ISSN:0260-1818    

DOI:10.1039/IC98077FX001

出版商:RSC    

年代:1980

数据来源: RSC

ISSN:0260-1818    

DOI:10.1039/IC98077BX003

出版商:RSC    

年代:1980

数据来源: RSC

摘要:

F. A. Hart A. G.Massey P. G. Harrison and J. H. Holloway Part 11 Group I11 By A. G. Massey 1 Boron A comprehensive literature survey covering the physiological effects of boron and its compounds as well as their applications in experimental biology and medicine is presented in the new book by Kliegel.' A detailed experimental and theoretical study has been made of the chemical vapour deposition of boron oia the reduction of boron trichloride with hydrogen. Surface kinetics are found to control the deposition rate over a wide range of temperatures.' The level of impurities (except of carbon and oxygen) in boron produced by hot-wire decomposition of boron tri-iodide decreases noticeably when the tri-iodide is recrystallized and zone refined before use.Between 900 and 1050 "C the deposit on the tungsten wire is a-rhombohedra1 boron; above 1100 "C it is P-rhombohedra1 boron whilst at 1100 "C a mixture of a-and p-forms is ~btained.~ The structure of B13C2 consists of two structural units a linear CBC chain and a B12 icosahedron distorted from ideal symmetry owing to the different external bonding partners. Static deformation density maps have been calculated for sections of interest in both units and three-dimensional pictorial representations of these deformation densities given.4 Two lower iron borides FeB and Fe2B have been studied by electron spectroscopy and their electronic structures discussed. The chemical bonding is metallic in nature with boron atoms (Fe'B) or boron chains (FeB) occupying interstitial regions in the metallic lattice of iron.5 Some chemical control of superconductivity in metal hexaborides is possible.For example plots of the superconducting critical temperature T, against x in Y1-,M,B6 (M = Yb Th or La) show a linear decrease of T with x in all three cases within the range 0 sx s0.2.6In LaB2C2 two planar infinite layers alternate along the c-axis. Within the ordered B-C network each atom is bonded to three others to form aromatic-like fused four- and eight-membered rings which contain equal numbers of carbon and boron atoms. The work confirms the structure proposed by Bauer and Nowotny in 1971.' 67 A. J. Canty N. Chaichit and B. M. Gatehouse Actu Crystullogr. 1980 B36 786. 68 A.J. Canty R. S. Tobias N. Chaichit and B. M. Gatehouse J.Chem. SOC.,Dalton Trans. 1980 1693. 69 M. J. Olivier and A. L. Beauchamp Znorg. Chem. 1980 19 1064. W. Kliegel 'Bor in Biologie Medizin und Pharmazie' Springer Verlag 1980. J.-0. Carlsson J. Less-Common Met. 1980,70 69 77 97; 71 1 15. J. Cueilleron and J. C. Viala J. Less-Common Met. 1979 65 167. A. Kirfel A. Gupta and G. Will Acta Crystullogr. 1980 B36 1311. D. J. Joyner 0.Johnson and D. M. Hercules J. Am. Chem. SOC.,1980,102 1910; J. Phys. Chem. 1980,84 542. K. Hiebl and M. J. Sienko Znorg. Chem. 1980 19 2179. ' J. Bauer and 0.Bars Actu Crystallogr. 1980 B36 1540. The Typical Elements Over 60 compounds have been used in a comparative survey of "B and 13C n.m.r. chemical shifts of three-co-ordinate boron compounds and carbenium ions; although the relationship between the two shifts is more complex than previously reported the trends allow comparison of pm-p, bonding between boron and its substituents with the w-charge delocalization in carbenium compounds.' Boranes.-A molecular orbital study of diborane shows that as the basis set is improved the electron density moves into the interior of the cluster particularly into the bonding regions.The decrease in electron density around the bridging hydro- gens when electron correlation is introduced contributes to their acidic character.'" Tritium-labelled diborane of high specific activity and 99% purity has been made by treating labelled KBH with phosphoric acid. The radiochemical recovery was ca. 29%." Anisotopic mass spectra of B4H10 B5H9 BSH11 B10H14 2-C1Bl0HI3 6-C1B10H13 and 2-IB loH1 have been obtained using high-resolution measurements; the use of a low ion-source temperature (SO-60°C) was necessary in order to avoid ther- molytic decomposition of the boranes." The heats of atomization of the boron hydrides can be correlated with a four-term linear equation based on the numbers of terminal and bridging B-H bonds nearest-neighbour boron atom pairs and an estimation of the resonance energy.This structure-resonance theory approach has the advantage in that no experimental bond length information is needed to generate a predicted AHavalue and thus can be used for calculations on intermediates in borane chemistry." Self-consistent charge calculations on derivatives of pen- taborane(9) are found to reproduce reasonably well previously published photoelec- tron spectra.12 Borane adducts of quinoline isoquinoline 2-aminopyridine 3-aminopyridine 4-aminopyridine and aniline can be prepared by interaction of the appropriate Lewis base with dimethyl sulphide-borane.Infrared and n.m.r. spectra of the aminopyridine complexes show that the BH unit is on the pyridine nitrogen atom in each case. l3 Vibrational spectra of isotopomeric acetonitrile-boranes have been recorded and fundamental vibrations assigned on the basis of C3,~ymmetry.'~ Tetrahydrofuran-bora+ne reactswith a variety of hosphanealkylenes to form the zwitterionic species R:PCH(R2)BH3."" In Me3 i!CH2BH3 it is found that the P-C(H2) bond has increased markedly in length (to 1.76 8,)from the double-bond value of 1.64 8 in the free Me3P=CH2.15b Dimethyl sulphide-borane gives an essentially quantitative yield of BH2C1-SMe2 when refluxed with an equimolar amount of carbon tetrach10ride.l~" An electron diffraction study has allowed an unambiguous identification of the cis-and trans-isomers of 1,2-dimethyldiborane.Dimensionally the two molecules B. Wrackeyer Z. Naturforsch. Teil B 1980 35b 439. (a) T.E.Taylor and M. B. Hall J. Am. Chem. SOC. 1980,102,6136;(6) Y.Murano G. Izawa and T. Shiokawa Radiochem. Radioanal. Lett. 1980 44 315. lo N. N. Greenwood T. R. Spalding and D. Taylorson J. Znorg. Nucl. Chem. 1980,42,317. W. C. Herndon and M. L. Ellzey Znorg. Nucl. Chem. Lett. 1980,16,361. P. Brint and T. R.Spalding J. Chem. SOC. Dalton Trans. 1980 1236. C. J. Foret M. A. Chiusano J. D. O'Brien and D. R. Martin J. Znorg. Nucl. Chem. 1980 42 165. F.Watari J. Phys. Chem. 1980,84,448. I5 (a)H. Schmidbaur G. Muller and G. Blaschke Chem. Ber. 1980,113 1480; (b)H. Schmidbaur G. Muller B. Milewski-Mahrla and U. Schubert ibid. p. 2575;(c)W. E.Paget and K. Smith J. Chern. SOC. Chem. Commun. 1980 1169. F. A. Hart A. G.Massey P. G. Harrison and J. H Holloway are almost identical although there appears to be appreciable Me--Me repulsion in the cis-compound.16 Unsymmetrical cleavage of both diborane(6) and tetraborane occurs on their reaction with bis(trimethylphosphine)diborane(4) -20°C $BZH6+B2H4(PMe3)2 B3H6(PMe3)iB2HI*Me3PBH3+Me3PB3H7+$B2H6 r.t. B4H10+B2H4(PMe3)2 -B3HdPMe3)hH; (1) Product (1)is fairly stable at room temperature and can be isolated; the triborane cation possibly has the structure (2).17 HH \/ H/B'H \I H-B-B-H L /\ L (2) Raman spectra of pentaborane(9) in the gaseous and liquid phases coupled with a moderately high-resolution i.r.spectrum of the gas have been used to verify previously proposed assignments.18 The mercury-photosensitized reactions of selec- tively deuteriated pentaborane(9) including 1-DB5Hs and p-DB5H8 have been investigated. From the proportions of H2 HD and D2in the photolysis products it is concluded that the primary reactive intermediate leading to product B10H14 and B10H16 is pentaborane(7) resulting from direct loss of molecular hydrogen.The elimination of H2 from any pair of H sites in B5H9 is a random but not strictly statistical process. The existence of the free-radical intermediate B5H8 suggested by previous workers to account for the formation of B10H16 was not substantiated:19 B5HT+B5H9+ B&&' \ B10H16 Pentaborane(9) reacts slowly at -20 "C with an excess of trimethylphosphine to form B5H9.2PMe3; at 0 "Cfurther reaction produces a mixture of B2H4.2PMe3 and a new hypho-class compound tris( trimethy1phosphine)-triborane(S) B 3H5-3 PMe3. At room temperature the B2H4.2PMe3 sublimes out of the mixture and the B3H5 adduct is converted into B6Hl0.2PMe3. A similar sequence of reactions occurs when tetramethylethylenediamine and 1,2-bis(dimethylphosphino)ethane adducts of B5H9 are treated with an excess of trimethylphosphine.It was not possible to isolate B3H5.3PMe3 although it was shown to be stable at -23°C; when placed under conditions of dynamic vacuum at 0 "C it gives off trimethylphosphine and changes into B6Hlo-2PMe3.20 l6 L. Hedberg K. Hedberg D. A. Kohler D. M. Ritter and V. Schomaker J. Am. Chem. SOC.,1980 102,3430. M.Kameda and G. Kodama J. Am. Chem. SOC.,1980,102,3647. l8 V. F. Kalasinsky J. Phys. Chem. 1979,83 3239. l9 G.A.Kline and R. F. Porter Inorg. Chem. 1980 19,447. 2o M.Kameda and G. Kodama Inorg. Chem. 1980,19,2288. The Typical Elements 15 A new synthetic method for the production of 2-alkylpentaboranes(9) involves the treatment of [B5H8]- with alkyl halide [B5Hs]-+PhCH2Br (or CH2=CHCH21) + 2-RB5H8(11-13%) It is suggested that the p-Rderivative is first formed but that this rapidly isomerizes to the corresponding 2-substituted derivatives.21 When equimolar amounts of B5Hg and C2Me2 are heated in the liquid phase at 75 "C in the presence of 10 mol% dimethylacetylenehexacarbonyldicobaltas a catalyst a 22% conversion of pen- taborane into 2-(cis-but-2-enyl)pentaborane(9)(3) occurs.Compounds such as (3) have been proposed as the first-step intermediates in thermally induced carbaborane syntheses and it was thus expected that (3) might easily be converted into car- baboranes. This proved to be the case; rapid passage of (3)through a heated tube at 355 "C in vacuo gave 86% conversion into carbaborane products. The two major species formed were 2-Me-3-Et-C2B5H7 and 2-Me-4-Et-C2B5H7.22 Pentaborane(11) reacts with an excess of trimethylphosphine to form the bis(trimethy1phosphine) adduct of tetraborane(8) B5H11+ 3PMe3 -+ B4H8-2PMe3 + BH3.PMe3 HCW B3H7.PMe3+BH2C1-PMe3 The same adduct is formed when bis(trimethy1phosphine)-pentaborane(9) is treated with hydrogen THF B5H9.2PMe3+ HCI B4H8.2PMe3+ BH2CI.THF Y & r.t.B4HgPMe3+ BH2C1.PMe3 Irradiation of neat B2H6 or B2H6-B5H9 mixtures with the output of a CW C02 laser operating at 973.3 cm-' induces an apparent thermal reaction in which decaborane( 14) is produced with the two pentaboranes as intermediates. When B2H6-B5H9 mixtures are irradiated up to 65% of the starting materials that undergo reaction are converted into B10H14 less than 1400 photons being required to produce each The X-ray structures of two conjuncto-boranes 2,2'-bi(nid~-decaboranyl), m.pt.178 "C and 2,6-bi(nido-decaboranyl),m.pt. 154 "C have been discussed; the inter- cluster B-B bond lengths are 1.692 and 1.679 A respectively. There is a lengthen- ing of 0.015 in the intracluster B-B distances around the substituted boron atom.25 The external B-B bonds are similar in length to that quoted (1.698 A) last year for 1,5'-(B10H13)2.26A single isomer of bis(nido-decarboranyl) oxide (B10H13)20 is formed in the reaction of concentrated sulphuric acid with " D. F. Gaines and M. W. Jorgenson Inorg. Chem. 13,90,19 1398. '' R.Wilczynski and L. G. Sneddon J. Am. Chem. SOC.,1980,102,2857. 23 G. Kodama and M.Kameda Inorg. Chem. 1979,18,3302. 24 A.Hartford and J. H. Atencio Inorg. Chem. 1980,19 3060. 25 S.K. Boocock N. N. Greenwood J. D. Kennedy W. S. McDonald and J. Staves J. Chem. SOC.,Dalton Trans. 1980 790. 26 J. W. Pinson G. M. Brown and L. L. Ingram Inorg. Chem. 1979,18 1951. F. A. Hart A. G. Massey P. G. Harrison and J. H. Holloway Bl0HI2(SR2)2. The two B10H13 groups are joined at the 6,6'-positions to the oxygen atom to give a BOB angle of 139.1'; the B-0 distance is 1.358 Cyclohexene adds to B10H12(SMe2)2 giving 9-cyclohexyl-5(7)-(dimethylsul-phide)-nido-decaborane( 11) (4),28 the boron atoms of which form a nido-decaborane framework containing eight terminal hydrogens and three bridging hydrogens [B(6)-B(7); B(8)-B(9); B(9)-B(10)].29 The migration of the SMe2 group from position 6 to position 5 is thought to occur after the hydroboration of B(9)-H has occurred.Treatment of BlOHI1(C6Hl1)SMe2 with sodium hydride induces cage closure and the formation of the 2-C6H1 anion.*' 1BloH9Z-c3 c2 c4 C8 0 (4) (Reproduced by permission from Inorg. Chern. 1980,19 1188) The U.V. photoelectron spectra of closo-l-SB9H9 and some of its 6- or 10-derivatives have been used to obtain a qualitative description of the highest occupied molecular orbitals of 1-SB9H9. These consist of a pair of framework orbitals involving B 2p and S 3p functions lying in the surface of the sphere containing the cage atoms followed closely by a pair of framework orbitals involving mainly B 2p functions from atoms in the equatorial belt.30 Metal1oboranes.-In tetracarbonyl[2-bromoheptahydrotriborato(l-)]manganese the B3H7Br group acts as a bidentate ligand being bound by two Mn-H-B bridge-bonds to the octahedrally co-ordinated manganese; the bromine atom is attached to the unique boron in an exo-position (5).31aA new mode of co-ordination has been discovered for the octahydrotriborate ion in p-bromo-hexacarbonyl[oc-tahydroboratoldimanganese where it acts simultaneously both as a bidentate ligand to each manganese atom and as a bridge between them (6).31b 27 N.N. Greenwood W. S. McDonald and T. R. Spalding J. Chem. SOC., Dalton Trans. 1980 1251; J. D. Kennedy and N. N. Greenwood Inorg. Chim. Acta 1980,38 93. 28 E.I.Tolpin E. Mizusawa D. S. Becker and J.Venzel Inorg. Chem. 1980 19 1182. 29 E. Mizusawa S.E. Rudnick and K. Eriks Inorg. Chem. 1980,19 1188. T. P.Fehlner M. Wu B. J. Meneghelli and R. W. Rudolph Inorg. Chem. 1980 19,49. 30 31 (a)M. W. Chen J. C. Calabrese D. F. Gaines and D. F. Hillenbrand J. Am. Chem. SOC.,1980,102 4928;(b)M. W. Chen D. F. Gaines and L. G. Hoard Inorg. Chem. 1980 19,2989; (c) J. D. Odom and T. F. Moore ibid. p. 2651. The Typical Elements (Reproduced by permission from i.Am. Chem. SOC.,1980 102,4928) (6) (Reproduced by permission from Znorg. Chem. 1980,19,2989) Multinuclear n.m.r. studies on difluorophosphine derivatives of tetraborane(S) B4H8PF2X(X=F C1 Br I or H) have established in all cases except X = H that the molecules exist as geometrical isomers (endo and exo placement of the phos- phine with respect to the folded B4framework).At low temperatures rotation about the P-B bond in the endo-isomer becomes slow on the "F n.m.r. time-scale and rotational isomers [e.g (7a) and (7b)l are observed. In the PF3 and PFJ adducts only one rotational isomer of the endo-form is observed whereas two rotational isomers are found for the PF2Cl and PF2Br adducts. (In all the complexes rotation (74 (7b) (Reproduced by permission from Inorg. Chem. 1980,19,2651) F. A. Hart A. G. Massey P. G. Harrison and J.H. Holloway about the P-B bond in exo-isomers remains rapid with respect to the 19Fn.m.r. time-scale.) In agreement with previous studies no evidence was obtained for geometrical isomers of B4H8PF2H.31C The reaction of B5Hs-y Fez' and C5H5- in THF at -78 "C followed by work-up of the products in air gave violet 2-(q5-C5H5)FeB5Hlo(8) yellow 2-(q5-C5H5)FeB10H15 and ferrocene plus traces of other ferraboranes.A pentagonal- pyramidal structure with iron in the base and five bridge-hydrogens (3 B-H-B; 2 Fe-H-B) on the open face is proposed for (8). On being heated to 175 "C (8) rearranged to violet 1-(q5-C5H5)FeB5H10 in which the iron atom is considered to be at the apex of the pyramid; this isomer is a direct structural analogue of ferrocene containing a cyclic B5Hlo- ligand isoelectronic with CsH5-. The structure of 2-(q5-C5H5)FeB10H15is thought to consist of an eleven-vertex icosahedral fragment with five B-H-B bridges in the open face and the iron atom in the equatorial belt adjacent to the apex Although unreactive to many reagents bis(nido-decaboranyl) oxide reacts smoothly with ci~-[PtCl~(PMe~Ph)~] to give several compounds one of which is the unusual bis-p-(2,3,4-q3-nido-hexaboranyl)-bis-(dimethylphenylphosphine)diplatinum(i't-Pt) [Pt2(q 3-B6H9)z(PMezPh)z] (9).Within each nido-B6H9- ligand the two non-hydrogen-bridged basal boron-boron bonds act as a two-electron donor to a different platinum atom; thus each ligand acts as a bidentate bridge.326 The ten-vertex platinaheteroboranes 9,9-(PPh3)z-6,9- XPtBsHlo (10) are produced in high yield when Pt(PPh,) reacts with nido-4-XB8H12 (X = CH2 NH2 or S). ESCA studies show that the heteroatoms of the borane ligands do not influence the electron dtF2ity on the platinum atom probably because they are too far away from the metal.Me-p-Pt -Pt -P -Me H,+Ay> B \/ (94 (9b) (Reproduced from J. Chem. SOC.,Chem. Commun. 1980 37) 32 (a) R. Weiss and R. N. Grimes Inorg. Chem. 1979,18,3291; (b)N. N. Greenwood M. J. Hails J. D. Kennedy and W. S. McDonald J. Chem. SOC. Chem. Commun.. 1980,37; (c) K. Base B. Stibr and I. A. Zakharova Synth. React. Inorg.-Metal-Org. Chem. 1980 10 509. The Typical Elements PPh 0 Pt Ox (10) Molecular orbital studies show that a characteristic feature of the azaboranes arachno-4-NB8H13 arachno-B9H12NH- nid0-10-N-7,8-C~BgH1~ and 1,2-NCBloHll is for the nitrogen to form polar and whenever possible two-centre bonds. The boron atoms attached to nitrogen are less negative than most of the other borons in the same Aqueous polyselenide or polytelluride solutions react with B9HI3.SMe2 to form the B9H12X- (X = Se or Te) anions isolated as their tetramethylammonium salts.Oxidation of these salts with iodine produced the B9H11X molecules in benzene or the B9Hl1X.MeCN adducts in the presence of acetonitrile. Pyrolysis of B9HllX gave mixtures of B9H9Se and BllHllSe.34 The anion B9H12S- reacts with potassium polyselenide to give B9H9SSe and with potassium polysulphide to produce B9H9S2. The products were assumed to have the same structure as that previously reported for B9H9Se2. Controlled partial degrada- tion of these compounds is possible by treatment with potassium hydroxide KOH aq.HCI B9H9SSe -+ b B7H9SSe KOH B9H9Se2 4C,H,-NMe3CoC12 b B9H9Se2Co(C5H5)+B9H9Se(CoC5H& (11) (12) Compounds (11) and (12) are thought to have a nido twelve-vertex structure and a closo icosahedral structure respecti~ely.~~ Treatment of KB9HlzS (or KBloHllSe) with As203 in basic solution gives B8H8As2S (or B8H8As,Se).Base degradation of B8H8As2S followed by reaction with C5Hs-and CoCl, produces the nido eleven-atom heteroborane B7H7AszSCo(CsH5) in low yield.36 Anions and Cations.-The tetrahydroborates continue to receive active interest. Magnesium tetrahydroborate is formed in high yield when anhydrous magnesium chloride is treated with an excess of NaBH in boiling ether.37 In the gas phase MeA1(BH4) is monomeric with a planar CAlB skeleton and five-co-ordinate aluminium; both tetrahydroborate groups are bidentate.38 Although bidentate BH4 groups also occur in (2,9-dimethyl-1 ,lo-phenanthroline)tetrahydroboratocopper(I) (CU-B = 2.08 it is thought that the RBH3- ion in solid RBH3(PMePh2)3Cu 33 J.Bicerano and W. N. Lipscomb Inorg. Chem. 1980 19 1825. " G. D. Friesen R. L. Kump and L. J. Todd Inorg. Chem. 1980,19 1485. 35 G. D. Friesen A. M. Barriola P. Daluga P. Ragatz J. C. Huffman and L. J. Todd Znorg. Chem. 1980 19,458. '' A. M. Barriola T. P. Hanusa and L. J. Todd Inorg. Chem. 1980,19,2801. " V.N.Konoplev Zh. Neorg. Khim. 1980,25 1737. 38 M.T. Barlow C. J. Dain A. J. Downs,P. D. P. Thomas and D. W. H. Rankin J. Chem. SOC.,Dalton Trans. 1980 1374. 39 B. E. Green C. H.L. Kennard C. J. Hawkins G. Smith B. D. James and A. H. White Acra Crystallogr. 1980,B36,2407. 20 F. A. Hart A. G. Massey P. G. Harrison and J. H. Holloway and RBH3(PMePh2),Ag (R=H or C02Et) is bound to the metal by a single hydrogen bridge. An equilibrium between singly and doubly bridged species may occur in Scandium yttrium and lanthanide tetrahydroborates can be isolated as bis- or tris-(tetrahydrofuran) adducts by treating the metal chlorides with either LiBH or NaBH in THF. In SC(BH,)~.~THF the tetrahydroborate behaves as both a biden- tate and terdentate ligand whereas it is terdentate only in Y(BH4)3.2THF and LII(BH,)~-~THF.,~ The extremely air- and moisture-sensitive MoH(BH,)(PM~~)~ made from trichlorotris(trimethy1phosphine)molybdenum and NaBH4 contains a bidentate tetrahydroborate group.42 Inelastic electron tunnelling spectroscopy has been used to study the reactions of zirconium tetrakis(tetrahydrob0rate) supported on alumina.For example with water vapour it was shown that the BH groups remaining on the zirconium as well as those migrating on to the support change from a terdentate to a bidentate geometry. Hydrolysis took place readily even at 300 "Cand the presence of 0-BH2 groups was confirmed. No exchange occurred with either D20or D2.43 A complete assignment of the bands in the vibrational spectra of U(BH4)4 has been accom- plished. Some strong bands in Hf(BD4) and Zr(BD4), assigned by other workers as Fermi resonance doublets probably arise from inactive modes which become active on incomplete deuteriation., Diborane is one of the decomposition products arising from the 253.5 nm photoly- sis of U(BH,) vapour.No photolysis occurred over a three-hour period when radiation of wavelengths 488 or 5 14.5 nm was Neptunium(1v) tetrahydro- borate is monomeric in the solid state; the triply bridging BH groups are dispersed tetrahedrally about the neptunium atom (Np-B = 2.46 A). The compound has a vapour pressure of about 10 mmHg at room tempe~ature.~~ Sodium hydridotrimethylborate is tetrameric in benzene. In the solid state the tetramer which has one molecule of ether associated with it has a structure consisting of alternating sodium and hydrogen atoms at the corners of a very distorted cube. One sodium atom is co-ordinated to the ether molecule and all the hydridic hydrogens are each bonded to the boron of a BMe3 group (13).47 A new method for the preparation of NaBH3CN involves the smooth reaction that occurs between sodium cyanide and BH3.THF in THF Iron(@ complexes of general formula [Fe{BH3(CN)}2{P(OR)3}4] (R = Me or Et) can be prepared in two ways metathetically by reaction of FeC12.2H20 with NaBH3CN and appropriate phosphite in either methanol or acetonitrile or electrochemically by anodic dissolution of iron in acetonitrile solutions of the phosphite and 40 J.C. Bommer and K. W. Morse Znorg. Chem. 1980,19 587. 41 0.V. Kravchenko S. E. Kravchenko V. B. Polyakova and K. N. Semenenko Koord. Khim. 1980,6 76 1030; U. Mirsaidov A. Rakhimova and T. N. Dymova Zzv.Akud. Nuuk. SSSR Neorg. Muter. 1979,15 1585. ** J. L. Atwood W. E. Hunter E. Carmona-Guzman and G. Wilkinson J. Chem. SOC.,Dalton Truns. 1980,467. 43 H. E. Evans and N. H. Weinberg J. Am. Chem. SOC.,1980,102,872,2548,2554. 44 R. D'Cunha V. N. P. Kaimal and V. B. Kartha Spectrochim. Actu Part A 1980 36,907. 45 N. Ghiassee P. G. Clay and G. N. Walton Znorg. Nucf. Chem. Lett. 1980,16 149. 46 R. H. Banks N. M. Edelstein B. Spenser D. H. Templeton and A. Zalkin J. Am. Chem. Soc. 1980 102 620. 47 N. A. Bell H. M. M. Shearer and C. B. Spencer I. Chem. SOC.,Chem. Commun. 1980,711. 48 B. C. Hui Znorg. Chem. 1980,19 3185. The Typical Elements (13) (Reproducedfrom J. Chem. SOC.,Chem. Commun. 1980,711) NaBH3CN. The metathetic method in methanol gives trans-isomers; both methods give cis- and trans-isomers when acetonitrile is used as the solvent.The cyanide nitrogen atom of the BH3CN groups is the donor site.,' Without phosphite present electrolysis of an acetonitrile solution of NaBH3CN at an iron electrode yields [Fe{BH3(CN)}2(NCMe)4]; at molybdenum or vanadium anodes the sodium salt is oxidized to Na[BH,(CN)BH2(CN)].'* In ammonium tetraphenylborate the NH4+ ion at a site of DZdsymmetry is orientated in a way consistent with the expectation from a simple model based on Coulombic interaction; i.r. spectra at 10 K and room temperature suggest that the distortion of the ammonium ion from Tdsymmetry is only slight. It is concluded that the cation must be regarded as hydrogen-bonded but the potential field due to the surrounding four phenyl groups offers little resistance to the bending (and probably also to the librational) motion of the ion." A number of new transition-metal tetraphenylborates in which one of the phenyl rings acts as a hexa-hapto ligand have been de~cribed.'~" Sodium tetraphenylborate may be used to phenylate tellurium under mild Ph2TeC12+NaBPh4 5Ph3Te+BPh4-TeC14+NaBPh4 C6H6 b Ph3Te'BPh4-Lithium has octahedral co-ordination in lithium tetra(chlorosulphato)borate LiB(SO3C1), three of the six oxygen atoms coming from the same B(SO,Cl),- 49 A.Drummond J. F. Kay J. H. Morris and D. Reed J. Chem. SOC.,Dalton Trans. 1980,284. J. F. Kay J. H. Morris and D. Reed J. Chem. Soc. Dalton Trans. 1980 1917. 51 W. J. Westerhaus 0.Knop and M.Falk Can. J. Chem. 1980,58 1355. 52 (a)D. A. Owen,A. Siegel R. Lin D. W. Slocum B. Conway M. Moronski and S. Duraj Ann. N.Y. Acad. Sci. 1980 333,90; P. Albano and M. Aresta J. Organomet. Chem. 1980 190 243; (6)R. T. Ziolo C. J. Thornton A. C. Smith D. D. Titus C. S. Smith and N. Buono,J. Organomet. Chem. 1980 190 C64. 22 F. A. Hart A. G. Massey P. G. Harrison and J. H. Holloway ani~n.'~ Lithium tetrakis(trimethylsily1)borate is formed when methyl borate is treated with an excess of LiSiMe3; sub-stoicheiometric quantities of trimethylsilyl- lithium fail to produce B(SiMe3)3. Trimethyl- and triethyl-boranes give Li[R3BSiMe3].54Trifluorosilyltrihydroborate and bis(trifluorosily1)dihydroborate anions are the products when silicon tetrafluoride is allowed to react with tetra- butylammonium tetrahybroborate in dichloromethane at room temperature.Only BF4- and GeF are formed when germanium tetrafluoride is used." The "F n.m.r. chemical shifts for M' tetrafluoroborates show a linear correlation with Pauling cation radii except for M = NH when the anomaly is suggested to be In the complex [CoL4(FBF3)]BF4*Hz0 due to hydrogen b~nding.'~ (L = 2,6-lutidine N-oxide) one of the BF groups is thought to be unidentate; decomposition occurs at 70-80 0C:57 F The first stage in the thermal decomposition of tetra-alkylammonium haloborates involves the loss of one male of alkyl halide to give R3NBX3 (R= Et or Bu X = Cl Br or I). Further heating produces more alkyl halide boron trihalide and polymeric materials.58 Thallium(1) and tetramethylammonium salts of B3H8- react with cobalt phosphine complexes CoXL and CoX2L2 to give B3H7L with varying amounts of BzH42L and BH3L but no cobalt-borane derivatives.However TlB3H8 and trans-Ir(CO)C1(PPh3) produced IrlI1(q 3-B3H7)(CO)H(PPh3)2.59 In bis[hydrotris-( 1-pyrazolyl)borato]iron(11)(14) the iron atom is in the low-spin state whereas in the dimethyl analogue bis[hydrotris-(3,5-dimethyl-l-pyrazolyl)borato]iron(~~) (15) it is high-spin. Both molecules possess essentially D3d symmetry in the solid state with Fe-N distances of 1.973 8 (14) and 2.172 8,(15); thus the iron-nitrogen bond is 0.199 8 longer for high-spin iron(I1) than for low- spin iron(II).60 The nickel atom in bis[hydrotris-(1-pyrazolyl)borato]nickel(~~) has a trigonally distorted octahedral co-ordination as previously found for cobalt in the isostructural CO" complex.The two terdentate ligands adopt a mutually staggered conformation with the six pyrazolyl rings strictly planar.61 The com- plexes AuClz[pzzBPh2] AuC12[pz3BH] AuC~,[(M~,~Z)~BH] and AuClz(pz4B) (pz = pyrazolyl Mezpz = 3,5-dimethylpyrazolyl) are produced in the reactions of poly(pyrazoly1)borate anions with HAuC14. The gold(II1) atoms probably adopt square-planar co-ordination in these derivatives.62" Forty-two compounds of Rh and Ir containing the hydrotripyrazolylborate group have been described:62b 53 G. Mairesse and M. Drache Acta Crystallogr. 1980 B36 2767. 54 W. Biffar and H. Noth Angew. Chem. Znt. Ed. Engl.1980 19 58. " S.Brownstein J. Chem. SOC.,Chem. Commun. 1980,149. '' R. E.J. Sears J. Chem. Phys. 1980,72,2888. '' C. M. Mikulski L. S. Gelfand E. S. C. Schwartz L. L. Pytlewski and N. M. Karayannis Inorg. Chim. Acra 1980 39 143. S.U.Sheikh J. Therm. Anal. 1980,18,299. 59 N. N. Greenwood J. D. Kennedy and D. Reed J. Chem. SOC.,Dalton Trans. 1980,196. 6o J. D. Oliver D. F. Mullica B. B. Hutchinson and W. 0.Milligan Znorg. Chem. 1980,19 165. G. Bandoli D. A. Clemente G. Paolucci and L. Doretti Cryst. Strucf. Commun. 1979,8 965. 62 (a)N.F. Borkett M. I. Bruce and J. D. Walsh Aust. J. Chem. 1980,33,949;(b)S. May P. Reinsalu and J. Powell Znorg. Chem. 1980.19 1582. The Typical Elements 23 /(HBpz3)RhCI,L; L = PR3 AsR3 py NR3 RNC or CO / HZ-NEt (HBpz3)RhC12(MeOH) + E~~NH[(HB~z~)R~C~~H] Or nyL (HBpz3)RhY2L; Y = acetate no ligand L; Y = CF3CO0 L =H20 A survey of the processes available for preparing B Hn2- clusu-hydroborates (n =6-12) has been p~blished.~~ salts can be ob- High yields of C~USO-B~~H~~~- tained by reaction of either sodium or potassium tetrahydroborate with triethyl- amine-borane at 200-250 "C in a high-boiling hydrocarbon A nearly icosahedral anion occurs in (NEt3H)2B12H12; the mean B-B distance is 1.781A.65 Partial fluorination of K2Bl2HI2 can be achieved by treatment with liquid hydro- gen fluoride in an autoclave.66 Li2B10Cl10 are suggested as chemically and Li2B12Cl12 stable electrolytes for use in non-aqueous sohtion~.~~ The (e~ter)~BF~' cations formed in benzoate ester-BF3-BX mixtures at low temperatures are thought to originate from a reaction involving a mixed-halide adduct ester.BF2X+ ester $ (ester),BF,+X-; X = C1 or Br The reaction 2(Me2N)3P0.BF3 S BF2[(Me2N)3P0]2+3 BF4-occurs spontaneously in the hexamethylphosphoramide-BF3 system the degree of ionization being 0.13 in CDC13 solution at 27 "C.Oxygen is the donor atom of the hexamethylphosphoramide ligand.69 Bivalent cations of boron having the general formulae A3B2+ or AA'2B2+ where A and A' are pyridine or substituted pyridine can be synthesized by nucleophilic displacement on either Me3NBHBr2 or a dihaloboron adduct of a pyridine. The reaction occurs via the mechanism slow R-PY Me3NBHBr2+R-py +Me3N+(R-py)BHBr2 -(R-~Y)~BHB~' +Br-(R-py)*BHBr++Br-+R-py + (R-P~)~BH~' +2Br-The cations are stable to decomposition by boiling acid but decompose slowly in hot base; (~-M~-P~),BH(PF~)~ is even inert to refluxing bromine or to chlorine in nitromethane at 85 OC." Carbaboranes.-A review with 229 references describes cobalt complexes of the carbaborane~.~' It has been suggested that MNDO calculations are likely to prove as useful in carbaborane chemistry as they did in the case of the boron hydride~.~~ 6' N.T. Kuznetsov K. A. Solntsev and A. V. Agafonov Koord. Khim. 1979,5 1297. V. V. Volkov arid I. S. Posnaya Zh. Neorg. Khim. 1979 24,2824. 65 G. Shoham D.Schomburg and W. N. Lipscomb Crysr. Strucr. Commun. 1980,9,429. 66 N.A.Zhukova N. T. Kuznetsov K. A. Solntsev Yu. A. Ustynyuk and Y.K. Grishin Zh. Neorg. Khim. 1980,25 690; N.A. Zhukova N. T. Kuznetsov and K. A. Solntsev ibid. p. 923. 67 J. W. Johnson and W. S. Whittingham J. Electrochem.SOC.,1980 127 1653; A. N.Dey and J. Miller ibid. 1979,126 1445. 68 J. S.Hartman and B. D. McGarvey Inorg. Chim. Acra 1980,44 L39. 69 J. S.Hartman and P.Stilbs J. Chem. SOC.,Dalton Trans. 1980 1142. 70 M.A. Mathur and G. E. Ryschkewitsch Inorg. Chem. 1980,19,887 3054. E. V. Leonova Russ. Chem. Rev. 1980 147. 72 M. J. S. Dewar and M. L. McKee Inorg. Chem.. 1980,19 2662. F. A. Hart A. G. Massey P.G. Harrison and J. H. Holloway The first two-dimensional n.m.r. study of "B-'H systems has been carried out on the carbaborane clos0-2,4-C~B~H~.~~ Relative energies have been calculated for (CH),(BH), (CH)2(BH)2BMe and (CH)2(BF)3 in the isomeric forms 1,s-trigonal bipyramidal 1,2-planar 1,2-trigonal bipyramidal 2,3-square pyramidal 1,3-planar and 2,3-trigonal bipyramidal.The 1,s-trigonal-bipyramidalform is considerably more stable than the other structures for (CH),(BH) and (CH)2(BH)2BMe but the 1,2-planar and 1,s-trigonal-bipyramidal forms are about equally stable for (CH)2(BF)3.74 Thermolysis of 1,5-C2B3H5 in a hot-cold reactor (400 OC-room temperature) caused coupling of the cages to give 2,2'-(C2B3H4)2 and 2,2'-3,2'-(C2B3H4),-1,5-C2B3H3. The D2dconformation of the 'dimer' is assumed to be dictated by a .rr-type interaction across the exopolyhedral B-B Seven-vertex pentagonal-bipyramidal cages occur in 2,3-Me2-1 ,2,4,5 -(C5H5),Co2C2B3H3 and 2,3-Me2-1,2,4,5-(CsH5)2CoFe(H)C2B3H3; one cobalt occupies an equatorial vertex while the other cobalt (or iron) is in an apical position.In both cases the framework carbon atoms occupy adjacent positions in the equator (16).76 (16) (Reproduced by permission from Inorg. Chem. 1980,19,2384) A bench-scale preparation of nido-2,3-C2B4Hs derivatives is now available start- ing from BsH9 or B3Hs- salts. Pentaborane is first treated with either Et3N or Me2S to give B5H9.2L which then reacts with but-2-yne or phenylacetylene forming R'R2C2B4H6. The pentaborane can be generated in situ from B3Hs- and all the following reactions carried out in the same vessel (using up to 25 g of B3Hs- Et4N+B3H8-+HCl 2Et4NB3H7C1+ B5H9+2Et4NCl+$B2H6+Hz B5H9+C2Me2+Et3N + Me2C2B4H6+Et,NBH (20%) Chlorination of 2,4-C,B5H7 with Cl2-A1Cl3 gives almost exclusively 5,6-C12C2B5H5 in which the chlorine atoms are on adjacent low-co-ordination borons.73 D. C. Finster W. C. Hutton and R. N. Grimes J. Am. Chem. SOC.,1980,102,400. " G. D. Graham D. S. Marynick and W. N. Lipscomb J. Am. Chem. SOC.,1980,102,2939. " E. L. Anderson R. L. DeKock and T. P. Fehlner J. Am. Chem. SOC.,1980,102,2644. 76 R. N. Grimes E. Sinn and R. B. Maynard Inorg. Chem. 1980,19,2384. " N. S. Hosmane and R. N. Grimes Inorg. Chem. 1980,19,3294. The TypicalElements In contrast 1,6-C2B4H6 reacts with Cl2-A1Cl3 to form 2,4-ClzC2B4& where substi- tution has occurred at opposite vertices on the octahedral cage. Some cage decompo- sition accompanies the chlorination and is more serious with the smaller car- baborane; it is thought that HCl is responsible since control experiments using HCl-AlC1 showed that the carbaboranes gave MeBCl, C12BCH2BC12 and BCl,.The chlorinated cages seem more susceptible to cleavage than the parent car- baborane~.~~ The proton affinities of 1,6-C2B4H6 and 2,4-C2B5H7 are 204h4 and 173k 1kcal mol-’ respectively. It is pointed out that the large difference between these affinities correlates with the fact that CB5H7 (isoelectronic with C2B4H7’) exists whereas CB6H8 (isoelectronic with C2BsH8+) is ~nknown.~’ Trimethylamine does not react with 2,4-C2B5H7 up to the decomposition temperature whereas secondary and primary amines cleave the cage. However substitution of NMe on to the cage can be accomplished by starting with the 5-chloro~arbaborane:~~ + NMe3 -B BCI + ~-C~-~,~-CZBSH~ [C2B5H6NMe3]BCI4-1 1 adduct -(17) Sealed-tube pyrolysis of ~~ido-lu,,~-{tran~-(Et,P)~PtH}-lu~,~-H-2,3-Me~-2,3-C2B4H4 affords [~loso-l,l-(Et~P)~-2,3-Me~-1,2,3-PtC~B~H~] (18) which possesses a highly distorted pentagonal-bipyramidal cage with a novel C2 conformation of the Pt(PEt,) fragment.In contrast pyrolysis of [nidO-E.L4,5-{tranS-(Ef3P)2PfH}-~5,6-H-2,3-C2H4B6 proceeds with migration of the cage carbons to give [closo-1,l- (PEt3)2-1,2,4-PtC2B4H6] (19) which may also be made directly from either 1,6- C2B4H6 or 5-Me,N-2,4-C2B4H6.81 Several ruthenacarbaboranes with hyper-closo cages have been synthesized. For example [hyper -closo-2,3 -Me2-6-(CH2= CHCH2C6H4PPh2)-6,2,3 -RuCzB7H7] has a structure which can best be described in terms of a C2B7 fragment of aruchno geometry occupying nine vertices of an eleven-vertex octadecahedron with a ruthenium atom in a ‘non-vertex’ position and within bonding distances of six atoms in the open face.82 Formaldehyde and 7,8-C2B9HI2- react in dilute hydrochloric acid at 20 “C to give a high yield of 4,5-dicarba-nido-nonaborane(ll) 4,5-C2B7Hll which is now one of the most readily available intermediate-sized carbaboranes.It can be used to ” C. Takimoto G. Siwapinyoyos K. Fuller A. P. Fung L. Liauw W. Jarvis G. Millhauser and T. Onak Inorg. Chem. 1980,19 107. 79 D. A. Dixon Inorg Chem. 1980,19,593. G. Siwapinyoyos and T. Onak J. Am. Chem.SOC., 1980,102,420. G. K. Barker M. Green F. G. A. Stone and A. J. Welch J. Chem. SOC.,Dalton Trans. 1980 1186. C. W. Jung R. T. Baker C. B. Knobler and M. F. Hawthorne J. Am. Chem. SOC.,1980,102 5782. F. A. Hart A. G. Massey P. G. Harrison and J. H. Holloway C(13 H(71 (18) (19) (Reproduced from J. Chem. SOC. Dlalton Trans. 1980 1186) synthesize metallo-carbab~ranes:~~ C6H6 4,5-C2B7Hll+ Pt(PPh3)d -Pt(PPh3)2C2B7Hll (80%) The latter platinum complex is isoelectronic with the B10H142-anion and contains an unusual arrangement of neighbouring CH2and CH groups in the open hexagonal face of the ten-vertex skeleton (20). p PRlj CH 0 BH OH (20) A series of eleven-vertex Rh Ir and Ru phosphinometallocarbaboraneshas been prepared by reactions of undecahydro-5,6-dicarbo-nido-decarborate(1-) with metal chloride-phosphine complexes NaCzB8Hl +IrClL + [closo-1,l -L2-1-H-1,2,4-IrC2BgHlo] n = 2 L = PMe2Ph; n = 3 L = PPh3 83 J.Plesek B. Stibr and S. Hermanek Chern.Ind. (London) 1980,626;B. Stibr S. Hermanek J. Plesek K. Base and I. A. Zakharova ibid. p. 468. 27 The Typical Elements i" [nido-9,9-L2-9,7,8-RhCzBsHl for L=PPh3 or PEt3 NaC2B8H1 + RhCIL3 [nido-9,9,9-L3-9,7,8-RhCz€38H11] for L=PMe3 or PEt3 NaC2B8H1 + RuHCI(PP~~)~[closo-1,1,3-(PPh3)3-1-H-1,2,4-RuC2B8H9] -D In the latter complex a triphenylphosphine ligand has replaced a terminal B-H hydrogen atom of the carbaborane ligand. In solution [nido-Rh(PEt3)3(C2BsH11)] dissociates PEt3 reversibly to form [nido-Rh(PEt3)2(C2BsH11)], which partially isomerizes to [closo- 1,l-(PEt3)*-1-H-1,2,4-RhC2BsHlo] on tand ding.^^ The structure of 1,lO-C2BsHlo has been determined by electron diffraction in the gas phase.The basal B(2)-B(3) distance (1.850A)is slightly longer than the equatorial B(2)-B(6) distance (1329 A).s5 Reaction of [Pt2(p-~y~lo-octa-1,5-diene)(PEt3)4] with 5,6-dicarba-nido-decaborane affords 9-H-9,9-(Et3P)2-plo,ll-H-7,8,9-C2PtB8Hloon (21) which pyrolysis at 100"C loses hydrogen and forms 9-H-9,10-(Et3P)2-7,8,9-C2PtBsH9 (22). Both polyhedra contain open CCPtBB faces and may therefore be classified as nido but in neither case was it possible to locate the hydrogen atoms associated with the heteroborane face.86 (21) (22) (Reproduced from J.Chem. SOC., Chem. Commun. 1980,627) In the structure of 2,3 -dimethyl-4,7 -dihydroxy- 1O-bromo-2,3 -dicarba-closo -undecaborane Me2C2B9H6(OH)2Br the hydroxy-groups are on adjacent vertex positions the configuration of the cage being between a closo C2,and a nido C5 icosahedral fragment. The distortion from the closo structure toward an approxi- mately nido fragment is attributed to donation of electron density from the lone-pair electrons on the two oxygens to the molecular orbital framework of the polyhedron. '* C. W. Jung and M. F. Hawthorne J. Am. Chem. SOC.,1980,102,3024. E. G. Atavin V. S. Mastryukov A. V. Golubinskii and L. V. Vilkov J. Mol. Struct. 1980,65. 259. 86 G. K. Barker M. Green F. G. A. Stone A. J. Welch and W. C. Wolsey J.Chem.Sac. Chem. Commun. 1980.627. F. A. Hart A. G. Massey P. G. Harrison and J. H. Holloway This in effect increases the skeletal electron count from the closo n + 1pairs towards nido n +2 pair^.^' The dicarbadodecahydro-nido-undecaborateanion is readily oxidized by mercuric chloride the products depending on the solvent used? (3)-8-THF-lr2-C2B9H1 1 HgC12+K(3)-1,2-C2B9H12 pyridd (3)-4-py-1,2-C2B9H11 + (3)-8-py-1,2-C2B9Hll In Cs[Me3C2B9H9] the anion is an eleven-vertex fragment of an icosahedron with the carbon atoms in ortho positions in the C7C8B9B'oB" open face and the three methyl groups on B9B"B11 atoms. Atom B(10) also carried a terminal hydrogen atom and has the methyl group in an axial orientati~n.~' The reaction of [RhCl(PPh,),] with an excess of Cs[7-butenyl-7,8-C,B9Hll] in refluxing methanol gives [closo-1,3-p-(q2-3,4-CH2=CHCH2CH2)-3-H-3-PPh3-3,1,2-RhC2B9Hlo] (23) which is a very reactive hydrogenation catalyst in a variety (23) :producedfrom J.Chem. SOC.,Chem. Commun. 1980 849) of solvents. In the presence of triphenylphosphine (23) takes up hydrogen to form [cl~so-l-butyl-3-H-3,3-(PPh~>,-3,1,2-RhC~B~H~~], which is also an effective catalyst. This latter reaction demonstrates the facile hydrogenation of the alkenyl side-chain postulated as the first step in hydrogenation to produce an open co-ordination site on the rhodium." It is possible to transfer in high yield the 87 M. F. Leonowicz and F. R. Scholer Inorg. Chem. 1980,19 122. L. I. Zakharkina Y.N. Kalinin and G. G. Zhigareva Zzu. Akud. Nuuk SSSR Ser. Khim. 1979,2376. 89 N. I. Kirillova M. Y. Antipin S. P. Knyazev V. A. Bratsev Yu. T. Struchkov and V. I. Stanko Zzu. Akad. Nauk SSSR,Ser. Khim. 1979,2474; Cryst. Struct. Commun.,1980,9,599. 90 M. S. Delaney C. B. Knobler andM. F. Hawthorne J. Chem. SOC.,Chem. Commun. 1980,849. The Typical Elements a ; R'=R~=H 08H b ; R'= Rz-0 c ; R'-H RfPh aCH d ; R'= H R2=Me e ; R'R*=~ ec Scheme 1 (Reproducedfrom J. Chem. SOC.,Chem. Commun. 1980,677) F. A. Hart A. G. Massey P.G. Harrison and J. H. Holloway H(PPh3)2Rh moiety from one R'R2C2BgHg carbaborane fragment to another (see Scheme l)'Ia. A complete assignment has been made of the peaks in the "B n.m.r. spectrum of 3,3-(Et3P),-3-H-3 1,2-RhCzB9H1 .'Ib The crystal structure of 3,9-[cis-(H),-trans-(P( p-t01yl)~}~Ir]-3,9-p -(H)z-nido-7,8-C2B9Hlo(24) formally consists of a cis-[(H),-{P( p-t~lyl)~}~Ir]+ fragment bonded to (24) (Reproduced from J.Chem. SOC.,Chem. Commun. 1980,80) two terminal B-H groups of a C2BgH12- anion. The crystal displays an unusual disorder featuring the carbaborane cluster in that packing is apparently determined by the phosphines leaving the carbaborane cluster free to adopt one of two different orientations in a 60 :40 ratio. Each orientation of the cluster is constrained so that the carbon positions are identical and the iridium atom is bound to the same two B-H bo~nds.'~ Arylacetylene groups may be substituted onto 1,2-dicarba-closo-dodecaborane using the reaction sequence shown in Scheme 2.93 The substitution of a fluorine atom on to B(9) of icosahedral dicarbaboranes to give 0-and rn -R'CBloH9(F-9)CR2 (R'=R2 =H or Me; R1 =Ph R2 = H) can be achieved by treating R1CBloH9[Tl(02CCF3)z-9]CR2 Bromina-with boron trifl~oride-ether.~~ 91 (a)T.B. Marder J. A. Long and M. F. Hawthorne J. Chem. SOC., Chem. Commun. 1980,677;(6) W. C. Kalb C. W. Kreimendahl D. C. Busby and M. F. Hawthorne Inorg. Chem. 1980 19 1590. 92 J. A. Doi R. G. Teller and M. F. Hawthorne J. Chem. SOC.,Chem. Commun. 1980 80. 93 A.N. Novikov M. G. Grigorev V. N. Kalinin N. 1. Kobelkova E. S. Krongauz and A. P. Travnikova Zh. Obshch. Khim. 1979,49,2121. 94 V. I. Bregadze A. Y. Usyatinskii and N. N. Godovikov Izv. Akad.Nauk SSSR Ser. Khim. 1979,2836. The Typical Elements m-or p-IC6H4 R' = m-or p-PhCrCC6H4 Scheme 2 tion of o-carbaborane using bromine in trifluoroacetic acid gives 9-BrCzBloH11.95 An excess of sulphur in the presence of AICl converts o-carbaborane into 9,12- and m-carbaborane into 9,lO- and 5,9-dithiols melt CZBioH12+3S+4AlC13 ____* C2B1oHio(SH)Z 160"C Any monothiols formed simultaneously were removed by chromatography or cry~tallization.~~ Acetone reacts with 9,12-(HS)z-1,2-C2BloHlo to form a cyclic thioacetal 9,12-isopropylidenedithio-1,2-dicarba-cZoso-dodecaborane,in which the isopropylidenedithio-group is bonded to two adjacent boron atoms of the carbaborane cage (25; mean B-S=1.846 .Me ,y ~s'c-* C,B,H,O BNS' 'Me (25) The structures of .1-But-o-carbaborane 1-trimethylsilyl-2-methyl-o-carbaborane and 1-trimethylstannylmethyl-o-carbaboranehave been deter-mined.98 Oxidative splitting of carbaborane thiirans and dihalodisulphides has been accomplished using chlorine in a waterdichloromethane solvent (Scheme 3).99 CH2CI Me,CH-C-C -CH2v "5" Me,CH-C-C -CH2cH/ \/ BlOHlO s \/ \S0,CI BlOHlO ,S0,CI H [R-C-C-CH,C-S$r 0-5°C R-C-C-CH2CH \/ I + \/ \ BioHio CH,Br B,oHlo CH2Br Scheme 3 Thermal decarboxylation of 1-RHgC00-1,2-C2BloH10 (R =Me or Ph) gives the corresponding o-carbaboranylmercurials. loo One of the products of the reaction between bis(methylcarbaborany1)chlorophosphineand methylcarbaboranyl-lithium is (26) which presumably arises via metallation of some of the methyl groups.1o' " Y.A. Oldekop N. A. Maier A. A. Erdrnan Z. P. Zubreichuk and V. P. Prokopovich Zh. Obshch. Khirn. 1980,50,471. 96 J. Plesek Z. Janousek and S. Herrnanek Collect. Czech. Chem. Commun. 1980,45 1775. 97 V.Subrtova A. Linek and J. Hasek Acra Crystallogr. 1980,B36,858. N. I. Kirillova,T. V. Klimova Yu. T. Struchkov and V. I. Stanko Izv. Akad. Nauk SSSR,Ser. Khim. 1979,2481;Zhur. Strukt. Khim. 1980,21 166. 99 A. V. Kazantsev and T. V. Shustova Zzv. Akad. Nauk Kaz. SSR,Ser. Khim. 1979.76. loo Y. A.Oldekop N. A. Maier A. A. Erdman and V. P. Prokopovich Vestsi Akad. Navuk B SSR Ser. Khim. Navuk 1979,85. lo' N. G. Furmanova A. I. Yanovskii Yu. T. Struchkov V. I. Bregadze N. N. Godovikov A. N. Degtyarev and M. I. Kabachnik Zzv.Akad. Nauk SSSR,Ser. Khim. 1979 2346. F. A. Hart A. G. Massey P. G. Harrison and J. H. Holloway /B(O HI0 /C-CMe [MeC-Ch P-CH2-C-C-P \/ \/ \ BlOHlO BloHlo CH,-C-CMe \/ (26) BlOHlO The first cyclic and linear phosphazenes substituted with o-carbaboranyl groups have been synthesized as shown in Scheme 4."' BlOHlO /\ Scheme 4 The product (27) from the reaction between [(PhCH2)3P]2PtC12 and 1-Li-2-Me- CZBlOHlO has the carbaborane group a-bonded to the platinum.lo3 The Pt-P-C-B metallocycle of (28) was obtained by the insertion of platinum into an ortho BH bond of a diphenyl-(o -carbaboranyl)phosphine molecule. Both cages retain approximately icosahedral geometry. lo4 Ph I (PhCH2)2P-CH \/ Pt /\ (PhCH2)JP C-CMe \/ BlOHlO (27) Octahedral products were obtained from the oxidative addition of HX or X2 molecules (X=Cl Br or I) to square-planar trans-[Ir(o-carb)(CO)L2] (carb =2-R-1,2-C2BloHlo or 7-R-1,7-C2BloHlo; R =H Me or Ph; L =PPh3 or PMePh2).The HX adducts reductively eliminate Hca~b."~ The structure of the air-stable 9-methylsulphonyl-1,7-dicarba-cZoso-dodecaborane,9-MeS0,-1,7-lo' A. G. Scopelianos J. P. O'Brien and H. R. Allcock J. Chem. SOC.,Chem. Commun. 1980 198. lo3 S.Bresadola N. Bresciani-Pahor and B. Longato. J. Organomet. Chem. 1979,179,73. L.ManojloviC-Muir K.W. Muir and T. Solomun,J. Chem. SOC.,Dalton Trans. 1980,317. lo' B. Longato F. Morandini and S. Bresadola Inorg. Chim. Acta 1980 39 27. The Typical Elements CZBIOHll has been solved (B-S=1.876 Treatment of 1,7-(C1C0)z-1,7-CzBloHlo with triethylsilane in the presence of 5% Pd-C as catalyst gives 1,7-diformyl-m-carbaborane.'07 9-Acetyl-rn-carbaborane is formed from acetyl chloride and bis-(9-rn-carbaboranyl)mercury in the presence of aluminium trichloride.lo8 Photolysis of the nido-ferraborane B4H8Fe(C0)3 in the presence of an alkyne RCrCR produces good yields of the tetracarbon carbaboranes R4C4B4H4.An intermediate in the Me& reaction was the unstable Me4C4B4H4Fe(C0)3; evidence was also presented for the formation of six- and eight-carbon carbaboranes in this systern.lo9 Oxidative fusion of carbaborane units using transition metals has allowed the synthesis of several C4B species (n = 8-11) e.g.:l10 FeC12+ 2,3-MezC2B4H5-+ B5H8- + Me&.&& + Me4C4BllHll + [Me2CzB4H41FeH2EMe2CzB5Hsl Me4C4B9H11 [OI FeCl2+ 2,3-Me2C2B4H5-+ BH4-+ [Me2C2B4H4]FeH2-Me4C4B&8 The cage in [PhzPCH2CHzPPhz]NiMe4C4B8H8 resembles a 14-vertex c1oso poly-hedron (bicapped hexagonal antiprism) from which one vertex has been removed and is the first example of a 13-vertex nido cage (29).The CoC4B7 cage of C5H5CoMe4C4B7H7 (30) is also unprecedented and consists of an irregular basket- shaped framework with one carbon atom bridging three framework atoms across the open top of the basket. (29) and (30) are related since one can formally convert a COC4B8 system (analogous to NiC4B8) into the observed CoC4B7 species by CW) (Reproduced by permission from Inorg. Chern. 1980,19,2087) K.Maly A. Petrina V. Petricek L. Hummel and A. Linek Acra Crysfallogr. 1980 B36,181. lo' G. Rabilloud and B. Sillion J. Organomer. Chem. 1980 182 275. lo* L. 1. Zakharkin and I. V. Pizareva Izv. Akad. Nauk SSSR,Ser. Khim. 1979 1886. T. P. Fehlner J. Am. Chem. SOC.,1980 102 3424. N. S. Hosmane and R. N. Grimes Znorg. Chem. 1980,19,3482. F. A. Hart A. G. Massey P.G. Harrison and J.H. Holloway removal of one BH unit and linkage of two carbon atoms; both are 2n +4 electron framework species."' By treating Me4C4BsHs with sodium naphthalenide FeC12 and NaC5H5 in THF it is possible to substitute a ferrocenyl group on to a boron atom to give 4- [C5H5FeC5H4]-2,3,7,8-Me4c4BsH,. The B(4)-C bond is relatively short which suggests that a .rr-interaction occurs between the C5H4 ring and the carbaborane skeleton.'12 A rationalization of the peculiar skeletal geometry exhibited by CSH5CoFeMe4C4BSHs(31) requires two alternative bonding models since it is impossible from crystal data alone to distinguish unambiguously between true covalent bonding involving B(8) and B(2')/B(6') and an apparent or pseudo double face-capping caused by geometric and steric (31) (Reproduced by permission from Inorg. Chern. 1980,19,2478) Halides.-The BF2 radical has been generated under equilibrium conditions by reaction of both SF6 and BF3 with boron in an effusion cell at 1600-1800 K and identified and thermochemically characterized by mass spectrometry. The standard enthalpy of formation A@298(BF2) = -120.0*4 kcal mol-' which is about 20 kcal less negative (less stable) than previous values; ionization potential of BF = 8.84* 0.10 eV.These result~"~ show the FB-F bond to be 70 kcal mol-' weaker than the B-F bond and 59 kcal mol-' weaker than F2B-F; the bond dissociation sequence is D:(F2B-F) 169 Dz(FB-F) 110 Dz(B-F) 180 kcal mol-'. A crystal structure determination on boron trifluoride carried out at -131 "C shows the molecules to be planar (mean B-F = 1.287 8,) with the angle FBF = 118-122'. Taking into account B...Fcont.icts between 2.68 and 2.71 8,the boron '" R. N. Grimes E. Sinn and J. P. Pipal Inorg. Chem. 1980 19 2087. ''* R. N. Grimes W. M. Maxwell R. B. Maynard and E. Sinn Inorg. Chem. 1980,19 2981. R. B. King E. K. Nishimura and K. S.RaghuVeer Inorg. Chem. 1980,19 2478. '14 K. H. Lau and D. L. Hildenbrand J. Chem. Phys. 1980,72,4928. The Typical Elements atoms have trigonal-bipyramidal co-ordination. Each molecule is linked uia such contacts with a total of four molecules into a three-dimensional array. '15 Adiabatic electron affinities of several boron trihalides have been estimated from the determination of threshold kinetic energies for the reaction Cs + BX3 + Cs' + BX3- using a crossed-molecular-beam apparatus. The electron affinities are <O.O 0.33 0.69 0.94 and 0.82 (*0.2)eV for BF3 BC13 BC12Br BClBr2 and BBr3 respective1y.'l6 Triethylenediamine (TED) forms TED -2BF3 when treated with BF3 in diethyl ether and TED. BF3 when THF is used as the Bivalent tin has an unshared electron pair in its valence shell which allows a potential donor capability but in practice only a few instances have been reported where such tin compounds form stable adducts with main-group Lewis acids.However boron trifluoride reacts with tin(1r) halide adducts to give compounds thought to have Sn+B bonds e.g. (32). The isomer of (33) SnC12tTMED +BF3 can be made from TMED BF3 by the addition of SnC12.1'8 SnX2NMe3 (X = C1 Br or I) +BF3 -+ . Sn . x" 'x (32) (33) The complex mixtures arising from the reaction of ammonia-borane with BX3 (X = F C1 or Br) in diethyl ether have been studied by n.m.r. spectroscopy. Among the new compounds detected were H3N -BH2C1 H3N * BHC12 Et2O * BH2Br and Et20 -BHBr2."' When isotopically selective multiphoton dissociation by a C02 laser is attempted on boron trichloride-oxygen mixtures it is found that a thermal reaction 2BC13 -t$02 -* B203 + 3c12 contributes significantly to the dissociation under irradiation.Within limits a buffer gas quenches this side reaction through collision processes. 120 Phosgene a common impurity in boron trichloride can be removed by laser-induced decomposition. The decomposition is interpreted in terms of a thermally derived process in which the reaction rate is dependent upon the temperature within the beam envelope.'21 High-resolution i.r. spectra of BCl and BC12F dissolved in solid argon and solid krypton have been recorded. The lines are very narrow so that the absorption bands of the different boron and chlorine isotopomers are well resolved.Slight 11' D. Mootz and M. Steffen Angew. Chem. Znt. Ed. Engl. 1980 19,483. E. W. Rothe B. P. Mathur and G. P. Reck Inorg. Chem. 1980,19,829. 11' H. C.Brown and B. Singaram Znorg. Chem. 1980 19,455. C. C. Hsu and R. A. Geanangel Znorg. Chem. 1980,19,110. '19 M. G. Hu and R. A. Geanangel Znorg. Chem. 1980,19,3297. 120 H. Kojima T. Fukumi K. Fukui and K. Naito J. Phys. Chem. 1980,84 2528. lZ1 C.Riley and L. Maclean J. Am. Chem. Sac. 1980,102 5108. F. A. Hart A. G. Massey P. G. Harrison and J. H. Holloway perturbations in the spectra of the trichloride suggest that lattice-induced distortion of the molecule from planarity may occur.122 Proton radiolysis carried out with simultaneous recording of the i.r. spectrum of BX3-argon mixtures showed the formation of HBC1 and HBBr2.It is suggested that the BX2 radical was produced in the experiments and that HBX was formed via the free-radical reaction of H with BX2 during sample condensation. Peaks attributed to BC12 and BBr2 radicals could be observed just above the parent v3 modes. Photoionization in place of radiolysis gave absorptions assigned to BC13+ and BBr3+.123 Electron diffraction techniques have been used to determine the structures of Me3NBC13 (N-B = 1.652 A) Me3NBBr3 (N-B = 1.663A) and PMe3BC13 (P-B = 1.941 A). The rotational barriers in the two trimethylamine adduct~"~~ are considerably greater than those in Me3NBF3; the barrier in PMe3BC13124b is 3.8f0.7 kcal mol-'. Calculated force constants show that the B-As bond strengths in the adducts Me3AsBX3 (X = C1 Br I) decrease in the sequence I >Br >C1 the order being the same as that of adduct stabilities determined by calorimetry.The B -As stretching frequencies were assig- ned between 640 and 740 cm-' much higher than previously assumed.125 The synthesis of HBC12 from BCl and HZ after irradiation by pulsed C02 laser is a thermal reaction which is a function of the concentration of the ground-state transient product BCl. The basic reaction leading to dichloroborane is'26 BCI+HCl + BHCI2 A detailed Raman spectral study shows that nitrosonium tetrachloroborate formed by condensing NOCl and BCl together should be given the ionic formula- tion NO'BCl,-; however dissociation readily occurs into largely unassociated NOCl(g) and BCl,(g).After making a number of assumptions AH,"(NOBC14)(c) -2RT was given127 the value 447 kJ mo1-I In dichloromethane solution (Me3Si),NSiMe2H and Me3SiN(SiMe2H) were chlorinated in high yield by boron trichloride giving (Me3Si)2NSiMe2C1 and Me3SiN(SiMe2C1)2. Depending on the reaction conditions the t-butylamines Bu'N(SiMe3)(SiMe2H) and Bu'N(SiMe,H) gave either simple H/Cl exchange products or the silylaminoboranes Me,Si(Me,SiCl)N-BCl(H) and (Me2SiC1)2N-BH2 which result from a C-N bond cleavage process. In the case of Me3Si(SiMe2H)NMe the trimethylsilyl-N bond was selectively cleaved to give Me2SiC1N(Me)-BCl(H). 12' The presence of C1 causes profound changes in the flash photochemistry of BI,. For example BCl and B13 gave a weaker BI spectrum than with pure BI, but also gave an intense spectrum of vibrationally excited BCl".The effect of filters showed that BCl* was not formed directly by photolysis because the absorbed photons did not have enough energy to do this. Another feature of the spectrum was the appearance of atomic B spectral lines possibly due to the reaction'29 BIZ+ BCl* -* BI,Cl+B. W. B. Maier and R. F. Holland J. Chem.Phys. 1980 72 6661. 123 J. H.Miller and L. Andrews J. Am. Chem.SOC.,1980 102 4900. 12' (a)K. Iijima and S. Shibata Bull.Chem.SOC.Jpn. 1980,53,1908;(b)K.Iijima and S. Shibata ibid. 1979,52,3204. 12' Y. Gushikem and F. Watari J. Chem. SOC. Dalton Trans. 1980,2016. A. P.Nikonorov and E. N. Moskvitina Vestn.Mosk. Univ.Khim.1980 21 84. 12' A. Finch P. N. Gates andT. H. Page J. Znorg. Nucl.Chem. 1980 42 292. R.H. Neilson Znorg. Chem. 1980 19 755. lZ9 A. G. Briggs and R. E. Simmons Naturnissenschaften 1980,67,402. The Typical Elements The boron sub-chlorides and sub-bromides have been briefly reviewed.13' An empirical method has been used to predict the enthalpies of formation of several three- and four-co-ordinate boron compounds including B2F3Cl B2FC13 F2BBC12 and FC1BBFC1.13' Chloramines readily cleave the B-B bonds in diboron com- pounds:132 B2(NMe2)4+ Me2NCl + (Me2N)2BC1+ (NMe2I3B B2C14+ EtNCI + BC13+ EtNCI-BCl2 2B2CI4+ EtNCI -B 2BC13+ C1,B-N(Et) BC1 Theoretical studies suggest that B4F4 (once synthesized) and B4C14 may exist under certain conditions as either the tetrahedral or the planar isomer or a mixture of both.133 Oxidation of BgC19'-and B9Br92- anions yields the corresponding neutral clusters BgC19 and B9Br9.Radicals of the type B9X9' (X = C1 Br or I) could be isolated as air-stable coloured salts via either oxidation of B9X92- or reduction of B9X9; hence the redox sequence B9X9'- $ B9X9-$ B9X9 was e~tab1ished.l~~ It has been confirmed that diboron tetrabromide decomposes thermally to give BBr3 and B,Br (n = 7-10). The "B n.m.r. spectra of B9Br9 and BloBr10 show only singlets even when the samples are cooled to -60 0C.135 Pyrolysis of triethylammonium deca- bromodecaborate(2-) in a vacuum at 430 "C gives predominantly MeB9Br8; on varying the conditions it is also possible to detect the formation of EtB9Brs Me2B9Br7 Me(Et)B9Br7 and B9Br9.136 Water-sensitive boron trihalide adducts of C5H5Fe(C0)2C(=O)Me have been synthesized the donor site being the acyl oxygen atom.137 A structure determination on the air-stable [C5H5(OC)Fe(MeCO)(PriCO)]BF2shows the compound to be a metalla-p-diketonate complex of boron (34).The ligand ring has a non-planar boat All the boron trihalides react with the [fa~-(OC)~Re(MeC0)~1'- ion to give the neutral complexes (35)in which the triacylrhenium ion acts as a trioxygen chelating ligand.When treated with AgBF in primary alcohols these halogeno- complexes give the alkoxy- derivative^.'^^ 130 A. G. Massey Chem. Br. 1980 588. 131 J.-C. Elkaim S. Pace and J. G. Reiss J. Phys. Chem. 1980 84 354."* W. Haubold and K. Zurmiihl Chem. Ber. 1980,113,2333. 133 D. A. Kleier J. Bicerano and W. N. Lipscomb Inorg. Chem. 1980 19 216. 134 E. H. Wong and R. M. Kabbani Inorg. Chem. 1980,19,451. 13' N. A. Kutz and J. A. Morrison Znorg. Chem. 1980,19,3295. 13' D. Saulys and J. A. Morrison Inorg. Chem. 1980 19 3057. 13' R. E. Stimson and D. F. Shriver Inorg. Chem. 1980 19 1141. 138 P. G. Lenhert C. M. Lukehart and L. T. Warfield Inorg. Chem. 1980,19 2343. 13' C. M. Lukehart and L. T. Warfield Inorg. Chim. Acru 1980,41,105;D. T. Hobbs and C. M. Lukehart Inorg. Chem. 1980,19 1811. F. A. Hart A. G. Massey P.G. Harrison and J. H. Holloway Heterocyclic Derivatives.-Dark blue pentaphenylborole (36) can be synthesized from l,l-dibutyl-2,3,4,5-tetraphenylstannole and phenylboron dichloride in toluene.It is reduced by potassium in THF giving brownish-red K2(36) which is derived from the new 6v-electron anion (36)2-. The metal derivatives C5H5Co(36) and (cod)Pt(36) are made by irradiation of a toluene solution of C5H5Co(CO) and (36) and by ligand substitution between Pt(~od)~ and (36) respectively (cod = cyclo-octa-1,5-diene). 140 Ph ,Ph Ph Ph Ph Ph I Ph (36) The A3-1,2-azaboroline ring in (37) acts as a v-donor molecule to iron in the compound Fe2(C0)4(37)2 formed when (37) is heated with pentacarbonyliron; an X-ray structure determination was carried out on crystals of the cis-isomer (38) but the trans-complex was also present in the crude reaction pr~duct.'~' ,N-Bu' Ph (37) 3,4-Diethyl- 1,2,5-trimethyl- 1,2,5 -azadiborolene (39) can be obtained via the reaction shown.It acts as a 'sandwich' ligand towards transition metals giving complexes such as (OC),Fe(39) C5H5Co(39) and Ni(39),; however it does not favour the formation of triple- and quadruple-decker complexes as does the thiadiborolene (40).14*Cleavage by C5H5-of triple-decker sandwich compounds derived from (40)(Scheme 5)leads to anionic mononuclear complexes which are synthetically (40)C0(4O)C0(40)+ C5H5-+ CsH5C0(40)+ [(40)C0(40)]-4FeCI (40)Co(40)Fe(40)Co(40) (C0)3Mn(40)Fe(C5H5) + C5H5-+ (C5H5)2Fe+ [Mn(C0),(40)]-4MCI,(M = Fe Co or Ni) (OC)3Mn(40)M(40)Mn(CO)3 Scheme 5 140 G. E. Herberich B. Buller B. Hessner and W. Oschmann J. Organomet. Chem. 1980,195,253.14' J. Schulze and G. Schmid Angew. Chem. Int. Ed. Engl. 1980 19 54. 142 W.Siebert H. Schmidt and R. Full 2. Nuturforsch. Teil B 1980 35 873. 143 W. Siebert W. Rotherrnel C. Bohle C. Kriiger and D. J. Brauer Angew. Chem. Int. Ed. Engf. 1979 18 949; see also W. Wiebert C. Bohle and C.Kriiger ibid. 1980,19 746. The Typical Elements Starting from bifunctional (Me,Si)X derivatives and diboryl compounds it is possible to synthesize a variety of heterocycles 144 Me Me m C1zBC(Me)=C(Me)BCl2 + (Me3Si)2Y + ClB BCl + 2 Me3SiC1 Y’ Y = S NMe or MeN-NMe Compounds similar to (41) can be made from 1,2,5-thiadiborolenes and hydrazine derivatives. Treatment of (42) with tri(acetonitri1e)tricarbonylchromium gives (42)Cr(C0)3 in which the planar six-membered ring is bonded ‘sandwich fashion’ to the n C1zBCHzCHzBC1z+ Me$SiN(Me)N(Me)SiMe3-+ CIB BCI \I N-N Me Me (41) Et Et MeB,/-\BM + R’NH-NHR’ + MeB BMe S’ N-N R‘ R2 (42) R’= R2 = H or Me R’=H RZ= Me No boron derivatives of carbohydrazide OC(NHNH2)* have been described in the literature since it is soluble onIy in protic media (which are not normally used in boron chemistry).By using a two-phase system however it has been shown that NMe3BH3 and THFBH3 will react slowly under reflux with a vigorously stirred slurry of OC(NHNH& in toluene or THF respectively to give 1,2,4,5-tetra-aza-3- boracyclohexan-6-one. ‘46 HH N-N OC(NHNH,) + LBH -+HB/\,C=O \ N-N HH (43) 1,2,4-Triaza-3-sila-5-borolidines are accessible via N,N’-dilithio-N,N-dimethyl-hydrazine and Br(Me)BN(Me)SiMezBr (44).14’Permethylated silaborazines e.g.(43 may also be prepared from (44) and similar derivatives. These silaborazines react selectively by replacement of the silicon by phosphorus on treatment with Me Me Br Me Me \/ \ Me N-N\ ECI MeN-NMe N-N + BNSiMe,Br + MeB/ ”‘ ,SiMe 2.I \ /\ / MeB ECl N’ Li Li Me IAA\ na-Me 1VlG E=P or As 144 W. Haubold and A. Gemmler Chem. Ber. 1980,113,3352. W. Siebert R. Full H. Schmidt J. von Seyerl M. Halstenberg and G. Huttner J. Organomet. Chem. 1980,191,15. 14‘ J. Bielawski and K. Niedenzu Znorg. Chem. 1980 19 1090. 14’ K.Barlos and H. Noth 2. Nuturforsch.. Ted B 1980,35,407. F. A. Hart A. G. Massey P. G. Harrison and J.H. Holloway Me Me -Me Me N-Li BrB Me,Si + \ NMe Me,Si NMe / \I N-Li BrSi N-Si Me Me2 Me Me (45) Me Me Me Me FB\ MeB\ /NMe + PX3 (X = C1 or Br) + MeB IN-B\ NMe \/ N-SI N-P Me Me Me X (46) phosphorus trihalides giving compounds of the type (46); the halogen atom remain- ing on the phosphorus readily undergoes a variety of substitution The eight-membered S-N-B ring (47a) formed via the reaction shown is non- planar and adopts the conformation shown in (47b).'49 Bidentate chelate reagents incorporating a suitable group (e.g. OH or NH ) man ' ortho position to an azo-group react with diphenylboronic acid anhydride or boron trihalides resulting in six-membered-ring formation [e.g. (48)]. When a terdentate azo-chelate is used the products contain two six-membered heterocyclic rings [e.g.