completes the series [Cr(NH,),l3+--------[Cr(H,0),]3+.298 Experiments with the %o isotope indicate that theexchange of the cobalt atom between the ions [CO(NH3)6]2+ and [Co(NH,),I3+is faster in liquid ammonia than in aqueous ammonia. The effect is as-sociated with the unusual nature of the electron in liquid ammonia.299Photochemical reactions of some cobalt (111) and chromium(II1) complexeshave also been examined.3mAvailable data on the relative affinities of ligand atoms for acceptormolecules and ions have been reviewed.301 The stability constants for com-plexes of the silver ion with sulphonated aromatic ethers, sulphides, andselenides illustrate that the ether oxygen has little tendency to co-ordinate,while sulphides and selenides form complexes of moderate stability.Therelative affinities of nitrogen, phosphorus, and arsenic compounds as ligandsin silver complexes have also been compared.302 The first stability constantsof the metanilate, 3-~ulphotriphenylphosphine, and 4-sulphodiphenyl sulphideions with the cadmium ion are all smaller than for analogues with the silverion; dative x-bonding from metal to ligand thus falls sharply at the end ofthe transition series.,”293 D. L. Ball and E. L. King, J . Amer. Chem. SOC., 1958, 80, 1091.294 R. E. McCarley, D. S. Martin, and L. T. Cox, J . Inorg. Nuclear Chem., 1958, 7 ,113.295 F. Basolo, P. H. Wilks, P. G. Pearson, and R. G. Wilkins, ibid., 1958, 6, 161.296 R.C. Calkins and N. F. Hall, J . Amer. Chem. Soc., 1958, 80, 5028.297 C. M. Cook and F. A. Long, ibid., p. 33.298 E. Jrargensen and J. Bjerrum, Acta Chem. Scand., 1958, 12, 1047.299 J. J. Grossman and C. S. Garner, J. Chem. Phys., 1958, 28, 268.300 A. W. Adamson and A. H. Sporer, J . Inorg. Nuclear Chem., 1958, 8, 209.301 S. Ahrland, J. Chatt, and N. R. Davies, Quart. Rev., 1958, 12, 265.302 S. Ahrland, J. Chatt, N. R. Davies, and A. A. Williams, J . , 1958, 264, 276.3O3 Idem, J., 1958, 1403ADDISON AND GREENWOOD : THE TRANSITION ELEMENTS. 145Anhydrous ethylenediamine and propylenediamine react with the moreionic transition-metal chlorides, e.g., VCI,, CrCl,, to give [V en,]Cl,, [V pn3]C1,,and [Cr en3]Cl,, whereas the covalent TiCl,, VCl,, and MoCl, are solvolysed.Ferric chlonde is first reduced to the ferrous state, then forms the outer-orbital complex [Fe en,]C12.304 An asymmetric complex ion can influencethe reaction of a racemic attacking ligand by favouring reaction by oneenantiomer. This has been illustrated by treating (+)-[Co(EDTA)]- withracemic propylenediamine, when (+ )-propylenediamine reacts more rapidlythan the (-)-isomer. Treatment of (&)-[Co(EDTA)]- with (-)-propylene-diamine gives partial resolution of the racemic complex ion.305 The metal-thiourea (thi) complexes [Pt(thi),Cl,], [Pt(thi),]Cl,, [Pd(thi),]Cl,, [Zn(thi),Cl,],and [Ni(thi),(SCN),] have sulphur-to-metal bonds.In contrast, urea formsnitrogen-to-metal bonds with platinum(I1) and palladium(II), and oxygen-to-metal bonds with chromium(IIr), iron(m), zinc(II), and copper(I1) .306Characteristic frequencies in the infrared spectrum of some carbonato-metal complexes have been assigned. Three strong bands are found whichare absent from the spectra of ionic carbonates.The results have addedinterest in view of the similarity in the structures of the carbonate andnitrate i0ns.~0' A survey has also been made of the infrared spectra at-tributable to the nitro-group in complexes. As with carbonyl and thio-cyanato-groups, this technique is of value in determining whether the nitro-group is in terminal or bridging positions, or whether two groups are cis- ortrans- to one another.308Cobaltous complexes of some amino-acids are known to take up molecularoxygen in a reversible reaction which does not involve change in metalvalency.The product fromthe irreversible oxidation of the cobalt (11) glycylglycine complex is identicalwith glycylglycine cobalt(m), so that irreversible oxidation does in factinvolve change in valency of the Formation constants of iron(I1)and manganese(I1) with tetraethylenepenta-amine have been determined.Attempts to oxygenate these complexes were uns~ccessful.~~0 Whenhydroxyl ions are added to solutions containing the triethylenetetra-amine-cobalt(I1) ion [Co(trien)12+, the complexes [Co(trien) OH]+ and a polymer[*O*Co(trien)*O*] are formed. The tris-2-arninoethylaminecobalt(II) ion[Co(tren)12+ forms [Co(tren)OH]+ and the dimer [C~,(tren)~(OH),,,]+. Onlythe latter can decompose hydrogen peroxide.311Ultraviolet spectra of thirty acetylacetone complexes have been reported,The nuclear magnetic resonance spectra of diamagnetic complexes provide nosupport for the postulate of benzenoid resonance in the chelate rir1gs.3~2 The304 G. W.A. Fowies and W. R. McGregor, J., 1958, 136.305 S. Kirschner, Yung-Kang Wei, and J. C. Bailar, J . Amer. Chem. SOC., 1957, 79,306 A. Yamaguchi, R. B. Penland, S. Mizuschima, T. J. Lane, C. Curran, and J. V.307 B. M. Gatehouse, S. E. Livingstone, and R. S. Nyholm, J., 1958, 3137.308 B. M. Gatehouse, J . Inorg. Nudear Chem., 1958, 8, 79.309 M. T. Beck, Naturwzss., 1958, 45, 162.310 H. B. Jonassen, A. Schaafsma, and I,. Westerman, J . Phys. Chem., 1958, 62,311 H.B. Jonassen and G. T. Strickland, J . .4mev. Chem. SOC., 1958, 80, 312.312 R. H. Holm and F. A . Cottnn, ibid., p. 5658.This is followed by an irreversible process.5877.Quagliano, ibid., 1958, 80, 527.1022146 INORGANIC CHEMISTRY.infrared frequencies assigned to the bent form of the uranyl group have beenobserved in uranyl a-diketone complexes.313 There are three crystallinemodifications of uranyl acetylacetone monohydrate, as well as crystallinesolvates of uranyl acetylacetone with ethanol, dioxan, acetylacetone, andacetophenone. The anhydrous compound is dimeric in benzene solution.314Partial resolution of acetylacetone-chromium(II1) and -cobalt (111) intooptically active fractions has been achieved in a column of ~ - 1 a c t o s e .~ ~ ~(b) Carbonyls, nitrosyls, cyanides, and related compounds. A novelsynthesis which is of particular value for the less accessible transition metalcarbonyls, e.g., Cr(CO),, consists of a reductive carbonylation of an ap-propriate salt of the metal with triethylaluminium and carbon monoxide.The reaction is conducted at high temperature and pressure, ether beingused as solvent.31e Di-isobut ylaluminium hydride has been used in similarreactions.,17 Monosubstitution products of chromium hexacarbonyl,Cr(CO),X, where X=NH, or C,H,N, are prepared by reactions involvingthe ions [Cr(CO)5]z- and [Cr,(CO),,H]- in liquid ammonia. Mechanisms ofthese reactions have been discussed.318By means of molecular-orbital theory it has been possible to reconcile thediamagnetism of iron dodecacarbonyl with the structureinvolving three bridging carbonyl groups between the metal atoms; thisdisposes of one major objection to this structure.319 Further substitutionproducts of iron carbonyls with nitrogen bases have been formulatedsatisfactorily on the basis of formation of the carbonylferrate anion.The piperidine and pyrollidine substitution products are salts of tetra-nuclear carbonylferrate, e.g., [Fe(C,H,N),] [Fe,(CO),,1. y-picoline gives[Fe(C,H,N),] [Fe,(C0),].320 Products of reaction of dicobalt octacarbonylwith a series of amines and nitriles can be represented in similar fashi0n,3~fand this is supported by infrared spectra.322 Iron carbonyl chalcogenides,Fe,X,(CO), (X=S, Se, Te), can be preparedby reaction of the [Fe(C0),l2- ion with /\> F~(co), sulphurous, selenious, or tellurous acid.Thecompounds are diamagnetic, hydrophobic, and( co”Fe\ x’/ (26) relatively stable. Infrared spectra supportthe structure (26). With a polysulphide, the tetracarbonylferrate iongives the ruby-red, volatile Fe,S,(CO),, which has a structure analogous tothat of the red Roussin salt.323(CO),Fe(CO),Fe (CO),Fe( CO),818 L. Sacconi, G. Caroti, and P. Paoletti, J . Inorg. Nuclear Chem., 1958, 8, 93;814 A. E. Comyns, B. M. Gatehouse, and E. Wait, J., 1958, 4655.315 T. Moeller and E. Gulyas, J . Inorg. Nuclear Chem., 1958, 5, 245316 H. E. Podall, J . Amer. Chem. SOC., 1958, 80, 5573.317 L. I. Zakharkin, V. V. Gavrilenko, and 0. Yu. Okhlobystin, Izvest.Akud. Nauk318 H. Behrens and W. Klek, 2. anorg. Chem., 1957, 292, 151.31s D. A. Brown, J . Inorg. Nuclear Chem., 1958, 5, 289.320 W. Hieber and N. Kahlen, Chem. Ber., 1958, 91, 2223, 2234.321 W. Hieber and R. Wiesboeck, ibid., pp. 1146, 1156.322 0. Vohler, ibid., p. 1161.323 W. Hieber and J. Gruber, 2. aaovg. Chem., 1968, 296, 91.J., 1958, 4257.S.S.S.R., Otdel. khim. Nuuk, 1958,, 100ADDISON AND GREENWOOD THE TRANSITION ELEMENTS. 147Further studies on organomanganese pentacarbonyls R*Mn(CO), havebeen published. The methyl, ethyl, and n-propyl compounds are preparedby the general reaction Na[Mn(CO),] + RI + R*Mn(CO), + NaI. Thebenzoyl derivative can also be prepared from bromopentacarbonyl-manganese and benzoylmagnesium chloride.324 The dimeric tetracarbonyl-rhenium halides [Re(CO)4X]2, where X = C1, Br, or I, result from thermaldecomposition of corresponding pentacarbonyl halides, into which they maybe reconverted by carbon monoxide at high temperature and pressure.Thetetracarbonyl iodide gives with pyridine a monomeric compoundRe(C,H,N),(CO),I, identical with that obtained by reaction of pyridinewith pent acarbon ylrhenium iodide .325Tetracarbonylmethylcobalt MeCo(CO), is analogous to the manganesecompound MeMn(CO),, but is only stable at low temperatures. It isprepared by a similar method.326 A molecular-orbital treatment of thebinding of the hydrogen atom in cobalt carbonyl hydride indicates thatCo-H bonding is important; the hydrogen atom lies within 1.2 A of thecobalt atom, and is thus buried in the electrical density of the metal atom.,,'When rhodium(1) complexes RhL,(CO)Cl (L = Ar,P, Ar,As, Ar3Sb) inchloroform are treated with a halogen, octahedral complexes of rhodium(m),RhL,(CO)X, (where X = C1, I), are obtained.These are monomeric,diamagnetic non-electrolytes. They have high thermal and chemicalstability; even the stibine complexes are not decomposed by boiling con-centrated hydrochloric acid or cold alcoholic alkali.328 Carbonyliridiumhalides Ir(CO),X and Ir(C0)2X, are known ; complexes involving otherratios have now been formed from carbon monoxide and potassiumhexahalogenoiridates a t high pressure. From K21rC16, the productsK [Ir (CO),Cl,.,] , K [Ir (CO) ,Br2.,], K [Ir(CO) Br,] , and K [Ir (CO),Br,] have beenisolated.They are probably d i m e r i ~ . ~ ~ ~The Raman spectrum of liquid Ni(PF,), supports a regular tetrahedralstructure. The force constant for stretching of the Ni-P bonds (2.71 x 105dynes/cm.) is considered to be remarkably low in view of other evidence thatthe bonds have appreciable double-bond character.=O Nickel carbonylreacts with excess of tristrifluoromethylphosphine at room temperature toform a mixture of the substitution products (CF,),P,Ni(CO), and[(CF,),P],Ni(CO),; high temperature favours the latter.=l It has not yetbeen possible to prepare the fully-substituted [(CF,),P],Ni. In fact,the disubstituted product fails to react with excess of (CF,),P at100". With the diphosphine P2(CF3),, nickel carbonyl gives a product(CO),Ni-P (CF,) , n P (CF,) ,*Ni (CO) ,, and the c y clo t e t raphos phine ( CF,P) alsogives substitution products not yet ~haracterized.,~, In view of thereluctance of diarsine to form the complex Ni[o-C,H,(AsMe,),],, it is of324 W.Hieber and G. Wagner, Annalen, 1958, 818, 24.325 E. W. Abel, G. B. Hargreaves, and G. Wilkinson, J., 1958, 3149.326 W. Hieber, 0. Vohler, and G. Braun, 2. Naturforsch., 1958, 13b, 192.327 F. A. Cotton, J . Amer. Chem. SOC., 1958, 80, 4425.328 L. Vallarino, J . Inorg. Nucleav Chem., 1958, 8, 288.329 L. Malatesta and M. Angoletta, ibid., p. 273.330 L. A. Woodward and J. R. Hall, Nature, 1958, 181, 831.331 H. J. Emel6us and J. D. Smith, J., 1958, 527.332 A. B. Burg and W. RIahler, J . A n w .Ckenz. SOC., 1958, 80, 2334148 INORGANIC CHEMISTRY.interest that the diphosphine o-C,H,(PEt,), forms a nickel(0) complex morereadily. The monochelate complex [o-C,H,(PEt,),]Ni(Co), is treated withthe diphosphine at 150", and the nickel(0) compound [o-C6H4(PEt,),],Niis obtained as red crystals, m. p. 241-243'. This can also be prepared bydirect solution of finely divided nickel in the ligand at 160°.333 Platinumforms zerovalent compounds with triarylphosphines, triarylarsines, andtriaryl phosphites more readily than does palladium. The compoundPt (PPh,), will disproportionate to give the co-ordinatively unsaturatedPt(PPh,),, and in common with other phosphine derivatives, reacts withcarbon monoxide to give mixed carbonyl-phosphine compounds, e.g.,The mechanism whereby molecular hydrogen is evolved from aqueouscobaltous cyanide-potassium cyanide solutions has presented a problem formany years.The kinetics of hydrogen evolution have recently been studied.Addition of alkali metal ions increases the rate, which is also pH-dependent.= Considerable progress towards a solution of the problem hasbeen made by the observation that in these solutions a proton resonanceoccurs at a position characteristic for a proton bound to a metal atom. Theproton is derived from water, since an atmosphere of hydrogen is notnecessary for appearance of the resonance line, which also disappears onintroduction of oxidizing agents. The ion [HCo(CN),I2- is postulated asthe hydrogenated species.336 Re-examination of the infrared spectra of thecyanides K4[Ni(CN),l2 and K,[Co(CN),], suggests that they contain metal-metal bonds.The structure of the cobalt complex ion is then analogousto that for Re2(C0)10.337 The infrared spectrum of the ion [Ni(CN),]4-,which is isoelectronic with nickel carbonyl, shows one main band at1985 cm.? consistent with a tetrahedral structure.=The strongly covalent metal-nitrate ion bonding first observed inanhydrous cupric nitrate exists in a similar ferric compound also. Ferricchloride reacts with a dinitrogen tetroxide-ethyl acetate mixture, yieldingpale brown crystals of empirical formula Fe(NO,),,N,O,. This compoundcan be sublimed in a vacuum at 120". Infrared spectra and magneticsusceptibility support a structure NO+[Fe(N0,)4]- for the solid; in thevapour a pentaco-ordinated complex Fe(N0) (NO,), seems probable, whichhas analogies with iron pentacarbon~l.~~ Measurement and classificationof the infrared spectra of over 50 metal-nitric oxide complexes is a valuablecontribution to structural studies in this fieldsM0 In most complexes bond-ing occurs by donation of two electrons from the nitric oxide group, togetherwith coupling of the unpaired electron with an unpaired d-electron of themetal to give a x-bond.There are examples in which nitric oxide can bondin a manner resembling metal-olefin complexes. The N-O stretching333 J. Chatt and F. A. Hart, Chem. and Ind., 1958, 1474.333 L. Malatesta and C. Cariello, J . Inorg. Nuclear Chem., 1958, 8, 561; J., 1958,335 N.K. King and M. E. Winfield, J . Amer. Chem. SOC., 1968, 80, 2060.336 \v. p. Griffith, L. Pratt, and G. Wilkinson, Nature, 1958, 182, 466.337 W. P. Griffith and G. Wilkinson, J . Inorg. Nuclear Chem., 1958, 7 , 295.3313 M. I;. Amr El Sayed and R. K. Sheline, J . .4mer. Chem. SOC., 1958, 80, 2047.339 C. C. Addison, B. J. Hathaway, and N. Logan, Proc. Chem. SOC., 1958, 51.340 J. Lewis, R. J . Irving, and G. Wilkinson, J . Irzorg. Nicclear Chem., 1958, 7, 33.Pt(C0)2(PR3)2'3342323ADDISON AND GREENWOOD : THE TRANSITION ELEMENTS. 149frequencies lie in the range from -1940 cm.-l to 1045 cm.-l, compared withthe narrower range from -2100 to 1850 cm.-l for the carbonyls.340 Certaincomplexes can be formulated as containing the NO- group; these includethe nitrosopentammine-, nitrosopentacyano-, and nitrosonitrito-cobaltions.3q1 The first exists in two forms, red and black.The black form,previously thought to have an appreciable magnetic moment, is now knownto be diamagnetic.3q2 It is therefore now feasible to regard the blackcompound as dimeric, with the two NO groups forming a hyponitritestructure, whereas the red form has an NO- structure.=l The paramagneticspecies [Fe(H,O),N0I2 +, [Fe(NH,),N0I2', and [Fe(EtOH),N0J3+ havesp3d2 outer-orbital bonding with NO+ ~o-ordination.~~ In the complex ion[Fe(CN),N0]3- the iron is in the iron(I1) state; nitric oxide co-ordinates tothe metal by two electrons only, the odd electron remaining localized on theligand.=, The structure [Fe(NO),]-NO+ was first suggested by Sidgwickfor tetranitrosyl iron.The infrared spectrum indicates that three nitricoxide units bond as NO+ and one as NO-. The spectrum has two frequenciessimilar to those observed for Fe(NO),Cl, with which the suggested structure[Fe(NO),] +NO- is analogous.w The complex Ru,N,O,,, which is precipi-tated by reaction of nitric oxide with ruthenium tetroxide in carbon tetra-chloride solution, was believed to be one of the few compounds containingbidentate nitrate groups; the structure (N03)2NO*Ru~O*Ru~NO*(N0,)2 wassuggested. However, reactions of its aqueous solutions more nearly corre-spond with the presence of one nitrato-group per atom of ruthenium, andthe structure (NO,) RuO,(NO) ,*O*(NO) ,O,Ru( NO,) is more probable.=Cryoscopic measurements with the complex K,[Ni(CN),NO] show it to beuninuclear.The corresponding carbonyl compound K,[Ni(CN),CO] derivedfrom Belucci's salt is binuclear, so that conclusions as to the mode of nitricoxide bonding based on direct comparison of the two compounds as monomersare not justified.=The structure of Roussin's black salt has been resolved by X-ray analysisof the salt CsFe,S,(NO),, H20. The atoms are arranged as in (27) and thereare no bridging nitric oxide groups.346 The bonding of the three iron atomsat the base of the tetrahedron, and the 3-co-ordinate sulphur, are similar tothose found in the red ethyl ester (28).347 The preferred electronic structurehas four non-bonding electrons on each iron atom, and one electron pair in ahighly delocalized molecular orbital among the four iron atoms, thus account-ing for the diamagnetism.346(c) OleJin and acetylene complexes.A possible structure for the com-pound Fe2C1,,H,0, formed from acetylene and iron carbonyl hydride wasgiven in Annual Reports for 1956 (p. 108). The problem has now beenlargely resolved by an X-ray determination of the structure of the analogous341 W. P. Griffith, J. Lewis, and G. Wilkinson, J . Inorg. Nuclear Chem., 1958, 7, 38.342 R. W. Asmussen, 0. Bostrup, and J. P. Jensen, Acla Chem. Scand., 1958, 12, 24.333 W. P. Griffith, J. Lewis, and G. Wilkinson, J., 1958, 99.344 J. M. Fletcher, J . Inorg. Nuclear Chem., 1958,8,277; F . S . Martin, J. M. Fletcher,345 R. Nast and H. Bohme, 2. Naturforsch., 1958, 13b, 625.946 G.Johansson and W. N. Lipscomb, J . Chem. Phys., 1957, 27, 1417; Acta Cryst.,347 J . T. Thomas, J. H. Robertson, and E. G. Cox, ibid., p. 599.P. G. M. Brown, and B. M. Gatehouse, J . , 1959, 76.1958, 11, 694150 INORGANIC CHEMISTRY.but-2-yne complex (29). One iron atom is in a five-membered ring; thesecond lies below this ring, and at a distance from it similar to that found intetracarbonyldicyclopentadienyldi-iron. At the same time, an Fe-Febond is believed to exist.a8 Dimethylacetylene and iron penta-carbonyl react in sunlight to give orange crystals having the empirical01NIFe00formula Fe(CO),(MeCiCMe),. This is not an addition complex; acid treat-ment gives duroquinol, so that the compound is actually a x-complex ofa quinone (30).The quinone skeleton is synthesised during complex form-ation, which offers a new preparative t e ~ h n i q u e . ~ ~ Iron tricarbonylcomplexes with di- and tetra-phenylcyclopentadienone have been preparedin a similar way.%" Structure (31) has been proposed for the butadienecompound C,H,*Fe(CO),. Its spectral and other properties are very similarto those of tricarbonylcyclohexadieneiron. The metal-carbon bond en-visaged is more closely related to that in ferrocene than to those in thechelate complexes of non-conj ugated d i ~ l e f i n s . ~ ~ ~More complex acetylides have been isolated. Complete replacement ofcyano-groups occurs when K,[Ni(CN),] reacts in liquid ammonia withpotassium salts of acetylene, propyne, and phenylacetylene, givingK,[Ni(C,R),].From a suspension of anhydrous nickel cyanide inliquid ammonia, potassium phenylacetylide precipitates the tetrammineNi(C2Ph),,4NH,.352 Following on the isolation of the tetra-ethynyl-3*8 A. A. Hock and 0. S. Mills, Proc. Chem. SOC., 1958, 233.349 H. W. Sternberg, R. Markby, and I. Wender, J . Amer. Chem. SOC., 1958, 80,350 G. N. Schrauzer, Chem. and Ind., 1958, 1403, 1404.351 B. F. Hallam and P. L. Pauson, J., 1958, 642.352 R. Nast and H. Kasperl, 2. anorg. Chem., 1958, 295, 227; R. Nast, I<. \-ester,1009.and H. Griesshammer, Chem. Ber., 1957, 90, 2678ADDISOS AND GREEKWOOD : THE TRAKSITION ELEMENTS. 151manganate, K,[Mn(C,H),], the hydrogen acetylide itself has been preparedby the reaction Mn(SCN), + 2KC,H + 4NH3 + Mn(C,H),,4NH3 +2KSCN in liquid ammonia and in the absence of air and moisture.In ahigh vacuum ammonia is lost, leaving black, explosive Mn(C,H),.353 Excessof potassium acetylide with cuprous iodide gives K,[Cu(C,H)J, but withmolar quantities, dicopper acetylide is obtained crystalline.=(d) Aromatic complexes. Tet racarbon ylc yclopen tadien ylvanadium canbe reduced by sodium in liquid ammonia : 355C,H,.V(CO), + 2Na Na,[C,H,.V(CO),] + COThe product contains vanadium in the formal -1 state, and falls into theisoelectronic series [C5H5*V(C0)3]2-, [C,H,*Cr(CO),]-, [C,H,*Mn(CO),]. Allcarbonyl groups are removed in the reaction C,H,*V(CO), + 2HC1 + 0, _+C,H,*VOCI, + 4CO + H,O; the blue-black, diamagnetic product is mono-meric and s ~ b l i m a b l e .~ ~The yellow crystalline compound formed by reaction of sodium cyclo-pentadienide with rhenium pentachloride in tetrahydrofuran, followed byvacuum sublimation a t 120-200", is not the expected neutral (C,H,),Re,but the hydride (C,H,),ReH. In contrast to other known transition-metalcomplex hydrides, it behaves as a base weaker than ammonia and with acidsformsS7 the cation [C,H,*ReH,]+. Reaction of carbon monoxide at 90"and 250 atm. pressure with the hydride gives3% the bright yellow, dia-magnetic carbonyl (C,H,),ReH(CO),. Slightly different conditions lead tothe formation of the tricarbonyl C,H,*Re(CO),, an air-stable yellow solid,m. p. 111-114", which is analogous to the manganese compound referredto above.359 Infrared and high-resolution nuclear magnetic resonancespectra of the compound (C,H,),ReH(CO), indicate that it is in fact di-carbonyl-n-cyclopentadienylcyclopen tadienerhenium (32).The hydrogenatom originally regarded as bonded to the metal is located in the cyclo-pentadiene ring.360Structure (33) has been confirmed for tetracarbonyldicylcopentadienyl-di-iron by X-ray crystallography. The proximity of the iron atomsa53 R. Nast and H. Griesshammer, 2. anorg. Chem., 1958, 293, 322.3,4 R. Nast and W. Pfab, ibid., 1957, 292, 287.S55 E. 0. Fischer and S. Vigoureux, Chem. Ber., 1958, 91, 2205.356 Idem, ibid., p. 1342.357 M. L. H. Green, L. Pratt, and G. Wilkinson, J., 1958, 3916.358 E. 0. Fischer and A. Wirzmuller, 2. Naturforsch., 1957, 12b, 737; see also E.0.359 R. L. Pruett and E. L. Morehouse, Chem. and Ind., 1958, 980.380 M. L. H. Green and G. Wilkinson, J., 1958, 4314.Fischer, J . Inorg. Nuclear Chem., 1958, 8, 268152 INORGANIC CHEMISTRY.(2.49 A) indicates an Fe-Fe bond.361 The formation of dicyclopentadienyl-rhodium from ruthenocene by neutron bombardmentn. Y -B, Y104R~(C5H5)2 __+c lo5Ru(C5H,), ___t 105Rh(C5H5)2has been detected.362 The microwave spectrum of nitrosylcyclopentadi-enylnickel, C,H,*NiNO, can arise only if the Ni-N-O atoms are strictlylinear and form an axis of symmetry normal to the cyclopentadiene~lane.~63 Reaction between nickelocene and nickel carbonyl in benzenesolution is as follows:Ni(C5H5), + Ni(CO), --W [C,H,*NiCO], + 2COThe red, diamagnetic nickel(1) product sublimes in vacuum at 80-90".This compound completes the series C,H,*V(CO),, [C5H5*Cr(CO),],,C,H,*Mn (CO),, [C,H,*Fe (CO) J2, C,H,*Co (CO),, [C,H,*NiCO],, each of whichis diamagnetic.The nickel compound decomposes at high temperatures togive the dark green paramagnetic product (C,H,),Ni3(C0),.364Triphenylchromium is obtained as the addition compound CrPh,(C,H,O),,a blood-red compound, by reaction of chromic chloride and phenylmagnesiumbromide in tetrahydrofuran (C,H,O). I t is extremely sensitive to moisture.When heated, it loses tetrahydrofuran; hydrolysis of the black residue givesdibenzenechromium and benzenediphenylchromium, which involves theunusual rearrangement of a covalently bonded phenyl group to a X-complex.365 The addition compound 3LiPh,CrPh3,2.5Et,0 has also beenprepared from chromic chloride and phenyl-lithi~m.~~~ Chromium(1) formsa mixed sandwich complex resembling the known manganese compoundMn(C,H,Me)C,H,.Chromic chloride is treated with equal molar quantitiesof phenyl- and cyclopentadienyl-magnesium bromide, and the orange ,paramagnetic product Cr(C,H,) (C6H6) (m. p. 227') is obtained.,67 Thereaction Cr(C,H,), + Cr(CO), + 2C6H6Cr(CO), proceeds in the presenceof benzene at 220". Tricarbonylbenzenechromium (m. p. 162") sublimes ina vacuum at 60-90°.368 In a simpler, more general method, tricarbonylderivatives of aromatic compounds can be prepared by heating chromiumhexacarbonyl under reflux in excess of the aromatic compound, or with amolar quantity in an inert solvent at 100-210".A wide range of aromaticcompounds (Ar) can be used, including hydrocarbons, primary, secondary,and tertiary amines, and methyl benzoate. All products have the generalformula ArCr(CO),. Molybdenum hexacarbonyl similarly gives a tri-carbonyl derivative with mesit ylene .369361 0. S. Mills, Acta Cryst., 1958, 11, 620.362 F. Baumgartner, E. 0. Fischer, and U. Zahn, Chem. Ber., 1958, 91, 2336.363 A. P. Cox, L. F. Thomas, and J. Sheridan, Nature, 1958, 181, 1157.364 E. 0. Fischer and C. Palm, Chem. Ber., 1958, 91, 1725; see also E. 0. Fischer,365 W. Herwig and H. H. Zeiss, J . Amer. Chem. SOC., 1957, 79, 6561.368 F. Hein and R. Weiss, 2. anorg. Chem., 1958, 295, 145.367 E. 0. Fischer and H. P. Kogler, 2.Naturforsch., 1958, lab, 197.368 E. 0. Fischer and K. ofele, Chem. Ber., 1957, 90, 2532.368 B. Nicholls and M. C. Whiting, Proc. Chem. SOC., 1958, 152; see also G. Natta,R. Ercoli, and F. Calderazzo, Chimica e Industria, 1958, 40, 287; E. 0. Fischer, K.Ofele, H. Essler, W. Frohlich, J. P. Mortensen, and W. Semmlinger, 2. Naturforsch.,1958, 13b, 458.J . Inorg. Nuclear Chem., 1958, 8, 268ADDISON AND GREENWOOJ) THE TRANSITION ELEMENTS. 153The field of metal-aromatic complexes has been extended to include awider variety of aromatic systems. X-Ray analysis of di-indenyliron showsthe iron atom to be situated between the five-membered rings, which areparallel and 3-43 A apart. The molecule has the gauche ~onfiguration.~~OMolybdenum carbonyl gives an azulene derivative C,,H,O,Mo, ; the moleculemay consist of two Mo(CO), groups, one of which is bound to the seven-membered and one to the five-membered ring.371 With cycloheptatriene, anorange-red crystalline derivative C,H,Mo(CO), is obtained, rather than atropylium compound.This sublimes in a vacuum at 85" and is believed tohave the structure (34). The six x-electrons form a delocalized system whichby-passes the methylene group.372 The corresponding tropylium ioncomplex has now been prepared, by treatment of compound (34) withtriphenylmethyl fluoroborate, and isolated as the complex [(C,H,+)Mo(CO)JBF4-.373 Similar compounds have been obtained by reaction with ironcarbonyls. Dicarbonylcycloheptatrienyliron, C,H,Fe(CO), (b. p. 70°/0.4mm.) , is a mobile, air-stable liquid.With azulene, pentacarbonylazulenedi-iron C,H,Fe,(CO), is formed as a red solid, which decomposes at 100" togive azulene again.374 Tricarbonylcycloheptatrienechromium has also beenprepared, together with a number of compounds in which a substituent ispresent in the l-position in the cycloheptatriene ring. Prolonged reactionbetween dicycloheptatrienyl and molybdenum carbonyl produced thecompound (35), and hexacarbonyl(dicycloheptatrieny1 ether) dimolybdenumhas also been prepared.375 Reactions with platinum halides give the com-pounds [C,H,*PtBr,], 376 and (C,H,),PtC1,.575Of particular interest is the formation of aromatic x-type complexes withheterocyclic compounds. Thiophen reacts with iron pentacarbonyl to give(C,H,S)Fe(CO),, m.p. 51", as pale red crystals soluble in most organicsolvents and readily sublimable,374 and with chromium hexacarbonyl to give(C,H,S)Cr(CO),. The properties of the latter indicate that it has thestructure (36) .377The Scandium Group and Lanthanides.-Lanthanum dicarbide has astructure of the calcium carbide type, with C-C distance (1.28 A) inter-mediate between double and triple bond distances. However, its con-370 J. Trotter, Acta Cryst., 1958, 11, 355.371 R. Burton and G. Wilkinson, Chem. and Ind., 1958, 1205.372 E. W. Abel, M. A. Bennett, and G. Wilkinson, Proc. Chem. SOL, 1958, 152.373 H. J. Dauben and L. R. Honnen. J . Amer. Chem. Soc., 1958, 80, 5570.374 R. Burton, M. L. H. Green, E. W. Abel, and G. Wilkinson, Chem.and Ind., 1958,575 E. W. Abel, M. A. Bennett, R. Burton, and G. Wilkinson, J., 1958, 4559.376 E. 0. Fischer and H. P. Fritz, 2. phys. Chem. (Frankfurt), 1958, 17, 132.377 E. 0. Fischer and K. ofele, Chem. Ber., 1958, 91, 2395.1592154 INORGANIC CHEMISTRY.ductivity is comparable with that of lanthanum metal, whereas calciumcarbide is an insulator. Since true salts of La2+ are unknown, lanthanumdicarbide can be described in terms of La3+C2,-, with the extra electron in aconduction band. The sesquicarbide La,C3 also contains C, ions and is ametallic conductor, though its conductivity is only half that of the dicarbideor the free A new carbide M3C has also been found which has thecubic sodium chloride type of structure except that it is deficient in carbon.It is found for elements M = Sm-Lu, but not when M = La, Ce, Pr, orNd.379 The slight volatility of lanthanum butoxide La(OBut), indicatesthat it is polymeric.s0 Lanthanum rhodium oxide LaRhO, has a distortedperovskite structure.381 Oxide monosulphides M20,S have been preparedfrom sesquioxides by reaction with carbon disulphide or thioacetamide andsubsequent reduction by hydrogen.Sm202S oxidizes at 620" in one step toSm202*S04, a member of a new isostructural series of lanthanide compoundsM202*S0,.382The Titanium Group.-Modern techniques in the chemistry and metal-lurgy of titanium production have been reviewed.383 When ammonia gas ispassed into a suspension of titanium trichloride in a mixture of benzene andacetylacetone, a dark blue hexaco-ordinated complex Ti(C,H,O,), separateswhich is sublimable in a vacuum.3M The related compound Ti(C,H,O,),Clis probably dimeric, with chlorine bridging, thus retaining hexa-co-ordin-ation.385 By reduction of a mixture of titanium tetrachloride and 2,2'-di-pyridyl (dipy) in tetrahydrofuran with lithium, Ti(dipy), (violet needles)and LiTi(dipy),,3-5C4H,O (black plates) are obtained; physical propertiesconfirm that they are compounds of titanium(0) and titanium( - I), respec-tively.386 Normal titanium sulphate, Ti(SO,),, is formed by reaction oftitanium tetrachloride with sulphur trioxide :TiCI, + 6S0, __t Ti(SO,), + 2S,0,C12Parachors derived from densities and surface tensions of monomerictertiary alkoxides of Ti, Zr, Sn, Ce, and Th indicate considerable intra-molecular congestion, accentuated by metal-oxygen bond contraction388Vapour pressures of titanium tetra-t-butoxide and -pentyloxide have beenmeasured with precision ; 389 the apparatus incorporates a new double-spoonpressure gauge.390 Reactions involving a chloro-alcohol, chloro-aldehyde , orchloroalkanecarboxylate have been used to prepare chloro-alkoxides of Ti,378 M.Atoji, K. Gschneidner, A. H. Daane, R. E. Rundle, and F. H. Spedding, J .379 F. H. Spedding, K. Gschneidner, and A. H. Daane, ibid., p. 4499.380 D. C . Bradley and M. M. Faktor, Chem. and Ind., 1958, 1332.381 A. Wold, B. Post, and E. Banks, J . Amer. Chem. SOC., 1957, 79, 6365.382 H. A. Eick, ibid., 1958, 80, 43.383 J. J. Gray and A. Carter, Roy.Inst. Chem. Monographs, 1958, No. 1.384 B. N. Chakravarti, Naturwiss., 1958, 45, 286.385 A. Pflugmacher, H. J. Carduck, and M. Zucketto, ibid., p. 490.386 S. Herzog and R. Taube, Angew. Chem., 1958, 70, 469.387 V. G. Chukhlantsev, Zhur. neorg. Khim., 1957, 2, 2014.388 D. C. Bradley, C. C. A. Prevedorou, J. D. Swanwick, and W. Wardlaw, J., 1958,389 D. C. Bradley and J. D. Swanwick, J., 1958, 3207.390 J. D. Swanwick, J., 1958, 3214.Amer. Chem. SOC., 1958, 80, 1804.1010ADDISON AND GREENWOOD: THE TRANSITION ELEMENTS. 155Zr, Ce, and Th, e.g., M(OX), and MCL(OX),, where X = CC1,-CMe2.391Zirconium forms a series of stable double alkoxides MZr(OR),, where R =Prn, Pri, Bun, and Bus, and M = Li, Na, or K. Many sublime or distilunchanged under reduced pressure.392 Complexes of titanium tetrafluoride,tetrabromide, and tetraiodide with various organic ligands (e.g., pyridine,nitriles) have been compared in stability with the known titanium tetra-chloride complexes; those of the tetraiodide are least readily formed.Fora given ligand and halide, the dissociation pressure is higher for the zircon-ium than the titanium complex.393 The complex(C5H5)2TiCI,A1(C2H,)2 shows catalytic activity in,cl, /Et ethylene polymerization ; from X-ray examinationthe structure is that shown in (37).394 BTi 'Et The interaction of the intermetallic compoundZrNi with hydrogen bears no resemblance to thezirconium-hydrogen system. The alloy forms adefinite hydride at a limiting composition ZrNiH,, and possibly a secondhydride ZrNiH.395 A technique has been developed which enables apowdered zirconium-oxygen flame to be operated.The flame temperature,4930" K at 1 atm. pressure, is the highest metal flame temperature recordedto date.Sg6 X-Ray diffraction of thorium germanides indicates at least sixgermanide phases. The phase of highest germanium content is ThGe(,.,+_,.,,.Tetragonal a-ThGe, is isostructural with a-ThSi,. The compounds ThGeand Th,Ge, are also discussed.3g7 In the acetylacetone complexTh(C5H,02),, the eight co-ordinating oxygen atoms form a square antiprismaround theThe Vanadium Group.-The hydrated oxides of niobium(v) andtantalum(v) (niobic and tantalic acids) will give water-soluble complexeswith a variety of a-hydroxy-acids, which may be phenolic or carboxylic.Niobic acid has a much greater solubility than tantalic acid in these solutions,but when the two acids are coprecipitated, part of the tantalum is carriedinto solution with the niobium as a result of the multinuclear character of thecomplexes.399 Thermal and X-ray analysis of the system Na,O-Nb,O,show the existence 400 of four compounds Na,O, 14Nb20,, Na20,4Nb,05,Na20 ,N b205 and 3Na20 ,Nb,O,.Vanadium tetrachloride reacts withalcohols in cold benzene forming compounds VCl,(OR),,ROH (R = Me, Et,Pr, Bu, or n-pentyl). On heating these products under vacuum at 150°,A1 .G?(37)391 D. C. Bradley, R. N. P. Sinha, and W. Wardlaw, J . , 1958, 4651; see also A. M.392 W. G. Bartley and W. Wardlaw, J., 1958, 422.ss3 H.J. Emeldus and G. S. Rao, J., 1958, 4245; see also J. Archambault and R.394 G. Natta, P. Corradini, and I. W. Bassi, J . Amer. Chem. SOC., 1958, 80, 755.395 G. G. Libowitz, H. F. Hayes, and T. R. P. Gibb, J . Phys. Chem., 1958, 62, 76.396 W. L. Doyle, J. B. Conway, and A. lT. Grosse, J , Inorg. Nuclear Chem., 1958,397 A. G. Tharp, A. W. Searcy, and H. Nowotny, J . Electrochem. SOC., 1958, 105,398 D. GrdeniC and B. Matkovie, Nature, 1958, 182, 465.399 F. Fairbrother, D. Robinson, and J. B. Taylor, J . Inorg. Nuclear Chem., 1958, 8,400 A. Reisman, F. Holtzberg, and E. Banks, J . Amer. Chem. SOC., 1958, 80, 37.El-Aggan, D. C. Bradley, and W. Wardlaw, J., 1958, 4643.Rivest, Canad. J . Chem., 1958, 36, 1461; R. Aubin and R. Rivest, ibid., p.915.6, 138.473.296; J., 1958, 2074156 INORGANIC CHEMISTRY.conversion into vanadium oxychloride alkoxides V,OCl,(OR), occurs.Molybdenum pentachloride reacts similarly.401 Volatile mixed alkoxides oftantalum Ta(OR)(OR'), are formed provided that R' is a branched alkylVanadium pentafluoride reacts with nitryl fluoride to form involatile,white N0,VF6, and with nitrosyl fluoride to give the nitrosonium saltNOoVF,. The corresponding hexafluoroniobates and hexafluorotantalatesare best prepared by reaction of the metal pentoxide and bromine trifluoridewith dinitrogen tetroxide or nitrosyl chloride. Chloryl hexafluorovanadateis stable only at low temperatures. Vanadium pentafluoride is convertedby sulphur dioxide or trioxide into the oxyfluoride VOF,; in contrast,niobium and tantalum pentafluorides give addition compounds formulatedas fluorosulphates e.g., NbF,(SO,F),. Direct action of pyridine with thepentafluorides also yields addition compounds, e.g., (C,H,N),NbF,.Theseare white solids, stable in air and readily soluble in ~ater.~W Ruff andLickfett in 1911 reported vanadium oxytrifluoride as having m. p. 300",b. p. 480". The vapour pressure has now been measured from 72.1"(122.7 mm.) to 122.8" (1519 mm.) ; the vapour pressure of the solid reaches760 mm. at 110", so that the compound is much more volatile than waspreviously reported. There is no melting or solid transition between 72"and 123°.404 The preparation of some addition compounds of vanadiumoxytrichloride (e.g., VOC1,,2X, where X = an amine or nitrile) and substitu-tion compounds (e.g., chloride alkoxides) has been described.405 Vanad-ium(1v) chloride undergoes partial solvolysis in liquid ammonia to give thecompound VCl(NH,),. The solubility of the latter in liquid ammoniacontaining ammonium chloride is attributed to ionic species of the typeNH,vC12(NH,),].QOG Niobium and tantalum pentachlorides and penta-bromides form 1 : 1 complexes with diethyl ether which decompose at 100"into ethyl halide and metal oxytrihalide; tantalum pentaiodide does notform an ether complex.407Although niobium pentachloride and pentabromide exist as monomerictrigonal bipyramidal NbC1, and NbBr, molecules in the vapour, the solidchloride consists of dimers Nb,ClIo, with two chlorine atoms bridging twooctahedra.NbBr, and TaC1, appear to be isomorphous with thisstructure.408 Conditions have been reported for the preparation andsublimation of niobium(1v) iodide by thermal decomposition of the penta-iodide, and for subsequent disproportionation to give niobium(Ir1) iodide.The grey tetraiodide, like the pentaiodide, is extremely sensitive to waterand oxygen, whereas the black tri-iodide is stable to air.409 Niobium tri-iodide, prepared from aluminium iodide and niobium pentoxide, has been401 D. C. Bradley, R. K. Multani, and W. Wardlaw, J., 1958, 4647.402 D. C. Bradley, B. N. Chakravarti, A. K. Chatterjee, W. Wardlaw, and -4. Whitley,408 H. C. Clark and H. J. EmelCus, J., 1958, 190.404 L. E. Trevorrow, J. Phys. Chem., 1958, 62, 362.405 H.Funk, W. Weiss, and M. Zeising, 2. anorg. Chem., 1958, 296, 36.408 G. W. A. Fowles and D. Nicholls, J., 1958, 1687.407 A. Cowley, F. Fairbrother, and N. Scott, J., 1958, 3133.408 A. Zalkin and D. E. Sands, Acta Cryst., 1958, 11, 615.409 J. D. Corbett and P. X. Seabaugh, J. Inorg. Nudear Chem., 1958, 6, 207.group.402J., 1958, 99ADDISON AND GREENWOOD : THE TRANSITION ELEMENTS. 157reduced in a current of hydrogen at 300" to the d i - i ~ d i d e . ~ ~ ~ The mixedhalides NbBrI,, TaBr,I, and TaBrI, have been produced by reaction of analuminium bromide-iodide mixture with niobium or tantalum ~entoxide.~llRecent developments in the chemistry of protactinium and neighbouringelements have been reviewed.412 A detailed examination has been made ofthe factors influencing the extraction of protactinium from chloride solutionsby a number of organic solvents.Results can be explained in terms of thedistribution of an ion-pair complex formed by a chloro-anion containing themetal, and an " onium " cation containing water and solvent m0lecules.4~~In nitric acid solutions the protactinium species consist of a series of hydroxo-nitrat o-complexes .414The Chromium Group.-The chemistry of chromyl compounds has beenreviewed.415 New chromyl compounds include chromyl fluoride chloride,416and chromyl acetate (m. p. 30.5°).a7 Chromous acetylacetone (m. p. 218")is obtained as a yellow powder from chromous acetate and acetylacetone insealed apparatus under pure nitrogen. It is oxidized vigorously in air, andmay ignite in oxygen.418 The reaction Cr,O,,- + ZNO,- _t N,O, +2Cr0,2-, followed by N,O, + 2N0, + 402, proceeds at a measurable rate infused potassium nitrate-sodium nitrate eutectic mixture at 250°.41s Bluecomplexes of chromium(II1) with o-phenylenebisdimethylarsine are non-electrolytes of the type [Cr(diarsine)X,,H,O], where X is a halogen.Fromgreen complexes [Cr(diarsine),X,] [Cr(diarsine) X,] the perchlorate [Cr(di-arsine),X,]ClO, is readily isolated. The magnetic moment of each com-pound is near 3.9 B.M., indicating that electron pairing has not takenplace.420 No diarsine complex containing three molecules of ligand co-ordinated to a single chromium atom was obtained,420 but the ligand 2,2'-dipyridyl forms the complex [Cr(dipy),].Proton magnetic resonance and infrared measurements show that theyellow solid which slowly separates from a nitric acid solution of ammoniummolybdate is the hydrate MoO3,2H,O, and not MoO,(OH),,H,O or(H,0)2+Mo0,2-.A monohydrate MoO,,H,O is also confirmed.42" Severalequilibria are involved in the vaporization of the oxides MOO,, Mo,O1,,MOO,, WO,, and WO, at high temperatures. The trioxide vaporizes to thetrimer (MOO,)&), while Mo,O,,(s) disproportionates to (MoO,),(g) andMoO,(s) ; the latter disproportionates further to (MOO,), and Mo(s). Thetungsten oxides behave similarly.423 Both 3 : 12- and 1 : 12-heteropoly-410 M. Chaigneau, Corn@. rend., 1957, 245, 1806.411 Idem, ibid., 1958, 247, 300.412 A. G. Maddock, X VI Internat.Congr. Pure A#. Chew., Experieittia Szcppl.413 A. G. Goble and A. G. Maddock, J . Inorg. Nuclear Chem., 1958, 7 , 94.414 C. J. Hardy, D. Scargill, and J. M. Fletcher, ibid., p. 257.415 W. H. Hartford and M. Damn, Chem. Rev., 1958, 58, 1.416 G. D. Flesch and H. J. Svec, J . Amer. Chem. Soc., 1958, 80, 3189.417 H. L. Krauss, Angew. Chem., 1958, 70, S02.418 G. Costa and A. Puxeddu, J . Inorg. Nuclear Chem., 1958, 8, 104.419 F. R. Duke and M. L. Iverson, J . Amer. Chem. Soc., 1958, 80, 5061.420 R. S. Nyholm and G. J. Sutton, J., 1958, 560.421 S. Herzog, I<. C. Renner, and W. Schon, 2. Naturforsch., 1957, 12b, 809.422 S. MariEiC and J. A. S. Smith, J . , 1958, 886.423 P. E. Blackburn, M. Hod, and H. L. Johnston, J . Plzys. Clzem., 1958, 62, 769.V I I , 1957, 213158 INORGANIC CHEMISTRY.acids of zinc with tungstate have been recognized. The chemistry of12-tungstozincic acid and its salts resembles that of 12-tungstophosphoricacid. The structure is similar but with zinc replacing phosphorus as thecentral atom.424 A white cyano-complex of molybdenum(Iv), KMo(CN),,is prepared directly from potassium cyanide and molybdenum trioxide, orfrom other cyano-complexes.The anion is uninuclear, and the molyb-denum atom believed to be penta~o-ordinate.~~~Tungsten hexafluoride reacts with sulphur trioxide to give the fluoro-sulphate WF,(SO,F),. With ammonia the tetra-ammine WF,(NH,), isformed, and similar addition compounds WF,(C,H,N), and WF,(CH,*NH,),are formed with pyridine and with methylamine.Pure tungsten hexa-fluoride does not react with alkali-metal fluorides under strictly anhydrousand grease-free conditions.426 The higher complex fluorides of tungsten (VI)are best prepared by addition of excess of the hexafluoride to the alkaliiodide in the presence of iodine pentafluoride. The compounds K2WF,,K,WF,, RbWF,, CsWF,, and CsWOF, have been characterized, and ananalogous series of molybdenum fluoro-complexes obtained by similarreactions. Magnetic properties of the complex fluorides MMoF,, MWF,,and MReF, (M = alkali metal) have been compared.427The infrared spectrum of uranyl nitrate hexahydrate is typical of anionic nitrate. However, the spectra of the di- and tri-hydrate are similarto that of rubidium uranyl nitrate, and are characteristic of compoundshaving co-ordinated nitrate groups.In the structures postulated for theselower hydrates some of the nitrate groups act as bidentate ligands.428Uranium tetrachloride forms addition compounds with amines and am-monia, of general formula UCl,,nRNH,. When R = H, Me, Et, then n = 2,2, and 1 or 2, respectively. A hydrazine addition compound UC14,6N2H, hasalso been identified.429 Phase equilibria in the systems NaF-ZrF,,UF4-ZrF,, and NaF-ZrF4-UF4 have been examined in detail. The uraniumsystems are of interest as potential fuels in fluid reactors.&OThe Transuranium Elements.-Reviews on recent research on theactinide elements,&l and on the transuranic elementsJa2 have been publishedduring the year.Reversible equilibrium amongst the four oxidation statesof plutonium is maintained at all times, but reaction between Pu3+ andPu022+ is demonstrably slow. The kinetics of the reaction Pu3+ +Pu022+ Pu4+ + PuO,' have been studied spectrophotometrically, thePuO,2+ absorption peak at 8304 crn.-l being used. Reaction rate isindependent of hydrogen-ion concentration.= With vanadium(II1) in place424 D. H. Brown and J. A. Mair, J., 1958, 2597.425 M. C. Steele, Austral. J . Chem., 1957, 10, 404.426 H. C. Clark and H. J. EmelCus, J., 1957, 4778.427 G. B. Hargreaves and R. D. Peacock, J., 1958, 2170, 3776, 4390.428 B. M. Gatehouse and A. E. Comyns, J., 1958, 3965.429 I. Kalnins and G. Gibson, J . Inorg. Nuclear Chem., 1958, 7 , 56.430 C. J. Barton, W.R. Grimes, H. Insley, R. E. Moore, and R. E. Thoma, J . phys.Chem., 1958, 62, 665; see also C. J. Barton, H. A. Friedman, W. R. Grimes, H. Insley,R. E. Moore, and R. E. Thoma, J . Amer. Ceram. SOC., 1958, 41, 55.431 G. T. Seaborg, X V I Internal. Congr. Pure AppZ. Chem., Experientia Suppl. V I I ,1957, 63.432 H. J. EmelCus, Chem. and Iitd., 1958, 1276.493 S. W. Kabideau and R. J. Mine, J . Phys. Clrcnz., 1958, 62, 617ADDISON AND GREENWOOD : T H E TRANSITIOPU' ELEMENTS. 159of plutonium(m), the stoicheiometry of the reaction is PuO,2+ + V3+ +H20 + Pu02+ + V02+ + 2H+.434 Other reactions for which kinetics andmechanism have been examined include neptunium (111)-neptunium(v)plutonium(v1)-uranium(1v) ,m6 and the reduction of neptunium(v1) toneptunium(v) by hydrogen peroxide.m7Partition coefficients have now been determined for (Th, Np, Pu) (NO,),and (U, Np, Pu)O,(NO,), between aqueous nitric acid and tri-n-butylphosphate (TBP).All are strongly extracted, and form disolvatesM (NO,),, 2TBP and MO, (NO,) ,, 2TBP.a Absorption spectra of plu tony1nitrate in dibutylcarbitol show the presence of both the dinitrate and thetrinitrate. The latter has a much higher partition coefficient for extractionfrom nitric acid solution, and is formed preferentially. The associationconstant for the reaction PuO,(NO,), + HNO, --w HPuO,(NO,), is4 & l.439 All the plutonium(1v) present in nitrate solutions above 1 ~ -concentration, or in 1AM-nitric acid, is in the form of undissociatedPu(NO,),. The only plutonium(1v) species present in concentrated nitricacid is HzP~(N0,),.440 A solution containing plutonium in the plutonium-(v) state only has been prepared by mixing equal quantities of plutonium(II1)and plutonium(v1) in 0.2~-nitric acid.The reaction PU(III) + PU(VI) _tPU(IV) + Pu(v) occurs; the plutonium(1v) is extracted into dibutylhydrogen phosphate in benzene, leaving plutonium(v) in the aqueousphase .*lAnhydrous plutonium(1v) sulphate is not a suitable form in whichplutonium can be weighed in gravimetric analysis, since its compositionvaries slightly with the temperature at which it is prepared from the hydrate.Dilute aqueous solutions become turbid a t a rate which depends on con-centration. An anionic complex is probably formed by sulphate ionsliberated by hydrolysis; electromigration experiments on a solution of thesulphate in water revealed the presence of much anionic, but negligiblecationic, plutonium.u2 Ozone converts plutonium(1v) into plutonium(v1) inmacro-concentration in dilute sulphuric acid and in the absence of catalysts,thus permitting preparation of pure plutonium(v1) sulphate solutions.Therate of oxidation is much slower than in dilute nitric or perchloric acid, owingto increased stabilization of plutonium(1v) by sulphate complex formation.443Studies have been made of equilibria involving oxalate complexes ofplutonium(II1) ,444 the plutonium( IV) oxalate complexes [Pu (C,O,) I,+-,[PU(C,O,),]~, [Pu(C,O,),]~-, and [PU(C~O,),]~-, plutonium(1v) carbonate434 S.W. Rabideau, J . Phys. Chem., 1958, 62, 414.435 J. C. Hindman, J. C. Sullivan, and D. Cohen, J . Amer. Chem. SOC., 1958,80, 1812.436 T. W. Newton, J . Phys. Chem., 1958, 62, 943.437 A. J. Zielen, J. C. Sullivan, D. Cohen, and J. C. Hindman, J . Amer. Chem. SOC.,438 I<. Alcock, G. F. Best, E. Hesford, and H. A. C. McKay, J . Inorg. Nuclear Chem.,439 T. V. Healy and A. W. Gardner, ibid., 1968, 7, 245.440 J. A. Brothers, R. G. Hart, and W. G. Mathers, ibid., p . 85.441 T. L. Markin and H. A. C. McKay, ibid., p . 298.442 J. L. Drummond and G. A. Welch, J., 1958, 3218.443 D. W. Grant, J . Inorg. Nuclear Chem., 1958, 6, 69.444 A. D. Gel'man, N. N. hlatorina, and A . I. Moskvin, Doklady Akad. Naitk S.S.S.R.,1958, 80, 5632.1958, 6, 328; T.Sato, ibid., p . 334.1957, 117, 88160 INORGANIC CHEMISTRY.c ~ m p l e x e s , ~ ~ and oxalate and carbonate complexes of the plutonium(v1)species.M6 Methods for the preparation of two new plutonium phosphatesPuPO, and PuP,O, employ plutonium oxalatophosphates as inter-mediate~.~' Plutonium dioxide has a formula in the range PuO,,,.,,depending on starting material and ignition temperature. Thus the productmade by ignition at 1200" is stoicheiometric; that made by ignition ofplutonium salts in air a t 870" has a higher molecular weight. Plutoniummetal or its hydride reacts with graphite at 900" to give the monocarbidePuC. A sesquicarbide Pu,C, was also formed when the oxide PuO, wasreduced by graphite at 1800". Both carbides are easily hydrolysed by boil-ing water or dilute acid.448 Conditions for the preparation of neptuniumoxides have been modified and improved.449 A technique being used whichpermits spectral examination of submilligram amounts of solids, theabsorption spectra of curium(Iv) fluoride and americium(rv) fluoride havebeen measured for comparison with spectra of the trifluorides of thesee1ements.m The ion-exchange behaviour, and dissociation constants, ofEDTA complexes of americium, curium, and californium show that EDTA isa useful separating agent.451 Americium oxalate, dried in a vacuum atroom temperature, exists as the heptahydrate.When heated in air thispasses through the 4-, 3-, 1-, and 06hydrates, giving the anhydrous oxalateat 240". Conversion into the dioxide is complete at 470", with no evidencefor carbonate formation during final decomposition.In vacuum, decom-position to the sesquioxide Am,O, occurs.452It is reported that in many scores of experiments, workers at Berkeley,California, have been unable to repeat the preparation of the 251 or 253isotope of element 102 (having a-activity of 8-5 MeV) claimed to have beenproduced by bombarding 244Cm with 90-Mev ions of 13C4+. The claim tohave prepared nobelium by this method is therefore disputed. More recentexperiments, using the new Berkeley heavy-ion linear accelerator, haveproduced *NO, an or-emitter. The daughter element 250Fm is separated 453by taking advantage of recoil on decay of 254No. Helium-ion bombardmentof WEs has led to identification of a new isotope 255Md.This has a half-lifeof about QThe Manganese Group.-The mechanism of oxidation by compounds ofmanganese 4 5 5 ~ ~ and of chromium 455 has been reviewed. Manganese(I1)forms compounds [Mn(diarsine),XJ with o-phenylenebisdimethylarsine,445 A. D. Gel'man and A. I. Moskvin, Doklady Akad. Nauk S.S.S.H., 1958, 118, 493;Zhur. neorg. Khim., 1958, 3, 956, 962.446 A. D. Gel'man and L. E. Drabkina, ibid., p. 1105; L. Drabkina, ibid., p. 1109.447 C. W. Bjorklund, J. Amer. Chem. SOL, 1957, 79, 6347.448 J . L. Drummond and G . A. Welch, J., 1957, 4781; J. L. Drummond, B. J.McDonald, H. M. Ockenden, and G. A. Welch, J., 1957, 4785.44s D. A. Collins and G. M. Phillips, J. Inorg. Nuclear Chem., 1958, 6, 67.450 W. T. Carnall, P.R. Fields, D. C. Stewart, and T. K. Keenan, ibid., p. 213;L. B. Asprey and T. K. Keenan, ibid., 1958, 7, 27.451 J. Fuger, ibid., 1958, 5, 332.463 T. L. Markin, ibid., 1958, 7, 290.455 A. Ghiorso, T. Sikkeland, J. R. Walton, and G. T. Seaborg, Phys. Rev. Letters,454 L. Phillips, R. Gatti, A. Chesne, L. Muga, and S. Thompson, ibid., p. 215.455 W. A. Waters, Quart. Rev., 1958, 12, 277.456 J. W. Ladbury and C. F. Cullis, Chem. Rev., 1958, 58, 403.and decays by orbital electron capture to 255Fm.1958, 1, 17, 18ADDISON AND GREENWOOD THE TRANSITION ELEMENTS. 161(X = halogen). A red manganese(II1) complex [Mn(diarsine)Cl,,H,O]C10,contains four unpaired electrons.s7 Rhenium(II1) complexes of the type[Re(diarsine),X,]ClO, are prepared by heating under reflux per-rhenic acid,the diarsine, hypophosphorous acid, and the appropriate halogen acid inalcohol.Vigorous reduction of the rhenium(II1) complexes, e.g. , with sodiumstannite, gives rhenium(I1) complexes [Re(diarsine),X,] ?58 Oxidation bychlorine or bromine gives the new complex [Re(diarsine),Cl,]ClO,; theoctaco-ordination of the rhenium(v) atom is of particular interest.459Potassium octacyanorhenate(v) K,[Re(CN),] and the rhenium(v1) com-pound K,[Re(CN),] show this octaco-ordination and, with the exception ofthe well-known molybdenum and tungsten compounds, they are the onlyoctaco-ordinated cyanides so far reported.460Rhenium mono- and tri-iodides have been identified as decompositionproducts of the tetraiodide. The reduction of per-rhenic acid by hydriodicacid gives black rhenium tetraiodide; the tri-iodide is a black crystallinesolid obtained by heating the tetraiodide in a sealed tube at 350".Whenheated to constant weight at 110" in a stream of nitrogen the tetraiodidegives the monoiodide ReI, which when heated further in a vacuumdecomposes to the free Ammonium hexaiodorhenate(1v) decom-poses to rhenium metal at 700" in a vacuum.462 Per-rhenyl fluorideRe0,F is obtained in good yield by the reaction 463 KReO, + IF, =Re0,F + IOF, + KF. Complexes of rhenium dichloride with water,hydrogen chloride , pyridine, and acetic acid have been de~cribed.,~Potassium pertechnetate may be converted into hexahalogeno-complexesby the following series of reactions:HCI HEr HIKTcO, --+ K2TcCI, __t K,TcBr, __t K,Tcl,KIThe magnetic susceptibility, absorption spectra, and crystal structures ofthese compounds resemble closely those of the corresponding rheniumcompound^.^^The Iron Group.-Nine primary alkoxides of iron, Fe(OR),, have beenprepared either from ferric chloride, the alcohol, and ammonia, or by alcoholinterchange.All except the methoxide volatilize unchanged in a vacuum.The normal alkoxides Fe(O*C,H,,+,),, where 'yt = 1-5, are trimers in boilingbenzene, but that of neopentyl oxide is dimeric. The influence of chainstructure has been studied for ten further branched-chain alkoxides?66Iron(1v) nitrilotriethoxide is obtained by the reaction NH4FeCl, +(HO*C,HJ,N,HCl + 4NH, _t Fe(O*C,H,),N + 5NH4C1. On addition ofether to the solution, green crystals of the monohydrate separate, and457 R.S. Nyholm and G. J. Sutton, J., 1958, 564.458 N. F. Curtis, J. E. Fergusson, and R. S. Nyholm, Chern. and Ind., 1958, 625.459 J. E. Fergusson and R. S. Nyholm, ibid., p. 1555.480 R. Colton, R. D. Peacock, and G. Wilkinson, Natuve, 1958, 182, 393.R. D. Peacock, A. J. E. Welch, and L. F. Wilson, J., 1958, 2901.462 A. A. Woolf, J . Inorg. Nuclear Chem., 1958, 7, 291.463 E. E. Aynsley and M. L. Hair, J., 1958, 3747.464 A. S. Kotel'nikova and V. G. Tronev, Zhur. neorg. Khim., 1958, 3, 1008.465 J. Dalziel, N. S. Gill, R. S. Nyholm, and R. D. Peacock, J., 1958, 4012.466 D. C. Bradley, R. K. Multani, and W. Wardlaw, J., 1958, 126, 4153.REP.-VOL. LV 162 INORGANIC CHEMISTRY.evaporation of a solution of the hydrate gives the anhydrous com-pound. It is polymeric, like the aluminium compound.467 Iron exists inmixed oxidation states in the fluoride Fe2F5,7H,0 (rFeF,,FeF3,7H,0).When heated at 100" this yellow hydrate is converted into the red trihydrateFe,F5,3H,0, and at 180" into blue-grey anhydrous Fe,F,.468 The phasediagram for the system FeC1,-KCl shows two compounds: KFeCl,, congruentm.p. 399", and K,FeCl,, incongruent m. p. 380".469 A mass-spectrometricstudy shows that at low temperatures (650" K) the vapour of ferrous chlorideis mainly monomeric, though the quantity of dimer Fe,Cl, increases rapidlywith temperature.470 When ferrous chloride is kept at 250-300" in anatmosphere of bromine, sublimation occurs, and mixed halide moleculesform the major species in the vapour phase.471The ruthenium@) species Ru3+, RuC12+, and RuCl,+ have been charac-terized in aqueous solution, ion-exchange resins being Ruthen-ium(I1) complexes with o-phenylenebisdimethylarsine, [Ru(diarsine),XJ,resemble those formed by manganese@). Oxidation gives ruthenium(II1)complexes containing the cation [Ru(diarsine),XJ+, which resist furtheroxidation.Osmium forms analogous complexes which can be oxidized bynitric acid to osmium(1v) compounds, e.g., [Os(diarsine),XJ (c104),.473 Theinfrared spectrum of potassium osmiamate K[OsO,N] confirms that theanion is a distorted tetrahedron, with three 0s-O bonds and one Os-N bond.Both this compound and potassium nitrilopentachloro-osmate, K,[OsCl,N] ,are diamagnetic.,7, Neither metallic ruthenium or osmium, nor theirdioxides, react with phosphorus trifluoride, but the tetroxides readily react.Ruthenium tetroxide gives (RuO,),,PF, at -lOO", and Ru04,PF3 a t 20".Osmium tetroxide behaves similarly, except that the compound (OsO,),,PF,must be heated to 70" before further addition of fluoride occurs.The com-pounds are black and very hygroscopic. By contrast, phosphorus trichlorideand tribromide reduce ruthenium tetroxide to give RuO,,PCl, andRuO,,PBr, ; osmium tetroxide is reduced by phosphorus trichloride toOSO,,PC~,.~~~ Aqueous solutions of the acid H,0sF6 have been prepared byion-exchange methods, and from the solution those salts M,OsF, (M = NH,,NMe,, Na) may be obtained which are not readily available by alternativeroutes.Iridium compounds behave similarly.476The most volatile product of the reaction between osmium metal andfluorine gas was first described in 1913 by Ruff and Tschirch as having m. p.32.1", b. p. 45.9", and was identified as osmium octafluoride. The synthesishas now been re-examined. Molecular-weight determinations and chemicalanalysis of a product having identical physical properties leave no doubtthat it is the hexafluoride OsF,, rather than OsF,. This is supported by467 K. Starke, J. Inorg. Nuclear Chem., 1958, 6, 130.468 G. Brauer and M. Eichner, 2. anorg. Chem., 1958, 296, 13.469 H. L. Pinch and J. M. Hirshon, J. Amer. Chem. Soc., 1957, 79, 6149.470 R. C. Schoonmaker and R. F. Porter, J.Chem. Phys., 1958, 29, 116.471 L. E. Wilson and N. W. Gregory, J . Amer. Chem. Soc., 1958, 80, 2067.472 H. H. Cady and R. E. Connick, ibid., p. 2646.478 R. S. Nyholm and G. J. Sutton, J., 1958, 567, 572.474 J . Lewis and G. Wilkinson, J. Inorg. Nuclear Chem., 1958, 6, 12.475 M. L. Hair and P. L. Robinson, J., 1958, 106.476 M. A. Hepworth, P. L. Robinson, and G. J, Westland, J., 1968, 611ADDISON AND GREENWOOD : THE TRANSITION ELEMENTS. 163X-ray diffraction, and by infrared and Raman spectroscopy. The octa-fluoride has had a significant place in chemical theory, so that it is importantto note that the compound known for many years as the octafluoride is infact the he~afluoride.~~~The Cobalt Group.-By the reaction [Co(NH,),]X, + 3KPH2 __tCo(PH,), + 3KX + 6NH, (where X = NO, or I), a cobalt derivative ofphosphine is obtained which is analogous to the metal amide.This isstrongly pyrophoric and decomposes spontaneously at 0" : Co(PH,), __tCo(PH), + 14H2. This second product is highly polymeric.478 Durrant'ssalt, K,[Co(C,O,),OH,H,O], has a bridged and binuclear structure. It isformed from cobalt(I1) solutions in excess of oxalate by the action of oxygen-carrying oxidants (H,O,, OCl-) . The one-electron oxidant Ce4+ gives 479instead [c0(c,o,),]3-. Complexes of the cobalt cyanides Co(CN),, Co,(CN),,and Co(CN), with dipyridyl and with phenanthroline have been described.aoRhodium and iridium form complexes in which a low valency is stabilized by2,2'-dipyridyl, and thus resemble cobalt.For example, reduction of thecomplex [Rh(dipy),] (ClO,), by borohydrides, sodium amalgam, or zincamalgam gives the bisdipyridyl salt [Rh(dipy),]C10,,3H,0.af In spite ofprevious statements, there is now evidence from spectrophotometry that acomplex is formed in solution between EDTA and anionic rhodium( 111) .482New hexaco-ordinated iridium complexes containing unidentate SOZ-groups, e.g., [Ir(S0,),C1,]5- and [Ir(S0,),(NH3)4]-, have been described.483The Nickel Group.-The factors which determine the formation of tetra-hedral nickel(I1) complexes are now better understood as a result of experi-ments on bistriphenylphosphine complexes. It was already known that thecomplexes (Et,P),NiX, (X = C1, Br, I) were diamagnetic, with trans-planarstructure, while (Et,P),Ni(NOJ, was paramagnetic and possibly tetrahedral.The complexes (Ph,P),NiX, (X = C1, Br, I, NO,) are now found to be para-magnetic and tetrahedral, although (Ph,P),Ni(SCN), is diamagnetic andprobably trans-square planar.In general, tetrahedral complexes ofnickel@) are formed only when ligands have insufficient perturbing power togive rise to spin-pairing, and when the steric requirements of the ligandsfavour this ~ t r u c t u r e . ~ ~ The complex Ni(en),(NCS), is blue and para-magnetic, but the co-ordination of the nickel ion is trans-octahedral, withNi-N distances of 2-10 A to the ethylenediamine and 2.15 A to the isothio-cyanate. A co-ordination octahedron also exists in [Ni(en) (H,O),] (NO,),,which is again blue and paramagnetic.485 This would indicate that the blue477 B.Weinstoclc and J. G. Malm, J . Amer. Chem. SOG., 1958, 80, 4466.478 0. Schmitz-Du Mont, F. Nagel, and W. Schaal, Angew. Chem., 1958, 70, 105.479 A. W. Adamson, H. Ogata, J. Grossman, and R. Newbury, J . Inorg. Nuclear480 E. Paglia, Atti Accad. naz. Lincei, Rend. Classe Sci.fis. mat. nut., 1958, 24, 725;481 B. Martin and G. M. Waind, J., 1958, 4284; Proc. Chem. Soc., 1958, 169; J .482 W. MacNevin, H. D. McBride, and E. A. Hakkila, Chem. and Ind., 1968, 101.483 V. V. Lebedinskii and 2. M. Novozhenyuk, Zhur. neorg. Khim., 1957, 2, 2490;484 L. M. Venanzi, J . , 1958, 719; J . Inorg. Nuclear Chem., 1958, 8, 137; see also485 E. C. Lingafelter, Nature, 1958, 182, 1730.Chem., 1958, 8, 319.L.Cambi and E. Paglia, J . Inorg. Nuclear Chem., 1958, 8, 249.Inorg. Nuclear Chem., 1958, 8, 551.1958, 3, 286.G. Giacometti, V. Scatturin, and A. Turco, Gazzetta, 1958, 88, 434164 INORGANIC CHEMISTRY.colour in paramagnetic nickel@) complexes is not indicative of tetrahedra1co-ordination, as has been suggested.m6 However, the whole question isby no means fully solved. In formazan complexes of the type shown in(38), there is considerable steric hindrance fromAr' Ar the aryl groups (Ar), which should favour tetra-/J=N, hedral configuration. However, the compoundsNi C'R are diamagnetic; this has been interpreted interms of a distorted planar structure retaining(38) dsP2 bondingm' A structure analysis of singlecrystals of the compound Ni(CN),,NH,,$H,Oreveals a modified form of the tetragonal planar nickel complex found in thebenzene compound Ni(CN),,NH,,C,H,.The layers are staggered so thatthe projecting ammonia groups of one layer point towards the holes in thesquare network of its neighbours. Single crystals of the benzene compoundin the presence of moisture change to this hydrate structure.&* Ammines ofnickel cyanide have been further and additional structuralinformation on the benzene clathrate obtained from magnetic measurementsand infrared ~pectra.4~0Normal o-bonds between palladium and organic groups can be stabilizedby appropriate co-ordination ; organopalladium compounds prepared in-clude the complexes (PEt,),PdMe,, (PEt,),PdPh,, and corresponding phenyl-ethynyl and dimethylaminophenyl compounds.491 NNN'N'-Tetramethyl-o-phenylenediamine reacts readily with an aqueous solution of the compoundK,PdCl, giving yellow needles of the stable complex C,H4(NMe2),,PdC1, ;corresponding bromo- and iodo-derivatives have been isolated.Thisis an interesting example of stability produced by chelation where the ligandsthemselves have poor co-ordinating p0wers.4~~ The ability of dimethyl-o-methylthiophenylarsine (chel) to function as a chelating ligand is demon-strated by the formation of paramagnetic nickel(11) complexes Ni(chel),X,(X = C1, Br, I). Palladium(I1) forms two types, Pd(chel)X, (whichare non-electrolytes in nitrobenzene) and Pd(che1) ,X,. The compound[Pd(chel),](ClO,), has the conductivity expected of a bi-univalent electrolytein nitr~benzene.~~,There is a well-defined absorption band (at about 2000 cm.-l) in theinfrared spectrum of the stable hydrides (PR,),PtHX (R = alkyl and X =halogen or other univalent acid radical) attributable to the Pt-H stretchingfrequency.The Pt-H bond strength vanes with X to an extent which isrelated to the trans-effect exerted by X. An impure palladium analogue(PEt,),PdHCl, and a new platinum hydride (PEt,),PtH,Cl,, have beendescribed.494 X-Ray analysis of the compound (Et4N),[Pt2Br6] has con-R. q N -N=NH Ar "-"' Ar'486 L. I. Katzin, Nature, 1958, 182, 1013.487 H. Irving and J. B. Gill, Proc. Chem. Soc., 1958, 168.468 J. H. Rayner and H. M. Powell, J.. 1958, 3412.489 E. E. Aynsley and W. A. Campbell, J., 1958, 1723.'90 M.Kondo and M. Kubo, J . Phys. Chem., 1957, 61, 1648; R. S. Drago, J. T.Kwon, and R. D. Archer, J . Amer. Chem. SOL, 1958, 80, 2667.491 G. Calvin and G. E. Coates, Chem. and Ind., 1958, 160.492 F. H. C. Stewart, ibid., p. 264.493 S. E. Livingstone, J., 1958, 4222.404 J. Chatt, L. A. Duncanson, and B. L. Shaw, Chem. and Ind., 1958, 869ADDISON AND GREENWOOD: THE TRANSITION ELEMENTS. 165firmed the existence of a planar bromo-bridged anion [Pt2Br6I2-; dimericions also exist in solution.495 The visible and ultraviolet spectra of a seriesof ions [Pt(NHs),Cl~4_,~]('-2,+ where n = 0-4, have been interpreted interms of the orbital-energy diagram for d-electrons on the platinous ion.496Further studies of the N-H stretching bands in the infrared spectra ofcomplexes of the type trans-[L,am MC1J (where L = ligand, am = amineand M = Pd or Pt) give evidence for interaction between the N-H bonds ofco-ordinated amines and the non-bonding d-electrons of the metal atoms.497The Copper Group.-There has been continued interest in binuclearcompounds of copper containing Cu-Cu bonds. Magnetic moments smallerthan the theoretical value are observed for a series of trico-ordinated copper-(11) complexes (e.g., with Ei-bromo- and 5-nitro-salicylylideneanthranilic acid)which are discussed in terms of the Cu-Cu distance in dimer molecules.4B8Cupric monochloro- and dichloro-acetates have dimeric molecules in bothdioxan solution and the crystal, but dimerization does not occur with thetrichloroa~etate.~~~ The dark green cupric derivative of diazoaminobenzeneis dimeric and diamagnetic in benzene. There is strong evidence that themolecule adopts a configuration (39) similar to that for copper acetate. Thediamagnetism arises from direct intramolecular exchange between copperatoms, supported vertically in contact byfour bridging Ph*N,*Ph groups. [The Phgroups are omitted from structure (39) forclarity.] The spin paramagnetism is com-pletely quenched in this compound, in con-trast to the partial quenching observed incopper alkanoates.m In the copper-(39) dimethylglyoxime complex the two ringsare at an angle of 28", so that the nitrogenatoms are in a distorted tetrahedron round the copper atom. This is incontrast to the coplanar system given by the nickel, palladium, and platinumcomplexes. 501The infrared spectrum of solid anhydrous copper nitrate differs from thatfor the ionic nitrates [e.g., Cd(NO,),] ; there are strong bands in the regions1592-1504 cm.-l and 1289-1264 cm.-l, and at 1016 cm.-l which are charac-teristic of the co-ordinated nitrate group. The vapour spectrum is simplerthan that of the solid, and a new band appears at 1088 cm.-l which is notobserved for the solid.502 The techniques used in the manipulation of coppernitrate vapour have now been d e s ~ r i b e d . ~ ~ The monomeric nature of theN ~ - ~ ~ / 7 N. J d N ' 7N-cu.N495 C. M. Harris, S. E. Livingstone, and N. C. Stephenson, J., 1958, 3697.J. Chatt, G. A. Gamlen, and L. E. Orgel, J., 1968, 486.J. Chatt, L. A. Duncanson, and L. M. Venanzi, J . Inorg. Nuclear Chem., 1958,M. Kishita, Y . Muto, and M. Kubo, Austral. J . Chem., 1957, 10, 386; 1958, 11,40e R. Tsuchida, S. Yamada, and H. Nakamura, Nature, 1958, 181, 479.C. M. Harris and R. L. Martin, Proc. Chem. SOC., 1958, 259.601 E. Frasson, R. Zannetti, R. Bardi, S. Bezzi, and G. Giacometti, J . Inorg. Nuclear602 C. C. Addison and B. M. Gatehouse, Chem. and Ind., 1958, 464.C . C. Addison and B. J. Hathaway, J., 1958, 3099; C. C. Addison, B. J. Hatha-8, 67; J., 1958, 3203.309.Chem., 1958, 8, 452.way, and N. Logan, J . Inovg. Nuclear Chem., 1958, 8. 569166 INORGANIC CHEMISTRY.vapour has been confirmed from its mass spectrum which also indicates thepresence of Cu(NO,)+, CuO+, and Cu+ species formed by dissociative ioniz-ation of Cu(NO,),(g) in the ion source.6oQ Unexpected volatility has beenfound in copper perchlorate also. Nitrosyl perchlorate reacts with copperoxide, cupric chloride, nitrate or perchlorate dihydrate, yielding in a vacuumat 200" a crystalline sublimate Cu(ClO,),-,(NO,),; f i frequently correspondsto unity. Further fractional sublimation yields pure anhydrous copperperchlorate, which is thermally stable to 130" and melts at 230-240" onrapid heating. Like cupric nitrate the perchlorate is soluble in manyoxygen- and nitrogen-containing solvents.rn5 Copper forms azide-complexions such as Cu,(N,),-, Cu(N,),-, Cu(N,),2-, and Cu(N,),4- which readilydecompose in water with separation of the simple azide Cu(N,),. From aspectrophotometric study of copper perchlorate-sodium azide aqueoussolutions, the ion Cu(N,)+ has now been identified.m A sodium-goldazide NaAu,.,N,., has been obtained as orange-red needles.507The structure of thelsoliasilver perchlorate-benzene complex C6H6,AgC104has been refined. The benzene ring is distorted; the C-C distancesnearest the silver ions are 1.35A, whereas the others are 1*43A.508Tervalent as well as bivalent silver has been formed a t a rotating-discelectrode in alkaline s o l ~ t i o n , ~ ~ and anodic oxidation of silver fluoride andsilver nitrate baths also gives an oxide in which the valency of the silverexceeds X-Ray diffraction has confirmed that auric chloride existsin the solid state as planar dimeric molecules Au,Cl,, as in the gas.511The Zinc Group.-When water vapour is passed over zinc oxide at1300", the quantity of solid which vaporizes is a linear function of thewater-vapour pressure; Zn(OH), is the volatile species.512 The course ofautoxidation of alkylcadmium compounds is similar to that of Grignardreagents or alkylboron compounds. Reaction of a cadmium alkyl with anorganic hydroperoxide or dissolved oxygen in ether solution gives organo-peroxy-cadmium compounds Cd(0*OR),.513The infrared spectrum of amidomercurysulphonic acid indicates that itis an inner salt H,N+*Hg*S0,-.514 The compound formed by absorption ofethylene in methanolic mercuric acetate is usually assigned the formulaMeOCH,*CH,*Hg*OAc, though evidence for such a structure has beenlimited. The proton resonance spectrum of this compound, and also of therelated compound HO*CH,*CH,*Hg*OH, now provides strong support forthese structures.515 The mercury derivative of dithizone has been studiedby X-ray diffraction, the red crystals Hg(C13HllN4S)2,2C5H5N, which504 R. F. Porter, R. C. Schoonmaker, and C. C. Addison, Proc. Chem. SOL, 1959, 11.605 B. J . Hathaway, ibid., 1958, 344.506 G. Saini and G. Ostacoli, J. Inorg. Nuclear Chem., 1958, 8, 346.607 G. T. Rogers, ibid., 1958, 5, 339.508 H. G. Smith and R. E. Rundle, J . Amer. Chem. SOC., 1958, 80, 5075.510 W. S. Graff and H. H. Stadelmaier, J. Electrochem. SOC., 1958,105, 446.611 E. S. Clark, D. H. Templeton, and C. H. MacGillavry, Acta Cryst., 1958, 11, 284.512 0. Glemser, H. G. Volz, and B. Meyer, 2. anorg. Chem., 1957, 292, 311.518 A. G. Davies and J. E. Packer, Chern. and Ind., 1958, 36, 1177.51p K. Brodersen, Chem. Ber., 1957, 90, 2703.516 F. A. Cotton and J. R. Leto, J. Amer. Chem. SOC., 1958, 80, 4823.Yu. V. Pleskov, Doklady Akad. Nauk S.S.S.R.. 1957, 117, 645ADDISON AND GREENWOOD: THE TRANSITION ELEMENTS. 167crystallize from aqueous pyridine, being used. The primary bonding tomercury is through the sulphur atoms.516 Perfluoro-derivatives of alkyl-mercurials and alkylmercuric halides react with alkali halides to formcomplex ions. Conductivity measurements indicate the existence of com-plexes KHg(CF,),X and K,Hg(CFJ,X, (X = halogen) .617C. C. ADDISON.N. N. GREENWOOD.516 M. M. Harding, J., 1958, 4136617 H. J. EmeICus and J. J. Lagowski, Proc. Chem. SOL, 1958, 231

ISSN:0365-6217    

DOI:10.1039/AR9585500111

出版商:RSC    

年代:1958

数据来源: RSC

摘要:

ORGANIC CHEMISTRY1. INTRODUCTIONSTEADY development is reported this year in many branches of organicchemistry. The use of high-speed computers has facilitated the complexcalculations necessary for progress in applying quantum organic chemistryto complex structures. There has been much interest, both theoreticaland experimental, in the spectroscopic and other properties of carboniumions. Kinetic isotope effects continue to be an extremely important toolin elucidating the nature of the rate- and product-controlling steps ofchemical reactions, and many applications, both to hererolytic and tohomolytic processes, have been noted.An important series of papers has appeared dealing with the mechanismsof nitrosation by the nitrosonium ion and its carriers. Arylpentazoles havebeen obtained by the reaction between aromatic diazonium chlorides andlithium azide, and some of their properties have been studied.Nuclear and proton magnetic resonance spectroscopy continue to havemany applications in organic chemistry; among them is the location ofsubstituents in furan rings and in N-heteroaromatic systems and the deter-mination of the ring fusion of decalins.A new heterocyclic aromaticsystem, containing the -NH:BH- groups in positions 9,10 of phenanthrene,has been described. Important stereospecific syntheses in the yohimbineand reserpine series of alkaloids have been reported, and there has beenmuch progress in the chemistry of the curare alkaloids.Interest in synthetic and naturally occurring polyenes and poly-ynes hascontinued, and a naturally occurring polyene chlorohydrin has beenidentified.There is an increasing emphasis on both the biogenesis and thelaboratory synthesis of terpenes. Partially demethylated triterpenes havebeen discovered and the " biogenetic gap" between the steroids andtriterpenes reduced.Among outstanding advances reported in the field of nucleic acids areincluded the recognition that these substances are generally mixtures ofdifferent species varying in molecular weight and possibly also in nucleotidesequence; the isolation of several purine bases not formerly recognised ascomponents of naturally occurring nucleic acids; and the synthesis of someoligodeoxynucleotides. In the section dealing with carbohydrates themain stress is laid this year on developments in the chemistry of poly-saccharides.+ -T.G. H.P. B. D. DE LA M.2. QUANTUM ORGANIC CHEMISTRYONE of the truisms of quantum chemistry is that, since the fundamentallaws of electron quantum mechanics are known, chemical problems are alCRAIG : QUANTUM ORGANIC CHEMISTRY. 169in principle soluble by calculation, and that nothing stops the solutions’being obtained but the sheer complexity of the equations that have to besolved. Up to the last few years the complexity was almost always avoided,and the equations were drastically altered into simpler ones that could besolved without too much trouble. Simplification of the quantum-mechanicalequations corresponds to making assumptions about the physical characterof the system (such as assuming that nuclear motion does not affect theelectron energies in a molecule), and the calculations, usually empirical, thenrefer to a “ model ” system which has some, but not all, of its properties incommon with the real system.Everything hinges on making the rightsimplifying assumptions to get answers close to the physical ones.It is possible to discern two trends in current attitudes. High-speedcomputing enables very complex calculations to be made quickly, and somakes possible an altogether new range of exact theoretical studies of simplemolecules, as well as approximations (for example by M.O. methods) tolarge ones. Then, in regard to model studies, much more attention is beingpaid to the techniques for incorporating the empirical quantities, such asspectral intervals or ionization potentials, that go into the calculations.This not only leads to better results but also often reduces the amount ofcalculation by which the results are obtained from the starting data; itimproves the illustrative value of the model, allowing one to form a picturemore readily of the physical processes which make the real system behaveas it does.Moreover it lightens the problems of finding answers by theoreti-cal methods to practical problems, such as the colour to be expected of ahitherto unknown hydrocarbon. Although much important progress hasbeen made along these lines of finding the most fruitful and simple ways ofintroducing experimental values of one quantity into the calculation ofanother, much scope remains for similar ingenuity, for example, in calcul-ations of dipole moments and spectral intensities, which are not yet in agood state.Still more remains in the field of reactivity and reaction be-haviour, which are essentially two- or many-system problems and so are ofan altogether greater difficulty. Significant progress in the latter field wasdescribed in the last Rep0rt.lIn the two-year period under review about 350 papers in which quantummechanics are applied to organic molecules have been listed in CurrentChemical Papers. A large majority deal with the properties of aromaticmolecules and other x-electron systems, for example, the electron distri-bution in the ground state and the electronic absorption spectrum.Therehas been important progress in the methods used for hydrocarbons, in theirrapid extension to nitrogen-heterocycles, to the negative and positivearomatic ions, and to the calculation of ionization potentials. Smallergroups of the papers reflect sustained interest in new theories of the electronicstructure of the simplest organic molecules, radicals, and ions, in hyper-conjugation, in the potential harrier in ethane, and in the interpretation ofnuclear magnetic resonance and electron spin resonance spectra. An in-creasing but still small number of papers deal with reactivity and substitutionby employing theories, now having some significant successes, which treatAnn. Reports, 1966, 63, 126170 ORGANIC CHEMISTRY.transition states by means of localization energies or similar concepts, insteadof ground-state properties such as electron densities.In this Report mention will be made of the main fields of enquiry, butsuch is the volume of published work that the individual papers quoted areoften only representative of a large number generally similar in method oroutlook.In the period since thelast Report the development described there concerning semi-empiricaltheories of x-electrons has continued, some new variations of method havebeen described, and many applications have been made to individual mole-cules.When non-empirical calculations (A.S.M.O.) of the spectra ofx-electron systems are properly completed by including configurationalinteraction (C.I.),3,4 they give fairly good agreement with experiment forcertain types of molecular states, but appear to under-estimate the stabilityof others that have a high degree of ionic character, such as the lBlu andlElu states of benzene.W. E. Moffitt concluded that the prime difficultylay in the calculated size of purely intra-atomic energy terms, such as thedifferences of binding energy between trigonally hybridized C+, C, and C-,and he gave a semi-empirical theory (“ atoms in molecules,” A.I.M.) inwhich calculated differences between these quantities were replaced byexperimental values, the other energy terms being obtained non-empiricallyas before. Much subsequent work has confirmed the value of the centraltheme of the A.I.M. method, namely, that the non-empirical element incalculations of this kind should be confined to interatomic effects, but it hasshown also that the results are very sensitive to the way in which the empiri-cal quantities are brought in.Hurley showed that the original techniqueowed its good account of the binding energy of H, to a cancellation of errorsand has investigated some other difficulties. Arai7 has treated the samequestion. Hurley * and Arai have now independently proposed new waysof making the intra-atomic energy correction. Both give better results, ata certain cost in added complication. The “ intra-atomic correlation cor-rection ” (I.C.C.) of Hurley, and the “ deformed atoms in molecules ”(D.A.I.M.) of Arai have been described and critically compared in a recentre vie^.^ ,Of the modified methods, only I.C.C. (in a simplified form) hasso far been applied to a x-electron sy.stem,l0 and the results set against thosefrom A.I.M.and A.S.M.O. with configuration interaction.* In A.I.M. theintra-atomic correction in benzene was found by comparing the differencebetween the ionization potential and the electron affinity of an isolatedcarbon atom in its trigonally hybridized valence state with the differencebetween the same quantities calculated by using Slater orbitals appropriate%-Electron Theory.-Semi-em$iricaZ methods.M. Goeppert-Mayer and A. L. Sklar, J. Chem. Phys., 1938, 6, 645.a D. P. Craig, Proc. Roy. SOC., 1950, A , 200, 474. * R. G. Parr, D. P. Craig, and I. G. Ross, J . Chem. Phys., 1950, 18, 1561.No.49, p. 40.N. Polgar, J., 1958, 430.R. E. Harman, Quart. Rev., 1958, 12, 93WHITHAM : ALIPHATIC COMPOUNDS. 229tram-pentaene chromophore. Mild oxidative degradation has led to aproposal 80 of the partial structure (33). One of the degradation pro-ducts (34) has also been obtained from the pentaene antibiotic fungichromin.slthereby indicating a probable structural similarity. Several other polyeneantifungal antibiotics are known which may well be of related structure.82O-CO-CarH,r-lsO~=~(OH)Me*CH.CH(OH)fCH=CH],*CH=CMe*CH*OH OHC*[CH=C H],*C H=CMe*CHO I(33) (34)Oleandomycin appears to be a macrolide antibiotic of the more conven-tional type , containing glycosidically bound desosamine and ~-0leandrose.~~The lactones heptanolide and octanolide have been prepared by aBaeyer-Villiger reaction of peroxytrifluoroacetic acid with cyclohexanoneand cycloheptanone respectively.@Nitrogen Derivatives.-A novel synthesis of isocyanides involves treat-ment of formamides in pyridine with toluene-$-sulphonyl chloride 85 orphosphorus oxychloride.86 The Beckmann rearrangement of ketoximebenzenesulphonates in the presence of hydrogen sulphide affords thiocarboxy-amides ; these are also obtained from N-substituted carboxyamides byconsecutive treatment with benzenesulphonyl chloride, pyridine , andhydrogen ~ulphide.~~ Further work on naturally occurring isothiocyanatesis reported.=9.HETEROCYCLIC COMPOUNDSReviews.-Naturally occurring furans, the lichen acids, oxygen-hetero-cyclic fungal metabolites ,3 lignans from PodophyZZ~m,~~ hydroxy-flavansand -flavensJ4b brazilin and h~ematoxylin,~ the products obtainable fromketones, ammonia, and sulphur,6 0xazolidine-2,4-diones,~ melamine,*a andrecent work on pyridazines Sb have been reviewed.The proceedings of twosymposia on heterocyclic chemistry have been publi~hed.~General.-Nuclear quadrupole resonance spectroscopy has been applied loto the study of the electronic structures of heterocyclic compounds, andproton magnetic resonance spectroscopy to the detection and location ofsubstituents in furan ringsu In studies of the tautomerisrn of numerousN-heteroaromatic compounds, cc- and y-hydroxy-compounds have beenfound to be predominantly amidic.12Interest in new aromatic systems is illustrated by the synthesis l3 of the9-aza-lO-bora-derivative (1) of phenanthrene and its substitution products107 J.A. Zderic, A. Bowers, H. Carpio, and C. Djerassi, J . Amer. Chem. SOC., 1958,108 R. M. Dodson and R. D. Muir, ibid., 1958, 80, 5004.80, 2596.1 J. Levisalles, Perfumery Essent. Oil Record, 1958, 49, 504, 627.2 C. A. Wachmeister, Svensk kem. Tidskr., 1958, 70, 117.3 W. B. Whalley, Progr. Org. Chem., 1958, 4, 72.4 (a) J. L. Hartwell and A. W. Schrecker, Fortsclzr. Chern. org. Naturstofle, 1958,15,84; (b) K. Freudenberg and K. Weinges, ibid., 1958,16, 1.5 (Sir) R. Robinson, Bull. Soc. chim. Frunci, 1958, 125.F. Asinger and M. Thiel, Angew. Chem., 1958, 70, 667; cf. Ann. Reports, 1957,54, 242.7 J. W. Clark-Lewis, Chern.Rev., 1958, 58, 63.8 (a) B. Bann and S. A. Miller, ibid., 1958, 58, 131; (b) J. Druey, Angew. Chem.,1958, ‘SO, 5.Q “ Current Trends in Heterocyclic Chemistry,’’ ed. by A. Albert, G. M. Badger,and C. W. Shoppee, Buttenvorths, London, 1958; “ Les He’t6rocycles OxygCnCs,”C.N.R.S., Paris, 1947.10 M. J. S. Dewar and E. A. C. Lucken, J., 1958, 2653.l1 E. J. Corey, G. Slomp, S. Dev, S. Tobinaga, and E. R. Glazier, J . Amer. Chew.12 S. F. Mason, J., 1957, 4874, 5010; 1968, 674.13 M. J. S. Dewar, V. P. Kubba, and R. Pettit, J., 1958, 3073, 3076.Soc., 1958, 80, 1204286 ORGANIC CHEMISTRY.and of various five-membered ring systems containing boron. The formerclosely resemble phenanthrenes spectroscopically. In the same connexion,although the compounds are not heterocyclic, the greatest interest attachesto the demonstration that phenylpentazole is formed in the reaction betweenbenzenediazonium chloride and lithium azide. The arylpentazoles areunstable, though some have been obtained crystalline and their ultravioletspectra have been recorded.14Small Rings.-Oxazirans 15a are the initial products of irradiatingnitrones,lbb and have been used as a source of nitrosoalkanes.15" A newmethod for preparing epoxides of +unsaturated ketones,16 and means ofdetermining the stereochemistry of epoxy-ethers and their ring-openedderivatives have been described.17 Structures of the type (2) (from deoxy-benzoin) have been confirmed l8 for the desaurins " formed from ketonesand carbon disulphide in the presence of bases.( 3 )Five-membered Rings.-Pyrroles.Extensive ultraviolet and infraredspectroscopic studies of pyrroles have been presented.lg Diels-Alderaddition occurs between acetylenedicarboxylic acid and l-benzylpyrrole ; 20that between benzyne and l-methylpyrrole 21 gives the bases (3) and finally(4). With ally1 bromide, potassiopyrrole unexpectedly gives 2- rather thanl-allylpyrrole.22 The primary products of reaction between pyrroles andninhydrin, alloxan, or isatin are alcohols such as (5), which acids convertinto dyes. Reaction with two mols. of these reagents produces compoundsin the manner of (6). The yellow product from proline andninhydrin has the structure (7), and the purple-red product is (Q).M 2-Methylpyrrole is responsible for most of the colour produced by Ehrlich'sreagent in the Elson-Morgan assay of hexosamine~.~~ Examination of the14 R.Huisgen and I. Ugi, Chem. Ber., 1957, 90, 2914; I. Ugi and R. Huisgen, ibid.,15 (a) Ann. Reports, 1957, 54, 240;' (b) J. S. Splitter and M. Calvin, J . Org. Chem.,16 N. C. Yang and R. A. Finnegan, J . Amer. Chem. SOC., 1958, 80, 5845.17 C. L. Stevens and T. H. Coffield, J . Org. Chem., 1958, 23, 336; C. L. Stevens and18 P. Yates and D. R. Moore, ibid., p. 5577.19 U. Eisner and P. H. Gore, J., 1958, 922; U. Eisner and R. L. Erskine, ibid., p.20 L. Mandell and W. A. Blanchard, J . Amer. Chem. SOC., 1957, 79, 6198.21 G. Wittig and W. Behnisch, Chem. Ber., 1958, 91, 2358.22 P. A. Cantor and C. A. VanderWerf, J .Amer. Chem. SOC., 1958, 80, 970.23 A. Treibs, E. Herrmann, and E. Meissner, Annulen, 1958, 612, 229.24 A. W. Johnson and D. J. McCaldin, J., 1958, 817.25 J. W. Cornforth and (Mrs.) M. E. Firth, ibid., p. 1091.1958, 91, 531; I. Ugi, H. Perlinger, and L. Behringer, ibid., p. 2324.1958,23, 651; (c) W. D. Emmons, J . Amey. Chem. SOL, 1957, 79, 6522.A. J. Weinheimer, J . Amer. Chem. SOC., 1958, 80, 4072.971SCHOFIELD AND SWAIN : HETEROCYCLIC COMPOUNDS 287diazo-coupling reactions of a range of pyrroles shows an order of reactivityin line with the electronic characters of substituents, greater reactivity in1-methylpyrrole than in pyrrole, and the failure of some a-unsubstitutedpyrroles to react when powerful electron-attracting substituents are0-(7)0present.26 3-Hydroxypyrroles show no ketonic properties and give onlysome hydroxyl reactions; C-acylation occurs more readily than 0-acylation .27In hot, slightly alkaline solution, acetamidoacetaldehyde gives 3-acet-amidopyrrole.28 The Schiff’s bases from p-keto-esters and esters of cc-amino-acids are cyclised to 3-hydroxypyrroles under Dieckmann condition^.^^Tetracyanoethylene reacts with pyrrole to give tricyano-2’-pyrrylethylene,and is a prolific source of pyrroles and other heterocyclic compounds. It isconverted by sodium sulphide into 2,5-diamino-3,4-dicyanothiophen whichundergoes base-catalysed rearrangement to 5-amino-3,4-dicyanopyrrole-2-thiol. Tricyanovinyl compounds R*C(CN)=C(CN), (for example, R = Ph)give, with thiols R’SH, the pyrroles (9).30Pyoluteorin, an antibiotic from Pseudomonas aemginosa, is a pyrrolederivative (lo) .31 X-Ray studies indicate structure (11) for kainic (digenic)acid,32” the chief anthelmintic from the seaweed Digenea simplex Agardh.32b26 A.Treibs and G. Fritz, Annalen, 1958, 611, 162.27 A. Treibs and A. Ohorodnik, ibid., p . 149.28 J. W. Cornforth, J . , 1958, 1174.29 A. Treibs and A. Ohorodnik, Annalen, 1958, 611, 139.30 T. L. Cairns, R. A. Carboni, D. D. Coffman, V. A. Engelhardt, R. E. Heckert,E. L. Little, E. G. McGeer, B. C. McKusick, W. J. Middleton, R. M. Scribner, C. W.Theobald, and H. E. Winberg, J . Amer. Chem. SOC., 1958, 80, 2775 et seq.31 R. Takeda, ibid., p . 4749.32 (a) H. Watase and I. Nitta, Bull. Chem. SOC. Japan, 1957, 30, 889; (b) S.Mura-kami, T. Takemoto, and 2. Shimizu, J . Pharm. SOC. Japan, 1953, 73, 1026; 1954, 74,560288 ORGANIC CHEMISTRY.Furans. Commercially available 2-methylallyl chloride and butane-1,2,4-triol have been used as sources of 3-substituted fur an^.^^Bullatenone from Myrtus buZZata, originally thought to be a y-pyrone, is2,3-dihydro-2,2-dimet hyl-3-oxo-5-phenylfuran .34 Details of the synthesisof (&)-ipomeamarone (12), and discussions of its chemistry,published.35CH2.CHMe2H Hhave been(13)Thiophens. 2-Vinylthiophen undergoes diene addition with maleicanhydride and benzoquinone, as does 3-vin~lthionaphthen.~~ Derivativesof the type (131, formed by high-dilution cyclisation, can be desulphurised tocyclic hydrocarbons or ketones3' Mono-olefins give not only polysulphideswith sulphur, but also cyclic products.2,6-Dimethylocta-2,6-diene withsulphur at 140" gives several reduced thiophens, and similar compounds (14)arise by cyclising ketones R*CH(SH)*CH2*CH2*COMe.381-Phenyl-5-prop-l-ynylthiophen has been isolated from Coreopsis g r a d -AxoZes. With phosphorus pentachloride 4-nitrosopyrazoles give inter-mediates R*C(Cl)=N*N=C(CN)R, which are cyclised by ammonia to 5-amin0-3,6-disubstituted-1,2,4-triazine~.~~Deuteration of imidazole is pH-controlled, proceeding initially at the4,5-positions in deuterium oxide alone, but at position 2 in the presence ofsodium deuteroxide.4l The blue pigment formed by oxidising glycosin(2,2'di-imidazolyl) with hydrogen peroxide is the di-N-oxide (15) .42 Thehighly reactive carbonyldi-l-imidazole 43a has been used in peptide synthesis,since with carboxylic acids it gives l-acylimidazoles which provide amideswith a m i n e ~ .~ ~ ~33 H. Wynberg, J . Amer. Chem. Soc., 1958, SOj 364; J. W. Cornforth, J . , 1958, 1310.34 W. Parker, R. A. Raphael, and D. I. Wilkinson, J., 1958, 3871.35 T. Kubota and T. Matsuura, J., 1958, 3667; T. Kubota, Tetrahedron, 1958, 4,36 W. Davies and Q. N. Porter, J., 1957, 4958.37 Ya. L. Gol'dfarb, S. 2. Taits, and L. I. Belen'kii, Izvest. Akad. Nauk S.S.S.R.,Otdel. khim. Nauk, 1957, 1262.38 L. Bateman, R. W. Glazebrook, C. G. Moore, M. Porter, G. W. Ross, a i d R. W.SaviIle, J., 1958, 2838; L. Bateman, R. W. Glazebrook, and C. G. Moore, ibid., p.2846; L.Bateman and R. W. Glazebrook, ibid., p. 2834.39 J. S. Sorensen and N. A. Sorensen, Acta Chem. Scand., 1958, 12, 771.40 R. Fusco and S. Rossi, Tetrahedron, 1958, 3, 209.4 1 A. Grimison and J. H. Ridd, PVOC. Chem. SOC., 1958, 256; R. J. Gillespie, A.Grimison, J. H. Ridd, and R. F. M. White, J., 1958, 3228.42 R. Kuhn and W. Blau, Annalen, 1958, 615, 99.43 (a) Ann. Reports, 1957, 54, 243; (b) G. W. Anderson and R. Paul, J . Auner. Chem.~ Z O Y U .3968; T. Kubota and T. Matsuura, Bull. Chem. SOC. Japan, 1958, 31, 491.SOL, 1958, 80, 4423SCHOFIELD AND SWAIN : HETEROCYCLIC COMPOUNDS. 289Six-membered Rings.-Pyridines and piperidines. Infrared data onmany derivatives of pyridine and pyridine 1-oxide are now available.P4Sulphonation of pyridine in presence of mercuric sulphate at 275" givesmainly pyridine-3-sulphonic acid, but at higher temperatures some 4-isomer and 4-hydroxypyridine are also f0rmed.4~ The product obtained 46by oxidising pyridine-4-thiol with nitric acid is not pyridine-4-sulphonicacid, but di-4-pyridyl disulphide dinitrate.47 4-Fluoropyridine is unstable'at ordinary temperatures, rapidly giving a pyridylpyridinium compound.2-Fluoropyridine, unlike the other 2-halogenopyridines, behaves similarly.48Arenesulphonyl chlorides react with 4-methyl- or 4-ethyl-pyridine in thepresence of a tertiary base to give sulphones (16; R = H or Me).49" Azidinium '' salts (17; one form shown) (similar products can be made inthe thiazole, benzothiazole, thiadiazole, and quinoline series), obtained from2-chloro-1-ethylpyridinium borofluoride and azide ions, behave like diazon-ium salts.With dialkylamines they give tetrazens, and with azides givetriazacarbocyanines.m Hydrazinium salts (18), prepared from pyridinequaternary salts containing reactive 4-substituents, undergo oxidativecoupling with phenols in the presence of ferricyanide, and with dialkyl-anilines in an oxidising acidic sol~tion.~l 1,2-Di-(6-brornomethyl-2-pyridy1)ethane is converted in moderate yield by butyl-lithium into di-(pyridine-2,6-dimethylene) (19), which, like di-m-xylylene, may have a" stepped " structure.52 2-Vinylpyridine hydrobromide is converted byheat into the compound (20), which with piperidine forms 1-(2-2'-pyridyl-ethyl) ~iperidine.~~Mercuric acetate causes 2- and 2,6-substitution in pyridine N-oxide, andnot 4-sub~titution.~ The N-oxide quaternary salt (21) is converted byalkali into 2-vinylpyridine and formaldehyde, but the reaction of the lower44 A.R. Katritzky, A. M. Monro, and (in part) J. A. T. Beard, D. P. Dearnaley, andN. J. Earl, J., 1958, 2182; A. R. Katritzky and J. N. Gardner, J., 1958, 2192, 2198;A. R. Katritzky and A. R. Hands, J., 1958, 2195, 2202; A. R. Katritzky, J., 1958,4162.45 H. J. den Hertog, H. C. van der Plas, and D. J. Buurman, Rec. Trav. chim.,1958, 77, 963.46 E. Koenigs and H. Kinne, Bey., 1921, 54, 1357.47 J. Anguli and A. M. Muricio, Chenz. and Ind., 1958, 1175; A. M. Comrie and J. B.4a J.-P. Wibaut and W. J. Holmes-Kamminga, Bull.SOC. chim. France, 1958, 424.413 2. Foldi, Chenz. and Id., 1958, 684.so H. Balli, Angew. Chem., 1958, 70, 442.61 S. Hiinig and G. Kobrich, Annalen, 1958, 617, 181, 216; S. Hunig, Angew. Ckem.,Se W. Baker, K. M. Buggle, J. F. W. McOmie, and (in part) D. A. M. Watkins, J.,63 V. Boekelheide and W. Feely, J . Amer. Chem. Soc., 1958, 80, 2217.54 M. van Ammers and H. J. den Hertog, Rec. Truv. chim., 1958, 77, 340.Stenlake, J., 1958, 1853.1958, 70, 215.1958, 3594.REP.-VOL. LV 290 ORGANIC CHEMISTRY.quaternary homologue is complex.53 2-Phenylpyridine N-oxide is nitrated10-100 times faster than 2-phenylpyridine, and the reaction with this oxideand 4-phenylpyridine N-oxide produces more of the m-nitro-compound thanis the case with the non-oxygenated derivative^.^^ Selenium dioxide reactsmore quickly with 4- than with 2-methylpyridine, and these oxidations areretarded if the picolines are present as quaternary salts or N-oxides.A$methyl group is not attacked.56With ethoxide, hydroxyl, or cyanide ions a number of 3-substitutedpyridinium salts form pseudo-bases, probably at the 6-po~ition.~' Protonmagnetic resonance spectroscopic studies of deuterated dihydro-N-methyl-nicotinamide, formed by reducing nicotinamide methiodide in deuteriumoxide, confirm the 1,4-dihydropyridine structure of these models of diphos-phopyridine nucleo tide.58 Dithionite reduction of 3,5-dicarbamoyl- 1- (2,6-di-chlorobenzy1)pyridinium bromide gives an intermediate formulated as(22; R = CH,*C6H,C1,), which with acid is converted into the correspond-ing 1,4-dihydropyridine; it' is suggested that the formation of 1,4-di-hydro-compounds in natural coenzyme reductions may proceed throughinitial 1,2-additi0n.~~ Nuclear magnetic resonance studies indicate thatthe diethyl dihydro-1,2,6-trimethylpyridine-3,5-dicarboxylate, previouslythought to be a 1,2-dihydro-compound, is in fact the 1,4-isomer: thisevidence throws doubt upon the diagnostic tests believed to distinguish1,2- from 1,4-dihydro-structure~.~~ Methohalides of pyridine and alkyl-pyridines are generally reduced by sodium borohydride to a mixture ofpiperidines and A3-piperideines.62 As well as the expectedcyclopentylamines, piperidines result from the reduction oftertiary nitrocyclopentanes with lithium aluminium h ~ d r i d e .~ ~The antibiotic, fusarinic acid, 5-n-butylpyridine-2-carboxylicacid, has been synthesised from 2,6-lutidine; 64 and baikiain(23), the amino-acid from Rhodesian teak heartwood, byDiaxines. Pyrimidine undergoes 3,4-addition reactions with aryl55 A. R. Hands and A. R. Katritzky, J., 1958, 1754.56 D. Jerchel, J . Heider, and H. Wagner, Annalen, 1958, 613, 153; see also D.57 A. G. Anderson, jun., and G. Berkelhammer, J . Org. Chem., 1958, 23, 1109.58 R. F. Hutton and F. H. Westheimer, Tetrahedron, 1958, 3, 73.59 K. Wallerfels and H. Schiilz, Angew. Chem., 1958, 70, 471.60 A. F. E. Sims and P. W. G. Smith, Proc. Chem. SOC., 1958, 282.61 Ann. Reports, 1957, 54, 245.62 M. Ferles, Coll. Czech. Chem. Comm., 1958, 23, 479.63 G.E. Lee, E. Lunt, W. R. Wragg, and H. J. Barber, Chem. and Ind., 1958, 417;G. E. Lee, W. R. Wragg, S. J. Corne, N. D. Edge, and H. W. Reading, Nature, 1958,181, 1717.64 E. Hardegger and E. Nikles, Helu. Chim. Ada, 1957, 40, 2428.R5 N. A. Dobson and R. A. Raphael, J., 1958, 3642.C02H(23)H 0cyclisation of the cis-olefin BzN*CH,*CH:CH*CH,*CHBrCO,H.~Jerchel and H. E. Heck, ibid., p. 171SCHOFIELD AND SWAIN : HETEROCYCLIC COMPOUNDS. 291Grignard and lithium reagents : hydrolysis and oxidation of the productsgive 4-arylpyrirnidines.66 Some 4-hydroxypyrimidines react with chloralto give, after hydrolysis, 4-hydro~ypyrimidine-5-aldehydes.~~ Pyrazinegives mono- and di-N-oxides, whilst pyrimidine and pyridazine appear toform only mono-derivatives.66y 68Oxygen heterocycles.6-Substituted a-pyrones have been synthesisedfrom 2-chlorovinyl ketones and ethoxymagnesiomalonic ester.69 With N-bromosuccinimide, dihydropyran gives a mixture of 5-bromo-3,4-dihydro-2H-pyran, 2,3-dibromotetrahydropyran, and 3-bromotetrahydro-2-succin-imidopyran.70 A re-investigation of the action of acrylonitrile and p-bromo-propionic acid on kojic acid showed that no new product is formed;potassium cyanide yields the cyanohydrin.71 Monoarylmethylene derivativesof 2,6-dimethyl-4-pyrone are obtained in good yield by using potassiumhydroxide as condensing reagent. Acylation of the pyrone in presenceof zinc chloride in boiling xylene gives 3-acyl or diacyl derivatives,further cyclisation occurring with laevulic acid to yield the bicyclic com-pound (24) .72Anibine (25; R = 3-C5H,N) and 4-rnethoxyparacotoin (25; R = 3,4-CH,O,:C,H,) have been isolated from and the structure of theformer compound confirmed by synthesis.74Large Rings.-Dibenzamil, the compound obtained by decomposingphenyl azide in aniline, has the structure (26) (or a double-bond isomer).',Interest in the chemistry of oxepin (27) is shown by the synthesis of2,3,6,7-, and 2,3,4,7- te trahydro-oxepin , and of dibenz [b, f] oxepin and its2-nitro-derivative.7666 H.Brederick, R. Gompper, and H. Herlinger, Angew. Chem., 1958, 70, 57.67 R. Hull, J., 1957, 4845.68 W. H. Gumprecht, Diss. Abs., 1958, 18, 64.69 N. K. Kochetkov and L. I. Kudryashov, Zhur. obshchei Khim., 1958, 28, 1511.7O J.R. Shelton and C. Cialdella, J . Org. Chem., 1958, 23, 1128.7l C. D. Hurd and S . Trofimenko, J. Amer. Chem. SOC., 1958, 80, 2526.72 L. L. Woods, ibid., p . 1440.7 3 0. R. Gottlieb and W. B. Mors, ibid., p. 2263.74 E. Ziegler and E. Nolken, Monatsh., 1958, 89, 391.75 R. Huisgen, D. Vossius, and M. Appl, Chem. Ber., 1958, 91, 1 ; R. Huisgen andM. Appl, ibid., p . 12.76 J. Meinwald and H. Nozaki, J . Amer. Chem. SOC., 1958, 80, 3132; S. Olsen andR. Bredoch, Chem. Be?., 1958, 91, 1589; J. D. Loudon and L. A. Summers, J., 1957,3809292 ORGANIC CHEMISTRY.Condensation of f uran with ace tone gives oct ame thy1 te traoxaquatereneOxidation of dithiols +-C,H,(O*[CH,],=SH), by air in the presence ofcupric ions gives the cyclic disulphides (29). An interesting attempt tomake “ daisy-chain ” molecules by such cyclisations of the inclusion com-pounds from the dithiols and dextrin failed.78Polypyrroles and Related Compounds.-The use of permanganate oxida-tion in conjunction with paper-chromatographic analysis of the resultingpyrrole acids is a useful degradative tool in the porphyrin field.Thediscovery of the triacid (30) in the oxidation products of phaeophorbide aand mesophEophorbide a is not easily understood in terms of Fischer’ss t r u c t ~ r e s . ~ ~ Application of the method to a number of bile pigments showsthat all the common members of this group possess the “ IX-cc ” structure,being derived from biliverdin.80 Chromic acid oxidation of stercobilin 81provides confirmation for the structure (31 ; P = CH,*CH,*CO,H) suggestedfor this compound by Birch 82 and indicates for durobilin the expression (32).(28; x = 01.77Fischer’s structure for bacteriochlorophyll receives support from dehyd-rogenation studies of the derived bacteriochlorin-e, trimethyl ester and thecopper derivative of the acetyl~hlorin.~~ Treatment of the pyrrole ester (33)with lead tetra-acetate (a reagent which, as would be expected, gives theacetoxymethyl 84385 and not the hydroxymethyl derivative *,), followed byhydrogenolysis and boiling in acetic acid, led to the isolation of copro-porphyrin I11 triethyl ester (as 34) with only traces of isomers.Similarlythe triethyl ester (35) gave uroporphyrin I11 (36) as the chief product.87 Anew mechanism to account for the conversion of 2-(substituted methyl)-SAXTON: ALKALOIDS.306acetate,16 and from the infrared spectrum l6?l7 in the region 2800-2700cm.-l. Dehydrogenation of matrine or allomatrine with mercuric acetategives, in addition to the normal dehydro-base, a hydroxydehydro-derivative(3),16 which can be hydrogenated to a mixture of stereoisomers. One ofthese, sophoranol (4), is a constituent of the roots of SoPhora flavescens.18The position of the hydroxyl group in hydroxylupanine (5) and baptifolinehas been rigorously established by conversion of the former into 13-ax-hydroxysparteine, which was identified by total synthesis. This series oftransformations involved epimerisation of the 13-substituent ; hence in thesealkaloids the hydroxyl group has the equatorial conformation.lgPyridine Group.-The conformations of conhydrine 2oj 21 and pseudo-conhydrine2Z23 have been deduced.The former belongs to the erythro-series, and C(2) corresponds to the L-amino-acids, hence it can be formulatedas (6). In pseudoconhydrine (7), the hydroxylated carbon atom belongsto the DG series, while C(2) corresponds to the D-amino-acids.(-)-Homostachydrine, the methyl betaine of (-) -pipecolic acid, occursin alfalfa (Medicago sativa), and is frequently a contaminant of stachydrineisolated by the usual extraction procedure^.^^Quinoline Group.-Eduleine, the alkaloid of Casimiroa edulis, has beenidentified as 7-methoxy-l-methyl-2-phenyl-4-quinolone, which also occursin Lunasia a m a ~ a .~ ~ Two syntheses of evolitrine, and two further synthesesof dictamnine, have been reported.26Isoquinoline Group.-The Russian contributions to the elucidation andsynthesis of the Ipecacuanha alkaloids are summarised in a recent article.27A further non-stereospecific synthesis of (&)-emetine, similar in principleto the earlier Russian synthesis, has been reported.28 Comparison of anintermediate in this synthesis with material obtained from cincholoipon ethylester, in which the substituents in the piperidine ring are known to be cis,has confirmed that the 10- and ll-substituents are trans oriented in emetine(8).29 The evidence relating to the conformation of the 1’-hydrogen atomhas been variously interpreted,29, 30 but axial hydrogen seems more likelysince emetine is stable to strong bases (Wolff-Kishner conditions), and hydro-genation of the methyl ester corresponding to (9) gives almost exclusivelythe tertiary base possessing the same stereochemistry as emetine.30 Theseconclusions regarding its stereochemistry have been confirmed by the firststereospecific synthesis of (-)-emetine, which also embraces the totall7 F.Bohlmann, Chem. Ber., 1958, 91, 2157.F. Bohlmann, D. Rahtz, and C. Arndt, ibid., p. 2189.F. Bohlmann, E. Winterfeldt, and H. Brackel, ibid., p. 2194.2o J. Sicher and M. Tichy, Chem. and I n d . , 1958, 16.21 R. K. Hill, J . Amer. Chem. SOC., 1958, 80, 1609.22 Idem, ibid., p. 1611.23 K. Balenovic and N. Stimac, Croat. Chem. Acta, 1957, 29, 153.24 G.Wiehler and L. Marion, Canad. J . Chem., 1958, 36, 339.F. Sondheimer and A. Meisels, J . Org. Chem., 1958, 23, 762.26 R. G. Cooke and H. F. Haynes, Austral. J . Chem., 1958, 11, 225; T. Sato and27 R. P. Evstigneeva and N. A. Preobrazhensky, Tetrahedron, 1958, 4, 223.29 A. Brossi, A. Cohen, J. M. Osbond, P. A. Plattner, 0. Schnider, and J. C. Wickens.30 A. R. Battersby, ibid., p. 1324.M. Ohta, Bull. Chem. SOC. Japan, 1957,30, 708; 1958, 31, 161.M. Barash and J. M. Osbond, Chem. and Ind., 1958, 490.ibid., p. 491306 ORGANIC CHEMISTRY.syntheses of psychotrine and ceph~eline.~~ The crucial stages in this synthesisinvolve trans-addition of diethyl malonate to the dihydropyridone [lo; R =CH,*CH,*C,H,(OMe),], hydrogenation of the ester (9) to give the productcontaining axial hydrogen, and hydrogenation of (+)-O-methylpsychotrine(8, with C,l,N double bond), to give mainly (-)-emetine (8), togetherwith some of the l-epimeric (-)-isoemetine.EtSeveral other synthetic investigations in the isoquinoline field have alsobeen completed; syntheses of (-J-)-~tephanine,~% (&)-crebanine,s and( j-)-corydine have been recorded.Indole Group.-The perennial grass, PhaZaris arundinacea L., contains5-metho~y-Nb-rnethyltryptamine.~ Psilocybin, the psychotropic principleof the Mexican fungus, Psdocybe mexicana, and several other Psilocybespecies, has been shown by degradation and synthesis to have structure (11) ;this is the first recorded example of a phosphorylated indole derivative, andthe first 4-hydroxylated tryptamine derivative to be isolated from naturalA Russian synthesis of yohimbine, from the previously synthesisedyohimbone, has been claimed, but little or no confirmatory evidence has beenprovided; infrared spectra and rotations are not quoted, and the meltingpoints of intermediates are not always in close agreement with publishedvalues, where a~ailable.~' An outstanding contribution to indole alkaloidchemistry is the total stereospecific synthesis of pseudoyohimbine by vanTamelen and his collaborators.38 The starting material was the adductfrom 9-benzoquinone and butadiene (12), which was converted into(+)-pseudoyohimbine (13) by the reactions shown in the Chart.Sincepseudoyohimbine has already been converted into yohimbine (14), the total31 A.R. Battersby and J. C. Turner, Chem. aud Ind., 1958, 1324.32 D. H. Hey and A. Husain, J., 1958, 187633 T. R. Govindachari, K. Nagarajan, and C. V. Ramadas, J., 1958, 983.34 D. H. Hey and A. L. Palluel, J., 1957, 2926; N. Arumugam, T. R. Govindachari,35 S. Wilkinson, J., 1958, 2079.36 A. Hofmann, R. Heim, A. Brack, and H. Kobel, Exfierientia, 1958, 14, 107; A.37 L. A. Aksanova and N. A. Preobrazhensky, Doklady Akad. Nawk S.S.S.R.,36 E. E. van Tamelen, M. Shamma, A. W. Burgstahler, J. Wolinsky, R. Tamm,K. Nagarajan, and U. R. Rao, Chem. Ber., 1958, 91, 40.Hofmann, A. Frey, H. Ott, T. Petrzilka, and F. Troxler, ibid., p. 397.1957, 117, 81.and P. E. Aldrich, J . Amer. Chem. SOC., 1958, 80, 6006SAXTON : ALKALOIDS. 307synthesis of the latter is also complete.This synthesis also constitutes aformal synthesis of P-yohimbine (17-epimer of yohimbine), since this can beobtained from yohimbine by several methods, the simplest of which involvesdirect isomerisation of the axial 17-hydroxyl group to the more stable0 H C. H 2 C.'-hOH7,MeO,C*"OH ('3) O*CHOReagents: I , Zn-AcOH, then CI*CH,*CO,Et.KOBut, then saponification, then decarboxylation,then Ag,O. 2 , COCICOCI, then tryptamine. 3, OsO,, then Pt-H,, then HIO,. 4, H,PO,-H,O,then MeOH-HCI, then LiAIH,. 5, Hydrolysis of lactol e t h e r , then acetylation, then eliminationof AcOH. 6 , OsO,, then HIO,. 7, Hydrolysis, then Cr0,-H,SO,-MeOH, then (-)-camphor-sulphonic acid.equatorial conformation by means of potassium t - b ~ t o x i d e .~ ~ Additionof the elements of methanol to apoyohimbine yields p-yohimbine methylether,40 while reduction, by potassium borohydride, of yohimbinone (theOppenauer oxidation product of yohimbine under appropriate conditions)gives p-y~himbine.~~ A novel method proceeds through the previouslyunknown yohimbic acid lactone, obtained by reaction of yohimbic acid withethyl chloroformate ; this on acetolysis furnishes p-yohimbine acetate.41In a memorable communication full details of the synthesis of reserpineby Woodward and his co-workers have been published.42 Two independentA. Le Hir and E. W. Warnhoff, Compt. rend., 1958, 246, 1564.40 W. 0. Godtfredsen and S . Vangedal, A d a Chem. Scand., 1957, 11, 1013.41 P. A. Diassi and C.M. Dylion, J . Amer. Chem. SOC., 1958, 80, 3746.42 R. B. Woodward, F. E. Rader, H. Bickel, A. J. Frey, and R. W. Kierstead, Teira-hedron, 1958, 2, 1308 ORGANIC CHEMISTRY.syntheses of the degraded corynantheine-type alkaloid, flavopereirine, havealso been described.43In relation to the possible mode of biosynthesis of oxygenated yohimbineand deserpidine derivatives, it is noteworthy that the microbiologicaloxidation 44 of certain yohimbine analogues in the presence of cultures ofCunninghamella blakesleana or Streptomyces aureofaciens leads to hydroxyl-ation at position 10 or 18. Mainly on the basis of spectrographic evidence,and on molecular-rotation analogies between a-yohimbine and seredine, thelatter is formulated as 10,11-dimethoxy-a-yohimbine.45The unique a-orientation of the 15-hydrogen atom in ajmalicine andcorynantheine, and of the biogenetically equivalent 4-hydrogen atom incinchonamine has been demonstrated by conversion of ajmalicine intodihydrocorynantheane, and of corynantheine and cinchonamine into thecommon degradation product (15) .& Since dihydrocinchonidine has recentlybeen converted into dihydrocin~honamine,~~ this stereochemical identityalso applies to position 4 of the major Cinchona alkaloids.Re-examination of mitraphylline (16) has confirmed that it is the oxindoleTs = p-C,H4Me-S0,analogue of ajmalicine ; the constitution (16) includes tentative speculationsregarding its stereochemistry.Uncarine-A and -B are regarded as stereo-isomers of mitraphylline.48 Closer investigation of the alkaloids of Taber-nunthe iboga has revealed the presence of three new alkaloids, together withvoacangine; 49 the isolation of the last base confirms the relationship of theTabernanthe and the Voacanga alkaloids, previously demonstrated by theconversion of voacangine into ibogamine.Stemmadenia Donnell-Smithii, the first member of this species to beinvestigated, also contains both Tabernanthe and Voacanga alkaloids,4s A.Le Hir, M.-M. Janot, and D. Van Stolk, Bull. SOC. chim. France, 1958, 551;I<. B. Prasad and G. A. Swan, J., 1958, 2024.44 W. 0. Godtfredsen, G. Korsby, H. Lorck, and S. Vangedal, Experientia, 1958, 14,88; S. C. Pan and F. L. Weisenborn, J . Amer. Chem. Soc., 1958, 80, 4749.45 J.Poisson, N. Neuss, R. Goutarel, and M.-M. Janot, Bull. Soc. chim. France,1958, 1195.46 E. Wenkert and N. V. Bringi, J . Amer. Chem. Soc., 1958, 80, 3484.47 E. Ochiai and M. Ishikawa, Pharm. Bull. (Japan), 1957, 5, 498.48 J. C. Seaton, R. Tondeur, and L. Marion, Canad. J . Chem., 1958, 36, 1031; T.49 D. F. Dickel, C. L. Holden, R. C . Maxfield, L. E. Paszek, and W. I. Taylor, J. Nozoye, Ann. Report ITSUU Lab., 1958, 9, 66.Amer. Chem. SOC., 1958, 80, 123SAXTON : ALKALOIDS. 309together with (+)-quebrachamine and a new base, ~ternmadenine.~~ Afurther new alkaloid from Voacanga africana, voacangarine, is probably ahydroxyvoacangine (17; R = CO,Me, R’ = OH), since saponification,decarboxylation, and treatment with toluene-P-sulphonyl chloride inpyridine gave a hexacyclic quaternary salt (18); reduction of this withsodium and ethanol gave a mixture of bases, among which ibogaine (17;R = R = H) was identified.51 A closely related alkaloid, iboxygaine, hasrecently been extracted from an Iboga species; this could be 21-hydroxy-ibogaine (17; R = H, R’ = OH), but it is formulated as its 20-hydroxy-isomer, since it is reported to contain C-methyl and to give the iodoformreaction. Reaction with toluene-P-sulphonyl chloride gave a quaternarysalt, for which the constitution (18) is also p o s t ~ l a t e d .~ ~Full details are now available of the selenium dehydrogenation ofibogaine, ibogamine, and tabernanthine,53 and of the synthesis of theproducts obtained from ib0garnine.~4 Additional degradations of thesealkaloids have also been described ; a particularly interesting sequenceinvolved preparation of the related indoxyl, e.g., (19) from ibogamine, whichwas then converted into the toluene-9-sulphonyl derivative of its oxime.When this was heated in aqueous pyridine cleavage of the molecule occurredto give anthranilonitrile and the tricyclic ketone (20), which was furtherdegraded to S-ethyl-6-rnethylq~inoline.~~The earlier report that aspidospermine contains an N-methyl group hasbeen shown to be erroneous; this deduction was based on an atypicalnuclear magnetic resonance spectrum, and on an unreliable (in this series)Herzig-Meyer detemination. The formation and cleavage of aspidosper-mine [14C]methiodide to give inactive aspidospermine excludes the presenceof an N-methyl group.The von Braun degradation of this alkaloid is nowinterpreted 55 as indicating that the environment of Nb is (-CH,),N*CH<.Two brief reviews summarise recent work by Schmid,Karrer, and their collaborator^.^^ The progress in this immensely com-plicated group during the current year has been spectacular, and muchclarification has been achieved. The quaternary carboline alkaloidmavacurine has been converted into the related indoxyl, fluorocurine. Theintermediate dihydroxymavacurine has been identified as C-alkaloid Y ,57hence it is also referred to as C-profluorocurine. The shift to longer wave-lengths of the ultraviolet maxima of C-alkaloid Y, calebassine (C-toxiferineII), and other alkaloids, in alkaline solution is now attributed to an N,-carbinolamine, or vinylogous, grouping ; in the case of calebassine, this hasbeen confirmed by the preparation of the corresponding methyl ether.58Curare grozlp.50 F. Walls, 0.Collera, and A. Sandoval, Tetrahedron, 1958, 2, 173.51 D. Stauffacher and E. Seebeck, Helv. Chim. A d a , 1958, 41, 169.52 R. Goutarel, F. Percheron, and M.-M. Janot, Compt. rend., 1958, 246, 279.63 M. F. Bartlett, D. F. Dickel, and W. I. Taylor, J . Amer. Chem. Soc., 1958, 80,54 H. B. MacPhillamy, R. L. Dziemian, R. A. Lucas, and M. E. Kuehne, ibid.,p. 2172.86 H. Conroy, P. R. Brook, M. K. Rout, and N. Silverman, ibid., p. 5178.50 P. Karrer, H. Schmid, K. Bernauer, F. BerIage, and W. von Philipsborn, Angew.Chem., 1958, 70, 644; P.Karrer, Bull. SOC. chim. France, 1958, 99.57 H. Fritz, T. Wieland, and E. Besch, Annalen, 1958, 611, 268.58 K. Bernauer, H. Schmid, and P. Karrer, Helv. Chim. Acta, 1958, 41, 673.1263 10 ORGANIC CHEMISTRY.The identification of caracurine VII with the Wieland-Gumlich aldehyde(21; R = OH) provides the first rigorous proof that the alkaloids of theSouth American Strychnos species belong to the strychnine type, and is ofspecial interest in connection with the role attributed to this aldehyde inthe biosynthesis of these alkaloid^.^^ The Nb-methosalt of (21; R = OH)also occurs in calebash curares,a while C-curarine I11 (C-fluorocurarine) isbelieved to be the corresponding quaternary salt of (21; R = H) with a2,le-double bond. The importance of the Wieland-Gumlich aldehyde inthis series is emphasised by its isolation from the acid degradation ofcaracurine Va (nortoxiferine-I) ; similarly, toxiferine-I gives the corres-ponding Nb-methosalts.60y 62 The re-synthesis of caracurine Va and toxi-ferine-I from these fission products establishes the constitution of these“ dimeric ” alkaloids; caracurine Va is (22; R = OH), and toxiferine-I isthe related bis-quaternary compound.The conversion of ‘* heminor-dihydrotoxiferine ” and the Wieland-Gumlich aldehyde into a commonderivative proves that the former has structure (21 ; R = H) ; consequently,“ nordihydrotoxiferine ” is represented by (22; R = H), and dihydro-toxiferine is the corresponding bis-quaternary compound.62Lochneram, the Nb-methyl quaternary derivative of lochnerine, has beenisolated from Rio Negro curares, and characterised as the tetraphenyl-boronate; it is curious that ozonolysis gives only acetaldehyde, whileauthentic lochnerine, as well as lochnerine prepared from lochneram, giveboth acetaldehyde and f~rmaldehyde.~~Pyrrolizidine Group.-Crotalaria retusa L., a poisonous Australian weed,contains several alkaloids, among which retusine, hitherto unknown, isformulated as (23), since hydrolysis gives the amino-alcohol (24) and twoepimeric acids of structure (25) A related species, Crotalaria spectabilis60 K.Bernauer, S. K. Pavaranam, W. von Philipsborn, H. Schmid, and P. Karrer,8o A. R. Battersby and H. F. Hodson, Proc. Chem. SOC., 1958, 287.61 W.von Philipsborn, H. Meyer, H. Schmid, and P. Karrer, Helv. Chim. Ada,e2 K. Bernauer, H. Schmid, and P. Karrer, ibid., p. 1408; K. Bernauer, F. Berlage,63 W. Arnold, F. Berlage, K. Bernauer, H. Schmid, and P. Karrer, i f i d . , p. 1505.64 C . C. J. Culvenor and L. W. Smith, Austral. J . Chew?., 1957, 10, 464, 474.Helv. Chim. A d a , 1958, 41, 1405.1958, 41, 1257.W. von Philipsborn, H. Schmid, and P. Karrer, ibid., p. 2293SAXTON : ALKALOIDS. 311Roth., contains monocrotaline and spectabiline, which is an acetylmono-crotaline.64(-)-Heliotridane has been converted by successive Hofmanndegradations and hydrogenations into (+)-3-methylheptane. Accordingly,the absolute configuration of (-)-heliotridane is as shown in (26;. R = H),and in isoretronecanol as in (26; R = OH).65 These conclusions arecontrary to those obtained by application of molecular-rotation arguments.66nCH.CH2RRH2f:HCPhenanthridine Group.-Several new alkaloids have been added to thisgroup during the year under review.67 Progress in the structural investig-ations in this field is mainly due to Wildman and his co-workers.De-gradation of hzmanthamine has afforded N- (4,5-methylenedioxy-2-phenyl-benzy1)glycine and 4-4'-methoxycyclohexyl-5-methyl-1,2-methylenedioxy-benzene, identical with the product of hydrogenation of dihydrotazettinemethine. Hence, hzmarithamine has formula (27; R = OMe, R' = H), andthe stereochemistry of ring c is the same as that of tazettine.68 Crinamineis probably its 3-methoxy-epimer.Hzmanthidine, earlier assumed topossess the tazettine skeleton, is now believed to be represented by (27;R = OMe, R' = OH) ; this formulation is in better accord with its properties,e.g., the oxidation of dihydrohaemanthidine to a bridged lactam, which, frompreliminary observations, behaves as an amino-alcohol rather than a normall a ~ t a m . ~ ~ In this series several interesting transformations have beeneffected by means of sodium and pentyl alcohol, which eliminates aryl- orallyl-methoxyl gr0ups.~0 For example, hzmultine, a new base fromHamanthus multiflorus, is formulated as (27; R = R' = H), since it can beobtained by demethoxylation of hzmanthamine and ~rinamine.7~ Similarly,65 F. L. Warren and M. F. von Klemperer, J., 1958, 4574.66 N.J. Leonard, Chem. and I n d . , 1957, 1455.13' H. G. Boit and W. Dopke, Naturwiss., 1958, 45, 85; H. G. Boit, W. Dopke, andW. Stender, ibid., p. 262; L. Paul and H. G. Boit, Chem. Ber., 1958,91, 1968; L. J. Dry,M. Poynton, M. E. Thompson, and F. L. Warren, J., 1958, 4701.68 H. M. FaIes and W. C. Wildman, Chem. and I n d . , 1958, 561.6Q S. Uyeo, H. M. Fales, R. J. Highet, and W. C. Wildman, J . Amer. Chenz. Soc.,1958, 80, 2590.70 H. M. Fales and W. C . Wildman, ibid., p. 4395.'l H. G. Boit and W. Dopke, Chem. Ber., 1958, 91, 1966312 ORGANIC CHEMISTRY.falcatine is an ar-methoxycaranine, while narcissidine probably has structure(28; R = OH, R’ = OMe), since demethoxylation gives, among otherproducts, pluviine (28; R = R’ = H).70The ethanophenanthridine skeleton of crinine has been established byits conversion into crinane (29; R = H), which was also ~ynthesised.~,I(27) R‘RThe position of the hydroxyl group in crinine was confirmed 72 by Hofmanndegradation of oxocrinine, which yielded an optically inactive methinebase (30).Consequently, crinine is represented as (29; R =OH, with a1,2-double bond) ; powelline is an ar-methoxycrinine, and buphanisine andbuphanidrine are the corresponding 3-methyl ethers.72 Finally, undulatinehas been shown to be the epoxide of buphanidrine.73Erythrinu Group.-Synthetic support for the constitution of a-erythroidinehas been provided by the synthesis of two degradation products (31 ; R = 0)and (31; R = :CH*CH-CH,*OH). Since both CC- and p-erythroidine can bedegraded to the same diene, these two alkaloids only differ in the positionof a double bond; in confirmation, it has been shown that a-erythroidine(32) is isomerised to p-erythroidine by hot alkali.74Diterpene Group.-Two reviews, one concerning the Delphinium alkaloids,and another the Aconite-Garrya alkaloids, are welcome additions to alkaloid1iterat~x-e.~~ One of the remaining doubtful structural features of atisineis the position of the ally1 alcohol system; this has now been located as in(33) by elimination of C(7) and the methylene group, to give a 8-keto-acid.The final product (34; R = 0) of this degradation is of interest, since theacid (34; R : H,) should be obtainable from the Garrya alkaloids and thusafford a method for interrelating these two series.76 Further evidence insupport of this structure is provided by the selenium dehydrogenation of anisoatisine derivative, which affords 6-isopropyl-l-methylphenanthrene, andby synthesis of 6-ethyl-l-methyl-3-azaphenanthrene (35), the dehydro-72 W.C. Wildman, J . Amer. Chem. SOL, 1958, 80, 2567.73 E. W. Warnhoff and W. C. Wildman, Chem. and Ind., 1958, 1293.74 V. Boekelheide and G. C . Morrison, J . Amer. Chem. SOL, 1958, 80, 3905.75 L. Marion, X V I t h Internat. Congr. Pure Appl. Chem. ; Experientia, Suppl. VII,76 D. Dvornik and 0. E. Edwards. Chem. and Ind., 1958, 623.1957, 328; K. Wiesner and 2. Valenta, Fortschr. Chem. org. Naturstoffe, 1958, 16, 26SAXTON : ALKALOIDS. 313genation product of ati~ine.~’ The synthesis of compound (35) constitutesthe first unequivocal evidence relating the nitrogen atom to the remainderof the molecule.The alternative location of the ally1 alcohol system(positions lS,19) is excluded by the observation that reduction of related( 3 ‘ )Me0 * 0(33) (34)ketones by sodium borohydride yields a mixture of epimeric alcohols;since position 19 is hindered, reduction of a 19-ketone would be expected toyield only one of the epimeric 19-alcohols.76~ 77 Ajaconine has been identifiedas 9-hydroxyatisine, the 9-hydroxyl group being cis to the heterocyclicbridge and equatorial; this work also determines the position of the carbonylgroup in atidine, and is of particular interest in connection with the proposedbiosynthesis of lycoct~nine.~~Napellonine is now known to be identical with songorine, and this hasresulted in the correction of some anomalies in their ~hemistry.7~ Sincedehydrogenation gives 7-ethyl-1,lO-dimethylphenanthrene and 7-ethyl-l-methy1-3-azaphenanthreneJ and since songorine contains an N-ethyl group,the structure proposed earlierso must be replaced by one containing a10,17-bond, as in (36).79In two independent investigations the relation previously suspectedbetween lycoctonine (37; R = R” = R”’ = Me, R’ = H) and delpheline(38; R = H) has been confirmed.The more direct method involvedmethylation of delpheline with sodium hydride and methyl iodide to givethe ether (38; R = Me), which, on acid hydrolysis, afforded deoxylycoc-tonine.sl In the second approach, demethoxylation of anhydrodeoxyly-coctonam, followed by oxidation with selenium dioxide, gave the diketo-lactam (39), which, as expected, was identical with dehydrodemethylene-77 S.W. Pelletier, Chern. and Ind., 1958, 1116; D. M. Locke and S. W. Pelletier,78 D. Dvornik and 0. E. Edwards, PYOC. Chem. SOC., 1958, 280.79 K. Wiesner, S. Ito, and 2. Valenta, Experientia, 1958, 15, 167.J . Amer. Chem. SOC., 1958, 80, 2588.Ann. Reports, 1957, 54, 261.M. Carmack, J. P. Ferris, J. Harvey, P. L. Magat, E. W. Martin, and D. W. Mayo,J . Amer. Chenz. SOC., 1958, 80, 497314 ORGANIC CHEMISTRY.oxodelpheline pinacone.S2 Deltaline, a new alkaloid from Delphiniumbarbeyi and D. occidentale, has structure (38; R = Ac), with an additionalhydroxyl group; reaction with thionyl chloride, followed by reduction withlithium aluminium hydride, converts it into delpheline.81The structure (37; R = R’ = Me, R” = R”‘ = H) proposed earlier fordelcosine 83 has now been shown to be untenable, since oxidation of oxo-delcosine , the lactam corresponding to delcosine, gives didehydro-oxo-delcosine, which is a diketone containing keto-groups in 5- and 6-memberedrings.Accordingly, delcosine is now formulated as (37; R = R”‘ = H,R’ = R” = Me), and this has been verified by preferential methylation ofthe hydroxyl group in the 5-membered ring, which yields delsoline (37;R = H, R = R” = R”’ = Me).M In these formulgtions for delcosine anddelsoline the stereochemistry is not proved; however, the formation of acarbinolamine ether on permanganate oxidation of delsoline suggests thatthe hydroxyl group in ring A is cis with respect to the nitrogen bridge, i.e.,opposite to the configuration of the corresponding methoxyl group inlycoc tonine .85Miscellaneous.-The chemical evidence relating to the structure ofannotinine has been discussed in details6Further work on the synthesis of muscarine and its stereoisomers hasbeen des~ribed,~~,~* including a new synthesis of (j-)-mu~carine.~~ Twogroups have recorded the resolution of (j-)-muscarine by means of di-p-toluoyltartaric acid, and the isolation of pure (+ )-muscarine, identical withnatural muscarine .88HOMeOR”‘37)CH 2* OR‘H- 0 M e.OMeCO2HICH2ICHHOIC’ ‘CH382 0.E. Edwards, L.Marion, and K. H. Palmer, Canad. J . Chem., 1958, 36, 1097.83 R. Anet, D. W. Clayton, and L. Marion, ibid., 1957, 35, 397; R. Anet and L.84 V. Skaric and L. Marion, J . Amer. Chem. SOC., 1958, 80, 4434.S5 F. Sparatore, R. Greenhalgh, and L. Marion, Tetrahedron, 1958, 4, 157.88 K. Wiesner, 2. Valenta, W. A. Ayer, L. R. Fowler, and J. E. Francis, ibid., p. 87.87 C. H. Eugster, F. Hafliger, R. Denss, and E. Girod, Helv. Chim. A d a , 1958, 41,205, 583, 705.88 Idem, ibid., p. 886; H. C. Cox, E. Hardegger, F. Kogl, P. Liechti, F. Lohse, andC. A. Salemink, ibid., p. 229.a9 T. Matsumoto and H. Maekawa, A?zgcw. Chem., 1958, 70, 507.Marion, ibid., 1958, 36, 766OVEREND: CARBOHYDRATES. 315Chaksine, a monoterpene alkaloid of Cassia absus L., is unusual in thatit contains a guanidine system in the molecule.An important product ofalkali fusion is the tricarboxylic acid (40), which is accompanied by Z-methyl-pimelic acid; the latter can also be obtained by oxidation of chaksine.These properties are best explained by the constitution (41) for c h a k ~ i n e . ~ ~J. E. S.11. CARBOHYDRATESIN last year's Report there was no reference to polysaccharide chemistry.This was not the result of a slackening of interest, and in fact the majority ofchemists who work with carbohydrates are concerned with this aspect ofthe subject. In this Report the emphasis is on oligo- and poly-saccharidesand some of the developments during the past two years will be described.Consideration of the enzymology of polysaccharides is omitted although it isappreciated that important evidence concerning polysaccharide structure isobtained frequently by this approach to the problem.Polysaccharides-An extensive review of cereal carbohydrates has beenpub1ished.lMethods for the fractionation of polysaccharides and detection of theircomponents continue to attract attention.The precipitation of neutralpolysaccharides by cationic detergents,2 the use of barium hydroxide as aselective precipitant for hemicelluloses,3 and the fractionation of alginateswith manganous and ferrous salts4 have been examined and found to beuseful methods for separating polysaccharides. The selective precipitationwith " Cetavlon " (cetyltrimethylammonium bromide) of neutral poly-saccharides which form borate complexes has been s t ~ d i e d .~ Phosphateprecipitation is useful for the isolation of a clinical dextran fraction;fractionation is achieved and schemes can be devised for the separation ofmany neutral polysaccharides. Some advantages accrue if ultrafiltrationis used for fractionation.' The fractionation of potato starch by centrifug-ation in alkali * and the separation of amylose from amylopectin by anextraction-sedimentation procedure have been discussed. Investigationsof the differential thermal analysis lo and electrophoresis on columns l1 andon paper l2 of saccharides have had useful results. While it is possible toseparate polysaccharides which have entirely different structures byO0 K. Wiesner, 2. Valenta, B.S. Hurlbert, F. Bickelhaupt, and L. R. Fowler, J .Amer. Chem. Soc., 1958, 80, 1521; G. Singh, G. V. Nair, K. P. Aggarwal, and S. S.Saksena, J . Sci. Ind. Res., India, 1958, 17, B, 332.I. A. Preece, Roy. Inst. Chem. Lectures, Monographs, and Reports, 1967, No. 2.H. Palmstierna, J. E. Scott, and S. Gardell, Acla Chem. Scand., 1957, 11, 1792.H. Meier, ibid., 1958, 12, 144.R. H. McDowell, Chem. and Ind., 1958, 1401.S . A. Barker, M. Stacey, and G. Zweifel, ibid., 1957, 330.L. Lacko, J. M%lek, and J . DvorAkovA, ibid., 1958, 1553; see also Coll. Czech. Chem.' K. C. B. Wilkie, J. K. N. Jones, B. J. Excell, and R. E. Semple, Canad. J . Chem.,* H. Baum and G. A. Gilbert, J . Colloid Sci., 1956, 11, 428.lo H. Morita, Analyt. Chem., 1957, 29, 1095.l2 E.Eurcik and W. Beutmann, Naturwiss., 1957, 44, 42.Comm., 1958, 23, 361.1957, 35, 795.E. M. Montgomery and F. R. Senti, J . Polymer Sci., 1958, 28, 1.B. J. Hocevar and D. H. Northcote, Nature, 1957, 179, 488316 ORGANIC CHEMISTRY.electrophoresis in a borate buffer,13 the inhomogeneity of a single poly-saccharide cannot be ascertained in this way. Replacement of the boratewith S~-sodium hydroxide gives some improvement and by its use it hasbeen shown that many polysaccharides hitherto assumed to be essentiallyhomogeneous can be separated into two or more components.14 Forexample, a range of amylopectins was found, not only to be hetero-geneous, but also to differ from each other. Glycogens were composed of twofractions and laminarin (from L.digitata and L. cloustoni) was heterogeneous,as was a wide range of gums. Heterogeneity was found in hemicellulosesfrom maize hulls, wheat and flax straw, and ramie grass : the so-called hemi-celluloses from aspen wood, slash pine, loblolly pine, and western hemlockwere heterogeneous. The crystalline xylans produced from beech wood andbarley straw, and the galactomannan of sugar-beet pulp were homogeneous.Fructans from rye flour, perennial rye grass, and dahlia were homogeneousbut the fructans from the ti root and from cocksfoot contained two com-ponents. Carrageenin l5 and agar l6 were mixtures. Heparin, hyaluronicacid, and chondroitin sulphate behaved individually as homogeneouspolymers but were easily separated from each other. The method appearsto be extremely useful for the examination of polysaccharide preparations.A spectrophotometric determination of total carbohydrate l7 and acolorimetric method for the determination of linkage in hexosamine-containing compounds l8 have been described.The carbazole reaction hasbeen adapted for the estimation of glucuronolactone, glucose, and xylose insolutions containing any or all of these compounds in the concentrationrange 10-100 pg./ml. The method has been used successfully with someacidic poly~accharides.~~ An infrared spectrophotometric procedure for theanalysis of cellulose and modified cellulose,2° an infrared microtechnique forthe identification of carbohydrates,21 and the differentiation of y- and6-aldonolactones 22 (in y-lactones carbonyl absorption occurs at 1765-1790 crn.-l, whereas in 8-lactones it is at 1726-1760 cm.-l> have been reported.A new chemical method for the determination of molecular weights ofcertain polysa~charides,~~ a procedure for mi~ro-methylation,~~ and a micro-method for the estimation of cellulose 25 are of interest.The natural occurrence of several new sugars has been recognised.2-O-Methyl-~-fucose has been identified in plum-leaf polysaccharides.26 Thel3 K.W. Fuller and D. H. Northcote, Biochem. J . , 1956, 64, 657.l4 B. A. Lewis and F. Smith, J . Amer. Chem. Soc., 1957, 79, 3929.l5 Cf. D. B. Smith and W. H. Cook, Arch. Biochem. Biophys., 1953, 45, 232.l6 Cf. C. Araki and K. Arai, Bull. Chem. Soc. Japan, 1956, 29, 543.la J.A. Cifonelli and A. Dorfman, J . Biol. Chem., 1958, 231, 11.lo J. M. Bowness, Biochem. J., 1957, 67, 295.2o R. T. O'Connor, E. F. Du PrB, and E. R. McCall, Analyt. Chem., 1957, 29, 998.21 F. E. Resnik, L. S. Harrow, J. C. Holmes, M. E. Bill, and F. L. Greene, ibid.,22 S. A. Barker, E. J. Bourne, R. M. Pinkard, and D. H. Whiffen, Chem. and Ind.,23 A. M. Unrau and F. Smith, ibid., 1957, 330.24 H. S. Isbell, H. L. Frush, B. H. Bruckner, G. N. Kowkabany, and G. Wampler,25 G. G. Dearing, Nature, 1957, 179, 579.26 J. D. Anderson, P. Andrews, and L. Hough, Chem. and Ind., 1957, 1453.B. R. Hewitt, Nature, 1958, 182, 246.p. 1874.1958, 658.Analyt. Chem., 1957, 29, 1523OVEREND: CARBOHYDRATES. 317position of the O-methyl group is of biogenetic interest since other naturallyoccurring deoxy-0-methyl sugars carry the methoxyl substituent a tposition 3 (see Andrews and Hough 27 for experiments on the biosynthesis ofplum-leaf polysaccharides) .An aldoheptose, possibly D-glycero-L-manno-heptose, occurs in lipopolysaccharides of Haemophilus bronchsepticus,H. pertussis, and*H. parapertussis.28 It seems probable that, as in othermembers of the Pasteurella group, aldoheptoses are of general occurrence inlipopolysaccharides from strains of P. sejbti~a.~~ It is confirmed that L-guluronic acid residues exist in alginic acid.30There are several reports of the formation of polysaccharides by poly-condensation of glucose. The polymerisation of D-glucose by hydrogen ionsin dimethyl sulphoxide has been examined.31 Non-crystalline polymers areformed when m-D-glucose is heated in the presence of metaboric acid.32 Theproduct is heterogeneous as to both size and bond structuqe. In the highlybranched polyoses 1,4- and 1,6-linkages predominate.No information isavailable about the precise stereochemistry of these bonds but probably thereis a fairly high ratio of cc- to p-links. The polycondensation of a-D-glucose a t140-170" in a vacuum and in the presence of 0.164% phosphorous acid hasbeen studied.33 Addition of tetrahydrothiophen dioxide prevented formationof insoluble gels in melt polymerisations. Raising the polymerisation tem-perature increases the degree of branching in the polymers, and the fractionsof higher molecular weight also have a higher degree of branching.=The enormous output of research on cellulose chemistry continuesunabated and a wide range of derivatives of the polysaccharide is beinginvestigated. 3-Oxoglucose units exist in oxidised cellulose.% An assess-ment has been made of the reactivity of cellulose in a~etylation,3~ and thepreparation and properties are described of acetates, modified acetates,37and mixed esters.38 A mechanism of interaction of trifluoroacetic acidwith cellulose is outlined.39 Preparation of xanthate esters 4O and nitration,4127 P.Andrews and L. Hough, Biochem. J., 1957, 67, 1 1 ~ .28 A. P. Maclennan, ibid., p. 3 ~ .29 A. P. Maclennan and C. J. M. Rondle, Nature, 1957,180, 1045; cf. D. A. L. Davies,ibid., p. 1129.30 D. W. Drummond, E.L. Hirst, and E. Percival, Chem. and Ind., 1958, 1088;cf. F. G. Fischer and H. Dorfel, Z. physiol. Chem., 1955, 302, 186.31 I;. Micheel and W. Gresser, Chem. Bey., 1958, 91, 1214.32 H. W. Durand, 31. F. Dull, and R. S. Tipson, J . Amer. Chem. Soc., 1958, 80, 3691.33 P. T. Mora and J. W. Wood, ibid., p. 685.34 P. T. Mora, J. W. Wood, P. Maury, and B. G. Young, ibid., p. 693.35 B. Lindberg and 0. Theander, Acta Chem. Scand., 1957, 11, 1355.38 C. J. Malm, K. T. Barkey, J. T. Schmitt, and D. C. May, Ind. Eng. Chem., 1957,49, 763; see also C. J. Malm, L. J. Tanghe, H. M. Herzog, and M. H. Stewart, ibid.,1958, 50, 1061.37 C. J. hfalni, K. T. Barkey, M. Salo, and D. C. May, ibid., 1957, 49, 79; F. A. H.Rice and A. R. Johnson, J . Amer. Chem. SOC., 1957, 79, 5049; J.F. Haskins and G. G.Sundenvirth, ibid., p. 1492.s* W. Voss and H. Reimschussel, Makromol. Chem., 1958, 28, 110.39 A. L. Geddes, J . Polymer Sci., 1956, 22, 31.*O E. G. Adamek and C. B. Purves, Canad. J . Chem., 1957, 35, 960; 2. Rybicki,Przemysl Chem., 1957, 13, 18.*1 T. Urbanski and A. Siemaszko, Bull. Acad. polon. Sci., C1. 111, 1957, 5, 1145;S. Watanabe, J . Chem. SOC. Japan, I n d . Chem. Sect., 1958, 61, 370, 374; T. S. A. Pad-manabham, S. K. Ranganathan, T. N. Rawal, and L. R. Sud, J . Sci. I n d . Res., India,1957, 16, B, 414318 ORGANIC CHEMISTRY.and the location of substituents in the products ( x a n t h a t e ~ , ~ ~ nitrates 43),continue to occupy chemists.c yanomet h yl ,45 carbox yme t h ydrox ye t h yl ,47 hydroxypropyl,48 a-hydr-~xyphenethyl,~~ thi~urethane,~~ ~ h t h a l a t e , ~ ~ methane~ulphonyl,~~ and chloro-compounds.53 The thermal decomposition of cellulose 54 and its acetate 55has been investigated. a-Hydroxy-nitriles have been recognised among thereduced-pressure ignition products of cellulose nitrate.5s The absence ofother non-gaseous nitrogenous substances was demonstrated.By theignition of [14C]cellulose nitrate, labelled at positions 1 and 6 of the anhydro-glucose units, it was demonstrated that C(0 gives mainly carbon dioxide andsmaller amounts of formic acid and glyoxal (from C(l) and C(d), and C(s) givespredominantly formaldehyde with smaller amounts of formic acid andcarbon dioxide.67Attempts a r t being made to determine how the two components ofstarch are incorporated into the granule and how the physical nature of thegranule governs the efficiency and ease of fractionation.Water preferentiallyleaches short-chain linear material from potato-starch granules.58 Itsaction is both inefficient and incomplete in comparison with conventionalmethods involving complete disruption of the granular structure. Theimportance of oxygen-free conditions to prevent amylose degradationin the fractionation of potato starch has been empha~ised.~~ A criticalexamination has been undertaken of the behaviour of oat and wheatstarch on fractionation by dispersion and aqueous leaching.60 The granularstarch in sweet corn (Zea mays) is a typical cereal starchs1 whose pro-perties are unaltered by the coexistence in the grain of water-solubleOther derivatives studied include4a E.P. Swan and C. B. Purves, Canad. J . Chem., 1957, 35, 1522; A. K. Sanyal,E. L. Falconer, D. L. Vincent, and C. B. Purves, ibid., p. 1164; J. K. Miller and J. D.Geerdes, Abs. Amer. Chem. SOC. Meeting, Miami, 1957, 3 ~ .43 E. L. Falconer and C. B. Purves, J . Amer. Chem. SOC., 1957, 79, 5308.44 V. Derevitskaya, M. Prokof’yeva, and 2. Rogovin, Zhur. obshchei Khim., 1958,28, 716; I. Croon, B. Lindberg, and A. Ros, Svensk Papperstidn., 1958, 61, 35.46 N. M. Bikales, A. H. Gruber, and A. L. Rapoport, Abs. Amer. Chem. SOC. Meeting,Miami, 1957, 1 ~ .4~ D. K. Basu and P. K. Choudhury, 7. Indian Chem. Soc., 1958, 35, 173; C.Simionescu and N. Asandei, Chim.analyt., 1958, 40, 204.47 H. H. Brownell and C. B. Purves, Canad. J . Chem., 1957, 35, 677.48 G. Froment, Ind. chim. belge, 1958, 23, 3.48 G. Montegudet, Compt. rend., 1957, 244, 2178.50 A. L. Allewelt and W. R. Watt, Ind. Eng. Chem., 1957, 49, 68.51 C. J. Malm, J. W. Mench, B. Fulkerson, and G. D. Hiatt, ibid., p. 84.52 R. W. Roberts, J . Amer. Chem. Soc., 1957, 79, 1175.53 R. L. Boehm, J . Org. Chem., 1958, 23, 1716.54 A. Pacault and G. Sauret, Compt. rend., 1958, 248, 608; 0. P. Golova and R. G.Krylova, Doklady Akad. Nauk S.S.S.R., 1957, 116,419; 0. P. Golova, A. M. Pakhomov,Ye. A. Andriyevskaya, and R. G. Krylova, ibid., 1957, 115, 1122; 0. P. Golova, A. M.Pakhomov, and Ye. A. Andriyevskaya, Izvest. Akad. Nauk S.S.S.R., Otdel. khim. Nauk,1957, 1499.55 H.Maeda, K. Saito, and T. Kawai, J . Chem. SOC. Japan, Ind. Chem. Sect., 1958,61, 605.56 M. L. Wolfrom, A. Chaney, and P. McWain, J . Amer. Chem. Soc., 1958, 80, 946.57 F. Shafizadeh and M. L. Wolfrom, ibid., p. 1675.58 J. M. G. Cowie and C. T. Greenwood, J., 1957, 2862.59 Idem, J., 1957, 4640; see also G. A. Gilbert, Starke, 1958, 10, 95.6o -4. W. Arbuckle and C. T. Greenwood, J., 1958, 2626.C . T. Greenwood and P. C. Das Gupta, J., 1958, 707OVEREND : CARBOHYDRATES. 310glucosans.62 Apparently acid-treatment preferentially affects the amorphousrather than the crystalline region of the potato-starch granule.63 Althoughboth the amylose and the amylopectin component were degraded, the latterwas broken down preferentially.Similar results were obtained with wheat-starch granules64 but the rate of degradation was less than for potato,probably owing to the more compact structure of wheat starch. Radio-chemical evidence has been provided for heterogeneity in wheat starch.65A comprehensive linkage-analysis of floridean starch (from Dilsea e d d i s )has established that it contains a small proportion of 1,3-~-1inkages.~~ Thedegree of multiple branching in an amylopectin (or glycogen) can beevaluated from the chain lengths of the corresponding muscle-phosphorylaseand P-amylase limit d e x t r i n ~ . ~ ~ A range of glycogens showed small butsignificant differences in degree of multiple branching, and amylopectinsshowed a similar range of values. Accordingly the marked physicochemicaldifferences between glycogen and amylopectin cannot be related todifferences in the degree of multiple branching.The dextrinisation of maize 68 and wheat 69 starch is accompanied byconsiderable transglycosidation and the development of a highly .branchedstructure.The action of O.Fi~-sodium hydroxide at 100" on amylose is oftwo main types : I' degradation " producing mainly D -glucoisosaccharinic,formic, and lactic acid, and a " stopping " reaction affording alkali-stableamylose probably bearing terminal D-glucometasaccharinic acid units.70Glyoxylic and D-erythronic acids are the principal products from the hypo-chlorite oxidation of , maize-starch arnyl~pectin.~~ Optimum conditionshave been determined for the oxidation by chlorous acid of periodate-oxidised maize starch.72 The extent of formylation of starch is dependentupon the ratio of formic acid to starch and on the water content of thesystem.73 The preparation and properties of mixed esters of amylose havebeen outlined.74The molecular structure of glycogens has been re~iewed.~j A comparisonof the molecular weights of glycogens extracted from rabbit liver by' hotalkali and by cold trichloroacetic acid indicates that the latter methodyields material which approximates most closely to native gly~ogen.'~Ultracentrifugal analysis of 23 glycogens, isolated from various sources,showed that most of the samples were polydisperse : the molecular weightsand P.C. Das Gupta, J., 1958, 703.62 Cf. S. Peat, W. J. Whelan, and J .R. Turvey. J., 1956, 2317; C. T. Greenwood63 J. M. G. Cowie and C. T. Greenwood, J., 1957, 2658.64 A. W. Arbuckle and C. T. Greenwood, J., 1958, 2629.65 A. S. Perlin, Canad. J . Chem., 1958, 36, 810.66 S. Peat, J. R. Turvey, and J. M8n Evans, Nature, 1957, 179, 261.67 A. M. Liddle and D. J. Manners, Biochem. J.. 1955, 61, X I I ; J . , 1957, 4708.68 J. D. Geerdes, B. A. Lewis, and F. Smith, J . Amer. Chem. SOC., 1957, 79, 4209.6Q G. M. Christensen and F. Smith, ibid., p. 4492.70 G. Machell and G. N. Richards, J., 1958, 1199.72 B. T. Hofreiter, I. A. Wolff, and C. L. Mehltretter, ibid., p. 6457.73 I. A. Wolff, D. W. Olds, and G. E. Hilbert, ibid., p. 3860.74 Idem, I n d . Eng. Chem., 1957, 49, 1247.75 D. J. Manners, Adv. Carbohydrate Chem., 1957, 12, 262.76 W.A. J. Bryce, C. T. Greenwood, and I. G. Jones, J . , 1958, 3845; cf. C. T.R. L. Whistler and R. Schweiger, J . Amer. Chem. SOC., 1957, 79, 6460.Greenwood and D. J. Manners, Proc. Chem. SOC., 1957, 26320 ORGANIC CHEMISTRY.of the main components lie in the range 3-9 x lo6. It was concluded 77that it is difficult to avoid degradation during the extraction of glycogen.Further evidence from periodate oxidations confirms that the averagelength of chains in glycogens is normally about 12 glucose residues.78Investigations of the extraction and fracti~nation,~~ and the structure,B* ofbrain glycogen have been reported.The characterisation of dextrans by the optical rotation of theircuprammonium complexes,81 and the relation between specific opticalrotation and branching of dextrans,82 have been examined.Some phos-phoric esters of dextran have been synthe~ised.~~ Experiments with baker’syeast glucan indicate that it is a linear polymer of p-D-glucopyranose unitsin which 1,3- and 1,6-linkages are arranged at random or in sequences suchthat a group of at least three 1,6-linkages is flanked on either side by 1,3-linkages.84 The combined proportion of non-reducing end-groups and1,6-links is 1 per 10 glucose residue^.^^^^^ Warsi and Whelan86 havereinvestigated the structure of pachyman and have shown that it is a polymerof p-glucose containing only 1,3-linkages : Takeda 87 had previouslyerroneously concluded that 1 ,&linkages were present.Purified isolichenin and lichenin from Iceland moss (Cetraria islandica)have been characterised by methylation and periodate oxidationa8 It hasbeen confirmed that lichenin is a linear polymer of p-D-glUCOSe containingboth 1,3- and 1,4-linkages.Chanda et aE.88 consider the ratio of 1,3- to1,4-linkages to be 3 : 7, whereas Peat and his co-workers *9 calculate theratio to lie between 1 : 2 and 1 : 3 and suggest that the lichenin chain is arepeating sequence of p-cellotriose units joined through 1,3-bonds. Iso-lichenin consists solely of D-glucose residues united by cc-1,3- and or-1,4-linkages in the relative proportion 3 : 2. The molecule appears to be linearwith an average chain length of 42-44 glucose units.8*The linkagesin soluble and insoluble laminarin have been analysed by partial hydrolysisand it has been confirmedg0 that the principal bond is of the 1,3-type,between p-D-glucopyranose residues.In a hydrolysate of insolublelaminarin 14 mono-, di-, and tri-saccharide products were identified; 91 ofthese D-glucose, D-mannitol, laminaribiose, gentiobiose, l-O-p-glucosyl-mannitol, laminaritriose, 3-O-gentiobiosylglucose, 6-O-p-laminaribiosyl-glucose, and 1-O-p-laminaribiosylmannitol are considered to be trueImportant papers about laminarin have been published.77 W. A. J. Bryce, C. T. Greenwood, I. G. Jones, and D. J. Manners, J., 1958, 711.78 D. J. Manners and (in part) A. R. Archibald, ibid., 1957, 2205.7s B. I. Khaikina and L. S. Krachko, UKrain. biokhim. Zhur., 1957, 29, 10.so Ye. Ye. Gonchareva, Doklady Akad.Nauk S.S.S.R., 1957, 112, 899.81 T. A. Scott, N. N. Hellman, and F. R. Senti, J . Amer. Chem. SOC., 1957, 79, 1178.82 C. E. Rowe, Chem. and Ind., 1957, 816.83 A. Gallo and A. Vercellone, Chimica e Industria, 1957, 39, 1.84 S. Peat, W. J. Whelan, and T. E. Edwards, J., 1958, 3862.86 S. Peat, J. R. Turvey, and J. M. Evans, J., 1958, 3868.a8 S. A. Warsi and W. J. Whelan, Chem. and Ind., 1957, 1573.89 S. Peat, W. J. Whelan, and J. G. Roberts, J., 1957, 3916.90 S. Peat, W. J. Whelan, and H. G. Lawley, J., 1958, 724.91 Idem, J., 1958, 729.K. Takeda, Mem. Tottori agric. Coll., 1935, 3, 1.N. B. Chanda, E. L. Hirst, and D. J. Manners, J . , 1957, 1951OVEREND CARBOHYDRATES. 321structural fragments of laminarin. The presence of mannitol has beenreported by other workers Peat et aLgl suggest that the laminarinmolecules consist of unbranched chains of @-1,3-linked glucose units oc-casionally interrupted by p-1,6-linkages and that some but not all areterminated by mannitol.It is considered that soluble laminarin probablyhas a similar structure but contains a higher proportion of mannitol and off3-1,6-linkages (cf. Anderson et aLg2). Fig. 1 shows the suggested structureand the di- and tri-saccharides which would be produced by partialhydrolysis.6-0-/3-Larninaribiosyl- 1-O-p-Glucosyl-Laminaribiose Gentiobiose glucose mannitolt t t tJ- J.Laminaritriose 3-O-~-Gentiobiosylglucose 1 -0-P-Laminaribiosyl-mannitolKey: 0 = D-glucopyranose unit; M = mannitol.(N.B. Some of the molecules do not contain mannitol.)FIG.1Peat et uLg1 preferred to leave open the question of branching but Hirstand his colleagues 93 have evidence which supports a branched structure unlessthe 1,6-linkages occur exclusively near the end of the chains. Successiveperiodate oxidation and degradation with phenylhydrazine of laminarin gaveafter three oxidations and two degradations a residual oxopolysaccharide.Polysaccharides derived from timbers, grasses, and cereals continue toattract world-wide attention. Information concerning lignin-carbohydratebonding is discussed in several publication^.^^ Arabogalactans from thewoods of European larch (Larix d e c i d u ~ ) , ~ ~ white spruce [Picea glauca(Moench) VOSS],~~ and Jack pine (Pinus banksiana Lamb) 97 have beenstudied.The material from larch is highly branched: the framework of themolecule consists of chains of 1,3-linked P-D-galactopyranose units, themajority of which carry side chains containing an average of two 1,6-linkedp-D-galactopyranose residues. The majority of the arabinose occurs as 3-0-p-L-arabofuranosyl-L-arabofuranosyl side chains. The structural features ofspruce arabogalactan are generally similar. A unique structure cannot beformulated for Jack pine arabogalactan but it seems that a chain of92 A. M. Unrau and F. Smith, Chem. and Ind., 1957, 1178; F. B. Anderson, E. L.Hirst, and D. J. Manners, ibid., p . 1178; F. B. Anderson, E. L. Hirst, D. J. Manners,and A. G. ROSS, J., 1958, 3233.93 E. L. Hirst, J.J. O’Donnell, and E. Percival, Chem. and Ind., 1958, 834.94 B. 0. Lindgren, Svensk Papperstidn., 1958, 61, 669; R. Nelson and C. Schuerch,J . Polymer Sci., 1956, 22, 435; A. Hayashi and I. Tachi, J . Agric. Chem. SOC. Japan,1956, 30, 442, 791.95 G. 0. Aspinall, E. L. Hirst, and E. Ramstad, J., 1958, 593.s~ G. A. Adams, Caiiad. J . Chem., 1958, 36, 756.97 C. T. Bishop, ibid., 1957, 85, 1010.REP-VOL. LV 322 ORGANIC CHEMISTRY.1,6-linked D-galactopyranose units is terminated a t the non-reducing end byan unsubstituted D-galactopyranose or L-arabofuranose residue. Throughposition 3 of some of the galactose units other 1,6-linked chains of D-galacto-pyranose units are attached and some are terminated by L-arabofuranoseunits. At one point in the molecule branching occurs through positions 3and 4 instead of 3 and 6 of a D-galactopyranose residue.Most of theglycosidic linkages are of the P-configuration. When hydrolysed underconditions sufficiently mild to cleave almost exclusively only furanosidiclinkages an arabogalactan from Larix occidentalis yielded a mixture ofarabinose, galactose, 3-O-p-~-arabopyranosyl-~-arabinose, 6-O-P-~-galacto-pyranosyl-D-galactose, and a trisa~charide.~~ A glucomannan from westernred cedar (Thuja plicata Donn) (glucose : mannose = approx. 1 : 2.5) issimilar to glucomannans from other woods, being a short, predominantlystraight-chain polymer in which the units are linked by 1,4-p-glycosidicbonds. Graded hydrolysis afforded cellobiose, mannobiose, glucosido-mannose, mannosidoglucose, and a mannotrio~e.~~ Similar di- and tri-saccharides were obtained from a glucomannan from western hemlock(Tsuga heterophyZZa) .loo The glucomannan fraction of sitka spruce (Piceasitchensis) hemicellulose contains a t least two essentially linear components,a p-1,4-linked glucan and a p-1,4-linked glucomannan.lo1 Two gluco-mannans from Norwegian spruce (Picea abies) have been studied by themethylation and the periodate oxidation procedure : lo2 they have the samegeneral structure, being composed essentially of a-1,4-linked sugar residues ;each molecule has 3 4 branch points, which are attached to the 3-position ofglucose residues ; the non-reducing end-groups are principally mannoseresidues.Graded hydrolysis indicates that in loblolly pine (Pinus takda)glucose and mannose residues are linked by p-glycosidic bonds in a poly-saccharide (or group of polysaccharides) which is distinct and separablefrom the residual ‘‘ a-cellulose ” of the Pentosan and hexosanfractions of hemicelluloses from aspen wood (Populis tremuloides) have beenexamined.lo4 By conventional methods it has been demonstrated that thehemicellulose of the wood of white elm (Ulmus americana) contains 1851,4-linearly linked p-D-xylopyranose residues, every seventh of whichcarries a single terminal side chain of 4-O-methyl-~-glucuronic acid attachedby an a-glycosidic bond through C(g.lo5 In the hemicellulose of white birch(Betula papyrifera) there is a chain of a minimum of 110 and a maximum of190 p-1 ,&linked D-xylopyranose units.On the average, every eleventhanhydroxylose unit carries a t position 2 a single glycosidically bonded4-O-methyl-~-g~ucuronic acid residue.lo6 The water-soluble hemicellulose9s H. Bouveng and B. Lindberg, Actu Chem. Scand., 1956, 10, 1515.99 J. K. Hamilton and E. V. Partlow, J . Amer. Chem. SOC., 1958, 80, 4880.100 J. K. Hamilton and H. W. Kircher, ibid., p. 4703.101 G. 0. Aspinall, R. A. Laidlaw, and R. B. Rushbrook, J., 1957, 4444; cf. G. G. S.Dutton and K. Hunt, J . Amer. Chem. SOC., 1958, 80, 5697.102 I. Croon and B. Lindberg, Actu Chem. Scand., 1958, 12, 453.103 J. K. N. Jones and T. J. Painter, J., 1957, 669.104 J. K. N. Jones, E. Merler, and L. E. Wise, Canud. J . Chem., 1957, 35, 634.105 J .K. Gillham and T. E. Timell, ibid., 1958, 38, 1465; cf. ibid., p. 410.106 C. P. J. Glaudemans and T. E. Timell, J . Amer. Chem. SOC., 1958, 80, 1309; cf.J. K. Gillham and T. E. Timell, Svensk Pupperstidn., 1958, 81. 540OVEREND CARBOHYDRATES. 323from American beachwood (Fagas grandifolia) differs in some respects fromthat derived from the European variety.lo7 Forty-five p-D-xylopyranoseunits are 1,4-linked and there is a branch point at position 2 of a xylose unit.Five 4-O-methy~-~-g~ucuronic acid residues are joined as single terminal sidechains of the xylose units of the main structure by a-1,2-bonds. Theuronic acid distribution along the chain is unknown but the acids cannot beattached to the units forming the branch points or to the non-reducing end.A brief account of the hemicellulose of Japanese beachwood has appeared.lWEuropean larch (Larix decidua) hemicellulose fractions contain a xylancomprised of unbranched chains of about 100 1,4-linked p-D-xylopyranoseresidues with every fifth or sixth residue carrying a terminal 4-O-methyl-~-glucuronic acid residue linked through position 2, and a smaller proportionof xylose residues carrying, on position 3, side chains terminated by L-arabo-furanose units.log On the present evidence it is impossible to state whetherthe L-arabofuranose residues are attached directly to the backbone of xyloseresidues or whether 1,4-linked D-XylOSe units are interposed with thearabinose residues terminating a longer side chain. By analogy with otherxylans the former alternative is more probable.Examination of jutehemicellulose I by partial acid hydrolysis and methylation leads to thepartial structure (1) for the polysaccharide : approximately every seventhresidue carries a D-G~A group and the degree of branching in the xylosechain is small. Probably in the case of jute hemicellulose, as with otherxylans, a range is present of closely related molecular species of the samegeneral type which differ in their more detailed structures. Formula (2) isI1 I(1) D-G~A D-xylp(u-Xylp = D-xylopyranose ; D - G ~ A = 4-O-methyl-~-glucuronic acid.)A 4 I x-x-x-x-x-I(2) Afavoured for the highly branched barley araboxylan. Barley huskhemicellulose has also been studied and contains many of the structuralfeatures encountered in other xylans.l12 The highly branched araboxylanfrom rye flour is built up of 1,4-linked p-D-xylopyranose residues with ap-proximately every second xylose unit carrying a terminal L-arabofuranoselinked through position 3.113 The xylan chain in the araboxylan from maizecobs is extensively branched with L-arabinose units attached in short, linear107and R,108109110G.A. Adams, Canad. J . Chem., 1957, 35, 566; cf. G. 0. Aspinall, E. L. Hirst,, S. Mahomed, J., 1954, 1734.S. Machida, M. Inano, and Y. Matsumura, Bull. Chem. SOC. Japan, 1957, 30, 201.G. 0. Aspinall and J. E. McKay, J., 1958, 1059.G. 0. Aspinall and P. C. Das Gupta, J., 1958, 3627.111 G. 0. Aspinall and R. J. Ferrier, J., 1958, 638.112 Idem, J., 1957, 4188.113 G.0. Aspinall and R. J. Sturgeon, J., 1957, 4469324 ORGANIC CHEMISTRY.side chains.l14 The wood xylans which have been examined are all charac-terised by the presence of 4-O-methy~-~-g~ucuronic acid residues attached asside chains to D-xylose by 1,2-linkages. The proportions of uronic acidgroups are in general somewhat higher in the xylans from soft woods (15-20%) than in those of hard woods (8-15%). Some of these xylans alsocontain a small proportion of L-arabofuranose residues. In contrast, thexylans from cereals are in general characterised by a higher proportion ofarabinose groups and a lower proportion of uronic acid groups.Increasing attention is being given to the isolation, characterisation, andstructural investigation of polysaccharides derived from micro-organisms.Considering the difficulties involved in this work it is stimulating to note theprogress being made, only a fraction of which can be outlined here.Theglobulin, concanavalin-A,, has been used to ascertain whether certain bacterialglucans are related to glycogen or amyl~pectin.~~~ The glycogen ofEscherichia coli B has been fractionated into portions severally of high andlow molecular weight (molecular weights = 40-90 x lo6 and <2 x 106),116which have been related to the metabolism of the organism. A techniquehas been devised for labelling with 14C the glycogen of these cells withoutlabelling the protein to any appreciable extent.l17 The capsular poly-saccharide of Aerobacter aerogenes (N.C.T.C. 418) has a branched structurecontaining D-glucose and D-mannose residues with some of the formerpresent as non-reducing end-groups.The glucose residues are linkedmainly 1,4- but a few are 1,3-linked. Non-reducing end-groups (ca. 1 in 40)of glucuronic acid are a-1,4-linked to D-mannose residues which in turn arelinked to the remaining sugar units through the 3-po~ition.l~~ The linkageof the remaining mannose residues in the repeating unit has still to bedetermined. An acidic polysaccharide elaborated by A erobacter aerogeneson hydrolysis gives rhamnose, glucose, mannose, glucuronic acid, andaldobiuronic acids in which the major component is glucuronosylmannose.~~~Galactose, N-acetylglucosamine, and N-acetylgalactosamine (molar ratio2 : 1 : 1) are the components of a polysaccharide extractable fromB.s~btiZis.~~O Pneumococcus-specific polysaccharides have been examined.The type VIII material is a linear polymer of high molecular weight inwhich the repeating unit is -0-P-D-glucopyranosyluronic acid-( 1 --+ 4)-O-p-D-glucopyranosyl-( 1 __+ 4)-O-~-~-glucopyranosyl-( 1 _+ 4)-0 - a-D-galacto -pyranosyl-( 1 + 4)-.121 Recent immunochemical studies 122 indicated thattype XIV polysaccharide contained non-reducing end-groups of D-galactosetogether with D-galactose residues linked P-1,3- or P-l,S-, or involved inp-1,3,6-branch points. These conclusions have been examined by a chemical114 R. L. Whistler and G. E. Lauterbach, J . Amer. Chem. SOL, 1958, 80, 1987.115 J. A. Cifonelli and F.Smith, ibid., 1957, 79, 5055.116 T. Holme, T. Laurent, and H. Palmstierna, Acia Chem. Scand., 1958, 12, 1559.117 T. Holme and H. Palmstierna, ;bid., 1956, 10, 1557.118 S. A. Barker, A. B. Foster, I. R. Siddiqui, and M. Stacey, J., 1958, 2358.119 S. A. Barker, A. B. Foster, S. J. Pirt, I. R. Siddiqui, and M. Stacey, Nature,120 N. Sharon, ibid., 1957, 179, 919.121 J. K. N. Jones and M. B. Perry, J . Amer. Chem. SOC., 1957, 79, 2787.122 M. Heidelberger, S. A. Barker, and B. Bjorklund, ibid., 1958, 80, 113; P. A.Rebers, S . A. Barker, M. Heidelberger, 2. Dische, and E. E. Evans, ibid., p. 1135.1958,181, 999OVEREND : CARBOHYDRATES. 326method.123 Mannans from C. diphtheriae 124 and B. polymyxa 1% have beenstudied. The predominant glycosidic linkage in the branched poly-fructoside produced from sucrose by a Corynebacterium sp.is of the p-2,6-type.126 A lipopolysaccharide from Salmonella paratyehi A containedglucose, galactose, mannose, rhamnose, and a new 3,6-dideoxyaldohexose,for which the name " paratose " has been suggested.127 This compound isidentical with synthetic 3,6-dideoxy-~-ribo-hexose.~~~~Di-, Tri-, and Oligo-saccharides-The widespread use of graded hydrolysisfor the examination of polysaccharides has focused attention on methodsfor the isolation, characterisation, and synthesis of di-, tri-, and oligo-saccharides. Aspects of this subject have been reviewed.128 A semimicro-procedure for the investigation of oligosaccharides has been reported.lZ9Details are available for a preparative method of isolation of isomaltoseand gentiobiose from an acid-reversion mixture of D-glUCOSe.130 Koj ibiose 131and laminaribiose 132 have been isolated from hydrol." Graded acid-hydrolysis of chitosan followed by N-acetylation yields a polymer-homologous series of which the first 7 members have been isolated and~haracterised.l3~ Trehalose has been extracted from Porrocaeccuum decipienslarvae,134 and am-trehalose was isolated from the blood of Antheraeapolyphemzts 135 and was identified as a major blood sugar of insects.It hasbeen shown 136 that 4-0- and not 3-O-methyl-~-glucuronic acid (as claimedby Das Gupta and Sarkar 137) is a component of an aldobiuronic acid fromjute fibre hemicellulose. Montreuil 138 has isolated from human milk13 sugars other than lactose, all of which contain galactose and glucose,and most of them fucose and acetylglucosamine also.There seems littledoubt that these compounds are in many cases identical with a series of sub-stances obtained by Malpress and Hytten 139 from human milk by different123 S. A. Barker, M. Heidelberger, M. Stacey, and D. J. Tipper, J., 1958, 3468.124 0. K. Orlova and Ye. P. Yefimtseva, Biokhimiya, 1956, 21, 505.125 D. Murphy, C. T. Bishop, and G. A. Adams, Canad. J . Biochem. Physiol., 1956,126 G. Avigad and D. S. Feingold, Arch. Biochem. Biofihys., 1957, 70, 178.127 (a) D. A. L. Davies, A. M. Staub, I. Fromme, 0. Luderitz, and 0. Westphal,Nature, 1958, 181, 822; (b) C. Souquey, J. Tolonsky, E. Lederer, 0. Westphal, and 0.Liideritz, ibid., 1958, 182, 944.128 M.G. Blair and W. Pigman, Angew. Chem., 1957, 69, 422; M. Stacey, Bio-khimiya, 1957, 22, 241; R. Kuhn, Bull. Soc. Chim. biol., 1958, 40, 297; Angew. Chern.,1957, 69, 23.129 L. Hough, B. M. Woods, and M. B. Perry, Chem. and Ind., 1957, 1100.130 M. L. Wolfrom, A. Thompson, and A. M. Brownstein, J . Amer. Chem. SOC.,131 A. Sat0 and K. Aso, Nature, 1957, 180, 984.132 A. Sato, K. Watanabe, and K. Aso, Chem. and Ind., 1958, 887.133 S. A. Barker, A. B. Foster, M. Stacey, and J. M. Webber, J., 1958, 2218; Chem.and Ind., 1957, 208; cf. S. T. Horowitz, S. Roseman, and H. J. Blumenthal, J . Amey.Chem. Soc., 1957, 79, 5046.34, 1271.1958, 80, 2015.134 D. Fairbairn, Nature, 1958, 181, 1593.135 G. R. Wyatt and G.F. Kalf, J . Gen. Physiol., 1957, 40, 833.1313 H. C. Srivastava and G. A. Adams, Chem. and Ind., 1958, 920.137 P. C. Das Gupta and B. P. Sarkar, Textile Res. J., 1954, 24, 1071.138 J. Montreuil, Bull. SOC. Chim. biol., 1957, 39, 395.139 F. H. Malpress and F. E. Hytten, Nature, 1957, 180, 1201; Biochem. J., 1958,* Hydro1 is the mother liquor obtained after the separation of glucose froni an acid68, 708.hydrolysate of sweet-potato starch326 ORGANIC CHEMISTRY.fractionation procedures. Lactodifucotetraose and lacto-N-fucopentaoseI1 from human milk have been assigned structures (3) 140 and (4) 141 re-spectively.Enzymic syntheses have been described of 3-0- and 6-0-P-~-galacto-pyranosyl-D-glu~ose,~~~ 6-0-~-~-ga~actopyranosy~-~-ga~actose,~~~ 2-0-a-D-CH-0-C-H I 1 I I f 3HO+H IIIH-C-OHH-C-OHO--THCH,(3)CH,-OHU /7H HO-C-H I H-7-oHH-t-oHO-THICH-OH II H-C-OHB0BH-C- 0CH,-OH I(4) CH3140 R.Kuhn and A. Gauhe, AIznaZen, 1958, 611, 249.1 4 1 R. Kuhn, H. H. Baer, and A. Gauhe, Chem. Bey., 1958, 91, 364.142 J. H. Pazur, C . L. Tipton, T. Budovich, and J. M. Marsh, J . Amer. Chem. SOC.,1958, 80, 119OVEREND CARBOHYDKATES. 327glucopyranosyl-D-glucose (koj ibiose) ,143 O-p-D-gluco(and galacto) pyranosyl-(1 -+ 4)-O-[a-~-glucopyranosyl-( 1 __t 2)]-D-glUCOSe,1u a-lactosyl-p-fructo-furanoside,145 O-a-D-glucopyranosyl-( 1 + 6)-O-a-~-glucopyranosyl-( 1 +2) -p-~-fructofuranoside,~~~ and 3-O-~-~-glucopyranosyl-~-xylose.~~~ Anenzyme from S. fragdis disproportionates 6-O-~-~-galactopyranosy~-D-g~ucoseto glucose, galactose, and O-p-D-galactopyranosyl-( 1 _+ 6)-p-~-galacto-pyranosyl-(1 + 6)-~-glucose.~~~ With acetate as its.sole carbon sourceA . rtiger " 152 " produces mannitol, arabinitol, erythritol, glycerol, maltose,and cca-trehalose e~tracellularly.~~~ Fructose and cello-biose, -triose, and-tetraose, together with oligosaccharides which are not cellodextrins, wereformed when Acetobacter acetigenwn was grown on a defined medium contain-ing glucose.150 A homologous series of oligosaccharides produced byB. arabinosaceous (Birmingham) in a medium containing sucrose and 3-0-methyl-D-glucose is formed by successive addition of glucosyl units ina-1,6-linkage to 3-O-methyl-~-glucose.~~~Chemicalsyntheses have been outlined of 5-0-~-~-xylopyranosyl-~-arabinose,~~~ 2-0-p-D-xylopyranosyl-L-arabinose,l% 5-O-~-D-ga~actopyranosyl-~-arabinose,~~~ 6-0- ~-D-xylopyranosyl-~-gdact ose 3-0- p-D-galact opyranosyl-~-gdactose,1563-O-a-~-glucopyranosyl-~-glucose,~~~ 6-0-~-D-glu~osylmaltose,~~~ methyl[methyl - (4 - 0 - methyl - cc - D - galactopyranosyluronate)] - a - D - galacto-pyranosid~ronate~l59 and l-glyceritol-D-galactopyranosides.160Completion of the unequivocal proof by methylation of the structures ofisomaltose and gentiobiose is reported.130 A direct chemical proof has beenfurnished for the occurrence of the sucrose linkage in raffinose andstachyose.161 Establishment of the configuration a t the anomeric centre ofthe fructose moiety of sucrose completes the proof of its structure by purelychemical means.162 These results, together with previous X-ray evidence,permit the conclusion that the isorotation rules do correlate configurationwith rotation in the case of fructofuranosides. It is likely that the samesituation will apply to other ketofuranosides. The configuration ofA simplified synthesis of oligosaccharides has been rep0rted.15~143 K.Aso, K. Shibasaki, and M. Nakamura, Nature, 1958, 182, 1303.144 R. W. Bailey, S. A. Barker, E. J. Bourne, P. M. Grant, and M. Stacey, J., 1958,145 G. Avigad, J . Biol. Chem., 1957, 229, 121.146 S. A. Barker, E. J. Bourne, and 0. Theander, J., 1957, 2064.147 S. A. Barker, E. J. Bourne, G. C. Hewitt, and M. Stacey, J., 1957, 3541.148 J. H. Pazur, J. M.Marsh, and C. L. Tipton, J . Amer. Chem. SOC., 1958, 80,149 S. A. Barker, A. G6mez-SAnchez, and M. Stacey, J., 1958, 2583.150 T. K. Walker and H. B. Wright, Arch. Biochem. Biofihys., 1957, 69, 362.151 S. A. Barker, E. J. Bourne, P. M. Grant, and M. Stacey, J., 1958, 601.152 H. Bredereck, A. Wagner, and G. Faber, Angew. Chem., 1957, 69, 438.153 D. H. Ball and J, K. N. Jones, J., 1957, 4871.154 G. 0. Aspinall and R. J. Ferrier, J., 1958, 1501; Chem. and Ind., 1957, 819.155 I. J. Goldstein, F. Smith, and H. C. Srivastava, J . Amer. Chem. SOC., 1957,79,3858.158 D. H. Ball and J. K. N. Jones, J., 1958, 905.157 S. Haq and W. J. Whelan, J., 1958, 1342.158 A. Klemer, Angew. Chem., 1957, 69, 638.159 M. Gee, F. T. Jones, and R. M. McCready, J .Org. Chem., 1958, 23, 620.160 B. Wickberg, Acta Chem. Scand., 1958, 12, 1187.161 A. K. Mitra and A. S. Perlin, Canad. J . Chem., 1957, 35, 1079.16% R. U. Lemieux and J. P. Barrette, J . Amer. Chem. SOC., 1958, 80, 2243.1895.1433328 ORGANIC CHEMISTRY.glycosidic linkages in several reducing di- and tri-saccharides has beendetermined by the conversion of each substance into the corresponding2-O-glycosylglycerol, the configuration of which was readily e~tab1ished.l~~Compounds so examined include 3-O-~-~-galactopyranosyl-~-galactose, 3-0-a-D-galactopyranosyl-L-arabinose, 3-O-P-~-arabopyranosyl-~-arabinose, 2-0-p-D-xylopyranosyl-L-arabinose, 3-O-~-~-xylopyranosyl-~-arabinose, and4-O-~-~-xylopyranosyl-~-xylose, all partial hydrolysis products of poly-saccharides. Likewise the configuration in O-a-D-mannopyranosyl-( 1 +2)-O-~t-~-mannopyranosyl-( 1 + 2)-D-mannOSe was established.lM 2-033-D-Xylopyranosyl-L-arabinose (which originally was thought to possess thea-configuration 165) was the sole exception to correlation between theconfigurations now reported and those assigned previously.Owing to its importance in graded hydrolysis serious attention is beinggiven to the acid-reversion of monosaccharides.The major productsformed when glucose is heated in O.33~-sulphuric acid (with or withoutpretreatment with formic acid) are 1,6-anhydro-~-~-gluco-pyranose and-furanose. The remainder of the product consists of a group of glucosedisaccharides in which isomaltose and gentiobiose predominate.166 Theamounts of sugars so formed provide a guide to the quantities of reversionproducts likely to be encountered as artefacts in partial hydrolysates ofpolyglucoses.The acid reversion of D-mannose yields a complex mixtureof di- and oligo-saccharides from which 6-0-a- and 6-O-p-~-mannopyranosyl-D-mannose and (?)-4-O-p-~-mannopyranosyl-~-rnannose have been ob-tained.167 L-Arabinose is converted in part into 3- and 4-O-P-~-arabo-pyranosyl-L-arabinose together with other di- and tri-sa~charides.~~~~ 168Acid-reversion of D-xylose gives a mixture of oligosaccharides, five of whichwere isolated, namely, xylobiose, O-a-D-xylopyranosyl a-D-xylopyranoside,and 3-O-ct-~-xylopyranosyl-~-xylose and its corresponding 2- and 4-0-is0mers.16~ Obviously the isolation of a-linked xylose-containing di-saccharides on hydrolysis of a xylose-containing polymer should be treatedwith reserve.The production of a single disaccharide of this type is anindication that it is not an artefact. Reversion of 2-acetamido-2-deoxy-~-glucose with moist hydrogen chloride yields a series of oligosaccharides fromwhich 2-acetamido-6-0-(2-acetamido-2-deoxy-a- and -p-D-glucopyranosy1)-2-deoxy-~-glucose has been isolated and characteri~ed.~~~Periodate Oxidation.-The sequence in which sodium periodate attacksthe a-glycol groups of monosaccharides was investigated for aldo-hexoses and-pentoses.l71 It was concluded that oxidation of aldoses proceeds ex-clusively by stepwise oxidation from the hemiacetal grouping down the163 A.J. Charlson, P. A. J. Gorin, and A. S. Perlin, Canad. J . Chem., 1956, 34, 1811;1957, 35, 365; cf. P. A. J. Gorin and A. S. Perlin, ibid., 1958, 36, 999.164 P. A. J. Gorin and A. S. Perlin, ibid., 1957, 35, 262.166 R. L. Whistler and D. F. Durso, J . Amer. Chem. SOC., 1950, 72, 677.166 S. Peat, W. J. Whelan, T. E. Edwards, and (Mrs.) 0. Owen, J., 1958, 586.167 J. K. N. Jones and W, H. Nicholson, J., 1958, 27.168 Cf. F. A. H. Rice, J . Amer. Chem. SOG., 1956, 78, 6167; L. Hough and J. B.169 D. H. Ball and J. K. N. Jones, J., 1958, 33.170 A. B. Foster and D. Horton, J., 1958, 1890.171 S. A. Warsi and W. J. Whelan, Chem. and Ind., 1958, 71; cf. F. S. H. Head,Pridham, Chem. and Ind., 1957, 1178.ibid., p. 360OVEREND: CARBOHYDRATES.329molecule. There is further evidence that sugars are oxidised in their cyclicforms, with the formation of intermediary esters.172 Differing rates ofhydrolysis of these esters have been related to the inductive effects of electro-philic groups in the alcohol component (5-8; R = CO,H > CHO >CH,*OH > Me, H). Cyclic acetal structures have been proposed for theRCHO4O--H&O\CHO + OHC HO <>H,OH --+ OHC+ 2H.CO2HOH (6) R 1 (7) A-(5) OHC+OHperiodate-oxidation products of g l y c ~ s i d e s , ~ ~ ~ their 4 : 6-O-benzylidene 174and 6-deoxy-derivatives.l75 A similar situation is found in periodate-oxidised polysac~harides.~~~ A steric effect in the oxidation of glycosideshas been noted.l77Anhydrides.-It has been demonstrated that in the sugar series a neigh-bouring trans-0-acetyl group exerts a directive influence on the scission ofan ethylene oxide by acidic reagents, and carbonium-type intermediateshave been suggested.178 Treatment of methyl 2,3-anhydro-4,6-0-benzyl-idene-a-D-guloside with 0.1N-sulphuric acid gives mainly 3,6-anhydro-~-ga1acto~e.l~~ When the corresponding 2,3-anhydro-alloside, -mannoside,and -taloside were similarly treated some 3,6-anhydro-products were formed.It was shown that loss of the glycosidic methoxyl group precedes anhydrideformation.The formation of 3,6-anhydro-sugars from the 2,3-anhydrideshas hitherto been noted only under alkaline conditions. The productfrom the alkaline treatment of methyl 2,3-di-O-benzoyl-4-0-tosyl-6-0-trityl-a-D-glucoside (9) is a mixture of methyl 3,4-anhydr0-6-0-trityl-a-D-galactoside (10) and methyl 2,3-anhydro-6-0-trityl-a-~-guloside (1 1 ;R = CPh,) .180 The ammonolysis of methyl 2,3-anhydro-~-ribofurano-179 L.Hough, T. G. Taylor, G. H. S. Thomas, and B. M. Woods, J., 1958, 1212.173 I. J. Goldstein and F. Smith, J . Amer. Chem. SOC., 1958, 80, 4681.174 R. D. Guthrie and J. Honeyman, Chem. and I n d . , 1958, 388.175 I. J. Goldstein, B. A. Lewis, and F. Smith, J . Amer. Chem. SOC., 1958, 80, 939.176 I. J. Goldstein and F. Smith, Chem. and I n d . , 1958, 40.177 E. F. Garner, I. J. Goldstein, R. Montgomery, and F. Smith, J . Amer. Chem,179 J. G. Buchanan, J., 1958, 2511.179 Idem, Chem. and Ind., 1958, 654.180 Idem, J., 1958, 995.Soc., 1958, 80, 1206330 ORGANIC CHEMISTRY.side has been reported.lsl Methyl 4,5-0-benzylidene-%O-tosyl-a-~-altro-side shows extreme lability and is converted into methyl 2,3-anhydro-4,6-O-benzylidene- a-D-alloside by acid-washed alumina.la2 4,1’,6’-Tri-0-tosylsucrose penta-acetate is converted by sodium methoxide into 3,6-anhydro-a-~-ga~actopyranosy~-l,4 :3,6-dianhydro-p-~-fructoside 162 (see p.327).The above-mentioned anhydroalloside, on treatment with ammoniaand subsequent N-acetylation, gives methyl 2-acetamido-4,6-O-benzylidene-2-deoxy-a-D-altroside (as monohydrate) which on total hydrolysis affords2-amino-l,6-anhydro-2-deoxy-~-~-altropyranose.~~~ Mechanisms of anhy-dride formation in sugars have been discussed.lWW. G. 0.12. THE NUCLEIC ACIDSIT is the purpose of this Report, covering work carried out mainly duringthe past two years, to give a general indication of the trends in nucleic acidresearch and then to give a more detailed discussion of a few aspects whereprogresss has been considerable.There has been less emphasis on theorganic chemistry of the acids, but the number of papers on physicochemicaland biophysical aspects of the subject has risen.Much work continues to be devoted to the synthesis of analogues of thenaturally occurring heterocyclic bases, nucleosides, and nucleotides and totheir incorporation into the nucleic acids of organisms. These studies are,for the most part, related to questions of cancer chemotherapy and chemicalmutagenesis.l The biosynthesis of nucleotides, or, more generally, theenzymology of nucleic acids, purines, and pyrimidines, continues to receivemuch attention.2 Rapid progress is being made in the study of nucleic acidfunction.The relationship of deoxyribonucleic acids (DNA) to the centralproblems of genetics is now firmly founded. The intense interest in thisfield is made clear in the published proceedings of a symposium on “ TheChemistry of Heredity,’’ where enlightening papers on a wide variety oftopics involving the nucleic acids are collected. The closely related studyof ribonucleic acids (RNA) in protein synthesis is also making rapidh e a d ~ a y . ~Progress has been made, and is reported on below, in the study of thenucleic acids from the point of view of their conformations and hydro-dynamic properties in solution and of the processes involved in theirdenaturation. Much congruous information is being obtained by physico-chemical studies of biosynthetic polyribonucleotides.It is evident that181 C. D. Anderson, L. Goodman, and B. R. Baker, J . Amer. Chem. SOL, 1958, 80,188 K. S. Ennor, J. Honeyman, C. J. G. Shaw, and T. C. Stening, J., 1958, 2921.18s A. B. Foster, M. Stacey, and S. V. Vardheim, Nature, 1957, 180, 247; Acta184 F. Micheel and A. Klemer (with R. F!ftsch), Chem. Bey., 1958, 91, 194.1 Cf. Ciba Foundation Symposium on The Chemistry and Biology of Purines,”2 L. A. Heppel and J. C . Rabinowitz, Ann. Rev. Biochem., 1958, 27, 613.3 “ The Chemistry of Heredity,” Ed. McElroy and Glass, The Johns Hopkins Press,4 R. B.Loftfield, Progr. Biophysics Bio$hys. Chem., 1957, 8, 347.5247.Chem. Scand., 1958, 12, 1605.Churchill and Co., London, 1957.Baltimore, 1957BROWN: THE NUCLEIC ACIDS. 331with a few possible exceptions the isolated nucleic acids are polydispersemixtures of different molecular species with the same general structure, sothat a direct attack on nucleotide sequence has not been possible. Instead,methods of determining the degree of randomness of distribution have beeninvestigated and the fractionation of isolated nucleic acids and the isolationof nucleic acids from particular cell fractions have received more attention.With the much clearer understanding of nucleic acid structure available,attention is being directed, anew, to the isolation and characterisation ofnucleoprotein~.~ Of these the viruses represent a special case and a greatdeal of structural information is now available, particularly on tobaccomosaic virus, largely through X-ray crystallographic work.6Ribonucleic Acids.-The general structure of RNA as a 3’,5’-linkedpolynucleotide has not been questioned.Branching through phosphotri-ester linkages in a bacterial RNA and in intact tobacco mosaic virus RNAhas been rendered very improbable, in confirmation of earlier work. Ofexceptional interest are the discoveries of bases other than the long-recognised adenine, guanine, cytosine, and uracil. Littlefield and Dunnhave found thymine (1 ; R = Me), 2-methyladenine (Z), 6-methylamino-purine (3; R = H, R’ = Me), and 6-dimethylaminopurine (3; R = R’ =Me) in ribonucleic acids from several sources, including yeast. Liver(1) (2) (3) (4) (5)microsome RNA contains the last two.The methylated guanine derivatives(4; R = H, R = Me; and R = R’ = Me) and (5) are also rather wide-spread.10 They occurin minute quantities, corresponding to 1 4 . 0 5 % of the uracil residues, butappear to be linked into the nucleic acid in the usual manner since, in mostcases, the corresponding nucleosides and nucleotides have been demon-strated after appropriate degradation. The question arises whether thesetrace-components are distributed through all the nucleic acid molecules inthe isolated material or whether they are functional components of particularacids contained in the specimen.Some support for the latter view is foundin the distribution of a new component nucleotide detected in yeast 1 2 9 1 35 J. A. V. Butler and P. F. Davison, Adv. Enzymol., 1957, 18, 161.6 R. E. Franklin and K. C. Holmes, Biochim. Biophys. Actu, 1956, 21, 405; R. E.Franklin in Symposium on “ Protein Structure,” Ed. Neuberger, Methuen, London,1958, p. 271.7 R. A. Cox, A. S. Jones, G. E. Marsh, and A. R. Peacocke, Biochim. Biophys. Aclu,1956, 21, 576. * D. E. Koshland, N. S. Simmons, and J. D. Watson, J . Amer. Chem. SOC., 1958,80, 1005.10 M. Adler, B. Weissman, and A. B. Gutman, J . Biol. Chem., 1958,230, 717; D. B.Dunn and J. D. Smith, Proc. IVth Internat. Congr. Biochem., Vienna, 1958.11 H. Amos and M. Korn, Biochim. Biophys.Acta, 1958, 29, 444.12 E. F. Davis and F. W. Allen, J . Biol. Chem., 1957, 227, 907.13 W. E. Cohn, Fed. PYOG., 1958,17,203: J . Amer. Chem. Sot., 1959,81, in the press.5-Methylcytosine has been found in E. coli RNA.11J. W. Littlefield and D. B. Dunn, Nulure, 1958, 181, 254332 ORGANIC CHEMISTRY.and pancreatic RNA; l4 this is particularly concentrated in the ‘‘ soluble ”RNA fraction.l2, l4 The corresponding nucleoside appears to be uniquelydistinguished from those previously isolated in that its chemistry is indicativeof a C-glycoside; the linkage is not broken by acid. Other evidence suggestsa 5-substituted uracil structure and (1; R = ribofuranosyl) is proposed.13Kemp and Allen l4 also reported other unidentified components in theguanylic acid fraction of hydrolysates of these ribonucleic acids.Several papers have described attempts to fractionate isolated ribo-nucleic acid.Elution from “ ECTEOLA ”-cellulose anion-exchange columnswith phosphate buffer gives different elution patterns for RNA isolated fromdifferent sources and from the same source by different methods;15 allfractions are heterogeneous. Other methods include precipitation withneutral salts l6 and counter-current distribution in 2-methoxy- or 2-butoxy-ethanol-phosphate systems.17 Two nuclear and one cytoplasmic (micro-somal) fraction have been separated from several tissues, and their baseratios and metabolic activity studied.ls The cytoplasmic RNA of cellsappears to be divided between the microsomes and a “ soluble ” fraction ofrelatively low molecular weight of which l0-20% is very activernetab~lically.~~ The “soluble” RNA is a necessary component in theearly stages of protein synthesis.20 Evidence has been given21 that foractivity the terminal nucleotide sequence must be as in (6; R = H) whereA and C represent adenine and cytosine residues ; P-amino-acyl derivativesof adenosine-5’ phosphate 22 then transfer the amino-acidto the residue (6; R = H) to give a 2’- or 3’-ester (6;R = amino-acyl).The evidence for the position of theamino-acid residue rests on the removal by ribonuclease ofan adenosine ester of the amino-acid which is periodate-insensitive until hydroly~ed.~~ The enzymic introductionof the adenine and cytosine nucleotides has been (6)studied.21,24>25 Hoagland 26 has recently reviewed the rapid developments inthis field.It should be realised that, since tracer methods are used,evidence for a terminal sequence as in (6) is not an indication of its presencein all the isolated soluble RNA: the amount may only be a fraction of thetotal.TheAOHOR “P .- J P lMost isolated ribonucleic acids are probably complex mixtures.14 J. w. Kemp and F. W. Allen, Biochim. Biophys. Acta, 1958, 28, 51.15 D. F. Bradley and A. Rich, J . Amer. Chem. SOC., 1956, 78, 5898.16 K. MiUra, T. Kitamura, and Y. Kawade, Biochim. Biophys. Acta, 1958, 27, 420.17 K. S. Kirby, Biochem. J., 1958, 68, 1 3 ~ .18 y. Hotta and S. Osawa, Biochim. Bi0phy.b. A C I Z , 1958, 28, 642.19 H. T. Shigeura and E.Chargaff, ibid., 1958, 30, 434.20 M. B. Hoagland, M. L. Stephenson, J. F. Scott, L. I. Hecht, and P. C. Zamecnik,21 L. I. Hecht, P. C. Zamecnik, M. L. Stephenson, and J. F. Scott, ibid., 1958, 233,22 Symposium on “ Amino Acid Activation,” BOG. Nut. Acad. Sci., U.S.A., 1958,2s H. G. Zachau, G. Acs, and F. Lipmann, ibid., p. 885.24 L. I. Hecht, M. L. Stephenson, and P. C. Zamecnik, Biochim. Biophys. Acta, 1958,2s E. S. Cannellakis, ibid., 1957, 25, 217.26 M. B. Hoagland, Proc. IVth Internat. Congr. Biochem., Vienna, 1958.J . Biol. Chem., 1958, $281, 241.954.44, 67.29, 460BROWN: THE NUCLEIC ACIDS. 333earlier claim that RNA from tobacco mosaic virus had both 3’- and 5’-phos-phate end groups has been reconsidered and there is now no evidence for thelatter type; 27 probably the earlier work was carried out on degradedmaterial. Recent work leads to the belief that there is one nucleic acidmolecule in an infective particle.This should correspond to a calculatedmolecular weight of 2-3 x lo6. A value of 2.1 x lo6 was found bysedimentation studies of RNA isolated by the phenol method.28 Measure-ments of intrinsic viscosity indicate that the RNA is in the form of a flexible,moderately coiled chain several thousand A in length,29J0 which findsconfirmation in electron-micrographical studies.32 The kinetics of chainbreaking by, e.g., ribonuclease30 or heat,31 show that nearly every breakcaused degradation and it is concluded that the molecule, unlike DNA, issingle-stranded. The large drop in optical rotation and increase in ultra-violet absorption consequent on mild degradation are thought to indicate asuperstructure retained by hydrogen bonds between contiguous nucleotideresidues2* Deamination can be effected without chain scission, and alter-ation of only a very few of the residues is sufficient to cause loss of infec-tivity or, possibly, m ~ t a t i o n .~ ~ ~ ~ If the molecular weight of 2 x lo6 isconfirmed the question of a 3’- or 5’-phosphate end group must presumablybe reopened since the earlier methods were insufficiently sensitive to detectone nucleotide in 6000. There is a real possibility that the isolated tobaccomosaic virus RNA which has retained its infectivity is one molecular species;the advantages of this for chemical studies are obvious.Staehelin 35 hasmade a close study of the reaction of the RNA with [14C]formaldehydeunder various conditions.Methods of degradation of RNA which break internucleotide linkagesare now well understood. Little, heretofore, has been done to effectremoval of the purine and pyrimidine residues. Hydrazine, applied earlierto the preparation of ribose phosphates from uridine and cytidine phos-phates, reacts with RNA to give a product almost devoid of pyrimidine basesand with an increased reducing capacity, but no evidence for the molecularweight of the “ ribo-apyrimidinic acid ” was given.36 The reaction ofbromine with nucleosides and nucleotides has received further at tention.37~ 38Purine derivatives are relatively inert but addition of bromine water (2 mol.)causes loss of light absorption in uracil and cytosine derivatives.Theproducts react with mild alkali giving substances, possibly acyclic, which areeasily split by acid, to ribose or ribose phosphate; 38 application to poly-nucleotide degradation may be a possibility.27 K. K. Reddi and C. A. Knight, Nature, 1957, 180, 374; R. E. F. Matthews and28 A. Gierer, Nature, 1957, 179, 1297.29 Idem, 2. Naturforsch., 1958, 13b, 477.30 Idem, ibid., p. 485.31 W. Ginoza, Nature, 1958, 181, 958.32 R. G. Hart, Biochim. Biophys. Acta, 1958, 28, 457.33 A, Gierer and K.-W. Mundry, Nature, 1958, 182, 1457.34 H. Schuster and G. Schramm, Z . Naturforsch., 1958, lsb, 697.35 M. Staehelin, Biochim. Biophys. Acta, 1958, 29, 410.36 S.Takemura, J . Biuchem. (Japan), 1957, 44, 321.37 T. Suzuki and E. Ito, ibid., 1958, 45, 403.38 W. E. Cohn, Biochem. J., 1956, 64, 28 P.J. D. Smith, ibid., p. 375334 ORGANIC CHEMISTRY.The varied effects of radiation, some of which are reversible, on livingorganisms are a continual source of interest and certainly in some of thesethe nucleic acids are involved. Several studies have been based on theoriginal observation by Sinsheimer, that ultraviolet irradiation of uridylicand cytidylic acid 39 in aqueous solutions leads to loss of ultraviolet absorp-tion and that this can be recovered by mild treatment by heat or dilute acid.The reversible photolysis of uracil gives 4,5-dihydro-4-hydroxyuracil (7) ,*Oand that of lJ3-dimethyluracil the corresponding derivative (8),41 bothstructures being confirmed by synthesis.Further irradiation of com-pound (8) gives NN’-dimethylmalonamide (10) via the barbituric acidderivative (9).42 At least three different reactions occur on irradiation ofuracil in aqueous solution, of which the first alone is reversible.& Thesensitivity of bases, especially thymine, to ultraviolet light is different in thefrozen state from that in aqueous solution.44 Shugar and Wierzchowski 45have made a study of quantum yields and reversibility in the photolysisof many pyrimidines. Hydrogen-bonding between the pyrimidine andthe sugar rings in nucleosides seems to play an important part in thereaction. Indirect evidence is obtained for about l0-15% reversibilitywith RNA, but a greater value is obtained with apurinic acid.Irradiationwith X-rays causes the formation of labile phosphate esters from purineand pyrimidine nucleotides in aqueous solution,46 and of guanine and2,4-diamino-5-formamido-6-hydroxypyrimidine from guanylic acid andg~anosine.~’Deoxyribonucleic Acid.-The chemistry of deoxyribonucleosides andnucleotides has been reviewed.@ In addition, this period has seen the firstsyntheses of natural deoxynucleosides, viz. , 2’-deo~yuridine,~~ thymidh1e,4~, 50and 2’-deo~yadenosine.~l 6-Methylaminopurine (3; R = H, R’ = Me)must now be added to the bases found in DNA.5239 R. L. Sinsheimer, Radiation Res., 1957, 6, 121.40 A. M. Moore, Canad. J . Chem., 1958, 36, 281.4 1 S. Y .Wang, M. Apicella, and B. R. Stone, J . Amer. Chem. Soc., 1956, 78, 4180.42 S. Y . Wang, ibid., 1958, 80, 6196.43 A. Rorsch, R. Beukers, J. Ylstra, and W. Berends, Rec. Truv. chim., 1958, 1’7,44 R. Beukers, J. Ylstra, and W. Berends, ibid., p. 729.45 D. Shugar and K. L. Wierzchowski, Biochim. Biophys. Acta, 1957, 23, 657; 1957,46 M. Daniels, G. Scholes, and J. Weiss, J., 1956, 3771.47 G. Hems, Nature, 1958, 181, 1721.48 A. M. Michelson, Tetrahedron, 1958, 2, 333.49 D. M. Brown, D. B. Parihar, C. B. Reese, and (Sir) Alexander Todd, J., 1958, 3035.fO G. Shaw and R. N. Warrener, Proc. Chem. Soc., 1958, 81.5 1 C. D. Anderson, L. Goodman, and B. R. Baker, J . Amer. Chem. Soc., 1958, 80,52 D. B. Dunn and J. D. Smith, Biochem. J . , 1958, 68, 627.423.25, 355.6453BROWN: THE NUCLEIC ACIDS.335As with RNA, it is clear that isolated DNA is a mixture of differentspecies varying in molecular weight 53 and, presumably, in nucleotidesequence. Chromatographic fractionation has been On calc-ium phosphate columns, DNA can be separated from products of deoxy-ribonuclease degradation of high molecular weight. Bendich and hisco-workers 56957 find that * ' ECTEOLA "-cellulose anion-exchange columnshave excellent resolving power, giving extensive fractionation with quantit-ative recovery. They conclude that molecular size and shape are importantfactors in the fractionation and are able to separate DNA from polyadenylicacid and from a DNA of identical source but in which 5-bromouracil partlyreplaces thymine.The results of fractionation of bacterial transformingfactors have been discussed.58 The DNA fractions obtained in this workshow considerable variation in base ratios. While the purine : pyrimidineratio is always close to unity, rather wide variations in the adenine : thymineand guanine : cytosine ratios are noted. This is at variance with the strictbase complementarity usually associated with the base-pairing in the double-helical DNA structure due to Watson and Crick; Donohue and Stent havediscussed other possible base-paired systems.59 One other observationbriefly noted by Bendich et aL5' is of considerable interest although as yetunexplained. Suspensions of " ECTEOLA "-cellulose appear to causepolymerisation of monodeoxyribonucleotides and of dialysable fractionsformed by deoxyribonuclease action on DNA ; non-dialysable products areformed, susceptible to deoxyribonuclease digestion.If, as is currently believed, DNA's have molecular weights of severalmillion and are mixtures, it is not at all clear how chemical end-group andsequence determinations can be made.Several studies take a less ambitiousobjective and attempt to discover whether the overall nucleotide arrange-ment does or does not correspond to a mathematically randomdistribution of the four major component mononucleotides. This involvesbreaking the molecules into smaller fragments and relating the amount ofeach produced to that expected from calculation, or comparing the amountsfrom DNA specimens from diverse sources.In this way Astrachan andVolkin 6o have detected chromatographic differences between two 'phageDNA's when these were degraded by heat to give large polynucleotides, butnot at the level of deoxyribonuclease degradation products ; thus, at higherlevels of organisation differences appear. Jones and Stacey have continuedtheir study of the degradation products derived from apurinic acid thio-acetals, the basis of which was discussed in Ann. Reports, 1956,53,265. Theyconclude that the nucleotides in the DNA of Mycobacterium Phlei are not53 C. Sadron, J. Pouyet, and R. Vendrely, Nature, 1957, 179, 263; J. A. V. Butler,D. J. R. Laurence, A. B. Robins, and K. V. Shooter, ibid., 1957,180, 1340.54 G. Semenza, Arkiv Kemi, 1957, 11, 89.55 R.K. Main and L. J. Cole, Arch. Biochem. Biophys., 1957, 68, 186.56 M. Rosoff, G. di Mayorca, and A. Bendich, Nature, 1957, 180, 1355.57 A. Bendich, H. B. Pahl, G. C. Korngold, H. S. Rosenkranz, and J. R. Fresco,58 A. Bendich, H. B. Pahl, and S. M. Beiser, Cold Spring Harbor Symp. Quant. Biol.,59 J . Donohue and G. S. Stent, Proc. Nat. Acad. Sci., U.S.A., 1956, 42, 734.60 L. Astrachan and E. Volkin, J. A m y . Ckem. SOC., 1957, 79, 130.J . Amer. Chem. SOC., 1958, 80, 3949.1956, 21, 31336 ORGANIC CHEMISTRY.randomly distributed.61 Chargaff and his co-workers have extended theirwork on the acid-degradation of DNA and the chromatographic fraction-ation 62 and estimation of the products.63 In acid, DNA rapidly loses purineresidues, and the apurinic acid formed then breaks down by an eliminationyielding nucleoside-3’,5’ diphosphates and oligonucleotides of the generalform Py(n)*P(n + 1).Some confirmation of this mechanism is afforded bya study of the degradation of a series of dideoxynucleotides. Understandard hydrolytic conditions specimens of DNA from ten sources werefound to give product patterns indicating wide variations in pyrimidinenucleotide distribution; at least 70% of the pyrimidines occurred as oligo-nucleotide tracts containing three or more residues in a row. Generally thearrangement is considered to be far from random. In these experiments,further acid-degradation of the initially produced fragments had to beallowed for, eg., the conversion of nucleoside diphosphates into monophos-phates. In a valuable contribution, Burton and Peterson show that DNAis degraded by 66% formic acid containing 2% of diphenylamine (but not inits absence), with negligible production of monophosphates.The mechanismof this reaction is not clear, but phosphate elimination in the intermediateapurinic acid may be facilitated by enamine formation. They conclude, inagreement with others, that there is a bias against sequences of the type-PUT-Py- p-Pu- in DNA.Results complementary to the above should be obtained by the degrad-ation of “ deoxyribo-apyrimidinic acid.” Takemura 65 claims to haveprepared this material by reaction of DNA with hydrazine; 20-30% of theproduct remains undialysable; this is devoid of pyrimidine bases, and theadenine : guanine ratio remains unaltered.Treatment of this with diluteacid or of apurinic acid with hydrazine is claimed to give material consideredto be poly(deoxyribose phosphate). Further details would be welcome, butit should be noted that titration studies 66 indicate a chain length for dialysedapurinic acid of only ten nucleotide units, considerably smaller than earlierestimates.The purines are more reactive than the pyrimidines of DNA towardsalkylation by methyl sulphate or by “ nitrogen mustard.’’ 67768 Reactionat the 7-position is demonstrated by the isolation of 7-methylguanine 68after alkylation of deoxyguanylic acid ; the glycosidic linkage in theintermediate is very labile. X-Irradiation of DNA has been studiedf urt her.69Kornberg and his co-workers have achieved, for the first time, the61 A.S. Jones, M. Stacey, and B. E. Watson, J., 1957, 2454; A. S. Jones and62 W. E. Cohn and E. Volkin, Biochim. Biophys. Acta, 1957, 24, 359.63 H. S. Shapiro and E. Chargaff, ibid., 1957, 23, 451; 26, 596, 608.64 K. Burton and G. B. Peterson, ibid., 1957, 26, 667.65 S. Takemura, ibid., 1958, 29, 447.66 E. Hurlen, S. G. Laland, R. A. Cox, and A. R. Peacocke, Act& Chem. Scand.,67 B. Reiner and S. Zamenhof, J . Biol. Chem., 1957, 228, 475.68 P. D. Lawley, Biochim. Biophys. Acta, 1957, 26, 450; Proc. Chem. SOC., 1957,69 M. Daniels, G. Scholes, J. Weiss, and C. M. Wheeler, J . , 1957, 226.M. Stacey, Chem. SOC. Special Publ., 1957, No. 9, p. 129.1956, 10, 793.290BROWN: THE NUCLEIC ACIDS.337biosynthesis of DNA in a cell-free An enzyme from E. coliextracts has been purified over 2000-fold and has been shown to catalysethe conversion of a mixture of the four deoxynucleoside-5’ triphosphates toa material behaving like DNA, with concomitant release of pyro-ph~sphate.~O Highly polymerised DNA and Mg++ must be present.Omission of any one component reduces the rate of synthesis to 0.5%.A net synthesis of more than ten times the weight of DNA primer addedhas been obtained and the new DNA has the natural 3’,5’-internucleotidelinkage.71 Substitution of substrate analogues for the natural nucleosidetriphosphates allows their incorporation and, for example, deoxyuridinetriphosphate incorporates uracil specifically in place of thymine,72 givingadditional support for Watson and Crick’s base-pairing hypothesis.Theenzymic reaction between DNA and a single deoxynucleoside triphosphateleads, apparently, to the addition of one or, a t the most, a very few nucledtideresidues to the end of the DNA chain; it is pointed out that this may be ofvalue in end-group determination^.^^ Davidson and his co-workers haveshown the incorporation of rHlthymidine into DNA-like material inextracts of mammalian cells, increased by addition of DNA to the system.740 T T T T T THO-7-HO. .-( ‘ I )The chemical synthesis of DNA-like molecules is far from sight, butKhorana et al. have devised methods for the preparation of oligodeoxy-nucleotides. Basically, they effect the condensation between a monoalkylphosphate and an alcohol by means of toluene-9-sulphonyl chloride orpreferably, dicyclohexyl carbodi-imide in anhydrous pyridine.In this waythey have prepared several dideoxynucleotides by condensation of protectedintermediate^.^^ The reaction with thymidine-5’ phosphate (1 1) alone ledto polymerisation, and oligomers (12; n = 0-3) were separated from thereaction mixture by chromatography on cellulose anion-exchangers and~haracterised.~~ Cyclic oligonucleotides (13) were formed concurrently andthese too were isolated.In many discussions of the conformational aspects of the DNA macro-molecule, the hydrogen-bonded double-helical structure is a basic tenet.70 I. R. Lehman, M. J. Bessman, E. S. Simms, and A. Kornberg, J .B i d Chem.,1958, 233, 163.71 M. J. Bessman, I. R. Lehman, E. S. Simms, and A. Kornberg, ibid., p. 171.72 &I. J. Bessman, I. R. Lehman, J. Adler, S. B. Zimmerman, E. S. Simms, and73 J. Adler, I. R. Lehman, M. J. Bessman, E. S. Simms, and A. Kornberg, ibid., p.74 J. N. Davidson, R. M. S. Smellie, H. M. Keir, and A. H. McArdle, Nature, 1958,75 P. T. Gilham and H. G. Khorana, J . Amer. Chem. SOC., 1958, 80, 6212.713 G. M. Tener, H. G. Khorana, R. Markham, and E. H. Pol, ibid., 1958, 80, 6223;A. Kornberg, Proc. Nat. Acad. Sci., U.S.A., 1958, 44, 633.641.182, 589.W. E. Razzell and H. G. Khorana, ibid., p. 1770338 ORGANIC CHEMISTRY.More detailed descriptions of the A and the B form based on refined X-raystudies have been given 77 and a newly discovered (C) form of the lithiumsalt, formed reversibly from the B form, has been described.78 A modelconsistent with the X-ray data is related to the B form by moving the basepairs 2 A away from the helical axis and tilting them by about 5", and thereare 9.3 base pairs per turn of the helix.A detailed infrared-spectral studyof the sodium salt of DNA gives results regarding molecular configurationsin accord with those from X-ray work.79 Of exceptional interest are experi-ments by Meselson and Stahl,80 who observed the distribution of 15N amongmolecules of bacterial DNA by density gradient centrifugation followingtransfer of a uniformly 15N-substituted E. coli population to a 14N-medium.They find: " (1) that the nitrogen of a DNA molecule is divided equallybetween two subunits which remain intact through many generations ;(2) that, following replication, each daughter molecule has received oneparental subunit; and (3) that the replicative act results in moleculardoubling." Thus the theory of DNA replication receives confirmation,although the mechanism remains a mystery.Shooter has reviewed the physical chemistry of DNA.*l The conform-ation of the DNA molecules in saline solution has been variously described,as, for example, that it is highly extended, although not rod-like, but gentlycoiled in a random fashion.82 More attention has been paid recently to theprocess of " denaturation " of DNA which results from changes in pH,ionic strength, and temperature, singly and in combination, and the actionof other reagent^.^^-^^ Denaturation occurs when a critical number of theintramolecular hydrogen-bonds are irreversibly broken, leading to apermanent loss of the helical configuration.It can be followed titrimetricallyand by changes in optical density and in molecular dimensions as determinedby, inter alia, sedimentation, viscosity, and light-scattering measurements.Reduction of the ionic strength of DNA solutions to low values causesd e n a t u r a t i ~ n , ~ ~ , ~ ~ a fact which vitiates some earlier studies. It is wellknown that when a saline solution of DNA is titrated from neutrality to77 R. Langridge, W. E. Seeds, M. R. Wilson, W. C. Hooper, M. F. H. Wilkins, and78 D. A. Marvin, M. Spencer, M. H. F. Wilkins, and L.D. Hamilton, Naturc, 1958,70 G. B. B. M. Sutherland and M. Tsuboi, Proc. Roy. Soc., 1957, A , 239, 446.80 M. Meselson and F. W. Stahl, Proc. Nat. Acad. Sci., U.S.A., 1958, 44, 671.81 K. V. Shooter, Prop. Biophysics Biophys. Chem., 1957, 8, 309.82 P. Doty, B. B. McGill, and S. A. Rice, Proc. Nut. Acad. Sci., U.S.A., 1958,44, 432.83 L. F. Cavalieri, M. Rosoff, and B. H. Rosenberg, J . Amer. Chem. SOC., 1956, 78,84 A. R. Peacocke, Chem. SOC. Special Publ., 1957, No. 8, p. 163.85 A. R. Matheson and S . Matty, J . Polymer Sci., 1957, 23, 747.86 R. A. Cox and A. R. Peacocky, ibid., p. 765.87 Idem, J., 1958, 4117.88 E. P. Geiduschek, J . Polymer Sci., 1958, 31, 67.8Q G. Zubay, Biochim. Biophys. Acta, 1958, 28, 644.QO P. Ehrlich and P. Doty, J .Amer. Chem. Soc., 1958, 80, 4251.91 S. A. Rice and P. Doty, ibid., 1957, 79, 3937.92 E. L. Duggan, V. L. Stevens, and B. W. Grunbaum, ibid., p. 4859.09 L. F. Cavalieri and B. H. Rosenberg, ibid., p. 5352.94 J. Hermans and A. M. Freund, J . PoZymer Sci., 1958, 28, 229.95 V. L. Stevens and E. L. Duggan, J . A m y . Chem. SOC., 1957, 79, 5703.L. D. Hamilton, J . Biophys. Biochem. Cytol., 1957, 3, 767.182, 387.5239BROWN: THE NUCLEIC ACIDS. 339pH 2-6 and back at 25", a hysteresis in the curve is noted, due to liberationof titratable basic groups, and the molecule becomes irreversibly collapsed.Titration to intermediate pH values leads to a family of backward-titrationcurves from which the degree of denaturation can be calculated, but if only10-15y0 of the hydrogen-bonds are broken these are re-formed on returnto neutrality.If 75% are broken the structure becomes unstable and rapiddisorganisation then leads to the completely denatured form.84@, 8'Hydrogen-bond breaking, it is supposed,89 involves protonation on N(l) of theadenine and cytosine residues. If the titration is carried out at orbelow 0" the curve becomes reversible and the DNA is not denat~red.8~988Geiduschek 88 comments that if, as is generally supposed, titration to pH 2.6involves the rupture of the hydrogen-bonds then the major contribution tothe stabilisation of the double-helix secondary structure is made by otherforces. Nucleates from different sources, it may be noted, also show stabilitydifferences,m the origins of which are unresolved.Denaturation by alkali is essentially similar to that caused by a~id.~OThere is a sharp transition a t pH 11.7-11.9, marked by a ten-fold loweringin intrinsic viscosity and a three-fold reduction in the radius of gyration with-out change in molecular weight.It is concluded that the denatured DNAconsists of randomly coiled, highly flexible chains that remain paired andhighly contracted owing to substantial numbers of non-periodically arrangedintramolecular hydrogen-bonds. This picture is also drawn of heat-denaturedDNA 91-94 in which the changes appear to be due to " melting out " of tractsof hydrogen bonds, i.e., a co-operative breakdown of the highly organisednative structure over a small temperature range.g1 Heat-deformed DNA canbe separated from unheated material by precipitation with lead ions.95DNA molecules can apparently be fragmented, with double chain-scission, leaving hydrogen-bonds intact, by sonic waves 82 and by passingsolutions through an a t ~ m i s e r , ~ ~ the latter method being claimed to giveessentially monodisperse material; y-rays appear to break both inter-nucleotide and hydrogen bondsg7Synthetic Polyribonuc1eotides.-The advantages of having availableoligo- and poly-nucleotides in which the nature of the constituent mono-nucleotides is controlled are obvious.In consequence a considerablevolume of work has appeared since the demonstration by Grunberg-Managoand Ochoa that an enzyme from Axotobacter vinelandii can catalyse thereversible formation of polynucleotides from nucleoside-5' diphosphates withloss of orthophosphate [viz., n nucleoside-5' PP =z+ (nucleoside-P)n + %PI.Similar enzymes have been detected in M .Zysodeikticus,98 in E. coZi,99 and inliver nuclei.100 The Azotobacter enzyme has been extensively purified 101and with this fraction a lag period in its action is noted which can beabolished by addition of polynucleotides lol or oligonucleotides 102 to the913 L. F. Cavalieri, J . Amer. Chem. SOC., 1957, 79, 5319.97 A. R. Peacocke and B. N. Preston, J . Polymer Sci., 1958, 31, 1.98 R. F. Beers, jun., Arch. Biochem. Biophys., 1958, 75, 497.99 U. 2. Littauer and A. Kornberg, J . Biol. Chem., 1957, 226, 1077.100 R. J. Hilmoe and L. A. Heppel, J . Amer. Chem.SOC., 1957, 79, 4810.101 S. Mii and S. Ochoa, Biochim. Biophys. Ada, 1957, 26, 445.102 M. F. Singer, L. A. Heppel, and R. J. Hilmoe, ibid., p. 447340 ORGANIC CHEMISTRY.system and, at least in the latter case, the primer becomes incorporated intothe polymer. Full details have now been given of the structures of thepolynucleotides containing one base and a mixture of bases.lo3 They areall 3',5'-linked polymers and by controlled degradation, mainly withenzymes, a valuable array of different oligonucleotides can be prepared(e.g., those represented by the symbols (14-18), and the correspondingA A A A A A A A U A A U~ p ~ p ~ p (18)dimers and tetramers). Phosphorolysis of these,lM and of a variety ofribonucleic acids,105 has been studied.Poly(rib0thymidine phosphate) hasbeen prepared from the synthetic 5-methyluridine-5' pyrophosphate.lWMichelson 107 has made substantial progress in chemical synthesis andhas obtained polymers containing one or more monomer types with averagechain lengths of up to twenty units, but in which both 2',5'- and 3',5'-inter-nucleotidic linkages are present. Nucleoside-2',3' phosphates (19) wereconverted into mixed anhydrides (20) by means of diphenylphosphoro-chloridate and, with base, polymerisation occurred. Hydrolysis of theintermediate (21) by water then gave the polynucleotide (22).B B B BThe biosynthetic polynucleotides have been extensively studied byphysicochemical methods ; changes in pH, ionic strength, metallic ions, and103 L. A. Heppel, P. J. Ortiz, and S. Ochoa, J . Biol. Chem., 1958, 229, 679, 695.lo4 M. F. Singer, ibid., 1958, 232, 211.105 S. Ochoa, Arch. Biochem. Biophys., 1957, 69, 119; P. Lengyel and S. Ochoa,106 B. E. Griffin, (Sir) Alexander Todd, and A. Rich, Proc. Nat:Acad. Sci., U.S.A.,10' A. M. Michelson, Nature, 1958, 181, 303.Biochim. Biophys. Acta, 1958, 28, 200.1958, 44, 1123BROWN: THE NUCLEIC ACIDS. 341temperature often have profound and inter-related effects on their structuresand interactions in solution. Thus polyadenylic acid in aqueous saltsolution consists of flexible, randomly coiled molecules .lo8 Reduction of thepH to below 5 causes an abrupt transition. Changes in the sedimentationconstant and viscosity occur and A,,, changes from 257 to 252 mp withincrease in optical density. The evidence suggests that a rigid, interruptedmultiple-helical structure has been formed composed of various numbers ofpolyadenylic acid mole~ules.~0~~~0~ It is suggested loS that the lowering ofthe electrostatic energy by titration of about half of the adenine groups isresponsible for the stability of the structure; no intermediate states are noted.The transition of this ordered structure to a random coil over a narrowtemperature range (near 75") is reminiscent of the similar behaviour of DNA,accounted for by co-operative breakdown of the inter-base hydrogen-bonds.X-Ray diffraction diagrams from polyadenylic acid fibres and two possiblemodels which find some agreement with them have been discussed.ll0Further work on the interaction between polyadenylic acid and poly-uridylic acid has appeared.ll1-ll6 By using a continuous variation techniquea 1 : 1 complex can be observed, stable a t pH 7.4 in salt solution and charac-terised by a lowered optical density. In presence of Mg++ or Mn++ anothercomplex, containing uracil and adenine in the ratio 2 : 1, can be discerned,less stable than the 1 : 1 complex.1119112 The hypochromic effect, infraredmeasurements,lf5 the breakdown of the complex at high and low pHvalues,l14 and the prevention of its formation by formaldehyde114 areconsistent with hydrogen-bonding between adenine and uracil residues inadjacent polynucleotide chains. Felsenfeld, Davies, and Rich 111,112 thinkthat the first complex is an interrupted double helix in which very few " gaps,''or non-hydrogen-bonded regions, are left 113 and that the second complex is atriple helix. Zubay 116 has discussed the need for Mgff in the formation ofthe latter and has proposed a model for the three-stranded molecule whichis consistent with preliminary X-ray diffraction results. Beers andSteiner 114 consider that the linear variation of optical density withadenine : uracil ratio would appear to make any abrupt transition from adoubly- to a triply-stranded structure unlikely.Thesubstance a t 66% humidity has an organised helical structure and a three-chain model seems to fit the crystallographic data best. A 1 : 1 and a 2 : 1complex between polyinosinic and polyadenylic acids is formed and opticaldensity changes (hypochromic effect) together with ultracentrifugation andPolyinosinic acid has been studied as fibres and in solution.117108 J. R. Fresco and P. Doty, J . Amer. Chem. Soc., 1957, 79, 3928.109 R. F. Steiner and R. F. Beers, jun., Biochirn. Biophys. A d a , 1957, 26, 336;R. F. Beers, jun., and R. F. Steiner, Nature, 1957, 179, 1076; R. F. Steiner and R. F.Beers, jun., J . Polymer Sci., 1958,31, 53; R. C. Warner, J . Biol. Chem., 1958, 229, 711.110 R. S. Morgan and R. S. Bear, Science, 1958, 127, 81.111 G. Felsenfeld and A. Rich, Biochirn. Biophys. Acta, 1957, 26, 457.112 G. Felsenfeld, D. R. Davies, and A. Rich, J . Amer. Chem. Soc., 1957, 79, 2023.11s G. Felsenfeld, Biochim. Biophys. Acta, 1958, 29, 133.114 R. F. Beers, jun., and R. F. Steiner, Nature, 1958, 131, 30.116 H. T. Miles, Chem. and Ind., 1958, 591; Biochim. Biophys. Acta, 1958, 27, 46.118 G. Zubay, Nature, 1958, 182, 388.117 A. Rich, Biochim. Biophys. Acta, 1958, 29, 502342 ORGANIC CHEMISTRY.X-ray studies are taken to indicate two- and three-stranded helicalstructures.ll* A helical complex is also formed between polyinosinic andpolycytidylic acids.llg The importance of these triple-helical structures tocurrent views on genetic information transfer has been stressed.112J20Michelson 121 has discussed the basis of the hyperchromic effect i.e. theincrease in optical density observed when polynucleotides (even di-nucleotides) 122 are hydrolysed or when organised structures such as DNAare denatured.D. M. B.D. M. BROWN.C. A. BUNTON.D. P. CRAIG.A. G. DAVIES.P. B. D. DE LA MARE.J. ELKS.T. G. HALSALL.W. D. OLLIS.W. G. OVEREND.J. E. SAXTON.K. SCHOFIELD.T. SWAIN.G. H. WHITHAM.G. H. WILLIAMS.11* A. Rich, Nature, 1958, 181, 521.119 D. R. Davies and A. Rich, J. Amer. Chem. SOC., 1958, 80, 1003.120 G. Zubay, Nature, 1958, 182, 1290.121 A. M. Michelson, ibid., p. 1502.122 M. Privat de Garilhe and M. Laskowski, J. B i d . Chem., 1956, 223, 661

