INORGANIC CHEMISTRY.THAT interest in inorganic chemistry is sustained and indeed is increasing isevident from the extent and variety of the contributions covered by thefollowing report. Again the Reporters have been concerned to present asbalanced a picture as the space a t their disposal allows of those topics whichhave excited curiosity.The first volume of the FIAT Review of German Science (1939-46),Inorganic Chemistry, was the only one available to the Reporters last yearand a considerable amount of material was drawn from it. The scope of theremaining five volumes which have now been issued precludes our drawingmuch from them this year. The work covers the whole field from biblio-graphy to instrumentation, is well indexed, and is graced by main tablesof contents in each volume in English as well as German.The recommence-ment of issues of the 8th edition of Gmelin’s “ Handbuch ” is welcomed,Selenium (B), Antimony (B), and Platinum-group metals (ruthenium,rhodium, palladium) having so far been issued.to one who laid a cornerstone of modern inorganic chemistry. EspeciallyGoldschmidt will be remembered for showing the three main considerationsgoverning the forms of co-ordination adopted by a crystal structure, namely,the relative numbers, the ratio of radii, and the polarisability of its ions.was discussed a t the Amsterdam meeting ofthe I.U.C. in September, 1919, and the names of the elements and of theI.U.C. itself were considered.The practice of placing the superscript representing the mass numberof an isotope after the symbol of the element is officially frownedupon. All but the purists will be thankful that the redefinition of the litreas a cubic decimetre will now permit the identity 1 ml.= 1 C.C. and allowsome of us to revert to our natural use of the latter unit.That the discovery and application of nuclear fission has providedstrong, almost overwhelming, impetus to inorganic chemistry is now acommonplace. Nevertheless, the evidence of its truth in the shape ofnumerous papers poses a problem in these Reports; for there is much thatis of a purely physical nature which is, however, of vital interest to chemistsusing, or measuring, isotopes. It seemed best to confine attention here to :(a) preparation or enrichment of isotopes in a particular chemical state,( b ) tracer work to elucidate an inorganic problem, (c) chemical identificationof products of a nuclear reaction, (d) determination of natural isotope abund-ances leading to atomic weight values. Facts about individual isotopescoming under the above headings will be dealt with as the element occursin the Periodic Table.A moving and just tribute is paid in the Goldschmidt Memorial LectureInorganic nomenclatureJ.D. Bernal, J., 1949, 2108. Chem. Eng. News, 1949, 27, 2996DODD AND ROBINSON. 87Rlention may be made of a number of articles and reviews : H. J.EmelBus,4 on recent advances in radiochemistry, fission products, the4n + 1 radioactive series, the actinons, material largely drawn from de-classified reports : J. V.Dunworth,5 w. G. Morley,6 and R. Spence,? re-spectively, on the operational characteristics of the Harwell piles, productionof radio-isotopes, and chemistry of a.tomic energy: the abundance ofelements and isotopes in relation to the origin * of the chemical elementsand to nuclear structure9 (the empirical approach). G. T. Seaborg andI. Perlman 10 have tabulated all known isotopes together with abundancesand references to all original papers. H. E. Suess l1 arrives at a value of4-5 x lo9 yrs. for the age of the elements on the basis of (corrected)abundance rules. H, Thode l2 has reviewed isotope abundance in Naturewith special reference to variations in relative abundances of isotopes of aparticular element depending on the source.(Variations in boron havealready been reported. Variations in sulphur have been recently discovered-see p. 106.) J. Mattauch 13 and others l4 have reviewed isotope separation.A further review on radio-isotopes as tracers has been given by P. E.Yankwich l5 and a colloquium 16 and other papers l7 have been publishedon use and technique of isotope exchanges.The interaction of nuclear and chemical energies during nuclear reactionsis an engaging topic-the chemical state in which a newly created elementwill appear being dependent on many factors. A. G. Maddock l8 hasreviewed present knowledge on the chemical effects of nuclear recoil, and thevalency states of various fission products Sc, Te, I, Ce, and Br have beenstudied.19 The implications contained in suggestions such as La3+ --+Ce4+ + P- and Se032- --+ Br0,2- + p- are manifold.Attention must also be drawn to the symposium 2o held in March, 1949,by the Chemical Society in conjunction with the Chemistry Division, A.E.R.E.W.B. Lewis, Chem. Inst. Canada, Proc. Conf. hluclear Chem., 1947,16; 0. Volkoff,ibid., p. 20; L. G. Cook, ibid., p. 40; L. Yaffe, ibid., p. 117.Nature, 1949, 163, 624.Ibid., p. 2.Research, 1949, 2, 73.Ibid., p. 115.* R. A. Alpher, H. Bethe, and G. Gamow, Physical Rev., 1948, 73, 803; (Miss)M. G. Mayer and E. Teller, ibid., 1949, 76, 1226; P. S. de Toledo and G. Wataghin,ibid., 1948, 73, 79.0. Rloncke, Experientia, 1949, 5, 232, 440; P. Lacroute, Compt. rend., 1948, 226,1804; P. Chanson, ibid., p.997.lo Rev. Mod. Physics, 1948, 20, 585.l2 Research, 1949, 2, 154.l4 G. W. Dunlap and R. M. Lichtenstein, Elect. Eng. N . Y., 1948,65,469 ; 0. Erbacher,l5 Analyt. Chem., 1949, 21, 318.l6 J . Chim. physique, 1948, 45, 141.l7 M. Haissinsky and B. Pullman, J. Phys. Radium, 1947, 8, 33; (Mme.) P. Daudel,l1 Experientia, 1949, 5, 226, 278.l3 Angew. Chem., 1947, 59, A , 37.Angew. Chem., 1947, 59, A , 6.R. Daudel, (Mlle.) M. Martin, Bull. SOC. chim., 1949, D, 68.Research, 1949, 2, 556.l9 W. H. Burgus, T. H. Davies, R. R. Edwards, H. Gest, C. W. Stanley, R. R.2o J., 1949, 2nd Suppl. Issue.William, and C. D. Coryell, J . Chim. physique, 1948,45, 16588 INORGANIC CHEMISTRY.This covered the chemistry of the heavy elements, ( ( cis- and trans-uranics,”preparation, nuclear aspects and applications of radioactive tracers.In the discussion at the above symposium the problem of the actinongroup was prominent (still do the terms Zanthunon, proposed by Marsh, andact inon, consequently, appear preferable t o Eanthanide and actinide).Theconfusion of terminology is still evident in the actinon controversy. ThusE. Hayek and T. Rehner 21 find evidence which ( ( seems t o contradict thehypothesis of the beginning of an actinide group with thorium.” It seemsthat two ideal courses are open to the trans-actinium elements : (i) to fill upthe 6d shell and behave as members of ‘( normal groups,” (ii) to fill up the 5fshell to form an actinon series, analogous to the lanthanons. That thorium,protactinium, and uranium evidently exhibit some characteristics of bothdoes not prevent the elements neptunium to curium from adopting the placesin the actinon series that they would if the first three were to exhibit un-equivocally the expected number of 5f electrons.Thus the series to whichneptunium to curium almost certainly belong is one which probably has itsorigin in actinium even if the first three members of the series are renegade.On account of the divergence of those three elements, H. Haissinsky22called the series uranides to which the higher elements belong, thoughactinon (or -ide) seems preferable and more generally acceptable. Themore detailed chemistry of the lanthanons and actinons is, as last year,treated as a separate group. For convenience, thorium, protactinum,and uranium are dealt with under the same group, though the justificationfor that is now the real issue.The theory of ( ( half-bonds ” as advanced by R.E. Rundle has alreadybeen noted23 in connection with the hydroborons and other electron-deficient molecules. Space does not permit discussion here except to notethat the theory suggests the possibility of resonance between X-M Xand X M-X where only one orbital of the central atom is involved, e.g., ap orbital, utilising both (‘ ends ” in applying the maximum overlappingprinciple. One electron pair is thus involved in two effective ‘( half-bonds.”The theory has been applied to various valency problems, to hydrob0rons,~4ato aluminium alkyl~,~~b to the tetramethylplatinum tetramer,2k to metallicborides,24d t o other interstitial cornpo~nds,~~e and t o electron-deficientmolecules generall~.~~f Rundle has preferred the term ‘( excess orbital ”structures.Miscellaneous matters of interest include : colloquia on the chemicalbond 25 and on solid reactions; 26 the induced valency change, describedby P.W. Selwood 27 as (‘ valence inductivity,” brought about when atransition-group oxide is supported on a. high-area surface with which i t21 Experientia, 1949, 5, 114.23 Ann. Reports, 1947, 44, 52.24 (a) J. Amer. Chem. Soc., 1947, 69, 1327; ( b ) ibid., p. 2075; (c) ibid., p. 1561;25 J. Chim. physique, 1949,46, 187.26 Bull. Xoc. chirn., 1949, D, 23.22 J., 1949, S 241.(d) ibid., p. 1719; (e) Acta Cryst,, 1948,1, 180; (f) J.Chem. Physics, 1949,17, 671.27 J. Arner. Chern. Xoc., 1948, 70, 883DODD AND ROBINSON. 89may become isomorphous (as iron oxides and manganese oxides on rutile) ; 28heat of formation and stability of binary inorganic compounds; 29 the re-ported isolation 30 from unspecified natural materiaJs of new elements ofatomic number greater than 92. Two reports 31 of the American ChemicalSociety committee on atomic weights are available for 1948 and 1949-results of individual determinations will be mentioned below. 0. Kuba-chewski 32 has classified the elements into true metals, meta-metals, semi-metals, and non-metals according to values of electrical conductivity,co-ordination number, entropy, volume ratios, and changes in those quantitieson melting.A. R. Powell33 gives details of purification of the metals,palladium, cobalt, zirconium, iridium, niobium, tungsten, platinum,molybdenum, tantalum, rhodium, titanium, and nickel, used in the newbadge of office for the President of the Royal Institute of Chemistry. Mentionmust also be made of the general conclusion which W. F. Giauque34 hasreached after particular consideration of the dehydration of magnesiumhydroxide ( q . ~ . ) , namely : " that many equilibrium measurements involvinggases and finely divided dry solids produced by the evolution of gases, orformed by reaction with gases, do not correspond to properties of macroscopicmaterials."Group 0.