(49)].l5O Ph Me NSiMe N-B-N \4 4 \\ 2C1,BPh +2 S --* Me,S SMe + 4Me,SiCI /\ \\ 4 Me NSiMe N-B-N Ph (49) Several methods are available (Scheme 6) for the synthesis of 1,3,2-dithiaboroles which represent a new class of 6r-electron heterocy~le.'~~ A variety of other new ring systems containing diboron units have been synthesized starting from silicon reagents (Scheme 7). The 1,3-dithia-2-sila-4,5-diboracyclopentane (51) and the 1,4,2,3,5,6-dithiatetraborinan(52) have non-planar rings.15* Tricarbonyl(1-methy1borinato)manganese is obtained by treating Co(C5H5BMe)2 with decacarbonyldimanganese; the borinate ring can be acetylated with a MeCOC1-AlCl3 mixture to give (53) although partial degradation does occur to give the [(toluene)Mn(C0)3]' cation as a by-product.lS3 14* K. Barlos and H. Noth Z. Naturforsch. Ted B 1980,35,415. 149 H. W. Roesky S. K. Mehrotra and S. Pohl Chem. Ber. 1980 113,2063. lS0 E.Hohaus and K. Wessendorf 2. Naturforsch. Ted B 1980 35 319. R. Goetz and H. Noth Z. Naturforsch. Teil B. 1980,35 1212. H. Noth H. Fusstetter H. Pommerening and T. Taeger Chem. Ber. 1980,113,342. lS3 G. E. Herberich B. Hessner and T. T. Kho J. Orgunomet. Chem. 1980,197,1. 41 The Typical Elements s\Sn,s R=Me Ph C1 Br OMe OCMe3 or SMe Me Scheme 6 R2N NR, /B -B\ -(BNEt,S) s\ s B-B B' R,N NR2 NEt (52) Scheme 7 0 II C-Me QMe + MeCOCl 4,@Me.-*IC' Mn(C013 Mn(C0I3 (53) All six atoms in the heterocyclic ring of cyclopentadienyl( 1,4-dimethyl-1,4- diboracyclohexa-2,5-diene)cobalt (54) formed as shown are within bonding dis- tance of cobalt but the two boron atoms bend away from the metal and the ring elongates slightly in the BB dire~ti0n.l~~ The boron sulphide B8S16 has a remarkable porphine-like structure which is exactly planar and consists of four 1.2,4,3,5-trithiadiborolanrings linked by sulphur Me Me 0 Me B 80°C (;5 0 MeMgI ec0 (By '.-, (')+ C5H5Co(C0)2 __* I.__.co ,. -' -. *.-a (3 B B 0 0 Me Me Me (54) G.E. Herberich B. Hessner S. Beswetherick J. A. K. Howard and P. Woodward J. Organomet. Chem. 1980,192,421. F. A. Hart A. G. Massey P.G. Harrison and J. H. Holloway bridges.This extremely water-sensitive compound can be made either by heating a 1 1.5 mixture of B2S3 and S under carefully controlled conditions or by treating 3,5-dibromo-1,2,4,3,5-trithiadiborolan (55)with trithiocarbonic acid in dilute CS solution. The latter polymer is made up of sulphur-linked B2S3 ?-BrB BBr + SC(SH);! -B B&6 + CS2 + HBr + (B2S4)x S' (55) (6%) Boron-Nitrogen Compounds.-Probably the most interesting boron compound described this year is the orange-red hexakis(dimethylamino)cyclohexaborane B6(NMe2)6 which slowly crystallizes from the distillation residue of the (Me,N),BCl-Na/K reaction. The B6 ring has a chair conformation and all the boron and nitrogen atoms are in planar co-ordination (average B-N = 1.40.$; average B-B = 1.70 A).156 Vibration frequencies calculated using MNDO have been used to assign the i.r.spectrum of aminoborane and B2N2Hs and then to make predictions about spectra of the unknown species vinylborane and B2N2H4.lS7 Assignments have also been proposed for the fundamental frequencies in the vibrational spectra of bis(dimethy1- amino)halogenoboranes (Me2N),BX (X = C1 Br or I). Extensive coupling of fundamentals precludes a diagnostic use of the B -X stretching frequency without some consideration of the environment of the boron atom.1s8 Ammonia- carboxyborane H3NBH2COOH is a centrosymmetric hydrogen-bonded dimer in the solid state. This borane analogue of glycine showed anti-tumour and anti- hyperlipidemic activity when tested in mice.lS9 The effect of angle strain on the structures of the cyclic amino-boranes (56)-(59) has been described in (56)the BN system is very nearly trigonal and co-planar.The two methylene carbons attached to each nitrogen also only deviate slightly from the N3 plane; (57) is considerably more strained if the BN3 array remains planar; in (58) and (59)a planar BN3 array is impossible unless the three nitrogen atoms adopt pyramidal geometry. The strain is reflected in the physical properties of these aminoboranes (56)and (57)are monomeric but (59)is always dimeric (with tetrahedral and four-co-ordinated B and N atoms). The molecule (58) represents the cross-over point of stability it is a dimer in solution and a monomer in the gas phase. 160 (N-Lithiomethylamino)dimethylborane formed from t-butyl-lithium and Me2BNMeH is an excellent reagent for the preparation of a variety of N-functional n pJn n n (%J (y-J (56) (57) (58) (59) lS5 B.Krebs and H.-U. Hurter Angew. Chem. Znt. Ed. Engl. 1980,19 481. H. Noth and H. Pommerening Angew. Chem. Znt. Ed. Engl. 1980,19,482. lS7 M. J. S. Dewar and M. L. McKee J. Mol. Struct. 1980 68 105. K. E. Blick E. B. Bradley D. P. Emerick and K. Niedenzu Z. Anorg. Allg. Chem. 1980 467 177. lS9 B. F. Spielvogel M. K. Das A. T. McPhail K. D. Onan and I. H. Hall J. Am. Chem. Soc. 1980,102 6343. 160 J. E. Richman N.-C. Yang and L. L. Andersen J. Am. Chem. SOC.,1980 102 5790. The Typical Elements 43 aminodime t hylboranes :16’ Me \ Me NLi +Me2BBr +Me2B-N-BMe2 / Me Me2B \ Me Me NLi +MeB(C1)NMe2 +Me2B-N-B-NMe2 / Me Me2B \ NLi +HgC12 +Hg[NMe BMe& / MezB N.m.r.and vibrational spectroscopy data support the existence of a linear C=N-B skeleton in monomeric iminoboranes of the type R:C=N-BR$. This allene-like arrangement of the central moiety of the compounds does not seem to enhance the N-B bond strength by interaction of this bond with the vicinal C=N bond. Rather in the case of R2 being a hydrocarbon group the nature of the N-B bond is similar to that found in (monoamino)diorganoboranes,R:NBR;.l6’ N’,N’-Diorgano-N-organo-trimethylsilylureas react with halogenodiorgano-boranes to yield ureidoboranes (60),of which twenty have been described.163 Similar reactions give thioureidoboranes and isothi~ureidoboranes.’~~ R’ R2 Et R’ Et\ / \ / N-C-N Et/ & \SiMe3 + R3 /B-X\ 4 Et‘ N-C-N 6 \B-P I A series of bis(bory1)hydrazines has been prepared by several routes (Scheme S) including ring opening of 2,3,4,5-tetramethyl-l-thia-3,4-dia~a-2,5-diborolidine.’~~ Me Me Me Me Me,SiN-NSiMe +MeBBr N-N Me, \ Me B’ / \ Me Me Me Me Me,SiNJ Me,N NMe P-N\ N-N Me,Si /SiMe +MeBBr + I\ N-N MeBBr BrBMe Me Me kSiOMe Me Me Me Me / N-N N-N \ I MeB BMe Me$ :BMe +MeBBr 0’ N-N Me Me Scheme 8 H.Fusstetter G. Kopietz and H. Noth Chern. Ber. 1980,113 728; H. Fusstetter and H. Noth ibid. p. 791. 162 D. P. Emerick L. Komorowski J. Lipinski F. C. Nahm and K. Niedenzu 2.Anorg. Allg. Chem. 1980,468,44. 163 W. Maringgele 2.Anorg.Allg. Chern. 1980,467 140. 164 W. Maringgele 2.Naturforsch. Teil B 1980 35 164. 165 K. Barlos and H. Noth 2.Narurforsch. Ted B 1980,35 125. F. A. Hart A. G. Massey P. G. Harrison and J. H. Holloway A wide variety of open-chain and cyclic sulphonamido-boranes can be synthesized by reactions of the type shown in Scheme 9.'66 R' R' / / MeS02N +XBR2R3 + MeS02N (X = C1 or Br) \ \ SiMe3 BR2R3 H F3C(CF2)3S02NCHR'CH20H+ R2BX2 -+ 0' Scheme 9 The first example of a pyrazolylborane containing a trigonal boron atom 1,3-dimethyl-2-(pyrazol-l'-yl)-1,3,2-diazaboracyclohexane (61) has been prepared by the thermolysis of a mixture of 1,3-dimethyl-l,3,2-diazoboracyclohexanewith pyraz01e.'~~ Me (-N;B-N/a -N Me (61) When nitrosodurene is treated with sodium tetrahydroborate in the presence of alcohols a free radical is formed for which the structure C6HMe4N(O*)BH2 was given.168 However this has been challenged by Crozet and T~rdo;'~~ they suggest that such radicals are ionic RN(O*)BH,-M'.Boron-Oxygen Compounds.-The process of solvent extraction of boron from aqueous solution has been reviewed.17' It is now thought that the postulated bipyramidal B203 molecule (62) is only a very minor component of gas-phase boric oxide and is probably only a minor component of the liquid; it is a highly strained SCF calculations give the equilibrium geometry shown in (63) for the boric oxide m01ecule.'~~ A Raman spectral study on vitreous and molten boric oxide has shown that boroxole rings become decreasingly important at elevated temperatures; thus at 1860°Cthe B03 triangles belong predominantly to a random-network configuration.The heat of R (62) (63) 166 W. Maringgele and A. Meller J. Organomet. Chem. 1980 188 401. 16' K.Niedenzu and W. Weber J. Organomet. Chem. 1980,195,25. D. Rehorek R. Herzschuh and H. Hennig Inorg. Chim. Acta 1980,44,75. 1980,102 5696. Am. Chem. SOC. J.Tordo,P.Crozet and P.M. 16' *'' C. G. Brown and B. R. Sanderson Chem. Ind. (London) 1980,68. L.C. Snyder and Z. Wasserman J. Chem. Phys. 1980,73,998. A.I. Dement'ev N. G. Rambidi V. Y. Simkin I. A. Topol N. F. Stepanov and B. I. Zhilinskii J. Mol. Struct. 1980,68 199. The Typical Elements 45 transformation of B03 triangles in boroxole rings to BO triangles in a random network is 6.4f0.4 kcal per mole of borox01e.~~~" The electronic structures of B203 H3B03 and BN have been determined using a variety of electron spectral techniques.173b Mannitol is a stronger borate complexant than glucose as might have been predicted from their molecular structures. Complexed boric acid is not a simple monobasic acid but probably exists as a mixture of different acids the composition of which depends on the ratio of undissociated to dissociated H3B03 in solution. Only ribose of the three carbohydrates studied formed a stable solid complex with undissociated boric The complexes that can be detected by I9F n.m.r. in aqueous mixtures of boric acid and ammonium bifluoride include BF4- BF30H- B2F602- BF302- BF2(0H)2- BF(OH),- B303F;- and B303F4(OH)2-.17s The phase diagram Tus.p of europium(r1) metaborate consists of four regions EuB204(I; room temperature) (111) (IV; 50 kbar 850 "C) and the decomposed phase EuB407 + Eu2B205. Phases (I) (111) and the decomposed phase are antifer- romagnetic whereas (IV) has a tendency to be paramagnetic. There was no phase (11) as found in the case of SrB204.176 Europium(I1) tetraborate EuB407 has a structure consisting of a three-dimensional (B407)a network of BO tetrahedra each europium ion being surrounded by nine oxygen atoms. The Eu2' ions are too far apart for magnetic interaction and EuB407 is simply a paramagnet obeying the Curie-Weiss law.177 The lanthanide magnesium borates LnMgB5010 possess two- dimensional (B5OlO5-), layers linked together by the Ln3' and Mg2+ ions.'7s A new and improved synthesis has been described for boracites complex-cage compounds of general formula M3B7013X where M is a bivalent metal and X is a univalent anion.Lithium metaborate and a metal dihalide (used as the hydrated salt) are heated for some hours in a pressure vessel to 270 "C and 26 atm before being rapidly cooled to room temperat~re:'~~ 7LiB02+ 3MX2+ H20 -B M3B7013X+ 5LiX + 2LiOH X= C1 M = Mgor Zn; X =Br M = Co or Ni Several boracites studied by thermogravimetry were found to decompose rather than melt so that melt techniques will not be feasible for growth of crystals.'80 The decomposition occurs in several stages (for M = Co Fe or Zn; X = C1 or I boracites); the first step involves the formation of MO * B203 B203 and MC12 or (M + 12).The final products are B2O3 and MO (or free zinc for M = Zn).Is1 173 (a)G.E. Walrafen S. R. Samanta and P. N. Krishnan J. Chem. Phys. 1980,72,113; (6)D.J. Joyner and D. M. Hercules ibid. p. 1095. H. B. Davis and C. J. B. Mott J. Chem. SOC.,Faraday Trans. 1,1980,76,1991; see also A. Mikan and M. Bartusek Collect. Czech. Chem. Commun. 1980 45 2645. 17' B. N. Chernyshov G. P. Shchetinina and E. G. Ippolitoz Koord. Khim. 1979 5 1788; Zh. Neorg. Khim. 1980 25 1468. 176 K.Machida G. Adachi J. Shiokawa M. Shimada and K. Koizumi Chem. Lett. 1980,81;Inorg. Chem. 1980,19,983. K.Machida G.Adachi and J. Shiokawa Acta Crystallogr. 1980,B36,2008. 17' B. Soubat M. Vlasse and C.Fouassier J. Solid State Chem. 1980 34 271. 179 M. Delfino and P. S. Gentile Inorg. Chim. Acta 1980 45 L109; M. Delfino G.M. Loiacono and P. S. Gentile ibid. 1980,43 59. M. Delfino and P. S. Gentile Thermochim. Acta 1980 40 333. L. G.Vedenkina A. V. Steblevskii A. S. Alikhanyan V. I. Bugakov V. P. Orlovskii and V. I. Gorgoraki Izu. Akad. Nauk SSSR,Neorg. Muter. 1980,16 1301. F. A. Hart A. G. Massey P. G. Harrison and J. H. Holloway Potassium borosilicate K20.B2O3-4SiO2 has a structure based on a framework built of linked (Si B)04 tetrahedra in such a way that each corner oxygen atom is shared by two tetrahedra. The framework which contains rings of six tetrahedra and of four tetrahedra has large cavities forming continuous channels and these are occupied by the potassium ions.182 The reactions of trigonal boron acids RB(OH)2 with fully protonated chelating ligands are characterized by a mechanism that involves proton transfer in a rate- limiting ring-closure step.Correlations of rate constants with the acidities of the boron acid and ligand are direct consequences of this mechanism. Borate anions RB(OH)3- react with rate constants three or four orders of magnitude higher.lB3 Oxygen-17 n.m.r. chemical shifts of thirty B-0 compounds containing three-co- ordinate boron can be interpreted in terms of a B-0 ?r-interaction. A decrease in the ?r-bond order is indicated by the shift data along the series (R,B),O>(RBO) > R2BOR> RB(OR)2>B(OR)3 (R = Me or Et).lB4 1,3-Dipolar reagents with an unsaturated CNO-skeleton undergo 1,3-0rganobor- ation when treated with triorganoboranes (Scheme The reactions of N,N-diorganoace tamides with organoboranes have also been studied (Scheme 11).IB6 H A*+,o-+BR3 -* H/c\ N' Ph N Me Ph Me HR Scheme 10 0 0-BMe2Br II // Me2NCMe+ BrBMe2 + Me-C \ NMe2 0 Me$/'\?Me, II LiCH,CNMe + BrBMe -* HCyO I NMe Scheme 11 M.Ihara and F. Kamei Yogyo Kyokaishi 1980,88 32 (Chem.Abs. 1980,92 86 2652). lE3 L.Babwck and R. Pizer Inorg. Chem. 1980,19,56. lE4 W. Biffar H. Noth H. Pommerening and B. Wrackmeyer Chem. Ber. 1980,113,333. P. Paetzold and G. Schimmel 2. Nuturforsch. Teil B 1980 35. 568. W. Maringgele 2.Anorg. Allg. Chem. 1980,468 99. The Typical Elements 47 Substitution of one bridge hydrogen atom of bis-( 1,2-cycloheptanedione- dioximato)nickel(iI) (64) by the diphenylboron group occurs on refluxing the nickel complex with 2-aminoethanol-diphenylboron chelate; an excess of the latter chelate gives the bis(dipheny1boron)nickelcomplex (65).18' dB'O \ P-H-o\ / \ I O-H***O .'"\ Ph Ph (65) Boron-Sulphur Compounds.-The transient species MeB=S'88 and C1B=S'89 have been studied by microwave spectroscopy; they were made by passing S2X2 over heated boron at about 1000 "C.The value of 1.5352 8 for the B-C distance in the former molecule represents the first measurement on a bond formed between an sp3-hybridized carbon atom and an sp-hybridized boron atom.Hydroboration Reactions.-Hydroboration has been the subject of a recent b00k.l~' An ab initio molecular orbital study on the C&+BH3 reaction suggests that the hydroboration reaction proceeds through a two-step process.First a loose three-centre .rr-complex is formed in the early stages without an energy barrier and then it is transformed into the product (EtBH,) via a four-centre transition state this process being the rate-determining ~tep.'~' An "B n.m.r. study has been made of the various intermediates formed in the hydroboration of 3-methylbuta-1,3-diene and ~yclo-octa-1,5-diene.'~~ A range of alkenylsilanes has been subjected to hydroboration with BH,.THF and 9-BBN; the latter reagent was found to give more regiospecific Dimethyl sulphide- dibromoborane Me2S.HBBr2 readily undergoes hydroboration with alkynes to give alkenyldibrom~boranes.'~~ The products of alkynes hydroborated by 9-BBN (=R2)react with sodium methoxide to give Na[R,B(OMe)R'] where R' is an alkenyl group.When this salt is added to CuBr-SMe at 0 "C the prepared copper complex rapidly decomposes to give the coupled product R'-R' in high ~ie1d.l~' The kinetics of hydroboration of alkenes with 9-borabicyclo[3.3.l]nonanedimer (9-BBN)2 exhibit interesting characteristics. With reactive alkenes such as hex-1 -ene or 2-methylpent-1 -ene the reaction exhibits first-order kinetics i.e. first order in (9-BBN)2 and zero order in alkene. With less reactive alkenes (e.g. cyclohexene W. Fedder F. Umland ad E. Hohaus Monatsh. Chem. 1980 111,971. C. Kirby and H. W. Kroto J.Mol. Spectrosc. 1980,83,1. C. Kirby and H. W. Kroto J. Mof.Spectrosc. 1980,83 130. 190 H. C. Brown 'Hydroboration' Benjamin-Cummings 1980. 191 S. Nagase N. K. Ray and K. Morokuma J. Am. Chem. SOC.,1980,102,4536. 19* R.Contreras and B. Wrackmeyer Z. Natutforsch. Teil B 1980 35 1229 1236. 193 J. A.Soderquist and H. C. Brown J. Org. Chem. 1980 45,3571. 194 H. C. Brown and J. B. Campbell J. Org. Chem. 1980,45,389. 19' J. B. Campbell and H. C. Brown J. Org. Chem. 1980,45,549; 550. 48 F. A. Hart A. G. Massey P.G. Harrison and J. H. Holloway or 1-methylcyclohexene) the reaction shows three-halves-order kinetics being first order in alkene and one-half order in (9-BBN)2. These results can be accounted for in terms of the following mechanisms (9-BBN)z * 2(9-BBN) 9-BBN +alkene * B-alkyl-9-BBN With reactive alkenes the rate-determining step is the dissociation of the dimer; with less reactive alkenes the reaction of alkene with the monomer becomes the rate- determining step.For some olefins such as 2-methylbut-2-ene and cis-hex-3-ene neither is the rate-determining step and the reaction has kinetic behaviour between that of first and three-halves Alkenes and alkynes undergo facile hydroboration at the 9-position with 6-thia- nido-decaborane( 1l),6-SBgH1 ; acetylene gives a double-hydroboration product 9,9'-MeCH-(6-SB9Hlo)2. Pyrolysis of 9-R-6-SBgHlo (R = alkyl) gives the 2- 6- and 10- isomers of C~OSO-R-~-SB~H~.~~~ Organoborane Chemistry.-In the complex (C0)2FeMe(PMe3)2CNBPh3 the triphenylborane group is bound to the cyanide nitrogen atom (B-N= 1.592 Two groups199*200 have described the stabilization of tetra-alkyldiborane(4) derivatives by the use of bulky substituents (Scheme 12).Only three t-butyl groups can be introduced into the molecules; the fourth group has to be the less sterically demanding methyl neopentyl or surprisingly trimethylsilyl. The tetra-alkyl- diboranes do not react at room temperature with MeOH NH3 N2H4 or pyridine; some are even stable towards oxygen. But But But OMe ButLl \ / Me3CHZLI 32(OMe)4+2Bu'Li + \B-B ,' -B-B -B2But3(CH2CMe3) Me0,' \But But,' \OMe c1 NMe2 But NMe2 BU' c1 BCI \ / BuXi \/ Bu'Li \ ' -B-B B-B ___) B-B ___* B2But3Cl Me2N' \c1 Me2N,' \But Cl/' \But 1LiMe B2But3Me Scheme 12 The structure and spectroscopic properties of CS[(CF~)~BFJ have been reported.Apparently because of C. -.F(B,C) interactions one B-C bond has a staggered and the other an eclipsed conformation in the solid state.201 A general and convenient method for preparing trialkylhydroborates is to treat trialkylboranes with t-butyl- lithium at -78 "C. The formation of LiR3BH and isobutylene is apparently due to kinetic rather than thermodynamic factors.202 H. C. Brown K. K. Wang and C. G. Scouten Proc. Natl. Acad. Sci. USA 1980,77,698. B. J. Meneghelli M. Bower N. Canter and R. W. Rudolph J. Am. Chem. Soc. 1980 102,4355. 19* D.Ginderow Acta Crystallogr. 1980,B36,1950. 199 W.Biffar H. Noth and H. Pommerening Angew. Chem. Int. Ed. Engl. 1980,19,56. K.Schiilter and A. Berndt Angew. Chem. Int. Ed. Engl. 1980,19,57. D.J. Brauer H. Buerger and G. Pawelke J. Orgunomet. Chem. 1980 192 305. z"2 H. C. Brown G. W. Kramer J. L. Hubbard and S. Krishnarnurthy J. Organomel. Chem. 1980 188,1. 19' 19' The Typical Elements Thexylchloroborane made by treating thexylborane Me2CHCMe2BH2 with hydrogen chloride in ether is a useful reagent for making mixed organ~boranes:’~~ H CH2CH2R’ CH2CH2R’ / H2C=CHRI / R2Li / HCMe2CMe2B HCMe2CMe2B dHCMe2CMe2B ‘Cl \c1 \R2 Carbonylation of B -alkyl-9-borabicyclo[3.3. llnonane B-R-9-BBN in the pres- ence of a modest excess of Li(Me0)3AlH produces an intermediate which is reduced by LiAlH4 to provide a high-yield stereospecific synthesis of the homologous B-CH2R-9-BBN.204 The four-membered heterocycle l,l-dimethyl-1,3-azoniaboratacyclobutane(66) can be made in good yield via the reaction shown.It is stable towards and soluble in water but is hydrolysed in dilute The radical anion of 1,4-diborabenzene stabilized by 1,2-dimethoxyethane (67) has been prepared and its e.s.r. spectrum anal ysed. 206 H$-NMez Me3NBH2CH2NMe3+C1-+Me3CLi --* v (66) DME F F 1 Me[B]Me 5Me[.B)Me ___) Me(B-)Me 2~ I.-Me Me DME Me M~ -2KF Me ‘-** Me B B B F F -t (unstable) DME (67) The synthesis of alkyl-substituted 1,4-dimethyl-1,4-diboracyclohexa-2,5-dienes (68) can be achieved by treating dialkylacetylenes with a C8K-MeBBr2 mixture. It was assumed that the products arose by direct addition of free borylene MeB to the a~etylene.’~’ RR rn MeB BMe LJ RR (68) Chlorodivinylborane208a and cyclic ligands containing divinylborane-like units2’*’ readily form r-complexes with a variety of transition metals as shown in Scheme 13.Insertion of methylborylene into the C-H bonds of benzenetricar-bonylchromium to give (69) has been achieved.’09 ’03 G. Zweifel and N. R. Pearson J. Am. Chem. SOC.,1980,102 5919. H. C.Brown T. M. Ford and J. L. Hubbard J. Org. Chem. 1980,45,4067. ’05 G.F. Warnock and N. E. Miller Inorg. Chem. 1979 18 3620. ’06 W. Kaim H. Bock P. Hawker and P. L. Timms J. Chem. SOC.,Chem. Commun. 1980 577; Chern. Ber. 1980,113,3196. S.M.van der Kerk A. L. M. van Eekeren and G. J. M. van der Kerk J. Organomet. Chem. 1980 190 C8.’08 (a) G. E. Herberich E. A. Mintz and H. Muller J. Orgunornet. Chem. 1980 187 17; (b) G.E. Herberich M. Thonnessen and D. Schmitz ibid. 1980 191 27. *09 S.M. van der Kerk and G. J. M. van der Kerk J. Orgunomet. Chem. 1980,190,C11. F. A. Hart A. G. Massey P. G. Harrison and J. H. Holloway -BCI + Me,Sn(CH=CH,) -+ CIB(CH=CH,) (CsHs)Co(CO) 7BCI hv I/ =Y Co(C5H5) X/--\BPhu Pd(cod)CI2 rn X = CMe2 SiMe2 or (CH2)2 xwBph XABPh u Scheme 11 n n Me Cr(co) WCQ3 (69) Several new 1-bora-adamantanes have been described. Cyclization of triallyl- borane with 1,l-dimethylallene gives (70a) which can be converted into the methoxy-derivative (70b) by treatment with methyl alcohol. Reaction of (70b) with tetraethyldiborane then produces 4,4-dimethyl-l-bora-adamantane in 58% yield.210 Similar reactions have been used to obtain (71) from which the l-bora- can adamantanes (72a),"' (72b),212 and (72~)~'~ be made by treatment with (70)a; R = ally1 (71)a; R' = R2 =H (72)a; R' =R2 = H b; R=OMe b; R'=Me,R2=H b; R1=Me R2=H c; R1=H,R2=Me c; R'=H,R2=Me THF.BH3.Cleavage of 1-bora-adamantane with bromine gives (73a) which reacts with methanol or water in the presence of triethylamine to produce (73b) and (73c) respectively. On treatment with 10% sodium hydroxide (73c) cyclizes to (74).214 Lithium 1-alkyl- 1-bora-adamantanes obtained from LiR and (72a) give 7-methylene-3-alkyl-3-borabicyclo[3.3. llnonanes on reaction with acetyl chloride. The methylene group can be hydrogenated to methyl by hydrogen and platinum.215 It is concluded from a 'H and 13C n.m.r.study of 3-borabicyclo[3.3.1]nonanes that 'lo B. M. Mikhailov V. N. Srnirnov 0.D. Smirnova E. P. Prokofev and A. S. Shashkov Zzv. Akad. Nauk SSSR,Ser. Khim. 1979,2340. '11 B. M. Mikhailov T. K. Baryshnikova V. G. Kiselev and A. S. Shashkov Izv. Akud. Nauk SSSR,Ser. Khim. 1979,2544. 212 B. M. Mikhailov T. V. Potapova and A. S. Shashkov Zzu. A4kad.Nauk SSSR,Ser. Khim. 1979,2724. '13 B. M. Mikhailov M. E. Gurskii and A. S. Shashkov Izv. Akud. Nauk SSSR,Ser. Khim. 1979,2551. B. M. Mikhailov L. S. Vasil'ev and V. V. Veselovskii Zzv. Akad. Nauk SSSR,Ser. Khim. 1980 1106. '15 B.M. Mikhailov M. E. Gursky T. V. Potapova and A. S. Shashkov J. Organomet. Chem. 1980,201 81. 51 The Typical Elements CH,Br Lcf (73)a; R=Br b; R=OMe c; R=OH (74) a double chair conformation is adopted when the boron is three-co-ordinate and that this changes to the chair-boat form when four-co-ordinate boron is present.216 Mikhailov has reviewed the current Russian work on 1-and 2-bo~a-adamantanes.~~~ 2 Aluminium Aluminium atoms react spontaneously with water at 15 K to give HAlOH whereas the heavier members of Group I11 form M...OHz and M2*..0H2 adducts.The HGaOH and HInOH species but not HTlOH can be formed by photolysis of the respective adducts; further photolysis produces MOH. The M2 --OH adducts apparently rearrange when photolysed to a hydrogen-bridged dimetal species which in turn is converted into M20:2'8 H M + H,O +M,.-OH hu -+ / \ \/0 M M -% M,O + H Nitrites are often used as inhibitors in car cooling systems so it is particularly worrying to note that after an induction period aluminium corrodes catastrophically in aqueous solutions of sodium nitrite even at room temperature.The products are ammonia hydrogen and p-A1(OH)3.219 Inelastic electron-tunnelling spectroscopy allowed detection of the following species in a study on the corrosion of aluminium by carbon tetrachloride AICI AICl, A1Cl3 *Ccl3 C2Cls and CC13'A1C14-.220 An electron diffraction study has confirmed that AIH3.2NMe3 does not dissociate appreciably in the gas phase. The structure is very similar to that found in the solid state (AI-N = 2.19 A)."' Triethylenediamine TED reacts instantaneously and quantitatively with alane in diethyl ether or THF to give TED.AIH3."7 An n.m.r.study (27Al,7Li) of lithium tetrahydroaluminate in ether over the concentration range 3.75-0.0075 moll-' suggests that multiple ion formation occurs at the higher concentrations and that ion pairs are formed at low concentra- tions. The 27Al resonance only showed evidence of AI-H coupling at concentrations below 0.15 mol 1-'.222 The mixed anions AIH4-,C1,- (n= 1,2 or 3) are formed in redistribution reactions between tetrabutylammonium tetrachloroaluminate and tetrabutylammonium tetrahydroaluminate; the latter also reacts with iodine to give Bu"~NAIH~-,~,.~~~ '16 M. E. Gursky A. S. Shashkov and B. M. Mikhailov J. Organomet. Chem. 1980,199,171. '" B.M. Mikhailov Pure Appl Chem.1980 52,691. "* R. H. Hange J. W. Kaufman and J. L. Margrave J. Am. Chem. Soc. 1980,102,6005. 219 P.J. Hyde and I. M. Ritchie Aust. J. Chem. 1980 33 169. ''O R. M. Ellialtioglu H. W. White L. M. Godwin andT. Wolfram J. Chem. Phys. 1980,72 5291. '"V.S.Mastryukov A. V. Golubinskii and L. V. Vilkov Zh. Strukt. Khim. 1979 20 921. 222 H.Noth 2. Naturforsch. Teil B,1980,35 119. 223 L.V.Titov V. D. Sasnovskaya and V. Y. Rosolovskii Zzu. Akad. Nauk SSSR Ser. Khim. 1980,967. 52 F. A. Hart A. G. Massey P,G. Harrison and J. H. Holloway In its p metastable form RbAlF has a structure built up from two [A1F4/,F2-] layers of AlF6 octahedra connected by four corners in the (001) plane; the Rb ions are located between the layers. At 588 K the crystals transform into the stable cy -form.224 The equilibrium configuration of the ion pair Cs'AlF4- in the gas phase has the Cs' lying on an extension of the perpendicular drawn from the centre of the AlF tetrahedron through the mid-point of an edge.In Cs'AlC1,- the Cs' lies on a perpendicular drawn from the centre of the AlCl tetrahedron through the mid-point of a Tetrameric structural units [(F4/1AlF2/2)4]8- occur in Ba3(A1F6)2 and not isolated AlF6,- ions as found in cryolite.226 High-resolution i.r. and Raman spectra have been obtained and discussed for A12C16 molecules isolated in Ar and N2 matrices at very low temperature^.^^^ At the sublimation point the gas above aluminium trichloride contains about 1mol O/O of A13C19 (75) in addition to the dimer A12C16.228 Gaseous aluminium chloride and oxygen begin to react slowly at about 400 "C and appreciably above 800 "C to form aluminium oxide and chlorine.229 C1 Al CI' c1 I I CI,AI ,AICl C1 (75) Benzo-15-crown-5 forms a 1:2 (ether :AlCl,) complex with aluminium tri- chloride in benzene-diethyl ether solvent; on recrystallization from methanol the stable 1:1adduct is During efforts to make the (Me2N)3Si+ ion a 1:1 complex was formed between aluminium chloride and (Me,N),SiCl in methylene dichloride; the donor site is a nitrogen atom on one of the dimethylamino-gr~ups.~~~ Molar enthalpies of dissolution of aluminium trihalides in acetonitrile and THF have been measured; all values were negative being in the order AH (most negative) < A1Br3<AlC13.If the measurements were attempted in the open air preferential hydration of the solutes Aluminium trichloride dissolves in liquid sulphur dioxide to give electrically conducting solutions the properties of which have been explained in terms of the equilibrium233 SO2 +A1C13 $ SOCl++AlOC12-Aluminium has tetrahedral co-ordination in solid CuA12C18 (76); a distorted octahedral co-ordination about copper is completed by two chlorine atoms at 2.96A. The reflectance spectrum of the solid is very similar to that of gaseous CuA12C18 suggesting that the latter also has structure (76).234 Two new gaseous 224 J. L. Fourquet F. Plet and R. De Pape Acta Crystallogr. 1980 B36 1997. 225 K. P. Petrov V. A. Kulikov V. V. Ugarov and N. G. Rambidi Zh. Strukt.Khim. 1980 21 71. 226 R. Domesle and R. Hoppe Angew. Chem. Int. Ed. Engl. 1980,19,489. 227 M. Tranquille and M. Fouassier J. Chem. SOC., Faraday Trans 2 1980 76 26. H. Schafer and U. Florke 2. Anorg. Allg. Chem. 1980,462 173. 229 Y.Shoji K. Tatsumi R. Matsuzaki and Y. Saeki Bull. Chem. SOC.Jpn. 1980,53 269. 230 F. Wada and T. Matsuda Bull. Chem. SOC. Jpn. 1980 53,421. *" A. H. Cowley M. C. Cushner andP. E. Riley J. Am. Chem. SOC.,1980,102,624. 232 M. Galova and D. Kladekova Collect. Czech. Chem. Commun. 1980,45 2300. 233 J. E. Dubois M. Delamar and P. C. Lacaze Electrochim. Acta 1980 25,429. 234 H. Schafer M. Binnewies R. Laumanns and H. Wachter 2.Anorg. Allg. Chem. 1980,461,31. The Typical Elements 0 (77) species PdA1Cl5 and Pd2Al2ClI0 in addition to the known PdA12C18 have been detected by mass spectrometry in the reaction between A12C16 and palladium dichloride.235 In the absence of carbon monoxide AlBr3 induces a rapid alkyl migration in M~M~I(CO)~, PhCH2Mn(C0)5 CSHSFeMe(C0)2 and C5HSMoMe(C0)3 to give acyl complexes.In MnC(OA1p -Br-Br,)Me(CO) a bromine atom from the AIBr3 fills the sixth co-ordination site of the manganese thereby creating a five-membered ring (77). Analogous acetyl complexes are formed by M~MII(CO)~ and AlC13 or BF3.236 Aluminium tribromide has also been used to catalyse the first insertion of CO into an Re-C cr-bond (Scheme 14).237 R CO-HZO (COLReC) -(CO)3Re aMe2 -(CO),Re AIBr Br Me2 21-O Br Scheme 14 An n.q.r. study has been made of the charge distribution and structure of several halogeno-aluminates and -gallates M'M"'X4 M'M"'2X7 and C6H6.CuA1C14 (M'=Ga Na K NH4 Rb or CS).~~~ The complex anions formed in reactions of aluminium and gallium trihalides with either cyanate or thiocyanate ions may be studied by 27Al and 6g*71Ga n.m.r.For example it is found that A1C13 and potassium thiocyanate give AlCl,NCS- AlC12(NCS)2- and A1(NCS)63- but in the bromide system only AlBr3NCS- could be detected.239 Fluoroaluminium and fluorogallium phthalocyanine polymers (PcAlF) and (PcGaF), were prepared by first carrying out a template reaction between MC13 and phthalonitrile and then treating the product with base aqueous HF and pyridine; vacuum sublimation at ca. 500"C (Al) or ca.460 "C (Ga) gave mats of fine crystals. Partial oxidation of these linear polymers with iodine markedly increased their electrical conductivity for example by a factor of lo8for the gallium A simple direct-transmission i.r. technique has been devised to obtain the spectra of acidic and basic melts in the AlC1,-1-butylpyridinium chloride system. The v3 band of AlCl,- shows splitting confirming that tetrahedral distortion occurs in the "' U. Florke and H. Schafer 2.Anorg. Allg. Chem. 1979,459,140. ''' S.B. Butts S. H. Strauss E. M. Holt R. E. Stimson N.W. Alcock and D. F. Shriver J. Am. Chem. SOC.,1980,102,5093. 237 E. Lindner and G. von Au Angew. Chem. Int. Ed. Engl. 1980,19,824. 238 A. Fichtner and A. Weiss 2.Naturforsch. Teil B 1980,35 170. 239 V.P. Tarasov S. P. Petrosyants G. A. Kirakosyan and Y. A. Buslaev Koord. Khim. 1980,6,52. 240 P. M. Kuznesof K. J. Wynne R. S. Nohr and M. E. Kenney J. Chem. SOC.,Chem. Commun. 1980 121;3. P. Linsky T. R. Paul R. S. Nohr and M. E. Kenney Inorg. Chem. 1980,19,3131. 54 F. A. Hart A. G. Massey P.G. Harrison and J. H. Holloway melt; the spectra also support the suggestion that A12C17- possesses a bent Al-Cl-A1 bridge.241" Sustained conversion of light energy into electrical energy can be achieved with n-GaAs electrodes in this melt.241b The technique of spectroelectrochemistry has been applied for the first time to a study of molten chloroaluminates. For example it is confirmed that in basic KCl-AlCl melts bright yellow NbV is reduced to purple NbIV in a simple elec- trochemical reduction.The sulphur system is considerably more complex and although the overall electrochemical reaction is S+acidic NaC1-AlCl3 melt SIV(as SC13+) at least five intermediate oxidation states were Sulphide ions and AlCl,- react in a 1:1ratio in chloride or caesium chloroalumi- nate melts forming clear solutions sometimes with gel precipitates. In basic solutions the chain-like species [Al,S,-1C12,+2]"- is thought to be formed; It has low values of about 34 in dilute solution but in concentrated solutions higher values of n are reached until finally n approaches infinity and the polymeric compound AlC1,SCl is formed. In acid solutions release of chloride from the polymeric ions occurs and an increasing number (m)of sulphide-chloride double bridges (78) are formed giving the ions [AlnSn-1C12n+2-m](n-m)-.243 C1 -*./ \ ..-'Al Al' / \/ \ S (78) A number of polycyclic aromatic hydrocarbons undergo self -protonation in the aprotic liquid SbC13-10 mol % AlC13 in the range 100-130 "C. The function of the aluminium chloride is to enhance the oxidizing power of the Sb"'/Sbo couple.244 A structural investigation of (Y -A1203 at 2170 K and 300 K shows that significant changes occur in the positional parameters of the aluminium atoms and slight changes in those of oxygen; the distorted hexagonal close packing of the oxygen atoms becomes more regular at 2170 K and the aluminium atoms move towards the vacant octahedral interstices between the oxygen layers.The two independent A1-0 distances are 1.971 and 1.852A at 300K and 2.024 and 1.880A at 2170 K.245Four crystalline phases were noted for calcium aluminate CaA1204 in a high-pressure-high-temperature study; in contrast the corresponding gallate undergoes only one phase change.246 Only two i.r. bands shift appreciably with change in the tervalent metal ion M for a variety of alums (M=Al Ti V Cr or Fe). These were assigned to the antisymmetric metal-ligand stretch v3 and the antisymmetric metal-ligand bend v4 of the M(H20)63+ compIe~.~~~ 241 (a) R. J. Gale and R. A. Osteryoung Inorg. Chem. 1980 19 2240; (b) P. Singh K. Rajeshwar J. DuBow and R. Job J. Am. Chem. SOC.,1980,102,4676. 242 G. Mamantov V. E. Norvele and L. Klatt J. Electrochem. Suc. 1980 127 1768.243 R. W. Berg S. von Winbush and N. J. Bjerrum Inorg. Chem. 1980,19,2688. 24* A. C. Buchanan A. S. Dworkin and G. P. Smith J. Am. Chem. SOC.,1980,102,5262. 245 N. Ishizawa T. Miyata I. Minato F. Marumo and S. Iwai Acta Crystallogr. 1980 B36 228. 246 S. Ito K. Suzuki M. Inagaki and S. Naka Muter. Res. Bull. 1980 15 925. "'S. P. Best R. S. Armstrong and J. K. Beattie Znorg. Chem. 1980,19 1958. The Typical Elements 55 A 1 1complex is formed between tris-acetylacetonatoaluminium and lanthanide shift reagents generated from fod. From the 27Al shifts it was concluded that a large proportion of 4f electron spin is transferred to the 27Al nucleus and that the hyperfine splitting constant of aluminium is When anhydrous aluminium perchlorate is dissolved in donor solvents such as acetonitrile or THF the originally bidentate ClU groups become unidentate; similarly in A1(ClO,),-3H2Q all the perchlorates are unidentate.Addition of tetrabutylammonium perchlorate to solutions of aluminium perchlorate gives Bu4NAl(C1O4),; the complex (Bu,N)~A~(C~O~)~ can be prepared by reaction of CsAl(ClO,) and Bu4NC10 in a 1:2 ratio.249 Lewis bases can attack sodium tetrachlorosulphatoaluminate at either the sulphur or the aluminium NaAl(S03C1)4+ 4H20 -+ NaAl(HS04)4+ 4C1 NaAl(SO,CI) + 4F-+ NaAlF + 4S03C1-The predominant species formed when lithium tetrahydroaluminate and t-butyl alcohol are mixed in THF is L~(Bu'O)~AIH~. Although no Li(Bu'O)AlH3 could be detected a slow equilibrium was found to exist between L~(Bu'O)~AIH~ Li(Bu'O),AlH and LiA1H4.251 An acid phosphate H30[A13(H2P04)6(HP04)2] 4H20 crystallizes out when aluminium is dissolved in 85% phosphoric acid until an A1:P ratio of 1:4.5 is reached.The crystals contain layers consisting of A106 octahedra which share vertices with 02P(OH) and O,POH tetrahedra. Within these layers are vacancies which are occupied by the H30+ ions. The water molecules are fixed between neighbouring layers by hydrogen A theoretical study has been made of AlCH, AlCH2 and AlCH. The ground state of AlCH2 does not contain A1-C double bonds; such bonds are present in an excited state 21 kcal above the ground state. Similarly the state with a structure AlGCH is 86 kcal above the ground The direct synthesis of higher trior- ganoaluminium derivatives has been described.For example at 160 "Cand 100atm aluminium hydrogen and 2,4,4-trimethylpent-l -ene produce tris-(2,4,4-trimethyl- penty1)aluminium in over 50% yield.2S4 A structural investigation of the complex [Me3Al(ONNMeO)AlMe2] formed when nitric oxide and trimethylaluminium react together shows that the AlMe3 group is bonded to an oxygen atom (79) and not a nitrogen as previously thought. Me2Alr-TMe P-" Me,Al (79) 248 M. Hirayama and K. Kitami J. Chem. SOC.,Chem. Commun. 1980 1030. 249 Z.K.Nikitina and V. Y. Rosolovskii Zh. Neorg. Khim. 1979,24 2390; 1980,25 134. M. Drache and J. Heubel Bull. SOC.Chim. Fr. 1980 105. D. A. Home. J. Am. Chem. SOC.,1980,102,6011. 252 D. Brodalla and R. Kniep 2. Naturforsch.Ted B 1980,35 403. 253 D. J. Fox D. Ray P. C. Rubesin and H. F. Schaefer J. Chem. Phys. 1980,73 3246. '"A. V. Kuchin G. A. Tolstikov V. P. Yur'ev V. I. Ponomarenko C. N. Kurilenko R. A. Nurushev and L. I. Akhmetov Zh. Obshch. Khim. 1980,50 911. F. A. Hart A. G. Massey P. G. Harrison and J. H. Holloway The oxygen atoms in the corresponding gallium heterocycle (80)are not sufficiently basic to co-ordinate to GaMe3.255 Paramagnetic organoaluminium complexes which can be cationic anionic or neutral depending on the ligand and solvent are formed when AIR3 sodium and nitrogen ligands react together (Scheme 15).256 AIR, I AIR +AIR + Na -+ \/ A1 R2 Scheme 15 A number of unsaturated heterocycles containing aluminium have been synthe-sized from organoaluminium derivatives of acetylenes and cumulenes (Scheme 16).Pentamethylcyclopentadienylmagnesiumchloride reacts with dimethylaluminium chloride to give [q3-Me5C5Al(C1)Mel2in which only three carbon atoms of the R THF \/ (ref. 257) R‘ ’THF Ph Ph(R A1)2CCECC(AIR2),Ph -* heat (ref.258) RAI R Ph THF 1 Ph C=C=C=C\ AlEt / hv+ II CPh II (ref. 259) Et,AI / \Ph PhCAI/C\ THFt Et / .ITH:*CPh Scheme 16 255 S. Amirkhalili P. B. Hitchcock J. D. Smith and J. G. Stamper J. Chem. Soc. Dalton Tram. 1980 2493. 256 W. Kaim J. Organomet. Chem. 1980 201 C5. 2s7 H. Hoberg and F. Aznar Angew. Chem. Int. Ed. Engl. 1980 19 146. 258 H. Hoberg and F. Aznar J. Organomet. Chem. 1980,193 155. 259 H. Hoberg and F.Aznar 3. Organomet. Chem. 1980 193 161. The Typical Elements (81) C5Me5 rings appear to interact with the aluminium atoms (81).260One of the products formed in good yield from the reaction between dicyclopentadienylzir- conium dichloride and triethylaluminium is the rather unusual AI;Zr-p-chloro-1- [dicyclopentadienylzirconio(lv)l-2,2-bis(diethylalumino)ethane (82).261Triethyl-aluminium reacts with tetracyclopentadienylzirconiumto give di-(q 5-cyclopen- tadienyl)-2,2-bis(diethylalumino)ethylzirconiumcyclopentadienide (83).The C5H5 C-CH H2 I AIEt (82) (83) group above the two aluminium atoms is arranged symmetrically in the crystal between two neighbouring zirconium atoms and is considered to be an anion.262 Another product from the same reaction (Scheme 17) is (C5H5)3ZrH..-AlEt, in which the ZrHAl distance is 3.66 AIEt (C5H5)4Zr+AIEt3 -+(C5H5)3ZrEt-(C5H5)3ZrCH2CH2A1Et2 CH=CH2 AIEt AIEt, J \ / 1 / (C5H5)3Zr-H-.A1 (C5H5)3ZrCH2CH J \ '.+CH2=CHA1Et Et2 a1et2 (C5H5)3ZrH...AIEt3+AIEt 11 (C5H513ZrH +(AIEt3)2 Scheme 17 260 P. R. Schonberg R. T. Paine and C. F. Campana J. Am. Chem. Soc. 1979,101,7726. 261 J. Kopf W. Kaminsky and H.-J. Vollmer Cryst. Struct. Commun. 1980 9 197. 262 J. Kopf H.-J. Vollmer and W. Kaminsky Cryst. Struct. Commun. 1980 9 271. 263 H. Sinn W. Kaminsky H.-J. Vollmer and R. Woldt Angew. Chem. Int. Ed. Engl. 1980 19 390. 58 F. A. Hart A. G. Massey P. G. Harrison and J H. Holloway Controlled reaction of NaAIR and NaAIR3H (R = Me Et or MeCH=CH2) with water in a 2 1 ratio produces Na2(R3A10A1R3) from which the free alumoxane R2A10AlRz (84) may be obtained by treatment with ally1 bromide.Alkali-metal hydrides react with (84)to give M(HR2AIOAlR2).264 Amines form 1 1complexes with (84) which decompose on heating to alkanes and aluminium amide~:~~' Et / Et4A120+ MeNH2 + 1 1 complex -B C2H6+ Et2AIOAI \ NHMe Slightly distorted tetrahedral co-ordination occurs about aluminium in the p-xylene solvate of Cs[AIMe212] Al-1=2.647 A; AI-C = 1.98 A.266The thiocyan- ate group is N-bonded to the aluminium atom in CS[AIM~~NCS].~~~ Trisilylalkylaluminium derivatives selectively insert sulphur trioxide into the Al-C bond without cleavage of the silicon-carbon bond 268 [RMe2Si(CH2) &A1 + 3so3 + [RMezSi(CH2) S020I3AI Tris(trimethylsilyl)aluminium269 and tetrakis(trimethylsilyl)aluminates270 have been synthesized using the reactions Hg-ether Me3SiC1+ A1 + Li AA1(SiMe3)3.ether ether-vac.Na + (Me3S&Hg + A1(SiMe)3.ether--+ NaA1(SiMe3)4.xEt20 -NaA1(SiMe3)4 pentane 3 Gallium A 'H n.m.r. study has shown that the bleomycin antibiotics form 1 1 complexes with Ga"' in aqueous solution; it is assumed that gallium displaces a proton from the (Y -amino-group of the diaminopropionamide moiety of the drugs thus implicat- ing this position in the metal binding. The bleomycins are a family of glycopeptide antibiotics some of which are used in tumour scanning as carriers for various radionuclides including 67Ga.271 Stability constants and other data have been evalu- ated for complexes formed in aqueous solution between Ga'" and ten multidentate ligand~.~'~ Two complexes GaA' and Ga(HA)2' were detected in the Ga"'-5- nitrosalicylate (HA-) system.The reaction between. HA- and Gal" can be regarded as occurring first through interaction between the metal ion and the carboxylate group of the ligand giving rise to a unidentate carboxylato-complex; the second step involves ring closure and depr~tonation.~~~ 264 V. V. Gavrilenko L. A. Chekulaeva V. A. Antonovich and L. I. Zakharkin Izv. Akad. Nauk SSSR Ser. Khim. 1980 231. 265 A. Piotrowski A. Kunicki and S. Pasynkiewicz J. Organomet. Chem. 1980 186 185. 266 R. Rogers and J. L. Atwood J. Cryst. Mol. Struct. 1980 9 45.267 R. Shakir M. J. Zaworotko and J. L. Atwood J. Cryst. Mol. Struct. 1980 9 135. "* G. Sonnek G. Miiller and K.-G. Baurngarten J. Organomet. Chem. 1980 194 9. 269 L. Rosch and G. Altnau J. Organomet. Chem. 1980,195,47. 270 L. Rosch and G. Altnau 2. Nuturforsch. Teil B 1980,35 195. '" R. E. Lenkinski B. E. Peerce J. L. Dallas and J. D. Glickson J. Am. Chem. SOC.,1980 102 131. "' R. J. Motekaitis and A. E. Martell Inorg. Chem. 1980 19 1646. 273 B. Perlrnutter-Hayman F. Secco E. Tapuhi and M. Venturini J. Chem. SOC.,Dalton Trans. 1980 1124. The Typical Elements 59 Using a combination of microwave i.r. and Raman spectroscopy the first struc- ture determination of a gallane complex GaH NMe, has been achieved (Ga-N = 2.111 The vibrational spectra of Me3P * GaH3 and Me3P GaD in the solid state at low temperature have been studied and interpreted on the basis of C, molecular symmetry.The force constant of the Ga-P stretching mode was considerably lower than that of Ga-N in Me3N -GaH, so one would expect PMe3 to be a weaker base than NMe,. However previous competition reactions by Greenwood showed that the donor strength of Me3N towards GaH3 is either equal to or only slightly greater than that of PMe,. It would appear that adduct stability for this class of compound cannot be predicted directly from the magnitudes of the stretching force constant of the dative bond.275 A chlorine-bridged dimeric structure is suggested for the rather unstable molecule dichlorogallane. From this and previous data the generalization was made that when there is a choice between H and C1 as bridging atoms beryllium magnesium and boron have bridge hydrogens whereas gallium has bridging chlorine.276 Germanium is chemically transported as GeGaCl when heated with gallium tri~hloride."~ KGaCl exists in three enantiotropic forms (I) stable below -25 "C (11) stable between -25 and ca.130"C and (111)above 130"C up to the melting point (259 "C); the latter form crystallizes with the KAlC14 Adduct formation involving C~,G~BU"~-~ and Me,NH3-Z (x z = 0-3) was found to be dependent on x 2 and T with acid affinity towards base decreasing in the order GaCl > C12GaBu> CIGaBuz> GaBu3 and base affinity for acid in the order NH3> MeNH2> Me2NH> Me,N.The results were explained by steric and/or inductive effects in the acids and steric back-strair eflccts in the bases.279 Ethylgalliumtetracarbonyliron is obtained as a dimeric tetrahydrofuranate when ethylgallium di-iodide is stirred with sodium tetracarbonylferrate(2-) in THF B2 [EtGaI2I2+ Na2Fe(CO) + [(THF)EtGaFe(CO)4]2 -B2(Et)GaFe(CO)4 B = py; B2 = bipy or TMED The bipyridyl complex contains tetrahedrally co-ordinated gallium and trigonal- bipyramidal iron.280 Tris(trimethylsily1s)of all Group IIIB metals are known now that tris(trimethy1- sily1)gallium has been prepared via the sequenceZ8l THF GaC1 + 6Li + 3Me3SiC1 -Ga(SiMe,),.THF+ 6LiCI -10°C 1sublimation in UQCUO Ga(SiMe3) 274 J. R. Durig K. K. Chatterjee Y. S. Li M. Jalilian A.J. Zozulin and J. D. Odom J. Chem. Phys. 1980,73,21. 275 J. D. Odom K. K. Chatterjee and J. R. Durig J. Phys. Chem. 1980,84 1843. 276 0.T. Beachley and R. G. Simmons Inorg. Chem. 1980,19,783. 277 H. Schafer 2.Anorg. Allg. Chem. 1980,461 29. 278 G. Meyer and E. Schwan 2. Anorg. AIIg. Chem. 1980,468 82. 279 R. A. Kovar J. A. Johnson and R. L. Cook Inorg. Chem. 1980,19 3264. 280 T. H. Cymbaluk and R. D. Ernst Inorg. Chem. 1980 19,2381. "' L. Rosch and H. Neumann Angew. Chem. Int. Ed. Engl. 1980,19 55. 60 F. A. Hart A. G. Massey P. G. Harrison and J. H. Holloway Trimethylsilylmethyl derivatives of gallium have also been synthesized GaC13+ Me3SiCH2MgX -+ (Me3SiCH2)3Ga (ref. 282) Et2GaCH21+ Me3SiMgC1 -+ Et2GaCH2SiMe3 (ref. 283) Ga(CH2SiMe3)3+ nGaX3 -+ Ga(CH2SiMe3)3-,X (X = C1 or Br) (ref.282) Tris(trimethylsiIy1methyl)gallium reacts with alkali-metal hydrides in benzene or dimethoxyethane to give products such as [KGa(CH2SiMe3),I2 and [NaGa(CH2SiMe3),I3 which appear to have been formed via reductive elimination. Bent Ga-Ga double bonds are considered to be present in these 01igomers.~~~ Sodium tetrahydrogallate reacts with a-olefins in THF to give high yields of NaGa(CH2CH2R)4(R= Bu C5Hll or C6H13); a mixture of (C5H5),TiCl and NaAlEt acts as an effective catalyst for the system.28s The dimethyl(N,N-dimethylethanolamino)(1-pyrazolyl)gallato ligand (85) is ter- dentate in the complex (~~)Mo(CO),(~~-CH,SM~);~~~ its 3,5-dimethyl analogue (86) is similarly terdentate in (86)Ni(N2CsH7)2GaMe2,287 (86)M(C7H,)(CO) (M = Mo or W),288 (86)NiN0,289 and (86)Fe(N0)2.290 (85) R=H Me,Ga/ (86) R=Me \ 0 NMe, \I Trimethylgallium and trimethylindium react with N,N‘-dimethylacetylhydrazine (87) and N,N’,N”-trimethylacetimidohydrazine (88) to form monomeric heterocycles wich immediately add a further trimethylmetal molecule to one of the nitrogen atoms (89).291 Me-..,XcCMe I MeC-N-NMe MeC-N-NMe MeIM\,,fie II I I II Me I /\ 0 Me H MeN H Me,M Me (87) (88) (89) X = 0 or NMe Cleavage of N-trimethylsilyl groups by gallium halides has been used to prepare amido-dihalogenogallanes (90) and thioureidodichlorogallanes(91).292 OR OR I’ II / CF3-N-N ’ +GaX3 -+ Me3SiX+CF3-C-N \ SiMe3 ‘GaX2 (90) 282 0.T. Beachley and R.G. Simmons Znorg. Chem. 1980 19 1021. 283 K.-D. Fuhrmann and F. Huber Z. Nuturforsch. Teil B 1980,35 1376. 284 0.T.Beachley and R. G. Simmons Inorg. Chem. 1980,19 3042. 285 V.V.Gavrilenko V. S. Kolesov and L. I. Zakharkin Zzv. Akad. Nauk SSSR Ser. Khim. 1980 960. 286 K. S.Chong S. J. Rettig A. Storr and J. Trotter Can. J. Chem. 1980,58 1080. 287 K.S.Chong S. J. Rettig A. Storr and J. Trotter Can. J. Chem. 1980,58 1091. 288 K.S.Chong and A. Storr Can. J. Chem. 1980,58 2278. 289 K.S. Chong S. J. Rettig A. Storr and J. Trotter Can. J. Chem. 1979,57 3107. 290 k.S.Chong S. J. Rettig A. Storr and J. Trotter Can. J. Chem. 1979,57 3113. 291 F.Gerstner H.-D. Hausen and J. Weidlein J. Orgunomet. Chem. 1980 197 135. 292 A. Meller W. Maringgele and R. Oesterle Monatsh.Chem. 1980 111 1087. The Typical Elements S R S R II / ' Et2N-C-N / +GaC13 -B Et2N-C-N \ SiMe3 \ GaC12 (91) Two configurational isomers (92a and b) of bis(dimethylgal1ium)-N,N'-dimethyl-dithio-oxamide have been prepared using the reaction shown. The two fused five- membered rings in both isomers are almost planar.293 Me S Me.. ,N-Y/S,~~.,M~ Me ... ,N-c's -Me I I. + I Ga 2GaMe + (HNC-I) -Me I Me Me'Ga\N/ctS' Me 'Me Me Me (92a) (92b) 4 Indium The complex structures of a-InC1 and P-InCI can be understood by examining the effects of the lone pair on the indium atom.294 Details for the electrochemical syntheses of indium trihalide adducts incorporating acetonitrile pyridine 2,2'- bipyridyl and triphenylphosphine ligands are now available.295 If RX is added to the electrochemical cells RInX2 derivatives are formed; addition of R:NX produces R:N[RInX3].296 Although the nuclear spin of "'In is and gives rise to broad lines the chemical shifts in "'In n.m.r.due to ligand change or changes in co-ordination number are sufficiently large to minimize this factor (unless species of low symmetry are involved when no signal is observed). Using "'In n.m.r. equilibria among mixed tetrahalogenoindates were studied and for example twelve lines were observed for the system InC14- + InBr4-+ In14-.297 Oxidation of InIr2X6*- ions with a halogen Y2 has been shown to yield complexes InX3Y-; the InX2Y2- anions are formed from In'X2-+ Y2. Benzene was used as solvent so that the products precipitated out before any redistribution reactions could occur.298 The first mixed-valency ternary indium (1,111) chloride C~~1n'(In~~'Cl~) has been prepared either from a 2 1 1CsC1-InC1-hC13 mixture or by reducing Cs31n2C19 with metallic indium.It is a colourless solid which undergoes disproportionation 3111'+21n0+ In"' when exposed to moist air.299 Discrete tetrabromo-trans-diaquoindate(I11)ions occur in KInBr4.2H20; In-0 = 2.261 A In-Br = 2.606,2.621 Hydrogen-bonding reduces the sym- metry of the [InCI5H20I2- ion found in K21nC15.H20 to C20.301 Raman spectroscopy was used to identify the vapour species above heated indium halides. Above the monohalides are the gaseous InX molecules whilst dimer- monomer equilibria occur in trihalide vapours.Complexes in equilibrium with their 293 T. Halder H.-D. Hausen and J. Weilden 2. Naturforsch. Ted B 1980 35 773. 294 C. P. J. M. van der Vorst and W. J. A. Maaskant J. Solid State Chem. 1980,34 301. 295 J. J. Habeeb F. F. Said and D. G. Tuck J. Chem. SOC. Dalton Trans. 1980 1161. 296 J. J. Habeeb F. F. Said and D. G. Tuck J. Organomet. Chem. 1980,190 325. 29' B. R. McGarvey C. 0.Trudell D. G. Tuck and L. Victoriano Znorg. Chem. 1980 19 3432. 298 J. E. Drake J. L. Hencher L. N. Khasrou D. G. Tuck and L. Victoriano Znorg. Chem. 1980,19,34. 299 G. Meyer Naturwissenschaften 1980,67 143. 300 J. P. Wignacourt G. Mairesse and P. Barbier Acta Crystallogr. 1980 B36 669. 301 J. P. Wignacourt A. Lorriaux-Rubbens P. Barbier G. Mairesse and F.Wallart Spectrochim. Acta Part A 1980,36,403. 62 F. A. Hart A. G. Massey P. G. Harrison and J. H. Holloway dissociation products are formed in the vapours over liquid InX2 and InA1X4:302 InInX4(g> $ InX(g)+InX3(g)+InzXdg) InAIXdg) $ InX(g) +AlX3(g) The blue CoIn2Cl8 complex is present in the vapour when solid CoCl2 is heated to 950-1 100 K with gaseous InCl,; increasing the temperature and/or decreasing the InCl pressure causes CoIn2C18(g) $ InC13(g)+CoInC15(g) Six oxygens from different SO groups octahedrally co-ordinate indium (In-0 = 2.125 A) in triammonium indium(Ir1) trisulphate (NH4)31n(S04)3. The In06 octahedra are linked by SO tetrahedra to form infinite chains along the c-axis; the NH4+ ions connect these chains together.304 Layers of [In(Se04)2.2H20]- ions occur parallel to the (100) plane in ammonium diselenatoindate tetrahydrate NH41n(Se04)2-4H20.The indium atom is octahedrally cc-ordinated to six oxygens the two oxygen atoms from the water molecules being trans to each other; two free water molecules and an ammonium ion are distributed between the layers.3o5 Both and tris(pentane-2,4-dionato)indium(111), the mono~linic~~~ orthorhombi~~~' In(a~ac)~, have been studied by X-ray crystallography. In the structure of pentaindium tetrasulphide In& there is a three-dimensional network of corner-sharing In2S3 tetrahedra with one of the indium atoms at the centre of a tetrahedron and the others at a common corner of the surrounding four tetrahedra. The co-ordination of indium is thus either 4111 or 1In and 3S.308 In both the thioindates Rb61n2S6 and Rb41n2S5 the (111~s~)~- group isoelectronic with the gas-phase molecule In2& is the basic unit.," (93) 111~s~~-(94) r1n2s51z4-Unexpectedly judging from the accepted ionic radius of In3' the indium is found to lie rigorously in the 4N plane of the porphyrin ring in the one-dimensional polymer methanesulphonato(5,lO,l5,20-tetraphe1iylphorphyrinato)indium(111).~~~ '02 P.L. Radloff and G. N. Papatheodorou J. Chem. Phys. 1980,72,992. 303 G. H. Kucera and G. N. Papatheodorou J. Phys. Chem. 1979,83,3213. '04 B. Jolibois G. Laplace F. Abraham and G. Nowogrocki Acta Crystallogr. 1980 B36 2517. 'OS E. A. Soldatov E. A. Kuzmin and V. V. Iiyukhin Zh. Strukt. Khim. 1979 20 1081.306 J. G. Rodriguez F. H. Cano and S. Garcia-Blanco Cryst. Struct. Commun. 1979,8 53. 307 G. J. Palenik and K. R. Dymock Acta Crystallogr. 1980 B36 2059. 308 T. Wadsten L. Arnberg and J.-E. Berg Acta Crystallogr. 1980 B36 2220. 'Q?. H.-J. Deiseroth 2.Naturforsch. Teil B 1980,35 953. 'l' P. Cocolios P. Fournari R. Guilard C. Lecomte J. Protas and J. C. Boubel J. Chem. Soc. Dalton Trans. 1980,2081. The Typical Elements The macrocyclic ligand in chloro-(5,10,15,20-tetraphenylphorphyrinato)indium(111) is non-planar being domed towards the indium atom which is itself 0.61 A above the mean plane of the four pyrrole nitrogen~.~~' Changing the chlorine atom for a methyl group forces the indium still further away fiom the nitrogen atoms until at 0.78 A it is the furthest ever observed for square-pyramidal metallo-porphyrin In bis-[ 2 -(dime thy1amino)me thylphenyl]chloroindium(~~~) the indium has dis tor- ted trigonal-bipyramidal co-ordination with an InC2Cl equatorial plane and apical In-N bonds (95).,13 H2 Trimethyl- and triethyl-indium react with alkali-metal hydrides to give MInR3H; on heating to 100 'C these complex hydrides decompose into MInR4.,14 5 Thallium The primary product formed between O2 and thallium atoms frozen in matrices of nitrogen and argon is the metal superoxide species T1+02-analogous to the superoxides of the alkali metals.Various secondary reaction products are formed by diffusive aggregation; these include the superoxide dimer Tl02-02TI (D2d) and a rhombic T102Tl species (D2h).Addition of thallium atoms to the latter yields a suboxide dimer (T120)2.315 Oxidation of thallium(1) to thallium(@ by aqueous acid peroxodisulphate solutions does not involve direct reaction between TI' and S2OS2-. A chain reaction occurs initiated by SOL-formed by thermal decomposition of peroxodisulphate ions.316 In the yellow a-modification of T12C13 there are nine independent types of thallium atom; three of these are surrounded octahedrally by six chlorine atoms (2.50- 2.65 A) and the other six have seven eight or nine neighbours at distances varying between 3.06 and 3.83 A. This agrees with its formulation as thallium(1) hexa- chlorothallate(~~~).~~' In T1C13.4H20 and TlBr3.4H20 thallium has a slightly distor- ted trigonal-bipyramidal co-ordination involving three halogens in the equatorial plane and two axial water A similar thallium co-ordination is found in the bis-(4-pyridinecarbonitrileN-oxide) complex of TlCl,; the axial ligands in this case are the oxygen atoms of the two N-oxide Distorted tetrahedral thallium co-ordination with ClTlCl angles of 106.9' and 114.8' occurs in KTIC14.320 Crystals of Na3T1C16.12Hz0 can be made by mixing 311 R.G. Ball K. M. Lee A. G. Marshall and J. Trotter Znorg. Chem. 1980 19 1463. 312 C. Lecomte J. Protas P. Cocolios and R. Guilard Acta Crystallogr. 1980 B36,2769. 313 M. Khan R. C. Steevensz D. G. Tuck J. G. Noltes and P. W. R. Corfield,Znorg. Chem. 1980,19,3407. 314 V. V. Gavrilenko V. S. Kolesov and L. I. Zakharkin Zh.Obshch. Khim. 1979 49 1845. 315 B. J. Kelsall and K. D. Carson J. Phys. Chem. 1980,84 951. 316 M. Kimura T. Akazome K. Takenaka and A. Kobayashi Bull. Chem. SOC.Jpn. 1980,53,1271. 317 R. Bohme J. Rath B. Grunwald and G. Thiele Z. Nuturforsch. TeilB 1980 35 1366. 318 J. Glaser Acta Chem. Scand. Sect. A 1979 33.789. 319 E.Gutierrez-Puebla A. Vegas and S. Garcia-Blanco Acta Crystallogr. 1980,B36,145. 320 J. Glaser Acta Chem. Scand. Sect. A 1980,34 75. F. A. Hart A. G. Massey P. G. Harrison and J. H. Holloway aqueous solutions of TlCl and NaCl in a C1 T1 ratio greater than six and evaporating the mixture at room temperature; six chlorines complete a slightly distorted octa- hedron about the thallium (average TI-Cl = 2.593 Slow evaporation of an aqueous mixture of TlBr3 and KBr (in a 1:3 ratio) gives only the tetrabromothallate KTlBr4.2H20 (TI-Br = 2.554 The gaseous T12S04 molecule has DZd Three types of thallium(II1) double selenates can be prepared M'Tl"'(Se04)2 (M = K Rb Cs Tl' or NH4) M'3Tl'1'(Se04)3 (M = Rb K,or Cs) and M'5Tl"'(Se04)4 (M = K or Tl').324 The kinetic results for the direct dissociation of potassium and thallium(1) cryp- tates show that they behave in a very similar manner which is pleasing as T1' is often used as a probe in biological systems.However in terms of rate constants and activation parameters the acid-catalysed dissociation process is significantly different for thallium and potassium 222-cryptates in water.325 In thallium(1) tetra-acetatothallate(rI1)chelated T1r''(MeC02)4- anions are linked together in an hexagonal array by seven-co-ordinate T1' cations (Tl-0 = 2.88-3.15 A) the lone pair showing non-stereoactivity.This is consistent with a model which predicts that T1' will form short bonds and have a low co-ordination number and a stereoactive lone pair when the counter-ion is a strong base but otherwise will form longer bonds and have a co-ordination number greater than six.326No Pd-TI bond occurs in the dinuclear carboxylates PdT1(02CR)5 (96).327 A thermal study of the complex oxalate Rb[Tl"'(C204)2(H20)2]~2H20 showed that dehydration occurs initially to be followed by redox decomposition of the T1"' salt to a T1' salt; finally a mixture of Rb2C03 and oxides of thallium is formed.328 The *"Tl n.m.r. spectra of eleven thallium(1) alkoxides in toluene are consistent with the predominance of the tetrameric species [TIOR] in solution.Although the 203 Tl-205Tl coupling constant was sensitive to the nature of the system under study there appeared to be no correlation between it and any properties of the alkyl group R.329 321 J. Glaser Acta Chem. Scand. Sect. A 1980,34 141. 322 J. Glaser Acta Chem. Scand. Sect. A 1980 34 157. 323 K. P. Petrov V. V. Ugarov and N. G. Rambidi Zh. Strukt. Khim. 1980,21,159. 324 J. Tudo and B. Jolibois J. Less-Common Metals 1980,70 25. 325 R. Gresser D. W. Boyd A. W. Albrecht-Gary and J. P. Schwing J. Am. Chem. Soc. 1980,102,651. 326 I. D.Brown and R. Faggiani Actu Crystallogr. 1980 B36 1802. 32' A.F.M. J. van der Ploeg G.van Koten and K. Vrieze Inorg. Chim. Actu 1980 38 253. 328 S.R.Sagi K. V. Rarnana and P. M.S. Rao J. Therm. Anal. 1980 18,291. 329 P.J. Burke R. W. Matthews and D. G. Gillies J Chem. Soc. Dalton Trans. 1980 1439. The Typical Elements 65 Diethyldithiocarbamatodiphenylthallium(II1)is monomeric with four-co-ordinate thallium and a CTlC angle of 148". On the other hand diphenyltropolonatothal-lium(II1) is dimeric and contains five-co-ordinate thallium with a CTlC angle of 163". From these structures and previous work it was conchded that there was no correlation between the CTlC angles and the co-ordination number of the thallium atom.330 The thallation of benzene and toluene can be achieved by a solution of T12O3in trichloroacetic acid. Unfortunately the scope of the reaction is limited since no thallation occurred with anisole thiophen nitrobenzene benzaldehyde or methyl benzoate; neither do benzene and toluene react when acetic chloroacetic or dichloroacetic acids are The reaction of cyclopentadienylthallium with several electrophilic olefins has been described C5H5Tl+ (CN)zC=C(CF3)2 -+ Tlt[CSH4C(CF3)2CH(CN)J These new derivatives were found to be useful for the synthesis of substituted cyclopentadienyls of metals such as iron manganese and copper 332 Tl'[C5H4C(CN)=C(CN)2]-+ CSHSFe(CO)zI+ C5HSFe[CSH4C(CN)=C(CN)~] Tl'[C5H4C(CF3)zCH(CN)z]-+ CSH5Fe(C0)21-+ C5H5Fe[CSH4C(CF3)zCH(CN)~] Di-~-chlorobis[bis-(2,3,5,6-tetrafluorophenyl)(triphenylphosphine 0xide)thal-1ium(111)] is dimeric with unsymmetrical chlorine bridges (TI-Cl = 2.541,2.936 A); the thallium has approximately trigonal-bipyramidal co-ordination in which the equatorial positions are occupied by two carbon atoms and the more tightly held chlorine.333 The acceptor properties of (ar~l)~TlX towards uncharged ligands decreases in the order C6F5 =r 4-HC6F4>2-HC6F4>C6Hs.334 Reaction of TIRzX TlX3 or TlX,- with LiR (R = C6Fs or C6C15) leads to anions of the type TlR4- TIRlZRz2- or TlR63- all of which can be isolated with bulky cations.335 Bis(trimethylsilylmethyl)chlorothallium(III)is dimeric with each four-co-ordinate thallium bonded unequally with two bridging chlorine atoms; the geometry about thallium is based on a trigonal bipyramid with one equatorial position vacant and both axial TI-C bonds slightly bent towards the vacant The ionic complex T1'{Hg[Ge(C6F5)3J3}-* 1SDME is formed when Hg[Ge(C6F5)3]2 is treated with metallic thallium in dirneth~xyethane.~~' 330 R.T. Griffin K. Henrick R. W. Matthews and M. McPartlin J. Chem. Sac. Dalton Trans. 1980 1550. 331 S.Uemura H. Mujoshi M. Wakasugi M. Okano 0.Itoh T. Izumi and K. Ichikawa Bull. Chem. Sac. Jpn. 1980 53 553. 332 M. B. Freeman and L. G. Sneddon Inorg. Chem. 1980,19 1125. 333 K.Henrick M. McPartlin R. W. Matthews G. B. Deacon and R. J. Phillips J. Organomet. Chem. 1980,193,13. 334 G. B. Deacon and R. J. Phillips J. Organomet. Chem. 1980 199 15. 335 R. Uson A. Laguna and J. A. Abad J. Organomet. Chem. 1980,194,265. 336 F.Brady K. Henrick R. W. Matthews and D. G.Gillies J. Organomet. Chem. 1980 193 21. 337 M.N.Bochkarev N. I. Gur'ev L. V. Pankratov and G. A. Razuvaev Inorg. Chim.Acta 1980,44,L59.