ISSN:0365-6217    

DOI:10.1039/AR9585500168

出版商:RSC    

年代:1958

数据来源: RSC

摘要:

BIOLOGICAL CHEMISTRY1. INTRODUCTIONIT is inevitable that reports on the progress of biological chemistry shouldcontain reviews relating to enzymes, carbohydrates, proteins, or fats, andthree of this year's reviews fall into one or other of these categories. Thefirst Report deals with the important problem of the part played by metalsin the catalytic activity of enzymes. It appears that there are at least fourtypes of metal-dependent, enzyme, one in which the metal functionsprimarily in combination with the substrate, and three in which the metalis firmly associated with the enzyme. The second Report is concerned withcarbohydrates, but has the intriguing title of '' rare sugars." There is awide variety of unusual sugars in Nature, but it often happens that the raresugar of today becomes a commonplace one tomorrow, as has alreadyhappened with some of the pentuloses.The amazing versatility of livingtissues in transforming one sugar into another, apparently rare, is wellillustrated in this Report. Phosphoglycerides are compounds whosebiological functions are not yet fully understood. They are involved,inter alia, in the structure of cell membranes and are therefore concerned inthe very important problem of membrane permeability. Their occurrencein brain and nervous tissue is of considerable significance. The thirdReport deals with the isolation and characterization of naturally-occurringphosphoglycerides which are a necessary prerequisite to the understandingof their biological functions. The last Report diverges somewhat from thestudy of natural compounds and deals with an aspect of the biochemistryof foreign organic compounds.This field of biochemistry is now developingrapidly and is of considerable importance, especially in its applications topharmacology and toxicology. Hydroxylation is but one of the mechanismsused by the body for metabolizing foreign compounds, and in the case ofaromatic compounds, the study of their hydroxylation raises very interestingquest ions concerning the orient at ion of h ydrox ylat ion. Furt hennore,orientation is related to species and is of particular significance where certaincarcinogenic compounds are concerned.R. T. W.2. METALS AND ENZYMESIT is well known that certain metals play an essential part in the action ofmany enzymes.During the last few years a large number of detailedreview articles 1-9 have appeared on specific aspects of the subject of metals1 T. P. Singer and V. Massey, Rec. Chem. Progr., 1957, 18, 201.2 B. L. Vallee, Proc. IVth Internat. Congr. Biochem. (Vienna), 1958, Symposium3 B. L. Vallee, Adv. Protein Chem., 1955, 10, 317.4 B. G. Malmstrom and A. Rosenberg, Adv. Enzymol., 1959, 21, in the press.5 H. R. Mahler, ibid., 1956, 1'7, 233.8 D. J. D. Nicholas, Nature, 1957, 179, 800.No. V I I I , in the press344 BIOLOGICAL CHEMISTRY.and enzyme catalysis, and there has been a symposium on the subject.1°However, there appear to be few articles which attempt to review the wholefield. It has been found necessary to limit the literature covered for thisReport to the reviews listed and to papers on selected aspects of more recentwork.Classification.-It is, of course, possible to classify metal-dependentenzymes according to the types of reaction which they catalyse or accordingto the nature or assumed function of the metal.However, the types ofexperimental method which have to be employed in studying the r6le of themetal in the action of an enzyme vary widely according to the affinity ofthe metal for the protein. Hence, a more convenient classification for thepurposes of this Report is based on the strength and type of bonding of themetal to the protein and relates to the experimental methods which havehad to be employed to obtain information on the function of the meta1.2~4~9Thus, it is convenient to distinguish between metal-activated enzymes(group I) to which the metal ions are somewhat loosely bound, and metallo-enzymes (group 11) which contain specific metals firmly attached to theprotein, and which are regularly isolated in this state.The metalloenzymesmay be further sub-divided (groups IIA and IIB, respectively) accordingto whether or not the metal can be removed reversibly by procedures suchas dialysis against a chelating or complexing agent. Where the metalcannot be removed these reagents may be capable of inhibiting the enzymicactivity by combining with the metal without detaching it from the protein(group IIBi) or may be without effect on the activity (group IIBii), thusproviding a further subdivision of enzyme types.(A disadvantage of thisclassification is that as experimental data on a particular enzyme accumulateit may be necessary to transfer it from one category to another. However,as the discussion in this article has been limited largely to well-characterizedenzymes, this need not concern us.) In subsequent sections each type ofenzyme enumerated above will be discussed and illustrated by referenceto one or more specific enzymes which appear to have been studied in somedetail. The classification scheme, with details of the enzymes to beconsidered, is illustrated in the accompanying Table.Possible Functions of Metals.-Definite information on the exact partplayed by the metal is available for relatively few enzymes at present.However, a number of possible types of involvement can be considered.In metal-activated enzyrne~,~ the metal may merely combine with thesubstrate; the metal-substrate complex which is thus formed is then thetrue substrate of the enzyme.Alternatively, the metal may combine withthe enzyme, or be permanently present in it in the case of a metalloenzyme,in such a way that the ‘‘ active centre ” is stabilized by the metal. Themetal can then perform its function simply, for example, by holding twopeptide chains in the right orientation; alternatively it can be more directly7 K. J. P. Williams, “ The Enzymes,” VoI. 1, Academic Press, New York, 1958,p. 391.8 P. George and J. S. Griffith, ibid., p. 347.9 B. G. Malmstrom, “ The Mechanism of metal-ion activation of enzymes.Studieson enolase,” Almqvist and Wiksells Boktryckeri AB, Uppsala, 1956.10 Biochem. SOC. Symp., 1958, No. 15Some metal-dependent enzymesMetal-dependent4enzymes-1, metal-activatedenzymesIIIA, dissociablemetalloenzymes i i [II, metalloenzymesEnzymep y rophosphataseleucine amino-peptidaseI enolasenitrateperoxidase { a-amylasef alcohol dehydro-reductaser for metals chrome-c re-MgMgZn>MoFeCaZnFe1 ductasesuccinic dehydro- Fefic for metalsoxidase Fe1 IIB, nondissociableI metalloenzyme346 BIOLOGICAL CHEMISTRY.involved, and its presence can modify the properties of certain functionalgroups of the protein in a manner which facilitates their interaction withthe substrate.(In this type of metal dependence it is possible for irreversiblechanges to occur in the protein, though not necessarily at a rapid rate, ifthe metal is dissociated from the enzyme. Hence, the presence of theappropriate metal may be advantageous to obtain maximum stabilityduring the storage of an enzyme, while it is also essential for its catalyticactivity.11)A further possibility is that the bonding which occurs between thesubstrate and the enzyme protein in the enzyme-substrate complex may bepartly or wholly through the metal. In other words, there may be bondsfrom the metal both to the protein and to the substrate, in addition to anydirect protein-substrate bonds. In this case, if the metal is dissociablefrom the enzyme, the enzyme-substrate complex is correctly consideredas a ternary enzyme-metal-substrate c o m p l e ~ .~ ~ ~ Another function forthe metal is that instead of the substrate, a coenzyme (such as DPN * orFAD) may be linked more or less permanently to the protein through themetal. It is even possible for the protein, the coenzyme, and the substrateall to be bound simultaneously by the metal. Steric considerations suggestthat this last alternative may not be common, but examples are the iron-porphyrin enzymes in which the planar hzmatin molecule has the metalat its centre; the metal is bound directly to the protein but is still exposedfor possible interaction with the substrate. Similar complexes in whichthe metal is supposed to be bound to the protein, the substrate, and thecoenzyme simultaneously have been postulated by Mahler and Douglasfor a non-porphyrin enzyme.12With oxidative enzymes, if the metal is capable of existing under physio-logical conditions at more than one oxidation level the function of the metalmay be to be reduced by the substrate and re-oxidized by the electronacceptor.Finally, the metal may have a function in stabilizing someintermediate in the enzymic reaction other than the primary enzyme-substrate complex. If the reaction is oxidative, this function might be,for example, to increase the stability of a semiquinone intermediate byincreasing the resonance possibilities, as proposed for metalloflavoproteinsby Mahler.5 The metal could then undergo valency change in the courseof the reaction without actually being in the electron transfer pathway ”proper.It is of course possible for a given metal to perform a number of thefunctions discussed above simultaneously in the same enzyme.In subse-quent sections of this Report, what is known of the function of the metal inspecific enzymes will be discussed in detail, with some indication of the typeof experimental information from which the conclusions have been drawn.11 E. H. Fischer, W. B. Sumerwell, J. Junge, and E. A. Stein, Proc. IVth Intevnat.Congr. Biochem. (Vienna), 1958, Symposium No. V I I I , in press.12 H. R. Mahler and J. Douglas, J . Amer. Chem. SOL, 1957, 79, 1159.* The following abbreviations are used in this Report: DPN, Diphosphopyridinenucleotide ; TPN, triphosphopyridine nucleotide : FAD, flavjn adenine dinucleotide ;FMN, riboflavin 5’-phosphate; DPNH, TPNH, FADH, and FMNH, reduced forms ofabove compoundsBRAY AND HARRAP: METALS AND ENZYMES.347Group I. Metal-activated Enzymes-Metal-activated enzymes are thesubject of. a review in a forthcoming issue of Advances in Enzymology.(It should be noted that enzymes of this group are referred to as I‘ metallo-enzymes 9 ” or “ metal enzymes ” by Malm~trom,~ since in some cases theenzymes have been shown to be completely inactive in the absence of a metal.However, according to Vallee’s terminology the word ‘‘ metalloenzyme ”is reserved for enzymes with firmly bound non-dissociable metals. Thus, thenomenclature in the present review is slightly different from that of eitherof the other reviewers and incorporates features from both.The difficultiesencountered in attempting to obtain information on the exact function ofthe metal in metal-activated enzymes have been discussed by Vallee;in only a few cases have they been overcome, though reports on the activationof enzymes by added metals, especially magnesium, calcium, and manganese,are numerous.13 Three enzymes of this group will now be referred to indetail.Kinetic evidence 14915s4 for inorganic pyrophosphatase is consistent withmagnesium’s exerting its effect by combination with the substrate ratherthan with the enzyme. The true substrate is thus supposed to be themagnesium-pyrophosphate complex, and free pyrophosphate ions causeinhibition by competing with this for the enzyme.Magnesium is probablynot itself capable of combining tightly with the active site of the enzyme.l4Another enzyme in this group on which some mechanistic studies havebeen made is leucine arnino-peptidase.l6 The enzyme has been prepared inan apparently homogeneous state, and its activation by combination witheither magnesium or manganese has been found to be consistent with a mass-action combination of the metal with the active centre of the enzyme.Slowness of the activation process may be due to changes occurring in theprotein rather than to slow combination of the metal.l’s18 Variouspossible mechanisms whereby the metal-enzyme complex might interactwith the substrate have been discussed theoretically by Rabin,l8 but noneof them was found to be completely satisfactory.Results are clearer for enolase than for any other enzyme of the group;enolase can be obtained highly pure l9 and the function of the metal, whichcan be magnesium, manganese, ferrous iron, or zinc, has been studied by anumber of methods by Malmstrom and his c o - w o r k e r ~ .~ ~ ~ ~ ~ ~ Kinetic dataare consistent with a metal-enzyme complex interacting with the substrate togive a ternary enzyme-metal-substrate complex. This conclusion issupported by independent work by Wold and Ballou.20u The extent ofinteraction between the substrate and the metal and between the enzymeand the metal has been measured, and equilibrium dialysis and electron spinl3 M.Dixon and E. C. Webb, “ Enzymes,” Longmans, London, 1958, p. 182.l4 E. A. Robbins, M. P. Stulberg, and P. D. Boyer, Arch. Biochem. Biophys., 1955,15 L. Bloch-Frankenthal, Biochem. J., 1954, 57, 87.16 E. L. Smith and D. H. Spackman, J . Biol. Chem., 1955, 212, 255, 271.17 B. G. Malmstrom and L. E. Westlund, Arch. Biochem. Biophys., 1956, 61, 186.18 B. R. Rabin, in ref. 10.19 B. G. Malmstrom, Arch. Biochem. Biophys., 1957, 70, 68.20 F. C. Happold and R. B. Beechey, in ref. 10.2m F. Wold and C. E. Ballou, J . BZoZ. Chem., 1957, 227, 301, 313.54, 215348 BIOLOGICAL CHEMISTRY.resonance studies 21 taken in conjunction with the kinetic data indicate thatonly one metal atom bound to the protein is concerned with enzymic activity.Additional metal atoms may be taken up, but are bound less strongly tothe protein; they may be related to the inhibition which occurs at highmetal concentrations.4~Group IIA.Dissociable 1Metalloenzymes.-It is of course impossible todraw a strict dividing line between any of the groups into which metal-dependent enzymes have been divided in this Report, since the dissociationconstants of the metals from the protein may not fall into sharply definedgroups. However, it is convenient to define a dissociable metalloenzymeas one which normally contains a specific metal when isolated, and fromwhich the metal can be removed with loss of enzymic activity, while theactivity so removed can be restored by re-addition of the metal.A good example is nitrate reductase, which has been extensively studiedby Nicholas and Nason.It is a metalloflavoprotein ti and, although it hasnot been obtained pure,22*23 the evidence on the function of the metal (molyb-denum) appears to be quite c1ear.l~~~ The reaction sequence believed tooccur is :TPNH + Flavin --t Mo -w NO,-The arrows represent the ‘‘ electron transfer pathway ” and the evidence 1on which the scheme rests can be summarized as follows: (a) Flavin (FMN)is reduced enzymically by nitrate reductase in the presence of TPNH. Thisreaction takes place in the presence of cyanide, or if the molybdenum-freeenzyme, obtained by dialysis against cyanide, is substituted for the nativeenzyme. (b) FMNH can act as electron donor in place of TPNH in theenzymic reduction of nitrate to nitrite.Molybdenum is necessary for thisstep, and the reaction does not take place in the presence of cyanide or ifthe molybdenum-free enzyme is employed. (c) FMNH can be oxidized bymolybdate in the presence of nitrate reductase. (a) Nitrate can be reducedto nitrite by reduced molybdate in the presence of the enzyme.Although, as pointed out by Singer and Massey,l to argue from changesoccurring in an externally added excess of molybdenum to the molybdenumoriginally present in bound form in the enzyme is not necessarily valid,nevertheless it seems highly probable that the molybdenum of nitratereductase participates in the electron-transfer sequences of the enzyme asshown in the scheme. The molybdenum of the enzyme may possibly bepresent in the form of a phosphomolybdate complex.23Another well-known enzyme which belongs to this group is the iron-porphyrin enzyme peroxidase.Such enzymes differ from other knownmetalloenzymes in that the metal, although bonded to the protein, is alsotightly bound to a coenzyme, Le., the porphyrin molecule, and the protein-free iron-containing porphyrin (hzmatin) can readily be isolated as such.Thus in the case of peroxidase, resolution, which is brought about by21 B. G. Malmstrom, T. V%nng&rd, and M. Larsson, Biochim. Biophys. Actu, 1958,30, 1.2% W. F. Anacker and V. Stoy, Biochem. Z., 1958, 830. 141.s3 S. C. Kinsky and W. D. McElroy, Arch. Biochem. Biophys., 1958, 73, 466.84 D. J. D. Nicholas and A. J. Nason, J . Bid. Chew., 1954, 211, 183BRAY AND HARRAP: METALS AND ENZYMES.349acidification in the cold in the presence of acetone,25 splits off hzematinrather than the free metal ions, leaving the protein which is catalyticallyinactive. Activity is restored by the re-addition of hzmatin to theapoenzyme. Studies on peroxidase have been extensive, and a completediscussion of them is beyond the scope of this Report. However, it can bestated that the iron is apparently in the ferric state and is never reducedbelow this.Z6 A number of complexes which are formed from the enzymein the presence of peroxide and an electron donor have been characterized,though their nature is uncertain; it is possible that in the course of thereaction, the iron is oxidized to valencies higher than three,27 though thishas been questioned by Williams.28Recent workll has thrown new light on the importance of calcium inthe action of a-amylases. It has been shown that the enzyme isolated froma number of sources contains this metal and that dialysis against ethylene-diaminetetra-acetic acid causes loss of enzymic activity; under favourableconditions activity can be completely restored by adding calcium salts tosolutions of the apoenzyme so prepared.Endogenous calcium also has aremarkable stabilizing action on the enzyme, and if the metal is removed,proteolytic enzymes (which frequently contaminate crude preparations ofa-amylases) inactivate it rapidly, while the calcium-containing nativeenzyme is resistant to such agents.Two other recent pieces of work on enzymes of the group can be mentionedbriefly.A method has now been found 29 of removing zinc reversibly fromcarboxypeptidase, thus giving new evidence on the importance of the metalin the action of this enzyme. The possibility that iron may be involved inenzymic transaminations is raised by the work of PatwardhanJ30 who foundthat a partially purified vegetable transaminase lost about 8rds of its activityon dialysis against a chelating agent, and that activity could be fullyrestored by adding ferrous iron but not other metals to the dialysedpreparation. This appears to be the first indication of metal involvementin enzymic transamination, though work on model systems has suggestedthat metals may be important in such reactions.31Group IIBi.Non-dissociable Metalloenzymes inhibited by ReagentsSpecific for Metals.-A number of enzymes which contain firmly boundmetals lose their activity in the presence of chelating or complexing agents,though dialysis against the reagents does not result in liberation of themetal from the enzyme.Vallee 293 has made detailed studies on enzymes of this group, particularlyon the zinc-containing enzyme, alcohol dehydrogenase.2 The enzyme hasbeen isolated highly pure from yeast and also from liver. As generallyisolated from the latter source it contains two atoms of zinc per mole andfrom the former four atoms per mole. In the yeast enzyme, it is possible25 H. Theorell, " The Enzymes," Vol. 2, Academic Press, New York, 1951, p. 397.26 B.Chance, op. cit., p. 428.27 E. C . Slater, in ref. 10.28 R. J. P. Williams, Chem. Rev., 1956, 56, 299.29 B. L. Vallee, J. A. Rupley, T. L. Coombs, and H. Neurath, J . Amer. Chew. SOC.,30 M. V. Patwardhan, Nature, 1958, 181, 187.31 J. B. Longenecker and E. E. Snell, J . Amer. Chem. SOC., 1957, 79, 142.See also discussion remarks following paper.1958, 80, 4750350 BIOLOGICAL CHEMISTRY.for further metal atoms to be bound by the protein, and Vallee distinguishesbetween the “ intrinsic ” zinc, which is liberated irreversibly with loss ofenzymic activity by dialysis at pH values below 5-5, and extrinsic ” zinc,which is sometimes bound to the enzyme in addition to the intrinsic metaland which can be removed by treatment at pH 6; enzymic activity isincreased slightly by removal of the extrinsic metal.Isotope studies haveconfirmed the distinction between the two types of zinc in the enzymemolecule and have shown that they are not interchangeable. Four atomsonly of intrinsic metal are present in yeast alcohol dehydrogenase and theseare firmly bound to the protein. The coenzyme is less firmly bound thanthe metal, and the enzyme can take up four molecules of DPN reversibly.Alcohol dehydrogenase is inhibited by a number of chelating and metal-complexing agents, and this, together with the parallelism between loss ofintrinsic zinc at low values of pH and loss of activity, strongly suggests thatthe metal is essential for activity. Detailed studies of the inhibition by1,lO-phenanthroline have shown that the reagent does not remove the metalfrom the enzyme and that inhibition is competitive with the coenzyme butnot with the substrate.Complex formation between the enzyme and thechelating agent has been demonstrated spectroscopically and the dissociationconstant of the complex, as deduced from such direct measurements, is ingood agreement with the value from inhibition data. Thus the conclusionsthat the zinc is an essential part of the enzyme, which is concerned withbinding the coenzyme but not the substrate, and that chelating agentsinhibit by blocking the metal without removing it, seem to be well estab-lished.The evidence for the function of the metal in DPNH-cytochrome-creductase is much less clear cut. This enzyme is an iron-containing flavo-protein and has been discussed recently by Singer and Massey 1 in a reviewarticle on the function of metals in metalloflavoproteins generally.According to these authors the complete reversible resolution of the enzymeappears to be difficult to achieve, and the evidence for it does not seem to beentirely conclusive. (Hence it has been included here, and not undergroup IIA.) However, it has been clearly shown that the enzyme containsiron, and further that a number of chelating and complexing agents have aninhibitory effect on it when cytochrome-c is employed as electron acceptorbut apparently not when indophenol is the acceptor.Unfortunately,evidence as to the mechanism by which these reagents act is lacking; theymight combine with the iron of the enzyme (cf. alcohol dehydrogenase), theymight detach it, or they might conceivably interact with the metal of thecytochrome, if this is accessible to chelating agents, rather than with thatof the enzyme.Evidence that valency changes occur in the iron duringthe enzymic reaction is based on attempts to determine by colorimetricmethods the valency of the inorganic iron liberated by denaturing theenzyme after pre-treatment with the substrate or the electron acceptor.However, the artefacts which may occur in such experiments make theresults of little va1ue.lMahler 5 has suggested that the electron acceptors of metalloflavo-proteins fall into two categories, to which he refers as 1- and 2-electroBRAY AND HARRAP: METALS AND ENZYMES.351acceptors; cytochrome-c and indophenol, respectively, are examples fromthe two groups. According to him, the metal of such enzymes is essentialonly for interaction with one-electron acceptors and its presence or absenceis of no consequence if a 2-electron acceptor is employed. However, boththe classification of electron acceptors and the evidence for this partialdependence on the metal have been questioned for DPNH-cytochrome-creductase, and for other metalloflavoproteins, by Singer and Massey.lThus, in the absence of further work it must be conceded thatlittle is known about the part played by iron in DPNH-cytochrome-creduct ase.Group IIBii. Non-dissociable Metalloenzymes not Inhibited by ReagentsSpecific for Metals.-If an enzyme contains metal atoms which cannot beremoved reversibly, and if chelating and complexing reagents do not inhibitthe enzymic activity, the problem of demonstrating what function, if any,the metal has in the activity of the enzyme is one which is not readilysolved by any of the experimental methods which have been discussed sofar.Indeed, the only one of these methods which can possibly be appliedis that discussed in the previous section in relation to DPNH-cytochrome-creductase which depends on attempting to follow calorimetrically valencychanges of the metal, after liberation by denaturation. As already stated,artefacts often make it difficult to interpret results from this technique.1Succinic dehydrogenase is an iron-containing flavoprotein which hasbeen extensively studied by Singer, Kearney, and The ironis firmly bound and appears from carefully controlled experiments of thetype just described to be in the ferric state.34 The chelating agents 1,lO-phenanthroline and pyrocatecholdisulphonate are capable,33 under certainconditions, of reacting with the iron without removing it from the enzyme,forming coloured chelates; during reaction with phenanthroline the iron isreduced.The rate at which these chelates are formed is greatly increasedby the presence of sodium dithionite, organic mercurials, and urea. Thesereagents are supposed33 to act by causing structural changes within theprotein. Measurements of the enzymic activity of the chelates are handi-capped by the fact that some inactivation invariably occurs in controlexperiments under the conditions necessary for their formation ; nevertheless,it seems that the enzyme can function satisfactorily with at least half of itsiron chelated, and Massey= concludes that it is probable that valencychanges do not occur in any of the four iron atoms of his enzyme duringreaction, and that the metal atoms are normally ‘‘ buried ” in the proteinmolecule.The most promising methods of following valency changes in transition-metal atoms bound firmly to protein molecules are provided by the relatedphysical properties of magnetic susceptibility and electron spin resonance.These depend on differences in the magnetic properties of the metal atomsat different valency levels.Both methods have very recently been applied to the copper-containing32 T. P.Singer, E. B. Kearney, and V. Massey, Adv. Enzymol., 1957, 18, 65.33 V. Massey, Biochim. Biophys. A d a , 1968, 30, 500.34 Idem, J . Bid. Chem., 1957, 229, 763352 BIOLOGICAL CHEMISTRY.enzyme laccase. (This enzyme belongs to group IIA as reversible resolutionhas been obtained; 35 however, it is conveniently discussed here since themagnetic techniques may prove particularly useful for study of group IIBiienzymes.) It has frequently been assumed36 that the copper of laccaseundergoes valency change during the enzymic reaction and though thestoicheiometry of the reduction of the enzyme by the substrate and itsre-oxidation by the electron acceptor has been followed,37 these experimentsmay not in themselves be sufficient to show that the metal is in fact the partof the enzyme being reduced and oxidized.However, the evidence for thishas now been greatly strengthened by the work of Nakamura= and ofMalmstrom and his co-worker~.~~ The former used the susceptibilitytechnique and the latter the electron spin resonance method, and bothconcluded that the metal in the resting enzyme was cupric copper, thatexcess of substrate reduced this to the cuprous state, and that oxygenreoxidized it. However, Malmstrom adds the warning that even now, sinceno attempt has yet been made to correlate the kinetics of the valencychanges with those of the enzymic reaction, it is not possible unequivocallyto relate the changes with the catalytic action of the enzyme.Lastly, the iron- and molybdenum-containing flavoprotein xanthineoxidase will be considered.This enzyme has been the subject of muchdetailed study by a number of Claims that reversible resolutionof molybdenum could be achieved have not been substantiated, while ironis very firmly bound. Colorimetric methods have suggested that the ironremains in the ferrous state under all conditions; 41 however, valencychanges in the iron (or possibly molybdenum) have been proposed but notconclusively proved, on the basis of experiments with mercurial and otherreagents.43.44 Chelating and complexing agents have remarkably littleeffect on xanthine oxidase, ethylenediaminetetra-acetic acid and d i ~ y r i d y l , ~ ~in addition to carbon monoxide, pyrophosphate, a ~ i d e , ~ ~ fluoride, and thio-cyanate,47 all being virtually without effect.Only cyanide inhibits, but asthe kinetics of the inhibition are c0mplicated,~6 and in any case the reagentcan form complexes with either iron or molybdenum, in addition to possiblereaction with FAD,48 it has not so far been possible to draw any definiteconclusion on the function of the metals from these results. Salicylate35 C. R. Daivson and W. B. Tarpley, ‘‘ The Enzymes,” Vol. 2, Academic Press,38 T. P. Singer and E. B. Kearney, “ The Proteins,” Vol. 2, Academic Press, 1954,37 T. Nakamura, Biochim. Biophys. Ada, 1958, 30, 538.38 Idem, ibid., p. 640.39 B. G. Malmstrom, R. Mosbach, and T. Vannggrd, Nature, 1959, 183, 321.40 F.Bergel and R. C. Bray, in ref. 10.4 1 Symposium on Inorganic Nitrogen Metabolism, 1956, Johns Hopkins Press, Balti-42 E. C. De Renzo, Adv. Enzymol., 1956, 17, 293.43 I. Fridovich and P. Handler, J . Bid. Chem., 1958, 231, 899.44 I. Fridovich and P. Handler, ibid., 1958, 233, 1581; P. Handler, personal com-45 D. A. Richert and W. W. Westerfeld, J . Bid. Chem., 1954, 209, 179.46 M. Dixon and D. Keilin, Proc. Roy. SOL, 1936, B, 119, 159.47 I;. Bergel and R. C. Bray, unpublished experiments.48 L. S. Dietrich and B. F. Harland, J . Biol. Chem., 1956, 219, 383.1951, p. 454.p. 135.more, p. 492.municationBAYNE: RARE SUGARS. 363also inhibits the enzyme weakly49 but nothing is known of its mode ofaction though it could be via interaction with a metal.Very recently, new evidence from electron spin resonance studies hasbeen presented by Bray, Malmstrom, and Vanng5rd.m The results areinterpreted as indicating that the iron remains in the ferrous state, whilethe molybdenum is reduced in the presence of the substrate (xanthine) andre-oxidized by the electron acceptor (oxygen). The formation of FAD freeradicals was also demonstrated in these experiments, which perhaps offerthe most convincing evidence so far obtained with any metalloflavoproteinfor valency changes in a protein-bound metal during enzymic reactions.R.C . B.K. R. H.3. RARE SUGARS*THE recognition that few enzymes acting on carbohydrates are completelyspecific in their action has led to the use of many unusual sugars in theinvestigation of biological processes. Many have been shown to act asenzyme substrates or inhibitors, identified in such complexes as antibioticsand polysaccharides, and demonstrated as reaction intermediates.Chro-matography has been indispensable in their identification, and isotopelabelling in tracking their progress in reaction sequences. A valuable sourceof information in this field is the comprehensive review of monosaccharidebiosynthesis by Hough and Jones1The following subjects are excluded from review : oligosaccharides;branched-chain sugars; 2 cyclitols; alditols, in spite of the interest of currentwork on the teichoic acids.3Tetroses.-D-Eryt hrose, D-threose, and L-eryt hrulose enter metabolismby a preliminary reduction in Aerobacter ae~ogenes.~ In Alcaligenes faecaliserythrose is phosphorylated to an ester which is probably erythrose 4-ph~sphate.~ Dickens and Williamson have observed that, with yeastcarboxylase, lithium 3-hydroxypyruvate is decarboxylated yielding, not theexpected glycollaldehyde, but L-erythrulose.Pentoses.-All four ketopentoses are found in biological systems.Kinases for the aldopentoses are not widely distributed in nature andseveral of these enter metabolism by isomerisation to ketopentose. D-Xylulose (D-~hYeO-pentUlOSe) 5-phosphate, not D-ribulose (D-erythro-pentdose)5-phosphate, is now recognised as the substrate of transketolase in animals,plants, and micro-organisms.'48 F.Bergel and R. C. Bray, Nature, 1956, 178, 88.50 R. C. Bray, B.G. Malmstrom, and T. VanngArd, Biockem. J., 1959, 71, 2 4 ~ ; inthe press.L. Hough and J. K. N. Jones, Adv. Carbohydrate Chem., 1956, 11, 185.F. Shafizadeh, ibid., p. 263.J. J. Armstrong, J. Baddiley, J. G. Buchanan, B. Carss, and G. R. Greenberg, J.,N. H. Tattrie and A. C. Blackwood, Canad. J . Microbiol., 1957, 3, 946.H. H. Hiatt and B. L. Horecker, J . Bacterial., 1956, 71, 649.F. Dickens and D. H. Williamson, Nature, 1956, 178, 1349.1958, 4344.' B. L. Horecker and A. H. Mehler, Ann. Rev. Biochem., 1955, 24,207; E. Racker,* Throughout this Report the term sugar phosphate implies sugar-PO,H,.Harvey Lectures, 1957, 51, 143.REP.-VOL. LV 354 BIOLOGICAL CHEMISTRY.Pentoswia. The key observation that pentosuria is increased byglucuronogenic drugs suggested the experiment of administering glucurono-lactone.8 This increases excretion of L-xylulose in pentosuria and causesit to appear in the urine of the normal s ~ b j e c t .~ Ribulose is also reportedto be present.l* With [6-13C]glucur~nolactone the urinary L-xylulose isunlabelled but 50% conversion of [ l-13C]glucuronolactone into [~J~CI-L-xylulose has been demonstrated. in a pentosuric subject.11 Enzyrne prepar-ations from guinea-pig liver catalyse the reduction of D-glucuronic acid toL-gulonic acid,12 and oxidative decarboxylation of the latter to ~-xylulose,l~with 3-oxo-~-xyZo-hexonic acid as the likely intermediate.14 L-Gulonic acidcan be isolated from the urine after administration of [l-14C]-~-glucose or[6-14C]-D-glucuronic acid.15 A pathway from glucose to L-xylulose ispresent in animal tissues since uridinediphosphoglucose may be convertedinto uridinediphosphoglucuronic acid l6 from which glucuronic acid isenzymically 1iberated.l' There are conflicting reports l4 on the conversionof L-galactonic acid, from D-galacturonic acid, into L-xylulose.The further metabolism of L-xylulose in the normal animal requires axylitol dehydrogenase (L-xylulose reductase) which is present in guinea-pigliver rnitochondria.l8 This enzyme catalyses specifically the intercon-version of L-xylulose and xylitol.It is accompanied by a less specificenzyme which catalyses the interconversion of xylitol and D-xylulose.D-Xyhdokinase, required for the entry of D-XylUlOSe into the pentosephosphate cycle, has been found in animal tissues.lg Isotope-labellingexperiments, involving the incorporation of the label of [6-14C]-~-gulonateinto liver glycogen in rats, confirm the existence of the following pathwayfrom D-glucuronic acid to D-glucose via L-xylulose and the pentose phosphatecycle : 2OUDP-glucuronic - D-glucuronic L-gulonicacid - acid glucose --t UDP-glucose --t acid4- D-xylulose + xylitol + L-xylulose pentose phosphate - D-xylulosecycle - &phosphate* M.Enklewitz and M. Lasker, J . Biol. Chem., 1935, 110, 443.lo S. Futterman and J. H. Roe, ibid., p. 257.11 0. Touster, R. M. Mayberry, and D. B. McCormick, Biochim. Biophys. Acta, 1957,12 H, G. Hers, " Le Me'tabolisme du Fructose," Editions Arscia, Brussels, 1957,13 Shiugi Ishikawa and Kyoko Noguchi, J .Biochem. (Japan), 1957, 44, 465.14 (a) G. Ashwell, J. Kanfer, and J. J. Bums, Fed. Proc., 1958,17, 183; (b) C. Bublitz,15 J. J. Burns, J . Amer. Chem. Soc., 1957, 74, 1257.16 J. L. Strominger, E. S. Maxwell, H. M. Kalckar, and J. Axelrod, J . Biol. Chem.,17 V. Ginsburg, A. Weissbach, and E. S. Maxwell, Biochim. Biophys. Acta, 1958,18 S. Hollmann and 0. Touster, J . Amer. Chem. Soc., 1956, 78, 3544; J . Biol.19 J. Hickman and G. Ashwell, ibid., 1958, 232, 737.2O J. J. Burns, P. G. Dayton, and F. Eisenberg, Biochim. Biophys. Acta, 1957, 25,0. Touster, R. M. Hutcheson, and L. Rice, ibid., 1955, 215, 677.25, 196.p. 145.A. Grollman, and A. L. Lehninger, Biochim. Biophys. Acta, 1958, 27, 221.1957, 224, 79.28, 649.Chem., 1957, 225, 87.647BAYNE: RAKE SUGARS.365Xylitol is incorporated as readily as D-ribose into liver glycogen inguinea-pigs.21 The glucose-labelling pattern is not consistent with reversalof the direct pathway from glucose to L-xylulose; the UDP-glucose +UDP-glucuronic acid reaction is irreversible.16 Varying reports on theparticipation of lactone and free acid forms of the aldonic and uronic acidsin these reactions may be partly explained by a recent characterisation ofextensive lactonase activity in animal tissues.22The exact location of the metabolic block which causes pentosuria hasnot been identified but an interesting study of ribose labelling following theadministration of labelled glucuronic acid, together with imidazolylaceticacid, to normal and pentosuric subjects has been reported.The urinaryexcretion product of imidazolylacetic acid contains D-ribose which is notlabelled in the pentosuric subject although the urinary L-xylulose is labelled;but there is moderate ribose labelling in normal subjects. This is probablynot an important route of ribose bio~ynthesis.~~A search for xylitol in the urine of the pentosuric subject resulted in theunexpected discovery of ~-arabitol,~* the alternative reduction product ofL-xylulose.The following scheme for pentose fermentation by Lacto-bacillus plantarum, based on a series of investigations, has been advanced: 25D-ribose --t D-ribose 5-phosphate =+ D-ribulose 5-phosphateL-Ribulose.it acetyl phosphate+triose phosphateD-xylose =++= D-xylulose _____) D-xylulose 5-phosphate __+?tL-arabinose L-ribulose --* L-ribulose 5-phosphateThis micro-organism also contains a 2-deo~yribokinase.~~ The enzymesconcerned with L-arabinose metabolism have been partially purified.27 Theenzyrnic isomerisation of L-arabinose to L-ribulose is highly specific.L-Ribulokinase, which catalyses the phosphorylation of L-ribulose to L-ribulose&phosphate, shows some activity with D-ribulose. The C,-epimerase whichconverts L-ribulose 5-phosphate into D-xylulose 5-phosphate is absent fromA . aerogenes grown on pentoses other than L-arabinose. It is surprising thatinduction of this enzyme should require L-ribulose 5-phosphate when theother substrate, D-XylUlOSe 5-phosphate, is presumably a normal pentosemetabolite of the organism.28 Bacterial L-arabinokinases have beenreported.29a1 D.B. McCormick and 0. Touster, J . Bid. Chent., 1957, 229, 451.J. Winkelman and A. L. Lehninger, ibid., 1958, 233, 794.23 H. H. Hiatt and J. Lareau, ibid., p. 1023; H. Hiatt, Biochim. Biophys. Acta, 1958,24 0. Touster and S. 0. Harwell, J . Bid. Chem., 1958, 230, 1031.25 E. C. Heath, J. Hurwitz, B. L. Horecker, and A. Ginsburg, ibid., 1958,231, 1009.27 F. J. Simpson, M. J. Wolin, and W. A. Wood, ibid., 1958, 230,457; E. C. Heath,B. L. Horecker, P. 2. Smyrniotis, and Y . Tagaki, ibid., 1958, 231, 1031; D. P. Burmaand B. L. Horecker, ibid., p. 1039; idem, ibid., p. 1053.28 M. J. Mrolin, F. J. Simpson, and W. A. Wood, ibid., 1958, 232, 559.28 For references, see I.C. Gunsalus, B. L. Horecker, and W. A. Wood, BactevioZ.Rev., 1955, 19, 79.28, 645.G. F. Domagk and B. L. Horecker, ibid., 1958, 233, 283356 BIOLOGICAL CHEMISTRY.Other pentoses. The occurrence of D-arabinose in Nocardia asteroides 30suggests a taxonomic relation with B. tubercuZ~sis.~~ Pseudomonas saccharo-PhiZa oxidises it to D-arabono-y-lactone which is enzymically hydrolysed toD-arabonic acid. Pyruvic and glycollic acids are the products of thefermentation, 3-deoxy-2-oxo-~-g~cero-pentonic acid being an intermediate.32Another route of D-arabinose utilisation involves isomerisation to D-ribulo~e.~~Little is known of the metabolism of the lyxoses but the mannoseisomerase of P. saccharophiZa catalyses the interconversion of D-lyxose and~-xylulose.~~ D-Lyxose is a poor source of kojic acid in AspergiZZusflavus,and L-lyxose barely supports growth.34 D-Xylose is oxidised to D-xylonicacid in calf lens.% Reduction to xylitol is reported to be the first step in itsu t ilisation in PeniciZZiwn c h r y s o g e n ~ m .~ ~Hexoses.-Fourteen of the sixteen aldohexose configurations have beenidentified in cell constituents or intermediates.D-Allose 6-phosphate is the likely product of the action of transketolaseon a mixture of octulose %phosphate and glyceraldehyde 3-ph0sphate.~'D-Allose is utilised by wheat 38 and readily fermented by Aerobacter aero-genes.39 D-Allose and D-altrose are phosphorylated by brain hex~kinase,~~and D-allose by yeast he~okinase.~~The biosynthesis of L-galactose has been reviewed.l D-Talose is acomponent of the antibiotic, hygr~mycin,~~ and is utilised for growth byhuman cell cultures.43Early reports of the occurrence of L-glucose have not been confirmed,but it may be an intermediate in the synthesis of N-methyl-L-glucosamine.45A report that L-glucose, and other L-sugars, are absorbed from the intestine,and possibly phosphorylated, as readily as the D-isomers is at variance withmost of the published work in that field.Several ketohexoses are formed by alditol dehydrogenases 47 but few,other than D-fructose and L-sorbose, have been implicated in biologicalprocesses. L-Sorbose is not a precursor of ascorbic acid48 but labelled L-30 C. T.Bishop and F. Blank, Canad.J . Microbiol., 1958, 4, 35.31 W. N. Haworth, P. W. Kent, and M. Stacey, J., 1948, 1221.32 N. J. Palleroni and M. Doudoroff, J . Biol. Chem., 1956, 218, 535.J3 S. S. Cohen, ibid., 1953, 201, 71.34 H. R. V. Arnstein and R. Bentley, Biochem. J., 1956, 62, 403.s5 R. van Heyningen, ibid., 1958, 69, 481.86 C. Chiang, C . J. Sih, and S. G. Knight, Biochim. Biophys. Actu, 1958, 29, 664.5' E. Racker and E. Schroeder, Arch. Biochem. Biophys., 1957, 66, 241.3* A. C. Neish, Canad. J . Biochem. Physiol., 1955, 33, 658.as H. A. Altermatt, F. J. Simpson, and A. C. Neish, Canad. J . Microbiol., 1966,1,473.40 A. Sols and R. K. Crane, J . Biol. Chem., 1954, 210, 681.41 A. Sols, G. de la Fuente, C. Villar-Palasi, and C. Asensio, Biochim. Biofihys.Ada,42 P. F. Wiley and M. V. Sigal, jun., J . Amer. Chem. SOC., 1958, 80, 1010.48 H. Eagle, S. Barban, M. Levy, and H. 0. Schulze, J . Biol. Chem., 1958,233,651.44 F. B. Power and F. Tutin, Abh. Wellcome Chem. lies. Laboratories, No. 57,pp. 1-10, Sept. 1905; Chem. Zentr., 1906, 77, 11, 1623; H. Saha and K. N. Choud-hury, J.. 1922, 1044.4s G. D. Hunter, Giorn. Microbiol., 1956, 2, 312.46 K. Yamaguchi, J . Biochem. (Jafian), 1956. 43, 399.47 D. R. D. Shaw, Biochem. J., 1956, 64, 394.48 J. J. Burns, E. H. Mosbach, S. Schulenberg, and J. Reichenthal, J . Biol. Chenz.,1958, 30, 42.1955, 214, 607BAYNE: RARE SUGARS. 357sorbose is metabolised to glucose , presumably after phosphorylation byliver fructokina~e.4~ L-Sorbose is not phosphorylated by brain or yeast 41hexokinase but L-sorbose 1-phosphate , which inhibits brain hexokinase asan analogue of glucose 6-~hosphate,~ is formed by aldolase from L-glycer-aldehyde and dihydroxyacetone phosphate.The reverse reaction mayprovide a route for the utilisation of ~-sorbose.51 A metabolic pathway forL-glyceraldehyde exi~ts.5~ D-Tagatose is a product of hydrolysis of a plantgum 53 and is present in the lichen Rocella linearis.64 It is readily phosphory-lated by liver fru~tokinase.~~Heptoses.-Davies 56 has provided extensive chromatographic data foridentification of the aldoheptoses which have been found in Nature only aspolysaccharide constituents in Gram-negative bacteria. In certain strainsof E. coli and of Shigella Jlexneri and S. sonnei, L-glycero-Dmanno-heptose ispresent.67 One strain of Chzromobacterium violaceurn contains D-gbcero-D-galacto-heptose, and another strain contains a heptose which is eitherD-gbcero-D-manno-heptose or its optical enantiom~rph.~~ L-gbycero-D-manno-Heptose is utilised by many micro-organisms 59 and D-g&cero-D-galacto-heptose is oxidised slowly by Acetobacter suboxydans.60 D-glycero-D-manno-Heptose is interconvertible with sedoheptulose (D-dtro-heptulose)in the presence of the mannose isomerase of P.saccha~ophila.~~The role of sedoheptulose phosphates in the pentose phosphate pathwayis well established.' A non-oxidative mechanism for formation of sedo-heptulose 7-phosphate from glucose 6-phosphate has been described.61 Themechanism of conversion of sedoheptulose 1,7-diphosphate into shikimicacid, by a mutant of E .coli, has been investigated.62There have been few metabolic studies on other ketoheptoses. Simonand Kraicer 63 have reviewed earlier work on Dmanno-heptulose, the sugarof the avocado pear, and described its metabolism in fasted rats. Injectionof manno-heptulose causes both production and non-utilisation of glucose ;the resulting hyperglycaemia is insulin-responsive. Adrenalectomy abolishes40 Ref. 12, p. 77.H. A. Lardy, V. D. Wiebelhaus, and K. M. Mann, J . Biol. Chem., 1950, 187, 325.51 T. C. Tung, K. H. Ling, W. L. Byrne, and H. A. Lardy, Biochim. Biophys. Acta,52 Ref. 12, p. 52.53 E. L. Hirst, L. Hough, and J. K. N. Jones, Nature, 1949, 163, 177.54 B. Lindberg, Acta Chem. Scand., 1955, 9, 917.55 F.Leuthardt and E. Testa, Helv. Physiol. Acta, 1950, 8, C67.56 D. A. L. Davies, Biochem. J . , 1957, 6'4, 253.57 M. W. Slein and A. W. Schnell, Proc. SOC. Exp. Biol. N.Y., 1953, 82, 734; W.68 A. P. MacLennan and D. A. L. Davies, Biochem. J., 1957,66,562; D. A. L. Davies,59 B. W. Moore, A. C. Blackwood, and A. C. Neish, Canad. J . Microbiol., 1954, 1,6o A. Dalby and A. C. Blackwood, ibid., p. 733.61 A. Bonsignore, S. Pontremoli, G. Fornaini, and E. Grazi, BUZZ. SOC. Chim. biol.,1957, 39, Suppl. 11, 77.62 P. R. Srinavasan, D. B. Sprinson, E. B. Kalan, and B. D. Davis, J . Bz'ol. Chem.,1956, 223, 913; P. R. Srinavasan and D. B. Sprinson, Fed. Proc., 1958,17, 315.63 E. Simon and P. F. Kraicer, Arch. Biochem, Biophys., 1957, 69, 592; E.Simon,P. F. Kraicer, and C. Shelesnyack, 4th Internat. Congr. Biochem., Abs. Communications,1958, p. 103.1954, 14, 488.Weidel, 2. physiol. Chem., 1955, 299, 253.Nature, 1957, 180, 1129.198358 BIOLOGICAL CHEMISTRY.the gluconeogenesis but not the diabetogenic effect. About one-third of themanrto-heptulose is metabolised, the remainder being excreted.The action of transaldolase and transketolase on a mixture of ribose 5-phosphate and fructose 6-phosphate results in the successive formation of an%carbon ketose, presumably D-glycero-D-altro-octulose %phosphate, and ahexose phosphate which should be D-allose 6-phosphate. These reactionsare slow and their physiological significance is uncertain.37Amino-sugars.-Several reviews 64 have dealt with biochemical aspectsof the amino-sugars.Neuraminic acid.Since the last Reporta it has been confirmed thatthe primary product of mild alkaline hydrolysis of N-acetylneuraminic acidis D-InannOSamine , which rapidly epimerises to D-ghCOSamine in alkalineconditions.66 The biosynthetic pathway to neuraminic acid is not yetknown but a key to the origin of the mannosamine moiety may be theobservation that the product of the action of an extract of rat liver onuridinediphosphoglucose is N-acetylmannosamine , not N-acetylgalactos-amine. N-Acetylmannosamine was identified by X-ray diffraction, bydegradation to lyxose by ninhydrin, and by its specific participation in theenzymic synthesis of N-acetylneuraminic acid.Amino-sugars from antiobiotics.These have been described in tworeviews.6@p68 Recently, kanosamine, from kanamycin, has been identifiedas 3-amino-3-deoxy-~-g~ucose.~~ Full configurational studies of amosamine,desosamine, rhodosamine, mycaminose , and mycosamine have not beencompleted.Knowledge of the chemical nature of the bacterial cellwall 70 is advancing from work in three main fields: the effect of penicillinon cell-wall synthesis,7l the lytic action of lysozyme,72 and the invasion ofbacterial cells by bacteriophage particles.73 Penicillin causes the accumu-lation, in Gram-positive organisms particularly, of several uridine nucleotidescontaining both L- and D-amino-acids and a new amino-sugar which has beennamed muramic acid and identified as 3-0-a-ethoxycarbonyl-~-glucosamine.~~Muramic acid is present in a wide variety of bacteria 75 but has not been foundin plants or animals.Peptides containing it are liberated from one layer ofthe cell wall by certain types of phage, and lysozyme digests of cell wallscontain amino-sugar complexes of which muramic acid is a component.Muuramic acid.I34 (a) H. H. Baer, Fortschr. chem. Forsch., 1958, 3, 822; (b) K. Heyns, Stgrke, 1957,9, 85; ( c ) F . A. Hommes, Chem. Weekblad, 1958, 54, 645.I35 W. J. Whelan, Ann. Reports, 1957, 54, 319; see also I?. Zilliken and M. W. White-house, Adv. Carbohydrate Chem., 1958, 13, 237.66 R. Kuhn and R. Brossmer, Annulen, 1958, 616, 221 ; J. Brug and G. B. Paerels,Nature, 1958, 182, 1159; S. Roseman and D. G.Comb, J . Amer. Clzem. SOC., 1958, 80,3166.137 D. G. Comb and S. Koseman, Biochim. Biophys. Acta, 1958, 29, 653.66 E. E. van Tamelen, Fortschr. Chem. org. Naturstofle, 1958, 16, 90.69 M. J. Cron, D. L. Evans, F. M. Palermiti, D. F. Whitehead, I. R. Hooper, P. Chu.70 E. Work, Nature, 1957, 179, 841.71 J. T. Park and J. L. Strominger, Science, 1957, 125, 99.73 M. R. J. Salton, Bacteriol. Rev., 1957, 21, 82.78 W. Weidel, Ann. Rev. Microbiol., 1958, 12, 27.74 R. E. Strange, Biochem. J., 1956, 64, 2 3 ~ ; L. H. Kent, ibid., 1957, 67, 5 ~ .7 5 C. S. Cummins and H. Harris, J . Gcit. Microbiol., 1956, 14, 583.and R. U. Lemieux, J . Amer. Chem. SOC., 1958, 80, 4741BAYNE: RARE SUGARS. 359Strominger 76 has prepared bacterial extracts which catalyse a specificcondensation between uridinediphospho-N-acetylglucosamine and phospho-enol pyruvate.It is not established whether talosamine (2-amino-2-deoxy-~-talose) is a natural component of chondroitinsulphuric acid orwhether it is formed from galactosamine during isolation and hydr~lysis.~~An unidentified amino-sugar is a constituent of a uridine nucleotide fromCarcinus m a e n a ~ .~ ~D-Fucosamine has been isolated from the specific polysaccharide of C.violace~m.7~ Other new bacterial amino-sugars are an aminohexuronic acid ,probably 2-amino-2-deoxy-~-g~ucuronic acid, from the Vi antigen of E. coliand Salmonella typh0sa,3~ and a diamino-hexose from B. s ~ b t i l i s . ~ ~ ~ ~ 8oDeoxy-sugars.-2-Deoxy-~-arabo-hexose. 2-Deoxyglucose is of specialinterest since it is phosphorylated by yeast hexokinase and, although itdoes not occur in Nature, is a substrate for glucose oxidase (notatin),82 andis oxidised by A .suboxydans.s3 Its 6-phosphateJ unlike glucose 6-phosphate ,does not inhibit animal hexokinases, and 2-deoxyglucose can be used toisolate the hexokinase reaction. The free sugar is an inhibitor of yeastferrnentation,sl of bacterial growth,s4 of glucose utilisation by rnuscle,85 andof tumour growth; 86 these effects may be due to interference with sugaruptake,87 or phosphorylationJS8 or to selective inhibition of phosphogluco-isomerase by 2-deoxyglucose 6-~hosphate.*~ The symptoms of 2-deoxy-glucose intoxicati~n,~~ like those produced by gluco~one,~~ resemble theeffects of insulin hypoglycaemia.Rhamnose and f k o s e .L-Rhamnose (6-deoxy-~-mannose) occurs widelyin plant polysaccharides , plant glycosides , and bacterial polysaccharides.Englesbergg2 has described the formation, as a single mutational event inOther amino-sugars.76 J. L. Strominger, Biochim. Biophys. Acta, 1958, 30, 645.77 M. J. Crumpton, Nature, 1957, 180, 605; H. Muir, Biochem. J., 1967, 65, 33P;R. Heyworth and P. Walker, 4th Internat. Congr. Biochem., Abs. Communications,1958, p. 7.78 P. W. Kent and M. R. Lunt, Biochim. Biophys. Acta, 1958, 28, 657.7s M. J. Crumpton and D. A. L. Davies, Biochem. J., 1958, 70, 729.79a N. Sharon and R. W. Jeanloz, Biochim. Biophys. Acta, 1959, 31, 277.80 W. R. Clark, J. McLaughlin, and M. E. Webster, J .Biol. Chem., 1958,81 G. E. Woodward and M. T. Hudson, J . Franklin Inst., 1955, 259, 543.82 A. Sols and G. de la Fuente, Biochim. Biophys. Acta, 1957, 24, 206.84 M. Schick, B. Landau, and D. P. Tschudy, J . Bact., 1958, 75, 414.86 H. A. Ball, A. N. Wick, and C. Sanders, Cancer Res.. 1957, 17, 235; H. I. Nakadaand A. N. Wick, J . Bid. Chem., 1956, 222, 671; see also D. M. Kipnis and C. F. Cory,ibid., 1959, 234, 171.87 A. Sols, G. de la Fuente, and F. Alvarado, 4th Internat. Congr. Biochem., Abs.Communications, 1958, p. 78.E. Helmreich and H. N. Eisen, ibid., p. 70; D. M. Kipnis, Fed. Proc., 1958,17, 254.as A. N. Wick, D. R. Drury, H. I. Nakada, and J. B. Wolfe, J . Biol. Chem., 1957,224, 963.s1 S. Bayne and J. A. Fewster, Adv. Carbohydrate Chern., 1956, 11, 43.92 E.Englesberg, Arck. Biochem. Biophys., 1957, 71, 179.280, 81.(a) J. A. Fewster, Biochem. J., 1958, 69, 582; (b) T. E. King and V. H. Cheldelin,H. I. Nakada and A. N. Wick, J . Biol. Chem., 1956, 222, 671.ibid., 1958, 68, 3 1 ~ .B. R. Landau and H. A. Lubs, Proc. SOC. Exp. Bid. Med., 1958, 99, 124360 BIOLOGICAL CHEMISTRY.PasteureZZa pestis, of rhamnose isomerase, catalysing the conversion of L-rhamnose into L-rhamnulose (6-deoxy-~-fructose) , and L-rhamnulokinase.Similar enzymes are present in E. coli, and the phosphorylation product isprobably L-rhamnulose l-ph~sphate.~~ Pseudomonas aeruginosa contains anunusual rhamnolipid in which two molecules of L-rhamnose are combinedwith two molecules of 3-hydroxydecanoic acid.Hauser and Karnovsky 94have shown that the label of [6-14C]-~-fructose is incorporated almostexclusively into c(6) of the rhamnose of the rhamnolipid. Direct conversionof D-frUCtOSe into L-rhamnulose would require epimerisation at CQ), C(,), andC,) and reduction of the C(,>-hydroxyl group of the sugar. The biosyntheticpathway may, therefore, involve cleavage of the fructose carbon chain intotwo three-carbon units which, suitably modified, are recombined withoutint erconversion.L-Fucose (6-deoxy-~-galactose) is of particular interest since it occurs inblood group specific substances, and in milk oligosaccharides, as well asbeing widely distributed in micro-organisms and plants. I t enters meta-bolism in a mutant strain of E. coli by isomerisation to L-fuculose (6-deoxy-~-tagatose).~~ Aerobacter cloacae 96 and A .aerogenes 97 convert labelledD-glUCOSe into L-fucose of extracellular polysaccharide without configurationalinversion and with little randomisation of the label. The problem of bio-synthesis thus resembles that of L-rhamnose. A biosynthetic pathway fromlactaldehyde involving epimerisation at C,) of L-sorbose 1-phosphate has beensuggested.98Dideoxy-sugars. A fascinating pattern of natural occurrence of 3,6-dideoxyhexoses has been revealed.99 When the specific polysaccharides ofthe endotoxins of various SaZmoneZZae are hydrolysed there is a rapidliberation of 3,6-dideoxyhexoses.100 These occupy terminal positions onlateral chains of the polysaccharides and are important determinants ofantigenic specificity in the micro-organisms.Four distinct sugars havebeen identified.99 Abequose is 3,6-dideoxy-~-xyZo-hexose, tyvelose is 3,6-dideoxy-D-arabino-hexose, paratose is 3,6-dideoxy-~-ribo-hexose, and colitoseis 3,6-dideoxy-~-xylo-hexose. Ascarylose, from a glycolipid of the eggenvelope of a parasitic worm , Parascaris equorum, is 3,6-dideoxy-~-arabino-hexose.l01Other deoxy-sugars. The deoxy-sugars of the cardiac glycosides ,lo2 andantibioticsJ68 have been surveyed.Aldonic and Uronic Acids.-Ascorbic acid. In animals which do notrequire dietary vitamin C the biosynthetic pathway from glucose to ascorbicacid which has been demonstrated in the intact rat, but not in the guinea93 D. M. Wilson and S. Ajl, J .Bact., 1957, 73, 415.94 G. Hauser and M. L. Karnovsky, J . Biol. Chem., 1958, 233, 287.95 M. Green and S. S. Cohen, ibid., 1956, 219, 557.96 E. C. Heath and S. Roseman, ibid., 1958, 230, 511.n7 S. Segal and Y . J. Topper, Biochim. Biophys. Acta, 1957,25,419; J. F. Wilkinson,gs Po Chao Huang and 0. N. Miller, J . Biol. Chem., 1958, 230, 791.So E. Lederer, C. Fouquey, 0. Liideritz, J. Polonsky, S. Stirm, and 0. Westphal,loo R. Tinelli and A. M. Staub, ibid., p. 194.101 C. Fouquey, J. Polonsky, and E. Lederer, Bull. SOC. Chim. biol., 1968, 40, 315.l02 T. Reichstein, 4th Internat. Congr. Biochem., Symposium I, in press.Nature, 1957, 180, 995.4th Internat. Congr. Biochem., Abs. Communications, 1958, p. 197BAYNE: RARE SUGARS. 36 1pig,lo3 is identical, to the stage of L-gulonolactone, with the pathway toL-xylulose.Lehninger and his co-workers 14b have postulated that theimmediate oxidation product of L-gulonate (and L-galactonate) is 3-0x0-L-xylo-hexonate , which , with a pig-kidney enzyme system , may yield eitherascorbic acid or L-xylulose. New evidence for 2-oxo-L-xylohexonolactoneas an intermediate in the biosynthesis of ascorbic acid has been r e ~ 0 r t e d . l ~ ~ ~Although [l-14C]ascorbic acid gives 14C0, and the label of [2,3,4,5,6-14C]ascorbic acid is incorporated uniformly into liver glycogen , metabolismvia L-xylulose and the pentose phosphate pathway does not account for allthe experimental observations. L-Xylose has been isolated after additionof labelled ascorbic acid to guinea-pig liver homogenate.Labelled L-xyloseis incorporated more readily than ascorbic acid into liver glycogen in guineapigs and may, therefore, be an intermediate in the conversion of ascorbicacid into g1yc0gen.l~~ In another investigation lo5 active decarboxylationof labelled ascorbic acid was demonstrated in a rat-kidney system; theproduct is not L-xylose, L-xylulose, or L-xylosone. Incorporation of theradioactive label into C(s) as well as C(l) of the glucose residues in liver glycogenafter administration of [6-14C]ascorbic acid suggests that there is an alter-native pathway to the pentose phosphate one.lO6 The place of oxalic acid lo4in the metabolism of ascorbic acid is not known.In plants there is evidence for biosynthesis of ascorbic acid from glucosewithout configurational inversion.lo7 Loewus and his co-workers haveshown that, when [l-14C]~-glucose is administered to detached ripeningstrawberries and to germinating cress, 70% of the 14C in ascorbic acid is atThe mechanism of the C(,)-epimerisation, which occurs also in the bio-synthesis of rhamnose, fucose, and iduronic acid, is not known.In thest rawberry, s tem-feeding with [ l-14C] -D-glucuronolac tone gives [6-14C] -L-ascorbic acid but this is regarded as a pathway dependent upon the intro-duction of a specific carbon source which is not normally used by the plantfor this purpose.lo7 When [6-14C]-~-glucurono~actone is used increasedoutput of carbon dioxide can be demonstrated. This implies a pathwayfrom glucuronic acid to the pentose phosphate cycle similar to that inanimal tissues.Neish lo8 found that D-xylose incorporated, mainly into Ccl>,more 14C than did D-glucose after the administration of [1-14C]-~-glucuronate.This labelling could be explained by double inversion of configuration.These observations, and the finding that 14C from labelled ascorbic acid israpidly incorporated into the free sugar of the strawberry, suggest a rBle forascorbic acid as an intermediate in carbohydrate metabolism. ~-OXO-D-ribo-hexonic acid, believed to be an intermediate in pentose formation,log ispostulated as the precursor of L-ascorbic acid:lo3 J. J. Burns and C. Evans, J . Biol. Chem., 1956, 223, 897.103a J. Kanfer, J . J. Burns, and G. Ashwell, Biochim.Biophys. Acta, 1959, 31, 556.lo( P. C. Chan, R. R. Becker, and C. G. King, ibid., 1958, 231, 231.lo5 J. J. Burns, J. Kanfer, and P. G. Dayton, ibid., 1958, 232, 107.lo6 P. G. Dayton, F. Eisenberg, jun., and J. J. Burns, Fed. PYOC., 1958, 17, 209.lo' F. A. Loewvs, B. J. Finkle, and R. Jang, Biochim. Biophys. Ada, 1958,loB A. C. Neish, Canad. J. Biochem. Physiol., 1958, 36, 188.lo9 B. L. Horecker, in W. D. McElroy and B. Glass, '' Phosphorus Metabolism,"30, 629.Vol. I, Johns Hopkins Press, Baltimore, 1951, p. 117362 BIOLOGICAL CHEMISTRY.D-glucose D-glucose 6-phosphate 4 6-phospho-~-gluconateIt pentoseL-ascorbate + [3-oxo-6-phospho-~-~iibo-hexonate] =+ phosphateJ-D-glucuronatecyclet - D-xylulose I 1 L-gulonate --t [3-oxo-~-xyZo-hexonate] -+ L-xylulose -t[D-galacturonate] d L-galactonate D-X yloseL-Galactono-y-lactone dehydrogenase, of the " inversion " pathway,llohas been purified from pea and cauliflower mitochondria by Mapson andBreslow.lll It has no action on L-gulonolactone, but D-altronolactone,which has the same configuration at C,,) and C,, as L-galactonolactone, isslowly attacked, presumably with formation of D-erythro-ascorbic acid.Esters of galacturonic acid, but not the free acid, are reduced by pea enzymesto L-galac t onolac tone .112Uronic and aldonic acid metabolism in bacteria.The products of D-glucuronate (1) and D-galacturonate (5) metabolism in E. coli adapted tothese substances,l13 and in Erwinia carotovora,ll4 are not L-gulonate and L-galactonate but D-mannonate (3) and D-altronate (7).Immediate pre-cursors of D-mannonic acid and D-altronic acid are 5-oxo-~-lyxo-hexonicacid (D-fructuronic acid) (2) and 5-oxo-~-arabino-hexonic acid (D-tagaturonicCH,*OHcoH0C.HHOC-HH0.C.HI II I II + I + III ICHOHC*OHH0.C.HCO,Hco I H-C-OHI \ I H.F.OH I CH3H'C*oH HC.0 HH-C*OH HC-OHCO,H CO,H(1) (2) (3)CH,*OHCH,-OH CO,Hlo CH,*OHHC-OH I I III - - - + I - + II I IIHC*OHH0.C.H H0C.HHO-C-H H0.C.H HC-OHHC*OHCO,H CH,*OH H'7-oH CO,H(5) ( 6 ) (7)CiHOH.C'oH CHZO*P03H,I110 L. W. Mapson, F. A. Isherwood, and Y. T. Chen, Biochem. J., 1953, 56, 21.L. W. Mapson and E. Breslow, ibid., 1958, 68. 395.112 L. W. Mapson and F. A. Isherwood, ibid., 1956, 64, 13.118 G. Ashwell, A.J. Wahba, and J. Hickman, Biochim. Biophys. Actu, 1968, 80,114 W. W. IGlgore and M. P. Starr, ibid., p. 652.186BAYNE RARE SUGARS. 363acid) (6) formed by an aldose-ketose type of isomerisation from D-glucuronicacid and D-galacturonic acid. In E. coli both hexonic acids are convertedinto 3-deoxy-2-oxo-~-erythro-hexonic acid (4) which is cleaved to pyruvicacid and triose phosphate.l13In A . aerogenes 5-oxo-~-&xo-hexonic acid is phosphorylated to its 6-phosphate which is cleaved to dihydroxyacetone phosphate and tartronic~emia1dehyde.l~~5-0xo-~-xylo-hexonic acid (6oxogluconic acid, L-sorburonic acid), aproduct of glucose oxidation in Acetobacter spp., is readily metabolised byA . suboxydans in the presence of additional readily-oxidised ~ubstrate.8~"A reductase which converts 5-oxo-~-xylo-hexonate into D-gluconate hasbeen identified in various micro-organisms adapted to the former.l16Klebsiella spp.showed slight kinase activity for 5-oxo-~-xylo-hexonate.The bacterial metabolism of 2-oxo-~-arabo-hexonic acid (2-oxogluconicacid) has been reviewed by Wood, and Rao has surveyed oxoaldonic acidmetabolism by acetic acid bacteria.l17 The product of decarboxylation of2,5-dioxo-~-threo-hexonic acid (2,5-dioxogluconic acid) , formed from glucosevia 2-oxo-D-arabo-hexonic acid by A . melanogenum, has not been identified.ll*The intermediate, which is ultimately converted into a-oxoglutaric acid,yields a crystalline p-nitrophenylhydrazone. D-Lyxuronic acid has beenreported as a glucose metabolite in this micro-~rganism.~~~New uronic acids.The brown algae (Phaeu+hycae) contain threehexuronic acids : D-glucuronic acid, D-mannuronic acid, and L-guluronicacid.120 L-Guluronic acid residues have been identified in alginic acid.121The uronic acid component of chondroitinsulphuric acid B (@-heparin) isL-iduronic acid.122 In the polysaccharide, sulphate ester linkages are at C(*)of galactosamine residues, and L-iduronic acid is linked at C(3).123L-Guluronic acid and L-iduronic acid are C(,)-epimers of D-mannuronicand D-glucuronic acid , respectively. They are also potential isomerisationproducts of 5-oxo-~-xy~o-hexonic acid. Since the label of [6-14C]-~-g1ucoseis incorporated into the carboxyl group of L-iduronic acid of chondroitin-sulphuric acid B 124 biosynthesis presumably proceeds by CC,,-epimerisationrather than configurational inversion.The labile glucuronides formed in the metabolismof aromatic amines may be glucuronosylamines.126 Enzymatic synthesisof N-phenylglucuronosylamine by guinea-pig liver microsomes has beenGlucuronosylamines.115 R.A. McRorie and G. D. Novelli, Nature, 1958, 182, 1504.116 J. DeLey, Biochim. Biophys. A c f a , 1958, 27, 653.117 W. A. Wood, Ann. Rev. Microbiol., 1957, 11, 253; M. R. R. Rao, ibid., p. 317.llS M. Ameyama and K. Kondo, Bull. Agric. Chem. SOC., Japan, 1958, 4, 271.lZo F. G. Fischer and H. Dorfel, 2. physiol. Chem., 1955, 302, 186.121 D. W. Drummond, E. L. Hirst, and E. Percival, Chem. and Ind., 1958, 1088.laa J.A. Cifonelli, J. Ludowieg, and A. Dorfman, Fed. Proc., 1957, 16, 165; P. Hoff-les R. W. Jeanloz and P. A. Stoffyn, Fed. Proc., 1958, 17, 249.lZ4 L. Roden and A. Dorfman, J . Biol. Chem., 1958, 233, 1030.125 J. N. Smith and R. T. Williams, Biochem. J., 1949, 44, 239, 242, 250.lZ6 E. Boyland, D. Manson, and S. F. D. Orr, ibid., 1957, 65, 417; see also S. R. M.A. G. Datta, R. M. Hochster, and H. Katznelson, Canad. J . Biochem. Physiol.,1958, 36, 327.man, A. Linker, and I<. Meyer, Science, 1956, 124, 1252.Bushby and A. J. Woiwod, ibid., 1956, 63, 406364 BIOLOGICAL CHEMISTRY.reported; 127 at pH 6 and 37" it is hydrolysed readily.have visualised the formation of l-amino-derivatives of " fructuronic acid "from N-glucuronosylamines by Amadori rearrangement , a mechanism whichis implicated in the biosynthesis of tryptophan.129Duff 130 has published further observ-ations on the metabolism of glucose to 6-O-acetylglucose in Bacillusmegaterium.Acetylcoenzyme A is probably supplied from pyruvate forester synthesis. The natural ester is a mixture of the Q- and the p-anomer of6-O-acety~-~-g~ucopyanose ; it is readily metabolised by the alligator. 131Comparison of cell-wall composition of lysozyme-resistant and lysozyme-sensitive strains of Micrococcus lysodeikticus showed no major differences insugars or amino-acids. The resistant strains contain much more O-acetylmaterial.lS2 Deacetylation and reacetylation are accompanied by changesin resistance of the cell-wall material to lysozyrne.Removal of O-acetylgroups from intact cells increased their sensitivity to lysozyme. Lysozymeresistance may be due either to the absence from a bacterial cell-wall polymerof the 1 -+ 4 link between N-acetylglucosamine and N-acetylmuramicacid, or in species which possess this linkage, to the presence of one or moreO-acetyl groups in each disaccharide unit.An Alcaligenes species produces oxoglycosides from lactose,lactobionate, maltose, and maltobionate. The oxo-group is at C, of theglycosyl radical, not the ag1yc0ne.l~~ The natural occurrence and biologicalaction of D-glucosone have been reviewed.g1 The production of glucosoneby plasmolysates of AspergiZZus parasiticus 134 has been ~0nfirmed.l~~ D-Glucosone inhibits the hexose transportase of yea~t.8~ A further study of itseffect on yeast metabolism has been re~0rted.l~~ Reversal of the glucosoneinhibition of anaerobic glycolysis in ascites turnour cells by cysteine 13' is anunexpected finding.Con$guration and conformation.Specificity studies of a " substrate ornon-substrate '' type, often carried out with a limited range of structuralspecies, may provide useful information for tracing metabolic pathways, butare of limited value in assessing the stereochemical basis of substratespecificity. Configurational alteration at one particular carbon atom of asugar substrate may affect the reaction rate because (a) the potentiallyreactive group is no longer suitably situated,138 (b) there is decreased enzyme-substrate affinity through loss of a binding group,4O or (c) the new situationHeyns and BaltesMiscellaneous.-Sugar acetates.Oxo-sugars.127 J.Axelrod, J. K. Inscoe, and G. M. Tomkins, J . Biol. Chem., 1958, 232, 835.12* K. Heyns and W. Baltes, Chem. Ber., 1958, 91, 622.129 For references, see F. Lingens, M. Hildinger, and H. Hellmann, Biochim. Biophys.130 R. B. Duff and D. M . Webley, Biochem. J., 1958,70,520.131 R. E. Reeves, R. A. Coulson, T. Hernandez, and F. A. Blouin, J . Amer. Chem.132 W. Brumfitt, A. C. Wardlaw, and J. T. Park, Nature, 1958,181, 1783; W. Brum-133 M. J. Bernaerts and J. DeLey, Biochim. Biophys. Acta, 1958, 30, 661.134 C. R. Bond, E. C. Knight, and T. K . Walker, Biochem. J., 1937, 31, 1033.135 S. Bayne, unpublished results.138 M.T. Hudson and G. E. Woodward, Biochim. Biophys. Acta, 1968, 28, 127.137 W. D. Yushok and W. G. Batt, Abs. 131st Meeting Amer. Chem. SOC., 1967,13* R. Bentley, Nature, 1965, 176, 870.Acta, 1958, 30, 668.Soc., 1957, 79, 6041.fitt, J. Path. Bact., 1958, 75, 517.p. 12DDAWSON : ADVANCES I N PHOSPHOGLYCERIDE CHEMISTRY. 366of the substituents on the carbon atom causes steric interference with bindingor reaction.40 Rate determinations alone are insufficient. It is necessaryto measure affinity, and studies with selected deoxy-sugars have beeninvaluable in the investigation of the bonding of hydroxyl groups of sugarsto enzymes and transporting systems. It has been concluded that thehydroxyl group at C,,, is unimportant for substrate combination with brainhexokina~e.~~ In the intestinal absorption of monosaccharides, however, ahydroxyl group in the D-glycero-configuration at C(z> is necessary for activetransport .139Although Bourne and Stephens 140 predicted the application of con-formational analysis to enzymic transformations of carbohydrates, only afew studies of this kind have been reported.l3*J41 LeFevre and Marshall 142have provided an interesting analysis of instability factors for the pyranose-ring conformations of a number of monosaccharides and their carrier-complex dissociation constants in the human red-cell transportase system.The system shows an uncomplicated requirement for the C1 conformation.This may be a general requirement for entry of pyranoses into biologicalsystems since those sugars which, in the pyranose form, assume the 1Cconformation are usually metabolised by either isomerisation to a ketose orreduction to an alditol , both processes involving the open-chain modificationof the sugar.lGS. B.4.RECENT ADVANCES IN PHOSPHOGLYCERIDE CHEMISTRYTHE outstanding progress in phosphoglyceride chemistry during recentyears is mainly due to the development of physicochemical methods offractionation. This has led not only to the isolation of a number of newnaturally-occurring phospholipids, but it has also stimulated structuralstudies and interest in their metabolism.General Techniques for the Isolation of Phospholipids.-The phospholipidsthat exist in living tissues are probably bound in the form of lipoproteins.When they are extracted from the tissue, it is necessary to use a polarsolvent such as methanol to disrupt these complexes and extract the lipidsin the form in which they are isolated.The solvent, in extracting lipidsubstances, also carries with it a good deal of material which is usuallyregarded as water-soluble, e.g. , free amino-acids. This is only partiallyremoved by subsequent solvent fractionation of the extracted phospho-lipids, and two techniques have been developed to effect its removal. Oneconsists of allowing the lipids in chloroform-methanol to equilibrate withan aqueous phase under carefully specified conditionsJ1S2 and the other of139 T. H. Wilson and R. K. Crane, Biochim. Biophys. Actu, 1958, 29, 30.140 E. J. Bourne and R.Stephens, Ann. Rev. Biochem., 1956, 24, 79.141 T. Posternak and D. Reymond, Helv. Chirn. Acta, 1955, 38, 195; S. A. Barker,E. J. Bourne, E. Salt, and M. Stacey, J., 1959, 563.142 P. G. LeFevre and J. K. Marshall, Amer. J . Physiol., 1958, 194, 333.143 Y. J. Topper, J . Biol. Chem., 1957, 225, 419; P. D. Bragg and L. Hough, J..J. Folch, I. Ascoli, M. Lees, J. A. Meath, and F. N. Le Baron, J . Bid. Chem.,J. Folch, M. Lees, and G. H. Sloane-Stanley, ibid., 1967, 226, 497.1957, 4347.1951.191, 833366 BIOLOGICAL CHEMISTRY.passing their solution in an organic solvent down a cellulose column whichremoves the water-soluble impurities. Once the lipids have been preparedfree from these impurities, the phospholipids can be separated from neutrallipids by precipitation with acetone, or by the use of a silicic acid column.4Another recently introduced technique is to dialyse a solution of the lipidsin organic solvent through a rubber membrane which allows neutrallipids to escape and retains phospholipids. To describe recent methodsthat have been developed for the fractionation of phospholipid mixturesinto their individual components is beyond the scope of this Report.How-ever, it is possible to generalize and to indicate trends in these separations.On the whole, counter-current distribution and the use of ion-exchangeresins have been disappointing, while electrophoresis has had only limitedalthough promising application.6 The most notable advances have comeabout through refinements of solvent fractionation and the use of silicicacid and alumina column chromatography.By using the differentsolubilities of brain Kephalins in chloroform-ethanol, Folch 7 3 8 was able toseparate phospholipid fractions from brain containing serine, ethanolamine,or inositol, and with very little cross contamination between the fractions.This clearly meant that the kephalin fraction was more complicated thanhad been hitherto suspected, and led to the recognition by Folch of thepresence of considerable quantities of phosphatidylserine and diphospho-inositide as well as classical kephalin or phosphatidylethanolamine.The introduction of alumina column chromatography in lipid fractionationoccurred early,g but it was not until comparatively recently that the adsorb-ent was successfully used for resolving phospholipids almost quantitativelyinto fractions containing choline and fractions not containing choline.10An even more useful adsorbent for phospholipid chromatography is silicicacid which was introduced into lipid chemistry by Trappe.ll AlthoughMcKibbin and Taylor l2 obtained a partial separation of the ethanol-insoluble liver phospholipids on silicic acid, it was not until the work of Lea,Rhodes, and Stoll13 on egg phospholipids that the great possibilities ofsilicic acid chromatography became apparent. By using this adsorbentwith varying amounts of methanol in chloroform as eluting solvent, goodfractionations have been obtained of the liver phospholipids,14 and heart-muscle phosph01ipids.l~It must be noted that while biochemists often regard such isolatedphospholipids as pure, from the chemical standpoint the products areC .H. Lea and D. N. Rhodes, Biochem. J., 1953, 54, 467.4 B. Borgstrom, Acta physiol. Skand., 1952, 25, 101; E. J. Barron and D. J. Hana-G. J. van Beers, H. de Iongh, and J. Boldingh, " Essential Fatty Acids," Ed. byH. Zipper and M. D. Glantz, J . Biol. Chem., 1958, 230, 621.J. Folch, ibid., 1942, 146, 35.S. J. Thannhauser and P. Setz, ibid., 1936, 116, 527.han, J . Biol. Chem., 1958, 231, 493.H. M. Sinclair, Butterworths Scientific Publications, 1958, p. 43.* Idem, ibid., 1949, 177, 497.lo D. J. Hanahan, M. B. Turner, and M. E. Jayko, ibid., 1951, 192, 623.l1 W. Trappe, Biochem. Z . , 1940, 306, 316.l2 J.M. McKibbin and W. E. Taylor, J . Biol. Chem., 1952, 196, 427.l3 C. H. Lea, D. N. Rhodes, and R. D. Stoll, Biochem. J., 1955, 60, 353.l4 D. J. Hanahan, J. C. Dittmer, and E. Warashina, J . Biol. Chem.. 1957, 228, 685,l5 G. M. Gray and M. G. Macfarlane, Biochem. J., 1958, 70, 409DAWSON : ADVANCES IN PHOSPIIOG1,YCERIDE CHEMISTRY. 367extremely heterogeneous. Thus, on hydrolysis, they generally yield acomplex mixture of fatty acids indicating that a variety of chemical entitiesexist in the preparation. Furthermore, they are often contaminated withthe analogous plasmalogen, although this can be avoided to some extent bystarting with material low in aldehydogenic lipid, e.g., egg-yolk or liver. Inspite of such deficiencies these new methods of isolation of " individual "phosphoglycerides (pure with respect to their base or inositol composition)have led to striking advances in structural and enzyme chemistry which willnow be discussed.Lecithin (Phosphatidylcholine) .-The older method of preparation oflecithin by precipitation as the double salt with cadmium chloride16 hasbeen largely superseded by column chromatography on alumina and silicicacid.l09l3J7 Lecithins from natural sources have the L-configuration anda-structure, the p-glycerophosphoric acid present in acid hydrolysates arisingfrom the migration of the phosphoryl group from the a-carbon atom.lsaoThus Baer and his collaborators 21 synthesized L-a-dipalmitoylglycerylphos-phorylcholine and showed it to be identical in its physical properties withnaturally-occurring dipalmitoyl-lecithin. Long and Maguire 22 measuredenzymically the amount of L-a-glycerophosphate in alkaline hydrolysatesof soy-bean lecithin and found that the amount present could only havebeen given by L-a-lecithin.In an extension of these studies 23 naturallecithin was hydrolysed enzymically to produce the diglyceride, which washydrogenated and phosphorylated to yield the corresponding phosphatidicacid. On alkaline hydrolysis only L-a-glycerophosphate was obtained,again confirming the L-configuration and a-structure for the parent lecithin.On very mild hydrolysis of lecithin with aqueous methanolic sodiumhydroxide, the fatty acids are removed and L-a-glycerylphosphorylcholinecan be recovered from the hydroly~ate.~~ The same compound can beobtained after a more prolonged catalytic hydrolysis with mercuric chloridein aqueous ethanol25 or by synthesis.26 The diester can be reconvertedinto L-a-lecithin in reasonable yield by acylation with palmitoyl chloride indry chl~roform.~~ On prolonged alkaline hydrolysis of natural lecithin amixture of a- and p-glycerophosphoric acid is formed and it has beensuggested that the subsequent hydrolysis of the initially produced L-ct-glycerylphosphorylcholine proceeds via a cyclic triester 2o or diester.28Cyclic 1,2-glycerophosphate has recently been synthesized 28 but no paper-l6 M.C. Pangborn, J . Biol. Chem., 1951, 188, 471.l7 D. N. Rhodes and C . H. Lea, Biochem. J., 1957, 65, 526.l8 J. Folch, J .B i d . Chem., 1942, 146, 31.l9 E. Baer and M. Kates, ibid., 1948, 175, 79.2o Idem, ibid., 1950, 185, 615.21 Idem, J . Amer. Chem. SOC., 1950, 72, 942; E. Baer and J. Maurukas, ibid., 1952,22 C. Long and M. F. Maguire, Biochem. J., 1953, 54, 612.23 Idem, ibid., 1954, 57, 223.24 R. M. C. Dawson, Biochim. Biofihys. Acta, 1954, 14, 374; Biochem. J., 1956,26 N. H. Tattrie and C. S. McArthur, Canad. J . Biochem. Physiol., 1955, 33, 761.26 E. Baer and M. Kates, J . Amer. Chem. SOC., 1948, 70, 1394.27 N. H. Tattrie and C. S. McArthur, Canad. J . Biochem. Physiol., 1957, 35, 1165.28 T. Ukita, N. A. Bates, and E. Carter, J . Bid. Chem., 1955,216, 867; D. M. Brown,74, 158.62, 689.G, E. Hall, and H. M. Higson, J., 1958, 1360368 BIOLOGICAL CHEMISTRY.chromatographic evidence could be obtained for the presence of a similarcompound in alkaline hydrolysates of lecithin.% However, this could wellbe due to the instability of the cyclic ester in alkaline solution 28 so that it ismerely a transient intermediate.Natural lecithins show appreciable variation in their fatty acid composi-tion; generally, on hydrolysis, a mixture of saturated and unsaturatedfatty acids is obtained.However, a fully saturated lecithin (dipalmitoyl)has been isolated from the larval form of the cat tapeworm 29 as well as frommammalian lung, spleen, and brain,3O and one with two unsaturated acids(L-a-dipalmitoleoyl) from yeast .31 Baer, Buchnea, and Newcombe 32 haverecently published an elegant synthesis of a doubly unsaturated lecithin(L-a-dioleoyl) starting with D-isopropylideneglycerol.Lyso1ecithin.-A valuable new technique has been introduced for theenzymic preparation of lysolecithin by Hanahan,=~~* who found that snakevenom would hydrolyse lecithin very rapidly in wet ether; the lysolecithinformed, being insoluble in ether, is precipitated and is thus readily separ-able from any residual lecithin.On oxidation of enzymically-preparedlysolecithin with permanganate to a carboxylic acid followed by acidhydrolysis , phosphoglyceric acid is the sole phosphorus compound obtained,indicating that the venom enzyme has attacked the a-position excl~sively.~~This conclusion was reached independently by Long and Penny,36 whoshowed that, after catalytic hydrogenation of the lysolecithin, one moleculereacted with four equivalents of potassium dichromate, indicating thepresence of a primary alcohol group.With these results, it has been possibleto show that in the naturally-occurring lecithins the unsaturated fatty acidsare esterified in the a-position and saturated in the p-position of theglycerol.37 However, recent results would suggest that this partition isnot as selective as originally belie~ed.~8In the presence of acid or an enzyme extract from Penicillium notatum,the acyl group on the p-position of lysolecithin can migrate to the a-po~ition.3~ The resulting a-acyl-lecithin differs considerably from thep-isomer in its physical properties and susceptibility to enzymic attack.A number of reports have suggested that free lysolecithin occurs intissue in ~ i ~ 0 .4 0 However, these will need confirmation, for there is apossibility that the compound may be formed during the process of isolation.Thus lysophosphatidylethanolamine can be readily formed from ethanol-29 A. Lesuk and R. J. Anderson, J. Biol. Chem., 1941, 139, 457.30 S. J. Thannhauser, J. Benotti, and N. F. Boncoddo, ibid., 1946, 166, 669; S. J.31 D. J. Hanahan and M. E. Jayko, J . Amer. Chem. Soc., 1952, 74, 5070.32 E. Baer, D. Buchnea, and A. G. Newcombe, ibid., 1956, 78, 232.33 D. J. Hanahan, J. Biol. Chem., 1952, 195, 199.34 D. J. Hanahan, M. Rodbell, and L. D. Turner, ibid., 1954, 206, 431.35 D. J. Hanahan, ibid., 1954, 207, 879.36 C. Long and I. F. Penny, Biochem.J., 1954, 58, xv.s7 D. J. Hanahan, J. B i d . Chem., 1954, 211, 313.38 D. N. Rhodes and C. H. Lea, Nature, 1956, 117, 1129; Y. Inouye and M. Noda,39 M. Uziel and D. J. Hanahan, J. Biol. Chem., 1957, 226, 789.40 E.g., L. Douste-Blazy, Compt. rend., 1954, 239, 460; G. B. Phillips, Proc. Nut.Acad. Sci. N.Y., 1957, 43, 566; R. F. Witter, G. V. Marinetti, L. Heichlin, and M.Coltone, Analyt. Chem., 1958, 30, 1624.Thannhauser and N. F. Boncoddo, ibid., 1948, 172, 135.Arch. Biochem. Biophys., 1958, 76, 271DAWSON : ADVANCES I N PHOSPHOGLYCEHIDE CHEMISTRY. 309amine plasmalogen on a silicic acid column,15 and lysolecithin from lecithinin the presence of water at room ternperat~re.~~ In this respect, evidencehas been obtained that the cardiac-active monopalmitoylglycerylphos-phorylcholine isolated from liver and adrenal medulla is largely derivedfrom an inactive precursor, choline-plasmalogen, which occurs in thesetissues.42A series of saturated lysolecithins have been synthesized starting fromthe l-benzyl ether of glycerol,43 but the position of the phosphorylcholinegroup in these compounds is doubtful because of the possibility of migrationto the vacant hydroxyl group on the glycerol.Phosphatidyle thanolamine (Kephalin) .-Although diacylglycerylphos-phorylethanolamine (kephalin) had been recognized in biological samplesfor many years, it was not until the classic work of Folch 7 that a relativelypure preparation was obtained from brain phospholipids.Even this islikely to have been contaminated with ethanolamine plasmalogen.44Fortunately, egg- yolk phosphat idylet hanolamine can be readily fractionatedon a silicic acid column l3 and this contains no appreciable plasmalogen.Other preparations of naturally-occurring phosphatidylethanolamine havebeen made from liver phospholipids and soy-bean phospholipid^.^^ Fullysaturated L- and DL-a-phosphatidylethanolamines have been synthesized, 4 6 ~ *and on acid and alkaline hydrolysis eventually yield a mixture of a- andp-glycerophosphoric acids4’ Thus, as with lecithin, the finding of 13-glycero-phosphoric acid in hydrolysates of kephalin can no longer be regarded asevidence for the existence of P-kephalin.The mild alkaline hydrolysis ofphosphatidylethanolamine yields initially glycerylphosphorylethanolamine z4which presumably, by analogy with lecithin hydrolysis, is the L-a-isomer.L-a-Glycerylphosphorylethanolamine has been synthesized and on vigorousalkaline or acid hydrolysis yields a mixture of x- and p-glycerophosphoricacids 47 presumably by phosphoryl migration after the formation of a cyclicintermediate.It is interesting that on acid hydrolysis of liver and yeastphosphatidylethanolamine significant quantities of phosphorylethanolaminecan apparently bePhosphatidy1serine.-Although MacArthur as early as 1914 50 had sus-pected that part of the kephalin N of brain phospholipid was in the a-amino-carboxylic acid form, it was not until 1941 that Folch 5137 isolatedfrom the fraction a serine-containing phospholipid which he named phos-phatidylserine.By analysis of the cleavage products obtained on acid41 G. I;. Lambert, J. P. Miller, and D. V. Frost, Amer. J . Physiol., 1956, 186, 397.42 E. Titus, H. Weiss, and S. Hajdu, Science, 1956, 124, 1205.43 R. L. Baylis, T. H. Bevan, and T. Malkin, “ Report a t Conference on BiochemicalProblems of the Lipids,” Ghent, Butterworths, London, 1956.44 E. Klenk and P. Bohm, 2. $hysioZ. Chem., 1951,288, 98.45 Idem, ibid., 1955, 299, 248; C. R. Scholfield and H. J. Dutton, J . B i d . Chem..1955, 214, 633.46 E. Baer, J. Maurukas, and M. Russell, J . Amer. Chem. SOC., 1952, 74, 152; P. E.Verkade and L. J. Stegerhoek, Proc. Acad. Sci. Amsterdam, B, 1958,61, 155.47 E. Baer, H. C. Stancer, and I. A. Korman, J . Biol. Chem., 1953, 200, 251.48 E.Baer and H. C. Stancer, J . Amer. Chem. Soc., 1953, 75, 4510.49 J. C. Dittmer, J. L. Feminella, and D. J. Hanahan, J . Biol. Chem., 1958,233, 862.50 C. G. MacArthur, J . Amer. Chem. Soc., 1914, 38, 2397.51 J. Folch, J , Biol. Chem., 1941, 139, 973370 BIOLOGICAL CHEMISTRY.hydrolysis and studying its oxidation with periodic acid and reaction withnitrous acid and ninhydrin, the structure was designated as that of astearoyloleoylglycerylphosphorylserine.5z Baer and Maurukas synthesizedL-a-distearoylphosphatidyl-L-serine and found that it was identical with thereduction product of the phosphatidylserine isolated from ox brain.53 TheL-configuration and a-structure were confirmed by treating the hydrogenatedproduct with diazomethane which by an interesting reaction (diazometho-lysis) cleaves the compound at the ester bond between the nitrogenous andphosphatidic acid port ions .53 The result ant dex t roro t at ory phospha t idicacid dimethyl ester could have arisen only from L-a-phosphatidylserine.Brown and Osborne have suggested a mechanism for the diazometholysisin which, after methylation to yield a phosphotriester, the serine is lost asan imine or possibly by P-elimination.A new synthesis of DL-a-phosphatidylserine has recently been introducedconsisting of the interaction of glycerol l-iodide 2 : 3-distearate and N-benzyl-oxycarbonyl-DL-serine benzyl ester 3-(silver phenyl phosphate) followed bycatalytic h y drogenol ysis .55P hosphatidy linosi t ol (Monophosp hoinositide) .-Faure and Morelec-Coulon 58 obtained from wheat germ a crystalline phospholipid which theyfound on hydrolysis contained fatty acid, glycerol, inositol, and phosphatein the molar proportions 2 : 1 : 1 : 1 with only one of the acid groups of thephosphoric acid being free. The subsequent isolation by various methodsof a similar monophosphoinositide from heart m ~ s c l e , ~ ~ J ~ l i ~ e r , ~ , ~ ~ yeast,5gpeas,m and soy-bean61 indicates that it is of wide occurrence in Nature.Faure and Morelec-Coulon 56 suggested that the phospholipid was a diacyl-glycerylphosphorylinositol and this is supported by the products of acidhydrolysis which yields inositol monophosphate and glycerophosphoric acidin the proportions of about 3 : l,62*58960s59 as well as free glycerol, inositol,and inorganic phosphate.From mild-alkaline hydrolysates of crude livermonophosphoinositide, Hawthorne and Hubscher 63 have recently separatedoptically active glycerylphosphorylinositol. On further hydrolysis withalkali the diester gave a mixture of inositol monophosphate and glycero-phosphoric acid. Glycerylphosphorylinositol has also been demonstratedas a product of the enzymic attack of monophosphoinositide with P. notatamextracts.@sm Hanahan and Olley 59 showed that diglyceride was a productof the brief acid hydrolysis of liver and yeast monophosphoinositide which62 J. Folch, J. Biol. Chem., 1948, 174, 439.53 E. Baer and J. Maurukas, ibid., 1955, 212, 25, 39.54 D. M. Brown and G. 0. Osborne, J., 1957, 2590.55 T.H. Bevan, T. Malkin, and J. M. Tiplady, J., 1957, 3086.56 M. Faure and M. J. Morelec-Coulon, Compt. rend., 1953, 236, 1104; M. J. Morelec-Coulon and M. Faure, Bull. SOC. Chim. biol., 1957, 39, 947; 1958, 40, 1071.57 M. Faure and M. J. Morelec-Coulon, Compt. vend., 1954, 238, 411; Bull. Soc.Chim. biol., 1958, 40, 1067.58 J. M. McKibbin, J . Biol. Chern., 1956, 220, 537; R. M. C. Dawson, Biochem. J.,1958, 68, 352.58 D. J. Hanahan and J, N. Olley, J . Biol. Chem., 1958, 231, 813.60 A. C. Wagenknecht and H. E. Carter, Fed. Pvoc., 1957, 16, 266.61 E. Okuhara and T. Nakayama, J . Biol. Chem., 1955, 215, 295.g* J, N. Hawthorne, Biochem. J., 1955, 59, ii.63 J. N. Hawthorne and G. Hubscher, ibid.. 1959, 71, 195.64 R. M. C .Dawson, Biochim. Biofhys. Acta, 1958, 27, 228DAWSON ADVANCES IN PHOSPHOGLYCERIDE CHEMISTRY. 37 1indicates that the two fatty acids are esterified to the glycerol and this isalso suggested by the isolation of pentamethylinositol from the hydrolysisof fully methylated soy-bean monophosphoinositide.61All hydrolysis studies on monophosphoinositide must be interpretedin the light of recent studies by Brown and his c ~ l l a b o r a t o r s , ~ ~ ~ ~ ~ whichemphasize the ease of phosphoryl migration during the hydrolysis ofanalogous compounds (e.g., esters of cis- and trans-cyclohexenediol hydrogenphosphate with glycerol and other alcohols). Phosphoryl migration duringthe acid and alkaline hydrolysis of monophosphoinositide is suggested bythe complexity of the hydrolysis products obtained compared with theequivalent hydrolysis of phosphatidyl-choline and -ethanolamine.Further-more, because of the likelihood of phosphoryl migration, it is doubtful if theposition of attachment of the phosphate to the inositol can be determinedby merely identifying the inositol monophosphate isomers produced on thechemical hydrolysis of monophosphoinositide. One possible way of doingthis would be to hydrolyse away the inositol monophosphate en~ymically,~~, 68but here again an enzymically catalysed phosphoryl migration must be apo~sibility.~~ It has been shown that synthetic vzyoinositol 2-phosphate isidentical with the inositol monophosphate prepared enzymically from phyticacid,69 and recent studies suggest that this also applies when the monoesteris isolated after chemical hydrolysis of phytic acid.70Diphosphoin0sitide.-By solvent fractionation, Folch 8s 71 prepared aphospholipid from ox brain whose basic composition corresponded to twomolecules of phosphoric acid and one each of glycerol, inositol, andfatty acid.On acid hydrolysis the main phosphorus product was identifiedas an inositol diphosphate ; titration and periodate oxidation indicatedthat this was the meta-isomer. Sloane-Stanley 72 and Hawthorne 73 haveboth suggested on the basis of such results that the compound has a cyclicstructure, the glycerol being linked in the 1 and 3 positions to the phosphateson the inositol ring. However, as with monophosphoinositide, the strongpossibility that phosphoryl migration occurs during acid hydrolysis mustbe borne in mind.e5y66Phosphatidic' Acid.-Phosphatidic acid (diacylglycerophosphoric acid) isof biological interest not only because it is a metabolic product resultingfrom the hydrolysis of lecithin by phospholipase D,74*75 but also becauseit is very probably implicated in the biosynthesis of phospholipids andtrigly~erides.~~.'~ It is not present in animal tissues in vivo in appreciable65 D.M. Brown and H. M. Higson, J., 1957, 2034.66 D. M. Brown, G. E. Hall, and H. M. Higson, J., 1958, 1360.67 J. N. Hawthorne and P. Kemp, reported during a communication to the LipidSection of IVth Internat. Congr. Biochem., Vienna, 1958.68 R. M. C . Dawson, Biochim. Biophys. Acta, 1959, in the press.69 P.Fleury, A. Desjobert, and J. Lecocq, BUZZ. Soc. Chim. biol., 1954, 36, 1301.70 D. M. Brown and G. E. Hall, J., 1959, 357.71 J. Folch, J . Bid. Chem., 1949, 177, 505.72 G. H. Sloane-Stanley, Symp. Biochem. Soc., 1952, No. 8, 44.73 J. N. Hawthorne, Biochim. Biophys. Acta, 1955, 18, 389.7* D. J. Hanahan and I. L. Chaikoff, J . B i d . Chem., 1948, 172, 191.75 M. Kates, Canad. J . Biochem. Physiol., 1955, 33, 575.76 S. W. Smith, S. B. Weiss, and E. P. Kennedy, J . Biol. Chem., 1957, 228, 915.77 R, M. C, Dawson, Biol. Rev., 1957, 32, 188372 BIOLOGICAL CHEMISTRY.concentrations 78,79 although its presence can be revealed 8o by heavilylabelling the intact animal with phosphorus-32. L-a-Phosphatidic acid canbe prepared en~yrnically,~~ and syntheses have been reported of the fullysaturated, distearoyl, dipalmitoyl, and dimyristoyl L-oc-phosphatidic acidsand the corresponding racemic compounds.82, 8334 Olley 85 found thatdistearoyl phosphatidic acid hydrolysed rapidly at the acyl ester bonds inaqueous ethanol at room temperature (see also ref.82) although in contrast tothis it has recently been reported to be fairly stable in dilute aqueous acid.80On alkaline hydrolysis of phosphatidic acid, phosphoryl migration does notoccur so that synthetic diacyl-a-glycerophosphoric acids and phosphatidicacid isolated enzymically give only a-glycerophosphoric a ~ i d . ~ ~ , ~ ~ , Onacid hydrolysis phosphoryl migration occurs, giving a mixture of the ct- andthe p-isomer of glycerophosphoric acid.20Polyglycerophospholipids including Cardiolipin and Phosphatidylglycerol.-Pangborn 8 8 s 89 isolated a complex nitrogen-free phospholipid from beefheart (cardiolipin) which appeared to be a mixed fatty acid ester ofa polyglycerophosphoric acid.Subsequently, similar compounds wereisolated from l i ~ e r , ~ ~ , ~ ~ and fish muscle.92 Two recent preparations ofcardiolipin have been reported, one involving fractional precipitation ofthe barium and the other chromatography on silicic acid.15 Cardio-lipin appears to be a somewhat unusual naturally occurring phosphoglyceridein that the mixed fatty acids it contains are nearly all unsaturated.15Recent results suggest that the basic structure of cardiolipin contains threeglycerol, two phosphoric acid, and four fatty acid residues.15 The kineticsof hydrolysis are complex, and phosphoryl migration is likely to occur.Mild alkaline hydrolysis yields initially a polyglycerophosphate, butacid hydrolysis also splits the diester bonds, giving phosphomonoesters.Macfarlane and Gray l5 have suggested the structurefor cardiolipin and Macfarlane 94 obtained evidence for this by periodateoxidative degradation of the polyglycerophosphoric acid prepared fromcardiolipin by mild alkaline hydrolysis.Baer 95 has synthesized both L-78 R. M. C. Dawson, ‘I Biochemistry of the developing nervous system,” AcademicPress, N.Y., 1955, p. 268.79 G. V. Marinetti, R. F. Witter, and E. Stotz, J . Biol. Chem., 1957, 226, 475.80 L. E. Hokin and M. R. Hokin, ibid., 1958, 233, 800.82 J.H. Uhlenbroek and P. E. Verkade, Rec. Trav. chim., 1953, 72, 395.8s L. W. Hessel, I. D. Morton, A. R. Todd, and P. E. Verkade, ibid., 1954, 73,84 S. Mostert, L. J. Stegerhoek, and P. E. Verkade, ibid., 1958, 77, 133.85 J. Olley, Chem. and Ind., 1954, 1069.86 J. J. Rae, Biochem. J., 1934, 28, 152.87 J. H. Uhlenbroek and P. E. Verkade, Rec. Trav. chim., 1963,72, 558.88 M. C. Pangborn, J . Biol. Chem., 1942, 143, 247.89 Idem, ibid., 1947, 168, 351.90 J. M. McKibbin and W. E. Taylor, ibid., 1952, 196, 427.81 R. M. C . Dawson, Biochem. J., 1958, 68, 352.92 M. D. Garcia, J. A. Lovern, and J. Olley, ibid., 1956, 62, 99; J. Olley, ibid., p. 107.93 M. Faure and M. J. Morelec-Coulon, Ann. Inst. Pastew, 1956, 91, 537.Q4 M. G.Macfarlane, Nature, 1958, 182, 946.95 E. Baer, J . Biol. Chem., 1952, 198, 853.RlO-CH ,.CH (OR2)*CH ,-O*PO(O H).O-C H,CH (0 H).C H ,*O*PO (OH)*O.C H ,*CH (0 RS)*CH ,*O R4E. Baer, ibid., 1951, 189, 235.150DAWSON ADVANCES IN PHOSPHOGLYCERIDE CHEMISTRY. 373and D-isomers of fully saturated tetra-acylbis-(a-glycery1)phosphofic acidswhose basic composition corresponds to the polyglycerophosphoEpidsisolated from fish muscle 92 (4 fatty acids : 2 glycerol : 1 phosphorusatom).Recently, Benson and Maruo 96 have isolated from the phospholipids ofScenedesmus and higher plants a polyglycerophospholipid which appearsto be diacylglycerylphosphorylglycerol (phosphatidylglycerol). On mildalkaline hydrolysis only diglycerolphosphoric acid was produced, and thepresence of two free hydroxyl groups was shown by conversion into theisopropylidene derivative and by oxidation with lead tetra-acetate.Di-L-a-glycerolphosphoric acid has recently been synthesized 97 and it wouldbe interesting to see whether this is identical with the product isolatedfrom the plant phosphatidylglycerol. Baer and Buchnea 98 have recentlydescribed a procedure for the synthesis of a-phosphatidyl-a-glycerols whichpermits the preparation of all four stereoisomers.Plasmalogens (Acetal Phospholipids) .-It has been recognized thatanimal tissues possess plasmalogens other than those containing ethanol-amine. Klenk and Bohm found a serine plasmalogen in brain and Klenkand Gehrmanng9 and later Rapport and AlonzolOO showed that cholineplasmalogen accounted for a major portion of the isolated lecithin fractionof beef heart, a conclusion which apparently also applies to the lecithinfraction of ram spematozoaJ0l There is also probably an inositol plasmalogenin brain.lo2 In 1953, two groups103 recognised that the plasmalogens inthe crude lipid extracts of tissues were much more stable to acid than theplasmalogens subsequently isolated by methods depending on their stabilityto alkaline hydrolysis. This suggested that hydrolysis of the naturalplasmalogens had occurred during the isolation, and Klenk and Debuch lo*provided sound evidence that the natural ethanolamine plasmalogen ofbrain contained a fatty acid as well as a long chain aldehyde.That this wasalso true for the choline plasmalogen of beef heart was shown when Klenkand Debuch lo5 hydrolysed it at 37" with acetic acid and isolated lysolecithin.Rapport and Alonzo 99 independently reached the same conclusion onestimating the aldehyde content of beef-heart lecithin by a new photometricmethod.When the ethanolamine plasmalogen of brain (isolated after mildalkaline hydrolysis of the phospholipids) is catalytically hydrolysed withmercuric chloride , only the a-isomer of glycerylphosphorylethanolamine isobtained,lo6 which indicates that this plasmalogen possesses the a-structurelike all other naturally-occurring phosphoglycerides so far studied. Rapport96 A. A. Benson and B. Maruo, Biochim. Biophys. Ada, 1958, 27, 189.97 E. Baer and D. Buchnea, Canad.J . Biochem. Physiol., 1958, 36, 243.98 Idem, J . Biol. Chem., 1958, 232, 895.99 E. Klenk and G. Gehrmann, 2. physiol. Chem., 1953, 292, 110.loo M. M. Rapport and N. Alonzo, J. Biol. Chem., 1955, 217, 199.lol J. A. Lovern, J. Olley, E. F. Hartree, and T. Mann, Biochem. J., 1957, 67, 630.lo2 K. Ohno, Sapporo Med. J., 1952,3, 128 (Chem. Abstracts, 1956,50, 9481).lo3 G. B. Ansell and J. M. Norman, Biochem. J., 1953, 55, 768; G. Schmidt, B.lo* E. Klenk and H. Debuch, 2. $hysioZ. Chem., 1954, 298, 179.lo5 Idem, ibid., 1955, 299, 66.lo6 S. J. Thannhauser, N. F. Boncoddo, and G. Schmidt, J . Biol. Chem., 1951,188,Ottenstein, and M. J. Bessman, Fed. Proc., 1953, 12, 265.423374 BIOLOGICAL CHEMISTRY.and Franzl lo7 found that snake-venom phospholipase A removed fattyacids from the plasmalogen-rich lecithin fractions of beef heart as rapidlyas from pure ovolecithin, which suggests by analogy that the fatty acid ison the or-po~ition.~~*~~ Chemical proof of this has recently been obtainedby Gray,los who isolated lysolecithin from mild acid hydrolysates of cholineplasmalogen and showed that this was the or-monoacyl isomer by oxidationwith permanganate and identification of the products of acid hydrolysis.Similar proof was also obtained for the ethanolamine plasmalogen.lOs Incontrast to these results, Marinetti and Erbland log have obtained chemicalevidence that in pig-heart choline plasmalogen the aldehyde group is linkedto C, of glycerol, which raises the question of species differences or possibly0: (3 migration during the procedures used to determine the position ofattachment.have recently obtained evidencethat the aldehyde group in crystalline lysoplasmalogen and natural plasma-logens is not attached by an acetal or hemiacetal linkage, but through anunsaturated ether linkage.Thus, on bromination, iodination, or hydro-genation, one double bond was lost with the disappearance of aldehydereactions. Iodination in methanol specifically differentiates between theunsaturation in @-unsaturated ethers and normal olefinic unsaturation.lllAdditional evidence for this linkage was obtained by Debuch,l12 whoozonized and further oxidized a fraction from brain, rich in ethanolamineplasmalogen, and isolated C,, and C17 fatty acids which could have arisenonly from an enol ether attachment. This conclusion is confirmed by theisolation of a labelled aldehyde when native plasmalogen is hydrolysed intritium water .I13The above results indicate that natural plasmalogens occurring inmammalian tissues have the structure (1) while those isolated after alkalinehydrolysis are lysoplasmalogens (2).Some uncertainty must still, however,exist about whether the aldehyde in some plasmalogens can be attachedat C+ of the glycerol. It has recently been claimed that choline plasmalogencontaining no esterified fatty acid exists in the sea anemone and that thisand sphingomyelin are the only phospholipids present in the species.l14Rapport and his collaboratorsCiH2.OH 7 H*o.C R2CH,*O*CO*R1 ICH,*O*P(OH)(:O)*OX (2) (iH*o*CH:CH CH,*O*P(OH)(:O)*OX ( I )R1 and R2 are hydrocarbon chains; X is esterified chotine or ethanolamineThe natural plasmalogens have not yet been isolated free from theirdiacylated analogues, although some fractionation has been obtained by107 M.M. Rapport and R. E. Franzl, J . BioZ. Chem., 1957, 225, 851.109 G. V. Marinetti and J. Erbland, Biochim. Biofihys. Acta, 1957, 26, 429.110 M. M. Rapport, B. Lerner, N. Alonzo, and R. E. Franzl, J . Bid. Chem., 1957,111 M. M. Rapport and R. E. Franzl, J . Neurochem., 1957, 1, 303.112 H. Debuch, ibid., 1958, 2, 243; 2. physioE. Chem., 1958, 311, 266.113 R. J. Blietz, 2. physiol. Chem., 1958, 310, 120.114 W. Bergmann and R. A. Landowne, J . Org. Chenz., 1958, 23, 1241.G.M. Gray, Biochem. J., 1958, 70. 425.225, 859DAWSON : ADVANCES IN PHOSPHOGLYCERIDE CHEMISTRY. 375chromatography on cellulose acetate.l5 A synthesis of natural plasmalogenhas not yet been reported although Malkin and his collaborators115 havedescribed the preparation of the acetals of glycerylphosphorylethanolamine.Minor Phospholipids.-From the phospholipids of egg yolk which arestable to alkaline hydrolysis, Carter, Smith, and Jones 116 have recentlyobtained a fraction which they identified as the phosphorylethanolaminederivative of batyl alcohol. Similar glycerol ether phospholipids are alsoprobably present in mammalian tissues, Malkin and Poole 117 have isolatedfrom groundnuts a complex phospholipid containing glycerophosphoricacid, inositol monophosphate, and ethanolamine residues in equimolecularproportions together with three sugar residues and two fatty acids.Reportscontinue to be made of the presence of other phospholipids in animal tissues,but in each case these will need to be confirmed before they are accepted asauthentic. These include a threonine-containing phospholipid in tunny-fish muscle,lls a phospholipid containing glutamic acid in rat liver,llg acomplex kephalin from sheep brain,120 and “ malignolipin ”, a phospholipidcontaining choline and spermine, from tumour tissue.121Phosphoglyceride Biosynthesis.-In conclusion, it is pertinent briefly torecord the striking advances that have occurred recently in our under-standing of phosphoglyceride biosynthesis. It is now believed that themetabolic steps leading to lecithin and phosphatidylethanolamine synthesisin living organisms are as follows.An enzyme, designated choline phospho-kinase, catalyses the phosphorylation of choline or ethanolamine withadenosine triphosphate, giving phosphorylcholine or phosphorylethanol-amine.122 These phosphorylated bases then react enzymically with cytidinetriphosphate, giving Pl-cytidine 5’-P2-choline pyr~phosphate,~~~ or thecorresponding ethanolamine analogue. Finally, these complex cytidinecompounds react enzymically with a D-1 ,2-diglyceride, giving lecithin orphosphatidylethanolamine and cytidine monophosphate.124 It is not yetcertain how ~-1,S-diglycerides are formed in tissues, but it is probable thatthey arise by the enzymic dephosphorylation of phosphatidic acid 76 whichcan itself be formed by the acylation of glycerophosphoric acid.125 Thesemetabolic steps in the synthesis of, eg., lecithin can be represented thus:Choline + adenosine triphosphate + phosphorylcholine + adenosinePhosphorylcholine + cytidine triphosphate + cytidine diphosphateCytidine diphosphate choline + D-1,Z-diglyceride + lecithin + cyti-diphosphatecholine + pyrophosphatedine monophosphateM.J. Egerton and T. Malkin, J., 1963, 2800; T. Malkin, Progr. Chem. of Fats,Pergamon Press, 1957, 4, 121.116 H. E. Carter, D. B. Smith, and D. N. Jones, J. Biol. Chem., 1958, 232, 681.117 T. Malkin and A. G. Poole, J., 1953, 3470.H. Igarashi, K. Zama, and M. Katada, Nature, 1958, 181, 1282.119 L.0. Pilgeram and D. M. Greenberg, J . Biol. Chem., 1955, 216, 465.120 F. D. Collins, Nature, 1958, 182, 865.121 T. Kosaki, T. Ikoda, Y. Kotani, S. Nakagawa, and T. Saka, Science, 1958, 127,128 J. Wittenberg and A. Kornberg, J. Biol. Chem., 1953, 202, 431.1176376 BIOLOGICAL CHEMISTRY.Recent evidence suggests that the biosynthesis of phosphatidyl-inositoland -serine may be somewhat different from that of lecithin or phosphatidyl-ethanolamine, but the r81e of cytidine derivatives is again indicated.126A more detailed discussion of advances in phosphoglyceride metabolismis given in two recent re~iews.1~7*77R. M. C. D.5. THE HYDROXYLATION OF FOREIGN AROMATIC COMPOUNDS IN THEANIMAL BODYWHEN aromatic compounds are administered to animals, they may beconverted into hydroxy-derivatives in which the hydroxyl group is attacheddirectly to the ring.Four types of such hydroxylated metabolites havebeen found : (i) phenols, (ii) 1,Z-dihydroarene-1,Z-diols, (iii) 1,Z-dihydro-arenemono-ols, and (iv) N-acetyl-S-( 1,Z-dihydro-2-hydroxyary1)cysteines(premercapturic acids). The last three types contain partially hydrogenatedaromatic rings. A compound which yields all four types of metabolite isnaphthalene. When fed to rats or rabbits, this gives rise to 1- and 2-naphtho1,l 1 ,Z-dihydronaphthalene-1,Z-diol (2) ,2 1,Z-dihydro-l-naphthol (3) ,3and N-acet yl-S- (1 ,Z-dihydr0-2-hydroxy- 1 -naphthyl) -L-cysteine (4) .*H OH H OH H S.CH2.CH(NHAc)*C0,H-A OH A x , H A x , H "\(i(rHOHCertain alkylbenzenes are also hydroxylated in the body, but the hydroxylgroup is not introduced into the ring but into the side-chain.Thus, in therabbit, ethylbenzene is converted into a-methylbenzyl(i) The Formation of Phenols in wiwo.-Most aromatic compounds giverise to phenols in the animal body. Benzene, for example, is converted intophenol, catechol, quinol, and 1,2,4-trihydroxybenzene in the rabbit6Formation of phenols appears to be orientated and this orientation isinfluenced by substituents.123 L. F. Borkenhagen and E. P. Kennedy, ibid., 1957, 227, 951.124 S. €3. Weiss, S. W. Smith, and E. P. Kennedy, J . Biol. Chem., 1958, 231, 53; E. P.125 A. Kornberg and W. E. Pricer, J . Biol. Chem., 1953, 204, 345.lZE B. W. Agranoff, R. M. Bradley, and R.0. Brady, J . Biol. Chem., 1958, 233,127 E. P. Kennedy, Canad. J . Biochem. Ph.ysiol., 1956, 34, 334.1 E. D. S. Corner and L. Young, Biochem. J., 1954, 58, 647.3 E. Boyland and J. B. Solomon, ibid., 1955, 59, 618.Kennedy and S. B. Weiss, Fed. PYOC., 1956, 15, 381.1077; G. Hiibscher, R. R. Dils, and W. F. R. Pover, Nature, 1958, 182, 1806.L. Young, ibid., 1947, 41, 417.(a) E. Boyland, P. Sims, and J. 13. Solomon, ibid., 1957, 66, 4 1 ~ ; ( b ) E. Boylandand P Sims, ibid., 1958, 68, 440; (c) R. H. Knight and L. Young, ibid., 1958, 70,111.J. N. Smith, R. H. Smithies, and R. T. Williams, ibid., 1964, 56, 320.J. W.. Porteous and R. T. Williams, ibid., 1949, 44, 66; D. V. Parke and R. T.Williams, zbad., 1953, 54, 231PARKE AND WILLIAMS: AROMATIC COMPOUNDS I N THE ANIMAL BODY.377Hydroxylation of monosubstitzcted benzenes. Many, but not all, mono-substituted benzenes are converted into phenols in the animal body.(Compounds such as benzoic acid, ethylbenzene, and acetophenone are not,because they can, apparently, undergo alternative metabolic reactions morereadily.) If the substituent group is ortho-para-directing, the compoundis hydroxylated in the body in the ortko- and para-positions. In the rabbitand the rat, the +-phenol is the predominant metabolite and in someinstances the o-phenol has not been detected (see Table 1). Except forthe case of chlorobenzene, m-phenols have never been reported as meta-bolites of this type of substituted benzene, In the case of phenol,' it hasbeen shown with carbon-14 that, in the rabbit, ten times more quinol thancatechol is excreted, when the dose is about 50-60 mg./kg.TABLE 1.Phenolic metabolites of vnonosubstitzcted befinxenes in rabbits.CompoundPhenolAnisoleAnilineAcetanilideDiethylanilinePhen ylureaDiphenyl (in rats)Diphenyl etherMetabolitesQuinol, catecholp-Methoxyphenol, o-methoxyphenol *p-Aminophenol, o-aminophenolp-Hydroxyacetanilide lop-Diethylaminophenol l1p-Hydroxyphenylurea l24-Hydroxydiphenyl13p-Hydroxydiphenyl etherWhen the substituent is m-directing, the substituted benzene ishydroxylated in all three positions. The predominant metabolites arem- and fi-phenols together with smaller amounts of o-phenols. Nitro-benzene l4 labelled with carbon-14 and benzonitrile 15a~ are metabolizedto the corresponding o-, m-, and p-phenols in the rabbit.Benzoic acid 15ais not hydroxylated in the body, for it is metabolized by conversion intohippuric acid and (benzoyl g1ucosid)uronic acid, both of which are readilyexcreted.In chlorobenzene the substituent is regarded as ortho-para-directing.In the rabbit, chlorobenzene l6 yields 4-chlorocatechol as the principalhydroxylated metabolite, and Phalogenocatechols are also the main phenolsformed from fluoro-, bromo-, and iodo-benzenes.17 Chlorobenzene is alsometabolized to o-, m-, and +-chlorophenols in the rabbit 17918 and in thelocust .19D. V. Parke and R. T. Williams, Biochem. J., 1953, 55, 337.H. G. Bray, S. P. James, W. V. Thorpe, and M.R. Wasdell, ibid., 1953, 54, 547.J. N. Smith and R. T. Williams, ibid., 1949, 44, 242.lo Idemlibid., 1948, 42, 538; B. B. Brodie and J . Axelrod, J . Pharmacol., 1948,94, 29.l1 F. Horn, 2. physiol. Chem., 1937, 249, 82.la H. G. Bray, H. J. Lake, and W. V. Thorpe, Biochem. J., 1949, 44, 137.l3 H. D. West, J. R. Lawson, I. H. Miller, and G. R. Mathura, Arch. Biochem.l4 D. V. Parke, Biochem. J., 1956, 62, 339.l5 (a) J. N. Smith and R. T. Williams, ibid., 1950,46, 243; (b) H. G. Bray, 2. Hybs,*6 J. N. Smith, B. Spencer, and R. T. Williams, ibid., 1950, 4'9, 284.17 W. M. AZOUZ, D. V. Parke, and R. T. Williams, ibid., 1963, 55, 146.l9 T. Kikal and J. N. Smith, Biochem. J.. 1958, 69, 5 2 ~ .Bioflhys., 1956, 60, 14.and W. V. Thorpe, ibid., 1951, 48, 192.J.N.. Smith, personal communication378 BIOLOGICAL CHEMISTRY.The pattern of hydroxylation of monosubstituted benzenes in theanimal body is thus similar to that of hydroxylation by the free hydroxylradical. Weiss and his co-workers have shown that hydroxylation of phenolmby the free radical yields catechol and quinol, of nitrobenzene o-, m-, and$-nitrophenols, and of chlorobenzene 22 o-, m-, and p-chlorophenols. Thiswould suggest that hydroxylations in vivo are carried out by an enzyme-generated free hydroxyl radical.Studies in vitro have shown that the hydroxylation of foreign aromaticcompounds, but not of normally occurring substrates such as L-phenyl-alanine and L-tryptophan, is carried out by rat- and rabbit-liver microsomesin the presence of oxygen and triphosphopyridine nucleotide.23 In themicrosomes, aniline is hydroxylated to o- and 9-aminophenol, acetanilideto 9-acetamidophenol, and benzene to phenol.Ferrous iron and a thiolgroup appear to be involved in the enzyme system. Furthermore,if the hydroxylation of acetanilide by liver microsomes is studied in thepresence of 1802, the isotope is incorporated into the hydroxyl group of the9-acetamidophenol formed.% No oxygen-18 is found in the hydroxyl groupif H,180 is used. It seems unlikely, therefore, that the free hydroxylradical is involved in these hydroxylations. Mason 25 suggests that theliver-hydroxylating system is a mixed-function oxidase (in which oneoxygen atom is added to the substrate and the other is reduced) and that thehydroxylating agent is a complex of an iron enzyme with molecular oxygen,which is formulated as E-Fe++O,.This complex is transformed intoE*Fe++O as a result of hydroxylation of the substrate AH :E*Fe++O, + AH __t AOH + E*Fe++Oand E*Fe++O then undergoes TPNH-specific reduction to regenerate thefree enzyme. Alternatively E*Fe++O, may undergo TPNH-specific reduc-tion to E-Fe++O which may be the hydroxylating agent.Species diferences in the hydroxylation of monosubstituted benzenes.Much of the work on the metabolism of monosubstituted benzenes has beencarried out with rabbits, but now observations are being extended to otherspecies. With aniline, it has been found that in all species studied, anilineis hydroxylated in the o- and +-positions, but that the ratio $-amino-phenol : o-aminophenol varies with species.26 Differences in the extentof hydroxylation at various positions are of considerable significance whencarcinogenic compounds are involved (see p.351).Table 2 shows that in the cat, dog, and ferret, o-aminophenol is formedin amounts equal to or greater than the amounts of 9-aminophenol, and itis suggested 26 that a different enzyme is necessary for the ortho-hydroxylation2O G. Stein and J. Weiss, J., 1951, 3265.21 H. Loebl, G. Stein, and J. Weiss, J., 1949, 2074; 1950, 2704.z2 G. R. A. Johnson, G. Stein, and J. Weiss, J., 1951, 3275.23 (a) C. Mitoma, H. S. Posner, H. C . Reitz, and S. Udenfriend, Arch. Biochem.&4 S. Udenfriend, C . Mitoma, and H.S. Posner, 130th Meeting Amer. Chem. Soc.,*5 H. S. Mason, Adv. Enzymol., 1957, 19, 79, 128, 177.26 D. V. Parke and R. T. Williams, Biochem. J., 1956, 63, 12~.Biophys., 1956, 61, 431; (b) J. Booth and E. Boyland, Biochem. J . , 1957, 66, 73.1956, Abstracts of papers, 54cPARKE AND WlLLIAMS: AROMATIC COMPOUNDS I N THE ANIMAL BODY. 379from that required for para-hydroxylation. Posner 27 has also found thatif acetanilide is incubated with cat-liver microsomes o-hydroxyacetanilideas well as @-hydroxyacetanilide is formed, whereas with rabbit-livermicrosomes only the para-isomer is formed. In the rat, P-iodophenol is themain hydroxylated metabolite of iodobenzene,28 whereas in the rabbit4-iodocatechol is the main metabo1ite.l’ Again with chlorobenzene, nearly30% of the dose is excreted by the rabbit as 4-chlorocatechol and 2-3y0 asTABLE 2.The ratio p-aminophenol : o-aminophenol @lo) in the urineSpecies Pi0 Species PI0of animals given [14C]aniline.Gerbil .................. 15 Hen .................... 4Hamster ................ 10 Ferret.. ................ 1Rat .................... 5 Cat .................... 0.4Guinea pig .............. 11 Mouse .................. 3Rabbit. ................. 6 Dog .................... 0.69-chlorophenol, whereas in the locust m- and p-chlorophenol and Pchloro-catechol are produced in roughly equal amounts (about 10% each).19 Itappears possible that orientation of hydroxylation in vivo is dependent uponspecific enzymes and that species differences in orientation are due to thepresence of such enzymes.Phenolic metabolites of $olycyclic aromatic hydrocarbons.A numberof polycyclic aromatic hydrocarbons are converted in vivo into phenols (seeTable 3). The mechanism of the formation of these phenols is unknown,but it has been assumed that they are derived from 1,2-dihydro-1,2-dihydroxy-precursors .29TABLE 3. Phenolic metabolites of polycyclic hydrocarbons.NaphthaleneFluorene 2-Hydroxyfluorene 31Chrysene 1-HydroxychrysenePyrene1,2-Benzanthracene 4’-Hydroxybenzanthracene 341,2 : 5,6-Dibenzanthracene3,4-Benzopyrene1- and %Naphthol, lJ2-dihydroxynaphtha1ene 1* 303-Hydroxypyrene, 3,s- and 3,l O-dihydroxypyrene 332’-Hydroxy- and 2’,“’-dihydroxy-dibenzanthracene 35 (in4’,4’’-Dihydroxydibenzanthracene 36 (in rats and mice)5-, 8- and 10-Hydroxybenzopyrene 37rabbits)The orientation of the hydroxyl groups of the phenolic metabolitesof fluorene, chrysene, 1,2-benzanthracene, and 1,2 : 5,6-dibenzanthraceneand B.N. La Du, Ann. Rev. Biochem., 1958, 27, 431.27 H. S. Posner, personal communication, also cited by B. B. Brodie, J. R. Gillette,28 G. C. Mills and J. L. Wood, J . Biol. Chem., 1953, 204, 547.29 E. Boyland, Biochem. SOC. Symp., 1950, No. 5, 40.3o E. Boyland and P. Sims, Biochem. J., 1957, 06, 38.31 W. J. P. Neish, ibid., 1948, 43, 533.32 I. Berenblum and R. Schoental, ibid., 1949, 44, 604.33 K. H. Harper, Brit. J . Cancer, 1957, 11, 499; see also A. H. Conney, E. C. Miller,a4 I. Berenblum and R. Schoental, Cancer Res., 1943, 3, 686.26 J.Cason and L. F. Fieser, ibid., 1940, 62, 2681.37 I. Berenblum and R. Schoental, Cancer Res., 1946, 6, 699; 0. Pihar and J.and J. A. Miller, J . B i d . Chem., 1967, 228, 753.J. A. LaBudde and C. Heidelberger, J . Amev. Cheun. SOL, 1958, 80, 1225.Spaleny, C h i n . Listy, 1956, 50, 296380 BIOLOGICAL CHEMISTRY.suggests that these compounds are not hydroxylated at the centres ofgreatest reactivity but at centres of secondary reactivity (see formulae below).Fluorene I ,2-Benzant hraceneReactive centre 9Metabolic hydroxylation a t 2Reactive bond 3,4 (K region)Reactive centres 9, 10 (L region)Metabolic hydroxylation at 4’ (M region i s 3’,4’)C h ryseneReactive bond I I , 12 (K region)Metabolic hydroxylation at I(M region is 1,2)I ,2 : 5,6-DibenzanthraceneReactive bond 3, 4 (K region)Reactive centres 9 and 10 (L region)Metabolic hydroxylation at 4’,4’’ (rat) and 2’,2”(rabbit) (M region is 3’,4’ and 1’,2’)This is not true, however, for pyrene and 3,4-benzopyrene which arehydroxylated both at the most reactive centres and at centres of secondaryreac tivi ty.33Pyrene 3,4-BenzopyreneReactive bond 6,7 (0Reactive centre 5Metabolic hydroxylation at 5, 8, and 10Reactive bond 1,2 (K)Reactive centre 3Metabolic hydroxylation at 3, 8, and 10According to Pullman and Pullman 58 the majority of polycyclic hydro-carbons contain two regions which are of particular importance for theirchemical behaviour.These are the K region which contains a bond of thetype of the 9,lO bond in phenanthrene and the L region which containscarbon atoms of similar reactivity to the 9 and 10 carbons in anthracene(there is no L region in pyrene or benzopyrene).Furthermore, there hasbeen postulated for some hydrocarbons an M region where metabolicperhydroxylation is supposed to take place. In lJ2-benzanthracene (seeabove), for example, the K region is at the 3,4 bond, the L region includesthe 9 and 10 carbon atoms and the M region covers the 3‘,4‘ bond. Theformation of metabolites by hydroxylation at sites of secondary reactivity38 A. Pullman and B. Pullman, Adv. Cancer Res., 1955, 3, 117PARKE AND WILLIAMS: AROMATIC COMPOUNDS IN THE ANIMAL BODY. 381has been explained by assuming that the reactive K region of the hydro-carbon becomes attached to tissues and that hydroxylation of this region isthereby blocked.Hydroxylation, however, now occurs at sites of secondaryreactivityz9 which are now activated in the addition complex of hydro-carbon and tissue.39 That the K region of 1,2 : 5,6-dibenzanthracene isinvolved in linkage with tissues has been shown by Bhargava and Heidel-berger,40 who have also isolated from the skin of mice treated with [9,10-14C]-dibenzanthracene, a metabolite in which the 3,4 bond has been split, namely2-phenylphenanthrene-3,2’-dicarboxylic acid (5).Furthermore, in mice, there have been detectedproducts resulting from metabolic attack on the Kand L regions of dibenzanthracene, namely the 9,lO-CO~H quinone, the 3,4-quinone, and 4’,4’’-dihydroxy-dibenzanthracene 9,10-q~inone.~l The view thatcertain polycyclic hydrocarbons are attacked in viuoonly at points of secondary reactivity will probablyhave to be revised as more information becomesavailable on the metabolism of these compounds.Speciesdifferences in the hydroxylation of aromatic compounds have been correlatedwith differences in susceptibility to the carcinogenic action of certaincompounds.This was first observed with the carcinogen, 2-naphthylamine(6). In susceptible species, eg., dog, this compound is converted to a con-@pSpecies diferences in the hydroxylation of polycyclic compounds.siderable extent into 2-amino-l-naphthol which is carcinogeni~,~~ whereas ina resistant species, e.g., rabbit, it is converted mainly into 6-amino-2-naphthol.2-Acetamidofluorene (7) is carcinogenic to the rat but not to the guinea pig.Percentage of ether-extractable metabolites found in the rat and the guineap i g obtained f r o m urine after treatment with p-glucuronidase.Derivative excreted Rat Guinea pig1-OH ...................... 5.9 0.093-OH ......................4.5 0.185-OH ...................... 42 2-17-OH ...................... 32 958-OH ...................... 3.1 1.9In both species, 1-, 3-, 5-, 7-, and 8-hydroxy-2-acetamidofluorene have beendetected as metabolites, but there are considerable differences in the amountsof these metabolites excreted (see Table).3s B. Pullman and J . Baudet, Corn@. rend. Soc. Biol., 1954, 238, 964.40 P. M. Bhargava and C.Heidelberger, J. Amer. Chem. Soc., 1956, 78, 3671; P. M.41 C. Heidelberger, H. I. Hadler, and G. Wolf, ibid., 1953, 75, 1303.42 G. M. Bonser, D. B. Clayson, and J. W. Jull, Lancet, 1951, 2, 286; D. B. Clayson,43 J. H. Weissburger, E. K. Weissburger, and H. P. Morris, Cancer lies., 1958, 18Bhargava, H. I. Hadler, and C. Heidelberger, ibid.,1955, 77, 2877.J. W. Jull, and G. M. Bonser, Brit. J. Cancer, 1968, 12, 222.1039382 BIOLOGICAL CHEMISTRY,A most striking species difference has been found with 1,2 : 5,6-dibenz-anthracene which is carcinogenic to rats and mice and is converted in thesespecies into 4’,4”-dihydroxy-deri~atives,~~ whereas in the resistant rabbitit is converted into the 2’-hydroxy- and 2‘,2’’-dihydroxy-deri~atives.~Phenolic metabolites of heterocyclic compounds.Phenols have beenisolated as metabolites of certain heterocyclic aromatic compounds (seeTable 4). The hydroxyl groups in these phenols are usually located at thecarbon atom most active in electrophilic substitution.TABLE 4. Phenolic metabolites of some heterocyclic systems.CompoundPyridineQuinolineAcridineIndoleSkatolePhenothiazineCoumarin *Metabolites3-Hydroxypyridine 443-Hydro~yquinoline,~~* 46 6- and 8-hydroxyquinoline.47 2,6- and5,6-dihydroxyquinoline 463-Hydroxyacridone 483-Hydroxyindole 495- and 7-Hydroxyskatole 503-Hydroxy- and 3,7-dihydroxy-phenothiazine 513- and 7-Hydroxycoumarin 5a* Coumarin also undergoes hydroxylation to a minor extent in positions 5, 6 and8 .6 5When the heteroatom is nitrogen as in pyridine, quinoline, and indole,one of the phenols produced metabolically is a 3-hydroxy-derivative.Hydroxylation also occurs in the benzo-ring or rings, as in the case ofquinoline, acridine, and phenothiazine, in positions that are equivalent tothose ortho and para to the heterocyclic nitrogen atom. Thus, 6- and8-hydroxyquinoline have been detected as metabolites of quinoline in theH Hrabbit. Both benzo-rings are hydroxylated para to the heterocyclic nitrogenatom in phenothiazine. In skatole, the 3-position is substituted andapparently hydroxylation now occurs in the benzo-ring in positions (5 and 7)that are ortho and para to the heteroatom.When an enzyme preparation from rabbit liver is incubatedwith quinoline,the latter is converted into Z-hydroxyquinoline.M In the intact rabbit,2-hydroxyquinoline is not excreted as a metabolite of quinoline, but the44 J.N. Smith, personal communication.45 L. Novak and B. B. Brodie, J . B i d . Chem., 1950,187, 787.46 J. N. Smith and R. T. Williams, Biochem. J., 1955, 60, 284.47 B. Scheunemann, Arch. Exp. Pathol. Pharmakol., 1923, 100, 51.48 H. Fuhner, ibid., 1904, 51, 391.49 C. Neuberg and E. Schwenk, Biochem. Z., 1917, 79, 387.50 P. Decker, Naturwiss., 1957,44, 330; C. E. Dalgliesh, W. Kelly, and E. C. Horn-ing, Biochem. J., 1958, 70, 1 3 ~ .51 (a) F. DeEds, C. W. Eddy, and J. 0. Thomas, J . Pharmacol., 1938,64,250; ( b ) G. H.Benham, Canad. J . Res., 1945, %,E, 71 ; (c) H . B. Collier, D.E. Allen, and W. E. Swales,ibid., 1943, 21,D, 151.52 J. A. R. Mead, J. N. Smith, and R. T. Williams, Biochem. J., 1958, 68, 67.58 M. Kaighen and R. T. Williams, unpublished results.W. E. Knox, J . Biol. Chem., 1946, 163, 699PARKE AND WILLIAMS: AROMATIC COMPOUNDS IN THE ANIMAL BODY. 383formation of 2 : 6-dihydroxyquinoline suggests that 2-hydroxyquinoline isformed in vivo but is further metabolized, for the 2,6-derivative is a knownmetabolite of 2-hydro~yquinoline.~~ Other examples of 2-hydroxylationof nitrogen heterocycles have been found with nicotinamide,= cinchonine,and quinine.57 The mechanism of the 2-hydroxylation of nitrogen hetero-cycles may be different from other forms of aromatic hydroxylation, sinceit has been shown that, in the hydroxylation of nicotinic acid to 6-hydroxy-nicotinic acid by an enzyme preparation of Pseudomonas juorescens, theoxygen added to the 6-position is derived 58 from H,1*O and not from lSO,.Coumarin is metabolized in animals mainly to 3- and 7-hydroxycoumarh1,but the use of [14C]coumarin shows that hydroxylation also occurs to aminor extent in other positions (i.e., 5, 6, and 8).The position 59 of greatestelectron density in coumarin is 3, and it is this position that undergoes themain hydroxylation in the rabbit.(ii) 1,2-Dihydroarene- 1,2-diols.-These compounds are of particularinterest in the metabolism of aromatic compounds, since it has been postu-lated that they are the precursors of Dihydroarenediols aredehydrated by dilute acid to phenols, and there is little doubt that whenphenols are isolated from urine which has been treated with acid, they maybe derived partly from dihydroarenediols and their conjugates.A list ofthe dihydroarenediols that have been isolated from the urine of rats orrabbits is given in Table 5.TABLE 5. Biosynthetic 1,2-dihydroarene-l,2-diols.Precursor DiolChlorobenzene . . . . . . . . . . . . . . 4-Chlorocyclohexa-3,5-diene-trans-l, 2-diolAnthracene . . . . . . . . . . . . . . . . . . 1,2-Dihydroanthracene-trans-1,2-diol 62Naphthalene . . . . . . . . . . . . . . . . 1,2-Dihydronaphthalene-trans-l,2-diol2-Methylnaphthalene . . . . . . . . 1,2-Dihydro-7-methylnaphthalene-1,2-diolPhenanthrene . . . . . . . . . . . . . . . . 1,2-Dihydrophenanthrene-truns-1,2-diol and 9,lO-Indene .. . . . . . . . . . . . . . . . . . . . .dihydrophenanthrene-trans-9,l O-diol 63cis- and truns-Indane-1,2-diol 64The orientation of the phenols found in the urine of animals dosed withbenzene derivatives can be explained if appropriate dihydroarenediols are55 J. N. Smith and R. T. Williams, Biochem. J., 1954, 56, 325.56 W. E. Knox and W. I. Crossman J . Biol. Chem., 1947, 168, 363.57 B. B. Brodie, J. E. Baer, and L. C. Craig, ibid., 1951, 188, 567.58 A. L. Hunt, D. E. Hughes, and J. M. Lowenstein, Biochem. J., 1957, 66, 2 ~ .50 I. Samuel, Compt. rend. SOC. Biol., 1955, 240, 2534.6O J. N. Smith, Biochem. SOC. Symp., 1950, No. 5, 15.81 A. J. Grimes and L. Young, Biochem. J., 1956, 62, 11~.82 E. Boyland and A.A. Levy, ibid., 1935, 29, 2679; J. Booth and E. Boyland, ibid.,83 E. Boyland and G. Wolf, ibid., 1950, 47, 64; J. Booth, E. Boyland, and E. E.64 C . J. W. Brooks and L. Young, Biochem. J., 1956, 63, 264.1949, 44. 361.Turner, J., 1950, 2808384 BIOLOGICAL CHEMISTRY.postulated as precursor^.^^ Thus the conversion in vivo of aniline intoo- and @-aminophenol can be explained if 2,3-dihydro-2,3-dihydroxy-aniline and 3,4-dihydro-3,4-dihydroxyaniline are postulated as intermediates,since on dehydration the 2,3-diol would yield o-aminophenol and the 3,4-diol,9-aminophenol. In each case the hydroxyl group remaining on the aromaticring is located on the carbon atom normally attacked by electrophilicreagents.66 With nitrobenzene similar diols can be postulated, but thesewould yield two phenols each:The difference between the dehydration of the dihydroarenediols of anilineand nitrobenzene can be explained if the stability of the ionic transitionstates in the dehydration is considered.The dehydration of a 3,4-dihydro-arene-3,4-diol can take the following course :XOHi , -H+. ii, -OH-.If X is a meta-directing group, no extra resonance stabilization is conferredupon either of the transition states, (9) and ( l l ) , and the dehydration of thediol (10) could proceed in both directions with comparable velocities toyield a mixture of m- and p-phenols. On the other hand, if X is ortho-para-directing, extra resonance stabilization is possible in the transition state (1 1)and the dihydroarenediol should yield the @-phenol (12) , rather than them-phenol (8).Similar arguments could be used for a 2,3-dihydroarene-2,3-diol.The evidence for the conversion of dihydroarenediols into monohydricphenols in tissues is at present unconvincing. Booth and Boyland 23367 haveshown that when naphthalene is incubated with rat-liver microsomes it isconverted into 1,2-dihydronaphthalene-lJ2-diol and l-naphthol but notinto 2-naphthol (for rabbit-liver microsomes see ref. 23a). However, whenl,2-dihydronaphthalene-lJ2-diol is incubated with the microsomes, it isnot converted into l-naphthol and it appears that the dihydroarenediol andthe naphthol are produced by different enzymes.67 Support for this viewhas come from the study of benzene. In rabbit- or dog-liver microsomes,benzene was converted into phenol, and no evidence was obtained that a65 D.Robinson, J. N. Smith, and R. T. Williams, Biochem. J., 1951, 50, 228.66 G. M. Badger, J., 1949, 2497.67 J. Booth and E. Boyland, Biochem. J., 1958, 70, 681PARKE AND WILLIAMS: AROMATIC COMPOUNDS IN THE .ANIMAL BODY. 385dihydroarenediol was formed.68 Cyclohexa-3,5-diene-1,2-diol has beensynthesized by B. Witkop,@ and when this compound is incubated withliver microsomes it is not converted into phenol. In fact, the diol can berecovered at the end of the incubation. However, if the cyclohexadienediolis incubated with " rabbit liver acetone powder " in the presence of TPN itis converted into catech01.~~ Thus, the evidence obtained with tissues andfractionated tissues suggests that dihydroarenediols are not precursors ofmonohydric phenols, that dihydroarenediols and monohydric phenols areformed in separate reactions, and that dihydroarenediols may be precursorsof catechols.However, Corner and Young70 have shown that in thewhole rat, 1,2-dihydronaphthalene-trans-1,2-diol is converted into (1,2-dihydro-2-hydroxy-1-naphthyl g1ucosid)uronic acid (R = C6H906) ,(1-naphthyl g1ucosid)uronic acid (R = C6Hg06), 1-naphthyl hydrogensulphate acid (R' = SO,H), and 2-naphthol, all of which are metabolites ofnaphthalene. It seems at present that results in vivo and in vitro do notagree, but the study of the metabolism of these compounds in isolatedtissues and cell fragments has not yet proceeded very far.(iii) 1,2-Dihydroarenemono-ols.-When certain polycyclic hydrocarbonsare administered to animals, the urines excreted contain metabolites whichyield the original hydrocarbon after treatment with dilute mineral acids.This has been observed with naphthalene, anthracene, and phenanthrene ; 71%methylnaphthalene ; quinoline ; 46 phenothiazine ; 51c and coumarin.53Acenaphthane, chrysene, 3,4-benzopyrene, 1,2 : 5,6-dibenzanthracene, andmethylcholanthrene are not excreted as acid-labile hydrocarbon precursors.71The amount of the dose which is excreted as these hydrocarbon precursorsis 13-1'?y0 for naphthalene, 4-7% for phenanthrene, and 2-3% foranthracene, when fed to rats; and 10% for quinoline and 14% for coumarin,fed to rabbits.With phenothiazine, only man and the pig excrete the acid-labile precursor, and none was detected in the urines of horse, dog, sheep,and rabbit .51cBourne and Young72 suggested that the acid-labile precursor ofnaphthalene was l,Z-dihydro-2-naphthol, which is known to yieldnaphthalene on treatment with acids.This precursor, however, has since68 H. S. Posner, Ph.D. Thesis, George Washington University, 1958, and personal69 P. K. Ayengar, 0. Hayaishi, M. Nakajima, and I. Tomita, Amer. Chem. SOC. Abstr.70 E. D. S. Corner and L. Young, Biochem. J., 1955, 61, 132.7 1 L. H. Chang and L. Young, Proc. SOC. Exp. Biol. Med., 1943, 53, 129.72 I1I. C. Bourne and I,. Young, Ckem. and Id., 1933, 52, 271.communication.Spring Meeting, 1958, p. 29a.RE P--VOL . 1.V 386 BXOLOGICAL CHEMISTRY.been shown to be a derivative of the unknown 1,Z-dihydro-l-naphthol,namely (1,2-dihydro-l-naphthyI g1ucosid)uronic acid.3 The latter (13) isalso excreted, together with small amounts of free 1 ,%&hydronaphthalene-1,2-diol (16), in the urine of rats dosed with 1,2-dihydronaphthalene (14),and Boyland and Solomon suggest that (14) might be an intermediate inthe formation of the uronic acid (13) from naphthalene.The metabolismof naphthalene may thus involve an initial reduction to 1,2-dihydronaphtha-lene which is subsequently hydroxylated a t the reduced positions to give1,Z-dihydro-l-naphthol (15) and 1,2-dihydronaphthalene-l,Z-diol (16).H, ,0*C6H906 H, PH\ ? if---/ IH OHi, acid. ii, in v i m(iv) N-Acetyl-S- ( 1,2-dihydr0-2-hydroxyaryl) cysteines-Mercapt uric acids(S-aryl- or -alkyl-N-acetyl-L-cysteines) were discovered about the sametime by Baumann and Preusse and by Jaffd 73 as metabolites of certainchlorinated hydrocarbons. These early workers believed that mercapturicacids were excreted in a combined form since they could be isolated onlyafter treatment of the urine with mineral acids. Recently: it has beendemonstrated that some mercapturic acids do, in fact, arise from acid-labileprecursors or " premercapturic " acids which seem to have structuresanalogous to 1,2-dihydroaryl-l,2-diols.Premercapturic acids have been shown to be metabolites of benzene,fiuorobenzene, chlorobenzene, bromobenzene, iodobenzene, naphthalene,and anthra~ene,~ all of which had previously been shown to yield mercapturicacids. It is probable that all mercapturic acids, previously isolated asmetabolites of aromatic hydrocarbons and certain of their nuclear halogenderivatives, in which the acetylcysteine group is directly attached to thearomatic ring, are derived from the decomposition of premercapturic acids.However, benzylmercapturic acid (N-acetyl-S-benzyl-L-cysteine) , a know-nmetabolite of benzyl chloride, in which the acetylcysteine group replacesthe chlorine atom in the side-chain, is not excreted as an acid-labileprecursor .4cThe excretion of premercapturic acids occurs in rabbits, rats, mice,hamsters, guinea pigs, and humans after administration of naphthalene,&and in rats and rabbits dosed with benzene, fluoro-, chloro-, bromo-, andiodo-benzene and anthra~ene.~~ The premercapturic acid of naphthalenehas been isolated from rabbit's urine. It is decomposed after 30 minutes'heating at 100" in vaczco, or within seconds by treatment with N-mineral73 E. Baumann and C. Preusse, Ber., 1879, 12, 806; M. Jaffe, ibid., p. 1092PARKE AND WILLIAMS: AROMATIC COMPOUKDS IN THE ANIMAL BODY. 387acids, to yield 1-naphthylmercapturic acid and 1- and 2-naphthol. Theelemental analysis and infrared and ultraviolet absorption spectra suggesta 1,2-dihydronaphthol structure (17) and (18).Both (17) and (18) should undergo dehydration to l-naphthylmer-capturic acid. Elimination of N-acetylcysteine, which has been shown tooccur 4c on acidification, would account for the simultaneous formationH S.CH~.CH(NHAC)*CO~H HO S*CH2*CH( NHAc)-C02H a' (18)of naphthols. However, the simultaneous formation of both 1- and 2-naphthol is difficult to explain if the precursor is identified solely with eitherstructure (17) or (18), and the possibility of an acid-induced migration ofthe hydroxyl group has been suggested to account for this anomaly.4bThe evidence to date, however, favours structure (17), which could, moreover,exist as cis- and trans-isomers.The amount of 1-naphthylmercapturic acid formed on acidification ofthe premercapturic acid is dependent on the pH, and it is suggested thatin some cases acidification of premercapturic acids may yield mainlyhydroxy-compounds.& Thus in the metabolism of certain foreign organiccompounds, where a phenol but no mercapturic acid has been isolated, theorigin of the phenol may in fact be a premercapturic acid.Injectionof rabbits with 1- and 2-naphthol, (+)-1,2-dihydronaphthalene-trans-l,2-diol, or S-1-naphthyl-L-cysteine does not lead to the excretion of thenaphthylpremercapturic acid. Traces were produced, however, when1,2-dihydronaphthalene was injected, but this may not be an intermediatein the formation of the premercapturic acid since the dehydrogenationin V ~ V O of 1,2-dihydronaphthalene to naphthalene might Boylandand Sims have suggested that the initial product may be the unknownnaphthalene 1,2-epoxide (19). This subsequently reacts with the thiolgroup of cysteine, glutathione, or tissue proteins to form intermediateswhich after acetylation would yield the naphthylpremercapturic acid (17)toget her with its isomer N-ace t yl-S- 1,2-dihydro-l-hydroxy-Z-naph thyl) -L-cysteine (20). This latter could also be reduced in vivo to give the knownmetabolite, 1,2-dihydro-1-naphthol (5).The mode of formation of premercapturic acids is obscure.acid Naphthalenein viva 1 lviv0 (17) ___t I-naphthylmercapturic acid + I- and 2-naphtholsin vivo acid(I 9) -e (20) __+ 2-naphthylmercapturic acid + I-naphtholreduction in vivo(15) __+ (13388 BIOLOGICAL CHEMISTRY.This view is supported by the fact that a small amount of a substance, whichmight well be (20), was detected in the urine of rabbits dosed withnaphthalene.Another mercapturic acid precursor has been isolated from tissues ofrats fed with [1311]iodoben~ene.~~ This precursor yields fi-iodophenyl-cysteine on acid hydrolysis and when fed to rats is excreted in the urineas p-iodophenylmercapturic acid and other metabolites.D. V. P.R. T. W.S. BAYNE.R. C. BRAY.R. M. C. DAWSON.K. R. HARRAP.D. V. PARKE.R. T. WILLIAMS.74 G. C. Mills and J. L. Wood, J . Biol. Chew., 1956, 219, 1