-The interest in this group centres in experiments 35 now inprogress with the helium isotope 3He, naturally rare (1 part in 1.2 x lo6parts) but now available artificially.F. London36 has pointed to the im-portance of the results of S. G. Sydoriak, E. R. Grilly, and E. F. Hammell 37in the solution of the He-I1 pr0blem.3~ The unorthodox behaviour ofliquid helium *He can be explained if Bose-Einstein statistics are applied.If that can be justified, Fermi-Dirac statistics should apply to 3He,which would not then be expected to exhibit the abnormalities of liquidHe-11. That liquid 3He shows no discontinuity of flow velocity in coolingfrom 3" K., to 1.05" K., whereas liquid 4He shows a sudden increase below2.19" R., suggests that the Bose-Einstein statistics form a correct basis forthe explanation of liquid He-11.E.Wiberg and K. Karbe39 have been unable to find any evidence ofcompound formation between the inert gases argon, xenon, and krypton,and boron trifluoride, sulphur dioxide, hydrogen sulphide, dimethyl ether,or methanol. Boron trifluoride is not even miscible with liquid argon,xenon, or krypton.28 P. W. Selwood, T. E. Moore, M. Ellis, and K, Wethington, J. Amer. Chem. SOC.,29 A. E. Van Arkel, Research, 1949, 2, 307.30 B. Gysae and H. Korsching, 2. Naturforsch., 1947, 2, A , 415.31 G . E. F. Lundell, J . Amer. Chem. Soc., 1948, 70,3531 ; 1949, 71, 114.32 Trans. Faraday Soc., 1949,45, 931. 33 J . Proc. Royal Inst. Chem., 1949, 476.34 J . Amer. Chem. SOC., 1949, 71, 3192.35 H. A. Fairbank, C. T. Lane, L. T. Aldrich, and A. 0. Nier, Physical Rev., 1948, 73,36 Nature, 1949, 163, 694.38 L.Meyer and W. Band, Natumoiss., 1949,5,5.1949, 71. 69.3.729; J. G. Daunt, R. E. Probst, and H. L. Johnston, ibid., p. 638.37 Physical Rev., 1949, 75, 303.2. a m g . Chem., 1948,2!56,30790 INORGANIC (XIEMISTRY.Mass-spectral investigation 40 of isotope ratios in krypton and xenonhas given atomic weight values 83.91 and 131.31 respectively as againstInternational (1948) values 83.7 and 131.3.Group 1.-The main emphasis in this group has been on the chemistryof copper and its compounds and there is little relating to hydrogen andthe alkali metals. The preparation of 99% pure hydrogen deuteride hasbeen achieved 41 by reaction of deuterium oxide with lithium aluminiumhydride in n-butyl ether a t 0".The lower explosion limit in the reactionbetween hydrogen and nitrous oxide has been further investigated 42-thefact that molecular oxygen poisons the reaction (at 720-4330", 100-250 mm.total pressure, 40--80~0 N,O) suggests that a found minimum in the explosionlimit pressure-temperature curve is due to 2N,O --+ 2N, + 0, and conse-quent poisoning by H + 0, + M ---+ HO, + M. W. H. Schechter, J. K.Thompson, and J. Kleinberg43 have studied the oxidation of sodium in liquidammonia solution and find that rapid oxidation at -35" gives some oxidehigher than NaO,, though with slow oxidation a.t -77" and with precautionsagainst formation of NaNH, an oxide of empirical formula NaO,.,, , corre-sponding to 4Na0, : Na202, is formed. Sodium superoxide, NaO,, hasbeen prepared 44 in 92% yield from oxygen and sodium peroxide at 400-500" and about 30 atm.pressure. An effective magnetic moment of 2.07 B.m.was found, corresponding to 2-04 B.m. for the potassium compound 45. Thedissociation pressure of potassium hydride from 402" to 481" has beenmeasured 46 and the melting point of potassium hydroxide remeas~red.~'The value of 410" & 1" for the latter is higher than previously supposed,owing, it is suggested, to the exclusion of water by several hours' heating.H. F. Duckworth and B. J. Hogg*8 have determined the isotopic con-stitution of copper and arrive at a value 63.542 & 0.006 for the atomicweight, in excellent agreement with 0. Honigschmid and T. Johann~en?~whose chemical determination of 63.542 was accepted for the last revisionof the International value.H. Brown and M. G. Inghram 50 calculated63.55 on the basis of isotope abundance in terrestrial and meteoric copper.The oxidation of copper foil has been further investigated 51 with the aidof a tracer, 64Cu, and the distribution of the 64Cu+ ion in the copper(1) oxidelayer is offered as further evidence that diffusion of Cu+ is the rate-determin-ing step in oxidation. The preparation 52 of copper(1) sulphide by high40 M. Lounsbury, S. Epstein, and H. G. Thode, Physical Rev., 1947,72, 517.41 I. Wender, R. A. Friedel, andM. Orchin, J. Amer. Chem. SOC., 1949, '71, 1140.42 C. P. Fennimore and J. R. Kelso, ibid., p. 3706.44 S. E. Stephanon, W. H, Scheehter, W. J. Argersinger, and J.Kleinberg, ibid.,45 E. W. Neurnann, J. Chem. Physics, 1934,2, 31 ; see also Ann. Reports, 1947,44,62.4 7 R. P. Seward and K. F. Martin, J. Amer. Chem. SOC., 1949, 71, 3564.48 Physical Rev., 1947, 71, 212.6o Physical Rev., 1947, 72, 347.61 G . W. Castellan and W. J. Moore, J. Chem. Physics, 1949, 17, 41 ; see also Ann.bB R. Xol6 and R. Hocart, Compt. rend., 1949, 229, 424.$3 Ibid., p. 1816.p. 1819.A. HQrold, Compt. rend., 1947, 225, 249.49 2. anorg. Chem., 1944, 252, 364.Reports, 1948, 45, 86DODD AND ROBINSON. 91compression at room temperature of copper-sulphur mixtures has beenreported with X-ray confirmation. Copper(1) ~ e l e n i d e , ~ ~ Cu2Se, is the onlyproduct of the system copper-aqueous copper sulphate-selenium so long asall components are present.The system forms an electrolytic couple ofwhich copper is the negative electrode and selenium the positive. In thepresence of excess of selenium the oxidation by selenium, slow at roomtemperatures, commences as soon as all the copper is dissolved. The violetselenide Cu3Se, is formed. Further oxidation, accelerated a t highertemperatures, yields copper(I1) selenide.Basic copper chlorides 54 and double hydroxychlorides of copper( 11)and bivalent nickel, cobalt, magnesium, zinc, and cadmium 55 have beenstudied by W. Feitknecht and K. Maget. Cu(0H)Cl and four modificationsof 3Cu( OH),,CuCl,, or Cu,(OH),Cl (of which one is atacamite, not readilyprepared artificially) have been prepared and confirmed by X-ray analysis.No stable compound 2Cu(OH),,CuC12 appears to exist.The double hydroxy-chlorides studied were of the general formula 3Cu(OH),,MCl, formed by re-action between copper(1) oxide and solutions of the metal chlorides. Furtherhydrolysis studies 56 by H. Guiter include copper (11) sulphate, chloride, andnitrate, degree of hydrolysis increasing in that order, and the presence ofionic species Cu(OH)(NO,),2-, CUCL,(OH)~-, CU(SO,),(OH)~-, and Cu(OH)+has been suggested. Further to F. Karosy's observations of a volatile coppercompound formed on thermal decomposition of copper( 11) formate, re-ported 57 last year in connection with the attempted preparation of coppercarbonyl, A. Keller and F. Korosy 58 have identified the volatile compoundas copper(1) formate, which sublimes in vucuo at about 100" and decomposesat a higher temperature into copper, hydrogen, and carbon dioxide.Othercopper(I1) salts of fatty acids give unstable volatile copper(1) salts, andsilver gives salts similar to those of copper(1).Ethylenediamine (en),59 hydroxyethylenediamine (hn),60 diethylene-triamine (dnt) and other complexes of copper(I1) have been studiedspectroscopically and photometrically. [Cu(en)I2+, [Cu(en),12*, [Cu(hn)12+,[Cu(hn),I2+, [ C ~ ( h n ) ~ f ~ + , and [Cu(dnt),12+ are reported. The stability ofthe bis(diethylenetriamino)c~pper(II) ion suggests that copper is exhibitinga co-ordination number of six. The formation and existence of coppercyanide complexes only appears 62 possible when copper is present in higherconcentration than 0.5mlsr.m C .Goria, (fazzetta, 1940, 70,461.s6 Helu. Chim. Acta, 1949, 32, 1639; A. F. Wells, Acta Cryst., 1949, 2. 173.b5 Helv. Chim. Acta, 1949, 32, 1653.56 Bull. SOC. chim., 1948,15,945; Compt. rend., 1949, 228, 589.37 Ann. Reports, 1948, 45, 87.i~~ Nature, 1948, 162, 580.s8 H. B. Jonassen and T. H. Dexter, J . Amer. Chem. Soc., 1949, 71, 1553.6o J. L. Harvey, C. I. Tewksbury, and H. M. Haendler, ibid., p, 3641.dl H. A. Laitinen, E. I. Onstott, J. C. Bailar, and Sherlock Swam, ibid., p. 1550;J. G. Breckenridge, Canadian J. Res., 1948, 26, B, 11.B. Norberg and B. Jacobson, Acta Chem. Scad., 1949, 3, 17492 INORGANIC CHEMISTRY.A critical literature survey has been recently published,63 along with newwork, on the compounds formed by acetylene with copper and silver.Thereported existence of several complex salts is doubted, including many saidto contain Ag*C=CH. Silver acetylide shows considerable solubilityin aqueous solutions of silver perchlorate, and the formation of complexesof the form (Ag+),(Ag,C,),, or (Ag+),(C,2-), is assumed. A complexAg2C,,2AgC10, has been identified. On passing acetylene into suecientlyconcentrated copper(1) chloride solutions, in the presence of potassiumchloride, yellow or orange precipitates appear.64 It is suggested that thesecontain the group (CuCI),(C,2-), analogous to (Ag+),(C,2-) of which fhesolid nitrate exists.65 The equilibrium Ag,C, + 2H+ += C2H2 + 2Agf hasbeen measured.66The oxidation of iodine by solutions of silver sulphate in sulphuric acidappears, from kinetic studies,67 to involve two processes the first being fastand the second slow and rate-determining :21, + 2H,O + Ag,SO, --+ 2AgI + €€,SO, + 2HOI3HOI + Ag2S0, + 2AgI + H,SO, + HIO,No doubt these are themselves composite but the oxidising power of suchsolutions is thought to be due to IO- and 10,- ions rather than to the presenceof hydrogen peroxide.Hydrolysis and decomposition of aqueous tetrachloroaurate(II1) solu-tions have been investigated by N.Bjerrum.6s Hydrolysis to form[Au(OH),Cl, -,I- occurs rapidly for replacement of the first two chlorineatoms but thereafter is slow. No aquo-complexes are formed. Reductionto univalent gold by the reaction AuC1,- --+ AuC1,- + C1, also occurs.Normal potentials for a number of related electrode reactions are also given.W.L. Gent and C. S. Gibson 69 have prepared diethylthiocyanatogold andshown i t to be dimeric. The compound is remarkable for the resistanceof sulphur-gold linkages to the co-ordinating action of nitrogenous bases.The structure (I) is preferred to (11).CN,S--C=N\%EC-S/Et2Au AuEt,(I.) CN (11.1Group II.