ISSN:0260-1818    

DOI:10.1039/IC9807700012

出版商:RSC    

年代:1980

数据来源: RSC

摘要:

F. A. Hart A. G. Massey P. G. Harrison and J. H. Holloway Part 111 Groups JV and V By P. G. Harrison 1 GroupIV Carbon Silicon and Germanium.-Unstable Intermediates. A value of 5.4(* 1)x lo3 has been determined for the equilibrium constant for the singlet $ triplet intercon- version of diphenylcarbene.' The associated free-energy difference is 5.1(*1) kcal mol-' at 25 "C. A variety of carbenes silylenes and germylenes have been the subject of ab initio calculations. The singlet state of dibromocarbene is 8 kcal mol-' lower than the corresponding triplet state.2 Energetics of the three isomers methylsilylene silylmethylene and silaethylene and their interconversion have been studied in detail. Singlet silylmethylene is calculated to be 69 kcal mol-' higher in energy than silaethylene with a barrier to the 1,2-hydrogen shift from singlet silaethylene to singlet methylsilylene of ca.40 kcal mol-'. In contrast the energy differences involved with silylmethylene and silaethylene are much less. Singlet methylsilylene is predicted to be 11.6 kcal mol-' lower in energy than singlet silaethylene with an energy barrier for the 1,2-hydrogen shift from singlet silyl- methylene to singlet silaethylene of 13 kcal mol-'. If however carbon and silicon d-orbital functions are included in the calculation the energy separation and barrier to the 1,2-hydrogen migration reduce to only 0.4 and 3 kcal mol-' respectively. Hence it would appear that singlet silylmethylene may not be a kinetically stable species relative to the double-bonded isomer.For the triplet species triplet methyl- silylene is more stable than triplet silaethylene by 19 kcal mol-' whereas triplet silylmethylene is predicted to Iie 7 kcal mol-' above triplet ~ilaethylene.~ The germylenes GeX2 (X = H F Me) all have singlet ground states with singlet-triplet energy gaps of 10 64 and 14 kcal mol-' respectively. The bond distances (rGeJ and angles (XGeX) of the singlet states were calculated to be 1.608 and 93" (X =H) 1.76 A and 97" (X = F) and 2.02 8 and 98" (X= Me).4 A simple general method for the synthesis of long-chain unsaturated carbenes (1)has been developed that involves base-initiated elimination from alkynyl vinyl triflates as shown in Scheme 1. The alkadienyl- and alkatetraenyl-idenecarbenes OS02CF3 I R,C=C-(CGC) -H 11 n = 1,2 iii 1 + [R2C=C-(C=C) t- R2C=(C=C)n =C J (1) Reagents i Bu'OK; ii Bu'OH; iii -CF,SO,-Scheme 1 ' K.B. Eisenthal N. J. Turro M. Aikawa J. A. Butcher C. DuPuy G. Hefferon W. Hetherington G. M. Korenowski and M. J. McAuliffe J. Am. Chem. SOC.,1980,102,6563. * C. W. Bauschlicher J. Am. Chem. SOC.,1980,102,5492. J. D.Goddard Y. Yoshioka and H. F. Schaeffer J. Am. Chem. SOC.,1980,102 7644. J. C.Barthelot B. S. Roch G.Trinquier and J. SatgC J. Am. Chem. SOC.,1980 102 4080. The Typical Elements are electrophilic most likely singlets and unencumbered showing little or no steric effects upon s~bstitution.~*~ Unstable silicon intermediates continue to arouse much attention. Photo- lytically induced ring contraction of (Me2Si)6 is the standard method of generating dimethylsilylene.Methylphsnylsilylene has been obtained by photolysis of Me3SiSiMePhSiMe3.7 Dimethylsilylene inserts efficiently into 0-H single bonds of alcohols to yield alkoxydimethylsilanes. Use of EtOD affords SiMe,(OEt)D. Insertion into both bonds occurs with water and deuterium oxide yielding tetramethyldisiloxane and [2H2]tetramethyldisiloxane respectively. The reaction with primary and secondary amines proceeds similarly with insertion into N-H bonds leading to aminodimethylsilanes.8 Sequential insertion into Si-H and Si-OR occurs with silanes and alkoxysilanes giving high yields of unsymmetrical di- tri- and tetra-silanes e.g. as shown in Scheme 2.9 Me2Si: Me3SiH -Me&H + Me7Si2H + Me9Si4H 28.5% 2 2 O/O 11O/O Mel%: Me,SiOEt -MeSSi20Et + Me7Si30Et + Me9Si40Et 10O/O 25 O/O 32'/o ,-SiLSiMe, Me I 22.5 '/o 27.5 '/o 34% Scheme 2 Both thermally and photolytically generated dimethylsilylene deoxygenates cyclo-octatetraene oxide.The favoured mechanism for the reaction involves the formation of an intermediate ylide (2) but whether this ylide actually extrudes dimethylsilanone [route (a)]or simply acts as a 'silanone transfer agent' [route (b)] could not be conclusively determined from the data (Scheme 3).1° Difluorosilylene has been shown to be much more reactive in the gas phase than previously thought. The major product of reaction with butadiene in the gas phase P. J. Stang and M. Ladika J. Am. Chem.SOC.,1980 102 5406. P.J. Stang and T. E. Fisk J. Am. Chem. SOC.,1980 102 6813. ' M. Ishikawa K. I. Nakagawa R. Enokida and M. Kumada J. Organomet. Chem. 1980,201,151. T.-Y. Y. Gu and W. P. Weber J. Organomet. Chem. 1980,184,?. T.-Y. Y.Gu and W. P. Weber J. Organomet. Chem. 1980,195,29. lo W.F.Goure and T. J. Barton J. Organomet. Chem. 1980,199,33. F. A. Hart A. G. Massey P. G. Harrison and J. H. Holloway %;.' + O=SiMe 0 Me,Si' 'SiMe, I I n V t Me-ii-Me v 31 MP Scheme 3 is l,l-difluorosilacyclopent-3-ene(3) which together with a small amount of 1,1,2,2-tetrafluoro-l,2-disilacyclohex-4-ene (4)is formed via a siliran intermedi- ate." Similar intermediates have been postulated in the reaction of difluorosilylene SiF, n Si CaiF /\ FF (4) with substituted ethylenes where all major products (polymers disilacyclobutanes disilacyclohexanes and open-chain compounds) have been characterized by n.m.r.Polymer is always formed in highest yield but the relative proportions of the other products vary significantly with the substituent. Again an excited siliran intermedi- ate is proposed which either ring opens or relaxes to its ground state followed in either case by further reaction as shown in Scheme 4.'* The gas-phase reaction of difluorosilylene with halogen-substituted ethylenes such as cis-and trans-difluoroethylene vinyl chloride and vinyl fluoride yields only compounds formed l1 T.-L. Hwang and C.-S. Liu J. Am. Chem. Soc. 1980 102,385. l2 W. F.Reynolds J.C. Thompson and A. P.G. Wright Can. J. Chem. 1980 58,419,425,436. The Typical Elements SiF, cSiF < LSiF2 SiF + \= i, SiF SiF / SiF polymer SiF2-SiF, I/ SIF CH2=CH-CH2-SiF2-SiF2-CH2CHCH3 Scheme 4 from insertion of monomeric silylene into the carbon-halogen bonds e.g. Scheme 5. In the gas phase therefore difluorosilylene reacts rather simply in a carbene-like manner with initial attack of the silylene at the C=C double bond followed by rearrangement whenever possible. Otherwise polymerization occurs. Reactions H SiF3 H H \/ cis-or trans-CHF=CHF + SiF2 -+ \/ /c=c\H + /c=c\ SiF3 H F (64%) (36%) Scheme 5 under co-condensation conditions are much more ~omplex.'~ Bis(trimethylsily1)-silylene (Me2Si)*Si generated in the gas phase by the flow pyrolysis of tris(tri-methylsily1)silyl methoxide or chloride rearranges to afford a 60% yield of 1,1,4,4-te trame th yl- 1,2,4 -trisilacyclopen tane (5) by a rat her complex process.l3 T.-L. Hwang Y.-M. Pai and C.-S.Liu J. Am. Chem. SOC.,1980,102,7519. l4 Y. S.Chen B. H. Cohen and P. P. Gaspar J. Organornet. Chern. 1980,195 C1. F. A. Hart A. G.Massey P. G. Harrison and J. H. Holloway Several new routes to sila-olefins (silenes) have been developed although both vibrational spectra (on an argon matrix)15 and structural parameters (gas phase by electron diffraction)16 have been obtained for 1,l-dimethylsilaethylenegenerated by the original method of silacyclobutane pyrolysis. The value obtained for the silicon-carbon double bond distances 1.83(4)A is rather longer than those predic- ted by ab initio calculations (mostly for silaethylene) which vary in the range 1.63-1.75A.Contrary to previous opinion disproportionation of silyl radicals to sila-olefins is an important process competitive with radical recombination in both gas and liquid phases.17-19 The sila-olefins may be trapped by using (deuteriated) alcohols [e.g.,equation (l)]. Me3COD 2Me3Si. -D Me3SiH + CH2=SiMe2 --+ Me3COSiMe2(CH2D) (1) Trimethylsilyl- and trimethylgermyl-diazomethanes are quantitative silene and germene precursors.20 Thus thermolysis or pyrolysis of bis(trimethy1-sily1)diazomethane yields initially the carbene (6) which rearranges to the silene (7). This species may then be trapped by reagents such as methanol benzaldehyde N2 Me I1 / Me3Si-C-SiMe3 -+ [Me3Si-C-SiMe3] -+ Me2Si=C \ (6) SiMe3 (7) Scheme 6 2,5-dimethylbuta-l,3-diene, or deuterium oxide or in their absence dimerizes as shown in Scheme 6.Bis(trimethylgermy1)diazomethane similarly affords the analogous germene (8). Thermolysis of the mixed diazomethane (Me3Si)-Me / Me2Ge=C \ GeMe3 (8) (Me3Ge)CN2 affords only the silene but photolysis yields products arising from both silene and germene formation in a 4 1 ratio. Thermolysis of (Me3Si),CSiPh2F proceeds with loss of Me3SiF to give a mixture of three products i.e. the diastereoisomeric forms of l-dimethylsila-2-trimethylsilyl-3-(methylphenylsila~in-dane and 1,3-bis(dimethylsila)-2(dimethylphenylsilyl)indane.All three are isomers of the sila-olefin (Me3Si)2C=SiPh2 (9) and their formation is suggested to arise by l5 L.E. Gusel’nikov V. V. Volkova V. G. Avakyan and N. S. Nametkin J. Organomer. Chem. 1980 201 137. ‘‘ P. G. Mahaffy R. Gutowsky and L. K. Montgomery J. Am. Chem. SOC., 1980,102,2854. ” S. K. Tokach and R. D. Koob J. Am. Chem. SOC.,1980,102,376. B. J. Cornett K. Y. Choo and P. P. Gaspar J. Am. Chem. SOC.,1980,102 377. l9 L. Gammie I. Safank 0.P. Strausz R. Roberge and C. Sandorfy J. Am. Chem. SOC., 1980,102,378. *’ T. J. Barton and S. K. Hoekman J. Am. Chem. SOC., 1980 102 1584. The Typical Elements (Me3Si)3CSiPh2F 1-Me,SiF (Me2PhSi)2C=SiMe2$ (Me3Si)2C=SiPh~$ (Me3Si)(Ph2MeSi)C=SiMe2 (9) 11 (Me3Si)(PhMe2Si)C=SiMePh Scheme 7 the initial generation of (9) followed by the rapid establishment of the equilibrium shown in Scheme 7.The observed products of the equilibrium are formed by internal cyclization reactions involving the addition of aryl C-H bonds across the Si=C double bonds.” Halosilanes of the type [(Me,Si),C]SiR,X (R=Me or Ph; X = F C1 Br or I) react in boiling 2 M-MeONa-MeOH yielding products of the type (Me2Si),CHSiR,OMe also involving an intermediate sila-olefin. In this case it is suggested that the reaction proceeds via an elimination analogous to the E2 eliminations of alkyl halides involving synchronous attack of methoxide ion at a trimethylsilyl group liberation of halide X- and the formation of (Me3Si)2C=SiR2 species.22 Germenes (10)are formed by the reaction of germylenes GeX2 (X =Phz PhC1 or F2),with diazo compounds such as phenyldiazomethane and ethyl diazoacetate (Scheme 8).With added copper powder the germene is formed directly by the + + N2 N2 H H I +I X2Ge + CH-R -+ X2Ge-C-H %XzGe-6’ X,Ge=C / R \R I Scheme 8 interaction of the germylene and the liberated carbene. In the absence of trapping agents the germenes (10) polymerize but with methanol form the addition products Ph2Ge(OMe)CHzR in ca. 10% yield and undergo pseudo-Wittig reactions with aldehyde^.'^ Silabenzene (11;R =H) and silatoluene (11;R = Me) have both been generated by retro-ene cleavage reactions. Silabenzene may also be generated by ester pyrolysis (Scheme 9). The two sila-arenes are stable in argon matrices at very low temperatures (10-23 K) and 0J+OJfiH / Si t~ Si Si H I H’ I R’LU R 03 6 C; (11) Me Reagents i A -propene; ii A -MeCO,H.Scheme 9 C. Eaborn D. A. R. Happer P. B. Hitchcock S. P. Hopper K. D. Safa S. S. Washburne and D. R.M. Walton J. Organornet. Chem. 1980,186,309. 22 C. Eaborn D. A. R.Happer and K. D. Safa J. Organomet Chem. 1980,191,355. 23 P.Riviere A. Castel and J. SatgC J. Am. Chem. SOC.,1980,102 5413. F. A. Hart A. G.Massey P. G. Harrison and J. H. Holloway U.V.and vibrational data have been recorded. The U.V. spectrum of silabenzene is as expected for a T-perturbed benzene with three bands at 212,272 and 320 nm. The photoelectron spectrum of silabenzene has also been rec~rded.~~.~’ Molecular O=Si=S26 and 0=SiFZ2’ have both been isolated in argon matrices.The former from the reaction of SiS with atomic oxygen generated by microwave excitation is the first compound with a Si=S double bond (bond order 1.9 from force-constant data). The latter is produced by the reaction of SiO with fluorine and is planar exhibiting the expected six fundamentals in the infrared. Ab initio calculations suggest that the two most stable forms of the ‘silylenoid’ SiHzLiF are the ion-pair SiH2Li’F- and the H2Si=FLi complex.28 Molecular Compounds. Ab initio STO-3G calculations predict that dicyanoketen is 62.8 kcal mol-* lower in energy than its isomer di~yano-oxiran.~~ Both dicyanoketen3’ and di~yanothioketen~l may be generated in the gas phase in which they are stable at low pressures.Slow warming of the quinone (12) to 60°C in 0 vacuo yields dicyanoketen [equation (2)]. Whereas pyrolysis of (4-0~0-13 dithietan-2-y1idene)malononitrile (13) at 40 “C and 0.05 mbar affords the sulphur analogue which may be continuously generated in this way over a prolonged period in a flow system. NC Ncxs>o * ‘c=c=s + co2 NC S /NC (13) Pyrolysis of 1,2,3-selenadiazole in the gas phase at 720 K gives selenoketen CHz=C=Se.32 The 2 1 addition product of sulphur trioxide to dicyane has the planar bicyclic structure (14) which has CZh~yrnmetry.~~ HC(SO,F), a colourless evil-smelling low-melting crystalline solid has a planar [CS,] skeleton and is B. Solouki P. Rosmus H. Bock and G. Maier Angew.Chem. Znt. Ed. Engl. 1980 19 51; G.Maier G.Mihm and H. P. Reisenauer Angew. Chem. Znt. Ed. Engl. 1980 19 52. ” C. L. Kreil 0.L. Chapman G. T. Burns and T. J. Barton J. Am. Chem. SOC.,1980,102 841. 26 H. Schnijckel Angew. Chem. Znt. Ed. Engl. 1980 19 323. ’’ H.Schnockel J. Mol. Struct. 1980,65 115. ’’ T.Clark and P. von R. Schleyer J. Organomet. Chem. 1980,191 347. 29 J. B. Moffat J. Mol. Struct. 1980,62 213. 30 A. Hotzel R. Neidlein R. Schulz and A. Schweig Angew. Chem. Znt. Ed. Engl. 1980 19 739. 31 R.Schulz and A. Schweig Angew. Chem. Znt. Ed. Engl. 1980,19,740. 32 H.Bock S. Aygen P. Rosmus and B. Solouki Chem. Ber. 1980 113 3187. 33 A.Gieren U. Riemann and B. Dederer 2.Anorg. Allg. Chem. 1980 468 15. The Typical Elements extremely acidic.Its acid strength lies between those of fluorosulphuric and nitric acids and is probably due to mesomeric distribution of the negative charge of the C(SO,F),-anion. Combination of the compound with water is very ex other mi^.^^ The perfluorinated cyclic disulphone (15) results from the oxidation of the corresponding cyclic disulphide with CrO,-HNO,. The four-membered ring of (15) is planar with the fluorine and oxygen atoms in a plane orthogonal to each other and the ring plane. This method fails for the analogous perchlorinated disulphide (16). However the perchlorinated disulphone (17) can be obtained by initially S CI O*S4" c1 c1 O*SQ0 c1 \/\/ \/\/ c1,c/\CCI /c\/c\ cc \/ CI s CI c1 /\/\c1 S o//s,'0 (16) (18) Reagents i KMnO, HOAc; ii CrO, HNO oxidizing the disulphide to (18)using KMn04-HOAc followed by treatment with Cr03-HN03.Above 120 "C (17)loses tetra~hloroethylene.~~ The reaction of perfluoroisobutene with thiazyl fluoride in the presence of CsF yields (19). With thiazyl fluoride NSF2C(CF3) is obtained which isomerizes above CsF. 130"C 2NSF +2(CF3)2C=CF2 ____* 2{NES-C(CF,)3} 4 (CF3)3C-N=S=N-S-C(CF3)3 (19) 110 "C to (CF3)3CNSF2 (Scheme 10). In contrast to (CF3),NSF, NSF2C(CF3) is a Lewis acid and forms the 1:1adducts (CF3)3CSF2N-MF5 (M =As or Sb). In 50% aqueous KOH (CF,),NSF hydrolyses to the primary amine (CF3)3CNH2.36 34 G. Kloter H. Pritzkow and K. Seppelt Angew. Chem. Znt. Ed. Engl. 1980 19 942. "R. Seelinger and W. Sundermeyer Angew. Chern. Int. Ed.Engl. 1980 19,203. 36 A. Waterfield W. Bludssus R. Mews and 0.Glernser Z. Anorg. Allg. Chern. 1980 464 268. F. A. Hart A. G. Massey P. G. Harrison and J. H. Holloway Sublimation in U~CUOthrough a Vycor tube heated to 585°C transforms tetrafluorodicarboxylic anhydride into perfluorocyclopentadienone (20).This is stable in the pure form at -196 OC,or as a solution at somewhat higher temperatures and can be kept for several hours in a gas storage bulb at low pressure. At room temperature (20) dimerizes to give a single isomer independent of the phase -co (vapour neat liquid solution in solvents ranging widely in polarity). The dimer appears to be the exo-isomer (21),the bridging carbonyl of which readily hydrates to afford (22).Photolysis of (20)at 25378 in the vapour phase smoothly yields perfluorocyclo-octatetraene (23).37 Electron-diff raction data have been reported for several compounds including 1,1,1,2-tetrafl~oroethane,~~ 1,l-difl~oroethane,~' bromoacetyl trifl~oroethane,~~ chloride and bromide;l chloroacetyl ~hloride,~' carbonyl cyanide,43 carbonyl seleno- and thio-carbonyl difl~oride,~' thiocarbonyl and trifluoromethylperoxyl 37 M.W. Grayson W. D. Saunders and D. M.Lemas J. Am. Chem. Soc. 1980,102,414. 38 G. N. D. Al-Ajdah B. Beagley and M. 0.Jones J. Mol. Struct. 1980,65 271. 39 V. Mom P. A. G. Huisman F. C. Mijhoff and G. H. Renes J. Mol. Strucf.,1980,62,95. 40 B. Beagley M. 0.Jones and N. Houldsworth JMol. Struct. 1980,62 105. 41 0.Steinnes Q. Shen and K. Hagen J.Mol. Struct.1980,66 181. 42 0.Steinnes Q. Shen and K. Hagen J. Mol. Struct. 1980,64 217. 43 V. Typke M. Dakkouri and F. Schlumerger J. Mol. Struct. 1980,62 111. 44 M. Nakata K. Kohara T. Fukuyama K. Kuchitsu and C. J. Wiikins J.Mol. Strucf. 1980,68 271. 45 D. Christen H. Oberhammer W. Zeil A. Haas and A. Darmode J. Mol. Struct. 1980 66 203. "J. R. Durig Y. S. Li and D. D. Desmarteau J. Mol. Struct. 1980.68 81. The Typical Elements 75 Photolysis of solutions of iso- and n-pentasilane in 2,3-dimethylbutane at room temperature causes decomposition to higher and lower silanes. The main reactions in both cases involve the formation of disilane and branched octasilanes or trisilane and branched heptasilanes (uit Scheme 1l).47 Photolysis of linear polysilanes such SiH3 SiH3 i1 Si2H6 + H3Si-SiH-Si-SiH2-SiH3 1 51h3 2H3Si-SiH-SiH2-SiH3 SiH3 51h3 1 Si3H8 + H3Si-SiH2-Si-SiK2-SiH3 1 51h3 Si2H6 + H3Si-SiH2-SiH2-SiH-SiH2-SiH2-SiH3 1 51h3 2n-SiSH12 \Si3Hg + H3Si-SiH2-Si-SiH2-SiH2-SiH3 1 51h3 Scheme 11 as SisH8 n- and iso-Si4Hl0 and n-Si5H12 in the presence of acetone in 2,3-dimethylbutene leads to the formation of new mono- and poly-isopropoxysilanes [e.g.equations (3) and (4)].48 Acid hydrolysis of the isopropoxysilanes affords the corresponding bis(silany1) ethers. /T Me2CHOSiH(SiH3)2 Si3Hs + Me2C0 (3) Me2CHOSiH2SiH2SiH3 (SiH3)3SiH + Me2C0 -+ (SiH3)3SiOCHMe2 (4) The claim that bis-(o-pheny1enedioxy)silane (cf. last year’s Annual Report) is planar in the crystalline phase has been criticized.Unit-cell dimensions for the material were suspiciously similar to those of catechol bringing into doubt the chemical identity of the crystals (p-d)~ Multiple bonding in the Si-0 bonds of H3COSiH3 H3SiOSiH3 and H3SiOOSiH3 seems to be only of minor importance..The ionic character of the bond is also much higher than estimates from electronegativity arguments.” The structure of dodeca(phenylsi1asesqui-oxane) (PhSi)12018 obtained in small quantities from attempted recrystallization of [PhSiF(NMe)] from acetone has a SI2Ol8core comprising four ten-mem6ered and four eight-membered fused silicon-oxygen rings with approximate DZd 47 F. Feher and I. Fischer 2.Anorg. Allg. Chem. 1980,446 23. 48 F. Feher I. Fischer and D. Skrodzki 2.Anorg.Allg. Chem. 1980 466 29. 49 J. D. Dunitz Angew. Chem. Znt. Ed. Engl. 1980 19 1034; G. Nagorsen and H. Mayer Angew. Chem. Int. Ed. Engl. 1980,19 1034. 50 H. Oberhammer and J. E. Biggs J. Am. Chem. Soc. 1980,102,7241. 76 F. A. Hart A. G. Massey P. G. Harrison and J. H. Holloway ~ymmetry.'~ Gas-phase structures of silyl f~rmate~~ have and methyl~ilatrane~~ been studied by electron diffraction. The latter compound possesses C3"symmetry but the rather long Si-N distance (2.45(5)A} is indicative of essentially no dative N +Si bonding in the gas phase [cf. the solid phase where the N-Si bond distance is only 2.175(4)A]. The N-Si bond distances in the two silatranones (24) are even 0-,s1-0 rC'^'O 01 shorter [R = m-CF3C6H4,2.106(3) and R = p-FC6H4 2.129(3)A] again reflect- ing dative bonding interactions.In both compounds the Si-OC(=O) bond distance is very long (1.72A).54The reaction of tris(dimethy1amino)chlorosilane with aluminium(II1) chloride in dichloromethane affords the crystalline adduct (25)." Me2" 'Cl c( "'cl Examples of stable silirans and silirens have been synthesized. Hexamethylsiliran (26) is obtained by ring-closure of bis-(a-bromoisopropy1)dimethylsilaneusing magnesium in THF. (26) is highly reactive towards atmospheric oxygen and mois- ture. Decomposition occurs on heating in solution at 60-75°C resulting in the p2 Mg-THF Me&-/\CMe (26) extrusion of dimethylsilylene which can either add to the tetramethylethylene also produced in the decomposition regenerating the siliran or insert into the reactive siliran ring giving octamethyl-l,2-disilacyclobutane,or ~ligornerize.~~ Organoger-manium and organotin hydrides give ring-opened products most probably uia a radical mechanism as shown in Scheme 12.57 " W.Clegg G.M. Sheldrick and N. Vater. Acta Crystallogr. Sect. B 1980,36,3162. '* W.Belt S. Cradock and D. W. H. Rankin J. Mol. Struct. 1980,66,159. " Q.Shen and R. L. Hilderbrandt J. Mol. Struct. 1980,64,257. 54 L.Parkanyi P. Henesei and E. Popowski J. Organomet. Chem. 1980 197 275. '' A.H.Caolew M. C. Cushner and P. E. Riley J. Am. Chem. SOC. 1980,102 624. 56 D. Seyferth D. C. Annarelli S. C. Vick and D. P. Duncan J. Orgunomet. Chem. 1980,201 179. " D.Seyferth J. EscudiC M. L. Shannon and J.SatgC J. Organomet. Chem. 1980,198 C51. The TypicaL Elements 77 R3MH -B R3M. + H. Me2Si /\Me2C-CMe2 Me I Me + R3M* -+ R3M-Si-CMe2-CMe2 I M = Ge or Sn Me I R3MSi-CMe2CMe2H + R3M. I Me Scheme 12 Stable silirens (27) result from the photolysis of 1,l-dimesityl-1-ethynyldisilanes. Neither compound is affected by atmospheric oxygen water or alcohols at room RCGCSiSiMe R = Ph or SiMe3 temperature but the less sterically hindered siliren (28) reacts quantitatively with methanol within a few minutes to afford the ring-opened product (29) as shown in Scheme 13.’* Ph SiMe I Me Ph ,SiMe FH Scheme 13 1,3,2,4-Dithiadisiletanscontaining bulky organic substituents have been obtained by the copyrolysis of hexaorganodisilanes with elemental sulphur or sulphur hexafluoride or better by the reaction of 1,1,2,2-tetraorganodisilaneswith ele- mental sulphur (Scheme 14).Monomeric silathiones R2Si=S are not available by this route.59 ’* M.Ishikawa K. Nishimura H. Sugisawa and M. Kumada J. Organomet. Chem. 1980,194 147. ’’M.Weidenbruch A. Schafer and R. Rankers J. Organomet. Chem. 1980,195 171. 78 F. A. Hart A. G. Mussey P.G. Harrison and J. H. Holloway SF, R3SiSiR3 + R4Si + R2Si -3R2SiF2+ S \ \R,Si HR2SiSiR2H-+ R2SiH2+ R2Si ' Scheme 14 Permethylated cyclosilanes (SiMe2) (n = 4 or 5),can be obtained by methylation of the corresponding perchlorinated cyclosilanes using dimethylzinc.60 Decamethyl- cyclopentasilane reacts with elemental sulphur and selenium in decalin at 190"C (E to yield the six-membered-ring products ~yclo-(Me~Si)~E= S or Se).Dodecamethylcyclohexasilane is unreactive under the same conditions.61 Redistri- bution equilibria between five- six- and seven-membered permethylated cyclo- silanes (Me2Si) (n = 5 6 or 7) have been studied between 30 and 58°C. Enthalpies indicate that the stabilities of the rings increase in the order 5 < 7 < 6 but the differences are smaller than for the corresponding cycloalkanes probably because the silicon compounds are less affected by steric repulsions and angle strain.62 Two other cyclic silicon compounds containing silicon-metal bonds are worthy of note. Reaction of dicyclopentadienyltitanium dichloride with a,w-Li2Si4Ph8 yields (30)as a green air-stable solid which is unstable in chloroform solution and forms bis-solvates with THF acetone benzene and toluene.62 In octaphenyl-2,4,6,8- tetrasila-1,5-dimercuracyclo-octane(3l),linear Si-Hg-Si groups are linked by Ph CP ,CP .-Ph,Si /Ti SiPh 'Ph \ I Si -Si Ph2 Ph2 (30) Ph methylene bridges to give an eight-membered ring in a chair conformation.Bis(triphenylsily1)mercury also possesses a linear Crystals of trimethyl-silyl-lithium comprise discrete centrosymmetric hexameric [LiSiMe3I6 units with a " E. Hengge H. G. Schuster and W. Peter J. Organomet. Chern. 1980,186 C45. 61 M. Wojnowska W. Wojnowski and R. West J. Organomet. Chem. 1980,199 C1. 62 L. F. Brough and R. West J. Organomet. Chem. 1980 194 139. 63 M. S. Holtman and E.P. Schram J. Organomet. Chem. 1980,187,147. 64 W. H. Isley E. A. Sadurski T. F. Schaaf M. J. Albright T. J. Anderson M. D. Glick and J. P. Oliver J. Organomet. Chem. 1980 190,257. The Typical Elements core of lithium atoms surrounded by trimethylsilyl groups. The geometry of the [Li6] core can be described in terms of a six-membered ring in a highly folded chair conformation with an acute seat-to-back angle or alternatively as a distorted octahedron severely compressed along a three-fold axis so as to form a shortened ring antiprism. The trimethylsilyl groups lie above the six triangular side faces6’ Hexameric trimethysilyl-lithium reacts with tetramethylethylenediamine to yield the crystalline adduct (LiSiMe3)2(TMED)3. Both species react with simple aromatic and unsaturated compounds containing acidic protons to afford metalated products and trimethylsilane.With benzene (LiSiMe3)2(TMED)3 yields Me,PhSi and lithium hydride quantitatively and with toluene gives products arising from metalation of the side-chain.66 Reaction of trimethylsilyl-lithium with trimethyl borate in hexane produces the microcrystalline salt Li[B(SiMe,),].67 Treatment of dicyclopenta-dienylvanadium with trichlorosilane in benzene yields bis(trichlorosily1)dicyclo-pentadienylvanadium (32) presumably via an initial oxidative-addition step. Cp2W(H)SiC13is obtained similarly from Cp2WH2 and HSiCL6* The silyl-platinum complex {Pt(p-H)(siMe2Ph)[P(C6Hll)3]}2 decomposes in hexane at reflux temperature to afford a low (10%)yield of the diplatinum complex (33).The complex has Cisymmetry in which the platinum silicon and phosphorus Me/\ Me atoms are essentially coplanar and the two platinum atoms are asymmetrically bridged by the two dimethylsilyl groups.The hydrido ligands are located trans to the shorter Pt-Si bonds at a distance of 1.788 from the platinum atoms sites which are also only 1.72 8 from the silicon atoms and which therefore might be considered to bridge the longer Pt-Si The structure of cyclopentadienylgermane CpGeH, is essentially unchanged in the gas phase and in the crystal at 160K. In both phases the ring is planar and ”W. H. Isley T. F. Schaaf M. D. Glick and J. P. Oliver J. Am. Chem. Soc. 1980 102 3769. 66 R.Balasubramanian and J. P. Oliver J.Organornet. Chem. 1980 197 C7. 67 W. Biffar and H. Noth Angew. Chem. Int. Ed. Engl. 1980,19 58. A. M. Cardoso R. J. H. Clark and S. Moorhouse J. Organomet. Chem. 1980,186 241. 69 M. Auburn M. Ciriano J. A. K. Howard M. Murphy N. J. Pugh J. L. Spencer F. G. A. Stone and P. Woodward. J. Chem. SOC.,Dalton Trans. 1980 659. 80 F. A. Hart A. G. Massey P. G. Harrison and J. H. Holloway bound to the metal in a monohapto fa~hion.~' The crystal structure of the bis- benzene solvate of hexaphenyldigermane is rather unusual with each digermane molecule sandwiched between two arene molecules as in (34).71 The [Gel4 ring in cy~lo-(GePh~)~ is square and nearly planar.72 Dodecaphenylcyclohexagermane can be isolated from solutions either pure with either two or seven molecules of benzene of crystallization or with two moles of toluene of crystallization.The crystal structure of the (Ph2Ge)6*7C6H6 solvate contains hexagermane molecules in a flattened chair conf~rmation.~~ The reaction of bis(triphenylgermy1)cadmium with nickelocene in toluene at room temperature yields red crystals of (35) as a toluene FP YP Ph3Ge-Cd-Ni-Cd-Ni-Cd-GePh3 I I Ph Ph GePh3 GePh3 (34) (35) Ph Ph I Ph\ fiph L jGT /<Ph (CO),Fe -Fe(CO) (36) solvate containing a chain of seven metal atoms which is linear at each of the cadmium atoms. It is readily oxidized by air and highly soluble in aromatic and aliphatic hydrocarbon^.'^ The orange crystalline complex (36) results from the reaction of pentaphenylgermole with di-iron ennea~arbonyl.~~ Germyl-substituted enneacarbonylmethylidenetricobalt complexes (37; M = Co E = C L = GeR C13-,,) can be obtained by the reaction of the parent enneacarbonylmethyl- idenetricobalt with alkylchlorogermanes R,C13-,GeH (n = 2 or 3) in refluxing benzene under an atmosphere of carbon Similar methylidene silyl- idene and germylidene nonacarbonyltri-iridium clusters (37; M = Ir E-L = CMe CPh SiMe or GeMe) have been prepared by the reaction of NaIr(CO) with C13CR (R = Me or Ph) C13SiMe3 or C13GeMe.766 Silicates.Silicon-29 n.m.r. has been employed for structural studies of silicates both in aqueous media and also in the solid state. In solution essentially only 70 M. J. Barrow E. A. V. Ebsworth M. M. Harding and D. W.H. Rankin J. Chem. SOC.,Dalton Trans. 1980 603. 71 M. Drager and L. Ross 2.Anorg. Allg. Chem. 1980,469,115. 72 L.Ross and M. Drager J. Organomet. Chem. 1980 199 195. 73 M.Drager L. Ross and D. Simon Z. Anorg. Allg. Chem. 1980 466 145. 74 S. N. Titova V. T. Bychkov G. A. Domrachev G. A. Razuvaev Yu. T. Struchkov and L. N. Zakharov J. Organomet. Chem. 1980,187 167. 75 M. D. Curtis W. M. Butler and J. Scibelli J. Organomet. Chem. 1980 192 209. 76 (a) D. Seyferth and H. P. Withers J. Organomet. Chem. 1980 188 329; (b) W.Krupps and G. Schmidt J. Organomet. Chem. 1980 202 379. The Typical Elements orthosilicate ions are present at low concentrations and at higher concentrations the lack of fine structure indicates the presence of species in which all the silicon atoms are eq~ivalent.'~ In the solid the combination of high-speed magic-angle spinning with high-power proton decoupling and wherever possible polarization transfer has been used to achieve 1 p.p.m.resolution. Although ionization and cation influence are reflected in the 29Si chemical shifts the isotropic 29Si shifts are generally the same for both solids and solutions and depend mainly on the degree of condensation of the silicon-oxygen tetrahedra. In solid aluminosilicates addi- tional paramagnetic shifts appear which correlate well with the degree of substitution by al~miniurn.~~ Changes in the pH or concentration of sodium silicate solutions produce changes in the degree of polymerization of the silicate species. At high pH above ca.10 or 11depending on concentration equilibrium after such changes is rapidly estab- lished but at lower pH equilibrium is approached much more slo~ly.~~~~~ Concen-trated solutions of tetraethylammonium silicates with a molar ratio TEA Si of 22.8 1 contain mainly double three-ring silicate anions but in addition small amounts of mono- di- tri- tetra- cyclotetra-silicates double four-ring and other polycyclic silicate anions are also present. Crystallization at low temperature from such solutions yields the crystalline double three-ring complex [NEt4],[Si6OlS]-57H2O. Concentrated solutions with TEA Si ratios of 0.8-0.6 contain mainly double three- double four- double five- and probably double-six- ring silicate anions and yield a solid tetraethylammonium double four-ring silicate on crystallization.81 Crystalline silicic acids are strong solid acids with surface acidities ranging from Ho < -3 (H2SiI4Oz9*5.4H20) to Ho =r 2.3 (H2Si2O5) measured with Hammett indicators.These observed high surface acidities probably result from regular extended hydrogen-bonding systems including surface water molecules. Thermal dehydration only reduces the surface acidity to 2.3-3.3.82 Tin and Lead.-Biualent Compounds. Bis(pen tame thylcyclopentadienyl) tin(II) from tin(I1) chloride and lithium cyclopentadienide in THF has an angular sandwich structure (38) in which the angle subtended at tin by the two Csaxes is ca. 144". The tin-carbon distances are not all equal and fall in the range 2.567-2.776 8 with three short and two longer distances to each ring.Treatment of (38) with HBF4 affords the mono-pentamethylcyclopentadienyltin cation (39) (as the BF4-salt) in which the tin-carbon distances are reduced to 2.462 A.83In the air-stable complex (C~CO[P(O)(OE~),],}~S~ the tin atom is sandwiched between the two terdentate ligands as in (40). Spectroscopic data indicate the equivalence of all six P=O--Sn interactions and no tin lone-pair stereochemical 77 R. K. Harris J. Jones C. T. G. Knight and P. Pawson J. Mol. Sfruct. 1980,69 95. '' E.Lippmaa M. Magl A. Samoson G. Engelhardt and A. R. Grimmer J. Am. Chem. SOC.,1980 102,4889. L. S.Dent Glasser and E. E. Lachowski J. Chem. SOC.,Dalton Trans. 1980 393. L. S.Dent Glasser and E. E. Lachowski J.Chem. Soc. Dalton Trans. 1980 399. *' D. Hoebbel G. Garzo G. Engelhardt R. Ebert E. Lippmaa and M. Alla 2. Anorg. Allg. Chem. 1980,465,15. 13* H. J. Werner K. Beneke and G. Lagaly Z. Anorg. Allg. Chem. 1980,470 118. 83 P.Jutzi F. Kohl P. Hofmann C. Kriiger and Y. H. Tsay Chem. Ber. 1980,113,757. i34W.KIaui J. Organomet. Chem. 1980,184,49. F. A. Hart A. G. Massey P. G. Harrison and J. H. Holloway M Monomeric two-co-ordinate germanium tin and lead bis(ary1oxides) (41) have been prepared either by metathesis between the metal chloride and lithium aryloxide or by -pyrolysis of the bis[bis(trimethylsilyl)amido]-metal derivative. Crystal structures of the germanium and tin compounds exhibit low OM0 bond angles [Ge 92.0(4)” Sn 88.7(2)”] and short metal-oxygen distances [Ge 1.806(8)A Sn 2.008(4)A].’’ Group exchange between triorganotin hydroxides and dichlorostannylene(pentacarbony1)-chromium and -tungsten yields the dihy- droxystannylene-metal complexes (42) [equation (S)].The complexes are like tin(I1) hydroxide itself highly associated involatile sparingly soluble and decom- M(C0)&CI2*THF + 2R3SnOH -+ 2R3SnCl + (CO)SMSn(OH)2 (5) M = Cr W (42) pose without melting above ca. 1500C.86 The cubane-type [Sn4N30] cage compound (43) can be obtained by hydrolysis of the ‘open’ aminotin(I1) cage compound (44) 13’ B. Cetinkaya I. Gumrukcu M. F. Lappert J. L. Atwood R. D. Rogers and M. J. Zaworotko J. Am. Chem. SOC.,1980,102,2088. 86 W. W. DuMont and B. Neudert Angew. Chem. Int.Ed. Engl. 1980.19 553. The Typical Elements but not by hydrolysis of the closed cage (45). Conversion of (43) into (45) may be accomplished by treatment with trimethylaluminium (Scheme 15)." R In sharp contrast to tin(@ diethyldithiocarbamate and methyldithiocarbonate whose structures comprise isolated monomeric molecules with two chelating ligands attached to the metal tin(I1) 0,O'-diphenyldithiophosphate has the centrosym- metric dimeric structure (46). The dimer is held together by two-co-ordinate tin-sulphur bonds plus a long 7r-interaction between the tin atoms and one of the phenyl groups of the bridging dithiophosphate. The tin-centre-of-ring distance (3.655 A) is rather long being longer than the analogous distances found in the M.Veith and H. Lange Angew. Chem. Znt. Ed. Engl. 1980,19,401. F. A. Hart A. G. Massey P. G. Harrison and J. H. Holloway arene complexes C6H6Sn(A1C14)2*C6H6 and C6H6SnC1(A1C14) which range from 2.74 to 2.90w.88Lead has distorted octahedral co-ordination in the two dithio- carbamate compounds Pb(S2CNR2)2 (R = Me or Pri) built up from two un-symmetrically chelating ligands and two further longer intermolecular Pb- -S inter-actions as in (47).89.90 Quadrivafent Compounds. Electron diffraction data have confirmed the planarity of the [NSn3] skeleton of tris(trimethylstannyl)amine (Me3Sn)3N. The geometry about tin is tetrahedral [Sn-C = 2.166(5)& Sn-N = 2.038(3)& NSnC = 108.q1.5)0].91 Treatment of triphenylstannyl-lithium with carbon disulphide fol-lowed by an alkyl iodide yields the C-stannyldithioesters (48) as air-stable violet S 4 Ph,SnLi + CS2 +[Ph3SnCtI-] Li+ Ph,Sn-C \SR (48) R = Me,Et needle-shaped crystals.The ethyl derivative has a tetrahedral configuration at tin.92 In contrast ethyl trimethylplumbyldiazoacetate Me3PbC(N2)C02Et from the reaction of Me3PbN(SiMe3)2 and HC(N2)C02Et has the five-co-ordinate chain structure (49) in which the bridging ligand is fixed in the 2-(1)conformation with I ? Me Pb-Me Me’ I 0 Pb (49) J. L. Lefferts M. B. Hossain K. C. Molloy D. van der Helm and J. J. Zuckerman Angew. Chem. Int. Ed. Engl. 1980 19 309. 89 H. Iwasaki Actu Crystullogr.. Sect. B,1980 36 2138. go M. Ito and H. Iwasaki Acta Crystullogr. Sect. B 1980 36 443.L. L. Khaikin A. V. Belyakov G. S. Koptev A. V. Golubinskii and L. V. Vilkov J. Mol. Strut. 1980,66 191. 92 P. R. Bolz U. Kunze and W Winter Angew. Chem. Znt. Ed. Engl. 1980 19 220. The Typical Elements 85 an almost linear CNN group.93 Stannyl- and plumbyl-diazoalkanes are quite reac- tive and participate in [3 + 21 cycloaddition reactions with dimethyl acetylenedicar- boxylate which are accompanied by a spontaneous rearrangement of the initially formed isopyrazoles to the more stable pyrazoles (Scheme 16).94The diazoalkanes R MMe \ CN + Me0,CC-CC0,Me -* / Me,M MMe C0,Me C0,Me M = Sn or Pb R = Me3As or Me3Si Scheme 16 also undergo cleavage of the M-C(N2) bond [e.g. equations (6) and (7)]. The structures of both trimethyltin and trimethyl-lead azides have been determined (Me3Sn)2CN2+ Me3SiN3 + Me3Sn(Me3Si)CN2+ Me3SnN3 (6) Me3PbC(N2)C02Et + Me3GeN3 -+ Me3GeC(N2)C02Et+ Me3PbN3 (7) and are very similar with a-bridging azide groups symmetrically spanning planar [Me3M] groups to give zig-zag chains (50)with almost perfect trigonal-bipyramidal co-ordination at the N Me 0 Me I It I H2N-Sn-O-C-CH2-NH2-Sn Me/\ Me Ml ‘Me Five- and six-co-ordination is very common for tin-oxygen compounds.Crystals of trimethyltin glycinate comprise stacks of linearly polymeric molecules bridged axially at the trigonal-bipyramidally co-ordinated tin atoms through the amino nitrogen (51). The [SnC3] units are distinctly non-planar with the tin atom being displaced towards oxygen.Intra- and inter-chain hydrogen-bonding also OCCU~S.~’ The geometry at tin in tricyclohexyltin acetate is intermediate between distorted 93 M. Birkhahn E. Glozbach W. Massa and J. Lorberth J. Organomet. Chem. 1980,192 171. 94 M. Birkhahn R. Hohlfeld W. Massa R. Schmidt and J. Lorberth J. Organornet. Chem. 1980 192 47. 95 R. Allrnann R. Hohlfeld A. Waskowska and J. Lorberth J. Orgunomet. Chem. 1980,192 353. 96 R.Allrnann A. Waskowska R. Hohlfeld and J. Lorberth J. Orgunomel. Chem. 1980,198 155. ” B. Y. K. Ho K. C. Molloy J. J. Zuckerman. F. Reidinger and J. A. Zubieta J. Organomet. Chem. 1980,187,213. 86 F'. A. Hart A. G. Massey P. G. Harrison and J. H. Holloway tetrahedral and distorted trigonal-bipyramidal with additional intra- and inter- molecular interactions between the carbonyl oxygen atom and tin at 3.11 and 3.70 A respectively as in (52).'* Diorganotin N-methyliminodiacetates (53)exhibit 0 /-2.08 ALl ,,~.llA 0 R-SnLR 3.7Qi I ? II 0 CH2 I Me ,Me Me' H/O\ H (54) temperature-dependent 'H and 13C n.m.r.spectra interpreted on the basis of a dissociative-inversion mechanism. In water it appears that the six-co-ordinate species (54) is pre~ent.~' 1-Organostannatranes are associated into trimers with six-co-ordinate tin in apolar solvents although 1-0rganothiostannatranes remain monomeric in a wide range of 1,3-Dichloro-l,1,3,3-tetramethyldistannoxanehas the centrosymmetric dimeric structure (55) which is held in a two-dimensional polymeric lattice by anionic chloride bridges.The central [Snz02] ring is essentially planar and the geometry of both endo- and exo-tin atoms is similar each forming contacts to six neighbouring 98 S. Galogero P. Ganis V. Peruzzo and G. Tagliavini J. Organornet. Chem. 1980,191 381. 99 A. Tzschach K. Jurkschat A. Zschunke and C. Miigge J. Organornet. Chem. 1980,193,299. loo K. Jurkschat C. Mugge A. Tzschat A. Zschunke and G. W. Fischer 2.Anorg. Allg. Chem. 1980 463 123. '01 The Typical Elements atoms in a distorted arrangement midway between trigonal-bipyramidal and octa- hedral. The structure of the ethyl homologue was only partry solved owing to problems "of disorder. The major component (75%) is similar to the methyl com- pound but the second component is best described as a series of alternating [R4Sn202] and [R2SnX2] units in which two of the latter units are chelated by the [Sn,O,] four-membered ring.lo' [ClEt,SnOSnEt,Cl] reacts with 2,2'-bipyridyl yielding Et,SnCl,.bipyridyl and the tristannoxane adduct [ClEt2SnO-SnEt,OSnEt,Cl]*$bipy for which Mossbauer data indicate trigonal-bipyramidal co-ordination for all the tin atoms.lo2 The 3-thio-1,2,3-stannathiaphospholans(56) undergo configuration inversion at phosphorus via a five-co-ordinate transition state.lo3 The tin-lanthanide bonded compounds [(Me3SiCH2)3Sn]3Ln*DME (Ln = Pr or Nd) (57) have been obtained by the reaction of the tin hydride (Me3SiCH2)3SnH with the [(Me3Si)2N]3Ln compounds. Analogous reactions with triphenylgermane and triethyltin hydride are complicated by the cleavage of the co-ordinated DME to afford compounds of the type (R3M),Ln(OCH2CH20Me)3-n-DME (n = 1or 2 R3M = Ph3Ge or Et,Sn).The compounds (57) are weakly coloured and sensitive to oxygen and water. Reagents such as hydrogen chloride 1,2-dibromoethane benzoyl peroxide and silver trifluoroacetate cleave the Sn-Ln bond.lo4 Both organotin and organolead compounds react with [Pt(C2H4)(PPh3)2] to yield tin- and lead-platinum bonded complexes. Reaction with trimethyltin chloride yields ci~-[PtMe(SnMe~Cl)(PPh~)~]. Similar Sn-C insertion occurs mith Sn2Ph6 and a wide range of compounds R3SnX [X = Cl Br I NMe OAc N(CO)(CH,)2CO OMe or OSnPh,] but insertion into the Sn-N bond occurs with Me3Sn[N=C(CF3)2].'oS Initial insertion into the Pb-C bond of Pb2Ph6 occurs yielding cis-[PtPh(Pb,Ph,)(PPh,),l which subsequently decomposes in solution to cis-[PtPh(PbPh3)(PPh3),].The latter complex may also be obtained from tetraphenyl-lead. Trimethylphenyl-lead and triphenyl-lead bromide sipilarly afford products of insertion into Pb-Ph bonds but insertion into the Pb-Cl bond of trimethyl-lead chloride yields cis-and trans-[PtC1(PbMe3)(PPh3)2].106 The Pb-Fe bonded complex CpFe(CO),PbMe decomposes very readily and quantitatively according to equation (8).lo7 c~,Fe(Co)~PbMe~CpFe(CO)2Me + [PbMe2] -B $Pb + $Me4Pb (8) -* lo' P. G. Harrison M. J. Begley and K. C. Molloy J. Organomet. Chem. 1980,186 213. lo* S. L. Chadha P. G. Harrison and K. C. Molloy J. Organomet. Chem. 1980 202 247.lo3 C. Mugge H. Weichmann and Z. Zschunke J. Organomet. Chem. 1980,192,41. loo G. A. Razuvaev G. S. Kalinina and E. A. Federova J. Organomet. Chem. 1980,190,157. G. Butler C. Eaborn and A. Pidcock J. Organomet. Chem. 1980,185,367. lo' T. A. K. Al-Allaf G. Butler C. Eaborn and A. Pidcock J. Organomit. Chem. 1980,188 335. lo' K. H. Pannell J. Organornet. Chem. 1980,198 37. F. A. Hart A. G. Massey P. G. Harrison and J. H. Holloway 2 GroupV Nitrogen and Phosphorus.-Open-chain Compounds. An ab initio study of the electronic structure of the ground triplet and low-lying singlet states of formyl-nitrene HCON and formylphosphinidene HCOP has shown that the first two excited states ('A' and 'A")lie 36.8 and 39.0 kcal mol-' (in the case of HCON) and 26.8 and 27.9 kcal mol-' (in the case of HCOP) above the 3A"triplet state.In either case there is very little conjugation between the formyl group and the Group V atom."' N-(Amidosulphonyl)hydroxylamine,H2NS02NHOH is a colour- less crystalline solid that has been isolated pure in only 2% yield from the reaction of fluorosulphonylamine and hydroxylamine. It is readily soluble in water to give neutral so~utions.~~~ The model Wittig reaction [equation (9)] has been the subject of a detailed ab initio SCF calculation. The reaction takes place in an essentially concerted way. Ph3PCH2 + CH20 + Ph3PO + C2H4 (9) Starting from PH3CH2 + CH20 an oxaphosphetan ring is formed uia a very small energy barrier. This ring system corresponds to a local minimum on the energy hypersurface.The energy barrier for the dissociation of the ring into PH30 + C2H4 is ca. 25 kcal mol-' and the total reaction energy change is calculated to be ca. -45 to -50 kcal mol-'.llo An amino-oxophosphane stabilized by co-ordination to a transition metal (58) has been obtained by the route shown in Scheme 17. Both (59) Reagents i Cr(CO),; ii SO Scheme 17 (58) and (59) are pale-yellow crystalline air-sensitive solids the structures of which were confirmed by X-ray diffraction.lll N-Isocyaniminotriphenylphosphorane Ph3PNNC formed in the reaction shown in equation (lo) is surprisingly stable HCO-NHNH2 + 2PPh3 + -+ Ph3PNNC + 2HCC13 + 2NEt3HCI + PPh30 (10) 2CC14 + 2NEt3 (decomposition point 159-160 "C) and also forms complexes such as M(CO)5*CNNPPh3."2 The crystal structure of an isomer of Ph,PNNC lo' A.Mavridis and J. F. Harrison,J. Am. Chem. Soc. 1980 102 7651. Io9 M.Boldhaus K. Brink and C. Bliefert Angew. Chem. Int. Ed Engl. 1980 19,943. 'lo R. Holler and A. Lischka J. Am. Chem. Soc. 1980,102,4632. 'I1 E. Niecke M. Engelmann H. Zorn B. Krebs and G. Henkel Angew. Chem. Int. Ed. EngL 1980 19,710. '12 B. Weinberger and W. P. Fehlhammer Angew. Chem. Int. Ed. En& 1980,19 480. The Typical Elements triphenylphosphinocyanamide Ph3PNCN,'l3 and also that of triphenylphos-phinodicyanomethylidene Ph3PC(CN)2,"4 have been determined. Structural data €or the two compounds are compared in structures (60)and (61). 1.151 A 1.150 A 1.427 A 120.2" 1.594 A Tris(diphenylamino)phosphine (Ph2N)3P has been synthesized by the amination of either phosphorus(II1) chloride or bis(dipheny1amino)chlorophosphine with diphenylphosphine in the presence of triethylamine or trimethylsilyldiphenylamine.With elemental sulphur it affords (Ph2N),PS but aqueous acid gives (Ph2N)2PH0. 'I5 The reaction of the phosphorus amides HP(0)(NMe2)2 and OP(NMe2)3 with phosphorus(rI1) chloride in the presence of pyridine yields the compounds OP(NMe2)20P(NMe2)0P(NMe2)20 and OP(NMePC12),. The latter may be converted into the fluoro-analogue OP(NMePF2)3 by treatment with anti- mony(II1) or arsenic(II1) fluoride.'l6 A general method for the preparation of multidentate fluorophosphane ligands such as S(CH2CH20PF2)2 and OP(OPF2) by reaction of organic or inorganic ROH compounds with S(PF2)2 has been described."' Hydrolytic degradation of polymeric phosphorus suboxide 'P40' and of the P4 molecule in aqueous ethanolic sodium hydroxide yields the phosphinophosphite [OP(0)HPH2]- ion.''' The dimethyl- ammonium salt of the unstable trithiophosphoric acid has been obtained from the reaction of P(NMe2)3 with hydrogen sulphide in hexane.The analogous sodium salt formed by treatment with sodium ethoxide in ethanol decomposes on heating to sodium tetrathiophosphate and phosphine.''' Reaction of trimethylphosphorane with 2-chloroethylsilane proceeds uia elimina-tion of ethylene followed by transylidation to afford the C-silylphosphorane (62) as shown in Scheme 18. In the gas phase (62) has a PCSi bond angle of 123" Me,$-CH, (L Me3PCH2SiH3' C1- A Me3PCH2SiH3 H3sik&c' Reagents i -C,H,; ii Me,P=CH2 Scheme 18 J.Kaiser H. Hartung and R. Richter 2.Anorg. Allg. Chem. 1980,469 188. 'I4 R. Richter H. Hartung S. Deresch and J. Kaiser Z. Anorg. Allg. Chem. 1980 469 179. M. J. Babin 2.Anorg. Allg. Chem. 1980,467 218. E. Fluck and S. Kleemann 2.Anorg. Allg. Chem. 1980 461 187. E. R. Cromie G. Hunter and D. W. H. Rankin Angew. Chem.,Znt. Ed. Engl. 1980 19 316. l'* G. Grossmann G. Ohms B. Thomas and I-k A. Lehmann Z. Anorg. Allg. Chem.,1980 465 127. '19 F. See1 and G. Sindler Z. Anorg. Allg. Chem. 1980 470 167. 90 F. A. Hart A. G. Massey P. G. Harrison and J. H. Holloway consistent with planar geometry at the ylidic carbon atom 120 Dehydrochlorination of (Me,Si)PhC(H)PCl with DABCO-NEt affords (Me,Si)PhC=P-C1 the first such P-halogeno-functionalized methyIenephosphorane.121 Bis(trimethylsily1)-phenylphosphine reacts with carbonyl compounds and carbon disulphide and with the latter reagent the crystalline methylidenephosphine (63)is formed via the red unstable 1:1 adduct (64).122 With formaldehyde addition of both Si-P bonds Ph s-Ph SSiMe, \ i PhP(SiMe,) + CS -+ \ptc/ --* P=c\ Me,Si /I si "s SSiMe Me3 (63) (64) to the carbonyl group occurs giving the adduct PhP(CH20SiMe3)2 but with DMF an addition-elimination reaction takes place yielding NN-dimethylaminomethyl- idenephenylphosphane [equation (1l)].The dimer (65) is also obtained as a by-product.123 PhP PhP(SiMeB),+ Me2NCOH -B \C-NMe + Me3SiOSiMe3 (11) H/ H\C/NMe2 /\ Ph-P P-Ph \/ C /\ Me,N H Metathesis between CP(CO)~F~X (X= C1 or Br) and lithium bis(trimethy1- sily1)phosphide yields Cp(C0)2FeP(SiMe3)2 which reacts further with tetracar- bonylnickel and enneacarbonyldi-iron to give the phosphido-bridged complexes Cp(C0),Fe[p-P(SiMe3),INi(CO) and Cp(CO)2Fe[p-P(SiMe3)2]Fe(CO)4, U.V.irradiation of the latter complex produces the carbonyl-bridged complex Cp(CO)Fe[p-CO-p-P(SiMe3)2]Fe(CO)4. 124 Ring and Cage Compounds. As in previous years numerous studies of ring and cage compounds containing phosphorus have appeared. The diphosphasiliran (BU'P)~S~P~~a regular triangular [P2Si] three-membered ring.12' Four-has membered ring systems have been obtained in various ways.[I3 + 13Cyclocondensa-lZo E. A. V. Ebsworth D. W. H. Rankin B. Zimmer-Gasser and H. Schmidbaur Chem. Ber. 1980 113,1637. 12' R. Appel and A. Westerhaus Angew. Chem. Int. Ed. Engi. 1980 19 556. lZ2 G. Becker G. Gresser and W. Uhl Z. Anorg. Allg. Chem. 1980,463 144. '23 G. Becker and 0.Mundt 2.Anorg. Allg. Chem. 1980,462 130. 124 H.Schafer 2.Anorg. Allg. Chem. 1980,467 105. lZ5 K.F.Tebbe Z. Anorg. Allg. Chem. 1980 468 202. The Typical Elements tion of the potassium or trimethylsilyl triphosphanes with organodichlorophosphines yields cyclo-(P4Ph4) and cyclo-(P4Ph3But). In solution at room temperature cyclo- (P4Ph4) rearranges to principally (P5Ph5) but under the same conditions the t-butyl analogue is stable.126 Reaction of trimethylsilylphosphorane with bis(t-buty1)mer- cury leads to the formation of cy~lo-[P~(SiMe~)~] via the intermediate symmetric diphosphane H(SiMe3)P-P(SiMe3)H.Solvolysis of the silyltetraphosphane by methanol yields P5H5 whereas thermolysis results in the formation of (Me,Si),P cycl~-[P~(SiMe~)~] Linear, and other products of higher phosphorus ~0ntent.I~~ cyclic and cage phosphinosilanes all form complexes with transition-metal car-bonyls. Me2Si[PBut(SiMe3)l2 displaces two carbonyl ligands from Ni(C0)4 to form the diphosphine-chelated ring complex (66) whereas four-membered cyclic disiladiphosphanes and hexamethyltrisilatetraphosphanortricyclene,P4(SiMe2)3 But SiMe But Cr(CO) \P/ \D' /-\ /l\ Me,Si Ni(CO) Me$; .SiMe, \/ \/ P P /\ I Me,Si But But (66) (67) But Ni(C0)3 But Ni(CO)3 -\P/ \/ /\ Me,Si SiPh Me,Si /1 \SiMe, \/ \/ P P I But (68) function as unidentate ligands in the complexes (67)-(70).The latter cage com- pound may also act as a bridging ligand as in (71).'28-130Trimethylheptaphosphane can be isolated in high yield by treatment of Li3P7 with methyl bromide in THF M. Baudler and G. Reuschenbach 2.Anorg. Allg. Chem. 1980,464 9. M. Baudler G. Hofmann and H. Hallab 2.Anorg. Allg. Chem. 1980 466 71. G. Fritz and R. Uhlmann 2. Anorg. Allg. Chem. 1980,463 149. G. Fritz and R. Uhlmann 2.Anorg. Allg. Cham. 1980,465 59. "O W. Honle and H. G. von Schnering Z. Anorg. Allg. Chem. 1980,465 72. F. A. Hart A. G.Massey P.G. Harrison and J. H. Holloway oc oc at -60 "C and possesses the same nortricyclene structure as P4(SiMe& although two isomers differing in the orientation of the methyl groups can be discerned.13' Refluxing the N-silyldiazadiphosphetidene (72) in acetonitrile yields the cage compound (73) which on heating on a sealed tube at 156-158°C for several days is quantitatively converted into the adamantane isomer (74).132 *.J R I /N\ P -2Me3SiCI 2 CIP P-N-SiMe, \/ N I R 'N' (72) R =PI-' R' (73) The triazaphosphabicyclo[3.3.O]octane (75) obtained by transamination from tris(dimethylamino)phosphine,is a mobile liquid that undergoes reversible poly- merization on standing (Scheme 19).Reaction with dicarbonyl compounds such as 13' M.Baudler W. Faber and J. Hahn 2.Anorg. Allg. Chem. 1980 469 15. 13' 0. J. Scherer K. Andres C. Kruger Y. H. Tsay and G. Wolmerhauser Angew. Chem. Inf. Ed. Engl. 1980 19,571. The Typical Elements R (76) Reagents i on standing; ii heat in uacuo; iii RCOCOR (R = Me or Ph) Scheme 19 biacetyl and benzil gives the five-co-ordinated adducts (76),which are stereochemi- cally rigid up to 95 "C. In contrast to the analogous six-membered ring compound (77) undergoes rapid intramolecular ligand exchange at room ternperat~re.'~~ X-Ray irradiation of [HP(OCH,CH,),N]BF produces the species (78) in which phosphorus has a trigonal-bipyramidal configuration with the unpaired electron in an apical 0rbita1.I~~ The reaction of Pri2N-P=NBu' with sulphur dioxide proceeds as shown to yield the air- and moisture-sensitive crystalline ring compound (79) which has an almost ideal boat c~nformation.~~~ 133 D.B. Denney D. Z. Denney D. M. Gavrilovic P. J. Hammond C. Huang and K. S. Tseng J. Am. Chem. SOC.,1980,102,7072. 134 4. H. H. Hamerlinck P. Schipper and H. M. Buck J. Am. Chem. SOC.,1980,102,5679. 13' E.Niecke H. Zorn B. Krebs and G. Henkel Angew. Chem. Int. Ed. Engl. 1980,19,709. F. A. Hart A. G. Massey P. G. Harrison and J. H. Holloway 0-s=o Pri2N-P=NBu' +SO2 -+ 3 1 O=S=NBU' Z'2 \ + P-0 /\ [Pr',N-P=O] -+ 0 P-NPr', \ P-0 / / N. Pf2 (79) Phosphazenes. The tris(trich1orophosphino)carbenium cation [C(N=PCl,),]+ has approximate C,,symmetry with the [C(NP),] skeleton as well as one chlorine atom per [PCl,] group almost c0p1anar.I~~ Silylated monoamides X2P(0)NHSiMe3 (X = OEt or NEt,) do not give the expected trichlorophosphazenes X2P(O)-N=PCI3 on reaction with phosphorus(v) chloride but rather the isomeric N-dichlorophos- phon ylp hosp hazenes (80).137 0 c1 0 c1 c1 c1 0 I II II \d/ X2P-NH-SiMe & X2d/ -bX2P=N-PCI2 \N'H 'C1 (80) Reagents i PCl,; ii -HCl Scheme 20 Phosphazene-phosphanes R,P=N-P(OR') (R = Me or NMe2 R' = CH2CF3) react with trimethylsilyl azide to afford the N-silylated diphosphazenes R3P=N-P(0R'),=N-SiMe3 which are decomposed by air to the phos-phazenophosphonamidic acid esters R3P=N-P(O)(OR')(NH,).Thermolysis of Me3P=N-P(OR'),=N-SiMe gives the phosphazenyl-phosphazenes [N=P(N=PMe3)OR']n.'36 The structures of hexa-aziridinocyclotriphosphazene,N3P3(NC2H4)6 and its tris-carbon tetrachloride solvate have been determined.Endocyclic bond distances and valence angles are very close to those in N3P3(NMe2)6 and the main difference between the two compounds lies in the hybridization of the exocyclic nitrogen atoms which in the aziridinyl compound have a pronounced pyramidal geometry. In the carbon tetrachloride solvate the N3P3(NC2H4)6 molecules occupy hexagonal channels in the host carbon tetrachloride lattice. 139p140 1-Meth yl-3,333-136 U. Muller Z. Anorg. Allg. Chem. 1980 463 117. L. Riesel and C. Taschner 2.Anorg. Allg. Chem. 1980,465 120. 138 E. P. Flindt 2.Anorg. Allg. Chem. 1980,461 193. 139 J. F.Labarre G. Levy and F. Sournies J. Mol. Struct. 1980.63 127. 140 J. Galy R. Enjalbert and J.-F. Labarre Acta Crystallogr. Sect. B 1980 36 392. The Typical Elements 95 tetraphenylcyclotriphosphazeneforms the cis-square-planar complexes (81) with platinum(I1) and palladium(I1) chloride in a~etonitri1e.l~~ In the structure of the cyclotetraphosphazene (82) the sulphur diamide unit and its substituents are coplanar causing a half-boat conformation for the six-membered ring. The [P4N4] ring has a flattened crown-saddle conformation with the phosphorus atoms arranged nearly at the corners of a Poly(dimethylphosphazene) (Me2PN), has been prepared as an opaque flexible film by heating the phos- phinimine Me,Si-N=PMe,(OCH,CF,) at 190"C in uacuo.The material is soluble in dichloromethane chloroform and ethanol but insoluble in water acetone THF and hexane. 143 (8'1) M = Pd or Pt Nitrogen-Sulphur Ring Systems. S4N4 reacts with copper(I1) chloride dihydrate in propan-2-01 to yield the complex CuC12*S4N4 the structure of which comprises parallel chains in which the octahedrally co-ordinated copper atoms are bridged by chlorine atoms and the S4N4 ring as in (83).The conformation and dimensions of the heterocycle remain essentially unchanged on complexation. 144 When the reaction is carried out in acetonitrile however the polymeric complex (84) is NdS-N /N\S s\ I N-Pt-CI / I S\/ (83) isolated which contains a planar bridging [S,N J ligand and square-pyramidally co-ordinated ~0pper.l~~ Reaction of S4N4 with cis-PtCl,(NCPh) in toluene yields the deep purple complex (85),containing the terdentate [S4N3] ligand.'46 The reactions of cyclotetrathiatriazenium chloride vapour with hot (ca.300 "C) metal surfaces have been studied. With iron the products are S3N2Cl S4N4 and (NSCl), whereas with titanium TiC14 and elemental sulphur and nitrogen are 14' A. Schrnidpeter K. Blanck H. Hess and H. Raffel Angew. Chem. Int. Ed. Engf. 1980 19 650. 14* A. Cieren and B. Dederer Z. Anorg. Allg. Chem. 1980,467,68. 143 P. Wisian-Neilson and R. H. Neilson J. Am. Chem. SOC.,1980,102 2848. 144 U. Thewalt 2.Anorg. Alfg. Chem. 1980,462 221. U. Thewalt and B. Muller Z. Anorg. Alfg. Chem. 1980 462 219. 146 H. Endres and E. Galantai Angew. Chem. Znt.Ed. Engf. 1980 19 653. 14' F. A. Hart A. G. Massey P. G. Harrison and J. H. Holloway produced. Reaction at a silver surface is a useful method for the preparation of S2N2.I4' Triphenylarsine promotes an 8 +5 ring contraction of S4N402 yielding the asymmetrically substituted sulphamide (86).14* \/ S The structures of two five-membered heterocyclic derivatives S3N2+ S03CF3-*iMeCN and S3N2(NS02F) have been determined. In the former the ring is planar and two cations are connected through weak S--Sinteractions to form dimers with a chair configuration (87). The ring in S3N,(NS02F) is not planar and the [FS02N] group is covalently bound to a suIphur atom (88).149 Qualitative MO arguments can rationalize all essential structural features of S4N5- S4N5+ and S5N6."' 0 Arsenic.-Reaction of trimethylchlorosilane with Na3As-K3As (from NaK and arsenic powder in DME) affords tris(trimethylsily1)arsinein high yield.Treatment with methyl-lithium in THF or DME results in the formation of dimeric LiA~(siMe~)~, which crystallizes with two molecules of THF or one of DME and reacts with various chloro-compounds (Scheme 21). The (silyl)(pivaloyl)arsine RAS(S~M~~)~ COBu' LiA~(siMe~)~ RAs / 'SiMe3 (Me3Si)2AsAs(SiMe3) As Me&// 'SiMe2 Me2Si[As(SiMe2)212 + (Me3Si)2As Reagents i alkyl halide; ii Bu'COCI; iii Ph,CHCIBrCH,CH,Br; iv Me,SiCl,; v 240 "C,several days. Scheme 21 14' 14' A. J. Bannister and Z. V. Hauptmann J. Chem. SOC.,Dalton Trans. 1980 731. H. W. Roesky M. Wilt W.Clegg W. Isenberg M. Nolterneyer and G. M. Sheldrick Angew. Chem. Int. Ed. Engl. 1980,19 943. 149 B. Krebs G. Henkel S. Pohl and H. W. Roesky Chem. Ber. 1980 113,226. 150 R.Bartetzko and R. Gleiter Chem. Ber. 1980 113,1138. The Typical Elements R I / COBu' /OSiMe Me,SiO \/As\/But RAs -* RAs=C --* cc \ \ /\ /\ SiMe Bu' Bu' As OSiMe, I (89) rearranges at high temperatures or under U.V. irradiation to the propylidene- arsine (90) which dimerizes to form the diarsetan (91).151,152 Antimony and Bismuth.-The structures of several antimony compounds have been described. That of the 1:1adduct of antimony(II1) chloride and diphenylamine comprises dimeric units with a .rr-type interaction between antimony and one phenyl group of the amine resulting in pseudo-octahedral co-ordination for the Distorted octahedral co-ordination with bridging chlorine atoms is also present in the chloroantimony anions SbC1,- and SbC152-.'54 The antimony chloride ethoxides SbCl(OEt) and SbCl,(OEt) both have two-dimensional layer structures in which both types of ligand function as bridging groups.Again antimony has distorted octahedral co-~rdination.'~~ Four antimony carboxylate structures have been repor- ted during the past year. Diphenylantimony acetate156 and (R)-tris(trifluoroace- tat~)antimony'~' have quite different structures. The former has the acetate-bridged structure (92) whereas the latter comprises discrete molecules with unidentate Ph 0 Mk (92) carboxylate groups and crystallographically imposed C3symmetry.In contrast in the two antimony(v) fluoride trifluoroacetates Sb2C02(CF3)F9 (93) and Sb20C02(CF3),F (94) the carboxylate again functions as a bridging ligand and \ I CF3 CF3 (93) (94) G. Becker G. Gutekunst and H. J. Wessely Z. Anorg. Allg. Chem. 1980,462 113. G. Becker and G. Gutekunst Z. Anorg. Allg. Chem. 1980,470 131 144 157. Is3 A. Lipka 2.Anorg. Allg. Chem. 1980 466 195. A. Lipka 2.Anorg. Allg. Chem. 1980,469 229; ibid.,1980 467 218. G. E. Binder W. Schwarz W. Rozdzinski and A. Schmidt Z. Anorg. Allg. Chem. 1980 471 121. S. P. Bone and D. B. Sowerby J. Organomet. Chem. 1980,184,181. Is' D. P. Bullivant M. F. A. Dove and M. J. Haley J. Chem. SOC.,Dalton Trans. 1980 105. F. A. Hart A. G.Massey P.G.Harrison and J. H. Holloway the antimony has distorted octahedral co-~rdination.'~~ Crystals of the oxalate Na3H(C204)2SbOF*2H20 contain pseudo-seven-co-ordinated [SbOF(C204)2I4-anions in which both oxalate groups and the oxygen atom occupy equatorial sites and the fluorine and lone pair the axial positions of a pentagonal bipyramid (95).159 F The antimony(II1) oxide sulphate Sb10(S04)2*2H20 contains two types of poly- hedra; a distorted pseudo-trigonal [:Sb04] bipyramid and distorted [:Sb05] octahedra which are connected in pairs by edge-sharing.I6' Two types of co-ordination are also present in triphenylantimony catecholate hemihydrate. Two distinct discrete molecules are present in the crystal. In one the antimony is co-ordinated by three phenyl groups and a chelating catecholate ligand to give one of the few examples of distorted square-pyramidal geometry.In the other molecule the water is weakly co-ordinated to antimony completing a distorted octahedron.161 Reaction of methyl- and trifluoromethyl-sulphonic acid methyl esters with anti- mony(v) chloride yields dimeric tetrachloroantimony(v) sulphonates [SbC14(S03R)](R = Me or CF3).162 The thermal decomposition of tetraphenylantimony(v) arenethiolates Ph4SbSAr is complex and most probably proceeds by a free-radical pathway. Products include Ph3Sb biphenyl benzene ArSPh and ArSSAr. 163 The ligands in tris-(1-pyrrolidenecarbodithioato)antimony(III) chelate antimony unsymmetri- cally to give pentagonal-pyramidal geometry. The lone pair occupies the other axial site of the bi~yrarnid.'~~ Higher bismuth oxides have been obtained by hydrolysis of bismuthates(v) under various conditions.Besides BiOz the existence of four different phases of Bi205 CP ,co ,Mn-CO' Mn Oc1 Mnc/ 'CP 0 \Mn-cO 'I oc CP lS8 D. P. Bullivant M. F. A. Dove and M. J. Haley J. Chem. Soc. Dalton Trans. 1980 109. R. Fourcade P. Escande B. Ducourant and G. Mascherpa Z. Anorg. Allg. Chem. 1980 465 34. "O J. Douglade and R. Mercier Acta Crystallogr. Sect. B,1980 36 2919. M. Hall and D. B. Sowerby J. Am. Chem. SOC.,1980,102,628. "* G. E. Binder and A. Schmidt Z. Anorg. Allg. Chem. 1980,467 197. 163 J. L. Wardell and D. W. Grant J. Organomet. Chem. 1980 188 345. 164 C. A. Kavounis S. C. Kokkou P. J. Rentzepis and P.Karagiannidis Acta Crystallogr. Sect. B 1980 36 2954. The Typical Elements were ~haracterized.'~~ Few bismuth structures have been determined. The two anions BiBr6-and Bi2BrIo2-are both octahedral.'66 Diphenylbismuth isopropylxanthate is pyramidal with weak sulphur bridging,16' whereas {BiC1[Mn(Cp)(CO)2]2}2 is dimeric with bridging chlorines (96).16'