ISSN:0365-6217    

DOI:10.1039/AR9585500343

出版商:RSC    

年代:1958

数据来源: RSC

摘要:

ANALYTICAL CHEMISTRY1. INTRODUCTIONAs in our previous Report, attention has been concentrated on originalpapers rather than abstracts. The division into sections is on the samegeneral lines as last year except that we have decided to combine the Generaland Miscellaneous sections under the one heading of General Analysis. Thesections are therefore as follows : General. Conventional Qualitative andQuantitative Inorganic and Organic Analysis. Physical Methods of Analysisunder the headings : (a) electrical methods; (b) polarography ; (c) chromato-graphy; (a) absorption spectroscopy; (e) emission spectroscopy. Micro-chemical Methods. Radio-chemical Methods. Apparatus.Under each heading we have tended to mention inorganic applicationsfirst, following these by organic applications.In the course of preparation of the Report, we have noted certain matterswhich seem to merit special attention.There is no doubt that there is agreat tendency to place many conventional methods of analysis on anautomatic basis, in particular in order that plant processes may be moreefficiently controlled. The interest in gas-liquid and gas-solid chromato-graphy is being maintained at a high level, the greatest emphasis beingprobably on more sensitive means of detection of separated fractions. Inpaper chromatography we have noted a tendency to change the method ofapplication of the test, whilst in polarography a great deal of work is beingcarried out using alternative electrodes to the conventional droppingmercury electrode. Non-aqueous titrimetry and flame photometry arebecoming increasingly important, whilst there is a great tendency todetermine innumerable elements by final absorptiometric procedures at aparticular wavelength in the visible region. The possibilities of toluene-3,4-dithiol as an analytical reagent are beginning to be realised, whilstanalysts in many fields are finding the flask combustion method of pre-liminary combustion in oxygen to be an excellent and simple method ofopening up organic samples.2.GENERALAs mentioned above, the automatic instrumental analysis of processstreams is becoming more and more common. In this respect the contribu-tion of Bertram and his co-workers1 is significant. They have devised anautomatic instrument composed essentially of a derivative polarographand a rotary-valve proportioning system, which will analyse process streamscontaining high concentrations (100-200 g./l.) of uranium.The uraniumconcentration of the process stream is recorded every 15 minutes with a highorder of accuracy and reproducibility, attributed mainly to the resistance-capacitance method of derivative polarography using a reversible scanningAnalyt. Chem., 1958, 308 354.1 H. W. Bertram, M. W. Lerner, G. J. Petretic, E. S . Roszkowski, and C. J. Rodden390 ANALYTICAL CHEMISTRY.procedure. The principle of an automatic titration unit designed by Brownand Weir,2 which enables them to take a definite volume of ammonia solutionfrom a plant process, to dilute this solution with a selected volume of water,and then to titrate the diluted solution with standard acid to a definite pH,is likely to be of value in other plant control tests.The method adopted bythese authors enables them to record the result and to repeat the sequenceof operations at regular time intervals.Yet another example of automatic analysis is described by Crumley,3who has designed an instrument for the automatic determination of sulphurtrioxide and sulphuric acid vapour in flue gases. The SO, is absorbed inpropan-2-01, and the sulphate precipitated as barium salt which is measuredphotoelectrically. In the range 10-100 p.p.m. the instrument givesresults which are more consistent than those normally obtained by manualdeterminations made by established methods.Also on the subject ofatmosphere analysis, Helwig and Gordon have described an apparatusfor continuous sampling, analysis, and recording of the sulphur dioxidecontent of the air. The method is based on the production of the red-violetcolour caused by reaction of the gas with pararosaniline hydrochloride inacid media.A useful contribution to the several improvements made recently on theWinkler method for the determination of dissolved oxygen in water has beenpresented by Griffiths and Ja~kman.~ In their procedure the iodinetitration is carried out potentiometrically, a glass and platinum electrodepair being used, and the glass electrode is used as reference in a highly acidmedia. The end-point potential difference is reproducible and thus thetitration can easily be put on an automatic and recording basis.Briggset aZ.6 have also developed a novel method for the continuous recordingof the dissolved oxygen content of natural waters and sewage effluents inthe range 0-15.0 p.p.m. by weight of oxygen; the method can be used withwater flowing past the electrodes. The principle of polarographic reductiona t an applied voltage of -0.5 v with respect to a zinc anode is used in thetest. The cathode is quite unconventional, being a capillary of wide internaldiameter, i.e., 0.8 mm., sloping upwards in the solution under test.Chemists concerned with the regular analysis of amino-acids will find themethod of Spackman et a1.' of interest. They have designed an automaticinstrument which records the ninhydrin colour value of the effluent fromion-exchange columns.The eluted material, mixed with a measured flowof ninhydrin reagent, is heated, and the absorbance measured continuouslyat 570 and 440 mp. The instrument will deal with protein and peptidehydrolyzates in 24 hr. and the analysis of blood plamsa, urine, etc., can becompleted in 48 hr. The precision of the method is &3% for the range0.1-3.0 pmoles of each amino-acid separated by the ion-exchange columns.Also constructed for the greater part with well-known commercial instru-2 J. F. Brown and R. J. Weir, Analyst, 1958, 88, 491.4 H. L. Helwig and C. L. Gordon, Analyt. Chem., 1958, 30, 1810.5 V. S. Griffiths and M. I. Jackman, Analyt. Chim. Acta, 1957, 17, 603.6 R.Briggs, G. V. Dyke, and G. Knowles, Analyst, 1968, 83, 304.7 D. H. Spackman, W. H. Stein, and S. Moore, Analyt. Chem., 1958, 30, 1190.P. H. Crumley, J . Inst. Fuel, 1958, 212, 378HASLAM AND SQUIRREL : GENERAL. 391ments, a simple apparatus has been designed by Barrollier et aL8 for thesemi-automatic tracing of the extinction curves of chromatograms andpherograms. A galvanometer light spot reflected from a curved steelmirror is registered as an extinction curve by means of a recorder. The useof this apparatus for quantitative determination of amino-acids by directphotometry of the chromatograms is described.Included in the many papers of general interest is that which describesa new principle put forward by Specker et aL9 for the determination oflithium in alkali chlorides which may have been recovered as such as aresult of various analytical operations.The dried alkali chlorides areextracted with cyclohexanone or acetone, and the lithium in the extracts nowdetermined either photometrically (at 366 mp) or by conductometrictitration with standard copper perchlorate solution. The basis of the testis that, under the experimental conditions, an intense reddish-orangecomplex of the formula Li(CuCl,),nCOR, is produced. Small amounts ofoxide in such substances as lithium nitride and calcium carbide have beendetermined by Juza, Pruff, and Witt.lo The preparation is dissolved inwater-free methanol plus water-free acetic acid, and the water resultingfrom the oxide titrated at 0" with Karl Fischer reagent.Interestingobservations are made on the preparation of water-free methanol, acetic acid,and pyridine.Geilmann l1 has developed methods of determination of certain readilyvolatile elements such as thallium, cadmium, indium, and lead. He hasused the principle to determine " nanograms," i.e., thousandths of amicrogram, of, e.g., lead in copper and filter-paper and thallium in tobacco.The sample is heated in a stream of gas such as hydrogen or nitrogen, andthe volatilised element, e.g., lead or thallium, collected on a cold finger.The cold finger may take the form of an electrode if spectrographic deter-minations are to be carried out subsequently. Alternatively, a quartz coldfinger may be employed if the sublimate is to be dissolved and determinedby chemical procedures.Ion-exchange membranes based on artificialresins l2 are likely to prove of value in analytical separations, e.g., of mag-nesium from aluminium and in preparative chemistry involving thepreparation of complex compounds such as the cobaltammines.The measurement of chloride-ion concentration in dilute solutions( 1 . 0 ~ to ~O+M) has been carried out by Stern et aZ.,I3 and the results expressedas pC1. The measurements are made on a standard pH meter, with asilver chloride indicator electrode and a saturated calomel referenceelectrode. The instrument is standardised by using known chloride solutions(O-~N-KC~ = pC1 1-11; O-O~N-KC~ = pC1 2-04) and measurements can thenbe made on as little as 1 ml. of sample solution.The pC1 can be convertedinto chloride-ion concentration by reference to the appropriate relationship8 J. Barrollier, J. Heilmann, and E. Watzke, J . Chromatog., 1958, 1, 434.9 H. Specker, H. Hartkamp, and E. Jackwerth, 2. analyt. Chem., 1958, 163, 111.10 R. Juza, H. Pruff, and H. Witt, ibid., 159, 277.11 W. Geilmann, ibid., 160, 410.12 E. Blasius and G. Lange, ibid., p . 169.13 M. Stem, H. Shwachman, T. S. Light, and A. J. de Bethune, Analyt. Chem., 1958,30, 1506392 ANALYTICAL CHEMISTRY.curve. The method has been applied to the determination of chloride insweat and no pre-treatment other than dilution of the sample is required.For the turbidimetric determination of small amounts of sulphate,Vosloo and Sampson14 prefer to use a nephelometer rather than anabsorptiometer.In an investigation of the method they conclude that,although the turbidity produced by precipitation as barium sulphate isreproducible, yet it is not strictly proportional to the amount of sulphatepresent, and it is dependent on the volume at which precipitation is carriedout and on the crystal size of the barium chloride used to effect precipitation.The turbidity is, however, independent of temperature and is stable for8 hour. The method, described in detail, appears superior to other formsof the test. The work of Tufts and Lodge l5 on the identification of halideand sulphate in submicron particles using the electron microscope will nodoubt be of use to analysts faced with problems connected with air pollutionand the examination of fine particles.The particles are identified bycharacteristic spot tests after collection on an appropriate substrate, thereagent for chloride being mercurous fluorosilicate and for sulphate a mixtureof barium and lead nitrates. The appearance of the spots resulting fromthe particles, when viewed in the electron microscope, is characteristic andthe size is proportional to the size of the original particles. Hence, as wellas identification, a particle count and a particle-size distribution of eachspecies can be determined after an experimental calibration or proportionalityfactor for each has been determined. A discrepancy in the previouslypublished figure for the solubility of 4-amino-4’-chlorodiphenyl sulphatehas been found by Bengtsson,16 who gives the reason for the discrepancywhich resulted in the previous figure’s being low by a factor of 10.The acidicdissociation constant and solubility of the free arnine are also given, and itsuse as a reagent for the microanalytical determination of sulphate is discussedin the light of the new experimental results.The determination of small amounts of hydrogen cyanide in air, i.e.,down to 1 p.p.m. v/v, by a specific test depends for its success on thepreparation and storage of filter papers of proved performance.17 Thesepapers are of known weight and have total iron, ferrous iron, sulphate, andalkali contents between certain narrow limits. After passage of air con-taining hydrogen cyanide through the papers, they are immersed in sulphuricacid solution to yield Prussian-blue colours proportionate to the amountsof hydrogen cyanide absorbed.A method previously used for the determination of water in paper hasnow been adapted by S.Hill and A. G. Dobbs18 to its determination ingranulated sugar. The sample is weighed, sealed in a thin glass ampoule,which is then enclosed in a flask that can be evacuated. After evacuationof the flask the ampoule is broken and, by the grinding action of four steelballs, the sugar is ground to a specific surface of not less than 3500 sq. cm.per g. The water is now driven off by heating the flask and contents for14 P. B. B. Vosloo and D. Sampson, S. African Ind. Chemist., 1958, 12, 48.15 B. J. Tufts and J. P.Lodge, jun., Analyt. Chem., 1958, 30, 300.16 T. A. Bengtsson, Analyt. Chim. Acta, 1958, 18, 353.17 B. E. Dixon, G. C. Hands, and A. F. Bartlett, Analyst, 1958, 83, 199.18 S. Hill and A. G. Dobbs, zbid., p. 143HASLAM AND SQUIRRELL: GENERAL. 39315 hr. at 60°, the water being collected in a cold trap surrounded by ethanoland solid carbon dioxide. This condensed water is finally allowed toevaporate into a space of known volume; the pressure exerted in thisvolume is a measure of the water content. S. D. Gardiner and H. J. Keyte l9have investigated the problem on quite different lines. Their method,whether before or after grinding, i.e., whether for free or total moisture,involves reaction of the water with a chloroform solution of cobaltousbromide and the production of cobaltous bromide hydrate which is filteredoff.Its amount, determined by evaporation of known aliquot parts ofthe cobaltous bromide reagent before and after reaction with the sugar, is ameasure of the water absorbed by the sugar.In connection with the examination of salt-water and other swimming-pools, Johannesson 20 has developed useful methods of determination ofmonobromamine and monochloramine in water. In one method the wateris treated with a neutral o-tolidine reagent containing sodium hexameta-phosphate which acts as a combined buffer and sequestering agent. Themonobromamine produces a blue quinonoid derivative which is titratedwith ferrous ammonium sulphate solution. After this, iodide is added, andthe monochloramine produces another blue compound which is titratedwith ferrous ammonium sulphate solution.Alternatively, with a rotatingplatinum electrode and a saturated calomel electrode, the monobromaminecan be titrated amperometrically with phenylarsenoxide solution. Oncompletion of this titration, iodide is added and monochloramine nowtitrated with the same solution.Difficulties in the determination of phthalates in propellants containingnitro-aromatic compounds have been overcome by Nonvitz.21 In hismethod the phthalate ester is extracted with ether and the nitro-compoundsare reduced by boiling with a specified concentration and volume of aceticacid and zinc. The phthalate is then extracted from the acetic acid solutionby means of light petroleum, and determined volumetrically by a hydrolysisprocedure. The extent of any interference by other esters and compoundspresent in propellants has been tabulated.Guenther 22 has utilised methyl-magnesium iodide as Grignard reagent for the gasometric determinationof the silanol group in complex silanols and silicone resins. A solution ofthe sample is added in a specially designed apparatus to 2~-Grignard reagent,butyl ether being used as solvent and methane as the inert gas. Theadvantages of the method are simplicity and efficiency at room temperature.Other interesting tests have been developed for the determination ofalkyl- and aryl-chlorosilanes in air.23 These are based on the colorimetricreaction of the substituted silane with a solution of tetramethyldiamino-benzophenone in aniline.Phenyltrichlorosilane can be determined colori-metrically by reaction with anhydrous aluminium chloride and a benzenesolution of tetramethyldiaminobenzophenone. In addition, a usefulcryoscopic method which may find application in other ways has beenl9 S. D. Gardiner and H. J. Keyte, Analyst, 1958, 83, 150.2O J. K. Johannesson, ibid., p. 155.21 G. Norwitz. Analyt. Chim. Acta, 1958, 19, 216.22 F. 0. Guenther, Analyt. Chem., 1958, 30, 1118.23 F. D. Krivoruchko, J . Analyt. Chem. (U.S.S.R.), 1957, 12, 245394 ANALYTICAL CHEMISTRY.detailed by Mullen for the determination of the y-isomer in the impure" benzene hexachloride " isolated from various dip-washes. Portions ofthe isolated impure benzene hexachloride are dissolved both in benzene andin a pure sample of the y-isomer.The depression of the solvent freezing pointis measured in each case, and from the results obtained the proportion ofy-isomer in the original sample can be calculated. The use of the benzenesolvent allows the effective molecular weight of the impure extract to bedetermined. Interesting methods have been developed by Paul 25 in thebiochemical field for the determination of the major constituents of samplesof tissue of about 1 mg. dry weight. Lipids are extracted with fat solvents,and the amount in the extract determined by dichromate oxidation. Ex-traction with cold N-sulphuric acid now yields a second fraction; carbo-hydrates are determined in this fraction by the anthrone test.Extractionwith hot N-perchloric acid solution yields a third fraction containing morecarbohydrate and the nucleic acids. The carbohydrate is determined by theanthrone method, and the total nucleic acids by measurement of the ultra-violet absorption a t 268 mp. Deoxyribonucleic acid is determined inde-pendently in this fraction by the indole test and hence ribonucleic acid isobtained by difference. Protein nitrogen is determined in the residue fromall the above extractions by a modified Kjeldahl procedure. Also two newmethods for the oxidative determination of blood alcohol are described byKirk et a1.26 The first method uses a modified form of dichromate oxidationof the alcohol after steam-distillation from a folded filter paper impregnatedwith acid salts to retain any basic components in the blood sample.Aldehydes and ketones and any organic acids are retained by washingthrough an alkaline mercuric oxide suspension.After oxidation, the excessof dichromate is determined by the conventional procedures. The secondmethod utilises a diffusion technique and oxidation of the diffused alcoholby an enzyme preparation containing liver alcohol dehydrogenase andco-enzyme 1. The absorbance of the enzyme oxidation product is measuredat 340 mp. The apparatus used is extremely simple.3. QUALITATIVE AND QUANTITATIVE INORGANIC AND ORGANIC ANALYSISQualitative.-Clark has summarised much of his work on toluene-3,4-dithiol as a general analytical reagent in qualitative analysis.27 The reagentcan be used for many of the purposes for which hydrogen sulphide has beenused in the past.It has certain advantages; e.g., it can be added inregulated amounts and the complexes which it forms with various metallicions are often highly coloured and moreover they coagulate readily. Thereactions can often be made highly selective by appropriate choice of operat-ing conditions. Objections to the reagent on the grounds of its instabilitymay be overcome by generation of the substance when required from itsdiacetyl derivative or its zinc salt. As a result of further work, Clark2824 J. D. Mullen, Analyt. Chim. Acta, 1958, 18, 189.B6 J. Paul, Analyst, 1958, 83, 37.26 P. L. Kirk, A. Gibor, and K. P. Parker, Analyt. Chem., 1958, 30, 1418.27 R.E. D. Clark, Analyst, 1958, 83, 396.28 Idem, ibid., p. 103HASLAM AND SQUIRRELL : QUALITATIVE AND QUANTITATIVE. 396has drawn attention to other very useful properties of diacetyldithiol. Itis a very useful reagent for the coagulation of Group I1 sulphides and forsulphur in acid solution. In addition, it catalyses the reduction of arsenatesand molybdates in the presence of hydrogen sulphide and acts as a precipitantfor tungsten(v1) in dilute acid solution in the absence of silicate.Useful specific reagents and spot tests have been described with applic-ation to inorganic analysis. Goldstein and Stark-Mayor z9 have definedconditions under which glyoxal bis-(2-hydroxyanil) can be used as a specifictest reagent for calcium; the test is particularly applicable to the detectionof calcium oxide in admixture with other colourless oxides and to the detec-tion of calcium in pharmaceutical products.According to Xavier’s ~ o r k , ~ Othere appears to be considerable doubt as to whether 2-mercaptoquinolinewill find application for quantitative work. On the contrary, it is likelythat it will prove to be a sensitive spot reagent for copper and palladium,with which it yields orange-yellow colours.Extending their work on the use of naphthalene derivatives in organicanalysis, Anderson, Garnett, and Lock31 have described the use of2-hydroxy-6-nit ronaphthalene-8-sulphonic (7-hydroxy-3-nitronaphthalene-l-sulphonic) acid as a new fluorimetric reagent for the detection of tin in thepresence of many other ions.When tin is present in the spot of the testsolution treated with a O-lyo solution of the ammonium salt of the reagent adark purple colour showing faint fluorescence is observed. After spray-ing with 15~-ammonium hydroxide solution, however, an intense bluefluorescence is produced. Other ions give coloured spots which are notfluorescent; 10-8 g. of stannous tin can be detected under the conditions ofthe test.Feigl, Goldstein, and Rosel132 have put forward a useful test for thedetection of trace amounts of chloride in fine chemicals. The test substanceis heated with chromic-sulphuric acid. mixture, and the vapours evolvedare passed through 4,4’-bisdimethylaminothiobenzophenone paper, withwhich free chlorine gives a blue coloration.The test will detect silverchloride in the presence of the ferrocyanide, ferricyanide, thiocyanate, andcyanide of silver. Also on the detection of anions, Coldwell and McLean 33have shown that under the influence of short ultraviolet radiation diphenyl-amine and nitrate salts react photochemically to form a yellow product.This reaction has been used in a sensitive and specific spot test for nitrate ion,which is carried out on a filter-paper support. It is possible to detect1 pg. of NO,- in 0-01 ml. of solution by this test.In the field of organic qualitative analysis, Soloway and Rosen 34 haveclassified organic compounds according to their effectiveness in promoting orinhibiting chelation between ferric chloride and n-propyl gallate. It isreported that this classification, used in conjunction with others based on29 D.Goldstein and C. Stark-Mayor, Analyt. Chim. Ada, 1958, 19, 437.30 J. Xavier, 2. analyt. Chem., 1958, 163, 182.31 J. R. A. Anderson, J. L. Garnett, and L. C . Lock, Analyt. Chim. Ada, 1958, 19,32 F. Feigl, D. Goldstein, and R. A. Rosell, 2. analyt. Chem., 1957, 158, 421.33 73. B. Coldwell and S. R. McLean, Canad. J . Chem., 1958, 36, 652.34 S. Soloway and P. Rosen, Analyt. Chem., 1957, 29, 1820.256396 ANALYTICAL CHEMISTRY.solubility, elementary analysis, and reaction to acid-base indicators, willpositively identify many classes of compound and will distinguish somealiphatic compounds from their aromatic counterparts. KolSek and hisco-workers 35 have shown that P-dimethylaminobenzaldehyde appears tohave particular advantages for the characterisations of primary aromaticamines.The Schiff's bases produced by the reaction of the aromatic aminewith the reagent are readily isolated and possess high and sharp meltingTwo tests devised by Trofimenko and Sease= have made it possiblereadily to differentiate nitriles, N-unsubstituted amides, and N-mono- or-di-substituted amides. In the first test the sample is decomposed byheating with soda-lime. Any ammonia or amine liberated is detected byvola t ilisat ion into met hanolic copper sulphat e solution, characteristicreactions being observed. In the second test account is taken of the form-ation of organomercury compounds by those amides having a hydrogenattached to the amide nitrogen.In the presence of ignited calcium oxideo-aminophenol and glyoxal unite to give the intensely red inner complexcalcium salt of a Schiff's base. This reaction 37 forms the basis of new spottest reactions for o-aminophenol and glyoxal.have shown that 2-diphenylacetylindane-l,3-dionel-hydrazone is potentially a most valuable reagent for identification andcharacterisation of carbonyl compounds, giving crystalline derivatives withwell-defined melting points and showing strong fluorescence in solutionand in the solid state. It is suggested that this fluorescence might be ofuse for the identification of carbonyl compounds by paper or columnchromatography. The azines are easily prepared by refluxing the aldehydeor ketone with the reagent in a solvent containing an acid catalyst.Eventhe long-chain alkyl carbonyl compounds form crystalline derivatives asdistinct from the oils usually obtained with 2,4-dinitrophenylhydrazine., Quantitative (Gravimetric) .-Development of gravimetric methods hasbeen confined largely to inorganic analysis. For example, Riley39 hasshorn that water and carbon dioxide may be determined simultaneouslyand speedily in rocks and minerals. The sample is heated to 1100-1200° ina silica tube in a stream of nitrogen. Oxides of nitrogen are removed fromthe products of heating by passage over heated copper wire at 700". Thetube containing the copper wire also contains silver pumice for the removal ofsmall amounts of sulphur compounds. The water is determined gravi-metrically by absorption on magnesium perchlorate. After removal ofwater, excessive amounts of sulphur compounds are removed by passagethrough a bubbler containing chromium trioxide in phosphoric acid beforegravimetric absorption of carbon dioxide on soda-asbestos.A macro-procedure previously developed for the macro-gravimetricdetermination of beryllium has now been adapted for the correspondingmicro-determination.The beryllium is precipitated and weighed aspoints.Braun and Moshera5 J. KolSek, N. Novak, and M. Perpar, 2. analyt. Chern., 1957, 159, 113.a6 s. Trofimenko and J. W. Sease, Analyt. Chem., 1958, 30, 1432.87 F. Feigl and D. Goldstein, 2. analyt. Chem., 1958, 163, 30.$8 R. A. Braun and W. A. Mosher, J . Amer. Chem.SOL, 1958, 80, 3048.39 J. p. Riley, Analyst, 1958, 83, 42HASLAM AND SQUIRRELL QUALITATIVE AND QUANTITATIVE. 397[Co ( NH3)6] [ (H,O) ,Be,( CO,) 2( OH),] ,3H,O and the factor for conversion toBe is 0-041. The procedure40 is particularly useful for the determinationof beryllium in the-presence of iron, aluminium, and magnesium, which areheld in solution by means of the disodium salt of ethylenediaminetetra-acetic acid. 5-Hydroxy-4-azaphenanthrene has been described byJakubke 41 as a suitable reagent for the gravimetric determination of cupriccopper. The copper is precipitated as a chelate from alkaline tartratesolutions by an alcoholic solution of the reagent; chromium(III), iron(III),aluminium(m), bismuth(m), lead(@, and zinc(11) do not interfere.J. E.Banks,42 in continuing his work on the gravimetric uses of benzene-phosphinic acid, has put forward a micro-method for the determinationof iron. As little as 2 mg. of ferric iron can be precipitated quantitativelyas ferric benzenephosphinate. An advantage of the micro-method, apartfrom speed, is that errors due to solubility of the precipitate in wash-liquorsare much reduced. New information has been given by Ramana Rao*on the oxine complex of molybdenum. He has shown that under deiinedconditions the precipitate is not formed at pH values higher than 2.24.In the estimation of other metals by the oxine method interference due tomolybdenum may be avoided by using a high pH value; no other externalcomplexing agent is necessary.Pietsch 44 has made a critical examination of the precipitation of uraniumwith cacodylic acid in the presence of many other metals.Uranium may bedetermined gravimetrically by this test ; glass fdters are much more suitablefor the filtration of the precipitate than are filter-papers. A thorough studyof the experimental conditions for the quantitative precipitation of phos-phorus as 3-oxine-l-phospho-12-molybdate has been made by Gottschalk 45in the range 10-0.5 mg. of P and also in the range 1 4 . 0 5 mg. of P. Hedeals with the relative correction which has to be applied in different casesbecause of solubility losses and also with the determination of phosphorusin FeIII EDTA-masked solutions as well as in certain unmasked solutionsof bivalent cations.Quantitative (Volumetric) .-Conventional volumetric analytical methodshave as usual been very numerous and we are able to review but a few.Newprimary standards are always of interest and sodium hydrogen diglycollatehas been suggested by Keyworth and Hahn 46 as a new primary standard foralkalimetric work. The salt is easily prepared, recrystallised, and dried togive a material which assays at 100.OO~o & 0.05%. It is soluble in waterand gives easily detectable end-points when titrated with phenolphthaleinas indicator.Many new indicators have been described, and ion-exchange resinsincorporating Thymol Blue, Bromocresol Green, and phenolphthaleinindicators have been used successfully by Miller 47 in acid-base titrations.40 Th. I. Pirtea and G.Mihail, 2. analyt. Chem., 1958, 159, 205.4 1 D. Jakubke, ibid., 160, 6.42 J. E. Banks, Analyt. Chim. Acta, 1958, 19, 331.43 D. V. Ramana Rao, ibid., 1957, 17, 538.J1 R. Pietsch, 2. analyt. Chem., 1958, 159, 343.G. Gottschalk, ibid., p. 257.16 D. A. Keyworth and R. B. Hahn, Analyt. Chem., 1958, 30, 1343.1' W. E. Miller, iFid., p. 1462398 ANALYTICAL CHEMISTRY.The advantages of the resin indicators are that they are in a separate phasefrom the solution and thus do not contaminate it for further work and arerecoverable for re-use. The resin may also be loaded to the limit of itsion-exchange capacity with indicator, resulting in a highly concentrated“ point ” indicator. The indicator PAR (4-2’-pyridylazoresorcinol) 48appears to have particular advantages in the titration of tungstates withstandard lead solution.The titration is carried out at boiling temperaturein the presence of hexamethylenetetramine as buffering agent ; the titrantmust be added at a definite slow rate.Copper phthalocyaninesulphonic acid 49 has proved a particularly usefulindicator for titrations of dilute uranium(1v) solutions at room temperaturewith standard ceric sulphate solution in the presence of sulphuric and phos-phoric acids. The indicator correction is quite low and the principle ofthe test may be extended to the corresponding titrations of molybdenum(v)and arsenic@) solutions. This versatiie indicator 50351 has also been usedwith success for the cerimetric titration of quinol and in the pennanganatetitration of iron(II), uranium(Iv), and potassium ferrocyanide.New indicators have also been used for complexometric titrations andwe include these together with a few of the many papers describing more ofthe growing uses of EDTA in analytical chemistry. In an address to theSociety for Andytical Chemistry on Recent Deselopments in Chelatometry,R.Pfibi152 draws attention to the effect of pH on complex formation byEDTA and to new indicators for complexometric titration such asXylenol Orange, Methylthymol Blue, Thymolphthalenone and Fluorexone,Glycine-Thymol Blue and Glycine-Cresol Red as well as certain azo-dyes.As a result of the introduction of these indicators there are new possibilitiesin the reagents used to screen certain cations in complexometric work.Eriochrome Blue SE 53 in the presence of a green screening agent, Acid GreenG, has been shown to be a useful indicator for the titration, at high pHvalues, of zinc, cadmium, magnesium, lead, nickel, and manganese withEDTA.Many interesting possibilities have been opened up by the discovery 5pthat several bivalent metals, such as lead, zinc, calcium, and magnesium, canbe determined potentiometrically by an EDTA procedure.Excess ofEDTA is added to the solution and this excess, often in the presence ofother complexing agents, is back-titrated in the pH region 8-12 by meansof a standard solution of mercuric nitrate. A silver electrode amalgamatedwith mercury is used as indicator electrode, and a calomel electrode asreference.The principle has been extended to the corresponding determin-ation of thorium 55 and to the determination of small amounts of aluminiumand manganese.56 The aluminium (or manganese) is complexed with excess48 R. Puschel, E. Lassner, and R. Scharf, 2. analyt. Chem., 1958, 163, 344.49 T. P. Sastri and G. G. Rao, ibid., p. 1.50 I d e m , ibid., p. 263.51 I d e m , ibid., p. 266.62 R. Piibil, Analyst, 1958, 83, 188.5s A. A. Abd. El Raheem and Abdel-Aziz M. Amin, 2. anaZyt. Chem., 1958,163, 340.54 H. Khalifa, R. Patzak, and G. Doppler, ibid., 161, 264.55 H. Khalifa, ibid., p. 401.18 I d e m , ibid., 1958, 163, 81HASLAM AND SQUIRRELL : QUALITATIVE AND QUANTITATIVE. 399of EDTA, and this excess is back-titrated a t the appropriate alkaline pHwith standard mercuric nitrate solution, a silver-mercury amalgam electrodebeing used as indicator electrode.In determining chromium(II1) in chromicacid solutions, Weiner and Ney5' have shown that it is necessary first toremove chromate. This is precipitated and removed as mercurous chromate,and excess of mercurous reagent is precipitated and removed as chloride.The tervalent chromium is now complexed by boiling with excess of EDTAbefore back-titration of the excess with standard nickel solution, murexidebeing used as indicator.The metal content of salts of organic acids commonly used as paintdriers can be conveniently determined by a direct and simple methoddue to Lucchesi and H i ~ - n . ~ ~ The salt is dissolved in alcohol-benzenesolution, and the metal chelated with EDTA without prior decom-position of the salt.The excess of EDTA is then back-titrated withzinc chloride to the Eriochrome Black T end-point. Some of the metalsto which the method is applicable are calcium, cobalt, zinc, lead, andmanganese.General inorganic volumetric methods include that for the determinationof aluminium in bauxite and other aluminous materials, which can becarried out rapidly and precisely by a method described by Watts.59 Potass-ium fluoride is added to the aluminium solution at pH 10, and the hydroxidewhich is thus liberated is titrated with standard acid back to the original pH.The titration can be carried out in the presence of any iron and titaniumprecipitated as hydroxides, and interfering calcium can be precipitated asoxalate.Picolinic acid and quinaldinic acid are very effective reagents for theseparation of palladium from other ions.Majumdar and Sen Gupta60761have shown that the palladium in such precipitates can be readily determinedby volumetric procedures in which either (a) the precipitate is dissolved inpotassium cyanide, and the excess of cyanide determined by back-titrationwith standard silver solution in ammoniacal media with potassium iodidesolution as indicator, or (b) the precipitate is dissolved in potassium nickelcyanide, liberating an equivalent amount of nickel, which is titrated withthe sodium salt of ethylenediaminetetra-acetic acid, murexide being used asindicator.In the reduction of uranium(v1) solutions by passage through zincreductors, not all the uranium is recovered from the reductor in theuranium(1v) condition; this is the state which is desirable if the amountpresent is to be determined by titration with oxidising agent.Rao andRao,62 however, have shown that if the uranium(v1) solution is treatedwith diethyl ether and sulphuric acid, then exposed to bright sunlight orthe light from a high-pressure mercury vapour lamp, quantitative con-version only into uranium(1v) takes place.57 R. Weiner and E. Ney, 2. Analyt. Chem., 1958, 161, 432.58 C. A. Lucchesi and C. F. Hirn, Analyt. Chem., 1958, 30, 1877.59 H. L. Watts, ibid.. p. 967.60 A. I<. Majumdar and J. G. Sen Gupta, 2. analyt. Chem., 1958, 161, 179.61 Idem, ibid., p.181.62 V. Panduranga Rao and G. Gapala Rao, ibid., 160, 190400 ANALYTICAL CHEMISTRY.The analysis of metal vanadium oxygen compounds similar to 2MgO,VO,,where the state of oxidation of the vanadium may not correspond exactly to2.00 presents certain difficulties. These are solvede3 by the addition of aknown amount of standard permanganate to a solution of the sample, ie.,sufficient to convert the vanadium a t least above the oxidation stage V*+.The excess of permanganate is now back-titrated to the quadrivalent vanad-ium stage with standard ferrous sulphate, sodium N-methyldiphenylamine-+-sulphonate being used as indicator. The difference between the per-manganate and the ferrous sulphate titres gives a measure of the state ofoxidation of the vanadium. A modification of the procedure enables totalvanadium to be determined.LangM has shown that small proportions of borate can be determinedin aqueous extracts of certain fertilisers, by a rapid method which does notsuffer interference from either carbonates or phosphates.The methodinvolves titration of an acid extract to pH 6, followed by addition of mannitoland re-titration to pH 6. Szekeres and BakAcs-Polgar 65 have put forward arapid procedure for the determination of alkali bicarbonates in the presenceof alkali carbonates. The carbonate is first precipitated as barium carbonateby the addition of sodium or potassium chloride and barium chloride. Thebicarbonate in the suspension is now titrated with sodium hydroxidesolution, with phenolphthalein as indicator.A rather complicated methodhas been devised for the determination of chloride in connection with theexamination of de-caff einised coffee for traces of chlorinated hydrocarbonsolvent.66 This draws attention to the fact that much better methods areavailable for the determination of traces of chloride of which the authorsappear to be unaware. These authors precipitate and isolate the chlorideas silver chloride, then convert this into metallic silver with alkali andformaldehyde. The silver is dissolved in acid and determined by titrationwith dithizone solution.Archer 67 has developed methods for the titration of iodides, bromides,and chlorides which are based on titration of acetone solutions of the halidewith standard silver nitrate (usually in n-propyl alcohol solution), dithizonebeing used as end-point indicator. Modifications of the method enablecyanide and silver to be determined. The methods may also be adapted tothe determination of halogens in organic compounds after preliminarybreakdown by either the Carius procedure or the Schoniger oxygen com-bustion method.A useful paper by Sarson 68 describes how non-aqueoustitrations afford an accurate and rapid method of analysis of explosives.Organic and inorganic nitrates are first separated by hot isobutyl methylketone extraction, before titration with perchloric acid or tetrabutylammon-ium hydroxide to indicator end-points or by automatic titration. Variationsin titrant, indicator, and solvent permit differential determination of variousinorganic and organic nitrates.63 B.Reuter and J. Siewert, 2. analyt. Chem., 1958, 162, 175.64 K. Lang, ibid., 163, 241.65 L. Szekeres and E. Bakhcs-Polgar, ibid., 159, 414.66 H. Suter and H. Hadorn, ibid., 160, 335.6 7 E. E. Archer, Analyst, 1958, 83, 571.6 8 R. P. Sarson, Annlyt. Chein., 1958, 80, 932HASLAM AND SQUIRRELL QUALITATIVE AND QUANTITATIVE. 401Phosphorus in condensed sodium phosphates 69 can be readily deter-mined by a method in which the polyphosphate is hydrolysed extremelyrapidly with concentrated hydrochloric acid, and the resulting ortho-phosphate precipitated as quinine phosphomolybdate before titration withstandard alkali using an indicator end-point. Alternatively, the titrationis carried out automatically.A method, which may well have otherapplications, has been presented by Seidman 70 for the determination ofsmall amounts (as low as O . O O l ~ o v/v) of sulphur trioxide in stack gasescontaining up to 0.3% v/v of sulphur dioxide. The sulphur trioxide isabsorbed quantitatively in 80% propan-2-01 which prevents oxidation ofsulphur dioxide. The sulphate is then titrated with standard bariumchloride solution, Thorin being used as indicator. Ammonia and nitrogenoxides do not interfere. Krause and Busch71 have been interested inthiosulphate and the tri-, tetra-, and penta-thionates. They have describeda convenient method of oxidising these compounds to sulphate with a hotsolution of cerium(1v) in perchloric acid.The excess of cerium is then back-titrated with sodium oxalate, nitro-ferroin being used as indicator. Halideand dithionate interfere.We turn now to volumetric tests as applied to organic analysis. Aninteresting new test 72 has been developed for the determination of thechlorine content of some organo-chlorosilanes. The sample, in ether solution,is titrated with a solution of ammonium thiocyanate in acetone. Ammoniumchloride is produced as a result of the reaction, and the end-point in thetitration is recognised by the production of a persistent red colour due toferric thiocyanate, ferric chloride being added a t an appropriate point in thetitration. Grover and Mehrotra 73774 have paid particular attention to thepotentialities of alkaline hypobromite solution as a volumetric oxidisingagent in connection with the determination of ammonia (oxidised to nitrogenand carbon dioxide) and urea and thiourea (oxidised to sulphuric acid andnitrogen).The reagent oxidises both propan-2-01 and acetone quantitativelyto acetic acid and carbon dioxide; under controlled conditions, chromic acidoxidises propan-2-01 to acetone only. Hence, by procedures employingboth the oxidising agents, mixtures of propan-2-01 and acetone can bereadily analysed.A simple method for the determination of the equivalent weights ofphosphorus and sulphur esters and of alkyl halides described by Baldwinand Higgins 75 is based on the following principles. The ethanolamine saltof the ester or halide is first formed by refluxing the sample with the base.The solution of this salt is then passed down a column containing cation-exchange resin in the hydrogen form, the cation of the salt being exchanged forhydrogen; the free acid in the effluent from the column can be titrated, andthe equivalent of the original ester or alkyl halide calculated from the result.69505 172S.Zechner and V. Reppestam, 2. analyt. Chem., 1958, 163, 423.E. B. Seidman, Analyt. Chem., 1958, 30, 1680.R. A. Krause and D. H. Busch, ibid., p. 1817.T. Takiguchi, Analyst, 1958, 83, 482.73 K. C. Grover and R. C. Mehrotra, 2. analyt. Chem., 1958, 160, 267.54 Idem, ibid., p. 274.I . ’ W. H. Raldwin and C. E. Higgiiis, .47ro/j*t. Chew?., 1958, 30, 446. - 402 ANALYTICAL CHEMISTRY.Schulek and Maros76 have presented an iodometric method for thedetermination of methanesulphonic acid derivatives.The method, whichis particularly useful for medicinal products since it can be applied in thepresence of antipyrine and pyramidone, is based on decomposition of thesulphonic acid with potassium cyanide in moderately alkaline medium togive sulphite and glycollic acid. The sulphite is then titrated in acid mediawith standard iodine solution in the presence of the other degradationproducts and any excess of hydrogen cyanide.Under appropriate conditions 77 polyethylene oxides have been shown toreact with barium chloride and sodium tetraphenylborate to yield insolublesubstances of definite compositions, which may be used for the detectionand determination of the polyethylene compounds.The insoluble productsare readily analysed. On treatment with mercuric chloride solutionproportionate amounts of hydrochloric and boric acids are liberated whichmay then be determined by conventional procedures. In a short communic-ation Sant and Sankar Das78 have described a method for the assay oftributyl phosphate in organic solvents. The tributyl phosphate is convertedinto inorganic orthophosphate by fusion with sodium hydroxide at a lowtemperature. The orthophosphate is then titrated with standard bismuthylperchlorate, saturated 1,2-di[allyl(thiocarbamoyl)] hydrazine in chloroformbeing used as an extraction indicator.It is known that determinations of nitrogen in certain high polymersand copolymers, e.g., polyacrylonitrile , copolymers of vinyl chloride andacrylonitrile, polyvinylpyrollidone, and polyvinylcarbazole, may yieldlow results if conventional Kjeldahl procedures are used.Skoda andS c h ~ r y , ~ ~ however, have shown that if a digestion medium containing coppersulphate, mercuric oxide, sodium sulphate, and mercury is used in thedigestion, and thiosulphate added to the alkali required in the neutralisationof the digestion product, then accurate figures for nitrogen are obtained.Whitehurst and Johnsonso have developed a method for the chemicaldetermination of aliphatic nitriles. The solution of the nitrile is treatedwith hydrogen peroxide and a known amount of standard potassiumhydroxide solution. The solution is then concentrated, one mole of basebeing consumed for each mole of nitrile in the overall reaction of hydrolysingit to the salt of the corresponding acid.The excess of alkali is then deter-mined in the conventional way, and hence the concentration of nitrilecalculated.Huhn and Jenckel *l have shown that maleic acid-maleic anhydridemixtures may be analysed by a method involving (a) titration with aqueousalkali, in which both substances react, and (b) titration with sodium meth-oxide, in which the acid uses twice as much titrant as the anhydride. Theprinciple of the method has been applied to the analysis of mixed poly-merisates of maleic acid and anhydride containing large amounts of styrene.76 E. Schulek and L. Maros, Analyt. Chim. Acta, 1958, 19, 4.77 R.Neu, Fette u. Seifen, 1957, 59, 823.78 U. A. Sant and H. Sankar Das, Analyt. Chim. Acta, 1958, 19, 202.70 W. Skoda and J . Schury, 2. analyt. Chem., 1958, 162, 259.80 D. H. Whitehurst and J. B. Johnson, Analyt. Chem., 1958, 30, 1332.81 H. Huhn and E. Jenckel, 2. analyt. Chem., 1958, 163, 427HASLAM AND SQUIRRELL: PHYSICAL METHODS. 403Finally, Hennart and Merlin 82 prefer to use anhydrous propionic acidin place of acetic acid for the direct titration of quaternary ammoniumcompounds with perchloric acid in non-aqueous media. The titrationmethod, which is particularly useful for the assay of commercial products,can be carried out potentiometrically or by using Metanil Yellow; thisindicator is found to give its colour change exactly at the point of maximuminflection in the titration curve.4.PHYSICAL METHODSElectrical.-The papers presented at the Symposium on Modem Electro-chemical Methods of Analysis held in Paris, July, 1957, have been printedin the January/February issue of Analytzca Chimica A~ta.~3 In consequence,this volume will be of more than ordinary interest to those analysts usingelectrical methods in any form. Many branches of the subject are covered,and these include Chronopotentiometry, Amperometric titrations, Potentio-met ry, Coulomet ry, Polarography, and High-frequency t itrat ions, Paperson adsorption kinetics and electrode processes and on newer methods ofelectrolytic conductivity measurement are also given, as well as a contro-versial feature on the desirability of adopting the coulomb as a universalstandard in place of the many chemical standards at present used.Under the heading of potentiometric methods the following work meritsattention. Based on studies made on some compounds as sensibilisatorsin the photolysis of silver halides, G.Asensi Mora 84 has described a rathernovel method of titration of halides in solution. Sodium thiosulphate isadded to the halide solution which is then brought to a pH of 6-6.5, andthe titration carried out with silver nitrate solution. A t the equivalencepoint, when a slight excess of silver ions is present, these ions react withthe thiosulphate to give Ag2S,03 which in turn decomposes to give riseto hydrogen ions: S,O,Ag, + H20 Ag,S + S 0 2 - + 2H+. A t theequivalence point there is thus a sharp change in pH which can be followedby using a pH meter and appropriate electrodes.The method has givenexcellent results for the titration of N/10- and N/100-solutions of all threehalides and thiocyanate solutions. Ivanova and Kovalenko 85 have shownthat calcium and magnesium, when present together in solution, can bedetermined with considerable accuracy by titration with potassium phos-phate solution and use of a zinc phosphate electrode.dead-stop ” andpotentiometric titration methods for the determination of primary aromaticamines with nitrous acid. They find that the potentiometric method ismore widely applicable and is less subject to interference than the dead-stopprocedure. A platinum-calomel electrode pair is used, and in titrations ofsulphanilamide and o-anisidine comparable precision is obtained whethercommercial automatic titrimeters or normal manual titrations are used.In the organic field, Butt and Stagg 86 have compared82 C.Hennart and E. Merlin, Chim. analyt, 1958, 40, 167.83 Analyt. Chim. Acta, 1958, 18, 1-184.84 G. Asensi Mora, Anales real SOC. espafi. FCs. QuCm., 1957, 53, B, 697.85 2. I. Ivanova and P. N. Kovalenko, J . Analyt. Chem. (U.S.S.R.), 1957, 12, 179.86 L. T. Butt and H. E. Stagg, Analyt. Chim. Ada, 1958, 19, 208404 ANALYTICAL CHEMISTRY.The titration of weak bases such as aniline in aqueous solution is alsopossible by the method of Critchfield and Johnson,87 who find that reasonableend-points can be obtained by making the solution 6-SM with respect to aneutral salt before titration.Indicators can be used for bases of ionisationconstant down to 1 x and potentiometric methods are applicableto bases with ionisation constants as low as 1 x Differential titrationsare also possible. Schouteden and Herbots88 are interested in polymersobtained by treating polyacrylamidoxime with hydroxylamine in sulphatesolution. The determination of free ammonia and hydroxylamine in suchpolymeric systems containing a large percentage of hydroxamic acid sidegroups is not possible without first removing the polymer. They thus firstprecipitate the polymer as its Fe(1rr) complex, and after removal of excessof Fe@) ions as Fe(OH), by addition of sodium hydroxide solution, titratethe mixed bases potentiometrically.Reasonable differential titration curvesare obtained by using 0.1N-hydrochloric acid as titrant and a conventionalpH meter with a glass-calomel electrode system.An important contribution to the work on titrations in non-aqueousmedia has been made by Yakubik et aZ.,89 who have described how, by usinga glass-silver electrode pair and the proper choice of solvent and titrant,potentiometric titration curves with sharp voltage peaks at the end-pointcan be obtained. The shape of the titration curves is similar to the firstderivative curves from ordinary potentiometric titrations. ConventionalS-shaped curves are obtained with very weak acids, and differential titrationsare possible by using sodium methoxide as titrant and neutralised pyridineas the titration solvent.Cundiff and his co-workers in three papers90-92 have added to theinformation about the use of the versatile titrant tetrabutylammoniumhydroxide.In the first they describe the use of the titrant for the deter-mination of the " equivalent " of 2 : 4-dinitrophenylhydrazones of aldehydesand ketones, which may be titrated as weak acids in pyridine solution.Isomerisation of the carbonyl compound does not affect the neutralisationequivalent, and the figure obtained is most useful in the characterisation ofthe derivative and parent aldehyde or ketone. The second paper givesmore information on the effect of solvent in the non-aqueous titration ofstrong acids, and pyridine is recommended for this purpose.This work iscontinued in the third paper which described how an impurity in the titrant,which can give rise to an error in the titration of strong acids or mixturescontaining strong acids, can be easily removed by passage over an ion-exchange column Amberlite IRA 400 (OH). This treatment makes thetitrant effective for titrating all types of acid but is not necessary for usewith weak or very weak acids alone. Harlow and Wyld 93 have shown thatinflections obtained in potentiometric titrations of very weak acids in acetone87 F. E. Critchfield and J. B. Johnson, Analyt. Chem., 1958, 27, 1247.88 F. Schouteden and J. Herbots, Makromol. Chem., 1958, 27, 256.89 M. G. Yakubik, L. W. Safranski, and J. Mitchell, A~zalyt. Chem., 1958, 30, 1741.90 A.J. Sensabaugh, R. H. Cundiff, and P. C. Markunas, ibid., p. 1445.91 R. H. Cundiff and P. C. Markunas, zbid., p . 1447.92 Idem, ibid., p . 1450.93 c;. .A. IlarIow and C. E. A. Wyld, ibid., p. 73HASLAM AND SQUIRRELL PHYSICAL METHODS. 405and pyridine are greatly affected by the acidity of the titrant solvent.They show that tetra-n-butylammonium titrants prepared in propan-2-01are superior for this work to titrants made in ethanol, methanol, or water.A rapid and simple procedure for the titration of amides or bases withperchloric acid in acetic acid or dioxan has been developed by Wimer.94The solvent used for the a i d e is acetic anhydride, and the end-point of thetitration is readily detected by means of a modified calomel-glass electrodepair in this medium.Coulometric methods have been extended, and an amperometric methodof end-point detection has been employed by Kennedy and Lingane 95 intheir method for the coulometric titration of uranium(v1) with electro-generated titanous ion at a platinum cathode in the presence of ferrous ionas catalyst.Even mixtures of vanadium(v) and uranium(v1) can be titratedowing to the fact that the reduction of V5+ occurs at a more oxidisingpotential than that of V4+ and U5+. Two amperometric end-points areobserved, corresponding to the reduction of V5+ to V4+ and to thesimultaneous reduction of V4+ to V3+ and U6+ to U4+. A measure ofthe titre due to uranium is thus obtained by subtracting twice the time tothe first end-point from the total time to the second end-point.A coulometric procedure has been developed by Arcandg6 by whichsmall quantities (18-240 pg.) of bromate can be determined with con-siderable accuracy.The bromate is allowed to react with bromide in acidsolution and the bromine liberated is titrated with electrically generatedcuprous copper. The method employs a dual platinum electrode indicatorsystem as an amperometric end-point detector. Calibration titrations are,however, necessary, and for accurate results the time for the calibrationtitrations should be within 10% of the time required for the sample titration.Thiourea 97 can also be determined coulometrically by using a mercury anodein a ground electrolyte containing sulphuric acid and potassium sulphate.The electrically generated mercury ions react with the thiourea to producea complex ion (Hg[CS(NH2)2]2)2’.In-a method due to Alfonsi 98 the best conditions for the successivedeposition of copper, lead, tin, and antimony by controlled-potentialelectrolysis from the same solution are described.The copper is depositedfirst at a cathode potential of 0.35-0.4 v against saturated calomel electrode(S.C.E.) from a solution at pH 5 containing ammonia, succinic acid, andhydrazine hydrochloride. The pH is now adjusted to 54-56, and the leaddeposited at a cathode potential of 0.6-0.65 v against S.C.E. The tin isnow deposited under specified conditions from an acidified solution, andfinally the antimony from the boiling solution at a cathode potential of0.45 v against S.C.E. The determinations are not affected by moderateamounts of Ni, Zn, Mn, Fe, Al.This method as applied to the analysisof brasses and bronzes has been described in a later paper.9994 D. C. Wimer, Analyt. Chem., 1958, 30, 77.95 J. H. Kennedy and J. J . Lingane, Analyt. Chim. Ada, 1958, 18, 240.96 G. M. Arcand, ibid., 19, 267.97 H. L. Kies and G. J. van Weezel, 2. analyl. Chem., 1958, 161, 348.9s B. Alfonsi, Analyt. Chim. Acta, 1958, 19, 276.99 Idem, ibid., p . 389406 ANALYTICAL CHEMISTRY.A procedure which promises wider applicability has been described byBaker loo for the rapid estimation of hydrofluoric acid in fuming nitric acid.The method is based on measurement of the spontaneous current ofelectrolysis of the diluted sample between an aluminium anode and aplatinum cathode in a polythene beaker and an amount of 0.6% vlv hydro-fluoric acid can be accurately and rapidly determined.Po1arography.-Advances in polarographic methods of analysis through-out the year have been largely due to the production of new and moresensitive instruments.Sawyer and his co-workers lol have developed anew polarograph. It utilises an x - y recorder for the direct measurementof the electrode potential or applied voltage, whilst correction for theIR drop in the cell is made by use of a third electrode. By this arrange-ment the authors have greatly reduced the sources of instrumental errors,and the accuracy of the direct reading of potentials is limited only by theaccuracy of the recorder itself.A new polarographic instrument whichautomatically corrects for the variation of the potential of the indicatorelectrode has been designed by S. Oka.lo2 With this instrument, whichincorporates an electronic servo-amplifier and a means of applying anauxiliary potential, any potential drop resulting from internal and externalresistances is continuously compensated for, thus eliminating the needfor a preliminary measurement of the potential drop as is required formanual correction.Kolthoff et aZ.lo3 have recommended the use of the rotating droppingmercury electrode for the analysis of solutions containing one or moreelectroactive species at concentrations of less than 10-4~. This recommend-ation is made after studies of the reproducibility of measurement of theresidual and limiting currents at the rotating dropping mercury electrodeat these low concentrations.Polyacrylamide is suggested as the idealmaximum-suppressor for use with the electrode since it is retained at themercury surface over the whole potential range and does not (unlike gelatine)combine with heavy metals.has shown that thallium, iron, and copper can readily bedetermined in high-purity cadmium metal. Thallium and iron are firstextracted from a solution of the chlorides of the elements in the sample bymeans of diethyl ether in 8N-hydrochloric acid, and are then determinedpolarographically. Copper is determined in a separate portion of the sampleby an extractive titration with a carbon tetrachloride solution of sodiumdiethyldithiocarbamate.The result of this test can also be confirmedpolarographically. E. Polecek lo5 has utilised the principle of oscillographicpolarography in the development of a method for the direct analysis ofsubstances in solid colloidal gels. Tin may be readily determined in food-stuffs by wet digestion with nitric acid, sulphuric acid, and hydrogenR. Carson100 B. B. Baker, Analyt. Chem., 1958, 30, 1085.101 D. T. Sawyer, R. L. Pecsok, and K. K. Jensen, ibid., p. 481.102 S . Oka, ibid., p. 1635.103 I. M. Kolthoff, Y. Okinaka, and T. Fuginaga, Analyt. Chim. Ada, 1958, 18, 295,104 R. Carson, Analyst, 1958, 83, 472.lo5 E. Polecek, 2. analyt. Chem., 1958, 162, I HASLAM AND SQUIRRELL : PHYSICAL METHODS.407peroxide. The reaction products are dissolved, and the tin in the solutionis determined, again by an oscillopolarographic testA most useful three-step polarographic method has been presented bySandler and Chung lo7 for the quantitative determination of hydrogenperoxide, formaldehyde, and acetaldehyde in solutions. The diffusioncurrent-concentration relationship for each pure substance is the onlycalibration datum required ; lithium chloride supporting electrolytes areused. Hydrogen peroxide is determined in an acid buffer solution in whichaldehydes do not interfere. Formaldehyde is determined in alkaline mediato which titanium tetrachloride is added to eliminate interference due tohydrogen peroxide, and acetaldehyde is estimated in similar solutions in thepresence of dimedone which reacts with and prevents interference from theformaldehyde.Garn and Gilroy have determined the maleic anhydridecontent of polyesters by carrying out a hydrolysis with aqueous potassiumhydroxide in the presence of chloroform or benzene. The aqueous layer isthen acidified, and the maleic acid determined polarographically.In the field of amperometric titration it has been demonstrated that itis possible to determine small amounts of gold even in the presence ofselenium , tellurium, and palladium by titration with quin01.l~~ The method,also suitable for the determination of gold in ores and sludges, uses a rotatingplatinum micro-electrode at a potential of 1 v with respect to the referencecalomel half cell.The titration is carried out in 2~-sulphuric at a tem-perature of 60". The sensitivity of the amperometric titration of fluoridewith thorium solution has been greatly increased in a method due toHarris,llO who uses a rotating palladium electrode. Large amounts ofchloride, nitrate, sulphate, perchlorate, borate , calcium, and magnesium aresaid to interfere slightly but small amounts of aluminium and phosphate(more than 1 p.p.m.) interfere seriously. As little as 20 pg. of fluoride per100 ml. of solution can be satisfactorily titrated.Polaro-voltric titrations (i.e. , titrations in which the end-point is detectedby measurement of the difference between an adjustable reference voltageand the polarisation voltage set up between two platinum micro-electrodesin the solution) have been applied most successfully by Walisch and Ash-worth 111 to the titration of highly dilute halide solution with silver nitratesolution.Even at the high dilution of 0.004~ an accuracy of &0.2% isclaimed for the method.Chromatography.-Under this heading some of the interesting applica-tions of paper and column chromatography including ion-exchange methodsare first described; this is followed by a section on gas-liquid and gas-solidchromatographic methods.A method of ascending paper chromatography, which has the advantageof concentrating rather than spreading the developed spots or streaks, has106 2. Malkas, 2. Lebensm.-Untersuch., 1957, 106, 257.107 S. Sandler and Yu-Ho Chung, Analyt. Chem., 1958, 30, 1252.108 P.D. Garn and H. M. Gilroy, ibzd., p. 1663.109 L. S. Reishakhrit and W. S. Sukhobokova, J . Analyt. Chem. (U.S.S.R.), 1967,110 W. E. Harris, Analyt. Chem., 1958, 30, 1000.111 W. Walisch and M. R. F. Ashworth, Analyt. Chim. Ada, 1958, 18, 632.12, 145408 ANALYTICAL CHEMISTRY.been described by Osawa.l12 The method uses a circular paper cut so thatit can be folded round to form a cone. If a continuous line of test solution isapplied to the paper, then the resulting developed chromatogram appears asa series of arcs concentrated towards the apex of the paper. The authorhas used the method for the separation and identification of green plant pig-ments. E. Blasius and W. Gottling 113 have contributed a rather interestingpaper on the paper chromatographic separation of the common cations.Preliminary chemical tests divide the cations into small groups which arethen separated on circular paper.The eluted substances, present in zones ofcharacteristic RF value, are distinguished by appropriate spray reagents. Itwould appear that condensed phosphates are used as tenderising agentsin the meat industry. Their analysis is of importance, and Schormuller andWurdig 114 describe paper-chromatographic methods for the separation ofmono- to hepta- and cyclotri- and cyclotetra-phosphates in commercial pre-parations. The various polyphosphates are separated as concentric zones,and hexametaphosphate is used as standard. Information is given on thebehaviour of the various phosphates with different eluting media.Duffield 115 has developed some interesting methods for the determinationof certain trace metals in crops such as wheat, barley, and oats, althoughthe tests have obvious applications in other fields.The sample is first ashedunder controlled conditions, and the boron determined in an aqueous extractof the ash. This involves the reaction of the borate with curcumin and thepaper chromatographic preparation and purification of the blue-green alkalireaction product of this borate-curcumin derivative. Copper, cobalt, andnickel, in the acid extract of the ash, are separated on paper with an ethylmethyl ketone-hydrochloric acid solvent ; rubeanic acid is employed forcolour development. Zinc is determined in the acid extract of the ash bycomplexing interfering elements with sodium thiosulphate, then determiningthe zinc by a mixed colour method involving the extraction of the zincdithizone complex at pH 5. Molybdenum is determined on the acid extractof the ash by a procedure involving paper-chromatographic separation frominterfering elements and dithiol colour development.Manganese is deter-mined on a similar acid extract by direct application of the periodateoxidation test .Organic applications include a novel approach which has been madeto the detection and approximate determination of traces of acrylonitrile.116As little as 1 pg. of acrylonitrile can be detected. Advantage is taken of thefact that acrylonitrile reacts with thiourea in the presence of hydrochloricacid to yield 2-cyanoethylisothiuronium chloride.This substance isseparated from the reaction products by paper chromatography, thendetected on the paper by spraying with ammoniacal silver solution.Extending their work on centrifugally accelerated paper chromatography,McDonald et aL1l7 have described the fundamental factors involved in112 Y . Osawa, Nature, 1957, 180, 705.119 E. Blasius and W. Gottling, 2. analyt. Chem.. 1958, 182, 423.114 J. Schormuller and G. Wiirdig, 2. Lebensm.-Untersuch., 1958, 107, 415.115 W. D. Duffield, Analyst, 1958, 83, 503.116 J. M. Stephek and V. M. tern&, ibid., p. 345.117 H. J. McDonald, L. R. McKendall, and E. W. Bermes, J . Chvomatog., 1958,1, 259HASLAM AND SQUIRRELL: PHYSICAL METHODS. 400obtaining good separation and reproducible chromatograms by the method.They have studied the variables which influence RF values, and havefractionated mixtures of Bromophenol Blue, Methyl Orange, and MethylRed as well as solutions of leucine, methionine, and glycine.In view of the increasing interest being taken in antioxidants, the paperby Ter Heide 11* on the paper-chromatographic separation of antioxidantsshould be noted.It is concerned with those antioxidants such as gallicacid, ethyl, n-propyl, n-butyl, n-pentyl, n-octyl, n-decyl, and n-dodecylgallate, 4-methoxy-2- and 3-t-butylphenol, and 4-methyl-2,6-di-t-butyl-phenol which now find their way into fats and oils. Useful information isprovided about the extraction of the antioxidant from the product.Thepaper chromatography is conventional; the developing reagent consists of aferric salt-potassium ferricyanide spray. The phenolic antioxidant reducesthe ferric salt and blue ferrous ferricyanide is produced a t appropriate pointsin the chromatogram.A semi-quantitative ascending-paper chromatographic method ofdetermining salicin has been devised by P e r ~ s o n . ~ ~ ~ The developing solventis butanol-acetic acid-water (4 : 1 : 5) and 2~-sulphuric acid is used as sprayreagent. The sprayed chromatogram is heated in a thermo-desiccator, andthe salicin appears as distinct pink spots. Organic peroxides have beendetected, identified, and estimated in small amounts by Abraham et aZ.,120using a chromatographic method. For the higher-molecular-weight com-pounds a procedure including reversed-phase chromatography on Silicone-treated paper is used, with a developing solvent of chloroform-ethanol-water and a spray reagent of acidified ferrous thiocyanate. For peroxidesof low molecular weight, which are too volatile for paper-chromatographicmethods, a gas-liquid chromatographic procedure is described.The chromatographic separation of the volatile fatty acids has receivedconsiderable attention.Osteux and his co-workers 121 have isolated theacids by steam-distillation, and after preliminary removal of cations andconcentration by passage over a sulphated ion-exchange resin, have convertedthe mixed acids into their morpholine salts. These salts are then chromato-graphed on paper by using a developing solvent containing butanol, cyclo-hexane, propylene glycol, ammonia, morpholine, and water for the straight-chain series, and containing benzyl alcohol saturated with 1.5N-ammoniafor the iso-series.The method has been used in connection with the deter-mination of the fermentation type or pattern of anaerobic bacteria.We turn now to the extensive use of ion-exchange methods. The stronglybasic anion-exchange resin Amberlite IRA 400, after conversion into theascorbate form, is used by Korkisch and Farag 1229123 in two methods usefulfor the analysis of steels and minerals. The first paper, dealing with thebehaviour of ascorbate complexes of vanadium, molybdenum, and tungsten,118 R. Ter Heide, Fette u. Seifeen, 1958, 60, 360.11s A.Persson, J . Chromatog., 1958, 1, 269.120 M. H. Abraham, A. G. Davies, D. €3. Llewellyn, and E. M. Thain, Analyt. chinz.121 R. Osteux, J. Guillaume, and J. Laturaze, J . Chrmatog., 1957, 1, 70.122 J. Korkisch and A. Farag, Microchim. Ada, 1958, 646.123 Idem, ibid., p. 659.Acta, 1957, 17, 499410 ANALYTICAL CHEMISTRY.describes how at pH 4 those complexes having a negative charge are absorbedon the resin. The vanadium can now be quantitatively eluted with 0 . 1 ~ -hydrochloric acid, together with only a very small proportion of tungstenand no molybdenum. Other components of steel, zliz., iron, chromium, andmanganese, do not interfere with this method of vanadium separation.The second paper, dealing with the photometric determination of smallamounts of titanium as the titanium-ascorbic acid complex, uses theexchange resin as a means of concentration of the titanium, at the same timeremoving it from such ions as iron, chromium, and nickel which interfere inthe direct photometric determination.The titanium concentrated on theresin is eluted with N-hydrochloric acid prior to photometric determination.Lederer 124 has extended his work on chromatography, using paperimpregnated with ion-exchange resins, to the separation of such systems asCu-Cd, Mn-Fe-UO,++, Th-Ce-Fe, Al-Zr, and Ti-Fe-Al. The filter paperused is impregnated with colloidal Dowex 50 resin, and the chromatogramdeveloped with various concentrations of hydrochloric acid. An advantageof the method is that the concentration of the acid required to give aseparation can be predicted from the equation xpH = R, + constant, wherex = valency of the cation and R, = log[(l/RF) - 13.Considerable attention has been paid to the correct conditions for theseparation of uranium from thorium.Tomic and others 125 utilise the factthat uranium in 6-5~-hydrochloric acid solution forms a negatively chargedcomplex which is absorbed on an Amberlite IRA 400 resin (in the chlorideform), whilst thorium is not absorbed. The uranium is subsequentlyeluted with 1N-hydrochloric acid and then determined by an improved formof fluorimetric procedure. A useful method126 has been developed for thedetermination of uranium in phosphates, coal ashes, and bauxites in whichthe uranium as its negatively charged ~ ( I v ) chloride complex, in ~N-HCI-ascorbic acid solution, is separated from interfering substances by passagethrough an anion-exchange column containing Amberlite IRA 400 (Cl-) .The uranium is then eluted with 1N-hydrochloric acid solution, and deter-mined in the eluate either by the polarographic method involving the catalyticnitrate wave or by the method which takes advantage of the fluorescenceof the sodium carbonat e-po t assium carbonat e-sodium fluoride fusionproduct.The use of ion-exchange resin to concentrate fluoride and free the samplefrom interfering ions has allowed Nielsen 12’ to develop a method fordetermining microgram quantities of fluoride at quite high dilution.Thefluoride ion concentrated on the resin column is eluted with increasingconcentrations of sodium acetate and determined colorimetrically withCyanine R, zirconyl nitrate, and hydrochloric acid, density measurementsbeing taken at 527.5 mp.IgUchi1Bs129 has studied the distribution co-efficients of the di-, tri-, tetra-, and penta-thionates between anion-exchange124 M. Lederer, J. Chromatog., 1958, 1, 314.126 E. Tomic, I. M. Ladenbauer, and M. Pollak, 2. analyt. Chem., 1958, 161, 28.126 J. Korkisch, A. Farag, and F. Heckt, ibid., p. 92.127 H. M. Nielsen, Analyt. Chem., 1958, 30, 1009.128 A. Iguchi, Bull. Chem. SOC. Japan, 1958, 31, 597.129 Idem, ibid., p. 600HASLAM AND SQUIRRELL : PIIYSICAL METIIODS. 41 1resins and hydrochloric acid solution, and also the distribution coefficientsof sulphate, thiosulphate, sulphite, and sulphide between the resin andalkaline nitrate solutions.As a result of these studies methods have beenworked out for the separation of mixtures of these compounds by ion-exchange chromatography.Ion-exchange chromatography has also found use in organic analysis.In an extension of the work on salting-out chromatography, Rieman andhis co-worker 130 have developed a new technique of solubilisation chromato-graphy by which mixtures of some four phenols and six aliphatic alcohols(C,-C,) have been separated. The procedure involves the elution fromion-exchange resin by means of aqueous solutions of acetic acid. The effectof the extent of cross-linking in the exchange resins, and the rate of flow andconcentration of the eluent on the behaviour of the compounds have beenreported, A second paperf3l describes the separation of ketones by usingaqueous solutions of acetic acid or lower alcohols as eluents.By this methodseven ketones were separated, the highest being undecan-2-one. A newmethod for the determination of the saponification number of oils and esterswhich yields more precise information about the esters under test has beendeveloped by Swann, Zahner, and M i l r ~ e r . ~ ~ ~ After saponification, thehydrolysis products are passed through a cation exchanger in the hydrogenform. The eluate contains the free acids and these are titrated directly bya potentiometric method, differential curves often being obtained when estermixtures are under test.The rapid increase in the use of gas-liquid and gas-solid chromatographicmethods has necessitated some degree of standardisation of units andtechnical terms used.In connection with this, Johnson and Stross 133 havereported the findings of a study group of the A.S.T.M. Committee onPetroleum Products and Lubricants. Terms relating to technique,apparatus, reagents, conditions of determination, and reporting results aredefined. Jowes and Kieselbachl= have suggested a revised set of unitsbased on kinetics rather than equilibrium data, which they indicate will givemore convenient recording and interpretation of results and facilitate amore exact control of quantitative separation processes. An alternativemethod due to Ambrose and his collaborators135 suggests that the datashould be recorded in terms of the relationship between elution temperatureand the partition coefficient or specific retention volume of the substance.By this method a quantitative approach to solvent composition is possible.The complexity of the detection instruments for use in gas-chromato-graphy apparatus has been a valid criticism of the method.Davis andHoward 136 have partly overcome this difficulty by designing a simple andeasily constructed instrument which employs a single thermistor as thedetector. The detector is placed near the exit tube of the column and forms130 J. Sherma and Wm. Rieman, tert., Analyt. Chim. Acta, 1958, 18, 214.131 Idem, ibid., 1958, 19, 134.132 W. B. Swann, R. J. Zahner, and 0.I. Milner, Analyt. Chem., 1958, 30, 1830.133 H. W. Johnson and F. H. Stross, ibid., p. 1688.134 W. L. Jowes and R. Kieselbach, ibid., p. 1590.135 D. A. Ambrose, A. I. B. Keulemans, and J. H. Purnell, ibid., p. 1582.136 A. D. Davis and G. A. Howard. J . Appl. Chem., 1958, 8, 183412 ANALYTICAL CHEMISTRY.one arm of a Wheatstone bridge driven through a potentiometer by a battery.A 10 mv full-scale deflection recorder is used. The authors describe thenecessary precautions and conditions for use of a thermistor detector, andthe overall sensitivity and response to differing materials are outlined.J. E. Lovelock137 has utilised the unique ionisation properties of argon asthe basis of a stable detector for use with gas-chromatographic apparatus.The theory of the operation of the device depends on the ionisation, bycollision with excited argon atoms, of molecules of the test substance inthe vapour phase.The response of the detector is similar for differentmolecular species of organic compounds and over a considerable range thisresponse is also linear.The problem of selecting the liquid substrate for use in gas-liquidchromatographic columns has been clarified by Tenney,l38 who has studied18 liquid substrates with respect to their selectivity towards various typesof hydrocarbon and oxygenated compound. His results permit the com-parison of retention characteristics between compound types at variousboiling point levels and show dipropionitriles to have the highest selectivityand squalane to be the best non-selective substrate for hydrocarbons.With regard to selectivity, too, Eggertson and Knight 139 have shown that,in the chromatography of hydrocarbon gases, adsorption on the surface ofthe support medium may be controlled to provide a wide naphthalene-paraffin selectivity by adjusting the amount of the solvent.With smallamounts of supported solvent they find paraffins are retarded, whereasnaphthalenes are retarded on a liquid-partition type packing.By designing a column capable of operating at temperatures up to 4W0,Ogilvie and his co-workers 140 have been able further to explore the realmsof high-temperature gas-phase chromatography. The column utilisedasphaltines as stationary liquid phase and bare wire thermal-conductivityfilaments in the conductivity detector cell.Higher-molecular-weightseparations were made, and the method was used for the determination ofn-paraffin distribution in waxes. Dupire and Botquin,la using a stationaryliquid phase of Silicone grease on a powdered Silocel C22 firebrick supportand helium as carrier gas in a column working between 220" and 250", haveseparated the heavy tar oils, naphthalenic oils, wash oils, and anthracenicoils. Excellent quantitative results have been obtained on complexmixtures in a high-temperature apparatus of their own design. Nogare andSafranski 14% have described a relatively simple high-temperature gas-chromatographic apparatus capable of resolution and estimation of high-boiling organic mixtures , e.g.J polyethylene glycols, phthalate esters, andSilicone oils.High-vacuum Silicone grease and commercial linear poly-ethylene are used as partition media a t temperatures of 150-355' in con-junction with platinum-filament thermal conductivity detectors operated at10-100" higher than the column temperatures. Excellent resolution is187 J. E. Lovelock, J . Cht'omatog., 1958, 1, 35.188 H. M. Tenney, Analyt. Chem., 1958, 30, 2.180 F. T. Eggertson and H. s. Knight, &id., p. 16.140 J. L. Ogilvie, M. C. Simmons, and G. P. Hinds, jun., ibid., p. 26.141 F. Dupire and G. Botquin, Andyt. Chim. Ada, 1958, 18, 282.142 s. D. Nogare and L. W. Safranski, Analyt. Chem., 1958, 30, 894HASLAM AND SQUIRRELL: PHYSICAL METHODS. 413obtained on relatively short columns.A second apparatus,l& suitable forthe analysis of impurities in organic mixtures at the parts per million level,utilises an amplifier to increase the signal from thermistor detectors. Theconditions necessary for obtaining low noise and drift are described, togetherwith examples of some specific applications of the method, e.g., the determin-ation of p.p.m. of propan-2-01 in benzene, benzene in toluene, cyclohexanein toluene, methanol in water, and other impurities in cyclohexane andtoluene.The growing general importance of gas chromatography in analysis isshown by the fact that a particular part of the Zeitschrift fGr analytischeChemie is devoted almost wholly to the subject. There are papers which dealwith the gas-chromatographic examination of such diverse chemicals asethylene,lU ~yclopentadiene,~~~ mono- and di- hydric phenols,146 and phenolsbefore and after rnethy1ati0n.l~' Work on the examination of perfumerymaterials is interesting because it brings out the possibility of examiningsuch substances by gas-chromatographic test both before and after treat-ment with chemical reagents; the purpose of the latter treatment is toremove such classes of substance as ketones, etc.,l& from the mixtures.Avery comprehensive paper deals with the choice of stationary phase in gas-chromatographic analysis; 149 detailed information is presented about thebehaviour of 120 substances on various stationary phases. Other con-tributions are concerned with the comparative merits of infrared andgas-chromatographic methods of examination of toxic solvent mixtures,lMwith the quantitative evaluation of separated chromatographic fractions,l51with the automatic registration of gas volumes following gas-chromato-graphic ~eparation,l5~ and with the substitution of a combination of gaschromatography and gravimetry for Podbielniak di~tillati0n.l~~ Using new-type packings consisting of heterocyclic amines on a Celite support,Zlatkis 154 has been able to resolve mixtures of the hexane isomers.Suchstationary liquid phases as squalane, isoquinoline, and quinoline-brucinemixture have been used with helium as the carrier gas. With the lattersystem such multicomponent mixtures as cyclohexane, methylcyclohexane,2,4-dime th ylpent ane, c yclopen t ane , 2-me t hylpen t ane,2,3-dimethylbutane, n-pentane, and isopentane have been analysed, withthe column temperature at 250".Studies in the composition of azeotropeshave been aided by the gas-chromatographic method of Haskin and hisc o - ~ o r k e r s , ~ ~ ~ who have described analytical methods for the study of a3-met h ylpent ane,143 C. E. Bennett, S. D. Nogare, and L. W. Safranski, Analyt. Chem., 1958, 30, 898.144 G. Nodop, 2. analyt. Chem., 1958, 164, 120.145 E. A. M. Dahmen and J. D. Van der Laarse, ibid., p. 37.146 J. JanAk and R. Komers, ibid., p. 69.147 G. Bergmann and G. Jentzsch, ibid., p. 10.148 E. Bayer, G. Kupfer, and Karl-Heinz Reuther, ibid., p. 1.149 G. Raupp, ibid., p. 135.150 E. G. Hoffmann, ibid., p. 182.151 G.Schomburg, ibid., p. 147.162 J. JanAk and K. Tesarik, ibid., p. 62.153 U. Schwenk and E. Weber, ibid., p. 169.154 A. Zlatkis, Analyt. Chem., 1958, 30, 332.J. F. Haskin, G. W. Warren, L. J. Priestley, jun., and V. Yarborough, ibid.,I). 217414 ANALYTICAL CHEMISTRY.number of ternary and quaternary mixtures including the systems acetone-met hanol-me t h yl acetate ; chlorofonn-propan-2-ol-et h yl methyl ketone ;acetonitrile-ethanol-triethylamine-water; and di-n-butyl ether-butan-1-ol-n-butyl acetate-water. The reproducibility of the methods ranged fromk0.5 to &4.4% of the figure found for the specific compositions studied.Haslam and Jeffs 156 have described methods to determine the nature ofmixed solvents in plastic adhesives and it is probable that these tests willhave other applications. The method of isolation of the solvent is described,as well as its preliminary gas-liquid chromatographic separation using adinonyl phthalate stationary phase.The subsequent examination of thesolvent on a polar (tritolyl phosphate) column and a non-polar (paraffinwax) column is outlined, as well as infrared and chemical tests which may becarried out on the separated products.Gas-liquid chromatography has also been used by Irvine and Mitchell 157for the separation of tar acids; some 28 phenolic compounds were identifiedby retention-time data and infrared spectroscopy. Amberg 1% has measuredthe relative elution times of a number of organic sulphur compounds fromglass columns containing tritolyl phosphate supported on 35-80-meshJohns Manville C-22 firebrick.The elution gas used is nitrogen at columntemperatures of 8A101°. The injection system consists of a heatedchamber at the column head inside which are two 60-mesh stainless-steelgauzes from which the liquid can be flashed on to the column after injectionthrough a self-sealing cap in the usual way. Both detector and referenceelements of the thermal conductivity monitor are placed at the column out-let with liquid nitrogen traps interposed between the two. These traps aredesigned to fit directly on to a mass-spectrophotometer, facilitating theready determination of the mass spectra of each fraction.Haslam, Hamilton, and Jeffs159 have developed a novel method ofdetermination of polyethyl esters in methyl methacrylate copolymers.Thealkoxyl groups in the polymer are converted into the corresponding iodides,which are purified and collected in n-heptane. After addition of methylenedichloride and ethylidene dichloride as markers, the mixture of methyl andethyl iodides, markers, and n-heptane is subjected to gas-liquid chrom-atography in order to obtain the proportions of the two iodides and hencethe amounts of the corresponding polyesters.A useful method of gas analysis has been developed by Timms, Konrath,and Chirnside for the determination of trace impurities such as hydrogen,argon, oxygen, nitrogen, methane, and carbon monoxide in carbon dioxidewhich may be used as coolant gas for nuclear reactors. In this method,carbon dioxide is removed by soda-lime, and moisture by magnesiumperchlorate. If required, oxygen is taken out by means of De-oxo catalyst.The separation of the various impurities is then effected on a column ofmolecular sieves.By appropriate use of hydrogen as carrier gas on the onehand and argon on the other hand, it is possible to obtain chromatograms156 J. Haslam and A. R. Jeffs, Analyst, 1958, 83, 465.157 L. Irvine and T. J. Mitchell, J . AppZ. Chem., 1958, 8, 425.158 C. H. Amberg, Canad. J . Chem., 1958, 36, 690.159 J. Haslam, J. B. Hamilton, and A. R. Jeffs, Analyst, 1958, 83, 66.160 D. G. Timms, H. J. Konrath, and R. C. Chirnside, ibid., p. 600HASLAM AND SQUIRRELL: PHYSICAL METHODS. 415from which the concentrations of the various impurities in carbon dioxidecan readily be deduced.R.N. Smith and his co-workers161 have found that, by using a gas-chromatography column consisting of two layers of silica gel separated byiodine pentoxide, they are able to separate and determine the components ofmixtures of (a) nitrogen, nitrous oxide, nitric oxide, and carbon monoxideor (b) nitrogen, nitric oxide, carbon monoxide, and carbon dioxide in10 minutes. The column at elevated temperatures oxidises carbon monoxideto carbon dioxide and nitric oxide to nitrogen dioxide.Absorption Spectroscopy (Inorganic) .-The use of absorption spectroscopyin analytical chemistry increases year by year and it was a noticeable featureof 1958 that very many excellent methods were developed based onabsorptiometric measurements in the visible region of the spectrum.Improvements in instruments have facilitated rapid methods of analysis ofcomplex mixtures. For example, differential spectrophotometric methodshave been extended by Banks and his co-workers,162 who have applied theprinciple to the analysis of neodymium-erbium, praseodymium-erbium, andpraseodymium-neodymium-samarium mixtures, and in addition havediscussed an accurate method for the measurement of small molarabsorptivities.Freund and Holbrook,l@ however, by application of theAlizarin Red differential method of Manning and have developeda method for the determination of zirconium in the presence of hafnium.The test is applied to a fixed sum of the elements as their oxides.A useful method of calibration or checking the wavelength scale of aspectrophotometer without the use of the conventional standard filters orsolutions has been described by Parthasarathy and Sar~ghi.l~~ They utilisethe so-called isosbestic point of indicator solutions.This is the point atwhich all transmittancy curves of an indicator solution intersect irrespectiveof pH. Thus, acidic and basic solutions made from equal amounts of thesame stock indicator solution are placed in matched cells and the differencein their absorbance is measured a t different wavelengths. The differencein transmittancy is zero at one specific wavelength only, e.g., 469 mp forMethyl Orange. Provided pure indicators are used, the method is free fromthe usual sources of calibration error. The isosbestic point of severalindicators is given.Bohnstedt and Budenz 166 have put forward a semimicro-method ofdetermination of arsenic, especially in steel and iron, etc.The materialis dissolved in perchloric acid and nitric acid, and the arsenic distilled astrichloride after treatment of the solution with ferrous sulphate, potassiumbromide, and hydrochloric acid. The neutralised distillate is treated with amolybdenum-blue reagent , and the resulting colour measured at 900 mp.The same authors have developed a photometric semimicro-method ofdetermination of sulphur in iron and steel, etc., based on the determination161 R. N. Smith, J. Swinehart, and D. G. Lesnini, Analyt. Chem., 1958, 30, 1217.162 C. V. Banks, J. L. Spooner, and J.W. O’LaughIin, ibid., p. 458.163 H. Freund and W. F. Holbrook, ibid., p. 462.164 D. L. Manning and J. C. White, ibid., 1955, 27, 1389.165 N. V. Parthasarathy and I. Sanghi, Nature, 1958, 182, 44.166 U. Bohnstedt and R. Budenz, 2. analyt. Chem., 1957, 159, 95, 102416 ANALYTICAL CHEMISTRY.of sulphur dioxide in combustion products arising from the iron, etc. Thecolourless N-sulphinic acid of Fuchsinleucosulphonic acid formed by actionof sulphur dioxide on Fuchsin, yields with formaldehyde a red product whichis measured at 580 mp.In a series of papers 1679168 Spier and Strickland have described methodsfor the determination of boron. In the first, those methods based on thereaction of boric acid and curcumin reagent to form red compounds, rubro-curcumin and rosocyanin, are detailed.The first two methods, suitablefor the ranges 2-15 and 0.5-4 pg. of boron respectively, are based on theevaporation of the boron distillate in the presence of sodium hydroxide andglycerol and removal of the bulk of the glycerol before ignition of theresidue at a dull red heat. This residue is now evaporated under carefullycontrolled conditions with a curcumin-oxalic acid reagent, and the ab-sorbancy of the rubrocurcumin thus formed is measured in ethyl alcoholsolution at 555 mp. In the third, more sensitive method the residues of theignition are treated with water and curcumin solution and neutralised withacetic acid before re-evaporation to dryness. This residue is treated witho-chlorophenol reagent under controlled conditions, and the absorbancy ofthe rosocyanin thus formed measured in aqueous alcohol solution a t 550 and630 mp.The principles of the methods of separation of boron by distillationfollowed by evaporation of the distillate are also described.Lilie1G9 has taken advantage of the fact that bismuth reacts withthionalid to develop a useful method for the determination of very smallamounts of bismuth in lead and tin. The method for lead involvespreliminary precipitation of the bulk of the lead as chloride, followed byfiltration and extraction of the bismuth from the filtrate as its chloroform-soluble thionalid complex. This is decomposed with sulphuric acid solution,and the bismuth in the acid extract determined by means of its colorimetricreaction with iodide in the presence of sulphite.Bismuth in tin is deter-mined by similar principles.The requirements of industry and medicine for the determination ofsmaller and smaller quantities of copper have long made necessary a moresensitive reagent for this element. Turkington and Tracey 170 have foundthat 1,5-diphenylcarbohydrazide is such a reagent, for it gives an extremelysensitive colour reaction with copper in basic solutions, which obeys Beer’slaw over the range 0.01-0.26 pg. of copper per 3 ml. of final coloured solution.The molar absorbance index of the complex is 158,800 at 495 mp comparedwith 12,700 for the copper diethyldithiocarbamate complex in pentyl alcoholmeasured at 440 my. The rate of the reaction is dependent on pH and inconsequence it is carried out in a buffered solution.An interesting method has been developed by Riedel 171 for the determin-ation of copper in nickel cathodes.From the solution of the sample, all thecopper and some nickel are brought together by extraction withcarbon tetrachloride and cadmium diethyldithiocarbamate. Treatment167 G. S. Spier and J. D. H. Strickland, Analyt. Chim. Acla, 1958, 18, 231.168 Idem, ibid., p. 523.169 H. Lifie, 2. analyt. Chem., 1958, 159, 196.150 R. W. Turkington and F. M. Tracey, Analyt. Chem., 1958, 30, 1699.171 I<. Riedel, 2. anal-vt. Chem., 1957, 159, 25HASLAM AND SQUIRRELL: PHYSICAL METHODS. 417with mercury salt now yields a new aqueous phase containing all the copperand some nickel.Subsequent complexing with ethylenediaminetetra-acetic acid followed by addition of excess of magnesium and cadmiumdiethyldithiocarbamate yields a mixture from which the copper can beextracted quite cleanly as its coloured diethyldithiocarbamate complex byusing carbon tetrachloride as solvent. 2-Furoyltrifluoroacetone forms anintense green chelate with copper which is quantitatively precipitated fromaqueous solution but can be extracted into organic solvents to yield a solutionwhich absorbs strongly at 660 mp. This property is the basis of a methoddescribed by Berg and Day 172 for the rapid and precise determination of aslittle as 1 mg. of copper at dilutions down to 5 p.p.m. Fe, Ce, V, and Ni arethe only serious interferences, since the other metal chelates are colourless,not extracted, or do not absorb at 660 mp.Ziegler 173 has described amethod by which appreciable proportions of copper can be determined byreaction with aminoacetic acid, in the presence of citrate buffer, a t a pH of2 - 9 4 . 1 . The test is fairly specific for copper and the colour of the reactionproduct is measured a t 735 mp.Blundy 174 and Simpson and Blundy 175 have developed interestingsolvent-extraction methods. In the first method, which is concerned withthe determination of chromium in the presence of iron, nickel, uranium, andcopper, the chromium is first oxidised to chromate with ammonium hexa-nitratocerate in hot acid solution. This chromate is then extracted withisobutyl methyl ketone from a solution M in hydrochloric acid.Extractionof the extract with water yields a solution of the chromate, which is thendetermined by the diphenylcarbazide reaction. Blundy and Simpson dealwith the determination of nickel in solutions containing uranium, thorium,copper, iron, and chromium. The nickel is precipitated as its 4-methylcyclo-hexane-l,2-dione complex in the presence of tartaric and thioglycollic acids.The nickel complex is extracted with toluene before absorptiometricmeasurement.A novel use of EDTA has been presented by Lott and Cheng176 in asimple method for the determination of iron in clay and limestone. TheEDTA serves two purposes : it prevents interference due to cations, and alsoproduces a colour with iron in the solution of the limestone sample in thepresence of hydrogen peroxide.The absorbance due to this colour ismeasured at 520 mp. Very good use of the comparatively new reagentfor iron, viz., bathophenanthroline (4 : 7-diphenyl-1 : 10-phenanthroline)previously described by Smith et aZ.,177 has been made by Booth andE ~ e t t . ~ ~ ~ They describe a method for the determination of iron (2-100 p.p.m.) in bismuth in which the iron in the hydrochloric acid solution ofthe sample is first reduced to the ferrous condition by means of stannouschloride. The reagent is then added, followed by a mixture of disodium172 E. W. Berg and M. C. Day, Analyt. Chim. Ada, 1958, 18, 578.173 M. Ziegler, 2. analyt. Chem., 1958, 183, 197.174 P. D. Blundy, Analyst, 1958, 83, 555.175 P.D. Blundy and M. P. Simpson, ibid., p. 558.176 P. F. Lott and K. L. Cheng, Analyt. Chem., 1957, 29, 1777.17' G. F. Smith, W. H. McCurdy, jun., and H. Diehl, Analyst, 1952, 77, 418.1 7 ~ E. Booth and J. W. Evett, ibid., 1958, 83, 80.REP-VOL. LV 41 8 ANALYTICAL CHEMISTRY.ethylenediaminetetra-acetate and sodium citrate. The ferrous complex isextracted with n-hexyl alcohol, and the optical density of the extractmeasured at 533 mp.A new colorimetric reagent for ferric ion in nitric acid solutions (0.3-2.5111) has been described by Holdaway and Willan~.l7~ The reagent,tris-(o-hydroxypheny1)phosphine oxide, gives a violet-red complex withferric ions which obeys Beer’s law over the concentration range 0-02-0.1 mg. of Fe3+ per ml. The only cation known to interfere in thedetermination of iron by this reagent is Ce4+ which should make its useattractive to many analysts.Underwoodlao has described the use of anew reagent, ethylenedi-(o-hydroxyphenylacetic acid), for the spectrophoto-metric determination of iron. The reagent forms a stable red complex withferric iron over a wide pH range and has been used for the determination ofiron in aluminium alloys. Interferences from other elements are no morenumerous than in other methods.Very small amounts of mercury in ores can be determined by a procedureput forward by Michal et aZ.18l After isolation of the mercury by distillationand removal of any free chlorine produced in the distillation by means offerrous sulphate solution, the mercury solution is brought to pH 5.Abenzene solution of mercupral is now added. Mercupral which possessesa strong yellow colour in benzene solution is produced by reaction of tetra-ethylthiuram disulphide with cupric salts. On reaction with mercurycompounds a diminution in yellow colour is produced and this reduction incolour is measured at 4 2 0 4 3 0 mp.An ingenious method has been devised by Sutcliffe and P e a k 182 for therapid determination of nickel in copper-nickel alloys. The alloy is dissolvedin nitric acid-phosphoric acid and, after evaporation and treatment withhydrogen peroxide to avoid the interference of manganese, the absorbancedue to nickel is measured at 3950 A. Another measurement is made a t4900 if to permit a background correction to be made.Cobalt(I1) is theonly cation which interferes in a useful and sensitive colorimetric methodfor the determination of nickel(rr) and copper(I1) described by Jonassenet aZ.183 The complexing reagent employed is disodium ethvl bis-(5-tetrazoly1azo)acetate trihydrate which with nickel gives a product whichabsorbs at 335 and 505 mp, and with copper a complex absorbing a t 268,300, and 535 mp.A new colorimetric method for the determination of small amounts ofselenium in the presence of sulphuric acid has been presented by Danzukaand Ueno.184 The reagent used is 3,3’-diaminobenzidine and interferenceof the sulphate ion is eliminated by the addition of a large excess ofammonium chloride. As little as 5 pg. of selenium per g.of sulphuric acidcan be determined. The problem of the determination of small amounts ofM. J. Holdaway and J. L. Willans, Analyt. Chim. Ada, 1058, 18, 376.I8O A. L. Underwood, Analyt. Chem., 1958, 30, 44.181 J. Michal, B. Pavlikov%, and J. Zjrka, 2. analyt. Chem., 1958, 159, 321.183 H. B. Jonassen, V. C. Chamblin, V. L. Wagner, and R. A. Henry, Analyt. Chem.,IB4 T. Danzuka and K. Ueno, Analyt. Chem., 1958, 30, 1370.G. R. Sutcliffe and D. M. Peake, Analyst, 1958, 83, 122.1958, 30, 1660HASLAM AND SQUIRRELL: PHYSICAL METHODS. 41 9silicon, i.e., down to O.OOOl%, in high-purity iron is one of considerablediffic~1ty.l~~ Chemically, it has been shown that the total silicon can bedetermined by procedures depending on production of a molybdosilicatecomplex and reduction to molybdenum-blue. The latter is measuredabsorptiometrically.The results obtained have now been checked by radio-activation of the iron samples. To the solution of the activated sample isadded silicon carrier. The silicon is isolated as purified silicic acid beforecounting.A very sensitive test for silver, capable of detecting 0.5 pg. per ml.and particularly effective in the presence of copper, has been put forwardby Ciuhandu and Giuran .l86 Copper solution and sodium sulphamido-benzoate are first added to the silver solution, followed by a known amountof sodium carbonate and sodium hydroxide solution and filtration. Thefiltrate retains a definite amount of copper. On reduction of this filtratewith carbon monoxide, a silver sol is produced suitable for photometricmeasurement. 5,7-Di-bromo-8-hydroxyquinoline lS7 appears to be a very satisfactory reagent forthe volumetric determination of tin.At pH 1.0 tin forms a complex withthe reagent which is soluble in isobutyl alcohol to yield a yellow solution,which is measured at 410 mp.Everest and Martin 188 have sought to develop a method for the deter-mination of thorium in medium- and low-grade ores. The method is onein which only one separation is required and which has an absorptiometricfinish in which small amounts of impurities (particularly zirconium) presentin the eluate can be tolerated. Their method involves the separation of thethorium from gross amounts of other elements by elution on a cellulose-alumina column.The thorium is determined by a selective absorptiometricfinish with APANS [1-(o-arsonophenylazo)-2-hydroxynaphthalene-3,6-di-sulphonic acid], mesotartaric acid being used as a masking agent for zirconium.A sensitive extraction method has been put forward by Ziegler et aZ.lB9 for thedetermination of small amounts of titanium in the presence of comparativelylarge amounts of foreign ions, e.g., ferric ions, which must first be reduced.The method depends on the production of the tributylammonium-titanium-sulphosalicylate complex and its extraction by chloroform. The complexis measured at 400 nip. G. Eckert and E. Bauersachs 190 have shown thattungsten, present to the extent of 3 4 % in cathodic nickel, can be deter-mined quite satisfactorily.The method involves a pre-reduction of thesample solution with stannous chloride before completion of the reductionto a definite valency state with titanous chloride. The reduced solution isthen treated with thiocyanate to yield a colour suitable for absorptiometricmeasurement.In a short communication Shibata and Matsumae 191 have outlined a newThe copper in the filtrate stabilises the silver sol.lS5 H. G. Short and A. I. Williams, Analyst, 1958, 83, 624.lE6 G. Ciuhandu and V. Giuran, 2. aizalyt. Chem., 1958, 159, 250.E. Ruf, 2. analyt. Chem., 1958, 162, 9.D. A. Everest and J. V. Martin, Analyst, 1957, 72, 807.M. Ziegler, 0. Glemser, and A. V. Baeckmann, 2. analyt. Chem., 1958, 160, 324.loo G. Ecltert and E. Bauersachs, ibid., 163, 161.ls1 S.Shibata and T. Matsumae, Bull. Chem. SOC. Japan, 1958, 31, 377420 ANALYTICAL CHEMISTRY.colorimetric method for the determination of micro-amounts of uranium.The method is based on the formation of the stable blue uranium complexof neo-thorone (o-arsonophenylazochromotropic acid) in aqueous solutionat pH 6-0. At 600 mp the molar extinction coefficient of this complexis about 25,000. Clinch and Guy lg2 have made considerable improvementsin the thiocyanate method for the determination of this element, and theirprocedure is well suited to the determination of uranium in low-grade oresand in thorium oxide. The uranium is extracted from a solution containingEDTA a t a pH of 3-5-3.9 with a 32.5% v/v solution of tributyl phosphatein carbon tetrachloride.The colour of the extract solution is measuredat 350 mp.A useful method for the determination of vanadium has been putforward by Cozzi and Raspi.lg3 The evaporated vanadium solution isdissolved in acid hydrogen peroxide solution and made anhydrous by theaddition of the reagents (viz., hydrochloric acid, glacial acetic acid, andmethyl salicylate) in solution in acetic anhydride. Under these conditionsa violet-blue colour is formed (Imx. = 565 mp) and as little as 1 pg. ofvanadium can be quantitatively detected. 4-Chlororesorcinol has beenused by Stewart and Bartlet lg4 as a useful reagent for the colorimetricdetermination of zinc. The zinc is separated from interfering cations byextraction as zinc diethyldithiocarbamate with chloroform under controlledconditions and then re-extracted into hydrochloric acid solution.Thezinc4-chlororesorcinol complex is now formed, and the colour which ismeasured at 640 mp obeys Beer’s law over the convenient range 0-1-5p.p.m. of zinc.Colorimetric procedures for the determination of anions include a rapidspectrophotometric method for the determination of microgram quantitiesof chloride in sweat and blood serum which has been described by Gerlachand Frazier.lg5 The prepared sample solution is brought to pH 3.3-3.5 bythe addition of nitric acid and the chloride is caused to react with an excessof mercury(I1) reagent. The excess of mercury(I1) ions is now determinedcolorimetrically by measurement, at 520 mp, of the co-ordination compoundformed by reaction with diphenylcarbazone at pH 3.2, Beer’s law beingobeyed within a concentration range of 0-240 pg.of chloride per 100 ml.Cyanide and thiocyanate in small amounts can often be determinedcolorimetrically by Aldridge’s method. By means of bromine-water thecyanide and thiocyanate are converted into cyanogen bromide which thengives a colorimetric reaction with a reagent containing pyridine and benzidine.Wagner lg6 has shown, in making tests on effluents containing large propor-tions of sulphide, that it is necessary to make an independent preliminarydetermination of sulphide and then to add a calculated excess of bromine inpotassium bromide before proceeding with the colorimetric reaction for totalcyanide plus thiocyanate.The cyanide is determined independently afterdistillation from acid solution.ls2 J. Clinch and M. J. Guy, Analyst, 1957, 82, 800.19s D. Cozzi and G. Raspi, Analyt. Chim. Ada, 1957, 17, 590.ls4 J. A. Stewart and J. C. Bartlet, Analyt. Chem., 1958, 30, 404.195 J. L. Gerlach and R. G. Frazier, ibid., p. 1142.196 F. Wagner, 2. analyt. Chem., 1958, 162, 106HASLAM AND SQUIRRELL: PHYSICAL METHODS. 421A rather novel procedure for the colorimetric determination of fluorideion has been described by Yasuda and Lambert.lg7 They use the classicalthorium-Alizarin Red S reagent, but support it on previously preparedsquares of filter paper. The solution under test is freed from interfering ionsby passage through an ion-exchange resin, and the pH adjusted to 3.5 priorto treatment with silver nitrate at boiling temperature and readjustment ofpH to 7.0.The prepared reagent paper is now dropped into an aliquotpart of the solution, whereupon anion exchange occurs on the paper andcolour proportional to the fluoride present is liberated into the solution. Thiscolour is measured in the usual way a t 520 mp.In the colorimetric determination of phosphate the reduction of molybdo-phosphate by stannous chloride to a molybdenum-blue colour, has notproved entirely satisfactory in the hands of some investigators. Whensolid ascorbic acid is used,198 and the reduction carried out at boiling point,the process is apparently quite satisfactory. The colours obtained are stableat room temperature and may be measured either visually or instrumentally.Ruf lg9 has made a comprehensive study of the pH and other conditionswhich are required in the determination of both silicic and phosphoric acidsby photometric procedures involving the use of ammonium molybdate andsodium molybdate.He draws attention to the error which may arise if thesilicic acid is present in solution in polymeric forms.Increasing use is being made of ultraviolet absorptiometric methodsfor the determination of such elements as iron and lead.determine iron in high-purity bismuth by solution of the sample in nitricacid, then conversion into the chlorides and measurement at 390 mpof a solution of the chlorides in constant-boiling hydrochloric acid. Atthis wavelength the ferric iron absorbs and the interference of bismuth isnegligible.The infrared spectra of the metal anthranilates such as thoseof CuZ+, Ni2+, Zn2+, Cd2+, Fez+, and Mn2+ are often very characteristic andparticularly so in the region 9-10 t/-. With binary mixtures of theseanthranilates of known weight, it is often possible to determine the propor-tions of the individual aiithranilates by measurement of the infrared spectraa t appropriate wavelengths.201 Mutschin and Maennchen 202 have made athorough study of the infrared spectra of diphosphoric acid, mono- anddi-sodium diphosphate, trisodium diphosphate as both mono- and mono-hydrate, tetrasodium diphosphate both anhydrous and as decahydrate, andtetrapotassium diphosphate in sodium chloride, potassium bromide, andczesium bromide solutions.Corbridge and Tromans 203 have indicated that the greater resolutionand increased definition of the diffraction lines recorded with a Guiniertype X-ray focusing camera, compared with those obtained with the usualDebye-Scherer type camera, offer several advantages for the identificationHigh and PlacitolQ7 S.K. Yasuda and J. L. Lambert, Analyt. Chem., 1958, 30, 1485.lQ8 D. N. Fogg and N. T. Wilkinson, Analyst, 1958, 83, 406.lQS E. Ruf, 2. analyt. Chem., 1958, 161, 1.J. H. High and P. J. Placito, Analyst, 1958, 83, 522.201 R. Neeb, 2. analyt. Chem., 1958, 161, 161.202 A. Mutschin and K. Maennchen, ibid., 160, 81.209 D. E. C . Corbridge and F. R. Tromans, Analyt. Chem., 1958, 30, 1101422 ANALYTICAL CHEMISTRY.and analysis of certain compounds, for example, phosphates.They presentthe X-ray data thus obtained for 60 crystalline sodium phosphates.Absorption Spectroscopy (Organic) .-Organic applications of absorptionspectroscopy have been numerous and two methods which, in conjunctionwith one another, can be used for the quantitative differentiation of tertiaryamines, amine salts, and/or quaternary amines have been put forward bySass et aZ.204 The first method is based on the reaction of amines withaconitic anhydride in toluene solutions at 100" to produce a coloured complexmeasured at 500 mp. The second procedure is similar but uses chloranilas reagent to produce a green colour measured at 610 mp. The sensitivitiesof the two methods are 3 pg.and 50 pg. per ml., respectively.A most useful procedure for the determination of small amounts ofthiourea or nitrite has been developed by Hutchinson and Boltz206 basedon the reaction of the two compounds to form thiocyanic acid. An excessof the one reagent is added to the solution containing the other being deter-mined, and the thiocyanic acid thus produced is measured by the ferricthiocyanate complex colour reaction. Use of the stable free radical a-di-phenyl-p-picrylhydrazyl has been made by Blois 2M for the determinationof antioxidants. The free radical in solution shows a deep violet colourwith an absorption band at 517 mp. This absorption and colour is due toan odd unpaired electron in the structure of the radical, and when thiselectron becomes paired owing to reaction with an antioxidant, there is acorresponding decrease in colour of the solution.This is the basis of themethod of antioxidant determination.The well-known reaction of esters of carboxylic acids with hydroxyl-amine hydrochloride giving hydroxamates which yield coloured reactionproducts with ferric salts has been studied in some detail by W. Pi1z.207An agreed procedure has been developed for the examination of esters ofacetic acid, i.e., with strict attention to the conditions required for thereaction with hydroxylamine, addition of the buffer, and colour development.Carbon monoxide can be determined in air by its reaction with the silvercompound of 9-sulphamidobenzoic acid in alkaline solution , with whichit yields a coloured silver solution.20* The range of the test has beenextended to cover 0.001-2%.Up to 06%, the extraction of the solutionis measured a t 420 mp, but above this concentration the measurement ismade at 610 mp.The iodoform reaction has been utilised by Takayama2OQ in a usefulmethod for the determination of small amounts of acetone in methylmethacrylate monomer. The acetone-containing sample is added to ahypoiodite solution, the colour of excess of iodine is discharged with thio-sulphate, and the iodoform formed extracted into chloroform solution.The absorbance due to iodoform is measured as 347 mp, and by referenceto an appropriate calibration curve the acetone content of the sample is204 S.Sass, J . J. Kaufman, A. A. Cardenas,and J.J.Martin, Analyt. Chem., 1958,30,529.205 K. Hutchinson and D. F. Boltz, ibid., p. 54.206 M. S. Blois, Nature, 1958, 181, 1199.207 W. Pilz, 2. analyt. Chem., 1958, 162, 81.208 G. Ciuhandu, ibid., 1958, 161, 345.2os Y. Takayama and F. Tokiwa, Bull. Chem. SOC. Jafian, 1958, 31, 369HASLAM AND SQUIRRELL: PHYSICAL METHODS. 423calcuIated. As little as O - O O l ~ o of acetone in methyl methacrylate monomercan be determined by this method.The availability of high-resolution spectrophotometers covering thenear infrared region has provided the analyst with a new tool. A paperby Goddu 210 has evaluated this region for the determination of unsaturationin organic compounds. He describes how both terminal methylene groupsand cis-double bonds can be selectively determined in a wide variety ofmaterials, and explains that other types of unsaturation do not interferewith terminal methylene determination. The bands at about 1.62 and2.10 p are used for determining terminal unsaturation and a band at 2-14p for cis-unsaturation.The potassium bromide disc technique has been adapted to suit micro-amounts of compounds which are soluble in organic solvents but insolublein water.211 Freeze drying is used exclusively for the preparation of thesample suspension in potassium bromide and precautions are taken to avoidcontamination of the mixture; the die for casting the disc is lubricatedwith graphite.The reproducibility of the discs prepared in this way issuch that the method is suitable for the quantitative infrared micro-analysisof binary mixtures of complex organic compounds.A semi-quantitativemethod for the determination of t-butyl groups has been prepared by Boogand I<unstJ212 mainly, they suggest, for the elucidation of the structure ofpure compounds. It appears that an infrared band near 1250 cm.-l andRaman bands near 1250 cm.-l and 745 cm.-l should be regarded as character-istic of the neopentyl group, while a Raman band near 925 cm.-l occurs withall types of t-butyl group. The sum of the intensities of the three Ramanbands can be plotted against concentration of t-butyl groups and gives areasonable straight-line relationship.Bartlet and Mahon 213 have described a useful application of differentialinfrared spectroscopy for the identification of vegetable oils and for thedetection of adulteration of one oil with another. The differential technique,for example, picks out the small differences in the spectra of olive and rape-seed oils, particularly in the 1200-900 cm.-l region, and a 10% contaminationof rape-seed oil in olive oil is readily detected.The effect of refining on thedifferential spectra of the oils has been studied and the principle of themethod of analysis extended to many vegetable oils, animal fats, andhydrogenated fats. The effect of the unsaturation in the oils on thisdifferential spectrum is also discussed.The infrared analysis of plasticisers obtained from plastic materials isfacilitated by a method due to Cachia et d 2 1 4 in which the mixed plasticisersare separated by column chromatography.The column is packed withsilica gel and Celite and the separations are achieved by elution with solventsincluding carbon tetrachloride-isopropyl ether and benzene-isopropyl210 R. F. Goddu, A~zalyt. Chem., 1957, 29, 1790.211 H. P. Schwarz, R. C. Childs, L. Dreisbach, S. V. Mastrangelo, and A. Kleschick,212 W. Boog and E. D. Kunst, Speclrochirn. Acta, 1957 Suppl., p. 568.*13 J. G. Bartlet and J. H. Mahon, J . Assoc. Ofic. Agric. Chern., 1958, 41, 450.214 M. Cachia, D. W. Southwart, and W. H. T. Davison, J . AppL Chem., 1958, 8,Appl. Spectroscopy, 1958, 12, 35.291424 ANALYTICAL CHEMISTRY.ether in different ratios. The component plasticisers are recovered byevaporation of the eluted fractions.Emission Spectroscopy .-The speed and direct applicability of spectro-graphic and flame photometric procedures have been fully exploited during1958.Fassel and Gordon 215 have devised an emission spectrophotometricmethod for the determination of oxygen in titanium, the precision of whichis said to be comparable to the vacuum fusion or bromination procedure.The method is based on direct-current excitation of a special electrodeassembly which provides a molten platinum bath after the arc is initiated.The oxygen in the titanium is rapidly liberated from this bath into an argonatmosphere, and the intensity ratio of the line pair (0) 7771 &(A) 7891 A isrelated to the oxygen content of the titanium sample. A new method hasbeen presented by Rusanov and Khitrov 216 for the spectrographic analysisof powder samples.The sample is carried in a stream of air and thusintroduced evenly into the discharge zone of a horizontal carbon or metallicA.C. arc which is initiated by a high-frequency discharge. The procedureis speedy and gives an increase in sensitivity and reproducibility. Electrodereactions are prevented, as well as fractional evaporation of the differentelements. Thus, because the radiation remains effectively constant themethod offers great possibilities for direct photoelectric measurement of theline intensities.An attempt has been made to devise rapid methods of analysis whichwill provide information about the mineral matter associated withAlthough alkalis are determined by a flame-photometric procedure, andsilica often by a gravimetric process, the main feature of the test is itsspectrographic nature.An appropriate solution of the coal ash or the wetdigestion product of a coal is treated with a chromium solution as internalstandard. Portions of this solution are absorbed by porous graphiteelectrodes and spectra are produced by the use of an uncontrolled condensed-spark discharge. Examination of the relative intensities of the appropriatelines in the spectrum enables one to obtain information about the content ofmajor elements such as aluminium, iron, titanium, calcium, magnesium, andmanganese very quickly; copper, strontium, and barium may also bedetermined.A paper by Fabian and Bode 218 may be of far-reaching importance inflame-photometric work.It is concerned with the flame-photometricdetermination of copper (a) in aqueous solution and (b) when the copper ispresent as a complex dissolved in an organic solvent immiscible with water.The copper complexes dealt with are those with sodium diethyldithio-carbarnate, cupferron, 8-hydroxyquinoline, and salicylaldoxime. With theappropriate solvent it is often possible to increase the sensitivity of theflame-photometric test very considerably as compared with the result inaqueous media. The interference of aluminium, silicic acid, and phosphoricacid in the flame-photometric determination of calcium has been largely215 V. A. Fassel and W. A. Gordon, Analyt. Chem., 1958, 30, 179.216 A. K. Rusanov and V.G. Khitrov, Spectrochim. Acta, 1958, 10, 404.217 K. Dixon, Analyst, 1958, 83, 362.H. Bode and H. Fabian, 2. analyt. Chem., 1958, 162, 328HASLAM AND SQUIRFCELL. 425overcome by the addition to the test solution of an amount of strontium 219which bears some relationship to the amount of calcium being sought, beforeflame-photometric examination. Fornwalt 220 has studied the effect of theconcentration of methanol upon the flame emission of the 352.5 mp nickelline in a 1 : 1 methanol-water solution, and also the effect of nickel on theflame emission of boron in 1 : 1 methanol-water solution for the oxide bandsystem at 518 mp. As a result, a rapid flame-photometric method for theestimation of nickel and boron in nickel-plating solution has been worked out.The interference of anions in the flame-photometric determination ofmetals is a serious one.Yofi: and Finkelstein z21 have overcome thisdifficulty due to phosphate and sulphate in the determination of calcium,in which these anions cause a fall in intensity. The addition of lanthanumor iron to the sample, it is postulated, replaces the calcium present as phos-phate or sulphate, allowing it to ionise to give the full intensity. Withoutthis addition, the calcium does not form ions from phosphate or sulphatesolutions even at the high temperature of the flame.The close similarity between the mass spectra of alcohols and hydro-carbons makes the determination of one in the presence of the otherimpracticable by mass-spectrographic methods. Langer and his co-workers 222 have overcome this difficulty by treating the mixture of hydro-carbon and alcohol with hexamethyldisilazane, which converts the alcoholinto its methylsilyl derivative, leaving the hydrocarbon unchanged.Thisderivative can be readily determined without prior separation, even in thepresence of water which is converted into hexamethyldisiloxane and has itsown distinctive mass-spectral peak. The authors suggest that the methodmight be useful for the determination of glycols, amines, and phenols.Atomic absorption spectroscopy is likely to be very useful for thedetermination of magnesium in plant materials, soil extracts, etc., as hasbeen shown by J. E. Allan; 223 Le., it will enable magnesium tests to becarried out with the same ease and reliability as the flame-photometricdetermination of sodium, potassium, and calcium.The principle of thetest is that a lamp is used as a light source which emits the line spectra ofmagnesium. The sample is sprayed into a flame alongside so as to providea reproducible and clearly defined cloud of atoms, and the light absorbed atthe wavelength of the resonance line by the unexcited atoms of magnesiumis measured.Micro-analysis.-The micro-determination of chlorine has received muchattention throughout the year. In a paper by Seligson et al. 224 an electro-metric method for the rapid titration of chloride in serum and other biologicalfluids is described. This method, which appears accurate, precise, andspeedy, utilises a silver-silver amalgam electrode pair and titration withsilver nitrate solution is carried out in sulphuric acid media, delivery of219 W.Schuhknecht and H. Schinkel, 2. Analyt. Chem., 1955, 162, 266.220 D. E. Fornwalt, Analyt. Chim. Acta, 1957, 17, 597.221 J. Yofi: and R. Finkelstein, Analyt. Chim. Acta, 1958, 19, 166.232 S. H. Langer, R. A. Friedel, I. Wender, and A. G. Sharkey, jun., Analyt. Chem.,223 J . E. Allan, Analyst, 1958, 83, 466.224 D. Seligson, G. J. McCormick, and K. Sleeman, CEinicaZ Chem., 1958, 4, 159.1958, 30, 1353426 ANALYTICAL CHEMISTRY.titrant being made from a Scholander micro-burette. A special electrodecircuit is described incorporating bucking potential controls by which theindicating galvanometer can be adjusted to read zero in the presence of aknown excess of chloride and 100 in the presence of a similar excess of silverions; with this means of standardisation the end-point occurs at a readingof 50 irrespective of small peculiarities in different electrode pairs.J.H. Cannon,225 drawing largely from the previous work of Kirk (1950),Schwartz (1933), Malmstadt and Fett (1954), and Baledel and Malmstadt(1952), has described an automatic method for chloride titration by whichas little as 10 pg. of chloride can be titrated with a precision of h0.2-0.3 pg. in a total titration time of 2 minutes. This apparatus consistsessentially of a silver-silver chloride electrode system and a horizontalcapillary burette fitted with automatic stopping devices controlled by anelectronic end-point detector.The titration is carried out in sulphuric acidsolution.For the micro-determination of chlorine in organic compounds also con-taining nitrogen and sulphur, Makineni and his co-workers 226 prefer to usea direct titration method which can be applied to wet or dry combustion pro-ducts. The halide is precipitated with silver, and the precipitate washed freefrom acids and from excess of silver solution before reaction with ion-exchangeresin Amberlite IRA 120 (H) at 70". The hydrochloric acid thus liberatedis titrated with standard mercuric nitrate solution, with use of diphenyl-carbazone indicator, or with standard silver nitrate solution by a conducto-metric procedure. A. R. Panicker and N. G. Banerjee227 have developedan ingenious method for the rapid determination of carbon and hydrogen inhighly volatile combustible organic liquids such as benzene and toluene.The sample is weighed out accurately in a three-bulb Pyrex-glass capillarywith open capillary end, then volatilised from this in a stream of nitrogenbefore combustion in added oxygen. Any residue in the sample tube isfinally combusted completely at an elevated temperature in a stream ofoxygen.Co,O, has been used by VeEera, Snobl, and Synek2= as a com-bustion catalyst for the micro-determination of carbon and hydrogen inorganic compounds; they report this oxide to be superior to all othercatalysts previously used, and it has the advantages of universalapplicability, simplicity, reliability, and speed.Results obtained by usingthis catalyst have been shown to have an accuracy equal to that obtainedby other methods.The method of preparation and typical analyses of a new multi-purpose microchemical standard have been described by Smith.229 Thecompound, 5-chloro-P-hydroxy-3-methoxybenzylisothiuronium phosphate,contains seven elements in reasonable quantities and in addition has amethoxyl group.Feigl and his co-workers have continued their work on spot-test analysis.They have shown that chloramine-T can be readily detected in the presence225 J. H. Cannon, J . Assoc. Ofic. Agric. Chenzists, 1958, 41, 428.226 S. Ma.kineni, W. McCorkindale, and A. C. Syme, J. AppZ. Chew., 1958, 8, 310.227 A. R. Panicker and N. G. Banerjee, Analyst, 1958, 83, 296.228 M.Teeera, D. Snobl, and L. Synek, Microchim. Acta, 1958, 9.229 W. H. Smith, Analyt. Chem., 1958, 30, 149HASLAM AND SQUIRRELL. 427of hypo~hlorite.~~~ The hypochlorite is first converted into chloride byreaction with hydrogen peroxide and zinc chloride solution. An alcoholicsolution of thio-Michler's ketone is now added; in the presence of chlor-amine-.r a blue oxidation product is produced. Very dilute solutions ofchloramine-T are without oxidative action on tetrabase ("""-tetra-methyldiaminodiphenylmethane) In the presence of iodide ions, how-ever, the base is catalytically oxidised to a blue product. This test is usefulin the detection of very small amounts of iodide in various waters and inorganic substances. In the biochemical field the same workers have alsodeveloped new spot tests for vitamin B, 232 and for ephedrine.2BA test which can be regarded as specific for orthophosphate has beenbased by Robinson and West 234 on the reaction of orthophosphate witho-dianisidine molybdate in acid solution, followed by addition of hydrazinehydrate.In this spot test a brown precipitate is fornied upon the additionof o-dianisidine molybdate if orthophosphate is present. The conversionof this brown precipitate into a blue colour when hydrazine hydrate is addedserves to confirm the presence of phosphate. Although specific for phos-phate, certain ions, particularly sulphide, complicate the interpretation ofthe results.Radio-chemical Methods-On the expanding subject of radio-chemicalanalysis, a critical survey of the factors which influence the accuracy ofthe determination of potassium in solution by the Geiger-Muller rapidradiological test has been made by H.Dresia and R. B e ~ k m a n n . ~ ~ ~ Trace-impurity determination by radio-chemical methods has been used byThompson et aLB6 in the examination of ultra-pure silicon; 29 elementshave been determined by using the combined technique of y-spectrometryand radiochemical separation with @-counting of the fractions. Theimpurities are classified into long-lived and short-lived elements accordingto the half lives produced from neutron activations, and the method is statedto be applicable to determinations in the parts per lo9 range.In a method for the determination of uranium dioxide in stainless steel,Silverman et aZ.237 have used a direct fluorescent X-ray procedure on aperchloric acid solution of the sample.The intensity of the radiation ismeasured with a scintillation counter, and strontium is used as an internalstandard. The determination suffers no interference from large amounts ofiron, chromium, and nickel, and reasonable accuracy is obtained in a four-pair count which can be completed in 12 minutes.Apparatus.-The development of new instruments and improved designof apparatus has continued to provide the analyst with the means for morerapid and accurate methods of test. Examples of a few of these develop-ments are described below.The nature of these complications is described.230 F. Feigl and R. A. Rosell, 2. analyt. Chem., 1958, 159, 335.231 F. Feigl and E. Jungreis, ibid., 1958, 161, 87.232 Idem, Clinica Chim. Acta, 1958, 3, 399.233 F. Feigl and E. Silva, J . Amer. Pharm. Assoc. (Sci. Edn.), 1958, 4'4, 460.234 J. W. Robinson and P. W. West, Microchim. J., 1957, 1, 93.236 H. Dresia and R. Beckmann, 2. analyt. Chem., 1957, 159, 1.2313 B. A. Thompson, 13. Ri. Strause, andM. B. Leboeuf, Analyt. Chem., 1958,30,1023.237 L. Silverman, W. W. Houk, and L. Moudy, ibid., 1057, 29, 1762428 ANALYTICAL CHEMISTRY.An apparatus, simple in design yet efficient and adaptable in use, hasbeen made by Strain 238 for the continuous electrochromatography of variousinorganic ions. The chromatographic medium is a tapered sheet of soft,thick, filter-paper supported on a block of modified polystyrene foam.A loose curtain of polyethylene film serves to cut evaporation losses ofsolvent.P U C & - , ~ ~ in connection with experiments on the electrophoresis ofhalogen complexes of many metals, has designed a heavy-current and high-tension electrophoresis apparatus. This apparatus, which is for use withfilter-paper, avoids the difficulties that occur in electrophoresis in baseelectrolytes that are concentrated and show greater electrical conductivity.The zones migrate along the paper strips with constant speed, and con-sequently mobility measurements can be made. With the apparatus themobility dependence of the chloro-complexes of Hg(n), Cd(II), Pb(II), andCU(II) on concentration and volume of solution used have been investigated.The application of paper electrophoresis in the field is now possible by usingthe portable apparatus described by Marini-Bettolo and Cochfr~goni.~~~The apparatus, including all accessories, is only 35 x 27 x 16 cm. in size,weighs 6.650 kg., and is powered by a 360-volt dry battery generator adjust-able by means of a potentiometer. It has been used in preliminary fieldanalysis of curarising alkaloids in plants and curares.Paulik, Paulik, and Erdey 241 have constructed a new type of apparatuswhich they described as a “ derivatograph.” With this apparatus they areable to carry out differential thermoanalysis, thermogravimetric, anddifferential thermogravimetric investigations simultaneously, and moreoverregister the results automatically. Application of the procedure enables theauthors to make very interesting observations on the mineral composition of,e.g., bauxite. The same authors a2 have extended the method to the gravi-metric micro-distillation of quite small amounts of mixed liquids. In thisway, they are able to determine the composition of such mixtures as benzene,ethyl alcohol, and water. A further aid to those chemists concerned withthermal analysis has been described by Williams et aLN3 in the form of aversatile differential thermal analysis apparatus. A constant reproducibletemperature gradient is established in a heavy-walled metal tube. Thesample holder containing the base and differential thermocouples is pulledin either direction through this tube at speeds required to produce thedesired temperature change.Miller and Deford 244 have made a useful contribution in the design of asimple apparatus for the quantitative hydrogenation of unsaturated com-pounds, using electrically generated hydrogen. The current used to producethe hydrogen by automatic electrolysis is measured on an electroniccoulometer which also serves as a recorder. The great advantage of the238 H. H. Strain, Analyt. Chem., 1958, 30, 228.239 2. Puck-, Analyt. Chim. Acta, 1957, 17, 476.240 G. B. hlarini-Bettolo and J. S. Cochfrugoni, J . Chromatog., 1958, 1, 182.241 F. Paulik, J. Paulik, and L. Erdey, 2. analyt. Chem., 1955, 160, 241.242 Idem, ibid., p. 321.243 D. D. Williams, R. D. Barefoot, and R. R. Miller, Analyt. Chem., 1958, 30, 492.244 J. W. Miller and D. D. Deford, Analyt. Chem., 1958, 30, 295HASLAM AND SQUIRRELL. 429method is that the accuracy appears independent of the size of sampleavailable for test.Those concerned with the evaluation and characterisation of smallamounts of materials by means of their melt viscosities will be interested ina simple melt viscometer designed by Small 2G which allows viscosities fromlo4 up to at least lo9 poises to be measured on 0.1 g. of material or less.Details of construction, use, and calibration are given.Finally, an electronic spectro-analyser has been developed by theFederal Telecommunication Lab0rat0rie.s.~~~ This instrument combines arecording device which encodes the spectral data on magnetic tape or paperand a reference " library " of infrared data on possible constituents, alsorecorded in numerical form on digital tape. The instrument also incorporatesa high-speed digital computer to calculate and record the analysis directly.J. HASLAM.D. C. M. SQUIRRELL.245 P. A. Small, J . Polymer Sci., 1958, 28, 223.240 Chem. Eng. News, 1958, 36, 62

ISSN:0365-6217    

DOI:10.1039/AR9585500389

出版商:RSC    

年代:1958

数据来源: RSC

摘要:

CRYSTALLOGRAPHY1. GENERALIntroduction.-This biennial Report follows those in Vols. 51 and 53, andcovers the years 1957 and 1958. As in other subjects, the spate ofpubIication continues: in the three specialist journals alone, Acta Crystal-lographica, Zeitschrift f u r Kristallographie, and Krystallogra$ya, somethinglike 750 communications appeared during the two years, so that coverageof the literature is necessarily incomplete, with a bias in favour of molecular-structure analysis.The Fourth Congress of the International Union of Crystallography metat McGill University, Montreal, in July, 1957, and summaries of the paperscommunicated are collected in Acta Crystallogra$hica.l This meeting waspreceded by a conference on current problems in Crystal Physics at theMassachusetts Institute of Technology, and the papers read there havebeen published inIn preparation are Vols.16-18 of " Structure report^,"^ dealing withall structure analyses published in the years 1952-1954; the first of theseat least should appear during 1959. The Society's Special Publication No.11 on interatomic distances should also be mentioned, as well as a reviewarticle * which discusses some critical problems in molecular-structuredetermination. An English translation of KrystalZogra$ya is now beingissued,5 though at present it is running more than a year in arrears. Vols.4-7 of " Solid State Physics " have appeared: the last includes a chapterby A. F. Wells reviewing and systematising the types of structure found in(mainly inorganic) crystals; whilst Vols.5 and 6 contain chapters by Kosterand C. S. Smith respectively on different aspects of crystal symmetry.Attention may be drawn to a sympo~ium,~ and to a set of review articles,8on the structure and properties of ice, to a lecture9 on crystalline ion-exchangers, and to a discussion lo which touches on the configuration ofmolecules in liquid crystals.As in former biennial reports, d(X-Y), or d ( X Y), stands for thedistance between bonded, or not directly bonded, atoms X and Y , and1957, 10, Part 12 (pp. 721-866).2 Rev. Mod. Phys., 1958, 30, 46-255.3 Oosthoek's Uitgevers, Utrecht. (Vol. 14, which contains an index to " StructureReports " up to 1950 as well as reports on a few analyses that had been omitted fromVols. 8-13, is expected to appear early in 1959.The Vo1.-presaged in the previousCrystallography report-covering the year 195 1, has been numbered 15.)D. P. Stevenson and J. A. Ibers, Ann. Rev. Phys. Chem., 1958, 9. 359.By the American Institute of Physics, New York.Edited by F. Seitz and D. Turnbull, Academic Press, New York.R. M. Barrer, Proc. Chem. SOC., 1958, 99.' PYOC. ROY. SOC., 1958, A , 247, 421-538.13 Ado. Phys., 1958, 7, 169-297.lo Discuss. Faraday SOC., 1958, 25SPEAKMAN : GENERAL. 43 1L(X-Y-2) for the valency angle a t Y. Limits of error, when stated, areestimated standard deviations.*The Groth Institute.-The marshalling of the ever-increasing mass ofscientific information, so that any part of it may be readily available asand when it is wanted, appears to be an almost hopeless task.In therestricted field of Crystallography, however, a determined effort is beingmade to meet the challenge. Pepinsky l1 has stated the crystallographicproblem in this form : In his “ Chemische ICrystallographie,” published in fivelarge volumes between 1906 and 1919, Paul Groth collected the classical,and particularly goniometric, measurements on perhaps 10,000 crystallinesubstances. Since 1919, and especially through the application of X-raydiffraction, possibly ten times as many substances have been studied, and,on an average, possibly ten times as much information is available abouteach. To bring “ Groth ” up to date, therefore, 500 volumes would need tobe written, and that at a time when-it has been said-the sum total ofinformation doubles itself every ten years.To cope with this situation, the Groth Institute has been founded, withits present home at Pennsylvania State University, and with Ray Pepinskyas its Director and Editor-in-Chief, and an initial staff of 20, which is to bemore than doubled during 1959.Its first object is to convert extant datainto punched-card form, When a body of data is thus deployed, it can behandled to great advantage by modern business equipment. Such handlingis extremely rapid, and it can be made error-free. The cards can be machine-sorted, for instance, so as to bring together related substances, or anydesired combination of properties; and, from any given array of cards, theinformation can be automatically printed out for rapid photolithographicreproduction.In this way it is ultimately intended to produce a series ofvolumes entitled “Groth’s Encyclopedia of Chemical and Physical Crystal-lography-Revised Edition.” The immediate task of the first two or threeyears is to deal with secondary sources of information-the numerousexisting tabulations and review articles; in the second phase, primarysources, Le., original papers, will be garnered, and it is hoped that new datacan be absorbed into the scheme as they arise.All knowninformation for perhaps 10,000 substances could be held on two million punchedcards; and the contents of these cards can be stored on a single roll of tape,roughly the size of this volume.Copies of the tape would be distributed tosuitable centres throughout the world. An I.B.M. 704 electronic computercan scan such a tape in about 15 minutes; and it is a simple matter toprogramme the machine to select and print out any desired kind, or com-bination of kinds, of datum : to take a trivial example, all known data aboutall carbon compounds which crystallise in the orthorhombic system but arepseudo-tetragonal within specified limits, which contain a hydrogen bondl1 Groth Institute, Summary Report No. 2, Pennsylvania State University, 1958.* The method most commonly in use for assessing the standard deviations ofcrystallographically derived molecular data is now thought, by its originator, to be alittle optimistic in its indications, when applied-as it often has been-to incompleteobservational material.Alongside this project, magnetic-tape recording will be used432 CRYSTALLOGRAPHY.shorter than 2.7 A, and which have a recorded transition temperature.The advantages of such a system are many; for instance, it would revealimportant discrepancies and gaps in our knowledge.In particular it wouldbe certain to lead to the discovery of new correlations between properties;which, incidentally, was one of the major objects Groth had in view whenplanning his monumental work.As a pilot-scheme for a method of approach that may-perhaps must-ultimately be applied to scientific information as a whole, the Groth Instituteis of great general interest. Its possible extension to the much vaster fieldof organic chemistry springs to mind at once.General Aspects of X-Ray Analysis and the Phase Problem.-ThoughX-ray diffraction cannot compete with spectroscopic methods in accuracywhere very simple molecules are concerned, or in the detailed insight itprovides into their structure, it is applicable to a much wider range ofsubstances.At present about 80% of all reported structure analyses arebased on X-rays.12 All crystal-diffraction methods depend on the feasibilityof solving the Phase Pr0b1em.l~ That the direct probability approach ofKarle and Hauptman l4 affords a general solution, as has been claimed, isnot yet accepted by most crystallographers. But it has enjoyed a notablesuccess with di-@-methoxyben~ophenone.~~ This substance has eightmolecules in a unit cell belonging to the space group P2Ja; so that, thoughthere are centres of symmetry (and hence the Phase Problem reduces toone of sign-determination), these are not used within the molecule: theasymmetric unit comprises two molecules, and 36 atoms, other than hydrogen,are to be located.In the absence of a heavy atom, or a planar molecule,or any other obviously favourable circumstance, the solution of this structureby conventional methods would seem a formidable task. Intensities hadbeen measured for over 4000 reflexions, and application of the probabilitymethod yielded signs for 270 of the more intense reflexions; when used in athree-dimensional electron-density calculation, these terms proved sufficientto indicate reasonable positions for the 36 atoms.The structure so foundhas been refined to a point where it can be accepted as correct. The struc-ture of colemanite, CaB,O,(OH),,H,O, had previously been determined bythe Karle-Hauptman method, and a full account of this work is nowpublished.leAnother direct approach, for which less generality had been claimed,has proved useful. Suppose that, for a centrosymmetric projection of aparticular structure, the twenty zonal reflexions of highest relative intensityare selected. The signs of two of these terms may be allocated arbitrarily,leaving 218 possible sign-combinations. One of these must be correct, butto compute and inspect half a million electron-density maps would beimpossibly laborious, even with massive computational aids.However, bysystematic application of Harker-Kasper inequalities or of the Sayre-Cochran equation,13 a reasonably small number (perhaps a score) of probable18 P. J. Wheatley, Ann. Rev. Phys. Chem., 1957, 8, 373.Is Ann. Reports, 1952, 49, 345; 1954, 51, 373.14 H. Hauptman and J . Karle, Acta Cryst., 1958, 11, 149, 264.16 I. L. Karle, H. Hauptman, J . Karle, and A. B. Wing, ibid., p. 257.16 C. L. Christ, J. R. Clark, and H. T. Evans, ibid., p. 761SPEAKMAN: GENERAL. 433sign-combinations could be picked out. Cochran and Douglas l7 andWoolfson 18 have devised tests which give figures-of-merit for these sets ofsigns, with the high probability that the correct set will have the bestfigure, or nearly so. The whole process can be made to work automaticallyon an electronic computer, which will finally calculate electron-densitydistributions for a few of the most meritorious sets.Armed with theconfidence that one of the resulting maps is almost certain to be correct, thecrystallographer should then be able to recognise the appropriate structureand verify it by further refinement in the usual way. Several projectedstructures, including those of nitroguanidine and of D-XylOSe, have beensolved by this method.The difficulty of such an approach, based on a comparatively smallnumber of terms, is that, in the imperfect map produced, it is hard torecognise the structure, unless the molecule is a rather simple one of knownchemical formula and with its individual atoms well resolved. This isillustrated in Wright’s analysis of g1~tathione.l~ The crystal is non-centro-symmetric, but the projection of the structure along the rather short c-axisis centred, for this aspect the problem becoming one of sign-determination;and the structure was ultimately solved by an application of the Cochran-Douglas method.Afterwards the authoress held a “ post mortem ” onthe various other methods that had proved unsuccessful.20 Each one isrepresented by an electron-density map, which in the light of after-know-ledge is recognisably near the truth, but which had failed to indicate thetrue structure a priori. The resemblance between these maps emphasisesthe point that the different methods of sign-determination are basicallyrelated; they represent differences of tactics rather than of strategy.A novel method was used in solving the structure of 1,2,4,5-tetrachloro-benzene,21 though it will not have wide application.The nuclear quadrupoleresonance due to the chlorine nuclei was observed for various settings of asingle crystal, and the results enabled the directions of the C-C1 bonds to bedetermined, hence indicating possible positions for the two molecules inthe unit cell. This structure was then confirmed by normal X-ray methods.The method developed by Bijvoet and his collaborators for deciding theabsolute configuration of a dissymmetric molecule is based onthe anomalous scattering from an atom whose inner electrons BrC)Me are disturbed by the type of X-rays used.Pepinsky and(1) Okaya22 have pointed out that this principle can be appliedto the solving of the Phase Problem at the same time. Forexample the conformation and absolute configuration of the ketone (1) weresimultaneously determined by taking advantage of the anomalous scatteringat the Br atom.2s0l7 W. Cochran and A. S. Douglas, Proc. Roy. SOC., 1955, A , 227, 486; 1957, A , 243,l8 M. M. Woolfson, Acta Cryst., 1958, 11, 277, 393.Is W. B. Wright, ibid., p. 632.2o Idem, ibid., p. 642.21 C. Dean, M. Pollak, B. M. Craven, and G. A. Jeffrey, ibid., p. 710.22 R. Pepinsky and Y . Okaya, Proc. Nat. Acad. Sci., 1956, 42, 286.23 Personal communication from Prof. Pepinsky.281. (See also W. Cochran and E. J. McIver, Acta Cryst., 1958,11, 892.434 CRYSTALLOGRAPHY.Quartz is optically active, its crystals embodying interlinked helices of-Si-O-Si-O-chains; but the absolute sense of these helices cannot befound by an ordinary X-ray analysis.When the structure of a crystal ofone enantiomorphic form of or-quartz is viewed along its c-axis, three helicalchains are seen within each unit cell; two are right-handed, and one left-handed and of half the pitch of the other two. Wooster pointed out someyears ago 24 the reasonableness of supposing that such a crystal would twistthe plane of polarised light in the same direction as the dominant helicesof atoms-that the “ light should follow the atoms ”; and hence that thisparticular enantiomorph should be laevorotatory (since the direction ofrotation is defined from the point of view of the observer of the light).Laevorotatory quartz should have its dominant helices right-handed, andvice versa.This suggestion has now been confirmed by the Bijvoet method.25When the Phase Problem has been solved for a particular structure, itsrefinement is a straightforward, if laborious, process, which now appearsto be fairly well understood. With the readier availability of electroniccomputers, increasing numbers of structures are being highly refined.Measured in the usual photographic manner, X-ray intensities are subjectto considerable errors (often exceeding 10%). More accurate data can bederived from counter-measurements, but these are time-consuming and notsatisfactory for the weaker reflexions; in any case, corrections for extinctionand absorption still need to be applied, and the former are especially difficultto assess.Provided the errors are random (which they may not be), refine-ment can still proceed fairly well because there is normally a large excessof observational data over derived structural parameters. Neverthelessthe time is ripe for the development of rapid, accurate, and automaticmethods of recording intensities. It should then be possible to extend thepotentialities of the X-ray method in a manner parallel to recent extensionsin the scope of the gaseous, electron-diff raction technique.26 The detaileddistribution of the electrons in a molecule might then come within reach ofthe X-ray crystallographer, as well as the finer details of the vibrations.The Location of Hydrogen Atoms and the Hydrogen Bond.-One reasonfor desiring accurate X-ray intensity measurements is that they facilitatethe location of hydrogen atoms.2’ In a well-refined analysis, the hydrogenatoms are usually included, though their positions are much less accuratelydefined than those of the heavier atoms. It continues to be the generalexperience that the X-H bond appears to be shorter when measured withX-rays than is found in other ways.However, there are some exceptions,%and the most obvious explanation for the discrepancy (that the position ofthe hydrogenic electron-density maximum does not coincide with that ofthe proton) has been que~tioned.~~24 W. A. Wooster, Reports Prop. Phys., 1953, 16, 67.26 A.de Vries, Nature, 1958, 181, 1193.28 A summary of recent developments in this field is included in ref. 4.27 R. E. Richards, Quavt. Rev., 1956, 10, 480. (See also Ann. Reports, 1954, 51,28 E.g., W. Drenth and E. H. Wiebenga, A d a Cryst., 1955,8,755; A. J. van Bommel[That the X-ray method sometimes finds29 F. L. Hirshfeld and G. M. J. Schmidt, J . Chem. Phys., 1957, 26, 923.376.)and J. M. Bijvoet, ibid., 1958, 11, 61.d(C-H) to be less than d ( 0 - H ) may also cause misgiving.SPEAKMAN GENERAL. 435Neutron diffraction seems to be the most useful method for locatingprotons, or deuterons, in crystals. Bacon and Gardner 30 have describedsuch a study of chrome alum. The general features of the structure and thepositions found for the heavier atoms agree very well with the classicalwork of Beevers and Lipson (1935); and now the positions of the fourcrystallographically distinct protons can be stated, perhaps within &O-03 A.There are two types of water molecule in the alum structure, one being inclose six-fold co-ordination round the tervalent (Cr3+) ion.These moleculesare in such an environment that hydrogen bonds can readily be made withone of the 0-atoms of the sulphate ion and with one water molecule of theother type, L(0 0 0) being 102". The protons of these watermolecules therefore lie very near to the direct 0 0 lines, with d(0-H) =1.02 and 1.03, d(O 0) = 2-66 A in each case, and L(H-0-H) = 107".The water molecules co-ordinated round the univalent (K+) ion are lessfavourably situated for bonding, L ( O 0 * 0) being 94".Only oneproton is then able to lie on the 0 * * O line, with d(0-H) = 1.03 andd(O 0) = 2-64 A; the other is significantly off the line, so as to yieldL (H-0-H) = 103", and in this case d(0-H), at 0.95, is perhaps significantlyshorter, and d ( 0 - 9 0), a t 2-72 A, certainly longer, than in the other bonds.According to the early work of Bernal and Megaw (1935), the crystalstructure of calcium hydroxide is remarkable in that the hydroxide ion doesnot appear to form any hydrogen bonds. (As in some other strongly basicsubstances, the OH-stretching frequency is corresponding high.*) Aneutron-diffraction study 31 now finds d(0-H) = 0.98 A; between neigh-bouring OH-groups, d(O * * * 0) = 3.33, d ( 0 * - * H) = 2.55, andd(H * * * H) =2-202 A, so that there is indeed no hydrogen bonding, and the contactresembles that between two neutral hydrogen molecules.The authorspoint out the sequence of d(0-H) values: 0.958 (H,O), 0.971 (OH), 0-98(OH-), and 1.030 A (OH+).Hexamethylenetetramine was one of the first organic molecules to beelucidated by X-rays; neutron diffraction3, now shows the protons to bein the expected positions where they complete the tetrahedral valencyarrangement round the carbon atoms. In the urea molecule neutrondiffraction 33 supports the results of nuclear magnetic resonance in findingthe hydrogen atoms to be coplanar with the others, but differs in findingd(N-H) = 0.99 & 0.02 A compared with 1.04 & 0.01.A detailed consider-ation of the vibrational frequencies of solid ureaN tends to support thelower of these two values.In most hydrogen bonds of the 0-H 0 type, the proton is unsym-metrically situated. It has been suggested that this might cease to be truewhen the bond is unusually strong and d ( 0 0) unusually short, 2.45 Abeing a recent estimate of the distance below which symmetry might be30 G. E. Bacon and W. E. Gardner, Proc. Roy. Soc.. 1958, A , 246, 78.31 W. R. Busing and H. A. Levy, J . Chem. Phys., 1957, 20, 563.32 A. F. Andresen, Acta Cryst., 1957, 10, 107.33 J. E. Worsham, jun., H. A. Levy, and S. W. Peterson, ibid., p. 319.34 M. Davies and L. Hopkins, Trans. Faraday SOL, 1957, 53, 1563.* 3690 cm.-' has been cited, but the spectrum in this region is complex (e.g., seeW.R. Busing and H. W. Morgan, J . Chem. Phys., 1958, 28, 998)436 CRYSTALLOGRAPHY.expected.% In a number of substances hydrogen bonds have been foundlying across a crystallographic element of symmetry, implying a formalcentering of the proton. As these bonds, though short, usually haved(O 0) greater than 2-45 A, it has generally been assumed that theeffective symmetry is merely statistical, though a neutron-diffractionanalysis of potassium hydrogen bisphenylacetate and some other evidence 36provide at least a prima facie case for believing that the symmetry might begenuine. In potassium hydrogen maleate, the space group is probablysuch that the anion is bisected by a crystallographic plane of symmetry asindicated by the broken line in (2), and it had been suggested on the basisof the infrared spectrum that the intramolecular hydrogen bond might be~ymmetrical.~~ This compound has now been studied by neutron diffrac-t i ~ n .~ ~ On the neutron-scattering map the proton appears as a circular“ peak ” centred on the symmetry-plane [d(O H 0) = 2.44 A].Owing to the experimental errors in deriving this map, a “ double-minimum ”situation is not absolutely ruled out; but a discussion of the vibrationalanisotropies of the atoms involved leads to the conclusion that “ a closeapproach to actual centering is implied.”An unorthodox view of the hydrogen bond has been expounded byZvonkova: 39 when X in X-H is sufficiently electronegative, the van derWaals radius of the hydrogen atom may be reduced by as much as 0.5below the commonly accepted value of about 1.2 A; in a bond of the typeX-H *Y, this reduction will lead to a low value for d(H Y), which willresult in a high electrostatic attraction, and which is now to be regardedas a normal van der Waals contact between H and Y.On this basis anexperimental value of d(N S) = 2.48 A in an intermolecular hydrogenbond in 2-mercaptobenzothiazole (“ Captax,” which is found to have thestructure 3) is accepted.*ODisorder and Crystal Structure Analysis.-The symmetry displayed by amolecule in the crystal is usually a lower limit. Of the fifteen non-trivialsymmetry elements possessed by the isolated benzene molecule, only thecentre is used in the crystal.As has also long been recognised, this rulemay be broken when the molecule has its orientation randomised by someform of disordering. Thus the ammonium ion must have tetrahedral35 C. A. Coulson, Reseurth, 1957,10, 149. (This critical 0 . . . 0 distance had earlierbeen put a t 2.3 A.)36 G. E. Bacon and N. A. Curry, Actu Cryst., 1957, 10, 524; R. F. Bryan and J. C .Speakman, ibid., p. 795; N. Albert and R. M. Badger, J . Chem. Phys., 1958, 29, 1193.37 H. M. E. Cardwell, J. D. Dunitz, and L. E. Orgel, J., 1953, 3740.38 S. W. Peterson and H. A. Levy, J . Chem. Phys., 1958, 29, 948.39 2. V. Zvonkova, Krystallografya, 1957, 2, 408.40 Ia. Tashpulatov, 2. V. Zvonkova, and G. S. Zhdanov, ibid., p. 38. (However, inthe particular NH . . . S bond in this crystal, some participation by the p-electrons ofthe S-at om is envisaged.SPEAKMAN: GENERAL.43733m (Td) symmetry, but the simple ammonium halides at room temperatureadopt the caesium chloride type of structure, so that the ammonium ion haseffective eight-fold cubic m3m (Oh) symmetry, with ‘‘ half-hydrogen atoms ”between the nitrogen and its eight neighbouring anions. The effect isexemplified in its most developed form in pentamethylene sulphide (thia-cyclohexane) , 41 which, like carbon tetrabromide, or like cyclohexane itself(but unlike pentamethylene oxide), displays virtually spherical symmetryin the crystalline state. Such anomalies have been interpreted in termsof “ rotation in the solid state.” In most cases literal rotation now appearsunlikely; rather the molecule can assume a greater or lesser number ofalternative orientations in space.If a t any instant a particular molecule’schoice of one of these possible orientations is completely randomised, themolecule will display enhanced symmetry. In the extreme form ofdisordering, occurring in thiacyclohexane or carbon tetrabromide, thecrystal is very soft or “ plastic ” and belongs to the cubic system, and theX-ray diffraction pattern shows very few reflexions. But in general arandomly disordered crystal may give a normal pattern. On the otherhand, incomplete randomisation leads to a great variety of complexphenomena, including additional reflexions which may be diffuse. Someof these latter types of disorder have been codified by Dornberger-Schiff .42Here we are concerned with the former type; for it has been detected inseveral crystals recently studied, and it is likely to impede the determinationof accurate atomic co-ordinates.In azulene (4), which may be taken as an example, there are twomolecules in the unit cell, and the absent reflexions unambiguously indicatethe space group to be PZ,/a.The situation thus far iswholly like that in the crystals of the isomeric naphthalene,and it implies that the molecules both possess a centre ofsymmetry. With azulene this conclusion is inadmissible,(4) and it can be evaded in either of two ways : (1) By supposingthe space group to be not PZ,/a, but Pa-the non-centrosymmetric analogue.Experimental discrimination in favour of the former was based on thenon-observance of four OkO reflexions with k odd; these absences could nowbe ascribed to their being ‘ I accidentally ” of low intensity, rather thanidentically zero.(2) By supposing the molecules to be disordered. Aswas reported in Vol. 53, by 1956 two groups of workers had independentlycome to the conclusion that (1) was the correct explanation,a because theyfound that a good measure of agreement between observed and calculatedstructure factors in the three principal zones could be obtained by placingthe azulene molecule in a cell of space group Pa, in the manner suggestedin Fig. l a . The agreement in this “ two-dimensional ” analysis was of akind that is usually held to carry conviction. However, it was necessaryto refine the structure by three-dimensional methods in order to deriveaccurate bond-lengths; and it has proved impossible to secure adequate41 S.Kondo, Bull. Cliem. SOC. Japan, 1956, 29, 999.42 K. Dornberger-Schiff, Acta Cryst., 1957, 10, 271.43 J.. M. Robertson and H. M. M. Shearer, Nuture, 1956, 177, 885; Y. Takeudi andR. Pepinsky, Science, 1956, 124, 126438 CRYSTALLOGRAPHY.refinement in terms of Pa. Satisfactory refinement immediately followedwhen explanation (2) was adopted,44 two centro-symmetrically relatedhalf-molecules being placed in a cell of space group P2,/a, as is shown inFig. Ib. The two electron-density projections differ only very slightly, aswill be seen, and this accounts for the good agreement for the zonal reflexionsgiven by the ordered structure.This disorder had been suggested byGunthard in 1949 from a comparison of the measured entropies of azuleneand n a ~ h t h a l e n e . ~ ~ That random orientation should obtain despite theconsiderable polarity of the azulene molecule is perhaps a little surprising.+%X -FIG. 1. Disorder in the crysfal of azulene: (a) the ordered structure based on P a ; (b) thedisordered structure based on P2,la. In each case the correspondingly derived electron-density projection i s shown. I n (b) two half-molecules are statistically related by thecentre of symmetry.The theoretically interesting central bond is now estimated to have d(C-C) =1.458 A, but it will be difficult to measure this as accurately as was originallyhoped. *Analogous disorder has been found in di-inden yliron .46 The individualmolecule has the gauche-conformation indicated in Fig.2a; two half-molecules of this type, centro-symmetrically related as shown in Fig. 2b,more satisfactorily reproduce the experimental observations. Again,1,Z-dichlorotetramethylbenzene has been shown 47 to be isostructural withhexamethyl- and hexachloro-benzene ; an electron-density projectionshows that each substituent group is effectively the same and statisticallyequal to (2/3 CH, + 1/3 Cl), with indications of vigorous torsional oscillationof the molecule about its pseudo-six-fold axis. Representative of a numberof similarly disordered structures is 4,4’-dibromoazoxybenzene, whosemolecule has apparent centro-symmetry in the crystal.&A rather different type of disorder was found during an accurate analysis44 J.M. Robertson, H. AT. M. Shearer, G. A. Sim, and D. G. Watson, Xature, 1958,46 H. H. Gunthard, Thesis, Zurich, 1949.46 J. Trotter, Acta Crysta., 1958, 11, 365..47 A. Tulinsky and J. G. White, ibid., p. 7.48 A. Addamiano, J . Phys. Chem., 1958, 62, 1018.* However, Mr. Watson reports that this value remains unchanged after consider-able further refinement of the (disordered) structure.182, 177SPEAKMAN : GENERAL. 439of the tripeptide, L-leucyl-L-prolylglycine : 49 as would be expected, onecarbon atom in the five-membered ring is out of the plane of the other fouratoms; what is unusual is that it is equally likely to be found on either sideof this plane.Conformational disorder of this kind might well prove to becommon in crystalline proteins. If it were so, the prospects of ultimatelyattaining detailed knowledge of their primary structure would be diminished.The Electronic Spectra of Crystals.*-Intermolecular forces in crystalsmodify the spectrum of a free molecule in a manner that depends on thecrystal structure as well as on the intensity and polarisation of the moleculartransition. Since this topic was last rep~rted,~O the prediction of crystal(a) (4FIG. 2. Disorder in the crystal of di-indenyliron: (a) shows the structure of the isolatedmolecule (the iron atom-represented by the large circle-lies between the parallel planesof the upper indenyl residue-represented by heavier lines-and of the lower-lighterlines); (b) shows two half-molccules statistically related by the centre of symmetry at theasterisk, one such half- molecule being drawn with broken lines.spectra from the known molecular (solution) spectrum has met withconsiderable success, the interpretation of the absorption by single crystalsof anthracene 51a and naphthalene 51b being now secure. The analysis of acrystal spectrum establishes the polarisation of the electronic transitions;hence its special importance lies in the fact that it provides a method ofgeneral applicability (the only such method at present) for the study ofelectronically excited states of molecules.Practical difficulties however-e.g., the fact that very accurate crystallographic data are necessary for asolution-have allowed theory 52 to outstrip experiment for the time being.Schnepp and McClure 53 have sought to determine the configurations ofthe methyl groups in hexamethylbenzene from the detailed vibrationalstructure of the 2500 (The positions of the carbon electronic transition.49 Y.C . Leung and R. E. Marsh, Acta Cryst., 1958, 11, 17.50 Ann. Reports, 1959, 52, 77A. Bree and L. E. Lyons, J., 1956, 2662; H.-H. Perkampus, 2. phys. Chem.(Frankfurt), 1957, 13, 278; J. Ferguson and W. G. Schneider, J . Chem. Phys., 1958,28,761.61b D. P. Craigand J. R. Walsh, J., 1958, 1613; D. S. McClure, J . Chem. Phys., 1956,24, 1.L. E. Lyons, J., 1958, 1347; W. T. Simpson and D. L. Peterson, J . Chem. Phys.,1957, 26, 588; J.Amer. Chem. SOC., 1957, 79, 2375.53 E.g., 0. Schnepp, J . Chem. Plzys., 1958, 29, 56.* The Reporter is indebted to Dr. J. C. D. Brand for the material i n this section4-40 CRYSTALLOGRAPHY.atoms were determined by X-rays first in 1928, and more exactly in 1939.)Above the transition-point ( l l o " ~ ) , it is tentatively suggested that one C-Hbond of each methyl group lies in the plane of the benzene nucleus, thesebonds being ordered, either all clockwise, or all anti-clockwise, round the ring(point-group 6/m or c 6 h ) . In the low-temperature form, it appears possiblethat the ring is elongated in the direction of the crystallographic b-axis, asa result of asymmetric forces acting on the methyl groups: only a two-foldsymmetry axis then remains.J.C. S.2. INORGANIC STRUCTURESElements and Simple Compounds.-The lattice constants of separatedlithium isotopes have been measured: for 6Li a = 3.5107 & 0.0009 A andfor 7Li a = 3.5092 & 0.0006 A, the larger value for the lighter isotope beingexplained by the greater zero-point energy of this isotope.54 A new crystal-line modification of boron has been prepared: this has one eicosahedralBl,.group in the unit cell, the arrangement of the boron atoms being verysimilar to that found in boron carbide.55 Full details of the tetragonal boronstructure have now been published: 56 the fundamental atomic arrangementdescribed previously in these Reports 57 is confirmed. In E-plutonium theprincipal co-ordination number is 14 associated with average d(Pu Pu) =3.20 A, but co-ordination numbers 12 and 16 are also found associated withaverage d(Pu Pu) = 3.11 and 3.31 A, re~pectively.~~ The rhombohedra1structure of mercury is retained on cooling to 5OK, no evidence being foundfor the transition suggested by Bridg~nan.~~ The adoption of the cubicclose-packed structure by the Group 0 elements has again been discussed,60as have also the anomalous X-ray reflexions from certain diamonds.61The bromine trifluoride molecule has a planar distorted T-shaped struc-ture with one short, 1.721 A, and two long, 1.810 hi, Br-F bonds, and withL(F-Br-F) = 86"13'.62 A T-shaped configuration is found also indiphenyliodonium chloride: d(1-C) = 2.08, d(I-Cl) = 3.08 A; L(C-I-C') =98", L (C-1-Cl) = 87", 174".63 There is a tetragonal pyramidal arrangementof fluorine atoms in the bromine pentafluoride molecule with the bromineatom situated below the base of the pyramid at 1.68 A from the apical, andat 1.78 from the basal, fluorine atoms.64 In the iodine heptafluoridemolecule five of the fluorine atoms are situated at the corners of a tetragonalpyramid, the iodine atom is below the base of the pyramid and the other64 E. J.Covington and D. J. Montgomery, J. Chem. Phys., 1057, 27, 1030.65 I,. V. McCarty, J . S. Kasper, F. H. Horn, B. F. Decker, and A. E. Newkirk,J . Amer. Chem. SOC., 1958, 80, 2592.68 J. L. Hoard, R. E. Hughes, and D. E. Sands, ibid., p. 4507.67 Ann. Reports, 1952, 49, 356.68 W. H. Zachariasen and F. Ellinger, Acta Cryst., 1957, 10, 776.69 C.S. Barrett, ibid., p. 55.6o J. Cuthbert and J . W. Linnett, Trans. Faraduy SOC., 1958, 54, 617,61 S. Caticha-Ellis and W. Cochran, Acta Crysf., 1958, 11, 245.62 D. W. Magnuson, J. Chem. Phys., 1957, 27, 223; see also ref. 64.63 T. L. Khotsyanova, Doklady Akad. Nauk S.S.S.R., 1956, 110, 71.64 R. D. Burbank and F. N. Bensey, jun., J. Chem. Phys., 1957, 27, 982SIM : INORGANIC STRUCTURES. 441two fluorine atoms are below the iodine atom, the molecule approximatingto mm(C2,) symmetry: d(1-F) = -1.71 (apical F atom), 1.83 A (others).65An electron-diff raction study confirms that S2C12 and S2Br2 have molecularstructures similar to H202 with dihedral angles of 83" and 84" respectively:d(S-S) = 1.97, d(S-C1) = 2-07, d(S-Br) = 2-24 A.66 In B2C1,, which hasa planar structure, d(B-C1) = 1.73, d(B-B) = 1.75 A: 67 in B2F4, which hasa similar structure, the boron-boron atom separation is shorter, d(B-B) =1-67, d(B-F) = 1.32 A.6s 0.02 A,in good agreement with the electron-diffraction value.69 B,Cl, (I) has D,,In BC1, at -165"c H(B-Cl) = 1.75CIH Imolecular symmetry; d(B-B) = 1.78-2.07, H(B-C1) = 1-70 d on average.70The boron atom arrangement in B6H,, is pentagonal pyramidal, d(E3-B) =1.596-1.795 A: the hydrogen atoms have been located and are arrangedas in (II).71The S4N4H4 molecule consists of a puckered eight-membered ring,similar in shape to the s8 molecule, of alternate sulphur and nitrogen atomswith d(S-N) = 1.6'74 & 0.004 A; L(S-N-S) = 122.2", L(K-S-N) =108.4", both &0.5".72 The dihedral angle is 99.4" (cf.99.3" in s8). Furtherrefinement of the structure of P4S3 leads to interatomic distances only slightlydifferent from those reported earlier; d(P-S) = 2.090, d(P-P) = 2.235 A.73P4S5 has a structure derived from that of P4S, by placing one sulphur atombetween two of the three phosphorus atoms forming the base of the P4S3molecule and another sulphur atom in the remaining tetrahedral position65 R. D. Burbank and F. N. Bensey, jun., J . Chem. Phys., 1957, 27,981.E. Hirota, Bull. Chem. SOC. Japan, 1958, 31, 130.67 M. Atoji, P. J. Wheatley, and W. N. Lipscomb, J. Chern. Phys., 1957, 27, 196.88 L. Trefonas and W. N. Lipscomb, ibid., 1958, 28, 54.6g M. Atoji and W. N. Lipscomb, ibid., 1957, 27, 195.70 R.A. Jacobson and W. N. Lipscomb, J . Anzer. Chern. SOC., 1958, 80, 6571.71 F. C. Hirshfeld, K. Eriks, R. E. Dickerson, E. L. Lippert, jun., and W. N. Lips-72 R. L. Sass and J. Donohue, A d a Cryst., 1958, 11, 497; E. W. Lund and S. R.7a Yuen Chu Leung, J. Waser, S. van Houten, A. Vos, G. A. Wiegers, and E. H,comb, J. Chern. Phys., 1958, 28, 56.Svendsen, Acta Chem. Scand., 1957, 11, 940.Wiebenga, Acta Cryst., 1957, 10, 574442 CRYSTALLOGRAPHY.with respect to one of these P atoms: d(P-S) = 1.94 A for this S atom,= 2.12 A otherwise, d(P-P) = 2-21 A.74 In ethylene thiocyanate thethiocyanate group appears to be non-linear, L (S-C-N) = 172-3°.75Nitramide, NH,*NO,, forms a planar molecule with d(N-N) = 1-40,d(N-0) = 1.18 A.76 The structures of a number of organosilicon com-pounds have been determined by electron diff ra~tion.~’Phosphates, Sulphates, etc.-In phosphorous acid the oxygen atoms aresituated at three corners of a distorted tetrahedron around the phosphorusatom with d(P-0) = 1.54 (twice), 1.47 A.Each molecule ,forms twohydrogen bonds in agreement with the formulation of the acid asH*PO(OH),.78 The structure of urea phosphate is based on alternatelayers of phosphate tetrahedra and of urea molecules with hydrogen bondingboth within and between the layers: d(P-0) = 1.523 (twice), 1.546, 1.565A.79 The structure of hydrosyapatite, Cal0(PO4),(OH),, has been refined :the improved atomic positions lead to a fairly regular PO, tetrahedron withd(P-0) = 1-53 A on average.Of the two crystallographically independentCa2+ ions in the structure one is co-ordinated to 9 oxygen atoms, d(Ca 0) =2.56 A on average, while the other is co-ordinated to 7 oxygen atoms,d(Ca 0) = 2-45 A on average.80 CaHP0,,2H,O contains corrugatedsheets of composition CaPO, with the water molecules in layers betweenthe sheets: each Ca2+ ion is co-ordinated to 8 oxygen atoms a t 2.54 A onaverage.81 P-K,PO,F is isostructural with p-K,S0,.82 The pyrophosphateion, P207,-, in Na,P207,10H,0 consists of two PO, tetrahedra sharing anoxygen atom in common: d(P-0) = 1.63 A in the case of the bridge oxygenatom: = 1-48 (twice), 1.45 A, otherwise; L(P-O-P’) = 134°.83 In thelow-temperature form of Na,P,Olo the triphosphate anior,s have two-foldaxial symmetry and consist of three PO, tetrahedra sharing corners incommon: 84 d(P-0) = 1.64 A (bridge oxygen atoms), 1.50 a (terminaloxygen atoms), a difference very similar to that reported in the case of theS,OlO2- The Na+ ions have a distorted octahedral co-crdination,d(Na 0) = 2.48 A on average.Copper sulphate and zinc sulphate are isostructural: the metal ion ineach case is at the centre of a distorted octahedron of oxygen atoms,d(M 0) = 2.14, d(S-0) = 1.50 A on average.86 NiSO, 87 and MgSO, 88are isostructural with CrV04,8Q the metal ions being in distorted octahedral71 S.van Houten and E. H. Wiebenga, Acta Cryst., 1957, 10, 156.75 R. Bringeland and 0. FOSS, Acta Chem. Scawd., 1958, 12, 79.7s C. A. Beevers and A. F. Trotman-Dickenson, A c f a Cryst., 1957, 10, 34.77 M.Yokoi, Bull. Chem. SOC. Japan, 1957, 30, 100, 106.78 S. Furberg and P. Landmark, Acta Chem. Scand., 1957, 11, 1505.79 R. V. G. Sundera-Rao, J. W. Turley, and R. Pepinsky, Acta Cryst., 1957,10, 435.A. S. Posner, A. Perloff, and A. F. Diorio, ibid., 1958, 11, 308.81 C. A. Beevers, ibid., p. 273.82 M. T. Robinson, J . Phys. Chem., 1958, 62, 025.83 I). M. MacArthur and C. A. Beevers, Acta Cryst., 1967, 10, 428.84 I>. R. Davies and D. E. C. Corbridge, ibid., 1958, 11, 315.86 P. A. Kokkoros and P. J. Rentzeperis, ibid., 1958, 11, 361.88 P. J. Rentzeperis and C. T. Soldatos, ibid., 1958, 11, 686.89 I<. Brandt, Arkiv K e m i , Min. Geol., 1943,17, A , 13; Structure Reports for 194.2-K. Eriks and C . H. MacGillavry, ibid., 1954, ‘7, 430.P.I. Dimaras, ibid., 1957, 10, 313.1944, 9, 181SIM : INORGANIC STRUCTURES, 443co-ordination by oxygen atoms. TiOSO,,H,O contains infinite chains,0-Ti-0-Ti *, held together by sulphate groups : a distorted octahedralarrangement of oxygen atoms around each Ti atom is completed by thewater molecules; d(Ti 9 0) = 1-91 A on average.90 Ce6O,(OH)4(SO& 91is isomorphous with the corresponding uranium compound 92 and containsisolated Ce,04(OH),12+ ions with d(Ce Ce) = 3-78, 3.83, d(Ce-0) = 2.22-2.39 A. In (CH3~NH,)Al(H20)6(S0,)2,6H,0 the A1(H20),3+ octahedraare slightly flattened, d(A1-0) = 1-89 L f , and the SO,2- ions possess trigonalsymmetry, d(S-0) = 1.494 (thrice), 1.473 In the structure of KHSO,there are two independent sets of HSO,- ions: one set is formed into dimersand the other set into infinite chains by hydrogen bonding, d ( O * * * O ) =2.67 A.The S(OH)O,- tetrahedra are fairly regular with d(S-0) = 1-52 Aon average, and each K+ ion is co-ordinated to 9 oxygen atoms, d(K 0) =2.86 i% on Distances in the anion C,H,*O-SO,- have beenredetermined; d(S-0) = 1-60 i% for the oxygen atom bonded to carbon, =1-46 A for the otherss5 In zinc toluene-9-sulphonate hexahydrate d(S-0) =1.43 A: the Zn atom is in octahedral co-ordination with oxygen atoms,d(2n-0) = 2.09 k 9 G In zinc salicylate dihydrate, on the other hand, theZn atom is tetrahedrally co-ordinated, d(Zn-0) = 2-05 A redeter-mination of the parameters in potassium pyrosulphite leads to d(S-S) = 2.21A in the S,O,,- anion:* which value falls satisfactorily between the values2.39 and 2-15 A reported in the anions S,042- and S20G2- respectively.Redetermination of the oxygen parameters in NaNO, and CaCO, leadsto d(N-0) = 1.218, d(C-0) = 1.294 A, both &0.004 In a neutron-diffraction study of Pb(NO,), a rather different value for the N-0 bondlength is obtained, namely, 1-27 & 0.02 A.1oo It is not clear, however,whether proper allowance for errors in bond lengths due to rotationaloscillations lol has been made in these determinations and the results mayhave to be revised.In Li,CO, each Li+ ion is surrounded tetrahedrally byfour oxygen atoms at 1-97 A.102 After further refinement of the atomicco-ordinates the anions in I<C10,,103 NH4C10,,lM and KMnO, lo5 appear tobe regular tetrahedra with d(C1-0) =-1-46, d(Mn-0) = 1-55 L f .TheSeO, groups in CuSe03,2H,0 are trigonal pyramidal with d(Se-0) = 1.76 Aand L(0-Se-0) = 99" on average. Each Cu atom is surrounded by threeoxygen atoms and a water molecule in a planar arrangement withd(Cu * - - 0) = 1.96 L f , and two further water molecules at 2.27 and 3.21G. Lundgren, A r k i v Kenei, 1956-1057, 10, 397.I d e m , ibid., p. 183.92 I d e m , ibid., 1963, 5, 349.s3 Y. Okaya, M. S . Ahmed, R. Pepinsky, and V. Vand, 2. Krist., 1967, 109, 367.s4 L. H. Loopstra and C. H. MacGillavry, Acta Cryst., 1958, 11, 349.s5 M. R. Truter, ibid., p. 680.96 A. Hargreaves, ibid., 1957, 10, 191.87 H. P. Klug, L. E. Alexander, and G. G.Sumner, ibid., 1958, 11, 41.s8 I. Lindqvist and M. Mortsell, ibid., 1957, 10, 406.ss R. L. Sass, R. Vidale, and J. Donohue, ibid., p. 567.loo W. C. Hamilton, ibid., p. 103.lol D. W. J. Cruickshank, ibid., 3956, 9, 757.lo2 J. Zemann, ibid., 1957, 10, 664.lo3 N. V. Mani, PYOC. I n d i a n Acad. Sci., 1957, 46, A , 143.lo* K. Venkatesan, ibid., p. 134.lo5 S. Ramaseshan, I<. Venkatesan, and N. V. Mani, ibid.. p. 95444 CRYSTALLOGRAPHY.complete a distorted octahedron around the metal atom.lo6 Silver thio-cyanate contains zig-zag chains Ag-SCN-Ag-SCN- in which thegroup SCNAg is probably linear but L(Ag-S-C) = 104"; d(Ag-S) = 2.43d(Ag-N) = 2.22 A.107 NH,Ag(SCN),, on the other hand,contains discrete AgSCN molecules along with NH4+and SCN- ions; d(Ag-S) = 2.474 A (intramolecular),= 2.630, 2.654, 2.742 A (intermolecular) ; L(Ag-S-C) =llOo.lo* In NaAsO, there are infinite chains formed bytrigonal pyramidal AsO, groups sharing corners in common (see inset) .logColemanite, CaB,O,(OH),,H,O, contains infinite boron-oxygen chains, thechain element consisting of two BO, tetrahedra and one BO, triangle joinedat corners to form a six-membered ring of composition B,0,(OH),2- withd(B-0) = 1.36 (triangle), 1.48 A (tetrahedra), on average.Each Ca2+ ionis surrounded by 7 oxygen atoms at 2.45 A on average.l1° Pinnoite,Mg0,B20,,3H,0, contains the anion B,0(OH),2- in which each boronatom is at the centre of a tetrahedron of oxygen atoms, two such tetrahedrasharing a corner in common; d(B-0) = 1.42-146 A.The Mg2+ ions areoctahedrally co-ordinated, d(Mg 0) = 2-04-2.12 A.111 In the low-temperature modification of sodium felspar, NaAlSi,O,, one of the fourtetrahedral sites is occupied preferentially by A1 atoms, d(A1-O) = 1.74,d(Si-0) = 1-61 A on average; whereas in the high-temperature modificationthe A1 and Si atoms occupy the tetrahedral sites at random, d(A1,Si-O) =1.65 A on average.l12 A refinement of the structural parameters of gros-sularite garnet, Ca,AI,(SiO,),, has been carried out; d(Si-0) = 1-64,d(A1-0) = 1.95, d(Ca 0) = 2.33, 2.49 A.113Oxides and Hydroxides.-The structure of Ago is very similar to that ofCuO, the metal atom forming four planar bonds; d(Ag-0) = 2.04, 2.35 A,L(0-Ag-0) = 79", 101°.114 The hexagonal form of mercuric oxide containsinfinite spiral chains, Hg-O-Hg-0 0 , with dimensions identical withthose reported for the planar chains in the orthorhombic form.l15 Zig-zagchains of ReO, octahedra joined by edges occur in the orthorhombic form ofReO,, the chains being connected mutually by octahedra sharing edges ;d(Re Re) = 2.61 in the chain.l16 In the monoclinic form of Sm,O,layers of approximately close-packed oxygen atoms alternate with layersof samarium atoms: each metal atom has seven oxygen neighbours a t2.25-3.12 ~%.l17 In NaOH,H,O the co-ordination of the sodium atom byoxygen atoms is tetrahedral, d(Na 0) = 2.36 A.118 In NaOH,7H200 I .. O-As-O-A5-. . .I0lo6 G. Gattow, Acta Cryst., 1958, 11, 377.lo7 I. Lindqvist, ibid., 1957, 10, 29.lo8 I.Lindqvist and B. Strandberg, ibid., p. 173.loQ J. W. Menary, ibid., 1958, 11, 742.ll1 F. Paton and S. G. G. MacDonald, ibid., 1957, 10, 653.11* R. B. Ferguson, R. J. Traill, and W. H. Taylor, ibid., 1958, 11, 331.113 S. C. Abrahams and S. Geller, ibid., p. 437.114 V. Scatturin, P. L. Bellon, and R. Zannetti, J . Inorg. Nuclear Chem., 1958, 8, 462.115 K. Aurivillius and I. Carlsson, Acta Chem. Scand., 1957, 11, 1069; Ann. Reports,116 A. Magndli, Acta Chem. Scand., 1957, 11, 28.11' D. T. Cromer, J . Phys. Chem., 1957, 61, 753.118 J. A. Wunderlich, Acta Cryst., 1957, 10, 462.C. L. Christ, J. R. Clark, and H. T. Evans, jun., ibid., p. 761.1956, 53, 392SIM : INORGANIC STRUCTURES. 445the co-ordination of the sodium atom is octahedralJ1lg and inNaOHJ4H,O it is trigonal bipyramida1.l2O Each Cu atom in callagh-anite, Cu,Mg2(OH),C0,,2H,O, has 4 hydroxyl groups as nearest neighboursat 2.00 A and a water molecule as next nearest neighbour at 2-23 A, theco-ordination being pyramidal , while each Mg atom is surrounded approxi-mately octahedrally by 4 hydroxyl groups, a water molecule, and an oxygenatom of the CO, group, d(Mg 0) = 2.03 A on average.121 The short-range order in tellurium oxide glass appears to differ little from that incrystallineTe0,; d(Te 0) = 1.95 (4 contacts) , 2-75 A (2 contacts).122 Thecrystal structures of the alkali peroxides have been elucidated: Na,O, hasthe anti-P-K,UF, type123 of structure.In the peroxide ion d(0-0) =1.50 A12*Lil+,V308 (0 < x < 0.5) contains zig-zag double chains of VO, octahedraand chains of VO, trigonal bipyramids sharing corners to form puckeredsheets, the Li+ ions being situated in octahedral interlayer sites and inadditional tetrahedral positions; d(V 0) = 1-59-2-36, d(Li 0) =2.25 A on a~erage.1~5 Double zig-zag chains of VO, octahedra joinedlaterally into sheets occur in haggite, Y@,,V20,,3H20, double octahedralchains alternate with single octahedral chains in the sheets in doloresite,3V20,,4H,O , while the sheets in duttonite, V204,2H,0, comprise singleoctahedral chains sharing mutually corners of the VO, octahedra.I nduttonite the V atoms appear to be displaced from the centres of the octahe-dra causing a short V 0 distance of 1.65 A.12s The V4+ ions in nolanite,(Fe,V)*V,O16, occupy octahedral sites in the close-packed oxygen framework,with d(V 0) = 2-03 A: the Fe2+ and V3+ ions are distributed overoctahedral and tetrahedral sites with d(Fe,V 0) = 2.00, 1-90 A,respectively.There is some evidence for preferential occupation of thetetrahedral sites by the V3+ i0ns.1~7 The ion V2086- in carnotiteK2(U0,),V208, is formed by two distorted trigonal bipyramidal VO, groupssharing an edge.128 Two polymorphs of PbUO, have been examined:the cubic form is isostructural with UO,, the tetragonal form with BaU0,.129The oxygen parameters previously assigned to orthorhombic U,O, havebeen shown to be incorrect : in the revised structure one third of the uraniumatoms are surrounded by 6 oxygen atoms at the corners of a distortedoctahedron, d(U 0) = 2-07, 2-18 A, and the remaining two thirds aresurrounded by 7 oxygen atoms at the corners of a distorted pentagonalbipyramid, d(U 0) = 2.07-2-42 A.l30In NiWO, the tungsten atoms are displaced by 0.30 A and the Ni atomsby 0.13 A from the centres of the octahedra of oxygen atoms: d(W 0) =119 P.W. Hemily, Compt. rend., 1953, 236, 1579.lZ1 G. Brunton, H. Steinfink, and C. TY. Beck, ibid., 1958, 11, 169.lZ2 G. W. Brady, J . Chem. Phys., 1957, 27, 300.lZ3 Structure Reports for 1947-1948, 11, 329.lZ4 H. Foppl. 2. anorg. Chem., 1957, 291, 12.lZ5 A. D. Wadsley, Acta Cryst., 1957, 10, 261.lZ6 H. T. Evans, jun., and M. E. Rlrose, ibid., 1958, 11, 56.lZ7 A. W. Hanson, ibid., p. 703.12& D. E. Appleman and H.T. Evans, jun., ibid., 1957, 10, 765.130 A. F. Andresen, ibid., p. 612.Idem, Acta Cryst., 1957, 10, 37.C . Frondel and I. Barnes, ibid., 1958, 11, 562446 CRYSTALLOGRAPHY.1.79-2-19, d(Ni 0) = 2.02-2-13 A.131 In CaAl,O, there are two kindsof Ca2+ ion, one co-ordinating with 6 oxygen atoms at 2.43 A on average,the other with 8 oxygen atoms at 2-36-3.17 A.13, Sr,Ti04, Ca,MnO,, andSrLaAlO, have the K,NiF, type of structure.l= Sr3Ti,0, and Sr4Ti30,,have structures related to that of Sr,TiO,; they contain double and trebleperovskite groupings, respectively, interleaved with SrO 1 a ~ e r s . l ~ ~CaFe,O, 135 resembles CaTi,O,: 115 the Fe atoms have an octahedral co-ordination, d(Fe o o 0) = 1-98-2-09 A, and the Ca2+ ions have a nine-foldco-ordination, d(Ca 0) = 2-53-3.41 A.CuO,Mn,O, has a normalspinel structure with Cu atoms in tetrahedral and Mn atoms in octahedralsites: it is suggested that the stabilisation of the Cu atoms in tetrahedralsites is brought about by electron transfer from the Mn atoms so that thecompound can be formulated as C U ~ M ~ ~ ~ ~ M ~ ~ ~ ~ , The A1 atoms inCa0,2Al,03 and Sr0,2Al,03 have a tetrahedral co-ordination, d(A1 0) =1.77 A on average.13' AgCrO, is isostructural with C U C ~ O , . ~ ~ ~ InZn,Mo308 half the Zn atoms are tetrahedrally co-ordinated, and the otherhalf of the Zn atoms and the Mo atoms are octahedrally co-ordinated, tooxygen atoms : the Mo atoms are bwded together triangularly, d(Mo Mo)= 2.53 A.139Sulphides, Nitrides, etc.-A rhombohedral form of MoS, has been prepared,differing from the hexagonal form in that the upper three S atoms of thetrigonal prism around the Mo atom are rotated 60" with respect to thelower three.140 Ti,+.S, (0.2 < x < 1) contains alternate filled and partiallyfilled sheets of metal atoms: each Ti atom has six S neighbours at 2.45 Ain an octahedral arrangement, half the S atoms are at the centres of trigonalprisms of Ti atoms, and the other half are at the centres of 0 ~ t a h e d r a .l ~ ~In livingstonite, HgSb,S,, each Sb atom has three S neighbours at 2.5-2.6 fiand the SbS, units are built into double chains of composition Sb,S,: twodistinct types of layer exist, double chains held together by S, groups,d(S-S) = 2.07 A, and double chains held together by Hg atoms forminglinear bonds to two S atoms, d(Hg-S) = 2.35 The system Cr-S hassix distinct phases in the range CrSo.95-1.50 with structures intermediatebetween the NiAs and Cd(OH), typesla Each Se atom in Ni3Se, issurrounded by six Ni atoms at the corners of a distorted trigonal prism,d(Se.9- Ni) = 2.37 A, and each Ni atom has four Se neighbours at thecorners of a distorted tetrahedron.lU Redetermination of the structure131 R.0. Keeling, jun., Acta Cryst., 1957, 10, 209.lsa M. W. Dougill, Nature, 1957, 180, 292.lS3 S. N. Ruddlesden and P. Popper, Acta Cryst., 1957, 10, 538.134 Idem, ibid., 1958, 11, 54.135 B. F. Decker and J. S. Kasper, Acta Cryst., 1957, 10, 332.136 A. P. B. Sinha, N. R. Sanjana, and A. B. Biswas, J . Phys. Chem., 1958, 62,lS7 E.R. Boyko and L. G. Wisnyi, A d a Cryst., 1958, 11, 444.lS8 H. Hahn and C. de Lorent, 2. anorg. Ckem., 1957, 290, 68.139 W. H. McCarroll, L. Katz, and R. Ward, Acta Cryst., 1957, 10, 792.ld0 R. E. Bell and R. E. Herfert, J . Amer. Chew. Soc., 1957, '79, 3351.141 A. D. Wadsley, Acta Cryst., 1957, 10, 715.ld2 N. Niizeki and M. J. Buerger, 2. Krist., 1957, 109, 129.143 F. Jellinek, Acta Cryst., 1957, 10, 620.ld4 R. P. Aganvala and A. P. B. Sinha, 2. anorg. Ckenz., 1957, 289, 203.191SIM INORGANIC STRUCTURES. 447of Sb,Se, 145 leads to an atomic arrangement in agreement with that proposedfor Sb,S, by Hofmann; l46 d(Sb-Se) = 2.58-2.78 A. In PdS, and PdSe,,which have deformed pyrites-type structures, each Pd atom is surroundedby four S (Se) atoms in a square planar arrangement with d(Pd-S) = 2.30,d(Pd-Se) = 2-44 A: two more S (Se) atoms complete the octahedral CO-ordination of the Pd atom with d(Pd W O S) = 3-28, d(Pd D O Se) = 3.25 A?47The co-ordination of I r atoms by Se atoms in IrSe, is octahedral, d(Ir Se)= 2-48 A on average.148 A number of related structures of the NiAs typehave been described in the V-Te ~ y s t e m .1 ~ ~ Each Ag atom in CuAgSe issurrounded by one Se atom at 2.67 A and four Ag atoms at 2.96 A: theSe atoms form sheets of flattened tetrahedra sharing corners, d(Se Se) =3.30 L$, the Cu atoms being located within these tetrahedra, d(Cu Se) =2-06, 2.50 A. The shortest Cu Ag separation is 2-98 A.150 In,AsSe andIn,AsTe have the zinc-blende type of struct11re.l~~After some controversy it now appears that both the ct- and the p-formof Si3N4 are hexagonal: each Si atom is at the centre of a slightly irregulartetrahedron of N atoms, each N atom being common to three tetrahedra,and the two forms differ in the way in which the tetrahedra are joined;d(Si-N) = 1.72, 1.75 A.152 Yttrium nitride has the NaCl type of structure,d ( Y N) = 2.44 A.153 A cubic form of boron nitride with the zinc-blendetype of structure has been prepared: 154 BAS and BP also have this type ofstructure.155PUP, PuAs, and PuTe have the NaCl type of structure,157 and a number ofABX, compounds with the chalcopyrite structure have been reported: Acan be Zn or Cd, B can be Si, Ge, or Sn, and X can be P or As.158 ZrAs is aLi7VP, and Li,VAs4 have the anti-fluorite type of145 N.W. Tideswell, F. H. Kruse, and J. D. McCullough, Acta Cryst., 1957, 10, 99.146 W. Hofmann, 2. Krist., 1933, 88, 225.147 F. Grarnvold and E. Rerst, Acta Cryst., 1957, 10, 329.148 L. B. Barricelli, ibid., 1958, 11, 75.149 F. Grarnvold, 0. Hagberg, and H. Haraldsen, Acta Chem. Scand., 1958, 12, 971.150 A. J. Frueh, jun., G. I(. Czamanske, and C. Knight, Z. Krist., 1957, 108, 389.ltl H. Hahn, Naturwiss., 1957, 44, 534.152 D. Hardie and K. H. Jack, Nature, 1957, 180, 332; S. N. Ruddlesden and P.153 C. 1’. Kempter, N. H. Krikorian, and J. C. McGuire, J . Phys. Chem., 1957, 61.154 R. H. Wentorf, jun., J . Chem. Phys., 1957, 26, 956.155 J. A. Perri, S. LaPlaca, and B. Post, Acta Cryst., 1958, 11, 310.156 K.Juza and W. Uphoff, 2. anorg. Chem., 1957, 292, 65.15’ A. E. Gorum, Acta Cryst., 1957, 10, 144.lf8 C. H. L. Goodman, Nature, 1057, 179, 828; H. Pfister, Acta Cryst., 1958, 11, 221.Popper, Acta Cryst., 1955, 11, 465.1237448 CRYSTALLOGRAPHY.layer structure of the TiAs type and ZrAs, has the PbC1, type of ~tructure.1~~HgPbP,, (111) , ZnPbP,,, and CdPbP,, contain linked double zigzag poly-phosphide chains; d(Pb-P) = 2-65, d(Hg-P) = 2.54, d(P-P) = 1.55, 2.40A.1s0 The rare-earth metals form dicarbides with the CaC, type of structure :in Lac, d(C-C) = 1.28 & 0.02 A. The rare-earth metals from La to Hoalso form sesquicarbides of the Pu,C, type containing C, groups: in La,C,d(C-C) = 1-32 & 0.03 A.1s1 The ternary phase M05Ss2 is isostructuralwith Cr5B3,1s2 Nb,Si,, and Ta5Si,: 163 electron counts provide evidence foran ordered distribution of B and Si atoms, the B atoms occupying trigonalprismatic holes and the Si atoms cubic antiprismatic holes in a layeredarrangement of Mo atoms; d(B Mo) = 2.36, d(B B) = 2-13, d(Si Mo)= 2.56, 2.77 A.164Halides.-Cupric fluoride has a distorted rutile-type structure with theCu atom at the centre of an elongated octahedron; d(Cu***F) = 1-93(4 contacts), 2.27 A (2 contacts).ls5 CrF, has a similar structure withd(Cr F) = 1-98, 2-01, 2-43 A in the distorted octahedron around the Cratom.CrF, has an undistorted VF, type of structure with d(Cr I;) =1.90 A.166 Distortions from octahedral symmetry also occur in the rutile-type compounds MnF,, FeF,, CoF,, NiF,, ZnF,,167 and PdF,,168 the effect be-ing most pronounced in FeF, where d(Fe * * * F) = 2.12 (4 contacts), 1.99 A(2 contacts).In MnF,, which has a VF, type of structure, d(Mn I?) =1.79, 1-91, 2.09 A.169 The distortions from octahedral symmetry in thesecompounds can be explained in terms of ligand-field theory.170 In RhF,,PdF,, and IrF, the F atoms are in hexagonal close-packing with the metalatoms at the centres of almost regular octahedra of F atoms sharing cornersin common: FeF,, COF,, and RuF, have the VF, type of structure in whichthe halogen atom arrangement is considerably distorted from hexagonal~lose-packing.l7~ The NH4+ ion in NH4C1,3NH, is surrounded tetrahe-drally by three NH, molecules and a C1- ion, d(N * Cl) = 3.26, d(N N) =2.88 N(C2H,),1 has a distorted wurtzite-type structure.173 A refine-ment of the structure of N(CH,),15 leads to d(1-I) = 3-17, 2.81 A, in theV-shaped anion: 174 the latter distance is rather closer to the distance in159 W.Trzebiatowski, S. Weglowski, and K. Lukaszewicz, Roczniki Chem., 1958,32, 189.160 H. Krebs and T. Ludwig, 2. nnorg. Chem.. 1958, 294, 257.l61 F. H. Spedding, K. Gschneidner, jun., and A. H. Daane, J . Amev. Chem. SOL,1958, 80, 4141; M. Atoji, I<. Gschneidner, jun., A. H. Daane, R. E. Rundle, and F. H.Spedding, ibid., p. 1804.162 F. Bertaut and P. Blum, Compt. rend., 1953, 236, 1055.lci3 E. Parthk, B. Lux, and H. Nowotny, Monatsh., 1955, 86, 859.1154 B. Aronsson, Actu Chem. Scand., 1958, 12, 31.165 C.Billy and H. M. Haendler, J . Amer. Chern. Soc., 1957, 79, 1049.166 K. H. Jack and R. Maitland, Proc. Chem. SOC., 1957, 232.167 W. H. Baur, Acla Cryst.. 1958, 11, 488.16* N. Bartlett and R. Maitland, ibid., p. 747.169 M. A. Hepworth and K. H. Jack, ibid., 1957, 10, 345.170 Ann. Reports, 1957, 54, 93.171 M. A. Hepworth, K. H. Jack, R. D. Peacock, and G. J. Westland, Actu Cryst.,172 I. Olovsson, Acta Chem. Scand., 1957, 11, 1273.173 E. Wait and H. hl. Powell, J., 1958, 1872.174 J. Broekema, E. E. Havinga, and E. H. Wiebenga, Actu Cryst., 1957, 10, 596.1957, 10, 63SIM : INORGANIC STRUCTURES. 449I, (2.67 A) than the previous estimate.17, TiOCl 176 is isostructural withFeOC1, InOHF,177 has a distorted ReO, type of structure, andZn5(OH),C1,,H,O has a layer structure with Zn atoms in both octahedraland tetrahedral co-ordination; d(Zn 0) = 2.16 (octahedral), 2.02 (tetrahe-dral), d(2n Cl) = 2-33 (tetrahedral).A neutron-diffraction study ofCuCl,,BH,O has shown all the atoms to be coplanar, with the bisectorof the angle H-O-H collinear with the Cu-0 bond; d(Cu-0) = 1.925,In the crystal GaC1, consists of Ga+ and tetrahedral GaC1,- ions withd(Ga-C1) = 2.19 A: each Ga+ ion is surrounded by eight C1 atoms at 3-22on average.lBO The Raman spectrum of solid NbC1, has been interpreted lB1in terms of the monomeric trigonal bipyramidal molecule of the vapourphase; but it appears from an X-ray study that in the solid the moleculesare dimeric, the Nb atoms being at the centres of two octahedra of Cl atomssharing an edge in common, d(Nb-Cl) = 2-56 (bridge C1 atoms), 2.25,2.30 A (others).182 The nuclear magnetic resonance spectrum of liquid SbF,has been interpreted in terms of zig-zag chains of SbF, octahedra sharingcorners in common.183 In the dimethyltellurium dichloride molecule theC1 atoms occupy the axial and the CH, groups two of the equatorial positionsof a trigonal bipyramid with d(Te-C) = 2.08, 2.10 5 0.03, d(Te-C1) = 2.48,2.54 & 0.01 A: the Cl-Te-C1 angle is 172" and is bent towards the CH,groups, not away from them, as might have been expected.lM In diphenyl-tellurium dibromide the Te-Br bonds are also not strictly collinear,L(Br-Te-Br) = 178.0" 0.003 A the Te-Br bondsare distinctly longer than the sum of the covalent radii, 2.51 A.185 TheSe-Se separation in p$'-dichlorodiphenyl diselenide is 2.333 & 0-015 A :in a- and @-selenium this distance is 2.34 A.186A re-examinationlB7 of the KBrF, structure has shown that a squareplanar configuration for the BrF,- ion satisfies the X-ray intensity data atleast as well as the previously reportedls8 tetrahedral model.A nuclearmagnetic resonance study of K,TiF, leads to d(Ti-F) = 1.916 & 0.020 A189in excellent agreement with the X-ray value of 1.917 & 0.026 A.190(NH,),TiBr6 has the K,PtC16 type of structure.191 A number of compoundsAMF, (A = Ba, Sr, Ca, Mg; M = Mn, Pb) have been examined: BaPbF,,d(CU-Cl) = 2.275 A.1790-2", and at 2.682175 Ann. Reports, 1952, 49, 367; see also Ada Cryst., 1956, 53, 395.176 H.Schafer, F. Wartenpfuhl, and E. Weise, 2. anorg. Chem., 1958, 295, 268.177 H. Forsberg, Acta Chem. Scand., 1957, 11, 676.1 7 8 W. Nowacki and J. Silverman, Acta Cryst., 1957, 10, 787.179 S. W, Peterson and H. A. Levy, J . Chem. Phys., 1967, 26, 220.180 G. Garton and H. M. Powell, J . Inorg. Nuclear Chem., 1957, 4, 84.181 J. Gaunt and J. B. Ainscough, Spectrochim. Actu, 1957, 10, 52.182 A. Zalkin and D. E. Sands, Acta Cryst., 1958, 11, 615.183 C. J. Hoffman, B. E. Holder, and W. L. Jolly, J . Phys. Chem., 1958, 62, 364.184 G. D. Christofferson, R. A. Sparks, and J. D. McCullough, Acta Cryst., 1958,11,185 G. D. Christofferson and J. D. McCullough, ibid., p. 249.186 F. H. Kruse, R. E. Marsh, and J. D. McCullough, ibid., 1957, 10, 201.287 W.G. Sly and R. E. Marsh, ibid., p. 378; S. Siegel, ibid., p. 380.188 Ann. Reports, 1956, 53, 396.189 J. A. Ibers and C. H. Holm, Acta Cryst., 1957, 10, 139.180 S. Siegel, ibid., 1952, 5, 683.181 J. Jander, H. Machatzke, and D. Mecke, 2. anorg. Ckem., 1968, 294, 181.7'82.REP-VOL. LV 450 CRYSTALLOGRAPHY.BaMnF,, and SrMnF6 have the BaGeF, type of structure with discreteoctahedral ions; SrPbF, contains both F- ions and linear chains ofPbF, octahedra sharing opposite corners; CaMnF, and MgMnF, have theVF, type of structure.lS2 The BOE32- ion in BaBOF, is tetrahedral withd(B-F) = 1.432, d(B-0) = 1.435 A.193 Distorted octahedral MF,- ionswith d(M-F) = 2.14 A occur in KNbF, and KTaF,: each K+ ion 1ssurrounded by eight F atoms at 2-50 A and four a t 2.94 A.194 Tetra-phenylarsonium tetrachloroferrate contains tetrahedral FeC1,- ions withd(Fe-C1) = 2-19 & 0.03 A: lg5 this distance in the Fe2Cl, molecule is 2.17 A,whereas in solid FeC1, it is 2-48 A.The crystal structure of tetramethyl-ammonium hexachloroantimoniate is based on the NaC1-type packing oftetrahedral N(CH,),+ and octahedral SbC1,- ions.lgG The anion Cr2C12- inCs,Cr2C1, consists of two distorted CrC1, octahedra sharing a face in common,and with the Cr atoms displaced away from the common face: d(Cr Cr) =3-12, d(Cr-C1) = 2.52 (bridge C1 atoms), 2.34 A (others).lg7 The similarstructure of K,W2Clg has been redetermined. In this case the W atomsare displaced towards the common face: d(W W) = 2.41 A, which isshorter than the distance of 2-52 A in metallic tungsten; d(W-Cl) = 2.48(bridge C1 atoms), 2-40 A (others).lg8Intermetallic CompoundS.-a-(V,Al) can exist over the compositionrange VA110-V2A1,1, the variable composition arising from the degree ofoccupancy of one particular site in which an A1 atom forms no bonds shorterthan 3.1 A: lg9 each V atom is surrounded eicosahedrally by twelve A1 atomswith d ( V - *Al) = 2.826 (6 contacts), 2.572 A (6 contacts), the latterdistance being considerably smaller than the sum of the 12-co-ordinatedradii.200 In V4A123 there are two types of v atom, one surrounded by tenA1 and two V atoms, and the other by twelve A1 atoms, d(V Al) = 2-88,2.60 A.201 The structures of WAI, and Mn4Al,, are related to that ofMnA1, : they contain similarly shaped co-ordination groups , well-definedlayers of atoms and some abnormally short contacts between the A1 atomsand the transition-metal atoms.In \vAl4, w A1 co-ordination of 10and 11 is present with d(W Al) = 2.53-2.86 A, the sum of the metallicradii being about 2.72 A; 202 and in Mn,Al,, the Mn atoms are in lo-foldco-ordination by A1 atoms, d(Mn Al) = 2-42-2.82 A.203 Each Pu atomin puA1, has twelve A1 neighbours at 3.01-3*06 A.2o4MoU, has the MoSi, type of structure, each U atom having four Moatoms at 2-96 and four U atoms at 2.87 A as neighbours.205 MgRh and192 R. Hoppe and K. Blinne, 2. anot'g. Chem., 1957,291,269; 1958, 293, 251.195 D. M. Chackraburtty, Acts Cryst., 1957, 10, 199.194 H. Bode and H. von Dohren, Zbid., 1958, 11, 80.195 B.Zaslow and R. E. Rundle, J . Phys. Chem., 1957, 61, 490.196 A. Ferrag, L. Cavalca, M. Cingi, and G. Magnano, Gazzetta, 1957, 87, 651.197 G. J. Wessel and D. J. W. Ijdo, Acta Cryst., 1957, 10, 466.198 w . H. %Tatson, jun., and J. Waser, ibid., 1958, 11, 689.199 A. E. Ray and J. F. Smith, ibid., 1957, 10, 604.200 p. J. Brown, ZbZd., p. 133.201 J. F. Smith and A. E. Ray, ibid., p. 169.202 J. A. Bland and D. Clark, ibid., 1958, 11, 231.203 J. A. Bland, ;bid., p. 236.204 A. c. Larson, D. T. Cromer, and C . K. Stambaugh, zbid., 1057, 10, 443.205 E. K. Halteman, ibid., p. 166SIM: INORGANIC STRUCTURES. 451ScRh have the CsCl type of structure with d(Mg Rh) = 2.68, d(Sc 9 Rh)= 2-78 A.206 Further compounds AX, with the (3-tungsten type of structurehave been described, A = Nb, Mo, V, Cr; X = Al, Ga, Sb: 207 there hasbeen controversy over the atomic radii applicable to this type of structure.208In Th,Bi, each Th atom has eight Bi neighbours at 3-32 A, and in ThBi,each Th atom has four Bi neighbours at 3.44 A, four a t 3.29 A, and one at3-26 A.209 Cs,Sb has a structure based on the NaTl type with the Na atomsreplaced by Cs atoms and the T1 atoms replaced by Cs and Sb atoms atrandom; d(Cs - - - Sb,Cs) = 3.96 A.21o The low-temperature form of LiPbhas a slightly distorted CsCl type of structure with d(Pb Li) = 3.077(2 contacts), 3.065 A (6 contacts).211The P-phase in the system Mo-Ni-Cr is related to the a-manganese anda-phase structures: atoms are found in 12-, 14-, 15-, and 16-fold co-ordination and there is distinct evidence for assigning the Ni atoms mainlyto the 12-co-ordinated sites, the Cr atoms mainly to the 14-co-ordinatedsites, and the Mo atoms to 14-, 15-, and 16-co-ordmated sites.212 Thesolubility of Si in a-FeCr has been discussed: electron counts provideevidence for the preferential occupation by Si atoms of sites with lowco-ordination number.213Co-ordination Compounds.-The metal atoms in Mn,(CO),, and Re,(CO),,are octahedrally co-ordinated to five CO groups and to the othermetal atom, the octahedron round one metal atom being rotated through45" with respect to the other octahedron: the metal-metal bond providesthe only link between the two halves of the molecule, d(Mn Mn) = 2.93,d(Re Re) = 3.02 A.214 A somewhat similar structure involving onlya metal-metal bond between the two halves ofa molecule has been established in the case of ,!,/* (C,H,),MO,(CO)~ with d(Mo Mo) = 3.22 A.215R------ Dicyclopentadienyldi - iron tetracarbonyl hasstructure (IV) with d(Fe Fe) = 2.49 & 0.02 & g A,216 in good agreement with the distance of2-46 A in iron enneacarbonyl.The structure ofthe but-2-yne complex of iron carbonyl hydride,Fe,C,,H,O,, has been shown to be (V), in which the iron atom Fe(B) iscovalently bonded to iron atom Fe(A) and sr-bonded to the chelatinggroup.217 The structure of the anion Fe,S,(NO),- present in Roussin'sblack salt has been established. There are four Fe atoms at the corners of aflattened tetrahedron with the S atoms above the centres of the three side206 V.B. Compton, Acta Cryst., 1958, 11, 446.207 E. A. Wood, V. B. Compton, B. T. Matthias, and E. Corenzwit, ibid., p. 604.208 S. Geller, ibid., 1956, 9, 885; 1957, 10, 380; L. Pauling, ibid., pp. 374, 685.209 R. Ferro, ibid., p. 476.210 K. H. Jack and M. M. Wachtel, PYOC. Roy. Soc., 1957, 239, A , 46.211 A. Zalkin and W. J. Ramsey, J . Phys. Chem., 1957, 61, 1413.212 D. P. Shoemaker, C. B. Shoemaker, and F. C. Wilson, Acta Cryst., 1957, 10, 1.213 B. Aronsson and T. Lundstrom, Acfa Chcm. Scand., 1957, 11, 365.214 L. F. Dahl, E. Ishishi, and R. E. Rundle, J . Chem. Phys., 1957, 26, 1750; L. F.215 F. C. Wilson and D. P. Shoemaker, J . Chem. Phys., 1957, 27, 809.216 0. S. Mills, Acta Cryst., 1958, 11, 620.217 A.A. Hock and 0. S. Mills, Proc. Chenz. SOC., 1958, 233.'c' (IV) aDahl and R. E. Rundle, Acia Cryst., 1957, 10, 782452 CRYSTALLOGRAPHY.faces; the Fe atom at the apex (Fer) has an NO group co-ordinated verticallyand each of the three basal Fe atoms (Feu) has two NO groups co-ordin-ated in such a way that the metal atom is at the centre of a distorted tetra-hedron formed by the two NO groups and the two nearest S atoms;d(FeI FeII) = 2.71, d(FeI1 FeII) = 3.57, d(Fe-S) = 2.38 A.218 In(C,H,),Fe,S,(NO), the Fe and S atoms are joined in a plane rhombus witheach Fe atom at the centre of a distorted tetrahedron of two S atoms andtwo NO groups, and each S atom is surrounded pyramidally by two Featoms and a C2H5 group; d(Fe Fe) = 2-72, d(Fe-S) = 2.27 A,L(Fe-N-0) = 167.5" & 3.5°.2190In Pt(NH,),PtCl, the square planar Pt(NH3)42+ and PtC1,2- ions arestacked over each other with d(Pt Pt) = 3-25 A.22o The Pt atoms incis- and trans-diamminedithiocyanatoplatinum (11) are surrounded in squareplanar arrangements by the N atoms of the ammonia molecules and theS atoms of the thiocyanate groups, these groups being inclined at about 76"to the plane of the complex; d(Pt-N) = 2.0-2.1, d(Pt-S) = 2.3 A.221Square coplanar configurations about the metal atom are reported also inbisacetylacetonenickel(I1) in the vapour phase, d(Ni-0) = 1.90 and inNiBr2,2P(C2HJ3, d(Ni-Br) = 2.30, d(Ni-P) = 2.26 A.223 Unlike the corre-sponding nickel compound, copper dimethylglyoxime has a nonplanarstructure, the two rings being inclined at an angle of about 28" to each other,418 G.Johansson and W. N. Lipscomb, Acta Cryst., 1958, 11, 694.21s J. T. Thomas, J. H. Robertson and E. G. Cox, ibid., p. 599.220 M. Atoji, J. W. Richardson, and R. E. Rundle, J . Amer. Chem. SOC., 1957, 79,221 Ya. Ya. Bleidelis, Krystallografiya, 1957, 2, 278; Ya. Ya. Bleidelis and G. B.222 S. Shibata, Bull. Chem. SOC. Japan, 1957, 30, 753.229 G. Giacometti, V. Scatturin, and A. Turco, Guzzettu, 1968, 88, 434.3017.Bokii, ibid., p. 281SIM INORGANIC STRUCTURES. 453d(Cu-N) = 1.89 A on average.224 -4 tetrahedral distribution of bondsabout the Cu atom is found in tetrakisthioacetamidecuprous chloride,d(Cu-S) = 2.345 & 0.002 A,225 and in dithioureacadmium dichloride eachCd atom is surrounded tetrahedrally by two C1 atoms at 2.50 A and twoS atoms at 2.45 A.226In N-methylureacadmium dichloride 227 and in diureacadmium di-chloride,228 on the other hand, the co-ordination of the Cd atom is octahedral,d(Cd-Cl) = 2.64, d(Cd-0) = 2.18-2.28 A.The reineckate complex ion[Cr(NCS),(NH,),]- has an octahedral trans-structure with linear NCSgroups: in the ammonium and pyridine salts L(Cr-N-C) = 180", whereasin the choline salt this angle is 156"; d(Cr-N) = 1.96, d(Cr-NH,) = 2.13 Aon average.229 In the octahedral bromodinitrotriamminecobalt(m) mole-cule one NO, group is in the trans-position with respect to the Br atom andin a cis-position with respect to the other NO, group, in marked contrast tothe corresponding chloro-compound where the two NO, groups are in trans-positions: d(Co-Br) = 2-45, d(Co-N) = 1.98 A.230 Dipyridinecopper di-chloride and the violet form of dipyridinecobalt dichloride contain polymericchains of MC14N2 octahedra; d(Cu-C1) = 2.28, 3.05, d(Cu-N) = 2.02 k ;d(Co-Cl) = 2.49, d(Co-N) = 2-14 A; 231 the blue form of a cobaltousdiammine, on the other hand, has a tetrahedral configuration about theCo at0m.~32Infinite spiral chains in which the Cu atom has probably assumed ansp2 hybridized state occur in KCu(CN),(VI) : thethree bonds formed by the Cu atom are verynearly coplanar and d(Cu-C) = 1.92, d(Cu-N) =2-05 A.233 The molecules of trimethylindium aretrigonal, d(In-C) = 2.06, 2.12, 2.15 A: themolecules are joined by linear In CH,-In bridges, d(In C) = 3.10,3.60 A, on either side of the molecular plane.234 In the silver nitrate-cyclo-octatetraene complex each Ag+ ion is bound strongly to one C,H,molecule, d(Ag C) = 26-24 A, and more weakly to a neighbouringC,H, molecule, d(Ag C) = 3.2 A, to form infinite chains.235 In thecomplex (C5H,),TiC12-A1(C2H5)2 the Ti and A1 atoms are tetrahedrallyco-ordinated and are linked by C1 atom bridges with d(A1 .Ti) = 3-5Aapproxima tely.Z36CN I . C-N-Cu-C-N- u.. 7 (VI) CNG. A. S.2z4 E. Frasson, R. Zannetti, R. Bardi, S. Bezzi, and G. Giacometti, J . Inorg. Nuclear225 M. R. Truter, A d a Cryst., 1957 10, 755.ees M. Nardelli, L. Cavalca, and A. Braibanti, Gazzetta, 1957, 87, 137.227 M. Nardelli, L. Coghi, and G. Azzioni, ibid., 1958, 88, 235.228 M.Nardelli, L. Cavalca, and G. Fava, ibid., 1957, 87, 1232.229 Y. Tak6uchi and Y . Saito, Bull. Chem. SOL. Japan, 1957, 30, 319.230 Y . Komiyama, ibid., 1958 31, 26.231 J. D. Dunitz, Acta Cryst., 1957, 10, 307.2a2 Ann. Reports, 1956, 53, 397; T. I. Malinovskii, Krystallografiya, 1957, 2, 734.233 D. T. Cromer, J . Phys. Chem., 1957, 61, 1388.234 E. L. Amma and R. E. Rundle, J . Amer. Chem. SOL, 1958, 80, 4141.235 F. S. Mathews and W. N. Lipscomb, ibid., p. 4745.236 G. Natta, P. Corradini, and I. W. Bassi, ibid., p. 755.Chem., 1958, 8, 452454 CRYSTALLOGRAPHY.3. ORGANIC STRUCTURESCarboxylic Acids and Related Compounds.-Monocarboxylic acids areusually dimerised in the solid state, by formation of a pair of hydrogenbonds between their carboxyl groups.An interesting example is the 1 : 1compound between palmitic (P) and stearic (S) acids: the crystal symmetryshowsB7 that the structure is not disordered with respect to P and Smolecules-as might perhaps have been expected-but has a regular arrayof P-S dimers. There are some exceptions to this rule of dimerisation,formic acid being the simplest example. Acetic acid, studied at about50j2% proves to have a similar structure ; each molecule is linked by hydrogenbonds, with d ( 0 0) = 2-61 A, to two others to produce infinite chains.An optically active 2-ethyl-2-methyleicosanoic acid has its carboxyl groupssimilarly linked, and its polymethylene chains adopt a novel type of packing,no doubt because of the obstructive effects of the side For someyears it has been known that cupric acetate hydrate has a peculiar dimericstructure, with a fairly strong direct bond between two copper atoms[d(Cu-Cu) = 2.64 A], and magnetic measurements had suggested a similararrangement in some other cupric carbo~ylates.~~~ Evidence in the samesense now comes from the infrared spectroscopy of the copper salts of mono-and di-chloroacetic acids,2q1 and those of propionic, butyric, valeric,hexanoic, octanoic, palmitic, and stearicThe structure of ammonium hydrogen D-tartrate has been determinedwith remarkable care,243 full three-dimensional intensity data being collectedby counter methods, so as to warrant refinement to a standard deviationof bond-lengths of &0-004 A.The three d(C-C) values do not differsignificantly from 1.527 A; one carboxyl group has d(C-0) = 1.261,1-263 A,the other 1.220, 1-311 A, the latter clearly being the un-ionised group, aswas confirmed by location of the hydrogen atom about 1.07 A from theappropriate oxygen.The other hydrogens of the tartrate residue werealso located, the peaks for those joined to carbon being higher than for thosejoined to oxygen, and d(C-H) = 1.00, 1.02, d(0-H) = 1.06, 1-09 A. Onthe other hand, there was no indication of the hydrogens attached to thenitrogen atom, which appeared spherically symmetrical ; the ion makeseight contacts with neighbouring oxygen atoms, and no doubt there isdisorder of the kind mentioned on p. 437.The analogous formation of pairs of hydrogen bonds by the carboxylgroups of dibasic acids leads to infinite chains; examples of this type ofstructure recently studied are malonic,244 the high-temperature (a) form ofpimelic,245 and phthalic 246 acids. In the first of these, the atoms are237 G.Degerrnan and E. von Sydow, Acta Chem. Scand., 1958, 12, 1176.238 R. E. Jones and D. H. Templeton, Ada Cryst., 1958, 11, 484.239 E. von Sydow, Acta Chem. Scand., 1958, 12, 777.240 Ann. Reports, 1954, 51, 390; 1956, 53, 405.241 R. Tsuchida, S. Yamada, and H. Nakamura, Nature, 1958, 181, 479.242 Idem, Bull. Chem. SOC. Japan, 1958, 31, 303.243 A. J. van Bommel and J. M. Bijvoet, Acta Cryst., 1958, 11, 61.244 J. A. Goedkoop and C . H. MacGillavry, ibid., 1957, 10, 125.245 M. I. Kay and L.Katz, ibid., 1958, 11, 289.246 JV, Nowacki and H. Jaggi, 2. Krist., 1957, 109, 272SPEAKMAN : ORGANIC STRUCTURES. 455nearly co-planar except the oxygens of one carboxyl group which aretwisted through nearly 90" from the plane by steric forces; in the last, bothcarboxyl groups are twisted considerably out of the plane of the benzenenucleus. A similar twisting is evident in the structure of ammoniumhydrogen ph t halate. 247One of the first amino-acids to be analysed with some precision wasglycine, studied by Albrecht and Corey in 1939. This structure has nowbeen carefully redetermined, with up-to-date methods of refinement .248The short C-N bond found originally is now amended to d(C-N) = 1.474 &0-005 A; d(C-C) = 1.523; and d(C-0) = 1.265, 1.261, in accord with thezwitterionic structure, which is further confirmed by location of thehydrogens with d(N-H) = O%,, and d(C-H) = 0.9, A.The carbon andoxygen atoms are co-planar, the nitrogen being 0.44 A from the plane.An analysis of the trigonal (7) form of glycine has been briefly reported.249This amino-acid forms isomorphous basic salts, diglycine hydrochloride andhydrobromide, and these structures have been a n a l y ~ e d , ~ ~ ~ the former toa higher degree of refinement. The neutral zwitterion and the positivecation, NH,*CH2*C02H, can be readily distinguished in the crystal : theformer has d(C-0) = 1.25,, 1.29,, which perhaps do not differ significantly,and the latter 1-22,, 1-36, A, which do. In both glycine residues d(C-N)(1-52,, 1.52,) and d(C-C) (1.48,, 1-48, A) differ notably from the corre-sponding bond-lengths in glycine itself.Hahn has collected and com-pared 251 the structural data for amino-acids and related compounds.Amongst other generalisations, he concludes that d(C-NH,) in amino-acidsis significantly longer than the normal d(C-N) of 1.47 A. To this generalis-ation the value now found in glycine appears to be a well-authenticatedexception.Other Acyclic Molecules.-The molecule of hydrazine adopts a gaucheconformation, as had been predicted by Penney and Sutherland in 1934 onthe basis of repulsion between the unshared @-electrons of the nitrogenatoms. That of diformylhydrazine (l), on the contrary, is planar accordingto a careful X-ray The hydrogen atoms, whose positions havebeen soundly determined, are distributed as shown, with d(C-H) = 0.94and d(N-H) = 0-82, and there is a strong intermolecular hydrogen bondwith d(NH 0) = 2.799 zf 0.006 A; while d(N-N) = 1.392 -j= 0-007,d(N-C) = 1-325 & 0.004, and d(C-0) = 1.214 & 0.005 A.Integrationof appropriate areas of the electron-density map enabled estimates to bemade of the net charges carried by the heavier atoms: that on the oxygenatom was -0-6 electron, that on NH +0.3. Similar values were obtainedby Tomiie 253 in a thorough theoretical treatment of this molecule; heconcludes that electrostatic attractions and repulsions between the charged++z47 Y. Okaya and R. Pepinsky, Acta Cryst., 1957, 10, 324.248 R. E. Marsh, ibid., 1955, 11, 654.249 Y.Iitaka, ibid., p. 225.250 T. Hahn and M. J . Buerger, 2. Krist., 1957, 108, 130, 419.251 T. Hahn, ibid., 1057, 109, 435.252 Y . Tomiie, C. H. Koo, and I. Nitta, Acta Cryst., 1958, 11, 774.Z6s Y. Tomiie. ibid., 1955, 11, 875456 CRYSTALLOGRAPHY.atoms are chiefly responsible for the tram-configuration about the centralbond, and for the S-shaped, rather than zigzag, conformation implied bythe positions of the oxygen atoms; the shortness of the N-N bond suggestssome conjugation, but this is not regarded as decisive in fixing the configur-ation. Azobis-N-chloroformamidine 254 (2) has a trans-configuration aboutthe N=N bond, as would be expected, and the molecule is very nearlyplanar with d(N-N) = 1.26 & 0.01, and d(N-C1) = 1.73 & 0.016 A.Mono-ethylammonium bromide, in the form stable a t ordinary temperatures, hasbeen analysed with considerable accuracy.255 The cation is strictly planar,except for the hydrogen atoms; d(N-C) = 1.499 & 0.012, d(C-C) = 1.521 &0.014 A, and L(C-C-N) = log$'; the three hydrogens attached to thenitrogen atom were located, and found to lie in directions pointing towardsbromide ions, d(N Br) being about 3.37 A.The structure of pentaerythritol was a subject of controversy in thedevelopment of X-ray analysis.256 Two up-to-date refinements are nowreported. One,257 in which the older two-dimensional X-ray data arereinforced by new three-dimensional, indicates considerable changes in thez-co-ordinates of the oxygen and methylenic carbon atoms, leading to&(C-C)'s being amended from 1.50 to 1.548 & 0.011, and d(C-0)'s from1-46 to 1.425 3 0.014 A.The using neutron diffraction, wasprincipally concerned with locating the hydrogen atoms. (For this purpose,both ordinary and OH-deuterated pentaerythritol were studied; sinceprotons and deuterons have neutron-scattering factors with opposite signs,the calculation of a " difference map " between the two isotopic specieseliminates the peaks due to the heavier atoms and enhances those due tohydroxylic hydrogen.) The hydrogen atoms were found to be in theexpected positions with d(C-H) = 1.09, 1.11 & 0.02, and d(0-H) = 0.94 &0.03 A. Determinations of the carbon and oxygen positions were lessprecise than in the X-ray analysis; in fact they support the earlier, ratherthan the amended, C-C and C-0 bond-lengths.An X-ray analysis ofmesoerythritol 259 finds the expected trans-centrosymmetrical conformationabout the central C-C bond, with the two hydroxyl groups in a gauche-conformation about each terminal C-C bond.The structure of thiourea has been carefully redetermined, partly withthe object of seeking changes in its structure when it acts as a ligand.260254 J. H. Bryden. Acta Cryst., 1958, 11, 158.255 F. Jellinek, ibid., p. 626.256 Ann. Reports, 1936, 33, 218; 1937, 34, 181.257 R. Shiono. D. W. J. Cruickshank, and E. G. Cox, Acta Cryst., 1958, 11, 389.258 J. Hvoslef, ibid., p. 383.259 A. Shimada, ibid., p. 748.260 N. R. Kunchur and M. R. Truter, J., 1958, 2551SPEAKMAN : ORGANIC STRUCTURES. 457The molecule is accurately planar, except possibly for the hydrogen atoms,which could not be located because of the presence of the heavy sulphuratom and of considerable thermal vibration of the whole molecule; afterapplying the appreciable correction (-0.01 A) for the apparent bondshortening effect due to the librational part of this motion, d(C-S) =1.71 & 0.01, and d(C-N) = 1.33 & 0.01 A.In dichlorobisthioureazinc,ZnC12[CS(NH2)2]2,261 two chlorines and two sulphur atoms are in tetra-hedral arrangement round the zinc, and d(C-S) at 1-78 differs from the valuein thiourea itself by an amount that is possibly significant. The phase-change in thiourea at 198"~ has been studied by proton magnetic resonance.262The vinylideneamine (3; Rf = R2 = CH,*SO,) had been found to havea strictly linear arrangement of the four atoms of the characteristic chain : 263the compound with R2 = Ph*S02264 has the N-methyl group slightly offthe line of the other three atoms, L(C-N-C) being 171", but this is attribut-(3)able to packing effects in the crystal; d(C=C) = 1.354 and d(C=N) = 1.148 A,and, as before, the sum of the nominal bond-orders a t the second carbonatom exceeds 5.The structures of the ions of aminoguanidine (4, and other bond-diagrams) ,265 and of triaminoguanidine [e.g., (5)] 266 have been determined,with similar results.In (4), d(C-N) = 1.32 for each of the equivalentbonds and 1.35 for the other, and d(N-N) = 1.42 A, whilst L(C-N-N) =116.5".The cation (5) has trigonal 3/m (C3J symmetry, and is planarexcept perhaps for the hydrogen atoms, with d(C-N) = 1.318 and d(N-N) =1-450 A, and L(C-N-N) = 120". The positions of the environing anionssuggest that the positive charge on (5) tends to lie on the inner nitrogenatoms, and that in each case the hydrogen atoms are distributed as shown.Aromatic Hydrocarbons and Related Compounds.-A full account of therefinement of the X-ray analysis of benzene at -3" is now available.267After correction for the torsional oscillation (with r.m.s. amplitude of 8")of the molecule about its senary axis, d(C-C) = 1.392 & 0-010 A. Thedetailed consideration of the molecular movements is of special interest, asit appears that neighbouring molecules tend to twist in opposite directions,180" out-of-phase, so as to maintain a greater separation between contiguoushydrogen atoms; the crystal contains planes of molecules, which thuslibrate rather like an array of enmeshed bevel-gears.A '' super-refinement261 N. R. Kunchur and M. R. Truter, J., 1958, 3478.262 M. W. Emsley and J. A. S. Smith, Proc. Chem. Soc., 1958, 553.265 Ann. Reports, 1956, 53, 412.2134 R. K. Bullough and P. J. Wheatley, Acta Cryst., 1957, 10, 233.265 J. H. Bryden, ibid., p. 677.266 Y. Okaya and R. Pepinsky, ibid., p. 681.26' E. G. Cox, D. W. J. Cruickshank, and J. A. S. Smith, Proc. Roy. Soc., 1958, A ,247, 1458 CRYSTALLOGRAPHY.of the structure of naphthalene, corresponding to that previously describedfor anthracene (and with similar findings), has been reported.268Aromatic hydrocarbons have planar molecules, unless they are over-crowded.A striking illustration of the rule of minimum symmetry (p. 436)is that the molecular plane never coincides with a crystallographic plane ofsymmetry: in the solid state there is always at least formal distortion fromthe ideal structure. A plausible exception may be discerned in acenaphthene(6), the correct structure for which was first indicated by Kitaigorod~kii,~~~and has now been refined.270 The unit cell contains four molecules andbelongs to the space group Pcm2,; all four are bisected meridionally bymirror-planes, but pairs of them are crystallographically distinct ; one pairpack together in a manner reminiscent of the graphite structure and lieaccurately in planes perpendicular to the c-axis, and thus in accordance withthe higher symmetry of the space group Pcmm.Although the two types ofmolecule differ crystallographically, their dimensions are substantially thesame: the bond between the methylene carbon atoms has d = 1-54 & 0.014A, and is not abnormally long as had formerly been supposed.The crystals of 2,3-4,5-dibenzocoronene (" benzbisanthene ") also containcrystallographically distinct, but dimensionally similar, molecules.271 Ananalysis of 9,lO-dibromoanthracene finds the molecule to be planar, withthe C-C distances not significantly different from those in anthracene.272Also probably planar is the molecule of 9 , lO-dihydro-1,2-5,6-dibenz-anthracene (7) ,273 though the corresponding unsubstituted hydroanthracenemolecule is folded.Another example of the occurrence of two sets of non-equivalentmolecules in the crystal is whose structure proved sur-prisingly difficult to elucidate.Each set of molecules is linked by hydrogenbonds into infinite chains. Phloroglucinol dihydrate has its moleculeshydrogen bonded into nearly flat sheets, between which weaker forcesoperate, with some disorder in the stacking suggested by the occurrence ofdiffuse reflex ion^.^'^ Repulsion between neighbouring oxygen and chlorineatoms causes slight distortion in 1,5-dichloroanthraquinone.276Heterocyclic Compounds.-Pyrazine (8; R = H) may now be added to268 D. W. J . Cruickshank, Acta Cryst., 1957, 10, 504.269 A.I. Kitaigorodskii, Zhur. $2. Kkim., 1949, 23, 1036.270 H. W. W. Ehrlich, Acta Cryst., 1957, 10, 699.271 J. Trotter, ibid., 1958, 11, 423.27a I d e m , ibid., p. 803.279 J. Iball and D. W. Young, ibid., p. 476.274 H. C. Watson and A. Hargreaves, ibid., 1957, 10, 368; 1958, 11, 556.376 S. C. Wallwork and H. M. Powell, ibid., 1957, 10, 48.2'6 M. Bailey, ibid., 1958, 11, 103SPEAKMAN : ORGANIC STRUCTURES. 459the number of aza-aromatic molecules for which accurate X-ray analysesare a~ailable.~" The molecule has crystallographic 2/m (C2J symmetry,and is therefore strictly planar, with d(C-N) = 1.334 & 0.015, d(C-C) =1.378 & 0.015, d(C-H) = 1-05 A, and L(C-N-C) = 115". Tetramethyl-pyrazine (8; R = Me) has also been studied with moderate accuracy; 278 themost notable difference from pyrazine itself is that d(C-C) = 1.43 & 0.01 A;the molecule appears to be planar despite the contiguity of the methylgroups, for which d(C-Me) = 1-51 A.Hirshfeld and Schmidt have extendedtheir analysis of the a-form of phenazine (9) to ~ O ' K , at which temperaturethe diminished thermal motions allow greater accuracy to be attained, andthey have refined their co-ordinates to &0.003 A.279 The bond-lengthsthey find do not differ significantly from those in anthracene, and they makethe wry observation that even the most careful X-ray analysis is not yetable to distinguish between these two molecules on the basis of bond-lengthsalone. The replacement of CH by N has no measurable effect.(Of courseother differences are detectable : the electron-density peaks at the nitrogenatoms are somewhat higher than those at carbon, and the bond-angles atnitrogen are less than 120°.280)('0) ( 1 ' )Amongst pyrimidine derivatives, special mention may be made oftheophylline (10; R = H) and caffeine (10; R = Me), whose isostructuralhydrates have been studied.=l Corresponding bond-lengths are verysimilar, and to those in uracil, and the average d(C-N) in the imidazolering appears to be significantly less than that in the pyrimidine ring. Theposition found for the water molecule in caffeine has caused some discussion:the structure was determined by projections (including generalised pro-jections) along the short c-axis (3.97 A); from this viewpoint two watermolecules are seen, 1.08 A apart and on either side of a centre of symmetry;even when they are supposed to have the maximum possible separation($ x 3.97 A) along the line of sight, their real distance apart amounts to nomore than 2-27 A, and the value derived from the detailed analysis was lessthan this. Two suggestions may be made to explain away this anomaly:the water-sites may be incompletely occupied, since the crystal is efflorescentand there is some doubt about its exact water-content; in projection theelectron-density peaks for the two water molecules overlap, and in thesecircumstances there is some tendency for their apparent separation to beerroneously low.282 An X-ray study of 5'-bromo-5'-deoxythyidine (1 1)277 P.J. Wheatley Acta Cryst., 1957,10,182. (For a micro-wave analysis of pyridine,see B. Bak, L. H. Nygaard, and J. R. Anderson, J . Mol. Spectroscopy, 1958, 2, 361.)278 D. T. Cromer, J . Phys. Chem., 1957, 61, 254.279 F. L. Hirshfeld and G. M. J. Schmidt, J . Chem. Phys., 1957, 26, 923.280 Ann. Reports, 1956, 53, 411.281 D. J. Sutor, Acta Cryst., 1958, 11, 83, 453.288 Ann. Reports, 1954, 51, 388460 CRYSTALLOGRAPHY.confirms the structure suggested by Brown and Lythgoe and finds the five-membered ring to be non-~lanar.~83Many years ago Bell and Bennett characterised a- and P-forms of dithiandioxide (12), which they supposed to be trans- and cis-isomers respectively.284Shearer 285 has now carried out an X-ray analysis of the former substance,which proves to have the ring in the " chair " form, with the S-0 bonds intrans- and axial positions; d(S-0) = 1.48 A, and L(C-S-C) = 98".Onthe other hand, the corresponding heterocyclic ring in dithianthren dioxide(13) is " boat " shaped, with the molecule folded along the S S line.286The a-form of the dioxide has diad crystallographic symmetry, and so musthave the anti-cis-configuration of the two S-0 bonds (since the syn-cis-0I OSD / s(13)0molecule could not be accommodated within the unit-cell dimensions). TheP-form is therefore supposed to be a trans-form, by exclusion. When eitherof these disulphoxides is oxidised, the same disulphone (14) should result,and it has been briefly reported that the structure of diphenylene disulphoneis in accord with this expe~tation.~~' Selenophen-2-carboxylic acid (15) 288has a nearly planar molecule, which dimerises in the usual way; d(Se-C) =1.81, 1.77 A.Other Cyclic Molecules.-The dimensions of small (particularly three-membered) rings are of special interest in relation to the theoretical viewthat their interatomic distances should be less than between correspondinglybonded atoms in open chains.Experimental evidence from micro-wavespectroscopy of simple cyclopropane derivatives supports this view,290and the results of some X-ray studies tend in the same direction. Thecarbohydrazide of cyclopropane (16) has been analysed with someaccuracy; 291 in the ring d(C-C) = 1-52, 1.49, 1.48 & 0.015 A, whilst theother d(C-C) = 1.48 A, which may imply slight conjugation between thecarbonyl group and the ring.In the naphthaquinone derivative (17), thetwo equivalent C-C bonds in the three-membered ring are significantlyshortened at 1-49 & 0.02 A; 292 the third bond, with d(C-C) = 1.56 &- 0.03 A,is equivocal, but the strain at these carbon atoms must be so severe that anormal cyclopropanoid distance between them would be surprising.2.93 M. Huber, Acta Cryst., 1957, 10, 129.2.94 H. V. Bell and G. M. Bennett, J., 1927, 1798.285 Personal communication from Dr. H. M. M. Shearer.m6 S. Hosoya and R. G. Wood, Chew. and Ind., 1957, 1042.287 S. Hosoya, ibid., 1958, 980.288 M. Nardelli and G. Fava, Gazzetta, 1968, 88, 229.289 C. A. Coulson and W. Moffitt, Phil.Mag., 1949, 40, 1.290 E.g., J. P. Friend and B. P. Dailey, J. Chem. Phys., 1958, 29, 577.291 D. B. Chesnut and R. E. Marsh, Acta Cryst., 1958, 11, 413.292 W. K. Grant and J. C. Speakman, J., 1958, 3753.(J., 1959, 1394.SPEAKMAN : ORGANIC STRUCTURES. 461Studies have been reported for a number of straight-chain fatty acids withmethylene groups looped on to the chains,293 but in these large moleculesthe accuracy of bond-length determination is not high enough to detectsmall changes.1,3-Di-~-bromobenzylidenecyclopentan-2-one (18) 294 has the aromaticgroups trans-trans to the carbonyl oxygen atom, and has bond-lengthswhich seem to show evidence of conjugation between the benzylidene andcarbonyl groups.Full, and slightly amended, details are now available of the tropoloniumcation (19),295 and a comparison can be made between the dimensionsshown here and those obtained in the corresponding study of the tropolonateanion.296 The chief differences are that thetwo C-0 bonds, though their lengths are againsensibly equal, are longer than those in theanion (1.28 A), and that the intervening C-Cbond is not longer than the other annularbonds; the standard deviation in the bond-lengths is rt0.023 A, so that some of the differ-ences in the ring are possibly significant.A nuclear magnetic resonance study of solidcyclo-octatetraene 297 confirms the " tub " con-formation of this molecule with h2m (D2J symmetry.The molecule in thecrystal of cyclododecane deviates only slightly from the same symmetry,the deviation being attributable to the crystal environment: 298 it can beroughly described as a square, with four nearly planar, zig-zag tetra-methylem chains along each side: each of the four carbon atoms at thecorners is held in common between two chains, and most of the distortionfrom normal conformation seems to be concentrated at these atoms, withL(C-C<) = 105". This compound is yet another instance of disorder; thestatistical structure consists of half-molecules related by reflexion throughthe mean plane of the ring.A study of the syn- and anti-oximes of P-chlorobenzaldehyde locatesthe hydrogen atoms in the former and thus confirms the classical formulationof oximes as > C=N-OH (and incidentally the respective configurations) .MQThe hydroxyl groups form hydrogen bonds with the nitrogen atoms of293 T. Brotherton and G.A. Jeffrey, J . Amer. Chem. Soc., 1957, 79, 5132.294 K. A. Becker, K. Plato, and K. Plieth, 2. Elektrochem., 1957, 61, 96.295 Y . Sasada and I. Nitta, Bull. Chem. Soc. Japan, 1957, 30, 62.296 Ann. Reports, 1956, 53, 413.297 1. J. Lawrenson and F. A. Rushworth, Nature, 1958, 182, 391.288 H. M. M. Shearer and J. D. Dunitz, Proc. Chem. SOC., 1958, 348.299 B. Jerslev, Nature, 1957, 280, 1410. (See also Thesis, Copenhagen, 1968.462 CRYSTALLOGRAPHY.other molecules; the syn-compound is thus dimerised by a pair of bondslike most carboxylic acids, whereas the anti-compound forms infinite chainslike acetic acid. The yellow form of arsenomethane, (AsCH,),, proves tohave a ring of five arsenic atoms, with d(As-As) = 2.43 A, each linkedradially to a methyl group with d(C-As) = 1.95 A; L(As-As-As) = 97",implying that the ring is puckered, as is the six-membered ring in arseno-benzene.300Molecular Compounds.-Quinhydrone, the 1 : 1 compound between benzo-quinone (Q) and quinol (H), might be expected to have Q and H moleculesindistinguishable, either because they are chemically equivalent, semi-quinonoid species, or because the crystal structure is disordered; and avery early X-ray study was in fact interpreted in terms of indistinguish-ability.Later work showed that Q and H are well differentiated in thecrystal, and a full account of a careful analysis is now a~ailable.~ol AlternateQ and H molecules are linked by hydrogen bonds, with d ( 0 0) = 2.71 A,into infinite chains.The chains are so arranged that in another crystallo-graphic direction almost parallel molecules are stacked, Q and H alternately,with only 3.16 A between the planes of the benzenoid rings. This style ofpacking occurs in other aromatic molecular and it is no doubtto be associated with the intense colour of quinhydrone and with its relativelyhigh density. The Q molecule is remarkably similar in its dimensions tothat in pure benzoquinone: 303 d(C=O) = 1.23, and 1.19; d(0C-CH) = 1.46,1-49; and d(HC-CH) = 1-34, 1.31 A respectively. The H molecule isconsiderably distorted from what might be supposed to be its ideal structure:for instance, d(C-C) = 1-42, 1*33,, 1.41 A for the three crystallographicallydistinct bonds, and the distortion closely resembles that found in the moleculeof 9-dimethoxybenzene.Hassel has reviewed 304 the work done at Oslo on the compounds betweenvarious electron-donors and the halogens, and he considers that electron-transfer takes place with formation, between the interacting molecules, ofdirectional bonds of virtually covalent rank.For example in (CH3)3N,12,the nitrogen and halogen atoms are c o b e a r ; d(N I) is 2-27 A, which isnot much more than the sum of the covalent radii (2.03) and d(1 I) =2.84 A, considerably more than the unperturbed value (2.66). [The corre-sponding complex with triethylamine has a heat of formation in solution of(-AH) 12 kcal., which argues for rather strong b0nding.~05] Again infavour of directional bonding is the zig-zag structure (20) adopted by the1 : 1 compound between acetone and bromine, with d(0 Br) = 2.82 A.306Especially interesting is the compound between benzene and bromine,studied at about -5O"c; parallel benzene rings are stacked 9.0 apart, andbetween them, strung out along the six-fold axis of the rings, are single300 J.H. Burns and J. Waser, J . Amer. Chem. SOC., 1957, 79, 859.801 H. Matsuda, K. Osaki, and I. Nitta, Bull. Chem. SOC. Japan, 1958, 31, 611.808 Personal communication from Prof. Robertson.804 0. Hassel, Mol. Physics, 1958, 1, 241.805 S. Nagakura, J . Amer. Chem. SOC., 1958, 80, 620.306 0. Hassel and K. 0. Stromme, Nature, 1958, 182, 1155.Ann. Reports, 1954, 51, 396.(J.Trotter, Thesis, Glasgow,1957.SPEAKMAN : ORGANIC STRUCTURES. 463bromine molecules, with a bromine atom 3.36 A from the centre of the ringas is suggested by (Zl).307In the well-known P-quinol clathrates studied by Powell, small moleculesare imprisoned within roughly spherical cavities in a rather rigid lattice ofhydrogen-bonded quinol molecules. In X-ray analysis, the imprisonedmolecule often shows enhanced symmetry of the type that suggests“ rotation.” Should literal rotation be occurring, it might be possible todetect rotational fine structure in the spectrum of the enclosed component.M e Me‘c’IIThis fine structure, however, will generally be debased, and even lost, owingto collisions with the walls of the cavity, unless the molecule be very small.The observation of vestigial fine structure in the CO, band at 2350 cm.-I ofthe spectrum of the carbon dioxide-quinol clathrate is attributed torotation .308Similar types of inclusion compound are formed by tri-o-thymotide(22).309 Their crystal structures are more complex, and are not yet knownin detail, but unit-cell dimensions and some other properties have now beenmeasured and compared for a long series of compounds having paraffinsand their derivatives as the enclosed molecules.310 van der Waals forceshere seem to play a large part in holding together the walls of the cavities,and therefore a greater flexibility exists in the room available, and severalkinds of structure are possible. When the imprisoned molecule is shorterthan -9Q A (e.g., n-BuBr), the inclusion is of the cavity type; otherwisethe included molecules lie along open channels, like those in the urea adductsof S~hlenk.31~ The space groups of many of these compounds require thearrangement of the trithymotide molecules to be dissymmetric, with theresult that any individual crystal constitutes an example of spontaneous307 0.Hassel and K. 0. Stromme, Acta Chem. Scand., 1958, 12, 1146.808 R. M. Hexter and T. D. Goldfarb, J . Inorg. Nuclear Chem., 1957, 4, 171.309 Wilson Baker, B. Gilbert, and W. D. Ollis, J., 1952, 1443.310 D. Lawton and H. M. Powell, J., 1958, 2339.311 W. Schlenk, jun., Annalen, 1949, 565, 204464 CRYSTALLOGRAPHY.resolution. In some cases, this deduction has been confirmed polari-metrically.The long-chain molecules in the urea adducts give rise to layer-lines ofdiffuse reflexions, the spacings of which depend upon the length of thechain.It has been shown that the relative intensities of these diffuselayer-lines might serve as an indication of the position of a substituentin the molecular chain.312Natural Products.-Over the last fifteen years, careful X-ray studies of aseries of amino-acids and simple polypeptides have provided a body ofknowledge fundamental to any understanding of protein structure. Thelatest additions to the series are gly~ine,~~8 L-cystine hydrochloride,313L-leucyl-L-prolylglycine m~nohydrate,~~ tosyl-L-prolyl-L-hydroxyprolinem~nohydrate,”~ and glutathione (L-glutamyl-L-cysteinylglycine) .19 Thedisorder in the proline ring of the third compound has been mentioned, andthere is also incomplete occupancy of the water-site in this crystal; but ingeneral these structures follow orthodox lines, with the peptide groupsnearly planar where they occur.The detailed crystal structures of three pyranose sugars are now known,a-rhamnose monohydrate 315 and a-arabinose 316 having been recently addedto a-glucose.In both cases the ring is of “chair ” form, with the sidegroups arranged lax2ax3eq4eq5eq (ax = axial, eq = equatorial) in rhamnose,and lax2eq3eq4ax in arabinose. A revision of the basic crystal structureproposed for cellulose by Meyer and Misch in 1937 has been suggested.317A full account of the analysis of dihydrohydroxyeremophilone hasappeared;3l8 it is pointed out that, in the light of new stereochemicalevidence regarding eremophilone itself, the absolute configuration originallygiven * has now to be reversed.The rings in cadinene dihydrobromide 319are in the “ chair ” form, and the two bromine atoms are cis to one anotherand axial, with the result that the two sides of the roughly planar moleculeare of opposite polarity; the packing of the molecules in the crystal can beinterpreted accordingly. A partial three-dimensional study 320 of calciferol4-iodo-3-nitrobenzoate confirms the structure for calciferol (23) which hadbeen suggested some years ago on the basis of two-dimensional work, andwhich has been supported on spectroscopic grounds by Braude andWheeler,321 and rules out the alternative proposed by Sondheimer andWheeler.322 Isostructural halides of a-7-bromocholesterol have been812 N.Nicolaides, F. Laves, and A. Niggli, J. Amer. Chew. Soc., 1956, 78, 6415.313 L. K. Steinrauf, J. Peterson, and L. H. Jensen, ibid., 1958, 80, 3835; see alsoA. F. Corsmit, A. Schuyff, and D. Feil, R o c . k. ned. Akad. Wetemchap., 1956,59, B, 470.314 A. F. Beecham, J. Fridrichsons, and A. McL. Mathieson, J. Amer. Chem. Soc.,1958, 80, 4739.315 H. M. McGeachin and C. A. Beevers, Acta Cryst., 1957, 10, 227.318 S. Furberg and A. Hordvik, Acta Chem. Scand., 1957, 11, 1594.317 K. C. Ellis and J. 0. Warwicker, Nature, 1958, 181, 1614.318 D. F. Grant, Actu Cryst., 1957, 10, 498.319 F. Hanic, Coll. Czech. Chem.Comm., 1958, 23, 1751.320 D. C. Hodgkin, M. S. Webster, and J. D. Dunitz, Chem. and Ind., 1957, 1148.821 E. A. Braude and 0. H. Wheeler, J., 1955, 320.328 F. Sondheimer and 0. H. Wheeler, Chem. and Ind., 1955, 714.* See Ann. Reeorts, 1966, 53, 414SPEAKMAN : ORGANIC STRUCTURES. 465revealing a structure corresponding to that of cholesteryl iodide.The results of an X-ray study of annotinine bromohydrin324 indepen-dently confirm a structure that has been proposed on chemical grounds.The full structure of muscarine has been determined by an analysis of itsiodide (24).3% The short intramolecular contact, with d ( 0 9 CH,) = 2-87 A,appears to be fairly well established, and it must represent a strong hydrogenbond of an unusual type. The structure proposed by Prelog and his co-workers for erythraline (25) has been confirmed and clarified by analysisof its hydrobromide.326 The two rings of the hydroindole residue lieapproximately in a plane perpendicular to that of the other three rings.The synthetic narcotic, D-methadone (26), has been studied as its (mono-clinic) hydrobr0mide~~~7 and its absolute configuration has been established.This is of interest because the L-enantiomorph is much more active physio-I.....g \+/(24)MeMe M e O nlogically than the D-form. The structures of kainic acid-the anthelminticprinciple from Digenia simplex Ag-and of the almost inactive allokainicacid have been determined, partly by way of their zinc salts3% Bothmolecules are represented by formula (27), and they differ only in respectof their configurations at the asterisked carbon atom.In a previous Report 329 the discovery by X-ray analysis of the whollyunknown structure of cryptopleurine was described. This structure hasnow been confirmed by synthesis.=O For once the normal r8les of organicchemist and crystallographer have been reversed.The first of a series of papers which are to describe the X-ray work onvitamin B,, has now been published; 331 it gives a perspective view of the323 H. Burki and W. Nowacki, 2. Krist., 1956, 108, 206.324 M. Przybylska and L. Marion, Canad. J . Chem., 1957, 35, 1075; M. Przybylska826 F. Jellinek, ibid., 1957, 10, 277.326 W. Nowacki and G. F. Bonsma, 2. Krist., 1958, 110, 89.327 A. W. Hanson and F. R. Ahmed, Acta Cryst., 1958, 11, 724.328 H. Watase and I. Nitta, Bull Chem. Soc. Japan, 1957, 30, 889; I. Nitta, H.329 Ann. Reports, 1954, 51, 397.330 C. K. Bradsher and H. Berger, J . Amer. Chem. SOC., 1957, 79, 3287; 1958, 80,930; P. Marchini and B. Belleaux, Canad. J . Chem., 1958, 38, 581.331 D. C. Hodgkin, J. Kamper, J. Lindsey, M. MacKay, J. Pickworth, J. H. Robert-son, C. Brink, J. G. White, R. J. Prosen, and K. N. Trueblood, Proc. Roy. SOC., 1957, A ,242, 228.and F. R. Ahmed, Acta Cryst., 1958, 11, 718.Watase, and Y . Tomiie, Nature, 1958, 181, 761466 CRYSTALLOGRAPHY.general strategy of the investigation. A preliminary X-ray study ofgramicidin has been reported,s2 crystal data having been collected andcompared for a number of derivatives of the cyclic decapeptide, gramicidin-S.A full solution of this structure is not yet in sight, but some tentativedeductions are made; if they are correct, they may require a reconsiderationof some current ideas on the chain-configurations of polypeptides.During the period under review, the most remarkable crystallographicachievement in the field of natural products has been the partial Fourieranalysis at Cambridge of the protein, spenn-whale myoglobin. [Butreference may first be made to the application of electron-spin resonanceto this and another crystalline hzmoglobin derivative: for they haveenabled one detail of the structure to be elucidated with almost incongruousaccuracy. With only the one paramagnetic atom present (Fe), the methodconcentrates attention on this atom alone, and on the symmetry of itsenvironment; and, by working with single crystals, it has been possible tomeasure the orientations of the hzm groupings with respect to the crystallo-graphic axes with an uncertainty of only about In various ways itis possible to introduce heavy atoms (such as Hg) into myoglobin withoutgreatly changing the structure and the unit-cell dimensions. By comparingthe diffraction patterns of several such derivatives, some attempt at asolution of the phase problem by the method of isomorphous replacementcould then be made. At the stage reported in early 1058, it had beenpossible to phase some 400 reflexions in this way, most of them corre-sponding to spacings exceeding 6 A. This represents but a low degree ofresolution, a t which individual atoms could not be discerned. But thethree-dimensional Fourier map derived enables the tertiary structure ofthe protein to be made out-ie., the general disposition of the coils of poly-peptide chains. The picture of the molecule that appears is forbiddinglycomplicated.334 Before finer details can be studied, phases will have to befound for a much greater number of reflexions, which must extend to muchcloser spacings. (For individual atoms to be resolved, reflexions withspacings down to about 2 would have to be available.) At the best, thisprogramme implies an arduous perseverance; but most of the workers inthis field have no doubt that the outlook is auspicious.J. C. S.G. A. SIM.J. C. SPEAKMAN.332 G. M. J. Schmidt, D. C. Hodgkin, and B. M. Oughton, Biochem. J., 1957, 65,333 J. E. Bennett, J. F. Gibson, and D. J. E. Ingram, Proc. Roy. SOC., 1957, A , 240,334 J. C . Kendrew, G. Bodo, H. M. Dintzis, R. G. Parrish, H. Wyckoff, and D. C.744, 752.67.Phillips, Nature, 1958, 181, 662. (See also ibid., 182, 764.