--The details of the redetermination of the atomic weight ofberyllium, by ratios BeC1, : 2Ag, BeCl, : 2AgC1 and BeBrz : 2Ag, BeBr, : BAgBr,63 R. Vestin and E. Ralf, Acta Chem. Scand., 1949,3, 101.1 3 ~ R. Vestin, ibid., p. 650.65 J. A. Shaw and E. Fisher, J . Amer. Chem. Soc., 1946, 68, 2745; Ann. Reports,1313 R. Vestin and A. Somersalo, Actu Chem.Scand., 1949,3, 125.13' (Mlle.) M.-L. Josien and M. D. A. Williams, BUZZ. Soc. chim., 1949, 16, 547, 551;68 Bull. SOC. chim. Belg., 1948, 5'9, 432,1948, 45, 88.(Mlle.) M.-L. Josien, Compt. rend., 1949, 228, 1021.69 J., 1949, 1835DODD AND ROBINSON. 93are now available.70 The value 9.013 -J= 0.0004 compares with 9.0126from mass-spectral data. The International value (1948) is 9.02. Thevapour pressure of beryllium metal at elevated temperatures has beenmeasured.71 L. Hackspill and J. Besson 72 have shown that the productionof pure beryllium by hydrogen reduction of beryllium chloride is rendereddiEcult by the proximity of the temperature of reduction to the fusionpoint of the metal and by the difficulty of finding an adequate supportinert to beryllium.The possibility of using beryllium bromide or iodideis discussed. A general article 73 by Besson on the preparation, technicaldevelopment, and uses of beryllium compounds is available. When watervapour is brought into contact with beryllium oxide a relatively rapidvolatilization occurs 74 which is greater than can be explained by the vapourpressure of beryllium oxide a t the same temperature. This is not observedwith beryl or magnesia. The volatilisation rate increases with increasedtemperature, and a t tempera.tures above 1250" an observable reaction occursto give a volatile compound which condenses, on cooling, with decompositionto beryllium oxide. The nature of the volatile compound is not apparent.The preparation, properties, and Raman spectra of diethylberyllium havebeen described.75In comparing34 the true dissociation pressure in the systemMg(OH), (cryst.) + MgO (cryst.) + H,O (g.) as determined by the thirdlaw of thermodynamics, with that obtained experimentally to an accuracyof 0.1 %, W.F. Giauque finds a 130% difference. He suggests that the lowerexperimental values are due to the colloidal nature of the magnesium oxideproduced under equilibrium conditions. Thus i t appears that equilibria,which are reproducible or even in agreement with the third law, cannotnecessarily be accepted as corresponding to the thermodynamic propertiesof macrocrystalline phases. S. J. Gregg and I. Razouk 76 have measuredthe rates of isothermal dehydration of precipitated magnesium hydroxideand natural brucite and find the rate and the heat of activation to vary fromsample to sample.The equilibrium MgCO, MgO + CO, has &Is0 beenmeasured.Further studies include basic magnesium nitrates,78 the system calciumsulphate-sodium ~hloride,'~ the hydrates of calcium sulphite,80 the kineticsand catalysis 81 of production of calcium carbonate from reaction between0. Honigschmid and T. Johannsen, 2. Naturforsch., 1946, 1, 650.71 R. B. Holden, R. Speiser, and I€. L. Johnston, J. Amer. Chem. SOC., 1948, 'SO,72 Bull. Xoc. chim., 1949, 16, 113. 73 Ibid., 1949, D, 15.74 C. A. Hutchison and J. G. Malm, J. Amer. Chem. SOC., 1949, '71, 1338.7 5 J. Goubeau and B. Rodewald, 2. anorg. Chem., 1949, 258, 162.76 J., 1949, S 36.77 E.Cremer, 2. anorg. Chem., 1949, %8, 123.78 (Mme.) L. Walter-LBvy, Compt. rend., 1948, 227, 1231.79 J. By6 and J. G. Kiehl, Bull. Xoc. chim., 1948,15, 847.81 R. Stumper and F. Classen, Compt. rend., 1949,228,83, 184.3897.F. W. Matthews and A. 0. MeIntosh, Canadian J. Res., 1948,26, B, 74794 INORGANIC CHBMISTRY.calcium bicarbonate and hydroxide and between calcium sulphate andsodium carbonate.Mass-spectrographic determinations 82 of 'isotope ratios in zinc andcadmium give values 65.40 and 112.42 for atomic weights comparedwith International values 65.38 and 112.41. The dissolution of cadmium 83and zinc 84 in nitric acid in the presence of platinum and a 1% solution ofm-phenylenediamine show little or no formation of nitric or nitrous oxidesor hydrogen, but ammonia and hydroxylamine increase considerably inamount.Equilibria involving mercury(I1) and halide ions have been studied byL.G. Sillen, who has surveyed 85 seven preceding papers by himself and hiscollaborators. For all halogens it was only found necessary to assume theexistence of HgX+, HgX,, HgX,-, and HgX,,-. J. Lamure has studied 86the oxychlorides and oxybromides of mercury and has further verified 87that mercury(1) oxide, Hg,O, is the primary product of the action of baseson mercury(1) salts. Previous negative evidence is explained by theobservation that the mercury(1) oxide is stable in water in the absence oflight but disproportionates to mercury and mercury(II) oxide on drying.Group IIL-The majority of the contributions to Group I11 chemistryconcern boron.High-purity boron has been prepared 88 by the hydrogenreduction of boron tribromide vapour in a quartz tube. Diborane anddiboron monohalides have been produced 89 by hydrogen reduction ofborane halides over active metals (aluminium, zinc, magnesium, moltensodium) at temperatures above 300". The reaction of gaseous boron halideswith active metal hydrides also yields diborane, wherefore i t is suggestedthat active hydrides are initially formed at the metal surfaces. Freezing-point measurements on the diborane-ammonia system a t 195" K. haveindicated a compound B,H,,xNH, but no sign of dissociation or associ-ation. Various bina.ry systems involving diborane and hydrogen chloride,boron trichloride, ethane, or boron trifluoride have been studied.Q1 W.Eggersgluess, A.G. Monroe, and W. G. Parker 92 have redetermined the heatof formation of boron trioxide and find a value of 281.1 zfr: 3.1 kcals./mole,as against previously published values of 279.9,93 349,94 and 335 95 kcals./mole.The higher values axe attributed to the use in both cases of impure boroncontaminated with combined hydrogen. If that is the case, the heat of82 W. T. Leland and A. 0. Nier, Physical Rev., 1948, 73, 1206.83 S. D. Radosavijevic, Bull. SOC. chim. Belgrade, 1948, 13, 83.84 A. M. Leko and S. D. Rados;Etvljevic, ibid., p. 90.E 5 Acta Chem. Scand., 1949, 3, 539.86 Bull. SOC. chim., 1948, 15, 1019..88 R. Kiessling, Acta Chem. Scand., 1949, 2, 707.89 D. T. Hwd, J . Amer. Chem.SOC., 1949, 71, 20.so G. W. Rathjens and K. S. Pitzer, ibid., p. 2783.91 L. V. McCarty, ibid., p. 1339.ss D. Berthelot, '' Thermochimie " (Paris 1897), Vol. 11, p. 122.s4 W. A. Roth and E. Boerger, Ber., 1937, 70, 48, 971.95 B. J. Todd and R. R. Miller, J . Amer. Chem. SOC., 1946,68,630.87 Compi!. rend., 1948, 228, 918.92 Trans. Faraday SOC., 1949,45,661DODD AXD ROBINSON. 95formation of diborane requires revision and becomes -26 kcals. /mole,compared with the previous value9* of +44 kcals./mole. Thus B2H6would be an endothermic compound. Methods of purification to bett'erthan 99% are reported, heats of formation 96 and vibrational spectra 97 ofvarious metal borohydrides have been measured, and the spectra have beenshown to be in agreement with the bridge structure formulati~n.~~ Alu-minium borohydride will ignite spontaneously in air ; 99 water vapour givingrise to rapid hydrolysis is a pre-requisite for explosion at room temperature.Reference has already been made in these Reports to the compounds oftype BH,,NH,, BH2*NH2, BH:NH, and their derivatives and polymers.A.B. Burg and C. L. Randolph2 have prepared compounds B2H,*NHMeand B2H,*NMe2 from diborane, methylamine, and dimethylamine, Thedimethyl compound is a stable solid (m. p. 74.5-75") and can be keptpermanently, The monomethyl compound un 3ergoes slow and reversibledissociation into diborane and the BH,*NHMe dimer, for which the bridgemodel (111) has been suggested.l Burg and Randolph now suggest astructure (IV) for the aminoborane and derivatives.Structure (IV) is thusintermediate between (111) and the hydrogen-bridge structure of diborane.(111.)Boron trifluoride3 has been shown not to react with phosphoric oxide,iodine pentoxide, or iodine, but combination with phosphorus trichloridegives BF,,PCl,, stable up to - 6". Structures and bond energies of a numberof fluoroborates and related compounds have been obtained4 from Ramanspectral data by J. Goubeau.in 60% yield by passing gaseous boron trichloride through a glow discharge.The compound has been well characterised ; vapour density indicates B,Cl, ;complete hydrolysis occurs with aqueous sodium hydroxide a t 70"; theliquid on standing a t room temperature for 72 hours gives 21 "/o decompositioninto boron trichloride and other undetermined chlorides ; with boron tri-bromide the compound B,Br, is obtained.The similar preparation andproperties of B214 have been described : i t is a crystalline pale yellow solidDiboron tetrachloride has been prepareds6 W. D. Davis, L. S. Mason, and G. Stegeman, J . Anzer. Chem. SOC., 1949, 71, 2775.s7 W. C. Price, H. C. Longuet-Higgins, B. Rice, and T. F. Young, J . Chem. Physics,1949, 17, 217.Ann. Reports, 1947, 44, 54.ss E. J. Badin, P. C. Hunter, and R. N. Pease, J . Amer. Chem. SOC., 1949, 71, 2950.Ann. Reports, 1948, 45,92 ; see also E. Wiberg, A. Bolz, and P. Buchheit, 2. anorg.J . Amer. Chem. Xoc., 1949, 71, 3451.P. Baumgarten, Ber., 1948, 80, 517.T. Wartik, R. Moore, and H. I. Schlesinger, J.Amer. Chem. Xoc., 1949, 71, 3265.W. C. Schumb, E. L. Gamble, and M. D. Banns, ibid., p. 3225.Chem., 1948, 256, 285; E. Wiberg, K. Hertwig, and A. Bolz, ibid., p. 177.4 Angew. Chem., 1948, 60, A , 7896 INORGANIC CHEMISTRY.which decomposes slowly at room temperature into BI, and black non-volatile (BI)z. G. Carphi has suggested that boric acid solutions containonly two ionic species in equilibrium, probably B503H2- and B03H2-.Some new alkali-metal perborates have been described by A. H. Fathallahand J . R. Partington.8A comprehensive phase-rule and X-ray investigation of the systemA1,O3-SO3-H2O, leading to the recognition of a dozen new compounds, hasbeen made by H. Bassett and T. H. Go~dwin.