ISSN:0260-1818    

DOI:10.1039/IC9807700066

出版商:RSC    

年代:1980

数据来源: RSC

摘要:

The Typical Elements Part IV Groups VI VII and VIII By J. H. Holloway 1 GroupVI Oxygen.-0- Singlet Oxygen and 02.The weak low-field line observed in the e.s.r. spectrum of cooled ice crystals containing trapped *OMradicals and attributed first to traces of some transition-metal impurity and more recently to H20+cations has been shown to be due to 0-ions. It appears that hydroxyl radicals formed when ice and various other aqueous systems are subjected to ionizing radiation at low temperature are extensively converted into 0-ions. It is presumed that the mechanism shown in equation (1)operates. The conversion is almost complete for -OD in D20.' The occasionally observed physical quenching of singlet oxygen by potentially reactive substrates has been postulated as a general phenomenon.Recently however it has been shown that physical quenching is incompatible with the data obtained for some substrates and consequently its prevalence is in doubt. Now photomicrocalorimetry has been used to determine photochemical quantum yields and reaction enthalpies for tetraphenylporphine-sensitized photo-oxygenation of several singlet oxygen acceptors. This has shown that under favourable conditions the quantum yield of photo-oxygenation is equal to the triplet yield of sensitizer. For less reactive acceptors and/or in solvents in which the singlet oxygen lifetime is short reaction quantum yields are acceptor-concentration dependent but have upper concentration limits equal to the sensitizer triplet yield. This shows that physical quenching of singlet oxygen by reactive acceptors does not occur.2n Interest in singlet oxygen in aqueous solutions has continued and study by the technique of making the singlet oxygen acceptor soluble in solutions of aqueous micelles continues to be refined.Reaction of 1,3-diphenylisobenzofuran,solubilized in aqueous solutions of sodium dodecyl sulphate with singlet oxygen generated either continuously or by flash photolysis has been studied as a function of oxygen G. Gattow and W. Klippel Z. Anorg. Allg. Chem. 1980,470 25 16' F. Lazarini and I. Leban Acta Crystallogr. Sect. B 1980,36,?745;F.Lazarini ibid. 1980,36 2748. M.Wieber; H. G. Ridling and Ch. Burschka 2.Anorg. Allg. Chem. 1980,470 171. 16* J. von Seyerl and G. Huttner J. Organomet.Chem. 1980,195,207. M. C. R. Symons J. Chem. Soc. Chem. Commun. 1980,675. (a) J. Olmsted 111 J. Am. Chem. Soc. 1980,102 66; (6)I. B. C. Matheson and R. Massoudi ibid. p. 1942;(c)B. A. Lindig M. A. J. Rodgers and A. P. Schaap ibid. p. 5590;(d)W.Ando Y. Kabe S. Kobayashi C. Takyu A. Yamagishi and H. Inaba ibid. p. 4526. F'. A. Hart A. G. Massey P. G. Harrison and J. H. Holloway concentration. The data have been analysed to indicate singlet molecular oxygen water-to-micelle transfer rates occurring via both molecular diffusion and energy- transfer mechanisms.2b In related experiments the lifetime of singlet oxygen in D20 using the water-soluble monitoring solute 9,lO-anthracenedipropionicacid has been measured.*' This has served to eliminate the possibility that the lifetime is in some way affected by the surfactant micelles.It has also provided information which is critical for biological studies where the differences between the rates and extents of oxidation in D20and H20 are often used as criteria for the implication of singlet oxygen in the process. Recently much attention has been focused on photo-oxygenation via a non- singlet oxygen mechanism. To elucidate the possibilities of the oxidation through direct coupling of the cation radical and the superoxide ion it is necessary to use both stable ion radicals. The first example in which the reaction of a sulphur cation radical and superoxide anion radical gave not only singlet oxygen by the annihilation reaction but also direct coupling has now appeared (Scheme 1).2d Scheme 1 The belief that solar energy harnessed by photochemical processes may be able to contribute to world energy requirements is supported by the results of a growing number of workers in this field.A comprehensive review on the various ways of photocatalytic conversion of solar energy has a~peared.~" The main emphasis is on the chemical route involving photocatalytic decomposition of H20 to O2 and H2 in the presence of platinum-group metals and other catalysts. A shorter and authoritative review which concentrates on water decomposition in the presence of platinum and ruthenium dioxide catalysts with trisbipyridylruthenium as the light sensitizer and methyl viologen as the carrier has also appea~ed.~' Recent work includes improved RuOz and studies on a variety of other metal oxide catalyst^.^"^^ In some cases however the decomposition products have been shown to be C02and H2 rather than O2and HZ.6a,b (a)K.1. Zamaraev and V. N. Parmon Usp. Khim. 1980 49 1457; (b)M. Gratzel Ber. Bunsenges. Phys. Chem. 1980 84,981. (a)M. Neumann-Spallart K. Kalyanasundaram C. Gratzel and M. Gratzel Helu. Chim. Acta 1980 63 1111; (6) J. Kiwi E. Borgarello E. Pelizzetti M. Visca and M. Gratzel Angew. Chem. Int. Ed. Engl. 1980 19 646. * (a) D. Costache Reu. Chim. (Bucharest) 1980 31 345; (b)M. Inai C. Iwakura and H. Tamura Denki Kagaku 1980,38 173. (a)G. McLendon and D. S. Miller J. Chem. Soc. Chem. Commun. 1980 533; (b)T. Kawai and T. Sakata ibid. p.694. The Typical Elements 101 Dioxygen-containing Species. Following the report of the isolation of simple co- ordination complexes Mn(PR3)X2 (R = alkyl or aryl R3 # Ph, X = Cl Br I or NCS) which are capable of reversible oxygenation,'" the formation of Mn(PR3)X2-0,in solution as a function of the partial pressure of dioxygen has been st~died.~' Equilibrium constants at 20 "C for dioxygenation of the complexes Mn(PR3)Br2 (R =Me2Ph Pr", or Bun3) and Mn(PPrn3)C12 in a number of solvents have been obtained. The Mn(PBun3)Br2 complex in 1,2-dichloroethane displays a dioxygen binding isotherm reminiscent of the hyperbolic myoglobin c~rve.~' Absorption/desorption experiments using labelled 160-160/180-180 mixtures with the Mn(PR3)X2 adducts have shown that both in the solid state and in solution in THF no difference in 160-160/180-180 gas composition was observed and hence no oxygen-oxygen bond breaking occurs in the absorption/desorption In the meantime other workers have reported their inability to isolate compounds of stoicheiometry Mn(PR3)X2 from solutions of MnBr2 or MnIz in THF to which tertiary phosphines had been added.All attempts to prepare Mn(PMe2Ph)Br2 have resulted in the formation of Mn(THF)Brz. Solutions of Mn(THF)Br2-PBun3 mix- tures in THF undergo irreversible oxidation when exposed to dioxygen and ulti- mately produce tertiary phosphine oxides. The reversible colour changes observed are attributed possibly to oxidation/reduction of Mn"/Mn"' species but no evidence for the reversible formation of dioxygen-manganese complexes was found.' Oxygen transport and storage by proteins have continued to excite interest in metal-dioxygen binding in complexes.It is well known that superoxides are charac- terized by end-on binding of O2 and peroxides by sideways binding and by their familiar ~(0-0)stretching frequencies 0-0 bond lengths and bond orders. However only sparse e.s.r. information about the net electronic charge on oxygen was available until recently. Now i.r. spectra in combination with electronic spectra have been interpreted in terms of net negative charge residing on the oxygen and there is an increase in electronic charge on dioxygen with decrease in electron affinity of the metal.' New studies of the kinetics of peroxo-complex formation of (polyaminopolycar-boxylato)dioxovanadate(v) have been carried out lo and reactivity of dioxygen and nitric oxide with Mn" complexes11a and electrochemical spectroscopic and mag- netic characterizations of Mn" Mn"' and MnIV complexes with the 3,5-di-t-butyl- catechol anion (DTBC) have been reported.'Ib The [Mn'V(DTBC)3]2- complex appears to be the first example of a reversible oxygen-binding metal centre that is complexed by catecholate ligands. However by far the most effort has been devoted to the study of cobalt-dioxygen complexes. The reductions of the p-superoxo species [CO~(NH,)~(~-O~,NH~)]~+ by the cobalt(I1) and [CO~(NH~)~,(~.-O~)]" pyridyl complexes [C~(terpy)~]~+ and [C~(phen)~]*+ and [C~(bipy)~]~+ have been confirmed as occurring via an outer-sphere mechanism the kinetics being ' (a) C.A. McAuliffe H. Al-Khateeb M. H. Jones W. Levason K. Minten and F. P. McCullough J. Chem. SOC.,Chem. Commun. 1979,736; (b)C. A. McAuliffe and H. Al-Khateeb Inorg. Chim. Acta 1980,45 L195; (c) M. Barber R. S. Bordoli H. Hosseiny K. Minten C. R. Perkin R. D. Sedgwick and C. A. McAuliffe ibid. p. L89. R. M. Brown R. E. Bull M. L. H. Green P. D. Grebenik J. J. Martin-Polo and D. M. P. Mingos J. Organomet. Chem. 1980,201,437. A. B. P. Lever G. A. Ozin and H. B. Gray Inorg. Chem. 1980,19 1823. lo S. Funahashi T. Midorikawa and M. Tanaka Znorg. Chem. 1980,19,91. '' (a)W. M. Coleman and L. T. Taylor J. Inorg. Nucl. Chem. 1980 42 683; (b)K. D. Magers C. G. Smith and D. T. Sawyer Inorg.Chem. 1980,19,492. F. A. Hart A. G. Massey P. G.Harrison and J. H. Holloway adequately described by Marcus Theory. Reduction potentials and self-exchange rates for the bound O2have been calculated for the first time. The low self-exchange rate so found can be accounted for by the large change in 0-0 bond length which occurs during the reduction. This provides a substantial Franck-Condon barrier to electron transfer.12 The nature of metal-oxygen binding in peroxo-Co" complexes has received considerable attention. Values of redox potentials have been inter- preted in terms of charge transfer from Co" to dioxygen on o~ygenation'~~ and frequencies of the oxygen to cobalt charge-transfer bands have been linearly related to the redox potentials of the complexes and to logKo,.'3b Evidence of reaction of co-ordinated dioxygen has been observed by virtue of extra stabilization through hydrogen bonding of the dioxygen in bis(salicy1ideniminato-3-propy1)methyl-aminocobalt(I1) complex when small amounts of 2,2,2-trifluoroethanol are added.I3' This is one of the few instances in which a clear-cut reaction of co-ordinated dioxygen has been observed.A series of five-co-ordinate Co" trisphosphine com- plexes which exhibit ligand-dependent distorted trigonal-bipyramidal or tetragonal-pyramidal geometries has been prepared. Complexes with both geometries bind dioxygen reversibly but dissociate a phosphine in the process to yield novel five-co-ordinate end-on-bonded dioxygen complexes. 13d Although the chemistry of cobalt-oxygen carriers is now fairly well understood it is only recently that kinetic studies have begun This year the kinetics of the decomposition of the p -peroxo-bis[penta-amine cobalt(~r~)] complex (1)[equation (2)] generated by fast one-electron reduction of the p -superoxo-complex H+ [(NH3)5Co.02.Co(NH3)5]4+ -+ 2C02++O2+ 10NH4+ (2) [(NH3)5Co.02.Co(NH3)5]4+, have been studied and the [H'] dependence of the first-order rate constants has been found to be consistent with the formation of a protonated non-reactive form.'4a The redox reactions between 0;-ion and the co-ordinated species in p-amido-p-superoxo-bis[bise~hylenediaminecobalt(~~~)] (2) and p-superoxo-bis[pentacyanocobalt(~~~)] (3) have been followed spectro- (2) en = ethylenediamine photometrically and rate constants determined for the ethylenediamine com-plexe~.~~~ Another novel area of investigation concerns the transfer of molecular oxygen from one metal to another.Dioxygen ligand transfer between cobalt and molybdenum has now been studied (Scheme 2) and the presence of the peroxo ligand confirmed by a standard iodometric titration which indicated the formation of one molecule of H202per molecule of (5).14' l2 G. McLendon and W. F. Mooney Znorg. Chem. 1980,19 12. l3 (a)W. R. Harris G. L. McLendon A. E. Martell R. C. Bess and M. Mason Inorg. Chem. 198G 19 21; (b) S. R.Pickens and A. E. Martell ibid. p. 15;(c) R. S.Drago J. P. Cannady and K. A. Leslie J. Am. Chem. SOC.,1980,102,6014;(d) R.S.Drago J. R. Stahlbush D.J. Kitko and 3. Breese ibid. p. 1884. l4 (a)M. Ferrer T. D. Hand and A. G. Sykes J. Chem. SOC.,Dalton Trans. 1980 14; (6)P. Natarajan and N. V. Raghavan J. Am. Chem. SOC.,1980,102,4518;(c) H.Arzoumanian R. Lai R. Lopez Alvarez J.-F. Petrignani J. Metzger and J. Fuhrhop ibid. p. 845. The. Typical Elements 2-L 0 J LO (4) (5) Scheme 2 ‘Picket-fence’ and ‘tailed’ porphyrins are excellent model compounds for haemo- globin their particular structural features being designed to prevent irreversible oxidation and provide five-co-ordination around the iron. Both of these features have been recently reproduced in a new class of model compound the ‘tailed picket-fence’ porphyrin in which the picket-fence porphyrin carries a covalently attached axial base.lsa These should be particularly useful in the study of oxygen binding in solution.Another species which is of relevance to model systems for haemoglobin and the nature of the trigger of the conformational change associated with the co-operative uptake of dioxygen is the high-spin (rneso-tetraphenylpor- phinato)bis(tetrahydrofuran)iron(II) complex in which the metal lies in the plane of the porphyrin ring.’5b Although this arrangement probably does not hold for any natural haemoprotein it does demonstrate conclusively that high-spin iron(I1) will fit into the porphyrin plane. Dicobalt co-facial porphyrin linked by four-atom bridges has produced a catalysed reduction of dioxygen to water. Rotating ring-disc voltametry was employed to diagnose the electrode reaction pathway and a possible reaction mechanism for the observed catalysis has been suggested.The results seem to demonstrate the participation of two metal centres in controlling the course of such multiple-electron processes.16 For several years it was believed that iron(I1) porphyrins and haem proteins are autoxidized via an inner-sphere mechanism. However on the basis of experiments with osmium porphyrins it was recently suggested that cytochromes can be autoxidized by an outer-sphere mechanism producing superoxides. Now work with osmochromes (osmium analogues of haemochromes) has demon- strated that outer-sphere electron transfer to dioxygen can occur from metallo- porphyrins with blocked axial positions when the superoxide is removed from the equilibrium.” Following the report that a 1 10-phenanthrolinecopper(1)complex cleaves DNA in an oxygen-dependent reaction it has been established that the oxidation of the copper(1) complex of 1,lO-phenanthroline (and related ligands) by oxygen proceeds via a superoxide intermediate but that diffusable superoxide is not directly involved in the DNA cleavage reaction.” The apparent vapour transport of O2AsF6 by sublimation proceeds via a revers- ible reaction [equation (3)] which involves a free-radical mechanism.This is in 02+A~F6-*OZF+AsFS (3) (a)J. P. Collman J. I. Brauman K. M. Doxsee T. R. Halbert E. Bunnenberg R. E. Linder G. N. Lamar J. Del Gaudio G. Lang and K. Spartalian J. Am. Chem. SOC.,1980 102 4182; (b) C. A. Reed T.Mashiko W. R. Scheidt K. Spartalian and G. Lang ibid. p. 2302. J. P. Collman P. Denisevich Y. Konai M. Marrocco C. Koval and F. C. Anson J. Am. Chem. Soc. 1980,102,6027. ”J. Billecke W. Kokisch and J. W. Buchler J. Am. Chem. SOC.,1980,102 3622. D. R. Graham L. E. Marshall K. A. Reich and D. S. Sigman J. Am. Chem. SOC.,1980 102 5419. 104 F. A. Hart A. G. Massey P. G. Harrison and J. H. Holloway contrast with the vapour transport of o2PtF6 02RuF6,and O2RhF6 which proceeds via dissociation and recombination with charge transfer [e.g.equation (4)I.l' O,+PtF,-* Oz+PtF (4) The possible existence of a dioxygen-chlorine monoxide complex C1O-O2 has been suggested since the introduction of this asymmetric species into photochemical models of the stratosphere could clarify the observed variability of CIO mixing ratios and influence estimates of O3destruction due to CH2ClF consumption.20 Oxygen Hydride Species.An experimental determination of the deformation elec- tron density in hydrogen peroxide by combination of X-ray and neutron diffraction measurements has been made. The oxygen atom has been observed to be in an sp3 hybridization state with one of the lone pairs involved in hydrogen bonding.21 A new value of AHf298(H02*)10.46 f2.5 kJ mol-' which is mid-way between = earlier published values has been determined from measurements of the tem- perature dependence of the rate constants for the forward and backward reactions [equation (S)] the equilibrium constant being combined with thermodynamic data HO2*+NO $ .OH+NO2 (5) AH and So,for NO *OH,and N02.22nThermochemical data for the gas phase and for aqueous solutions of HO&) have been used to estimate the electron affinity.When compared with related species the value of 181.2 f10.5 kJmol-' seems reasonable. The heat of aquation of HO& (8.4 f 10.5 kJmol-') was also obtained.226 Although recent I7O ~~.m.r.'~ and earlier theoretical and spectroscopic work has been interpreted to suggest a planar geometry for H30' another view of the n.m.r. data coupled with solid-state evidence has been used to conclude that H30+is pyramidal with a bond angle of -111.3°.24 Strong hydrogen-bonding has been extensively studied during the past ten years. An excellent review which pays special attention to 0-H-0 0-H-F and 0-H-X bonds has now appeared2'" and a shorter summary dealing with computer simulation of hydrogen-bonded liquids has also been p~blished.~'~ The orientation defect model has been used for quantitative estimates and for understanding the properties of H-bonded liquids such as HzO and extensions of the simple model have been discussed.26 Ab initio SCF-MO calculations have confirmed the non-rigid structure of the H20...HT; dimer and stretching force constants related to the v(F-H) and v(F-0) modes have been estimated.27 Related calculations on some complexes of the type (B.-.H-A)+ have revealed that four including (H20- -.He -.OH2)+ have unusually l9 J.E. Griffiths D. DiStefano and W. A. Sunder J. Raman Spectrosc. 1980 9,67.2o S. S. Prasad Nature (London) 1980,285 152. J.-M. Savariault and M. S. Lehmann J. Am. Chem. SOC. 1980 102 1298. 22 (a)C. J. Howard J. Am. Chem. SOC. 1980 102 6937; (b) S. W. Benson and P. S. Nangia ibid. p. 2843. 23 G. D. Mateescu and B. M. Benedikt J. Am. Chem. SOC. 1979,101 3959. 24 M. C. R. Symons J. Am. Chem. SOC. 1980,102,3982. 25 (a)J. Emsley Chem. SOC. Rev. 1980 9 91; (b) I. R. McDonald and M. L. Klein Faraday Discuss. Chem. SOC. 1978 No. 66 p. 48. 26 W. A. P. Luck Angew. Chem. Int. Ed. Engl. 1980,19 28. 27 Y. Bouteiller M. Allavena and J. M. Leclercq J. Chem. Phys. 1980 73,2851. The Typical Elements 105 short internuclear separations and show large charge gain round the protons.28 A microwave rotational spectroscopic study of isotopic derivatives of the H20..HF dimer has led to the conclusion that it has C, or C symmetry but with a low barrier to inversion of the configuration at the oxygen.29 Spectroscopic measure- ments on hydrofluoric acid have confirmed that the H30+-.F- ion pair or proton transfer complex is a predominant species in HF. The ionization process may be represented as follows [equation (6)] the equilibrium lying well to the right.30 H20+HF $ [H,O'...F-] H30f+F-(6) Calculations on the aqueous complexes X-H20 (X = F C1 Br or I) suggest that F-H20 is a dipole complex whereas the rest are hydr~gen-bonded.~~" Effects of this ion-molecule interaction in F-H20 on i.r. and Raman intensities of the OH stretching band in H20 have been investigated and the results for this model system have been used for discussion of the interpretation of the vibrational spectra of aqueous electrolyte Of course very few systems display O...H-.F hydrogen-bonding and it occurs in only a small number of crystals.Generally the length of 0.m-F in these species ranges from 2.56 to 2.86 A. A crystal structure determination of the 1 1 adduct of KF and succinic acid however has revealed an unexpectedly short hydrogen bond with 0--F = 2.440(4)A.32 Thermodynamic parameters for the formation of clathrate hydrates and deuteriohydrates of SF6 CF,Cl CF3Br CF31 CF2C12 CF2ClBr and CHClF2 have been determined by measuring vapour The effects of the sizes of guest molecules on the properties of hydrate clathrates of structure I1 have been investi- gated using vibrational spectroscopic The solid-state addition com- pound formed from water and pyridine which hitherto has been regarded as a dihydrate has now been characterized as a trihydrate.The structure (Figure 1)is unusual in that the water molecules are cross-linked two-dimensionally by five independent hydrogen bonds with the formation of four- five- and six-membered rings rather than the usual three-dimensional polyhedral ~tructure.~~ An i.r. spectroscopic study of water in perfluorosulphonate (Naifon) membranes indicates two distinct environments for the OH groups identified as 0-H. -0and O-H.-CF2 and it appears that a substantial proportion of the water molecules have OH groups exposed to the fluorocarbon en~ironment.~~" A related Fourier- transform i.r.study has yielded information on the effect of counter-ion type and degree of hydration upon the anionic sites in a Naifon exchange resin.35b Ozone Ozonides and Polyoxide Species. An ozone concentration of 13wt. O/O in the anodic gas (0,and 0,)has been obtained from the room-temperature electroly- 28 P. J. Desmeules and L. C. Allen J. Chem. Phys. 1980,72,4731. 29 J. W.Bevan Z. Kisiel A. C. Legon D. J. Millen and S. C. Rogers Proc. R. SOC.London Ser. A 1980,372,441. 30 P. A. Giguere and S. Turrell J. Am. Chem. SOC. 1980,102 5473. 31 (a)H. Kelrn J. Reinhold and H. Zwanziger Z. Phys. Chem. (Leipzig) 1980 261 771; (b)J. Sadley Adu. Mol. Relaxation Interact. Processes 1979,15 163. 32 J. Emsley D. J. Jones and R. S. Osborn J. Chem.SOC. Chem. Commun. 1980,703. 33 (a) V.N. Tezikov and D. Yu. Stupin Izu. Vyssh. Uchebn. Zaued. Khim. Tekhnol. 1979 22 1039; (6)D. Yu. Stupin ibid. 1980 23,416. 34 D.Mootz and H.-G. Wussow Angew. Chem. Int. Ed. Engl. 1980 19 552. 35 (a)M. Falk Can. J. Chem. 1980,58 1495;(b)S.R. Lowry and K. A. Mauritz J. Am. Chem. SOC. 1980,102,4665. F. A. Hart A. G.Massey P. G.Harrison and J. H. Holloway Q in pyridine sis of aqueous phosphate electrolyte between PbOz anodes on a titanium substrate.36 Monomeric ozonides [(7) and (8) Scheme 31 have been prepared by ozonization of 1,2-dichloroacenaphthylene(6) at 0°C in inert solvents the two 0 addition compounds being isolated by chromatography on silica geL3' Because of the importance of ozone to the phenomenon of air pollution in the troposphere and to the stability of the ozone layer in the stratosphere as well as for its general industrial importance there has been renewed interest in the detailed mechanism of its reactions.An authoritative discussion of the mechanism of elementary steps involved in ozone reactions with olefins and the subsequent decomposition of the primary ozonides and the mechanism of ozonation of satur-ated compounds and the decomposition of the products has been p~blished.~~" This shows that heterolytic pathways provide the major reaction channels and free-radical reactions play a minor role at temperatures below 0 "C.The mechanism of acid-catalysed decomposition is also not understood and various proposals 36 H. P. Fritz J.C. G. Thanos and D. W. Wabner Z. Naturforsch. TeilB 1979,34 1617. H. Seltzer S. Gab and F. Korte Angew. Chem.,Znt. Ed. Engl. 1980,19 474. 38 (a)P. S. Nangia and S. W. Benson J. Am. Chem. SOC.,1980,102,3105; (b)M. Miura and M. Nojima ibid.,p. 288. The Typical Elements 107 including one involving 0-0 bond fission in the first step have been suggested. Now the reactions of 11kinds of ozonides (1,2,4-trioxolans) with SbC1 and ClS03H in methylene chloride have been investigated and it has been shown that heterocyclic fission of the C-0 bond of the peroxide bridge affords 3,6-dialkyl-1,2,4,5-tetroxan (9) and/or 1,4-dialkyl-2,3,5,6,1 l-pentaoxabicyclo[5.3.l]undecane (10). By cleavage of the ether bridge however a mixture of ketone (aldehyde) and ester (carboxylic acid) is obtained in a molar ratio of 1:1.386 At the end of last year studies on the kinetics of the thermal decomposition of bis(pentafluorosu1phur)trioxide were extended by examination of the decomposi- tion in the presence of carbon monoxide.39 Oxygen Halides.Optimized conditions for the preparation of OF by the electrolysis of aqueous hydrogen fluoride in the presence of 0,and O3have been determi~~ed.~' SCF-MO calculations which include geometry optimization have been reported for O,C1 OzF OCF and OCCl.41" Related calculations on the structures and electronic properties of the OClz' and FClO' radical cations have also been Chemiluminescence from the reaction of 02Fradicals with Mg atoms in the gas phase have been interpreted in terms of the excited species stemming from a long-lived precursor which is probably MgF generated by the initial rea~tion.~' Sulphur.-Sulph ur Rings Poly a tomic Sulphur Cations and Sulph ur-Chalcogen ide Relatives.Solutions of dichlorodisulphane S2C12 in CS react with aqueous solutions of KI at 20 "C to give SzIzwhich decomposes spontaneoulsy to a mixture of sg sg sl0,s18 sz0,and larger homocyclic sulphur molecules in addition to I,. The reaction has been found to provide a convenient means of production of sg in 36% yield while SI2,s18,and Sz0appear in yields of less than 2% .43 Comparison of sulphur and selenium with respect to their critical properties and molecular compositions has been possible in a study of their densities up to supercritical condition^.^^ In a study designed to discover why zinc accelerates vulcanization of rubber evidence has been presented to show that vulcanization and presumably activation of Ss in the rubber is facilitated by the presence of anionic species.One possibility involves the production of [Zn(S2CNMe2)J and [Zn(C7H4NS,),(0H),]- which react with Ss on heating in xylene to give oils which may contain (S,CNMe2)- or (C7H4NS,)-(x > 1)either as free NR4+salts or bound to zinc.45 39 J. Czarnowski and H. J. Schumacher Int. J. Chem. Kinet. 1979,11,1089. 40 D. Hass and P. Wolter 2.Anorg. Allg. Chem. 1980 463 91. 41 (a)A. Hinchcliffe J. Mol. Strut. 1980,64 117; (b)A. Hinchcliffe ibid. p. 141. 42 R. D. Coombe and R. K. Horne J. Phys. Chem. 1980,84 2085. 43 H.-J.Mausle and R. Steudel Z. Anorg. Allg. Chem. 1980 463 27. 44 R. Fischer R. W. Schmutzler and F. Hensel J. Non-Cryst. Solids 1980 35-36 1295. 45 J. A. McCleverty N. J. Morrison N. Spencer C. C. Ashworth N. A. Bailey M. R. Johnson J. M. A. Smith B. A. Tabbiner and C. R. Taylor J. Chem. SOC.,Dalton Trans. 1980 1945. F. A. Hart A. G. Massey P. G. Harrison and J H. Holloway The aqueous oxidation of sulphur [equation (7)] has been investigated between 125 and 230°C and the results show that S (mainly as Ss rings) and S (mainly as chains) predominate at below and above 160'C respectively. The oxidations proceed differently for the two species.46 s+;o,+H,o -+ H~SO~ (7) Discussion about the possibility of isolation of a pure isomer S4Se4 with S and Se at alternate positions from a melt of equivalent amounts of sulphur and selenium has In the meantime thermal behaviour of sulphur-selenium mixtures at temperatures between 40and 450 "Chas shown that the polymerization threshold temperature of sulphur decreases with increasing selenium content.The formation of octa-atomic species Se8-,S (8 > x > 4) occurs only after the sulphur is in the liquid Chemical analysis mass spectroscopic Raman spectroscopic and X-ray diffraction methods have permitted the characterization of a number of sulphur-selenium phases [i.e.Se,- S (x = 2-7)] and complete X-ray single-crystal analyses of S7Se S6Sez S4Se4 and S3Se5 have shown that the first two have the y-S structure whereas the others have the a-Ses structure.However in all the structures there is considerable The intense coloration observed in the electrolyte on electrolysis of phosphorus- fluorosulphuric acid mixtures has been shown to be due to polyatomic sulphur cations and not phosphorus species.48" The existence of S16'+was first proposed as a result of the isolation of a red solid from the reaction of sulphur and AsF5 in anhydrous HF solution. Now crystals grown from a solution of the material believed to be SI6(AsF6),in a 2 :1mixture of so and S0,ClF at -25 "chave been shown to contain SI9*+(Figure 2). The structure contains discrete AsF6-anions and s19'+ cations the latter consisting of two seven-membered rings joined by a five-atom Figure 2 View of the SI9'+ cation (Reproduced by permission from Inorg.Chem. 1980,19 1423) 46 J.-P. Corriou and T. Kikindai J. Znorg. Nucl. Chem. 1981,42 9. 47 (a)H. H. Eysel and S. Sunder Indian J. Chem. Sect. A 1979 18,447; (6)A. Datta and V. Krishnan J. Thermal. Anal. 1979 17 31; (c) R. Laitinen L. Niinisto and R. Steudel Acta. Chem. Scand. Ser. A 1980 33,737. 48 (a)H. P. Fritz and 0.S. Huber Z. Naturforsch. Teil B 1980,35 530; (6) R. C. Burns R. J. Gillespie and J. F. Sawyer Znorg. Chem. 1980 19 1423. The Typical Elements 109 chain.48b The e.s.r. and absorption spectra of solutions obtained by the oxidation of sulphur with AsF5 in SO2have also been further investigated and the presence of SIQ2+, SS2+,and SS2+has been The cyclo-sulphur oxides S,O (n = 6-10) have been prepared by the oxidation of cyclic S by trifluoroperoxoacetic acid.Oxidation of sulphur with excess of the acid also produced S702 and S602.4QnCyclo-octasulphur monoxide is an unstable orange material. In an attempt to prepare more stable derivatives the synthesis of adducts with metal halides as electron acceptors has been investigated and the reaction with SbCl in CS at 20 "C and subsequent cooling has produced SsO-SbC15 (Figure 3). This contains SsO in an isometric conformation compared with SsO 2 Figure 3 Molecular structure bond lengths (pm) and torsional angles of S80-SbC15 (Reproduced from J. Chem. SOC.,Chem. Commun. 1980 180) itself which can be recovered from the adduct in its more usual conformation by recrystallization from acetone or carbon di~ulphide.~~' The preparation of cyclo- hexasulphur monoxide by oxidation of s6 with trifluoroperoxoacetic acid was reported in 1978 but crystals could not be obtained.Now the Sl2O2-2SbC1,.3CS2 adduct has been prepared by the reaction of S60 with SbCls in CS and the crystal structure determined. The conformation of the S12ring differs considerably from that of cyclo-dodecasulphur but the chair conformation of the six-membered rings of the two S60 component molecules can be seen in the S1202structure (Figure 4).4Qc Last year attempts to prepare &I+-containing compounds led to the preparation of [(s7I),I](SbF6),.2AsF,. Now (S71)4S4(A~F6j6 has been obtained according to equation (8).An analogous reaction with Br2 replacing 12 gave a product isomor- so 4ss+212 +9AsF5 4 (s71)4&(ASF6)6+3AsF3 (8) (11) tra2Br 1)+AsF~ $8 +3AsFs B S~(ASF~)~*XSO~(X (9) phous with (1 1) which is presumably (S7&)4S4(ASF6)6.The notion that the function of Br2 and I2 is catalytic was confirmed by the preparation of S4(A~F6)2 by reaction of Ss and excess of AsF5 in the presence of Brz which gave S4(A~F6)2.xS02 (x s 1) [equation (9)]. The structures of both new salts confirm the square-planar geometry of S42+and show that the s71+ unit is similar to that in [S71]+[SbF6]-.50 49 (a) E. Fluck Chem.-Ztg. 1980 104 206; (b)R. Steudel T. Sandow and J. Steidel J. Chem. SOC. Chem. Commun. 1980 180; (c)R. Steudel J. Steidel and J. Pickardt Angew. Chem. Int. Ed. Engl. 1980,19,325. 50 J. Passmore G. Sutherland and P.S. White J. Chem. SOC.,Chem. Commun. 1980 330. F. A. Hart A. G. Massey P. G. Harrison and J. H. Holloway C!La Figure 4 Intermolecular distances (pm) and torsional angles of SI2O2*2SbCl5.3CS2 (Reproduced by permission from Angew. Chem. Int. Ed. Engl. 1980 19 325) Other Ring Compounds Containing Predominantly Sulphur. Most sulphur homocyc- lic systems are stable only at low temperature but can in some cases (see section on sulphur-nitrogen compounds) be stabilized by introduction of heteroatoms into the rings. Several interesting such rings have been discovered this year. The fusion of a mixture of B2S3 and S in vacuo at 300°Cgives (BS2)g (Figure 5) which has a planar porphine-like structure. A second route to this compound involves the thiolysis of dibromotrithiadiborolan with H,S and gives the porphine-like product together with a polymeric chain compound involving S-linked B2S3 five-membered rings.51 Another new compound is decathiacylcotetradecane-6,7,13,14-tetraone S10(CO)4 (Figure 6),prepared by condensation of (C5H&TiS5 with oxalyl chloride in CS2.52 A cobalta-pentathia-heterocycle,(C5H5(PMe3)CoS5 (Figure 7) can be prepared by reaction of Ss with C5H5(PMe3)Co(p -C0)2Mn(CO)C5H4Me or C5H5(PMe3)Co( ring corresponds q2-CS2).The chair form of the six-membered COS~ to that of the compound (C5H5)2TiS5 and its vanadium analog~e.’~ Some errors in the hydrogen atom co-ordinates in the structure of (Me2N)3P0.2S7NH have been corre~ted.~~~.~ 51 B. Krebs and H.-U. Hurter Angew. Chem. Int.Ed. Engl. 1980,19,481. 52 H. W. Roesky H. Zamankhan J. W. Bats and H. Fuess Angew. Chem. Int. Ed. Engl. 1980,19,125. ” C. Burschka K. Leonhard and H. Werner 2.Anorg. Allg. Chem. 1980,464,30. 54 (a)J. C. Bollinger and T. Yvernault 2. Anorg. Allg. Chem. 1980 465 237;(b)J. Pickhardt and R. Steudel ibid. p. 239. The Typical Elements Figure 5 BBS16molecule with bond lengths (A) and bond angles (Reproduced by permission from Angew. Chem. Int. Ed. Engl. 1980 19,481) Figure 6 Molecular shape and interatomic distances (pm) in S10(CO)4 (Reproduced by permission from Angew. Chem. Int. Ed. Engl. 1980,19 125) Sulphur-Nitrogen Rings and Chains. Descriptions of ‘increased-valence’ structures and bonding for a wide range of mostly cyclic thiazyl compounds have been provided in which the 3d orbitals of sulphur have been omitted from the bonding An ab initiu MO study of S-N556vc and S-C55b conjugation has also been carried out.The molecules treated include (SN), (SN)4,55b*C SN oligomers the (SCH) isomers and their fluoro- and cyano-substituted counterparts. Sulphur 3d orbital participation is assumed in the ~cheme.”~ The first simple direct preparation of (SN) from solution by the reaction of (NSC1)3 and trimethylsilyl azide or sodium azide in acetonitrile has been reported. ’’ (a)R. D. Harcourt and H. M. Hugel J. Inorg. Nucl. Chem. 1981 43,239; (b)R.C.Haddon S. R. Wasserman F. Wudl and G. R. J. Williams J. Am. Chem. Soc. 1980 102 6687;(c) R.H. Findlay M. H. Palmer A. J. Downs,R. G. Egdell and R. Evans Inorg.Chem. 1980,19 1307. F. A. Hart A. G. Massey P. G. Harrison and J. H Holloway C6 c5 Figure 7 Molecular structure of C5H5(PMe3)CoS5 (Reproduced by permission from 2.Anorg. Allg. Chem. 1980 464 30) No evidence of an S2N2 intermediate was found. The synthesis is unsophisticated and can be carried out on a large The electrochemical behaviour of (SN) in acetonitrile solutions containing alkali-metal and silver salts has been Largely as a consequence of the relationship of S2N2 with (SN) the bonding and charge distribution has been a matter for speculation. Now X-ray photoelectron spectroscopy has been used to obtain core-level binding energies for gaseous S2N2 and hence an estimate of the charge distribution and extent of sulphur 3d orbital participation in the bonding.The results indicate that N(p.rr) -B S(d?r)back bonding is not necessary for a clear understanding of the bonding in S2N2 or S4N4.57 New routes to S4N4 are of importance because it is a valuable starting material for the preparation of inorganic and some organic sulphur compounds. Recently it has been prepared by the reduction of S4N3C1 or (NSCl) with iron. New routes to [SnC14(S4N,)2] [S4(NH),] and [(S5N5)(FeC14)] which avoid the use of the poten- tially explosive S4N4 have also been found.'* Reaction of S4N4 with CuC12.2H20 in organic solvents has yielded polymeric copper(I1) complexes CuC12-S4N459a and [CU(M~CN)C~~]~S~N~'~' in which the copper atoms are linked by S2N2 or S3N4 bridges. Photoelectron spectroscopy has been used to gain an overall picture of the structure of the S3N3 ring in several of its derivatives.60a Molecular and crystal 56 (a)J.Passrnore and M. N. S. Rao J. Chem. SOC. Chem. Commun. 1980 1268; (6)C. Bernard C. Tarby and G. Robert Electrochim. Acta 1980 25 435. 57 P. Brant D. C. Weber C. T. Ewing F. L. Carter and J. A. Hashmall Inorg. Chem. 1980 19 2829. 58 A. J. Banister A. J. Fielder R. G. Hey and N. R. M. Smith J. Chem. SOC. Dalton Trans. 1980,1457. 59 (a) U. Thewalt 2. Anorg. Allg. Chem. 1980 462 221; (b) U. Thewalt and B. Miiller ibid. p. 214. 6o (a) M. V. Andreocci M. Bossa V. Di Castro C. Furlani G. Mattogno and H. W. Roesky Gazz. Chim. Ztal. 1980 110 1; (b) B. Krebs G. Henkel S. Pohl and H. W. Roesky Chem. Ber. 1980 113 226.The Typical Elements Figure 8 Molecular shape and interatomic distances (pm) in the dimeric structure of [S3N2]+[SO3CF3]-.;MeCN (Reproduced by permission from Chem. Ber. 1980 113,226) s2 Figure 9 Molecular shape and interatomic distances (pm) in the molecule S3N2(NS02F) (Reproduced by permission from Chem. Ber. 1980 113 226) structures of [S3N2]'[S03CF ]-.$MeCN and S3N2(NS02F)have shown that in the ionic compound (Figure 8) the [S3N2]" radical cation is planar but in the covalently bonded compound (Figure 9) the S3N2ring is not.606 Reaction of S4N4with c~s-P~CI~(NCP~)~ which was expected to yield a compound in which the S4N4 group replaced the benzonitrile moiety gave a novel complex PtCl(S4N3) in which a formally singly negatively charged S4N3group is co-ordinated as a planar terdentate ligand to the Pt" (Figure Following the room-temperature study of the structure of [S4N3]+ two years ago a new low-temperature X-ray diffraction investigation on thiotrithiazyl nitrate has provided information on the nature of the interaction of the [S4N3]' with the anion and the electronic structure of [S4N,]'.62 61 H.Endres and E. Galantai Angew. Chem. Int. Ed. En& 1980,19,653. 62 G. Moss T.N. G. Row and P. Coppens Znorg. Chem. 1980 19,2396. F. A. Hart A. G. Massey P. G. Harrison and J. H. Holloway NZ N2 Figure 10 Molecular structure bond lengths (pm) and torsional angles of PtCl(S4N3) (Reproduced by permission from Angew. Chew. Int. Ed. Engl. 1980,19,653) Last year N4S4C12 was prepared for the first time.Treatment of the new compound with S2C12 has since been shown to give S3N3C12. Fluorination of N4S4C12 with AgF2 in CCl has yielded N4S4F4 and with NaF in MeCN the new thiazyl fluoride N4S4F2 has been Complexes of S4N4H4 with Ag[C104] were first made in 1977. Now the [(S4N4H4)2]' cation in 2S4N4H4.Ag[C104] (Figure 11)has been shown to have a sandwich structure with the S4N4 crowns arranged so that the sulphur atoms are nearer the cation and there are no Ag-N bonds. Another structural feature is that the S4N4 rings have approximately a staggered config~ration.~~ This is the first example of a crystal structure of a complex of a sulphur imide and the first proven example of donor sulphur rather than donor nitrogen in any sulphur nitride or imide adduct.Degradation reactions of sulphur-nitrogen rings are not usually clear-cut and often occur non-stoicheiometrically. It has now been shown that reaction of S4N402 (12) with triphenylarsane gives the asymmetrically substituted sulphamide (13) [equation (i~)].~' Reactions of cyclotetrathiatriazenium halides have attracted considerable attention this year. The chloride vaporized at 130°C reacts with Fe Ti and Ag 63 L. Zborilova P. Gebauer and J. Strnad Z. Chem. 1979,19,255. 64 M.B.Hursthouse K. M. A. Malik and S. N. Nabi J. Chem. Soc. Dalton Trans. 1980 355. 65 H. W.Roesky M. Witt W. Clegg W. Isenberg M. Noltemeyer and G. M. Sheldrick Angew. Chem. Int. Ed. Engl. 1980,19 943. The Typical Elements Figure 11 View of the [Ag(S4N4H4)2]+cation (Reproduced from J.Chem. Soc. Dalton Trans. 1980 355) (12) at 300°C to give respectively S3N2Cl S4N4 and (NSCI),; S N2 and TiCl,; and S2N2 Ag2S and AgCl. The isolation of S2N2 from the Ag reaction and the polymerization to (SN) have also been described.66" The reaction of S4N3C1 vapor- ized at 130°C with NaI on a glass support at 250°C gives a black iodinated poly(su1phur nitride) (SaNbIC) (a = 3.0 b =r 2.1 and c = OS),when the reaction mixture is cooled to 10°C. The compound is conducting moisture sensitive and decomposes above 40 "C in vacuo to give S S4N4 and 12.66b Iodinated polyhalides S4N313 S4N312Br and S4N31Br2 were also produced by reactions of the appropriate caesium trihalide and S4N3Cl. The action of iodine on S3N3C13 gives the analogous S4N31C12.The tribromide derivative S4N3Br3 is obtained by metathesis between alkali-metal tribromides and S4N3C1.66C Conductance behaviour of S4N3X(X = C1 66 (a) A. J. Banister and Z. V. Hauptman J. Chem. SOC.,Dalton Trans. 1980 713; (b) A.J. Banister and N. R. M. Smith ibid. p. 937;(c) H. Vincent Y. Monteil and M. P. Berthet J. Inorg. Nucl. Chem. 1980,42,5; (d) R.C. Paul R. P. Sharma R. D. Verma and J. K. Puri IndianJ. Chem. Sect. A 1979,18,516. 116 F. A. Hart A. G. Massey P. G. Harrison and J. H. Holloway or Br) and their adducts [S4N3][TeBr5] [S4N3]2[TeBr6] [S4N3][SbCI4] and [S4N4][SbBr4] has been studied in disulphuric chlorosulphuric and fluorosul- phuric acids.66d Reaction of S4NsCl with silylated sulphodi-imides or substituted urea in a 1:1 molar ratio leads to compounds of composition S4N5XSiMe3 (14).In a 2 :1 molar ratio (15a) and (15b) were obtained as explosive material^.^^ Work on other more S / YN, ss .X-N I \,Ci X = -N=SMe2=N- -N=S=N- -N=s=N- -N=S=N- or -N-C-N-I It I Me0 Me vu (a> (b) (4 (e> stable basket-like bicyclic sulphur-nitrogen compounds bGed on S5N6 (16) has continued. A facile synthetic route for the preparation of S5N6itself and S5N6(CH3)2 (17),using S4N4C12 and Me3SiN=S=NSiMe3 and Me3SiN=SMe2=NSiMe3 respec- tively as starting materials has been published. The observation of small quantities of S5N6 and S4N4 as by-products in the latter reaction has permitted a rationalization of the formation of S5N7SiMe5(18).The X-ray crystal structures of (17) and (18) have been determined.68 Me Me \/ S S /\ NN \ S' S Me N\/ NS Me/\N-SiMe Sulphur-nitrogen ring compounds containing boron6' or in the ring have also been prepared this year.An eight-membered boron-containing compound was synthesized by the reaction of dichlorophenylborane with S,S-dimethyl-N,N'- bis(trimethylsily1)sulphodi-imide[equation (1l)]and the X-ray single-crystal struc- 67 H. W. Roesky C. Graf and M. N. S. Rao Chem. Ber. 1980,113,3815. W. S. Sheldrick M. N. S. Rao and H. W. Roesky Inorg. Chem. 1980 19 538. 69 H.W. Roesky S. K. Mehrotra and S. Pohl Chem. Ber. 1980,113,2063. 'O (a) F.-M. Tesky and R. Mews Chem. Ber. 1980 113 2434; (b)A.Gieren B. Dederer R.Martin F. Schanda H. W. Roesky and M. Eiser ibid. p. 3904;(c) H.W.Roesky T. Miiller E. Wehner and E. Rodek ibid. p. 2802;(d)A.Gieren and B. Dederer 2.Anorg. AUg. Chem. 1980,467,68. The Typical Elements Ph Me\4N-SiMe Me N-B-N S + 4Me3SiC1 (11) + 2PhBC1 -\/ I yMe Me/ 'N-SiMe Me/ 'N-B-N' \Me I Ph (19) But I ture of the compound (19) was determined.69 The carbon-containing compounds include a series of A 6-thiadiazetidinones (20) prepared by the reaction of sulphur tri-imides (Bu'N)~S(NR,),and excess of RfNC0.70"The AsF adduct of 5-0x0-1,3A 4,2,4-dithiadiazole S2N2C0,has also been synthesized and shown to contain the planar five-membered S2N2Cring (Figure 12). 70b Related carbon-containing NI s2 Figure 12 Molecular structure of SzN2CO.AsF5 (Reproduced by permission from Chem.Ber. 1980,113,3904) species containing bicyclic ring systems were prepared by the reaction of trimethyl- silyl-substituted ureas (21a b) with S3N3C13 [equation (12)].70' The X-ray single- crystal structures of both the eight-membered ring of the boron-containing com- pound ( 19y9 and the bicyclic carbon-containing species (22)70c exhibit significant [ R2 \ 0II R'-N-C-N-R2 I I + S,N,CI -* RO=C ~ ~ ~ ~ >C1-+ 2Me3SiC1 {(12) Me3Si SiMe (21) a; R' b; R' = R2 = Me = Me R2 = Ph (22) deviations from planarity. The X-ray structure of another novel bicyclic compound in which a sulphur di-imide unit bridges one PNP unit in a cyclotetraphorphazene ring has shown that the sulphur di-imide unit and its substituents are coplanar.The cyclotetraphosphazene ring exhibits a flattened crown-saddle conformation.70d 118 F. A. Hart A. G. Massey P. G.Harrison and J. H. Holloway Three binary sulphur-nitrogen anions have been structurally characterized the bicyclic cage [S4N5]- the planar six-membered ring [S,N,]- and the planar cis-trans chain S4N-. It has now been shown that reaction of triphenylphosphine with S4N- in acetonitrile produces S3N- which reacts with NiC1 to give Ni(S3N),. Vibrational spectra of S3*N- ("N = 30% "N) suggest an -S-N=S=S arrange-ment of atoms in the anion.71 Thermal decomposition of [(Ph3P),N]+[S4N5]- in acetonitrile at 78 "C leads to the formation of the corresponding [S3N3]- and S4N- as reported last year.Full details of the structure determination of the sickle-shaped S4N- ion in [(Ph,P),N]'[S,N]- have also appeared.72a New thermal decomposition studies on Ph3P=N-S3N3 in acetonitrile have shown that Ph3P=N-S-N=S=S is formed. This contains a neutral sulphur-nitrogen chain with a similar shape to the S4N- These new data suggest that the terminal -S-N=S=S arrangement is an important structural feature in open-chain sul- phur-nitrogen compounds. Sulphur-imide species have been under investigation largely because of current interest in compounds containing sulphur-nitrogen double bonds. E.s.r. studies of the properties of radical anions produced by the one-electron reduction of some di-imido-sulphur compounds S(NR), and some of their complexes with Group 6A metal carbonyl derivatives have been carried New synthetic work includes the preparation of di-t-butylsulphur tri-irnides (Bu'N),S(NR) in high yield from the reaction of tri-t-butylsulphur tri-imide S(NBU')~ with isocyanates RNCO [R = perfluoroalkyl sulphonyl pentafluorosulphonyl FS02N=C(CF3)-].By the sarqe method the bis(trimethylsily1) derivative (Me,SiN),S[NCF(CF,),] is also produced.73 Sulphur-Nitrogen-Fluorine Compounds. The chemistry of thiazyl fluoride NSF and thiazyl trifluoride NSF3 has been authoritatively reviewed.74 New chemistry in this area includes reaction of NSF with (CF,),C=CF in the presence of CsF at 130 "C which gives (CF3),C-N=S=N-S-C(CF3)3. A similar reaction with NSF3 gives NSF2C(CF3)3 which isomerizes above 100 "C to (CF,),CNSF,.Unlike (CF,),CNSF, NSF,C(CF,) forms2 :1 adducts with AsF5 and SbF5.75a Sulphur- sulphur difluoride imides have been prepared using Hg(NSF&. The reaction of S2CI with Hg(NSF2) gives F2S=N-S-S-N=SF2 and OSCl and SFsNSC12 react with Hg(NSF,) to give O=S(F)NSF and F5SN=S(F)NSF2 The S-N and S-F distances in co-ordinated NSF in [Co(NSF)6][AsF6]2 have been shown by X-ray crystal structure determination to be much shorter than those in free thiazyl Vibrational spectroscopic studies on Lewis-acid derivatives of NSF3 have shown that the frequencies of the NSF3 normal vibrations are shifted to higher values. Force constant calculations indicate that the N-S bond strength increases by up to 40% of that in NSF3 depending on the Lewis acid employed.76 71 J.Bojes and T. Chivers J. Chem. SOC.,Chem. Commun. 1980 1023. 72 (a) T. Chivers W. G. Laidlaw R. T. Oakley and M. Trsic J. Am. Chem. SOC., 1980 102 5773; (b) T. Chivers R. T. Oakley A. W. Cordes and P. Swepston J. Chem. Soc. Chem. Commrtn. 1980 35. 73 (a)J. A. Hunter B. King W. E. Lindsell and M. A. Neish J. Chem. SOC.,Dalton Trans. 1980 880; (b)F.-M. Tesky and R. Mews Chem. Ber. 1980,113,2183. 74 0.Glemser and R. Mews Angew. Chem. Int. Ed. Engl. 1980 19 883. " (a) A. Waterfield W. Bludssuss R. Mews and 0.Glemser 2. Anorg. Allg. Chem. 1980,464 268; (6) I. Stahl R. Mews and 0. Glemser Chem. Ber. 1980 113 2430; (c) B. Buss P. G. Jones R. Mews M. Noltemeyer and G. M. Sheldrick Acta Crystallogr. Sect. B 1980 36 141. 76 F. M. Schnepel R.Mews and 0.Glemser J. Mol. Struct. 1980 60 89. The Typical Elements 119 Sulphur Chain Species and Polyanions. Although certain polymers such as (SN) and its derivatives doped polyacetylene and doped poly-p -phenylene exhibit high electrical conductivity they do not possess the processing characteristics desirable in a polymeric metal. However now electrical conducting p-type films wires and powders have been prepared by the oxidation of poly-p-phenylene sulphide (23) with AsF,. The product is the first melt and solution-processible polymeric precursor to a conducting (23) (24) It has been shown that caesium salts of a,w-dithiols react in dimethylformamide with a,@-dihalides to give dithia medium ring and macrocyclic compounds in good yield.78 These are useful for investigations of eleetron transfer between sulphur atoms.One-electron oxidation of 1,2-dithiacycloalkanes [e.g. (24)] has been studied by e.s.r. with reference to the planarity of the R-S'-'S-R group.79 The disulphide group is well recognized as a potential binding site for metal ions in biological systems and a tremendous amount of work associated particularly with iron-sulphur and molybdenum-sulphur bridged species has been published this year. This includes the first examples of 'double cubane' structures containing extended sulphur triple bridges." However this area is reviewed in the 'Transition Elements' section of this Annual Report. Of course disulphides also occur in non-metallic compounds. A new addition to known procedures for synthesizing symmetrical disulphides is the reaction of sodium borohydrides with thioamides [equation (13)].Since no reaction occurred NaBH R'-C-NR22 AR1CH2S.SCH2R' II MezCHOH S R' = aryl NRZ2= morpholino when R' = aryl and NR22 = NMe2 or when R' = alkyl and NR22 = morpholino it may be that the reactions are governed by steric factors.81a When (CF,),C(OH)SH was mixed with SC12 and C12 the compounds HO(CF3)2CSSSC(CF3)20H and HO(CF,),CSSC(CF,),OH respectively were formed.'16 Ligating properties of disulphides and thioethers with Ca2' and several 3d transition metals have shown that in general the complexes with soft metal ions are stronger than those with the hard metal ions. It also appears that the thioethers have better ligating properties than the disulphides." The isolation and first crystal structure determination of a thiosulphite 0,O'-di- ester a near relative of the disulphides has recently been reported.The compound 77 (a)J. F. Rabolt T. C. Clarke K. K. Kanazawa J. R. Reynolds and G. B. Street J. Chem. SOC. Chem. Commun. 1980 347; (b) R. R. Chance L. W. Shacklette G. G. Miller D. M. Ivory J. M. Sowa R. L. Elsenbaumer and R. H. Baughman ibid.,p. 348. 78 J. Buter and R. M. Kellogg J. Chem. SOC.,Chem. Commun. 1980 466. 79 H. Bock and U. Stein Angew. Chem. Znt. Ed. Engl. 1980 19 834. T. E. Wolff J. M. Berg P. P. Power K. 0.Hodgson and R. H. Holm Znorg. Chem. 1980 19 430. (a)S. A. Okecha Chem. Ind. (Londm) 1980 788; (6)Q.-C. Mir and J. M. Shreeve Inorg. Chem. 1980,19 1510.82 H. Sigel K. H. Scheller V. M. Rheinberger and B. E. Fischer J. Chem.SOC., Dalton Trans. 1980,1022. F. A. Hart A. G. Massey P. G. Harrison and J.H. Holloway U,O-bicyclohexyl-1,l’-diylthiosulphite (26),was prepared by the reaction of the diol (25)with bisbenzamidazol-1-yl sulphide in CCI [equation ( 14)].83 S // -N /= benzimidazol-1-yl \ The crystal structure of dimorpholinotetrasulphane (Figure 13)has revealed that the NSSSSN chain in the molecule occurs in the trans,trans-form the S-S bonds alternating only slightly in length along the chain.s4 Figure 13 Molecular structure of dimorpholinotetrasulphane (Reproduced from J. Chem. SOC.,Dalton Trans. 1980 632) The di-alkali-metal trisulphides Na2S3,s5a Rb2S3 and CszS3856 have been prepared by the reaction of the elements in liquid ammonia at high pressure and their crystal structures have been determined.In all cases the structures contain bent S3’-polyanions as a characteristic feat~re.~~~’~ The resonance Raman spectra of the blue species in CsC1-A1Cl3 molten salts indicate that S3-radicals are present to some extent in this system X-Ray single-crystal structure examination of RbzS5 has shown that this contains unbranched Ssz-chains.85d Sulphur Oxides Sulphur Oxide Halides and Related Compounds. A crystal structure determination on Fe,(CO),(S)SO has shown it to be the first example of a compound containing the SO ligand. The compound was prepared by the reaction of sulphite with Fe3(CO),1H- which is formed by partial oxidation of Fe(C0),z-.s6 Energies of hydrogen-bonding charge distributions and dipole moments of SO SOz,SO3,Me2S0 MeZSO2 (MeO),SO and (MeO),SOZ and their linear hydrogen- bonded complexes with HF have been obtained by semiempirical CND0/2 calcula- tion~.~’~ The hydrogen-bridged cation [Me2SO-.-H--OSMez]’ with a very short R3 D. N. Harpp K. Stelion and C. J. Cheer J. Chem. Soc. Chem. Commun. 1980 825. 84 0.Foss and V. Janickis J. Chem. SOC.,Dalton Trans. 1980,632. 85 (a) P. Bottcher Z. Anorg. Allg. Chem. 1980 467 149; (b)P. Bottcher ibid. 1980 461 13; (c) R. W. Berg N. J. Bjerrum G. N. Papatheodorou and S. Von Winbush Inorg. NucL Chem. Lett. 1980,16 201; (d)P. Bottcher Z. Kristallogr. 1979 150 65. 86 L. Mark6 B. Mark6-Monostory T. Madach and H. Vahrenkamp Angew.Chem. Znt. Ed. Engl. 1980,19,226. 87 (a) A. E. Lutskii A. F. Korunova R. G. Islamov and V. A. Vetrov Teor. Eksp. Khim. 1980 16 88; (b)B. R. James R. H. Morris F. W. B. Einsten and A. Willis J. Chem. Soc. Chem. Commun. 1980 31. The Typical Elements 121 0.-H--0bond length of 2.42 A has been found in salts of tetrachlororhodate(II1) containing sulphoxide ligand~.~'~ This is the first direct evidence of protonated sulphoxides although it has been thought for some time that such species might be important in some organic reactions carried out in Me2S0 and in acid-catalysed decomposition of sulphoxides. Thermal decompositions of Naz[S20,] and K2[S203] have shown that polysul- phides are formed. In the presence of air sulphate salts are produced.It has been confirmed that the decompositions take place via sulphite intermediates.88 In a study of charge-transfer complexes of the type SO,-X- SOCl,.X- SOBr2.X- SO2CI2.X- Se02-X- and SeOCl,.X- (X = C1 Br I or SCN) in the solvents MeCN DMSO and their mixtures it has been shown that the stability constant value depends on the solvent employed and in mixed solvents on the mole fractions used." The nature of the chemical bonding of SO to transition-metal and other sub- strates continues to be of interest particularly with respect to determining factors which dictate the mode of binding (pyramidal coplanar or side-on-bonded) and the reactivity of the attached SO,. Crystal structure determinations of Rh(ttp)Cl(SO,) and [Rh(ttp)(CO)(SO,)](AsF,) [ttp = bis-(3-diphenylphosphino-propyl)phenylphosphine] have shown that both contain square-pyramidal co-ordi- nation units with apical pyramidal SO2 ligands.The neutral chloride compound is the most dissociatively and oxidatively stable pyramidal complex yet reported and has the shortest known metal-pyramidal SO distance.90a Single-crystal X-ray structure determinations on Mo(CO),(phen)(SO,) and Mo(C0)2(bipy)(S02)2 have shown that they contain side-on-bonded q2-type interactions of SO with the transition metals the latter compound containing q2-S02 ligands trans to one an~ther.~'' This brings the number of complexes in which side-on-bonding of SO has been confirmed to four. The structure of Fe2(C0)8S02 in which the SO ligand bridges the two metals was determined some time ago and now vibrational spectro- scopic data has been correlated with the structural inf~rmation.~" The temperature dependence of the reaction of SO with the OH radical in argon and sulphur hexafluoride has been studied using a flash-photolysis-resonance-fluorescence technique." Oxygen K-spectra together with X-ray emission and photoelectron spectra have been used to examine the electronic structures of SO,2-and SO,2-and their selenium and tellurium analogue^.^' Reaction of SO with SbF3 in liquid SO solution results in the formation of F2SbS03F FSb(S03F), and Sb(SO,F), the composition of the product depending on the molecular ratio of the reactants.93a Raman and 19F n.m.r.data have shown that reaction of SO with PF5 produces Sn03n-1FZ (n = 3-7).93b An X-ray single- crystal structure analysis of the 2 :1 addition product of the reaction of SO with K.D. Cleaver and J. E. D. Davies J. Chem. SOC. Dalton Trans. 1980 245. 89 S. B. Salama D. D. Salameh S. Wasif M. M. Omer M. M. Nour and M. Ajmal J. Mol. Struct. 1980,60,73. 9" (a) G. P. Eller and R. R. Ryan Inorg. Chem. 1980 19 142; (6) G. J. Kubas R. R. Ryan and V. McCarty ibid. p. 3003; (c)S. Sourisseau and J. Corset fnorg. Chim. Acta 1980 39 153. " G. W. Harris R. Atkinson and J. N. Pitts jun. Chem. Phys. Lett. 1980 69 378. 92 N. Kosuch G. Wiech and A. Faessler J. Electron Spectrosc. Relat. Phenom. 1980 20 11. 93 (a)J. Touzin and L. Mitacek Collect. Czech. Chem. Cornmun. 1979 44 2751; (b)J. Touzin and L. Mitacek 2.Chem.1980,20 32; (c)A. Gieren U. Riemann and B. Dederer Z. Anorg. Alfg. Chem. 1980 468 15. F. A. Hart A. G. Massey P. G. Harrison and J. H. Holloway 01 N 1' Figure 14 Molecular structure of 1,2,3-oxathiazolo[5,4-d][ 1,2,3]oxathiazole-2,2,5,5- tetroxide (Reproduced by permission from 2.Anorg. Allg. Chem. 1980,468 15) cyanogen (CN), has shown that the compound is a formal 'criss-cross' cycloaddition compound (Figure 14) in which the bicyclic ring system is planar.93c Although 'disulphene' has been known for some time all attempts to prepare the corresponding perfluoro-compound have failed. Following unsuccessful attempts to electrofluorinate disulphene perfluorodisulphene (28) and its per- chloro-analogue which are the smallest cyclic disulphones have been prepared by a chemical method.The perfluoro-derivative is obtained by the reaction of tetrafluoro-1,3-thietan (27) with excess of chromium trioxide in boiling fuming nitric acid [equation (15)l.'" (28) The preparation of trifluoromethyltrifluoromethanesulphonatehas been studied and differences with earlier work have been discussed in detail.95" The synthesis of a large number of trifluoromethanesulphonate derivatives of perfluoroalkyls has also been reported. The preparations have resulted from the reactions of chlorine(1) and bromine(1) trifluoromethanesulphonates with perfluoroalkyl halide^.'^' The scope of the reaction of fluorocarbon halides with chlorine fluorosulphate and mixtures of chlorine and bromine fluorosulphate to produce RfOSOzF compounds has also been inve~tigated.~" The neutron diffraction structure determination on K3[03SON(S03)2]-was published three years ago.This together with a new 1.5Hz0 X-ray single-crystal structure determination on K2[03SONHS03](Figure 19 has permitted the interpretation of the i.r. and Raman spectra of these species. Aqueous solution spectra have also been re~orded.'~ 94 R. Seelinger and W. Sundermeyer Angew. Chem. Znt. Ed. Engl. 1980 19 203. 95 (a)R. E. Noftle Znorg. Nucl. Chem. Lett. 1980 16 195; (b) Y. Katsuhara and D. D. DesMarteau J. Am. Chern. Soc. 1980 102,2681; (c) C. J. Schack and K. 0.Christie J. Fluorine Chem. 1980 16 63. 96 J. R. Hall R. A. Johnson C. H. L. Kennard G. Smith B. W. Skelton and A. H. White J. Chem. SOC.,Dalton Trans.1980 2199. The Typical Elements Figure 15 Molecular structure of the 03SONHS032-anion (Reproduced from J. Chem. SOC., Dalton Trans. 1980 2199) Patents for the preparation97n and purification9" of SOF2 have been published. An ab initio molecular orbital study on the sulphonyl radicals XSO (X = H Me NH, OH F or C1) together with the simplest sulphinic acid HS02H and related species have suggested that the radica! site in XS02 is significantly delocalized over the entire functional A high-pressure mass spectrometric technique has been used to study the first four addition reactions of SO2 on to C1- [equation (16)]. From the enthalpy change for the first two of these reactions and A-.Bn +B A-*Bn+I n =0-3 from the heats of formation of C1- and SO2 the heats of formation of [S02Cl]- and [(SO,),Cl]- have been calculated.99a Thermodynamic data on SO2C1F were also needed in order to assess its role in preparative chemistry.Recently its heat of formation was measured and those of S02Br2 S02BrF and HS03Br have been estimated.996 Reduction of S0,CIF with either LiAIH or NaBH has been shown to give the metal chloride and fluoride and H2S.'Oo The new hypohalites CF3S03CI and CF3S03Br have been prepared by the reactions of CF3S03H with C1F and CF3SO3C1 with bromine respectively. Both are thermally unstable at room temperature. The low-temperature Raman spectrum of the hypochlorite has been assigned on the basis of C1 symmetry and Raman spectra for CF3S02F and CF3S020H have also been reported for the first time."' Electrochemical fluorination of C1CH2S02C1 has been shown to yield CF, CF3C1 S02F2 SF6 CF3S02F and C1CF2S02F as the main products.'02 97 (a) R.Dlaske G. Furcht and H. Hanneg Ger. (East) P. 139935 (C1. C01B9/08) 30 Jan. 1980 Appl. 155 845 07 Jun. 1971 5 pp; (b) G. Urban Ger. Offen. 2 831 413 (CI. C01B17/45) 31 Jan. 1980 Appl. 17 Jul. 1978 7 pp. 98 R. J. Boyd A. Gupta R. F. Langler S. P. Lownie and J. A. Pincock Can. J. Chem. 1980 58 331. 99 (a)R. G. Keesee and A. W. Castleman jun. J. Am. Chem. SOC.,1980 102 1446; (b)M. Cartwright and A A Woolf J. Chem. SOC. Dalton Trans. 1980 817. loo D. K. Padma V. S. Bhat and A. R. Vasudevamurthy Indian J. Chem. Sect. A 1980 19,471. lo' Y. Katsuhara R. M. Hammaker and D.D. DesMarteau Znorg. Chem. 1980 19,607. lo* P. Satori and W. Habel J. Fluorine Chem. 1980,16,265. F. A. Hart A. G. Massey P. G. Harrison and J. H. Holloway Fluorosulphuric and other Halogeno-0x0-acids and their derivatives. Fluorosulphuric acid and its chemistry have been reviewed.'03 Fluorination of graphite-HS03F mixtures at ca. 200°C has been shown to yield a pale-yellow compound with the empirical composition (CF;yHS03F) (x -0.97 y -0.05). Additional fluorina- tion of this material at 275-530 "C produced the compound (CF1.23-1.25)n the thermal stability of which depends on the nature of the initial graphite.lo4" The Raman spectra of stage I graphite-fluorosulphuric acid intercalation compounds have shown that the free S-0 bonds are longer in the intercalate than in the liquid acid.Fluorosulphates have been a source of considerable interest. The new salt [NF4][S03F] has been prepared by the reaction of [NF4][SbF6] with CsS03F in anhydrous HF at -78 "C and the decomposition of the salt at 10"C has provided a convenient synthetic route to FOS0,F. 105a Gold(III) fluorosulphate has emerged as an excellent fluorosulphate ion acceptor giving [Au(SO~F)~]-. This has been exploited in the synthesis of [Au(SO,F)~]- salts containing the cations Br3+ Br5+ [Br(S03F)2]' and [I(S03F)2]'.'05b 1.r. and Raman spectra of the strongly associated liquids of general formula ASF,(SO,F)~_ (n = 2-4) have shown the presence of fluorosulphate bridges in these species. The study has also been extended to As"' fluoride fluorosulphates.lo5' The use and value of fluorosulphates and tri-fluoromethanesulphonates as compounds with 'super-leaving groups' have been demonstrated in organic chemistry. This has been used in recent research aimed at the development of new electrophilic reagents with greater reactivity and higher selectivity which would obviate the need for Friedel-Crafts catalysts and permit control of the isomeric ratio of reaction The fluorosulphonyl group is of interest in the highly acidic tris(fluorosu1- phonyl)methane HC(S02F), which has been prepared from acetanilide. Some of its chemistry has been investigated.lo6 The fluoroxysulphate ion discovered last year has been investigated more closely. Aqueous fluoroxysulphate decomposes to form 02,H202,and [HSOJ and the oxidation occurs at a rate convenient for detailed study.A mechanism has been proposed in which the rate-determining steps are the interaction of S04F-with H20 to form HS05- and H202. The H202probably interacts further with S04F- by means of a free-radical chain reaction to give oxygen. Oxidation reactions were also investigated.lo7 Sulphur Halides. The properties and reactions of some sulphur fluorides have been reviewed.lo8 In an n.m.r. investigation of a variety of chloride compounds 35C1 chemical shifts for a number of chlorides of sulphur have been reported."' Io3 R. E. Eibeck in 'Kirk-Othmer Encyclopedia of Chemical Technology' 3rd Edn. ed. M.Grayson and D. Eckroth Wiley New York Vol. 10,p. 812. lo4 (a) A.S. Nazarov A. M.Danilenko and I. I. Yakovlev Zh. Neorg. Khim 1980,25,350;(b)B. Iskander P. Vast A. Lorriaux-Rubbens M. L. Dele-Dubois and P. Touzain Mater. Sci. Eng. 1980 43,59. lo' (a)K. 0.Christe R. D. Wilson and C. J. Schack Inorg. Chem. 1980 19 3046; (b)K. C.Lee and F. Aubke ibid. p. 119;(c) F. Aubke J. Fluorine Chem. 1980 15 59; (d)F.Effenberger Angew. Chem. Int Ed. Engl. 1980 19 151. G. Kloter H.Pritzkow and K. Seppelt Angew. Chem. In?.Ed. Engl. 1980,19 942. lo' R. C. Thompson and E. H. Appelman Inorg. Chem. 1980,19,3248. lo* R. E. Eibeck and W. Mears in 'Kirk-Othmer Encyclopedia of Chemical Technology' 3rd Edn. ed. M. Grayson and D. Eckroth Wiley New York Vol. 10,p. 799. lo9 K. Barlos J. Kroner H. Noth and B. Wrackmeyer Chem. Ber. 1980,113,3716. The Typical Elements Mixtures of FSSF F2SS SF, and SF6 have been obtained from reactions of sulphur or COS with elemental fluorine and FSSF has been freed from the impurities and isolated at -78 'C.lloa1.r.and Raman spectra of FSSF and F2SS in an argon matrix have been obtained for both pure 32Sand 34Sanalogues. This has permitted a new improved vibrational assignment to be made and force constants were also calculated. The photochemical behaviour of the isomers in the matrix was also studied."ob In an attempt to prepare [S21]+[AsF6]-(cf. [S2F]'[AsF6]-) by reaction of S,'+[ASF~]-~with an excess of iodine S2142C[A~FJ2 was obtained. It was then also synthesized quantitatively in liquid SO according to equation (17). The crystal so2 $Ss +21 + 3AsF5 -+S2142+(AsF6-)2 +AsF3 (17) structure shows that the S2142+ cation has a distorted right-triangular prismatic structure with one S2 and two Iz units joined by weak S-I bonds (Figure 16).The S-S bond distance is the shortest reported in an isolated compound and is indicative of the presence of a 3p.rr-3~~ bond and a bond order greater than 2."' Figure 16 Molecular structure of the SZI~~+ cation (Reproduced from J. Chem. Soc. Chem. Commun. 1980,289) Although SC1 has been known for some time SF2 was prepared for the first time only two years ago. This year finally the elusive dibromide and di-iodides have also been prepared for the first time. Mixtures of S2C12 with bromine or iodine in excess argon were passed through a microwave discharge and the products of the reaction were collected on a cold finger at 9 K.The reaction pathway is outlined in equation (18).The natures of the new species were confirmed by i.r. spectros- Photoelectron spectra of SBr2 and SeBr have also been obtained.'"' In the meantime SF2 and the related molecule CF3SF have been shown to exhibit unusual chemical equilibria with their dimers F3SSF and CF3SF2-SCF3.112C 'lo (a) A. Haas and H. Willner 2.Anorg. Allg. Chem. 1980 462 57; (b) A. Haas and H. Willner Spectrochim. Acta Part A 1979 35 953. ''I J. Passmore G. Sutherland T. Whidden and P. S. White J. Chem. SOC. Chem. Commun. 1980 289. (a) M. Feuerhahn and G. Vahl Znorg. Nucl. Chem. Letr. 1980 16 5; (b) E. Nagy-Felsobuki and J. B. Peel Chem. Phys. 1980 45 189; (c) W.Gombler A. Haas and H. Willner Z. Anorg. Allg. Chem. 1980,469 135. F. A. Hart A. G. Massey P. G. Harrison and J. H. Holloway ClSSCl 2 CI + .SSCI x2s+*c1 A patent on the preparation and use of sulphur tetrahalide-metal halide deriva- tives of formula SX,'MY,-(X = F or C1 Y = halogen n = 4-6) has been taken out. Four new compounds of this family SC13'GaC14- SCl3'InCl4- SC13+TeC15- and 2SC13'ZrC162- have also been prepared and their Raman spectra have been Detailed solid-state vibrational spectra on the stable and metastable forms of SC13'IC14- have confirmed the distortion from square planarity of the IC14- ions in the stable form. On the basis of Raman and n.q.r. spectra the distortion in the metastable form is similar to that found in Na[IC14].2H20.These distortions have been discussed in terms of secondary bonding interactions in the solid The i.r. spectra of SF4 isolated in argon and neon matrices have been recorded at 4 K and 32S-34Sisotopic shifts have been used to resolve ambiguities concerning the assignments of the deformation mode^."^" These problems have been further settled by the computation of a force field for SF4 from known experimental data by an a6 initio Photochemical reaction of SF4 with ClF has been studied and two significant reaction pathways have been identified. The first is molecular addition to yield SF5Cl and the second a typical laser-induced radical process which gives S2F10 and C12.114c A beam of mass-selected SF5' ions has been crossed with the radiation from a pulsed COz laser.Direct measurement of the distribution of the lifetimes of i.r. multiple-photon pumped SF5+ ion molecules prior to their dissociation into SF4+ and F was made and this has provided data on the distribution of the total internal energy of the molecules excited by the absorption of the i.r. radiation.'l5 A new report on the fluorination of molten elemental sulphur with gaseous fluorine at 180-200 "C has appeared."6 Negative ion formation in SF6 has been studied by observing the collisions of a SF6 beam with a beam of argon atoms in Rydberg states which acted as a source of electrons of about zero energy.'l7 Through advances in high-temperature chemistry it is now possible to measure the stepwise bond dissociation energy of a number of multivalent compounds in which a central atom is surrounded by identical ligands.This has been exploited in studies on the chemiluminescent reactions of SF6and SF4with metastable calcium and strontium atoms under single-collision conditions. In combination with known heats of formation the results have permitted deduction of successive bond dissoci- '13 (a) R. Hulme U.S.P. 4 172 115 (Cl. 423-276; COlB17/45) 23 Oct. 1979 Appl. 628 590 04 Nov. 1975 6pp; (b)F. W. Poulsen Inorg. Nucl. Chem. Lett. 1980 16 355; (c) A. Finch P. N. Gates T. H. Page. K. B. Dillon and T. C. Waddington J. Chem. SOC. Dalton Trans. 1980 2401. 'I4 (a) K. 0.Christe H. Willner and W. Sawodny Spectrochim. Acta Part A 1979 35 1347; (b) W. Sawodny K. Birk G. Fogarasi and K.0. Christe Z.Nuturforsch. Teil B 1980 35 1137; (c) C. Naulin and R. Bougon J. Chem. Phys. 1980,72 2155. '" A. Von Hellfeld B. Arndt D. Feldman P. Fournier and K. H. Welge Appl. Phys. 1980 21 9. '16 V. K. Kansal and D. G. Jaole Chem. Age India 1979,30 391. 'I7 J. P. Astruc R.Barbe and J. P. Schermann J. Phys. B 1979 12 L377. The Typical Elements 127 ation energies for the SF6 molecule.' Earlier bond dissociation energy values together with data from negative ion charge-transfer reactions have been used to re-evaluate the electron affinity of the SF5radical.'lsb The thermal decomposition of SF6 in the presence of metals and silicone resin laminates has been ~tudied."~" The degradation of epoxy insulating materials by arc-decomposed SF6,'19' and SiO and porcelain materials by electric discharge- decomposed SF6,'19' has also been investigated.Bond lengths and "F chemical shielding in SF6 and its selenium and tellurium analogues have been estimated for these species at low temperature in their clathrate hydrates.I2' Sulphur hexafluoride is probably the most studied molecule in i.r. laser photo- chemistry. This is because of its similarity to UF6 and its strong absorption of CO laser radiation. Although such studies have continued this year this area is normally covered in Section C of Annual Reports (Physical Chemistry) and will not be dealt with here. The compound SF5Br has been established as a useful reagent for introducing SF5 groups into carbon compounds. Recent work on SF5Br addition to seven fluoro-olefins shows that the SF group attacks the less hindered site of the olefint21a which supports a mechanism proposed for this reaction two years ago.'21b The new perfluoro-oxaziridine (29) has been synthesized by dehydrofluorination of F5SN(H)CF,00CF3 with NaF.This is only the second example of a perfluorinated compound of this type.122 The single-crystal structure of H2C=SF4 has shown that the sulphur atoms have approximately a trigonal-bipyramidal environment. The CH2 group occupies the position of the non-bonding electron pair in SF,. The hydrogen atoms are found in the plane of the S C and axial F This geometry has also been confirmed by an ab initio study whereas four possible molecular models were given for O=SF4. 123b The simplest fluorinated sulphur(v1) imide FN=SF4 has recently been synthesized starting from C12N-SF5.The molecule is rigid like CH2=SF4 with the F-N= group in the equatorial position. 123e Attention has been drawn to the reactions of difluorosulphur imides RN=SF2 with elemental fluorine. In photolytic reactions in Pyrex containers the *I8 (a)T. Kiang and R. N. Zare J. Am. Chem. SOC. 1980 102 4024; (b) C. Lifshitz T. 0. Tiernan and B. M. Hughes J. Chem. Phys. 1980,72,789. 'I9 (a) K. Hirooka and M. Shirai Nippon Kagaku Kaishi 1980 165; (6) S. Tominaga H. Kuwahara and K. Hirooka IEEE Trans. Power Appar. Syst. 1979 PAS 98 2107; (c) T. Suzuki S. Nakayama and T. Yoshimitsu ZEEE Trans. Electr. Insul. 1980 EI-15 53. 120 S. K. Garg J. A. Ripmeester and D. W. Davidson J.Magn. Reson. 1980 39 317. '*'(a)Q. C. Mir R. Debuhr C. Hang H. F. White and G. L. Gard J. Fluorine Chem. 1980 16 373; (6) A. D. Berry and W. B. Fox,J. Org. Chem. 1978,43 365. 122 A. Sekiya and D. D. DesMarteau Znorg. Chem. 1980 19 1330. 123 (a)A. Simon E.-M. Peters D. Lentz and K. Seppelt Z. Anorg. Allg. Chern. 1980 468 7; (6) H. Oberhammer and J. E. Boggs J. Mol. Strucr. 1979 56 107; (c) D. D. DesMarteau and K. Seppelt Angew. Chem. Znt. Ed. Engl. 1980,19,643; (d)I. Stahl R. Mews and 0.Glemser ibid. p. 409. 128 F. A. Hart A. G.Massey P. G.Harrison and J. H. Holloway reaction of FsC2N=SF2 with fluorine has produced a variety of compounds via an intermediate which is probably FSCZNSFJ- Tetrathiafulvalenes. Although strictly they are organic in nature the high sulphur content and 'metallic' properties make these substances of interest to inorganic chemists.Their preparation usually involves three- or four-step syntheses. Recently however a one-step synthesis which gives 2045% yields has been achieved by heating 2-thioxo-1,3-dithioles with Co2(CO) in boiling benzene or toluene solutions. The disulphurization achieved appears to be geceral for 2-thioxo-l,3- dithioles with a variety of (R) The recent synthesis of 1,3,5,7-tetrathiapentalene-2,6-dionehas also rendered the possibility of producing a wide variety of novel tetrathiafulvalene derivatives.124b Single crystals of adducts of thia-donors have usually been prepared by potentiostatic electrocrystallization. Now a marked improvement has been found if galvanostatic (constant current) control is Slow cooling of a hot acetonitrile solution of tetrathiafulvalene ("F) and iodine yields a mixture of crystalline products including crystals of high iodine content which are TTF.13.A single-crystal X-ray structure analysis has shown that the adduct is composed of integrated stacks of TTF' dimers interspersed between pairs of tri-iodide ions.125b The electrical properties of tetrathiafulvalene-tetracyanoquinodimethanecom-plex126a and [2.2]-and [3.3]-tetrathiafulvalenophanes'26b have been investigated with respect to different molecular architectural arrangements within the crystals. Selenium and Tellurium.-Elements and Polyatomic Cations. A new singlet state of diatomic tellurium has been and laser-induced fluorescence of diatomic ~elenium'*~~'~ and diatomic tellurium127c in noble gas matrices has been reported.A new rhombohedra1 form of selenium composed of hexameric rings has been identified and characterized by X-ray methods,128a and its i.r. spectrum has been measured and compared with that of amorphous selenium.128b The crystal structure of y-monoclinic selenium a new allotrope of cyclo-octaselenium obtained from a solution of dipiperidinotetraselane in CS2 has shown that it consists of crown-shaped Se8 rings.Iz9 The kinetics of crystal growth of trigonal selenium from the vapour phase have been studied and evidence has been produced which suggests that the active species in crystallization is Se2.I3' The first-order Raman spectra of trigonal selenium and tellurium have been measured under pressure up to the semiconductor-metal transition points at room temperature and the results have been interpreted in 124 (a)G.Le Coustumer and Y. Mollier J. Chem. SOC.,Chem. Commun. 1980,38; (b)R. R. Schumaker and E. M. Engler J. Am. Chem. Soc. 1980,102,6651. 125 (a) P. Kathirgamanathan and D. R. Rosseinsky J. Chem. SOC., Chem. Commun. 1980 356; (b) R. C. Teitelbaum T. J. Marks and C. K. Johnson J. Am. Chem. Soc. 1980,102,2986. 126 (a) H. A. Staab J. Ippen C. Tao-pen C. Krieger and B. Starker Angew. Chem. In?. Ed. Engl. 1980,19 66; (b)J. Ippen C. Tao-pen B. Starker D. Schweitzer and H. Staab ibid. p. 67. (a)C. Effantin J. D'incan J. Verges M. T. MacPherson and R. F. Barrow Chem. Phys. Lett. 1980 70 560; (b)F.Ahmed and E. R. Nixon J. Mol. Spectrosc. 1980 83 64; (c) V. E. Bondybey and J. H. English J. Chem. Phys. 1980 72 6479. 12* (a) Y. Miyamoto Fukuoka Daigaku Rigaku Shuho 1979 9 1; (b) K. Nagata K. Ishibashi and Y. Miyamoto Jpn. J. Appl. Phys. 1980 19 1569. lZ9 0.Foss and V. Janickis J. Chem. Soc. Dalton Trans. 1980,624. 13' H. C. Shu and B. Wunderlich Polymer 1980 21 521. The Typical Elements terms of transitions to the puckered layer-type structure of the high-pressure monoclinic-type phase of tellurium. 13' Mossbauer spectra of tellurium under press- ure have also provided evidence of a new phase at higher pressures with a more symmetrical structure than the hexagonal phase.132 Equations of state of liquid selenium44 and structural and electronic transformations in liquid and tellurium1336 have been studied.Work carried out on sulphur-selenium binary sy~tems~'~-~ is reported under Sulphur. Following the synthesis of the heteropolyatomic cation [Te2Ses]2+ several years ago SelO(AsF& and Se10(SbF6) have now been prepared in SO by the oxidation of selenium metal with AsF5 and SbF5 respectively in the presence of excess of metal [equation (19)]. The tetrachloroaluminate salt Se10(A1C14)2 has also been SO2 lose + 3MF5 Selo(MF& +MF3 (19) __+ M=As or Sb prepared by disproportionation of Ses(AIC1,) in SO,. The crystal structure of the hexafluoroantimonate salt has shown that the Selo2' cation is a six-membered boat-shaped ring linked across the middle by a chain of four Se atoms (Figure 17).The ion is isostructural with [Te2Ses12+. 134 An ab initio pseudo-potential SCF-MO study of the Te4'+ cation has accounted for the observed optical absorption spectrum reasonably well and has suggested an explanation for the origin of the hitherto unassigned weak band. Comparison of the observed and calculated. vibrational frequencies for the ion however suggests an assignment that is different from the tentative assignment already in the 1iterat~re.l~~ Figure 17 Perspective view of the Selo2+cation (Reproduced by permission from Inorg. Chem. 1980,19 1432) 13' K. Aoki 0.Shimomura S. Minomura N. Koshizuka and T. Tsushima J. Phys. SOC.Jpn. 1980 48 906. 