ISSN:0365-6217    

DOI:10.1039/AR9585500430

出版商:RSC    

年代:1958

数据来源: RSC

摘要:

INDEX OF AUTHORS’ NAMES.Aaron, H. S., 217.Abel, E. W., 114, 126, 147,Abraham, M. H., 409.Abraham, R. J., 35.Abrahams, S. C., 444.Acklin, W., 235.Acs, G., 332.Adam, C. T., 196.Adamek, E. G., 317.Adams, G. A., 321, 323,Adams, R., 272, 295.Adams, R. M., 141.Adams, R. N., 69.Adamson, A. W., 144, 163.Addamiano, A., 438.Addison, C. C., 129, 148,165, 166.Adicoff, A., 31.Adler, J., 337.Adler, M., 331.Aebli, H., 278.Agar, J. N., 67, 68.Agarwal, H. P., 69.Agarwala, R. P., 446.Agerman, M., 132.Aggarwal, K. P., 315.Agranoff, B. W., 376.Ahmed, F. R., 465.Ahmed, M. S., 443.Ahrland, S., 18, 144.Aikazyan, E. A., 69, 74.Ainscough, J. B., 449.Ajl, S., 360.Akabori, S., 216.Akagi, S., 283.Akhrem, I. S., 266.Akhtar, M., 221.Akishin, P., 96, 101.Aksanova, L.A., 306.Albert, N., 436.Albrecht, R., 273.Alcock, K., 159.Aldrich, P., 242.Aldrich, P. E., 306.Alexander, L. E., 443.Alfonsi, B., 405.Ali, M. E., 235.Allan, J. E., 425.Allen, A. D., 193.Allen, D. E., 382.Allen, F. W., 331, 332.Allen, H. C., 101.Allen, M. J., 67.Allen, P. E. M., 35.Allen, P. W., 31, 33.Allen, R. G., 221.153, 271.325.Allewelt, A. L., 318.Allinger, J., 217, 234.Allinger, N. L., 234, 259.Allison, G. F., 140.Allison, M. F. L., 200.Allred, A. L., 123.Almenningen, A., 101, 102.Alonzo, N., 373, 374.Altermatt, H. A., 356.Altshuller, A. P., 129.Al-Urfali, R., 68.Alvarado, F., 359.Amberg, C. H., 414.Ambrose, D. A., 411.Ames, G. R., 259.Ameyama, M., 363.Amin, A.-A.M., 398.Amma, E. L., 100, 123,Ammar, I. A., 75, 78.Amos, H., 331.Amr El Sayed, M. F., 148.Anacker, W. F., 348.Anand, N., 242.Anbar, M., 190, 194.Anderegg, G., 12, 18.Andersen, J. R., 101, 102.Andersen, R. E., 100.Anderson, A. G., jun., 267,Anderson, C. D., 231, 330,Anderson, C. H., 298.Anderson, C. J., 215.Anderson, F. B., 321.Anderson, G. W., 288.Anderson, J. D., 316.Anderson, J. H., 177.Anderson, J. R., 459.Anderson, J . R. A., 395.Anderson, L. C., 206.Anderson, R. B., 210.Anderson, R. C., 9.Anderson, R. G., 218, 267.Anderson, R. J., 368.Anderson, W., 71.Anderson, L. H., 132.Andreas, H., 227.Andreev, M. M., 233.Andresen, A. F., 435, 445.Andrews, E. B., 48.Andrews, L. J.. 258.Andrews, P., 316, 317.Andrews, T.M.. 28.Andriyevskaya, Ye. A.,Anet, R., 314.Aniert, L. G., 36.453.290.334.318.467Angoletta, M., 147.Anguli, J., 289.Angus, A. B., 125.Anno, T., 172.Ansell, G. B., 373.Antar, M. F., 259.Antikainen, P. J., 13, 24.Antonov, I. S., 118.Aoki, M., 35.Apicella, M., 334.Appel, R., 130, 137, 138.Appl, M., 291.Appleman, D. E., 445.Arai, K., 316.Arai, T., 170.Arakawa, E. T., 104.Araki, C., 316.Arbuckle, A. W., 318, 319.Arcand, G. M., 405.Archambault, J., 155.Archer, E. E., 400.Archer, R. D., 164.Archibald, A. R., 320.Archibald, L. B., 66.Arcus, C. L., 197.Arends, C. B., 60.Arens, J. F., 222.Areoste, H., 58.Arganbright, R. P., 206.Arigoni, D., 240, 246, 247,Armstrong, J.J., 353.Arndt, C., 304, 305.Arnold, J. W., 82, 83.Arnold, R. T., 258.Arnold, W., 310.Arnot, C., 85.Arnstein, H. R. V., 356.Aron, M. A., 298.Aronsson, B., 448, 451.Arthur, H. R., 284.Arumugam, N., 306.Asandei, N., 318.Ascoli, I., 365.Asensio, C., 356.Asher, R. C., 124.Ashikari, N., 31.Ashwell, G., 354, 361, 362.Ashworth, M. R. F., 407.Ashworth, P. J., 223.Asinger, F., 285.Asmussen, R. W., 149.Aso, K., 325,327.Aspinall, G. O., 321, 322,Asprey, L. B., 160.Assony, S. J., 266.Astill, B. D., 294.249, 277.323, 327468 INDEX OF AUTHORS’ NAMES.Astrachan, L., 335.Atherton, F. R., 192.Atherton, N. M., 35.Atkinson, B., 35.Atoji, M., 153, 441, 448,Aubin, R., 155.Audrieth, L. F., 134.Augood, D. R., 205, 207.Aukward, J.A., 27.Aurivillius, K., 444.Ausloos, P., 39, 91.Austen, D. E. G., 202.Austin, J. M., 17.Avigad, G., 325.Axelrod, J., 354, 364, 377.Ayabe, Y., 68.Ayengar, P. K., 385.Ayer, D. E., 304.Ayer, W. A., 314.Ayerst, G. G., 294.Aynsley, E. E., 139, 161,Ayres, D. C., 233.Ayscough, P. B., 39, 90.Aziz, G., 201.Azouz, W. M., 377.Azzioni, G., 453.452.164.Babayeva, V. P., 141.Bacarella, A. L., 10.Bach, S. R., 228.Bachman, G. B., 119.Back, E., 13.Backstroni, H. L. J.. 93.Bacon, G. E.. 435, 436.Bacon, R. G. R., 125.Baddiley, F., 353.Baddiley, J., 299.Bader, A. R., 206.Bader, F. E., 307.Badger, G. M., 255, 384.Badger, R. M., 436.Baeckmann, A. V., 419.Baer, E., 372, 373, 367-Baer, H. H., 326, 358.Baer, J.E., 383.Bafna, S. L., 187.Bagchi, P., 244.Bagdasaryan, K. S., 93,Bagnall, K. W., 139.Bagozkaya, I., 73.Bailar, J. C., 142, 145.Bailey, M., 458.Bailey, P. S., 214, 251.Bailey, R. W., 327.Bailey, W. J., 230, 232.Bak, B., 101, 102, 108,459.BakAcs-Polgar, E., 400.Baker, B. B., 406.Baker, B. R., 330, 334.Baker, F. B., 20.Baker, W., 268, 269, 289,370.207.463.Bakh, N. A., 94.Balashova, N. A., 71.Baldwin, W. H., 401.Balenovic, K., 305.Balint, A. E., 218.Balk, P., 173.Ball, D. H., 327, 328.Ball, D. L., 144.Ball, H. A., 359.Ball, S., 229.Ballantine, J. A., 296.Balli, H., 289.Ballov, C. E., 347.Baltes, W., 364.Bamford, C., 200.Bamford, C. H., 27, 32.Ban, M. I., 174.Banerjee, N. G., 426.Banks, C.V., 415.Banks, E., 154, 155.Banks, J. E., 397.Bann, B., 285.Bannister, E., 127.Baran, J . S., 304.Baranova, E. G., 93.Barash, M., 305.Barawell, D. C., 94.Barb, W. G., 27.Barban, S., 356.Barber, G. W., 272.Barber, H. J., 290, 298.Barber, H. S., 211.Barchewitz, P., 59.Bardi, R., 165, 453.Barefoot, R. D., 428.Barker, G. C., 68, 69.Barker, S. A., 315, 316,324, 325, 327, 365.Barkey, K. T., 317.Barltrop, J. A., 242.Barnard, M., 236.Barnard, P. W. C., 190.Barner, R., 233, 252.Barnes, I., 445.Baron, C., 283.Barr, E. W., 25, 180.Barrer, R. M., 430.Barrett, A. H., 95.Barrett, C. S., 440.Barrette, J. P., 327.Barricelli, L. B., 447.Barrollier, J., 391.Barron, E. J., 366.Barrow, G. M., 66.Barrow, R.F., 48, 97, 112.Barson, C. A., 29.Bartlet, J. C., 420.Bartlet, J. G., 423.Bartlett, A. F., 392.Bartlett, H. J., 78.Bartlett, J. H., 78.Bartlett, M. F., 309.Bartlett, N., 448.Bartlett, P. D., 183, 188,Bartocha, B., 117, 230.189, 213.Bartolome, E., 60.Barton, C. J., 158.Barton, D. H. R., 219, 241,Barton, G. M., 263.Barton, J. W., 269.Bascombe, K. N., 13.Basolo, F., 11, 16, 25, 144.Bass, A. M., 56.Bass, R., 82.Bassett, E. W., 303.Bassi, D., 106.Bassi, I. W., 100, 155,Bastiansen, 0.. 101, 102.Basu, D. K., 318.Basualdo Drivila, W. H.,Bateman, L., 210, 288.Bates, N. A., 367.Bates, R. B., 236.Bates, R. G., 7-9.Batres, E., 275.Batt. W. G., 364.Battersby, A. R., 304-Battiste, M. A., 188.Bauder, A., 266.Baudet, J., 381.Baudler, M., 99, 131.Bauer, E., 83.Bauer, S.H., 83.Bauersachs, E., 419.Baughan, E. C., 135.Baum, H., 315.Baumann, E., 386.Baumann, P., 235.Baumann, W., 259.Baumgartner, F., 152.Baumgarten, H. E., 298.Baur, W. H., 448.Bax, C. M., 120.Baxendale, J. H., 12.Baxter, J. N., 245.Bayer, E., 413.Bayer, W., 256.Bayer-Helms, F., 23.Bayles, J. W., 13, 23.Baylis, R. L., 369.Bayne, S., 359, 364.Baynten, H. G., 252.Bazley, N. W., 80.Bear, R. S., 341.Beart, J. A. T., 289.Beaton, J. M., 248.Beatty, P. M., 41.Beavers, L. E., 297.Beck, C. W., 445.Beck, H., 210.Beck, M. T., 146.Becke, F., 255.Becke-Goehring, M., 126,Becker, K. A., 461.Becker, R. R., 361.Beckmann, R., 427.249, 278.453.141.306, 310.133, 134, 136-138INDEX OF AUTHORS’ NAMES. 469Beckwith, A.L. J.,207,277.Beecham, A. F., 464.Beechey, R. B., 347.Beer, R. J. S., 296.Beers, R. F., jun., 339,Beevers, C. A., 442, 464.Begun, G. M., 104.Behnisch, W., 263, 286.Behrens, H., 146.Behringer, L., 194, 286.Beichl, G. J., 118.Belen’hil, L. I., 288.Bell, E. W., 228.Bell, H. V., 460.Bell, I., 283.Bell, M. R., 297.Bell, R. E., 446.Bell, R. P., 13, 21, 24,Bellamy, L. J., 66, 118.Belleaux, B., 465.Bellon, P. L., 444.Belov, V. N., 237.Belskij, I. F., 210.Bender, M. L., 180, 186.Bendich, A., 335.Benedict, W. S., 58, 60,BeneSovB, V., 238.Bengough, W. I., 27.Bengtsson, T. A., 392.Benham, G. H., 382.Benjamin, B. M., 196.Benkeser, R.A., 206, 208,Bennett, C. E., 413.Bennett, E. W., 206.Bennett, G. M., 460.Bennett, J. E., 466.Bennett, M. A., 153, 271.Benotti, J., 368.Bensey, F. N., jun., 440,Benson, A. A., 373.Benson, S. W., 8, 27.Bent, H. A., 108.Bentley, R., 263, 356, 364.Benz, E., 112, 262.Berenblum, I., 379.Berends, W., 334.Berg, D., 20.Berg, E. W., 417.Bergel, F., 352, 353.Berger, C. R. A., 211Berger, G., 130.Berger, H., 465.Bergmann, E. D., 34, 215.Bergmann, G., 413.Bergmann, W., 274, 283,Bergstrom, S., 284.Beringer, F. M., 25.Berisford, R., 89.Berkelhammer, G., 290.Berkowitz, J., 112.341.188.61, 105.221.441.374.Berlage, F., 309, 310.Berliner, E., 181.Bermes, E. W., 408.Bernadi, J. L., 184.Bernaerts, M. J., 364.Bernauer, K., 309, 310.Berndt, D., 73.Bernstein, B.S., 296.Bernstein, H. J., 178.Bernstein, S., 272.Bersche, H. W., 259.Berson, J. A., 258.Bertaut, E. F., 133.Bertaut, F., 448.Berthier, G., 172.Bertin, D., 273.Bertram, H. W., 389.Bertrand, M., 224.Bertz, T., 214.Berzins, T., 69, 72.Besch, E., 309.Besnai’nou, S., 177.Bessel, C. J., 229.Bessman, M. J., 337, 373.Best, G. F., 159.Bestmann, H. J., 220.Bethell, D., 179, 199, 252.Beukers, R., 334.Beutmann, W., 315.Bevan, C. W. L., 304.Bevan, T. H., 369, 370.Bevington, J. C., 28, 29,Bewick, A., 69.Beyer, D. L., 303.Beyer, E., 213.Beyler, R. E., 273, 276,Bezzi, S., 165,453.Bhargava, P. M., 381.Bharucha, K. R., 274.Bhattacharyya, B. K., 277.Bhattacharyya, S.C., 238.Bickel, A. F., 232, 270.Bickel, H., 307.Bickelhaupt, F., 112, 271,Bickoff, E. M., 301.Biechler, S. S., 186.Biedermann, G., 11.Biellmann, J.-F., 247.Biemann, K., 242.Bigeleisen, J., 42, 103,Bigelow, L. A., 125.Biggerstaff, W. R., 276.Biggs, A. I., 20.Bigley, D. B., 242.Bigou, J. P., 213.Bijvoet, J. M., 454.Bikales, N. M., 318.Biletch, H., 34.Bill, M. E., 316.Billy, C., 448.Binks, J. H., 206.Binns, S. V., 249.36, 203.277.315.180.Birch, A. J., 212, 246, 251,Bircumshaw, L. L., 70.Bird, G. R., 104.Birkinshsw, J. H., 303.Birks, J. B., 92.Birss, F. W., 86.Bishop, C. T., 321, 325,Bissot, T. C., 117.Biswas, A. B., 446.Bjerrum, J., 7, 14, 144.Rjerrum, N., 15.Bjorklund, B., 324.Bjorklund, C. W., 160.Blacet, F.E., 41, 49, 64,Blackadder, D. A,, 198.Blackburn, P. E., 157.Blackwood, A. C., 353,Blades, A. T., 87.Blades, C. E., 33.Bladon, P., 276.Blair, M. G., 325.Blanchard, E. P., jun., 237.Blanchard, L. P., 48.Blanchard, W. A., 286.Bland, J. A., 450.Blank, F., 356.Blasius, E., 391, 408.Blau, W., 288.Bleakney, W., 43.Bleidelis, Ya. Ya., 452.Blickenstaff, R. T., 277.Blietz, R. J., 374.Blinne, K., 127, 450.Bloch, K., 226, 246, 272.Bloclr-Frankenthal , L.,Blois, M. S., 422.Blomquist, A. T., 221, 236.Blouin, F. A., 364.Blount, B. K., 245.Blum, P., 448.Blumenthal, E., 191.Blumenthal, I-I. J., 325.Blumenstein, A., 32.Blundy, P. D., 417.Bochvar, D. A., 268.Bockris, J. O’M., 68, 70,Bode, H., 424, 450.Bodo, G., 466.Boehm, H.P., 124.Bohm, P., 369.Boehm, R. L., 318.Bohme, H., 149.Boekelheide, V., 268, 289,294, 312.Boer, H., 212.Bogdanova, A. V., 207.Bogorad, L., 302.Bogucki, R. F., 12.Bohlmann, F., 222, 223,292, 302.356.55.357.347.73-77.304, 305470 INDEX OF AUTHORS’ NAMES.Bohnstedt, U., 415.Boit, H. G., 311.Bokii, G. B., 452.Boldingh, J., 366Bolhofer, W. A., 230Boltz, D. F., 422.Boncoddo, N. F., 368, 373.Bond, C. R., 364Bonhoeffer, K. F., 79.Bonner, J., 227.Bonner, W. A., 196.Bonnet, Y., 265Bonnett, R., 293.Bonser, G. M., 381.Bonsignore, A., 357.Bonsma, G. F., 465.Bonvin, J. F., 302.Boog, W., 423.Boone, J. L., 116.Booth, A. N., 301.Booth, E., 417.Booth, H., 295.Booth, J., 378, 383, 384.Bordwell, F.G., 185Borg, 0. F., 12.Borgstrom, B., 366Borino, G. B., 107.Borkenhagen, L. F., 375.Borkovec, A., 257.Borman, A., 272.Borg, S., 242.Bostrup, O., 149.Botquin, G., 412.Bottini, A. T., 261.Boudart, M., 89.Boudart, M. J., 84, 86.Bourdais, J., 34.Bourne, E. J., 316, 327,Bourne, M. C., 385.Bourns, A. N., 188.Bouveng, H., 322.Bouy, P., 140.Bowen, E. J., 91.Bowen, H. J. M., 100Bowers, A., 277, 285.Bowers, R. C., 70.Bowers, V. E., 7, 8.Bowness, J. M., 316.Boyd, A. N., 207.Boyer, J. H., 255.Boyer, J. P., 249.Boyer, P. D., 347.Boyko, E. R., 446.Boyland, E., 363, 376, 378,379, 383, 384.Boys, S. F., 64.Brack, A., 306.Brackel, H., 305.Brade, H., 189.Bradley, D. C., 19, 123,127, 143, 1 5 6 1 5 6 , 161.Bradley, D.F., 332.Bradley, R. M., 376.Bradsher, C. K., 297, 465.Brady, G. W., 27, 445.365.Brady, 0. L., 180.Brady, R. O., 376.Brandstrom, A., 25.Brand&, C. I., 132.Bragg, P. D., 365.Braibanti, A., 453.Brand, J. C. D., 194.Brandon, R. L., 263.Brandt, P., 88.Bratoz, S., 66.Brauchle, H. H., 137.Braude, E. A., 194, 464.Brauer, G., 162.Braun, G., 147.Braun, J., 217.Braun, R. A., 396.Braunholtz, J. T., 297.Bray, H. G., 377.Bray, R. C., 352, 353.Bredereck, H., 327.Brederick, H., 291.Bredoch, R., 291.Bee, A., 439.Breene, R. G., 57, 61.Breitenbach, J. W., 35, 36.Breiter, M., 73, 74.Brenneisen, P., 294.Brenner, A., 70.Brenner, G., 242.Breslow, D. S., 34.Breslow, E., 362Breslow, R., 231, 268.Brewer, L., 111.Brey, M., 239.Brezina, M., 67.Briggs, L.H., 245.Briggs, R., 390.Brindell, G. D., 206.Bringi, N. V., 296, 308.Brink, C., 465.Brink, N. G., 228, 230.Brinton, R. K., 39.Bristow, G. M., 33.Britt, J. J., 246, 247.Brockerhoff, H., 227.Brockmann, H.. 257.Brodersen, K., 166.Broderson, S., 62, 103.Brodie, B. B., 377, 379,Brody, 0. V., 19.Broekema, J., 448.Broekema, R., 222.Broide, H. P., 201.Brook, P. R., 309.Brooks, C. J. W., 383.Brooks, W. V. F., 60.Brossi, A., 305.Brossmer, R., 358.Brothers, J. A., 159.Brotherton, T., 461.Brotherton, T. K., 261.Brown, B. R., 211, 300,Brown, D. A., 106, 146.Brown, D. E., 100.382, 383.302.Brown, D. H., 158.Brown, D.M., 334, 367,Brown, F. H., 92.Brown, G. B., 298.Brown, G. H., 68.Brown, H., 97.Brown, H. C., 116, 179,210, 211.Brown, H. W., 130.Brown, J. F., 390.Brown, M., 233, 236.Brown, M. P., 127.Brown, P. J., 450.Brown, P. G. M., 16, 149.Brown, R. D., 172, 298.Brown, R. G., 100.Brown, T. L., 55, 65, 66,Brown, W. H., 292.Brownell, H. H., 318.Brownstein, A. M., 325.Brownstein, S., 198, 258.Bruce, J. M., 296.Bruck, P., 185.Bruckner, B. H., 316.Brug, J., 358.Bruice, T. C., 186.Brumfitt, W., 364.Brunton, G., 445.Bryan, R. F., 436.Bryant, P. J. R., 14.Bryce, W. A., 89.Bryce, W. A. J., 319, 320.Bryce-Smith, D., 205.Bryden, J. H., 456, 457.Bublitz, C., 354.Buchanan, J. G., 293, 299,329, 353.Buchel, K. H., 303.Buchi, G., 304.Buchnea, D., 368, 373.Buchschacher, P., 277.Buchta, E., 256.Buchwald, H., 133.Buck, M., 10.Buckingham, A.D., 65.Buckingham, R. A., 177.Buckley, R. P., 2C6.Budenz, R., 415.Budovich, T., 326.Biichi, G., 232, 242.Biichler, A., 104.Bunzen, K., 113.Buerger, M. J., 446, 455.Biirki, H., 465.Ruffleb, H., 255.Buggle, K. M., 268, 289.Buisman, J. A. K., 283.Buist, G. J., 180.Bullock, E., 292.Bullough, R. K., 457.Bullock, J. D., 223, 303.Bumgardner, C. L., 231.Buncel, E., 213.Bune, N. Ya., 78.370, 371.233INDEX OF AUTHORS' NAMES. 471Bunker, P. L., 88.Bunnett, J . F., 179, 188,Bunton, C. A., 12, 130, 188,Burbank, R. D., 440, 441.Burcik, E., 315.Burg, A. EL, 116, 147.Burgess, R. H., 89.Burgstahler, A.W., 306.Burlant, W. J., 31.Burma, D. I?., 355.Burnell, R. H., 263.Burnelle, L., 48, 63, 105.Burnett, G. M., 28, 32, 34,Burns, E. A., 22.Burns, J . H., 462.Burns, J. J., 354, 356, 361.Burstein, S., 192, 240.Burton, K., 336.Burton, M., 50, 93.Burton, R., 153, 271.Burton, W. K., 76, 77.Burwell, R. L., 192.Busch, D. H., 401.Buselli, A. J., 33.Bush, W. V., 224.Bushby, S. R. M., 363.Busing, W. R., 435.Butenandt, A., 298, 300.Butler, J. A. V., 72, 331,Butt, L. T., 403.Buttery, R. G., 50, 255.Buurman, D. J., 289.Byers, F., 66.Byrne, W. L., 357.Bystrow, D., 121.Cabral, J. De O., 18.Cabrera, N., 76, 77.Cachia, M., 423.Cadogan, J. I. G., 209.Cady, G. H., 141.Cady, H. H., 162.Caflisch, E. G., 220.Caglioti, L., 240, 249, 292.Caglioti, V., 107.Cain, B.F., 245.Cainelli, G., 247.Cairns, T. L., 287.Cais, M., 245.Calderazzo, F., 152.Caldwell, E. V., 127.Calhoun, C. M., 192.Califano, S., 66.Calkins, R. C., 144.Callis, C. F., 14.Callomon, J. H., 97.Callomon, H. J., 60.Callow, R. K., 279, 280.Calvert, J. G., 41.Calvin, G., 164.Calvin, M., 92, 229, 286.251, 252, 263, 294.190, 192-198.35, 37.335.Buu-HoY, Ng. Ph., 300.Cambi, L., 163.Cameron, D. D., 284.Campbell, D. H., 117.Campbell, I. G. M., 217.Campbell, N. L., 124.Campbell, T. W., 29.Campbell, W. A., 139, 164.Canady, W. J., 13.Cannellakis, E. S., 332.Cannon, C. G., 66.Cannon, J. H., 426.Cannon, J . R., 293.Canonica, L., 303.Cantor, P. A., 286.Cantrall, E.W., 244.Caramazza, R., 13.Carassiti, V., 143.Carhino, L. A., 220.Carboni, R. A., 287.Cardani, C., 296.Cardenas, A. A., 422.Cardini, C. E., 303.Carduck, H. J., 154.Cardwell, H. M. E., 436.Careri, G., 80.Cariello, C., 148.Carlin, R. B., 197.Carlson, W. L., 193.Carlsson, I., 444.Carlston, R. C., 122.Carmack, M., 313.Carnall, W. T., 160.Caroti, G., 146.Carpenter, G. B., 97.Carpio, H., 285.Carr, M. D., 252.Carra, S., 172.Carrick, W. L., 196.Carroll, D. F., 134.Carson, R., 406.Carss, B., 353.Carter, A., 154.Carter, C., 177.Carter, E., 367. 'Carter, H. E., 370, 375.Casella, J., jun., 224.Caserio, F. F., 195.Caserio, F. F., jun., 231,Caserio, M. C., 179, 215,Casey, E. J., 79.Cashion, J.K., 83.Cason, J., 379.Castells, J., 275.Castle, R. N., 299.Castro, C. E., 258.Catalano, E., 105, 109.Caticha-Ellis, S. , 440.Caton, J. A., 24.Cava, M. P., 232, 270.Cavalca, L., 450, 453.Cavalieri, L. F., 338, 339.Cavill, G. W. K., 237.Cazes, J.. 218.Celmer, W. D., 229, 231.232, 269.261.Cerfontain, H., 90.Cernk, V. M., 408.Chackraburtty, D. M., 450.Chadha, N. R., 29.Chaigneau, M., 157.Chaikoff, I. L., 371.Chakravarti, B. N., 154,Chalandon, P., 120.Chamberlain, J. W., 245.Chambers, V. S., 33.Chamblin, V. C., 418.Champetier, G., 33.Chan, P. C., 361.Chan, W. R., 301.Chance, B., 349.Chanda, N. B., 320.Chandorkar, K. R., 302.Chaney, A., 318.Chang, F. C., 277.Chang, L. H., 385.Chang Shih, 207.Chanmugam, J,, 50.Chantry, G.W., 97.Chaplen, P., 303.Chapman, D. D., 242.Chapman, 0. L., 263, 264.Chargaff, E., 332, 336.Charlson, A. J.. 328.Charman, H. B., 217.Charton, M., 85.Chatt, J., 142, 144, 148,Chatterjee, A. K., 156.Chaudhuri, A. C., 244.Chaudhuri, N., 50.Chaudhry, G. R., 242, 300.Chaykin, S., 246.Cheesman, G. H., 140.Cheldelin, V. H., 359.Chemerda, J. M., 277, 284.Chen, D., 186.Chen, M. M., 181.Chen, Y. T., 362.Cheng, C. C., 299.Cheng, K. L., 417.Chesne, A., 160.Chesnut, D. B., 178, 460.Chetwyn, A., 13.Chiang, C., 356.Childs, R. C., 423.Chilton, H. T. J., 41.Chin-Hua Shih, 195.Chirnside, R. C., 414.Chisholm, M. J., 227.Chiurdoglu, G., 241.Chloupek, F., 186.Chmiel, C. T., 188.Cholnoky, L., 224.Chopard-dit-Jean, L.H.,Chopin, J., 300, 301.Choudhury, K. N., 356.Choudhury, P. K., 318.Choudhury, S., 250.Chowdhury, D. K., 211.156.164, 269.226472 INDEX OF AUTHORS’ NAMES.ChrCtien, A,, 140.Christ, C. L,, 432, 444.Christensen, B., 229.Christensen, D., 108.Christensen, G. M,, 319.Christie, M. I., 89.Christman, D. R., 304.Christofferson, G. D., 99,Christyakov, A. L., 268.Chu, P., 358.Chukhlantsev, V. G., 154.Chung, Y.-H., 407.Chupka, W. A., 112.Cialdella, C., 291.Cifonelli, J. A,, 316, 324,Cihal, Vl., 78.Cingi, M., 450.Ciuhandu, Gh., 419, 422.Cizek, J., 68.Claasen, H. H., 105, 139.Clampitt, B. H., 33.Clar, E., 256, 257, 266, 268.Clark, D., 450.Clark, D. J., 192.Clark, E. S., 166.Clark, H.C., 139, 156, 158.CIark, J., 299.Clark, J. R., 432, 444.Clark, K. J., 237.Clark, R. E. D., 394.Clark, R. J., 123.Clark, V. M., 272, 293.Clark, W. R., 359.Clarke, R. L., 231.Clark-Lewis, J. W., 285,Clayson, D. B., 381.Clayton, D. W., 314.Cleveland, P. C., 106.Clinch, J., 420.Clingman, W. H., 210.Closson, R. D., 218.Coates, G. E., 133, 164,Cocker, W., 239.Cockerill, D. A., 295.Cochfrugoni, J. S., 428.Cochran, J. C., 25, 180.Cochran, W., 433, 440.Coffey, R. S., 264.Coffield, T. H., 286.Coffman. D. D., 208, 209,214, 287.Coghi, L., 453.Cohan, N. V., 63.Cohen, A., 305.Cohen, D., 159.Cohen, I., 129.Cohen, S. G., 209.Cohen, S. R., 16, 22.Cohen, S. S., 356, 360.Cohn, W. E., 331, 333, 336.Colburn, C.B., 130.Coldwell, B. B., 395.Cole, J. E., 281.449.363.300, 301.Cole, L. J., 335.Cole, T., 97.Coleman, B. D., 32.Coleman, L. E., jun., 34.Coleman, W. E., 270.Colin, G., 124.Coller, B. A. W., 298.Collera, O., 309.Collier, H. B., 382,Collins, C. J., 196.Collins, D. A., 160.Collins, E., 27.Collins, F. D., 375.Collins, J. C., 281.Collis, M. J., 128.Collman, J. P., 143.Colton, R., 161.Coltone, M., 368.Comb, D. G., 358.Compton, V. B., 451.Comrie, A. M., 289.Comte, P., 302.Comyns, A. E., 146, 158.Connick, R. E., 12, 18, 26,Conney, A. H., 379.Connor, T. M., 98, 135.Conradi, J. J., 172.Conroy, H., 309.Considine, W. J., 229.Convery, R. J., 207.Conway, B. E., 74, 76.Conway, D. C., 86.Conway, J.B., 155.Cook, C. M., 144.Cook, D., 102.Cook, D. L., 276.Cook, G. B., 64, 105.Cook, W. H., 316.Cooke, R. G., 272, 305.Cookson, R. C., 233.Coombs, T. L., 349.Cooper, F. C., 298.Cooper, R. S., 70.Cope, A. C., 229,233, 236.Corbett, J. D., 122, 135,Corbett, R. E., 241.Corbridge, D. E. C., 131,Cordner, J. P., 200.Corenzwit, E., 451.Corey, E. J., 229, 244, 277,Corne, S. J., 290.Corner, E. D. S., 376, 385.Zornforth, J. W., 226, 247,Zornforth, R. H., 226, 247.Zorradini, P., 100, 155,:orran. P. G., 82.zorsaro, G., 24.Zorsmit, A. F., 464.Zory, C. F., 359.Zosta, G., 157.162.156.421, 442.284, 285.286, 287, 288.453.Costain, C. C., 95.Cotten, G. R., 35.Cotton, F. A., 98, 107, 123,Cottrell, T. L. 83.Coulon, R., 57.Coulson, C.A., 63, 176,178, 206, 436, 460.Coulson, R. A., 364.Couture, A. M., 192.Covington, E. J., 440.Cowan, M., 95.Cowie, J. M. G., 318, 319.Cowley, A., 156.Cowperthwaite, M., 87.Cox, A. P., 97, 100, 152.Cox, E. F., 53.Cox, E. G., 149, 452, 456,Cox, G. F., 205.Cox, H. C., 314.Cox, J. S. G., 247, 273.Cox, L. T., 144.Cox, R. A., 331, 336, 338.Coyne, D. M., 217.Cozzi, D., 420.CrabbC, P., 240, 247, 272,Cragg, L. H., 30.Craig, D. P., 134, 170, 176,Craig, L. C., 383.Cram, D. J.. 196, 259.Cramer, F., 292, 298.Cramer, R., 208.Cramm, D. J., 217.Crane, F. L., 226.Crane, R. K., 356, 365.Craven, B. M., 433.Crawford, B., 60, 62, 101,Crawford, B., jun., 62.Crawford, B. L., 56, 57, 58,Crawford, B.L., jun., 55.Crawford, J. V., 207.Crawford, V. A., 95.Cremlyn, R. J. W.. 192Cretcher, L. M., 193.Criegee, R., 214, 269.Cripps, H. N., 209, 224.Crisan, C., 218, 230.Cristol, S. J., 206, 233.Critchfield, F. E., 404.Crocket, D. S., 141.Crofts, P. C., 133.Cromer, D. T., 444, 450,Cron, M. J., 358.Crone, H. G., 49.Croon, I., 318, 322.Crosby, G. A., 90,Cross, A. D., 242.Cross, B. E., 246.Cross, P. C., 60.Crossman, W. I., 383.145, 147, 166, 271.457.301.251, 436.108.60, 61, 108.453, 459INDEX OF AUTHORS’ NAMES. 473Crow, T. I., 106.Cruickshank, D. W. J., 443,456, 457, 458.Crumley, P. H., 390.Crumps, J. W., 230.Crumpton, M. J., 359.Crunden, E. W., 192.Crundwell, E., 233.Crutchley, D. J., 296.Cserr, R., 218.Csuros, Z., 30.Cubicciotti, D., 112.Cullis, C.F., 160.Culvenor, C. C. J., 310.Cummings, C. S., 358.Cummings, W., 302.Cumper, C. W. N., 102.Cundiff, R. H., 404.Curl, R. F., 98, 107.Curran, C., 145.Currell, D. L., 255.Curry, H. L., 19.Curry, N. A., 436.Curtin, D. Y., 230, 233,Curtis, N. F., 161.Cuthbert, J., 440.Cuvigny, R., 221.Cuvigny, T., 218, 230.Cvetanovic, R. J., 54, 89.Cyvin, S. C., 101.Czamanske, G. K., 447.258.Daane, A. H., 154, 448.Daasch, L. W., 134.D’Adamo, A. F., 304.Daev, N. A., 237.Dahl, L. F., 451.Dahmen, E. A. M., 413.Dahn, H., 195.Dailey, B. P., 102, 460.Dainton, F. S., 27, 32.Dalby, A., 357.Dalby, F. W., 97.Dale, J. W., 139.Dalgliesh, C. E., 295, 382.Dallinga, G., 27, 174.Daly, J.W., 237.Dalziel, J., 161.Damaskin, B., 75.Dammers-de Klerk, A., 93.Damon, E. B., 112.Danby, C. J., 86.Daniels, M., 334, 336.Danilova, V. N., 121.Dannals, L. E., 33.Dannenberg, H., 274.Danti, A., 104, 107.Danyluk, S. S., 10.Danzig, M. J., 228.Danzuka, T., 418.Darrin, M., 157.Das, H. S., 402.Das Gupta, P. C., 318, 319,Datta, A. G., 363.323, 325.Datta, S. P., 8, 9.Dauben, H. J., 153, 271.Dauben, W. G., 239, 283.Daudel, R., 178.David, I. A., 281.Davidson, J. M., 118.Davidson, J. N., 337.Davidson, N., 88.Davidson, N. R., 97.Davies, A. G., 166, 182,188, 212, 213, 214, 217,409.Davies, C. W., 19, 20, 24.Davies, D. A. L., 317, 325,Davies, D. I., 207.Davies, D. R., 131, 341,Davies, E.W., 21.Davies, M., 107, 435.Davies, N. R., 144.Davies, P. W., 105.Davies, R. O., 82.Davies, W. , 288.Davies, W. G., 21.Davis, A. D., 411.Davis, B. D., 357.Davis, E. F., 331.Davis, M. M., 14.Davis, R. E., 212.Davison, P. F., 331.Davison, W. H. T., 423.Davoll, J., 299.Dawber, J. G., 129.Dawson, C. R., 352.Dawson, L. R., 19.Dawson, R. F., 304.Dawson, R. M. C. , 367,370,Day, A. C., 242.Day, A. R., 186, 299.Day, J. N. E., 190.Day, M. C., 417.Dayton, P. G., 354, 361.Dean, C., 433.Dean, F. M., 250.Dean, M. H., 204.Dearing, G. G., 316.Dearnaiey, D. P., 289.de Bethune, A. J., 391.de Boer, E., 172, 174.de Boer, J. H., 123.de Bruijn, S., 173.de Bruyn, P. L., 71.Debuch, H., 373, 374.Decius, J. C., 104, 130.Decker, B.F., 114, 440,Decker, P., 382.Decot, J., 241.De Eds, F., 301, 328.Deford, D. D., 428.de Garilhe, M. P., 342.Degerman, G., 454.de Graaf, G. B. R., 51.Dehm, H. C., 281.357, 359.342, 442.371, 327.446.Dehn, J. S., 182.de Iongh, H., 366.Deissmann, W., 114.de la Fuente, G., 356, 359.Delahay, P., 68, 69, 72, 73,74.de la Mare, P. B. D., 179,183, 193, 195, 297.de Laurent, C., 446.De Ley, J., 363, 364.Dellobelle, J. , 244.Deluzarche, A. R. J., 127.de Mayo, P., 242, 249.Demok, E., 226.den Hertog, H. J., 209, 289.Denney, D. B., 182.Dennison, D. M., 62.Deno, N. C., 179, 198.Denss, R., 314.De Pree, D. O., 218.De Prima, C. R., 57.de Paulet, A. C., 273, 278.De Renzo, E. C., 352.Derevitskaya, V., 318.Dermer, 0. C., 207.Desaulles, P. , 284.Desjobert, A., 190, 371.Deskin, W. A., 140.De Tar, D. F., 207, 254.Dev, S., 285.Dever, J. K., 119.Devin, C., 128.Deviney, M. L., 9.de Vries, A,, 434,Dewar, M. J. S., 172, 174,176, 198, 205, 265, 285.Dewhirst, K. C., 259.Dhar, M. L., 229, 242.Dhar, M. M., 242.Dhar, S. K., 125.Diamond, R. M., 17.Diassi, P. A., 307.Dibeler, V. H., 88.Dickel, D. F., 308, 309.Dickens, F., 353.Dickens, J. E., 25.Dickens, P. G., 82, 174.Dickerman, S. C., 206,Dickerson, R. E., 100, 115,Dickey, E. E., 303.Dickson, A. D., 57.Diebel, R. F., 8.Diecke, G. H., 103.Diehl, H., 417.Diehl, P., 98.Dieminger, K., 294.Diener, W., 119.Dietrich, L. S., 352.DiGiorgio, V. E., 98.Dils, R.R., 376.Dilaris, I., 192.di Mayorca, G., 335.Dimaras, P. I., 442.DiMilo, A. J., 200.207.441474Dinsmore, H. L., 61.Dintzis, H. M., 466.Diorio, A. F., 442.Dippy, J. F., 11.Dirkse, T. P., 79.Dische, Z., 324.Ditter, J. F., 108.Dittmer, J. C., 366, 369.Dixon, B. E., 392.Dixon, K., 424.Dixon, M., 347, 352.Dixon, R. N., 97.Djerassi, C., 228, 235, 240,245, 247, 248, 272, 273,285, 301.Dobbs, A. G., 392.Dobriner, K., 56.Dobson, N. A., 290.Dodd, G. M., 296.Dodd, R. E., 37, 39.Dodson, R. M.. 285.Dorfel, H., 317, 363.Dopke, W., 311.Doering, C. H., 274.Doering, W. von E., 50, 51,52, 53, 184, 214, 216,217, 224, 252.Dogonadze, P. P., 69.Dohmen, H., 369.Doi, K., 263.Doisy, E. A., 275.Doisy, E. A., jun., 275.DolejS, L., 240, 241.Dolgoplosk, B.A., 30.Dolin, P., 74.Domagk, G. F., 355.Donaldson, N., 25 1.Donnelly, D. M. X., 300.Donnet, J. B., 36.Donohue, J., 99, 335, 441,Donovan, F. W., 240.Doppler, G., 398.Dorfman, A., 316, 363.Dorfman, R. I., 284.Dornberger-Schiff, K., 437.Dornow, A., 254.Doron, V., 125.Doss, K. S. G., 69.DostAl, K., 138.Dostrovsky, I., 190.Doty, P., 338, 341.Doudoroff. M., 356.Dougill, M. W., 446.Douglas, A. E., 96.Douglas, A. S., 433.Douglas, J., 346.Dousek, F. P., 30.Douste-Blazy, L., 368.Dowding, A. L., 188.Downer, J. M., 35.Downes, A. M., 208.Dows, D. A., 83.Doyle, W. L., 155.Drabkina, L. E., 160.Drago, R. S., 114, 164.443.'DEX OF AUTHORS' NAMES.Draus, F., 187.Drayson, F.K., 228.Drefahl, G., 221.Dreiding, A. S., 233, 252.Dreiding, M. S., 303.Dreisbach, L., 423.Drenth, W., 434.Dresia, H., 427.Drew, C. M., 41.Dreyfuss, P., 33.Drikamer, H. G., 143.Drill, V. A., 272.Druey, J., 285, 299.Drummond, D. W., 317,Drummond, J. L., 159,160.Drury, D. R., 359.Dry, L. J., 311.Drysdale, J. J., 264.Dubois, J. T., 86.Duchesne, J., 48, 105.Dutting, D., 235.Duff, R. B., 364.Duffield, W. D., 408.Duggan, E. L., 338.Duinker, P. M., 212.Duke, F. R., 157.Dull, M. F., 317.Duncan, J. F., 16, 196.Duncanson, L. A., 118,Dunin. C. I., 20.Dunitz, J. D., 436, 453,Dunnn, A. F., 57.Dunn, D. B., 331, 334.Dunsmore, H. H., 10.Dupire, F., 412.Dupont, G., 244.Du Pr6, E. F., 316.Durand, H. W., 317.Durand, M.H., 221.Durand-Dran, R., 207.Durham, R. W., 41.Durie, R. A., 96.Durr, K., 300.Durrell, W. S., 34.Durso, D. F., 328.Dusza, J. P., 283.Dutta, P. C., 244.Dutton. G. G. S., 322.Dutton, H. J., 369.Duval, C.. 143.DvorbkovA, J., 315.Dvorken, L. V., 258.Dvornik, D., 312, 313.Dyall, L. K., 261.Dyatkina, M. E., 271.Dyke, G. V., 390.Dylion, C. M., 307.Dymova, T. N., 116.Dyne, P. J., 48.Dziemkn, R. L., 309.363.164, 165.461, 464.Eaborn, C., 125, 217.Eade, R. A., 249.Eagle, H., 356.Earhart, H. W., 252.Earl, N. J., 289.Earnshaw, A., 143.Eastham, J. F., 253.Eastman, R. H., 237.Eaves, D. E., 29.Eberhardt, W. H., 23.Ebied, F. M., 217.Ebsworth, E. A. V., 126.Eckert, G., 419.Economy, J., 232.Eddy, C.W., 382.Edelmann, K., 31.Edge, N. D., 290.Edgren, R. A., 276.Edmison, M. T., 207.Edward, J. T., 189.Edwards, L. J., 187.Edwards, 0. E., 245, 312,Edwards, T. E., 320, 328.Edw-xds, T. H., 100.Edwards, W. R., 252.Effinger, J., 208.Egerton, M. J., 375.Eggers, D. F., 58, GO,Eggers, H., 267.Eggertson, F. T., 412.Ehrenstein, M., 272.Ehrlich, H. W. W., 458.Ehrlich, P., 114, 338.Eia, G., 36.Eichenberger, K., 299.Eichner, M., 162.Eick, H. A., 154.Eigen, M., 26.Eisen, H. N., 359.Eisenberg, F., 354.Eisenberg, F., jun., 361.Eisenbraun, E. J., 236.Eisenstadt, M., 112.Eisinger, J. T., 95.Eisner, U., 286, 293.Eiszner, J. R., 50.Ekstedt, D. L., 117.El-Abbady, A. M., 206.El Aggan, A. M., 19, 155.Elderfield, R.C., 295.Eliel, E. L., 179, 184, 209,Ellict, J. S., 12.Elliott, W. H., 275.Ellinger, F., 440.Ellis, B., 276.Ellis, K. C., 464.Ellison, F. O., 63.Elphimoff-Felkin, I., 278.El Raheem, A. A. A.,Els, H., 229, 231.Elsasser, W. M., 58.El Sayed, M. F., 107.Elvidge, J. A., 298.Elving, P. J.. 68.313.61.211, 234.398INDEX OF AUTHORS’ NAMES. 475Emelkus, H. J., 126, 127,139, 147, 155, 158, 167.Emerson, 0. H., 301.Emery, A. R., 106, 108,Emmons, W. D., 129, 286.Emsley, M. W., 457.Ende, H., 299.Engel, C. R., 277.Engelbrecht, A., 138.Engelhardt, V. A., 287.Engelsma, J. W., 208.England, B. D., 252.Englesberg, E., 359.Enklewitz, M., 354.Ennor, K. S., 330.Enslin, P. R., 249.Entschel, R., 224.Eppstein, S.H., 284.Epstein, J., 25.Erametsa, O., 136.Erbland, J., 374.Ercoli, A., 277.Ercoli, R., 152.Erdey, L., 428.Erdtman, H., 242.Eriks, K., 100, 115, 441,Ermolaev, V., 90.Errede, L. A., 33, 48,Ershler, B. V., 74.Erskine, R. L., 286.Eschenmoser, A., 265.Ess, R. J., 212.Essler, H., 152, 271.Eugster, C. H., 314.Evans, A. G., 23.Evans, C., 361.Evans, D. L., 358.Evans, E. E., 324.Evans, H. T., 432.Evans, H. T., jun., 444,Evans, J. E. F., 117.Evans, J. I., 10.Evans, J. M., 320.Evans, J. V., 197.Evans, W. C., 304.Evans, W. L., 179.Evelyn, S. R., 302.Everest, D. A,, 419.Everett, D. H., 9, 10.Evers, E. C., 118, 125,Evett, J. W., 417.Evstigneeva, R. P., 305.Excell, B. J., 315.Eyring, H., 44, 80, 90, 108,Fabbri, G., 107.Faber, G., 327.Fabian, H., 424.Fagerlund, U.H. M., 283.Fahey, R. C., 180.117.442.260.445.130.177.Fainberg, A. H., 25, 180,Fairbairn, D., 325.Fairbrother, F., 121, 155,Faircloth, R. L., 69.FajkoS, J., 276.Faktor, M. M., 154.Falconer, E. L., 318.Fales, H. M., 311. 6Falk, M., 12, 13.Fang, F. T., 181, 209.Farag, A., 409, 410.Farber, M., 214.Farkas, E., 272.Farkas, L., 300.Fassel, V. A., 424.Fateley, W. G., 107, 108.Faure, M., 370, 372.Fava, A., 183.Fava, G., 453, 460.Favini, G., 172.Fayard, F., 36.Feakins, D.. 10.Feates, F. S., 10.Fedotov, N. S., 118.Feelenberg, A. P., 96.Feely, W., 289.FCher, F., 136, 137.Feigl, F., 395, 396, 427.Feil, D., 464.Feingold, D. S., 325.Feinstein, A., 187.Feldman, U., 211, 254.Feldman, W.R., 194.Felsenfeld, G., 341.Felsing, W. A., 9.Feltz, A., 132, 133.Feminella, J, L., 369.Fenton, S. W., 270.Ferguson, J., 439.Ferguson, R. B., 444.Fergusson, J. E., 161.Ferington, T., 29.Ferles, M., 290.Ferrari, A., 450.Ferrier, R. J., 323, 327.Ferris, J. P., 313.Ferris, L. M., 18.Ferro, R., 451.Ferstandig, L. L., 219.Fessenden, R. W., 107.Fetizon, M., 244.Fewster, J. A., 359.Ficini, J., 218, 230.Field, F. H., 45, 47.Field, L., 214.Fielding, H. C., 303.Fields, P. R., 160.Fieser, L. F., 206, 275, 277,Fife, W., 197.Figgis, B. M., 143.Fike, C. T., 72.Filimonow, W., 121.Finch, A., 119.181.156.379.Fink, W., 142.Finkelstein, M., 214.Finkelstein, R., 425.Finkle, B.J., 361.Finnegan, R. A., 213, 286.Firth, M. E., 286.Fischer, A., 187.Fischer, B. A., 295.Fischer, E. H., 346.Fischer, E. O., 151, 152,Fischer, F. G., 317, 363.Fischer, H., 224, 254.Fischer, L., 19, 67.Fish, R. W., 124, 252.Fish, W. A., 283.Fishman, J., 272, 276.Fitts, D. D., 258.Fitzpatrick, J. T., 294.Flade, F., 78.Flaherty, P. H., 19.Flautt, T. J., 131.Fleischmann, M., 69, 73,Flesch, G. D., 157.Fletcher, J. M., 149, 157.Fletcher, W. H., 104.Fleury, J. P., 33.Fleury, P., 371.Fliege, E., 137.Flitsch, R.. 330.Flores, S. E., 301.Florianovich, G. M., 76.Flower, R. H., 137.Flowers, H. M., 228.Flowers, R. H., 14.Fluck, E., 136.Foldi, Z., 289.Foppl, H., 445.Fogg, D. N., 421.Fogg, P.G. T., 82.Fokina, L. A., 75.Folch, J., 365, 366, 367,369, 370, 371.Fonken, G. S., 275.Fono, A., 203, 214, 230.Force, C. G., 295.Ford, D. L., 237.Ford, M. C., 29, 203.Fornaini, G., 357.Fornwalt, D. E., 425.Forrest, H. W., 299.Forsberg, H., 449.Forst, W., 86.Forsyth, W. G. C., 301.Foss, O., 137.Foster, A. B., 193, 324,325, 328, 330.Fouquey, C., 360.Fournier, J., 239.Fowden, L., 183.Fowler, L. R., 314, 315.Fowles, G. W. A., 127, 145,Fox, T. G., 32.Frade, H. F., 217.153, 271.74, 77.1564’76 INDEX OF AUTHORS’ NAMES.Francis, J. E., 314.Franck, U. F., 78, 79.Frank, F. C., 76.Frank, R. L., 207.Franklin, J. L., 45, 47,88, 175, 331.Franzl, R. E., 374.Fraser, R. R., 233.Frasson, E., 165, 300, 453.Fray, G. I., 237.Frazer, J.W., 119.Frazer, M. J., 120.Frazier, R. G., 420.Freamo, M. , 48.Freeman, G. R., 86.Freeman, J. H., 138.Freeman, R., 26.French, C. M., 10, 19, 118.French, D. M., 28.French, W. N., 292.Fresco, J. R., 335, 341.Freudenberg, K., 285, 302Freund, A. M., 338.Freund, H., 415.Frey, A., 306.Frey, A. J., 307.Frey, H. M., 49, 51, 89.Frey, S. W., 25, 180.Freyberger, W. L., 71.Fridovich, I., 352.Fridrichsons, J., 464.Fried, J., 272.Friedel, R. A., 425.Friedman, H. A., 158.Friedman, S., 210.Friend, J. P., 102, 460.Friess, S. L., 192.Frittum, H., 35.Fritz, H., 309.Fritz, H. P., 153, 271.FrkAfi, J., 138.Frohlich, W., 152, 271.Frolen, L. J., 23.Froment, G., 318.Fromme, I., 325.Frondel, C., 445.Frost, D.V., 369.Frost, R. E., 126.Frueh, A. J., jun., 447.Frumkin, A. N., 69, 70,71, 72, 73, 74, 75.Frush, H. L., 316.Fry, A., 196.Fry, J. S., 125.Frydman, M., 13.Fryth, P. W., 298.Fueno, T., 31.Fuger, J., 160.Fuginaga, T., 406.Fuhner, H., 382.Fujii, Y., 216.Fujimori, E., 92, 93.Fujimoto, S., 34.Fulkerson, B., 318.Fuller, K. W., 316.Funabashi, K., 177.Funamizu, M., 263.Funk, F. H., 295.Funk, H., 156.Funt, B. L., 27.Fuoss, R. M., 18, 19.Furberg, S., 442, 464.Furman, N. H., 69.Furst, K. J., 254.Furst, M., 92.Furukawa, J., 31, 213.Furuoya, T., 91.Fusco, R., 288.Futterman, S., 354.Gabbard, R. B., 277.Gagnaux, P., 121.Gainer, H., 205.Galatry, L., 57.Gallagher, B. S., 272.Galli, J.R., 33.Gallo, A., 320.Gallup, G. A., 49, 61.Gamboni, G., 230.Gamlen, G. A., 165.Gamellin, C. R. , 265, 266.Ganguly, A. K., 301.Garcia, M. D., 372.Garcia-Fernandez, H., 136.Gardell, S., 315.Gardi, R., 277.Gardiner, S. D., 393.Gardner, A. W., 69, 159.Gardner, D. M., 130.Gardner, J. A. F., 263.Gardner, J. N., 289.Gardner, P. D., 267.Gardner, R. D., 263.Gardner, W. E., 435.Garland, R. B., 282.Garn, P. D., 407.Garner, A. Y., 53.Garner, C. S., 144.Garner, E. F., 329.Garner, R. H., 232.Garnett, J. L., 395.Garrett, E. R., 187.Garst, J. F., 28, 205.Garton, G., 449.Garver, E. E., 139.Garvin, D., 84.Gaspert, B., 244.Gasser, R. P. H., 26.Gatehouse, B. M., 145,146, 149, 158, 165.Gates, H. S., 20.Gatti, R., 160.Gattow, G., 444.Gaudemar, M., 219.Gauhe, A., 326.Gaunt, J., 449.Gavrilenko, V.V., 146.Gawron, O., 187.Gallaghan, J., 118.Gaydon, A. G., 85.Geary, A., 78.GBczy, I., 30.Geddes, A. L., 317.Gee, G., 136.Gee, M., 327.Geerdes, J. D., 318, 319.Geering, E. J., 25.Gehman, H., 32.Gehrmann, G., 373.Geiduschek, E. P., 338.Geiger, F. E., 95.Geilmann, W., 391.Geissman, T. A., 250, 301.Gelinek, J., 135.Geller, S., 444, 451.Gel’man, A. D., 159, 160.Gender, W. J., 224.Gentles, M. J., 253, 274.George, J. H. B., 23.George, M. V., 218.George, P., 344.George, W., 98.George, 2. M., 89.Georgian, V., 278.Gerber, H., 138.Gerischer, H., 69, 73, 74,Gerlach, J. L., 420.German, D. E., 33.Gerrard, W., 114, 118, 120,Gersmann, H.R., 34.Geske, D. H., 140.Gesser, H., 49, 91.Ghanem, N. A., 36.Ghiorso, A., 160.Giacometti, G., 39, 163,165, 452. 453.Gibb, T. R. P., 155.Gibor, A., 394.Gibson, G., 158.Gibson, J. F., 466.Gierer, A., 333.Gigu&re, P. A., 12, 13, 86,Gilbert, B., 463.Gilbert, D. X., 117.Gilbert, E. C., 130.Gilbert, G. A., 315, 318.Gilbert, J. N. T., 249.Gilbert, W. W., 264.Gilham, P. T., 337.GiIkerson, W. L., 19.Gill, E. K., 86, 91.Gill, J. B., 164.Gill, N. S., 143, 161.Gillespie, R. J., 14, 111,Gillette, J. R., 379.Gillham, J. K., 322.Gilman, H., 118, 218, 255.Gilroy, H. M., 407.Ginger, R. D., 186.Ginoza, W., 333.Ginsburg, A., 355.Ginsburg, V., 354.Gintz, F. P., 128.Siradot, P. R., 116.77.121, 126.141.137, 288INDEX OF AUTHORS’ NAMES.477Girard, C., 197.Girod, E., 314.Gioumousis, G., 45.Giuran, V., 419.Glantz, M. D., 366.Glaser, A., 298, 299.Glasstone, S., 80.Glaudemans, C. P., 322.Glazebrook, A. L., 49.Glazebrook, R. W., 288.Glazer, H., 64.Glazier, E. R., 285.Glemser, O., 115, 137, 166,Glick, H. S., 87.Gliemann, G., 106.Glogger, I.. 189.Glover, E. E., 297.Gmelin, R., 229.Goble, A. G., 157.Goddard, D. R., 128.Goddu, R. F., 423.Godtfredsen, W. O., 307,Goedkoop, J. A., 454.Gohr, H., 79.Goeppert-Mayer, M., 170.Goering, H. L., 182, 197,Gokhstein, Ya. P., 68.Gold, J., 228.Gold, V., 179, 187, 190,199, 209, 252.Goldblatt, M., 106.Golden, J. A., 83.Golden, J. H., 292.Golden, S., 202.Goldfarb, T.D., 463.Gol’dfarb, Ya. L., 288.Goldfinger, G., 32.Goldstein, D., 395, 396.Goldstein, I. J., 327, 329.Golebieski, A., 174.Golike, R. C., 65.Golova, 0. P., 318.Golton, A. V., 60.Gomer, R., 37.G6mez-S6,nchez, A., 327.Gompper, R., 291.Gonchareva, Ye. Ye., 320.Goode, W. E., 32.Goodman, C. H. L., 447.Goodman, L., 330, 334.Goodwin, T. H., 101.Goody, R. M., 60.Gordon, A. R., 19.Gordon, A. S., 39, 41.Gordon, C. L., 390.Gordon, W. A., 424.Gordy, W., 95.Gore, I. Y., 226.Gore, P. H., 187, 286.Gorenbein, Ye. Ye., 121.Gorin, P. A. J., 328.Gorsich, R. D., 218, 255.Gorton, B. S., 299.419.308.217.Gorum, A. E., 447.Gottlieb, 0. R., 291.Gottling, W., 408.Gottschalk, G., 397.Goubeau, J., 107, 108, 118.Gould, S., 43.Goutarel, R., 308, 309.Govindachari, T.R., 242,Gowan, J. E., 300.Gowenlock, B. G., 41.Graber, R. P., 277.Graboyes, H., 299.Granacher, J., 98.Graff, W. S., 166.Graham, G. D., 20.Graham, J. R., 19.Graham, W. A. G., 117.Grahame, D. C., 71, 72.Gramshaw, J. W., 302.Grange, P., 141.Grant, D. F., 464.Grant, D. W., 159.Grant, P. M., 327.Grant, W. K., 460.Grard, F., 50.Gratch, S., 32.Gray, C. H., 292.Gray, G. M., 366, 374.Gray, J. J., 154.Gray, P., 110, 129.Gray, S., 218.Grazi, E., 357.GrdeniE, D., 155.Greasley, P. M., 193.Green, B., 245.Green, D. H., 31.Green, F. C., 237.Green, L. G., 112.Green, &I., 217, 360.Green, M. L. H., 151,Green, P. B., 300.Greenbaum, M. A., 258.Greenberg, D.&I., 375.Greenberg, G. R., 353.Greene, F. L., 316.Greene, J. L., 254.Greenfield, H., 210.Greenhalgh, R., 314.Greenwood, C. T., 318,319,320.Greenwood, N. N., 99, 119,120, 121, 122, 131, 132.Gregoriou, G. A., 284.Gregory, H., 223.Gregory, N. W., 162.Grelecki, C. J., 48.Gresser, W., 317.Griesshammer, H., 150,Griffin, B. E., 340.Griffing, V., 82.Griffith, J. S., 344.Griffith, W. P., 148, 149.Griffiths, H. W., 119.306.153.151.Griffiths, V. S., 19, 390.Grigorovich, A. H., 138.Grigor’yev, A. I., 113.Grimes, J. N., 383.Grimes, W. R., 158.Grimison, A., 288.Grimshaw, J., 303.Grisebach, H., 302.Griswold, E., 122, 123.Grob, C. A., 185, 204, 214,230, 259, 278, 294.Grob, E. C., 225.Groeneveld, W.L., 134.Grranvold, F., 447.Grollman, A., 354.Grosse, A. V., 155.Grossman, J., 163.Grossman, J. J., 144.Grove, J. F., 246.Grover, K. C., 401.Gruber, A. H., 318.Gruber, J., 146.Gruen, H., 230, 258.Grunbaum, B. W., 338.Grundemeier, W., 198.Grunwald, E., 9, 10, 17,Grunze, H., 131, 132.Gryszkiewicj - Trochimow -Grzybowski, A. K., 8, 9.Gschneidner, K., 154.Gschneidner, I<., jun., 448.Gubler, A., 284.Gudmunsen, C. H., 197.Gunthard, H. H., 438.Guenther, A. H., 96.Guenther, F. O., 393.Guex, W., 226.Guggenheim, E. A., 8, 16.Guillaume, J., 409.Gulyas, E., 146.Gumprecht, W. H., 291.Gunn, S. R., 112.Gunning, H. E., 91.Gunsalus, I. C., 255.Gunstone, F. D., 227.Gunthard, H. H., 266.Gut, M., 284.Guthrie, R.D., 329.Gutman, A. B., 331.Gutmann, V., 111.Gutowsky, H. S., 26, 202.Gutsche, C. D., 233.Guy, M. J., 420.Gwynn, D., 197.Haas, C., 65,Haas, H. C., 28.Haas, H. J., 210.Haase, H., 201.Haber, R. G., 234,Hackerman, N., 78.Hackspill, L., 18.Haden, W. L., 37.Hadler, H. I., 381,181.ski, O., 201478 INDEX OF AUTHORS' NAMES.Hadorn, H., 400.Hadwick, T., 188, 196.Hadzi, D., 66.Hafliger, F., 314.Haendler, H. M., 141, 448.Hafner. K., 266, 267.Hagberg, O., 447.Hahn, H., 446, 447.Hahn, R. B., 397.Hahn, T., 455.Hahn, W., 213.Haines, R. M., 29, 205.Hair, M. L., 161, 162.Haissinsky, M., 139.Hajdu, S., 369.Hakkila, E. A., 163.Halevi, E. A., 63, 180.Hall, C. D., 214.Hall, G. E., 367, 371.Hall, J. R., 99, 107, 121,Hall, N.F., 144.Hallam, B. F., 150.Hallam, H. C., 95.Hallam, H. E., 66.Halleux, A., 256.Halpern, B., 249.Halpern, O., 235, 272, 303.Halpern, V., 235, 272.Halsall, T. G., 244, 284.Halteman, E. K., 450.Ham, E. A., 230.Hamann, S. D., 35.Hamer, W. J., 9.Hamill, W. H., 47.Hamilton, J., 414.Hamilton, J. K., 322.Hamilton, L. D., 338.Hamilton, W. C., 63, 443.Hammer, C. F., 60.Hammick, D. LI., 198.Hammond, G. S., 28, 181,197, 198, 205.Hanack, M., 234.Hanahan, D. J., 366,368-Hancock, E. B., 193.Hancock, J. E. H., 270.Handler, G. S., 177.Handler, P., 352.Hands, A. R., 290.Hands, G. C., 392.Hanewald, K. H., 283.Hank, F., 464.Hanks, P. A., 82.Hannah, R. W., 60.Hansen, J. H., 232.Hansen, R. S., 72.Hanson, A.W., 445.Hanson, G. E., 62.Hanson, H., 61.Happold, F. C., 347.Haq, S., 327.Haraldsen, H., 142, 447.Haranath, P. B. V., 96.Harborne,. J. E., 300, 303.147.371.Hardegger, E., 208, 290,Hardie, D., 447.Hardie, R. L., 205.Harding,'M. M., 167.Hardt, H. D., 113.Hardvik, A., 137.Hardy, C. J., 157.Hardy, K. D., 234.Hardy, R., 35.Harfenist, M., 211.Hargreaves, A., 443, 458.Hargreaves, G. B., 147,Hariharan, T. A., 105.Harland, B. F., 352.Harlow, G. A., 404.Harman, D., 213.Harman, R. E., 228, 230.Harned, H. S., 67.Harper, B. J. T., 304.Harper, D. C., 184.Harper, K. H., 379.Harris, A., 245, 246.Harris, C. M., 165.Harris, G., 245.Harris, G. B., 301.Harris, G. S., 132, 133.Harris, H., 358.Harris, J.J., 119.Harris, M. M., 179.Harris, W. E., 407.Harris, W. S., 23.Harrison, B. C., 116.Harrison, I. T., 282, 283.Harrow, L. S., 316.Hart, F. A., 148.Hart, H., 124, 252, 300.Hart, R. G., 159, 333.Harteck. P., 88.Hartford, W. H., 157.Hartkamp, H., 391.Hartman, L., 228.Hartmann, H., 106, 142.Hartree, E. F., 373.Hartshorne, N. H., 136.Hartwell, J. L., 285.Harvey, J., 313.Harvey, R. G., 212.Harwell, S. O., 355.Hasegawa, S., 30.Hasegawa, T., 284.Hashimoto, Y., 249.Haskins, J. F., 317, 413.Haslam, J., 414.Hass, D., 133.Hasse. H., 269.Hasse, K., 232.Hassall, C. H., 301.Hassel, O., 140, 462, 463.Haszeldine, R. N., 137,Hatchard, W. R., 207.Hatefi, Y., 226.Hathaway, B. J., 129,148, 165, 166.314.158.139.Hathway, D. E., 301, 302.Hauptman, H., 432.Hauser, A., 262.Hauser, C.R., 216, 253,Hauser, G., 360.Hauser, R., 261.Havens, R., 60.Havens, R. J., 60.Havinga, E., 283.Havinga, E. E., 96, 448.Hawke, J. G., 188.Haworth, W. N., 356.Hawthorne, J. N., 370,Hay, J. E., 300.Hayano, M., 284.Hayaishi, O., 386Hayashi, A., 321.Hayashi, K., 28.Hayatsu, R., 283.Hayes, A., 292.Hayes, H. F., 155.Hayes, W. K., 239.Haynes, G. R., 263.Haynes, H. F., 305.Haynes, L. J., 300Hazen, G. G., 277.Heacock, R. A., 297.Head, F. S. H., 328.Healy, R. M., 120.Healy, T. V., 159.Hearne, J. A., 12.Heath, E. C., 355, 360.Hebdon, E. A., 128.Hecht, L. I., 332.Heck, H. E., 290.Heckert, R. E., 287.Heckt, F., 410.Hedberg, K., 102.Hedberg, L., 102.Heeks, J.S., 175.Hefferman, M. L., 172,298.Heichlin, L., 368.Heidelberger, C., 379, 381.Heidelberger. M., 324, 325.Heider, J., 200.Heilbron, (Sir) I., 225.Heilbronner, E., 265.Heilmann, J., 391.Heim, R., 306.Hein, F., 152.Heine, H. W., 181.Heller, C. A., 39, 41.Heller, K., 284.Hellman, N. N., 320.Hellmann, H., 364.Helmreich, E., 359.Helwig, H. L., 390.Hemily, P. W., 445.Hems, G., 334.Henbest, H. B., 226, 235,236, 275.Henderson, W. A., 53.Henglein, F. M., 292.Hennart, C., 403.258.371INDEX OF AUTHORS’ NAMES. 479Henrich, G., 36.Henry, P. M., 25.Henry, R. A., 418.Heppel, L. A., 330,339,340.Hepworth, M. A., 162, 448.Herber, R. H., 120.Herbert, J. B. M., 191.Herbots, J., 404.Herbst.P., 223.Herfert, R. E., 446.Herington, E. F. G., 10.Herk, L., 87, 208.Herlinger, H., 291.Herman, R., 58, 60, 61, 80.Herman, R. C., 61.Hermann, G., 105.Hermans, J., 338.Hernandez, T., 364.Herout, V., 238, 239, 241.Herold, A., 124.Herran, J., 301.Herrmann, E., 286.Herron, J . T., 88.Hers, H. G., 354.Herschbach, D. R., 102,Hershaft, A., 122.Hershberg, E. B., 253, 274,Hertler, W. D., 220.Hertler, W. R., 277.Herwig, \IT., 152, 222.Herz, J., 32.Herz, W., 241, 266.Herzberg, G., 95, 176.Herzfeld, K. F., S2.Herzog, G., 121.Herzog, H. L., 253, 274.Herzog, H. M., 317.Herzog, S., 154, 157.Hesford, E., 18, 159.Heslinga, L., 222.Hess, H., 283.Hess, H. J., 215.Hessel, L. W., 372.Hetherington, G., 128.llettler, H., 131.Hetzer, H.E., 14.Heublein, G., 221.Heumann, T., 78.Heusler, K., 282.Heusner, A., 263.Heussler, K., 79.Hewitt, B. R.. 316.Hewitt, G. C., 327.Hexter, R. M., 463.Hey, D. H., 203, 207, 306.Heyns, K., 358, 364.Heyworth, R., 359.Hiatt, G. D., 318.Hiatt, H. H., 353, 355.Hickey, F. C., 283.Hickman, J., 354, 362.Hickman, J. R., 217.Hickner, R. A., 206, 221.Hickson, D. A., 72.109.275.Hieber, W., 146, 147.Hiebert, G. L., 65.Higgins, C. E., 401.Higginson, W. C. E., 130.High, J. H., 421.High, L. B., 247, 273.Highet, R. J., 281, 311.Higson, H. M., 367, 371.Htguchi, J., 63, 98.Hilbert, G. E., 319.Hildinger, M., 364.Hilgetag, G., 217.Hill, R. K., 306.Hill, S., 392.Hilmoe, R. J., 339.Hilton, J., 190.Himes.R. C., 101.Hindman, J. C., 159.Hinds, G. P., jun. 412.Hine, J., 48, 51, 200.Hinshelwood, (Sir) C. N.,86, 198.Hinterberger, H., 237.Hirai, N., 30.Hirn, C. F., 399.Hirota, E., 97, 101, 109,Hirschfeld, H., 282.Hirschfeld, M. A., 59.Hirschfelder, J. O., 44.Hirschmann, F. B., 280.Hirschmann, H., 280.Hirschmann. R., 277.Hirshfeld, F. C., 441.Hirshfeld, F. L., 100, 115,Hirshon, J. M., 162.Hirst, E. L., 317, 320, 321,Hirst, J., 304.Hisatsune, I. C., 60, 61.Hiser, R. D., 294.Hitchcock, D. I., 13.Hitchings, G. H.. 299.Hitzemann, G., 136.Hlavka, J. J., 222.Hoagland, M. B., 332.Hoard, J. L., 115, 440.Hoare, D. E., 87.Hoare, J. P., 70, 74.Hobbs, W. E., 106.Hocevar, B. J., 315.Hoch, M., 157.Hochster, R.M., 363.Hock, A. A., 150, 222, 451.Hodgkin, D. C., 293, 464,Hodson, H. F., 310.Hoeg, D. F., 180.Hoehn, W. M., 273.Hoffman, C. C. W., 101.Hoffman, C. J., 135, 449.Hoffman, F., 273, 276, 277.Hoffman, P., 363.Hoffmann, A. K., 52, 184,441.434, 459.323, 357, 363.465, 466.216.Hoffmann, E. G., 413.Hoffmann, F. W., 212.Hofmann, A, 296, 306.Hofmann, H., 12, 134.Hofmann, U., 124.Hofmann, W., 447.Hofreiter, B. T., 319.Hofstra, A., 14.Hogg, J. A., 274, 275.Hogg, M. A. P., 124.Hoijtink, G. J., 173, 174.Hokin, L. E., 372.Hokin, M. R., 372.Holbrook, K. A., 192.Holbrook, W. F., 415.Holdaway, M. J., 418.Holden, C. L., 308.Holden, J. R., 134.Holder, B. E., 135, 449.Holding, A. F. le C., 112.Holland, R., 97.Hollander, J.M., 111.Hollenberg, J. L., 109.Holliday, A. K., 119, 128.Hollmann, S., 354.Holm, C. H., 449.Holm, R. H., 145.Holm, R. J., 60.Holman, R. J., 227.Holmberg, R. W., 11.Holme, T., 324.Holmes, J. C., 316.Holmes, K. C., 331.Holmes, R. R., 133.Holmes-Kamminga, W. J.,Holness, N. J., 183.Holroyd, R. A., 54.Holtzberg, F., 155.Holtzclaw, H. F., 143.Holub, M., 239.Holzmann, R. T., 119.Holznagel, W., 138.Hommes, F. A., 358.Honeyman, J., 329, 330.Honnen, L. R., 153, 271.Hood, G. C., 13, 26,Hooper, I. R., 358.Hooper, W. C., 338.Hopkins, C. Y., 227.Hopkins, L., 435.Hoppe, R., 127, 450.HorAk, M., 238, 240, 241,Hordvik, A., 464.Horecker, B. L., 353, 355,Horn, F., 377.Horn, F.H., 114, 440.Hornbeck, J. A., 43.Horner, L., 210, 232, 270.Hornig, D. F., 60, 61, 65,Horning, E. C., 304, 382.Horning, M. G., 247.Horowitz, R. M., 300, 301.289.249.361.81, 87480 INDEX OF AUTHORS’ NAMES.Horowitz, S. T., 325.Horton, D., 328.Hosoya, S., 460.Hotta, Y., 332.Hough, L., 316, 317, 325,328, 329, 353, 357, 365.Houk, W. W., 427.House, H. O., 230.Howard, G. A., 250, 411.Howard, J. R., 12.Howden, M. E. H., 274.Howe, R., 245.Howk, B. W., 221.Howland, L. H., 33.Hrutford, B. F., 263, 294.Hsia, S. L., 275.Huang, P. C., 360.Huang, R. L., 209.Huang, W.-Y. , 277.Hubele, A., 234.Huber, K., 79.Huber, M., 460.Hudec, J., 233.Hudson, M. T., 359, 364.Hudson, R. F., 184, 191,Hudson, R. L., 232.Hubscher, G., 370, 376.Hiickel, W., 234.Hiinig, S., 289.Huffman, J.W., 295.Huggett, C. M., 32.Hughes, D. E., 383.Hughes, E. D., 25, 179,183, 193, 195, 198, 217.Hughes, G. H., 249.Hughes, R. E., 115, 440.Hughes, S. R. C., 11, 19.Huhn, H., 402.Huisgen, R., 189, 194, 229,261, 262, 286, 291, 294.Hug, K. M. S., 70, 75.Hull, R., 291, 298.Humber, L. G., 245.Hume, D. N., 23.Hume, D. O., 18.Hummers, W. S., 123.Humphrey, R. E., 140.Hunt, A. L., 383.Hunt, H., 188.Hunt, K., 322.Hunt, M. W., 298.Hunter, G. D., 356.Hunter, W. T., 231.Hunziker, F., 274.Hurd, C. D., 291.Hurlbert, B. S., 315.Hurlen, E., 336.Hurley, A. C., 170.Hurni, H., 137.Hurwitz, J., 355.Husain, A., 306.Hush, N. S., 173.Hustrulid, A., 45.Hutcheson, R. M., 354.Hutchings, B.L., 298.192, 217.Hutchinson, K., 422.Hutton, R. F., 290.Hutton, T. W., 283.Huyser, E. S. , 206.Hvoslef, J., 466.Hybs, Z., 377.Hyde, G. E., 60.Hyman, H. H., 14.Hyne, J. B., 9.Hytten, F. E., 325.Iball, J., 458.Ibers, J. A., 94, 95, 430,Ibl, N., 70.Ichishima, I., 109.Idler, D. R., 283.Iffland, D. C., 258.Igarashi, H., 375.Iguchi, A., 410.Ihruman, K. G., 253.Iitaka, Y., 455.Ijdo, D. J. W., 450.Ijlstra, J., 334.Ikeda, Y., 216.Ikegami, N., 263.Ikekawa, N., 298.Ikoda, T., 375.Iliceto, A., 183.Iloff, P. M., jun., 237.Imai, M. , 29.Inamoto, N., 36.Inano, M., 323.Indelli, A., 18, 24, 25.Indictor, N., 29.Ingbermann, A. K., 206.Ingold, (Sir) C. K., 25, 179,183, 190, 217.Ingold, K. U., 38.Ingram, D.J. E., 35, 202,Ingri, N., 13.Inhoffen, H. H., 283.Inouye, Y., 368.Inscoe, J. K., 364.Insley, I%, 158.Inukai, T., 179.Ireland, R. E., 277, 294.lrmscher, K., 283.Ironside, C. T., 256.Irvine, L. 414.Irving, H., 164.Irving, R. J., 148.Irwin, R. S., 125.Isaacs, H., jun., 237.Isayeva, L. S., 252.Isbell, H. S., 316.Iseda, S., 248.Isenberg, I., 201.Isfendiyaroglu, A. N., 28.Isherwood, F. A., 362.Ishikawa, M., 308.Ishikawa, S., 354.Ishishi, E., 451.Isler, O., 224, 225, 226.Ito, E., 333.449.466.Ito, K., 31.Ito, S., 313.Ivanov, D., 238.Ivanova, R., 75.Ivanova, Z. I., 403.Iverson, M. L., 157.Ives, D. A. J., 249.Ives, D. J. G., 10.Ivin, K. J., 27, 38.Iwasaki, I., 71.Iwasaki, M., 35.Izumi, Y., 216.Jach, J., 86.Jack, K. H., 447,448,451.Jackman, G. B. , 303.Jackman, L. M., 230.Jackman, M. I., 390.Jackson, B. G., 188, 212,ackson, J. L. , 202.ackson, M. J., 119.ackson, R. J., 197.ackwerth, E., 391.acob, T. A. , 284.acobs, R. L., 212.acobsen, H. I., 212.acobson, R. A., 116, 441.acox, M. E., 83.aeger, R., 237.affe, J. H., 59, 65.affe, M. , 386.aggi, H.. 454.agow, R. H., 180.akobovits, J., 180.akubke, D., 397.ames, A. N., 205.ames, D. G. L., 32.ames, S. I?., 377.amieson, J. W. S., 89.amieson, S. E. , 206.anAk, J., 413.ancke, R., 30.ander, G., 12, 19, 67, 134,244.135.Jander, J., 130, 449.Jang, R., 361.Janjic, D., 121.Janot, M.-M., 308, 309.Jantzen, E. , 227.Janz, G.J., 10.Jarolim, V., 249.Jaspers, W. J., 27.Javick, R. A., 70.Jayko, M. E., 366, 368.Jeanloz, R. W., 359, 363.Jeffers, W., 128.Jefferson, E. G., 187, 190.Jeffrey, G. A., 433, 461.Jeffs, A. R., 414.Jeger, 0.. 239, 240, 247,Jellinek, F., 446, 456, 465.Jenckel, E. , 402.Jenker, H., 214.Jenkins, A. D., 27, 28, 32.249, 277INDEX OF AUTHORS’ NAMES. 481Jenkins, I. L., 68.Jenkins, R. H., 276.Jenne, H., 136.Jenner, E. L., 208, 209.Jennings, K. R., 84, 128.Jenny, E. F., 25, 179, 261.Jensen, A., 25.Jensen, E. V., 212, 277.Jensen, F. R., 270.Jensen, J. P., 149.Jensen, K. K., 406.Jensen, L. H., 464.Jensen, S. L., 224.Jentzsch, G., 413.Jerchel, D., 290.Jerslev, B., 461.Jonck, P., 123.Johannesson, J.K., 393.Johansson, G., 149, 452.John, K., 134.Johns, J . W. C., 97.Johns, W. F., 276.Johnson, A. R., 317.Johnson, A. W., 255, 264,286, 292, 293, 302.Johnson, F. A., 141.Johnson, G. R. A., 378.Johnson, H. E., 229.Johnson, H. W., 411.Johnson, J . A., jun., 299.Johnson, J. B., 402,404.Johnson, J. R., 297.Johnson, J. S., 11.Johnson, W. S., 215, 281,Johnston, H. L., 157.Johnston, K. M., 209.Johnston, R., 32.Jonas, J., 236.Jonassen, H., 12.Jonassen, H. B., 145, 418.Jonathan, N., 107.Jones, A. C., 13, 26.Jones, A. S., 331, 336.Jones, D. J., 137.Jones, D. N., 375.Jones, E. R. H., 223, 226,Jones, E. T., 281.Jones, F. B., 34.Jones, F. T., 327.Jones, G., 297.Jones, I. G., 319, 320.Jones, J. B., 304.Jones, J .H., 297.Jones, J. K. N., 315, 322,324, 327, 328, 353, 357.Jones, J. R., 23.Jones, L. H., 12, 104, 106,Jones, R., 98, 115.Jones, R. E., 454.Jones, R. N., 56, 57, 64,Jones, W. J., 107, 215.Joos, W., 198, 260.284.247, 273, 275, 276.107.272.REP-VOL. LVJolly, W. L., 135, 449.Joly, R., 273.Jordan, D. E. , 233.Jordan, E., 234.Jordan, E. F., jun., 34.Jordan, J . , 70.Jorgensen, E., 144.Joshi, C. G., 300.Josien, M. L., 141.Joslyn, M. A., 303.Jowes, W. L., 411.Judd, C. I., 237.Julia, S., 265.Jull, J. W., 381.Junge, J., 346.Jungmann, R., 275.Jungreis, E., 427.Jurd, L., 300, 301.Jursa, A., 91.Just, G., 277.Juveland, 0. O., 206.Juza, R., 113, 123, 124,Juza, V. A., 78.Kammerer, H., 210.Kaesche, H., 78.Kagan, F., 233.Kagarise, R.E., 65, 102.Kahlen, N., 146.Kaighen, M., 382.Kair, P. E., 18.Kaiser, H., 266.Kaizerman, S., 30.Kakchana, H., 11.Kalan, E. B., 357.Kalckar, H. M., 354.Kalf, G. F., 325.Kalish, T. V., 75.Kallmann, H. P., 92.Kalnins, I., 158.Kalowy, J., 255.Kalvoda, J., 239, 277.Kambara, T., 69.Kamiyama, H., 109.Kammermaier, H., 74.Kamper, J. , 465.Kanfer, J., 354, 361.Kantor, S. W., 216.Kaplan, L. D., 58.Kapland, L. H., 99.Kapur, S. L., 29.Karelsky, M., 207.Kariyone, T., 249.Karle, I. L., 432.Karle, J., 432.Karnovsky, M. L., 360.Karrer, P., 224, 299, 309,Kasha, M., 90, 93.Kashikar, M. D., 302.Kasper, J. S., 114,440,446.Kasperl, H., 150.Katada, M., 375.Katayama, K., 250.Kates, M., 367, 371.391, 447.310.Katritzky, A.R., 120, 289,Katsura, S., 263.Katz, D., 34.Katz, J. J., 14, 141.Katz, L., 446, 454.Katzin, L. I., 164.Katznelson, H., 363.Kaufman, F. , 88.Kaufman, J. J., 422.Kaufmann, H. P., 211.Kawai, K., 103.Kawai, T., 318.Kawade, Y., 332.Kawano, T., 30.Kawase, Y., 300.Kay, M. I., 454.Kay, R. L., 10.Kayama, K., 170, 178.Kazakova, Ye. B., 118.Kearney, E. B., 353, 352.Keay, L., 191.Keay, R. L., 192.Kebarle, P., 89.Keck, J. C., 88.Keefer, R. M., 258.Keeling, R. O., jun., 446.Keenan, T. K., 160.Keilich, G., 253.Keilin, D., 352.Keir, D. S., 56.Keir, H. M., 337.Keith, J. N., 126.Kelkar, G. R., 238.Kell, G. S., 19.Keller, J. W., 104.Keller, W. J., 233.Keller-Schierlein , W., 23 1.Kelly, R.L., 60.Kelly, W., 295, 382.Kelso, J. R., 88.Kemmuller, H., 204.Kemp, J. W., 332.Kemp, P., 371.Kemp, W., 266.Kempster, C. P., 447.Kende, A. S., 242, 278.Kendrew, J. C., 466.Kendrick, L. W., jpn., 196.Kennedy, A,, 130.Kennedy, E. P., 371, 375,Kennedy, J. H. , 405.Kenner, G. W., 192, 292.Kent, L. H., 358.Kent, P. W., 356, 359.Kenttamaa, J., 17.Kenyon, J., 188, 216, 217.Kerber, R., 30.Kergomard, A., 213.Kerr, J. A., 39, 41.Keistead, R. W., 259.Kettle, S. F. A., 127.Keulemans, A. I. B. , 41 1.Keyes, R. W., 104.Keyte, H. J., 393.290.376.482 INDEX OF AUTHORS’ NAMES.Keyworth, D. A., 397.Khaikha, B. I., 320.Khalifa, H., 398.Khan, N. A., 212, 228.Kharasch, M., 230.Kharasch, M.S., 203, 205,Kharasch, N., 266.Khastgir, H. N., 250.Khitrov, V. G., 424.Khorana, H. G., 337.Khotsyanova, T. L., 440.Kiamud-din, M., 297.Kice, J. L., 209.Kiefer, B., 296.Kieffer, W. F., 25, 180.Kierstead, R. W., 307.Kies, H. L., 405.Kieselbach, R., 411.Kikal, T., 377.Kikindai, M., 19.Kilgore, W. W., 362.Kilpatrick, M., 14, 190.Kimber, R. W. L., 255.Kimel, S., 59, 65.Kincaid, J. F., 32.King, C., 230.King, E. J., 8.King, E. L., 20, 144.King, F. E., 245, 248, 295.King, G., 228.King, G. C., 361.King, G. S. D., 256.King, H. G. C., 301.King, N. K., 148.King, T. E., 359.King, T. J., 245, 248, 302.King, W. T., 62.Kinne, H., 289.Kinoshita, K., 96.Kinsky, S. C., 348.Kipnis, D. M., 359.Kirby, G. W., 272.Kirby, K.S., 332.Kircher, H. W., 322.Kirk, D. N., 273.Kirk, P. L., 394.Kirkbride, B. J., 137.Kirmse, W., 232, 270.Kirschner, S., 125, 145.Kishida,.Y., 283.Kishita, M., 165.Kistiakowsky, G. B., 37,48, 49, 52, 53, 54, 85, 88,89, 91.214.Kitahara, Y., 263.Kitaigorodskii, A. I., 458.KiMmura, H., 246.Kitamura, S., 225.Kitamura, T., 332.Kivalo, P., 18, 75.Kivelson, D., 62.Kiyama, R., 60.Kjaer, A., 229.Klages, F., 189.Klanberg, F., 122.Klein, H. M., 112.Klein, M. J., 116.Klein, R., 202.Kleinberg, J., 122, 123.Kleinerman, M., 73.Klek, W., 146.Klement, R., 132.Klemer, A., 327, 330.Klemm, W., 142.Klemperer, W., 60, 104.Klenk, E., 227, 369, 373.Kleschick, A., 423.Klieger, E., 220.Klimentova, N. V., 213.Kline, R.J., 158.Klotz, I. M., 9.Klug, H. P., 443.Knasheva, N. M., 79.Knau, H., 92.Knauss, E., 262.Knight, C., 447.Knight, C. A., 333.Knight, E. C., 364.Knight, H. S., 412.Knight, J. D.. 217.Knight, R. H., 376.Knight, S. G., 356.Knorr, C. A., 74.Knotnerus. J., 212.Knowles, G., 390.Knox, J. H., 50, 51, 52, 89.Knox, G. R., 271.Knox, L. H., 51.Knox, W. E., 382, 383.Knutson, D., 232.Kobayashi, A., 225.Kobayashi, H., 78.Kobel, H., 306.Kobozev, N. I., 135.Kochetkov, N. K., 291Kochetkova, A. P., 114.Kochi, J. K., 181.Kodama, G., 116.Kobrich, G., 289.Kogl, F., 314.Kogler. H. P.. 152.Kohnlein, E., 128.Konig, H., 294.Koenigs, E., 289.Koestler, R. C., 271.Kohn. E. J., 134.Koide, S., 177.Kokkoros, P.A., 442.Kok-Peng Ang, 10.Kolczynski, J. R., 32.Kolditz, L., 132, 133, 135.Kolesnikov, G. S., 213.Koller, E., 232.Kolotyrkin, Ya. M., 78, 79.KolSek, J., 396.Kolski, T. L., 117.Kolthoff, I. M., 406.Komers, R., 413.Komiyama, Y.. 143, 453.Kondo, K., 363.Kondo, M., 164.Kondo, S., 437.Konecky, M. S., 118.Konrath, H. J., 414.Koo, C. H., 465.Kooyman, E. C., 208.Kopitovskil, Yu., 207..Koppel, H. C., 299.Kor, S. K., 26.Korkisch, J., 409, 410.Korman, I. A., 369.Korn, M., 331.Kornberg, A., 337, 339,Kornblum, N., 215.Korngold, G. C., 335.Korsby, G., 308.Korte, F., 303.Kortiim, G., 10, 67.Koryta, J., 76.Korytnyk, W., 300.Kosaki, T., 375.Koshland, D. E., 331.Kosower, E. M., 23, 181.Kostkowski, H.J., 56, 58.Kotake, M., 237.Kotani, M., 170, 178.Kotani, Y., 375.Kotel’nikova, A. S., 161.Kotlan, J., 219.Kotlensky, W. V., 116.Koton, M. M., 28.Koulkes, M., 22 1.Koutecky, J., 68, 69.Kovalenko, P. N., 403.Kowkabany, G. N., 316.Kozlowski, M. A., 284.Kozminskaya, T. K., 119.Krachko, L. S., 320.Kramer, H., 300.Kraicer, P. F., 357.Krakower, G. W., 247.Krasnaya, Zh. A., 226.Kraus, C. A., 18.Kraus, J. W., 41.Kraus, K. A., 11.Krause, K., 69.Krause, R. A., 401.Krauss, H. L., 157.Krebs, H., 111, 448.Krebs, K., 109.KrejEi, K., 138.Kresge, A. J., 199, 202.Kreutzer, A., 283.Kriegsmann, H., 107.Krikorian, N. H., 447.Kriner, W. A,, 125.Krisher, L. C., 102.Kristoff, J. J., 100.Krivoruchko, I?. D., 393.Krongauz, V.A., 93.Krueger, P. J., 66.Krumholz, P., 23.Kruse, F. H., 447, 449.Kruse, W., 136.Krylova, R. G., 318.Kryukova, T. A., 75.375Kubba, V. P., 285.Kubo, M., 164, 165.Kubota, T., 241, 288, 300.Kuchen, W., 133.Kucherov, V. F., 233.Kuchitsu, K., 102.Kudryashov, L. I., 291.Kuehne, M. E., 309.Kuhn, R., 210, 215, 225,254, 288, 325, 326, 358.Kuhn, S. J., 140.Kuipers, G. A., 58.Kulkarni, A. B., 300, 302.Kullick, W., 260.Kullnig, R. K., 235.Kumamoto, J., 190.Kunchur, N. R., 456, 457.Kundu, N., 278.Kunst, E. D., 423.Kuntz, I., 25.Kupfer, G., 413.Kuratani, K., 64.Kuri, Z., 91.Kursanov, D. N., 265, 266.Kurz, J., 234.Kurzbach, E., 130.Kusch, P., 112.Kustova, S. D., 237.Kutner, A., 34.Kutschke, K. O., 38, 90.Kuzminskii, A.S., 36.Kuznetsova, N. A., 226.Kwart, H., 199.Kwon, J. T., 164.Kydd, P. H., 53.Kyeda, R. J., 217.Kyi, Z.-Y., 294.Kynaston, W., 10, 120.Laber, G., 252.Labhart, H., 174.LaBudde, J. A., 373.Lacko, L., 315.LaCount, R. B., 255.Ladbury, J. W., 160.Ladenbauer, I. M., 410.La Du, B. N., 379.Laets, K. V., 237.LaFlamme, P. M., 216, 224.Laturaze, J., 409.Lagemann, R. I., 106.Lagerstrom, G., 13.Lagowski, J. J., 167.Lahey, F. N., 248.Laible, R. C., 33.Laidlaw, R. A., 322.Laidler, D. S., 112.Laidler, K. J., 13, 80, 86,Laird, R. K., 48.Laitinen, H. A., 69, 72, 73,Lake, H. J., 377.Lake, P., 79.Laland, S. G., 336.LaLonde, R. T., 233.91, 186.75.INDEX OF AUTHORS’ NAMELamb, J., 82, 109.Lambert, G.F., 369.Lambert, J. D., 82.Lambert, J. L., 421.Lamberton. A. H., 185.Lampe, F. W., 45,47.Lamdau, B., 359.Landau, B. R., 359.Landau, L. 120.Landel, A., 124.Landis, P. S., 185.Landmark, P., 442.Landowne, R. A., 374.Lane, T. J., 108, 145.Lang, K., 400.Langbein, G., 284.Lange, E., 79.Lange, G., 391.Langer, S. H., 425.Langridge, R., 338.Langseth, A., 62, 103.LaPlaca, S., 447.Lappert, M. F., 114, 118.Lardon, A., 276.Lardy, H. A., 357.Lareau, J., 355.Larson, A. C., 450.Larson, H. O., 215.Larsson, M., 348.Lascombe, J., 141.Lasker, M., 354.Laskowski, M., 342.Lassner, E., 398.Laubengayer, A. W., 123.Laver, W. M., 258.Laughlin, R. G., 50.Laumas, K. R., 301.Laurence, D. J. R., 335.Laurent, T., 324.Laurie, V.W., 95.Lauterbach, G. E., 324.Laves, F., 227, 464.Lavie, D., 249, 250.Lavorel, J., 93.Lawesson, S. O., 214.Lawley, H. G., 320.Lawley, P. D., 336.Lawrence, G. S., 22.Lawrence, K. S., 19.Lawrenson, I. J., 102, 461.Laws, G. F., 283.Lawson, J. E., 214.Lawson, J. R., 377.Lawton, D., 463.Laxton, J. W., 11.LazBr, M., 28.Lazarus, A. K., 258.Lea, C. H., 366, 367, 368.Leach, S., 202.Leake, J. C., 195.Leavitt, F., 34, 206.Le Baron, F. N., 365.Lebedinskii, V. V., 163.Le Blanc, F., 91.Leboeuf, M. B., 427.le Boulch, N., 283.483Lecocq, J., 371.Lecompte, J., 65.Lecomte, J., 143.Leden, I., 17.Lederer, E., 226, 242, 325,Lederer, M., 410.Lednicer, D., 258.Lee, G. E., 211. 