~ Methods of productionand the properties of aluminium fluoride have been critically reviewed.1°H.Brintzinger l1 has determined the ionic weight of the aluminate ion,among others, and the indication is that it is a binuclear complex, either[ (HO),A1(OH)~l( 0H)J4- or [ (HO),A102Al(OH)4]6- where the aluminiumatoms are linked by an oxygen-bridge structure.Ethylenediamine compounds of indium have been prepared anddescribed.12Though there is exchange l3 between uni- and ter-valent thallium inaqueous solution, H. McConnell and N. Davidson l4 have found no evidencefor exchange of 204Tl between the two valency states in solid TI2&, andTI2C1,. The implication is that the ions of the two valency states do notoccupy equivalent positions in the lattices of those compounds. The halidesT12X3 are more coloured than the halides of unmixed valency, but theabsorption spectrum shows no significant interaction absorption.Fromtitration curves of thallium(1) nitrate and sodium thiosulphate, the existenceof a number of the thiosulphate-thallium complex anions has been deduced.15Lanthanons and Actinons.--Isotopic constitutions have been deter-mined mass-spectrographically for lanthanum, cerium, l6 praseodymium,neodymium,17 and samarium.ls Resultant atomic weight values, withinternationaJ values in parentheses, are respectively 138.92 (138*92), 140.10(140.13), 140.92 (140~92)~ 144.25 (144-27), 150.35 (15043).N. E. Ballou19 has discussed the existence of promethium in Nature,and C. Feldmann 2O has described its arc spectrum. The magnetic suscepti-bilities of yttrium ,21 samarium,22 gadolini~m,~3 and thulium 24 have beendetermined.N. K. Dutt 25 has described the composition and isolationBull. Soc. chim., 1949, 16, 334.Nature, 1949, 164, 952. @ J., 1949, 2239.10 T. R. Scott, Counc. Sci. I d . Res. Australia, 1947, Bull. 230.I f 2. anorg. Chem., 1948, 256, 98.1 2 G. J. Sutton, J . Proc. Austral. Chem. Inst., 1948, 15, 356.la R. J. Prestwood and A. C. Wahl, J . Amer. Chern. Soc., 1949, 71, 3137.l4 Ibid., p. 3845.l5 J. Kamecki and J. Wolny, Roczn. Chem., 1948,22, 48.l6 M. G. Inghram, R. H. Hayden and D. C. Hess, Physical Rev., 1947,72, 967.l7 Idem, ibid., 1948, 74, 98. Idem, ibid., 73, 180.2o J . Amer. Chem. Soc., 1949, 71, 3840.21 0. M. M. Hilal and S. Sugden, J., 1949, 135.22 S.Sugden and S. R. Tailby, ibid., p. 136.25 J. Indian Chem. Soc., 1949, 26, 405.l9 Ibid., p. 630.Idem, ibid., p. 137. 24 Idern, ibid., p. 139DODD AND ROBINSON. 97of several double thiosulphates of the lanthanons, and an improved synthesisof lanthanon '' acetylacetonates " has been devised.26 The purificationof lanthanum has been effected 27 by precipitation of the hydroxide by air-borne ammonia, the method enabling a close control of pH. R. C. Vickery 28has also investigated the solubility of lanthanon hydroxides in fused ammoniumnitrate with a view to lanthanum purification and separation of cerium andyttrium. H, Hartmann 29 has examined discrepancies in the literatureconcerning lanthanon carbides and cyanamides. A complex of insolublepraseodymium trifluoride has been prepared,30 which is soluble and probablyhas the formula KPrF4.Samarium has been isolated31 from lanthanonmixtures by reduction of SmCl, to SmC1, by magnesium in absolute alcoholcontaining a few drops of concentrated hydrochloric acid. Samarium(I1)hydroxide, citrate, fluoride, and carbonate were then obtained by precipitation.When acid solutions of cerium(1V) perchlorate are exposed to ultra-violet light, reduction to cerium(II1) occurs with evolution of oxygen.L. J. Heidt and M. E. Smith32 have presented evidence for a mechanisminvolving the formation of cerium(1V) dimers. This is supported by thefurther kinetic measurements of D. Kolp and H. C. Thomas.33 Thus :hvZCeIv + Ce2V+Ce2r*CeaV* + H20 -3 2Ce111 + 2Hf + 40,Inhibition by Ce3+ ions is thought to be mainly due to deactivation of theenergetic dimer.It occurs to the Reporters that collision with Ce3+ ionsmight be more effectual in deactivation than other collisions by virtue ofexchange between the dimer and Ce3+ ions. The dimeric ions are supposedto be [Ce-O-CeI6+, [HO-Ce-O-CeJ5+, and/or [HO-Ce-O-Ce-OHI4 t .Some further general accounts of the chemistry of the actinons areavailable, and the work of W. H. Zachariasen34 on the crystal chemistryof 4j and 5j elements must be mentioned. This includes a summary ofstructural information on 55 new compounds : for a more detailed accountsee the Crystallographic Section of these Reports. Z. Szab0,35 on thebasis of periodicity in a number of physical properties, supports the idea ofthe actinon series.T. J. Hardwick36 and R. E. Connick37 have sum-marised methods of preparation and present knowledge of valencies exhibitedby the actinons. The absorption spectra38 of anhydrous chlorides ofuranium(IV), neptunium(IV), plutonium(III), and americium(II1) show sharplines clustered in groups. This characteristic is similar to the lanthanons.26 J. G. Stites, C. N. McCarty, and L. L. Quill, J . Amer. Chem. SOC., 1948, 70, 3142.27 R. C. Vickery, J., 1949, 2506.29 Angew. Chem., 1948, 60, A , 74.30 T. P. Perros and C. R. Naeser, J . Amer. Chem. Soc., 1949,7l, 3847.31 A. F. Clifford and H. C. Beachell, ibid., 1948, 70, 2730.82 Ibid., p. 2476.34 Acta Cryst., 1949, 2, 388, 390.36 Chem.Inst. Canada, Proc. Conf. Nuclear Chem., 1947, 44.57 R. E. Connick, J., 1949, S 235.5 8 S. Freed and F. J. Leitz, J . Chern. PhySics, 1949,17, 540.28 Ibid., p. 2508.33 Ibid., 1949, 71, 3047.35 Physical Rev., 1949, 76, 147.REP.-VOL. XL-. 98 INORGANIC CHEMISTRY.Even at room temperature, americium salts show the sharpest lines knownfor crystals, only europium(1II) salts being comparable. Thus the basicelectronic state 'Po, with six 5f electrons, is very probable for Am3t.J. T. Yang and M. Haissinsky3B have described a chromatographicseparation, on a synthetic resin amberlite IR-100, of actinium and lanthanum.Iodides of thorium(II1) and (11) have been prepared40 and are deeplycoloured compounds analogous to lower zirconium and hafnium iodides.450-550' ThI, + Th T,-~T' 2Th1,ZThI, + 2Th1, 3Th1, + Th G' 4Th1, 7' 450-550' 550-600"Hydrolysis of the salts is vigorous and yields thorium(1V) salts andhydrogen equivalent t o the reducing power.A. G . Maddock and G. L.Miles 41 have described some coprecipitation experiments with protactiniumwherein they found, with a variety of reducing agents, no evidence for a loweroxidation state of protactinium than five. They also give a new method forextraction in which protactinium is precipitated with manganese dioxide.On the other hand, G. BouissiBres and &I. Haissinsky42 have claimed afluoride of a lower valency of protactinium, both in tracer and in ponderableamount, by use of zinc amalgam and the Jones reductor. The fluoride,which is insoluble and can be precipitated without carrier or withlanthanum(II1) fluoride, is clearly of value for separation of protactinium.A variety of electropositive metals have been shown 43 to displace protactiniumfrom hydrofluoric acid solution.The hydrolytic behaviour of uranium, plutonium, and neptuniumin valency states (111) and (IV) has been studied.** The hydrolysis Pu3+ +H20 = Pu(OH)~+ + H+ occurs with pK = 7-23 in 0*069~-perchloratesolution ; a similar hydrolysis is suggested for uranium(II1) and neptun-ium(III), though their study is rendered very difficult by their powerfulreducing properties.The hydrolysis M4+ + H,O = MOH3+ + H+ takesplace up to 90?& for uranium(1V) and 50% for plutoniurn(IV), and eventually,above pH - 1, there is formation of polymers analogous to those formed byzirconium( IV) and neptunium(1V).However, the U(II1)-U(1V) reversiblecouple has been measured45 polarographically in acid solution and is in-dependent of hydrogen-ion concentration, suggesting U3+ =& U4+ + einvolving unhydrolysed ions. The hydrolysis of uranium tetrafluoridein the vapour phase a t 200--500" has also been studied.46 Uranium(V)39 Bull. Soc. chim., 1949, 16, 546.40 J. S. Anderson and R. W. M. D'Eye, J., 1949, S 244 ; E. Hayek and T. Rehner,Experientia, 1949, 5, 114.4 1 J . , 1949, S 248.42 Compt. rend., 1948, 226, 573; J., 1949, S 248.43 (Mme.) M. Camarcat, G . Boussihres, and M. Haissinsky, J . Chim. physique, 1949,44 K. A. Kraus and F. Nelson, U.S. Atomic Energy Commission Report, 1948, 1888.45 E. S.Kritchevsky and J. C. Hindman, J . Amer. Chem. Soc., 1949, 71, 2096.46 L. Domange and (Mile.) M. Wohlhuter, Compt. T e d . , 1949,228 1591.46, 153DODD AND ROBINSON. 99solutions have been prepared 47 by electrolytic reduction and have beenshown to have an optimum stability against disproportionation in the rangebetween pH 2 and 4. The formula UO,+ for the ions present is consistentwith the behaviour of the solution on passage of oxygen through it. NearpH 2, species U4+, U*OH3+, UO,', and UOZ2+ coexist in equilibri~m.~~ Afurther electrochemical study 49 of uranium and plutonium suggests that theion UO,+ disproportionates as soon as it is formed, but the pH is notspecified and no doubt was greater than 2 , A mechanism for uranium(V)disproportionation has been suggested 50 thus : UOit + Hi --+ UO*OH2t,UO,T + UO*OH2+ UO?+ + UO*OH+, UO*OH+ + stableU(1V) species.That the U(V) ion is U02+ is verified by ths insensitivity of the coupleUO,+ =+ UO?