13* A. A. Opalenko and Z. Zallam Phys. Status Solidi B 1980 99 K27.133 (a) W. W. Warren jun. and R. Dupree Phys. Rev. B 1980 22 2257; (b)J. E. Enderby and M. Gay J. Non-Crysr. Solids 1980,35-36 1269. 134 R. C. Burns W.-L. Chan R. J. Gillespie W.-C. Luk J. F. Sawyer and D. R. Slim Znorg. Chem. 1980,19 1432. M. J. Rothrnan L. S. Bartell C. S. Ewig and J. R. Van Wazer J. Comput. Chem. 1980 1 64. F. A. Hart A. G. Massey P.G. Harrison and J. H. Holloway Other Selenium- and Tellurium-containing Ring and Chain Species and Polyanions. The structures of tris(ethy1enethiourea-S)tellurium(II) perchlorate and two other modifications of tris(trimethy1enethiourea-S)tellurium(II) perchlorate have been determined by X-ray single-crystal methods and have revealed that the cations consist of 'planar' dimeric L*T~(P-L)~T~L~ species (e.g.see Figure 18). 136 Figure 18 Perspective view of the dimeric cation of hexakis(ethy1enethiourea)ditellurium(IZ) perchlorate (Reproduced by permission from Inorg. Chem. 1980 19 1053) The thermal decomposition of 1,2,3-selenadiazole (30) in the gaseous phase has been investigated by photoelectr~n~~~~*~ and shown to and mass ~pectro~copy'~~~ yield the selenoketen. 137a*b Thermolysis of the related selenadiazole (3 1) gives fulvaselone (32).137a Although the preparation of telluranthrene has been reported the synthesis does not seem to be reproducible. However perfluorothianthrene and perfluoroselenanthrene were successfully prepared some time ago and now the telluro-derivative (33) has been synthesized and its structure determined.13' F F A complete X-ray structure analysis has shown that Ba4Sb4Sell a compound of unusual stoicheiometry and structure contains one tran~-Sb,Se~~- two cis -Sb2Se42- two SbSe3,- and two Se2,- ions as well as Ba2' cations (see Figure 19).The compound can be prepared by fusing together a mixture of Ba(MeC02), Sb and Se in a 1 :1 :10 ratio.139 136 A. S. Foust Inarg. Chem. 1980 19 1050. 13' (a)R. Schulz and A. Schweig Angew. Chem. Int. Ed. Engl. 1980 19 69; (b) H.Bock S. Aygen P. Rosmus and B. Solouki Chem. Ber. 1980,113,3187. D.P.Rainville R. A. Zingaro and E. A. Meyers J. Fluorine Chem. 1980 16 245. G.Cordier R. Cook and H. Schafer Angew. Chem. Int. Ed. Engl. 1980 19 324. The Typical Elements 1011 Figure 19 The selenoantimonate(Ixz) ions in Ba4Sb4Sel1 (Reproduced by permission from Angew.Chem. Int. Ed. Engl. 1980,19,324) Rotational barriers in H2Se2 and H2Te2 have been cal~u1ated.l~~ Full details of the structure of the diselane Se2(NC4H80)2 first reported three years ago in a preliminary communication have now appeared.141a The preparation of diphenyl diselenide by the reaction of PhBr with magnesium and selenium in diethyl ether followed by reaction of the resultant PhSeMgBr with bromine has been and the mass spectrum has been studied in detail. l4lCTrifluoromethyl diselenide (F3C)2Te2 has been obtained from the reaction of C2F6 with tellurium in a chemical plasma. The compound has also been found in small amounts in the plasma-induced reactions of C2F6 with TeX4 (X = C1 or Br).141d Dimorpholino-tri- and -tetra-selanes and dipiperidinotetraselane have been pre- pared by heating black selenium powder with morpholine or piperidine in the presence of Pb304.'42 The structures of the triselane Se3(NC4H,0)2141" and the two tetraselanes Se4(NC4H80) and Se,(NC5Hl,)2'42 have been reported.The tetraselanes are isomorphous and contain unbranched non-planar chains of selenium atoms which are N-bonded at the ends. These are the first crystal structures of diaminoselanes and the first structures of compounds containing tetraselenium chains. 14' The rubidium and caesium trichalcogenides Rb2Se3 CS~S~~,~" Rb2Te3 and CS~T~~~~~ have been obtained by the reaction of the mixed elements in liquid ammonia at high temperatures and pressures.The selenides and Cs2Te3 have the 140 C. S. Ewig E. H. Mei and J. R. Van Wazer Mol. Phys. 1980 40 241. 14' (a)0.Foss and V. Janickis J. Chem. SOC., Dalfon Trans. 1980 628; (6)H. J. Reich M. L. Cohen and P. S. Clark Org. Synth. 1980 59 141; (c) A. Benedetti C. Preti G. Tosi and P. Zannini J. Chem. Soc. Dalton Trans. 1980 1467; (d)M. Schmeisser R. Walter and D. Naumann Z. Anorg. Allg. Chem. 1980,464 233. 142 Dalton Trans. 1980 620. 0.Foss and V. Janickis J. Chem. SOC. 143 P. Bottcher J. Less-Common Met. 1980,70 263. 132 F. A. Hart A. G. Massey P. G. Harrison and J.H. Holloway K2S3-type structure and Rb2Te3 has the K2Te3-type ~tructure.~~~~~~~ Both contain bent polyanions as a characteristic feature. Selenium and Tellurium Hydrides and their Alkyl and Aryl Derivatives.Selenium hydride has been prepared by the reduction of selenium with CO and H20 in the presence of a base.144 An improved synthesis of CF3SeH has also been reported and melting points boiling points and enthalpies and entropies of vaporization as well as mass spectra are reported for this and CF3SeCF3.145 Details of the methods and the mechanisms for the conversion of selenides and tellurides to hydrocarbons by reaction with triphenyltin hydride (RMPh+RH; M=Se or Te) have been described.146 Several bis-selenides and their derivatives have been prepared. The reaction of bromine with oligomeric or polymeric selenoformaldehydes has yielded (BrCH2)2Se147a and Ph2Se has been obtained as a decomposition product from the low-temperature disproportionation of [C6FsSeHMe]'-SbF5.0S02F-.'47b The structure of (q5-C5H4),Se in the tri-iodide salt of diferrocenyl selenide has been determined by single-crystal X-ray methods.'47' Although a number of homolytic substitution reactions of dialkyl selenides are known [equation (20)] intermediate selenuranyl radicals [R2SeX]* have never been X*+R2Se -+ RSeX+R.(20) detected. Now however e.s.r. spectra have been assigned to the a* selenuranyl radicals R2Se*X (R = alkyl or aryl) detected in solution during the photochemical generation of X- [CF3C* R'C(O)S* Me3CO* or Me3SiO*] in the presence of dialkyl or alkyl aryl ~e1enides.l~~ A number of mercapto-acid compounds of tellurium(I1) of general formula (RS)*Te [R = Ph 2-CI0H7 H02CCH2CH2 H02CCHMe H02CCH2 2- HO2CC6H4 H02CCH2CH(C02H) Na02CCH2CH2 or NH402CCH2CH2] have also been prepared and chara~terized.'~~ Selenium and Tellurium Compounds with Bonds to Nitrogen or Phosphorus.The first report of laser magnetic resonance spectra and high-resolution i.r. and micro- wave spectra of the nitrogen selenide radical (NSe) has appeared.15' An X-ray diffraction study and a 13Cand 31Pn.m.r. investigation of Se=PMe3 have provided an opportunity to consider the relative accuracy of the geometrical data obtained from the two techniques. Comparison of the P-Se bond lengths obtained by the two methods shows that the J(PSe) spin-spin coupling is highly anisotropic. 15' Bis(di-t-butylphosphino)tellurium(II),obtained via the reaction shown [equation 144 N.Sonoda K. Kondo K. Nagano N. Kambe and F. Morirnoto Angew. Chem. Znt. Ed. Engl. 1980 19,308. 145 W. Gombler and H. U. Weiler J. Fluorine Chem. 1980 15 279. 146 D. L. J. Clive G. J. Chittattu V. Farina W. A. Kiel S. M. Menchen C. G. Russell A. Singh C. K. Wong and N. J. Curtis J. Am. Chem. SOC. 1980,102,4438. (a) E. Weissflog Phosphorus Sulfur 1980 8 87; (b)G. G. Furin 0. 1. Andreevskaya and G. G. Yakobson Izv. Sib. Otd. Akad. Nauk SSSR Ser. Khim. Nuuk 1980 2 100; (c)J. A. Kramer F. H. Herbstein and D. N. Hendrickson J. Am. Chem. SOC. 1980 102 2293. J. R. M. Giles B. P. Roberts M. J. Perkins and E. S. Turner J. Chem. Soc. Chem. Commun. 1980 504. 149 S. A. Gardner J. Organomet. Chem. 1980 190 363. I5O H. Uehara and K. Hakuta Proc.Yamada Conf. Free Radicals 3rd. 1979 221 ed. Y. Morino I. Tanaka and E. Hirota Yarnada Sci. Found. Osaka. A. Cogne A. Grand J. Laugier J. B. Robert and L. Wiesenfeld J. Am. Chem. Soc. 1980,102 2238. 14' The Typical Elements 133 (21)] and independently from Na,Te and Bu',PCl is formed very readily. This is the first example of a tellurium compound substituted only with R2P groups and 2But2P-Te-SiMe3 -+ (Me3Si)2Te+ Bu'2P-Te-PBut2 (21) its reactions have prompted discussion of the bonding in the molecule and in other tellurium-phosphorus compounds. 152 Selenium and Tellurium Oxides and Related Species. Laser magnetic resonance for the vibration-rotation transitions of SeO(,Z) has been reported for the first time.15' A recent preparation of Se205 from the reaction of Se02 with H2Se207 has yielded crystals from which an X-ray structure determination has been possible.The structure consists of zig-zag chains [-Se(0)-O-Se(02)-O-] with alternat- ing SeIV and SeV' atoms. Each selenium atom is co-ordinated tetrahedrally Se"' by four 0atoms SeIV by three 0atorns and a lone pair. The structure is significantly different from that of Te205 because oi the tendency of tellurium towards octahedral co-ordination Te205containing both four- and six-valent Te which gives rise to a three-dimensional layer structure. 153 In the meantime the structure of (NH4),Se205 has been shown to consist of Se2052- and NH4+ ions hydrogen-bonded into a three-dimensional net~0rk.l~~ Study of a number of tellurium derivatives by ESCA has shown that mixed oxide compounds (Te205 Te409 H2Te206) do not show evidence of two oxidation numbers because of the gaps between the maximum and the width at half height of the peaks associated with TeIVand Tev1.155 A number of reactions of Se03 have been reported.According to 19Fn.m.r. and Raman spectroscopic data PF5 reacts with Se03 to give Se,03,-1F2 (n = a4),but with excess of PF5 POF3 and SeO2F2 are formed.93b With AsF in equimolar quantities SeO reacts slowly to give AsFSe04 which on standing produces a second substance with the same composition but with different physical properties. Raman spectra indicate that both are linear polymeric molecules in which the arsenic and selenium atoms are oxygen bridged. Thermal decomposition of both (AsFSeO,) species gives AsF, SeOF2 Se02 and AS~05.l~~ Reaction of SeO with SbF3 in liquid SO yields Se02F2 and a polymeric crystalline substance which contains [Se03F]- and [Se 03n+1]2-anions.93a A structural investigation of lithium hydrogen selenite has shown that the HSe03- ions form spiral chains of SeO groups interlinked by hydrogen bonds.The structure is stabilized with Li' ions which have close contacts to four oxygen atoms thus forming a three-dimensional net~0rk.I~~ Work on selenites and tellurites includes an examination of the electronic struc- tures of Se032- and Te032- by means of oxygen K-spectra and X-ray emission and photoelectron spectro~copy,~~ a study of the low-frequency Raman spectrum of NaH3(Se03)2,158 and an e.s.r.investigation of the ferroelastic transition in "* W.;W. du Mont Angew. Chem. Int. Ed. Engl. 1980 19 554. Z. Zak Z. Anorg. Allg. Chem. 1980 460 81. 154 S. Chomnilpan Actu Crystullogr. Sect. B 1980 36 675. 15' F. Daniel J. Moret M. Maurin M. M. Phu Uy P. Baillif and B. Blake Rev. Chim. Miner. 1980 17 25. J. Touzin and L. Mitacek Collect. Czech. Chem. Commun. 1979 44 2743. 15' S. Chomnilpan and R. Liminga. Actu Crystallogr. Sect. B 1979,35 3011. '" V. P. Dmitriev L. M. Rabkin and L. A. Shuvalov Fiz. Tverd. Tela 1980 22 1114. 134 F. A. Hart A. G. Massey P. G. Harrison and J. H. Holloway KH3(Se03)2 under uniaxial pressure. 159 Crystal structures of Na2Te03 and Ag2Te03 have been reported the silver salt being shown to have a distorted NaCl structure.'60 Very little chemistry of the selenite group appears to have been studied.However the complex mechanism of the reaction of selenious acid with two simple alkane- thiols in aqueous dioxan over a variety of acidities has been investigated in detail.161 Although the data pertain to the reaction of simple thiols with selenite in a non-enzymatic system it may well help define the pathways by which inorganic selenium is initially incorporated into living systems. Crystallographic data coupled with dielectric studies for NH4HSe0 and ND4DSe04 have shown that the hydrogen selenates represent a new example of a small family of hydrogen-bonded crystals in which the deuteriation leads to significant changes of the dielectric properties with the small changes that occur in the crystal lattice.162 The crystal structure of the paraelectric phase of RbHSeO has also been investigated and the hydrogen-bonding in this phase has been shown to be similar to that in the ferroelectric Single-crystal examination of NH,HTeO has shown that the structure is characterized by chains of (TeO,) octahedra which share two edges and are also linked by short hydrogen The lattice dynamics of K,SeO in and near the incommensurate phase transitions have been studied by Raman and theoretically.1646 Temperature-dependent fine structure observed in the Raman spectra of pure and Na- Rb- and Cs-doped K2Se04 has been interpreted to mean that previously reported defect- induced scattering arises from intrinsic defects. 164c The structure of the adduct of orthotelluric acid and urea has been shown to consist of infinite layers of Te(OH)6.2CO(NH2)2 connected through hydrogen bonds (Te-0-H.-.O-C). Within these layers the Te(OH)6 molecules are hydrogen- bonded to similar neighbouring molecules and urea New structure determinations on Te(OH)6.Cs2HP04 and Te(OH)6.Cs2HP0,.2CsH2P0, have shown that in common with other phosphate-tellurates the main feature of the structures is the coexistence of two types of anions in the unit cells.166 A structural investigation on basic tellurium nitrate has led to a reformulation of the compound as [Te204H][N03] with a basic structural element consisting of a two-dimensional puckered [Te204H]' network and discrete NO3- anions. 16' Selenothionate Anions and Tellurium Sulphate Complexes.An interesting feature of the higher polythionates and organic non-cyclic polysulphides is the 70-1 10" dihedral angles found within the polychalcogen chains. Now crystal structure determinations on K2SeS3O6.H20 and [C0(en)~Cl~]SeS~0~ have shown that in the selenotetrathionate dianion the dihedral angles [S(l)-Se-S(3)-S(4)] are 81.16 and 159 P. Cevc R. Blinc R. Srinivasan I. ZupanEiE and L. A. Shuvalov Phys. Status Solidi A 1980,57,789. 16" R. Masse J. C. Guitel and I. Tordjman Muter. Res. Bull. 1980 15,431. J. L.Kice T. W. S. Lee and S. Pan J. Am. Chem. SOC.,1980 102,4448. Z.Czapla and L. Sobczyk Phys. Status Solidi A 1980,58 K161. 163 (a) A. Waskowska S. Olejnik K. Lukaszewicz and Z. Czapla Cryst. Struct. Commun.1980,9 663; (b)L.Benmiloud J. Moret M. Maurin and E. Philippot Acta Crystallogr. Sect. B 1980,36 139. (a) S. Ya. Vetrov A. N. Vtyurin Yu.A. Popkov and V. F. Shabanov Fiz. Nizk.Temp. (Kiev),1979 5 1193; (6) M.S. Hague and J. R. Hardy Phys. Rev. B 1980,21,245;(c)N.E.Massa F. G. Ullman and J. R. Hardy Ferroelectrics 1980 25 601. J. Loub W.Haase and R. Mergehenn Acta Crystallogr. Sect. B 1979,35 3039. M.T. Averbuch-Pouchot A. Durif and J. C. Guitel Muter. Res. Bull. 1980 15 387. 16' J. Anderson M. H. Rapposch C. P. Anderson and E. Kostiner Monatsh. Chem. 1980,111 789. The Typical Elements 119.07' respectively (Figure 20).168aIn the diselenotetrathionate dianion however which has been examined crystallographically in two crystalline modifications of [CO(~~)~C~,]~S~~S~O,.H~O, the dihedral angles [S(1)-Se( 2)-Se( 3)-Se (4)] are 88.5 and 92.6" respectively (Figure 21).168b The selenotrithionate ion in K2SeS206 has also been studied and in this ion the bond angle at selenium is 97.90(4)" which is smaller than that found in any other polythionate.'68' In all cases the structures have been rationalized by comparison with those of other known polythionates and poly-sulphur and poly-selenium ring and chain compounds.Figure20 Views ofthe anions in K2SeS3O6*H20 (right) and [Co(en)2C12]2SeS306(left). [The views are down the SeS(3) bonds with S(3) hidden and so illustrate the differences in the dihedral angles S(l)-SeS(3)-S(4)] (Reproduced by permission from Inorg. Chem. 1980 19,1040) Figure 21 View of the anion in one modification of [Co(en)2Cl2I2Se2S206.H20.(The view is down the Se(2)-Se(3) bond with Se(3) hidden and so shows the dihedral angle) (Reproduced by permission from Inorg.Chem. 1980,19,1044) Stepwise stability constants have been determined for a number of sulphate complexes of tellurium(1v) in solution by an ion-exchange method.169 Oxide Halides and Organo-oxo Derivatives of Selenium and Tellurium. A value for A\H7(SeOF2) published last year has been The stability constants for the charge-transfer complex SeOC12.X- (X = C1 Br I or SCN) have been measured in MeCN DMSO and their Secondary bonding which causes deviations from structures predicted on the basis of Gillespie-Nyholm Theory continues to be of interest. Significant distortions (a)A.S. Foust V. Janickis and K. Maroy Znorg. Chem. 1980,19,1040;(b)A.S.Foust V. Janickis and K.Maroy ibid. p. 1044;(c)A.S.Foust and V. Janickis ibid. p. 1063. 16' B.I. Nabivanets E. N. Oganesyan E. E. Kapantsyan and G. G. Babayan Zh. Neorg. Khim. 1980 25,567. "O (a)A.A.Woolf J. Fluorine Chem. 1980,15,533; (b)N.W. Alcock and J. F. Sawyer J. Chem. SOC. Dalton Trans. 1980,115. 136 F. A. Hart A. G. Massey P.G. Harrison and J. H. Holloway from primary geometry about the seleninyl dichloride unit in SeOClZ.C4H8O2 have been observed in an X-ray single-crystal structure investigation. The packing in the compound involves infinite layers of SeOC12 bridged by dioxan molecules and further cross-linked by Se-O...Se interactions. The structure is the first in which SeOC12 forms three secondary bonds to oxygen with the SeOC12 being classed as amphoteric.170b Differential thermal analysis and total pressure measurements have shown that TeI4 is only slightly soluble in Te02 and an oxide halide of the type Te6011X2 (X=halogen) is not formed. The existence of TeO12 in the gas phase however was derived from the transport behaviour of TeOa with I2 and Te14 respectively and its heat of formation and entropy were ~btained.'~' The major product of the thermal decomposition of Te6Ol1Cl2 has been shown by mass spectrometry to be TeOClZ and the standard thermodynamic functions of gaseous TeOC12 have been calculated. Matrix-isolation i.r. studies on the vapours from the thermal decomposi- tion have yielded frequencies of the normal modes of vibration of TeOC12 and a normal co-ordinate analysis was performed.172 Reaction of excess of PF with Se03 has been shown to give Se02F2 and POF3.93b E.s.r. spectra of the phenylseleninyl Ph2Se0,173a and the phenylselenonyl Ph2Se02,173bradicals trapped in single-crystal matrices have been obtained. The spin density on the selenium atom in the phenylseleninyl radical is twice as great as that in the phenylselenonyl radi~a1.l~~~ Selenium and Tellurium Halides and their Organo-substituted Derivatives. The chemiluminescence that results when H2Te and fluorine are mixed has been attributed to the previously unobserved TeF ~adica1.I~~ The X-ray crystal structure of P-SeBr has shown that the compound consists of BrSe-SeBr Photoelectron spectra of Se2C12 SeC12,176 and SeBr2112b have been obtained all of which correlate well with those of the more stable sulphur analogues.Valence ionization energies of the transient TeC12 and TeBr2 have also been obtained by photoelectron spectro~copy."~ Melting points boiling points and enthalpies and entropies of vaporization have been reported for CF3SeX (X = C1 or Br).14' An electron diffraction study of the structure of phenylselenenyl bromide PhSeBr has shown that the bromine atom is rotated 68.4"out of the plane of the remaining Raman spectroscopic studies on the SeC14-SbC15179a and TeC14-SbC1,'79b systems in the solid and molten states have been carried out. In the solid state SeC14-SbC15'79a and two crystal modifications of TeC14.SbC15179b occur.The structures in the melts can be described in terms of the equilibrium (22) which lies to the left. Mixtures H. Opperrnann G. Kunze E. Wolt G. A. Kokovin I. M. Sitschova and G. E. Osipova Z. Anorg. Allg. Chem. 1980,461 165. 17' G.H.Westphal F. Rosenberger P. R. Cunningham and L. L. Arnes J. Chem. Phys. 1980,72 5192. 173 (a) R.Franzi M. Geoffroy and N. Leray J. Organornet. Chem. 1980 193 315; (b)M.Geoffroy and N. Leray J. Chem. Phys. 1980 72 775. 174 D. E. Newlin G. W. Stewart and J. L. Gole Can. J. Phys. 1979 57 2217. 17' D.Katryniok and R. Kniep Angew. Chem. Int. Ed. Engl. 1980 19 645. 176 E.Nagy-Felsobuki and J. B. Peel J. Chem. SOC.,Faraday Trans. 2 1980,76 148. G. Jonkers C. A. De Lange and J. G. Snijders Chern.Phys. 1980,50 11. N. M. Zaripov M. V. Popik L. V. Vilkov and T. G. Mannatov Zh. Strukt. Khim. 1980,21,37. 179 (a) W. Brockner and A. F. Demiray 2. Naturforsch. Teil A 1980 35 766; (b)W. Brockner and A. F. Demiray 2.Anorg. Allg. Chem. 1980,469 27. 17' The Typical Elements 137 MeC1,' +SbC16- MC14+SbCls (22) Me = Se or Te with other stoicheiometries contain only the 1:1 adduct together with excess of chalcogenide tetrachloride and antimony pentachloride although in the SeCl case some part-decomposition to Se2C12 and C12 also occurs. 179a,b The tetrabromides SeBr and TeBr have been shown to produce SeBr3' and TeBr,' ions when dissolved in chlorosulphuric acid and solutions of SeCl in chlorosulphuric acid contain both SeCl,' and Se42+ ions.18o The tribromo-cations have also been prepared as [seBr,][AsF,] and [TeBr,][AsF,] either from thz elements and an excess of bromine and AsF, or from Se,(AsF& or Te4(AsF6) with excess of brDmine.The hexafluoroantimonate derivative [SeBr3][SbF6] has been prepared from Se4(SbF6)2 and bromine. The reaction pathways have been discussed in detail. The Raman spectra of the salts were also obtained assignments being confirmed and force constants derived from normal co-ordinate analyses.lS1" The X-ray crystal structures of [SeBr,][SbF,] and [TeBr,][AsF,] have been determined and the cations in each salt have been shown to have C3vsymmetry.'81b A value for AH:(SeF4) which was published last year has been found to be erroneous because of wrong values used in the calculation.A new value has now been determined and data for selenium(1v) fluoride and its neighbouring main- group fluorides have been discussed in terms of the periodic pattern of Earlier X-ray crystal structure determinations by Krebs and his co-workers on TeC1 and TeI have been verified by the application of other techniques. Thus the polysynthetic twinning in the c-centred monoclinic TeC1 system has been corrobor- ated by an order-disorder interpretationlS2" and the nature of the bonding in TeI single crystals has been confirmed by 1271 n.q.r. studies.1826 The chemical transport of Ti02183a and MOO^^^^^ with TeCl and TeBr respec- tively has been investigated and in the TiOz-TeC14 case the transport chemistry has been shown to be governed by the reactions shown in equations (23) and (24).lS3" Ti02(,)+ 2TeC14(, = 2TeOC12(,)+TiC14(,) (23) TeC14(g,= TeC12(, +Clzc, (24) Kinetic studies on both the oxidation and the reduction of TeXV have been carried out.The kinetics of reduction of TerV ion with ascorbic acid in HC1 was found to be first order with respect to each reactant and second order The reaction of CeXVwith TerV is first order with respect to CeIV and of fractional order with respect to TeIV. In the course of this latter study kinetic and spectrometric evidence for the formation of CeIV complexes with both TeIV and Te"' was ~btained.'~,' The synthesis and structural chemistry of organotellurium(1v) complexes have attracted considerable attention this year. The reaction of TeC1 with 2,6-diacetyl- R.C. Paul D. S. Dhillon D. Konwer and J. K. Puri Indian J. Chem. Sect. A 1980 19 473. lE1 (a) W. V. F. Brooks J. Passmore and E. K. Richardson Can. J. Chem. 1979 57 3230; (b) J. Passmore E. K. Richardson T. K. Whidden and P. S. White ibid. 1980,58 851. (a) K. 0. Backhaus Krisr. Tech. 1979 14 1157; (b)T. Okuda K. Yamada and H. Negita Bull. Chem. SOC.Jpn. 1980 53 2659. (a)F. Rosenberger J. Crysf. Growih 1980 49 607; (b) M. Ritschel and H. Oppermann Krist. Tech. 1980 15 395. (a) G. Marcu G. Pop I. Pop and C. Nascu Reu. Chim. (Bucharest) 1979 30 1101; (b) L. S. A. Dikshitulu V. H. Rao and S. N. Dindi Indian J. Chem. Sect. A 1980 19 203. F. A. Hart A. G. Massey P. G. Harrison and J. H. Holloway Figure 22 Molecular structure of TeCl3(C9HsNO2) (Reproduced by permission from J.Organornet. Chern. 1980,184,417) pyridine in methylene chloride or THF has given rise to a new type of organotel- lurium(1v) compound in which the organic radical is bonded to the tellurium as a terdentate ligand (Figure 22). Analogous complexes have been formulated for the condensation products of TeC14 with 2-acetylpyridine 2-acetylcyclohexanone and 3-acetyl-7-methoxycoumarin.1*saThe quest for information about the state of aggregation or organotellurium trihalides has prompted interesting X-ray structure investigations on the trichloride tribromide and tri-iodide of (alkoxypheny1)tel-lurium(1v). The chloride (4-EtOPh)TeCI3 crystallizes as a polymer (Figure 23)with approximately square-pyramidal co-ordination of each tellurium which is linked Figure 23 Molecular structure of (4-EtOPh)TeC13 (Reproduced by permission from Inorg.Chem. 1980,19 2487) (a) H. J. Gysling H. R. Luss and S. A. Gardner J. Organornet. Chem. 1980 184 417; (b) P. H. Bird V. Kumar and B. C. Pant Inorg. Chem. 1980 19,2487; (c)D. P. Rainville and R. A. Zingaro J. Organornet. Chem. 1980 190 277; (d)D. P. Rainville R. A. Zingaro and E. A. Meyers Cryst. Struct. Commun. 1980 9 77; (e) T. S. Cameron R. B. Amero C. Chan and R. E. Cordes ibid. p. 543; (f) T. S. Cameron R. B. Amero and R. E. Cordes ibid. p. 539. The Typical Elements Figure 24 Molecular structure of (4-EtOPh)TeBr3 (Reproduced by permission from Inorg. Chem. 1980 19 2487) to the next through a single bridging chlorine.The bromide (4-EtOPh)TeBr3 (Figure 24) and the iodide (4-MeOPh)Te13 both crystallize with a dimeric molecular unit in which the two approximately square-pyramidal tellurium co-ordination poly- hedra are cis-fused through two bridging halogens.185b In the alkoxyphenyltellurium compounds the tellurium atoms are five-co-ordinate. This is also true of the recently prepared185C phenyltellurium trichloride PhB~~.~cl~.~Te (34),in which the tellurium (34) X and Z = C1 or Br has five-fold co-ordination with a lone pair of electrons on the axis opposite the carbon to form an and the compound cis-2-ethoxycycloheptyltri-bromotellurium(Iv) 2[TeBr3C7H120Et] in which the tellurium is bonded to three bromines a carbon of the cycloheptyl ring and the oxygen of the EtO In (p-tolyl)(2-chlorocyclohexyl)dichlorotellurium(1~) p-MeC6H4TeC1,C6HlO however the tellurium is four-co-ordinate.lssf It has been shown that RTeC1,Ph is reduced under mild conditions by Ph3SnH.146 New monomeric chelated aryltellurium(1v) compounds have been prepared from the reactions of PhTeCl, Ph2TeC12 4-PhOC6H4TeCI3 and phenoxatellurium 10,lO-dichloride with a variety of bidentate chelating ligands.lg6 An X-ray crystal structure determination on crystals of phenoxatellurium 10,lO-dichloride has shown that the monomeric units (Figure 25) are arranged into discrete tetrameric clusters through Te-..Cl secondary bonding (Figure 26). The Te4C16 core is arranged in a ‘step’ structure rather than the familiar ‘cubane’ The monomers of the related diphenyltellurium(1v) difluoride however are linked through long Tea -*Fbridging bonds with chains (Figure 27).la7’ Another interesting and unusual molecular and solid-state structure is that of 1,1 -dichloro-2,5 -bis-(N-chloro thioimino) -3,4 -dicy anoselenophen (Figure 28).The M. V. Garad S. Gopinathan and C. Gopinathan Indian J. Chem. Sect. A 1979 18 267. (a) J. D. Korp I. Bernal J. C. Turley and G. E. Martin Inorg. Chem. 1980 19 2556; (b) F. J. Berry and A. J. Edwards J. Chem. Soc. Dalton Trans. 1980,2306. F. A. Hart A. G.Massey P. G. Harrison and J. H. Holloway Figure 25 Molecular structure of monomer of phenoxatellurium 10,lO-dichloride (Reproduced by permission from Inorg. Chem. 1980 19 2556) Figure 26 Arrangement of tetrameric clusters of phenoxatellurium 10,lO-dichloride (Reproduced by permission from Inorg.Chem. 1980 19 2556) compound was produced as black prisms by treating (NC),C=C(CN) with H2Se and mixing the resultant 2,5-diamino-3,4-dicyanoselenophen with SC1z.188 The Ph2SeX (X=Cl or Br) radical has been identified by e.s.r. spectroscopy in X-irradiated single crystals of Ph3SeBr Ph2SeBrz and PhzSeClz. It appears that the unpaired electron in the radical probably lies in a Se-Xo* orbital which is orientated perpendicular to the CSeC plane.'*' Although crystal structures of salts of the type R3TeX in which X is a polyatomic anion have been determined no structures of compounds containing monatomic anions have previously been studied. Now an examination of the crystal and molecular structure of unsolvated triphenyltelluronium chloride has shown that it is dimeric and predominantly covalent in the solid state.Each tellurium is five-co-ordinate in a distorted square- pyramidal geometry the two square pyramids sharing a common basal edge through the bridging chloride ions. ''* F. Wudl and E. T. Zellers J. Am. Chem. SOC. 1980,102 5430. R. Franzi M. Geoffroy L. Ginet and N. Leray J. Phys. Chem. 1979 83 2898. R. F. Ziolo and M. Extine Inorg. Chem. 1980 19 2964. The Typical Elements 141 4 b/t Figure 27 Chain structure of diphen ylteilerium (IV)difluoride (Reproduced from J. Chem. SOC. Dalton Trans. 1980 2306) Figure 28 Molecular structure of 1,l -dichloro-2,5-bis(chlorothioimino)-3,4-dicyanoseleno-phen (Reproduced by permission from J.Am. Chem. SOC. 1980,102,5430) Hexachlorotellurate(1v) species have received a considerable amount of attention this year. Raman spectroscopy has been used for the characterization of solid and molten mixtures of TeCI and PC15. The solid 1:1mixture contained the [TeCl,]," -anion and in the molten state there are equilibria between [TeCI,],"- [TeCI,]*- 142 F. A. Hart A. G. Massey P. G. Harrison and J. H. Holloway and lower charged species. The spectra of TeC1,-rich samples indicate different species such as [Te3CIl3]- [Te2Cllo]2- and (TeC15],"-. 19' Low-temperature luminescence spectra of CsMX6 (M = Se or Te X = C1 or Br) have provided data indicative of a Jahn-Teller distortion in the Iy3Tlu) excited High-resolu-tion X-ray powder diffraction patterns using the Guinier technique have yielded revised data for K~Tec16.~'~ Other X-ray crystallographic work includes examina- tion of the structure of bis(pyridinium)hexachlorotellurate(Iv) which consists of layers of [TeC16]'- ions alternating with double layers of C&N+ ions,194a and bis-[2,3 -di hydro -3 -hydroxythiazolo (2,3 -b)benzo thiazolium] hexachlorotellur- ate(Iv)-dioxan which contains two crystallographically distinct [TeCl6I2- anions.1946 Mossbauer studies on [TeX6]'- (X = C1 or Br) formed when benzene solutions of the tellurium tetrahalide are treated with Ph4AsX are normal. However '"Te Mossbauer parameters from (Ph.,A~)~Tecl~ precipitated from solutions of TeOz in concentrated HCl suggest that the anion is distorted towards C3,,symmetry.Ther- mogravimetric studies have shown that the decompositions of (NH4),TeX6 and (Ef4N),TeX6 to TeX and ammonium halide are clean but that those of (Ph,A~)~Tecl~ are more complex.195 The hexabromoselenic(1v) acid hydrate (H502)2SeBr6.4H20 has been prepared from solutions of SeBr4 in concentrated aqueous HBr. Although the isolated crystals are stable only at low temperature a crystal structure at -100°C has been deter- mined. The crystals contain regular octahedral [SeBr6I2- The crystal structure of the hexaiodotelluric acid octahydrate H2Te16*8H20 has also been studied and shown to contain [TeI6I2- units.'966 Conductance behaviour of [S4N3]- [TeBr5] and [S4N3],[TeBr6] in disulphuric chlorosulphuric and fluorosulphuric acids has been studied.66d The dimeric bromotellurate(1v) species (Ph4P)2Te2Br10 has been prepared by reaction of TeBr with Ph4PBr in solution in a benzene-acetonitrile mixture.An X-ray crystal structure determination has shown that the [Te2Brlo12- ions consist of edge-sharing distorted TeBr6 octahedra. The vibrational spectra of the ion have been re~0rted.l~' Little is known about tetrafluorotellurates(v1). Although a range of alkoxyfluorotellurates is known no alkoxyfluorotelluric acids have been reported. However now both cis-and trans-isomers of (HO),TeF, together with HOTeF40Me and (Me0),TeF4 have been prepared and all the tetrafluorotellur- ates(v1) in Scheme 4 have been isolated and characterized by spectroscopic means and elemental anal~sis.'~' 19' W.Brockner and A. F. Demiray 2.Anorg. Allg. Chem. 1980,461 205. 192 R. Wernicke H. Kupka W. Ensslin and H.-H. Schmidtke Chem. Phys. 1980,47 235. 193 H. Henke J. Appl. Crystallogr. 1980 13 305. 194 (a) P. Khodadad B. Viossat P. Toffoli and N. Rodier Acta Crystallogr. Sect. B 1979 35 2896; (6) K. Von Deuten W. Schnabel and G. Kiar Cryst. Struct. Commun. 1980 9 761. E. R. Clark W. R. McWhinnie J. Mallaki N. S. Dance and C. H. W. Jones Inorg. Chim. Acta 1980,41 279. (a) B. Krebs and M. Hein Z. Nututforsch. Teil B 1979 34 1666; (b)D. Katryniok R. Kniep and D. Mootz Z. Anorg. Allg. Chem. 1980,461 96. B. Krebs and K. Buescher Z. Anorg. Allg. Chem. 1980 463 56. W. Totsch and F. Sladky J.Chem. SOC., Chem. Commun. 1980 927. 19' 19' 19' 19' The Typical Elements 48% HF-0 96% H2SO4 (H0)6Te Atrans-HOTeF40-BH+ Atruns-(HO)zTeF41 trans -MeOTeF40-BMet & trans -(MeO)2TeF4 96% H2SOa -trans-HOTeF40Me 96% HZSO4 F5TeO-BH+ -Hzo' b C~S-T~F~O~~-(BH+)~-cis-(H0)2TeF4 1 CH2N2 cis-MeOTeF40-BMe+ cis-(MeO)zTeF4 96% HZSO4 96% HzSO, E+ cis-HOTeF40Me -cis-MeOTeF,O-BH+( +BH+F-) 1MeOH-B FsTeO-BHf B = organic base such as pyridine imidazole or trimethylamine Scheme 4 Tetraselenotetracenes Tetraselenafulvalenes and their Relatives. A new series of radical-cation salts the tetraselenotetracene iodides of three different stoicheiometries TSeT-I (x = 0.5,0.71 or 0.77) have been synthesized and their structural and physical properties have been investigated.The conducting properties are potentially as good as those of the charge-transfer complexes belonging to the tetrathiafulvalene-tetracyanoquinodimethaneseries.199 New synthetic routes to the sym-diselenadithiafulvalenes have been reported,200 and new efficient methods for the preparation of tetramethyltetraselenafulvalene TMTSF which use dichloromethylene/ (dimethy1)ammonium chloride with hydro- gen selenide and an organic base rather than employing carbon diselenide have been devised.201a*b The physical properties of (TMTSF)2PF6202"" and four other highly conducting salts (TMTSF)2X (X = [AsFJ [SbF6]- [BF4]- or have been studied in detail. The magnetic susceptibility of tetramethyltetraselenafulvalene-dimethyl-tetracyanoquinodimethanidehas been measured in its highly conducting state under pressure.203 Crystallographic data for hexamethylenetetraselenafulvalene-perfluorotetracyanoquinodimethane have shown that it is isomorphic with the tetracyanoquinodimethane derivative.204 199 P.Dalhaes C. Coulon S. Flandrois B. Hilti C. W. Mayer G. Rihs and J. Rivory J. Chem. Phys. 1980,73 1452. M. V. Lakshmikantham and M. P. Cava J. Org. Chem. 1980,452632. (a)F. Wudl and D. Nalewajek J. Chem. Soc. Chem. Commun. 1980 866; (6)L.-Y. Chiang T. 0. Poehler A. N. Bloch and D. 0.Cowan J.Chem. Soc. Chem. Commun. 1980,866. 202 (a)K. Bechgaard C. S. Jacobsen K. Mortensen H. J. Pedersen and N. Thorup Solid State Commun. 1980,33 1119; (6)H. J. Pedersen J.C. Scott and K. Bechgaard ibid. 1980,35,207; (c)D. Jerome A. Mazaud M. Ribault and K. Bechgaard C.R. Hebd. Seances Acad. Sci. Ser. B 1980 290,27. 203 U. Hardebusch W. Gerhardt J. S. Schilling K. Bechgaard M. Weger M. Miljak and J. R. Cooper Solid State Commun. 1979,32 1151. *04 T. J. Emge T. J. Kistenmacher W. Bryden and L. K. Frevel J. Appl. Crystallogr. 1980 13 95. 144 F. A. Hart A. G. Massey P. G. Harrison and J. H. Holloway 2 GroupVII Reviews of General Interest.-A well referenced book which summarizes both main-group and transition-element fluorine chemistry has been and inorganic fluorine chemistry has been reviewed element by element in the Kirk- Othmer Encyclopedia of Chemical Technology.206 An excellent short review has focused attention on the preparation and use of 18 F in inorganic fluorine chemistry for example for the determination of labilities of element-fluorine bonds and for the identification of reaction intermediates.It also includes coverage of organic syntheses involving labelled inorganic fluorinating agents.’” Other reviews of interest include a summary of the chemistry of graphite fluoride,*08 a discussion of the use of organic and inorganic fluorine compounds in energy technology,209 and a summary of the safe handling of fluorine and chlorine fluorides.’10 Halogen Atom Chemistry.-The formation physical and physico-chemical proper- ties and reactions of atomic fluorine2” and the reaction of atomic fluorine with molecular hydrogen212 have been reviewed.The Raman spectroscopy of atomic fluorine in a heated static chamber has been studied. The results indicate that Raman scattering can be used as a probe for atomic fluorine. 21 The rate constants for the F+H and F+D2 reactions over a wide temperature range have been Structure-reactivity correlations have also been discussed and applied to the X + H2 and C1+ HX (X = halogen) series of gas-phase Rate constants for the F+ HCI reaction have been determined by analysis of the time dependence of the vibrational chemiluminescence of HF,215a and for the reactions F+ Br2 F + HBr and F+ O2 by the method of measuring the time of laser-radiation stop on rotational-vibrational transitions of the HF molecule as a function of the initial time of light-emission initiation Hydrogen fluoride i.r.chemiluminescence from the reactions of F atoms with HCl HBr and HI has been used to assign vibrational-rotational populations of the HF product.216 The reaction of fluorine atoms with CH without radiation in solid argon at 25 K has shown that this reaction requires almost zero activation energy. The photo- chemical combination has produced CH,F- -HF and H3C. * .HF complexes the 205 D. Naurnann ‘Fluorine and Fluorine Compounds; Special Inorganic Chemistry Vol. 2’ Steinkopff Darrnstadt 1980. 206 C. B. Lindahl and D. T. Meshri in ‘Kirk-Othmer Encyclopedia of Chemical Technology’ 3rd. Edn. ed. M. Grayson and D. Eckroth Wiley New York Vol. 10 p. 655 1980 and the following articles. 207 J. M. Winfield J. Fluorine Chem. 1980 16,1.N. Watanabe Kagaku Sosetsu 1980 27 37. ’09 J. Portier Actual. Chim. 1980 7. ’lo R.L. Farrar jun. and E. J. Barber Report 1979 K/ET-252 46 pp. Avail. NTIS; from Energy Res. Abstr. 1979,4 (19) Abstr. No. 48 962. ’I1 V. Bezrnel’nitsyn V. F. Sinyanskii and B. B. Chaivanov Khim. Plazmy 1979 6 89. ’”J. B.Anderson Ado. Chem. Phys. 1980 41,229. 213 J. C. Cummings and D. P. Aeschliman Opt. Commun. 1979 31,165. 214 (a)E. Wurzberg and P. L. Houston J. Chem. Phys. 1980 72,4811; (6)R.F. Heidner 111 J. F. Bott C. E. Gardner and J.‘ E. Melzer ibid. p. 4815; (c)N. Agmon and R. D. Levine Zsr. J. Chem. 1980 19,330. 215 (a)I. W. M. Smith and D. J. Wrigley Chem. Phys. Lett. 1980 70 481; (6)N. F. Chetbotarev Kinet. Katal. 1979 20 1381. *I6 K. Tamagake D. W. Setser and J.P. Sung J. Chem. Phys. 1980,73 2203. The Typical Elements 145 matrix-i.r. spectra of which have been studied in These results comple- ment those obtained last year from microwave discharge combination of Ar-CF4 or Ar-NF3 with CH4. In the meantime i.r. examination of the products from the reaction of Ar-CO and Ar-NF mixtures in a microwave discharge deposited on a window at 14 K has revealed the presence of FCO and F2C0 in the matrix. This has permitted a detailed examination of the vibrational and electronic spectra of FC0.217b The dynamics of the reactions of fluorine atoms with NH3 N2H4,218a and N3H2I8' have been studied by i.r. chemiluminescence. In the case of hydrazoic acid the results suggest that the reaction proceeds via a long-lived HFN intermediate species.218b The kinetics of the F+NO+He and the F+NO+NO reactions have been measured in a flow reactor using e.s.r.and rate constants for the abstraction reactions C1 +NOCl C1+ SF5Cl and Br + NOBr have been investi- gated using a flash photolysis-time-resolved mass spectrometry The laser flash photolysis of iodine in the gas phase has provided second-order rate constants for iodine atom combination.220 The Halogen Elements.-It has been pointed out that the overvoltage of working electrolytic fluorine cells has been over-estimated by approximately 1V the difficulty arising through confusion over values of the decomposition voltage.221" The observation that C1- Br- or I-could be photo-oxidized in non-aqueous (MeCN) solution without deterioration of the MoY2 (Y = S or Se) photoanode has led to the discovery that sustained visible light-driving generation of chlorine and bromine [according to equations (25) and (26)] in aqueous solutions is possible using n-type semi-conducting MoY~.~~~~ -2e-2Br-(aq)-+ Br2(aq) [Eo(Br2/Br-)= +0.86 V us.SCE] (26) Further calculations on the best potential-energy model for the chlorine crystal structure have shown that the assumption of a molecular dipole and a space group symmetry lower than Cmca is not necessary.222 The blue-black iodine-starch complex has been shown to contain the pentaiodide anion as the major chrom~phore.~~~ The laser-stimulated chemical reaction of I2 with C2H2 has been shown to yield mostly C2H212 and traces of C2H214.A mechanism for the reaction has been proposed and on the basis of thermal experiments shown to be n~n-thermal.~~~ (a) G. L. Johnson and L. Andrews J. Am. Chem. Soc. 1980 102 5736; (6) M. E.Jacox J. Mol. Spectrosc. 1980,80 257. '18 (a) D. J. Douglas and J. J. Sloan Chem. Phys. 1980,46,307;(6)J. J. Sloan D. G. Watson and J. S. Wright ibid. 1979,43 1. 219 (a)P.Kim,D. I. Maclean and W. G. Valence J. Phys. Chem. 1980,84,1806;(6) D.Price and E. Ratajczak Bull. Acad. Pol. Sci. Ser. Sci. Chim. 1979 27 195. 220 J. M. Zellweger and H. Van den Bergh J. Chem. Phys. 1980,72,5405. (a) 0.R. Brown Electrochim. Acta 1980 25 367; (6) C.P.Kibiak L. F. Schpeemeyer and M. S. Wrighton J. Am. Chem. SOC. 1980,102 6898. 222 L.-Y. Hsu and D. E. Williams Inorg. Chem.1980 19 2200. 223 R. C.Teitelbaum S. L. Ruby and T. J. Marks J. Am. Chem. SOC.,1980,102,3322. 224 V. S. Kushawaha J. Am. Chem. SOC.,1980,102 256. F. A. Hart A. G.Massey P. G. Harrison and J. H. Holloway Homolytic Cationic and Anionic Halogen Species.-The spectrum of radiation generated by LiF-FZf,F2- active medium”5a and the kinetics of accumulation and generation of F2+centres in lithium fluoride have been studied. The first example of a positive halogen ion cryptate formed by complexation of molecular iodine with the [2,2,2] cryptand (35) has been reported. The compound was characterized by n.m.r. and voltamperometric A An improved synthetic route to [IZ][Sb2F1J and [Brz][Sb3F16] by the oxidation of bromine and iodine by bis(fluorosulphury1) peroxide S206F2 followed by solvoly- sis in excess of SbF5 has been reported and magnetic spectroscopic and some chemical properties of the dihalogen cations have been described.’” The ”’I Mossbauer spectrum of [12][Sb2F11] has been measured together with those of a number of anionic iodine species and a reasonable correlation between the quad- rupole coupling constant and ligand electronegativity has been found.228 A number of [Au(SO,F),]-salts containing the cations Br3+ Br5+ [Br(S03F)2]+ and [I(SO,F),]’ have been prepared and characterized by vibrational ~pectro~copy.’~~~ The relative binding energies of positrons on the halides C1- Br- and I- in water have been studied.In contrast to the theoretical results for the vacuum case the binding energy of the [Xe-,e’] state has been found to increase in the series C1- Br- I-.’” Complexation of small cations by crown ethers and cryptates is well known and has found a variety of applications but selective complexation of small anions is relatively unknown.However it has now been shown that a dinuclear isocyanide nickel(I1) complex has the ability to bind C1- and Br- selectively in the presence of larger anions such as thio~yanate.’~’ Examination of the chemical forms of radioiodine in boiling water reactor systems has shown that during normal operation I-and perhaps HI0 are the major species in the reactor water and condensate. The dominant species following reactor shutdown is 103- resulting from radiation-induced oxidation of iodide The radiolysis of iodide ions in dilute aqueous solutions has been investigated under a variety of conditions in order to clarify the effect of radiation on iodine which forms iodate.2316 The iodide-ion-selective electrode has been applied to the study 22s (a)V.A. Grigorov V. E. Gorbovskoi E. F. Martynovich and S. N. Mysovskii Pis’ma Zh. Tekh. Fiz.,1979,5 1431; (b)T.T.Basiev Yu. K. Voron’ko S. B. Mirov V. V. Osiko and A. M. Prokhorov Pis’ma Zh. Eksp. Teor. Fiz.,1979,30,661. 226 J. L. Pierre H. Handel P. LabbC and R. Le Goaller J. Am. Chem. SOC.,1980 102 6574. 227 W.W.Wilson R. C. Thompson and F. Aubke Inorg. Chem. 1980,19 1489. 228 T.Birchall and R. D. Myers J. Chem. SOC., Dafton Trans. 1980 1060. 229 J. R.Andersen N. J. Pendersen P. Christensen and 0.E. Mogensen J.Phys. Chem. 1980,84,1295. 230 W.L. Gladfelter and H. B. Gray J. Am. Chem. SOC., 1980,102,5909. 231 (a) C.-C. Lin J. Inorg. Nucl. Chem. 1980,42 1093; (b)C.-C. Lin ibid. p. 1101. The Typical Elements 147 of the kinetics of the periodate reaction with iodate. The rate equation is -d[IO,-]/dt = (5.9&1)dm3 mol-' s-' [I-][IO,-] in the pH range 3.51-5.31. In contrast to earlier studies no hydrogen-ion dependence of the rate was Fluorine molecular ions (F2-)in y-irradiated (NH4)2BeF4 single crystals at 77 K have been investigated by e.s.r. methods.233 The 12'1 Mossbauer spectrum of the 13-anion has been obtained.228 Matrix reactions of alkali iodide and iodine molecules have been performed to produce M'13-in order to compare the spectroscopic properties of the M+13- ion pair in solid argon with that of 13-in solution.The data for the matrix and solution species were in excellent agreement and this suggests that the matrix reaction technique may be suitable for producing other less stable polyhalide~.~~~ The trihalogenide species S4N313 and S4N3Br3 have been shown to be less stable than the related iodated mixed trihalogenides but more stable than S4N31.66C The structure of the blue-black iodine complex of amylose which is the linear helical component of starch has been studied by resonance Raman and 1291 Mossbauer spectroscopy and shown to contain Is-as the major Hydrogen Halides.-The manufacture properties and uses of hydrogen fluoride have been briefly reviewed.235 The kinetics of the reactions of hydrogen and vibrationally excited hydrogen mo1e~~le~~~~~*~ with molecular fluorine and of hydrogen with fluorine in the presence of hydrogen have been studied.In an investigation of the product energy distribution in the series of reactions of atomic hydrogen with halogen fluoride which gives HF and the halide atom detailed rate constants for the reactions involving BrF and IF have been obtained by i.r. chemiluminescence methods.237 The autoprotolysis constant of HF has been evaluated from potentiometric titrations of solutions of H' with F-. The fluoride-ion concentrations were deter- mined with the help of a silver electrode acting in the presence of HCI and AgCl as a fluoride-ion Raman spectra of crystalline HF and DF have been recorded at low temperatures and assignments of all the fundamental modes have been made.239 The i.r.technique has been used to monitor column densities of HF and HCl and HF :HC1 ratios in the bulk atmosphere and in the strato~phere.~~' R~tational~~' and vibrational energy transfer of HC1242 have been measured. 232 C. Marques and R. A. Hasty J. Chem. Soc. Dalton Trans. 1980 1269. 233 K. Matsuki K. Ohno and J. Sohma J. Phys. SOC.Jpn. 1979,47 1897. 234 L. Andrews E. S. Prochaska and A. Loewenschuss Inorg. Chem. 1980 19,463. 235 J. F. Gall in 'Kirk-Othmer Encyclopedia of Chemical Technology' 3rd Edn. ed. M. Grayson and D. Eckroth Wiley New York Vol. 10 p. 733 1980. 236 (a) G. V. Vasil'ev E. F. Makarov and Yu. A. Chernyshev Fiz.-Khim.Protsessy Gazov. Kondens. Fazakh 1979 15 through Chem. Abstr. 1980,93,54860u; (b)V. L. Orkin and A. M. Chaikin Kinet. Katal. 1979 20 1367; (c) V. L. Orkin and A. M. Chaikin Fiz.-Khim. Protsessy Gazou. Kondens. Fazakh 1979 24 through Chem. Abstr. 1980,93 54 861v; (d)G. A. Kapralova V. L. Orkin V. G. Fedorov and A. M. Chaikin Kinet. Katal. 1979 20 828. 237 D. Brandt and J. C. Polanyi Chem. Phys. 1980,45 65. 238 R. Gut J. Fluorine Chem. 1980 15 163. 239 A. Anderson B. H. Torrie and W. S. Tse Chem. Phys. Lett. 1980 70 300. 240 P. Marche A. Barbe C. Secroun J. Corr and P. Jouve C. R. Hebd. Seances Acad. Sci. Ser. B 1980 290 369. 241 G. H. Wegdam J. Mol. Struct. 1980,61 87. 242 B. Schramm and H. Rapp Ber. Bunsenges. Phys. Chem. 1980,84 850. 148 F.A. Hart A. G.Massey P. G. Harrison and J. H. Holloway Theoretical dipole moment functions of the HF HCl and HBr molecules in their electronic ground states have been calculated from highly correlated ab initio wavefunctions and found to be in good agreement with recent The structure of solvation aggregates about fluoride ions in liquid hydrogen chloride has been investigated by i.r. and isotropic and anisotropic Raman spectra of HCl solutions of Et4NF. The structure is evidently ordered and the solvation number is 4. The radius of the first sphere of solvation ('Cl-H.-F) was found to be 3.1 Solutions of HBr in sulpholane C4H8SO2 are brown in colour owing to the presence of Br2. 1.r. and U.V. investigations have established that the equilibrium shown in equation (27) occurs in the K C4H8S02+ 2HBr C4HsSO +Br2 +H20 K = 2.4 x at 20 "C Ab initio valence-bond wavefunctions for the four-electron three-centre bonding incorporating the Hls and F2p orbitals in the HF2- anion have been Heats of solution of KF and CsF in aqueous HF (O-lOOo/~ HF) have been Analysis of the 'H and "F n.m.r.lineshapes of polycrystalline samples of CaF2.2HF SrF2.HF and BaF2.HF have shown that the difluoride ions exhibit various degrees of In i.r. studies on solid NaHF2 the v3 stretching frequency of HF2- as an isotropic solid solute in NaDF2 has two components but v3 of DF2in NaHF appears as a single band.2486 Reaction between NF4SbF6 and CsF at -78°C has been shown to give NF4'HF2-.nHF which is stable in HF solution at room temperature.The composition thermal stability spectroscopic properties and decomposition of the solid have been An i.r. study of HF-SbF5 solutions has shown that H3F2+ and solvated H3F2+ ions are the predominant cationic species over a wide concentration range. The H2F+ion was observed only in solutions containing high SbF concentration^.^^^ Ab initio studies on H2F2 and H3F3 and infinite (HF) chains251b have been carried out. Pressure-broadened linewidths for the fundamental of HF have been determined by laser absorption experiments. Hydrogen fluoride polymer formation was observed and the average chain length was found to be 4.6.252 A considerable amount of work has been carried out on hydrogen halide hydro- gen-bonded complexes. Stationary points on the energy hypersurface of HF-HC1 were found to correspond to HF-..HCl HCI-.HF quasilinear structures and a cyclic The effects on the i.r.and Raman intensity on the CN stretching band of the HCN molecule when hydrogen-bonded to HF have been investigated 243 H. J. Werner and R. Pavel J. Chem. Phys. 1980 73 2319. 244 B. Desbat and P. V. Huong J. Mol. Struct. 1980,63,25. 24s J. Emsley V. Gold and M. J. B. Jais J. Chem. SOC.,Dalton Trans. 1980 2028. 246 R. D. Harcourt and W. Roso,Int. J. Quantum Chem. 1979,16 1033. 247 J. Thourey G. Perachon and P. Germain J. Fluorine Chem. 1980 15 315. 248 (a)N. K. Moroz A. M. Panich T. D. Fedotova and S. P. Gabuda Zh. Strukt. Khim. 1979 20 814; (b)E. Spinner Aust. J Chem. 1980 33 933. 249 K. 0.Christie W. W.Wilson and R. D. Wilson Znorg. Chem. 1980 19 1494. 2so B. Bonnet and G. Mascherpa Inorg. Chem. 1980 19 785. 251 (a) P. N. Swepston S. Colby H. L. Sellers and L. Schaefer Chem. Phys. Lett. 1980 72 364; (b) A. Karpfen Chem. Phys. 1980 47,401. 2s2 J. J. Hinchen and R. H. Hobbs J. Opt. SOC.Am. 1979 69 1546. 2s3 P. Hobza M. M. Szczesniak and Z. Latajka Chem. Phys. Lett. 1980 74 248. The Typical Elements 149 and the results compared with data for the HCN- ..Li’ Determinations of the geometries of the HCN. -HF,2546 MeCN. -HF,254c and Bu‘CN. -*HF254d heterodimers have been determined by microwave2s4bd and in the case of Bu‘CN.-.HF i.r,254d spectroscopy. For the MeCN and Bu‘CN complexes a number of other spectroscopic constants have also been Microwave spectros- copy has also been used to identify and characterize the XH..CO (X =F C1 or Br) hydrogen-bonded dimer~.~~~~ Ab initio SCF-MO calculations have yielded cubic and quadratic force constants for the FH. -OH2 and FH. -.0Me2 complexes. In contrast to earlier calculations with the most extended basis set the equilibrium geometry of the FH. -.OH2 complex does not have definite C2”chara~ter.~”~ Another theoretical investigation has accurately reconstructed the fundamentals and first overtones of the H stretching bands of FH. -.0Me2 and FH-.-OEt2 and their deuteriated analogues.255b The He-I photoelectron spectrum of the gas-phase C1H. -.0Me2 complex has been interpreted with the aid of MO calculations to suggest that the measured monomer-to-dimer ionization potential shifts are due to an inductive transfer of electron density of about 0.05 e from the Me20 to HCl.256a A similar MO study has provided data on geometries and energies for a series of complexes RF...HF (R = H Me NH2 or Halogen-Nitrogen Species.-The diazidoiodate PPh4[I(N3)*] has been prepared from PPh4N3 and IN3 in CH2C12.An X-ray single-crystal structure determination on the compound has shown that the structure consists of PPh4+ cations and [N3-I-N3]-anions. The azido-groups appear to be bent but because of possible packing disorder evidenced by large and strongly anisotropic temperature factors of two of the N atoms even at low temperature exact details of the anion structure are not certain.257 1.r. spectra of NMe4[I(N3)2] and PPh4[I(N3)2] have been reported and assigned.257 The new high-yield routes to unstable halogen azides and isocyan- ates have permitted vacuum-u.v.photoelectron spectra to be obtained for XN3 (X=C1 or Br) and XNCO (X=Cl Br and I). The spectra have provided an interesting investigation into how the orbitals of a linear pseudohalide grouping are perturbed by an off-axis halogen atom.258 Halogen Oxides Oxide Fluorides and Compounds with Halogen-Oxygen or Halogen-Sulphur Bonds.-Reactions between chlorine and amines at low tem- perature have been shown to give a variety of products. Amines with reactive protons in the a-position to nitrogen yield azomethinium chlorite and the chlorite or chlorate of the protonated base those with reactive protons in other positions give amidochlorates and the salt of the protonated base and those without reactive 254 (a)J.Sadlej Adv. Mol. Relaxation Interact. Processes 1979,15,173;(b) A. C.Legon D. J. Millen and S. C. Rogers Proc. R. SOC.London Ser. A 1980 370 213; (c)J. W. Bevan A. C. Legon D. J. Millen and S. C. Rogers ibid. p. 239;(d) A. S.Georgiou A. C. Legon and D. J. Millen ibid. p. 257;(e) A. C.Legon P. D. Soper M. R. Keenan T. K. Minton T. J. Balle and W. H. Flygare J. Chem. Phys. 1980,73 583. 255 (a)Y. Bouteiller M. Allavena and J. M. Leclercq Chem. Phys. Lett. 1980,69 521; (b)Y.Bouteiller and Y. Guissani ibid. p. 280. 256 (a)F. Carnovale M. K. Livett and J. B. Peel J. Am. Chem. Soc. 1980 102 569; (b)P.Ruelle and G. Leroy Adv. Mol. Relaxation Interact. Processes 1980,16,131.257 U.Muller R. Dubgen and K. Dehnicke 2.Anorg. Allg. Chem. 1980,463 7. 258 D. C.Frost C. B. Macdonald C. A. McDowell and N. P. C. Westwood Chem. Phys. 1980,47,111. 150 F. A. Hart A. G. Massey P.G. Harrison and J. H. Holloway protons simply give adducts of amine and chlorine dioxide. This is the first report of amidochlorate~.~~~ Oscillating bromate oxidative reactions are useful for investigating problems concerning concentrational kinetics and the theory of oscillations and waves. Recent data on these reactions has now been surveyed with particular reference to the mechanism of the reactions.260 X-Ray emission spectroscopy has been shown to be a sensitive measure of the relatively small amount of 3d orbital participation in the bonding of the C104- ion.261 The relative catalytic effectiveness of a variety of metal oxides on the thermal decomposition of KC1O4 has been investigated by thermogravimetry and by isother- mal weight-loss technique and the Arrhenius parameters for the catalysed processes have been determined.262 Attempts to synthesize NF4+X04- (X = C1 Br or I) by metathesis between NF4SbF6 and CsX04 have shown that NF4C104 can be obtained as an unstable white solid and that the NF4Br04 salt is of marginal stability in HF solution.Efforts to isolate solid NF4Br04 resulted in explosions. The NF4104 salt was not obtained owing to the ready fluorination of 104- to IF402- by both HF and BrF5. The NF4C104 salt was fully characterized by vibrational and "F n.m.r. spectroscopy.The preparation of NF4+XF40- (X = C1 or Br) salts by reaction of NF4SbF6 and CsXF40 was also attempted. However with BrF40- fluoride abstrac- tion occurred with resultant formation of NF3 F2,and BrF30 and when CsClF40 was used a displacement reaction occurred with BrFs to give CsBrF6 and C1F30.249 The X-ray crystal structure determination of the heteropolyperiodate [Co43t137+024H12]3-, in which 17+06 octahedra share 0 atoms with lower-charged Co3+ ions has been used to draw attention to three main characteristics which atoms must have to become heteropoly addenda. These are (a)small size relative to the radius ratio indicated for octahedral packing with oxygens (b) ability to change readily in solution between tetrahedral and octahedral co-ordination with 0 and (c) high positive charge.It is also pointed out that many new heteropoly structures should be possible in which 17+06 octahedra share 0's with transition- metal atoms forming finite networks with varying geometries and since co-ordin- ated waters can be replaced by other ligands many organic derivatives should be possible.263 The oxidation of elemental iodine with ozone in strong inorganic acids has been shown to be a mild method for the preparation of iodosyl compounds. The for- mations of iodosyl sulphate (IO),SO, iodosyl fluorosulphate 10(S03F) and iodosyl nitrate 10(N03) in the appropriate concentrated acids have been described and their vibrational spectra have been The disproportionation of dilute aqueous iodine solutions which contain hypoiodous acid HOI has been studied by a combination of spectrophotometric and potentiometric methods and shown to yield iodate and iodide.The rate ex- pression for the disproportionation has been determined for the pH range 7-14.265 The reactions of iodic acid HI03 and periodic acid H5106 with F20POPOF2 259 J. Jander and K.-P.Reich 2.Anorg. Allg. Chem. 1980,465 41. 260 A.M.Zhabotinsky Ber. Bunsenges. Phys. Chem. 1980 84,303. 261 J. A.Tossell Znorg. Chem. 1980,19,3328. 262 L.W.Collins Znorg. Chim. Acta 1980 39 53. 263 L.C.W. Baker L. Lebioda J. Grochowski and H. G. Mukherjee J. Am. Chem. SOC., 1980,102,3274. 264 M.Schmeisser D. Naumann and E. Renk 2.Anorg. Allg. Chem. 1980 470 84. 265 T. R. Thomas D. T. Pence and R. A. Hasty J. Inorg.Nucl. Chem. 1980 42 183. The Typical Elements 151 have been shown to give the new compounds I02P02F2 and I03P02F2. Raman spectra have shown that the cation in I02P02F2 is the monomeric 102+species but suggest a dimeric structure for the Io3+ ion in Shielding anisotropies of 19Fnuclei in C103F have been determined by analysis of the rigid-lattice n.m.r. lineshape of the molecule enclathrated in D20 The standard enthalpy of formation of crystalline (IF302)2 has been determined as -984.0 f 18.0kJ mol-’ based on enthalpies of reaction with aqueous acidic iodide Both (IF30.1F302)2 and (SbF,-IF302) have been shown by X-ray single-crystal structure determinations to be cyclic molecules. The structure of (IF30.1F302)2 consists of two IF20 and two IF402units linked by asymmetric oxygen bridges to give a cyclic molecule.These are weakly bonded together in sheets by additional weak oxygen bridges.269“ The related (SbF5*IF302)2 exists as dimers with two antimony and two iodine atoms at the corners of a rhombus linked by asymmetric angular oxygen bridges. There are contributions to the structure from the ionic formulation [SbF4][IF402] but the main characteristic of the structure is its similarity to those of the pentafluorides typified by RUF~.~~” Mean amplitudes of vibration for IOF5 which are in excellent agreement with those obtained from electron diffraction and microwave measurements have been recalculated from known spectroscopic data using the method of characteristic Force constants and centrifugal distortion constants have also been calculated from previously published data.2706 cis-and trans-IF,O(FO) have been obtained by metathesis and decomposition of CSIO,F,.~~~ From its microwave spectrum chlorine thiocyanate has been shown to be ClSCN rather than the isothiocyanate CINCS in the gas phase.272 Interhalogen Compounds and their Alkyl Aryl and Pentafluorotellurate Deriva- tives.-Halogen fluorides have been reviewed.273 A linear correlation between the chemical shifts and the atomic charge on fluorine has been established for a wide range of binary Ionization potentials of ClF ClF2- and CIFs have been calculated by a discrete variational method.275 Dipole moments have been measured for the diatomic interhalogen The rotational spectra of all twelve stable isotopic species of CIF BrF BrC1 ICl and IBr have been observed and measured by microwave Laser-induced fluorescence studies of the reactions of fluorine atoms with iodine2”“ and with iodomethane and iodotriflu~romethane~~~~ have 266 A.Addou and P. Vast J. Fluorine Chem. 1980 16 89. 267 S.K. Garg J. A. Ripmeester and D. W. Davidson J. Chem. Phys. 1980,72 567. 268 A.Finch P. N. Gates A. J. Edwards and A. A. K. Hana J. Chem. SOC. Dalton Trans. 1980 869. 269 (a) R. J. Gillespie J. P. Krasznai and D. R. Slim J. Chem. Soc. Dalton Trans. 1980 481; (6) A. J. Edwards and A. A. K. Hana ibid. p. 1734. 270 (a)E. J. Baran Monatsh. Chem. 1979,110,1267; (6)V.Sengodan and K. G. Srinivasacharya Indian J. Phys. Part B 1979 53,255. 271 K.0.Christie and R. D. Wilson Inorg. Nucl. Chem. Lett. 1979 15 375. ’”R. J. Richards R. W. Davis and M. C. L. Gerry J. Chem. SOC. Chem. Commun. 1980,915. 273 A. J. Woytek ‘Kirk-Othmer Encyclopedia of Chemical Technology’ 3rd Edn. ed. M. Grayson and D. Eckroth Wiley New York Vol. 10,p. 722 1980. 274 L. May Latu. PSR Zinat. Akad. Vestis Khim. Ser. 1980 304. 275 G. L.Gutsev and A. E. Smolyar Zzv. Akad. Nauk SSSR Ser. Khim. 1980,745. 276 K.P.R. Nair Kem. Kozl. 1979,52 431. 277 R. E. Willis jun. and W. W. Clark 111 J. Chem. Phys. 1980,72 4946. 278 (a) R.J. Donovan D. P. Fernie M. A. D. Fluendy R. M. Glen A. G. A. Rae and J. R. Wheeler Chem. Phys. Lett. 1980,69,472;(6) L.Stein J. Wanner and H. Walther J. Chem. Phys. 1980,72 1128. 152 F. A. Hart A.G. Massey P. G. Harrison and J. H. Holloway been carried out. Emission and excitation spectra of iodine monofluoride in solid argon at 12 K279"and the emission spectrum and formation kinetics of IF in electron beam-produced plasmas279b have been studied. The kinetics and mechanism of reactions of ClF with hydrogen at 25-90 "C and 0.4-5.0 atm total pressure have also been Work on halogen trifluorides includes a mass-spectrometric study of electron- impact ionization of ClF from which bond energies of F2Cl-F and Cl-F the atomization energy of ClF2 and the heat of formation of ClF hav been obtained.280 The reaction of ClF3 with excess of silicon in a static system at high pressure has been investigated. At 19 500 Pa the the reaction can be accounted for in terms of equation (28) but at 54300 Pa equation (29) seems to apply."' Si + 2C1F3 -+ SiF4+2C1F (28) 3Si +4C1F3 -+ 3SiF4+ 2C12 (29) The latest in a series of papers on the gas-phase fluorination of bromine proposes a mechanism for the reaction and provides rate data for the reaction steps.282 Calculated ionization potentials of BrF and BrF using the SCF-(discrete variational)-Xa method have been used to interpret existing experimental photo- electron spectra for the Reports of the preparation of intercalation compounds of halogen trifluorides in graphite have appeared.A ClF intercalate results when the trifluoride is passed through graphite in hydrogen and the BrF compound can be obtained by treating powdered graphite with gaseous BrF at 50-127 0C.284b Thermal decomposition studies of C4F-(0.46 f O.Ol)ClF have show that at ca.310 "C the inserted ClF3 fluorinates the C4F matrix further. At ca. 420 "C gaseous chlorine is liberated and a fluorine-graphite matrix of empirical formulation C4F2.23 is produced which decomposes at 560 "C. Under vacuum the decomposition temperatures are The temperature dependence of 'H and I9Fn.m.r. spectra of ClF3-HF and BrF in fluorographite indicates reorientation and translational diffusion of the inserted molecules within the The alkyl and aryl iodides MeIyzSsa o-XC6H41(X = F C1 I Me CF, or OMe) rn-XC6H41 (X=F or Cl) and p-XC6H41 (X=F C1 Br I Me or N02)285b~C have been shown to react with elemental fluorine at low temperature in CCl3F to yield the corresponding alkyl or aryl iodine difluorides.In the case of the aryl compounds no attack on the aromatic rings occurs. The compounds have been characterized by 19Fand I3C and 'H n.m.r. and by Raman spectroscopy. 279 (a)J. C. Miller and L. Andrews J. Mof. Spectrosc. 1980,80 178;(6)S. B. Hutchinson J. G. Eden and J. T. Verdeyen Appl. Phys. Lett. 1980 37 374;(c) G. P. Zhitneva I. V. Ivantsova N. F. Chebotarev and S. Ya. Pshezhetskii Kinet. Katal. 1979,20 1375. A V.Dudin L. N. Gorokhov and A. V. Baluev Izv. Akad. Nauk SSSR Ser. Khim. 1979,2408. *'* V. F.Garanin Zh. Neorg. Khim. 1979,24,2892. 282 V. S.Arutyunov S. N. Buben E. M. Trofimova and A. M. Chaikin Kinet. Katal. 1980 21 337. 283 G. L.Gutsev and A. E. Smolyar Chem. Phys. Lett. 1980,71,296. 284 (a) Yu.I.Nikonorov and L. L. Gornostaev U.S.S.R. P. 707889 (Cl. COlB31/00)05 Jan. 1980 Appl. 2 514 073 27 Jul. 1977;(6)Yu. I Nikonorov U.S.S.R. P. 710 930 (Cl. C01B3/00) 25 Jan. 1980,Appl. 266 061,03 Jul. 1978;(c)A. S.Nazarov I. I. Yakovlev A. F. Antimonov V. M. Grankin V. B. Durasov and P. P. Semyannikov Zh. Neorg. Khim. 1980,25 1506; (d) Yu. I. Nikonorov and B.I. Obmoin ibid. p. 1511. 285 (a)D. Naumann and H. R. Feist J. Fluorine Chem. 1980,15 541; (6)D. Naumann and G. Ruther ibid.,p. 213;(c) I. Ruppert ibid. p. 173. The Typical Elements 153 Raman spectra of CIFs have been recorded between room temperature and 4 K and reorientation motions in the liquid phase have been deduced from Raman bandshape analysis.286 The ionization of ClF5 has been investigated by electron- impact mass spectrometry which has produced not only appearance potentials but also values of the electron affinities of ClF2 and ClF and the upper limit of the ionization potential of the ClF Studies of the *'Br and 121*123Sb n.q.r.spectra of BrF5 and its complexes with SbF5 BrFS.nSbF5 (n = 1 2 3 or 7) have been interpreted to indicate that CIFS has a greater donor capacity than BrFs.288 Following the preparation of C6FsIF4 some eight years ago it has now been shown that pentafluorophenylbromine(v)tetrafluoride C6FsBrF4 can be prepared by the oxidation of pentafluorophenyl bromide with elemental fluorine at 128 0C.289 The standard enthalpy of formation of IFShas been obtained from measurements of the heat of hydrolysis. The value obtained -884.7 f 1.1kJ mol-' is in agree- ment with earlier hydrolysis and fluorine-bomb results.290 The pentafluorotellurate(v1) of quinquevalent iodine I(OTeFs)5 has been pre- pared by reaction of IF5 with B(OTeF5)3 in the presence of iodine followed by reaction with Xe(OTeFs)2 under U.V.radiation. From n.m.r. data it has been shown that when I(OTeF5)2 is dissolved in IF5ligand exchange occurs with the formation of FxI(OTeF5)s-x. Similarly POF2(0SeF5) in IF5is in equilibrium with POF and F,I(OSeFs)s-x. It has also been demonstrated that reaction of IF5 with excess of B(OTeF5) at 80 "C gives 10(OTeF5)3.291 Hexafluorochlorine tetrafluorocuprate [CIF6][CuF4] has been prepared by shock-compression of a CuF2-CuCl reaction mixture and its crystal structure has been determined.292 Two new solid-solid transitions have been observed in IF7by means of I9Fand 127 I n.m.r.and 1271 n.q.r. studies and fast molecular rotations and slow molecular diffusion have been studied by relaxation 3 Group VIII The chemistry of noble-gas fluorides has been reviewed.294 A case has been made to modify the common definition for electronegativity to 'the power of an atom in a molecule to attract or hold electrons to itself'. It has also been pointed out that there is extraordinarily good agreement between the scales of Allred and Rochow Sanderson Mulliken and Pauling and that average values provide good estimates of noble-gas atom electronegativities for electron retention. These suggest that a continued effort to synthesize argon fluorides is 286 M.Drifford M. Gilbert P. Nectoux R. Rousson and J. M. Weulersse Proc. Int. Conf. Raman Spectrosc. 6th 1978,2 218 ed. E. D. Schmid R. S. Krishnan and W. Kiefer. Heyden London. 2e7 A. V. Dudin A. V. Baluev and L. N. Gorokhov Izo. Akad. Nauk SSSR Ser. Khim. 1980,487. 288 A. I. Kuz'min V. I. Shpanko G. N. Zviadadze V. F. Sukhoverkhov and B. E. Dzevitskii Zh. Neorg. Khim. 1979,24 2127. 289 J. A. Obaleye and L. C. Sams Inorg. Nucl. Chem. Lett. 1980 16 343. 29fl A. Finch P. N. Gates and M. A. Jenkinson J. Inorg. Nucl. Chem. 1980 42 1506. 291 D. Lentz and K. Seppelt Z. Anorg. Aflg. Chem. 1980 460 5. 292 A. S. Batsanov Yu. T. Struchkov and S. S. Batsanov Dokl. Akad Nauk SSSR 1980 251 347. 293 J. M. Weulersse J. Virlet and P. Rigny Mol.Phys. 1979 38 923. 294 M. Iwasaki Kagaku Sosetsu 1980 27 59. 295 L. C. Allen and J. E. Huheey J. Inorg. Nucl. Chem. 1980 42 1523. 154 F. A. Hart A. G. Massey P. G. Harrison and J. H. Holloway Following the characterization of the green Xe,' species observable when xenon(I1) is reduced in antimony pentafluoride solutions it has now been shown that the cation may be obtained by the reversible oxidation of xenon. In this method an equilibrium is established between Xe and [XeF][Sb2Fl1] with [Xe2][Sb2Fl,] in antimony pentafluoride The interest noted last year in van der Waals complexes of the noble gases has continued. Theoretical studies have been carried out on A~sHO,~~'" and Ar.H20297b which in the cases of HF HCl and H20 give results in good agreement with experimentally obtained data.297b Fourier-transform spec- troscopy coupled with pulsed nozzle beam techniques has yielded microwave spectra for A~BHC~,'~~" Kr-HC1,298",b ArSHBr and Kr-HBr298b complexes.The KreHF complex has also been studied by 83Kr n.q.r. spectroscopy and results have been interpreted in terms of charge transfer in the weak Kr-HF bond.298c According to one microwave the structure of the series of complexes is linear but the ascribes an angle of 63.7"to KrHC1. These two investigations are also in disagreement about the binding energy of KraHCl. In a study of the ArC2H2 complex in an expanded beam using radiofrequency and Stark-eff ect measurements it has been concluded that this molecule is T-shaped with the Ar atom located 3.25 A from the C2H2 axis in the equilibrium c~nformation.~~~ The noble-gas monohalides ArF ArC1 KrF KrCl KrBr XeF XeCl XeBr and XeI have been observed in transverse a.c.electric discharges of SF6 CF2C12 CH2Br2 and CH212 with the noble-gas element^.^" The formation relaxation and quenching of KrF,301a XeF,301a*b and XeC1301" have been studied and the results have important implications for the use of noble-gas halides for high-power lasers. The fluorescence decay of XeF* following photodissociation of XeFZ3O2" and the fluorescence of XeF* in chemical radiation collisions between Xe and F2302b have been studied. A broad-band emission from XeF" has been tentatively assigned to the excited triatomics ArXeF" and NeXeF" which arise from interaction of XeF" with the buffer gases.3o3 E.s.r.spectra of 84KrF and '36XeF in polycrystalline KrF, XeF, and XeF4 have been analysed to obtain information on the structures and dynamic parameters of radical The kinetics of decomposition of XeF radicals trapped in XeF2 296 L. Stein and W. W. Henderson J. Am. Chem. SOC.,1980,102,2856. 297 (a) S. P. So J. Mol. Struct. 1979 54 243; (6) W. Kolos G. Corongiu and E. Clementi Int. J. Quantum Chem. 1980,17,775. 298 (a)M. R. Keenan E. J. Campbell T. J. Balle L. W. Buxton T. K. Minton P. D. Soper and W. H. Flygare J. Chem. Phys. 1980 72 ?071; (b)T. J. Balle E. J. Campbell M. R. Keenan and W. H. Flygare ibid. p. 922; (c) E. J. Campbell M. R. Keenan L. W. Buxton T. J. Balle P. D. Soper A. C. Legon and W.H. Flygare Chem. Phys. Lett. 1980,70,420. 299 R. L. DeLeon and J. S. Muenter J. Chem. Phys. 1980,72,6020. 300 V. S. Shevera and A. K. Shuaibov Zh. Tekh. Fiz.,1980 50 728. 301 (a) D. W. Setser H. C. Brashears and T. D. Dreiling J. Phys. Colloq. (Orsay Fr.) 1980 195; (6) R. W. Waynant Appl. Phys. Lett. 1980 36,493. 302 (a)E. D. Poliakoff S. H. Southworth M. G. White G. Thornton R. A. Rosenberg and D. A. Shirley J. Chem. Phys. 1980,72 1786; (6) L. I. Gudzenko L. V. Gurvich V. S. Dubov and Ya. E. Lapsker Dokl. Akad. Nauk SSSR 1979,248,146. 303 M. Rokni J. H. Jacob J. C. Hsai and D. W. Trainor Appl. Phys. Lett. 1979,35729. 304 (a)0.E. Yakimchenko E. N. Degtyarev V. N. Prusakov and Ya. S. Lebedev Chem. Phys. Lett. 1980,72 373; (b)0. E. Yakirnchenko E. N.Degtyarev V. N. Prusakov and Ya. S. Lebedev Teor. Eksp. Khim. 1980 16 75. The Typical Elements 155 and XeF polycrystalline matrices have provided information on the mobility of the radical within the matrices and allowed an estimation of the chemical bond strength in the ground state of XeF.304b Evidence for the displacement of a heavier noble gas Ng from a vibrationally excited noble-gas halide NgX by a lighter noble gas has been Further SCF-MO studies on XeF2 and XeF4 have been carried and the multiple-scattered-wave-SCF-Xamethod has been used to calculate ionization potentials and charge distribution for XeF, XeC12 XeF4 and XeF6. The role of the 5d orbitals especially their increased significance for XeF and XeF6 has been The participation of 5d orbitals in the bonding of high-valent oxygen compounds has also been studied by examination of the K, and KplX-ray emission lines in xenon in XeF2 XeF, NaHXeO, and Na4Xe06 with respect to xenon in the hydroquinone lathr rate.^^" It has been claimed that XeF, free from contamination by XeF2 or XeF6 can be prepared by irradiation of a gaseous mixture of Xe and F2 (molar ratio3 1:2) in a reactor with walls coated with NiF2.Mixtures of Xe and F2(molar ratio = 1:2) give XeF2 and the rate of reaction is increased fourfold when ca. 1mol '/o of HF is added.308 The oxidative properties of XeF have been used in the determination of Cr3' and Mn2' in dilute sulphuric acid in the presence of AgN03. The ions are converted into Cr2072- and Mn02 respectively.309 Xenon difluoride has also been shown to react with [Pt(NH3)4]C12 in the solid state to give tran~-[Pf(NH~)~F~]Cl~ but in solution in MeCN this is converted into tran~-[Pf(NH~)~Cl~]F~.~~~ A new determination of the heat of formation of XeF2 obtained by the combus- tion of germanium in XeF2 is in close agreement with a value obtained eight years earlier by reaction of XeF2 with PF3.311 Existing thermodynamic data have been used to calculate successive one-electron potentials for the reduction of XeF2.312 Studies on the fluoride-ion acceptor properties of KrF2 XeF2 and XeF4 with BiF5 have complemented earlier work with AsF5 and BiF5.The adducts formed with BiF5 are KrF2-BiF5 XeF2-BiF5 XeF2.2BiF5 2XeF2.BiF5 XeF4.BiF5 and XeF4.2BiF5. Although ionic to the first approximation all have strong fluoride- bridge interactions between the respective anion and cation.313 Detailed 19Fand 129 Xe n.m.r.studies of the reaction of XeF2 with WOF and MoOF in solution have provided information on the nature of XeF2-WOF4 and XeF2.2WOF in solu- tion and on the hitherto unreported molybdenum analogues. Unambiguous evidence for larger polymeric species XeF2.nMOF4 (n = 3 or 4 M = Mo or W) and for isomerization between oxygen- and fluorine-bridged XeF groups in the 305 H. C. Brashears D. W. Setser and Y. C. Yu J. Phys. Chem. 1980,84 2495. 306 L. S. Bartell M. J. Rothman C. S. Ewig and J. R. Van Wazer J. Chem. Phys. 1980 73 367. 307 (a)L. Scheire P. Phariseau R. Nuyts A. E. Smith and V. H. Smith jun. Physica A (Amsterdam) 1980 101 22; (b)L.I. Molkanov Yu. S. Grushko Ya. K. Mishin and V. K. Isupov Zh. Eksp. Teor. Fiz. 1980 78,467. 308 K. Lutar A. Smalc and J. Slivnik Vestn. Slov. Kem. Drus. 1979 26 435. 309 S. A. Lempert D. B. Lempert N. N. Aleinikov and P. K. Agasyan Zh. Obshch.Khim. 1979,49,2172. 310 N. N. Zheligovskaya Yu. M. Kiselev and E. P. Krasovskaya Koord. Khim. 1980,6 1080. 3'1 V. Ya. Leonidov I. V. Timofeev and Yu. M. Kiselev Dokl. Akad. Nauk SSSR 1979 248 1375. 312 A. A. Goncharov Yu. N. Kozlov and A. P. Purmal Zh. Fiz. Khim. 1979,53 2685. 313 R. J. Gillespie D. Martin and G. J. Schrobilgen J. Chem. Soc. Dalton Trans. 1980 1898. 156 l? A. Hart A. G.Massey P. G.Harrison and J. H. Holloway XeF2.nWOF4 (n = 2 or 3) adducts has been found. Moreover studies of XeF2-MOF4 in HS03F solvent have provided evidence for the existence of a new class of fluorosulphate -bridged species (3 6).31 0 II FXeOSOMOF4 I F (36) Mossbauer and vibrational spectroscopic data on [K~F][AuF~]~~~ have confirmed the ionic formulation that was proven when the compound was first prepared.The surface chemistry of silicon surfaces exposed to XeF2 vapour and the chemisorption of SiF4 on silicon at room temperature and -150°C have been studied using XPS and AES.316 Pseudopotential SCF-MO studies of XeF5’ and XeF6 have shown that the structures of both are governed by a stereochemically active lone pair. The calcula- tions are at such variance with the ‘electronic isomers’ interpretation of the spectros- copy that there is little doubt of the invalidity of this concept.317 Complexes of XeF6 with LnF (Ln = La Pr or Nd) have been prepared with a 1 :1 stoicheiometry.Thermal decomposition of these complexes gives rise to 2LnF3-XeF6 and 3LnF3-XeF6 adducts. The stabilities of the 1 :1 and 2 :1species appear to decrease with increase in atomic number of the lanthanide.318 Perhaps the most interesting new advance in noble-gas chemistry this year is the characterization of the XeOF5- and [(XeOF,),F]- anions which comprise a new class of xenon(V1) oxyfluoro-anion. Vibrational spectroscopy and X-ray powder diffraction have shown that the XeOF5- anion displays a stereochemically active lone pair (37) and that the [(XeOF,),F]- polyanion consists of three equivalent XeOF4 groups bonded to an F- ion (38).,19 r F /F \F 314 J.H. Holloway and G. J. Schrobilgen Inorg. Chem. 1980 19 2632. 315 V. B. Sokolov V. G. Tsinoev and A. V. Ryzhkov Teor. Eksp. Khim. 1980,16 345. 316 T. J. Chuang J. Appl. Phys. 1980,51 2614. 317 M. J. Rothman L. S. Bartell C. S. Ewig and J. R. Van Wazer J. Chem. Phys. 1980 73 375. 318 S. N. Misra Zndian J. Chem. Sect. A 1979 18 530. 319 G. J. Schrobilgen D. Martin-Rovet P. Charpin and M. Lance J. Chem. SOC., Chem. Commun. 1980 894.