290.Lee, H.-H., 236.Lee, J., 102.Lee, W.H., 129.Leebrick, J. R., 218.Leeding, M. V., 248.Leeming, P. R., 301.Lees, E. B., 187.Lees, M., 365.Leete, E., 303, 304.Lefebvre, J., 12.LeFevre, P. G., 365.Lefort, M., 93.Le Goff, E., 182.LeGoff, P., 48.Legrand, M., 283.Le Hir, A., 307, 308.Lehman, G., 217.Lehman, I. R., 337.Lehmann, H. A., 121, 138.Lehmann, W. J., 108.Lehninger, A. L., 354, 355.Lehrle, R. S., 28.Leigh, C. H., 42.Leimgruber, W., 265.Lemieux, R. U., 235, 327,Lemin, A. J., 247.Lengyel, P., 340.Lennard, A., 193.Lennard- Jones, J. E., 64.Lennarz, W. J., 118.Leonard, N. J., 215, 236,Lerner, B., 374.Lerner, M. W., 389.LeRoy, D. J., 41, 89.Lesnini, D. G., 415.Lester, G. R., 19.Lester, R. L., 226.Lesuk, A., 368.Leto, J.R., 166, 271.Letsinger, L., 254.Letsinger, R. L., 217.Leung, Y. C., 439, 441.Leuthardt, F., 357.Levand, O., 215.Le-Van-Thoi, M., 245.Levich, V. G., 69.Levin, I. W., 60.Levin, S. H., 242.Levine, S. G., 216.Levisalles, J . , 285.Levisalles, J. E. D., 241.Levschin, V. L., 93.Levy, A. A,, 383.Levy, H. A., 435, 436, 449.Levy, L. B., 207.360.358.311484 INDEX OF AUTHORS’ NAMES.Levy, M., 356.Lew, H., 95.Lewis, B. A., 316, 319, 329.Lewis, E. S., 194, 207.Lewis, G. E., 255.Lewis, J., 99, 143, 148, 149,Lewis, J. C., 179.Lewis, J. W., 228.Lewis, L., 12.Lewis, S. N., 207.Lewis, T. D., 29, 203.Ley, K., 201.Liang, H. T., 188.Liao, C.-W., 232.Libowitz, G. G., 155.Lichtarowicz, A., 293.Lichtenwalter, G.D., 218.Lichtin, N. N., 19.Liddle, A. M., 319.Lide, D. R., 98, 108.Liebermann, S., 192.Liechti, P., 314.Liehr, W., 126.Lieser, K. H., 17.Lietzke, &I. H., 17.Light, T. S., 391.Liler, M., 69, 73.Lilie, H., 416.Lim, D., 33.Lin, I. D., 86.Lindars, J., 86.Lindberg, B., 317, 318, 322,Lindemann, M. K., 33.Lindgren, B. O., 321.Lindlar, H., 226.Lindqvist, I., 99, 132, 136,Lindstedt, G., 303.Lindsey, J. , 466.Lindstredt, S., 284.Ling, K. H., 357.Lingafelter, E. C., 163.Lingane, J. J., 405.Lingens, F., 364.Linholter, S., 213.Linker, A., 363.Linnell, R. H., 39.Linnett, J. W., 82, 84, 128,Linschitz, H., 93.Linstead, R. P., 292, 293.Linton, H. R., 98, 106, 107.Lipkin, D., 172, 173.Lipmann, F., 332.Lippert, E.L., 100, 113,Lippert, E. L., jun., 441.Lippincott, E. R., 101, 103,Lippincott, W. T., 118.Lippmann, E., 265.Lipscomb, F. J., 80.Lipscomb, N. N., 270.Lipscomb, R. D., 207, 208.162, 246.357.443, 444.174, 440.115.107.Lipscomb, W. N., 99, 100,115, 119, 149, 240, 441,452, 453.Lipsky, S., 93.Lister, M. W., 22.Littauer, U. Z., 339.Little, E. L., 287.Little, J. C., 236.Little, R. L., 270.Little, W. F., 271.Littlefield, J. W., 331.Litvyak, I., 127.Liu, C. H., 68.Liu, L. H., 247.Livingston, A. L., 301.Livingston, R., 91, 93, 99.Livingston, J. G., 133.Livingstone, S. E., 145,Llewellyn, D. R., 188, 190,Llinarcs, J., 218.Llopis, J., 73.Lloyd, D., 266.Lloyd, H. A., 304.Loan, L. D., 32.Lock, L.C., 395.Locke, D. M., 212, 313.Locksley, H., 249.Lockwood, J. V., 30.Lodge, J. P., jun., 392.Loebl, H., 378.Loeser, E., 299.Lowdin, P. -O., 178.Loewenthal, H. J. E., 263.Loewus, F. A., 361.Loftfield, R. B., 330.Logan, N., 148, 165.Lohse, F., 314.Loke, K. H., 284.Lombard, R., 120.Lombardino, J. G., 205.Long, C., 367, 368.Long, F. A. 14, 144, 184,Long, K. F., 255.Long, R. A. J., 207, 254.Longenecker, J. B., 349.Longuet-Higgins, H. C.,Loopstra, L. H., 443.Lorak, H., 308.Lord, R. C., 104, 107.Lorenz, W., 71, 72, 73, 76.Lossing, F. P., 38.Lothe, J. J., 36.Lotspiel, J. F., 99.Lott, P. F., 417.Loudon, J. D., 291.Loveland, J. W., 68.Loveless, F. C., 237.Lovell, R. J., 60.Lovelock, J. E., 412.lovern, J. A., 372, 373.Lowe, G., 225.;owe, J.U., 118.164, 165.193, 196, 409.188, 198, 199, 200.105, 178, 269.Lowenstein, J. M., 383.Lowry, G. G., 27.Lubs, H. A., 359.Lucas, R. A., 309.Lucas, V. E., 37.Lucchesi, C. A., 399.Lucien, H. W., 128.Lucius, G., 237.Lucken, E. A. C., 285.Ludowieg, J. , 363.Ludwig, T., 448.Ludemann, H., 137.Liidering, H., 79.Luderitz, O., 325, 360.Luttringhaus, A., 259, 262,Luijten, J. G. A., 127.Lukach, C. A., 179.Lukaszewicz, K., 448.Lukianenko, B., 188.Lumpkin, H. E., 175.Lund, E. W., 441.Lundgren, G., 443.Lundstrom, T., 451.Lunenok-Burmakina, V. A.,Luner, C., 91.Lunt, E., 211, 290.Lunt, M. R., 359.Luther, H., 120.Lux, B., 448.Lyman, R. L., 301.Lynch, B. M., 299.Lynch, M.F., 300.Lynn, K. R., 196.Lyons, L. E., 439.Lythgoe, B., 245, 282, 283.Lyubimova, A. K., 43.Maass, O., 20.Pvlabuchi, H., 139.McAleer, W. J., 284.McArdle, A. H., 337.MacArthur, C. G., 369.McArthur, C. S., 367.MacArthur, D. M., 442.McBee, E. T., 232.McBride, H. D., 163.McCaldin, D. J., 286.McCall, E. R., 316.McCarley, R. E., 144.McCarroll, W. H., 446.McCarron, F. H., 217.McCarty, J. E., 196.McCarty, L. V., 114, 440.McClure, D. S., 439.Maccoll, A., 185.McConnell, H. M., 97, 178.McCorkindale, W., 426.UcCormick, D. B., 354,McCormick, G. J., 425.McCoubrey, J. C., 81, 82,83.McCready, R. M., 327.bTcCullough, J. D., 99, 447,292.137.355.449INDEX OF AUTHORS’ NAMES. 485McCurdy, W. H., jun., 417.McCusker, P.A., 126.MacDiarmid, A. G., 125.McDonald, B. J., 160.MacDonald, S. F., 293.MacDonald, S. G. G., 444.McDonald, H. J., 408.McDowell, C. A., 39, 85.McDowell, R. H., 315.McElcheran, D. E., 89.McElroy, W. D., 348.McElvain, S. M., 236.McEwen, K. L., 171.McEwen, W. E., 197, 217.McFadyen, J. G., 196.McFadyen, J . S., 220.Macfarlane, M. G., 366,McFarlin, R. F., 211.McGarvey, B. R., 26.McGeachin, H. M., 464.McGeer, E. G., 287.McGill, B. B., 338.MacGillavry, C. H., 166,442, 443, 454McGinn, F. A., 258.McGlynn, S. P., 172.McGowan, I. R., 89.McGrath, W. D., 81, 84.McGregor, W. R., 145.McGuire, J. C., 447.Machatzke, H., 449.Machell, G.. 319.Machida, S., 323.McIver, E. J., 433.Mack, J. L., 116, 118.Mackay, D., 203.McKay, H.A. C., 18, 159.McKay, J. E., 323.MacKay, M., 465.McKean, D. C., 60, 61, 99.McKendall, L. R., 408.McKibbin, J. M., 366, 370,Mackie, J. M. D., 183.McKinley, J. D., 88.McKinley, J. D., jun., 84.Mackor, E. L., 14, 27, 72,Mackson, J. J., 255.McKusick, B. C., 287.McLaren, E., 12.McLaughlin, J., 359.McLean, J., 249.McLean, S. R., 395.Maclennan, A. P., 317, 357.McLennan, G., 266.MacMillan, J., 246.McMullan, R. K., 122.McMurry, T. B. H., 239.McNally, J. G., jun, 242.McNesby, J. R., 39, 41.MacNevin, W., 163.McNutt, W. S., 299.McOmie, J. F. W., 268,372.372.174.269, 289.MacPhillamy, H. B., 309.MaRae, E. G., 93.McRorie, R. A., 363.McSweeney, G. P., 33.McWain, P., 318.McWeeny, R., 171, 178.Madaeva, 0.S., 278.Madan, C. L., 303.Maddock, A. G., 157.Maeda, H., 318.Maekawa, H., 314.Maennchen, K., 421.Magat, M., 31.Magat, P. L., 313.Magee, J. L., 177.Magerlein, B. J., 274.Magnano, G., 450.MagnCli, A., 444.Magnien, E., 211.Magnuson, D. W., 440.Magrath, D. I., 298.Maguire, M. F., 367.Mahan, B. H., 54, 81.Mahler, H. R., 343, 346.Mahler, W., 147.Mahomed, R. S., 323.Mahon, J. H., 423.Mahowald, T. A., 275.Maier, G., 270.Maier, L., 133.Maier, M., 234.Maillard, A., 127.Maimind, V. J., 265.Main, R. K., 335.Mair, J. A., 158.Maire, J. C., 127.Maitland, R., 448.Major, R. J., 215.Majumdar, A. K., 143, 399.Makarova, Ye. I., 135.Maki, A., 104.Makineni, S., 426.Makrides, A. C., 75.Malatesta, L., 147, 148.MCilek, J., 315.Malinovskii, T.I., 453.Malkas, Z., 407.Malkin, T., 369, 370, 375.Mallard, W. C., 65.Malm, C. J., 317, 318.Malm, J. G., 105, 139, 163.Malmberg, C. G., 8.Malmstrom, B. G., 343,Malpress, F. H., 325.Mandel, M., 95.Mandelcorn, L., 39.Mandell, L., 286.Manella, G., 88.Mangoni, L., 292.Mani, N. V., 443.Mann, D. E., 97, 98.Mann, F. G., 297.Mann, K. M., 357.Mann, M. M., 45.Mann, T., 373.347, 348, 352, 353.Manners, D. J., 319, 320.Manning, D. L., 415.Mano, E. B., 34.Mansfield, G. H., 223.Manson, D., 363.Manson, J. A., 30.Mapson, L. W., 362.Maranville, L. F., 13, 24.Marbet, R., 226.Marchini, P., 465.Marcus, E., 258.Marcus, R. A., 42.Marcus, Y., 18.Margenan, H., 58.Margrave, J.L., 112.MariEiC, S., 157.Marinelli, L. P., 28.Marinetti, G. V., 368, 372,Marini-Bettolo, G. B., 428.Marion, L., 303, 305, 308,312, 314, 465.Markby, R., 150, 222, 271.Markham, E., 292.Markham, R., 337.Markin, T. L., 159, 160.Marks, B. S., 211.Markunas, P. C., 404.Marlatt, V., 284.Maros, L., 402.Marrian, G. F., 284.Marsh, G. E., 331.Marsh, J. M., 326, 327.Marsh, R. E., 439,449,456,Marshall, D., 235, 272.Marshall, G. P., 10.Marshall, J. K., 365.Marshall, W. L., 52.Marsi, K. L., 217.Marszak, I., 221.Martell, A. E., 12.Martin, B., 163.Martin, D. S., 144.Martin, E. W., 313.Martin, F. S., 149.Martin, H., 128, 129.Martin, J. J., 422.Martin, J. V., 419.Martin, K. J., 117.Martin, M. M., 113.Martin, R.L., 23, 165.Martin, R. N., 256.Maruo, B., 373.Marvel, C. S., 31, 34, 113.Marvin, D. A., 338.Maryott, A. A., 8.Mashiko, Y., 109.Mason, H. S., 378.Mason, S. F., 66, 181, 198,Massey, A. G., 119.Massey, H. S. W., 177.Massey, V., 343, 351.Masson, C. R., 38.Massoth, F. E., 117.374.460.285, 293486 INDEX OF AUTHORS' NAMES.Massy-Beresford, P. N.,Mastrangelo, S. V., 423.Mataga, N., 171.Mather, J., 192.Mathers, W. G., 159.Matheson, A. R., 338.Matheson, M. S., 202.Matheson, R. A., 17.Mathews, F. S., 453.Mathieson, A. McL., 464.Mathieson, D. W., 249.Mathieu, J., 283.Mathieu, J. P., 142.Mathura, G. R., 377.Matic, M., 227.MatkoviE, B., 155.Matorina, N. N., 159.Matschiner, J. T., 275.Matsuda, H., 68, 69, 462.Matsui, M., 299.Matsuii, A.M., 225.Matsumae, T., 419.Matsumoto, T., 314.Matsumura, Y., 323.Matsuura, N., 139.Mattauch, J., 111.Mattax, C. C., 69.Matthews, R. E. F., 333.Matthias, B. T., 451.Mattoo, B. N., 10.Matty, S., 338.Matubara, I., 172.Matuura, T., 288.Matyska, B., 30.Mauli, R., 240.Mauret, P., 218.Maurukas, J., 367, 369,Maury, P., 317.Mausner, M., 25.Mautner, H. S., 299.Maxfield, R. C., 308.Maxwell, A. F., 125.Maxwell, E. S., 354.May, D. C., 317.Mayberry, R. M., 354.Maybury, P. C., 112.Mayer, R., 201.Mayes, N., 31.Mayhood, J. E., 60.Mayo, D. W., 107, 313.Mayo, F. R., 34.Mazur, Y., 247, 273.Meacock, S. C. R., 189.Mead, J. A. R., 382.Meakins, G. D., 276.Meal, J. H., 62.Meath, J.A., 365.Mechoulam, R., 255, 283.Mecke, D., 449.Medvedev, S. S., 31.Meeks, R. C., 284.Meerwein, H., 51.Meguri, H., 250.Mehl, W., 73, 77.279, 280.370.Mehler, A. H., 353.Mehltretter, C. L., 319.Mehrotra, R. C., 401.Meier, H., 315.Meier, J., 12.Meinert, H., 124.Meinwald, J., 252, 263,264, 291.Meinwald, Y. C., 236.Meisels, A., 305.Meisels, G. G., 47.Meissner, E., 286.Meister, A. G., 106.Meister, P. D., 284.Melik-Gaikazyan, V. I.,Mellor, J., 112.Meloche, V. W., 23.Melton, C. M., 47.Melville, (Sir) H. W., 35,Menary, J. W., 134, 444.Mench, J. W., 318.Menchaea, H., 301.Mentzer, C., 300, 302.Menzer, W., 126.Mercer, M., 300.Merica, E. P., 295.Merkel, D., 241.Merler, E., 322.Merlin, E., 403.Merriman, P.C., 195.Meselson, M., 338.Mesrobian, R. B., 28.Messer, C. E., 112.Metlesics, W., 219.Metlin, S., 210.Metzinger, L., 213.Meuche, D., 265.Meuwsen, A., 130.Meyer, A., 208.Meyer, B., 166.Meyer, K., 363.Meyer, W. L., 284.Meyers, M. B., 274.Meyr, R., 229.Mhala, M. M., 197.Michal, J., 418.Micheel, F., 317, 330.Michel, H. O., 217.Michelson, A. M., 334,340, 342.Micka, K., 68.MiCoviC, V. M., 211.Middleton, W. J., 287.Mihail, G., 397.MihailoviC, M. L., 211, 231.Mii, S., 339.Mikami, R., 225.Mikhailov, B. M., 118, 119.Mikheyeva, V. I., 116.Milburn, R. M., 12.Miles, H. T., 341.Millen, D. J., 97, 128, 1.29.Miller, A., 49.Miller, A. A., 34.72.37Miller, D. G., 23.Miller, E. C., 379.Miller, E.H., 218.Miller, I. H., 377.Miller, J. A., 379.Miller, J. G., 186.Miller, J. I., 217.Miller, J. K., 318.Miller, J. P., 369.Miller, J. W., 428.Miller, 0. N., 360.Miller, R. R., 428.Miller, S. A., 285.Miller, W. E., 397.Millington, J. E., 215.Mills, G. C., 379, 388.Mills, I. M., 65, 57, 60, 62,63, 108, 177.Mills, J. A., 273.Mills, J. S., 247, 248.Mills, 0. S., 100, 150, 152,Milne, T. A., 112.Milner, G. W. C., 67.Milner, 0. I., 411.Milyutinskaya, R. I., 207.Minegishi, A., 64.Minkoff, G. J., 128.Minnema, L., 33.Mino, G., 30.Minturn, R. E., 72.Mironov, V. F., 218.Mishima, H., 304.Mislow, K., 258.Misra, G. S., 29.Mistry, S. N., 120.Mistryukov, E. A., 221.Mitchell, J., 404.Mitchell, T. J., 414.Mitchell, W.J., 187.Mitoma, C., 378.Mitra, A. K., 327.Mitra, G., 135.Mitra, R. B., 241.Mitschelen, H., 108.Mitsher, L. A., 245.Mitsuno, M., 301.Miura, K., 332. I Miyama, H., 34.Miyano, M., 225, 299.Miyazawa, T., 60, 105, 107.Mizirdicyan, E., 202.Mizuno, Y., 170, 178.Mizushima, S., 107, 108,109, 145.Moccia, R., 66.Mochel, W. E., 208.Mockel, F., 72.Moeller, T., 146.Mortsell, M., 443.Moffat, A., 188.Moffitt, W., 460.Moffitt, W. E., 170, 171.Morgans, D. B., 21.Moir, R. Y., 235.Mok, S. F., 25, 179.222, 451INDEX OF AUTHORS’ NAMES. 4137Molnar, J. P., 43.Mondon, A., 237.M6n Evans, J., 319.Monk,C.B.,9,10, 18,19,21.Monro, A. M., 289.Montag, W., 227.Montavon, M., 225.Montegudet, G., 318.Montermoso, J. C., 28.Montgomery, D. J., 440.Montgomery, E.M., 315.Montgomery, J. A., 299.Montgomery, R., 329.Montreuil, J., 325.Montroll, E. W., 80.Moodie, R. B., 214.Mooney, E. F., 121.Moore, A. M., 334.Moore, B. W., 357.Moore, C. G., 288.Moore, D. R., 286.Moore, G. E., 58, 60, 61.Moore, I-€. B., 117.Moore, L. O., 118.Moore, R. E., 158.Moore, S., 390.Mootz, D., 120.Mora, G. A., 403.Mora, P. T., 317.Morawetz, H., 187.Morehouse, E. L., 151.hlorelec-Coulon, M. J., 370,Morey, G. W., 131.Morgan, E. D., 228.Morgan, H. W., 435.Morgan, L. R., jun., 255.Morgan, R. S., 341.Moriarty, R. M., 277.hlorita, H., 315.Morita, K., 280.Morino, Y., 101, 102, 109.Moritz, A. G., 255.Moroe, T., 263.Morris, D., 95.Morris, D. M., 43.Morris, H.P., 381.Morris, R., 230.Morris, W. F., 119.Morrison, G. C., 312.Morrow, D. F., 215.Mors, W. B., 291.Mortensen, J. P., 152.Mortensen, P. J., 271.Mortimer, A., 229.Morton, I. D., 372.Morton, M., 33.Morton, R. A., 226, 272.Mosbach, E. H., 356.Mosbach, R., 352.Moseley, F., 38.Mosher, W. A., 396.Rlosier, B., 72.Moskvin, A. I., 159, 160.Moss, J. B., 253, 274.Mostert, S., 372.372.Moth, O., 239.Moudy, L., 427.Mousseron, M., 273, 278.Mrose, M. E., 445.Miihlberg, H., 71, 73,Miihlstadt, M., 265.Mueller, C. R., 179.Miiller, E., 201, 215, 229.Mueller, G. P., 276.Miiller, K., 232.Miiller, W. D., 12, 125.Miillner, F. X., 274.Muetterties, E. L., 120.Muga, L., 160.Muggleton, D. F., 19.Muir, H., 359.Muir, R.D., 285.Mukerjee, P., 20.Mukerji, B., 303.Mukherjee, S. L., 244.hiulholland, T. P. C., 246.Mullen, J. D., 394.Muller, N., 175.Mulliken, R. S., 94, 96, 175,Multani, R. K., 156, 161.Mundry, K.-W., 333.hlurai, K., 229.Murakami, S., 287.Murata, H., 103.Muricio, A. M., 289.Murphy, D., 325.Murray, H. C., 284.Murrell, J. N., 171.Musher, J., 235.Musso, H., 300.Mutschin, A., 421.Muth, K., 232, 270.Muto, I., 29.Muto, Y., 165.Myerson, A. L., 83.Mysels, K. J., 20.Nace, H. R., 277.Naef, H., 240.Kaher, G., 234.Nagakura, S., 462.Nagarajan, K., 306.Nagashima, T., 177.Nagayama, M., 78.Nagel, F., 163.Nagy, E., 224.Nair, G. V., 315.Nair, M. D., 295.Nair, V. S. K., 9, 12, 17.Nakada, H. I., 359.Nakagawa, I., 108.Nakagawa, S ., 375.Nakajima, M., 385.Nakamura, H., 165, 454.Nakamura, M., 284, 327.Nakamura, T., 352.Nakano, T., 235, 272.Nakayama, T., 370.hTancollas, G. H., 9, 12, 17,177.21.Nandi, U. S., 28.Napier, D. R., 232, 270.Napier, I. M., 255.Narayanan, C. R., 241.Nardelli, M., 453, 460.Nash, G. R., 9, 18.Nasipuri, D., 244.Nason, A. J., 348.Nast, R., 149, 150, 151.’Natta, G., 100, 142, 152,Nawa, H., 280.Nayatani, K., 29, 30.Nazarov, I. X., 221, 226,Neeb, R., 421.Neeman, bl., 215.Neher, R., 284.Neidlein, R., 234.Neish, A. C., 356, 357, 361Neish, W. J . P., 379.Nekrasov, L. I., 135.Nelson, N. A., 282.Nelson, R., 321.Nelson, R. D., 103, 107.Nerenberg, C., 297.Nes, W. R., 213.Nesmeyanov, A.N., 252271, 297.Neu, R., 402.Neuberg, C., 382.Neubert, G., 300.Neumann, H. M., 26.Neumann, W. P., 297.Neunhoffer, O., 201, 269.Neurath, H., 349.Neuss, N., 308.Neven, M. C., 186.Newbury, R., 163.Newcombe, ,4. G., 368.Newkirk, A. E., 114, 440.Newman, L., 23.Newman, M. S., 220, 221Newman, P. 258.Newton, A. S., 91.Newton, T. W., 20, 169.Ney, E., 399.Neyman, L. A., 265.Nicholas, D. J. D., 343Nicholls, B., 236, 271.Nicholls, D., 156.Nichols, B., 152.Nichols, J., 227.Nicholson, D. C., 292.Nicholson, W. H., 328.Nickerson, R. G., 34.Nickl, J., 299.Nicolaides, N., 227, 464.Nicolaus, R. A., 292.Nicoletti, R., 292.Nielsen, A. H., 104.Nielsen, H. H., 61.Nielsen, H. M., 410.Nieuwenhuis, J., 222.155, 453.233.253, 259.348486 INDEX OF AUTHORS’ NAMES.Niggli, A., 464.Niizeki, N., 446.Nikles, E., 208, 290.Nikolajeva, N.V., 75.Nikolajeva-Fedorovich,Nilsson, R. O., 17, 26.Nilsson, W. A., 228.Nishimoto, K., 171.Nishimoto, N., 250.Nishimura, A., 31.Nishimura, N., 30.Nisonoff, A., 33.Nitta, I., 287, 455, 461,Nixon, E. R., 60, 98, 106,Nixon, J. F., 121.Noble, J. A., 188.Noda, M., 368.Nodop, G., 413.Nolken, E., 291.Noth, H.. 117.Nogare, S. D., 412, 413.Noguchi, K., 354.Noland, W. E., 295.Noltes, J. G., 127.Nominb, G., 273.Nonaka, H., 237.Noren, B., 18.Norman, I., 201.Norman, J. M., 373.Norman, R. 0. C., 207.Normant, H., 218, 221,h’orris, W. G., 60.Norrish, R. G. W., 49, 80,North, A. M., 27.Northcote, D.H., 315, 316.Norton, F. J., 43.Norton, K. B., 250.Norwitz, G., 393.Notley, N. T., 33.Novak, L., 382.Novak, N., 396.Novelli, G. D., 363.Novoselova, A. V., 113.Novotnjl. L., 241.Novozhenyuk, 2. M., 163.Nowacki, W., 449, 454,Nowotny, H., 126,155,448.Noyce, D. S., 184.Noyes, W. A., jun., 39, 49.Nozaki, H., 291.Nozoe, T., 263, 266.Nozoye, T., 308.Nussim, M., 180.Nygaard, L. H., 101, 102,Xygren, V., 13.Nyholm, R. S., 111, 142,143, 145, 157, 161, 162.Nyquist, I. M., 57.Nystrom, R. F., 195, 211.N. V., 75.462, 465.107.230.84.465.459.Oakes, V., 298.Oathoudt, D. D., 252.Ochiai, E., 308.Ochoa, S., 339, 340.O’Connor, N. S., 300.O’Connor, R. T., 316.O’Donnell, J. J., 321.O’Donnell, J.T., 28.O’Driscoll, K. F., 31.O’Dwyer, M. F., 103.Ofele, K., 152, 153, 271.Oetjen, R. A., 105.Offeman, R. E., 123.Ogard, A. E., 143.Ogata, H., 163.Ogata, M., 263.Ogilvie, G. S., 187.Ogilvie, J. L., 412.Ognjanov, I., 238.Ogura, I., 241.Ohloff, G., 237, 242.Ohno, K., 373.Ohorodnik, A., 287.Ohta, M., 214, 230, 305.Oka, S., 406.Oka, T., 101.Okabe, H., 89.Okamoto, G., 78.Okamoto, Y., 179.Okano, S., 225.Okaya, Y., 433, 443, 455,Okhlobystin, 0. Yu., 146.Okinaka, Y., 406.Okuda, M., 172.Okuhara, E., 370.Okuhara, K., 35.Olah, G. A., 140.Olaj, 0. F., 36.O’Laughlin, J. W., 415.Oldham, K. B., 69.Oldham, K. G., 190.Olds, D. W., 319.Olin, A., 11.Oliveto, E. P., 275.Olivier, R., 78.Olley, J., 370, 372, 373.Ollis, W.D., 463.Olovsson, I., 448.Olsen, S., 291.O’Neill, A. N., 249.Onken, D., 284.Onsager, L., 18.Onstott, E. I., 75.Onyon, P. F., 27.Onyszchuk, M., 126.Opitz, H. E., 107.Orchin, M., 210.Oreskes, I., 187.Orgel, L. E., 20, 165, 269,Orlova, 0. K.. 325.Orr, J. C., 249.Orr, R. J., 34.Orr, S. F. D., 363.Ortiz, P. J., 340.457.436.Orttmann, H., 219.Orville-Thomas, W. J.,Osaki, K., 462.Osawa, S., 332.Osawa, Y., 408.Osbond, J. M., 305.Osborn, C. L., 267.Osborn, J. H., 270.Osborne, G. O., 299, 370.Osiecki, J., 235, 272.Ostacoli, G., 23, 166.Ostdick, T., 126.Osteux, R., 409.Otsu, T., 29, 30.Ott, H., 229, 296, 306.Ott, W., 292.Ottenstein, B., 373.Otter, R. J., 21.Otto, D., 74.Otto, R. J. A., 134.Oubridge, J.V., 14, 137.Ouellet, L., 192.Oughton, B. M., 466.Ourisson. G., 240, 247, 272.Ovenall, D. W., 28, 35.Overberger, C. G., 31, 34,Overend, J., 60, 101.Overend, W. G., 193.Owen, B. B., 67.Owen, B. D. R., 20.Owen, J., 142.Owen, L. N., 235.Owen, O., 328.Owen, T. C., 226.Owens, F. H., 236.Oxford, A. E., 206.Ozawa, K., 60.Pacault, A., 318.Packer, J. E., 166, 187,Paddock, N. L., 134, 176,Padley, P. J., 88.Padmanabham, T. S. A.,Padmoyo, M., 12.Paerels, G. B., 368.Paglia, E., 163.Pahl, H. B., 335.Pai, B. F., 242.Painter, T. J.. 322.Pakhomov, A. M., 318.Paldus, J., 68.Palermiti, F. M., 358.Palit, S. R., 28.Palko, A. A.. 120.Palleroni, N. J., 356.Palluel, A. L., 306.Palm, C., 152.Palm, W.E., 34.Palmade, M., 240.Palmer, D. R., 296.Palmer, H. B., 87.128.205.212.251.317INDEX OF AUTHORS’ NAMES. 489Palmer, K. H., 314.Palmer, R. C., 94.Palmork, K. H., 137.Palmstierna, H., 315, 324.Pammer, E., 142.Pan, S. C., 308.Panattoni, C., 300.Panckhurst, M. H., 20, 21,Pangborn, M. C., 367, 372.Panicker, A. R., 426.Paoletti, P., 146.Paoloni, L., 172.Papee, H. M., 13.Pappo, R., 281.Parham, F. M., 209.Parihar, D. B., 334.Pariser, R., 171.Park, J. T., 358, 364.Park, R. B., 227.Parke, D. V., 376, 377, 378.Parker, K. P., 394.Parker, L. J. F., 293.Parker, S. H., 231, 269.Parker, W., 288.Parker, W. E., 204.Parlin, R. B., 90.Parr, R. G., 170, 171.Parrish, R. G., 466.Parry, R. W., 116, 117.Parsons, A.E., 107.Parsons, R., 71, 74.Parsons, R. W., 143.Parthasarathy, N. V., 415.Parthe, E., 448.Partlow, E. V., 322.Parton, H. N., 17, 20.Panvish, D., 183.Pashler, P. E., 57.Pass, G., 128.Paszek, L. E., 308.Patai, S., 25, 179.Patat, F., 30.Paton, A., 248.Paton, F., 444.Patterson, A., 20.Pattison, F. L. &I., 215.Patwardhan, M. V., 349.Patzak, R., 398.Paul, A. D., 18.Paul, D. E., 172, 173.Paul, J., 394.Paul, L., 311.Paul, M. A., 14, 198.Paul, R., 288.Paulik, F., 428.Paulik, J., 428.Pauling, L., 108, 177, 451.Pauling, P., 143.Pausacker, K. H., 207.Pauson, P. L., 150, 271.Pavaranam, S. K., 310.Pavlath, A. E., 140.PavlikovB, E., 418.Payne, D. A., 114.Payne, D. S., 132.24.Payza, A. N., 297.Pazur, J.H., 326, 327.Peacock, R. D., 158, 161,Peacock, T. E., 171.Peacocke, -4. R., 331, 336,Peake, D. AI., 418.Peake, J. S., 107.Peaker, F. W., 28.Peal, W. J., 274.Pearce, E. M., 31.Pearce, M. L., 19.Pearl, I. A., 303.Pearson, P. G., 144.Pearson, R. B., 193.Pearson, R. G., 11, 13, 16,Pearson, R. K., 117.Pearson, T. G., 48.Peat, S., 319, 320, 328.Pecsok, R. L., 406.Pedersen, C. J., 204.Pedersen, D. L., 298.Pedersen, K. J., 13.Peeling, E. R. A., 210.Pegues, E. E., 26, 179.Pelizzoni, F., 303.Pelletier, S. W., 212, 313.Pelter, A., 247.Pendse, H. K., 299.Penfold, A., 172.Penfold, A. R., 237.Pengilly, B. W., 203.Penland, R. B., 145.Penner, S. S., 57, 58, 60.Pennington, F. C., 188.Penny, I. F., 368.Pentland, N., 74.Pepinsky, R., 433, 437,Percheron, F., 309.Percival, E., 317, 321, 363.Perevalova, E. G., 271.Perkampus, H.-H., 439.Perkins, P.G., 120.Perlinger, H., 194, 286.Perlin, A. S., 319, 327, 328.Perloff, A., 442.Perpar, M., 396.Perri, J. A., 447.Perrier, M., 22.Perrin, D. D., 22, 23.Perrot, R., 128.Perry, M. B., 324, 325.Person, W. B., 55, 56, 57,Persson, A., 409.Pesaro, M., 265.Peters, D., 251.Peterson, D. H., 284.Peterson, D. J., 218.Peterson, D. L., 439.Peterson, G. B., 336.Peterson, J., 464.Peterson, M. D., 94.448.338, 339.25, 184.442, 443, 455, 457.60, 65, 108, 140.Peterson, R. G., 303.Peterson, S. W., 435, 436,Petree, H. E., 236.Petree, M. C., 27.Petretic, G. J., 389.Petro, A.J., 267.Petrov, A. D., 218.Petrow, V., 273, 276.Petry, 0. A., 75.Petrzilka, T., 296, 306.Pettit, R.. 265, 266, 285.Pfab, W., 151.Pfister. H., 447.Pfleiderer, W., 298, 299.Pflugmacher, A., 119,154.Philbin. E. M., 300.Phillips, A. H., 246.Phillips, D. C., 466.Phillips, G. B., 368.Phillips, G. M., 160.Phillips, L., 160.Piccolini, R., 231, 269.Pichat, L., 195.Pickard, R. H., 216.Pickering. R. A., 234.Pickworth, J.. 465.Pierce, L., 109.Pietsch, R., 397.Pigman. W., 325.Pihar, O., 379.Piirma, I., 33.Pike, E. A., 213.Pilgeram, L. O., 375.Pilz, W., 422.Pimental, G. C., 97, 105,Pinch, H. L., 162.Pinder, A. R., 304.Pinder, J. A., 41.Pinkard, R. M., 316.Pirt, S. J., 324.Pirtea, Th. I., 397.Pistorius, C.W. F. T., 103,Pitt, C., 126, 217.Pitt, D. A,, 267.Pitts, J. N., 41.Pitzer, K. S., 98, 105, 107,Pivnutel, V. L., 121.Placito, P. J., 421.Plane, R. A., 22.Plato, K., 461.Plattner, P. A., 305.Pleskov, Yu. V., 166.Plieninger, H., 253, 295,Plieth, K., 461.Pliva, J., 238, 341.Plotnikova, G. I., 207.Plyler, E. K., 60, 95, 101,Pocker, Y., 23, 25, 179,Podall, H. E., 146.439.130.105, 106.109.296.105.195, 196490 INDEX OF AUTHORS’ NAMES.Poddubnaya, S. S., 237.Poisson, J., 308.Pokras, L., 14.Pol, E. H., 337.Polanyi, J. C., 41, 83, 85,Polecek, E., 406.Polgar, N., 228.Polhyan, E. S., 78.Pollak, M., 410, 433.Pollard, F. H., 137.Pollock, J. McC., 125.Polo, S. R., 62, 65.Polonsky, J., 360.Poynton, M., 311.Ponomarenko, V.A., 209.Pontremoli, S., 357.Poole, A. G., 375.PopjAk, G., 226, 247, 272.Pople, J. A., 105, 171, 178.Popov, A. I., 140.Popper, P., 446, 447.Port, W. S., 34.Porteous, J. W., 376.Porter, G., 49, 91, 93, 201.Porter, G. B., 135.Porter, G. R., 187.Porter, M., 288.Porter, Q. N., 288.Porter, R. F., 112,113,162,Posey, F. A., 16, 22.Posner, A. S., 442.Posner, 13. S., 378, 385.Post, B., 154, 447.Posternak, T., 300, 365.Postulka, S., 22.Potter, E. C., 75.Poulos, N. A., 283.Poulson, R. E., 26.Pouyet, J., 335.Pover, W. F. R., 376.Povlock, T. P., 118.Powell, A. L., 19.Powell, H. M., 142, 164,Power, F. B., 356.Powers, J. W., 215.Prasad, K. B., 297, 308.Prasad, R. N., 299.Pratt, L., 148, 151.Pratt, M.W. T., 110.Pratt, N. H., 193.Prazak, M., 78.Preece, A., 315.Prelog, V., 179, 231, 235,258.Preobrazhenskii, N. A.,226, 305, 306.Preston, B. N., 339.Preusse, C., 386.Prevedorou, C. C. A., 154.Prlbil, R., 398.Price, C. C., 207, 234.Price, T. S., 76.Pricer, W. E., 375.88.166.448, 449, 458, 463.Pridham, J. B., 328.Pridham, J. D., 303.Priestley, L. J., jun., 413.Prieto, A. P., 235.Prinzbach, H., 292.Pritchard, D. E., 174.Pritchard, H. O., 97.Pritchard, J. C., 199.Pritchard, J. G., 185, 193.Prokof’yeva, M., 318.Prosen, R. J., 465.Prosser, F. P., 48.ProStenik, M., 228.Prue, J. E., 16, 21, 24.Pruett, R. L., 151.Pruff, H., 391.Przybylska, M., 465.Pu&r, Z., 428.Piischel, R., 398.Pugh, A.C. P., 112.Pullin, A. D. E., 66, 125.Pullman, A., 251, 380.Pullman, B., 208, 251, 380,Purcell, R. H., 48.Purlee, E. L., 9, 17.Purnell, J. H., 411.Purves, C. B., 317, 318.Puxeddu, A., 157.Pyszora, H., 118.Quagliano, J. V., 108, 145.Quelet, R., 207.Quilico, A., 296.Quimby, 0. T., 131.Quinkert, G., 219,242,283.Raaen, V. F., 196, 263.Rabideau, S. W., 12, 158,Rabin, B. R., 347.Rabinovitch, B. S., 87.Rabinowitch, E., 92.Rabinowitz, J. C., 330.Rabinowitz, R., 212.Racker, E., 353, 356.Radwitz, F., 120.Rae, J. J., 372.Raeo, A. S., 238.Rahnke, J., 222.Rahtz, D., 304, 305.Rajadurai, S.. 242.Rajbenbach, A., 206.Ramadas, C. V., 306.Ramage, G. R., 237, 299.Raman, K., 244.Ramaseshan, S., 443.Ramsay, D. A., 48, 56, 96,Ramsden, H.E., 218.Ramsey, W. J., 451.Ramstad, E., 321.Randall, J. J., 252.Randerath, K., 298.Randles, J. E. B., 68, 76.Rangananthan, S. K., 317.381.159.97.Rank, D. H., 96.Ranz, W. E., 70.Rao, C. N. R., 97, 99.Rao, D. V. R., 397.Rao, G. G., 398, 399.Rao, G. S., 155.Rao, K. S., 96.Rao, M. R. R., 363.Rao, P. N., 244.Rao, P. T., 96.Rao, U. R., 306.Rao, V. P., 399.Rao, V. V., 96.Rapala, R. T., 272.Raphael, R. A., 233, 388,Rapoport, A. L., 318.Rapoport, H., 268, 294.Rappoldt, M. P., 283.Rapport, M. M., 373, 374.Raschig, H., 299.Rasmussen, S. E., 10.Raspi, G., 420.Rathbone, P., 129.Rathfelder, P., 198, 260.Rathjen, H., 51.Raupp, G., 413.Rausch, M. D., 34, 371.Rausser, R., 275.Ravel, J. M., 299.Rawal, T.N.. 317.Ray, A. E., 450.Ray, R. R., 202.Rayner, J. H., 164.Razzell, W. E., 337.Re, L., 238.Reading, H. W., 290.Ream, N., 83.Rebers, P. A., 324.Reddi, K. K., 333.Redfield, B., 296.Redlich, O., 13, 26.Reed, R. A., 130, 220.Reed, R. I., 273.Reed, W. L., 184.Reeder, J. A., 206.Reedy, A. J., 118.Reese, C. B., 334.Reeves, C. M., 64.Reeves, R. A., 259.Reeves, R. E., 364.Reeves, R. R., 88.Reichenthal, J., 356.Reichstein, T., 275, 276,Reid, C., 93.Reid, D. E., 221.Reid, D. H., 266.Reid, W. W., 302.Reifschneider, W., 272.Reilley, C. A., 13. 26.Reilley, C. N., 69, 72, 76.Reimschussel, H., 317.Reineke, L. M., 284.Reiner, B., 336.Reinheimer, J. D., 2.5, 180.290.360Reiser, A., 241.Reishakhrit, L.S., 407.Reisman, A., 155.Reiss, H., 64.Reitan, A., 103.Reitz, H. C., 378.Rembaum, A., 206.Rembold, H., 298.Renner, K. C., 157.Rentzeperis, P. J., 442.Renwer. J. F., jun., 200.Repenning, K., 221.Reppestam, V., 401.Rerick, M., 211.Resnik, F. E., 316.Rettie, G. H., 249.Reuter, B., 400.Reuther, K.-H., 413.Reyhling, J., 107.Reymond, D., 365.Reynolds, L. T., 107, 123.Reynolds-Warnhoff, P.,Rheiner, A., 283.Rhodes, I>. N., 366, 367,Riad, S., 78.Ricca, S., jun., 294.Ricci, J. E., 258.Rice, F. A. H., 317, 328.Rice, F. O., 48, 49.Rice, L., 354.Rice, 0. K., 37, 80.Rice, R. G., 134.Rice, S. A., 338.Rich, A., 332, 340, 341,Richards, A., 297.Richards, G. N., 319.Richards, R. E., 26, 98,135, 142, 235, 434.Richardson, J.W., 452.Richert, D. A., 352.Rickards, R. W., 246.Ricketts, R. W., 301.Ridd, J. H., 193, 200, 288,Riddiford, A. C., 70.Rieche, A., 213, 214.Ried, C., 258.Ried, W., 265.Riedel, K., 416.Riegel, B., 272.Rieke, A., 201.Rieman, W., tert., 411.Rigaudy, J., 275.Riley, J. P., 396.Rilling, H., 226, 246.Rinehart, K. L., 228.Ringold, H. J., 275, 277,Riniker, B., 272.Riniker, R., 235, 272.RistiE, S., 136.Ritchie, E., 249.Ritter, D. M., 218.Rittner, E. S., 95.304.368.342.297.DEX OF AUTHORS’ NAMES. 491Rivest, R., 155.Rivett, D. A. E., 249.Rivington, D. E., 22.Ro, R. S., 179, 184, 230.Robb, J. C., 38, 89, 193.Robbins, E. A., 347.Roberts, E. A. H., 302.Roberts, E. K., 37.Roberts, G., 272.Roberts, J.B., 301.Roberts, J. D., 53, 179,Roberts, J. E., 123.Roberts, J. G., 320.Roberts, R. M., 255.Roberts, R. W., 318.Robertson, A., 245, 246,Robertson, D. S., 139.Robertson, J. H., 149, 452.Robertson, J. M., 437.Robertson, P. S., 125.Robin, J., 57.Robins, A. B., 335.Robins, P. A., 281.Robins, R. K., 299.Robinson, D., 155, 384.Robinson, D. N., 295.Robinson, D. Z., 60.Robinson, G. C., 16, 180.Robinson, G. W., 98.Robinson, J. W., 427.Robinson, M. T., 99, 442.Robinson, P. L., 128, 162.Robinson, P. S., 139.Robinson, (Sir) R., 237,266, 285, 295, 303.Robinson, R. A., 9, 10.Robison, M. M., 188.Rochow, E. G., 123, 126,133, 218.Rocks, L., 99.Rodbell, Pvl., 368.Rodden, C. J., 389.RodCn, L., 363.Rodighiero, G., 300.Roe, J.H., 354.Rohnsch, W., 135.Rmt, E., 447.Rogers, G. T., 166.Rogers, M. T., 139, 273.Rogers, N. A. J., 242.Rogers, V., 269.RogiC, M. M., 211.Rogovin, Z . , 318.Roiter, V. A., 78.Rolfe, J. A., 23.Rollefson, R., 59, 60.Romo, J., 276.Rona, P., 211, 254, 254,Rondle, C. J. M., 317.Rorsch, A., 334.Ros, A., 318.Rosell, R. A., 395, 427.215, 231, 261, 269.303.465.263.Roseman, S., 325, 358, 360.Rosen, P., 395.Rosenberg, A., 343.Rosenberg, B. H., 338.Rosenberg, H., 271.Rosenberg, N. W., 48, 53.Rosenberg, S. D., 218.Rosenblatt, D. H., 25.Rosenblum, M., 271.Rosenkranz, H. S., 335.Rosenthal, D., 189, 234.Rosentock, H. M., 47.Rosoff, M., 335, 338.Ross, A. G., 321.Ross, G.W., 288.Ross, I. G., 170.Ross, W. A., 112.Rosselet, J. P., 284.Rossi, S., 288.Rossmann, M. G., 240,270.Rossotti, F. J. C., 13.Rossotti, H., 13.Roszkowski, E. S., 389.Roth, L. E., 117.Rothberg, G. M., 112.Rother, E., 132.Rothery, R. W., 61.Rothrock, T. S., 196.Rout, M. K., 309.ROUX, D. G., 302.Roux, M., 177.Rowe, C. E., 320.Rowlands, J. R., 173.Royals, E. E., 230.Rubin, 31. B., 281.Rubin, R. J., 61, 80.Ruddlesden, S. N., 446,Rudorff, W., 124, 135.Riiegg, R., 225, 226.Ruegg, W., 70.Ruetschi, P., 74.Ruf, E., 419, 421.Rundel, W., 215, 229.Rundle, R. E., 100, 123,154, 166, 448, 450, 451,452, 453.447.Rupley, J. A., 349.Rusanov, A. K.. 424.Rushbrook, R. B., 322.Rushworth, F. A., 102,Russell, G.A., 34, 209, 210.Russell, &I., 369.Russell, R. A., 56, 66.Rust, R. A., 29.Rutkin, P., 258.Rutledge, R. L., 202.Ryan, A. J., 303.Rybicki, Z., 317.Rybinskaya, I. M., 297.Rydon, H. N., 187, 298.RySAnek, A., 28.Ryschkewitsch, G. E., 119.Sacconi, L., 146.461492 INDEX OF AUTHORS’ NAMES.Sado, A., 172.Sadron, C., 32, 335.Saeki, S., 297.Safranski, L. W., 404, 412,Saha, H., 356.Saha, N. G., 28.Sahu, J., 91.Saigh, G. S., 48.Saini, G., 23, 116.Saito, K., 318.Saito, Y., 453.Saitow, A., 218.Saka, T., 375.Sakata, R., 31.Saksence, S. S., 315.Sala, O., 106.SalamC, L. W. F., 217.Salemink, C. A., 314.Salkoff, M., 83.Salo, M., 317.Salomaa, P., 188.Salt, E., 365.Salter, R., 82.Saltmarsh, O., 49.Salton, M.R. J., 358.Salvetti, O., 143.Sampson, D., 392.Samuel, D., 190.Samuel, I., 383.Samuelson, B., 284.Sanders, C., 359.Sanderson, R. T., 114.Sandiford, P. J., 57, 60.Sandler, S., 407.Sandler, S. R., 216.Sandorfy, C., 57.Sandros, K., 93.Sands, D. E., 100, 115,156, 440, 449.Sanghi, I., 79, 415.Sanjana, N. R., 446.Sandoval, A., 309.Sant, U. A., 402.Santappa, M., 30.Santucci, L., 118.Sanyal, A. K., 318.Sarceno, A. J., 108.Sarett, L. H., 277.Sarkanen, K., 93.Sarkar, B. P., 325.Sarrach, D., 135.Sarson, R. D., 400.Sartori, G., 107.Sarycheva, I. K., 226.Sasada, Y., 461.Sass, R. L., 99, 441, 443.Sass, S., 422.Sastri, T. P., 398.Satchell, D. P. N., 14, 190,199, 209.Sato, A., 325.Sato, N., 78.Sato, S., 54, 89.Sato, T., 159, 225, 305.Satterfield, C.N., 86.413.Saucy, G., 225, 226.Sauer, H., 128.Sauer, J., 261, 262.Sauer, J. C., 221.Sauer, K., 52, 89.Sauers, R. R., 274.Saunders, M., 252.Sauret, G., 318.Saville, B., 187.Saville, R. W., 288.Sawyer, D. T., 406.Saxton, J. E., 295.Sayigh, A., 214.Scaife, D. B., 18.Scales, B., 245.Scanlan, J . , 17 1.Scardiglia, F., 261.Scargill, D., 157.Scatturin, V., 163,444,452.Schaad, L. J., 200, 202.Schaafsma, A., 145.Schaal, W., 163.Schade, G., 237.Schafer, H., 124, 449.Schafer, J., 294.Schaeffer, G. W., 117.Schaeffer, H. J., 299.Schaeffer, R., 98, 115, 116.Schaffner, K., 249.Scharf, R., 398.Schatz, P. N., 60, 65, 104,Scheer, M. D., 202.Scheffler, K., 201.Scherer, H., 258.Scherer, J.R., 60, 108.Scheuchenpflug, D. R., 270.Scheunemann, B., 382.Schick, M., 359.Schiffer, L., 303.Schindler, A., 36.Schindler, O., 272, 275,Schinkel, H., 425.Sching, H., 238.Schipper, E., 227.Schissler, D. O., 43, 47.Schlag, E. W., 87.Schlechte, G., 201.Schlenk, W., jun., 463.Schlesinger, H. I., 119.Schlitt, R., 197.Schlogl, K., 223.Schlubach, H. H., 221.Schmalz, E. O., 73.Schmeckenbecker, A., 123,Schmeisser, M., 142.Schmid, E., 130.Schmid, H., 233, 252, 303,Schmid, R. W., 72, 76.Schmidhuber, W., 201.Schmidt, G., 373.Schmidt, G. M. T., 434,105.282,124.309, 310.459, 466.Schmidt, H., 124.Schmidt, L., 99, 124.Schmidt, M., 137.Schmidt, 0. T., 303.Schmidt, P., 299.Schmidt, W., 135.Schmier, G.L., 186.Schmitt, J. T., 317.Schmitz, E., 213.Schmitz-Du Mont, O., 163.Schneider, J., 267.Schneider, W. G., 178, 439.Schnell, A. W., 357.Schnepp, O., 439.Schnider, O., 305.Schober, G., 111.Schon, W., 157.Schonberg, A., 201.Schoenewaldt, E. F., 284.Schoental, R., 379.Schofield, J. A., 187.Schofield, K., 294.Scholder, R., 111.Scholes, G., 334, 336.Scholfield, C. R., 369.Schomaker, V., 99, 100.Schomburg, G., 413.Schoonmaker, R. C., 112,113, 162, 166.Schormuller, J., 408.Schotten, J., 137.Schouteden, F., 404.Schramm, G., 333.Schrauzer, G. N., 150, 222,Schrecker, A. W., 285.Schreiber, J., 265.Schreurs, J. W. H., 173.Schroder, G., 269.Schroeder, E., 356.Schroder, G., 29.Schroeder, W., 208.Schubert, A., 284.Schulz, H., 290.Schundehu tte, K.-H., 299.Schuerch, C., 321.Schutt, W., 273.Schuetz, R.D., 212.Schuhknecht, W., 425.Schujkin, N. I., 210.Schuldiner, S., 70, 74.Schulek, E., 402.Schulenberg, S., 356.Schuler, N. W.. 28.Schuler, R. H., 94.Schultz, D. R., 116, 117.Schultz, J. W., 60.Schulz, G. V., 27.Schulze, H. O., 356.Schulze, J., 133.Schumacher, E., 278.Schumeiko, A. N., 237.Schurin, B., 59.Schurin, B. S., 60.Schury, J., 402.Schuster, H., 262, 333.271INDEX OF AUTHORS’ NAMES. 493Schuyff, A., 464.Schwab, C. M., 129.Schwabe, K., 67, 71.Schwaebel, R., 194.Schwartz, A. W., 207.Schwarz, H. P., 423.Schwarz, R., 12, 125, 137,Schwarzenbach, G., 7, 9,Schweiger, R., 319.Schweiker, G.C., 211.Schwenecke, H. J., 265.Schwenk, E., 382.Schwenk, U., 413.Schwieter, U., 225.Scott, J. E., 315.Scott, J. F., 332.Scott, N., 156.Scott, T. A., 320.Scribner, R. M., 287.Scrocco, M., 107.Seabaugh, P. X., 156.Seaborg, G. T., 111, 158,Searcy, A. W., 155.Searles, R. A., 112.Sears, P. G., 19.Seaton, J. C., 308.Sebek, 0. K., 284.Seebeck, E., 309.Seeds, W. E., 338.Seeger, W., 234.Seel, F., 128, 194.Seese, W. S., 299.Segal, G. M., 233.Segal, H., 228.Segal, S., 360.Segal, W., 263.Segatto, P. R., 127.Segre, A., 294.Seidman, E. B., 401.Sekiyama, H., 177.Seligson, D., 425.Semenenko, K. N., 113.Semenov, D., 195.Semenov, N. N., 31.Semenow, D. A., 53.Semenza, G., 335.Semerano, G., 67.Semmlinger, W., 152, 271.Semple, R.E., 315.Sender, M., 69, 172.Sen Gupta, J. G., 399.Sengupta, P., 250.Sengupta, S. K., 250.Senise, I?., 22.Senkpiel, W., 137.Sensabaugh, A. J., 404.Senti, F. R., 315, 320.Serck-Hanssen, K., 227.Serota, S., 279.Seshadri, T. R., 301.Seta, Y., 246.Setton, R., 113.Setz, P., 366.138.12, 14, 142.160.Seuter, A.M. J. H., 134.Sevcik, A., 68.Seyferth, D., 133, 218.Shaffer, L. H., 213.Shaffer, W. H., 61.Shafferman, R., 114, 118.Shafig, M., 242.Shafizadeh, F., 318, 353.Shahak, I., 215.Shallcross, F. V., 97.Shamma, M., 306.Shapiro, D., 228.Shapiro, H. S., 336.Shapiro, I., 108.Shapiro, N. S., 75.Sharkey, A. G., jun., 425.Sharkey, W. H., 224, 264.Sharman, S. M., 195.Sharon, N., 324, 359.Sharp, R.F., 12.Sharples, L. K., 39.Shashona, V. E., 35.Shavitt, I., 64.Shaw, B. L., 164.Shaw, C. J. G., 330.Shaw, D. R. D., 356.Shaw, G., 334.Shaw, K. B., 292.Shchegoleva, T. A., 118.Shearer, H. M. M., 437,438, 460, 461.Shedlovsky, T., 10, 67.Sheehan, J. C., 222.Sheldon, E., 74.Sheldon, J. C., 129, 132,Shelesnyack, C., 357.Sheline, R. K., 107, 148.Shelton, J . R., 291.Shemyakin, M. M., 265.Shepelenkova, E. I., 237.Shepherd, G. G., 100.Shepp, A., 37, 38.Sheppard, J . C., 25.Sheppard, N., 246.Sheridan, J., 97, 100, 152,Sherma, J., 411.Sherratt, H. S. A., 300.Shibasaki, K., 327.Shibata, S., 419, 452.Shida, S., 90, 91, 176.Shigeura, H. T., 332.Shimada, A., 456.Shimanouchi, T., 107, 109.Shimizu, Z., 287.Shine, H.J., 197.Shiner, V. J., 184.Shinz, H., 230.Shiono, R., 456.Shipley, D. K., 210.Shipley, F. W., 210.Shirasaka, M., 284.Shive, W., 299.Shoemaker, C. B., 451.Shoemaker, D. P., 451.133.175.Shonleben, W., 303.Shoolery, J.N.,98,115,223.Shooter, K. V., 335, 338.Shoppee, C. W., 272, 274,Shore, S. G., 116.Short, H. G., 419.Shostakovsky, M. F., 207.Shoulders, B. A., 230, 258.Shryne, T. M., 217.Shugar, D., 334.Shuler, K. E., 61, 80.Shull, H., 63.Shvo, Y., 250.Shwachman, H., 391.Sibilia, J. P., 101.Sicher, J., 236, 305.Siddiqui, I. R., 324.Sidman, J. W., 172.Siebert, R., 284.Siedel, W., 292.Siegel, B., 116, 118.Siegel, H., 258.Siegel, M., 258.Siegel, S., 449.Siegmann, C. M., 282.Siemaszko, A., 317.Siewert, J., 400.Sigal, M.V., jun., 356.Sigg, H. P., 275.Sigwalt, P., 33.Sih, C. J., 356.Si-Hoe, S. S., 209.Sikkeland, T., 160.SillCn, L. G., 7, 11, 13, 14,Silva, E., 427.Silver, B., 190.Silverman, J., 449,Silverman, L., 427.Silverman, M. B., 218.Silverman, N., 309.Silverman, S., 58, 60, 61.Silversmith, E. F., 232.Sim, G. A., 438.Simamura, O., 36.Simes, J. J . H., 249.Simionescu, C., 318.Simmons, H. E., 228, 231.Simmons, M. C., 412.Simmons, N. S., 331.Simms, E. S., 337.Simon, E., 357.Simonetta, M., 172.Simonsen, J. L., 237.Simpson, E. A., 23.Simpson, F. J., 355, 356.Simpson, M. P., 417.Simpson, W. T., 172, 439.Sims, A. F. E., 290.Sims, P., 376, 379.Sinclair, H. K., 264.Singer, G.H., 24, 106,Singer, M. F., 339, 340.Singer, T. P., 343, 351, 352.Singh, G., 315.276.16, 142494Singh, N. L., 60.Singh, S., 209.Singleterry, C. R., 9.Sinha, A. P. B., 446.Sinha, R. N. P., 155.Sinn, H., 221.Sinn, V., 32.Sinnot, K. M., 97, 128.Sinsheimer, R. L., 334.Sisler, H. H., 119.Skancke, P. N., 102.Skaric, V., 314.Skatteberl, L., 232.Skell, P. S., 53, 198, 216,Skiens, W. E., 141.Skirrow, G., 204.Sklar, A. L., 170.Skoda, W., 402.Skorokhodov, I. I., 135.Skrobek, A., 278.Skvortsova, N. I., 237.Slater, C. A., 250.Slater, E. C., 349.Slater, N. B., 103.Sleeman, K., 425.Slein, M. W., 357.Sloan, M. F., 233.Sloane-Stanley, G. H., 365,Slomp, G., 285.Sly, W. G., 449.Small, P. A., 429.Smaller, B., 202.Smellie, R.M. S., 337.Smets, G., 28, 33.Smid, J., 208.Smit, P., 209.Smith, A. C. K., 27.Smith, A. H., 302.Smith, B. C., 129.Smith, D. B., 316, 376.Smith, D. F., 141.Smith, E. L., 293, 347.Smith, F., 316, 319, 321,324, 327, 329.Smith, G. E., 217.Smith, G. F., 417.Smith, H., 212, 245, 246,Smith, H. G., 166.Smith, H. M., 13, 24, 247.Smith, H. W., 298.Smith, J. A. S., 157, 457.Smith, J. D., 147, 331, 333,Smith, J. F., 450.Smith, J. M., 247.Smith, J. N., 363, 376, 377,382, 383, 384.Smith, L. W., 310.Smith, M., 235.Smith, M. J., 41.Smith, M. L., 138, 184.Smith, P. W. G., 290.Smith, R. D.. 228,231,284.221.371.251.334.DEX OF AUTHORS’ NAMES.Smith, R. N., 416.Smith, R. P., 177.Smith, R.W., 24.Smith, S. G., 181, 215.Smith, S. W., 371, 375.Smith, T. D. , 233.Smith, W. H., 426.Smith, W. R., 205.Smithson, J. M., 22.Smolinsky, G., 269.Smymiotis, P. Z., 355.Smyth, C. P., 267.Smyth, F. T. B., 300.Smyth, R. P., 108, 258.Smythe, L. E., 126.Sneen, R. A., 273.Sneezum, J. S., 266.Snegova, A. D., 209.Snell, E. E., 349.Snell, R. L., 233.Snobl, D., 426.Snyder, H. R., 118, 295.Sobin, B. A., 231.Sobolev, G. A., 96.Soffer, M. D., 239.Soldatos, C. T., 442.Solomon, D. H., 237.Solomon, I. J., 116.Solomon, J. B., 376.Solomons, C., 14, 137.Solomons, T. W. G., 297.Soloway, S., 395.Sols, A., 356, 359.Solt, M. L., 304.Somerfield, G. A., 211, 300,302.Sondheimer, F., 234, 247,255, 273, 283, 305, 464.Sonesson, A., 18.Sonnenfeld, E., 206.Ssrensen, J. S., 223, 288.Ssrensen, N.A., 223, 288.Ssrensen, P., 213.Sorm, F., 238, 239, 240,Sorokin, Yu , I., 94.Sosnovsky, G., 203, 214,SouEek, M., 240, 241.Souquey, C., 325.Southern, P. F., 207.Southwart, D. W., 423.Sowerby, J., 74.Spackman, D. H., 390.Spackman, D. L., 347.Spaleny, J., 379.Spandau, H., 122.Sparatore, F., 314.Sparks, R. A., 99, 449.Speakman, J. C., 10, 179,Specker, H., 391.Spector-Shefer, S., 228.Spedding, F. H., 154, 448.Spedding, H., 60.Speden, R. N., 241.241, 249.230.436, 460.Spell, A., 32.Spencer, B., 192, 377.Spencer, M., 338.Spice, J. E., 124.Spier, G. S., 416.Spiess, W., 138.Spinar, L. H., 112.Spiridonov, V. P., 96.Splitter, J.S., 229, 286.Spooner, J. L., 415.Sporer, A. H., 144.Spring, F. S., 247, 248, 249.Sprinson, D. B., 357.Spurr, R. A., 66.Srinavasan, P. R., 357.Srivastava, H. C., 325, 327.Stacey, F. R., 206.Stacey, F. W., 207.Stacey, M., 315, 324, 325,327, 330, 336, 356, 365.Stache, U., 283.Stadelmaier, H. H., 166.Staehelin, M., 333.Stafford, F. E., 185.Stafford, W. H., 266.Stafford, W. L., 266.Stagg, H. E., 403.Stahl, F. W., 338.Stambaugh, C. K., 450.Stammerick, H., 106.StanaCev, N. Z., 228.Stander, W., 311.Stankevich, I. V., 268.Stanley, C. R., 85.Stannett, V., 34.Stark-Mayor, C., 395.Starke, K., 162.Starr, M. P., 362.Staub, A. M., 325, 360.Staubach, K.-E., 69.Stancer, H. C., 369.Stauffacher, D., 309.Staveley, L.A. K., 13.Staverman, A. J., 33.Steacie, E. W. R., 38, 39,Stedman, G., 12, 130, 193.Steel, D., 60.Steele, M. C., 158.Stegerhoek, L. J., 369, 372.Stein, E. A., 346.Stein, G., 208, 378.Stein, T. W., 86.Stein, W. H., 390.Steinberg, N. G., 277.Steiner, R. F., 341.Steiner, W. A., 210.Steinfink, H., 445.Steinrauf, L. K., 464.Stening, T. C., 330.Stenlake, J. B., 289.Stent, G. S.. 335.StepBnek, J. M., 408.StCphan, J. P., 120.Stephen, M. J., 63.Stephens, D., 129.41, 49, 89, 90Stephens, H. L.. 24.Stephens, R., 365.Stephenson, J. S., 276.Stephenson, L. , 78.Stephenson, M. L. , 332.Stephenson, N. C., 165.Stern, K. H., 19.Stern, M., 78, 391.Sternberg, H. W., 150, 222,Stetter, H., 294.Stevens, B., 85, 86, 89, 104.Stevens, C.L., 286.Stevens, I. D. R., 194.Stevens, M. A., 298.Stevens, T. E.. 129.Stevens, T. S., 196, 220,Stevens, V. L., 338.Stevenson, D. P., 43, 45,47, 94, 95, 430.Stevenson, R., 248.Stewart, D. C., 160.Stewart, D. G., 266, 268.Stewart, F. H. C., 164.Stewart, G., 90.Stewart, G. H., 108, 177.Stewart, J. A., 420.Stewart, J. L., 248.Stewart, M. A. A., 139.Stewart, M. H., 317.Stiles, M., 188.Stilz, W., 262.Stimac, N., 305.Stimson, V. R., 185, 188.Stirm, S., 360.Stivers, E. C., 200.Stoffyn, P. A., 363.Stoicheff, B. P., 96, 109,Stokes, R. H., 9.Stokes, W. M., 283.Stoll, B., 138.Stoll, R. D., 366.Stone, B. R., 334.Stone, F. G. A., 114, 117,133, 230.Storey, B. T., 213.Stotz, E., 372.Stoudt.T. H., 284.Stoughton, R. W., 17.Stout, G. H., 303.Stoy, V., 348.Strachan, A. N., 49, 55.Strain, H. H.. 428.Straley, J. W., 60, 65.Strandberg, B., 444.Strange, R. E., 358.Stratton, R. F., 97.Strause, B. M., 427.Strauss, H., 265.Street, E. H., 130.Streibl, M., 249.Streitweiser, A., jun., 180,Strickland, G. J., 12.271.297.176.195.INDEX OF AUTHORS’ NAMEStrickland, G. T., 145.Strickland, J. D. H., 416.Strickson, J. A., 126.Stramme, K. O., 140, 462,Strominrrer. D.. 111.463.Strominier; J. L., 354, 358,359.Stross, F. H., 411.Stroupe, J. D., 32.Stuart, A. A. V., 174.Stulberg, M. P., 347.Sturgeon, R. J., 323.Style, D. W. G., 97.Subcasky, W. J., 73.Subramanian, P., 301.Subramanian, R. V., 29.Such?, M., 238.Sud, L.R., 317.Suen, T. J., 30.Sugden. T. M., 88.Suhr, H., 194.Sujishi, S., 126.Sukhobokova, W. S., 407.Sukurai, S., 216.Sullivan, J. C., 159.Sullivan, J. O., 88.Sumarakova, T., 127.Sumerwell, W. B., 346.Sumi, M., 239.Sumiki, Y., 246.Summers, G. H. R., 276.Summers, L. A., 291.Sumner, G. G., 443.Sundera-Rao, R. V. G.,Sundermeyer, W., 115.Sunderwirth, G. G., 317.Susz, B. P., 120, 121.Sutcliffe, F. K., 296.Sutcliffe, G. R., 418.Sutcliffe, L. H., 102.Suter, H., 400.Sutherland, G. B. B. M.,Sutherland, I. O., 293.Sutor, D. J., 459.Sutton, G. J., 123, 157, 161,Sutton, L. E., 120, 142.Suzuki, M., 34.Suzuki, S., 180.Suzuki, T., 333.Svec, H. J., 157.Svendsen, S. R., 72.Svoboda, M., 236.Swain, C.G., 26, 179, 200,Swalen, J. D., 109.Swan, E. P., 318.Swan, G. A., 297, 308.Swann, S., jun., 67.Swann, W. B., 411.Swanwick, J. D., 154.Swern, D., 34, 204.Swinehart, D. F., 8, 23.442.338.162.202.Swinehart, J., 415.Sqkora, V., 233, 238, 239.Syme, A. C., 426.Symons, M. C. R., 35, 202,Synek, L., 426.Szabolcs, J. , 224.Szekeres, L., 400.Szent-Gyorgyi, A., 20 1.Szinai, S., 249.Szpilfogel, S. A., 282.Szwarc, M., 33, 34, 42, 48,87, 206, 208, 260.Taber, H. W., 270.Tabuchi, D., 110.Tachi, I., 69, 321,Taft, R. W., jun., 179, 186,Tagaki, Y., 355.Tarts, S. Z., 288.Takahashi, N., 246.Takahashi, T., 247, 284Takai, M., 246.Takasi, K., 263.Takayama, Y., 422.Takeda, K., 320.Takeda, R., 287.Takemori, Y., 69.Takemoto, T., 250, 287.Taksemura, S., 333, 336TakCuchi, Y., 437, 453.Takiguchi, T., 401.Tal%t-Erben, M., 28.Tal’roze, V.L., 45.Talsky, G., 137.Tamara, K., 96.Tamm, C., 272, 273, 284.Tamm, R., 306.Tamura, S., 246.Tanabe, K., 51, 238.Tanaka, C., 106.Tanaka, Y., 91.Tanenbaum, S. W., 303.Tanghe, L. J., 317.Taniguchi, H., 10.Tanner, D. D., 196.Tanner, D. W., 93.Tapley, J. G., 202.Tarbell, D. S., 237, 242.Tarpley, W. B., 352.Tashpulatov, Ia., 436.Tate, J. T., 45.Tatevskii, V. M., 101.Tattrie, N. H., 353, 367.Taub, D., 278, 279.Taube, H., 16, 22, 143, 194.Taube, R., 154.Taylor, H. S., 44.Taylor, J. B., 155.Taylor, R. C., 106, 108Taylor, T. G., 329.Taylor, T. I., 189.Taylor, T. W. J., 194.Taylor, W.C., 242, 278.207.198.117496 INDEX OF AUTHORS’ NAMES.Taylor, W. E., 366, 372.Taylor, W. H., 444.Taylor, W. I., 245, 308,Taylor, W. J., 98.Tchen, T. T., 226, 227, 246.Teale, F. W. J., 90, 92.Tedoradse, G., 69.Teege, G., 237.Teeter, H. M., 228.Temple, C., jun., 299Templeton, D. H., 166,454.Tener, G. M., 337.Tenney, H. M., 412.ter Borg, A. P., 232, 270.Terenin, A., 90, 121.Ter Heide, R., 409.Tesarik, K., 413.Testa, E., 357.TeyssiC, P., 28.Thain, E. M., 191, 409.Thaker, K., 216, 217.Thaller, V., 229.Thannhauser, S. J., 366,Tharp, A. G., 155.Thayer, S. A., 275.Theander, O., 317, 327.Theimer, O., 67.Theobald. C. W.. 287.Theorell, H., 349.Thesing, J., 295.Thiel, M., 285.Thilo, E., 131, 132.Thirsk, H.R., 71, 74, 77.Thoma, R. E., 158.Thomas, A., 235.Thomas, B., 137.Thomas, B. R., 242.Thomas, G. H. S., 329.Thomas, G. O., 19, 21.Thomas, H. J., 299.Thomas, I. M., 143.Thomas, J. O., 382.Thomas, J. T., 149, 452.Thomas, L. F., 97, 100,Thomas, W. J. O., 107,108.Thompson, A., 131, 325.Thompson, B. A., 427.Thompson, C. R., 301.Thompson, H. W., 56, 60,Thompson, J. M., 223.Thompson, M. E., 311.Thompson, Q. E., 230.Thompson, R. H., 272.Thompson, S., 160.Thomson, R. H., 205.Thorpe, W. V., 377.Thrush, B. A., 80.Tibbs, S. R., 177.Tichy, M., 305.Tickner, A. W., 38.Tideswell, N. W., 447.Tidwell, E. D., 95, 105.309.368, 373.152, 175.66.Tien Chi Chen , 174.Tiensun, V. H., 105.Tierney, P. A., 116.Tillett, J.G., 193.Tillotson, M. J. L., 13.Timell, T. E., 322.Timmis, G. M., 299.Timms, D. G., 414.Tinelli, R., 360.Tiniakova, E. I., 30.Tiplady, J. M., 370.Tipper, C. F. H., 89.Tipper, D. J., 325.Tipson, R. S., 317.Tipton, C. L., 326, 327.Tischer, H., 130.Tischer, R. P., 77.Tishler, M., 273, 276.Titus, E., 369.Tjomsland, O., 137.Tobias, R. S., 11.Tobinaga, S., 249, 285.Tobolsky, A. V., 28, 29,31.Todd, (Sir) A. R., 192,272, 293, 334, 340, 372.Todd, M. N., 61.Tokiwa, F., 422.Toland, W. G., 219.Tolberg, W. E., 227.Tollin, G., 92.Tolonsky, J., 325.Tolstoya, T. R., 252.Tomic, E., 410.Tomiie, Y., 455, 465.Tomita, I., 385.Tomita, Y., 300.Tomkins, G. M., 364.Tondeur, R., 308.Toole, J., 29, 203.Topper, Y.J., 360, 365.Torto, F. G., 225.Touster, O., 354, 355.Townsend, J., 172.Townsend, M. G., 35, 202.Tracey, F. M., 416.Trachtenberg, E. W., 183.Trachtenberg, I., 72, 73.Traill, R. J., 444.Trappe, W., 366.Tratteberg, M., 101.Travers, R. B., 303.Traynham, J. G., 182,Trefonas, L., 99, 119, 441.Treibs, A., 286, 287, 292.Treibs, W., 219, 241, 265.Treter, K., 296.Tretter, J. R., 294.Treumann, W. B., 18.Trevorrow, L. E., 156.Trey, A., 296.Trinler, W. A., 34.Trippett, S., 245.Trischmann, H., 215.Trofimenko, S., 291, 396.188.Tromans, F. R., 421,Tronev, V. G., 114, 138,161.Trossarelli, L., 29, 203.Trotman-Dickenson, A. F.,39, 41, 50, 51, 52, 89,442.Trotter, J., 153, 438, 458,462.Troxler, F., 306, 296.Trueblood, K.N., 465.Triimpler, G., 70.Truter, M. R., 113, 443,452, 456, 457.Trzebiatowski, W., 448.Tschesche, R., 298.Tschudy, D. P., 359.Tsuboi, M., 338.Tsubomura, H., 66.Tsuchida, R., 165, 454.Tsuda, K., 238, 283, 297,Tsuruta, M., 284.Tsuruta, T., 31.Tiidos, F., 36.Tufts, B. J., 392.Tulinsky, A., 438.Tung, T. C., 357.Turco, A., 163, 452.Turgeon, J. C., 8.Turkington, R. W., 416.Turley, J. W., 442.Turnbull, L. B., 284.Turner, D. W., 194.Turner, E. E., 383.Turner, H. S., 119, 120.Turner, J. C., 306.Turner, L. D., 368.Turner, M. B., 366.Turner, R. B., 232.Turney, T. A., 130.Turvey, J. R., 319, 320.Tutin, F., 356.Tyree, S. Y., 132, 133.Tyrrell, H. J. V., 18.Ubbelohde, A. R., 82, 83.Udelhofen, J.H., 296.Udenfriend, S., 296, 378.Ueberwasser, H., 282.Uehara, R., 30.Ueno, K., 418.Ugi, I., 194, 229, 286.Uhlenbroek, J. H., 372.Uhlig, H. H., 79.Ukaji, T., 101.Ukita, T., 367.Ulmschneider, D., 118.Ulrich, S. E., 182.Underwood, A. L., 418.Ungnade, H. E., 232.Unik, J. P., 186.Unrau, A. M., 316, 321.Unterberger, R. R., 202.Uphoff, W., 447.Uprichard, J. M., 245.304INDEX OF AUTHORS’ NAMES. 497UrbAnski, T., 317.Urry, W. H., 50, 205, 206.Urscheler, H., 283.Uyeo, S., 311.Uziel, M., 368.Vanngard, T., 348, 352,Valenta, Z., 312, 313, 314,Vallarino, L., 147.Vallee, B. L., 343, 349.Van Alten, L., 60.van Ammers, M., 289.van Beers, G. J., 366.van Bommel, A. J., 434,Vand, V., 443.van de Kolk, G., 51.van der Bij, J.R., 208.van der Burg, W. J., 282.van der Kerk, G. J. M.,Van der Laarse, J. D., 413.van der Plas, H. C., 289.van der Waals, J. H., 14.VanderWerf, C. A., 217,VanderWerf, S., 222.van Dijlr-Rothuis, J. H.,van Doorn, A. B. C., 123.van Dorp, D. A., 282.van Eck, C. L. van P., 27.van Eenam, D. N., 253.Vangedal, S., 307, 308.van Heyningen, R., 356.Van Holde, K. E., 35.Van Hook, J. P., 28.van Houten, S., 441, 442.VanpCe, M., 50.van Schooten, J., 212.Van Stolk, D., 308.van Tamelen, E. E., 228,237, 242, 304, 306, 358.van Ufford, J. J. Q., 233.Van Wazer, J. R., 14.van Weezel, G. J., 405.Vardheim, S. V., 330.Varshni, Y. P., 103.Vassian, E. G., 23.Vaughan, J., 125, 187.Vdorin, Yu. A., 69.qerera, M., 198, 426.Venanzi, L.M., 163, 165.Vendrely, R., 335.Venkatakrishnan, S., 30.Venkatesan, K., 443.Venkateswarlu, I?. , 48.Vercellone, A., 320.Verdier, P. H., 109.Verkade, P. E.. 369, 372.Verma, G. S., 26.Vermilyea, D. A., 70, 78.Vernon, C. A., 190, 195,353.315.454.127.286.51.230.REP.-VOL. LVVester, K., 150.Vetter, K. J., 73, 74, 76,79.Vicltery, R. C., 124.Vidale, R., 443.Vignale, M. J., 19.Vignes, E. C., 187.Vigoureux, S., 151.Vilkov, L. V., 101.Villar-Palasi, C., 356.Ville, A., 302.Villotti, R., 247, 273.Vincent, D. L., 318.Vingiello, F. A., 257.Vischer, E., 284.Viscontini, M., 299.Visser, J. H., 134.Viterbo, R., 294.Vlcek, A. A., 68.Vodar, B., 57.Volz, H. G., 166.Vogel, E., 232.Vogel, M., 271.Vogelsong, D.C., 13.Vohler, O., 146, 147.Voigt, A., 266.Volkin, E., 335, 336.Volpi, G., 88.Volpi, G. G., 85.Volpin, M. E. (Vol’pin, M.Ye), 265, 266.von Dohren, H., 450.von Klemperer, M. F., 311.von Philipsborn, W., 309,von Sydow, E., 454.von Wittenau, M. S., 296.Vorov’yeva, G. A., 226.Vos, A.. 441.Vosloo, P. B. B., 392.Voss, W., 317.Vossius, D., 291,Wachmeister, C. A., 285.Wachtel, M. M., 451.Waddington, T. C., 141.Wade, K., 120, 122.Wadley, E. F., 252.Wadsley, A. D., 445, 446.Wadsworth, F. T., 210.Wadsworth, P. A., 47.Wagerle, R. R., 137.Wagenknecht, A. C., 370.Waggoner, J., 61.Wagner, A., 327.Wagner, C., 70.Wagner, C. D., 47.Wagner, C. R., 300.Wagner, F., 420.Wagner, G., 147.Wagner, H., 290.Wagner, K., 71.Wagner, V.I.., 418.Wahba, A. J., 362.Wahl, A. C., 25.Waight, E. S., 194.Waind, G. M., 23, 163.310.Wait, E., 146, 448.Walens, H. A., 279.Walburn, J. J., 218.Walisch, W., 407.Walker, J., 281.Walker, P., 369.Walker, T. K., 327, 364.Wall, M. E., 279.Waller, C. W., 298.Wallerfels, K., 290.Walling, C., 27, 29, 206,Wallis, R. F., 61.Walls, F., 309.Wallwork, S. C., 458.Walsh, A. D., 87, 94.Walsh, J. R., 439.Walsh, P. N., 97.Walshaw, C. D., 60.Walton, J. R., 160.Walz, H., 189.Wampler, G., 316.Wang, C. H., 209.Wang, S. Y., 334.Wannagat, U., 126.Warashina, E., 366.Warburton, B., 82.Ward, J. P., 266.Ward, R., 446.Ward, W. M., 105.Wardlaw, A. C., 364.Wardlaw, W., 19, 127, 154,Wardrop, A.W. H., 14.Warfield, R. W., 27.Warhurst, E., 41, 87.Warnant, J., 273.Warne, R. J., 119.Warneck, Y., 91.Warner, R. C., 341.WarnhoH, E. W., 281,Warren, C. K., 224.Warren, F. L., 311.Warren, G. W., 413.Warrener, R. N., 334.Warsi, S. A., 320, 328.Wartenpfuhl, F., 449.Wartik, T., 117.Warwicker, J. O., 464.Wasdell, M. R., 377.Waser, J., 100, 441, 460,Washbourn, K. D. R., 298.Washburne, R. N., 186.Wassermann, A., 23.Wasserman, H. H., 222.Watanabe, K., 325.Watase, H., 287, 465.Watelle-Marion, G., 23.Waters, D. N., 107.Waters, W. A., 29, 160,Watkins, D. A. M., 268,Watson, B. E., 336.212.155, 156, 161.307, 312.462.205, 207.289.498 INDEX OF AUTHORS’ NAMES.Watson. D., 200.Watson, D. G., 438.Watson, E.J. D., 284.Watson, H. C., 458.Watson, J. D., 331.Watson, W. H., jun., 100,Watson, W. W., 58.Watt, W. R., 318.Watts, H. L., 399.Watzke, E., 391.Waugh, J. S., 98, 107.Weatherley, T. L., 100.Weaver, J. R., 116.Weaver, W. M., 215.Webb, E. C., 347.Webber, J. M., 325.Weber, D., 57, 60.Weber, E., 413.Weber, G., 90, 91.Weber, H., 136.Webley, D. M., 364.Webster, M. E., 359.Webster, M. S., 464.Wechter, W. J., 259.Wedlake, D., 276.Weedon, B. C. L., 221, 224,Weglowski, S., 448.Weidel, W., 357, 358.Weijland, N. P., 174.Weil, K., 79.Weil, K. G., 79.Weiner, R., 399.U’einges, K., 285, 302.Weinheimer, A. J., 286.Weinreb, A., 92.Weinstock, B., 105, 139,Weinstock, J., 184, 207.Weintraub, A., 284.Weintraub, L., 298.Weir, R.J.. 390.Weis, J., 135.Weise, E., 449.Weise, W., 304.Weisenborn, F. L., 308.Weisfeld, L. B., 199.Weiss, A., 214, 230.Weiss, H., 369.Weiss, J., 99, 173, 208, 334,336, 378.Weiss, K., 206.Weiss, R., 152.Weiss, S. B., 371, 375.Weiss, W., 156.Weissbach, A., 354.Weissbach, H., 296.Weissburger, E. K., 381.Weissburger, J. H., 381.Weissrnan, B., 331.Weissman, H. B., 106.Weissman, S. I., 172, 173,Weissmantel, Ch., 71.Weizmann, A., 247.450.225.163.174.Welch, A. J. E., 161.Welch, G. A., 159, 160.Welch, V., 192.Wellendorf, M., 304.Wells, A. J., 56.Wells, C. F., 12.Wells, C. H. J., 52, 89.Welsh, H. L., 57, 60, 100.Wender, I., 150, 210, 222,271, 425.Wendler, N. L., 277, 278,279.Wenkert, E., 188, 212, 244,245, 296, 308.Wenograd, J., 66.Wentink, T., 88, 103, 105.Wentorf, R.H., jun., 447.Wepster, B. M., 179.Werbel, L. M., 295.Werner, H., 51.Werner, L. H., 294.Werst, G., 295.Wessel, G. J.. 450.Wessely, F., 219.West, H. D., 377.West, P. W., 427.Westerfield, W. W., 352.Westerhof, P., 283.Westerman, L., 145.Westheimer, F. H., 190,Westland, G. J., 162, 448.Westlund, L. E., 347.Westphal, O., 137,325,360.Wettstein, A., 282, 284.Weygand, F., 220.Whaley, H. A., 228.Whalley, W. B., 245, 246,Wharton, I?. S., 222.Wheatley, P. J., 99, 432,Wheeler, C. M., 336.Wheeler, D. H., 26, 227.Wheeler, 0. H., 464.Wheeler, T. S., 300.Whelan, W. J., 319, 320,327, 328, 358.Whiffen, D. H., 35, 60, 66,202, 316.Whistler, R.L., 319, 324,328.White, A. G., 12.White, A. W., 217.White, C. E., 101.White, D. M., 304.White, D. N., 97.White, E. G., 295.White, E. H., 194, 229.White, J. C., 415.White, J. D., 248.White, J. G., 438., 465.White, R. F. M., 230, 288.White, T., 301.White, W. N., 197.Whitehead, D. F., 358.290.285, 303.441, 457, 459.Whitehouse, M. W., 358.Whitehurst, D. H., 402.Whiteway, S. G., 38.Whitham, G. H., 292.Whiting, M. C., 152, 223,Whitley, A., 156.Wibaut, J.-I>.. 289.Wiberg, E., 114, 117.Wiberg, K., 200.Wiberg, K. B., 87.Wicli, G. S., 197.Wichers, E., 111.Wichterle, O., 33.Wick, A. N., 359. .Wickberg, B., 327.IVickens, J. C., 305.Wicker, K. J., 234.Wickers, E., 7.Wicki, W., 239.Wiebelhaus, V.D., 357.Wiebenga, E. H., 96, 434,Wiedemeier, H., 124.Wiegers, G. A., 441.Wiehler, G., 305.Wieland, H., 208.Wieland, K., 48.Wieland, I?., 282, 284.Wieland, T., 309.Wierzchowski, K. L., 334.Wiesboeck, R., 146.Wiesner, K., 312, 313, 314,Wiggins, T. A., 96.Wijnen, M. H. J., 39, 41,Wildi, B. S., 297.Wildman, W. C., 311, 312.Wilen, S. H., 209.Wiles, D. R., 24.Wiley, G. A., 252.Wiley, P. F., 356.Wiley, R. H., 34, 230.Wilken, P. H., 209.Wilkie, K. C. B., 315.Wilkins, M. F. H., 338.Wilkins, R. G., 144.Wilkinson, D. I., 288.Wilkinson, G., 99, 147, 148,149, 151, 153, 161, 162,271.229, 271.444, 442, 448.315.89, 91.Wilkinson, J. F., 360.Wilkinson, N. T., 421.Wilkinson, P. G., 97.Wilkinson, S., 306.W7ilks, 1’. H., 144.Willans, J. L., 418.Willi, A. V., 10.Williams, A. A., 144.Williams, A. I., 419.Williams, D. D., 428.Williams, D. G., 56, 60.Williams, G., 192.Williams, G. H., 203, 205,207, 209INDEX OF AUTHORS’ NAMES.Williams, H. L., 34.Williams, I. W., 24.Williams, J. H., 298.Williams, J. K., 224.Williams, N. R., 292.Williams, P., 209.Williams, R., 90.Williams, R. J . P., 22, 344,Williams, R. L., 66, 118.Williams, R. R., 47.Williams, R. T., 363, 376,377, 378, 382, 383, 384.Williams, R. W. J., 275.Williamson, D. H., 353.Willis, D., 244.Willis, J. B., 111.Willner, D., 250.Willstiitter, R., 206.Wilmshurst, J. K., 64, 245.Wilson, A., 134.M7ilson, A. M., 70.Wilson, B. D., 34.Wilson, D. M., 360.Wilson, E. B., 56, 62, 103,Wilson, F. C., 451.Wilson, L. E., 162.Wilson, L. F., 161.Wilson, M. K., 65, 95.Wilson, M. R., 338.Wilson, S. A., 124.Wilson, T. B., 55, 89.Wilson, T. H., 366.Wilson, W., 294.Wilt, J. W., 252.Wimer, D. C., 405.Winberg, H. E., 287.Windgassen, R. J., 268,Windsor, M. W., 91.Winfield, M. E., 148.Wing, A. B., 432.Wingfield, E. C., 60.Winkelman, J., 355.Winkhaus, G., 136.Winkler, C. A., 89.Winkler, F., 292.Winkler, G., 19, 67.Winstein, S., 16, 25, 180,181, 183, 215, 234.Winterfeldt, E., 305.Winternitz, F., 273, 278.Winterstein, A., 226.Wintzer, A., 221.Wirth, H. E., 117, 119.Wirwoll, B., 137.Wirzmuller, A., 161.Witkop, B., 296.Witnauer, L. P., 34, 204.Witt, H., 391.Witte, J., 229.Witten, B., 217.Wittenberg, D., 218.Wittenberg, J., 375.Witter, R. F., 368, 372.349.109.294.Wittig, G., 112, 198, 254,260, 262, 263, 271, 286.Wittman, A., 126.Wise, L. E., 322.Wisnyi, L. G., 446.Wiss, O., 226.Woiwod, A. J,, 363.Wold, A., 154,Wold, F., 347.Wolf, A. P., 304.Wolf, G., 381.Wolfe, J . B., 359.Wolff, I. A., 319.Wolfrom, M. L., 318, 325.Wolfsberg, M., 180.Woliii, M. J., 355.Wolinsky, J., 221, 242,306.Wolters, H. 13. M., 27.Wong, C. H., 99, 100.Wood, E. A., 451.Wood, J. L., 379, 388.Wood, J. W., 317.Wocd, L. L., 253.Wood, R. G., 4GO.Wood, W. A., 356, 363.Wood, W. D., 281.Woods, B. M.. 325, 329.Woods, L. L., 291.Woods, M. J. M., 20.Woodward, A. E., 28.Woodward, G. E., 369,364.Woodward, L. A., 23, 24,99, 106, 107, 121, 147.Woodward, R. B., 271,297,307.Woodworth, R. C.. 53.Woolf, A. A., 161.Woolford, R. G., 31.Woolfson, M. M., 433.Woolmington, K. G., 21.Wooster, W. A., 434.Work, E., 358.Wormall, T. W., 60.Worrall, I. J., 121, 132.Worrall, I. T., 99.Worsham, J. E., jun., 435.Wragg, A. H., 196.Wragg, W. R., 2 11,290,298.Wray, K. L., 88.Wright, A. N., 89.Wright, G. A., 130.Wright, H. B., 327.Wright, M. R., 93.Wright, W. B., 433.Wrigley, T. I., 275, 277.Wiirdig, G., 408.Wiirtele, L., 255.Wulfman, C. E., 174, 267.Wunderlich, J. A., 444.Wunsch, G., 126.Wurster, W. H., 87.Wyatt, G. R., 325.Wyatt,P. A. H., 14,129,137.Wyckoff, H., 466.Wyld, G. E. A, 404.Wyler, H., 303.499Wynberg, H., 288.Wyness, K. G., 1S9.Xavier, J., 395.Xuong, Ng. D., 300.Yagishita, K., 248.Yakubik, M. G., 404.Yamada, S., 165, 454.Yamaguchi, A., 107, 145.Yamaguchi, K., 356.Yamaguchi, M., 225.Yamaha, T., 303.Yamamoto, Y., 96.Yamanaka, T., 96.Yamashita, K., 225.Yamazaki, H., 90.Yang, D.-D. H., 205, 231.Yang, N. C., 205, 213, 214,Yannakopoulos, T., 70.Yarborough, V., 413.Yasuda, S. K., 421.Yates, P., 231, 286, 303.Yefimtseva, Ye. P., 325.Yensen, F. K., 270.Yofh, J., 425.Yoffe, A. D., 190.Yokoi, M., 442.Yorke, R. W., 98.Yoshizumi, H., 170, 178.Young, B. G., 317.Young, D. W., 458.Young, L., 376, 383, 385.Young, T. F., 13, 24.Young, W. G., 195, 277.Younger, P. A., 96.Yuan, C., 231, 268.Yuan-Lang Chow, 186.Yun Jen, 30.Yung-Kang Wei, 145.Yushok, W. D., 364.231, 236, 286.Zachariasen, W. H., 440.Zachau, H. G., 332.Zackrisson, M., 132.Zach, D., 235.Zahn, I T . , 152.Zahner, R. J., 411.Zajac, W., jun., 257.Zakharkin, L. I., 146.Zalkin, A., 100, 156, 449Zama, K., 375.Zamecnik, P. C., 332.Zamenhof, S., 336.Zander, M., 257.Zange, E., 189.Zannetti, R., 165, 444, 453.Zaslow, B., 450.Zderic, J. A., 275, 285.Zechmeister, L., 224, 255.Zechner, S., 401.Zeigenbein, W., 266.Zeising, M.. 156.Zeiss, H. Z-I., 152, 217, 222.451500 INDEX OF AUTHORS’ NAMES.Zeller, P., 224.Zemann, J., 443.Zenchelsky, S. T., 127.Zener, C., 86.Zengin, N., 141.Zervas, L., 192.Zetsche, K., 284.Zhdanov, G. S., 436.Zhigach, A. F., 118.Ziegler, E., 291.Ziegler, M., 417, 419.Zielen, A. J., 12, 159.Zielfelder, A., 121.Ziemann, H., 220.Zilliken, F., 358.Zimmerman, S. B., 337.Zimov’yev, A. A., 141.Zipper, H., 366.Zirngibl, L., 261, 262.Zlatkis, A., 413.Zook, H. D., 254.Zsuffa, B., 30.Zubay, G., 338, 341, 342.Zucketto, M., 154.Zuman, P., 67.Zverov, M. M., 207.Zvonkova, 2. V., 436.Zweifel, G., 315.Zwingelstejn, G., 302.Zfka, J., 418