+ + e to pH (presumably within the optimum stabilityrange).The existence of plutonium(V) in solution is deduced 49 from inter-action absorption in the spectra of mixtures containing Pu(1V) and Pu(V1).Furthermore, the reaction 2H20 + U4+ + 2Pu4+ _I, UOZ2+ + 2Pu3+ + 4Hfhas been shown to occur.Exchange of uranium, 233TJ being used, has been shown 51 to occur betweenU4+ and the uranyl ion UO,,+, and the rate of exchange increases twenty-fold on irradiation with a tungsten-filament lamp. Exchange of oxygenbetween water and the uranyl ion has indicated the formula U02k ratherthan U(OH)42- unless the latter ion has two oxygen atoms more weakly boundthan the other two.On the other hand, J. Faucherre 53 has proposedthe formula U,O4(OH),2 +, H. Guiter 54 has given evidence for U20,(OH),2f,UO,(OH)+, UO,(OH)NO,, and U0,(N03),0H2-, and S. Ahrland 55 hasshown that monomeric UO$+ only exists in aqueous solution below pH 2.J. Sutton 56 has made cryoscopic and absorption-spectral measurementsto prove the formation of U,OS2 + , U3OS2+, U,O,OH', U308( OH),, andU,08(OH)3- but not UO,(OH)+ or UOJOH),. The formation of complexesof uranium hexafluoride and the use of hydrogen fluoride-free materialfor the purpose have been discussed by H. Martin.57 Heats of vaporisation 58of solid and liquid uranium hexafluoride, and its density 59 by a flotationtemperature method have been recently measured. Measurements 6o ofspecific heat of uranyl fluoride have led to calculations of enthalpy and ofentropy.Redox titrations followed spectrophotometrically and isolation of the com-47 K.A. Kraus, G. L. Johnson, and IF. Nelson, U.S. Atomic Energy Commission48 K. A. Kraus and F. Nelson, ibid., p. 2517.4B R. H. Betts, Chem. I m t . Canada, Proc. Conf. Nuclear Chem., May, 1947, 68.50 D. M. H. Kern and E. F. Orlemann, J . Arner. Chem. SOC., 1949,71,2102.c x R. H. Betts, Canadian J . Res., 1948, 26, B, 702.53 Compt. rend., 1948, 227, 1367.54 Bull. Soc. chim., 1947, 14, 64.56 J . , 1949, S 256.58 J. F. Masi, J . Chem.Physics, 1949,17,755.5B H. J. Koge and M. T. Wechsler, ibid., p. 617.60 P. F. Wacker and R. K. Cheney, J . RBS. Hat. Bur. Stand., 1947,39,317.Report, AECD, 1948, 2460; J . Arner. Chem. Soc., 1949,71, 2510.56 Acta Chern. Scand., 1949, 3, 374.57 Angew. Chern., 1948, 60, A , 73100 INORGANIC CHEMISTRY.pound NaNpVIO,(OAc),, have established the existence of +4, 3.5, +6oxidation states of neptunium. Neptunium(V) is quite stable in acidsolution. A number of solid compounds of neptunium have been prepared,62including halides, oxides, oxysulphides, and nitrate. Detailed accountsare now available of the chemistry of plutonium 63 and of its first isolation 64in the pure state and in pure compounds. R. E. Connick andW. H. McVey 65 have identified two peroxy-compounds of plutonium(IV), abrown one, probably (Pu*O*O*PU*OH)~+ or (V), and a red one, probably(HO~Pu-O*O*Pu*OH)4+ or (TI).Group IV.-The production of diamonds in the laboratory has beenfurther discussed by D.P. Mellor,66 and a long article 67 by H. Brusset isavailable on the chemistry of elementary carbon. The conversion of Baf4C0,into more useful compounds containing the carbon isotope has been accom-plished as follows. Carbon dioxide is obtained by treatment with acid andis then reduced to methane, 14CH4, by hydrogen a t 330" over nickel-thoriumoxide catalyst,68 or to elemenary carbon, 14C, with magnesium.6g Themethane may then be converted into carbon tetrachloride, l4Ccl4, by photo-chlorination, and the amorphous carbon into hydrogen cyanide, H14CN,by treatment with ammonia at 1000".The bond energies of various carbon-metal linkages have been estimated 70from the heats of combustion of the corresponding metal alkyls (mainlymethyls).Very thorough purification of the compounds used led to revisedmelting points for dimethylcadmium ( - 2.4") and trimethylaluminium(15.4"). Linear structures for dimethyl-zinc and -mercury have beendeduced 71 from vibration spectra, and force constants have been calculatedfor the carbon-metal bonds. The C-Zn bond shows greater ionic characterthan the C-Hg bond.Carbonyl selenide, previously obtained 72a by the reaction of carbonmonoxide on selenium, and fairly fully characterised, has now been prepared 721,by passing earbonyl chloride over aluminium selenide at an optimum tempera-ture of 220".The resultant aluminium chloride has an autocatalytic effect61 J. C. Hindman, L. B. Magmusson, and T. J. La Chapelle, J . Amer. Chem. Soc.,1949, 71, 687.62 S. Fried and N. Davidson, ibid., 1948, 70, 3539.63 B. G. Harvey, Chem. Inst. Canada, PTOC. Conf. Nuclear Chem., May, 1947,60.64 B. B. Cunningham and L. B. Werner, J . Amer. Chem. SOC., 1949,71, 1521.6 5 Ibid., p. 1534. Ann. Chim., 1948, 3, 679.6 8 W. H. Beamcr, J . Amer. Chem. SOC., 1948, 70, 3900.'O L. H. Long and R. G. W. Norrish, Phil. Trans., 1948-49,241, 587.72 (a) T. G. Pearson and P. L. Robinson, J., 1932, 652 ; (a) 0. GIemser and T. Risler,66 Research, 1949, 2, 314.R. Abrams, ibid., 1949, 71, 3835.H. S. Gutowsky, J .Chem. Physics, 1949, 17, 128.2. Naturforsch., 1948. 3, B, 1DODD AND ROBINSON. 101on the reaction. A number of physical properties have been remeasured,and others determined for the first time. Carbonyl cyanide has been similarly~haracterised.'~ The preparation of carbonyl chloride from carbon tetra-chloride and oleum has been shown 74 to follow the course H2S207 + CCI, -+COCI, + 2HS03C1 and H2S0, + CCI, -+ COCI, + HCl + HS0,Cl. Thermo-dynamic properties of carbonyl chloride have been thoroughly examined byW1 F. Giauque and W. M. J0nes.7~ For such metal carbonyls and nitrosylsas Fe2(CO),, Co2(CO),, and Fe(NO),X (where X is S-K+, Cl,, I,, etc.),R. V. G. Ewens 76 has suggested bridge structures involving direct metal-metal linkage.Liquid anhydrous hydrogen cyanide has been thoroughly investigatedas a solvent by G.Jander and B. Griittner.77 Perchloric and nitric acidsare acidic in the solvent, which has a small conductivity probably due to2HCN =+ (H*HCN)+ + CN- C- (H,CN)* + CN-. Nitric acid is a weakacid and apparently loses its oxidising power in liquid hydrogen cyanide.Acid-base indicakors and the solvolysis of many salts, especially silver salts,are discussed. Iron(III), silver(I), and mercury(1) cyanides are amphoteric 78in the expect*ed sense : AgCN Ag+ + CN- and AgCN + CN- z+=Ag(CN)-. The trimethylammonium salt of the latter ion has been isolatedamong others. Sulphur dioxide and trioxide in the solvent have an acidicnature 79 but yield very unstable acid analogues, thus :OHSO, + HCN OS/ + NC*Sd + H+'m i \:I- Solvolysis of sulphuryl chloride leads to OS(CN)Cl.The oxidation of cyanide by iodine and the various redox systems involvingcyanide, iodide, iodine, and iodine cyanide have been studied,80 as has alsothe possible polymerisation 81 of cyanic acid.The existence of dicyanicacid is doubted; equilibrium between HOCN and HNCO is suggested andany polymerisation is reckoned to give cyamelide and cyanuric acid. Acomplete structural determination 8, of the mineral trona has been made andit is shown to contain the ion (HCz06)3- or [ 0 >C-0 . . . H . . . OJol'-.0 \OAttempts have been made to prepare a non-cubic modification of silicon,and an unstable, probably hexa.gona1, form has been obtained.83 Studies73 0.Glemser and V. Hiiusser, 2. Natetrforsch., 1948, 3, B, 159.74 R. K. Murphy and F. H. Reuter, J . Proc. Austral. Chem. Inst., 1948, 15, 144.75 J . Amer. Chem. Soc., 1948, 70, 120.76 Nature, 1948, 161, 530.7 8 Ibid., p. 114.7 7 Ber., 1948, 81, 102, 107.7s Ibid., 1947, 80, 279.R. Gauguin, Bull. SOC. chim., 1948,15, 1052.A. E. A. Werner and J. Gray, Sci. Proc. R. Dublin Soc., 1947, 24, 209.82 C. J. Brown, H. S. Peiser, and (Miss) A. Turner-Jones, Acta Cryst., 1949,2, 167.83 F. Heyd, F. Khol, and A. Kochanovskb, Coll. Czech. Chem. Cmm., 1947,12, 502102 INORGANIC CHEMISTRY.have also been made of sodium silicate hydrates,84 preparation of siliconsulphide~,~~ hydrolysis of silicon halides,s6 and the preparation of ethoxy-silicon fluorides.87 Magnetic-susceptibility measurements 88 have indicated[SnCI,(H,O),], [KSnCl,(H,O)], K2[SnC14], and K,[SnC1,(H20)2],H20 forSnCI2,2H,O, KSnCI,,H20, K,SnCI,, and K2SnCl, ,3H,O, respectively, andthe formulation is in agreement with the difficulty of dehydrating tin(I1)chloride hydrates, and poor electrical conductivityof its solutions.Hydrolysisstudies *@ of sodium stannates have sugggested the presence of species(NaHSnO,),, NaHSnO,, Na,HSn0,2+, and Sn0,H-.Radio-isotopes of lead have been used @O to investigate the exchangeof lead in the solid state between the nitrate and chromate, the chloride andchromate, the chloride and sulphate. There is a temperature thresholdof exchange which is related to the temperature of fusion of the salt. Thethermal decompositions of lead oxalate @l and nitrate @, have been studied.The action of heat on lead iodide 93 in vacuum and in the presence of oxygengave no visible decomposition at 729" in the first case and in the second casegave oxides of lead and some oxyiodides which were not isolated.Aceto-bromides and acetoiodides of lead have been prepared,@4 including a newcompound, Pb,(OAc),I.Preparation and properties of amides of titanium(II1) have been recentlyde~cribed,@~ e.g., Ti(NH,), and KTi(NH,),. H. R. Hoekstra and J. J.Katz 96 have prepared borohydrides of titanium(III), zirconium(IV),hafnium(IV), and thorium(1V). The last is the most salt-like, but all arethe most volatile compounds known for each element in the stated valencyConnick and McVey B7 have investigated0 QH the nature of complex species formed betweenii---il-c-cH=-CCE', zirconium(1V) and thienoyltrifluoroacetone (in-(= HX) set).Two-phase distribution between waterand benzene indicates that ZrX, is the only important species in benzenesolution. The nature of sulphates, fluorides, chloride, nitrate, peroxide, andoxalate of zirconium( IV) was also studied. Complex compounds betweenzirconium(1V) and alizarin and related compounds have been investigated 98and compared with the hafnium(1V) compounds.state.\S/BP H. Lange and M. von Stackelberg, 2. anorg. Chem., 1948, 256, 273.*5 L. Malatesta, Cazzxettu, 1948, 78, 702.86 J. Goubeau and R. Warncke, Angew. Chem., 1948, 60, A , 73.87 H. J. Emeleus and H. G. Heal, J., 1949, 1696.89 E.CarriAre, H. Guiter, and M. Ronso, BUZZ. SOC. chim., 1948,15, 946.@1 L. L. Bircumshaw and I. Harris, J., 1948, 1898.S2 A. Nicol, Compt. rend., 1948, 226, 253.93 Idem, Bull. SOC. chim., 1949, 16, 280.94 E. Grillot, ibid., 3.948, 15, 1035.95 0. Schmitz-Dumont, P. Simon, and G. Broja, 2. awrg. Chem., 1949, 258, 307.98 J . Amer. Chem. SOC., 1949, 71, 2488.9' Ibid., p. 3182.08 J. F. Flagg, H. A. Liebhafsky, and E. H. Winslow, ibid., p. 3630.E. Gaillot, Compt. rend., 1948, 226, 496.(Mlle.) E. Gleditsch and P. T. Cappelen, ibid., 1949, D, 64DODD AND ROBINSON. 