ISSN:0260-1818    

DOI:10.1039/IC9807700099

出版商:RSC    

年代:1980

数据来源: RSC

摘要:

3 The Transition Elements By F. A. HART and P. THORNTON Department of Chemistry Queen Mary College Mile End Road London El 4NS J. NEWBERY Department of Chemistry Goldsmiths' College New Cross London SE14 6NW Part I Scandium Yttrium the Lanthanides and the Actinides By F. A. Hart 1 Scandium A variety of reduced scandium halides are now known. The system sc CS3SC2C19 -csscc13 700 "C has been investigated and the shiny blue product found to have the hexagonal perovskite CsNiCl structure. This is similar to the Cs3Sc2C19 structure but with all Sc positions filled. Non-stoicheiometric phases exist between the two end-structures.' 2 Yttrium and the Lanthanides It is remarkable that much .more work has been done this year on the lanthanides than on the actinides.Beginning with the lower oxidation states solutions of Sm12 or Yb12 may easily be made by the quantitative reaction THF Sm(or Yb) + ICH2CH21-Sm(or Yb)12 + C2H4 The solids may be isolated as THF adducts; the solutions may be used for a variety of organic reductions.' The new compounds YC1 YBr Y2C13 and Y2Br3 have been made by heating Y with YCl or YBr at 1000-1150 K in tantalum capsules. They join the growing number of low-valent lanthanide halides which mostly contain metal octahedra with bridging halide ions. Y2C13 contains joined Y6Cls clusters with Y-Y = 3.266 3.638 3.694 A.' Several MO phases previously reported have proved to be highly contaminated with C H or N. A report has now appeared which describes the synthesis of pure face-centred cubic NdO and SmO by reaction of M203with metal.Golden yellow SmO (a = 4.943A) and NdO (a = 4.994A) are prepared at 1000 "C and pressures at or above 50 kbar. They show metallic conduction. No K. R. Poeppelmeir J. D. Corbett T. P. McMullen D. R. Torgeson and R.G. Barnes Inorg. Chem. 1980 19 129. 'P. Girard J. L. Namy and H. B. Kagan J. Am. Chem. SOC., 1980,102,2693. H. Mattausch J. B. Hendricks R. Eger J. D. Corbett and A. Simon Inorg. Chem. 1980.19 2128. 157 F. A. Hart J Newbery and P. Thornton reaction was observed for thulium; YbO made similarly has been previously rep~rted.~ Eu" is attracting attention because of its interesting fluorescent proper- ties arising from the 4f5d -+4f7transition. Eu2B204 and M(Eu)B204 (M = Sr or Ca) have been prepared by high-pressure synthesis and characterized.Thus Eu203 reacts with boron and H3B03 at 1000 "C during 3 h in vacuo to give Eu2B204. Further heating at 600-900 "C and 8-25 kbar gave various phases characterized by X-ray powder data. The best phosphor was Sr0.99E~0.01B204 which emits at 395 nm with 60% quantum efficiency at 313 nm excitation. The wavelength of the emission is strongly affected by the geometry of the ligand field.5 Complexes of EuC12 with crown ethers give a very intense emission at 433-467 nm the wavelength depending on the complex when irradiated in methanol at about 320 nm. Emission is up to 620 times more intense than the uncomplexed salt6 Turning from lower to higher oxidation states 2-5.5 mol dm- aqueous M,CO (M = K or Cs) 1mol dmP3 in KOH containing CeCI, PrCI, or TbC1 (0.1- 0.01 mol dm-3) was electrolytically oxidized for 3 h or oxidized by ozone.This procedure gave remarkable stable solutions of yellow Pr4' (A,, 283 nm) dark reddish-brown Tb4' (A,, 365 nm) and of course Ce4'. The alkaline medium provided considerable stabilization of the tetrapositive ions; Eofor Ce3'/Ce4' being only +0.05 V.' Much the greatest quantity of work has of course been upon the tripositive lanthanides and we begin with the solution studies. Enthalpies of solution for MBr (M = La-Er) and of Er metal and ErC1 in aqueous HCl have led to standard enthalpies of formation of MBr, ErCl, and Er3+(aq).8*9 Solutions of LaC1 in aqueous methanol in varied proportions were studied by '39La and 35Cl n.m.r.As methanol replaces water an increasing degree of La-C1 inner-sphere co-ordination occurs. There is rapid chloride exchange by a displacement process.1o Photoinduced electron transfer between Ce3+(aq) and Cu2'(aq) in sulphate solution has been studied by microsecond flash excitation techniques. The resulting Ce4' and Cu' complexes rapidly undergo reverse electron transfer. The primary photochemical process is bimolecular collision involving the lowest-energy 4f -P 5d excited state of Ce3'." The kinetics of the ligand-exchange reactions between Ce3' complexes of edta and diethylenetriaminepenta-aceticacid (dtpa) and the reactions of the cor- responding Tb3' system have been studied spectrophotometrically. For Tb3' the exchange takes place by both an H'-catalysed dissociative mechanism and by an associative pathway whereas for the Ce3' complexes the latter mechanism only is effective." Emission titrations have been used to investigate the adduct formation between several Eu3' P-diketonates and phosphate esters.Log K values range from 1.41 to 3.47 in CC14.13 Stability constants have been determined in aqueous solution J. M. Leger N. Yacoubi and J. Loriers Inorg. Chem. 1980 19 2252. K.-I. Machida G.-Y. Adachi J. Shiokawa M. Shimada and M. Koizurni Znorg. Chem. 1980 19,983. G.-Y. Adachi K. Tornokiyo K. Sorita and J. Shiokawa J. Chem. SOC.,Chem. Commun. 1980,914. D. E. Hobart K. Sarnhoun J. P. Young V. E. Norvell G. Marnantov and J. R. Peterson Inorg. Nucl. Chem. Lett. 1980 16 321.C. Hurtgen and D. Brown J. Chem. SOC.,Dalton Trans. 1980 70. J. Fuger L. Morss and D. Brown J. Chem. SOC.,Dalton Trans. 1980 1076. lo D. C. McCain J. Znorg. Nucl. Chem. 1980,42 1185. l1 R. P. Asbury G. S. Harnmond P. H. P. Lee and A. T. Poulos Inorg. Chem. 1980 19 3461. '' E. Brucker and I. Banyai J. Inorg. Nucl. Chem. 1980 42,749. l3 H. G. Brittain Inorg. Chem. 1980 19 640. The Transition Elements for complexation between Ce3+ Eu3+ Tm3' and Am3' and all three chloroacetates. Log K for any cation varies linearly with pK values of the anions.14 Various types of chiral interactions in aqueous lanthanide shift reagents leading to spectral resolution of enantiomeric substrates or to assignment of chirality have been Selection rules based on L S J quantum numbers and including perturbation by crystal-field effects and spin-orbit coupling have been developed in order to quantify factors governing the magnitudes of the chiroptical properties associated with f-f transitions in lanthanide complexes.l6 The correlation between luminescence lifetimes and numbers of co-ordinated water molecules has been further used to investigate solutions of Eu3+ and Tb3+ in malic acid. There are stepwise changes in the co-ordination environment of the metal ion as the pH is raised.17 A direct measurement of anisotropic magnetic susceptibilities can be obtained from the 2Hn.m.r. spectra of lanthanide or actinide complexes of known structure. The method depends on quadrupole coupling of the 2H nuclei which splits absorption lines at high field owing to partial ordering of the molecules in the field." The n.m.r.spectra of aromatic substrates olefins or phosphines are well shifted by M(f~d)~ (M = Pr or Yb fod = C3F7COCHCOCMe3) in association with Ag(fod) or AgCF,COCHCOMe. Thus toluene has its aromatic hydrogen resonances shifted 4 p.p.m. and resolved with couplings well defined." This paper describes an important development of an earlier method.20 An interesting series of papers has appeared concerning the n.m.r. spectra of lanthanide aquo- and dipicolinato- complexes. The 'H shifts of the dipicolinate ligands arise from a dipolar mechanism alone. The resulting conformational analysis shows the tris-complexes to be nine-co- ordinate tricapped trigonal prismatic in the second half of the series but that ligand mobility may be present in the first half.The relaxation time of the water protons has been used to determine hydration number. Thus the bis(dipico1inato) complexes have three H20 co-ordinated also and the mono-complexes have six H20 co-ordinated. In the aquo-complexes the very short s) correlation times of the proton relaxation rates predominantly arise from the cationic electron-spin relaxation. 21-24 * H and 13C n.m.r. shift data have been used to study the solution structures of complexes between La3' Pr3+ Eu3+ and Yb3+ with ethylene-1,2- dioxydiacetate ethylene-1,2-dithiodiacetate and ethylene-1,2-diaminodiacetate ions. The sulphur atoms in the thio-ligand do not ~o-ordinate.~' Crown and cryptate ligands continue to provide interesting studies.Using a potentiometric method the stability constants of lanthanide ions with the cyclic polyether 4,4'(5')-di-t-butylbenzo-18-crown-6were determined in propylene carbonate showing log K = 5.14 (La3') decreasing to 2.51 (Lu3'). For the M2+ ions log K = 7.60 (Sm2') and 7.31 (Yb2') -a great increase over the tripositive l4 D. D. Ensor and G. R. Choppin J. Inorg. Nucl. Chem. 1980 42 1347. l5 J. Reuben J. Am. Chem. SOC.,1980,102 2232. l6 F. S. Richardson Inorg. Chem. 1980 19 2806. S. Salama and F. S. Richardson Inorg. Chem. 1980,19 629. P. J. Domaille J. Am. Chem. Soc. 1980 102 5392. l9 T. J. Wenzel T. C. Bettes J. E. Sadlowski and R. E. Sievers J. Am. Chem. SOC., 1980 102 5903. D. F. Evans J. N.Tucker and G. C. de Villardi J. Chem. SOC.,Chem. Commun. 1975,205. B. M. Alsaadi F. J. C. Rossotti and R. J. P. Williams J. Chem. SOC., Dalton Trans. 1980 597. *' B. M. Alsaadi F. J. C. Rossotti and R. J. P. Williams J. Chem. SOC.,Dalton Trans. 1980 813 23 B. M. Alsaadi F. J. C. Rossotti and R. J. P. Williams J. Chem. SOC., Dalton Trans. 1980 2147. B. M. Alsaadi F. J. C. Rossotti and R. J. P. Williams J. Chem. SOC.,Dalton Trans. 1980 2151. *' G. R. Choppin and L. Kullberg Inorg. Chem. 1980,19 1686. 160 F. A. Hart J. Newbery and P. Thornton state. A reversible one-electron reduction was shown with an anodic shift of the polarographic wave.26 A series of complexes M(NO,),( 12-crown-4) (M = La-Lu) has been reported together with PrC13( 12-crown-4) and the possibly sandwich-type complex Pr(C1O4),( 12-crown-4)2.Their magnetic moments are 343% lower than free-ion value^.^' Lanthanide nitrates form three types of complex with 18-crown-6 (L) [M(N03)3L] [M(N0,)2Ll,[M(N03),l and [M(N03),(H20),].L. The structures of the first and third types have been reported. Thus [M(NO,),L] (M = La or Nd) show 12-co-ordination whereas in the third type (M = Gd) the 18-crown-6 is not co-ordinated to the nine-co-ordinate Gd3+ ion but is hydrogen-bonded to the co-ordinated water m01ecules.~~-~~ Complexes of lanthanide perchlorates with 18-crown-6 and di- tetra- and hexa-thia-18-crown-6 have been reported. They are M(C104),L(H20),(MeCN) (M = La Ce Pr Nd Sm Eu Ho or Yb x = 0 or 1 y = 0 l; or 2). The X-ray structure of [La(C104)2(H20)(dithia-18-crown-6)1C10 shows both S atoms co-ordinated (La-S = 3.030,3.045 A) and one bidentate and one unidentate c104-ion in the 10-co-ordinate complex cation.31 In an informative paper containing much thermodynamic data cyclic voltammetry has been used to investigate redox behaviour of Eu3' and Yb3+ 2,2,1- and 2,2,2-crj-ptates in water.The reduction is reversible with the M3' complexes being less stable than the M2+ because of enthalpy differences. The redox couple decreased from 626 mV for the aqueous Eu3' ion to 205 mV for the Eu3' complex with the 2,2,2-cryptate. Dis- sociation kinetics showed marked acid catalysis.32 Turning to papers purely or mainly concerned with X-ray crystal structures Lu(OH) is difficult to crystallize but crystals may be obtained by digestion of a gel with 9.7N-NaOH at 158 "C for 30 h.The structure shows a three-dimensional array has of octahedra with Lu-0 = 2.243 A.33 c~La(S0~)~irregularly nine-co-ordinated La (La-0 = 2.480-2.801 The P-diketonate Gd(aca~)~(H~O)~ is dimeric with Gd co-ordinated to six 0from the diketonate anions two 0from water molecules and an 0 from a diketonate anion 'belonging' to another Gd3+ ion. The repulsion energy of this (bidentate)3(unidentate)3type of co-ordination is con~idered.~~ The hydrated nitrate [La(NO3),(H2O),].H2O is 11-co-ordinate with La-OOitrate= 2.617-2.875 8 and La-O,,,, = 2.526-2.668 A.36 The somewhat similar salt K2[La(N03)5(H20)2] has slightly distorted icosahedral co-ordination of La with La-Onitrate = 2.595-2.791 A and La-O,,,, = 2.697 Another nitrato-complex (P~,As),[Eu(NO,)~] has ten-co-ordina-tion in a distortsd bicapped square-antiprismatic configuration with the mean Eu-0 = 2.48 The structures of [M{P(C6H,,)2S2}3] (M = Dy or Lu) have been 26 J.Massaux J. F. Desreux C. Delchambre and G. Duyckaerts Inorg. Chem. 1980 19 1893. " J.-C. G. Bunzli and D. Wessner Inorg. Chim. Acta 1980 44 L55. 28 J. D. J. Backer-Dirks J. E. Cooke A. M. R. Galas J. S. Ghotra C. J. Gray F. A. Hart and M. B. Hursthouse J. Chem. SOC., Dalton Trans. 1980 2191. 29 J.-C. G. Bunzli B. Klein and D. Wessner Inorg. Chim. Acta 1980 44 L147. 30 G. Bombieri G. de Paoli F. Benetollo and A. Cassol J. Inorg. Nucl. Chem. 1980,42 1347. 31 M. Ciampolini C. Mealli and N. Nardi J.Chem. Soc. Dalton Trans. 1980 376. 32 E. L. Yee 0.A. Gansow and M. J. Weaver J. Am. Chem. SOC.,1980,102 2278. 33 D. F. Mullica and W. 0.Milligan J. Inorg. Nucl. Chem. 1980 42 223. 34 N. Bukovec V. KauEiE and L. GoliE Acta Crysiallogr. 1980 B36 129. 35 M. C Favas D. L. Kepert B. W. Skelton and A. H. White J. Chem. SOC.,Dalton Trans. 1980,454. 36 B. Eriksson L. 0.Larsson L. Niinisto and J. Valkonen Inorg. Chem. 1980 19 1207. 37 B. Eriksson L. 0.Larsson L. Niinisto and J. Valkonen Acta Chem. Scand. Ser. A 1980 34 567. J.-C. G. Bunzli B. Klein G. Chapuis and K. J. Schenk J. Inorg. Nucl. Chew 1980 42 1307. The Transition Elements 161 determined in order to extend the series of known structures (those for M = Pr or Sm are known). The angle of twist of the three bidentate ligands in the trigonal structure can be related to the ligand bite angle.39 The template condensation of 1,2-diaminoethane with (CF3)2C(OH)CH2COMe in the presence of Ce(N03)3-6H20 in ethanol in air gives a bis-complex of the dianion (CF3),C(O-)CH,C(Me)=NCH2CHzN=C(Me)CH~C(O-)C(CF3)~com-(L).The plex [CeIVL2] shows approximate square-antiprismatic co-ordination to four N at 2.607-2.641 and 4 0 at 2.196-2.230 A."" Organo-lanthanide work this year has been mainly concerned with cyclo- pentadienyl complexes particularly of Yb2+. A number of solvated red EuZ+and red or green YbZ+ bis(pentamethylcyclopentadieny1) complexes have been prepared from EuC13 or YbC12 and NaC,Me in THF. The structure (X-ray) of [Yb(C,Me,),(THF)].$(toluene)shows two v5rings and one THF molecule to be co-ordinated (Yb-0 = 2.41 A; Yb-C av.= 2.66 A)."' The reaction of MeC5H5 with Yb(hex-3-yne) gives Yb(MeC5H4),THF which contains chains of Yb atoms bridged by methylcyclopentadienyl groups (Yb-CC,e,,,,,I = 2.76 8 av.; Yb-Cbrldge = 2.89 av.). This compound may also be produced by hydrogen reduction of (MeC5H4),Ybhle; in this case there is evidence for an unstable Yb3+ hydrido-c~mplex."~ Reduction of [{Yb(q -C5H4SiMe3),Cl}2] in THF by Na/Hg gives purple diamagnetic Y 3(C5H4SiMe3),(THF), which can be desolvated. The crystal structure shows two q5-rings (Yb-C = 2.75 A av.) and two co-ordinated THF molecules (Yb-0 = 2!.41 8,a~.)."~ Treatment of Yb metal with C5MeSI and LiI in ether gave Li[Yb"'(C,Me5)13] which spontaneously changed into purple Li[Yb"(C5Me5)12].44 When treated with LiC5Me5 in pentane-THF NdCl gave purple Li(THF),(C5Me5)2NtIC12; this compound probably has a dichloro-bridged ~tructure."~ 3 The Actinides There seems to be a slightly reduced level of activity in this area this year.Starting with thorium the X-ray crystal structure of ThC14(Ph2S0)4 shows dodecahedra1 co-ordination with C1 at the B sites and 0at the A sites (Th-C1 = 2.759,2.757 A; Th-0 = 2.46A; SOTh = 130° 135°).46 Some 2,2'-bipyridyl 1,l'-dioxide (L) complexes of thorium have been reported. They are Th(NO,),L ThX4L3 (X = C1 or Br) Th14L4 and Th(NCS)4L.47 The cyclo-octatetraene (cot) complex Th(cot) reacts with ThC14 in THFto give [ThCl,(cot)(THF),] which is a very air-sensitive compound which adopts two crystalline forms differing only in the molecular packing.The Th is co-ordinated to an q8-cot ring (Th-C = 2.69-2.75 A) two Cl(2.686 A) and two 39 A. A. Pinkerton and D. Schwarzenbach J. Chem. SOC.,Dalton Trans. 1980 1300. 40 J. H. Timmons J. W. L. Martin A. E. Martell P. Rudolf A. Clearfield J. H. Arner S. J. Loeb and C. J. Willis Inorg. Chem. 1980 19 3553. 41 T. D. Tilley R. A. Andersen B Spencer H. Ruben A. Zalkin and D. H. Templeton Inorg. Chem. 1980,19,2999. 42 H. A. Zinnen J. J. Pluth and W J. Evans J. Chem. Soc. Chem. Commun. 1980,810. 43 M. F. Lappert P. L. W. Yarrow J. L. Atwood R. Shakir and J. Holton J. Chem.SOC.,Chem. Commun. 1980,987. 44 P. L. Watson J. Chem. SOC.,Chcm. Commun. 1980 652. 4s A. L. Wayda and W.J. Evans Irorg. Chem. 1980,19,2190. 46 C. E. F. Rickard and D. C. Wodlard Acta Crystallogr. 1980 B36 292. 47 R. K. Agarwal A. K. Srivastava and T. N. Srivastava J. Znorg. Nucl. Chem. 1980 42 1347. I? A. Hart J. Newbery and P.Thornton THF (Th-0 = 2.57 A). The complex may be converted into T~(BH,),(CO~).,~ The pentamethylcyclopentadienyl (mcp) neopentyl (np) complex Th(mcp),(np)Cl pre- pared by reaction of Li(np) with Th(mcp),C12 shows some interesting reactions. It reacts with CO in toluene to give the pale yellow complex (1) (a = 2.37 A b = 1.18A c = 2.44 A),which is converted in toluene at 100"Cinto the colourless (2). However excess CO reacts with (1) to give the dark purple (3) which has a remarkable bridging enedione diolate ligand.,' mcP mcP /CM% I p,tJ I /O\ mcp-Thy-C-np mcp-Th /c=c\ H IH C1 c1 Turning now to uranium there has been little work on U3+ but the first crystal structure of a hydrated U3+ salt has appeared.The compound is NH4U(SO4),(H20), which can be manipulated in air. The U3+ ion is linked to two bidentate and to two unidentate ions and to three H20 (U-Osulphate = 2.37-2.60& U-Owater = 2.47-2.56 A). It is isostructural with the corresponding La-Tb compound^.^^ A few papers have appeared on U4+ compounds. The rather unstable UI has at length yielded half an X-ray-quality crystal. It is not isomorphous with ThI or UBr but has chains of edge-sharing octahedra with U-I = 2.92A (terminal) and 3.08,3.11 A (bridging). The structure was determined by both X-ray and neutron diffra~tion.~'Non-aqueous methods are superior for making U4+ tetrakis(diketonates) which can give poor yields from aqueous preparations.Various complexes have been prepared by admixture of UCl in ethanol with the P-diketone in toluene followed by removal of solvent under reduced pressure.52 In solutions of U(acac) or U(dbm), irradiation at the charge-transfer wavelengths causes reduction to U3+ as a primary process followed by thermal reoxidation to U4+ with abstraction of halogen from the solvent. Irradiation at f -+ f transition wavelengths in the presence of oxygen gives the uranyl bi~(diketonate),'~ The complex (Et4N)4[U(NCS)8] may be converted into (Et4N)[U(NCS)5(bipyridyl)2] 48 A. Zalkin D. H. Tempieton C. Le Vanda and A.Streitweiser Znorg. Chem. 1980 19 2560. 49 P. J. Fagan J. M. Manriquez T. J. Marks V. W. Day S. H. Vollmer and C. S. Day J. Am. Chem. SOC. 1980,102,5393. 50 J. I. Bullock M. F. C. Ladd D. C. Povey and A. E. Storey Znorg. Chim. Acta 1980 43 101. J. H. Levy J. C. Taylor and A. B. Waugh Znorg. Chem. 1980,19 672. '* V. L. De Vito and D. W. Wester J. Znorg. Nucl. Chem. 1980 42 1719. 53 S. Sostero 0.Traverso L. Magon P. Zanella and G. Scribona J. Chem. Soc.,Dalton Trans. 1980,1324. The Transition Elements 163 which is nine-co-ordinate with U-NNcs = 2.61-2.65 8 and U-Nbipy = 2.61-2.65 The glycolate [U(02CCH20H)4(H20)2] is a ten-co-ordinate distorted bicapped square antiprism where the anion co-ordinates through one carboxyl oxygen atom and the hydroxy-group with U-0 = 2.5498 (water) 2.404 and 2.3828 (carboxyl) and 2.411 and 2.506 8 (hydroxyl)." The 'H n.m.r.spectrum of (Ph4As)2[U(dipicolinate)3]in Me2S0 and CDCI3 shows over a range of tempera- tures that the dipolar and contact contributions to the paramagnetic shifts are of a similar magnitude. The contact effect is caused by spin delocalization in the u-A full report has now appeared of the reaction of LiCH2CH2PPh2 with UCI(C~HS)~, giving [{Ph2P(CH)CH2}2U2(C5H5)41.57 Reaction of UF with SbF gives UF5.2SbF5 which on being heated is converted into UF5.SbFS the crystal structure of which shows dodecahedra1 co-ordination of uranium by fluorine in the SbFS-bridged structure with U-F = 2.306-2.658 A (bridge) and 1.924-1.984 8,.(terminal).58 Remarkable new macrocyclic ligands with specific affinity for the UOZ2+ ion have been made.They are {-C(C02H)2(CH2)8-}3 and {-C(C02H)2C2H40C2H4- OCzH4-)3. The first ligand has log K = 16.4in aqueous solution the largest known for the UOZ2+ ion. When linked to a resin and immersed for four days in 5 1 Pacific Ocean water it extracted 6.85 pg of uranium (42%of that contained in the water).59 The X-ray structure of U02S04(urea)3 shows a close approximation to pentagonal- bipyramidal co-ordination with -U-0-SO2-0-U- in infinite chains and U-0 = 2.310-2.409 8 (urea) 2.380 and 2.407 8 (sulphate).60 Complexes have been described of U022+ with the ligands (4)and (5). These are converted into the uncharged complexes [U02L] [L = (6)or (7)] by the action of I R2 I R2 (4) R' = H R2 = 2-pyridyl (5) R' = H (6) R1absent R2 = 4-MeOC6H4C0 R2 = 2-pyridyl (7) R'absent R2 = 4-MeOC6H4C0 Some progress has been made in studies of the heavier actinides; Np(BH4) is similar to the Hf and Zr analogues in being 12-co-ordinated by tetrahedrally disposed terdentate BH4groups.It is very volatile (10 mmHg at 25 "C) and contrasts 54 R. 0.Wiley R. B. von Dreele and T. M. Brown Znorg. Chem. 1980,19 3351. '' N. W. Alcock T. J. Kemp S. Sostero and 0.Traverso J. Chem. SOC.,Dalton Trans. 1980 1182. 56 C. Miyake H. Sakurai and S. Imoto J. Inorg. Nucf. Chem. 1980,42 1725. 57 R. E. Cramer R. B. Maynard and J. W. Gilje Znorg. Chem. 1980,19,2564. 58 W. Sawodny and K. Rediess 2. Anorg. Allg. Chem. 1980,81,469. 59 I. Tabushi Y.Kobuke K. Ando M. Kishimoto and E. Ohara J. Am. Chem. SOC.,1980,102 5947. 6o H. Ruben B. Spencer D. H. Templeton and A. Zalkin Znorg. Chem. 1980 19 776. 61 G. Paolucci G. Marangoni G. Bandoli and D. A. Clemente J. Chem. SOC.,Dalton Trans. 1980,459. 62 G.Paolucci G. Marangoni G. Bandoli and D. A. Clemente J. Chsm. SOC., Dalton Trans. 1980 1304. F. A. Hart J. Newbery and P. Thornton with the Th Pa and U analogues which have e.g. UH2BH2Ubridges.63 Visible-u.v. spectra of Np species in aqueous nitric acid solution were not previously available in the open literature but have now been reported. Spectra of Np"' Np'" Np" and Np"' over the range 300-1400 nm are given. Owing to the coexistence of more than one species the spectra were deconvoluted digitally.64 249BkX (X = N P As or Sb) have been synthesized by heating 40 pg Bk (fromBkF4and Li) with excess P As or Sb at 540-690°C overnight in a quartz capillary.The nitride was made under different reaction conditions (1150 "C for 30 s). They all have the NaCl structure with a = 4.951,5.669,5.829 and 6.191 A re~pectively.~' Element 261104 has been synthesized by bombarding 248Cm with l80 ions. The recoil products were directed into a 'fast computer-controlled apparatus for performing chemical experiments' (a useful piece of equipment for any laboratory replacing scarce research students). The 26 1 104 was absorbed on a column containing a quaternary amine and showed in 12M-HCl complexation very similar to that of its homologue Hf.66

ISSN:0260-1818    

DOI:10.1039/IC9807700157

出版商:RSC    

年代:1980

数据来源: RSC

摘要:

F. A. Hart J. Newbery and P. Thornton Part 11 Groups IVA VA and VIA By J. E. Newtery 1 Introduction Work on the Group VIA elements vastly exceeds that published for the preceding transition elements. Consequently more selectivity has been employed in reviewing their chemistry. Similarly the coverage of organometallic species is somewhat restricted since another chapter of this Report deals solely with organometallics. Several reviews have appeared though only one' deals specifically with early transition elements. This concerns trinuclear clusters species of particular import- ance in 4d and 5d chemistry. Three basic structures are identified and some simple MO schemes discussed. Reviews of metallophthalocyanines* and transition-metal complexes with organoimido (NR) ligands3 both contain material of interest.Of more relevance to the Group VIA elements are two reviews on aspects of metal-sulphur donor complexes. The first4 deals specifically with the reactivity of metal-ion-sulphur bonds though the authors necessarily include much structural data to help interpret their collations of rates and redox and assorted spectroscopic properties. The second' is concerned with the X-ray photoelectron spectroscopy of these compounds. The S 2p chemical shifts are shown to be sensitive to the sulphur 63 R. H. Banks N. M. Edelstein B. Spencer D. H. Templeton and A. Zalkin J.Am. Chem. Soc. 1980,102 620. 64 H. A. Friedman and L. M. Toth J. Inorg. Nucl. Chem. 1980,42 1347. 6s D.Damien R. G. Haire and J. R. Peterson J.Inorg. Nucl. Chem. 1980,42 995. 66 E.K. Hulet R. W. hugheed J. F. Wild J. H. Landrum J. M. Nitschke and A. Ghiorso J.Inorg. Nucl. Chem. 1980,42,79. ' A. Muller R. Jostes and F. A. Cotton Angew. Chem. Int. Ed. Engl. 1980 19 875. * K. Kasuga and M. Tsutsui Coord. Chem. Rev. 1980,32,67. W. A. Nugent and B. L. Haymore Coord. Chem. Rev. 1980 31 123. C. G.Kuehn and S. S. Isied Prog. Inorg. Chem. 1980 27 153. R.A. Walton Coord. Chem. Rev. 1980 32 183. The Transition Elements 165 oxidation state and are used for example to distinguish between thiol or thioether binding and hence have relevance in discussing the nature of binding sites in metalloproteins. Vibrational fine structure in the electronic spectra of transition-metal complexes has been reviewed,6 with the species arranged in order of increasing number of d-electrons.2 Titanium Zirconium and Hafnium Zirconium has few well characterized cluster species. Zrl2Al4ClS1 isolated from a melt of ZrCl, A12C16 and Zr at 200°C contains zirconium in trigonal-prismatic co-ordination with [Zr3Cl6ln+ units.' Some work has appeared concerning correla- tions between the structure of [MX6]"- systems and electronic band theory. Ti203 with face-sharing octahedra is contrasted with V203,which involves edge-sharing.' Face-sharing chains of both sulphides and chlorides have also been studied.' The preparation and X-ray powder data on a series of complex halides formulated CsM"Ti"'F6 where M" is Mg Ni Zn Co Fe or Mn have been rep0rted.l' They appear to adopt a modified pyrochlore structure similar to that found in RbNiCrF6.The catalytic properties of titanium oxides have again produced interesting work. Ti02 has been shown to be capable of cleaving alkenes and alkynes." The procedure employs initial adsorption of water followed by admission of the hydrocarbon and U.V.irradiation. In the case of alkenes a correlation was observed between the cleavage rate and the ionization potential. Mixed species V2OS-TiO2 show enhanced activity over V205for benzene oxida- tion at 662 K though since the maximum rate was foundI2 with a V205 content of only 5% it seems strange to refer to the titanium oxide as the support. An NiQ-SrTi03 catalyst has been shown to provide an efficient surface for promoting the photodecomposition of water.13 It was found to be effective for over four days.A discussion of mechanistic possibilities involved in the reduction of CO by zirconium hydrides contains much interesting material on the co-ordination of CO.I4 The supported-complex catalyst of Zr(BH,) on AI2O3 has been investigated by the technique of inelastic electron tunnelling spe~troscopy.~~ This method yields data relating to the nature of the C-C and C-H bonds present after the surface has been exposed to alkynes and alkenes and also assists in structural analysis of the interaction between the catalyst and the support material. Zirconium hydrogen phosphate [Zr(HP04)2 -H20]has been shown to intercalate reversibly the cobaltocenium cation.I6 The process is accompanied by an expansion of the layer spacing from 7.6 to 12.0 A.M. Cieslak-Golonka A. Bartecki and S. P. Sinha Coord. Chem. Rev. 1980 31,351. ' J. Kleppinger J. Wrazel J. C. Calabrese and E. M. Larsen Inorg. Chem. 1980 19 3172. * (a) M. G. Vincent K. Yvon A. Griittner and J. Ashkenkai Acta Crystallogr. 1980 A36 803; (6) M. G. Vincent K. Yvon and J. Ashkenkai ibid. p. 808. M.-H. Whangbo M. J. Foshee and R.Hoffmann Inorg. Chem. 1980,19,1723. lo W.-D. Griebler and D. Babel Z. Anorg. Allg. Chem. 1980,467 187. C. Yun M. Ampo S. Kodama and Y. Kubokawa J. Chem. SOC.,Chem. Commun. 1980,609. 12 M. Inomata A. Miyamoto and Y. Murakami J. Chem. SOC.,Chem. Commun. 1980 233. 13 K. Domen S. Naito M. Soma T. Onishi and K. Tamaru J. Chem. SOC.,Chem.Commun. 1980 543. l4 P. T. Wolczanski and J. E. Bercaw Acc. Chem. Res. 1980 13 121. Is H. E. Evans and W. H. Weinberg J. Am. Chem. SOC.,1980,102 (a)872 (b)2548 (c) 2554. J. W. Johnson J. Chem. SOC.,Chem. Commun. 1980 263. 166 F. A. Hart J. Newbery and P. Thornton Most of the complex chemistry of these elements concerns oxygen-donor ligands. Some complex cyanides of titanium(II1) have been rep~rted.'~ Formulations of Rb5Ti(CN)8 Cs,Ti(CN), and K3Ti(CN)6 were observed. The magnetic moments and vibrational and visible spectra were used to support a common seven-co- ordinate environment for the titaniums. The titanium(II1) complex Ti(edta)(H,O)- has been shown to add oxygen to produce the known peroxy-species Ti(Oz)(edta)'-. A suggested mechanism is supported with stopped-flow kinetic data and the observation that H20 can only produce the same effect when present in a stoicheiometric excess.18a Peroxo- titanium species were also studied in a kinetic investigation concerning the mechan- ism of addition of hydrogen peroxide to various titanium(1v) species.'86 During the course of this investigation the structure of the complex Cs4[Ti04(nta),] -6H20was determined.Titanium was found to be in a distorted octahedral environment with p -ox0bridges. Peroxo-titanium(1v) porphyrin complexes have been synthe~ized'~" from the corresponding Ti"' complex; it was also found that19b when starting from a Ti'" species peroxo formation proceeds by substitution (the 0-0 of H202remaining intact) and with retention of configuration.Refluxing tetrakis(diethy1amino)zirconium in THF with diphenylsilanediol pro- duces in small yield a tris-complex of the ligand (1).An X-ray study has revealed the orientation adopted by the 12phenyl rings." Ph \ ,A0\ /Ph Si A-o/-Si \Ph Ph/ 1-adamantyl 2-adamantyl (1) (2) Titanium alkoxides involving adamantyl (2) groups have been reported.'l They are produced by alcohol exchange between the titanium isopropoxide species and the appropriate adamantyl alcohol. The presence of the bulky adamantyl groups results in high melting points (>350 "C) and relative inertness to atmospheric conditions. The ion (3) derived from 3-cyanopentane-2,4-dione,is a potential trifunctional ligand. It forms complexes with zirconium that are formulated [ZrCl,L,] and [ZrClL3] and i.r.data are used to support the co-ordination of the cyanide groups.22 (3) R=PhorMe D. Nicholls and T. A. Ryan Znorg. Chim. Acta 1980 41 233. (a) F. J. Kristine and R.E. Shepherd J. Chem. Soc. Chem. Commun. 1980 132; (b) K. Wieghardt U. Quilitzsch J. Weiss and B. Nuber Inorg. Chem. 1980 19 2514. l9 (a)J.-M. Latour B. Galland and J.-C. Marchon J. Chem. Soc. Chem. Commun. 1979,570;(6)J.-M. Latour J.-C. Marchon and M. Nakajima J. Am. Chem. Soc. 1979 101 3574. 2o M. A. Hossain and M. B. Hursthouse Znorg. Chim. Acta 1980 44 L259. M. Bochmann G. Wilkinson G. B. Young,M. B. Hursthouse and K. M. A. Malik J. Chem. Soc. Dalton Trans. 1980 901. 22 G. A. Lock and D. W. Thompson J. Chem. Soc. Dalton Trans.1980 1265. The Transition Elements 167 The species SiMe3(N3) has been used2 as an azide source in a reaction with titanium alkoxides (Ti)OR+ SiMe3(N3) -+ (Ti)N3+ SiMe3(0R) With Ti(OPr') only disubstitution results but when using TiCl(OR) both mono- (from the loss of OR) and di- (from the loss of Cl and OR) substitution are observed dependent upon the stoicheiometric ratio employed. Rather unusually these species are not prone to explode and so their chemistry may be investigated with relative ease. The azide group can be displaced by reaction with protic reagents (e.g.alcohols) or phosphines (with dinitrogen elimination). Monomeric (trimethylsily1)amide complexes of titanium zirconium and hafnium have been prepared24 by the reaction of excess LiN(SiMe3)2 with MCl,.MCl[N(SiMe,),] are roughly tetrahedral in the solid state and evidence of steric crowding was observed in that (for example) the closest non-bonded Me-Me distance is around 3.08 8 for the zirconium species. This crowding increases in the titanium compound and is reflected in solution with a much higher coalescence temperature for the methyl n.m.r. signals. An elegant simple and inexpensive route to organometallic halides of titanium zirconium and hafnium has been de~cribed.~' Compounds such as R2MX2L2 (L = MeCN or ibipy) are prepared by direct electrochemical oxidation of the metal in for example EtBr-MeCN-Et4NBr using a potential of ca. 50 V. The stability of titanium alkoxides involving adamantyl ligands (2) has already been noted and a further report26 from the same group has shown how adamantyl peralkyls may be prepared in high yield by mixing Ti(OPr') with Li(1-adme) in petroleum spirit.ZrR can also be synthesized by standard Grignard methods and has greater solubility than the titanium compound though both are sufficiently soluble for 'H n.m.r. data to be reported. On reaction with NO paramagnetic titaniurn(II1) d' species such as Ti(q-C5H5)2R (R = Ph or CH2Ph) lose both Cp and R groups to give Ti3(q-C5H5),04(NO) whereas the diamagnetic MIv alkyls (M = Ti or Zr) MR4 and MR2C12 (R = CH2SiMe3 or CH2CMe3) give complexes involving N-alkyl-N-nitrosohydroxylaminato-groups (Scheme l).27 These appear to be both uni- and bi-dentate for the six-co-ordinate titanium but solely bidentate for eight-co-ordinate zirconium.AR M-R+kO -* M-0 O=N R Scheme 1 23 R. Choukroun and D. Gervais J. Chem. SOC.,Dalton Trans. 1980 1800. 24 C. Airoldi D. C. Bradley H. Chudzynska M. B. Hursthouse K. M. A. Malik and P. R. Raithby J. Chem. SOC.,Dalton Trans. 1980 2010. 25 F. F. Said and D. G. Tuck Can. J..Chem. 1980,58 1673. 26 M. Bochmann G. Wiikinson and G. B. Young J. Chem. SOC.,Dalton Trans. 1980 1879. 27 A. R. Middleton and G. Wilkinson J. Chem. SOC.,Dalton Trans. 1980 1888. F. A. Hart J. Newbery and P. Thornton Of course the majority of Group IV organometallic species involve the participa- tion of the cyclopentadienyl (Cp) ring. Improved routes for the synthesis of [TiX3Cp] (X = C1 Br or I) involving the use of bis(trimethylsily1)Cp have been described.28 Zr(Cp),Ph reacts with methyl-lithium to give ZrMePh * 3Et20 which from its general behaviour appears to be polymeric.29 0x0-bridges are another feature of titanium chemistry and a partial multiple bond character is suggested3’ by the structure of the tetramer [(qs-C5H4Me)TiCl(,u -0)14.The structural data are used to suggest a possible hydrolysis route uia a dimeric intermediate from the parent compound (q2-C5H4Me)TiC13 (Scheme 2). CI Ic1 CP dimer monomer tetramer C’ Scheme 2 12 CH Scheme 3 Titanium species can be involved in olefin metathetical reaction^,^' such as the exchange reaction shown in Scheme 3. A possible intermediate in this interconver- sion has been isolated3 by the reaction of the titanium alkyl (4) with neohexene in benzene solution containing some pyridine.The metallacyclobutane produced (5) has been studied by ‘H and 13C n.m.r. and a number of reactions investigated. Related to this system is Cp,TiCH,CPh=CPh the structural analysis of which indicates planarity for the titanacyclob~tene.~~ (5) During an attempt to produce Cp3Zr(CH,CH2)A1Et2 which is a probable inter- mediate in Ziegler-type polymerization of ethene a crystalline species Cp,ZrH -AlEt was formed,34 with a Zr-A1 distance of 3.66 A. Both this com- A. M. Cardoso R. J. H. Clark and S. Moorhouse J. Chem. SOC.,Dalton Trans. 1980 1156. 29 G. A. Razuvaev L. I. Vyshinskaya G. A. Vasil’eva A. V. Malysheva and V. P. Marin Inorg. Chim. Acta 1980,44,L285.30 J. L. Petersen Inorg. Chem. 1980,19 181. 31 F.N.Tebbe G. W. Parshall and G. S. Reddy J. Am. Chem. SOC., 1978,100,361!. 32 T. R. Howard J. B. Lee and R. H. Grubbs J. Am. Chem. Soc. 1980,102,6876. 33 F.N.Tebbe and R. L. Harlow J. Am. Chem. Soc. 1980,102,6149. 34 H. Sinn W. Kaminsky H.-J. Vollmer and R. Woldt Angew. Chem. Inf. Ed. En& 1980 19 390. The Transition Elements 169 pound and Cp2ZrMe2 when mixed with partially hydrolysed A1Me3 i.e. [-Al(Me)-0-I, are extremely long-lasting catalysts towards ethene. The reactivity of alkyl halides towards Cp2Zr"bis(phosphines) has been assessed35 by n.m.r. The order RI>RBr>RCl was found and the product ratio between oxidative addition or the dihalide (Scheme 4) was found to be dependent upon the c~,z~"L + R -+ RX + c~,z~"'xL /-Rx/ J J\\ Cp,ZrX +L CpzZrRX+L Cp,ZrX +L CpzZrRX+L Scheme 4 alkyl halide structure branching favouring the latter product.An interesting hydrido-zirconium complex has been to catalyse hydrogen-transfer reac- tions such as the disproportionation of cyclohexa-1,3-diene to benzene and cyclo- hexene. ZrH(q'-L)(diphos) (diphos = PMe2CH2PMe2,q5-L is either of the dienyls C6H7or CgH11) is formed by treating ZrCl,(diphos) with Na-Hg and the diene. In the cg case a crystal structure is reported showing the co-ordination of five (sp') carbons at ca. 2.45 8 from the metal. Novel zirconium ylide complexes Cp2Zr[(CH2)2PMe2]X (X = H or Cl) are repor- ted.37 The hydride is produced by reaction of Cp'ZrRH with Me$CCH2 in toluene and addition of methyl chloride subsequently leads to the chloride species.3 Vanadium Niobium and Tantalum Mixed tellurium-M oxide systems (M = Nb or Ta) have been studied by a variety of techniques including Raman Phases such as [3Te02 * M2051 [3Te02.Ta205] [Te02.3Nb205] etc. have been characterized. Raman and i.r. spectra are also reported39 for a series of metavanadates MV03 (M = NH4 ND, K Rb or Co). The assignment of bands in both the solid state and solution (allowing for the differing structures of the VO tetrahedral chain) are discussed. 1.r. measurements and pH titrations were used in a characterization of cation-exchange processes involving Li2H5[PV12036] in ~olution.~' Magnetic susceptibility data have been used to discuss non-stoicheiometry in vanadium diselenide41 and niobium di~ulphide.~' A fluoride-selective electrode was used to measure the stability constants of the V"'-F-(log PI = 5 for p = 1.0mol dm-3).The standard enthalpy of formation of TaBr has been AH? TaBr,(c) at 298 K = -525.5 f2.1 kJ mol-'. The structure of CsNb6111 has been rep~rted.~' 3s G. M. Williams K. I. Gell and J. Schwartz J. Am. Ckem. SOC.,1980 102 3660. 36 M.B. Fischer E. J. James T. J. McNeese S. C. Nyburg B. Posin W. Wong-Ng and S. S. Wreford J. Am. Chem. SOC.,1980,102,4941. 37 K. I. Gell and J. Schwartz Znorg. Ckem. 1980 19 3207. 38 J. C.J. Bart and G. Petrini 2.Anorg. A&. Chem. 1980,(a)465,51; (b)466,81. 39 S.Onodera and Y.Ikegami Znorg. Chem. 1980,19,615. 40 R. Hagenbruch and H.Hahn 2.Anorg. Allg. Chem. 1980,467,126. 41 L.F. Schneemyer A. Stacy and M. J. Sienko Znorg. Chem. 1980,19 2659. 42 W. G. Fisher and M. J. Sienko Znorg. Chem. 1980 19 39. 43 R. D.Hancock F. Marsicano and E. Rudolph J. Coord. Chem. 1980,10,223. 44 A. D.Westland Can. J. Chem. 1980,58 938. 45 H. Imoto and J. D. Corbett Znorg. Chem. 1980 19 1241. F. A. Hart J. Newbery and P. Thornton This contains octahedra of niobium atoms face-capped by iodines (ca. 2.86 8 distant) with one further iodine attached to each niobium (at 2.988,) forming symmetrical bridges to adjacent clusters. Structural and magnetic properties of tetragonal tungsten-bronze-like species KxVF3 (x = 0.45-0.56) have been corre- lated46 with the value of x. A change from ferrimagnetic to antiferromagnetic (high x) behaviour was observed.Further magnetic studies are on the solid solution formed between VF2 and MgF2. Raman spectroscopy has been used to assign an Oh environment for Nb and Td for Ga in the species NbCl,.GaCl formed from the melt.48 Niobium is in a distorted pentagonal-bipyramidal co-ordination sphere in the complex fluoride Na2[NbF502]H20(6; distances in 8,). The reported complex chemistry of these elements covers a wide range of ligand species with no particular predominating donor atom. The crystal structure of P-VO(H,O),SO, where the vanadium exists in isolated octahedra has been reported.’’ Single-crystal polarized electronic spectra of a number of five- and six-co-ordinate V02+ species have shown” that the (3dX,)+ (3d,2) transition is not observed (<30 000 cm-’) for the six-co-ordinate compounds probably through the expected increase in ligand-field strength along the molecular z-axis.(6) (7) The tetraketone (7),which is 100%in the enol form (CDCI,) has been synthesized and several of its metal complexes have been rep~rted,’~ such as (VO)L,.H,O and (V02)2L2.H20. One reason for the interest in vanadium chemistry is the possible relevance to biological systems. EXAFS data have been ~btained’~ from the vanadium species in the living vanadocytes of tunicates (marine filter-feeding animals). The ‘best-fit’ was obtained by octahedral oxygen co-ordination suggesting that the living cells contain [V(H20)6]3” rather than more complicated species involving macrocycles.A number of interesting kinetic investigations have been published such as temperature-jump methods to in~estigate’~ V’” complex formation with vanil- lomandelic mandelic and thiolactic acids. These ligands were partly chosen since their pK values are such that complexes can form at the relatively low pHs needed when working with V02+. Rate constants of ca. 1X lo3dm3 mol-’s-* were ob- served. Roughly similar values (3.6 x lo3and 2 X lo2dm3 mol-’ s-l) are reported’’ 46 Y. S. Hong R. F. Williamson and W. 0.J. Boo Znorg. Chem. 1980 19 2229. 47 R. F. Williamson and W. 0.J. Boo Znorg. Chem. 1980 19 31. 48 G. Okon Z. Anorg. Allg. Chem. 1980 460 68. 49 R. Stromberg Acta Chem. Scand. Ser. A 1980 34 193. ’O M. Tachez and F. ThCobald Acta Crystallogr.1980 B36 1757. ” D. Collinson B. Gahan C. D. Garner and F. E. Mabbs J. Chem. Soc. Dalton Trans. 1980,667. ’’ D. E. Fenton C. M. Regan U. Casellato P. A. Vigato and M. Vidali Znorg. Chim. Acta 1980 44 L105. ” T. D. Tullius W. 0.Gillum R. M. K. Carlson and K. 0.Hodgson J. Am. Chem. Soc. 1980,102,5670. 54 T. M. Che and K. Kustin Znorg. Chem. 1980 19 2275. ” M. J. Hynes and B. D. O’Regan J. Chem. SOC.,Dalton Trans. 1980 7. The Transition Elements for the complexing of V02+by the enolate forms of some /3-diketones. Values of around 5 dm3 mol-' s-' are observed when the keto form and the undissociated enol form are involved. The kinetics of peroxo-complex formation with V02+edta-type complexes have formed the basis of a comprehensive The thermodynamic parameters of activation and a possible seven-co-ordinate transition state are also discussed.The reaction of Et2NOH with VO(Et2NCS2)3 producess7 a p -oxo-N,N-diethylhy-droxylamino-complex [(Et2N0)2V0]20. Each vanadium is at the centre of a pseudo-tetrahedron two apices of which are occupied by bidentate Et2N0 groups. Adamantoxides of vanadium(1v) and niobium-(rv) and -(v) have been reportedV2' They are prepared from the action of the alcohol on the appropriate diethylamide complex in ether. Suggestions that brown-green colour changes of vanadium alkoxides in different solvents are a result of a change from oligomer to monomer are not supported by the e.p.r. spectra of [V(O-ad),] which indicates a monomeric structure although the solution is brown.The NbIV compound is a fine crystalline solid in contrast to the only other known alkoxide [Nb(OEt)s] which is a red oil. Both the NbXV and NbV adamantoxides are monomeric in benzene. The tetra- tetrahydrothiophen adduct of NbzBr4Ss has formed the object of an X-ray structural analysis5* It contains (8)both a p-S and a p-(S2)bridge and also a possible Nb-Nb single bond (2.837 A). The e.p.r. spectrum of the tris(maleonitriledithio1-ato)niobium(Iv) species formed from reduction of NbCls by Zn-HC1-MeOH followed by addition of the complexing agent suggests an approximately trigonal- prismatic arrangement of the sulphur atoms around ni~bium.~' Other e.p.r. work includes data on eight-co-ordinate VIVand Nb'" dithiocarboxy- late cornpiexes.60 I I I l l \ H2C -CH Me H2C-CH Me (9) X=OorS The characterization of the first thiovanadyl species has been reported.61 The Schiff base complexes (9) and (10) of V02+ are treated with B2S3 in methylene chloride.E.p.r. data agree with the idea of greater covalency in the V=X bond and thus a lower charge density on the The methyl ester of cysteine forms a 2 :1complex with V02+ which exists in cis- and trans-form~.~~ Assignments are supported by i.r. Raman and e.p.r. data. 56 S. Funahashi T. Midorikawa and M. Tanaka Inorg. Chem. 1980 19 91. 57 L. Saussine H. Mimoun A. Mitschler and J. Fisher Nouu. J. Chim. 1980 4 235. 58 M. G. B. Drew I. B. Baba D. A. Rice and D. M. Williams Inorg. Chim. Acta 1980,44 L217. 59 J. Stach R.Kirmse W. Dietzsch I. N. Marov and V. K. Belyaeva Z. Anorg. Allg. Chem. 1980 466 36. 60 D. Attanasio C. Bellitto and A. Flamini Inorg. Chem. 1980 19 3419. 61 K. P. Callahan P. J. Durand and P. H. Rieger J. Chem. SOC.,Chem. Commun. 1980 75. 62 K. P. Callahan and P. J. Durand Inorg. Chem. 1980 19 3211. 63 H. Sakurai Y. Hamada S. Shimomura S. Yamashita and K. Ishizu Inorg. Chim. Acta 1980,46(Bl), L119. F. A. Hart J. Newbery and P. Thornton Niobium is one of the few metals to form an octacyano-complex. The structure of the Nb"' species64 KS[Nb(CN),] shows the expected dodecahedra1 environment but the Nb-C distances fall into two sets (2.28 and 2.24 A) whereas they are all 2.22 A in K,[Nb(CN),]. t-Butyl isocyanide has been to produce a complex (11) mer-VC13(CNB~')3 rather than the previously66 suggested insertion product (12).The complex TaC13[N(SiMe3)2]2 has a trigonal-bipyramidal configuration where the N(SiMe3)2 groups occupy equatorial The axial chlorines are bent away from the vertical with an angle ClTaCl of 168". An alleged scarcity of non-polymeric soluble Nb"' halide complexes has been alleviated by the synthesis68 of [NbC13( p-dio~an)]~ and [NbC12(0C6H4CHO)(THF)2]2.Several isothiocyanates of V" have been These have the formulation M,[V(NCS),] (M = NR4+ etc.) and i.r. and diffuse reflectance spectra are used to support their N-bonded character. Photoelectron spectra of M(NMe2)5 (M = Nb or Ta) have been and the species shown to be isostructural in the gas-phase.Non-explosive azides of vanadium VO(OPr')(N3)2 and VO(OCH2Bu')(N3), have been Their reactivity is similar to that of the corresponding titanium species. Finally in this section there are a few papers dealing with macrocyclic ligands. ESCA spectra of oxovanadium complexes of tetra-aza-[14]annulene (13) are shown71 to have the expected single N 1s peak whereas the ligand shows two peaks. Vanadyl phthalocyanine is polymorphic and the crystal structure of the stable phase I1 has been dete~mined.~~ The metal is situated 0.57 A above the plane in a square-pyramidal configuration and each species forms part of a system of roughly parallel sheets. A material extracted from Moroccan phosphate rock has been !y ENDOR methods to be a naturally occurring oxovanadium porphyrin.Vanadium is recognizable through its hyperfine splitting constants. 64 M. B. Hursthouse A. M. Galas A. M. Soares and W. P. Griffith J. Chem. Soc. Chem. Commun. 1980,1167. 65 L. D. Silverman J. C. Dewan C. M. Giandornenico and S. J. Lippard Inorg. Chem. 1980 19 3379. 66 M. Behnarn-Dehkordy B. Crociani M. Nicolini and R. L. Richards J. Organomet. Chem. 1979,181 69. 67 D. C. Bradley M. B. Hursthouse K. M. A. Malik and G. B. C. Vuru,-Jnorg. Chim. Actu 1980,44 L5. 68 L. G. Hubert-Pfalzgraf M. Tsunoda and J. G. Riess Znorg. Chim. Acta 1980 41 283. 69 L. F. Larkworthy and B. J. Tucker J. Chem. SOC.,Dalton Trans. 1980 2042. 70 M. H. Chisholm A. H. Cowley and M. Lattman J. Am. Chem. Soc. 1980,102,46. 71 K. Sakata M.Hashirnoto N. Tagami and Y. Murakami Bull. Chem. SOC.Jpn. 1980 53,2262. 72 R. F. Ziolo C. H. Grifiths and J. M. Troup J. Chem. SOC.,Dalton Trans. 1980 2300. 73 H. van Willigen C. F. Mulks A. Bouhaouss M. Ferhat and A. M. Roufosse J. Am. Chem.SOC.,1980 102,4846. The Transition Elements 173 Niobium(v) porphyrinates can be reduced by zinc amalgam to the Nb'" Cyclic voltammetry was used to discuss the probable mechanisms and the oxidation state confirmed by e.s.r. measurements. Turning to the organometallic chemistry of these elements it is noticeable that the published work covers a wider range of moieties than that on Group IV which appears to be dominated by Cp species. The structure of [TaCI,(py)(PhC=CPh)]-has been reported as (14).75 The chlorines are in an approximately planar configuration with the metal slightly displaced away from the pyridine.The mean Ta-C distance of 2.07 8 is taken as indicative of very strong binding of an approximately four-electron interaction. As usual with species of this type the co-ordination of the ethyne results in a lengthening of the C-C bond (to 1.82 A) and a bending of the Ph-(CC) axes (to 120" and 140"). The compound was made by the reaction of Ta,C16L3 (L = tetrahydro-thiophen) with PhCrCPh in toluene. The anion is obtained as a pyridinium salt after crystallization from pyridine-CH,Cl,. Octahedral alkylidene complexes M(CHR)L2X3 (M = Nb or Ta X = C1 or Br L = PMe, PPh3 etc.),can be made76 by a-hydrogen abstraction from M(CH2R),X3. A suggested scheme involving a seven-co-ordinate alkyl precursor and a transient five-co-ordinate alkylidene species is used to explain the production of complexes with a mixture of configurations (cis,mer-and trans,rner-).Few structures involving metallacyclopentane systems are known.77 Ta(7- C5Me5)(C4H8)Cl2shows an 'opened-envelope' configuration (15) rather than a puckered conformation for the TaC4 rings. Magnetic measurements on a series of mesityl vanadium compounds Li[V(mes),R(THF),] have been rep~rted.~' Improvements to the synthetic routes of many q-Cp compounds of niobium and tantalum are through the use of [Sn(u-Cp)R,] reagents. E.p.r. data on [Ta(u-Cp),(q -Cp),] have been reported; the unpaired electron is located basically in the 5d,zPy2 orbital." Photolysis of CpV(CO) produces Cp2Vz(CO)5,81 and further photolysis on this in the presence of PPh gives" Cp2Vz(CO),PPh3.The structures (16) of these two dinuclear species are remarkably similar both containing asym- metric CO groups. The non-appearance of cp,v2(c0)6 is ascribed to steric crowding and is rationalized with a series of space-filling models. 74 R. Guilard P. Richard M. El Borai and E. Laviron J. Chem. Soc. Chem. Commun. 1980 516. 75 F. A. Cotton and W. T. Hall Inorg. Chem. 1980 19,2352. 76 G. A. Rupprecht L. W. Messerle J. D. Fellmann and R. R. Schrock J. Am. Chem. Soc. 1980 102 6236. 77 M. R. Churchill and W. J. Youngs Inorg. Chem. 1980 19 3106. "G. Kriesel P. Scholz and W. Siedel Z. Anorg. Allg. Chem. 1980 460 51. 79 M. J. Bunker A.de Cian M. L. H. Green J. J. E. Moreau and N. Siganporia J. Chem. Soc. Dalton Trans. 1980 2155. A. H. Al-Mowali J. Chem. Soc. Dalton Trans. 1980 426. 81 L. N. Lewis and K. G. Caulton Inorg. Chem. 1980 19 1840. 82 J. C. Huffman L. N. Lewis and K G. Caulton Inorg. Chem. 1980 19 2755. F. A. Hart J. Newbery and P. Thornton of vanadocene Cp,V; with carbonyl sulphide COS produces a dinuclear compound 2cpzv + 2cos -+ (Cp2V)2(COS,) + co where the C0Sz2- ligand is bidentate through the sulphur to one vanadium and unidentate to the other via the oxygen. The metal-~-COS~~- system is almost planar and the complex has a total of two unpaired electrons. Reaction of PPh3 with V(CO)6 is known to give bis-replacement [to produce V(CO),(PPh,),] and disproportionation {to give [V(~olvent)~][V(CO),PPh~]~}.However if the reaction is carried out in CHzClz at -70 "C the monosubstituted complex V(CO)SPPh3 can be isolated.84 4 Chromium Molybdenum and Tungsten The large number of papers concerning these elements will be dealt with under the following sub-divisions (a)simple compounds halides oxides and sulphides; (b) co-ordination compounds; (c) organometallic compounds. Simple Compounds.-Halides. The preparation in high yield of Mo6ClI2 or Mo6BrI2.2H20 is achieved" by the conproportionation of molybdenum metal NaX and either MoCls or MoBr4. Polarized neutron diffraction data have been useds6 to study the spin-density around the Cr in K2Na(CrF6). It is found that the spin-density in the 3d orbitals has tZgsymmetry.MoOCl has been to have a square-pyramidal co-ordination environment similar to that of WOCl, with the metal situated slightly above the basal plane and having an associated chlorine (at greater distance) in the octahedral position. Gas-phase Raman and matrix-i.r. spectra have been measured" for Cr02F2. A clear assignment of the fundamental frequencies has been made and through measurements of the isotopic frequency shifts (50Cr "Cr 53Cr and ',Cr) bond angles of 102.5" (OCrO) and 124" (FCrF) have been estimated. Similar89 work with CrOC13 gives a ClCrCl angle of 105". Oxides. The structure of Mo'"aq has been investigated in First the solid-state environment was probed by a single-crystal X-ray study of the ion [Mo,O,(NCs),(H,o)]"- which was found to involve the species Mo30$+ (17).That 0 0 (17) 83 M.Pasquali C. Floriani A. Chiesi-Villa and C. Guastini Inorg. Chem. 1980 19 3847. 84 J. E.Ellis R. A. Faltynek G. L. Rochfort R. E. Stevens and G. A. Zank Inorg. Chem. 1980,19,1082. F. W. Koknat T. J. Adaway S. I. Erzerum and S. Syed Inorg. Nucl. Chem. Lett. 1980,16 307. 86 B. N.Figgis P. A. Reynolds and G. A. Williams J. Chem. SOC.,Dalton Trans. 1980,2348. 87 J. C. Taylor and A. B. Waugh J. Chem. SOC.,Dalton Trans. 1980 2006. I. R. Beattie C. J. Marsden and J. S. Ogden J. Chem. SOC.,Dalton Trans. 1980 535. 89 W. Levason J. S. Ogden and A. J. Rest J. Chem. SOC.,Dalton Trans. 1980,419. 90 R. K. Murmann and M. E. Shelton J. Am. Chem. SOC.,1980,102,3984. The Transition Elements this structure persists in aqueous solution is indicated by a series of “0 isotopic-exchange studies that demonstrated the complete resistance ( f2%) to exchange of the three bridging oxygens and the single capping oxygen.The remainder of this sub-section is concerned with iso- and hetero-polyanions. Amongst the diverse reasons for studying these species is a consideration of copper-molybdenum antagonism in ruminants. It has been demonstrated’’ that the formation of thiomolybdates of Mo0,S4-,2- (x = 0-3) is facile in animal rumen. A crystal structure of Rb4H8[H2W12040]-18H20 has been as lending credence to the presence of WIV3Ol3 subclusters in the usual Keggin-type structure. A new class of fluorotungstates has been synthesized using ”F n.m.r.as a control method.’ [H2W,,F6056]H8 appears to have a structure centred around the two non-exchangeable protons. SiV’vVvW100407- has been st~died’~ using e.p.r. A 15-line spectrum was observed consistent with an electron interacting with two ~ equivalent 51 nuclei. A fascinating structural report has appea~ed’~ concerning the grouping As~W~~~~~~~~~-. This shows antiviral and antitumoral activity in non-cytotoxic doses both in uiuo and in uitro. The ion acts as a ligand (L) and can form ML species with Group I or I1 metals being attracted particularly to K’ and Ba2’. ML further adds transition-metal ions to give MLM12 silver ions to give MLAg, or both to give MLMI2Ag2. Such a set of data could be interpreted by invoking a structure that has a number of different co-ordinating sites.X-Ray work on (NH4)23[NH4As4W400~40C02(H20)2]n H20 shows such a cyclic system with four AsW’O~~ subclusters joined by four extra W06 octahedral. At the centre of the system lies a co-ordinated NH4+ and around this site are four sub-sites that hold two Co” and two further NH4+ groups. Sulphides. This section is difficult to categorize. Species such as MS42- acting as ligands to other metals are discussed later under Coordination Compounds (Clusters). Structures of the related complexes [MO~O~S~(S~)~]*- and [Mo2(S2)6I2- have been reported. The structure of the former97 is shown (18). The latter species in the compound (NH4)2[Mo2(S2)6].2H20 is remarkable9’ for the presence of two crystal- lographically independent anions.Each Mo is co-ordinated ‘sideways-on’ by four S2*-groups two of which are bridging and two terminal. 91 N. J. Clarke and S. H. Laurie J. Inorg. Biochem. 1980 12 37. 92 Y. Jeannin J. P. Launay and M. A. Seid Sedjadi Inorg. Chem. 1980 19 2933. 93 Y.Jeannin J. P. Launay C. Sanchez J. Livage and M. Fournier Nouu. J. Chim. 1980,4,587. 94 F.Chaveau P. Doppelt and J. Lefebvre Inorg. Chem. 1980 19 2803. 95 M. M. Mossoba C. J. O’Connor M. T. Pope E. Sinn G. Hervi and A. TCzC J. Am. Chem. Soc. 1980,102,6864. 96 F. Robert M. Leyrie G. HervC A. TCzC,and Y. Jeannin Inorg. Chem. 1980 19 1746. 97 W.Clegg N. Mohan A. Miiller A. Neumann W. Rittner and G. M. Sheldrick Inorg. Chem. 1980 19,2066. 98 A. Miiller W. 0.Nolte and B. Krebs fnorg.Chem. 1980 19 2835. F. A. Hart J. Newbery and P.Thornton Work has been done on two interesting sulphide ions involving tungsten. Reduc- tion of WS4*-leads to the precipitation of W30Ss2-. This appears99 to be a chain structure with the oxygen on the central tungsten and four sulphur bridges. Metal- metal interaction may assist in the stabilization of this anion. W,S122- contains two W"' and two Wv atoms."' The chain structure (19) is held together by sulphur bridging and a metal-metal interaction between the middle (W") tungstens. The W-W distances in order are 3.16 2.95 and 3.10 8,. The middle tungstens are in square-pyramidal sulphur co-ordination elevated 0.7 8 above the plane. A more complex system is encountered with T12M09Sll. This consists1o1 of previously recognized Mo6 clusters but also a new Mo12cluster formed from the linear condensation of three Mo entities.Co-ordination Compounds.-Chemical applications of the EXAFS technique of much relevance to these metals have been described.'02 This section is arranged in increasing complexity. It commences with mononuclear species then bridged species clusters and finally metal-metal-bonded compounds. Mononuclear Complexes. The presence of Cr" as an intermediate in the oxidation of alkylaromatics in acetic anhydride by chromyl ethanoate has been detected by the observation of a relatively sharp e.p.r. line.lo3 (Either Cr'" or Cr"' would be expected to give a broad resonance signal.) Photochemical experiments with non- aqueous solutions of trans- Cr(tfa) (tfa = 1,1,1-trifluoropentane-2,4-dionate)show that isomerization predominates at wavelengths of ca.360 nm whereas at lower wavelengths redox decomposition becomes possible. lo4 Cr(OCHBu'2)4 has an approximately tetrahedral configuration about the metal with no excessive ligand crowding. lo5 The spatial arrangement is such however that the lack of oligomerization of this species (as compared with less bulky alkoxides) may be rationalized. Like the corresponding adamantoxide21 species this compound shows no e.p.r. signal down to 113K. Little work has been published on O/N donor ligands with chromium. The ligand ethylenediamine-NN'diacetic acid H2edda has been investigated'' with Cr"'. Some unconvincing Job's plots are used to show the possible existence of a 2:3 complex at pH 2.4 and a 1:1complex at pH 3.4.p-(2-Pyridyl)-cu-alanine,being a racemic mixture can form five geometric isomers of the formula M(~yala)~. Chromium(II1) forms the only meso-complex the all-trans configuration (20). A tris-complex A-fac-[Cr-(~-pyala),]H,O is also produced.0.r.d.-c.d. was used in the configurational assignments.107a A minor point occurs in this paper when the authors 99 A. Miiller W. Rittner A. Neumann E. Koniger-Ahlborn and R. G. Bhattacharyya 2.Anorg. Allg. Chem. 1980,461,91. loo F. SCcheresse J. Lefebvre J. C. Daran and Y. Jeannin Znorg. Chim. Acta 1980,45,L45. lo' M. Potel R. Chevrel and M. Sergent Acta Crysrallogr. 1980 B36,1319. lo' B.-K. Teo Acc. Chem. Res. 1980 13 412. F. Freeman C.R. Armstead M. G. Essig E. M. Karchefski C. J. Kojima V. C. Manopoli and A. H. Wickman J. Chem. SOC.,Chem Commun. 1980,65. C. Kutal D. B. Yang and G. Ferraudi Znorg. Chem. 1980 19 2907. lo' M. Bochmann G. Wilkinson G. B. Young M. B. Hursthouse and K. M. A. Malik J. Chem. SOC. Dalton Trans. 1980 1863. Io6 D. S. VeselinoviC D. V. RadanoviC and S. A. GrujiC Znorg. Nucl. Chem. Lett. 1980 16,211. lo' (a) S. E. Ebner and R. J. Angelici Inorg. Chem. 1980 19 1347; (b)H. Wanatabe S. Kuwata K. Naoe and Y. Nishida Bull. Chem. Soc. Jpn. 1968 41,1634; (c) L. N. Veselova and E. S. Chaman Zh. Obshch. Khim. 1972 42 1123. The Transition Elements give a self-citation regarding details of the ligand preparation. Not only does the reference not have these details but both the ligand and its resolution had been reported earlier by independent worker^.''^^^^ Magnetic susceptibility measurements on the D3d site symmetrical species [Cr(NH3),](C10,),Br.CsBr have been made in the range 40 mK4.2 K.Working at such low temperatures has led to improvements in precision and an unambiguous determination of both the sign and magnitude of the zero-field splitting. for ( -)D-[Cr(en)3]C13.2H20. Single crystal c.d. spectra have been rep~rted~'~ The kinetics of the hydrolysis of [Cr(tren)F2]+ have been observed"' in both basic and acidic media. In basic solution a base-catalysed fluoride release occurs whereas in acid conditions a two-step acid-catalysed process resulting in Cr-N rupture is found. Rate constants and activation parameters are reported.The complex cation [Cr(NH3),(CN)I2' has been synthesized' l1 in DMSO solution. After characterization it was used to study the kinetics of cyanide aquation. Two pathways were found one of which is acid catalysed. Cyanide release also forms the basis of a study' l2 on the photolysis of [Cr(en)z(CN)2]'. The cis-species does release cyanide but the trans-species only releases one end of an ethylenediamine ligand. Chromium(II1) forms 1 1 complexes with pyrazine (21) and in aqueous solution this is accompanied by protonation of the remote nitrogen. The equilibrium constant for the formation of the monoprotonated chromium complex has been measured113 as 1.5x104moldmp3 (at 294K) with a second-order rate constant of 3.6~ lo6mol-' dm3 s-' (at 301 K) about 100 times slower than anticipated.Some photochemistry of [Cr(bi~y)~]~+ has been reported. Many reactions have products that differ according to the solvent employed and it is ob~erved"~ that the use of DMF rather than water may allow a Cr" intermediate to be formed. The photochemical pathways of Cr(LL)33' luminescence have been studied"' and it is suggested that the 4T,+2E (intersystem crossing) process has. a similar probability in the 1,lO-phen and bipy complexes. In contrast a difference in ground-state quenching was found' l6 for the two compounds. ")' R. D. Chirico and R. L. Carlin Znorg. Chem. 1980 19 3031. H. P. Jensen Acta Chem. Scand. Ser. A 1980 34 355. '" M. J. Saliby P. S. Sheridan and S. K. Madan Znorg. Chem.1980 19 1291. 'I' P. Riccieri and E. Zinato Znorg. Chem. 1980 19 853. 'I2 A. D. Kirk and G. B. Porter Znorg. Chem. 1980 19,445. 'I3 T. G. Dunne and J. K. Hurst Znorg. Chem. 1980 19 1152. 'I4 G. B. Porter and J. Van Houten Znorg. Chem. 1980 19 2903. N. Serpone M. A. Jamieson and M. Z. Hoffman J. Chem. SOC.,Chem. Commun. 1980 1006. 'I6 R. Sriram M. Z. Hoffman M. A. Jamieson and N. Serpone J. Am. Chern. Soc. 1980,102 1754. 178 F. A. Hart J. Newbery and P. Thornton Amongst the few papers dealing with chromium(I1) complexes is one1l7 that details the preparation of thiourea adducts CrC1,-2(tu). These are formed in pro- panone solution and appear to be the first Cr" complexes with neutral S-donors. A polymeric nature is suggested. Na3[Cr(CNS)J.9H20 has an effective magnetic moment of 4.5 BM somewhat be!ow the expected value for high-spin Cr" and both magnetic data and i.r.spectra are used"' to suggest a non-polymeric nature. Complexes formulated A,[Cr(CNS),] (A = an organic base) however show antifer- romagnetic behaviour and are probably thiocyanate-bridged. Turning to the macrocyclic species an improved route to the trans-isomer [Cr[l4]ane-N4CI2]' from the cis-isomer (22) has been reported."' Kinetic studies on (R)Cr([15]ane-N4)-(H,0)2' reacting with HgT1 and MeHg" ions have been reported.12' The macrocycle has one more CH group than (22) and the R and H20 groups are trans. An SE2 mechanism is proposed and rate variations are correlated with the nature of R and the cation (a decreased rate being observed with increased steric bulk).The first example of an oxochromium N4-macrocyclic species has been claimed 12' CrO(substituted corrole). Spectral data are used to support an approximate square- pyramidal environment for the metal. Kinetic measurements on the use of vitamin B12s (formed by electrochemical reduction from B12) as a one-electron reducing agent have been obtained'22 for a series of chromium(II1) complexes Cr(H20)5X2f. n U An air- and moisture-sensitive hydrido-borohydride molybdenum(I1) complex has been shown to contain a bidentate BH4- MoH(BH,)(PM~,)~ is roughly octahedral with the phosphines in a plane. A rare example of a seven-co-ordinate nitrosyl is with [Mo(NO)(C2O4),l3-. The oxalate groups are bidentate (23).Another seven-co-ordinate entity HMO[P(OM~>,]~(O,CCF~) has been demon- stratedlZ5 to be pentagonal bipyramidal in the solid state with phosphites occupying the axial positions. N.m.r. studies show that the molecule is fluxional in solution the dominant process being not facile interconversion of polyhedra but phosphite exchange between the two non-equivalent sites. 'I7 L. F. Larkworthy and M. H. 0.Nelson-Richardson Znorg. Chim. Actu 1980 40 217. L. F. Larkworthy A. J. Roberts B. J. Tucker and A. Yavari J. Chem. Soc. Dalton Trans. 1980 262. C. K. Poon and K. C. Pun Znorg. Chem. 1980,19,568. 120 G. J. Samuels and J. H. Espenson Znorg. Chem. 1980 19 233. 12' Y. Matsuda S. Yamada and Y. Murakami Znorg. Chim.Acta 1980 44 L309. 12' J. H. Espenson and H.B. Gjerde Znorg. Chem. 1980,19 3549. 123 J. L. Atwood W. E. Hunter E. Carmona-Guzman and G. Wilkinson J. Chem. Soc. Dalton Trans. 1980,467. A. Miiller S. Sarkar N. Mohan and R. G. Bhattacharyya Znorg. Chim.Actu 1980 45 L245. S. S. Wreford J. K. Kouba J. F. Kirner E. L. Muetterties I. Tavanaiepour and V. W. Day J. Am. Chem. SOC.,1980,102 1558. The Transition Elements Two alkoxide structural studies have appeared. MoO[OC(CF3),I4 is roughly square pyramidal with the lone oxygen at the apex and the basal oxygens non-co- planar.126 The adamantoxide21 Mo(1-ado),NHMe2 has an approximately trigonal- bipyramidal shape with the NHMe2 and one alkoxy-group in the axial positions. The Mo-N bond at 2.32A is rather long and is probably affected by the bulky alkoxy-groups.A number of other species and much spectroscopic data are included in this article. Both the molecular structure and the absolute configuration of the oxodiperoxomolybdenum(v1) complex with a lactamide (L) ligand have been st~died.'~' The lactamide (24),has been shown to be bidentate through the oxygens the carbonyl being equatorial and the hydroxyl axial in a pentagonal-bipyramidal configuration about the molybdenum. MoO(O~)~L has the double-bonded oxo- group in the other axial position. Similar complexes but involving unidentate ligands and thus formulated MoO(O~)~L~ (L =py N-oxide R,PO or R3AsO) have been studied'28 with regard to the stability of the peroxo binding. Thermal and base- catalysed decompositions were investigated and it was found that the activation energies were essentially similar except for the py N-oxide complexes where a lowering was found.Me NMe 0 Et I 1.71 Et /CH-C' \ 214 \\ N-Mo-N' HO 0 \Et (24) Et/ '0' 11.9+()' 0 (25) Substituted hydroxylamido-complexes of molybdenum have again shown bidentate examples of ONR2 co-ordination. MoO2(0NEt2)* has the structures7 shown (25; distances in A) and more elaborate environments such as [MoO{H(Me)NO}2{HNC(S)N(Me)O}]have also been Other NO donor complexes have included Schiff -base (L) ligands.130 Cyclic voltammetric work indicates a possible correlation between the low-energy charge-transfer transition and the cathodic reduction potential for Mo02L(solvent) complexes. The next group of papers concerns species involving co-ordinated dinitrogen.An ESCA study of various dinitrogen complexes of Mo and W found that the qN variation within each NGN group was very small and it was thus not possible to decide which nitrogen was the most negatively charged.131 Ab inirio SCF molecular orbital calculations using a program that allows up to 50 atomic centres and 127 atomic basic functions (ATMOL/3) have been attempted on a number of dinitrogen s+ 6-complexes.132 It is suggested that the polarity for molybdenum is Mo-N-N with the reverse for ruthenium. The most complicated species tackled was [Mo(N~)~(PH~)~] and it will be some time before computer technology allows 126 D. A. Johnson J. C. Taylor and A. B. Waugh J. Znorg. Nucl. Chem.1980,43 1271. W. Winter C. Mark and V. Schurig Znorg. Chem. 1980,19,2045. 12' A. D. Westland F. Haque and J.-M. Bouchard Znorg. Chem. 1980 19 2255. 129 K.Wieghardt E. Hofer W. Holzbach B. Nuber and J. Weiss Znorg. Chem. 1980 19 2927. 130 (a)J. Topich Znorg. Chim. Actu 1980,46(Bl) L37; (b)C.A. McAuliffe A. C. Rice and W. E. Hill Znorg. Chim. Actu 1980 45 L115. 131 A. Malek B. Folkesson and R. Larsson Acta. Chem. Scand. Ser. A 1980,34 483. 132 J. N. Murrell A. Al-Derzi G. J. Leigh and M. F. Guest 1.Chem. SOC., Dalton Trans. 1980 1425. 180 F. A. Hart J. Newbery and P. Thornton calculations with the diphosphines favoured by most experimentalists. Dinitrogen complexes will now be considered in order of increasing phosphine complexity. Reaction of M(CO),(cycloheptatriene) (M = Mo or W) with P(cyclohexyl) in the presence of L'33 (L = N2 H2 C2H4 or SO2) produces tr~ns-M(CO)~(phos)~L.Flushing with argon removes L to give a possible five-co-ordinate complex M(CO)3(phos)2. A compound reported last year'34o as an (NHNH2) species has been reformu- lated134bas an hydride species [WHClBr(NNHJ(PMe,Ph),l' and used to discuss the mechanism of dinitrogen reduction in the system cis-[M(N2)(PMe2Ph),] (M =Mo or W). This gives a mixture of hydrazine and ammonia on treatment with HC1 in a variety of solvents whereas sulphuric acid favours ammonia production only. 1,2-Bis(diphenylphosphino)ethanecomplexes of the type [M(N,)X(dipho~)~]- (M = Mo or W X = SCN CN or N3) a correlation between E7Y2 and v(N2). This is used in a predictive fashion to identify labile complexes.A Raman study of the complex formulated MoC1(N2)(diphos)2 the previous suggestiont3' that a mixture of trans -MoC12(diphos) and tran~-Mo(N~)~(diphos)~ is present. Reactions of bis(dinitrogen) diphaphine molybdenum complexes with bromo- alkanes have been investigated; the initial step is M~(N~)~(diphos)~ + RBr 4MoBr(N2R)(diphos)2+N2 and the product reacts138 with sodium borohydride to give roughly equal quantities of amine (RNH2) and ammonia. Use of an a,~-dibromoalkane,'~~ Br(CH2) Br gives a similar [MoBr(N,R)(dipho~)~]Br product for n = 1 but complete elimination for n of nitrogen for n = 2 a cyclic species [MBrNk(CH2)n-lCH2(diphos)2]Br =4 or 5 and a mixture of the dinuclear [r(~-N~(CH~),N~][MBr(diphos)~]~ and [MoBr(N2R)diphos]Br for n = 6-12.The use of gem-dibromides gave similar N2R complex production for W e.g. to form [WBr(N2CHMe)(diphos)2]Br,but for Mo the reaction was much more compli~ated.'~" A report has appeared of the use of a triphosphorus ligand in a dinitrogen compound.14* Mo(NJ2(triphos)(L) [triphos = PhP(CH2CH2PPh2)2,L = PPhJ pro- duces ammonia by the reaction 2Mo(N2),(triphos)(L)+8HBr -+ 2NH4Br +2MoBr3(triphos)+3N2 +2L This is claimed as the first example of ammonia release where the fate of the metal ion has been determined unambiguously. [C15MoNR]- is attacked by water in acetonitrile to give an ion formulated as [(MOOC~~)~M~CN]~-. This has been by X-ray diffraction to contain 133 G. J. Kubas J.Chem. SOC.,Chem. Commun. 1980 61. 134 T. Takahashi Y. Mizobe M. Sato Y. Uchida and M. Hidai J. Am. Chem. SOC.,(a) 1979 101 2063; (b) 1980 102,7461. 135 J. Chatt G. J. Leigh H. Neukomm C. J. Pickett and D. R. Stanley J. Chem. SOC.,Dalton Trans. 1980 121. 136 H. M. Colquhoun and R. A. Head Inorg. Chim. Acta 1980 45 L123. 13' J. Chatt R.A. Head G. J. Leigh and C. J. Pickett J. Chem. Soc. Dalton Trans. 1978 1638. 13' G. E. Bossard D. C. Busby M. Chang T. A. George and S. D. A. Iske jun. J. Am. Chem. SOC.,1980 102,1001. 139 J. Chatt W. Hussain G. J. Leigh and F. P. Terreros J. Chem. Soc. Dalton Trans. 1980 1408. R. Ben-Shoshan J. Chatt G.J. Leigh and W. Hussain J. Chem. SOC.,Dalton Trans. 1980 771. 14' J. A.Baumann and T. A. George J. Am. Chem. SOC.,1980,102,6153.F. Weller U. Miiller U. Weiher and K. Dehnicke Z. Anorg. Allg. Chem. 1980 460 191. The Transition Elements 181 square-pyramidal [MoOC14]- and [MoOC14NCMe] where the N is trans to the oxygen. The complex ion [Mo(CN)~]~- has been studied by X-ray crystallographic pro- cedure~.'~~ It is pentagonal bipyramidal in the salt K,Na[Mo(CN),]2H20 but the K4 salt could be of lower symmetry (no suitable crystal was obtained). There are several reports of molybdenum species involving [S2CNR2]- ligands. The structure of [Mo02(S,CNEt2),] has been re-determined as (26);144 the basic shape is roughly octahedral with an OM0 angle of 105.6' and is completely consistent with usual Mo"' geometry. Reaction of this species with ArNSO (e.g. Ar=p-MeC,H,) at room temperature under nitrogen leads to the evolution of sulphur dioxide and the production of MoO(NAr)(S2CNEt2),.The reaction has been studied for various aromatic The compound formulated146 as [Mo~(N~P~)~(S~CNM~~)~] has been re-investi- gated.'47 Cyclic voltammetry 'H n.m.r. diffuse reflectance and i.r. spectra all suggest that it is a mixture of [Mo(N2Ph)(S2CNRd3] and [Mo(N~P~)~(S~CNR~)~]. 0 0 0 CH2 (27) Molybdenum has a great affinity for sulphur donors and there is much activity directed at the investigation of co-ordination sites that may prove important in gaining an understanding of biological species such as nitrogenase sulphite oxidase and xanthine oxidase. Mo(SCH~CH,SCH~CH~S)~ has all three sulphurs co-ordin- ated (of each ligand) and is of approximately trigonal prismatic (rather than octahedral) The ligand (L) derived from HSCR2CR2NR2 where R is various combinations of H and Me acts in a bidentate to give the following reaction M~O~(acetylacetonate)~ + 2LH -+ M002L2+ 2(Hacac) The structure (27) has been described as a skew-trapezoid bipyramid (i.e.a severely distorted octahedron).The S-S distance between adjacent ligands is only 2.76 A and a partial disulphide bond may be involved. Such a conformation could prove very important in Mo redox processes and help explain the wide range of observed potentials in Mo enzymes. Four papers have appeared concerning molybdenum porphyrin species. [MO(N~P~)~(TTP)I.P~NHNH,, where TTP is the dianion of meso-tetratolylpor-phyrin is obtained'" by the reaction of phenylhydrazine with MoCl,(TTP).The hydrazines are bent with an average MoNN angle of 149.1' and NNC of 128.6".A 143 M.B.Hursthouse K. M. A. Malik A. M. Soares J. F. Gibson and W. P. Griffith Inorg. Chim. Acta 1980,45 L81. 144 J. M. Berg and K. 0.Hodgson Inorg. Chem. 1980 19 2180. 14' S. Cenini and M. Pizzotti Inorg. Chim. Acta 1980 42 65. 14' A. Nakamura M. Nakoyama K. Sugihasi and S. Otsuka Inorg. Chem. 1979,18 394. 147 J. R. Dilworth B. D. Neaves and C. J. Pickett Inorg. Chem. 1980 19 2859. 14' J. Hyde L. Magin and J. Zubieta J. Chem. Soc. Chem. Commun. 1980 204. E. I. Stiefel K. F. Miller A. E. Bruce J. L. Corbin J. M. Berg and K. 0.Hodgson J. Am. Chem. SOC.,1980,102,3624. 150 J. Colin G.Butler and R. Weiss Inorg. Chem. 1980 19 3828. F. A. Hart J. Newbery and P.Thornton 'revisitation' of Mo(O)(TPP)X where TPP is the dianion of tetraphenylporphyrine and X = C1 or OR has been rep~rted."~ The chloro-species undergoes base hydroly- sis to give X = OH and some factors relevant to the formation of mononuclear hydroxy-species rather than p -oxo-dimers are presented. The synthesis of similar entities (X = NCS or Br) is also reported. The compounds were investigated by i.r. electronic absorption and e.p.r. spectr~scopy.'~~ Mo02(TTP) produced from the photolysis of Mo(O,),(TTP) has a strongly deformed porphyrin structure. The cis-oxygens are 1.71 and 1.74 8 from the The synthesis of some rather novel tungsten(I1) species was reported last year.154 W(CO),Cl(PPh,)(dcq) and W(CO),(PPh,)(dcq) (dcq = 5,7-dichloro-8-quinolinato) contain both hard and soft donors and their X-ray confirm the suggested seven-co-ordinate structures.K3W2C1 reacts with excess t-butyl isocyanide to give [(Bu'NC)~W]~+[W~~~~]~-. The seven-co-ordinate cation has been to have a distorted monocapped trigonal-prismatic shape (28)with a W-C (28) SiMe3(N3) reacts with excess WF6 to give WF5(N3). This has been to have octahedral symmetry around the tungsten with a bent azide-W system (angle of 157" at W-NNN similar to that found in some NCS complexes). The complex has the expected detonation characteristics and detailed preparative procedures and appropriate precautions are included in the report. W(C0)3(SCNMe2)2is another seven-co-ordinate species and has been in the solid state and solution.The X-ray structure is similar to that of (28) whilst 13 C n.m.r. shows two distinct intramolecular rearrangements resulting in a single 13 CO resonance at room temperature. [WCI,SR] can undergo two types of R-dependent degradation heterolytic to generate a carbonium ion or intramolecular elimination of R2S2 (especially for R = Ph) with R = Me or Ph leading to the most stable complex. A discussion of the various reaction schemes is presented. 159 Bridged Complexes. A study of the products formed by the reduction of 1,4-benzoquinone by chromous ion has led160 to the identification of five Crrrr products lS1 H. J. Ledon M. C. Bonnet Y. Brigandat and F. Varescon Znorg.Chem. 1980 19 3488. lS2 T. Imarura M. Terui Y. Takahashi T. Numatatsu and M. Fujimoto Chem. Lett. 1980 89. B. F. Mentzen M. C. Bonnet and H. J. Ledon Znorg. Chem. 1980 19 2061. 154 W. H. Batschelet R. D. Archer and D. R. Whitcomb Znorg. Chem. 1979 18 48. '" R. 0.Day W. H. Batschelet and R. D. Archer Znorg. Chem. 1980 19 2113. 156 W. A. La Rue A. T. Liu and J. San Filippo jun. Znorg. Chem. 1980 19 315. Is' J. Fawcett R. D. Peacock and D. R. Russell J. Chem. SOC.,Dalton Trans. 1980 2294. J. L. Templeton and B. C. Ward Inorg. Chem. 1980 19 1753. 159 P. M. Boorman and B. D. O'Dell J. Chem. SOC.,Dalton Trans. 1980 257. "" R. A. Holwerda and J. S. Petersen Znorg. Chem. 1980 19 1775. The Transition Elements 183 among which was [{(H20)5Cr}20]4+.The product ratios obtained are used to discuss the mechanism of electron transfer from Cr" to benzoquinone. The p -hydroxo species cis- [(NH3),Cr(OH)Cr(NH3)40H]4+has approximately octahedral symmetry about each the single bridging hydroxyl being almost equidistant (1.96 and 1.998,)from the metals but the CrOCr angle is bent to 142.8'. [Cr(en)(malonate)-(0H)l2 has a centre of symmetry about the di-p-hydroxo-bridge. The Cr-Cr distance of 3.00 8 is in line with other di-p -hydroxo-complexes.162 Acid-catalysed decarboxylation of a bridging carboxylate has been to proceed by essentially the same mechanism as that applicable to a bidentate (non-bridging) carbonato-ligand. During this investigation the structure of [([9]ane N3)2Cr2(0H)2C03]2+ with di-p -hydroxo and carbonate bridging was determined.The magnetic behaviour of the tetranuclear p -hydroxo-chromium analogue of Werner's brown salt [Cr{(OH)2Cr(en)2}3]"' has been between 4 and 280 K. Antiferromagnetic exchange interaction between the central Cr and the satellite atoms is the main feature. Two interesting single-element bridged compounds have been reported for Mo and W. [{MoO(02)(pydca)}2F]- where pydca is pyridinedicarboxylate has the symmetrically bridging F and the oxide in the axial positions and the bidentate O2 and terdentate pydca in the equatorial positions of an approximately pentagonal- bipyramidal molybden~rn.'~~ The trans-oxide could be the cause of the very long (2.135 A) Mo-F distance. [W2NC1,,]2- is centrosymmetric about the N the equatorial chlorides being closer (-2.30 A) to the tungsten than the trans axial C1 (-2.42 A).166 A mixed p -oxo-p -oxalato bridging system is postulated in a molybdenum(II1) species generated by the reaction (for example) of Mo(OH)~,oxalate ion and a-alanine (L).[MO~O(C~O,)L~(H~O)~](H~O)~ shows vibrational spectra and mag- netic behaviour consistent with a bridged The use of i.r. measurements to distinguish between the various Mo-0 possibilities (terminal bridging core- bridging) is discussed in a paper dealing with various diol and amino-alcohol complexes.168 Some complexes show the presence of an Mo203core and others of Mo20,. The aquation of [W204(edta)12-to W2042+ has been shown to first-order kinetics with kl ca. lop4s-l in 2 mol dm-3 HC1.Second-order rate constants for the oxidation of Wv to Wv' have also been determined. Spectroscopic data and a structure are rep~rted'~' which is for Mo~(OP~')~(NO)~ bridged symmetrically by isopropoxy-groups. The MONO moiety is almost exactly linear (179.4'). Cluster Compounds. Most of the species in this section concern molybdenum and the possibility of synthesizing compounds of bio-inorganic relevance. The Mo-16' D. J. Hodgson and E. Pedersen Znorg. Chem. 1980 19 3116. 16' J. W. Lethbridge J. Chem. SOC. Dalton Trans. 1980 2039. 163 K. Wieghardt W. Schmidt R. van Eldik B. Nuber and J. Weiss Znorg. Chem. 1980,19 2922. H. U. Giidel and U. Hauser Inorg. Chem. 1980 19 1325. A. J. Edwards D. R. Slim J. E. Guerchais and R. Kergoat J. Chem. SOC.,Dalton Trans.1980 289. 166 F. Weller W. Liebelt and K. Dehnicke Angew. Chem. Znt. Ed. Engl. 1980 19 220. B. Kurzak and S. Wajda Znorg. Chim. Acta 1980 46(B1),275. 16' C. Knobler B. R. Penfold W. T. Robinson C. J. Wilkins and S. H. Yong J. Chem. SOC.,Dalton Trans. 1980,248. lh9 A. B. Soares R. C. Taylor and A. G. Sykes J. Chem. SOC.,Dalton Trans. 1980 1101. 170 M. H. Chisholm J. C. Huffman and R. L. Kelly Znorg. Chem. 1980 19 2762. F. A. Hart J. Newbery and P. Thornton containing enzyme xanthine oxidase forms SCN- on treatment with CN- but without reduction of the molybdenum. The S22-bridges of [MO~'"S(S~)~]~- are cleaved with CN- and the new cluster species [Mo3S4(CN),IS- (29)is formed without molybdenum reduction. 17' Reaction of H2S on Mo(N tol)(S2P(OEt),} gives the tetranuclear [Mo(N to1)- S{S2P(OEt),}14;'H and ,'P n.m.r.spectra are used to that this may be the first authentic cuboid Mo structure that does not contain other metals such as iron (30). Before dealing with these cubane systems it is worth looking at some of the NC CN CN \I / NC \ / NC (29) (30) considerable number of reports that deal with the chelate ligand MoS42-. These ligands obviously contain empty metal d-orbitals in addition to the sulphur donor atoms and may thus be able to offer charge delocalization in a similar fashion to carbonyl groups. Considering the Mo species as the ligand (L) the first species to be discussed are M2L. The structure of (PPh3),Cu2MoS4 has been dete~rnined'~ and contains a central Mo with almost exactly tetrahedral configuration.The copper with the single phosphine has a shorter (2.21 A)Cu-P distance than the other copper atom (2.30 8 average). The presence of a high-spin Fe3' (Mossbauer spectroscopy) and e.p.r. measurements are used to a non-symmetrical structure for [(PhS)2FeS2FeMoS4]3-. Only one ML species has been the ion [Cl2FeMoS4I2- where both metals are tetrahedrally co-ordinated the iron being high-spin Fe2' The Mossbauer spectra also confirm the n-acceptor character of MoS4*-. Various ML2 species have been described. [(MoS~)~F~]~- has been prepared by two group^.'^^,'^^ Admixture of (R4N)2M~S4 with (R4N)[Fe(S,COC2H,),] pro-d~ces'~~ the better product. The X-ray structure (31) shows two bidentate MoS~~- ligands with all the angles slightly lower than tetrahedral.The central axis (MoFeMo) makes an angle of 172.6' Short (2.24A)Fe-S distances again reflect the charge- 17' A. Miiller and U. Reinsch Angew. Chem. Int. Ed. Engl. 1980 19 72. 17' A. W. Edelblut and R. A. D. Wentworth Inorg. Chem. 1980 19 1110. A. Muller H. Bogge and U. Schimanski Inorg. Chim. Acta 1980 45 L249. 174 R. H. Tieckelmann and B. A. Averill Inorg. Chim. Acta 1980,46(Bl) L35. 17' (a)A. Miiller R. Jostes H.-G. Tolle A. Frautwein and E. Bill Znorg. Chim. Acra 1980 46(B1) L121; (b)A. Miiller H. Bogge H.-G. Tolle R. Jostes U. Schimanski and M. Dartmann Angew. Chem. Inr. Ed. Engl. 1980 19 654; (c) R. H. Tieckelmann H. C. Silvis T. A. Kent B. H. Huynh J. V. Waszczak B.-K. Teo and B.A. Averill J. Am. Chem. Soc. 1980 102 5550. 176 J. W. McDonald G. D. Frieser and W. E. Newton Inorg. Chim.Acta 1980 46(B1) L79. D. Coucouvanis E. D. Simhon and N. C. Baenziger J. Am. Chem. Soc. 1980,102,6644. The Transition Elements 185 acceptance role of Mo in these structures. Pd(MS4)22- (M = Mo or W) and Pt(MS4)22- have been synthesized Details of the electrochemistry are discussed. 17' CO(WSJ~~-has also been re pa red."^ s-Mo ,\u-b[ s\ ' b's-cu-p-Fe /s\ Mo / S cui/ \ / \s/ \ s 'd S 'I (31) (32) Two unusual structures provide'" a link between this previous group of metal-ligand complexes and the more obvious cubane clusters that follow. (Cu3MoS3Cl)- (PPh3)3S has a distorted cubane-type cage but could be viewed (32) as a terdentate MoS,~- ligand complex.(Cu,W2S6)(PPh3),O2 has a distorted rectangular cage of alternate metal and sulphur atoms where the copper atoms carry the phosphines and the oxygens are bound to the tungstens but again a terdentate (WOS32-) ligand can be invoked. Most of the papers dealing with cubane-like structures concern triply bridged thiol species. A further example'81 (33) of this is the reported structure of [MO~F~~S~(SR)~~]~-. of such 'double-cubanes' (33)and The Mossbauer ~pe~tra~~~*~~~ (34)have indicated a mean oxidation state of around Fe2.61 thus suggesting that the Mo must be either Mo4' or Mo3'. N.m.r. spectra (R = Et or Ph) clearly distinguish between bridging and terminal SR g~0ups.l~~ The non-bridging SR groups of (34) can be replaced'" by halide if the compound is mixed with benzoyl halide in acetonitrile solution but prolonged treatment failed to displace the bridging groups.This reaction demonstrates for the first time that thiol groups are not a prerequisite for the stability of the (Fe3MoS,} core. Treatment of (34; R = Ph)5- with PhSH leads'" to the quantitative evolution of hydrogen and production of (34)3-. RS' SR R (33) (34) K. P. Callahan and P. A. Piliero Znorg. Chem. 1980 19 2619. A. Miiller R. Jostes V. Flemming and R. Potthast Znorg. Chim. Acta 1980 44 L33. (a) A. Miiller H. Bogge and U. Schimanski,J. Chem. SOC.,Chem. Commun. 1980,91; (b)A. Miiller H. Bogge andT. K. Hwang Inorg. Chirn. Acta 1980 39,71. T. E. Wolff J. M. Berg P. P. Power K.0.Hodgson and R. H. Holm Znorg. Chem. 1980 19 430. T. E. Wolff P. P. Power R. B. Frankel and R. H. Holm J. Am. Chem. Soc. 1980 102,4694. G. Christou C. D. Garner R. M. Miller C. E. Johnson and J. D. Rush J. Chem. SOC.,Dalton Trans. 1980,2363. G. Christou and C. D. Garner J. Chem. SOC.,Dalton Trans. 1980 2354. G. Christou and C. D. Garner J. Chem. SOC.,Chem. Commun. 1980 613. lS6 G. Christou R. V. Hageman and R. H. Holm J. Am. Chem. SOC.,1980,102,7600. 186 F. A. Hart J. Newbery and P. Thornton Metal-Metal-bonded Species. A short review of spectroscopic and theoretical aspects of metal-metal bonds has appeared in which the role of the 8-bond in structure and electronic spectra is discu~sed.’~’ Low-temperature polarized single-crystal absorption spectra have been obser- vedls8 for Cr2(acetate)4(H20)2.This species belongs to the group of compounds with symmetric bridging carboxylates (in the eclipsed configuration) and a rather long Cr-Cr bond (-2.4A). The data are analysed in terms of D4hsymmetry and fine-structure progressions used to estimate a v(Cr-Cr) (ground-state) in the 150-250 cm-’ range. The structures of similar species where the waters are replaced with pyrazine (21) or pyridine have been rep~rted.’~~ Related bridging ligands R’NC(0)R2 have been used to prepare a series of complexes which allow the effects of axial co-ordination on the Cr-Cr bond length to be assessed.190 An isomorphous set of quadruply bonded compounds has been ~ynthesized.”~ M2L4 (M = Cr Mo or W L = the anion of 6-chloro-2-hydroxypyridine)show M-M bond lengths of 1.955 2.085 and 2.177 A respectively which are slightly longer than those found with a related ligand (methyl instead of chloro).This is ascribed to inductive effects. The papers dealing with Mo and W derivatives will be reviewed in order of increasing bond order. Se~eral’’~ papers have reported details of dinuclear Mo or W complexes with bridging sulphur entities where a possibility of M-M bonding exists. [(R2S)C12W]2(SEt)3 has W-W of 2.50 A [Mo2(g4-S2)(g2-S02)CNJ4-has Mo-Mo of 2.73 A and [(Me-Cp)Mo(S)SMeI2 has Mo-Mo of 2.58 A. The former Mo species may well have no M-M bond but there is speculation that the latter could have a double bond. Molybdenum d3-d3 triply bonded entities i.e.those where the only inter-metal electrons are contained in ethyne-like one u-+ two .rr-type orbitals form the basis of an MO-photoelectron spectroscopic study. 193 Suggestions that such M2L6 species should favour an eclipsed conformation for small ligands are refuted partly by a lack of evidence for any T/S or 8* mixing that would be necessary to explain the stability of the eclipsed conformer. Calculations194 with the model system M02H6 indicate that any energy difference between conformers is ca. 4 kJ mol-’ suggesting that any conformational preference is a product solely of the ligands. An Mo~N~ species with an imposed-eclipsed conformation Mo~(M~NCH~CH~NM~)~, has virtually the same Mo-ligand distances as related species involving unidentate donor^.''^ ‘I3’ F.A. Cotton J. Mol. Struct. 1980 59 97. S. F. Rice R. B. Wilson and E. I. Solomon Znorg. Chem. 1980 19 3425. F. A. Cotton and T. R. Felthouse Inorg. Chem. 1980 19 328. 19” F. A.Cotton W. H. Ilsley and W. Kaim Znorg. Chem. 1980 19 3464 3475. 19’ F. A.Cotton W. H. Ilsley and W. Kaim Znorg. Chem. 1980,19,1453. 192 (a)P. M. Boorman V. D. Patel K. A. Kerr P. W. Codding and P. Van Roey Znorg. Chem. 1980 19,3508;(b)C.Potvin J.-M. BrCgeault and J.-M. Manoli J. Chem. SOC.,Chem. Commun. 1980,664; (c) M. Rakowski Dubois M. C. Van Derveer D. L. Dubois R. C. Haltiwanger and W. K. Miller J. Am. Chem. SOC.,1980,102,7456. 193 B. E. Bursten F. A. Cotton J. C. Green E. A. Seddon and G. C. Stanley J. Am. Chem. Soc. 1980 102,4579. 194 M.B.Hall J. Am. Chem. Soc. 1980 102 2104. 195 T.P. Blatchford M. H. Chisholm K. Folting and J. C. Huffman Znorg. Chem. 1980 19 3175. The Transition Elements 187 M2L14L22species of MGM previously characterized have been symmetric 1,2- substituted species. However MO~(NM~~)~(CH~S~M~~)~ to have has been ~hown”~ 1,l- and 1,2-(NMe2)2 isomers. Variable-temperature n.m.r. spectra were used to study conformers of each isomer. [Cp2M02(C0)4CN]- formed’” by the addition of CN- to CP~(MO),(CO)~ has a bridging cyanide in the solid state with probable cr-donation to one molybdenum and 7r-donation to the other (35). The molecule is fluxional in solution with a +N dC1 MoEMo (35) ‘windscreen-wiper’ mode of cyanide exchange (activation energy of 44 kJ mol-’) between the metals.N.m.r. studies of Mo~(NM~~)~ that the diamagnetic s~ggest”~ anisotropy of the Mo-Mo bond is -142 x m3 molecule-’ roughly half that found for an alkyne linkage. The conversion of Moo3 into [MoGMoI4+ derivatives has been demonstrated”’ by a three-step aqueous proceduse (Scheme 5). M~~(acetate)~, K4M02C18-2H20 electrolytic reduction ,MoC163- evaporation ,Mo2C193- HCI [MoEMoI4+ A e d u c tor Scheme 5 and K4M02(S04)4have all been prepared by this method. The chemistry of such quadruple-bond entities has advanced to a stage where the Mo~(O~CR)~*~L species with L in the axial positions can be referred2” to as ‘classical compounds’. The n.m.r. spectra of such complexes (L= Ph3P Me3P0 or But3P for example) and of a new structural type (L = Et3P or Me3P) where the carboxylate groups are divided between bidentate and unidentate co-ordination have been reported.Tungsten however has not yet been shown to form either a carboxylate W2(02CR)4 or the anion W2Clg4-. Thus attention falls at present on W2(L-L), where L-L = the anion of (36). With R = Me only two ligands can be replaced with [PhNC(Me)NPh]- even after boiling in diglyme.201 (W-W is 2.169 A.)With R = H the Mo equivalent produces Mo2Cls4- after refluxing2’’ with CsCl and HC1 in methanol but the W compound gives the oxidized product W2c1g3-. The structures of a number of tungsten phosphine species have been rep~rted.~’~ One of these W2C14(Me2PCH2CH2PMe2)2.C7H8, has the diphosphine ligands as chelating ligands rather than the expected bridging mode (37).The W-W bond is much longer (2.287 A) than that in other quadruply bound tungsten species (nearer to 2.16A). The attraction of the [Mo=Mol4’ system to carboxylate linkages is 19‘ M. H. Chisholm and I. P. Rothwell J. Chem. SOC.,Chem. Commun. 1980 985. 19’ M. D. Curtis K. R. Han and W. M. Butler Znorg. Chem. 1980 19 2096. 19’ M. J. McGiinchey Znorg. Chem. 1980 19 1392. ‘99 A. Bin0 and D. Gibson J. Am. Chem. SOC.,1980,102,4277. 2oo G. S. Girolami V. V. Mainz and R. A. Andersen Inorg. Chem. 1980 19 805. 201 F. A. Cotton W. H. Ilsley and W. Kaim Inorg. Chem. 1980 19 1450. 202 D. De Marco T. Nimry and R. A. Walton Inorg. Chem. 1980,19 575. 203 F. A. Cotton T. R. Felthouse and D. G. Lay J.Am. Chem. Soc. 1980 102 1431. F. A. Hart J. Newbery and P. Thornton R CH~-CH* (36) R=HorMe (37) by studies involving amino-acids and peptides. Only the carboxylates are co-ordinated (bidentate fashion) although first-row transition elements often have the nitrogen involved as well. The Mo =Mo bond in Mo2C14(phos) is cleaved by reaction with isocyanides (RNC) with the Formation205 of various mononuclear RNC-phosphine molyb-denum adducts. Further theoretical work206 on the gaseous dimolybdenum species (Mo2) gener- ated by flash photolysis on Mo(CO)~ is said to support a previous suggestion that a second u-bond is more important than a second 6-bond in accounting for the reported bond length of 1.93 A. Organometallic Compounds.-Since this area is surveyed in another chapter of this Report the coverage here is more abbreviated than in the preceding part.Carbonyl compounds are of course a fruitful source of gainful employment for inorganic chemists. Photochemistry bonding theory catalysis and carbene adducts have all been studied amongst the carbonyls of Cr Mo and W. Photolysis at 10 K of Cr(CO)5L (L=PMe3 or NMe,) results2" in expulsion of one CO group. The symmetry of the product (in the case of NMe,) changes with the temperature of the experiment .'08 Calc~lation~~~~ using the Xa scattered-wave MO approach are offered to support the idea of a high degree of synergism in carbonyl bonding in Cr(C0)6. 1.42 electrons are estimated as being donated with 1.25 e back-donated from the Cr 3d orbitals.A survey of compounds CP~M~(CO)~ analyses the various alternative geometries and attempts to begin the answer as to why some ligands are able to act in a bridging fashion.210 In a similar manner the preference or otherwise for a bridged or a quadruple metal-metal bond is assessed.211 A scale of ligand constants PL,based on the difference in one-electron oxidation between Cr(C0)5L and Cr(C0)6 has been established.212 It is claimed to be useful in the identification of complexes and binding sites. '04 (a)A. Bino F. A. Cotton and P. E. Fanwick Inorg. Chem. 1980 19 1215; (b) A. Bin0 and F. A. Cotton J. Am. Chem. SOC.,1980 102 3014. '05 T. E. Wood J. C. Deaton J. Corning R. E. Wild and R. A. Walton Inorg. Chem. 1980 19 2614. '06 B.E. Bursten F. A. Cotton and M. B. Hall J. Am. Chem. Soc. 1980 102 6348. '"'G. Boxhoorn G. C. Shoemaker D. J. Stufkens and A. Oskam Inorg. Chim.Acta 1980,42 241. '08 G. Boxhoorn D. J. Stufkens and A. Oskam J. Chem. SOC.,Dalton Trans. 1980 1328. *09 B. E. Bursten D. G. Freier and R. F. Fenske Inorg. Chem. 1980 19 1810. 210 E. D. Jemmis A. R. Pinhas and R. Hoffmann J. Am. Chem. SOC.,1980 102,2576. 211 S. Shaik and R. Hoffmann J. Am. Chem. SOC.,1980,102 1194. J. Chatt C. T. Kan G. J. Leigh C. J. Pickett and D. R. Stanley J. Chem. Soc. Dalton Trans. 1980 2032. The Transition Elements The kinetics of the process trans-Cr(CO),L2 + CO -+ Cr(C0)5L+L (L = various phosphorus and arsenic ligands) have been studied. The rate of dissociation seems to correlate best with the .rr-bonding capability.213 Hydrogenation of carbon monoxide has been shown to be catalysed by mono- nuclear carbonyls [e.g.M(CO) (M = Cr Mo or W)] supported on A1203as well as by polynuclear species. Although the oligomerization of these carbonyls cannot be ruled out the low loadings used make this an unlikely e~planation.~'~ The structure of [(CO)5CrCNEt2]' has been determined.215 The main feature of this compound is the long Cr-CNR2 bond (1.78 A) which taken with the C-N bond of 1.28 8 argues for a strong contribution from resonance formula (38b) + + + (CO),Cr_C-NEt ++ (CO),Cr=C=NEt ++ (CO)5Cr=C-NEt2 (384 (38b) (384 Interconversions between isomers via redox processes have been studied216 in (imid)2MoL(CO),.A complex series of processes was observed involving widely differing rates and half-wave potentials.Tetrahedral-type molecules involving four different corner atoms (three metals) have been resolved2" into enantiomers (39) by the use of the optically active ligand PMe(Pr)Ph. The solid-state structure of a similar species [Fe(CO),.Pt(CO)- (PR),.W(Co),(Cp)(CC6H4Me)] and synthetic strategies for such systems are reported.218 A chromium(1v) alkyl that is inert to water has been reported.26 Cr(adamantyl) is formed by direct action of the alkyl-lithium with Cr(OBu'),. Mo2(NMe2),(CH2SiMe3), with an Mo_Mo bond has interesting variable- temperature n.m.r. behaviour and the free-energy barrier to rotation about the bond is estimated219 as ca. 60 kJ mol-'. Mononuclear complexes containing alkynes are still comparatively rare.A series of compounds W(CO)(RCGCR)(S,CNR,), has been prepared220 by displacement of two carbonyls with the appropriate alkyne. N.m.r. studies support the four- electron donor view of alkynes in such systems and are used to estimate details of a ligand fluxional process. The conversionz2' of a bis-alkyne tungsten complex (40) into a metallocycloalkene species (41)has been recorded. Metallocyclic complexes are also discussed in an ab initio study of intermediates occurring in olefin metathesis 213 M. J. Wovkulich S. J. Feinberg and J. D. Atwood Inorg. Chem. 1980,19 2608. 'I4 A. Brenner and D. A. Hucul J. Am. Chem. SOC.,1980,102,2484. U. Schubert E. 0.Fischer and D. Wittmann Angew. Chem. Int. Ed. Engl.1980 19 643. 216 R. D. Rieke H. Kojima and K. Ofele Angew. Chem. Int. Ed. Engl. 1980 19 538. 'I7 F. Richter and H. Vahrenkamp Angew. Chem. Int. Ed. Engl. 1980 19 65. 218 M. Chetcuti M. Green J. A. K. Howard J. C. Jeffrey R. M. Mills G. N. Pain S. J. Porter F. G. A. Stone A. A. Wilson and P. Woodward J. Chem. SOC.,Chem. Commun. 1980 1057. 219 M. H. Chisholm and I. P. Rothwell J. Am. Chem. SOC.,1980 102 5950. 220 B. C. Ward and J. L. Templeton J. Am. Chem. SOC.,1980 102 1532. 221 J. L. Davidson L. Manojlovik-Muir K. W. Muir and A. N. Keith J. Chem. SOC.,Chem. Commun. 1980,749. F. A. Hart J. Newbery and P. Thornton and epoxidation processes. It is suggested that chromium should promote epoxida- tion but not metathesis whereas for molybdenum and tungsten C-C bond cleavage becomes more competitive.222 MC1(C0)2(q3-C3H4R)L2 [M = Mo or W L = P(OR),] takes up an approximately pentagonal-bipyramidal with the chloride and a carbonyl in the axial positions.The allyl ligand occupies two adjacent equatorial points. In solution the molecule is fluxional at room temperature but the solid-state structure seems to be retained <230 K. In similar species (L = NCMe) unidentate phosphine ligands displace the allyl group but bidentate phosphines take out the acetonitriles. The process has been to be first order in both Mo-complex and PMezPh (or PMePh2) and is thought to involve initial nucleophilic attack on the allyl group. A compound previously formulated W(CO)2(C5Hs)4 has been by X-ray work to be actually W(C0)2(q5-C5H5)(q3-C15H15) (42) rather than W(CO)2(q5- CsH5)(o-C5H5)3.This seems to be a novel arrangement for Cp rings -allylically bound rather than q-or u-and helps to clarify the otherwise complicated n.m.r. spectrum observed. This failed to simplify on raising the temperature and appeared to suggest the presence of some exceptionally high rotational barrier. (42) Some details of the synthesis and interconversions of a series of dinuclear molybdenocenes and tungstenocenes have been published.226 A few of the reactions are shown in Scheme 6 from the extensive study of isomers addition products and photolytic products. N.m.r. spectra are also reported. A multiply bound molybdenum phosphorus complex has been characteri~ed.~~’ MekCH2CH2N(MejPMo(qs-Cp)(CO)2 has the atoms of the phosphorus linkage roughly perpendicular to the Mo(CO)~ plane (43).The Mo-P distance of 2.21 A 222 A.K. RappC and W. A. Goddard J. Am. Chem. Soc. 1980,102,5114. 223 B. J. Brisdon D. A. Edwards K. E. Paddick and M. G. B. Drew J. Chem. SOC., Dalton Trans. 1980 1317. 224 D. A. Clark D. L. Jones and R. J. Mawby J. Chem. Soc. Dalton Trans. 1980 565. 225 R. D. Rogers W. E. Hunter and J. L. Atwood J. Chem. Soc. Dalton Trans. 1980 1032. 226 M. Berry N. J. Cooper M. L. H. Green and S. J. Simpson J. Chem. Soc. Dalton Trans. 1980 29. 227 L. D. Hutchins R. T. Paine and C. F. Campana J. Am. Chem. Soc. 1980,102,4521. The Transition Elements I I is suggested as having multiple-bond character and a possible MO scheme is presented.Further examples of q2-S02 complexes have been characterized. Mo(1,lO-phen)(C0),(q2-SO2) and Mo(2,2’-bipy)(CO),(q2-S0,) have dihedral S02/Mo angles of ca. 106”. A discussion of the vibrational spectra and bonding features is 0 Me Ph C I0 O Ncc H27 P-H2c.N’ Ph 0 \ ’-’ c Me 0 Ph (43) (44) included.228 Mo(CO),(PP h3) (SPPh,)* shows another q -sulphur ligand. 229 This compound was studied by X-ray structural analysis (44)as part of a wider investiga- tion involving M(CO),(SPPh,),L (M =Mo or W L =PPh3 or Cp). Considerable changes in the 31P n.m.r. signal of the SPPh ligand were observed.