ISSN:0365-6217    

DOI:10.1039/AR9585500467

出版商:RSC    

年代:1958

数据来源: RSC

摘要:

INDEX OF SUBJECTS.Abequose, 360.Absinthin, possible structure of, 241.Absorption spectroscopy, 415.Acenaphthene, crystal structure of, 458.Acetaldehyde, dtmn. of, 407.potential-energy barrier in, 109.Acetomycin, structure of, 230.Acetone, dtmn. of, 422.3p-Acetoxy-14,%eti-9( 11) -enoic acid,methyl ester, reduction of, 276.Acetylacetone complexes, structure of,145.Acetylene, production of, from benzene,255.Acetylene complexes, 149.Acetylenes, 220.vinyl-, synthesis of, 221.Acetylides, complex, 150.“ Acid I,” structure of, 275.“ Acid IV,” structure of, 275.Acids, volatile fatty, separation of, 409.Acid-base equilibria, 7.Acid-catalysed reactions, 198.Acid-catalysis, mechanism of, 187.Acidity constants, thermodynamic, pre-cision dtmn.of, 8.Acrylonitrile, dtmn. of, 408.Acyl-oxygen fission, 186.Adiponitrile, dimerisation of, 229.Adsorption in electrode processes, 70.Ajaconine, structure of, 313.Alcohol in blood, dtmn. of, 394.Alcohols, dtmn. of, in presence of hydro-Aldonic acid metabolism in bacteria, 362.Aldosterone, synthesis of, 281.Alicyclic compounds, 231.Aliphatic compounds, 220.Alkaloids, 303.biosynthesis of, 303.Alkyl-oxygen fission, 188.Alkylation, 215.Allene, dimensions of, 101.Allenes, 224.Allokainic acid, structure of, 465.Ally1 chlorosulphinates, decomposition of,Allylic diazonium ions, decomposition of,Aluminium, dtmn. of, 398, 399.Aluminium halides, complexes of, 121.Americium oxalate hydrates, 160.Amides, titration of, 405.Amines, dtmn.of, by absorption spectro-titrations, indicators in, 397.carbons, 425.195.195.sesquioxide, 160.scopy, 422.primary aromatic, dtmn. of, 403.501Amino-acids, crystal structure of, 464.cis- and trans-2-Amino-alcohols of largecyclohydrocarbons, basicity of, 236.o-Aminophenol, test for, 396.Amino-sugars, 358.Ammonium ion, crystal structure of, 437.a-Amyrin, structure of, 244.Anabsinthin, possible structure of, 241.Analytical chemistry, 389.Anhydro-saccharides, 329.Anibine, structure cf, 29 1.Aniline, titration of, 404.Anionotropic rearrangements, 194.Anthracene, 9’1 O-dibromo-, crystal struc-Anthraquinone, 1,5-dichloro-, crystalAntimony, electro-deposition of, 405.Antimony pentaff uoride, structure of, 135.Antioxidants, dtmn.of, 409, 422.Apparatus, analytical, 427.a-Arabinose, crystal structure of, 464.Arakyl halides and sulphonates, solvo-Arctiopicrin, structure of, 238.Arene-l,2-diols, l,%dihydro-, biosynthetic,Aromatic complexes, 15 1.Aromatic compounds, 251.Aromatic hydrocarbons, crystal structureAromatic rearrangements, 197.Aromatic ring, new procedure for openingArsenic, dtmn. of, in iron and steel, 415.Arsenious acid, structure of, in aqueoussodium salt, formulation of, 134.Arsenomethane, crystal structure of, 462.Arsenyl fluoride, preparation of, 134.Artemisin, stereochemistry of, 239.Aryl participation, 252.Arynes, 261.Ascarylose, 360.Ascorbic acid, 360.Aspidospermine, structure of, 309.Atisine, structure of, 312.Atomic weights, report on, 111.9-Aza-lO-boraphenanthrene, 285.Aza-compounds, di- and poly-, 297.“ Azidinium ” salts, 289.9-Azidofluorene, rearrangement of, 197.Azobis-N-chloroformamidine, crystalAzoles, 288.Azulene, crystal structure of, 437.Azulenes.266.ture of, 458.structure of, 458.tricyanide, 124.lysis of, 181.383.of, 457.of, 220.solution, 134.structure of, 456502 INDEX OF SUBJECTS.Baikiain, synthesis of, 290Barium chloride nitride, 114.Base-catalysed reactions, 198.Bauerenol, structure of, 248.Benzaldehyde, p-chloro-, crystal struc-ture of oximes of, 461.Benzene, conversion of, into acetylene,255.y-“ Benzene hexachloride,” dtmn. of, indip-washes, 394.Benzocyclobutene, 270.preparation of, 232.Benzocyclobutene-l-carboxylic acid, form-Benzoic acid, hydroxylation of, 208.Benzothiazole, 2-phenyl-, formation of,Benzoyl peroxide, decomposition of, in/3-2’-Benzoylcyclopropylpropionic acid,Benzyl ethers, cleavage of, by GrignardBenzylic carbanions, stability oi, 254.Benzyne intermediates, 260.Bergenin, structure of, 300.Beryllium, dtmn.of, 396.Beryllium halides, bond lengths in, 96.Bicarbonates, dtmn. of, 400.Bicyclo [5,2,1] decan- 10-one, formation of,Bicyclovetivenol, structure of, 241.Biological chemistry, 343.Biopterin, structure of, 298.Biosynthesis of alkaloids, 303.Bismuth, dtmn. of traces of, 416.Bismuth(1) chloride, 135.Blood alcohol, dtmn. of, 394.Boron, crystalline modification of, 114,Boron halides, 115, 119.monoamidotriphosphate, 131.X-ray analysis of, 457.ation of, 232.294.cyclohexane, 202.231.reagents, 209.oxyacetate, 11 3.233.440.dtmn.of, 416.crystal structure of, 441.hydrides, 115.trifluoride, deuterates of, 119.Borate, dtmn. of, 400.Diborane, laboratory preparation of,diammoniate, formulation of, 116.diphenyl-, 11 7.tetrafluoride, 119.structure of, 99.trioxide, structure of, 98.crystal structure of, 441.116.Diboron dioxide, structure of, 97.Hexaborane, 115.Metaborates, calcium, formulation of,Pentaborane, 11 8.294.dtmn, of, in water, 393.121.Bridged ring systems, heterocyclic,Bromamine, 130.Bromine, complexes of, with acetone andBromine pentafluoride, crystal structurewith benzene, 140.of, 440.trifluoride, crystal structure of, 440.Bromate, dtmn.of, 405.Bromyl fluoride, synthesis of, 141.Bullatenone, structure of, 288.Buphanidrine, structure of, 312.Buphanisine, structure of, 312.Butadiene, C-C bond length in, 101.n-Butyl halides, reaction of, with magnes-3-Butylpyridine, methylation of, 208.For butyl isomers, see S-butyl, T-butyl.Cadinene dihydrobromide, configurationCadinenes, absolute configurations of, 239.Cadinols, absolute configurations of, 239.Cadmium, high-purity, dtmn. of otherCEsium czsioformate, 113.Cafestol, structure of, 245.Caffeine, crystal structure, 459.Calciferol, structure of, 464.Calcium, dtmn. of, 424.ium, 205.of, 464.metals in, 406.in presence of nagnesium, 403.potentiometrically, 398.specific test for, 395.structure of, 442.Calcium hydrogen phosphate, crystalhydroxide, crystal stracture of, 435.Callaghanite, crystal structure of, 445.Canthaxanthin, synthesis of, 224.Capsorubin, partial structure of, 224.Carbides, 113.Carbohydrates, 3 15,Carbon, dtmn.of, in highly volatileliquids, 426.“ red,” 124.See also Graphite.crystal structure of, 448.Carbon dioxide, dtmn. of, in minerals,396.impurities in, 414.disulphide, bond lengths in, 96.monoxide, dtmn. of, 422.spectrum of, 95Carbonium ions, 252.Carbonyl compounds, test for, 396.Carbonyls, crystal structure of, 452.synthesis of, 146.Carboxyamides, hydrolysis of, 189.Carboxylic acids, 219.crystal structure of, 454.Carboxylic anhydrides, hydrolysis of, 190.Cardiolipin, 372.Carotenoids, 224.Cassanic acid, structure of, 245.Catalytic hydrogenation, 210.Cations, hydrolysis of, 11.“ Cerebrin base,” identity of, 228.Chaksine, structure of, 317.dipositive, 124.esters, hydrolysis of, 186INDEX OF SUBJECTS. 503Chloramine, dtmn.of, in water, 393Chloramine-T, detection of, in presence ofChloride, detection of trace amounts of,dtmn. of, in biological fluids, 392, 420,Chlorine, addition of, to A114- and A1t 4.6-dtmn. of, in organo-chlorosilanes, 401.Chloryl fluoride, preparation of, 141.Perchloric acid, hydrates of, 141.Perchloryl fluoride, structure of, 99.trans-4-Chlorocyclohexanol, solvolysis of,181.trans-2-Chlorocyclohexyl sulphide, hydro-lysis of, 182.5-Chloro-4-hydroxy-3-methoxybenzyliso-thiuronium phosphate as a micro-chemical standard, 426.N-Chloromorpholine, chlorination ofphenol by, 252.Chloroprene, C-C bond length in, 101.Chlorosilanes, alkyl- and aryl-, dtmn.of, inair, 393.Cholecalciferol, synthesis of, 282.5a-Cholestan-6-one, 3/3-acetoxy-, reactionof, with Grignard reagents, 275.Cholesterol, crystalline, action of Fenton’sreagent on, 277.Chromans, 299.Chromatography, uses of, in analysis,Chrome alum, crystal structure of, 435.Chromium, dtmn. of, 417.Chromium(m), dtmn. of, 399.hypochlorite, 426.395.425.3-ketones, steroidal, 273.407.Chromium, triphenyl-, addition com-pound of, with tetrahydrofuran, 152.Chromyl compounds, new, 157.Chrysanthenone, structure of, 237.Cinnolines, 298.Citrostadienol, structure of, 247.Clathrate compounds, crystal structure of,Coal, mineral matter in, analysis of, 424.Cobalt, nitroso-complexes of, 149.Cobalt carbonyl hydride, structure of,Cobalt (11) cyanide-potassium cyanide solu-Cobalt group, 163.463.147.tions, decomposition of, 148.Tetracarbonylmethylcobalt, 147.cis-Triamminetrinitrocobalt, 143.Tricobalt tetroxide as combustion cata-lyst, 426“ Coenzyme Q,” nature of, 226.Colchicine, partial structure of, 263.Colemanite, crystal structure of, 444.Colitose, 360.Complexometric titrations, indicators in,398.Condensed ring systems, heterocyclic, 294.Conhydrine, conformation of, 305.Co-ordination compounds, crystal structureCopolymerisation, 34.of, 451.Copper, dtmn.of, 397, 418, 424.traces of, 416.in cadmium, 406.in nickel cathodes, 416.electro-deposition of, 405.Copper compounds containing Cu-CuCopper(I1) derivative of diazoamino-Copper nitrate, anhydrous, 165.perchlorate, volatility of, 166.phthalocyaninesulphonic acid as indica-selenite, crystal structure of, 443.Copper-dimethylglyoxime complex, struc-Costol, configuration of, 238.Costunolide, structure of, 238.Coumarin, 7-methoxy-, photodimer of, 299.Coumcestrol, structure of, 301.Crinamine, structure of, 311.Crinane, structure of, 312.Crinine, structure of, 312.Crops, dtmn. of trace metals in, 408.Cryptostrobin, structure of, 301.a-Cryptoxanthin, identify with physo-xanthin, 224.Crystallography, 430.Cucuribitacins, 249.a-Cucurbitasterol, structure of, 283.Curare alkaloids, 309.Current-voltage curves, minima in, 75.Cyanide, dtmn.of, 420.Cyanoacetylene, structure of, 97.4-Cyano-2,6-di-t-butylphenoxyl radical,Cyanogen, v5(II,) vibration of, 105.Cyclazines, 268.Cyclobutanols, formation of, 231.Cyclobutene-cis-3,4-dicarboxylic acid, di-Cyclododecane, crystal symmetry of, 461.Cycloheptabenzindene, 267.Cyclohexanol, conformations of, 234.Cyclohexyl bromide, conformations of, 234.Cyclo-octa-l,3,5,7-tetraene, crystal sym-trans-Cyclo-octane, dipole moment of, 234.Cyclopentan-2-one, 1,3-di-p-bromobenzyl-idene-, crystal structure of, 461.Cyclopolyenes, 266.Cyclopropanecarbohydroxide, crystalstructure of, 460.Cyclopropyl chloride and cyanide, bondlengths and angles in, 102.Cyclotetraphosphine, tetraphenyl-, 133.Cysteines, N-acetyl-S-( 1,2-dihydro-2-hydroxyary1)-, 386.Deamination, mechanism of, 193.cis-Decalone, configuration of, 235.Delcosine, structure of, 314.Delpheline, structure of, 313.Delsoline, structure of, 314.Deltaline, structure of, 314,bonds, 165.benzene, 166.tor, 308.ture of, 165.201.methyl ester, isomerisation of, 232.metry of, 461.structure of, 102504 INDEX OF SUBJECTS.Deoxyribonucleic acid, 334.Deoxy-sugars, 359.“ Desaurins,” structure of, 286.Deuterium halides, bond lengths in, 95.nitrate, vapour pressure of, 129.Dextropimaric acid, structure of, 244.Dialkyl sulphides, hydrolysis of, 193.ON-Dialkylnitramines, hydrolysis of, 186.Diazines, 290.Diazomethane, structure of, 97.Diazotisation, mechanism of, 193.Dibenzamil, structure of, 291.1,2-5,6-Dibenzanthracene, 9,10-dihydro-,crystal structure of, 458.2,3-4,5-Dibenzocoronene, crystal structureof, 458.3,10-Dibenzylidenecyclodecane-l, 2-dione,isomerisation of, 236.5,7-Dibromo-8-hydroxyquinoline as re-agent for tin, 419.2,4-Dibromo-3-ketones, steroidal, de-hydrobromination of, 273.(Di-n-butyl-1ithium)sodium as metallatingagent, 112.Dichloroethylene, cis-1,2- and 1,l-, C-Cdistance in, 101.Digenic acid, structure of, 287.3,3,1 Gcr-Dihydroxy-5a-pregnan-2O-one, 284.Di-indenyliron, disorder in, 438.A1-, A4-, or All 4-3, 1 l-Diketones, pyrolysisDimethyldiacetylene, bond lengths in, 101.Di- (3-methyl-2-indolyl)phenylmethane,4,4-Dimethylpent-2-enyl ethyl ether, form-Dioscorine, structure of, 304.Diphenylene, substitution in, 269.Diphenyliodonium chloride, crystal struc-Diphosphoinositide, 371.Di(pyridine-2,6-dimethylene), structure of,Diradicals, addition reactions of, 52.biosynthesis of, 337.of, 274.295.ation of, 195.ture of, 440.289.combination of, 54.displacement reactions of, 51.insertion reactions of, 50.isomerisation of, 54.monoradical reactions of, 49.reactions of, 47.Disorder and crystal structure analysis,Diterpene group of alkaloids, 312.Diterpenes, 242.2,6-Di-t-butyl-4-triphenylmethylphenoxylradical, 201.Dithian dioxide, crystal structure of, 460.Dithianthren dioxide, crystal structure of,cis-1, 2-Divinylcyclobutane, instability of,Durobilin, structure of, 292.436.460.232.Echinuline, structure of, 296.EDTA, uses of, 398.Eduleine, 305.Electrical methods of analysis, 403.Electrochemistry, 67.Electrocrystallisation, 76.Electrode processes, methods of investig-v-Electron theory in organic chemistry,Electronegativity, scale of, for Group IVElectronic spectra of crystals, 439.Elucin, structure of, 230.Emetine, (-)-)- and (-)-, synthesis of, 305,Emission spectroscopy, 424.Energy transfer in adiabatic processes, 80.Enzymes, metal-dependent, 343.5,6-Epoxides, reaction of, with boron tri-Equilibria in non-aqueous solvents, 13.Equilin, synthesis of, 285.Eremophilone, dihydrohydroxy-, configur-Ergocalciferol, synthesis of, 282.Ergosterol peroxide, thermal rearrange-Erythraline, structure of, 465.mesoErythrito1, crystal structure of, 456.Erythrocentaurin, structure of, 300.a-Erythroidine, structure of, 312.Erythropterin, structure of, 299.Ethane, 1,2-dibromo-, torsional frequencypotential-energy barrier in 108.Ethyl formate, potential-energy barrier in,halides, potential-energy barrier in, 109.Ethylene, dimensions of, 101.Ethylene thiocyanate, crystal structure of,Explosives, analysis of, 400.Falcatine, structure of, 312.Fatty acids, 227.( f)-y-Fencholenic acicl, formation of, 237.Flavones and isoflavones, 301.Fluoradene, properties of, 268.Fluoride, amperometric titration of, 407.Fluorides of alkali metals, 112.Fluorine nitrate, decomposition of, 141.Formaldehyde, dtmn.of, 407.structure of, 98.Free radicals, combination of, 36.disproportionation of, 40.Free-radical intermediates, 202, 206.L-Fucose, 360.Furans, 288.Fusarinic acid, structure of, 290.Gallium dibromide, 121.Gallium-sulphur system, 122.ating, 68.170.elements, 123.306.diabatic reactions, 90.liquids and gases, 80.classification of, 344.fluoride, 274.ation of, 464.ment of, 274.in, 109.110.442.dtmn. of, 410, 421.halides, 122INDEX OF SUBJECTS. 506Gas-chromatography apparatus, detectorGeigerin, structure of, 241.General and physical chemistry, 7.Gentiopicrin, structure of, 303.Germacrol, structure of, 238.Germanium tetracyanide, 126.in, 411.Germane, preparation of, 126.Hexamethyldigermane, preparation of,Gibberellic acid, structure of, 246.Gleditsin, identity of, with mollisacacidin,Gliotoxin, structure of, 297.“ Glycerol borate,” 121.Glyoxal, test for, 396.Gold, dtmn.of, 407.Graphite, compound of, with sodium, 124.reactions of, 123.Graphitic oxide, 123.structure of, 457,127.301.Guanidine, amino- and triamino-, crystala-Gurjunene, structure of, 240.Hzmanthamine, structure of, 31 1.Hzmanthidine, structure of, 311.Hzmultine, structure of, 311.Halides, alkyl, dtmn. of equivalent weightof, 401.crystal structure of, 448.titration of, 400, 403.Halogens, compounds of, with electron-donors, crystal structure of, 462.Halogen oxides, bond lengths in, 96.( -)-Heliotridane, configuration of, 31 1.Hemicelluloses, 322.Heptoses, rare, 357.Heterocyclic compounds, 285.crystal structure of, 455.Heterolytic processes, 179.Hexabenzocoronene, synthesis of, 256.Hexachloroethane, potential-energy bar-Hexaphenylbenzene, non-planarity of,Hexa-1,3,5-triene, structure of, 101.Hexoses, rare, 356.Homolytic reactions, 201.Hopenone-I, structure of, 249.Humulinone, structure of, 250.Hybridisation and bond lengths, 175.Hydrazides, uses of, in synthesis, 220.Hydrazine, crystal structure of, 455.rier in, 109.102.tetrafluoro-, 130.tetramethyl-, structure of, 99.Hydrazinedisulphamide, 130.Hydrazinesulphonic acids, 130.Hydrocarbons, dtmn.of, in presence ofHydrofluoric acid, dtmn. of, in fumingHydrogen, dtmn.of, in highly volatileHydrogen, evolution of, in electrode pro-Hydrogen atoms, location of, 434.alcohols, 425.nitric acid, 406.liquids, 426.cesses, 74.Hydrogen bond, the, 434.Hydrogen cyanide, dtmn. of, in air, 392.tetramer, structure of, 125.Hydrogen peroxide, dtmn. of, 407.potential-energy barrier in, 109.Hydrogen (poly)peroxide, H,O,, 135.Hydroxyapatite, crystal structure of, 442.B-Hydroxy-ketones, dehydration of, 184.Hydroxylation in the animal body, 376.3p-Hydroxy-A5-steroids, dehydration of,274.Hygromycin, 356.Hypericin, 257.Hypobromite solution, uses of, 401.oxidation of, 274.Iboxygaine, structure of, 309.Ilexol, nature of, 248.Imidodisulphinamide, 138.Indazole, 3-amino-, 298.Indeno [2,1 -a]perinaphthene, 267.Indium chloride, bond lengths in, 96.Indole group of alkaloids, 306.Indoles, 294.Indolizidine, formation of, 294.Infrared intensities, 55.halides, 122.trimethyl-, 123.measurements of, in gas phase, 56.units and dimensions, 55.Inorganic chemistry, 11 1.Inorganic structures, crystallography of,Interhalogen compounds, 139.Intermetallic compounds, crystal struc-Iodide, detection of traces of, 427.Tri-iodide ion, structure of, 96.Iodine heptafluoride, crystal structure of,Ion association, conductance properties440.ture of, 450.440.in, 18.kinetic measurements of, 24.new techniques in, 26.spectrophotometry of, 20, 23.thermodynamics of, 16.Ions, adsorption of, in electrode processes,Ion-exchange resins as indicators in acid-Ion-molecule reactions, 42.( -j);Ipomeamarone, structure of, 288.Iresm, structure of, 240.Iridium carbonyl halides, 147.Iron, catalysis by, in a Mannich reaction,221.Iron, dtmn.of, in bismuth, 417, 421.in cadmium, 406.in clay and limestone, 417.dicarbonylcycloheptatrienyl-, 153.di-indenyl-, 153.micro-dtmn. of, 397.nitroso-complexes of, 149.tetranitrosyl-, structure of, 149.dodecacarbonyl, 146.70.base titrations, 397.Iron carbonylchalcogenides, 146506 INDEX OF SUBJECTS.Iron(m) chloride, reaction of, with di-Iron(iv) nitrilotriethoxide, 161.Di-iron, pentacarbonylazulene-, 153.Tetracarbonyldicyclopentadienyldi-nitrogen tetroxide, 148.iron, 151.Irone, synthesis of, 237.Isobutane, potential-energy barrier in, 109.p-Isocamphor, structure of, 237.Isocyanides, formation of, 229.Isodextropimaric acid, structure of, 244.Isolichenin, structure of, 320.Isoquinoline group of alkaloids, 305.Isoquinolines, 297.Isoquinuclidine, formation of, 294.Isorenieratene, structure of, 225.Isoretronecanol, configuration of, 31 1.Jatamanshic acid, structure of, 242.“Juniper camphor,’’ structure of, 239.Kainic acid, structure of, 287, 465.Kanosamine, 358.Kephalin, 369.Ketones, racemic, stereospecific reduc-tion of, by micro-organisms, 235.A1n 4-3-Ketones, steroidal, reduction of,274.Kinetics of chemical change, 36.Lactucin, constitution of, 241.Laminarin, structure of, 320.Lanthanides, 153.carbides of, 153.oxide monosulphides of, 154.Lanthanum dicarbide, 153.Large heterocyclic rings, 291.Laserpitine, structure of, 239.Lead, dtmn.of, potentiometrically, 398.electro-deposition of, 405.Lead imide, 128.tetramethyl-, reaction of, with lithiumtetra-acetate, oxidation by, 214.Plumbates, hexafluoro-, of alkaline-aluminium hydride, 127.earth metals, 127.Lecithin, 367.Ledol, structure of, 240.Leucocyanidine, cacao, structure of, 301.Lichenin, structure of, 320.Like radicals, combination of, 37.Lithium, dtmn. of, 391.isotopes, lattice constants of, 440.Lithium phenylborohydride, 11 7.Lithium-lithium hydride system, 11 2.Lophenol, structure of, 247.Lumicolchicines, 263.Lumisterol, structure of, 275.Lupinane group of alkaloids, 304.Lycoctonine, structure of, 313Lysolecithin, 368.Macrolides, 228.Magnesium, dtmn.of, 425.in presence of calcium, 403.potentiometrically, 398.Maleic acid-anhydride mixtures, analysisAlaleic anhydride, dtmn. of, in polyesters,of, 402.407.Manganese, complexes of, 161.Manganese carbonyls, 147.Mangostin, structure of, 303.Meerwein reaction, mechanism of, 206.2-Mercaptoquinoline as spot reagent, 395.Mercury, crystal structure of, 440.Mercury complexes, 166.+Menth-3-ene, racemisation of, 199.Metal hydrides, reduction by, 211.Metal-dependent enzymes, 343.Metalloenzymes, 347.dissociable, 348.non-dissociable, 349.D-Methadone, configuration of, 465.Methanes, deuterated and tritiated, forcesubstituted, structure of, 100.dtmn. of 398.dtmn.of, 418.Amidomercurysulphonic acid, 166.derivative of dithizone, structure of,166.constants in, 106.12-Methoxypodocarpa-8,11,13-triene,Methyl nitrite, potential-energy barrier in,Methylanilides, hydrolysis of, 189.( -J) -3-Methylcyclopentane-l , 2-dicarb-oxylic acids, configurations of, 236.2-O-Methyl-~-fucose, occurrence of, 3 16.3-Methylpentane-2,4-dione, enolisation of,Micro-anal ysis, 425.Minerals, analysis of, 409.Mitraphylline, structure of, 308.Molecular structure and molecular vibra-Molecular vibrations and force constants,Molybdenum alkoxides and derivatives,Molybdenum carbonyl, derivatives of,Molybdenum(v1) oxide, hydrates of, 157.Molybdenum, “ oxine ” complex of, 397.Monosaccharides, acid-reversion of, 328.Monoterpenes, 236.Muramic acid, 358.Muscarine, structure of, 465.Myoglobin, structure of, 466.Napellonine, identity of, with songorine,8-Naphthol, crystal structure of, 458.Naphthyridines, 1,6- and 2,7-, synthesisNarcissidine, structure of, 312.Nemotinic acid, labelled, 223.Neopentyl group, dtmn.of, 423.Neuraminic acid, 358.Nickel, dtmn. of, 417, 418.structure of, 244.110.200.tions, 94.102.156.153.vaporization of, 157.313.of, 298INDEX OF SUBJECTS. 507Nickel carbonyl derivatives, 147.Nickel group, 163.Nimbin, 250.Niobates of sodium, 155.Niobium halides, 156.Nitriles, dtmn. of, 402.Nitrogen, dtmn. of, in polymers, 402.Nitrosylcyclopentadienylnickel, 152.inorganic chemistry of, 125.Nitramide, crystal structure of, 442.Nitrate, test for, 395.Nitrides, crystal structure of, 446.Nitrite, dtmn.of, 422.Nitrogen dioxide, force constants in, 104.oxides, isomeric, 108.trifluoride, force constants in, 104.Nitrous oxide, force constants in, 104.Nitrosonium tetrafluorobromate, 140.Nitrosyl azide, 128.Nitrosyls, crystal structure of, 452.Nitroxyl, detection of, 130.Nitroxyl species (HNO), structure of,Nitryl chloride, 128.Nitryl oxychloride, 128.Dinitrogen tetroxide, reaction of, withferric chloride, 148.addition of, to double bonds, 129.97.Nitrones, irradiation of, 229.Nobelium, production of, 160.Nomilin, 250.Non-benzenoid aromatic compounds, 266.19-Nor-A4-3-ketones, reduction of, 274.Nucleic acids, 330.Nucleophilic substitution, 179.Obacunone, 250.Estrone, synthesis of, 28 1.Olefin complexes, 149.Optical resolution, 216.Organic chemistry, 168.theoretical, 179.a t aromatic carbon, 251.compounds, crystal structure of, 454..Organometallic compounds, 218, 271.Osmiamic acid, potassium salt, structureOsmium hexafluoride, formerly regardedOxalyl bromide, use of, for carboxylation,Oxazirans, 286.Oxepin derivatives, 291.Oxidation in organic chemistry, 212.Oxides, crystal structure of, 444.Oxindoles, 296.1-Oxolilolidine, structure of, 294.3-Oxo-steroids, methylation of, 273.0x0-sugars, 364.Oxy-acids in aqueous solution, 12.Oxygen, dissolved, dtmn. of, in water, 390.dtmn. of, in titanium, 424.molecular, oxidation by, 212.of, 162.as octafluoride, 163.219.Oxygen heterocycles, complex, 300.Oxyorceins, a-, p-, and y-, structures of,300.Pachymran, stucture of, 320.Palladium, separation of, 399.Paracyclophanes, 259." Paratose," 325, 360.Passivation, 78.Peltogynol, structure of, 30 1.Pendulin, structure of, 301.Penicilliopsin, 257.Pentaerythritol, crystal structure of, 456.Pentoses, rare, 353.Pentosuria, 354.Perchlorocyclopentadienes, hydrogenationof, 232.Perchlorocyclopentenes, hydrogenation of,232.Periodate, oxidation of saccharides by,328.Perlauric acid, decomposition of, 204.Peroxides, oxidation by, 212.Peroxy-salts, formulation of, 135.a-Phenazine, crystal structure of, 459.Phenols, formation of, in vivo, 376.Phenolic metabolites of heterocycIic com-Organopalladium compounds, lG4.pounds, 382.of polycyclic hydrocarbons, 379.Phenylallyl alcohols, rearrangement of,Phenylazotriphenylmethane, decomposi-Phenylcyclopropane, formation of, 231.Phenylpentazole, formation of, 286.5-Phenylpentyl radical, rearrangement of,Phloroglucinol dihydrate, crystal struc-Phosphate, dtmn.of, 421.Phosphates, crystal structure of, 442.hydrolysis of, 190.Orthophosphate, specific test for, 427.Pyrophosphates, hydrolysis of, 191.Phosphatidic acid, 371.Phosphatidylglycerol, 372.Phosphatidylinositol, 370.Phosphatidylserine, 369.Phosphoglycerides, 365.Phosphoglyceride biosynthesis, 375.Phospholipids, minor, 375.Phosphorus, dtmn. of, 397.195.tion of, 205.204.ture of, 458.in condenscd sodium phosphates, 40 1.Diphosphine, structure of, 99.Phosphoric acid, anhydrous, electricalconductivity of, 131.dichloro-, preparation of, 131.Phosphoronitrile halides, 133, 134.Phosphorous acid, crystal structure of,meta-, imide-amide of, 133.Phosphorous acids, resolution of deriv-esters, dtmn.of equiv. weight of, 401.pentabromide, dissociation of, 132.sulphides, crystal structure of, 441.442.atives of, 217.Triphenylphosphonium salts, 133.Photosantonic acid, structure of, 242.Phthalates, dtmn. of, in propellants, 393508 INDEX OF SUBJECTS.Phthiocerol, revised formulation of, 228.Physoxanthin, identity with cc-crypto-Pinnoite, crystal structure of, 444.Piperidines, 2 89.Plasmalogens, 373.Plasticisers, separation of, 423.Plumieride, structure of, 303.Plutonium, carbides of, 160.a-, crystal structure of, 440.oxidation states of, 158.oxalate, complexes of, 159.sulphate, properties of, 159.xanthin, 224.Plutonium (IV) dioxide, compositionof, 1 GO.Pluviine, structure of, 312.Polarography, 406.Polonium compounds, 139.Polycyclic compounds, aromatic, 255.Polyenes, 226.Polyethyl esters, dtmn.of, 414.Polyethylene compounds, detection anddtmn. of, 402.Polyinosinic acid, 341.Polymerisationof radicals, inhibition in, 35.initiation of, 28.retardation in, 38.termination processes in, 35.transfer processes in, 33.Polymers, growth reactions of, 32.Polypeptides, simple, crystrzl structure of,Polypyrroles, 292.Pol yribonucleo tides, synthetic , 339.Polysaccharides, 315.heterogeneity of, 316.pneumococcus-specific, 324.Polythionates, oxidation of, 401.Poly-ynes, 222.Porphins, 293.Porphyrins, 292.Potassium dichloroiodide hydrate, 140.hydroxide vapour, 112.pyrosulphite, crystal structure of, 443.Potential-energy barriers to internal rot-Powelline, structure of, 312.Prednisone acetate, ultraviolet irradiation‘‘ Premercapturic ” acids, 386.Propargyl chloride, C-C bond length in,Propene, potential-energy barrier in, 108.Propyl chloride, gauche form of, 102.Propylene oxide, potential-energy barrierProtactinium, extraction of, from organicProtohypericin, 257.( &)-Protolichesterinic acid, synthesis of,Pseudoconhydrine, conformation of, 305.Pseudoyohimbine, total stereospecific syn-Psiolcybin, structure of, 296, 306.Puromycin, structure of, 298.Pyroluteorin, structure of, 287.464.ations, 108.of, 277.101.in, 109.solvents, 157.228.t,hesis of, 306.Pyrazine, crystal structure of, 458.Pyrene, synthesis of, 256.Pyridine, structure of, 101.Pyridines, 289.Pyrocalciferol, structure of, 275.Pyrones, 291.Pyrrole, 3-acetamido-, formation of, 287.Pyrroles, 286.PyrroIo[2.1.5-cd]indolizine, 294.Pyrromethanes, 293.Quadricyclo [2.2.1. 02* 6 . 03* 5 ] heptane-2,3-d i-Quantum organic chemistry, 1GS.‘‘ Quaterenes,” 294.Quinhydrone, crystal structure of, 462.Quinolines, 297.Quinolizines, 297.Quinuclidine derivatives, 294.Radiation, effects of, on living organisms,Radicals, disproportionation of, 40.Radio-chemical methods of analysis, 427.X-Ray analysis, 432.Realgar, structure of, 136.Renieratene, structure of, 225.Retusine, structure of, 310.Rhamnose, 359.a-Rhamnose monohydrate, crystal struc-ture of, 464.Rhenium, complexes of, 161.iodides of, 161.Dicyclopentadienylrhenium hydride,Per-rhenyl fluoride, structure of, 99.Tetracarbonylrhenium halides, 147.Rhodeasapogenin, structure of, 280.Rhodium (III), octahedral complexes of,Ribonucleic acids, 331.L-Ribulose, 355.Rimuene, structure of, 245.Rosenonolactone, structure of, 246.Rosinidin, structure of, 300.Rosololactone, structure of, 246.Rotiorin, structure of, 303.Roussin’s black salt, structure of, 149.Rubidium fluoride, bond length in, 95.Ruthenium complex, Ru,N,O,,, structuretetroxide, complex of, with phosphorustetramethyl-, crystal structure of, 459.3-hydroxy-, formation of, 287.carboxylic acid, 233.334.polymerisation of, 27.See also Free radicals.151.147.of, 149.trifluoride, 162.Ruthenium (11) complexes, 162.Ruthenium(II1) species, 162.S-butyl alcohol, resolution of, 216.S-butylmercuric bromide, resolution of,Salicin, dtmn.of, 409.Salicylic acid, hydroxylation of, 208Sandmeyer reaction, mechanism of, 206.21INDEX OF SUBJECTS. 609$-Santonin, absolute configuration of, 239.( -)-a-Santonin, stereochemistry of, 239.Saponification number, dtmn. of, 41 1.Sargasterol, structure of, 283.Scandium group, 153.Sclareol, conversions of, 242.Selenium, dtmn.of, in sulphuric acid, 418.trifluoromethyl derivatives of, 138.Amidoselenic acid, ammonium salt, 138.Diselenic acid, potassium salt, 138.Selenides, crystal structure of, 447.Selenonyl fluoride, preparation of, 138.Selenophen-2-carboxylic acid, crystalstructure of, 460.Seredine, structure of, 308.Sesquibenihiol, configuration of, 238.Sesquiterpenes, 2 3 8.Silanol group, dtmn. of, 393.Silicon, dtmn. of, 419.complex of, with acetylacetone, 125.Silicon hydride, preparation of, 115.Cyclosiloxanes, reaction of, with boronDilsilyl oxide, structure of, 98.p-Ethylmethylphenylsilylbenzoic acid,Silane, chloromethoxytrichloro-, 125.Silicic acid, dtmn. of, 421.Silver, sensitive test for, 419.Silver perchlorate-benzene complex, struc-thiocyanate, crystal structure of, 444.a-Sitosterol, structure of, 247.Sodium arsenite, crystal structure of, 444.Sodium diphosphite, 131.Sodium felspar, crystal structure of, 444.Sodium-graphite, lamellar, 124.Sodium hydrogen diglycollate as primarySodium hydroxide hydrates, crystal skuc-Sodium a-sodioacetate, preparation of, 218.Sodium triphosphate, two forms of, 131.Songorine, identity of, with napellonine,Sophoranol, structure of, 305.Spectra, infrared, of liquids and solutions,64.See also pp.55 et seg.Spectrophotometers, calibration of, 415.Steels, analysis of, 409.Stercobilin, structure of, 292.Stereochemistry in aromatic series, 257.Steroid sapogenins, 279.Steroids, 272.Stipitatonic acid, structure of, 263.Strobopinin, structure of, 301.Sugar acetates, 364.Sugars, rare, 353.Sulphanes, synthesis of, 136.Sulphinic esters, rearrangement of, to sul-phones, 196.Sulphonic esters, hydrolysis of, 192.solvolysis of, 181.trichloride, 126.resolution of, 125.ture of, 166.standard, 397.ture of, 444.vapour, 112.313.of alicyclic compounds, 234.Sulphates, crystal structure of, 442.Sulphur, dtmn.of, in iron and steel, 415.Sulphur imides, 136.mono-bromide and -chloride, structureof, 97, 441.nitrides, 136.trioxide, dtmn. of, in flue gases, 401.Disulphuryl diazide, 138.di-isocyanate, 138.Polythionate ions, structure of, 137.Sulphamic acid, force constants in, 108.Sulphamyl fluoride, 137.Sulphides, crystal structure of, 446.Sulphur esters, dtmn.of equivalentSulphuric acid, dideutero-, properties of,Sulphuric esters, hydrolysis of, 192.Sulphuryl di-isocyanate, 138.Tetrathionyl tetraimide, 136.Thionyl imides, isomeric, 138.Suprasterol-11, structure of, 283.D-Talose, 356.Tantalum alkoxides, mixed, 156.T-butyl fluoride, C-F distance in, 101.weight of, 401.137.potential-energy barrier in, 109.groups, dtmn. of, 423.hydroperoxide, use of, for epoxidation,213.N-methyl-N-p-nitrophenylperoxycarb-amate, decomposition of, 204.Tellurium tetrahalides, complexes of, withDimethyltellurium dichloride, structureDiphenyltellurium dibromide, structurethiourea, 139.of, 99.of. 99.Tetrabenzyl pyrophosphate, alcoholysisof, 191.Tetrabutylammonium hydroxide, uses of,Tetracyanoethylene, use of, in syntheses,Tetrahydroalantolactone, stereochemistry1,2,3,4-Tetrahydro-l-naphthyl hydroper-Tetramethylammonium hydrogen dichlor-Tetramethylhydrazine, structure of, 99.Tetroses, rare, 353.Thallium, cyclopentadienyl-, 123.dtmn.of, in cadmium, 406.Thallium (I) t-pentyloxide, 123.Theaflavin, structure of, 302.Theophylline, crystal structure of, 459.Thiazyl chloride, tris-, 138.Thioacetamide, hydrolysis of, 189.Thiocarboxyamides, formation of, 229.Thiocyanate, dtmn. of, 420.Thiocyanogen chlorides, 125.Thiophenoxide ions, reactions of, 183.Thiophens, 288.Thiourea, complexes of, with telluriumas titrant, 404.287.of, 238.oxide, resolution of, 216.ide, 141.tetrahalides, 139510 INDEX OF SUBJECTS.Thiourea, crystal structure of, 456.dtmn. of, 422.titration of, colometrically, 405.Thorium, dtmn.of, 419.separation of, from uranium, 410.Thujone tribromide, structure of, 237.Thymidine, 5’-bromo-5’-deoxy-, crystalTin, dtmn. of, 419.structure of, 459.electrodeposition of, 405.organo-, compounds, 127.test for, 395.tetramethyl-, reaction of, wt h lithiumStannane, sodium derivatives If, 127.aluminium hydride, 127.Tissue, analysis of, 394.Titanium, complexes of, 154.dtmn. of, 419.Titanium (111) ion, use of, as titrant, 405.Titanium (IV) sulphate, 154.Titanates, crystal structure of, 446.Titrations in non-aqueous media, 404.Tokorogenin, structure of, 280.Toluene-3,4-dithiol, uses of, 394.Tolunitrile, use of, as oxidation catalyst,Torularhodin, synthesis of, 225.Totarol, structure of, 242.Transannular reactions , 235.Transition elements, 142.complexes of, 143.Transuranium elements, 158.Triammineacetylenemagnesium carbide,Tributyl phosphate, dtmn.of, 402.Tri-n-butyl phosphate as extraction sol-vent, 159.Tricyclovetivenol, structure of, 241.Trifluoroacetic acid, methyl ester, hydro-lysis of, 188.Tri-iodide ion, structure of, 96.Trimethyl phosphite, use of, in dehydro-bromination, 274.2,6,6-Trimethylcyclohexa-2,4-dienone, di-mer of, 232.1,2,3-Triphenylcyclopropenyl cation, 268.Triterpenes, 242.Tropane group of alkaloids, 304.Tropolonate anion, crystal structure of,Tropolones, 263.Tropolonium cation, crystal structure of,461.Tropones, 263.Tropylium derivatives, 265.Tungsten, dtmn. of, 419.Tungsten oxides, vaporization of, 157.Tyvelose, 360.“ Ubiquinone,” nature of, 226.219.113.461.Tungstates, titration of, 398.12-Tungstozincic acid, structure of, 158.Undulatine, structure of, 312.Unlike radicals, combination of, 39.Uracil, reversible photolysis of, 334.Uranium, dtmn. of, 397, 420.Uranium, separation of, from thorium,Uranium(zv), titration of, 398.Uranium(vI), reduction of solutions of,Uranium(vI), titration of, 405.410.399.Uranium dioxide, dtmn. of, 427.Uranium oxides, crystal structure of,Uranium tetrachloride, addition com-Uranyl nitrate hydrates, structure of,Urea, crystal structure of, 435.Urea phosphate, crystal structure of,Uronic acid metabolism in bacteria,Uronic acids, new, 363.Vanadium, dtmn. of, 400, 420.Vanadium alkoxides and derivatives,Vanadium group, 156.Vanadium oxides, crystal structure of,Vanadium oxytrifluoride, 156.Vegetable oils, identification of, 423.Vinyl monomers, growth of, 32,3-Vinylcyclobutanone, formation of, 232.Vinylidene dichloride, LClCCl angle in,Violacein, structure of, 296.Vitamin A, 224.Vitamin D, 282.Voacangarine, structure of, 309.Volatile elements, dtmn. of, 391.445.pounds‘of, 158.158.442.362.155.445.101.Water, dtmn. of, in granulated sugar, 392.Westphalen-LettrC rearrangement, 278.Xanthinin, structure of, 241.Xylans, 323.8-Yohimbine, synthesis of, 307.Yohimbine, total synthesis of, 306.Zinc, dtmn. of, 420.potentiometrically, 398.Zinc, dichlorobisthiourea-, crystal struc-ture of, 457.Zinc group, 166.Zinc salicylate, crystal structure of,toluene-p-sulphonate, crystal structurein minerals, 396.443.of, 443.Zirconium alkoxides, 155

ISSN:0365-6217    

DOI:10.1039/AR9585500501

出版商:RSC    

年代:1958

数据来源: RSC