103Group V,-A redetermination 99 of the chemical atomic weight of nitrogen,using ratios NH4Cl : Ag, NH,Cl : AgCl, NH,Br : Ag, and NH,Br : AgBr, hasgiven a value 14.008 identical with the International value (1948).Animproved apparatus for carrying out reactions in liquid ammonia a t itsboiling point has been described and provides for titration, filtration,and purification operations, Electron-diffraction measurements havebeen made on the fluoride N2F2, and distances worked out on the basis of aconfiguration F*N:N*F. Structural investigations giving bond lengths havealso been carried out in solid N20a3 and gaseous NO,.4 Methods of prepara-tion of nitrogen oxides have been discussed by L. Hackspill and J. Besson.G. Glockler gives a value 6-49 ev. (149-6 kcals./mole) for the heat of dissoci-ation of nitric oxide.The species involved in concentrated nitric acid and the evidence forions NO-, NO,+, H2N03+, etc., were discussed recently in these Reports.In addition to that, ultra-violet absorption of aqueous and anhydrous nitricacid in the range from 80HN03:20H20 to 76HN03:24N,0, has beenshown 8 to be consistent with the schemeZHO*NO, ,L 4 2 R 0 , 2N0,- + 2H30+X-Ray investigations 9 on crystalline (NO,*)(ClO,- ) have corroboratedRaman spectral results 10 and indicate a linear NO,+ ion.On the otherhand, W. R. Angus, R. W. Jones, and G. 0. Phillips have suggested l1 thatin liquid N205 and N204 respectively there is no necessity to postulateionisation but merely a state of polarisation NO,s+ - NO$-, NOS+ - NO,S-when, in the two cases, NO,+ and NO" are available but not present in thepure liquids. Thus electrolysis of N204 in glacial acetic acid between aniron cathode and a.platinum anode occurred only after addition of a crystalof sodium acetate. The reactions with sodium and liquid N204 and N,O,gave sodium nitrate and nitric oxide and nitrogen peroxide, respectively,indicating a t least the potential presence of the nitrosyl and nitronium ions.Liquid N20, as a solvent has also been considered by C. C. Addison and9* 0. Honigschmid and L. Johannsen-Grohling, 2. Naturforsch., 1946, 1, 656.2 S. H. Bauer, ibid., 1947, 69, 3104.3 J. S. Broadley and J. M. Robertson, Nature, 1'949, 164, 915.G. W. Watt, and C. W. Keenan, J . Amer. Chem. SOC., 1949,71, 3833.S. Classson, J. Donohue, and V. Schomaker, J . Chem. Physics, 1948, 16, 207.Bull. Soc. chim., 1949, 16, 479.J . Chem. Physics, 1948, 16, 604.Ann. Reports, 1947, 44, 74.R.N. Jones, G. D. Thorn, M. Lyne, and E. G. Taylor, Nature, 1947, 159, 163;E. G. Cox, G. A. Jeffrey, and M. R. Truter, Nature, 1948,162, 258.lo D. R. Goddard, E. D. Hughes, and C. K. Ingold, ibid., 1946, 158, 480.l1 Ibid., 1949, 184, 433.R. N. Jones, and G . D. Thorn, Canadian J . Res., 1949, 27, €3, 580104 INORGANIC CHEMISTRY.R. Thomson.12have suggested l3 an association between nitric acid and waterOther papers on the constitution of nitric acid solutionsHO-N \O rather than HO-N //O H- ... O>N-OH,/ O . . . H\O . . . H/or have considered l4 equilibria involving the ion pair H,O+*NO,- and thespecies (HNO,),NO,-. From a Raman spectral study the structure (VII)has been suggested l5 for the latter:\o..*H\o/ '0G.Jander and H. Wendt 16 have also used liquid anhydrous nitric acid asa solvent, in which phosphorus oxychloride, POCl,, undergoes solvolysis(POCl, + HNO, -3 HPO, + C1, + NOCl) and uranyl nitrate showsamphoteric character.J. R. Partington and A. L. Whynes have remeasured the vapour pressure 1'of nitrosyl chloride and studied its action la on various metals and theircompounds. Two new compounds, InCl,,NOCl and GaCl,,NOCl wereprepared.A low-temperature (450-900") preparation of phosphorus fromphosphates of bismuth, lead, and tin has been described. I?. E. Whitmore 2ohas shown that in the formation of 32P by neutron irradiation of sodiumsulphide, Na,3,S, the phosphorus practically all appears a s phosphate.Thus the recoiling phosphorus atom loses one or more electrons and is thusin oxidised form.Exchange of radio-phosphorus has been investigated 21between phosphorus trichloride and elementary phosphorus in carbondisulphide solution. The reactions and properties of the phosphorus sulphidesP,S,, P4S5, P4S,, and P4S,, have been discussed 22 as has the structure 23 of(PNCl,),. Evidence for the P-N ring structure of the last is presented.l2 J., 1949, S 211, S 218.l3 J. Ch6din and (Mme.) S. FQneant, Conzpt. rend., 1947,222,1424 ; J . Chim. physique,1948, 45, 66.l4 J. ChQdin, (Mme.) S. FhnBant, and R. Vandoni, Compt. rend., 1948, 226, 1722;J. ChBdin and R. Vandoni, ibid., 1948,227,1232 ; H. von Halban and M. Litmanowitwh.Helv. Chim. Acta, 1948, 31, 1963.15 J.ChBdin and (Mme.) S. FBnBant, Compt. rend., 1949, 228,242.Is 2. anorg. Chem., 1948, 257, 26 ; 1949, 258, 1 ; 259, 309.l7 J. R. Partington and A. L. Whynes, J . Physicui Coll. Chem., 1949, 53, 500.18 Idem, J., 1948, 1952.I@ P. Jolibois and J. C.Hutter, Compt. rend., 1949, 228, 1389.2O Nature, 1949, 164, 240.21 R. Muxart, 0. Chalvet, and P. Daudel, J . Chim. physique, 1949,46, 373.22 J. C. Pernet and J. H. Brown, Chem. Eng. News, 1949,27, 2143.23 H. Bode, Angew. Chent., 1948, 60, A , 67; see Quart. Reviews, 1949,3, 345DODD AND ROBINSON. 105The condensed phospha'tes have excited considerable interest recently,and the subject has been very thoroughly treated by B. T0pley.2~ It istherefore only necessary to mention papers which have appeared since on thethermal dissociation 24 of phosphoric acid and ammonium phosphates,the constitution 25 of Na3P30,, the X-ray structural examination 26 of(NH4),H2P20,, and the preparation 27 of the corresponding sodium salt byoxidation of red phosphorus with sodium chlorite.A critical literature survey 28 has been made-and experiments repeated-on the formation of solid hydrides of arsenic, antimony, and bismuth.The authors never obtained any solid h ydrides, whose existence they regardas still questionable.However, R. Nast 29 has prepared extremely unstableAs2H4 which debomposes at -100" to arsine and a red amorphous solid ofempirical formula ( A S ~ H ) ~ . Electrolytic oxidation of arsenic(II1) solutionshas given 30 no indication of a +4 oxidation state.The absorption spectraof mixed solutions of arsenic(II1) and arsenic(V) and of antimony(II1) andantimony(V) have been pl0tted.~1 The concentration dependence in thecase of antimony suggests the formation of an Sb(II1)-Sb(V) dimer. Hydro-lysis of [SbGCl,]- to [SbCl,(OH), -,]- apparently occurs, and H. Brintzinger 32assigns formuls Na[Sb(OH)6] and Na[Sb(OH),] to sodium antimonate andantimonite on the basis of dialysis experiments. Spectrophotornetric studieshave been made of complex ions present in bismuth thiocyanate 33 and bismuththiosulphate 34 solutions.The chemisorption of olefins on vanadium trioxide has been studied35in relation to the use of the oxide as a catalyst for hydrogenation. Com-pounds VC14N0, V,Cl,NO, and V2C1,(NO), have been all of whichsublime and yield vanadium tetrachloride and nitric oxide with water.A. G.Whittaker and D. M. Yost 37 have also investigated the dimerisation ofvanadium tetrachloride in carbon tetrachloride solution. Vapour pressuresof niobium and tantalum pentachloride and pentabromide and of tantalumiodide have been measured by K. M. Alexander and F. Fairbrother,38 who,incidentally, contest the name niobium and prefer columbium on historical24 H. N. Terem and (Mlle.) S . Akalan, Compt. rend., 1949, 228, 1437.25 E. Thulo and R. Ratz, 2. anorg. Chem., 1949, 258, 33.B6 B. Raistrick and E. Hobbs, Nature, 1949, 164, 113.2 7 E. Leininger and T. Chulski, J . Amer. Chem. Soc., 1949, 71, 2385.28 (Miss) C. Brink, G. Dallinga, and R. J. F. Nivard, Rec.Trav. chim., 1949, 68,29 Ber., 1948, 81, 271.31 J. E. Whitney and N. Davidson, ibid., p. 3809.32 2. anorg. Chem., 1948, 256, 98.34 F. Gallais and M. Brandela, Compt. rend., 1948, 226, 2148.35 V. I. Komarewsky and J. R. Coley, J . Amer. Chem. Soc., 1948, 70, 4163.36 A. G. Whittaker and D. M. Yost, ibid., 1949, 71, 3135.37 J . Chem. Physics, 1949, 17, 188.38 J., 1949, S 223 ; ibid., p. 2472 ; see also E. L. Wiseman and N. W. Gregory, J . Amer.234.W. M. Machevin and G. L. Martin, J, Amer. Chem. Soc., 1949, 71, 204.W. D. Kingery and D. N. Hume, J. Amer. Chem. SOC., 1949,71, 2393.Chem. SOC., 1949, 71, 2344106 INORGANIU OHEMISTRY.grounds. Complex fluorides of niobium and tantalum have been described,39as also a complex niobium sulphate,40 probablyK,Nb,I*1Nb"(OH)3(S04)6,9H,0.Group VI.-The interest in hydrogen peroxide continues.The thermalstability of concentrated hydrogen peroxide, in the range 50-100" and70-90% H202 by weight, has been recently studied 41 both in the presenceand in the absence of stabilisers. The preparation of Pyrex surfaces forreproducible results is a point of practical interest. W. F. K. Wynne-Jones 42has discussed the electrolytic properties of aqueous hydrogen peroxide, andM. G. Evans and N. UriP3 have remeasured the acid dissociation constantand the heat of dissociation, 2H,O, H30+ + H0,-. Their value of K(1.78 x 10-l2, &5%, at 20" and zero ionic strength) is more than twicethe value given by R. A. Joyner 44 (0.59-0-77 x 10-l2, at 0").Evans andUri's value of 8.2 kcals./mole for AH is in good agreement with Joyner'sdirect thermal measurement of 8-6 kcals. /mole. Electron affinities andsolvation energies for OH, O,H, O,, and 0,- are then calculated. Theproperties of the ion-pair complexes [ Fe( 0H)l2+, [ Fe( 0,H)l2 + areand differences in the absorption spectra discussed in terms of the electronaffinities of the OH and the 0,H radical. Such ion pairs, and the heat ofreaction 46 2Fe2+ + H,O, 2Fe3+ + 20H-, have considerable bearingon the iron(I1)- and iron(II1)-catalysed decomposition of hydrogen per~xide.~'Though there is general support for the basic Haber-Weiss mechanism,48V. S. Andersen49 has given experimental results which agree with themechanism Fe3+ + H0,- + [FeOHI2+ + 0, 0 + H0,- _I_, OH- + 0,.Uri 50 has investigated the effect of other ions on the peroxide decomposition,and the kinetics of the reaction between permanganate and hydrogenperoxide have been studied.51Variations as great as 2.5% and 5% respectively in the isotope abundanceratios 325 : 33S and 32S : 34S have been found 52 in sulphur from various sources.Generally, hydrogen sdphide in well wakers is low in the heavy isotope,and sulphates either in solution or as gypsum are enriched with the heavyisotope.This has been shown to occur even for sulphate and sulphide in thesame solution. The isotope 35S, produced artificially by the reaction39 G. S. Savchenko and I. V. Tananayev, J . Appl. Chem,. U.S.S.R., 1946, 19, 1093.4 O E. W. Golibersuch and R.C . Young, J . Amer. Chem. Soc., 1949, 71, 2402.4 1 W. C. Schumb, Ind. Eng. Chem., 1949, 41, 992.42 J . Chinz. physique, 1949, 46, 337.43 M. G. Evans and N. Uri, Trans. Paraday Soc., 1949,45,224.44 R. A. Joyner, 2. anorg. Chem., 1912,77, 103.45 M. G. Evans, P. George, and N. Uri, Tram. Faraday Soc., 1949, 45, 230.46 M. G. Evans, J. H. Baxendale, and N. Uri, ibid., p. 236.47 W. G. Barb, J. H. Baxendale, 9. George, and K. R. Hargrave, Nature, 1949,163,692; J. Weiss and C . W. Humphrey, ibid., p. 691; I. M. Kolthoff and A. I. Medalia,J . Amer. Chem. Soc., 1949, 71, 3777, 3784, 3789.413 Ann. Reports, 1947, 44, 65.50 J . Physical Coll. Chem., 1949, 53, 1070.61 (Mlle.) F. Fouinat, Compt. rend., 1949, 228, 1593.69 H. G. Thode, J. Macnamara and C.B. Collins, Canadian J . Bet?., 1949,27, B, 361.49 Acta Chem. Scad., 1948, 2, 1DODD AND ROBINSON. 