ISSN:0260-1818    

DOI:10.1039/IC9807700164

出版商:RSC    

年代:1980

数据来源: RSC

摘要:

The Transition Elements Part 111 Groups VIIA VIIIA and IB By P. Thornton 1 General As usual this section deals with reviews of a general nature or research involving a number of different metals. Of the many reviews that have appeared this year a **' G. J. Kubas R. R. Ryan and V. McCarty Inorg. Chem. 1980 19 3003. 229 H. P. M. M. Ambrosius J. H. Noordik andG. J. A. Ariaans J. Chem. SOC.,Chem. Commun.,1980,832. F. A. Hart J. Newbery and P. Thornton specially timely survey has been produced of transition-metal cryochemistry,’ covering the various experimental methods and metal clusters and complexes which can be prepared by this important new technique. A review2a of dithiolium salts and dithio-&diketone complexes is suitably complemented by another2’ of 1,l- dithiolato-complexes.In preparative work involving a range of metals there have been developments in studies of dinuclear complexes. The new tripod ligand (Et2NC2H4),NC2H40- (L) forms complexes [M2LJC104)2 with many bivalent first-row metals; electronic spectra and conductance studies suggest that these are trigonally bipyramidally co-ordinated dimers with the Cu complex much more antiferromagnetic than the Ni or Co ones.3 [M(salen)] (M = Mn Fe or Co) react with o-quinones to form [M(salen)(semiquinone)] containing M3+ antiferromagnetically coupled (except for Co) with the ligand’s unpaired ele~tron.~ It is proposed that the salen ligand is bent to give a cis-vacancy for the semiquinone and the authors suggest that the complexes are a model for ubiquinone’s role in the biological electron-transfer chain; the complex [Fe,(~alen)~(semiquinone)] was also prepared and is believed to have the semiquinone bridging two [Fe(salen)] units.X-Ray crystal structures show’ that the 1,3,5-triketonate complexes [C~~(la),(Me0H)~] and [Ni2(lb)2(py)4] have square-pyramidal Cu and octahedral Ni. Other complexes made in this work are [Cu2(la>2(H20)2I [Cu2(1b)2(MeOH)2l7 “i2(142(H20)41 and [CO~(W~(PY)~I; the antiferromagnetism shown by these complexes is analysed in terms of the electronic effects of the ligands and the extent to which the copper atoms are out of their square plane. Co and Ni complexes of many tetra-aza-macrocycles catalyse the electroreduction of C02 to CO in O.1M-KNO solution in H20 or 2 :1 H20-MeCN; the authors suggest that this reaction may be useful for the utilization of atmospheric C02.6 (1) a; R = CF3 ‘b; R = Me Calculations of band structures of MnX3- Nix3- and other polymeric halide complexes gave general predictions of the electric and magnetic properties of these face-shared octahedral polymers.Interpretation of the magnetic properties of the chain polymers M(4-phen~lpyridine)~Cl~ required for Mn the introduction of a molecular field term and for Ni a zero-field splitting which led to metamagnetism through ferromagnetic interactions with chains and antiferromagnetism between chains but for Cu the Heisenberg linear chain formula was sufficient.8 Electronic W. J. Power and G. A. Ozin Adv. Znorg. Chem.Radiochem. 1980 23 79. (a)T. N. Lockyer and R. L. Martin Prog. Znorg. Chem. 1980,27,223;(b)R. P. Burns F. P. McCullough and C. A. McAuliffe Adv. Znorg. Chem. Radiochem. 1980,23 211. L. Banci and A. Dei Znorg. Chim. Actu 1980 39 35. S. L. Kessel R. M. Emberson P. G. Debrunner and D. N. Hendrikson Inorg. Chem. 1980,19 1170. J. W. Guthrie R. L. Lintvedt and M. D. Glick Znorg. Chem. 1980 19 2949. B. Fisher and R. Eisenberg J. Am. Chem. Soc. 1980 102 7361. M.-H. Whangbo M. J. Foshee and R. Hoffmann Znorg. Chem. 1980,19,1723. W. E. Estes R. R. Weller and W. E. Hatfield Znorg. Chem. 1980 19 26. The Transition Elements 193 spectra and EHMO studies on metal clusters prepared in noble-gas matrices include work on Pdz Au2 Au, AgMn AgMo and AgCu.’ Other physical studies of general interest include the revised determination” of the diamagnetic susceptibility of H,tpp at almost double the value obtained from Pascal’s constants and a careful survey’’ of the i.r.spectra of carboxylate complexes from which it was concluded that chelation can be distinguished from bridging co-ordination by very low separa- tions of the COz stretching frequencies provided direct metal-metal bonding is absent. Reviews of biological aspects of metal chemistry abound. The first of a new series includes articles on superoxide dismutases copper-containing oxidases cytochrome P450 nucleotide complexes and haemerythrins and the second volume”’ provides very useful reviews by famous exponents of their spectroscopic and other physicochemical techniques.Many of these topics are included in another volume’3“ of reviews on metallobiochemistry which also contains a timely review on non-haem iron dioxygenases wherein metal ions are involved in essentially organic reactions and a review on bleomycins which are new interesting antitumour agents and metal complexes of glycopeptides. The two new volumes of yet another familiar series are subtitled ‘Carcinogenicity of Metal Ions’ (including development of malignant tissue and tumour diagnosis by 99mTc) and ‘Metal Complexes as Anticancer Agents’.13c This last volume coincides with an extensive and well illustrated review’3d on complexes of mono- and poly-nucleotides with 3d-elements particularly Cu and Mn. A general paper of importance in the ‘bioinorganic’ field shows how the electron-transfer distances in metalloproteins can be calculated from the rate constant for the process so that one can see that ligands need to penetrate protein interiors can compare model systems with proteins and can compare various spectroscopic with kinetic data on many types of metalloprotein.l4 2 Manganese Technetium and Rhenium Manganese.-The preparation and X-ray crystal structure have been reported” of the N,N’-dimethylurea (L) complex [MnL3Br,] the first high-spin five-co-ordinate Mn” complex with unidentate ligands.Another X-ray crystal structure of [Mn(1,4,7,10-tetraoxacyclodecane)2](Br3)2,is only the second of a transition metal with a 12-crown-4 ligand; with rather long Mn-0 distances of 2.31 8 this has a square-antiprismatic structure like its Na and Ca analogues.16 MnPS is much less antiferromagnetic when it is intercalated by [cocp2] [Cr(C6H6),] or allylamine W.E. Klotzbucher and G. A. Ozin Znorg. Chem. 1980,19 3767 3776 lo S. S. Eaton and G. R. Eaton Znorg. Chem. 1980 19 1095. ’’ G. B. Deacon and R. J. Phillips Coord. Chem. Rev. 1980,33,227. l2 (a)‘Advances in Inorganic Biochemistry’ ed. G. L. Eichhorn and L. G. Marzilli Elsevier-North Holland New York Vol. 1,1979; (6)‘Advances in Inorganic Biochemistry’ ed. D. W. Darnall and R. G. Wilkins Elsevier-North Holland New York Vol. 2 1980. l3 (a)‘Structure and Bonding’ ed. J. D. Dunitz et al. Springer-Verlag Berlin Vol. 40 1980; (6) ‘Metal Ions in Biological Systems’ ed. H. Sigel Dekker New York Vol.10;(c) ibid.,Vol. 11; (d)H. Pezzano and F. Pado Chem. Rev. 1980,80 365. l4 A. G. Mauk R. A. Scott and H. B. Gray J. Am. Chem. SOC.,1980,102,4360. 15 J. Delaunay C. Kappenstein and R. P. Hugel J. Chem. SOC.,Chem. Commun. 1980 679. 16 B. B. Hughes R. C. Haltiwanger C. G. Pierpoint M. Hampton and G. L. Blackmer Znorg. Chem. 1980 19. 1801. 194 F. A. Hart J. Newbery and P. Thornton and ferromagnetism appears below -40 K." The authors conclude that the in- truding molecules force rearrangement of the s-orbitals to break down the superexchange pathway for antiferromagnetism. (Me3NH)3[Mn2C17] shows triboluminescence the emission of light under mechanical stress in both the MnC16 chain units and the discrete [MnC1412- ions.18 The reaction of KMn04 with Mn(MeC02)2.4H20 often used to prepare Mn'" acetate gives with varied conditions [Mn12012(H20)4(MeC02)16].The X-ray crystal ~tructure'~~ distinguishes the eight Mn3+ from the four Mn4' by the former's exhibiting Jahn-Teller distortions in their MnO octahedra. Another interesting mixed oxidation state complex is [Mn3(3-Clpy)30(MeC02)6],whose X-ray crystal shows two Mn3' in a different environment from the Mn2' a distinction not found in the pyridine analogue. Much work again concerns the varied biochemistry of manganese. Complexes of Mn" which react with O2 have been reviewed." EHMO calculations2' on [Mn(porphyrin)Oz] show best agreement with absorption and e.p.r. spectra when an Mn'"-peroxide (edge on) model is used with Mn 0.5A above the N4 plane 0-0 = 1.49 A and the 0'0 axis staggered to the pyrrole nitrogens.The authors believe that the complexes contain not MnIV but Mn"' with an electron lost from the porphyrin. [Mn(tpp)O] is formed22a by the reaction of iodosylbenzene with the product from the BH4- reduction of [Mn(tpp)(MeCO,)]. The hypothesis of the involvement of high oxidation state Mn-0 species in photosynthetic processes is supported by the complex's ability to transfer oxygen to Ph3P forming an MnIII species. From a similar point of.'view but with special reference to cytochrome P450 similar results were obtained22b from [Mn(tpp)X] (X = Cl Br I or N3) but the reactive complex for X = C1 was believed22' to be the MnV compound [Mn(tpp)CIO]; this oxidizes e.g. C6H12 to C6HlICI + C6Hl10H.Other workers having realized that unco-ordinated N in co-ordinated imidazole in haemoproteins is always hydrogen-bonded to another base to give an imidazolate-like electronic distribution preparedz3 porphyrin complexes containing this anion including [Mn(im)z(tpp)] the first low-spin Mn"' porphyrin complex and the polymer [Mn(im)(tpp)] in which Mn-N(im) bonds alternate as two of 2.186A followed by two of 2.280 A explained by alternating low- and high-spin Mn"'. Further information on the perennial problem of the mode of co-ordination of nucleotides is given by the I3C I5N and 31P n.m.r. spectra of the Mn2'-AMP system which suggests that binding is to a'phosphate 0 N-7 the amine N and N-1 from another AMP.24 Spectroscopic and chemical studies of a new phosphatase enzyme from sweet potato tubers suggest that this contains Mnrrl with ligands including cysteine and tyrosine fragment^.'^ l7 R.ClCment J. J. Girerd and I. Morgenstern-Badarau Inorg. Chem. 1980,19 2852. l8 J. I. Zink G. E. Hardy and G. Gliemann Znorg. Chem. 1980 19 488. l9 (a)T.Lis Actu Crysfullogr.,1980 B36,2042; (6)A.R.E. Baikie,M. B. Hursthouse L. New P. Thornton and R. G. White J. Chem. SOC.,Chem. Commun. 1980,684. 20 W. M.Coleman and L. T. Taylor Coord. Chem. Rev. 1980,32,1. L. K. Hanson and B. M. Hoffmann J. Am. Chem. SOC.,1980,102,4602. 22 (a)I. Willner J. W. Otvos and M. Calvin J. Chem.SOC., Chem. Commun. 1980,964;(6)C. L.Hill and B. C. Schmidt,J.Am. Chem.SOC.,1980,102,6374; (c) J.T.Groves W. J. Kruper andR.C.Haushalter ibid. p. 6375. 23 J. T. Landrum K.Hatano W. R. Scheidt and C. A. Reed J. Am. Chem. SOC.,1980,102,6729. 24 G. C. Levy and J. J. Dechter J. Am. Chem. SOC., 1980,102,6191. '' Y.Sugiura H. Kawabe and H. Tanaka J. Am. Chem. SOC., 1980,102,6581. The Transition Elements 195 Technetium.-As its chemistry becomes more developed it is clear that technetium has many unique features and is not merely an unstable form of rhenium. For example in M-M bonded systems Tc shows a preference for oxidation state 2.5 instead of Re's favour of 3 as shown in the formation26a of [Tc2Cls13- by the zinc reduction of [TcCl6I2- as well as [Tc2Cls12- which can be converted by HBr into [Tc2Brs12-; Bu4N salts of all these were prepared and the Raman spectrum of both chlorides curiously showed v(Tc-Tc) at 307 cm-'.[Tc2Cls13- retains the 2.5 oxida- tion state when its ammonium salt reacts with 2-hydroxypyridine to give26b [Tc2(2- Opy),CI] which has the shortest Tc-Tc bond yet found at 2.095 A and v(Tc-Tc) at 383 cm-'. Many new cyanide complexes have been including K4[Tc(CN),].2H20 whose vibrational spectra suggest a pentagonal-bipyramidal structure K3[Tc02(CN),] probably in a trans-configuration K2[TcO(CN)5]-4H20 and K2[TcO(OMe)(CN),]. The red solutions of Tc thiocyanate complexes have been reinvestigated28 and found to contain Tc"' and TcrV not TcIV and Tc" as previously believed; the X-ray crystal structure of (Bu~N),[Tc(NCS)~] was also determined. [T~(diars)~Cl~]PF~ has been crystallographically to be the first eight-co-ordinate Tc complex.As part of a study of the use of 99mTc in radiophar- macy complexes of (03PXP03)4- [X = 0,CH2 or MeC(OH)] were prepared as resembling those which might concentrate in bones; the X-ray crystal structure shows that [Li(H20)3][Tc(OH){CH2(P03)2}]~~H20 is polymeric with chelating OPCPO units and bridging OH and OPO Rhenium.-The noteworthy developments in rhenium chemistry this year all involve Re"'. The X-ray crystal structure of K4[Re(CN)7].2H20 confirms31 that the anion has the pentagonal-bipyramidal structure deduced from vibrational spectra. An EHMO analysis of d4 dimers shows why some have no bridging ligands e.g. [Re2Cls12- or [Re2ClsL2I2-(L = unidentate ligand) whereas others such as [Re2C16(dppe)2] have two bridging ligand~.~~ The electrochemical reduction of [Re2X2(RC02),] (X = halide) to its monoanion adds an electron to a S*-orbiLal but no correlation was between and the electronic spectrum.From measurements of the heat of oxidation of Cs2[Re2Br8] by Br03- the quadruple Re-Re bond strength was estimated as 408 f50 kJ mol-'; the paper critically reviews the calculations and analogies used in such estimation^.^^ '' (a)W. Preetz and G. Peters 2.Nuturforsch. Ted. B 1980,35,797; (b)F. A. Cotton P. E.Fanwick and L. D. Gage J. Am. Chem. SOC.,1980,102,1570. 27 H. S. Trop A. G. Jones and A. Davison Inorg. Chem. 1980,19 1993. 28 H. S. Trop A. Davison A. G. Jones M. A. Davis D. J. Szalda and S. J. Lippard Inorg. Chem. 1980,19 1105.29 K. A. Glaven R. Whittle J.F.Johnson R. C.Elder andE. Deutsch J.Am. Chem. SOC.,1980,102,2103. 30 K. Libson E. Deutsch and B. L. Barnett J. Am. Chem. SOC., 1980,102,2476. 31 J.-M. Manoli C. Potvin J.-M. BrCgeault and W. P. Griffith J. Chem. SOC.,Dalton Trans. 1980 192 32 S. Shaik and R. Hoffrnann J. Am. Chem. SOC.,1980,102,1195. 33 V. Srinivasan and R. A. Walton Inorg. Chem. 1980 19 1635. '* L. R. Morss R. J. Porcja J. W. Nicoletti J. San Filippo and H. D. B. Jenkins J. Am. Chem. SOC., 1980 102 1923. F. A. Hart J.Newbery and P.Thornton 3 Iron Ruthenium and Osmium Iron(rr).-The reaction of CS2 MeC(CH,PEt,), and [Fe(H20)6](BF4)2 gives35 a diamagnetic complex [Fe{MeC(CH2PEt2)3}L]2' of the new zwitterionic ligand L (2). [Fe(pc)(pyz)], prepared from P-Fe" phthalocyanine and pyrazine has high electric conductance which is increased on doping with iodine and is lo6 greater than the conductance of [Fe(p~)(pyz)~].~~ An EXAFS study of solutions of [Fe(H20)6]"+f (n = 2 or 3) shows3' that these have similar radii in solution and in crystals a useful confirmation when metal- ligand bond lengths are used to interpret electron-transfer reactions.The iodate oxidation of Fez' has a complicated different from that of oxidation by Br03- or C103- and another complex mechanism of seven steps was for the familiar oxidation of Fez' by HN03 the slowest being the formation of HN02 and NO2 from NO and NO3-. The acceleration of the oxidation of [Fe(CN)6I4- by [Co(edta)]- at increased ionic strength was attributed to the forma- tion of the (Na'.[Fe(CN)6]4-) ion pair but for I > 0.1l mol dmP3 a deceleration attributed to the triplet (2Na'*[Fe(CN),]"-) was found but this could be foiled by the removal of one Na' with 18-cr0wn-6.~~ In studies of the lifetimes and spectra of [Fe(bi~y)~]~+ and related complexes the absorption band of this ion at 325 nm was assigned4* to a transition to 3T or 'T2,not a charge-transfer state.From a consideration of activation volumes in the controversial nucleophilic attack on trisdi-imine complexes of Fe'' it was concluded41 that a positive A V can be consistent with an associative mechanism when one allows for desolvation of the nucleophile. The value of high-field n.m.r. studies is shown by the detection4 of inequivalent ortho-hydrogens in [FeL3I2+ [L = (3)]; one of these hydrogens is locked just above an FeNCCN chelate ring and the unusual electronic environment in which it is located may be related to the catalytic properties of this ligand's complexes.(3) 35 C. Bianchini A. Meli A. Orlandini and L. Sacconi Angew. Chem. In?. Ed. Engl. 1980 19 1021. 36 0.Schneider and M. Hanack Angew. Chem. Int. Ed. Engl. 1980,19 392. 37 T. K. Sham J. B. Hastings and M. L. Perlman J. Am. Chem. SOC.,1980 102 5904. 311 (a)W. C. E. Higginson andD. A. McCarthy J. Chem. SOC.,Dalton Trans. 1980,797;(b)I. R. Epstein K. Kustin and L. J. Warshaw J. Am. Chem. SOC.,1980,102 3751. 39 D. H. Huchital and J. Lepore Inorg. Chim. Acta 1980 38 131. 40 C. Creutz M. Chou T.L. Netzel M. Okumura and N. Sutin J. Am. Chem. SOC.,1980 102,1309. 41 J. Burgess A. J. Duffield and R.Sherry J. Chem. Soc. Chem. Commun. 1980 350. 42 H. tom Dieck H. Bruder K. Hellfeldt D. Leibfritz,andM. Feigel Angew. Chem. In?.Ed. Engl. 1980,19 396. The Transition Elements 197 There are more results of magnetochemical interest. The X-ray crystal structure of the iodide salt of [Fe(2-pi~oIylamine),]~+ shows4 the cation has an equal mixture of fac-and mer-isomers; the latter are all high spin but the former are -70% low spin at room temperature. [FeL2](C104)2 [L = (4)] shows identical hysteresis in its 'T2 + *Alequilibrium in Mossbauer and X-ray experiments to indicate that the electronic and crystal effects have a common The resonance Raman (rR) spectra of a-di-imine Fe" complexes having an anion which absorbs at or near the cation's electronic absorption gave vibrational bands from the chromophore having the stronger absorption; for [WS4]'- salts two isomers were found; one was a spin triplet at all temperatures and the other showed a high spin-low spin eq~ilibrium.~' N I HNPh Iron(~~~).-x-Ray crystal structures have established [FeC13(4-CNpy)2] as a rare example46" of trigonal-bipyramidal Fe'" and Fe12(S2CNC4HJ2 as really466 the square-pyramidal Fe'" complex [FeI(S2CNC4H8)2].$12.The product formulated last year as [(Fepc),O,] has been shown4' by '*Oisotopic substitution in i.r. spectroscopy to be [(Fepc),O]. A thorough study4* of the effects of added solids especially charcoal on the reduction of Fe3'(aq) and [Fe(CN)6I3- by I-suggests that electron transfer proceeds from reductant to solid to oxidant but chemical decomposition on the surface e.g.of MoS2 to MOO, will release other species which may be catalysts. The reduction of [Fe(CN)SL]2- (L = 4,4'-bipy or py) by [Co(edta)I2+ was found49 to be an outer- sphere process with bridging compounds formed but acting as 'dead-ends'. A very interesting result is the discovery that such 'insoluble' compounds as Fe203 Fe304 and NiFe204 are rapidly dissolved by solutions of one-electron reducing agents the fastest being [V(picolinate),]- which dissolves Fe203 almost as fast as the diff usion-controlled limit.50 43 B. A. Katz and C. E. Strouse Znorg. Chem. 1980 19 658. 44 E.Konig G. Ritter W. Irler and H. A. Goodwin J. Am. Chem. SOC.,1980 102 4681. 45 R. S. Czernuszewicz K. Nakamoto and D. P. Strommen Znorg. Chem. 1980,19 793. 46 (a)J.-C. Daran Y. Jeannin and L. M. Martin Znorg. Chem. 1980 19 2935; (b)D. L. Kepert C. L. Raston A. H. White and D. Petridis J. Chem. SOC., Dalton Trans. 1980 1921. 47 C. Ercolani G. Rossi and F. Monacelli Znorg. Chim. Acta 1980 44 L215. J. M. Austin,T. Groenewald and M. Spiro,J. Chem.SOC.,Dalton Trans. 1980,854;T.Groenewald J. M. Austin and M. Spiro ibid.,p. 860. 4y J. Phillips and A. Haim Znorg. Chem. 1980,19 1616. M. G. Segal and R. M. Sellers J. Chem. SOC., Chem. Commun. 1980,991. F. A. Hart J. Newbery and P. Thornton A discussions1 of anomalies in the high spin-low spin conversion of solid Fe”’ complexes suggests that nucleation and growth mechanisms should be considered as exemplified by the slower and less complete conversion of well ground samples of [Feo.5Cr0.5L2](PF6) [L = (5)].Magnetic and Mossbauer studies of 4,4’,4”,4’”-sulphophthalocyanine complexes shows2 that [H3Fe(spc)].8H20 has a low-spin and an intermediate-spin form and that alkali-metal salts such as n (6) M= Fe ref. 53 M = Co ref. 153 Cs3[Fespc]-$CsOH-2H20have two different low-spin octahedral forms but there was no evidence for p-0x0-species in solid or solution. The X-ray crystal structure of the mixed-metal complex (6) showsS3 which of the two sites each metal adopts; the complex is antiferromagnetic with a quintet-septet separation of 289 cm-‘ The magnetic properties have been described of ferrofluids microcrystals of mag- netic.material (here Fe,O,) stabilized by a polymeric carrier fluid (here aqueous lignosulphonate); the paper gives a good introduction to the field and reviews various ferromagnetic phenomena clearly.54 The reaction of aqueous DMF or DMSO with [Fe2(C0),] gives the antiferromagnetic complexes [Fe203(DMF)- (H20Mor [Fe203(DMS0)2(H20)3(CO)l.55 Mixed-valence Compound~.-Reinvestigation~~of the thermal decomposition of Fe2Fs.7H20 and Fe2F5-2H20 has revised and clarified earlier work especially showing the existence of two different ‘dihydrates’ one of which is a fluorine- deficient phase. Much work has appeared on Prussian Blue compounds. For example the existence of low-temperature ferromagnetism despite the 10.16 8 separation of Fe3’ ions is clarified” by the detection by polarized neutron diffraction of up to 5% of the spin being transferred to Fe2’ sites.Porphyrin Complexes and Haem Proteins.-General Chemistry. This section describes experiments which are not dedicated to solving problems of one particular protein. 51 M. S. Haddad W. D. Federer M. W. Lynch and D. N. Hendrickson J. Am. Chem. Soc. 1980,102 1468. 52 J. C. Fanning G. B. Park C. G. James and W. R. Heatley J. Znorg. Nucl. Chem. 1980 42 343. ” J. Jaud Y. Journaux J. Galy and 0.Kahn Now. J. Chim. 1980 4 629. 54 K. L. Hassett L. C. Stecher and D. N. Hendrickson Znorg. Chem. 1980 19 416. 55 V. I. Spitsyn M. G. Felin S. I. Pakhomov N. A. Subbotina and A.I. Zhirov Russ. J. Inorg. Chem. (Engl. Transl.) 1980 25 709. 56 D. B. Brown E. G. Walton and J. A. L’ilts J. Chem. Soc. Dalton Trans. 1980 845. ” P. Day F. Herren A. Ludi H. U. Giidel F. Hulliger and D. Givord Helu. Chim. Actu 1980.63 148. The Transition Elements 199 Recrystallization of [Fe(tpp)] from THF gives high-spin [Fe(THF),(tpp)] whose X-ray crystal structure shows the six-co-ordinate Fe to be in the tpp plane confirming that porphyrins can accommodate high-spin Fe" although Fe-N distances are 0.05 8 longer here than in the low-spin analogue^.'^ [FeCl(N-Me-tpp)] the first air-stable Fe" porphyrin has the expected square- pyramidal structure but the Fe-N(methy1ated) bond is over 0.2 A longer than the other three Fe-N Oxygenation of Fe" porphyrins in toluene at -80 "C give the intermediates [Fe2(p~r)202] before the formation of [Fe,(por),O].This intermediate's antifer- romagnetism suggests that it contains Fell1 and OZ2-.If mixed porphyrins are used some scrambling occurs and complexes such as [Fe(tpp)OFe(oep)] are formed.60 [Fe(tpp)(CN),]-has been prepared as the first solid cyano-derivative of an Fe"' porphyrin; the X-ray crystal structure of the [K(Me,CO),]' salt shows6' the FeCN unit to be linear. Two papers6 describe the 'H n.m.r. spectra of Fe"' tpp complexes and imidazole adducts where the porphyrin is modified at one meso-position sometimes to incorporate an imidazole group for co-ordination. In these complexes the pyrrole resonances were split by restricted rotation and loss of four-fold symmetry perhaps with effects on bond lengths.[Fe,(tpp),SO,] prepared from [Fe2(tpp)zO] and H2S02 has unusually sharp 'H and 13C n.m.r. spectra allowing all the I3Cresonances to be assigned; the sharpness is attributed63 to relaxation of the high-spin Fe2' through the bridging sulphate. The X-ray photoelectron spectra of [Fe,(t~p)~X] (X = N or 0) and [Fe(por)X] (por = tpp or oep; X = C104 Br Cl or N3) together with earlier physical measurements show6 that the monomers and 0x0-dimer have high-spin Fe"' but the nitrido-dimer is low spin with two equivalent Fe in oxidation state 3.5. MO calculations on FerIrdimers [{(H2N)4Fe}2X] (X = 0,N or C) as models for porphyrin complexes show6' that the bridge need not be linear for 0,that linearity is slightly favoured for N and that suc'h a compound as [Fe,(tpp),C] if ever it is made will be linear and diamagnetic; the 0x0-dimers have four energy levels within 0.5 eV accounting for the complexity of their mag- netism.Cyclic voltammetry and electronic spectra show that [Fe,(tpp)20] reacts with HBF to give not [Fe,(tpp),O](BF,) as previously believed but a mixture of F-and BF,- salts of [Fe(tpp)]' with the fluoride known to be antiferromagnetic in one of its solid phases giving the anomalous magnetism.66 Electronic spectra and kinetic evidence suggest6' that [Fe(ttp)(O)L] (ttp = meso-tetra-m-tolyl-porphyrin; L = py pip or N-Meim) containing Fe'" is the active intermediate in the oxidation of Ph3P to Ph3P0 by [Fe2L2(ttp)202]. [FeL] [L = (7)] forms 1:l complexes in solution with .n-acceptor ligands PhNC Bu3P and (EtO),P which 58 C.A. Reed T. Mashiko W. R. Scheidt K. Spartalian and G. Lang J. Am. Chem. SOC.,1980 102 2302. 59 0.P. Anderson A. B. Kopelove and D. K. Lavallee Inorg. Chem. 1980 19 2101. ''D.-H.Chin G. N. La Mar and A. L. Balch J. Am. Chem. SOC., 1980,102,4344. W. R.Scheidt K. J. Haller and K. Hatano J. Am. Chem. SOC.,1980,102,3017. 62 H. Goff J. Am. Chem. SOC., 1980,102,3252;F.A. Walker ibid. p. 3254. 63 M. A.Phillippi and H. M. Goff J. Chem. SOC., Chem. Commun. 1980,455. 64 K. M.Kadish L. A. Bottomley J. G. Brace and N. Winograd J. Am. Chern. SOC., 1980 102 4341. 65 K. Tatsumi R. Hoffmann and M.-H. Whangbo J. Chem. SOC.,Chem. Commun. 1980,509. 66 I. A. Cohen D.K. Lavallee and A. B. Kopelove Inorg. Chem. 1980 19 1098. 67 D.-H. Chin G. N. La Mar and A. L. Balch J. Am. Chem. SOC.,1980 102 5945. F. A. Hart J.Newbery and P.Thornton tPP residue are more of the few low-spin Fe" five-co-ordinate porphyrin complexes.68" The corresponding imidazole (imH) and pyridine complexes were made@' when the ligand had short chains (x = 2) but with x = 3 a second ligand could co-ordinate; here 1-Meim gives a complex in doublet spin state. Some Co*' complexes were also made.68b Huernoglobin and Myoglobin. The model of 0 binding by metals as a pairing of metal spins with .rr*-electrons on O2has been reviewed and developed.69 A lucid short review of magnetism and bonding in oxyhaemoglobin followed by MO calc~lations~~ on [Fe(im)(por)O,] indicates that the diamagnetic ground state can best be represented as Fe"-02 not Fe"'-O; but a triplet state at.129 cm-' gives some temperature-dependent susceptibility. Oxygenation of Fe and Co complexes [ML(por)] [L = imH py or their deriva- tives RNH2 or R,P; por = (7)] showed that complexes where x = 2 gave higher 0 affinities than those for x = 3 though affinities were generally low as the cap restricts the movement of the metal back into the N4 plane.71 The rR spectra of the picket-fence porphyrin complexes [FeL(tpivpp)(02)] (L = substituted imi- dazole) the Fe-0 stretching mode correlates with the O2affinity; this was attributed to the steric effects of the alkyl groups in L and confirms that different complexes in this series can be used as models for comparing myoglobin and R-and T-state haem~globin.~~ In the ethanol solvate of the 2-Meim complex a model for T-state Hb 0 binding is reversible and non-co-operative but in the absence of EtOH there is higher affinity and the uptake is co-operative; the paper73 gives a useful survey of the stereochemistry of haemoproteins model compounds and the O2 adducts of each.Fe" complexes of new 'tailed picket fence' porphyrins (8) (the metaphors are rather mixed) have been prepared74 and should allow studies of 0 or CO binding in solution without the complication of the presence of a displaced imidazole ligand but aspiring experimentalists must use glove box techniques and a laboratory illuminated by a 25 W red lamp. 68 (a) P.E. Ellis R. D. Jones and F. Basolo J. Chem. SOC.,Chem. Commun. 1980 54; (b) P.E.Ellis J. E. Linard T. Szymanski R. D. Jones J. R. Budge and F. Basolo J. Am. Chem. SOC.,1980 102 1889. 69 R. S.Drago and B. B. Corden Acc. Chem. Res. 1980,13,353. Z. S. Herman and G. H. Loew J. Am. Chem. SOC.,1980,102 1815. 70 71 J. E. Linard P. E. Ellis J. R. Budge R. D. Jones and F. Basolo J. Am. Chem. SOC.,1980,102 1896. 72 M.A.Walters T. G. Spiro K. S. Suslick and J. P. Collman J. Am. Chem. Soc. 1980 102 6857. 73 G. B. Jameson F. S. Molinaro J. A. Ibers J. P. Collman J. I. Brauman E. Rose and K. S. Suslick J. Am. Chem. SOC.,1380,102,3224. 74 J. P.Collman J. I. Brauman K. M. Doxsee T. R. Halbert E. Bunnenburg R. E. Linda G.N. La Mar J. del Gaudio G. Lang and K. Spartalian J. Am. Chem. SOC.,1980 102 4182. The Transition Elements X Y = im[(CHA or 4 or (CH&NH]CONH or MeS(CH&,CONH The X-ray crystal structure of human [HbCO] at 2.7 A resolution the FeCO unit (assumed linear) to be at -13" to the normal to the N4 plane; in the a-units Fe is in this plane but it is -0.22 8 out of the plane in @-units. In the presence of inositol hexaphosphate which converts R-state Hb into the T-state [HbNO] shows a new rR band at 592cm-' in addition to the previous band at 553 cm-'; the authors conclude that the R + T transition involves the breaking of two Fe-imidazole From studies of equilibria and rates of reaction of CN-. or N3-with Mb it was concluded unlike earlier ideas that steric effects were small and that the high equilibrium constants had an electrostatic origin; the large activation entropy for [MbCN] was attributed to a conformation change.77 In a typical example of many good n.m.r.studies in this field the 'H spectra of sperm whale met-aquo Mb which contains high-spin Fe"' with deuteriation of selected positions gave the resolution of 17 and the assignment of 12 out of 22 haem resonances. The distal valine methyls were located the rneso-and pyrrole protons were found to be sensitive to a sixth ligand and the non-Curie law behaviour of the vinyl and propionate resonances was explained by these side-chains adopting temperature-dependent orientation^.^^ Peroxidases. How valuable high-field n.m.r.spectra are! The 360 MHz 'H spectra of horseradish peroxidase (HRP) support7' earlier e.s.r. evidence that Fe'" is in the mixed sextet-quartet spin state and has a proximal histidyl fifth ligand. The 'H n.m.r. spectra of HRP-I one oxidizing equivalent above the resting enzyme was interpreted"" as containing low-spin Fe'" not high-spin as proposed earlier and this is donfirmed by MO calculationsSob on [Fe(im)(porphine)O]. HRP-I1 may be modelled by [Fe(1-Meim)(ttp)O] (ttp = rneso-tetra-rn-tolylporphyrin) which contains isolated low-spin Fe'" and is formed when 1-Meim reacts with [Fe2(ttp)202] presumably with breaking of the 0-0 bond.81 Cytuchrurnes. The X-ray crystal structures2 of [Fe(oep)(C104)] shows square- pyramidal FeIII with Fe-0 = 2.067 A and the Fe 0.26 A out of the N4 plane; the 75 J.M. Baldwin J. Mol. Biol. 1980 136 103. 76 J. D. Stong J. M. Burke P. Daly P. Wright and T. G. Spiro J. Am. Chem. SOC.,1980 102,5815. 77 M. C. Smith and G. McLendon J. Am. Chem. SOC.,1980,102,5666. 78 G. N. La Mar D. L. Budd K. M. Smith and K. C. Langry J. Am. Chem. Soc. 1980,102,1822. 79 G. N. La Mar J. S. de Ropp K. M. Smith and K. C. Langry J. Biol. Chem. 1980,255 6646. 80 (a)G. N. La Mar and J. S. de Ropp J. Am. Chem. Soc. 1980 102 395; (6) G. H. Loew and Z. S. Herman ibid. p. 6173. 81 D.-H. Chin A. L. Balch and G. N. La Mar J. Am. Chem. Soc. 1980 102 1446. 82 H. Masuda T. Taga K. Osaki H. Sugimento Z.-I. Yoshida and H. Ogoshi Inorg. Chem. 1980.19. 950. 202 F. A. Hart J.Newbery and P. Thornton magnetic moment was interpreted as showing a pure quartet spin state despite a 13% fall from 275 to 77 K. An interesting feature in this structure is dimerization through a meso-C on one molecule with an a-C on a pyrrole ring in the next.82 Various [Fe(por)(CIO,)] complexes show 'H and 13C n.m.r. spectra indicating a quartet spin state in CDCI3 unlike the sextet state in toluene but with some sextet mixed in quantum-mechanically rather than by thermal equilibrium with the temperature dependence of spin state attributable to variable population of Kramer's doublets so that these complexes resemble cytochrome c' which may also have a quantum-mechanical spin ENDOR spectra of cytochrome P450 in the low-spin (resting) and high-spin (with complexed substrate) forms that Fe"' is co-ordinated by cysteinyl S but not histidine N in each case.[Fe(tpp)(SPh)(HSPh)] a model for cyt P450 appears from Mossbauer and e.p.r. spectra and magnetic studies to have two different Fe atoms both high spin at 300 K but having some lower spin state at lower temperatures perhaps with exchange effects. KO2 solubilized by dicyclo- hexyl- 18-crown-6 reacts with [Fe(tpp)] or [Fe(oep)] to give O2complexes which i.r. Raman and e.p.r. spectra indicate contain high-spin Fe'" and 022-, and so may be analogues of cytochromes which have one more electron than oxyglobins.86 The chemistry of cytochrome c oxidase has been reviewed.87 The reduction of this enzyme by [Ru(NH3)J2+ shows a fast phase in which an electron transfers to haem a and a slow second phase wherein it transfers to haem a3,but it was concludeds8 that this second phase was intermolecular unlike conclusions from earlier reductions by [Cr(H20)6]2'.The first application of combined rR and surface enhanced Raman spectroscopy (SERS) to biological systems allowed a study of cyt c on Ag electrodes when it was detected89 in its low-spin Fe" and Fe"' forms. Experiments of this type combining vibrational spectroscopy with electrochemical analysis could be useful in many areas of inorganic chemistry. The rate of reduction of cyt c by [Ru(NH3)J2+ varies with pH suggesting" that the low-spin form found in the solid with histidine N and methionine S both co-ordinated reacts faster than the intermediate-spin form (hist replaced by H20),which reacts faster than the high-spin form (hist and met both replaced by H20).In further developments in the chemistry of complexes of the type [Fe(por)XCu]"' containing a picket fence porphyrin ending in four py groups which co-ordinate Cu complexes where X is C1 or Br show Mossbauer spectra for Fe in a sextet-quartet spin equilibrium with almost no coupling with Cu but when X is CN both metals are uncoupled spin doublets and the authors stress the necessity for proper orientation of the Cu orbitals before exchange can occur as it does in 83 H. Goff and E. Shimomura J. Am. Chem. Soc. 1980,102,31. 84 R. Lo Brutto C. P. Scholes G. C. Wagner I. C. Gunsalus and P. G. Debrunner J. Am. Chem. Soc. 1980,102,1167. S. W. McCann F.V. Wells H. H. Wickman T. N. Sorrel] and J. P. Collman Inorg. Chem. 1980 19,621. 86 E. McCandlish A. R. Miksztal M. Nappa A. Q. Springer and J. S. Valentine J. Am. Chem. Soc. 1980,102,4268. 87 B. G. Malmstrom Biochim. Biophys. Acta 1979 549 281. R. A. Scott and H. B. Gray J. Am. Chem. Soc. 1980,102,3219. 89 T. M. Cotton S. G. Schultz and R. P. Van Duyne J Am. Chem. SOC. 1980,102,7960. 90 A. Adegite and M. I. Okpanachi J. Am. Chem. Soc. 1980 102 2832. The Transition Elements cyt c ~xidase.~'~ The X-ray crystal structure for the chloride complex shows long metal-C1 distances averaging 2.47 A showing only weak bonding; the magnetic moment varies with temperature in a complex fashion and the e.p.r. spectrum reveals the sextet state of Fe and the doublet state of CU.~'~ Other Haem Proteins.1.r. spectra suggest that quinone reacts with [Fe(tpp)] to form [Fe,(t~p)~X], where X is the hydroquinone dianion and the complex contains high-spin Fe'" antiferromagnetically coupled; the authors allege an analogy with the role of quinones in biological electron transport chains.92 Ferl and FeIrr complexes of dimethyloctaethylisobacteriochlorin(9)with two axial ligands (py CO 1-Meim) were prepared as models for sirohaem enzymes sulphite reductase and nitrite reductase; their electrochemical properties suggest that it is easier to remove an electron from the ring system than from Fe.93 H Me Et Et Et Et (9) Iron-Sulphur Proteins and Model Complexes.-Ferredoxins and Related Proteins. The most exciting development this year has been the discovery of a ferredoxin containing an Fe3S3 MO~sbauer~~~ first showed that and e.s.r.~pectra~~~'~ a ferredoxin from Azotobacter vinelandii contained a high-potential Fe4S4 protein and a low-potential protein containing three high-spin Fe'" atoms each co-ordinated by four S despite misleading core extrusion experiments which now imply that two Fe3S3 cores give three Fe2S2 cores on extrusion. The authors comment94u that earlier work on a ferredoxin from aconitase might also suggest a trinuclear core. The X-ray crystal structure at 2.5 A resolution confirms the spectroscopic results and shows that one of the three FeS4 tetrahedra is more distorted than the others. If this is more tightly held to the protein the extrusion of Fe2S2 units would be e~plained.~~' The Mossbauer and e.p.r.spectra of a ferredoxin from Desulfovibrio gigas that mediates electron transfer between cyt c3 and sulphite reductase shows that this is a tetramer of the Fe3S3 91 (a) K. J. Berry P. E. Clark M. J. Gunter and K. S. Murray Nouu. J. Chim. 1980,4,581;(b) M. J. Gunter L. N. Mander G. M. McLaughlin K. S. Murray K. J. Berry P. E. Clark and D. A. Buckingham J. Am. Chem. SOC.,1980,102,1470. 92 S. L. Kessel and D. NIHendrickson Inorg. Chem. 1980 19 1883. 93 C. K. Chang and J. Fajer J. Am. Chem. SOC.,1980,102,848. 94 (a)M. H. Emptage T. A. Kent B. H. Huynh J. Rawlings W. H. Orme-Johnson and E. Munck J. Biol. Chem. 1980,255 1793;(6) T.A.Kent B. H. Huynh and E. Munck Proc. Nud. Acad.Sci. USA 1980,77 6574;(c) C.D.Stout D. Ghosh V. Pattabhi and A. H. Robbins J. Biol. Chem. 1980 255 1797; (d) B. H. Huynh J.-J. G. Moura I. Moura T. A. Kent J. Le Gall A. V. Xavier and E. Miinck ibid. p. 3242. 204 F. A. Hart J. Newbery and P. Thornton The non-haem iron protein desulforedoxin also isolated from D. gigas appears to have two monomeric FeS units but different e.p.r. results from rubredoxin show that the FeS4 unit in the oxidized form has a different distortion from tetrahedral ge~metry.~' The complexes [Fe2s2{o-C6H4(CH2s)}2]2 and [Fe2S2(SC6H,R),]2- (R = H or Me) can be conveniently prepared by the reaction of FeCl, S and the Na thiolate. [Fe2Se2(SR),I2- was synthesized by this method and has similar 'H n.m.r. and electronic spectra and redox properties to its S analogue^.^^ FeC12-2H20 reacts with NaSPh in MeOH to give [Fe4(SPh),,12-; the X-ray crystal structure of the (Me,N) salt shows a (PhSFe)4 tetrahedron with an SPh group on each edge.The complex reacts with S to form [Fe4S4(SPh),I2- and PhSSPh and it is suggested that the anion may be an intermediate in the syn- thesis of this An 'H n.m.r. study of the redox equilibria of [Fe4X4(SR),]"- (X = S R = CH,Ph or p-C6H4Me; X = Se R = CH,Ph; n = 2 or 3) found rates ca. lo4 greater than for Fe4 ferredoxins or HP proteins the differences being attributed to the steric influence of the protein str~cture.~ A mixture of (Bu,N)~[F~~S~C~~] and PhLi catalyses the hydrogenation of stilbenes but (Bu,N),[F~~S,(SP~)~] is inactive.99 A kinetic study of the oxidation of the reduced form of an Fe ferredoxin in a manner previously applied to Fezand Fe4ferredoxins shows that the two Fe units react independently that [Pt(NH3)J4+ [CO(NH&]~+ and [C~(en)~]~+ associate first but then show outer-sphere electron transfer but that other oxidants react too quickly for a mechanism to be proposed.100 Molybdenum and Tungsten Complexes.This has been a very active area this year. The electronic structures of even simple complexes are curious. Thus MoS42- and [Fe(S2COEt),]- react lola to give [Fe(MoS,),]- with tetrahedral Fel*' in quartet spin state; the Et,N salt is isomorphous with the salt described last year as containing [Fe4M04S20]6-. On the other hand (Et,N),MoS4 and [Fe{S,CN(CH,),},] reactl0lb in CH2C12 to give (Et,N),[Fe(MoS,>,] also with quartet spin state so that Mo has been reduced here but in [X,Fe(MoS,)]'- (X = Ph p-C6H4Me or Cl) with planar FeS2Mo units n.m.r.magnetism and Mossbauer studies suggestl0lc Fe'" with some electron density transferred to MeV' but there appears to be less electron transfer to W in [C1,Fe(WS4)I2-' whose (Ph,P)(PhCH,NMe,) salt is isostructural with its Mo The reaction of (Ph4P)2[(PhS)2Fe(MS,)] (M = Mo or W) with (C7H7S),S in DMF gives (Ph4P)2[(Ss)Fe(MS4)]-~DMF, with bidentate MS and an FeSS chair ring but the authors were unable to distinguish Fe"'-MV bonding from Fe"-MV'; the similarity of the electronic spectrum to that of the Fe-Mo protein from Clostridiurn pasteurianum nitrogenase together with the isolation therefrom 95 I.Moura B. H. Huynh R. P. Hausinger J. Le Gall A. V. Xavier and E. Miinck J. Biol. Chem. 1980,255,2493. 96 J. G. Reynolds and R. H. Holm Inorg. Chem. 1980 19 3257. 97 K. S. Hagen J. M. Berg and R. H. Holm Inorg. Chim. Acta 1980 45 L17. 98 J. G. Reynolds C. L. Coyle and R. H. Holm J. Am. Chem. Soc. 1980 102,4350. 99 H. InoucandM. Suzuki J. Chem. Soc. Chem. Commun. 1980,817. loo F. A. Armstrong R. A. Hendersen and A. G. Sykes J. Am. Chem. Soc. 1980,102 6545. lo' (a)D. Coucouvanis E. D. Simhon and N. C. Baenziger J. Am. Chem. Soc. 1980 102 6644; (b) J. W. McDonald G. D. Friesen and W. E. Newton Inorg. Chim. Acta 1980 46 L79; (c) R. H. Tieckelmann H. C. Silvis T. A. Kent B. H. Huynh J. V. Waszczak B.-K. Teo and B. A. Averill J.Am. Chem.Soc. 1980,102,5550;(d)A.Muller R. Jostes H. G.Tolle A. Trautwein and E. Bill Inorg. Chim. Acta 1980,46 L121. The Transition Elements 205 of a fraction with a similar electronic spectrum to MoS42- suggests that MoSd2- is present in this protein.'"* (Ph4P)2[(C12Fe)2(MoS4)] has two FeS2Mo bridges (lo) and it is possible to distinguish different modes of co-ordination of MoS42- by rR spectra. lo3" The tetrahedral co-ordination of each metal ion was established crystallographically. 103h There is a subtle variation for [(PhS)2Fe2MoS6] prepared from [Fe2S2(SPh)4]2- and MoS~~-, as spectroscopic and magnetic data suggest a linear structure with a terminal MoS~~-ligand (ll),with an overall spin of arising from the interaction of the spins of the sextet outer Fe and the quintet inner Fe.losc PhS S \ ,s / \ A Fe Mo PhS There has been valuable consolidation in the chemistry of nitrogenase model complexes such as [{(RS)3Fe,S4M}2(p-SR)3] (M = Mo or W R = alkyl or aryl).High-field 'H n.m.r. can distinguish bridging from terminal RS groups the former having both contact and dipolar shifts but the latter only contact shifts.'04" New complexes of this type include [(C1,Fe3S4Mo)2(SR),]3~~ (R = Et or Ph)lo4= and [{(RS),Fe3S4Mo}2(SR)3] (R = C2H40H or CH2Ph) whose terminal SR groups react with PhCOX (X = C1 or Br) to form [(X3Fe3S4Mo)2(SR)3]" retaining the bridging SR In electrochemical studies of many complexes reversibility of the many reduction steps was given only for R = Et.lo4' In similar work directed to understanding hydrogenase [{(PhS)3Fe3S4Mo}2(SPh)3]3-was reduced to the (5-) anion electrochemically or with NaC,,H,; Mossbauer spectra show the presence of Fe" and the complex gives spontaneous quantitative evolution of H2 when mixed with a large excess of PhSH in DMA.'"4d In further studies of complexes containing two bridging SR groups and one bridging S atom anions ranging from (3-) to (5-) were found but when the bridging unit is Fe(SR)6 a range from (3-) to (6-) was seen with the first reduction step occurring on the bridging Fe.'05" X-Ray crystal structures of many complexes were reportedloSb including (3-) and (4-) ions with bridging Fe(SR)6 which has trigonal-prismatic co-ordination of Fe; for this Fe atom the Fe-S bond lengths in the (3-) ion average 2.309 A probably with low-spin Fe"' but in the (4-)ion the average is 2.52 A probably with high-spin Fe".I02 D. Coucouvanis N. C. Baenziger E. D. Simhon P. Stremple D. Swenson A. Kostikas A. Simopoulos V. Petrouleas and V. Papaefthymiou. J. Am. Chem. SOC.,1980 102 1730. 103 (a)A. Miiller S. Sarkar A.-M. Dommrose and R. Filgueira Z. Naturforsch. TeilB 1980 35 1592; (6) D. Coucouvanis N. C. Baenziger E. D. Simhon P. Stremple D. Swenson A. Simopoulos A. Kostikas V. Petrouleas and V. Papaefthymiou J. Am. Chem. Soc. 1980 102 1732; (c) R. H. Tieckelmann and B. A. Averill Inorg. Chim. Acta 1980 46 L35. 104 (a) G. Christou and C. D. Garner J. Chem. Soc. Dalton Truns. 1980 2354; (b)G. Christou and C. D.Garner J. Chem. Soc. Chem. Commun. 1980 613; (c) G. Christou C. D. Garner R. M. Miller C. E. Johnson and J. D. Rush J. Chem. SOC.,Dalton Trans. 1980 2363; (d) G. Christou R. V. Hageman and R. H. Holm J. Am. Chem. Soc. 1980,102,7600. 105 (a) T. E. Wolff P. P. Power R. B. Frankel and R. H. Holm J. Am. Chem. Soc. 1980 102 4694; T. E. Wolff J. M. Berg P. P. Power K. 0.Hodgson and R. H. Holm Inorg. Chem. 1980 19 430. F. A. Hart J. Newbery and P. Thornton Other Iron Proteins.-The X-ray structure of ferrichrome shows that this siderophore has a similar structure (12) to ferrichrome A though with some different organic groups and the same A-cis absolute configuration as the CrlI1 complex of desferriferrichrome."" The 27Al nucleus has been used to study Fe environments in hydroxamate siderophores as its spin of $ gives informative quadrupole broad- ening.The electronic spectra of the Fe'" haemerythrin derivatives with N3 or OH show the presence of two different sites attributed to the presence of two or three histidine ligands; deoxyhaemerythrin shows an octahedral FelI1 spectrum but the half-reduced protein shows stronger than usual absorption here probably because of electron delocalization in the Fe"."' excited state."* Magnetic susceptibility electronic spectra and reconstitution experiments suggestlog that ribonucleotide reductase from E. coli contains an Fe"'-O-Fe"' unit like haemerythrin. An e.s.r. study of Fe complexes of bleomycin and its derivatives and of 0 and NO adducts has been reported; the author cites interesting earlier work which has appeared in biochemical and pharmaceutical journals,lloa and describes analogous Co com- plexes .'lob Ruthenium.-The X-ray crystal structures of [{(Me3P)3HR~}2(p-H)] and [{(M~,P),Ru},(~-H)~] have been reported"' together with the preparation and n.m.r.spectra of these and other H and OH complexes. [(Ph3P)4R~H2] reacts with Cl(SiPh,),CI in benzene containing Et,N to give [(Ph3P),RuHC1I2 but under different conditions [(Ph3P)4R~H3]+ is believed to be formed in so1ution.l12 Many Ru complexes of 3-sulphophenyldiphenylphosphine have been prepared some of which catalyse hydrogenations of C=O or C=C.'113a The reaction of [RuC12(PPh3),] with various oximes produces many new complexes nearly all D.van der Helm J. R. Baker D. L. Eng-Wilmot M. B. Hossain and R. A. Loghry J. Am. Chem. SOC.,1980 102 4224. lo7 M. Llinas and A. de Marco J. Am. Chem. SOC., 1980,102,2226. log J. S.Loehr T. M. Loehr A. G. Mauk and H. B. Gray J. Am. Chem. SOC., 1980,102,6992. '09 L. Peterson A. Graslund A. Ehrenberg B.-M. Sjoberg and P. Reichard J. Biol. Chem. 1980,255 6706. 'lo Y. Sugiura J. Am. Chem. SOC.,1980,102,(a)5208,(b)5216. R. A. Jones G. Wilkinson I. J. Colquohoun W. McFarlane A. M. R. Galas and M. B. Hursthouse J. Chem. SOC., Dalton Trans. 1980 2480. J. M.Towarnicky and E. P. Schram Inorg. Chim. Acta 1980 42 33. (a) Z.Tbth F. Job,and M. T. Beck Znorg. Chim. Acta 1980 42 153;(6) A. R.Middleton J. R. Thornback and G.Wilkinson J. Chem. SOC.,Dalton Trans. 1980 174. The Transition Elements 207 having N-co-ordination of oxime but [Ru(M~,CNO)~(PP~~)~] has both oximes bidentate; the NH20- anion appears to be bidentate in [RuCl(NH,OH)(NH,O)- (PPh3)2].113b During studies of the anion of 2-hydroxy-6-methylpyridine (mhp) [R~(PPh,),(rnhp)~] was found"4a to have mhp chelating a single metal atom for the first time. [Ru2(mhp),].CH2Cl2 contains an Ru-Ru bond of length 2.238-k probably a double bond.114b The compound thought to be [R~(py)~Cl,] is really (pyH),[Ru3C19] the anion presumably being isostructural with [Re3Cl,] with Ru=Ru bonding; other salts of this anion were prepared some apparently being [RU,C~~,,]~-salts but containing free Cl-.115n The authors also propose that earlier formulations of [Ru,C~,,]~- are better considered as [(C12Ru)2(p-C1)2]2- also with an Ru=Ru double bond."5a Addition of Et4NC1 to the 'ruthenium blue' solution given by [Ru~(M~CO~)~C~] in 12M-HCl followed by evaporation gave green (Et4N)2(H703)2[R~3Cl12], a linear trimer (X-ray) with presumably two Ru"' out-side an Ru" with three RuC16 units sharing faces; the insignificant difference in the Ru-Cl(bridge) distances was attributed to the different electronic population of t2gorbitals having no effect on bond lengths.'15' Ammines.Kinetic studies suggest that [(NH,),Ru(NH,CH~CO,E~)]~+ is much more readily hydrolysed to the glycinate and H20 complexes than its Co analogue because it first rearranges116a to its linkage isomer [(NH3)5RuOc(OEt)CH2NH2]3+ and that reductions by [Ru(NH,)~]~+ of Pt'" halide complexes are outer-sphere processes despite the potential formation of halide-bridged intermediates.116b The H202 oxidation of various [RU(NH,)~L]~+ is believed'I7 to involve the ion's interaction with at least one H20 and the addition of H202 as a seventh ligand before electron transfer; catalysis by [H,O]+ is attributed to Fe'" impurities which allow a fast inner-sphere mechanism.The reduction of S2062-salts of [(NH3)5 ,,,Ru(py) or ,I3+ or [(NH3)4Ru(bipy)]3' by H2S deposits S and the Ru'I complexes so formed can then be oxidized to Ru" by 02,which forms H2C2; the reactions may be useful in handling H2S from industrial gas outlets.' The preparation of [{(NH3)5R~}20]X (X = PF6 Br or C1 n = 4 or 5) and the ND analogues is reported;"' electronic and X-ray p.e.spectra and magnetic data indicate that the two Ru are strongly coupled to give a mixed-valence Ru~~~,~~ = 5. species when n The rR spectra of 'ruthenium red' [RU~O~(NH,)~~]~+, 'ruthenium brown' [RU~O~(NH,)~~]~+, and analogues with four NH per Ru replaced by two en were used to assign120n vibrational and electronic transitions. The structure (13) of the S2032-salt of the red cation has been established crystallographically,120band the 'I4 (a)W. Clegg M. Berry and C. D. Garner Acta Crystallogr. 1980 B36 3110; (b)W. Clegg ibid. p. 3112. 'I5 (a)R. I. Crisp and K. R. Seddon Znorg. Chim. Ada 1980 44 L133; (6) A. Bino and F. A. Cotton J. Am. Chem.Soc. 1980 102,608. (a) A. Yeh and H. Taube J. Am. Chem. SOC.,1980 102 4725; (6) C. S. Glennon T. D. Hand and A. G. Sykes J. Chem. SOC.,Dalton Trans. 1980 19. ''' F. J. Kristine C. R. Johnson S. O'Donnell and R. E. Shepherd Znorg. Chem. 1980 19 2280. S. E. Diamond B. S. Tovrog and F. Mares J. Am. Chem. SOC. 1980 102 5908. '19 J. A. Baumann and T. J. Meyer Znorg. Chem. 1980 19 345. 12" (a)J. R. Campbell R. J. H. Clark W. P. Griffith and J. P. Hall J. Chem. SOC.,Dullon Trans. 1980 2228; (b) M. A. A. F. de C. T. Carrondo W. P. Griffith J. P. Hall and A. C. Skapski Biochim. Biophys. Acta 1980,627 332; (c) J. P. Hall and W. P. Grifith J. Chem. SOC. Dalton Trans. 1980 24 10. F. A. Hart J. Newbery and P. Thornton new complex [Ru~N~(NH~)~(OH)(H~O)~]C~~ is believed'20' to have an analogous structure featuring an Ru-N-Ru-N-Ru unit.Pyridine and Bipyridyl Complexes. The line-broadening of the 'H n.m.r. spectra of mixtures of [R~~(py)~O(MeC0~)~1 and its monocation was used to determine the kinetics of electron exchange an unusual experiment for polynuclear complexes. 12' The single-crystal electronic spectrum of [R~(bipy)~]'+ at studied in [Zn(bi~y)~]~+ 8 K revealed'22 spin-forbidden components to charge-transfer bands but matrix distortions lower the symmetry below D3.The nitro-complexes [R~(bipy)~L(NO,)l+ (L = various unidentate ligands) are readily oxidized electrochemically giving 1 1 mixtures of NO and NO3 complexes possibly after isomerization to the nitrito- isomers which then gain an 0 atom from a neighbouring nitro-c~mplex.'~~ [R~(bipy)~(py)(NO)]~+ with ROH when base is added giving alkyl nitrite complexes [R~(bipy),(py)(NO,R)]~+ (R = Me Et Pr' or Bu'); the alkyl nitrite co-ordinates through N and appears to be a good .rr-acceptor.The new mixed- valence cation [{(bipy)2C1Ru}2(Ph2PCH2PPh2)]3+, prepared by electrochemical oxi- dation of the new dication shows an intervalence transition which must arise from an outer-sphere process so that the ion is a useful model for outer-sphere electron- transfer rea~ti0ns.I~~ [Ru(terpy)(bipy)0I2+ can be generated electrochemically from [Ru(terpy)(bipy)(H2O>12' and the couple can be used for various catalytic oxidations,126 such as EtOH to MeC02-. The good synthetic intermediate [Ru(terpy)Cl,] can be converted into cis-and trans-[Ru(terpy)LC12] (L = R3P or py) but only the cis-isomer adds another Ph3P and the isomers also differ in electronic and n.m.r.spectra and in redox ~otentia1s.l~~ Photochemistry. The prospect of harnessing solar energy through the photochemistry of [Ru(bipy),l2+ and similar compounds has caused a rapid expansion of synthetic and kinetic studies in this area often with considerable experimental ingenuity which may benefit other topics. The field has been reviewed128 by one of its originators. A cell has been described129 which produces H2 and O2from the photochemical oxidation of [Ru(bipy),I2+ with S2082-using a Pt cathode and Ru02 anode and no other chemical species. The photoreduction of [(NH3)5Co(RC02)]2' by [R~(bipy)~]~+= p-or o-02NC6H4 or Ph) had quantum yields of 0.011 0.051 (R ''I J.L. Walsh J. A. Baumann and T. J. Meyer Inorg. Chem. 1980 19 2145. F. Felix J. Ferguson H. U. Gudel and A. Ludi J. Am. Chem. Soc. 1980 102 4096. F. R. Keene D. J. Salmon J. L. Walsh H. D. Abruiia and T. J. Meyer Inorg. Chem. 1980,19 1896. J. L. Walsh R. M. Bullock and T. J. Meyer Inorg. Chem. 1980 19 865. B. P. Sullivan and T. J. Meyer Inorg. Chem. 1980 19 752. B. A. Moyer M. S. Thompson and T. J. Meyer J. Am. Chem. Soc. 1980,102,2310. n7 B. P. Sullivan J. M. Calvert andT. J. Meyer Inorg. Chem. 1980 19 1404. D. G. Whitten Acc. Chem. Res. 1980 13 83. ''' M.-N. Spallart K. Kayanasundaram C. Gratzel and M. Gratzel Helu. Chim. Actu 1980 63 11 11. The Transition Elements 209 and 0.45 respectively indicating that the electron is transferred to Co for the benzoate but to the ligand for the nitrobenzoate~.~~~ To avoid electron-transfer back reactions which prevent build-up of [R~(bipy)~]' from reduced [R~(bipy)~]'+* Et2NCSz- and other dianions were added to give irreversible oxidation to disul- phides; this was not completely successful but addition of anthraquinone or dinitrobenzene as well gave their anions whose spectra could then be st~died.'~' The yield of Hz and O2from the [Ru(bipy)3]2'-methylviologen-Pt-Ru02 system was improved by co-depositing Pt and Ru02 on colloidal RuO2.I3* The use of complex (14) in which a polymeric ligand gives a heterogeneous system may helpfully inhibit wasteful back-reaction~.'~~" Linking a Pt electrode to the Ru complex through the R group in [(4-RNHCopy)R~(bipy)~NO~]"+= 1 or 2) (n may reduce the amount of catalyst needed and give good separation of products and electrode-controlled rates.'33b (CHCH,) .(CHCH,) (CHCH,) * (CHCH,) *oO4 *047 -683 3 0-266 6 / / / Br NN NN \/ Ru (biPY) r\ (14) N N = bipy The quenching of excited [R~(bipy)~L]~' = (15)] by methylviologen is faster [L in anionic micelles (e.g. sodium dodecyl sulphate) than in water but slower in cationic micelles (e.g. hexadecyltrimethylammonium but the mechan- ism of quenching by methylviologen is still The photochemistry of [R~(bipy)~L~]~+ (L = MeCN py or its derivatives) in low-polarity solvents gives efficient syntheses of [Ru(bipy)LX]+ or [R~(bipy)~X~] (X = C104 NO3 NCS NOz Br CF3C02 or 4-MeC,H4S03); the authors discuss solvent effects and ion-pairing on the photochemistry of Rurl bipyridyl com- p1e~es.l~~" gave remarkable results The photochemistry of ~is-[Ru(bipy)~(OH~)~]~+ 130 W.Bottcher and A. Haim J. Am. Chem. SOC.,1980,102 1564. 131 A.Deronzier and T. J. Meyer Znorg. Chem. 1980 19,2912. 132 J. Kiwi E.Borgarello E. Pelizzetti M. Visca and M. Gratzel Angew. Chem. Znt. Ed. Engl. 1980 19 646. 133 (a) M.Kaneko A. Yamada and Y. Kurimura Znorg. Chim. Acta 1980,45,L73;(b)H.D. Abruiia J. L.Walsh T.J. Meyer and R. W. Murray J. Am. Chem. Soc. 1980,102 3272. 134 (a)R.H.Schmehl and D. G. Whitten J. Am. Chem. SOC.,1980 102 1938; (b)G.L.Gaines Znorg.Chem. 1980,19,1710. I35 (a) B. Durham J. L. Walsh C. L. Carter and T. J. Meyer Inorg. Chem. 1980 19 860; (b)B. Durham S. R. Wilson D. J. Hodgson and T. J. Meyer J. Am. Chem. SOC., 1980,102 600. F. A. Hart J. Newbery and P. Thornfon including cis-trans photoisomerization and oxidation by C104-to trans-[R~(bipy)~(0H~)(OH)](C10,),, which is the first crystallographically established octahedral complex containing two trans-bipyridyl ligand~.',~' [RuL3I2+ [L = bipyrazyl (16)] though attacked by water is a more efficient photosensitizer than [Ru(bipy),lZc for the production of methylviologen monocation in ethanolic sol- utions also containing (HOC2H4),N; the authors conclude that [RuL312+* is quenched by triethanolamine and the resulting [RuL,]' is oxidized by methyl- viologen dication whereas [Ru(bipy),12+* cation is first oxidized by methylviologen and the RU"' cation is then reduced by triethan~lamine.'~~ The use of [Ru(bipy),12' in aspects of the chemistry of Rh and Ag is described in refs.180 and 288. Osmium.-New convenient syntheses of Ph3As complexes include'37 the reaction of Na2OsC1,.6H20 with Ph3As and NaBH4 in EtOH to give [OsH,(AsPh,),]. OsC15 is conveniently prepared138 from Oso and SC12; it reacts with Ph4AsC1 in C2F3C13 to form (Ph,+AS)[OSCl6] which is reduced by the solvent to (Ph4As),[OsC1,]. The preparation of nine isomers of [OS(NCS)~]~- is described,139 using ion-exchange chromatography to separate isomers and vibrational spectra to characterize each one.The electronic spectrum of [O~(bipy)~]~+ is similar14oa to that of its Ru analogue,122 but the higher spin-orbit coupling of the 0s complex gives stronger spin-forbidden bands. The use of this cation in photochemical work has been limited by the short excited-state lifetime but this can be increased by replacing one bipy ligand by other r-acceptors as in [O~(bipy),(MeCN),]~' or [o~(phen)~(Ph~PCH~PPh~)]~+; the phen complexes are comparable or better emit- ters than [R~(bipy),]~+.'~~' The triple bond deduced141 to be present in [O~~C1,(2-oxopyridine)~] is the first multiple 0s-0s bond recorded; unlike the Re analogue the NOsN angle is 180° not 90".[OS~N~(NH~)~(OH~)~]C~~ is analogous to similar Ru complexes. l2OC Reaction of [Os(S,CNR),] with S gives more complexes (17) and (18) of the S3CNR- ion Me?N MezN R.J. Crutchley and A. B. P. Lever J. Am. Chem. SOC.,1980 102 7128. 13' A. D. Harris and S. D. Robinson Znorg. Chim. Acta 1980 42 25. K. Dehnicke and R. Lossburg Z. Naturforsch. Teil B 1980,35 1525. 139 G. Peters and W. Preetz Z. Naturforsch. Teil B 1980 35 994. (a)S. Decurtins F. Felix J. Ferguson H. U. Giidel and A. Ludi J. Am. Chem. Soc. 1980 102 4102; (6)E. M. Kober B. P. Sullivan W. J. Dressick J. V. Caspar and T. J. Meyer J. Am. Chem. SOC.,1980 102 7383. F. A. Cotton and L. J. Thompson Inorg. Chim. Acta 1980 44 L247; J. Am. Chem. SOC. 1980 102 6437. The Transition Elements one also having Ss as a bidentate ligand;14'" both complexes are diamagnetic with 0s-0s bonds of 2.79 A much longer than the 2.35 A bond in the oxopyridine dimer.14' Further interesting dithiocarbamate chemistry is found in the monomer- dimer equilibrium in CHzC12 of [OS(E~,NCS~)~](PF~) where the dimer contains pentagonal-bipyramidal 0s (19) and in the preparation of diamagnetic [Os(Et,NCS,),(MeCN)]' and [OSC~(E~~NCS,)~].~~~~ 4 Cobalt Rhodium and Iridium Cobalt(Ir).-Co(CN) has been prepared143 and shown to be different from CO~[CO(CN)~], and to contain both high- and low-spin Co"; other new cyanide complexes prepared include (NH4)6[Co2(CN)10] KCo(CN), and K,Co(CN),.E.p.r. and i.r. spectra suggest that the halide complexes [CoL3X,] (L = Me,P Me2PPh or MePPh, X = F C1 or Br) have trigonal-bipyramidal geometry but the CN or SCN analogues have square-pyramidal geometry with S-bonded SCN and a trans configuration with an apical phosphine; the F CN and SCN complexes react with air when cooled possibly giving loss of phosphine and unidentate co-ordination of 02.144 fully deuteriated was The pyrazolyborate complex [CO{P~B(~Z),}~] to illustrate the determination of principal susceptibilities in paramagnetic com- plexes by high-field 'H n.m.r.[CO(~-NH~C~H~NH~),]](C~O~)~,salts catalyses the autoxidation like many Co" of 2-NH2C6H4NHz; two intermediates were found one a high-spin Co" complex and the other (low-spin) shown by its X-ray crystal structure to be a square- pyramidal complex (20) with a radical ligand. 146a [Co(dmg),py] and [Co(dmg),(Ph,P),] catalyse the oxidation of Ph3P hydroquinone and hydrazoben- zene probably uia the superoxide complex [Co(dmg),O,].146b The X-ray crystal structure of [Co2L5(NCS),].-2.7 H20 shows that each Co is co-ordinated by two NCS and one unidentate phenyltriazole [L (21)] and three triazoles bridge the two (20) (21) 14* (a)L.J. Maheu and L. H. Pignolet J. Am. Chem. SOC.,1980 102 6346;(b)S.H. Wheeler and L. H. Pignolet Inorg. Chem. 1980,19,972. 143 D. M. S. Mosha and D. Nicholls Inorg. Chim. Actu 1980,38,127. 144 R.S.Drago J. R. Stahlbusch D. J. Kitko and J. Breese J. Am. Chem. SOC., 1980 102 1884. P. J. Domaille J. Am. Chem. Soc. 1980,102,5392. 146 (a) M. Zehnder and H. Loliger Helv. Chim. Actu 1980,63,754;(6)S. Nemtth Z. SzeverCnyi and L.I. Simlndi Inorg. Chim. Acta 1980,44,L107.F. A. Hart J. Newbery and P. Thornton Co New dinuclear complexes containing bridging S atoms are [(triph~s),Co,(p-SMe)~]*+, which is antiferromagnetic and [(triph~s),Co~(p-S)~]~+ (n = 0 diamagnetic; n = 1 unpaired electron); all three have planar Co2S2 rings and Co-Co distances longer than 3.4 MacrocyclicComplexes.-There have been many new macrocyclic ligands this year. The CoCl2 complex (22) has five-co-ordinate Co and is a rare example148 of an ether 0 co-ordinating Co though the Co-0 bond is long (2.319A). To study Co analogues of haem proteins Co(PFJ2 and CO(NCS)~X (X = NCS NCO or N3) complexes were prepared of the 'dry cave' ligand (23). The (CH,) chain creates Me (23) a cavity 4.8-5.6 8 high and 6.65 8 wide in the Co'' complex but for Cot" the cavity is bigger and one NCS remains co-ordinated though becoming bent.149n Spectroscopic and equilibrium show that the Co" complex and others with similar ligands form 1 :1adducts with O2that are stable at room temperature approach Co myoglobin in stability and do not form peroxo-bridged dimers; the authors comment on the role of groups distant from metals in haem species in controlling O2affinity.The Co"' complex (24) is easily reduced to the dinuclear Co" complex (26);the unusual ease of this reduction is attributed to the coupling of the metal's reduction with that of the ligand by the Co** intermediate (25).150The reaction of O2 with (24) (25) 147 (a)D. W. Engelfriet G. C. Verschoor and W. den Brinker Acta Crystallogr.1980,B36,1554;(b) C.A. Ghilardi C. Mealli S. Midollini V. I. Nefedov A. Orlandini and L. Sacconi Inorg. Chem. 1980,19,2454. 148 G.R.Newkome D. K. Kohli and F. Fronczek J. Chem. Soc. Chem. Commun. 1980 9. 149 (a)J. C.Stevens P. J. Jackson W. P. Schammel G. G. Christoph and D. H. Busch J. Am. Chem. Soc. 1980 102 3283; (b)J. C.Stevens and D. H. Busch ibid. p. 3285. 150 1. A.Switzer and J. F. Endicott J. Am. Chem. Soc. 1980 102 1181. 213 The Transition Elements various [COL(H,O),]~’ complexes (L = macrocycle with four N donors) to give [(CO(H~O)L}~O~]~+ proceeds in two stages first forming a 1 1 adduct which then reacts with more Co complex to form the peroxo-bridged dimer;ls1 this second step has a wider range of rates. In search for an electrode which would give reduction of 0 to H20 at a positive potential and so help advances in fuel cells studies have been made1” of electroreduction by metalloporphyrin dimers bound to graphite electrodes with best results from a dicobalt complex some other systems giving H202 rather than H20.The mixed-metal complex (6; M = Co) is ferromag- netic through coupling of the orthogonal spins on Cu2+ and low-spin Co”; The Co” complex in which Cu is absent and the outer oxygens are protonated shows an abrupt doublet-quartet spin change at 80.3 K when two H20 co-ordinate Co but when two py are co-ordinated the transition occurs over the range 140-60 K.” Cobalt(rrI).-K,[C0(N0~)~]has been ~ynthesized”~ by the reaction of K3[CoF6] and N205.A 31P n.m.r. ~tudy”~ of solutions of [{CsHsCo(PO(OEt)z)3}zCo](PF6) gave AH0 and ASe for the ’T + ‘Al equilibrium already established in the solid state as the first such for CoIII. Ammines. The preparation of [{Co(NH3)sNCS},Hg](C104)6~H20 from Hg(C1O4) and [CO(NH,)~NCS](C~O~)~ in H20 represents the isolation of an intermediate in the Hg2’-promoted hydrolysis of halide or pseudohalide complexes.1s6 The pressure dependence and lack of l80incorporation during the base-catalysed isomerization of [CO(NH~),ONO]~’ and its Rh and Ir analogues to the nitro- complexes suggests1” that a conjugate base pre-equilibrium is formed; isomers of [CO(~~)~(ONO),]’’ or [Co(en),(ONO)(NO,)]” retain their configuration and chir- ality. The base hydrolysis of [(NH3)5 CoOP(02)OC6H4X-p]’ (X = H or NO,) a model system for phosphatase enzymes occurs not only by the usual SNICB mechanism with Co-0 bond breaking but also by intramolecular on the phosphate unit by the deprotonated NH3.In another phosphate derivative the [H2P3OI0l3- ion (X) already known to co-ordinate through adjacent phosphate units in one form of [Co(NH,),X]H,O has been by its X-ray crystal structure and C.-L. Wong J. A. Switzer K. P. Balakrishnan and J. F. Endicott J. Am. Chem. SOC.,1980,102,5511. 152 J. P.Collman P. Denisevich Y. Konai M. Marrocco C. Koval and F. C. Anson J. Am. Chem. SOC. 1980,102,6027. lS3 0.Kahn R. Claude and H. Coudanne Nouu. J. Chim. 1980,4 167. 154 M. I. Khalil N. Logan and A. D. Harris J. Chem. SOC.,Dalton Trans. 1980 314.lS5 P. Gutlich B. R. McGarvey and W. Klaui Znorg. Chem. 1980 19 3704. ’A. Pfeil T. P. Dasgupta D. A. Palmer and H. Kelm Znorg. Chim. Acta 1980 44 L23. 15’ W. G. Jackson G. A. Lawrance P. A. Lay and A. M. Sargesm Inorg. Chem. 1980,19,904. 158 (a)J. MacB. Harrowfield D. R. Jones L. F. Lindoy and A. M. Sargeson J. Am. Chem. Soc. 1980. 102,7733;(b)E. A. Merritt M. Sundaralingam and R. D. Cornelius ibid. p. 6151. 214 F. A. Hart J. Newbery and P.Thornton 31 P n.m.r. spectrum to form in solid and solution a linkage isomer with co-ordination by oxygens from the terminal phosphate groups. The kinetics of the reduction of the superoxide complexes [CO~(NH,)~(~-O~)(~-NH~)]~+ and [CO~(NH~)~,,(~-OZ)]'+by Co" polypyridyl complexes shows that these are outer-sphere proce~ses.~'~ Amine Complexes.Reconsideration of the base hydrolysis of halogeno-amine Co"' complexes suggests16o that this may be a concerted reaction / n / I/ r\. slow BH' + N=CO I/ B H-N-CO-X~ + X-/ 'I / /I A new method for the synthesis of co-ordinated disulphides from co-ordinated thiols is indicated161 by the reaction of [CO(~~)~(NH~C~H~S)]~+ with N-thioph- thalimides (27) in DMF (R = Me Et Pr' But,or Ph). In new results for complexes of sulphur oxoanions the static trans-effect is shown in the longest six-co-ordinate Co"'-Cl distance162nof 2.37 8 in trans-[C~(en)~Cl(SO~)]H~O and the longest Co"'-sulphite distance16" of 2.26 A in trans-[C~(en)~(SO~)~]; the photolysis162" of S-bonded [CO(~~)~(O~SC~H~NH~)]~+ gives the 0-bonded isomer as the first robust Co"' 0-bonded sulphinate complex and the reaction of Iz with aqueous cis-[Co(en>,(S2O3),]- gives trans-[Co(en)z(Hz0)(S303)]',isolated as [C~(en)~Cl-(S303)] containing the surprisingly stable s303'-ligand which gives substitution of water by NOz- or NCS- but a deposit of sulphur with C10,- or C1- and metal sulphides with Ag' Hgz2+ or Hg"; the structure S=S-SO is suggested with co-ordination by the central S.162d Hydrolysis of pyrophosphate is lo5 times faster in the presence of a Co"' polyamine complex with 31Pn.m.r.indicating that the anion co-ordinates three Co atoms during the rea~ti0n.l~~ The resolution and X-ray crystal structure of the new complex [Co(tren)(R-acac)].2Br.2H20shows that the optical activity arises from restricted rotation of the R group [6-Me-2,4-(N0z)zC6Hz] at the 3-position of a~ac.'~~ Contrary to earlier conclusions the X-ray crystal structure that a fac-isomer can be formed for [CoLC13] [L = (NHzC3H6)zNH] and I3C n.m.r.G. McLendon and W. F. Mooney Znorg. Chem. 1980,19 12. 160 R.W. Hay Znorg. Chim. Actu 1980 45 L83. D. L. Nosco R. C. Elder and E. Deutsch Znorg. Chem. 1980,19 2545. (a) C. L. Raston A. H. White and J. K. Yandell Ausr. J. Chem. 1980 33 419; (b)G. D. Fallon C. L. Raston A. H. White and J. K. Yandell ibid. p. 665; (c) H. Macke V. Houlding and A. W. Adarnson J. Am. Chem. SOC. 1980 102 6888; (d)J. P. Mittlernan J. N. Cooper and E. A. Deutsch J. Chem. SOC. Chem. Commun. 1980,733. 163 P. W. A Hubner and R.M.Milburn Znorg. Chem. 1980 19 1267. 164 Y. Nakano and S. Sato Znorg. Chem. 1980 19 3391. 165 E. K. Barefield A. M. Carrier and D. G. Vanderveer Znorg. Chim. Actu 1980 42 271. The Transition Elements 215 suggests that the fac-configuration is retained in [CoLL'],' (L' = 1,4,7-triaza-cyclononane). The reduction of resolved K[Co(edta)] by [CO(H~O)~](CIO~)~ in the presence of en in DMSO gives partially resolved [Co(en),I3+ the first stereoselective outer-sphere redox reaction. '66 0'-produced by pulse radiolysis of H20 reacts with the superoxide complexes [CO,(~~)~(~-O,)(~-NH~)]~+ and [Coz(CN)lo(p-0z)]5- to give O2and the corresponding 0''-cornplexe~.~"~ The rR spectra of [Co,(salen)2Lz(0,)] (L = py py0 DMF) showed ~(0-0)near 900cm-' and ~(CO-0) near 540cm-' and the excitation profile allowed identification16* of the Co-0 CT band near 500 nm.Rhodium.-Low Oxidation States. A 31P n.m.r. of many four-co-ordinate Rh nitrosyl complexes with polyphosphines (many newly prepared'"'') showed that all have pseudotetrahedral structures indicated exchange processes with unco- ordinated P and showed that chiral C centres had more effect on the spectrum than ciiiral Rh. The complexes [(triphos)M(P,)] (M = Rh or Ir) react with M'X2 and more triphos with NaBH4 if needed (M' = Co Ni or Rh X = BF4 or BPh4) to give170 [(triphos)M(P,)M'(triphos)]X, (n = 1 or 2) but the P3 bridging is not symmetrical (Ni-P = 2.33 2.37 2.56 A). The intramolecularly fluxional [RhH(PPr',),] has a planar RhHP unit at -150 "C but the HRhP angle is distorted to 70" by the phosphine's bulk; the authors that differences in rigidity are due to the steric needs of various PR3 ligands.[RhH(PEt&] and [RhH(PEt3)4] are also fluxional the latter existing in equilibrium with the former and PEt3.171" Fuller details have been pre~ented'~' of the neutron-diff raction structure of ' [H,Rh,{P(OMe),},] at 110 K with three square-planar Rh. The RhH2P2 planes are canted unequally to the Rh plane to give varying asymmetry in the Rh-H-Rh bridges. An earlier report of [RhCl(PMe,),] could not be repeated but the complex was prepared from [RhC1(PPh3),] via [Rh(PMe,),]Cl; the square-planar complex is crowded into a tetrahedral distortion and the paper describes other Rh (and Ru) compounds with PMe3.17' The ready oxidation of co-ordinated SO to SO4'-in [RhL(CO)(SOz)](AsF6) [L = PhP(C3H6PPh2)2] compared with its inertness in [RhLCl(SO,)] is reflected in the Rh-S bond lengths of 2.433 and 2.326A respectively the latter being the shortest M-S02(pyramidal) recorded; there is also a change in orientation of the SO probably resulting in more .rr-bonding in the chlor~-c~mplex.'~~ Rhodiurn(zz).Space allows only a selection of the many papers on dinuclear Rh" dimers appearing this year. The X-ray crystal structures of the previously reported 166 D. A. Geselowitz and H. Taube J. Am. Chem. SOC.,1980,102,4525. 167 P.Natarajan and N. V. Raghavan J. Am. Chem. SOC.,1980,102,4518. 168 K. Nakamoto M. Suzuki T. Ishiguro M. Kozuka Y. Nishida and S. Kida Znorg.Chem. 1980 19 2822. 169 (a) T. J. Mazanec K. D. Tau and D. W. Meek Znorg. Chem. 1980 19 85; (b) R. Uriarte T. J. Mazanec K. D. Tau and D. W. Meek ibid. p. 79. C. Bianchini M. Di Vaira A. Meli and L. Sacconi Angew. Chem. Znt. Ed. Engl. 1980,19,405. (a)T.Yoshida D. L. Thorn T. Okano S. Otsuka and J. A. Ibers J. Am. Chem. SOC., 1980 102 6451;(b)R. K. Brown J. M. Williams A. J. Sivak and E. L. Muetterties Znorg. Chem. 1980,19,370. R. A.Jones F. M. Real G. Wilkinson A. M. R. Galas M. B. Hursthouse and K. M. A. Malik J. Chem. SOC., Dalton Trans. 1980,511. P.G. Eller and R. R. Ryan Znorg. Chem. 1980 19 142. 17' 216 F. A. Hart J. Newbery and P. Thornton [Rh2(C03)4(H20)2]4- and [Rh2(CO3),Cl2I6- show that these have the usual car- boxylate-type bridging structure with Rh-Rh distances of 2.378 and 2.344 % (the shortest Rh-Rh bond yet) re~pective1y.l~~ The new phosphate complex [Rh2(H20) (H2P04),] prepared'75a from [Rh2(H20)2(MeC02)4] and a compara- tively long Rh-Rh bond of 2.485 %,.The mhp anion forms a number of Rh" complexes. Its Na salt reacts with [Rhz(MeOH)2(MeCOz)4] or RhC13.3H20 in MeOH to [Rh,(mhp),] with Rh-Rh 2.359 A probably a single bond (p.e. spectrum) and each Rh co-ordinated by two N and two 0.'76b However the reactions also give [Rh,(mhp),(Hrnhp)].$PhMe and [Rh4(mhp),]; each has three N and one 0 bonded to one Rh and three 0 and one N to the other so one axial position is blocked by three Me groups but Hmhp can co-ordinate at the other axial position in the former complex and a co-ordinated 0 from a neighbour fills the axial position in the latter but the Rh-Rh bonds are slightly longer (2.383 2.369 % respe~tively'~~~).Rhodium(m).A kinetic of substitutions in [Rh(en),XY]' (X = C1 Br I or OH Y = C1 or I) by Z (Cl Br or OH) found a range of behaviour from SNICB (e.g. X = Y = C1 Z = OH) through to SN2 (e.g. X = I Y = C1 Z = Br). Photoaquation of tran~-[Rh(NH~)~(oH)X]+ (X = C1 or Br) gives cis-[Rh(NH3),(H20)(OH)]"; this and earlier studies of cis-tetrammine complexes were explained178 by the rearrangement of the five-co-ordinate intermediate to give a more stable form with the strong 0-donor OH in a basal site. During measurements of the luminescence spectrum of [Rh(NH3)5C1]2+ in various solvents it was found'79 that the solvent replaced C1 in H20 or formamide but replaced NH3 for DMF DMSO or MeOH.Although [Rh(phen)J3+ is luminescent in a matrix at 77 K it is not so in so1ution.lR0 However the excited state has a significant lifetime in solution as shown by the detection of phosphorescence of [Cr(CN)J3-* or biacetyl and of the spectrum of Ph,NH' from added Ph,NH; the authors comment on an earlier observation of HZformation from aqueous solutions of [Rh(bi~y)~]~+ and (HOC,H,),N by saying that this is analogous to the Ph,NH reaction in which [Rh(~hen)~]~+ must be formed. They also conclude that when [R~(bipy)~]'+ and (HOC2H4)3N electron transfer from is present with [Rh(bi~y)~]~+ the excited Ru cation to Rh"' gives the Rh" cation which then forms H2and RuI'' which is reduced by triethano1amine.180 Iridium.-The X-ray crystal structure of the nitrosyl and quinone complex [Ir(NO)(PPh3)(0,C6Br4)] shows"' that this has NO' and catecholate forms of 174 F.A. Cotton and T. R. Felthouse Inorg. Chem. 1980 19,320. 175 (a)I. B. Baranovskii S. S. Abdullaev and R. N. Shchelokov Russ. J. Inorg. Chem. (Engl. Trunsf.) 1979 24 1753; (6) L. M. Dikareva G. G. Sadikov M. A. Porai-Koshits I. B. Baranovskii and S. S. Abdullaev ibid. 1980 25 488. 176 (a) M. Berry C. D. Garner 1. H. Hillier A. A. MacDowell and W. Clegg J. Chem. Suc. Chem. Commun. 1980 494; (b)W. Clegg Actu Crystulfogr.,1980 B36 2437; (c)M. Berry C. D. Garner I. H. Hillier and W. Clegg Inorg. Chim. Actu 1980 45 L209. 177 A. Po%and C. P. J. Vuik Inorg.Chem. 1980 19 1771. L. H. Skibsted and P. C. Ford Inorg. Chem. 1980 19 1828. 179 M. A. Bergkamp R. J. Watts and P. C. Ford J. Am. Chem. SOC.,1980 102,2627. "O R. Ballardini G. Varani and V. Balzani J. Am. Chem. SOC.,1980 102,1719. W. B. Shorthill R. M. Buchanan C. G. Pierpoint M. Ghedini and G. Dolcetti Inorg. Chem. 1980 19,1803. The Transition Elements 217 these ligands and indicates that catecholate is a good r-donor. [IrC1(N2)(PPh3),] reacts with the aryldiazo molecule N2C5C14 to give [IrCl(N2C5C14)(PPh3)2] whose rR spectrum indicates and X-ray crystal structure confirms the presence of linear IrNN and bent NNC units.182n Other new complexes of this ligand are [IrCl(N2C,C14)(PPh3)2L](L = PR3 Bu'NC or NO) [IrHC12(N2C5C14)(PPh3)2] and [IrC12(NO)(N2C5C14)(PPh3)2] complexes have been and analogous N2C5B~4 made.182b New easily prepared Ph3As complexes include',' [IrH3(AsPh3),] and [IrH2C1(AsPh3),] but the lack of nuclear spin on the donor atom makes structural assignments harder than for the PPh3 analogues.The photoaquation of 1r1'* ammine complexes occurs at all wavelengths probably with conversion into common excited states but irradiation at ligand-to-metal CT bands gives some variation depending on whether the solution is deaerated suggesting that some redox process is inv01ved.''~ In the first photolysis of a d6 complex not having N-donors [IrCl,(SEt,),] was converted into [{C12(SEt2)21r}- (p-C1)2] and [Cl,(SEt,) Ir(p-Cl)(p-SEt,)IrCl2(SEt,),l.'s4 The organic-soluble [Ir(PhPMe,),Cl,] may be a useful oxidant in the manner of water-soluble [IrCl6I2-; with the two-electron reductant [Pt(C,H,)(PPh,),] the 1r"'-Pt" complex [C12(PhPMe)21r(p-C1)2Pt(PPh3)2]+ formed as the is [IrC1,(PhPMe2),]- salt.lS5 Salts of [Ir(NO3),l2- can be made from [IrBr612- and N205 but not N204;powder X-ray diffraction suggests that the Cs salt may have a different structure from the K and Rb Salts.''' 5 Nickel Palladium and Platinum Nickel.-Various [Ni(PR3),] complexes convert RNO into RNO complexes with formation of R,PO possibly with [Ni(PR3),]+ as an intermediate.lg7 Zero-valent tetrahedral Ni complexes with the bipyridyl analogues RN=N-N=NR (R = Ph or 3,5-Me2C6H3) have been prepared.lS8 Ni(acac) reacts with Ph3P in the presence of Et2A1Cl to give among other products [Ni(Ph,P)(acac)J possibly with an unstable Ni ethyl species as inter- mediate.''' Camphorquinonedioxime (28)and its monoanion form complexes with bivalent Ni Pd Pt and Cu in which the neutral ligand can be unidentate or N,N-bidentate and the anion can be N,O-or N,N-bidentate and in which all four (28) (29) K.D. Schramm and J. A. Ibers Inorg. Chem. 1980,19,(a)1231;(b)2435. M. Talebiinasab-Sarvari A.W. Zanella and P. C. Ford Znorg. Chern. 1980,19 1835. G. B. Kauffman J. H.-S. Tsai M. H. Gubelmann and A. F. Williams J. Chem. SOC.,Dalton Trans. 1980,1791. D. M. P.Mingos and C. R. Webber Nouv. J. Chim. 1980,4,77. B. Harrison N.Logan and A. D. Harris J. Chem. Soc. Dalton Trans.,1980 2382. R.S.Berrnan and J.K. Kochi Znorg. Chem. 1980,19 248. I" P. Overbosch G. van Koten and 0.Overbeek J. Am. Chem. Soc. 1980,102,2091. A. N. Nesmeyanov L. S. Isaeva L. N. Morozova P. V. Petroskii B. L. Tumanskii B. V. Lokshin and Z. S. Klemenkova Inorg. Chim. Acta 1980,43,1. F. A. Hart J.Newbery and P. Thornton geometrical isomers of the ligand can be found.190 The electronic spectra of planar Ni" complexes that either themselves convert singlet Ozinto triplet Ozor resemble those that do so show a 'A 3B1,transition rather higher in energy than the 3E,-'A band for Ozat 7880 cm-' but sufficient intensity remains to permit the quenching pro~ess.'~' The potentially bidentate ligand ButzPCHzC(0)R (R = Ph or But) reacts with ethanolic NiClz to give'92 ~~~~~-[N~(BU'~PCH=C(O)R)~].The X-ray crystal struc- ture of [Ni(D-P-2-pyridyl-a -alanit~ate)~] reveals trans-amino-groups in the fac- configuration whereas for Co"' the carboxylates are trans ; the higher formation constant for Ni" of the complex with one D-and one L-form of the ligand is attrib~ted'~~ to the latter's adopting structure in which pyridine nitrogens can be trans. Just as amines react with sugars to form N-glycosides so does [Ni(en)3]2' giving complexes of multidentate ligands e.g. (29)with D-fructo~e.'~~ The tripeptide complex [Ni(2,6-Mezpy)(diglycinamide)] is stable to edta trien or acids; this unusual inertness is attrib~ted'~~ to a four-co-ordinate structure with the methyl groups obstructing axial attack whereas the more reactive Cu complex is five-co- ordinate.Macrocyclic Complexes. The X-ray crystal structure that the 1:1 adduct of 4,4'-bipy with [Ni2(dmg*BF2)4] retains the dimer unit the bipy polymerizing the structure by bridging to neighbouring dimers. The first macrocyclic complex incor- porating a piperidine ring has been prepared19' by the Hz-Raney Ni reduction of (30) to (31). The new macrocyclic complex (32) containing methyl vinyl ether groups (X = MeCOMe) was to make numerous other complexes of so-called 'superstructure' ligands with American saddle-like conformations (X = MeCOEt or MeCNRR including R = C10H20C02- CzH4py HzC=COMe MeC=NR the last two with the ring carrying a negative charge). Complexes of Ni(C104)z with the new ligands (33) and (34) were made using the reaction of cyclam with CZH4Br2; the new ligands are constrained to be planar not folded quadridentates so that rigidity can be imposed without ~nsafuration.'~~~ M.S. Ma and R. J. Angelici Inorg. Chem. 1980 19 363. 19' D. F. Evans J. Chem. SOC. Chem. Commun. 1980 1134. 19' C. J. Moulton and B. L. Shaw J. Chem. SOC.,Dalton Trans. 1980 299. S. R. Ebner B. J. Helland R. A. Jacobson and R. J. Angelici Inorg. Chem. 1980,19 175. lg4 S. Takizawa H. Sugita S. Yano and S. Yoshikawa 1.Am. Chem. SOC.,1980 102 7969. 19' J. M. T. Raycheba and D. W. Margerum Inorg. Chem. 1980,19 837. 196 F. S. Stephens and R. S. Vagg Inorg. Chim. Actu 1980,42 139. 19' 19' E. K. Barefield Inorg. Chem. 1980,19 3186. (a) W. P. Schammel L. L. Zimmer and D. H. Busch Inorg.Chem. 1980 19 3159; (b) K. P. Wainwright ibid. p. 1396. The Transition Elements n 11 U X (33) (34) (32) Pulynuclear Nickel(11) Complexes. [Niz(quinoline)2(PhC02)4] is one of the first Ni“ carboxylate dimers with the copper acetate ~tructure;’~~“ its e.p.r. spectrum and magnetism and the e.p.r. spectrum of the Cu analogue doped with Ni show that the overall antiferromagnetism includes a ferromagnetic contribution from overlap of the dZ2orbital on Ni with the dx2-y2orbital on Cu. The other new Ni” carboxylate dimer is [Ni2(quinaldine)2(Me3CCOz)4],with an Ni-Ni separation’996 of 2.75 A. The N-phenylsalicylaldiminate (X) complex [Nix2] reacts with MeC0’- to give [Ni2(MeC02)X4]- whose piperidinium salt contains’” an anion with two nickel atoms bridged by the acetate and two phenolic 0 atoms (35).Me I (35) New dinuclear Schiff-base complexes (36) have been prepared2’’ by using the MI1 complex as a ligand for M‘ (X = C& C3H6 or C2H4NHC2H4; M = Ni (36) X = C2H4 C3Hh or C2H4NHC2H4 (37) 199 (a)A. Bencini C. Benelli D. Gatteschi and C. Zanchini J. Am. Chem. Soc. 1980 102 5820; (b) N. I. Kirillova Yu. T. Struchkov M. A. Porai-Koshits A. A. Pasynskii A. S. Ansyshkina L. Kh. Minacheva G. G. Sadikov T. Ch. Idrisov and V. T. Kalinnikov Inorg. Chim. Acta 1980 40 115. 2oo R. J. Butcher J. W. Overman and E. Sinn J. Am. Chem. Soc. 1980,102,3276. 201 M. Vidali R. Graziani P. A. Vigato U. Cassellato D. E. Fenton and C. M. Regan Inorg. Chim. Acta 1980 38 85. F.A. Hart J. Newbery and P Thornton M' = Ni(H20)2 Cu or U02,or M = M' = Cu or VO). MeC(C2H4PPh2) (L) reacts with hydrated Nix2 (X = C1 Br or I) to form [Ni3L2X6] (37) in which each P of one ligand is bonded to a different Ni.202 New complexes of dinucleating ligands such as X (38) include [Ni3X2] which may have the polymeric structure (39).203 Higher Oxidation States. Ni" halides Nix2 react with L (40) in MeOH in the presence of KY to give [Ni2L4X]3Y (X = C1 or Br Y = PF6 BPh4 or BF,) which are oxidized by I2 to [Ni2L4X]41,; all these were shownzo4 by their Raman spectra to have a Ni-X-Ni bridge which can be formed even in the presence of the good bridging ligand NCS- 0 C N R :a: :aR C LJ (40) (41) I-doped [Nix] (X = 41) show electric conductance e.g.1-50 K' cm-' at 300 K for single crystals of [NiX11,8] for R = H with electron transfer between ligand ~-orbitals.*~~~ The porphyrin complex (42) is partially oxidized by I2 to [Ni(por)]- (I3) (n = 0.36 or 0.97); for n = 0.36 the Ni-Ni separation is long (3.77 A) but the material has chain conductance and its e.p.r. spectrum shows that the unpaired 'O' F. Cecconi S. Midollini A. Orlandini and L. Sacconi Znorg. Chim. Acta 1980 42 59. '03 P. Krautil and R. Robson J. Coord. Chem. 1980,10 7. *04 W. L. Gladfelter and H. B. Gray J. Am. Chem. SOC.,1980 102,5909. '05 (a)L.4. Lin T. J. Marks C. R. Kannewurf J. W. Lyding M. S. McClure M. T. Ratajack and T.-C. Whang J. Chem. Soc. Chem. Comrnun.,l1980 954; (b)T. E. Phillips R. P. Scaringe B.M. Hoffman and J. A. Ibers J. Am. Chem. Soc. 1980 102 3435; (c) C. J. Schramm R. P. Scaringe D. R. Stojakovic B. M. Hoffman J. A. Ibers and T. J. Marks ibid. p. 6702. The Transition Elements electron is on the ligand. The Curie law is surprisingly followed and this leads the authors into a disc~ssion~~~~ of charge transport in molecular crystals. [Ni(pc)] is oxidized by 1 to [Ni(pc)I,] (x d 3); for x = 1 the X-ray crystal structure shows the presence of 13- and the authors that this anion is at least a major part of the I content of all species up to x = 3. For the x = 1 complex the e.p.r. spectrum shows electron spin on the ligand and the complex has metallic conduct- ance along the stacking direction but this is lost abruptly at 55 K despite unchanged other properties (magnetism rR electronic and lZ9IMossbauer The unnecessary sobriquet of 'molecular metals' has been bestowed on these materials.Ni complexes of the oxime anion (43) [NiX](CIO,) [X = (43)] seem to contain206a Ni"' unlike the Ni'" produced by sexidentates with two terminal oxi- mates; one such ligand (44) forms [NiX](ClO,) [X = (44)] which is the first Ni'" complex to be resolved. R' ,N-0-RZkN (43) (44) Palladium.-The R3P and bridging C1 in the triangular cluster [(R3PPd)3(p-CI)- (p-PPh2)J are labile; oxidation by H202gives the probably linear Pd" trimer (45) and this complex reacts with PR3 to give according to 31P n.m.r. data trans-[Pd(PR,),C12] and (46).207 The potentially quadridentate amine tren forms four-co- ordinate [Pd(tren)X]' complexes (X = halide or NCS) with one NH group free (45) 2"6 (a)A.N. Singh and A. Chakravorty Znorg. Chem. 1980 19 969; (b)P. J. Heaney A. G. Lappin R. D. Peacock and B. Stewart. J. Chem. SOC., Chem. Commun. 1980,769. '07 S. J. Cartwright K. R. Dixon and A. D. Rattray Inorg. Chem. 1980 19,1120. 222 F. A. Hart J. Newbery and P. Thornton but this is in equilibrium with a five-co-ordinate complex in for X = NCS there is a change from N-to S-co-ordination when the anion is changed from NCS-to BPh4-. Complexes of a-di-imines RN=CHCH=NR (L) lacking the rigidity of bipy or phen show that this ligand can be uni-or bi-dentate in [MXzL1or 2] or [MC12L'] (M = Pd or Pt R = alkyl X = C1 Br or I L' = a phosphine or an arsine) sometimes with a C-H proton near the metal in unidentate forms and sometimes with interesting fluxional behavi01.x.~~~ New Pd" complexes with phospholes RP?-CH=CMe-CMe=C'H (L) [PdLzXz] (X = C1 Br or N3) show cis-configurations in the solid state (i.r.) but 'H 13C and 31P n.m.r.data suggest some cis-trans isomerism in CHC1 solutions; the authors suggest210that Pd-phosphole bonds are stronger than Pd-phosphine bonds because there is no structural reorganization on co-ordina-tion. The first P-co-ordinated phosphazene complexes [MLZClz][M = Pd or Pt L = (47)] have been prepared2" from (48). Conductance measurements and i.r. N Ph2P' *PPh, I1 I N P//N Me Me/\ H (47) (48) and n.m.r. spectra indicate that [Pd(diphos)(CN)](ClO,) preparedz1' from [Pd(diphos)(CN),] and AgC104 in MeCN is tetranuclear with a mixture of two possible structures (49) and (50).Complexes of bidentate ligands L such as Ph2AsC2H4PPh2,of the type [MLClz] (M = Pd or Pt) react with Ag' in the presence of L' (py DMSO DMF PPh3 or PPr,) to give [MLL'Cl]' or if L' is much weaker [M2LzCl2I2';the formation of the former was found to assist catalysis [Pd(diphos)(DMF)Cl]' being able to catalyse the hydrogenation of styrene in DMF unlike [Pd (dipho~)Cl~].~~ P-Pd-CN-Pd-P 3 P -Pd-CN-Pd-Pp7 I I I I N C C N C N N C I I I I P -Pd-NC-Pd-P P-Pd-NC-Pd-P Q P 1-J Q P 1-J Bu'OOH converts Pd(RC02)z (R = Me CCl, CF, or C5HI1) into [Pd4(RC02)4(Bu'02)4], the CCl complex having a Pd4 square bridged by Bu02 groups in the plane and by CI3CCO2groups alternately above and below the 2"8 S.N. Bhattacharya and C. V. Senoff Znorg. Chim. Actu 1980 41,67. 209 H. van der Poel G. van Koten and K. Vrieze Znorg. Chem. 1980,19 1145. 210 J. J. MacDougall J. H. Nelson F. Mathey and J. J. Mayerle Znorg. Chem. 1980 19 709. '11 A. Schmidpeter K. Blanck H. Hess and H. Riffel Angew. Chem. Int. Ed. Engl. 1980 19 650. *I2 J. A. Davies F. R. Hartley and S. G. Murray Inorg. Chim. Actu 1980 41 249. J. A. Davies F. R. Hartley and S. G. Murray Znorg. Chem. 1980 19 2299. The Transition Elements plane.214a The 'H and 13C n.m.r. spectra of [PdT1(R'C02)2(R2C02)3] prepared from Pd(R'CO2) and T1(R2C02) (R' = Me Et Pr' or Ph R2 = Me Et or Pr') suggest the dinuclear structure (5 l),with two different exchange processes occurring in R2 dC\ From 'H n.m.r.spectra it was concluded215 that AMP can interact with [Pd(dien)12' about equally well through N-1 and N-7 but that [Pd(en)12' forms a complex with N-1 of one AMP and N-7 of another; [Pd(dien)12+ co-ordinates inosine at N-1 above pH5.5 and at N-7 below this pH. Base-stacked structures are induced by [Pd(en)]" in inosine IMP AMP and GMP. The X-ray crystal structure of the first co-ordinate8 phenothiazine drug in [PdLCl,] [L = (52)] shows216 that the S atom co-ordinates to Pd but the quaternary N reaches back in a 'scorpion conformation' to give H bonding to a C1 cis to the co-ordinated S. Platinum.-Platinum (0). [PtL,] complexes (L = tertiary phosphine n = 2-4) were shown ,'' by 31P n.m.r.to be in equilibrium with [PtL,-l] and free L by associative and/or dissociative mechanisms with steric crowding affecting the AS term by interpenetration of ligands but not the AH term. Interesting oxygen-transfer reactions occur when SO converts [Pt(N,O,)(PPh,),] into [Pt(N02)2(PPh3)2] and NO converts [Pt(S02)(PPh3)2] into [Pt(S03)(PPh3)2] but both reactions also produce (53) probabIy by an insertion reaction.218 Platinum (11). There have been many interesting n.m.r. results this year. Enormous one-bond spin-spin couplings between Pt and Sn have been found2I9 in trans-[PtX(SnCl,)(PEt,),] (X = C1 or SnCl,). The "'Pt n.m.r. spectra of [PtC1,I2- and (a) H. Mimoun R. Charpentier A. Mitschler J. Fischer and R.Weiss J. Am. Chem. SOC.,1980 102 1047; (b)A. F. M. van der Ploeg G. van Koten and K. Vrieze Inorg. Chim. Acra 1980,38 253. 215 I. Sovago and R. B. Martin Znorg. Chem. 1980 19,2868. W. J. Geary N. J. Mason L. A. Nixon and I. W. Nowell J. Chem. SOC., Chem. Commun. 1980 1064. '17 B.E.Mann and A. Musco J. Chem. SOC., Dalton Trans. 1980,776. S. Bhaduri B. F. G. Johnson A. Khair I. Ghatak and D. M. P. Mingos J. Chem. SOC., Dalton Trans. 1980 1572. 219 K.-H. A. Ostoja Starzewski and P. S. Pregosin Angew. Chem. Znt. Ed. Engl. 1980 19 316; B. R. Koch G. V. Fazakerley and E. Dijkstra Znorg. Chim. Acra 1980 45 L51. F. A. Hart J. Newbery and P. Thornton [PtBr612- at very high field show220 splittings due to the isotopes of C1 and Br. The 15N chemical shift was established221 as a criterion for N-or S-co-ordination in [M(NCS),I2- (M = Pd Pt Zn Cd or Hg) and linkage isomers were found for the Pt complex in CH2C12.The phenyl rings in [Pt(PEt,),Cl(NHPh)] are coupled by reaction with AgPF6 in acetone to give (54) which gives a monocation with quinonoid bond lengths on PEt, I I PEt treatment with KOH.222 The self-condensation of 2-aminobenzaldehyde in the presence of [PtC1,I2- gives the usual quadridentate macrocycle but the intermediate (55) was This purple complex becomes orange in DMSO or MeCN in the dark as solvent displaces the carbonyl group to give a ‘swinging gate’ complex but the reaction is reversed by light.223b The reaction of [Pt(terpy)C1]C1.2H20 with HSC2H4NH2 and [PtC1,I2- the (4+) cation (56) which had first been identified in intercalation studies of nucleic acids with [Pt(terpy)(SC2H4NH3)I2+.The X-ray crystal of the NO salt of [Pt(~hen)~CN]’ shows the Pt to have square-pyramidal co-ordination with CN bonded at a basal site; the I3Cn.m.r. spectrum shows that this structure is retained in solution and the observation of similar U.V. spectra when OH- or SH-are added to [Pt(~hen)~]’+ suggests that these also form five-co-ordinate intermediates rather than attacking a ligand. n There have been many reports concerning stacked complexes with valuable consolidation of earlier work through preparations crystal structures conductance measurements and rR spectra. The field has been opportunely reviewed.226 Various Pt blues including trimethylacetamide Pt blue form 111 ‘Platinblau’ and cis-diammine-Pt a-pyridone blue have been studied by electronic absorption spectro- scopy EHMO calculations and redox titrations with Ce’” which showed that the first of these is a mixture of oligomers of variable chain length containing Pt-Pt 220 I.M. Ismail J. S. Kerrison and P. J. Sadler J. Chem. SOC., Chem. Comrnun. 1980 1175. ‘” P. S. Pregosin H. Streit and L. M. Venanzi Inorg. Chim. Actu 1980 38 237. ’’’ N. W. Alcock R. D. O’Sullivan and A. W. Parkins J. Chem. SOC.,Chem. Commun. 1980 1216. 223 (a)M. D. Timken R. I. Sheldon W. G. Rohly and K. B. Mertes J. Am. Chem. SOC.,1980 102 4716; (b)W. G. Rohly and K. B. Mertes ibid. p. 7939. 224 J. C. Dewan S. J. Lippard and W. R. Bauer J.Am. Chem. SOC.,1980,102 858. ”’ 0.Wernberg and A. Hazel] J. Chem. SOC., Dalton Trans. 1980 973. 226 A. E. Underhill and D. M. Watkins Chem. SOC. Rev. 1980,9,429. The Transition Elements 225 interactions in oxidation state greater than 2 and that all the species are generally similar but that the true composition of ‘Platinblau’ remains unclear.227 On being heated to dryness the pale-brown aqueous solution of K2PtC14 and H3P03 gave green K2[Pt2(H2P205)4].H20 whose green luminescence is attributed228 to a Pt-Pt bond (2.925 A) which is supplemented by four OPOPO bridges. Complexes with Biological Ligands. This topic has been very active this year. Many of the reports concerning mode of co-ordination of nucleic acid bases are com- plementary and there have been many similar proposals on the role of cis-[Pt(NH3)2X2] complexes in cancer chemotherapy.The X-ray crystal structure of ci~-[Pt(NH,)~(guanosine)~] that guanosine co-ordinates through N-7 and that the orientation of the guanosines renders Pt chiral. Co-ordination through N-7 is also found 229b for 9-ethylguanosine in [Pt(NH3)2(9-Et-guanosine)(l-Me-cytosine)]2’.[Pt(NH3)2(9-Et-guanosine-H)-(l-Me-cytosine)]+.3C104-; the latter authors note that co-ordination will change the hydrogen-bonding capacity of a base and that mispairing may follow in attempted DNA replication but the former paper and another the structure . of [Pt(NH2C3H6NH2)(5’-guanosine-monophosphate methyl ester)] simply note the probable distortion of DNA when this is co-ordinated to [Pf(NH3)zI2+.Other physical techniques besides crystallography have been applied in this area. The reaction of cis-[Pt(NH3),C12] with DNA was frozen after a 30min to 4 day interval and the mixture was dialysed to remove unbound Pt and analysed by gel electrophoresis to indicate that the most probable process is co-ordination to two near-neighbour guanine or cytosine Chromatographic ‘H n.m.r. and c.d. studiesz3’ of the reaction of cis-[Pt(NH3),(H,0),]” with various dinucleoside monophosphates showed that IpI and GpG gave N-7 N-7 chelation as does ApA which also forms other complexes with N-1 bonding; GpC and ApC form many complexes including one in which GpC chelates through N-7(G) and N-3(C). These authors also favour co-ordination of Pt by adjacent guanines but suggest that adjacent guanine and cytosine might also be an active From ‘H n.m.r.spectra of complexes of adenine guanine adenosine and guanosine with various transition-metal complexes including some antitumour agents it appears232 that octahedral environments favour N-7 co-ordination of adenine because the NH2 of the purine can then hydrogen-bond to the 0 of another ligand (e.g. MeCO or acac) but guanine cannot do this having 0 for NH2 but that both systems can co-ordinate in square-planar complexes where adenosine forms 227 M. P. Laurent J. C. Tewksbury M.-B. Krogh-Jesperson and H. Patterson Znorg. Chem. 1980,19 1656. 228 M. A.F. Dos Remedios Pinto P. J. Sadler S. Neidle M. R. Sanderson A. Subbiah and R. Kuroda J.Chem. SOC.,Chem. Commun. 1980,13. 229 (a) R. E. Cramer P. L. Dahlstrom M. J. T. Seu T. Norton and M. Kashiwagi Inorg. Chem. 1980 19,148;(b)R. Faggiani C. J. L. Lock and B. Lippert J. Am. Chem. SOC., 1980,102,5418;(c) L. G. Marzilli P. Chalilpoyil C. C. Chiang and T. J. Kistenmacher ibid. p. 2480. 230 G. L. Cohen J. A. Ledner W. R. Bauer H. M. Ushay C. Caravana and S. J. Lippard J. Am. Chem. Soc. 1980,102,2487. 231 J. C. Chottard J. P. Girault G. Chottard J. Y. Lallemand and D. Mansuy J. Am. Chem. Soc. 1980 102,5565. 232 N. Farrell J. Chem. Soc. Chem. Commun. 1980 1014. F. A. Hart J. Newbery and P. Thornton [{Pt(a~ac)Cl}~(adenosine)] through bridging by N- 1 and N-7. Raman difference spectra that guanosine monophosphate co-ordinates through N-7 to cis-and tran~-[Pt(NH~)~]~+ and cis-[AuMe2]' react but [Pd(en)12' tran~-[Pd(NH~)~]~+ at ring N and NH positions with no reaction from [Rh2(H20)2(MeC02)4] or [CO(NH3)5(H20)I3+ Addition of more metal ions to C~S-[P~(NH~)~]~+-DNA base complexes gives more complicated structures as shown for Ag' which gives (57) with cis-[Pt(NH3)2]2t and thymine.234 Me /M" H3N4>:;:G%H3 \/ Ag Pt Pt H35{.3-de 2<NgONH3 Me/ N\Me (57) 6 Copper Silver and Gold Copper(I).-KSPh reacts with Cu" dithiosquarate (dts) to give trigonal planar [Cu(SPh3)12- which reacts with more Cu' in MeCN to give [CU~(SP~)~]~-; this can also be made by displacement of dts from [C~~(dts)~]~- and has a tetrahedron of trigonal Cu surrounded by an S6 The interesting complexity of Cur complexes with phosphine sulphides is in the X-ray crystal structure of [CuLCl] [L = Ph2P(S)CH2P(S)Ph2] which contains two molecules of monomer with three-co-ordinate Cu to one molecule of dimer with two sulphur atoms bridging tetrahedral Cu.Following last year's [(P~,PCU)~(WOS,)CI] cage structure its Mo analogue has been and so has the double cubic [(P~,PCU)~(WOS~)~] analogue2376 of last year's complex with (C7H7)3P. Complexes of the new di-iminophosphines (58) (L) include [CuL]-(C104)*CH2C12 in which Cu has a strained tetrahedral configuration and (58) n = 2or3 233 M. R. Moller M. A. Bruck T. O'Connor F. J. Armatis E. A. Knolinski N. Kottmair and R. S. Tobias J. Am. Chem. SOC.,1980 102 4589. 234 B. Lippert and D.Neugebauer Znorg. Chim. Actu 1980 46 171. 235 D. Coucouvanis C. N. Murphy and S. K. Kanodia Znorg. Chem. 1980 19 2993. 236 E. W. Ainscough. A. M. Brodie and K. L. Brown J. Chem. Soc. Dalton Trans. 1980 1042. 237 (a)A. Miiller H. Bogge and U. Schimanski J. Chem. SOC.,Chem. Commun. 1980,91; (b)A. Miiller H. Bogge and T. K. Hwang Znorg. Chim. Actu 1980 39 71. The Transition Elements 227 [CuL(Bu'NC)](ClO,) which also shows tetrahedral Cu now with one imine N ~nco-ordinated.~~~ Copper(II).-The old problem of C1- and Br- copper(I1) complexes in solution has been tackled afresh in cationic reversed micelles (e.g.hexadecyltrimethylammonium bromide) with a greater abundance of [CUX,,];-~ anions with higher micelle The kinetics of NH3 substitution into [CU(H~O)~]'' have been used2,'= to calculate kinetics of H20 exchange; the authors discuss earlier values for this process and suggest that faulty analysis of Jahn-Teller effects gave wrong results.The unusually slow substitution of H20 in [Cu(H20)-{(Me2NC2H4)3N}]2+ to show an inter- by NCO- Cl- or Br- was interp~eted~~" change mechanism. In other kinetic studies the catalysis of 02-disproportionation by Cu"-histidine complexes was mainly attributed241 to the monoprotonated form [C~(hist)(histH)]~',so that an arrangement like this may occur in superoxide dismutase; this complex has a vacant sixth co-ordination site where 02-may co-ordinate and react with H' and more 02-to give O2and H202,so there is no need to postulate five-co-ordinate Cur.The substitution of N-ethylsalicylaldimine for N-t-Butylsalicylaldiminein its Cur' complex in alcoholic solvents seems to involve transfer of a proton from co-ordinated ROH to a phenolic 0 followed by breaking of Cu-0 bonds and replacement by the incoming ligand.242 The e.p.r. spectra of Cu" doped in [Zn(Ph3PO)2C12] led to a of bonding in pseudotetrahedral complexes from which it appears that low All values are caused by spin-orbit coupling including ligand contributions to this. The e.p.r. spectra of Cur' complexes of carnosine (P-alanyl-L-histidine) and L-anserine (P-alanyl-1-methylhistidine) show the systems have four different structures one of them dinuclear depending on stoicheiometry pH and tempereat~re.~~~' New X-ray crystal structures show that [Cu(acac)(hfac)(phen)] has a five-co- ordinate structure with unidentate hfac but that hfac is unco-ordinated in [Cu( acac) (phen) (H20)]( hfac)-H20 .2440 [Cu(bipy)(iminodiacetate)].6H20 contains244b square-pyramidal Cu in contrast to Cu(bipy)-(pyridine-2,6-dicarboxylate)-2H20which has [C~{py(C0,),}]~- acting as a unidentate ligand to [C~(bipy)~]*+.The structure of [CU(H~NC~H~NHC~H~NHC~H,NH~)(CIO~)~] shows a virtually planar CuN unit which is interpreted244C as showing a high stability for the Cu complex and may explain why this amine can be used to remove surplus Cu from sufferers from 238 J. C. Jeffery T. B. Rauchfuss and P. A._Tucker,Inorg. Chem. 1980 19 3306. 239 J. Sunamoto H. Kondo T. Hamada S. Yamamoto Y. Matsuda and Y. Murakami Inorg.Chem. 1980,19,3668. 240 (a) L. S. W. L. Sokol T. D. Fink and D. B. Rorabacher Inorg. Chem. 1980 19 1263; (b)J. H. Coates P. R. Collins and S. F. Lincoln Aust. J. Chem. 1980 33 1381. 241 1980 102 4916. J. Weinstein and B. H. J. Bielski J. Am. Chem. SOC. 242 H. Elias U. Frohn A. von Irmer and K. J. Wannowius Inorg. Chem. 1980,19 869. (a)A. Bencini D. Gatteschi and C. Zanchini J. Am. Chem. SOC., 1980 102 5234; (b)C. E. Brown W. E. Antholine and W. Froncisz J. Chem. SOC.,Dalton Trans. 1980 590. 244 (a) N. A. Bailey D. E. Fenton M. V. Franklin and M. Hall J. Chem. SOC.,Dalton Trans. 1980 984; (6)G. Nardin L. Randaccio R. P. Bonomo and E. Rizzarelli ibid.,p. 369; (c) T. G. Fawcett S. M. Rudich B. H. Toby R. A. Lalencette J. A. Potenza and H. J. Schugar Inorg.Chem. 1980 19 940; (d) P. J. M. W. L. Birker S. Gorter H. M. J. Hendriks and J. Reedijk Inorg. Chim. Acra 1980 45 L63. F.A. Hart J. Newbery and P. Thornton Wilson's disease. The complex [Cu(R2NCH2CH2NR2)I2' [R = (SS)] shows an unusual cis-lengthening of two Cu-N bonds those to en-type N.244d Dinuclear Complexes. Age cannot wither nor custom stale the infinite variety of copper(I1) dimers. [C~,(py)~Br,] forms a one-dimensional chain of dimers whose much weaker antiferromagnetism than that of [cU2Br6l2- is attributed245 to a reduced electron density at bridging Br by the trans-effect of py. Two more hydrogen-bond bridging dimers (60) have been in (60b) one H20 co-ordinates each Cu but the J values for these and related complexes do not follow the 0-0 separation.R R R (60) a; R = H b; R=Me Bridging carbonate complexes are prepared by reaction together of a polyamine 02,C02 and a Cu' halide or acetate; in [(Et4en)CuC1(p-C03)CuC1(Et4en)]two carbonate 0 co-ordinate one Cu and the third 0 bonds to the other c~.~~'-New carboxylate dimers include Cu2(CH2C1C02),(N-Etsal)(EtOH), which contains2" [Cu2(CH2C1CO2),] units and pairs of Cu bridged by two salicylate 0,the different pairs being linked by syn-anti CH2C1CO2 bridges. This contrasts with the ferromag- netic (61) with rare monatomic carboxylate bridges. (61) 245 D. D. Swank and R. D. Willett Inorg. Chem. 1980 19 2321. 246 J. A. Bertrand E. Fujita and D. G. Van Derveer Znorg. Chem. 1980 19 2022. 247 M. R. Churchill G.Davies M. A. El-Sayed M. F. El-Shazly J. P. Hutchinson and M. W. Rupich Inorg. Chem. 1980 19 201. The Transition Elements 229 Many complexes have been containing the bridging unit (62) (X = Y = 0 or NH; X = 0 Y = NH) with bi-or ter-dentate amines as other ligands; the room-temperature magnetic moments suggest than an 0-C-NH bridge is more effective that an 0-C-0 bridge but variable-temperature studies are needed here. A similar bridge system is in (63),where J -210 cm-' R2 R2 (63) whatever R' and R2 are; the authors suggest that this bridging unit may be found in proteins. Many new Cu'* complexes of cyclic (CO),,-ions (e.g. squarate n = 4) have been prepared with bipy phen and Et4dien.Unlike previous squarate dimers in which the bridging anion co-ordinates each Cu through two 0,the new complexes probably show only one 0 bonded to each CU.~~' A redetermination2" of the magnetism of [CU~(E~~NCS~)~] below 4 K found much weaker ferromagnetism than earlier reported.Rare examples of a dinuclear structure with just one bridge between two Cu2' ions are provided2'l by [C~~(cyclops)~X]+ [cyclops = (64) X = CN N3 Br or I]; as the appropriate orbitals are orthogonal the complexes are virtually magnetically dilute. The Cu2 complex of the cryptate (65) shows a temperature-dependent J H N.N. "-0"-0 >BF2 c NwN-o 248 (a)K. Nonoyama H. Ojima K. Ohki and M. Nonoyama Znorg. Chim. Acta 1980 41 155; (6) K. J. Berry D. St. C. Black C. H. Bos Vanderzalm G. I. Moss and K.S. Murray Znorg. Chim. Acta 1980 46 L21. 249 J. T. Reinprecht J. G. Miller G. C. Vogel M. S. Haddad and D. N. Hendrickson Inorg. Chem. 1980 19 927. J. A. van Santen A. J. van Duyneveldt and R. L. Carlin Znorg. Chem. 1980,19,2152. *'' A. W. Addison C. P. Landee R. D. Willett and M. Wicholas Znorg. Chem. 1980,19 1921. F. A. Hart J. Newbery and P. Thornton value below 55 K to flexibility of the ligand structure changing the orbital overlaps for superexchange; the changing e.p.r. spectrum agrees with this but the electronic absorption spectrum does not change with temperature. Another dinucleating ligand (66) forms [Cu2L(im)](C104) [L = (66)] in which each Cu is co-ordinated by three N from one ring one N of the bridging imidazolate and weakly to two C104- one of which bridges to the next dinuclear cation.This complex has an antiferromagnetic 8of 55 K despite a room-temperature magnetic moment of 1.95 BM.252b The X-ray crystal structure of the metalloporphyrin complex (67)shows substan- tial slipping of one ring over the other so that the Cu-Cu separation is 5.22 A but the interplanar distance is 3.52 A; unfortunately no magnetic or spectroscopic data are given.253 Polynuclear Complexes. A new product from CuC12-2H20 and N-(2-aminoethy1)piperazine (L) is (LH3)4C~5C122 which contains two unequally flattened CUC~~~-anion (68) which has long Cu-Cl tetrahedra and the new [CU,C~~~]~- 252 (a) 0. Kahn I. Morgenstern-Badarau J. P. Audiere J. M. Lehn and S. A. Sullivan J. Am. Chem.Soc. 1980 102 5935; (b) M. G. B. Drew C. Cairns A. Lavery and S. M. Nelson J. Chem. Soc. Chem. Cornmun. 1980 1122. 253 M. A. Hatada A. Tulinsky and C. K. Chang J. Am. Chem. Soc. 1980,102,7115. The Transition Elements 231 n bridging bonds (average 2.85 A) and is only weakly antiferr~magnetic.~~~ The X-ray crystal structure of [{CU(H~O)L}~CO~](NO~)~ [L = (69)] C032- bridging three Cu atoms the Cu303C unit having D3hsymmetry in the manner of B(OH)3. Anions of the oximes R'NCR2CR3NOH (R'= alkyl or aryl; R2 R3 = Me or Et) form trinuclear Cu" complexes with 0 or OH at the centre of a Cu3 triangle or with no atom at all at the centre; however all the complexes have one unpaired electron per trimer so the oximate bridges must transmit antiferromagnetic exchange.256 A general theory has been to explain the different magnetic behaviour of [Cu&40&] complexes (L = C1 Br py py0 DMSO or OC(NMe2)2 X = C1 or Br) with normal Heisenberg antiferromagnetism when L is a strong ligand but needing the Lines orbital degeneracy model when L is a weak ligand; however the paper curiously requires py to be a weaker ligand than halide.The inosinemonophosphate trianion (imp) forms [C~~(impj~(phen)~(H~O)~]*+, whose NO3- salt shows that each imp ligand is bonded to all four Cu and that 0-6 is co-ordinated the first example of this to be shown ~rystallographically.~~~ There have been further advances259 in the orbital overlap analysis of magnetic interactions of Cu2' with other metal ions notably V02' and Co2' (see also refs.53 and 153). The complex [{Cu(dien)},Fe(CNj6].6H20 has square-pyramidal Cu with a linear FeCNCu unit to an equatorial position on Cu and a non-linear FeCNCu link to an apical CU.~~' (L = en [c~L~]~[Fe(cN)~]~.nH~oor derivative) show magnetic properties of isolated ions but there are changes in electronic spectra and the relaxation times of the metals.261 The X-ray crystal structure of K2C~(C03)2 shows262 that unlike Na2CuC03 this is a three-dimensional polymer in keeping with the ferromagnetism below 6.6 K whereas the Na salt is antiferromagnetic. The strong antiferromagnetism of Cu(C204)*$H20 is largely lost when this is converted into CU(C~O~)(NH~)~*~H~O because the unpaired electron on Cu is now in an orbital which points to NH3 not c204.263 In other polymeric complexes derived from pyridoxamine [HL (70)] Cu(HL)(NO3),.H2O shows chelation by the phenolate and NH2 groups and polymerization through NO3 bridges but CuL2.2H20 shows similar chelation 254 L.Antolini G. Marcotrigiano L. Menabue. and G. C. Pellacani J. Am. Chem. SOC.,1980 102 5506. 255 G. Kolks S. J. Lippard and J. V. Waszczack J. Am. Chem. SOC.,1980 102,4832. 'sf S. Baral and A. Chakravorty Znorg. Chim. Acta 1980 39 1. 257 H. Wong H. tom Dieck C. J. O'Connor and E. Sinn J. Chem. Soc. Dalton Trans. 1980 786. 258 R. W. Gellert B. E. Fischer and R. Bau J. Am. Chem. SOC.,1980,102,7812. 259 0.Kahn and M. F. Charlot Nouu. J. Chim. 1980,4,567. 260 G. 0.Morpugo V. Mosini P. Porta G. Dessy and V. Fares J. Chem.Soc. Dalton Trans. 1980 1272. 261 I. Bertini C. Luchinat F. Mani and A. Scozzafava Znorg. Chem. 1980,19 1333. 262 A. Farrand A. K. Gregson B. W. Skelton and A. H. White Aust. J. Chem. 1980 33 431. 263 J. J. Girerd 0.Kahn and M. Verdaguer Znorg. Chem. 1980. 19 274. F. A. Hart J. Newbery and P.Thornton with bridging through hydroxymethyl groups.264 A new series of semi-conducting materials [CuL(t~nq)~] (L = bipy or phen tcnq = 7,7,8,8-tetracyanoquinodimethane)has been Mixed-valence Copper Compounds.-The layer structure of KCu4S3 which con- tains tetrahedral Cu in average oxidation state 1.25 gives266 a room-temperature conductance of 4000 R-'cm-' much higher than previously reported rising to 6 x lo4R-'cm-' at 20 K. Crystals formerly considered to be modifications of CuCN are now to be [CU,(CN),(NH,)~] [CU,(CN)~(NH~)~(H~O)] and [CU,(CN)~(NH,>~], the NH3 probably arising from hydration of CN-.The first two of these have polymeric structures including some Cu' in rare two-co-ordination. Copper(r1) acetate reacts with P(OR) in ROH to give268 green [CU,(M~CO~),(P(OR),}~]. For R = Et a polymeric structure was found with Cu{P(OEt),} units linked to CU~(M~CO~)~ units through a carboxylate 0; this complex reacts with more P(OEt) to give [CU(M~CO~){P(OE~>,}~] which reacts with bidentate ligands L to give [Cu(MeCO,){P(OEt),}L]. A number of new complexes involve sulphur donors. Reaction of 2,s-dithiahexane (dth) with CU(C~O~)~ in MeOH gives deep-green [C~,(dth),(C10~)~] which has all three Cu in similar tetrahedral sites and an e.p.r.spectrum described as resembling those of blue Cu Mixed-metal analogues of the previously reported [c~'~cd'6x12c~]5-[X = D-penicillamine HSCMe2CH(NH2)C02H] were prepared270 with the combinations (Cu'Ni") (Ag'Ni") (Ag'Pd"). A new Cu" cluster [CU~~X~~(M~CN)~](BP~~)~.~M~CN, has been prepared271 from l-methyl-2-mercaptoimidazole (HX); this contains a ring of eight four-co-ordinate Cu' with double S bridging with two more Cu' two-co-ordinate and two square-pyramidal Cu". This complex also has electronic absorption and e.p.r. spectra resembling those of blue Cu proteins. X-Ray p.e. spectra could distinguish Cu' Cu" and Cu"' in many complexes including some in which it has been or might be suggested that the ligands were reduced though they are The series [Cu2X] [Cu2X](ClO4) 264 K.J. Franklin and M. F. Richardson Inorg. Chem. 1980,19 2107. 265 M. Inoue and M. B. Inoue Inorg. Chim. Actu 1980,45 L129. 266 D. B. Brown J. A. Zubieta P. A. Vella J. T. Wrobleski T. Watt W. E. Hatfield and P. Day Inorg. Chem. 1980,19,1945. 267 C. Kappenstein and U. Schubert J. Chem. SOC., Chem. Commun. 1980 11 16. 268 J. A. Connor A. C. Jones and R. Price J. Chem. SOC., Chem. Commun. 1980 137. 269 W. K. Musker M. M. Olmstead R. M. Kessler M. B. Murphey C. H. Neagley P. B. Roush N. L. Hill T. L. Wolford H. Hope G. Delker K. Swanson and B. V. Gorewit J. Am. Chem. SOC., 1980 102 1225. 270 P. J. M. W. L. Birker J. Chem. SOC.,Chem. Commun.1980,946. 271 Y.Agnus R. Louis and R. Weiss J. Chem. SOC.,Chem. Commun. 1980 867. 272 (a)R. R. GagnC J. L. Allison C. A. Koval W. S. Mialki T. J. Smith and R. A. Walton J. Am. Chem. SOC. 1980,102 1905; (b) R. R. GagnC L. M. Henling and T. J. Kistenmacher Znorg. Chem. 1980,19 1226. The Transition Elements [Cu,X(CO)]C104 [X = (71)] have a Cu' together with Cu' in the first case and CuII in the others but [CU~X](C~O~)~-~H,O gave a spectrum indicating X-ray-induced reduction to a complex with two Cu each having a charge of 1.5. A similar result was found for the corresponding chloride but [CUZ~X](C~O~)~.~H~O gave spectra for Cur and Zny.272a The X-ray crystal structure of [Cu,X](C104) is unusually complex with Cur' in a normal square-planar site but with ca.$ of Cu' in a square-pyramidal site involving a 2.55 A interaction with C on a neighbouring Me I Me (71) molecule and the remaining Cu' in unusually for Cu' a square-planar site; the authors that although this structure does not favour electron delocaliz- ation it may be just one of many conformations in solution and that conformation changes may govern the intramolecular exchange rate. The dinuclear complex [Cu,X](C104), [X = (72)] has the octadentate macrocycle folded to bring the Cu pair so close (2.445 A) as to be able to form a Cu-Cu bond; only a single Cu line is seen in the X-ray p.e. Copper in Biology.-Low-temperature absorption and room-temperature c.d. and m.c.d. spectra of the blue copper proteins azurin plastocyanin and stellacyanin that these had a dX2-,,2 ground state in D2dgeometry with d-d bands at 5000-1 1200 cm-' and ligand-to-metal CT bands at 13000-22 000 cm-' from T-or u-orbitals in cysteine or T-orbitals in histidine.The 'H 14N,63*65Cu ENDOR spectrum of stellacyanin was recorded with complete determination of the Cu hyperfine splitting resolving a literature conflict and indicating that Cu is bonded to at least two N but that if there is a third N two must be related by an approximate inversion centre. 275 As models for blue copper proteins comparisons were made between the CuII and Co" complexes of the N,S system found with HB(3,5-Me2pz) with SR as a fourth ligand and the N2S2 system using SR with the new tripod ligand HB(3,5- Me,pz),(C7H7S); there was no marked change in electronic spectra but gll for Cu K.P. Dancey P. A. Tasker R. Price W. E. Hatfield and D. C. Brower J. Chem. Soc. Chem. Commun. 1980 1248. 274 E.I. Solomon J. W. Hare D. M. Dooley J. H. Dawson P. J. Stephens and H. B. Gray J. Am. Chem. Soc. 1980,102 168. 27s J. E.Roberts T. G. Brown B. M. Hoffman and J. Peisach J. Am. Chem. Soc. 1980,102,825. F. A. Hart J. Newbery and P. Thornton was changed and All seems more dependent upon the geometry of the complex.276 The electronic spectra have been reported and assigned for many Cu" complexes of imidazole and polypeptides involving imidazole units and shifts of bands are described when the imidazole ring is not free to rotate. Data for Cu proteins are reviewed and some CT assignments A number of models for bovine erythrocyte superoxide dismutase have been prepared by linking two Cu2' ions with an imidazolate bridge.278 Complex (73) shows an unusually wide range of pH for stability of an imidazolate bridge.278" In the asymmetrically bridged (74) the imidazolate ring is constrained to be in one CuN4 plane but can rotate out of the other CuN plane,278b and in complex (75) this ring is constrained into both CuN4 planes with this complex having only weak axial bonding.278' (73) (74) 0 0 (75) There has been significant progress in understanding haemocyanins.Differences in spectra and catalase activity between haemocyanins from various molluscs and arthropods are explained by the latter group having a more distorted active site and greater accessibility of an axial co-ordination site; the paper gives a useful general survey of the An EXAFS study280aof molluscan haemocyanin suggests that the resting protein contains three-co-ordinate Cu which becomes five-co-ordinate on oxygenation and that both forms have another Cu ca.3.5 A away. With additional rR and electronic spectral data it is concluded that the two Cu are bonded by three histidines in the deoxy-form with additional co-ordination 276 J. S. Thompson J. L. Zitzmann T. J. Marks and J. A. Ibers Inorg. Chim.Am 1980,46,L101. 277 T.G.Fawcett E. E. Bernaducci K. Krogh-Jespersen and H. J. Schugar J. Am. Chem. Soc. 1980 102 2598. 278 (a)P. K. Coughlin S. J. Lippard A. E. Martin and J. E. Bulkowski J.Am. Chem. Soc. 1980 102 7616;(b) R. N.Katz G. Kolks and S. J. Lippard Znorg. Chem. 1980,19,3845;(c) J. C.Dewan and S. J. Lippard ibid. p. 2079. 279 R. S.Himmelwright N. C. Eickman C. D. Lu Bien and E. I. Solomon,J. Am. Chem. SOC.,1980 102,5378. The Transition Elements by bridging 022-and a ligand from the protein (possibly a tyrosine) in the oxygenated form.280a Further rR studies2so6 suggest that two imidazole ligands are in the plane and one out of the plane in the oxy-form. This surprisingly did not show a Cu-O2 stretching mode; a band at 1075 cm-' was thought to be an electronic Raman band possibly a singlet-triplet transition in the Cu2 unit. As a model for haemocyanin a Cu' complex was prepared with (76),a rare example of a Cu' complex with N-donors; this forms a reversible complex with 02,believed to be a Cul' dimer with bridging 022-, but replacement of the imidazole units with pyridines gave a complex which could not be oxygenated.281 Tyrosinase has many chemical and spectral similarities with haemocyanin and it was concluded282 that it had easier accessibility for organic substrates.As a model for tyrosinase various Cu' complexes with bidentate amines were to catalyse the oxidations of alcohols the best yield of MeCHO from EtOH coming with [C~(4,4'-Me~bipy)~]Cl. Copper metallothionein has been isolated from Neurospora crussa and has a similar amino-acid sequence to Zn and Cd metallothioneins and probably contains Cu' bound to cysteine S. The protein is probably involved in Cu storage and detoxification and provision of Cu for tyr~sinase.~~~ The e.p.r.spectrum of the Cu" complex with conalbumin in the presence of CO,*-the two binding sites to be a histidine two tyrosines and a carbonate 0 in a square plane with an axial f120which is lost at pH greater than 8. The reactions of F- CN- and [Fe(CN)J3- with galactose oxidase and its deriva- tives produced by the alkylation of its histidine or the oxidation of its trypotophan have been studied by e.p.r. spectroscopy which shows that the enzyme has Cu" not Cul'* as earlier supposed the loss of the e.p.r. signal now being attributed286 to coupling of Cu" to a radical or to [Fe(CN)J3-. 280 (a)J. M. Brown L. Powers B. Kincaid J. A. Larrabee and T. G. Spiro J. Am. Chem. Soc.1980 102,4210; (b)J. A. Larrabee and T. G. Spiro ibid. p. 4217. 281 M. G. Simmons C. L. Merrill L. J. Wilson L. A. Bottomley and K. M. Kadish J. Chem. Soc. Dalton Trans. 1980 1827. 282 R. S. Himmelwright N. C. Eickman C. D. Lu Bien K. Lerch and E. I. Solomon J. Am. Chem. Soc. 1980,102,7339. 283 M. Munakata S. Nishibayashi and H. Sakamoto J. Chem. Soc. Chem. Commun. 1980,219. 284 K. Lerch Nature (London),1980,284,368. 285 J. L. Zweier J. Biol. Chem. 1980 255 2782. 286 M. E. Winkler and R. D. Bereman J. Am. Chem. SOC.,1980,102,6244. F. A. Hart J. Newbery and P. Thornton Finally in this very exciting area a review287 on caeruloplasmin draws attention to the general ignorance concerning this protein despite its having been known since 1948,one topic of general ignorance presumably being the correct spelling.Silver.-Silver metal is formed from the oxidative quenching of [Ru(bipy),12'* in MeCN or H20 probably uia Ag2+; the presence of reactive Ag in solution suggests that this may be a useful synthetic procedure for reactions of metal atoms.288a The Ag' complex of (77) forms approximately spherical vesicles with radius -430 A; irradiation in the presence of a cyanine dye or [R~(bipy)~(4,4'(C~~H~~)~bipy}]~+ gives irreversible electron transfer to form Ag atoms which are then stabilized inside the vesicle.288b In an unusual experiment designed to study the nucleation of solid materials in living tissue (e.g. CaCO, Fe304) the formation of Ag20 in vesicles of phos-phatidylcholine was by 'H n.m.r.to confirm the integrity of the vesicles and by electron microscopy to observe the formation of Ag,O when NaOH was added to vesicles already charged with Ag'. The first X-ray crystal structure of a sulphur imide complex shows that [Ag(S4N4H4),](C1O4).1.5H20 contains Ag in' a sandwich of S4N4H4crowns with four S co-ordinating Ag tetrahedrally; this is the first example of any S-N molecule co-ordinating through S.290a In other crystallographic work Ag(imidazole),C104 has been to contain an Ag equilateral triangle (Ag-Ag = 3.493A) with an Ag bonded radially to each of these (Ag-Ag = 3.051A) and a linear array of three Ag was found290c in the Ag' complexes of Ni" or Pd" camphor- quinonedioximates (28). Gold.-More cluster complexes have been described.[(Ph3PAu),C1](ClO4) has a C1-bridged dinuclear but the acute AuClAu angle of 82.7" gives "' S. H. Laurie and E. S. Mohammed Coord. Chem. Rev. 1980 33 279. '" (a) T. K. Foreman C. Giannotti and D. G. Whitten J. Am. Chem. Soc. 1980 102 1170; (b) K. Monserrat M. Gratzel and P. Tundo ibid. p. 5527. 289 J. L. Hutchinson S. Mann A. J. Skarnulis and R. J. P. Williams. J. Chem. SOC.,Chem. Commun. 1980,634. 290 (a)M. B. Hursthouse K. M. A. Malik and S. N. Nabi J. Chem. Soc. Dalton Trans. 1980 355; (b) G. W. Eastland M. A. Mazid D. R. Russell and M. C. R. Symons ibid. p. 1682; (c) M. S. Ma R. J. Angelici D. Powell and R. A. Jacobson Inorg. Chem. 1980 19,3121. 291 (a) P. G. Jones G. M. Sheldrick R. Uson and A. Laguna Acfa Crystallogr. 1980 B36 1486; (b) 0.Piovesana and P. F. Zanassi Angew. Chem. Inf. Ed. Engl. 1980,19,561; (c) M. K. Cooper G. R. Dennis K. Henrick and M. McPartlin Inorg. Chim. Acta 1980,45 L151. The Transition Elements Au-Au contacts of -3.06 A. [Au4(MeCS2),] has an Au rhombus with MeCS bridges alternately above and below its plane.291b [AU{(C,H~~)~P},(SCN)] is reduced by NaBH to [AU~{(C,H~,),P},(SCN)~], the first Au9 neutral complex and the first not obviously derived from a centred The X-ray p.e. spectra of various Au, Au9 and Aull complexes compared with those of mononuclear Au' complexes indicate contrary to earlier conclusions and MO calculations that there is little bonding between outside Au atoms.292 The X-ray and neutron-diff raction crystal structure of the MeCONMe,(dma) complex of [AuCl,]-that this is the (dma)2H' salt of [AuCl,]- not a six-co-ordinate Au complex as previously suggested.Comparison of the structures of [AuCl(dien)]C1(C104) and [AuCl{N( C2H4NH2)2}]( C104) shows that the depro -tonated amine has the greater static trans-effect with Au-Cl 2.27 and 2.33A respectively; the paper discusses the relevance of the data to substitution kinetics.294 292 P. M. Th. M. van Attekurn J. W. A. van der Velden and J. M. Trooster Znorg. Chem. 1980,19,701. 293 M. S. Hussain and E. 0.Schiemper J. Chem. SOC.,Dalton Trans. 1980 750. 294 G. Nardin L. Randaccio G. Annibale G. Natile and B. Pitteri J. Chem. SOC.,Dalton Trans. 1980 220.

ISSN:0260-1818    

DOI:10.1039/IC9807700191

出版商:RSC    

年代:1980

数据来源: RSC

摘要:

4 0rganometaIIic Chemistry ByA. J. DEEMING Department of Chemistry University College London London WClH OAJ J. EVANS Department of Chemistry The University Southampton SO9 5NH Introduction Volume 200 of the Journal of Organometallic Chemistry has been marked by a further set of personal accounts of research in this field." Plenary and sectional lectures from the IX IOMC in Dijon in September 1979b and Plenary lectures from the 7th International Congress on Catalysis in Tokyo in the summer of 1980' have been presented. The application of U.V. p.e.s. to transition-metal chemistry has been reviewed.d Several areas of metal alkyl chemistry have been reviewed including organomethyl complexes,e actinide organometallics,f organotin chemistryg and its biological applications," trifluoromethyl compounds,i and catalysis by organo-lithium.' Aspects of Ziegler-Natta catalysisk and hydroformylation' have also been reviewed.Other topics reviewed are transition-metal vapour cryochemistry," chiral metal centres," reactions of dinuclear cobalt dialkyls," platinacyclobutane chem- istry,' metal-mediated routes to steroids,q CO insertion and metal carbenes.s Aspects of metal carbonyl chemistry which have been surveyed include reactions in liquid ammonia,' pz-carbonyls," catalytic" and zirconium hydride" reduction of CO hydride photochemistry" and clusters,Y mixed-metal clusters,' comparisons between a J. Organomet. Chem. 1980 200. Pure Appl. Chem. 1980 52 545-754. Pure Appl. Chem. 1980 52,2051 ff. * A. H. Cowley Prog.Inorg. Chem. 1979 26,46. E.Maslowsky jun. Chem. SOC. Rev. 1980,9 25. T. J. Marks Prog. Inorg. Chem. 1979 25 223. A. G. Davies Adv. Inorg. Chem. Radiochem. 1980 23 1. R. J. Fessenden and J. S. Fessenden Adv. Organomet. Chem. 1980,18,275. R. J. Lagow and J. A. Morrison Adv. Inorg. Chem. Radiochem. 1980,23 178. ' A. F.Halasa D. N. Schulz D. P. Tate and V. D. Machel Ado. Organomet. Chem. 1980 18 55. Ir H.Sinn and W. Kaminisky Adv. Organomet. Chem. 1980,18,99. ' H. Siege1 and W. Himmele Angew. Chem. In?. Ed. Eng. 1980 19 178. W. J. Power and G. A. Ozin Adu. Inorg. Chem. Radiochem. 1980,23,80. " H. Brunner Adv. Organomet. Chem. 1980,18 152. R.Bergman Acc. Chem. Res. 1980,13,113. R.J. Puddephatt Coord. Chem. Rev. 1980 33 149. ' R.L. Funk and K. P. C. Vollhardt Chem. SOC. Rev. 1980,9,41. E. J. Kuhlmann and J. J. Alexander Coord. Chem. Rev. 1980 33 195. ' F. J. Brown Prog. Inorg. Chem. 1980,27,1. ' H. Behrens Adv. Organomet. Chem. 1980,18 2. " R.Colton and M. J. McCormick Coord. Chem. Rev. 1980,31,1. E. L. Muetterties and J. Stein Chem. Rev. 1979 79 479. P.T.Wolczanski and J. E. Bercaw Acc. Chem. Res. 1980,13 121. G. L. Geoffroy Prog. Inorg. Chem. 1980,27 123. A.P.Humphries and H. D. Kaesz Prog. Inorg. Chem. 1979,25 145. * W. L. Gladfelter and G.L. Geoffroy Adv. Organornet. Chem. 1980,18,207; G.L.Geoffroy Acc. Chem. Res. 1980 13,469. 239 A. J. Deeming and J. Evans metal clusters and boranes,"" catalysis by supported metal and metal surface co-ordination chemistry."' Other reviews on specific ligand types include those on organic isocyanides with zerovalent metals,ad chelating organic ligands with a phosphorus donor,"' diolefin cationic complexes of rhodium(I),"f boron heterocy- cles as ligands,"g and electron-rich nickel palladium and platinum compounds.ah The uses of [Fe(CO),(dieny)] complexes in organic synthesis"' and anionic alkene complexes with Li and K cations"' have been reviewed.