10735Cl(n,p)35S, appears 53 in chemical form which exchanges rapidly withsulphate when potassium, sodium, and iron(II1) chlorides are used. A95-100% yield of 35S is obtainable as sulphate, but only with difficulty inany other form. V. Croatto and A. G. Maddock 54 have shown that use ofrubidium chloride gives sulphur which may be obtained in 50% yield ashydrogen sulphide by treatment with aqueous hydrochloric acid containinga trace of hydrogen sulphide as carrier.The molar magnetic susceptibility of diatomic sulphur has now beenmeasured 55 at temperatures of 550--850", and as in the paramagneticoxygen atom, agreement was found with the theoretical value for S, in the,I: state.The proportions of S, in sulphur vapour were shown to be satis-factorily predicted by existing equilibrium data. The solubility of hydrogensulphide in liquid sulphur from 120" to 455" shows 56 an increase withtemperature before falling near the boiling point of sulphur. Polysulphideformation was indicated, a maximum solubility of 0.19 g. of H,S per 100 g.of sulphur being observed. Raman spectra of hydrogen polysulphides havebeen measured 57 and their base-catalysed decomposition discussed 58 interms of structure. (Mme.) D. Peschanski 59 has given evidence that sulphurdoes not dissolve in sodium sulphide to a greater extent than corresponds toNa,S,. D. L. Douglas, F. Nesbitt, and D. M. Yost 60 have not been able toconfirm any exchange of sulphur (ass) between hydrogen sulphide and carbondisulphide in benzene solution after 95 hours at 120", though R.R. Edwards,F. Nesbitt, and A. K. Solomon 61 reported exchange between 35S2- inaqueous solution and carbon disulphide in separate phases.The reaction between hydrochloric acid and a saturated solution of S,N,yields 62 a reddish-brown precipitate which changes gradually to an equi-molar mixture of S,N,C1 and ammonium chloride; S,N,Cl may also beprepared by reaction between S,CI, and S,N,. On dissol-ving it in waterand treatment with potassium iodide, insoluble S4N31 may be precipitated.The lower oxides and oxyacids of sulphur have been further studied byM. G ~ e h r i n g . ~ ~ F. See1 and H. Bauer 64 have made conductivity measure-ments of solutions of acetyl chloride and nitrosyl chloride in liquid sulphurdioxide, wherein the cations CH,*CO+ and NOf appear to be formed.Thereaction SO, + SCI,-+ SOCI, + SO, has been investigated 65 by using35S as a tracer. C. A. Andresen and C. E. Miller 66 have described a simple63 M. B. Wilk, Canadian J. Res., 1949, 27, B, 475.54 Nature, 1949, 164, 613.5 5 A. B. Scott, J . Amer. Chem. Soc., 1949, 71, 3145.5 6 R. Fanelli, Ind. Eng. Chem., 1949, 41, 2031.5 7 F. Feh6r and M. Baudler, 2. anorg. Chem., 1949, 258, 132.5 8 0. FOSS, K . Norske Vidensk Selskab. Forh., 1946,19, No. 20, 72.5s Compt. rend., 1948, 227, 770.6o J . Amer. Chem. SOC., 1949, 71, 3237.62 A. G. MacDiarmid, Nature, 1949, 164, 1131.63 Angew.Chem., 1948, 60, A , 69.65 R . Muxart, P. Daudel, and B. Bosoardin, J . Chim. physique, 1949,46,466.66 J . Amer. P?&arm. ASSOC., 1948, 37, 204.61 Ibid., 1948, 70, 1670.64 2. Naturforsch., 1947, 2, B, 397108 INORGANIC CHEMISTRY.method of preparing sulphamide, SO,(NH,),, and the preparation and pro-perties of sulphur monofluoride have been recorded.67The system H,Se-Se-Na,CO, has been investigated by A. Pappas and M.Haissinsky,68 who have found polyselenides, Na2Se2, Na,Se,, Na,Se,,whose formation is independent of the allotropic state of the selenium.Further measurements 69 have been made and a mechanism suggested forthe photo-oxidation of hydrogen selenide in the presence of selenium. Thepreparation of pure strontium and calcium selenides has been described,70and their use as infra-red phosphors discussed.Selenium and telluriumin the +4 oxidation state have been studied 7 1 polarographically; noevidence was found for Se2 or Te2+.The salts Na,Se(S20,),,3H,0, K,Se(S,O,),,I QH,O, Na,Te(S,O,),, andK,Te(S,O,), have been prepared 72 as the first salts of seleno- and telluro-pentathionic acids. The equilibrium Se(S0,);- + 2S20,2- =+ Se(S,O,);- +2SO,,- is observed, whereas the corresponding reaction between sulphite andpentathionate, S(S,O,);- + 2S0,2- ---+ S(S0,);- + 2S2O,,-, goes to com-pletion. The sodium selenopentathionate crystallises in small shiny yellow-green leaves and is very soluble in water. The potassium salt forms yellow-green needles. In alkalinesolution both seleno- and telluro-salts are hydrolysed with precipitation ofselenium and tellurium.The intermediates Se( OH), and Te(OH), aresuggested. E'urther papers include discussion of a variety of reactions oftelluri~rn,~, the electro-chemical properties 74 of telluric acid, and thepreparation and properties 75 of tellurium tetraiodide.Chromium dioxide, which has been recently suggested 76 as an activeintermediate in the photochemical oxidation of glycerol by dichromate inaqueous solution, has been obtained 77 as an amorphous brownish-black solid,stable up to 400°, by heating chromium(II1) oxide in air above 320".The thermal dissociation of chromium(V1) oxide has been studied.78 Copperchromites have been prepared 79 and shown to be related according toThe salts are stable when dry or in acid solution.CuO + CuIICr,O, 2% Cu1,Cr,04 + [O].Thiochromites and selenochro-mites, M,CrSe,, of the alkali metals have been preparedand examined by X-rays.in high purity67 L. M. Dubnikov and N. I. Zorin, J. Gen. Chem. Ru~sia, 1947,17, 185.6s A. Pappas and M. Haissinsky, Bull. SOC. chim., 1949,16, 645.6g E. W. Pittman, J., 1949, 1811; see Ann. Reports, 1948,45, 107.70 A. L. Smith, R. D. Rosenstein, and R. Ward, J . Amer. Chem. Xoc., 1947,69, 1725.71 J. J. Lingane and L. W. Niedrach, ibid., 1949, 71, 196.7% 0. FOSS, Acta Chem. Scand., 1949, 3, 435, 708.'3 E. Montignie, Bull. SOC. chim., 1948, 15, 180; J. Mayer and M. Holowatyj, Ber.,7 5 E. Montignie, Ann. Pharm. franp., 1947, 5, 239.76 K.Weber and W. Asperger, J., 1948, 2119.7 7 (Mme.) M. DorninB-Berg&s, Compt. rend., 1949, 228, 1435.7% F. 3%. Vasenin, J. Gen. Chem. Moscow, 1947,17, 450.79 J. D. Stroupe, J . Amer. Chem. SOC., 1949, 71, 560.1948, 81, 119. 74 F. Fouasson, Ann. Chim., 1948, 3, 594.W. Rudorff, W. R. Ruston, and A. Scharhaufer, Act@ Cryst., 1948,1, 196DODD AND ROBINSON. 109An X-ray and chemical study 81 of molybdenum oxides in the rangeMOO,,.^^-^^^ has been made, and molybdenum-blue hydrates Mo401,,H,0and Mo,O,,H,O identified, among others. G. W. Watt and D. D. Davies 82have prepared anhydrous molybdenum(II1) oxide by reaction betweenMOO, and potassium dissolved in liquid ammonia. In 8-6 and &2N-hydrochloric acid, hexavalent and quinquevalent molybdenum have beenshown 83 to exist as [Mo0,I2+ and [M00]3+ in the stronger acid and LMoO,]~*+and [Mo0-j26* in the weaker acid.The heat of formation of tungsten(V1) oxide has been measured,s4 andthat of tungsten carbide recalculated. Tungsten trifluoride was obtained 85as a reddish-brown solid by reduction of tungsten hexafluoride with benzeneat 110" in a nickel bomb.The action of hydrogen fluoride on tungsten(1V)oxide gives, at 500", a grey solid, WOE',, chemically inert to boiling alkalisand aqua regia. A polarographic study s6 of tungsten has shown three forms,green, red, and yellow, of tungsten(III), and a deep red tungsten(IV), as wellas a 3.5 oxidation state.Group VB,--A comprehensive article by H. R. Leech 6' is now availableon the production, both technically and in the laboratory, of fluorine.E.Wicke 88 has reviewed the published values of the dissociation energyof the fluorine molecule, and from measurements of thermal conductivityof fluorine at 1000" gives a value for D(F,) = 63 kcals./mole, as generallyaccepted. A. D. Gaunt and R. F. Barrow 89 have, however, calculated avalue 50 rfr 6 kcals./mole on the basis of the ultra-violet absorption ofrubidium and casium fluorides. On the basis of thermodynamic propertiesof OF, and C1F calculated from electron-diffraction and spectroscopic data,R. L. Potter regards the best value as even lower, suggesting 1-5 ev. (34-6kcals./mole). Though rapid exchange o f chlorine between chlorine gas andhydrogen chloride occurs even in the dark, no similar exchange of fluorinebetween fluorine gas and hydrogen fluoride has been observed.91 This has beenadvanced as evidence for exchange of the higher halogens occurring throughan intermediate HX3.While there is no production of ozone observed whenfluorine is passed through water a t O", approximately 1% of ozone is pro-duced 92 on passing fluorine through sodium hydroxide solution a t -55".New reactions of the halogen fluorides have been discussed by H. J.Emel6~s.~3 Salts of the form KBrF,, AgBrF,, BaBr,Fs,94 and KIF, 95 haveAnionic forms were also present.B L 0. Glemser and (Frl.) G. Lutz, Angew. Chem., 1948,60, A , 69.83 A. R. Tourky and H. K. El Shamy, J., 1949, 140.84 G. Huff, E. Squitieri, and P. E. Snyder, J. Amer. Chem, SOC., 1948, 70, 3380.85 H.37. Priest and W. C. Schumb, ibid., p. 3378.86 J. J. Lingane and 1,. A. Small, ibid., 1949, 71, 973.13' Quart. Reviews, 1949, 3, 22.8s Nature, 1949, 164, 753.O1 H. W. Dodgen, W. F. Libby, ibid., p. 951.O2 E. Briner and R. Tolun, HeEv. Chim. Acta;, 1948,31, 937.Oa Angew. Chem., 1948, 60, A , 73.O4 A. G. Sharpe and H. J. EmelBus, J., 1948,2135.J . Arper. Chem. SOC., 1948, 70, 3751.8 8 Angew. Chem., 1948, 60, A , 65.O0 J . Chem. Physics, 1949, 17, 957.s5 Idem, J., 1949, 2206110 INORGANIC CEEMISTRY.been obtained; the existence of ions BrF,+ and BrF4- in liquid BrF, hasbeen post~lated.