ISSN:0260-1818    

DOI:10.1039/IC9807700239

出版商:RSC    

年代:1980

数据来源: RSC

摘要:

A. J. Deeming and J. Evans Part I Alkyls Aryls Carbonyls Cyanides Carbenes and Carbynes By J. Evans 1 Metal Carbonyls Mononuclear Carbony1s.-Gas-phase X-ray p.e.s. spectra of LMn(C0)' derivatives have been recorded.' The Mn 2p C Is and 0 1s binding energies are all linearly related to the inductive constant uIand Pauling electronegativity of L. A precision of better than 0.1 eV is claimed for these energies. Measurements on a series of carbonyl and carbonyl nitrosyl derivatives have shown that in back-bonding to CO more charge is transferred to the carbon atom than the oxygen.2 Charge transfer to NO is as expected more evenly divided. 17 0N.m.r. spectra of some enriched metal carbonyls have been rep~rted.~ Studies on (C5H5)2Fe2(C0)4 are included and the bridging and terminal carbonyl resonances (for the cis-isomer) are separated by ca.200 p.p.m. This nucleus has advantages in the study of manganese ~arbonyls.~ No 55Mn-'70 coupling is observed and the effective resolution of different sites is better than in the more obvious I3Cspectra. 61 Ni' and 95M06 resonances have been directly observed. Even though both nuclei possess electric quadrupoles the signals yere fairly narrow and one-band couplings to phosphorus of ca.200Hz were observable. The 95M0 chemical shifts of (PhMe)Mo(C0)3 and Mo(C0)4(bipy) differ by ca. 1000p.p.m. Carbon-oxygen stretching frequencies of 2044 and 2030 cm-' have been ob- served for the zirconium and hafnium analogues of (C5Me5)2MH2(CO).7 Thus there aa C. E. Housecroft and K.Wade Gazz. Chim. Iral. 1980,110,87. ab B. C. Gates and J. Leito Chem. Tech. (Leipzig),1980 195 248. E. L. Muetterties Zsr. J. Chem. 1980 20 84. ad Y. Yamamoto Coord. Chem. Rev. 1980 32 193. ae I. Omae Coord. Chem. Rev. 1980,32 235. af M. A. Garralda and L. A. Oro Transition Met. Chem. 1980 5 65. ag W. Siebert Adv. Organomet. Chem. 1980 18 301. ah E. Uhlig and D. Walther Coord. Chem. Rev. 1980,33 3. A. J. Pearson Acc. Chem. Res. 1980,13,463. K. Jonas and C. Kriiger Angew. Chem. Znt. Ed. Eng. 1980,19 520. S. C. Avanzino H.-W. Chen C. J. Donahue and W. L. Jolly Znorg. Chem. 1980,19 2201. S. C. Avanzino A. A. Bakke H.-W. Chen C. J. Donahue W. L. Jolly T. Ho Lee and A. J. Ricco Inorg. Chem. 1980,19 1931. 'R. L. Kump and L. J. Todd J.Chem. SOC., Chem. Commun. 1980,292. R. L. Kump and L. J. Todd J. Organomet. Chem. 1980,194 C43. H. Schumann M. Meissner and H. J. Kroth Z. Naturforsch. Teil B 1980 35,639. A. F. Master R. T. C. Brownlee M. J. O'Connor A. G. Wedd and J. D. Cotton J. Organomet. Chem. 1980,195 C17. 'J. A. Marsella C. J. Curtis,?. E. Bercaw and K. J. Caulton J. Am. Chem. SOC.,1980 102,7244. Organometallic Chemistry 241 is a reduction in vco from the free-ligand value even though these are docomplexes. The back-bonding is thought to emanate from a filled MH bonding orbital. There have been a number of reports of electron-deficient or incipiently so metal carbonyl derivatives this year. These include isolation of the two 17-electron species V(CO),PPh38 and [Fe(C0)3(PPh3)2]t.9 Interestingly the reaction of Fe(C0)3(PPh3)2 and iodine was shown to involve electron transfer to produce the latter cation.This underwent a nucleophilic addition to form the 19-electron FeI(C0)3(PPh3)2 and these two species disproportionate to afford the final products Fe(C0)3(PPh3)2 and [FeI(CO),(PPh),]'. M(CO),(PCY~)~(M = Mo or W) have been synthesized as moderately air-sensitive black solids." They bind N, Ha and CZH4 (but not 0,) reversibly and CO and SO irreversibly. The H2M(C0)3(PCy3) adducts are very labile. No vMvIoHvibrations were observed but the tungsten derivative exhibited absorptions at 1568 (vWH),951 (aWHZ), and 464 cm-' which shift on deuteriation. An X-ray crystal structure determination on Mo(CO)~(S~CNP~',)~ has revealed a tri- gonal-prismatic co-ordination geometry and the 7r-systems of the dithiocarbamate ligands are thought to increase the stability of six-co-ordinate 16-electron inter- mediates in this arrangement." (C,H,)MO(CO)~BF has been shown to be a strong Lewis acid forming adducts with cyclic ethers uiz.[(C,H,)M?(CO&S] (BF,) at -30 OC.12 At -20 "C ring opening occurs for [(C5H5)Mo(C0)30CH2CHz]BF4 (1) affording [(C5H5)Mo(C0)30CH2CHzOCHzCHz]BF4 with excess ether. (1) reacts with acetone to yield [(CSHS)Mo(C0)30CMe20CH2dH2]BF4 initially and then (2) with excess acetone. (2) catalyses the formation of 2,2-dimethyl-1,3-dioxolan as shown in Scheme 1. (CSHS)Mo(C0)3BF4 also reacts with water vapour to yield the (2) = [(CsHs)Mo(CO)3(acetone)]BF4 Scheme 1 aquo-complex [(C,H,)MO(CO),(OH~)]BF~.'~ Solutions of the aquo-complex afford {p3-O[Mo(CO)2(C5H,)]3}BF4,characterized by X-ray diffraction.The aquo-complexes [M(CO),(OH2)]' have been isolated for manganese [from Mn(CO)sOC103]'4 and rhenium {from [Re(CO)SS02]AsF6 or Re(C0)5FA~FS}.1S Ethanol and dimethyl ether derivatives of rhenium were also synthesized. The (+)-enantiomer of the neomenthylpentadienyl complex (3) (Scheme 2) has been isolated and shown to possess an R-configuration by X-ray diffraction.16 Reaction with sodium iodide yields (4) in an S-configuration. Carbonyl displacement by iodide the rate of which is first order in (3) and I- thus occurs with retention of configuration at molybdenum. Iodide addition to either the metal or CO is thought to occur initially.J. E. Ellis R. A. Faltynek G.L.Rochfort R. E. Stevens and G. A. Zarb Znorg. Chem. 1980,19,1002. P.K. Baker K. Broadley and N. G. Connelly J. Chem. SOC., Chem. Commun. 1980,775. lo G. J. Kubas J. Chem. Soc. Chem. Commun. 1980,61. '' J. L.Templeton and B. C. Ward J. Am. Chem. SOC., 1980.102,6568. l2 K. Schloter and W. Beck 2.Naturforsch. Teil B 1980 35 985. l3 K. Schloter U. Nagel and W. Beck Chem. Ber. 1980,113 3375. l4 M. R.Snow and F. L. Wimmer Inorg. Chim. Acta 1980,44 Ll89. '' M.Oltmanns and R. Mews 2.Naturforsch. Teil B 1980,35 1324. '' J. W.Faller and Y. Shvo J. Am. Chem. SOC., 1980,102 5396. A. J.Deeming and J.Evans R* l+ R* I NaI The kinetics of the decomposition of HCo(CO) as in equation (1) has been re-investigated in hexane so1ution." The rate depends upon [CO]-l and is also 2HCo(CO) + H2+CO~(CO)~ (1) dependent upon [CO~(CO)~].Thus a second-order plot for the disappearance of the hydride is curved upward. CO also inhibits the rate of photochemical decomposition (with 366 nm light). CO~(CO)~ is the only absorber in this region; it totally absorbs the light. These results provide evidence for both Co(CO) and Co(CO) inter- mediates. Infrared spectroscopic evidence for Co(CO) has been obtained after photolysis of HCo(CO) in both argon and CO matrices in a cryostat." This was corroborated by e.s.r. which also showed the presence of H*in argon and CHO* in carbon monoxide. Flash photolysis (353 nm 5 ns) of a solution of Cr(C0)6 in perfluoromethylcyclo- hexane generates a transient which exhibits a broad electronic absorption at 620 nm.19 After 200 ns it decomposes to another product (A,, -485 nm).The initial transient is thought to be Cr(C0)5 (ti13 ns under CO and 38 ns under Ar) which reacts with Cr(C0)6 to form Cr2(CO)11 as the second species. Irradiation of the hexacarbonyl in liquid xenon solution in the presence of a trace of nitrogen generates CT(CO)~N~, which is stable in solution at -79 0C.20 No matrix-i.r. band-splitting effects occur in these solutions. Evidence for MO(CO)~N~ and Ni(C0),N2 was also obtained. There have been several reports of metal carbonyl complexes acting as homo- geneous catalysts for the water gas shift [equation (2)] a process which presently has efficient heterogeneous catalysts.One system is based on [Rh(CO)2Cl]2 HI acetic H,O+ CO = H2 +CO? (2) acid and water.2' Two different kinetics laws were found at ca. 90 "C and 65 "C. At the higher temperature Rh"' carbonyls predominate and loss of CO was thought to be the rate-determining step but at 65 "C Rh' species predominate and H2produc-tion from oxidation of the metal by protons was considered to be rate limiting. Another system used Fe(CO) in basic methanol.22 Some CO was required to prevent oxidation of iron to FeCO, but the rate is independent of CO. The R. W. Wegman and T. L. Brown J. Am. Chem. SOC.,1980,102,2494. l8 R. L. Sweany Inorg. Chem. 1980,19 3512. l9 R.Bonneau and J. M. Kelly J. Am. Chem. SOC.,1980,102 1220. 2o W.B.Maier jun. M. Poliakoff M. B. Simpson and J. J. Turner J. Chem. SOC.,Chem. Commun. 1980 587. 21 E. C. Baker D. E. Hendriksen and R. Eisenberg J. Am. Chem. Soc. 1980,102 1020. 22 A.D.King jun. R. B. King and D. B. Young J. Am. Chem. Soc. 1980,102 1028. Organometallic Chemistry OH-OH-Scheme 3 mechanism in Scheme 3 was proposed. Sulphur in the form of Na2S poisons the catalyst [Fe3(C0)9S2 is formed] but the Group VI hexacarbonyls Ru~(CO)~~ and OS~(CO)~~ are active in the presence of sodium sulphide in aqueous methanol at 1600C.23 Finally [R~Cl(CO)(bipy)~]Cl is photocatalytically active.24 Under argon (CsHs)2NbH3 reacts with Cr(C0)6 to form (CsHs)2NbH(C0).2s However under H2 this same mixture now affords ethane (-10% based on Nb) and metal oxides.The carbon atoms came from the hexacarbonyl. Ethylene appears to be formed from hydrogen atoms in (C5H5)2NbH3 and is then reduced by a hydrogen atom arising from gaseous hydrogen. Mo(CO)~ and W(CO)6 both afford methane and the latter also yields some ethane. There is i.r. evidence for Mg-O=C-Fe interactions in Mg[(CsH5)Fe(CO)2]2 * 4THF.26 Treatment with an excess HCl in THF at -198 "C yields methane ethylene and ethane; (C5HS)Fe(C0)2H is the soluble organometallic product. Comparison with other derivatives indicates that the metal-oxygen interaction is important. Adsorption of Mo(CO)~ on yA1203 has been shown to produce adsorbed Mo(CO) ~nits.~~.~' This is a very active CO methanation catalyst more active than traditional heterogeneous catalysts so evidently mononuclear complexes can medi- ate this process.28 An activated catalyst (heated to 500 "C under He) also catalysed methanation but this contained metal clusters of ca.40 A diameter.29 Dinuclear Carbony1s.-The M2L10 system has been investigated by EHMO cal- culation~.~~ Interconversion between non-bridged e.g. [Re2ClsL2l2- and doubly bridged e.g. V2(C0)8(PR2)2 systems is forbidden in the d4 manifold but is allowed for a d7-d' dimer such as Mn2(CO)lo. (CSH5)2Cr2(C0)4 has been similarly studied and found to possess little metal-metal triple bond ~haracter.~' Its high reactivity should more correctly be ascribed to two low-lying acceptor orbitals. (R'C2R2)Co2(C0)6 derivatives have been reduced electrochemically in situ in an e.s.r.cavity to form their radical anions.32 Frozen THF solution spectra were recorded and are completely anisotropic in g and aco. The unpaired electron is thought to reside in a b2 Co-Co* orbital. A. D. King jun. R. B. King and D. B. Young 1 Chem. SOC.,Chem. Commun. 1980,529. 24 D.J. Cole-Hamilton J. Chem. SOC.,Chem. Commun. 1980 1213. 25 K. S. Wong and J. A. Labinger J. Am. Chem. SOC. 1980,102 3652. 26 A. Wong M.Harris and J. D. Atwood J. Am. Chem. SOC. 1980,102,4529. 27 M. Laniecki and R. L. Burwell jun. J. Coiloid Interface Sci.,1980,75,95. A. Brenner and D. A. Hucul J. Am. Chem. SOC. 1980,102,2484. 29 R.G.Bowman and R. L. Burwell jun. J. Catal. 1980,63,403. 30 S. Shaik R.Hoffmann C. R. Fisel and R. H. Summerville J. Am. Chem. SOC. 1980,102,4555.31 E. D.Jemmis A. R. Pinhas and R. Hoffmann J. Am. Chem. SOC. 1980,102,2576. 32 B. M. Peake P. H. Rieger B. H. Robinson and J. Simpson J. Am. Chem. SOC.,1980,102,156. 244 A. J. Deeming and J. Evans X-Ray diffraction has revealed structural differences between (C5H5)2Ni2(C0)2 and (C5H4Me)2Ni2(C0)2.33 The former has two independent molecules in the unit cell both with bent Ni2(C0)2 units (-146" angle between the two Ni2C0 planes). However this moiety is planar in crystals of the methyl-substituted derivative; both have bent cores in solution. Heating a solution of (C5H5)2M02(C0)4(SR)2 (R = Ph or But) in heptane under reflux affords (C5H5)2M02(CO)2(SR)2.34 The Mo-Mo distance in the former type (R = Ph) is 394.0 pm consistent with a bond order of zero whereas in the dicarbonyl dimer (R = But) it is 261.6 pm more appropriate to a formal bond order of 2.Decarbonylation also causes the Mo2S2ring to become planar. Only one of the two dicarbonyl derivatives (R = Ph) forms its tetracarbonyl under 50 atm of CO. Reac- tion of H3Re3(C0)12 with dppm in refluxing n-octane yields the co-ordinatively unsaturated dimer (9,which possesses a rhenium-rhenium bonding distance of 289.3 pm.35 The dimer (5) forms an adduct with P(OMe) and [Re2(C0)6(dppm)- (RN=CH)H] with several isocyanides. However with MeCN two isomers are formed. One was shown to be (6) by X-ray diffraction. Ph2PnPPh2 PhzP4PPh2 IHI IHI (CO),Re/-'Re(CO) (CO),RS Re(C0)3 'H' hN' I1 A metal-metal bond can be generated simply by reactions of (C5Me5)Rh(C0)2 with HBF4.36 [(C5Me5)2Rh2(C0)3H]BF4 is generated and it provides a ready synthesis of the previously unknown (C5Me5),Rh2(CO),.The kinetics of substitution into CO~(CO)~ have been studied.37 While substitution by weak nucleophiles like 13C0 and AsPh seems to require a rate-determking CO loss the kinetics of the much faster phosphine reactions [e.g. reaction (3)] are more complex and are inhibited by oxygen. A radical chain mechanism after breakdown of a Co2(CO),L adduct into CO(CO)~L was proposed. Substitution of and CO(CO)~ MnRe(CO)lo by PPh3 PBu3 and P(OPh)3 has also been re-in~estigated.~~ L(C0)4MnRe(C0)5is formed early in the reaction but later products are (CO)5MnRe(C0)4L and L(C0)4MnRe(C0)4L. There are no homometallic products and the kinetic data can be accommodated by an Id mechanism with CO loss from manganese rather than homolytic cleavage of the metal-metal bond.33 L. C. Byers and L. F. Dahl Znorg. Chem. 1980,19 680. 34 I.B. Benson S. D. Killops S. A. R. Knox and A. J. Welch J. Chem. SOC.,Chem. Commun. 1980,1137. 35 M. J. Mays D. W. Prest and P. R. Raithby J. Chem. SOC.,Chem. Commun. 1980 171. J. Plank D. Riedel and W. A. Herrman Angew. Chem. Int. Ed. Engl. 1980 19 937. 36 37 M.Absi-Halabi J. Atwood N. P. Forbus and T. L. Brown J. Am. Chem. SOC.,1980,102,6248;N.P. Forbus P. Oteiz% S. G. Smith and T. L. Brown J. Organomet. Chem. 1980,193 C71. 38 D.Sonnenberger and J. D. Atwood J. Am. Chcm. SOC.,1980,102,3484.Organometallic Chemistry Synthesis of Rhz(CO)2(dppm)z has been This highly reactive complex forms adducts with a variety of donors such as CO and also catalyses acetylene hydrogenation to ethane. The CO adduct is Rhz(p-CO)(CO)z(p-dppm)z,which can be reversibly protonated to form [Rh2(p-H)(p-CO)(CO)z(p-dppm)z]+. The last complex established by X-ray diffraction catalyses the water gas shift reaction. CO~(CO)~ in diglyme solution has been found to provide a fairly active catalyst for the conversion of synthesis gas into ethanol and other C2oxygenates at 200 "C and 150atm.40 The attendant cobalt chemistry is evidently complex and a number of (7) novel structures were proposed. Treatment of a diglyme solution of CO~(CO)~ with 100 atm of CO at 200 "C yields cobalt carbide and a yellow oil (vco 2080 and 1800cm-') thought to be (7).Hydrolysis of a reaction solution has afforded a yellow gas which is proposed to have a stable component (8) and another (9) which eliminates acetone. The brown reaction solutions obtained from systems operating below 180"C exhibit i.r. bands due to Co2(CO)*,[C~(diglyme).][Co(CO)~]~, and (lo) thought to be in equilibrium with (11) (Scheme 4). As written (10) is particularly noteworthy since it has two 17-electron cobalt centres. However the yellow solutions obtained from runs above 200°C exhibit no metal carbonyl i.r. bands. Polynuclear Carbony1s.-A quantitative method for locating hydrogen atoms indirectly has been pre~ented.~~ The potential energy for all intramolecular contacts is optimized and a set of transferable parameters given.Previously unknown sites in for example HzOs6(CO)18 have been determined. One-term pseudopotential cal- culations have been used to study the preferred arrangements of polyhedra of 12 to 16 CO ligands around a cluster core.42 Experimentally determined structures generally had higher repulsive energies than the theoretically preferred ones. This could be due to a distortion determined by the metal polyhedron crystalline packing or perhaps experimental error. 39 C. P. Kubiak and R. Eisenberg J. Am. Chem. SOC., 1980,102 3637. R. J. Daroda J. R. Blackborow and G. Wilkinson J. Chem. SOC.,Chem. Commun. 1980 1098. 41 A. G. Orpen J. Chem. SOC., Dalton Trans. 1980 2509.42 R.E. Benfield and B. F. G. Johnson J. Chem. SOC.,Dalton Trans. 1980 1743. 246 A. J. Deeming and J. Evans 103 Rh n.m.r. has been directly observed for some cluster complexes.43 The spectrum of [Rh9P(C0)21]2- exhibits three phosphorus split doublets at -80 "C consistent with its capped square-antiprismatic metal structure. At room tempera- ture the Rh9 skeleton is fluxional at a rate sufficient to give a single sharp doublet. Only two resonances were observed for [Rh12(C0)30]2- in spite of there being three rhodium sites. However the third site was located by t3C{103Rh} A 13C n.m.r. n.m.~-.~~ study of some nickel clusters e.g. [Ni5(C0)12]2- and [Ni12(C0)21H]3- has been pre~ented.~~ This includes the detection of a new anion uiz. [Ni7(C0)15]2- which exhibits five 13C resonances.Three of these are due to terminal groups and the remainder to bridging groups; this is consistent with a capped trigonal-antiprismatic metal skeleton. The 'H n.m.r. spectrum of (C5H4Me)3Nb3(C0)7 (12) is temperature dependent.46 At 26°C there is an apparent mirror plane in the molecule due to a local rotation about Nbl. However above 20 "C the two types of cyclopentadienyl ligand interchange owing to a migration of the p3-q2-CO ligand over one face of the triangle. Comparison between the U.V. p.e.s. spectra of OS~(CO)'~ and H3Re3(C0)12 indicates that two bands at ca. BeV due to metal-metal bonding orbitals are replaced by a pair at ca. 12 eV.47 The latter bands in the hydride have been identified as three-centre two-electron MHM orbitals and on that basis a set of styx rules of the type used in borane chemistry have been proposed.A series of EHMO calculations on trinuclear metal carbonyls has led to a rationalization for the difference in electron counting behaviour between Ni3(C0)62- and M3(C0)9' containing The former only has one frontier orbital (an a2)1using the Ni pz and CO T*orbitals) likely to interact strongly with other groups above and below the planes. This will lead to relatively weak interactions between stacked triangles in e.g.,Ni6(C0)12~-(12) (13) Similar calculations have also been carried out on (C5H5)2Rh2(p-C0)2-~~ntaining The bonding description to another metal in e.g. [(C5H5)2Rh3(CO)4]- is similar to that of the Chatt-Dewar-Duncanson model for ethylene co-ordination.In keeping with this addition reactions across the formal metal-metal double bond in (C5Me5)2Rh2(C0)2 have been reported." These include addition of d lo platinum moieties to form complexes like (13). Photochemically generated fragments have 43 0.A. Gansow D. S. Gill F. J. Bennis J. R. Hutchinson J. L. Vidal and R. C. Schoening J. Am. Chem. SOC.,1980 102,2449. 44 B. T. Heaton L. Strona S. Martinengo and P. Chini J. Organomet. Chem. 1980 194 C29. 45 G. Longoni B. T. Heaton and P. Chini J. Chem. SOC.,Dalton Trans. 1980 1537. 46 L. N. Lewis and K. G. Caulton Znorg. Chem. 1980,19 3201. 47 J. C. Green D. M. P. Mingos and E. A. Seddon J. Organomet. Chem. 1980,185 C20. 48 J. Evans J. Chem. Soc. Dalton Trans. 1980 1005.49 A. R. Pinhas T. A. Albright P. Hoffmann and R. Hoffmann Helu. Chim. Acta 1980,63 29. N. M. Boag M. Green R. M. Mills G. N. Pain F. G. A. Stone and P. Woodward J. Chem. SOC.,Chem. Commun. 1980,1171. Organometallic I (cob OC/Mn 0 l.@Lo LrRr co-/CO+Co\ (C5Me5) (c5Me5)’ ‘c’ 0 (C5Me5) (C5Mes) o (14) (15) been added to the corresponding cobalt dimer and these generate two series of complexes e.g. (14)and (15),which differ by one bridging gro~p.’~ The Lewis base character of H20~3(C0)10 has also been exploited; Fe(C0)3 [from Fe2(CO),] and (C5H5)Co [from (C5H5)C~(C0)2] moieties have been added to the clu~ter.’~ and this same complex is The former reaction afforded H2FeO~3(C0)13 accessible from the reaction of H20s3(CO)lo with the nucleophile Fe(C0)42-.Thus the cluster is amphoteric in the Lewis sense. Carbonylation of Pd(N0&L2 (L = PPh3 PPh2Me or PPhMe2) has yielded Pd4(C0)’L4 cluster^.'^ A crystal structure determination of the PPhzMe derivative has shown that the Pd atoms are in a butterfly arrangement with each Pd-Pd bond (274.2pm) supported by a bridging carbonyl. [PPN],[OS~(CO)~,] has been shown to contain a bicapped octahedral osmium core in accord with skeletal electron counting rules.54 This compliance extends to the [OS&(CO)~~]~- anion which has a tetracapped octahedral metal unit.” The cluster is a C.C.P. fragment and each face contains seven metal atoms; the carbonyl groups are all approximately perpendicular to these faces reminiscent of metal surface studies.Protonation of [Rh14(C0)25]4- to yield [HRh14(C0)25]3- (16)causes little distortion of the b.c.c. metal ‘H{lo3Rh} and 13C{103Rh} n.m.r. experi- ments have located the five rhodium resonances (the interstital rhodium resonates ca. 5300 p.p.m. away from the external atoms) and also demonstrated that the hydride is interstitial and migrates within the Rhb,.v.,,dd cage and does not visit Rh,. a (16) [HRhdCO)& metal skeleton 51 L. M. Cirjak J.4. Huzng 2.-H. Zhu and L. F. Dahl J. Am. Chem. SOC.,1980,102,6623. 52 J. S. Plotkin D. G. Alway C. R. Weisenberger and S. G. Shore J. Am. Chem. Soc. 1980 102,6156. 53 J. Dubrawski J. C. Kriege-Simondsen and R. D. Feltham J. Am. Chem. Soc. 1980,102,2089. 54 P.F. Jackson B. F. G.Johnson J. Lewis and P.R. Raithby J. Chem. Soc. Chem. Commun. 1980,60. 55 P.F. Jackson B. F. G. Johnson J. Lewis M. McPartlin and W. J. H. Nelson J. Chem. SOC.,Chem. Commun. 1980,224. ” G.Ciani A. Sironi and S. Martinengo J. Organomet. Chem. 1980,192 C42; B. T.Heaton C. Brown D. 0.Smith L. Strona R. J. Goodfellow P. Chini and S. Martinengo J. Am. Chem. Soc. 1980,102 6175. 248 A. J. Deeming and J. Evans In contrast the additional external ligand in [Rh14(C0)26]2- causes a distortion of the metal polyhedron to an array intermediate between close packed and b.c.c. even though these Rh14 clusters are all isoele~tronic.~' Syntheses of a number of mixed-metal clusters have been reported. Treatment of with [R~~C(CO)I~]~' [CU(NCM~)~]' gives rise to an octanuclear complex [Rh6(CO)15C(C~NCMe)2].58 The copper atoms cap the triangular faces of the Rh6 trigonal prism and the Rh-Cu distance (266pm) indicates a relatively strong bond.(g2-HgBr)[R~3(C0)9(g3-C2B~t)] exists as a bromide-bridged dimer in the It is the first example of a mercury atom bridging two transition metals and again the heterometallic distance (274 pm) indicates a strong bond. The type of mixed-metal cluster formed when (Me3B2N)2[Fe3(CO)ll] is treated with a palladium(I1) or platinum(r1) halide complex is highly dependent upon the molar ratio of the two metals.60 The anions (17) are formed with a deficiency of the halide complex. All five (17) M=PdorPt metal atoms are coplanar in the palladium derivative but for the heavier central atom the two Fe2Pt rings have a 7" twist.This allows a stronger interaction to the semi-bridging carbonyl group. A higher proportion of platinum yields [Fe3Pt3(CO)15]2- and [Fe4Pt6(C0)22]2-. Treatment of (Me3BzN)2[Fe4(CO)13] and K2PdC14 gives a number of products including the remarkable (NMe3Bz)3[Fe6Pd6(Co)24H].The molecular structure consists of a central Pd6 trigonal antiprism and the six iron atoms bridge all but two trans faces. Resolution of the optically active cluster (18)has been effected by substitution with (R)-PMePrPh and separation of the two diastereoisomers by fractional crystal- lization.61 The absolute configuration of one of these (19),was determined by X-ray diffraction and regeneration of (18)was effected by carbonylation in the presence of methyl iodide.Two diastereoisomers of (20) have also been separated by t.l.c.62 Their CD spectra between 280 and 500 nrn are essentially mirror images demon- strating that these bands are due to the cluster unit. No interconversion was detectable after 20 min at 100 "C. (CsHs)(CO)z Ph (CO)3Fe/S\Co(C0)2L /4 (18) L=CO (19) L = (R)-PPhMePr (20) 57 S. Martinengo and A. Sironi J. Chem. SOC.,Chem. Commun. 1980 1140. '' V. G. Albano D. Braga S. Martinengo P. Chini M. Sansoni and D. Strumolo J. Chem. SOC.,Dalton Trans. 1980 52. 59 R. Fahmy K. King E. Rosenberg A. Tiripicchio and M. Tiripicchio Camellini J. Am. Chem. Soc. 1980,102,3626. 6o G. Longoni M. Manassero and M. Sansoni J. Am. Chem. SOC.,1980,102 3242. 61 F. Richter and H. Vahrenkamp Angew.Chem. Inf. Ed. Engl. 1980,19,65. 62 A. J. Arce and A. J. Deeming J. Chem. SOC.,Chem. Comm. 1980 1102. Organometallic Chemistry Twenty years after the synthesis of the first tricobalt-carbon compounds iridium analogues of formulae Ir3(CO),ER (E= C R =Ph or Me; E =Si or Ge R =Me) have been isolated from the reaction of NaIr(CO) and the appropriate RECl derivati~e.~~ The interstitial hydride in [HRU~(CO)~~]-has been located by neutron diff ra~tion.~~ It is interesting that this and [HCo6(CO),,]- both exhibit low-field chemical shifts as opposed to the Ni12 and RhI3 hydrides which resonate in the normal transition-metal hydride region. There is an obvious correlation with the anisotropy of the proton sites in these two sets. Several interesting papers have been published about metal carbides and related systems.Oxidation of [co6c(co)1~]2- by FeC13 causes a cluster structural change from trigonal prismatic to distorted ~ctahedral.~’ is The product [co~c(co)~4]- paramagnetic and has one long edge. The odd electron is considered to be in an antibonding orbital largely localized in that region. Reaction of [FeSC(CO)14]2- with a wide variety of potentially co-ordinatively unsaturated ML system has generateu a new series of hexanuclear metal carbides.66 For example [MOF~~C(CO),~]~- (21) was obtained from Mo(CO)~(THF)~. Oxidation of three of these by Fe3’ causes the loss of one iron atom. So oxidation of [RhFe5C(C0)16]- [formed from Rh2(C0),C12] yields [RhFe4C(C0)14]- (22).[Fe5N(C0)14]- has been obtained from (C0)3 2-M-CO -I (C0)3 1-TqY C\ (co)~F~’ cI‘Fe(C0)2 (co)3FeLjq%o / \Fe/Rh(c0)2 o$2!?$ Fe (CO)3 (cob (22) (21) the reaction of Na2Fe2(CO)8with an excess of Fe(CO)* with NOBF above 130 0C.67 Protonation by sulphuric acid occurs on a basal Fe-Fe edge of a square pyramid and not on the nitrogen. In the crystal the product HFeS(C0)14N has three bridging carbonyls and the nitrogen is 9.3 pm below the Fe4 basal plane. [Fe4N(CO),,]- is formed below 130“C and protonation affords HFe,N(CO),, in which the nitride bridges the four iron atoms in a butterfly configuration. The Fe4 butterfly structures have received considerable attention. Prolonged reaction of (NEt4)2[Fe5C(C0)14] with HC1 has yielded HFe4CH(C0)12 (23) which has a unique q2-CHgroup.68 Interestingly slow exchange between the two proton sites in solution and also with D20 has been demonstrated.The carbon-bound 63 W. Kruppa and G. Schmid J. Organomet. Chem. 1980,202,379. 64 P. F. Jackson B. F. G. Johnson J. Lewis P. R. Raithby. M. McPartlin W. J. H. Nelson K. D. Rouse J. Allibon and S. A. Mason J. Chem. SOC., Chem. Commun. 1980 295. V. G.Albano P. Chini G. Ciani M. Sansoni and S. Martinengo J. Chem. SOC., Dalton Trans. 1980 163. 66 M. Tachikawa A. C. Sievert E. L. Muetterties M. R. Thompson C. S. Day and V. W. Day J. Am. Chem. SOC.,1980,102 1725. 67 M. Tachikawa J. Stein E. L. Muetterties R. G. Teller M. A. Beno E. Gerbert and J. M. Williams J. Am. Chem. SOC., 1980,102,6648.68 M.Tachikawa and E. L. Muetterties J. Am. Chem. Soc. 1980,102,4541; M. A. Beno J. M. Williams M. Tachikawa and E. L. Muetterties ibid. p 4542. A. J. Deeming and J. Evans hydrogen is the first to be abstracted by NEt3 forming [HFe4(C0),,(p4-C)]-. Further reaction with the base affords [Fe4(CO)12(p4-C)]2- which reacts with sources of co-ordinatively unsaturated species to yield pentanuclear e.g. [RhFesC(C0)14]- or hexanuclear clusters e.g. [Mo~F~~C(CO),~]’-H Me (C0)3Fe$\ Fe(CO)3 ( Fe 3 (cob2HI 0)3 (co) /‘ 3Fee\-Fe( CO)3 /44&3 (co)3‘H ‘0 (23) (24) Methylation of the p3-C0 group in [Fe4(C0)13]2- to form [Fe4(CO)12(COMe)]- causes the three semi-bridging carbonyl groups to Subsequent pro- tonation causes a skeletal change from a tetrahedron to a butterfly as for the parent dianion; (24) is the Prolonged treatment of the dianion with HS0,CF3 gives rise to methane hydrogen and carbon monoxide.” Labelling studies demon- strated that the methane carbon is from the cluster’s CO groups and the hydrogen atoms emanate from the acid and not the hydrogen gas.Treatment of [Fe4(C0)12(COMe)]- with DS03CF3 similarly yields CD4,71 and careful 13C labelling studies have shown that the methane carbon is the carbon of the COMe ligand in this anion. This suggests that the ,u4carbon site in (24)is a favoured one for CO activation and perhaps the generation of methane from [Fe4(C0)13]2-involves HFe4(CO),,(COH) as an intermediate. The carbonylation product of [Rh12(C0)30]2- which had tentatively been ,described as [Rh12(CO)-34]2- has now been shown to be [Rhs(CO)ls]- which contains a trigonal bipyramid of rhodium The arrangement of CO ligands may differ between the solid state and solution.This anion and [Rh(CO),]- have been shown to be present between 50 and 200 “C under 500-1000 atm of CO-H2 using a variety of rhodium prec~rsors.~~ These solutions catalyse polyol formation and have an optimum temperature of -290 “C. The i.r. study indicated that larger clusters e.g. [Rh14(C0)2s]4- were also present under these conditions. The centred clusters [Rh6C(C0)15]2- [RhgP(C0)21]2- and [Rh17S2(C0)32]3- are also catalysts and show enhanced stability. Other carbonyls have been screened for synthesis gas conversion under 2000 bar of CO and HZat 230 “C in toluene and N-methyl- pyrrolidone.” The solvent was very important and the most active systems were Coz(CO)8-toluene RU~(CO),~-NMP Rh(CO)zacac-NMP and Ir4~C0)12-NMP.Liquid products such as methanol and methyl formate predominated. HCO(CO)~ was detected after the cobalt reaction was completed. Fe(CO)5 RU~(CO)~~ and Os3(CO)12 have also been studied in glymes and 2-rnethoxyethan01.~~ The latter 69 E. M. Holt K. Whitmire and D. F. Shriver J. Chem. SOC.,Chem. Commun. 1980,778. 70 P. A. Dawsog B. F. G. Johnson J. Lewis and P. R. Raithby J. Chem. SOC.,Chem. Commun. 1980,781. 71 K. Whitmire D. F. Schriver and E. M. Holt J. Chem. SOC.,Chem. Commun. 1980 780. ’* K.Whitmire and D. F. Shriver J. Am. Chem. Soc. 1980 102 1456. 73 A. Fumagalli T.F. Koetzle F. Takusagawa P. Chini S. Martinengo and B. T. Heaton J. Am. Chem. Soc. 1980,102 1740. 74 J. L. Vidal and W. E. Walker Inorg. Chem. 1980 19 896. 75 W. Keim M. Berger and J. Schlupp J. Catal. 1980,61 359. 76 R. J. Daroda J. R. Blackborow and G. Wilkinson 1 Chem. SOC.,Chem. Commun. 1980 1101. Organometallic Chemistry 25 1 solvent increased reactivity markedly. At 180"C under 180 atm of CO-H2 (1:2) methanol was formed with 45% selectivity but noterminal or bridging CO vibrations were obseqved from the retrieved solutions. A band at 1725 cm-' ascribed to Ru-C(O)O(H)(R) moieties was observed and on standing RU(CO)~ Ru~(CO),~ and an alkoxide gel were formed. Out of six elements studied only osmium clearly gave hydrido-species uiz.H,Os(CO) and H20s2(CO),. In acetic acid solution Ru~(CO)~~ all catalyse the conversion of H,Ru,(CO),~ and H3R~3(C0)9CMe CO-H2 into methyl acetate and ethyleneglycol dia~etate.~' Under 400 atm at 200°C the i.r. spectra indicate that RU(CO)~ is present and on work-up the ruthenium is isolated as RU~(CO)~~. Again the choice of solvent is critical. Carboxylic acids appear to be specific promoters for glycol formation. Carbonyl insertion into H2Ru(C0) to produce a formyl complex is thought to be involved. Several clusters e.g. Ir4(CO)12 and Rh6(C0)16 have been shown to promote the catalytic reduction of nitrobenzene to aniline by synthesis gas.78 Synthesis of new heterogeneous catalysts from metal carbonyls has also received much attention.Interaction of OS~(CO)'~ with silica gel has been shown to proceed via formation of HOs3(CO)lo(O-oxide).79 An EXAFS study found an 0s-0s bond length of 268 pm which is ca. 20 pm shorter than expected. Similar species have been identified on other oxide^.^^*'^ 1.r. studies have indicated that this type of species is also involved in the chemisorption of RU~(CO)~~ on alumina. Charac- terization of this last system by inelastic electron tunnelling spectrosopy has proved difficult; the cluster acts as a barrier to tunnellingS8' Interaction and thermal decomposition of RU~(CO)'~ on y-Al2o3 and silica H,Ru,(CO),~ and RU~C(CO)~~ gel have been studied and it is noteworthy that the nature of the surface carbonyl species (probably Ru" subcarbonyls) formed by 100"C is independent of the initial q-A1203 becomes red on contact with a hexane solution of Fe3(C0)12.83 This has been shown to be due to [HFe,(CO),,]- which may be extracted and isolated.This solid reduces nitroarenes to nitroamines and azoarene~.~~ After decomposition under CO-H2 this material has a higher Fischer-Tropsch selectivity for low molecular weight ~lefins.'~ Other iron carbonyls and oxides are similar. The y-A1203 decomposition product contains small iron particles (<2 nm) and give propene with 45% selectivity. At the end of the run the iron particles are now 20-50 nm in diameter. An activated Fe3(CO),,-Mg0 system also forms propene (32%)with methane (26%)and ethylene (9"/0)as the other major products.86 This same catalyst also converts ethylene into propene (70%) and other C1-C4 hydro- carbons.This suggests that the catalyst contains surface-bound C1 moieties which are 77 D. B. Dombek J. Am. Chem. SOC.,1980,102,6855. 78 T. Cole R. Ramage K. Cann and R. Pettit J. Am. Chem. SOC., 1980,102,6182. ''A. K.Smith B. Besson J. M. Basset R. Psaro A. Fusi and R. Ugo J. Organomet. Chem. 1980,192 C31;B. Besson B.Moraweck A. K. Smith J. M. Basset R. Psaro A. Fusi and R. Ugo J. Chem. SOC. Chem. Commun. 1980,569. J. Evans and B. P. Gracey J. Chem. SOC.,Chem. Commun. 1980,852. W.M.Bowser and W. H. Weinberg J. Am. Chem. SOC.,1980,102,4720. V.L.Kuznetsov A. T. Bell and Y. I. Yermakov J. Catal. 1980,65 374. 83 F. Hugues A. K. Smith Y. Ben Taarit J. M. Basset D. Commereuc and Y. Chauvin J.Chem. SOC. Chem. Commun. 1980,68. 84 H. Alper and M. Gopal J. Chem. SOC.,Chem. Commun. 1980,821. 85 D. Commereuc Y. Chauvin F. Hugues J. M. Basset and D. Olivier J. Chem. SOC.,Chem. Commun. 1980,154. 86 F. Hugues B. Besson and J. M. Basset J. Chem. SOC.,Chem. Commun. 1980,719. 252 A. J. Deeming and J. Evans either hydrogenated to methane or react with ethylene to form propene via a metallacyclobutane intermediate. Methods of anchoring clusters to oxides have also been investigated. Tetrairidium clusters have been bound to PPh2(CH2)3SILS7 and ruthenium and osmium clusters bound to HS(CH2)&L as HM3(CO)to[S(CH2)3SIL].80v88 This latter technique was also extended to other oxides of varying acidities." The use of bridging ligands as anchoring groups may stabilize the cluster and accordingly Co,(CO),CSIL and related species were synthesized from CO~(CO)~CS~C~~.Both H20s,(CO),PPh,- (CH2),SIL and OS~(CO)~~PP~~(CH~)~SIL catalyse ethylene hydrogenation but at a lower rate than their dissolved PPh2Et analogues.89 Both the anchored clusters become deactivated and this was correlated with the formation of H3Os3(C0),(CMe)PPh2(CH2)SIL, identified by its i.r. spectrum. 2 Carbonyl Analogues and COz Complexes An X-ray diffraction study on K,[Nb(CN)J has found a dodecahedra1 co-ordination geometry at Nb with significantly different Nb-C distances to the two types of cyano-ligand~.~~ Solid-state Raman data were also consistent with this but Raman and i.r. spectra of aqueous solutions clearly show a change of geometry to square antiprismatic.CS~[MO(CN)~] * 2H20 contains a new M(CN)s"-co-ordination geometry in the crystal viz. a trigonal prism with two square faces capped." The vibrational spectra of [Mo(CN),I4- in solution are consistent with a D5,,pentagonal-bipyramidal co-ordination This was also found for K,Na[Mo(CN),] * 2H20 in the crystal but the all-potassium salt is not isomorphous and is less symmetrical. Pentagonal-bipyramidal geometries have also been reported for K4[Re(CN),] -2H20 (X-ray ~tructure)~~ and its technetium analogue (vibrational data on solid and Oxidation of [Mo2S2(CN),J6- gives rise to a purple diamagnetic product which was isolated as (PPh4)4[( ~-S,)(~-SO,)MO,(CN)~].~~ Considering the bridging ligands as molecular SO and S2*- there are two Mo"' centres separated by 273.0 pm in the crystal.Treatment of [Mo~S(S~)~]~-with cyanide has yielded the trinuclear anion [( p3-S)(p2-S)3M03(CN)9]5-.96 The bridged Mo-Mo distances are 277.3 pm. The unsaturated complex (C5H5)2M02(C0)4 forms an adduct with cyanide and the crystal structure determination of (NEt4)[(CsH5)2M02(CO)4CN] has shown the cyanide ligand to be acting as a four-electron v1,q2donor.97 The geometry of this bridging ligand is presented in (25). " T. Catrillo H. Knozinger J. Lieto and M. Wolf Inorg. Chim. Acta 1980 44 L239. '' T. Catrillo H. Knozinger and M. Wolf Inorg. Chim. Acta 1980,45 L235. 89 S. C. Brown and J. Evans J. Organomet. Chem. 1980 194 C53. 90 M. B. Hursthouse A.M. Galas A. M. Soares and W. P. Griffith J. Chem. SOC. Chem. Commun. 1980 1167. 91 S. S. Basson J. G. Leipoldt L. D. C. Bok J. S. van Vollenhoven and P. J. Cilliers Acfu Crystullogr. 1980 B36,1765. 92 M. B. Hursthouse K. M. Abdul Malik A. M. Soares J. F. Gibson and W. P. Griffith Inorg. Chem. 1980,45 L81. 93 J. M. Manoli C. Potvin J. M. Brbgeault and W. P. Griffith J. Chem. Soc. Dalton Trans. 1980 192. 94 H. S. Trop A. G. Jones and A. Davison Znorg. Chem. 1980,19 1993. " C. Potvin J. M. BrCgeault and J. M. Manoli J. Chem. SOC. Chem. Commun. 1980,664. 96 A. Miiller and U. Reinsch Angew. Chem. Int. Ed. Engl. 1980,19 72. 97 M. D. Curtis H. R. Han and W. M. Butler Inorg. Chem. 1980 19 2096. Orga nometa llic Chemistry distances in pm (26) U.V.photolyses of K3Fe(CN)6 and K,Cr(CN)6 in potassium halide discs at 77 K have been monitored by i.r. Four new v(CN) bands are generated in each case. Although these fit the [M(CN)6I4- ion in the iron case the chromium product(s) remain uncertain. A new thiocarbonyl site has been located in (26),99which was obtained in 4% yield from the reaction of Fe3(C0)12 and CS under 10atm of CO-Ar. 0sCl2(Cl2)-(CO)(PPh3) (27) has been synthesized in high yield and provides a good route to a range of carbonyl analogues (Scheme 5).loo Crystal structure determinations on (27) and the thiocarbonyl have shown that the reaction with SH-maintains the stereo- chemistry at the osmium atom. OsHCI(CO)(PPh3)3 Hg(CC13)z OsCl2(CCl,)(CO)(PPh,)2 ,/bO (27) \x,"-OSC~~(CO)(PP~~),(CNR) OsC12(C0)2(PPh3)2 OSC~~(CO)(PP~~)~(CX) X=S,Se,orTe Scheme 5 CoC1 has been found to catalyse substitution into metal carbonyls by iso- cyanides.lo' In the presence of xylyl isocyanidc and pentacarbonyliron the cobalt exists as CoC12(XyNC)4. This procedure seems to give a general route to successive substitution products. mer-VCl3(CNBu') has been isolated from the reaction of VCl and the iso- cyanide"' and studied by X-ray diffraction. Two proton resonances were observed and the unique ligand trans to chloride was shown to exchange with free CNBu'. [V(CNBU')~]~+ was formed with excess isocyanide. Both six- and seven-co-ordinate Bu'NC and CyNC Cr" homoleptic isocyanides have been ~ynthesized."~ The electrochemistry of the CrL62+ salts has been compared with that of the phenyl isocyanide analogue.Whereas the one-electron oxidation to Cr3' is more favoured for the alkyl isocyanides the two one-electron reductions are less favoured. X-Ray p.e.s. data indicate little Cr -+ T*back-bonding in these complexes. In the presence of water as a promoter reaction of K3W2C19 with excess Bu'NC has afforded [w(cNBu')7]2+[w60,9]2-.104 The cation was shown to have a distorted capped trigonal-prismatic co-ordination geometry in the crystal. 98 G. B. Porter and A. J. Rest J. Chem. SOC.,Chem. Commun. 1980 869. 99 P.V.Broadhurst B. F. G. Johnson J. Lewis and P. R. Raithby J. Chem. SOC.,Chem. Commun. 1980 812. loo G. R. Clark K. Marsden W. R. Roper and L. J. Wright J. Am. Chem. SOC.,1980,102 1206.M. 0.Albers N. Coville T. V. Ashworth E. Singleton and H. E. Swanepoel J. Chem. SOC.,Chem. Commun. 1980,489;J. Organomet. Chem. 1980,199,55. lo' L. D.Silverman J. C. Dewan C. M. Giandomenico and S. J. Lippard Inorg. Chem. 1980 19 3379. lo3 W. S.Mialki T. E. Wood and R. A. Walton J. Am. Chem. SOC.,1980,102 7105. lo4 W. A.LaRue A. T. Liu and J. San Filippo jun. Inorg. Chem. 1980 19 315. 254 A. J. Deeming and J. Evans The crystal structure of H3[Rh4{CN(CHz)3NC}gC1][CoC14]4 * nHzO has been determined.lo5 This green species is active in the photoproduction of hydrogen from an aqueous solution containing rhodium complexes of this chelating isocyanide. It consists of a linear ClRh4Cl chain and the two isocyanide-bridged Rh-Rh bond lengths (292 pm) are longer than the linking central metal-metal bond (278 pm).A series of green organometallic polymers based on a square-planar unit of Rh(CNR),' has been prepared using a variety of di-i~ocyanides.'~~ The form of the two-dimensional polymeric unit is dependent upon the angles subtended by the axes of bridging isocyanides. X-Ray powder patterns indicated that these polymers were stacked with a Rh a -* Rh interaction between the layer of -330 pm. Isocyanide functionalization of a polymer and silica gel has been rep~rted.'~' Both these materials reacted with Rhz(C0)4C1z to yield materials containing anchored RNCRh(CO)zCl centres. Methylation of IrCl(dmpe)2COz by MeS03F has been shown to occur on an oxygen atom of the C02 ligand."' The product [Ir(dmpe)zC1C02Me]FS03 (28) exhibits v(C0) i.r.bands at 1630 and 1065 cm-' in accord with the presence of a C-0 double (115.1 pm) and single (136.6 pm) bond indicated by an X-ray diffraction study. Me l+ I 0\c'/o PIP Q:p) (28) 3 Alkyls Aryls and Acyls The molecular structure of Mg(CHzBu')z has been determined by electron diffraction.log The data fitted a linear co-ordination at magnesium with a metal- carbon bonding distance of 212.6 pm. A matrix-isolation study of the reaction of Mg atoms with methyl halides has provided evidence for H3CMgX species with C3" symmetry.'" Whereas atomic Ca and Sr also react Zn is inert under the experiment- al conditions. A thorough mechanistic study into the formation of Grignard reagents in ether solvents has been presented.'" The reaction rate is first order in both the alkyl halide concentration and the magnesium surface area.Alkyl iodide and secondary alkyl bromide reactions have mass-transport- or diffusion-controlled rates whereas less reactive bromides and most chlorides show chemical rate effects. Plausible alternatives for the rate-determining step were either X*abstraction from 10s K. R. Mann M. J. DiPierro and T. P. Gill J. Am. Chem. SOC., 1980,102 3965. 106 A. Efraty I. Feinstein F. Frolow and L. Wackerle J.Am. Chem. SOC., 1980,102,6341; Angew. Chem. Int. Ed. Engl. 1980,19,633; A. Efraty I. Feinstein F. Frolow and A. Goldman J. Chem. SOC.,Chem. Commun. 1980 864. 107 J. A. S. Howell and M. Berry J. Chem. SOC.,Chem. Commun. 1980 1039.108 R. L. Harlow J. B. Kinney and T. Herskovitz J. Chem. SOC.,Chem. Commun. 1980,813. 109 E. C. Ashby L. Fernholt A. Haarland R. Seip and R. C. Smith Acta Chem. Scand.,Ser. A 1980,34 213. 110 B. S. Ault J. Am. Chem. SOC.,1980,102 3480. 111 H. R. Rogers C. L. Hill Y.Fujiwara A. J. Rogers H. L. Mitchell and G. M. Whitesides J. Am. Chem. SOC., 1980,102,217; H. R. Rogers J. Deutch and G. M. Whitesides ibid. p. 226; H. R. Rogers R. R. Rogers H. L. Mitchell and G. M. Whitesides ibid. p. 231. Organometallic Chemistry 255 the alkyl halide by magnesium or electron transfer from the metal to the organic halide. The reaction rate of aryl bromides with magnesium is mass-transport limited in THF. This is also the case for aryl iodides in ether but the halides and chlorides do not fit this criterion in the less polar solvent.The zinc and cadmium derivatives of M[C(SiMe3),12 have been prepared and show great hydrolytic stability."' For example the zinc complex does not react with boiling concentrated hydrochloric acid. The I3C chemical shift differences between (C5DH4)SnMe3 and the perprotio compound are temperature dependent.'l3 This indicates that the deuterium atom perturbs the equilibrium of metal co-ordination sites in the cyclopentadienyl ring by removing their degeneracy. (C5H5)GeH3 has been studied by electron diffraction and also by X-ray crystallography at 160 K.lI4 The cyclopentadienyl ring is planar in both phases and the Ge-C distance was also invariant at 197 pm. Treatment of Et,SiCl with lithium has been shown to give a mixture of the ring compounds (EtzSi)5-8.115 Et,Si is eliminated by photolysis (254 nm) and can be trapped as Et3SiSiEtzH by Et,SiH; (EtzSi)4,5,a,,d6 are all formed from (Et'Si),.Evidence has been obtained for the reactive intermediate Me2SiCH2 (29). Me3Si radicals were generated by photolysis of Me3SiH in the presence of mercury,'l6 using Bu'OOBu' as a radical or from Hg(SiMe3)2,118 and appear to dis- proportionate to Me3SiH and Me2SiCHz; the latter was trapped as various addition products. Direct evidence for this intermediate has been obtained by electron diffraction studies on the reaction in Scheme 6.'19 By taking differences between the curves obtained under different conditions evidence for a small proportion of (29) with a Si=C bond length of 183 pm was obtained.Me Me I I rSi-Me CSi-Me Me -si-l I Me -tcZH4 Scheme 6 Silabenzene (31; R=H) and silatoluene (31; R=Me) have been generated by pyrolysis of (30).120-122 Short-length pyrolysis at 1000 K gave a mixture of the three compounds in Scheme 7. The U.V. p.e.s. spectrum of this mixture was analysed and the ionization potentials from the .sr-orbitals were assigned to be at 8.0 9.3 and 11.3eV.'" Flash pyrolysis onto a window at liquid helium temperatures allowed U.V. and i.r. characterization of the hetero-benzenelZ1 and -toluene."' C. Eaborn N. Retta and J. D. Smith J. Organomef. Chem. 1980 190 101. J. W. Faller H. H. Murray and M. Saunders J. Am. Chem. SOC.,1980 102 2306.'14 M. J. Barrow E. A. V. Ebsworth M. M. Harding and D. W.H. Rankin J. Chem. SOC.,Dalton Trans. 1980,603. 'Is C. W. Carlson K. Matsumura and R. West J. Organomet. Chem. 1980 194 C5. 'I6 S.K. Tokach and R. D. Koub J. Am. Chem. SOC., 1980,102,376. B.J. Cornett K. Y. Choo and P. P. Gaspar J. Am. Chem. SOC., 1980 102 377. 'la L.Gammie I. Safarik 0.P. Strausz R. Roberge and C. Sandorfy J. Am. Chem. SOC., 1980,102,378. 119 P. S. Mahaffy R. Gutowsky and L. K. Montgomery J. Am. Chem. SOC.,1980,102,2854. '*' B.Soulouki P. Rosmus H. Bock and G. Maier Angew. Chem. Znt. Ed. Engl. 1980 19 51. '*' G.Maier G. Mihm and H. P. Reisenauer Angew. Chem. Int. Ed. Engl. 1980 19 52. 122 C. L.Kreil 0.L. Chapman G.T. Burns andT. J. Barton J. Am. Chem. SOC.,1980,102,840.A. J. Deeming and J. Evans 256 A Si Si 0 + a+ I R' h R (30) (31) R=HorMe Scheme 7 (C5Me5)2Yb reacts with methyl-lithium to form Li[(C5Me5)YbMe2].'23 The reac- tion product from (C5H5)2Yb(p-Cl)2Li(ether)2 with the lithium reagent is solvent dependent. (C,Me,),Yb(Me)(THF) is formed in tetrahydrofuran while the chloride- and methyl-bridged heteronuclear complex (C5Me5)2(p-C1)(p-Me)Li(ether)2 can be isolated from ethereal solution. A new route to lanthanide acetylides has been ~ub1ished.l~~ Interaction of LiM(Bu'),(THF) (M = Sm Eu or Ln) and [(C5H5)2M'Me]2(M'= Er or Yb) with terminal acetylenes affords LiM(CCR),(THF) and [(C,H,),M'(CCR)] respectively with elimination of the appropriate alkane. Carbonyl insertion into the metal-carbon a-bond of (CSMe5)2ThC1(CH2Bu') yields an q2-acyl complex (32) (Scheme 8) characterized by X-ray diffracti~n.'~' Thermolysis at 100"C causes a hydrogen shift within the c6 ligand to form the vinyl alcoholate complex (33).A second product (34) was isolated after protracted exposure to CO and this dimer was also characterized by single-crystal X-ray diffraction. Labelling experiments showed specific incorporation of CO at the two stages. 0 0 BI *co /\ 100°C / C5Me5)2ThC1(CH2Bu')-+ (C5Me5)2Th-C*-CHJ3~f -+(C~Me512Th/\ (32) \c1 :=CH 1+CO (33) /c0 * ,CH~BU~ Bu'CH (34) Scheme 8 Reduction of first transition series metal halides by lithium with a naphthalene promoter has afforded synthetically useful reactive metal powders as black slur- M(C6F5)2 derivatives can be prepared using C6F51.These are solvated by the ether solvents used and the solvents can be displaced by other ligands to yield e.g. Co (C6F5)2(PEt3)2 and Ni(C6F5)2(PPh2H)2. lZ3 P. L. Watson J. Chem. SOC.,Chem. Commun. 1980,652. lZ4 W. J. Evans and A. L. Wayda J. Organomet. Chem. 1980,202 C6. 12' P.J. Fagan J. M. Manriquez T. J. Marks V. W. Day S. H. Vollrner and C. S. Day J.Am. Chem. SOC. 1980,102,5393. lZ6 A. V. Kavaliunas and R. D. Rieke J. Am. Chem. Soc. 1980,102,5944. Organometallic Chemistry Some interesting trinuclear alkyls have been synthesized from Re3C19 and Grig- nard reagent^.'^' For example reaction with MeMgCl in the presence of PEt2Ph has given Re3Me9(PEt2Ph)3 and Re3Me9(PEt2Ph)2.In the crystal the bis-phosphine complex has three bridging methyl groups (Re-Re 243-247 pm). Carbonylation of the blue Re3C13(CH2SiMe3)6 (35) yields Re3C13(CH2SiMe3)6(CO)J at -78 "c. Under similar conditions two moles of NO are adsorbed into an insertion product Re3C13[ON(CH2SiMe3)NO)(CH2SiMe3)5. Hydrogenolysis of (35) in THF occurs under H2 (2 atm) at 20 0C.128 Tetramethylsilane is eliminated leaving Re&- C1)6H(CH2SiMe3)9 in which there are two vertex-linked rhenium triangles. In benzene however Re6C16H6(CH2SiMe3)6 (36) is formed. (36) acts as an iso- merization and hydrogenation catalyst for terminal alkenes but is deactivated as Re6C16(CH2SiMe3)6 (37) is formed. The suggested structures of (36) and (37) both contain two eclipsed Re3 triangles.H H p -C1 omitted R = CH2SiMe (36) (37) MeWOC130Et2 has been obtained from the reaction of wOcl4 with Me2Mg.12' This complex is unstable at 20°C and eliminates a variety of organic products including methyl chloride methane ethylene and ethane and decomposition in the presence of an olefin causes catalytic metathesis. Labelling studies indicate that the methyl chloride is eliminated intramolecularly. Similar treatment of the oxychloride with (Bu'CH~)~M~ has yielded WOC1(CH2Bu')3 (38).l3'The molybdenum analogue was also prepared. With two moles of bisneopentylmagnesium W(0)(CH2Bu')4 is formed; I3C n.m.r. indicates a trigonal-bipyramidal geometry with three equatorial alkyl ligands in all of these five-co-ordinate complexes.(38) is not a metathesis catalyst in the pure state but is active with a WOCI impurity. Whereas reaction of 1,2-Mo2Br2(CH2SiMe3) with HNMe2 gives the expected product 1,~-Mo(NM~~)~(CH~S~M~~),, this isomer is only obtained in 5 % yield using LiNMe2.131 The major product is the 1,l-isomer and this requires an alkyl transfer across the metal-metal triple bond. The isomers do not interconvert and exhibit differing reactivities towards C02. Interaction of PMe with [(C5H5)Rh(CH21)(PMe3)2]I formed from (C5HS)Rh(PMe3)2 and methylene iodide has afforded the methylenephosphine 12' P. Edwards K. Mertis G.Wilkinson M. B. Hursthouse and K. M. Abdul Malik J. Chem. SOC., Dalton Trans. 1980 334. K.Mertis P.G. Edwards G. Wilkinson K. M. Abdul Malik and M. B. Hursthouse J.Chem. Sac. Chem. Commun. 1980,654. 129 E. L. Muetterties and E. Band J. Am. Chem. Soc. 1980,102,6572. 130 J. R. M. Kress M. J. M. Russell M. G.Wesolek and J. A. Osborn,J. Chem.SOC.,Chem. Commun. 1980 431. 13' M. H.Chisholm and I. P. Rothwell J. Am. Chem. Soc. 1980,102,5950;J. Chem. Soc. Chem.Commun. 1980,985. A. J. Deeming and J. Evans complex [(C5H5)Rh(CH2PMe3)(PMe3)2]12.'32 Interestingly strong Bronsted bases like NEt3 and NaOMe also give this ligand by a phosphine migration; [(C5H5)Rh(CH2PMe3)(PMe3)I]I is the product. Methylenephosphine zirconium complexes have been synthesized using the lithium reagent PPh2CH2Li.'33 For example reaction with (C5H5)2ZrC12 yields (C5H5)2Zr(CH2PPh2)2 and (C5H5)2ZrC1(CH2PPh2)as the major and minor prodwts respectively.A crystal structure determination of the latter indicated that the phosphorus atom was not co-ordinated to zirconium and the whole molecule could be used as a phosphine ligand to Cr(CO)5 and Fe(CO) moieties. Treatment ofjhe3irconium dichloride with CH2PPh3 has given the ylide complex (C5H5)2Zr(Cl)(CHPPh3) shown to contain a relatively short Zr-C a-bond (215.2 pm).l? Cjp-bony1 insertion into this bond gives an q2-acyl complex (C5H5)2Zr(Cl)[q2C(0)CHPPh3]. An unusual sequence of reac-tions has been reported starting from methylenetrimethylphosphine and (C5H5),Zr(H)(CH2Cy) (Scheme 9).135 These involve a series of P-C and C-C bond cleavages and formations. (C5H5)2ZrH(CH2Cy)+ PMe3CH2 -20 OC-r.t. - (C5H5)2ZrH(CH2CH2PMe2)+ MeCy1 MeCl 50 "C + CH4 (C5H5)2ZrCI(CH6Me3) (C5H5)2ZrCl(CH2CH2PMe2) 1 B~~OH (C5H5)2Zr(OB~t)2 + [PMe4]Cl Scheme 9 Addition of CNBu' to (q5-C5H5)Pt(q3-C3H5) has been shown to give a trans square-planar Pt" complex in which both organic ligands are now The kinetically formed frans-Pt(CNBut)2(q '-C5H5)( q '-C3H5) then rearranges to a thermodynamically controlled mixture favouring the cis-isomer.The first crystallo- graphically characterized q '-C5H5 ligand formed from a .sr-bonded ring has been rep~rted.'~' with PMe yields Re(NO)(CO)- Treatment of (CSH5)Re(NO)(CO)(Me) (PMe3)2(q '-C5H5)(Me). A simiIar transformation occurs with dmpe but reaction with PBu3 which requires elevated temperatures gives the anticipated carbonyl insertion (C5H5)Re(NO)(PBu3)(COMe), and CO substitution products.Palladation of the bipyridyl derivative (39) has afforded a complex of a quadri- dentate metallated ligand (40) (Scheme 10).13* This complex has a potential antitu- moral activity and will produce nicks in a DNA at low concentrations. The relative reaction rates of methyl iodide and methyl tosylates with various transition-metal nucleophiles have been The iodide rates span a range of 10" and the ratio of the two kI/kOTs,extends from lo9 down to but it was concluded that this ratio could not be used as a guide for a free-radical mechanism. Also for most complexes a log kI us. log kOTsplot was linear. Although this may be interpreted as evidence for a common SN2pathway CO(CN)~~- which reacts by a 13' R.Feser and H. Werner Angew. Chem. Znt. Ed. Engl. 1980 19 940. 133 N. E. Schore and H. Hope J. Am. Chem. SOC.,1980,102,4251. J. C. Baldwin N. L. Keder C. E. Strouse and W. C. Kaska 2. Nuturforsch. Tei[B 1980 35 1289. 13' K. I. Gel1 and J. Schwartz Inorg. Chem. 1980,19 3207. 136 N. M. Boag M. Green J. L. Spencer and F. G. A. Stone J. Chem. SOC.,Dalton Trans. 1980 1220. 13' C. P. Casey and W. D. Jones J. Am. Chem. SOC.,1980,102,6154. G. R. Newkome M. Onishi W. E. Puckett and W. A. Deutsch J. Am. Chem. SOC.,1980,102,4551. 139 R. G. Pearson and P. E. Figdore J. Am. Chem. SOC.,1980 102 1541. 13' Organometallic Chemistry Et02C C02Et C0,Et (39) Scheme 10 free-radical route also falls on this line. Competitive oxidative addition reactions of RX reagents with (C5H5)2ZrL2(L = PPhzMe or PPhMe2) have been in~estigated.'~' Two product types (C5H5)2ZrRX and (C5H5)2ZrX2 are formed and both the selectivity for the former and the reaction rate follow the order X=I>Br>Cl.These zirconium(I1) complexes are among the most reactive of oxidative addition substrates and are thought to follow a radical pathway involving ZrIII intermediates. Photolysis of Mn(CO)5(Me) and Mn(C0)5(COMe) in inert-gas and CO matrices at 12K causes loss of one CO group to form a trigonal-bipyramidal RMn(C0)4 complex.'41 Isotopic substitution data were used to show that the i.r. data fit an equatorial site for the organic ligand. These data also indicated that the MeMn(C0)4 intermediate was fluxional and this ought now to be considered when calculating the expected isotopic distributions in for example the decarbonylation of cis-Mn('2C0)4('3CO)(COMe).The results of a low-temperature investigation into the carbonylation of (C5H5)2ZrMe2 are presented in Scheme 11.142 The reorientation of 0'' I Scheme 11 Me the q2-acyl ligand has a low activation free energy (47.7 kJ mol-' at -123 "C) and the structure of the initial isomer suggests that the CO approaches from outside the ZrMe2 moiety. Interaction of MeMn(CO)5 or (C5H5)Fe(C0)2Me with (partially) dehydroxylated alumina causes a colour change. 143 For example the former complex exhibits a v(C0) band at 1510 cm-' and the i.r. evidence indicates that the species (41) is formed at the surface; the alumina evidently increases the CO insertion rate.Nitrosyl insertion reactions of early transition-metal alkyls have been reported in Nitric oxide co-ordinates to the metal in (C5H5)2NbMe2 at -78 "C [v(NO) indicates a bent nitrosyl]. Warming this adduct to room temperature allows the insertion reaction to proceed to form (C5H5),Nb(Me)(q20NMe). This complex eliminates MeNNMe to generate the do complex (C5H5)2NbO(Me) which reacts with more NO to form the reaction product obtained by reaction of (C5H5)2NbMe2 with NO at room temperature uiz. [Nb(C5H5)2(0)(ONMeNO)],,. 140 G. M. Williams K. I. Gell and J. Schwartz J. Am.Chern. SOC., 1980,102,3660. 14' T. M. McHugh and A. J. Rest J. Chem. SOC., Dalton Trans. 1980,2323. G.Erker and F. Rosenfeldt J. Organomef. Chem. 1980,188 C1.143 F.Correa R. Nakamura R. E. Stimson R. L. Burwell jun. and D. F. Schriver J.Am.Chem. SOC.,1980 102 5112. 144 A. R. Middleton and G. Wilkinson J. Chem. SOC., Dalton Trans. 1980 1888. 14' A. J.Deeming and J. Evans .Me CH2Ph l+ (42) A hydrido metal alkyl intermediate in the homogeneous catalytic hydrogenation of methyl-(2)-a-acetamidocinnamateby Rh(dppe)' in methanol has been detec- ted.145 The olefin forms an adduct with the unsaturated rhodium complex and it was shown by X-ray diffraction and 13C n.m.r. to co-ordinate by both the olefinic bond and the amido carbonyl oxygen atom. Exposure to hydrogen causes catalytic hydrogenation under ambient conditions but the intermediate (42)could be observed at -78 "C. Reductive elimination from three cis- and three trans-PdLzMez phosphine complexes has been studied.146 The cis-complexes underwent intramolecular eli- mination of ethane in co-ordinating solvents and the Pdo product could be trapped by diphenylacetylene. However two trans-complexes with unidentate phosphines iso- merized prior to elimination; (TRANSPHOS)PdMez did not eliminate ethane even at 100"C in DMSO. Interestingly addition of CD31 to the last complex generates CD3CH3 at 25 "C and this appears to involve a Pd'" intermediate. Pyrolysis of ~is-Pt(PEt~)~(o-xylyl)~ in xylene has been shown to form cis-(PEt3)2PtCH2C6H4CH2 in which metallation of a carbon 6 to the metal has oc- c~rred.~~~ The mechanism of the y-metallation during the thermolysis of cis- Pt(PEt3)2(CH2B~t)2 has been investigated.14* to form C~~-(PE~~)~$~CH~CM~~CH~ Dissociation of one phosphine occurs as the first step and the subsequent oxidative addition of the neopentyl CH group is reversible.The metallacycle is then formed irreversibly as neopentane is eliminated. There have been two interesting reports of the synthesis of four-membered I I metallacyclic rings starting from (C5H5)2TiCHzAlMe2C1 (43),which effectively acts as a source of (C5H5)zTiCH2. Reaction with diphenyl- and bis-trimethylsilyl-acetyl-ene in THF solution yields the titanacyclobutene complexes (44)(Scheme 12).149 CH RCCR / \l (C5H5)2Ti\/AlMe __* (C5HJ2Ti fR .Cl' 'c ' (44) R PhCCPh (45) R =Ph or SiMe3 R' =But or Pr' Scheme 12 14' A. S. C.Chen and J. Halpern J. Am. Chem. Soc. 1980,102 838. A.Gillie and J. K. Stille J. Am. Chem. SOC.,1980,102,4933. 14' S.D. Chappell and D. J. Cole-Hamilton J. Chem Soc. Chem. Commun. 1980,238. P.Foley R. DiCosimo and G. M. Whitesides J. Am. Chem. Soc. 1980 102,6713. 149 F. N.Tebbe and R. L. Harlow J. Am. Chem. Soc. 1980,102 6149. 14' Organometallic Chemistry The bonding scheme drawn was supported by the X-ray structure determination for the diphenyl derivative; this showed the C3M unit to be planar. Exchange of the acetylene units can be achieved at 85 "C and the methylene group in (44; R = SiMe3) equilibrates slowly with that in I3CH2=CMe2 at 55 "C suggesting Ti(CH2)(olefin) and Ti(CH2)(acetylene) intermediates. The AlMe2CI group can be abstracted readily by a 4-vinylpyridine-styrene copolymer and interaction with primary olefins then readily forms the metallacyclobutanes (45).150 Reaction with diphenylacetylene exchanges the elements of the unsaturated hydrocarbon to form (44) and the degenerate exchange with free olefin was monitored by deuterium labelling.The labelling experiments provided further evidence for a metallacyclobutane carbene- olefin equilibrium. Addition of a-picoline (L) to the Pt"' metallacycle [Pkl2(CHPhCH2CH2)I4 has been found to generate an ylide comples trans-PtCI2(CHLCH2CH2Ph)L. lS1Deu-terium labelling studies demonstrated that a 1,3-hydrogen shift had occurred and involved an initial a-hydrogen abstraction. Two sets of semiempirical molecular orbital calculations on the relationships between bis-olefin and metallacyclopentane moieties have been published.The interconversion was studied for an Fe(CO) system and stereoselective cyclization of unsymmetrical olefins was ~redicted.'~~ The substituent should be placed so that the olefin enters the reaction with its largest T*lobe P to the metal in the heterocycle. Thus cyclization is easier if the olefin is polarized with the positive end in the potential P-site. (46). The second study was concerned with Ziegler-Natta catalysis by TiC13Me containing octahedral sites. lS3 Comparisons have been made between the stability of (47) and (48) for Ti" Ti''' and TiIV species as part of an ethylene catenation process. Only Ti" favoured (48) and is thus disposed towards coupling to a titanacyclopentane.Indeed the coupled product C13MeTiCH2CH2CH2CH2 was more stable than (48). Benzometallacyclopentanes have been synthesized using a bis-o-xylyl Grig- nard.'54 Complexes of the type (C5H4R)2hCH2C6H4dH2 (R = H or SiMe3 M = Ti Zr or Hf) are very stable the zirconium complex (R = H) eliminates o-xylene only at 150°C or on photolysis. Carbonyl insertion into both metal-carbon a-bonds of a hafnium derivative has afforded (C5H4SiMe3)2~f[COCH2C6H4CH2CO] under ambient conditions. Similar complexes with a-SiMe3 substituents have been pre- pared for the three Group IV transition metals and their electrochemistry has been The ease of reduction falls along the series Ti >> Zr > Hf but the MI*' anion was observed by e.s.r.for even the heaviest metal. T. R. Howard J. B. Lee and R. H. Grubbs J. Am. Chem. SOC.,1980 102 6876. R. J. Al-essa and R. J. Puddephatt J. Chem. SOC.,Chem. Commun. 1980,45. A. Stockis and R. Hoffmann J. Am. Chem. SOC.,1980,102 2952. R. J. McKinney J. Chem. SOC.,Chem. Comm. 1980,490. M. F. Lappert T. R. Martin J. L. Atwood and W. E. Hunter J. Chem. SOC.,Chem. Commun. 1980 476. "' M. F. Lappert and C. L. Raston J. Chem. SOC.,Chem. Commun. 1980,1284. A. J. Deeming and J. Evans 1 I Nickelacyclopentene complexes such a bipyNi[COCPh=CPhCO] (49) have been synthesized by three routes from nickel(0) complexes.156 (49) acts as a source for several cyclic organic compounds. For example reaction with methylene chloride yields CH,COCPh=CPhCO.Reaction of the cobaltacyclopentadiene complexes (C,H,)(PPh,)Co(CPhCPhCPhCPh) with a phosphite causes substitution of the Group V donor and also a migration to a 1-alkoxyphosphole oxide complex e.g. (C,H,)CO[~)~-CP~CP~CP~CP~PO(OM~)]. 157 Both the substitution and the rear- rangement of the phosphite com lex follow first-order kinetics. A meso- and a dl-form of (C5H,)(PPh3)C*H(CN)] have been obtained from the reaction of (C5H,)Co(PPh3)(CH2CHCN) and acrylonitrile at 100 0C.158 Phosphine substitution of the meso-form (both CN groups towards the C5H5 ring) with PPhMe2 gave rise to two meso-forms and one dl-form. The two meso-forms isomerize faster and since the rate is independent of added PPhMe, this appears to be an intramole- cular process. A twisting mechanism via a pseudo-square-planar intermediate was proposed.A dimetallacyclopentane complex (50) has been synthesized from 00 (50) [(C5H5)2Co,(CO),]-and 1,3-propylene di-iodide. 15' At lOO"C it eliminates pro- pene and cyclopropane as the major and minor products respectively by an intramolecular process. Two cobalt-containing products are formed at 50 "C with added lilgands (L=PPh3 PMe3 or CO) viz. (C,H5)Co(CO)L and (C5H5)LCo[CH2CH2CH2C0]. A kinetic study indicated that ligand addition followed a reversible CO rearrangement to a bridging and terminal situation and this intermediate can decompose by two alternative routes. One is intramolecular and yields cyclopropane and (C5H,)Co(CO)L whereas the second involves additional ligand and yields both the organometallic products.The competitive. migration of methyl and phenyl groups in acyl rhenium anions has been investigated.16' Thermolysis of (NMe,)[cis-(CO),Re(COMe)(COPh)] (51)at 69 "C gives two products (NMe,)[cis-(CO),RePh(COMe)] (98%)and (NMe,)[cis- (CO),ReMe(COPh)] (2%). The minor product reacted much faster with PEt to form (NMe4)[fac-(CO),(PEt,)Re(COMe)(COPh)] than it isomerized to the major product indicating that methyl migration was faster than phenyl migration in the [(CO),Re(COMe)(COPh)]- intermediate. However the phenyl migration product is thermodynamically preferred. Treatment of the manganese analogue of (51) with PPh causes elimination of acetophenone with (NMe4)[Mn(C0),PPh3] as the manganese-containing product. 16' However using a 90% 13C-labelled acetyl carbon only gave 43% of the 13Cin the acetophenone carbonyl site.It was concluded that initial carbonyl loss generates [(CO),Mn(COMe)(COPh)]- which equilibrates lS6 H. Hoberg and A. Herrera Angew. Chem. Znt. Ed. Engb 1980,19,927. lS7 K. Yasufuku A. Hamada K. Aoki and H. Yamazaki J. Am. Chem. SOC.,1980,102,4363. Y. Wakatsuki and H. Yamazaki J. Chem. SOC.,Chem. Commun. 1980 1270. lS9 K.H.Theopold and R. G. Bergman J. Am. Chem. SOC.,1980,102,5694. 160 C. P.Casey and D. M. Scheck J. Am. Chem. SOC.,1980,102,2723. C. P.Casey and D. M. Scheck J. Am. Chem. SOC.,1980,102,2728. 263 Organometa llic Chemistry rapidly with [(CO),MnMe(COPh)]- prior to the kinetically less preferred phenyl migration product which eliminates acetophenone.Oxidation of (C,H5)Fe(C0)2Me by Ce'" or cupric triflate in the presence of acetonitrile has been shown to generate the green cation [(C5H5)Fe(CO)-(MeCN)(COMe)]'.'62 Oxidation of [(C,H,)Fe(CO)L(COMe)](L = CO or PPh3) also gives rise to 17-electron radical cations. These are suggested to be precursors to the oxidative decomposition of (C,H5)Fe(C0)2R derivatives. A series of stable Ir'" hydrido formyl complexes has been ~ynthesized.'~~ For example [Ir(PMe3)4]PF6 reacts with paraformaldehyde to form [cis-Ir(H)(CHO)- (PMe3)4]PF6. The formyl group can be reduced to a methyl ligand with an excess of borane. A sequence of hydroaddition reactions similar to that reported last year on (C,H,)Re(NO)(CO)(CHO) has been reported on osmium. (Scheme 13).164These include a hydroxymethyl hydride complex and a methyl hydride species both of which are stable.OS(CO)ZLZ(~~~-CH~O) 5 OS(CO)~L~(H)(CHO) 1 NaBH4 OS(CO)ZLZ(CH~I)I-Os(C0)2L2(Me)(I) 1aq. HCI 1Ag+-CH2Ci2-aq.EtOH Os(CO)2L2(CH20H)Cl [OS(CO)ZL~(CH~)(OH~)I+ OS(CO)~L~(CH~OH)H Os(CO),L2(Me)H L = PPh3 Scheme 13 (C5H5)2Zr(COCH2Cy)Cl is reduced by (C5H5)2ZrHCl to afford (52).16 (52) has two different zirconium atoms each with two diastereotopic cyclopentadienyl rings and accordingly exhibits four C5H5 proton n.m.r. resonances at -22 "C.By 59 "C these average to two and by consideration of the chemical shifts of these ring protons it was possible to show that exchange of carbon- and oxygen-bonded zirconium atoms was occurring uia an intermediate (53).The acetyl group in (C,H,)Zr(Me)- (COMe) is rapidly reduced by (C5H5)2M~H2 at 25°C to form (C5H5)2Zr(Me)- (OEt).166 The hydridic hydrogen atoms were shown to be specifically transferred to the methylene group of the ethoxy ligand. However the tungsten analogue yielded a different product (C,H,)2Zr(Me)OCHMeW(H)(C5H5)2, which is a likely inter- mediate in the hydrogen transfer. (52) R = CH2Cy (53) '" R. H. Magnuson S. Zulu W.-M. T'sai and W. P. Giering J. Am. Chem. Soc. 1980 102,6887. 163 D. L. Thorn J. Am. Chem. Soc. 1980,102,7109. 164 C. E. L. Headford and W. R. Roper J. Organomet. Chem. 1980,198 C7. 165 K. I. Gell G. M. Williams and J. Schwartz J. Chem. Soc. Chem. Commun. 1980 550. J. A. Marsella and K. G. Caulton J. Am.Chem. Soc. 1980 102 1747. A. J. Deeming and J. Evans Ta2(CsMe4Et)2C14H2absorbs 1mol of CO at 0 0C.167The product contains two different types of C5 rings and 'Hand 13C n.m.r. evidence indicated that the reactant had the structure (54). This complex forms an adduct (55) with PMe3 and by a combination of n.m.r. and X-ray diffraction cleavage of the formyl C-0 bond was established; the phosphine forms a bridging ylide ligand. I 'c' H/\ H c1 c1 I (C,Me,Et) PMe (54) (55) 4 Carbenes and Carbynes Low-temperature acidification of a solution of (C5H5)Fe(dppe)(CH20Et) has generated [(CsHs)Fe(dppe)(CH2)]+,168 which adds methylene to olefins. At -78 "C there are two methylene proton resonances and on warming these coalesce and form an averaged triplet at 20 "C.The methylene plane is perpendicular to the C5 ring; the rotation barrier was found to be 44 kJ mol-'. The synthesis of neopentylidene hydride complexes has been reported. 16' Reduc-tion of Ta(CH2Bu')C14 with sodium amalgam in the presence of PMe has allowed isolation of T~(CHBU')(H)CI~(PM~,)~ .which exhibits a very low carbene v(CH) at 2440 cm-'. (C5Me,)Ta(CHBu')(H)(C1)(PMe3) was similarly prepared from (C5Me5)Ta(CH2Buf)Cl3and it forms a carbyne complex (C5Me5)Ta(CBu')- (PMe3)2CI when heated to 60 "C with more PMe3. A hydrido-derivative of the last complex (C5Me5)Ta(CBut)(PMe3)2H, was also reported. A carbene-transfer reac- tion from tantalum to tungsten has been carried out [equation (4)].170 The tungsten product acts as a metathesis catalyst for but-1-ene and cis-pent-2-ene in the +WO(OBU')~+ T~(OBU')~C~+ T~(CHBU')(PE~~)~CI~ W(PEt3)2C12(0)(CHBu') (4) presence of AlC13.One phosphine ligand was abstracted using Pd(PhCN)2C12 to form the five-co-ordinate complex (56) which has the smallest carbene MCC (56) angle yet reported for a neopentylidene complex (141"). Less distorted complexes appear to be bettter metathesis catalysts. Ab inifio calculations have been used as a basis for calculations of AG changes for epoxidation cyclopropanation and meta- thesis by CrO2CI2 and MoCI2O2 on ethylene. '" Metathesis would not be anticipated 167 P.Belmonte R. R. Schrock M. R. Churchill and W. J. Youngs J. Am. Chem. SOC., 1980,102 2858. M. Brookhart J. R. Tucker T. C. Flood and J.Jensen J. Am. Chem. SOC.,1980,102,1203. 169 J. D. Fellmann H. W. Turner and R. R. Schrock J. Am. Chem. SOC., 1980 102,6608. 170 J. H. Wengrovius R. R. Schrock M. R. Churchill J. R. Missert and W. J. Youngs J.Am. Chem. SOC. 1980,102,4515. 17' A. K. Rappt and W. A. Goddard J. Am. Chem. SOC., 1980,102,5114. Organometallic Chemistry 265 for the 3d element but evidence was obtained for Cl,M(O)(CH,) as a catalytically active species for the heavier Group VI members. (C,H,)(CO>,Re[C(OMe)SiPh3] has been synthesized and it reacts with BF3 to form the carbyne complex [(C,Hs)(CO)2Re(CSiPh3)]+. 172 The carbyne carbon is susceptible to nucleophilic attack and so reaction with (NBu4)BH4 affords (CSH,) (CO),ReCHSiPh3. In the crystal the ReCSi angle is 135".[(C,H,)Re(NO)(PPh3) (CHPh)]' and other derivatives have been prepared by hydride abstraction at the a-carbon of the corresponding alkyl complex using the trityl cation at -70 0C.173 Two isomers are formed with opposite orientations of the benzylidene plane with respect to the Re-NO and Re-PPh3 bonds; the initial isomer is converted into the second at 10-20 "C. Nucleophilic addition occurs selectively on one of the faces of the carbon ligand the opposite to the site of CPh3+ attack. A complex of C30 Cr(CO),=C=C=C=O has been ~ynthesized.'~~ The C-1 and C-3 chemical shifts are 440.6 and 389.9 respectively and the i.r. spectrum of this complex includes a band at 2028 cm-' due to the symmetric stretch of C30. At 0 "C there is some decomposition to Cr(C0)6 and highly unsaturated organic products.The related metallabutatrienes (CSHS)Mn(C0)2=C=C=CR2 have also been re~0rted.l~' Thermolysis of this material causes elimination of R2C=(C)4=CR2 with (p-CCCR2)[Mn( CSHS)(CO)2]2 as the organometallic product. The synthesis of [Cr(CO),(CNEt2)]BF4 has been rep~rted."~ The carbyne Cr-C distance (178.2 pm) was found to be comparatively long indicating charge stabiliza- tion over the carbyne by the amido-group. Even in this situation the trans metal-carbonyl distance was long (197.5 pm) so in the absence of a stabilizing group this bond would be weakened further. Reaction (5) has been found to follow first-order kinetics and its rate is not markedly affected by solvent polarity or C0,177 so the rate-determining step appears to be an intramolecular process.Cr(C0),[C(NEt2)(SnPh3)]+ tran~-Cr(CO)~(CNEt2)(SnPh~) (5) W(CO),[CPh(OMe)] and W(CO),CPh2 have been found to polymerize both terminal and non-terminal a~ety1enes.l~~ This probably proceeds via an acetylene insertion into the metal-carbene bond. The kinetics of the insertion of Et,NCCMe into (CO),M[C(OMe)Ar] derivatives to form (57) have been studied."' The rates are first order in both complex and alkyne with large negative AS' values. This indicates an associative process thought to be the initial attack on the carbene carbon by the ynamine. Tungsten complexes were more reactive than their chromium analogues. (CO),M =C,c=c, \ "Etz DR Me OMe (57) 17* E. 0.Fischer P.Rustemeyer and D. Neugebauer Z. Nururforsch. Teil B 1980 35 1083. 173 W. A. Kiel G.-Y. Lin and J. A. Gladysz J. Am. Chem. SOC.,1980,102,3299; A. G. Constable and J. A. Gladysz J. Organomet. Chem. 1980 202 C21. 174 H. Berke and P. Harter Angew. Chem. Znr. Ed. Engl. 1980,19 225. 17' H. Berke Chem. Ber. 1980 113 1370. 176 U. Schubert E. 0.Fischer and D. Wittmann Angew. Chem. Znr. Ed. Engl. 1980,19,643. 177 H. Fischer J. Organomet. Chem. 1980 195 55. T. J. Katz and S. J. Lee J. Am. Chem. SOC. 1980,102,422 179 H. Fischer and K. H. Dotz Chem. Ber. 1980,113 193. 17' A. J. Deeming and J. Evans Stepwise reduction of an alkynyl ligand to an alkyl group has been reported.18' An isolated intermediate was [(C5H5)(dppe)Fe(CCMe,)1'.The a-carbon of the vinyl- idene group was found to be electrophilic and was reduced to [(C,H,)-(dppe)Fe(CH=CMe2)] in 20% yield.The /3 -carbon displays nucleophilic character and methylation by a Meerwein reagent yielded [(C5Hs)(dppe)Fe(CHCMe3)]+. Finally the carbene carbon is again electrophilic and reaction with NaBH gives rise to the neopentyl complex (C5HS)(dppe)FeCH2CMe3. The synthesis structure and reactions of O~(C-p-tolyl)Cl(CO)(PPh~)~ (58) have been rep~rted.~~'-'~~ Some of these are presented in Scheme 14. Crystal structure determinations on (58) (59) and (60) were carried out giving 0s-C distances of 177,183.9 and 190 pm respectively to the organic ligand. (58)exhibits an i.r. band at 1359 cm-' which was assigned as a v(0sEC)vibration. CI / L OC 2LiR OC\ I CI OSCI~(CCI~)(CO)L,+ OSGCR 2 \I 0s4C-R c1/I L CI/L \CI AgC10 -C 0 Li(BFt,H) H Li(BEt,H) CQ \c10 (60) R =p-tolyl L = PPh3 Scheme 14 Protonation of the Rh-Rh bond in (p-CH2)[Rh(C,H5)CO]2 occurs at -80 "C on the addition of hydrogen However on warming to 20 "C the halide counter-ion co-ordinates and the bridging hydride adds to the methylene group.The crystal structure determination of (C5H5)2Rh2(Me)(Br)(CO)2 revealed two bridging carbonyl groups with terminal methyl and bromide ligands on different rhodium atoms.'84 However addition of HBF4 to the neutral carbene complex allows A. Davison and J. P. Selegue J. Am. Chem. SOC.,1980 102 2455. G. R. Clark K. Marsden W. R. Roper and L. J. Wright J. Am. Chem. SOC.,1980,102,6576.la* G. R. Clark C. M. Cochrane W. R. Roper and L. J. Wright J. Organomet. Chem. 1980,199 C35. la' W. R. Roper J. M. Waters L. J. Wright and F. van de Mews J. Organomet. Chem. 1980 201 C27. la4 W. A. Herrmann J. Plank M. L. Ziegler and H. Balbach J. Am. Chem. Soc. 1980 102 5906. W. A. Herrmann J. Plank E. Guggolz and M. L. Ziegler Angew. Chem. Znt. Ed. Engl. 1980,19,651. Organometallic Chemistry isolation of [(p3-CH)(p2-C0)2{Rh(C5H5)}3]BF4, which exhibits a 13C resonance at S 303.6 due to the bridging methine 1igand.lg5 Other neutral carbene ligands of the type (p-CR1R2)[Rh(C5MeS)(CO)]zhave been prepared by the reaction of diazoalkanes with (p-CO)2[Rh(C5Me5)]z.'86 One of these the diphenylcarbene derivative loses CO to form the green (p-CO)(p-CPhz)[Rh(C5Me5)I2.The cobalt methylene analogue (p-CO)(p-CH2)[Co(C5Me5)12 was synthesized inadvertently during the attempted synthesis of CO(C~M~~)~ by the reaction of CoClz Bu"Li and C5Me5H in THF.18' Interestingly the two bridging ligands in this very air-sensitive dinuclear complex emanate from the enolate of acetaldehyde formed by Bu"Li cleavage of THF. Reaction of [Fe2(C0)8]2- with CH212 has been found to yield (p-CH2)(p- CO)z[Fe(CO)3]z as air-stable golden crystals. lg8 Whereas there are three bridging groups in the crystal like Fe2(C0)9 only terminal carbonyls ligands are evident in solution indicating a rearrangement to a structure with a methylene bridge only. Hydrogenation under pressure at 60 "C yields Fe,(C0)12 with methane as the major organic product; small amounts of acetaldehyde are also formed.The same organic products are obtained under an H2-CO mixture but propylene is formed if ethylene is used. Under a mixture of C2H4 and H2 methane and some propylene are eliminated and catalytic ethylene hydrogenation ensures. Interaction of (C5H5)2Fe2(C0)4 with methyl-lithium and subsequent protonation has been shown to give a vinylidene complex (p-CCH2)(p-CO)[Fe(CO)(C5H5)]2.'89 HBF causes proton addition to the methylene group to yield the ethylidyne complex [(p-CMe)(p-CO){Fe(C5H5)(C0)}z]BF4. The ruthenium analogues have also been prepared and hydride addition from NaBH4 has been observed on the alkylidyne carbon to form (p-CHMe)( p-CO)[ Ru( C5H5)( C0)l2. Borohydride reduction of the vinyl cations [(p-CHCH2)(p-CO)[M(C5Hs)(C0)]z]+ of iron and ruthenium has also been found to give the neutral ethylidene complexe~.'~~ Hydride addition also occurs on the CH group of the vinyl ligand in the ruthenium case to form (p-CO)z[Ruz(C5H5)2(CO)(CzH4)]. The bridging carbene complexes have also been synthesized by low-temperature photolysis of (CsH5)2Fe2(C0)4 with alkyl diazoacetates.192 One of these cis-(p-CHC0zB~')(p-CO)[Fe(C5H5)(CO)] was characterized by X-ray diffraction.(p-CCH2)[Mn(C5Hs)(CO)2] has been prepared and a single-crystal X-ray structure determination carried out on it.193 The @-carbon of the vinylidene ligand of this and the (p -CCHMe) derivative are nucleophilic and protonation of these complexes affords [(p-CCH2R){Mn(CSH5)(CO)z}z]+.194 The equilibrium (6) was found to lie completely to the right [Mn' = (CSH5)Mn(CO)z] indicating that [(p-CCH2Me)Mn'J'+(p-CCH2)Mn' (pCCHMe)Mn'2+[(p-CMe)Mn'z]+ (6) A. D. Clauss P. A. Dimas and J. R. Shapley J. Organomet. Chem. 1980 201 C31. T. R. Halbert M. E. Leonowicz and D. J. Maydonovitch J. Am. Chem. SOC.,1980 102,5101. C. E. Sumner jun. P. E. Riley R. E. Davis and R. Pettit J. Am. Chem. Soc. 1980 102 1752. lS9 G. M. Dawkins M. Green J. C. Jeffrey andF. G. A. Stone J. Chem.SOC.,Chem. Commun. 1980,1120. D. L. Davies A. F. Dyke A. Endesfelder S. A. R. Knox P. J. Naish A. G. Orpen D. Plaas and G. E. Taylor J. Organomet. Chem. 1980,198 C43. A. F. Dyke S. A. R. Knox P. J. Naish and A. G. Orpen J. Chem. SOC.,Chem. Commun.1980,441. 19' W. A. Herrmann J. Plank 1. Bernal and M. Creswick 2.Naturforsch. Ted B 1980,35,680. 193 K. Folting J. C. Huffman L. N. Lewis and K. G. Caulton Znorg. Chem. 1979,18 3483. L. N. Lewis J. C. Huffman and K. G. Caulton J. Am. Chem. SOC. 1980,102,403. A. J. Deeming and J. Evans the methyl substituent in the vinylidene complex reduces the basicity of the 0-carbon. Refluxing the unsaturated carbene complex (p-CHCH=CMez)[W(C0),32 in hexane causes loss of one of the carbonyl groups and co-ordination of the ethylenic group in (61) established by X-ray diffra~tion.'~' Phosphine addition reactions on (61) were found to follow two pathways (Scheme 15).196PMe3 and P(OEt) add to the organic ligand to form (62). However P(OEt) also gives rise to an isomer (63).These two isomers do not interconvert and one of them (63) loses a CO group to form (64). This form was also obtained by a deceptively simple CO substitution reaction with PPh3. Two products have been isolated from the reaction of ReC14(THF)z with Me3SiCHzMgC1.197One is Rez(CHzSiMe3)8Nz and the second is a bridged alk- ylidyne complex (p-CSiMe3)z[Re(CHzSiMe3)z]z, in which the Re-Re distance was found to be 255.7 pm. If the oxidation estate of Re is considered to be five then a metal-metal double bond would be anticipated. A series of heterometallic dinuclear complexes with a bridging carbyne ligand has been synthesized by the interaction of (C5H5)W(CO)z(C-p-tolyl) with co-ordinatively unsaturated species generated in situ.19' For example photolysis of (C6Me6)Cr(C0)3 and subsequent interaction with the tungsten complex generates (C5H5)W(CO)(p-C-p-tolyl)Cr(CO)z(C6Me6).The 13 C chemical shifts of the bridging carbon spans a range of 6 312-430. These complexes themselves react with a further unsaturated monomer to produce p3-carbyne complexes containing two or three different metal atoms.'99 Two types of complex are formed which differ by a count of two electrons in the metals' co-ordination sphere. Thus whereas reaction of Fez(CO) with PtW( ,uz-C-p-tolyl)- yields ( ~3-C-p [Fe(C0)3I [Pt(CO)- (CO)~(PE~~)~(CSHS) -tolyl)[W(CsHs)(CO>21 (PEt,)] the PMezPh analogue gives rise to (F -C-p-t0lyl)[W(C~H~)(C0)~]-195 J. Levisalles H. Rudler F. Dahan and Y. Jeannin J. Organomet. Chem. 1980 188 193.1 96 J. Levisalles F. Rose-Munch H. Rudler J. C. Daran Y. Dromzee and Y. Jeannin J. Chem. Soc. Chem. Commun. 1980,685. 197 M. Bochmann. G. Wilkinson A. M. R. Galas M. B. Hursthouse and K. M. Abdul Malik J. Chem. SOC. Dalton Trans. 1980 1297. 198 M. J. Chetcuti M. Green J. C.Jeffrey F. G.A. Stone and A. A. Wilson J. Chem. Soc. Chem. Commun. 1980,948. 199 M. J. Chetcuti M. Green J. A. K. Howard J. C. Jeffery R. M. Mills G. N. Pain S. J. Porter F. G. A. Stone A. A. Wilson and P. Woodward J. Chem. Soc. Chem. Commun. 1980 1057. Organome ta 1lic Chemistry [Fe(CO)3](p-CO)[Pt(PMe2Ph)2] The I3C chemical shifts of these carbyne carbon nuclei are further upfield (6 287-323) and at -100 "C the 13C n.m.r. spectrum of the PMe2Ph complex indicates that it is chiral.The complex is non-rigid above that temperature. Refluxing (C5H5)Co(CO) and diphenylacetylene in decalin has been shown to give rise to a complex with two face-bridging CPh ligands viz. (p3-CPh)2[C~(C5H5)]3.200 A variety of these derivatives has been synthesized from bis(trimethylsily1)acetylene and polyacetylenes. Some of these involve C-C bond cleavage. (p3-CSiMe3)2[Co(C5H5)]3 was obtained from Me3SiCCSiMe3 and treat- ment of this with [PhCH2NMe3]F afforded the bis-methine complex (p3- CH)2[Co(Cd&)13.

ISSN:0260-1818    

DOI:10.1039/IC9807700240

出版商:RSC    

年代:1980

数据来源: RSC