~~ Of particular interest is the actiong6 of iodine penta-fluoride on carbon tetraiodide and tetraiodoethylene. Compounds CIF,(b.p. -22.5"), in good yield, and C21F5 (b. p. 13") were obtained. Theseiodides do not form Grignard reagents under normal conditions but withmercury give CF3HgI and C,F5HgI. Ultra-violet irradiation of CF31in the presence of organic liquids indicates 97 the formation of CF, radicalswhich react with the solvent. The fluorination of methanol, or carbonmonoxide, in the presence of silver difluoride givesg8 a gas CF,*OF, withodour similar to fluorine, which liquefies to pale straw-coloured liquid at-95"; stable up to 450", it is a powerful oxidising agent. It did not provepossible to obtain CF,*OH by treatment with hydrogen.In a further contribution 99 on the photochemical reaction betweenhydrogen and chlorine, W. J. Kramers and L. A. Moignard have concludedthat the Nernst hypothesis must be modified and that chain inhibitorsare not completely destroyed by light.haveused radio-chlorine to study exchange between chlorine dioxide and chloride,chlorite, and chlorate ions.D. H. Derbyshire and W. A. Waters2 have shown that bromide-freehypobromous acid in mineral acid but not in approximately neutral solutionis very much more reactive as a brominating agent than free bromine. It issuggested that the hydrated bromine ion Br+,H,O is forined by HOBr + H+---+ (H,OBr)+.Further work on the nature of solutions of iodine is somewhat contra-dictory in character. N. E. Baylis has suggested that the spectra of iodineand bromine solutions can be adequately explained on the basis of thephysical properties of the solvent without postulating any special solute-solvent interaction.have found strong spectral evidence for an equilibrium I, + A + I,A,where A is the molecule of an aromatic hydrocarbon solvent molecule.No bands corresponding to the iodine-aromatic molecule interaction werefound for non-aromatic solvents.Spectrophotometric studies have suggested that no significant amountsof 12094- are present in periodic acid solutions but that species H,IO,-,H31062-, and H,I063- are involved.has been observed,6 the pyridinium salt of IC1,- being obtained and analysed.H.Taube and H. DodgenOn the other hand, H. A. Benesi and J. H. HildebrandThe reaction2SOC1, + 21- ---+ 2IC1,- + so, + s96 A. A. Banks, H. J. Emelbus, R. N. Haszeldine, and V.Kerrigan, J., 1948, 2188.97 R. N. Haszeldine and H. J. EmelBus, Research, 1948, 1, 715.98 K. B. Kellogg and G. H. Cady, J . Amer. Chem. SOC., 1948, 70, 3986.99 Trans. Paraday SOC., 1949, 45, 903.1 J . Amer. Chem. SOC., 1949, 71, 2501, 3330.8 Nature, 1949, 163, 764.Nature, 1949,164, 446; see C. N. Hinshelwood, J., 1947, 694.J. Amer. Chem. SOC., 1948,70,2832; 1949,71, 2703.C. E. Crouthamel, H. V. Meek, D. S. Martin, and C. V. Banks, i b a . , p. 3031.6 W. B. Brownell and L. C. ICing, ibid., p. 2926DODD AND ROBINSON. 111The reactions in the systems 12--N02-, 12-N3-, and Br2-N3- and the effecton them of thiosulphate and tetrathionate ions have been studied kinetically,and mechanisms have been pr~posed.~ The properties of astatine havebeen studied; the At- ion has been shown to exist in aqueous solution andat least two positive oxidation states have been observed.8The separation of technetium from molybdenum, from which it isproduced by proton bombardment, has been de~cribed.~ After precipitationof molybdenum with 8-hydroxyquinoline, the technetium is isolated byadsorption on copper sulphide produced by adding copper chloride andpassage of hydrogen sulphide. The per-rhena'tes of cobalt, nickel, man-ganese, and iron have again been prepared and described.1° Those of cobalt,nickel, and manganese confirm previous findings.Unusual colours in theiron salts suggest complex formation.Evidence has not been obtained for the rhenium oxyfluorides ReOF,and Re02F2 previously reported,llU but two new oxyfluorides ReOF, andRe02F3 have been prepared.l l b ReOF, is a cream-coloured crystalline solid,m. p. 3-;1.5", b. p. 55", liquid density 3.8 & 0.05 at 40°7 solid density 4.2 -& 0.05at the melting point. Re0,F3 is a pale yellow powder which begins to sinterat 90" and is liquid a t 95".Group VIII.-The ratio of isotopes in purified terrestrial and meteoriciron has been determined l2 by means of a mass spectrograph, and nodifference in proportion has been found either between different samplesof each variety or between the varieties themselves. The calculated atomicweight becomes 55.856 against the International value 55-85. Thermo-magnetic analysis has been used l3 to follow the decomposition 4Fe0-3Fe30, + Fe between 300" and 570".In this completely solid reaction,the effect of temperature of preparation, of composition, and of the presenceof Fe and l?e30, as centres of crystallisation has been studied. The solubilityof freshly precipitated " gelatinous " iron(II1) hydroxide has been measured 14and the vapour pressure and solubility of the hydrates of iron(I1) chloridehave been investigated.15 Evidence for the following equilibria has beenobtained l6 in the hydrolysis of iron(II1) chloride :2FeC12+ + 2H20 z+ [FeC1OHI22* + 2H+ZFe3+ + 2C1- + 2H20 + [FeCIOH]22+ + 2HC7 R. 0. GriEth and R. Irving, Trams. Faraday Xoc., 1949, 45, 305; G. Dodd and8 G. L. Johnson, R. F. Leininger, and E. Segrd, J . Chem. Physics, 1949,17, 1.10 W. T, Smith and G. E. Maxwell, J .Amer. Chem. Soc., 1949, 71, 578.l 1 (a) 0. Ruff and W. Kwasnik, 2. anorg. Chem., 1932, 209, 113; ( 6 ) E. E. Aynsley,l2 G. E. Valley and H. H. Anderson, J . Amer. Chem. Xoc., 1947, 69, 1871.l3 G. Chaudron and J. BBnard, Bull. SOC. chim., 1949, D, 117.lo U. R. Evans and M. J. Pryor, J., 1949, S 157.l5 H. Schsfer, 2. anorg. Chem., 1949,258,69.l8 H. Guiter, Bull. SOC. chim., 1948,15, 945.R. 0. Griffith ibid., p. 546; R. 0. GriEth and R. Irving, ibid., p. 563.E. Jacobi, Helv. Chim. Acta, 1948, 31, 2118.R. D. Peacock, and P. L. Robinson, unpublished results112 INORGANIC CHEMISTRY.and similar results have been obtained with chromium(II1) chloride. An-hydrous K,Fe(CO), and KHFe(CO), have been prepared,17 and the equili-brium constants K , = 4 x and K , = 4 x 10-l4 have been found forFe(CO),H, & He + Fe(CO),H- & 2H+ + Fe(CO),2-.Two papers de-scribe spectrometric studies of ferric thiocyanate. The first,18 discussingvarious isodielectric solvent pairs each of which had water in common, suggeststhat the species Fe,(CNS), and Fe(CNS)63- are responsible for the red colour,the former being the more intense. The second,lg relating to water with[Fe3+] : [CNS-] values ranging from 1 : 1 to 1 : 6, indicated that, in the range[Fe3+] = O.O143---0.0357~., species higher than FeCNS2+ occur and thatFe( CNS),+ preponderates in 0.5-1 M- solut ion.G. R. Hil120 has studied the oxidation of Co2+ by ozone, following thecourse of the reaction by absorption spectra of solutions of Co2+, Co1ITOH2+,and Co111Ac2+ in 0*2~-perchloric acid. A reinvestigation 21 of the familiarcolour change from pink to blue which takes place on the addition of hydrogenchloride to solutions of Co(I1) chloride has been made in ethyl alcohol-water mixtures, and it has been found that the stability of the blue increaseswith alcohol concentration and that the solution is decolorised by mercuricchloride through the formation of HgC1,2- ions. The Co(I1) complex[Co(H20)(CN),l3- is oxidised 22 by prolonged treatment with excess of alkalicyanide. The first two complexes are reduced by the dropping-mercuryelectrode to a Co(1) complex. Exchange between Co2+ and CO(NH&~+could not be detected and that between CO(NH,),~~ and CO(NH,),~+ wasvery s10w.23~24 The slow reaction C~*(en),,~ + C~(en),~+ Co(en),2T +C0*(en)~3+ has been carefully studied 25 in systems of known ionic strengths.The heat of activation is 15.1 kcals. and there is evidence that this includes anon-electrostatic component of appreciable magnitude.The solubility of N(OH), in dilute acid and base solutions shows it to be arelatively strong base.26 From the Raman spectrum of nickel carbonylthe long-accepted tetrahedral structure of the molecule has received furtherconfirmation.27 W. Hieber and R. Briick 28 have isolated a number of bi-nuclear nickel(1V) complexes one of which they have shown to be formedfrom the corresponding nickel(I1) complex by the disproportionation1 7 P. Knunholz and H. M. A. Stettiner, J. Amer. CJbem. Soc., 1949, 71, 3035.18 S. Baldwin and W. J. Svirbely, ibid., p. 3326.19 S. E. Polchlopek and J. H. Smith, ibid., p. 3280.20 Ibid., p. 2434.21 M. Bobtelsky and K. S. Spiegler, J., 1949, 143.22 D. N. Hume and I. M. Kolthoff, J. Amer. Chem. Soc., 1949,71, 867.S. A. Hoshowsky, 0. G. Holmes, and K. J. McCallum, Canadian J. Res., 1949,27, B, 258.24 K. J. McCallum and S. A. Hoshowsky, J. Chem. Physics, 1948, 16, 254.25 W. B. Lewis, C. D. Coryell, and J. W. Irving, J., 1949, S 386.2* K. H. Gayer and A. B. Garrett, J . Amer. Chem. SOC., 1949,71, 2973.27 B. L. Crawford and W. Horwitz, J. Chern. Physics, 1948,16, 147.28 Naturwiss.,. 1949, 36, 312DODD AND ROBINSON. 1132W1 -3 Nio + NiIV.forms nickel carbonyl :The change is induced by carbon monoxide, which4NiII(S,CS.+), + 4SH- + 8CO -+S(+.CS.S.),NiIV/ 'NP(S.CS.+), -+- 2Nio(CO), + 4+.CS.S-+ 2H2S.\S/The Ni2+ ion of nickel salts reacts 29 with potassamide in liquid ammoniaat -35.5" to give Ni(NH2),,2NH,. Thermal decomposition of this compounda t mm. pressure gives Ni(NH2), at 42-3", Ni3N, at 119*3", Ni3N a t 362",and the elements themselves a t 585". Further contributions to the eo-ordination compounds of platinum have been made by H. J. S. King30and by W. J. Lile and R. C. M[enzie~,~l and the study of tetramethylplatinumand trimethylplatinum tetramers has been continued.32R. S. Nyholm 33 has provided a useful up-to-date account of the stereo-chemistry of the Group VIII elements which includes a brief but adequateintroduction to the theoretical aspects of the subject.R. E. DODD.P. L. ROBINSON.G. W. Watt and D. D. Davies, J . Amer. Chene, Soc., 1948, 70, 3753.8o J., 1948, 1912.3x J., 1949, 1168.32 Ann. Reports, 1947, 44, 66; R. E. Rundle and E. J. Holman, J . Awae.r. Chem.33 Quart. Reviews, 1949, 3, 321.Soc., 1949, '41, 3264; G. Illuminati and R. E. Rundle, ibid., p. 3375