ISSN:0260-1818    

DOI:10.1039/IC99087FX001

出版商:RSC    

年代:1990

数据来源: RSC

ISSN:0260-1818    

DOI:10.1039/IC99087BX003

出版商:RSC    

年代:1990

数据来源: RSC

摘要:

3 Al Ga In TI By S. M. GRIMES Department of Chemistry Brunel University Kingston Lane Uxbridge Middlesex UB8 3PH This chapter follows a similar format to that in previous years providing a survey of the group 13 elements and reviewing the developments in the chemistry in particular the inorganic chemistry of Al Ga In and Tl that have appeared in the literature over the past year. Polyhedron has published’ thirty papers and four reviews in a ‘Symposium-in- Print’ issue on the group I11 (13) elements aluminium gallium and indium and a separate review article on the four elements has appeared in Coordination Chemistry Reviews.2 1 Aluminium Structural features of transition metal alumohydrides evaluated by X-ray structure analysis and the role of these compounds in the catalysis of homogeneous hydro- genation and isomerization of hex-1-ene have been re~iewed.~ The structures and dynamic properties of aluminium-group 16 derivatives in a second re vie^,^ are discussed under the headings (i) three-coordinate aluminium derivatives (ii) R,Al.ER$ addition compounds (iii) bridged four coordinate derivatives (iv) five coordinate aluminium derivatives and (v) six-coordinate organoaluminium com- pounds.The synthesis structures complexes and reactions of alumoxanes form the subject of a third re vie^.^ The binding of aluminium to human serum transferrin has been studied6 using difference ultraviolet spectrophotometry and from these data two macroscopic aluminium binding constants have been determined with the larger K value being associated primarily with A1 binding at the C-terminal site and the smaller value associated with the N-terminal site.Twenty-eight chelating ligands for Al Ga and In have been evaluated as binders of the M3+ ions in a simple human blood plasma model,’ and in another paper Jackson,8 investigated using a computer model of solution equilibria the aqueous chemistry of A13+ Ga3+ and In3+. The effect of a series of chelating agents on the species distribution of A13+ is also reported. ’ ‘Polyhedron symposia-in-Print Number 10 ed. A. R. Barron. Polyhedron 1990 9 Issops 2 and 3. G. Davidson Coord. Chem. Rev. 1990 102 146. B. M. Bulychev in ref. 1 p. 387. J. P. Oliver and R. Kumar in ref. 1 p. 409. S. Pasynkiewicz in ref. 1 p. 109. W.R. Harris and J. Sheldon Inorg. Chem. 1990 29 119. ’ D. J. Clevette and C. Orvig in ref. 1 p. 151. G. E. Jackson in ref. 1 p. 163. 23 24 S. M. Grimes Two papers by Despic and co-workers report investigations of the cathodic polarization of al~miniurn.'~'~ Abnormally high yields (>200%) of hydrogen were measured' during the cathodic polarization of aluminium in neutral salt solutions implying that a simultaneous dissolution of aluminium is an inherent part of the cathodic process. The second paper presents" the oxidation potentials of substances accumulated during the cathodic polarization process. In a two-part study of aluminium anodization in sulphuric acid and chromic acid solutions the kinetics of growth and chemical composition of the oxides formed" and the morphology and structures of the anodic oxidesI2 have been investigated.The porous structure of the oxides grown in the chromic acid solutions is less-ordered than that of oxides grown in sulphuric acid; all anodic oxides are amorphous and contain a mixture of A104 tetrahedra and A106 octahedra. In another paper13 the mechanism of plating on anodized aluminium having a porous anodic film has been studied and the basic parameters which must be controlled to achieve uniform plating discussed. A number of triarylvinyl halides and acetates were reduced with lithium aluminium hydrideI4 using various transition metal chlorides as catalysts. Dimethylaluminium hydride complexes of nickel (0)have been prepared' and the complexes (C7HI3N) (Me2A1H)Ni(CDT) and (C7HI3N) (Me2A1H)Ni(C2H4)2 are considered as model (0)-catalysed hydroalumination reaction of alkenes.X-Ray and neutron powder diffraction techniques have been used to solve and refine the P-and y-BaAlF structures.'6 Both structures crystallize in the monoclinic space group -the P-form in P2,/n and the y-form in P2 -and are built up from isolated infinite (AlF5)2,"- chains with AlF6 octahedra sharing corners in a cis-position. Close structural relationships are shown to exist between the Ba- A1 cationic subnetwork of a-BaAlF and the CrB-type structure; P-BaAlF and SrAg-type; y-BaAlF and the FeB-type. The cubic structure of (H30)2KAIF6 has been determinedI7 and found to be related to the elpsaolite (K,NaAlF,) structure in which the H30+ ions donate three very strong hydrogen bonds to nearly undistorted isolated A1F;- anions.A spectroscopic study of KCuAlF has confirmed'* that the crystals contain tetragonal compressed CuF:-octahedra which is consistent with the previously reported crystal structure determination. In orthorhombic crystals of NaCdAlF the aluminium octahedra form a new arrangement of linear transconnected [A1F5]2,"- chains running in the [OlO] direction between which Na and Cd ions in six- and seven-fold coordination respectively and an independent fluorine are located." Cationic tetrahedra around independent fluorine ions form chains of formula [FNaCd]?' running in the [OlO] direction. Hemon and Courbion" also report the structure of the low-temperature A.R. Despic J. Radosevic P. Dabic and M. Kliskic Electrochim. Acta 1990 35 1743. 10 A. R. Despic D. M. Drazic J. Balaksina Lj.Gajic-Krstajic and R. M. Stevanovic Electrochim. Acra 1990 35 1747. V. P. Parkhutik J. M. Albella Yu. E. Makushok I. Montero J. M. Martinez-Duart and V. I. Shershulskii Electrochim. Acta 1990 35 955. I2 V. P. Parkhutik V. T. Belov and M. A. Chernyckh Electrochim. Acra 1990 35 961. 13 A. Zagiel P. Natishan and E. Gileadi Electrochim. Acta 1990 35 1019. 14 C. A. Obafemi and C. C. Lee Can. J. Chem. 1990 68 1998. l5 K.-R. Porschke W. Kleimann Y.-H. Tsay C. Kruger and G. Wilke Chem. Ber. 1990 123 1267. 16 A. Le Bail G. Ferey A.-M. Mercier A. de Kozak and M. Samouel J. Solid State Chem. 1990 89 282. G. Frenzen and W. Massa Acta Cryst.Sect. C 1990 46 190. l8 K. Finnie L. Dubicki E. R.Krausz and M. J. Riley Znorg. Chem. 1990 29 3908. 19 A. Hemon and G. Courbion J. Solid State Chem. 1990 86 249. *' A. Hemon and G. Courbion J. Solid State Chem. 1990 84 153. Al Ga In TI 25 form of NaCaAlF (p-form) which is isotypical with P-LiMnFeF, and Na,Ca,Al,F,, in which A1 and Ca octahedra build up a three-dimensional network [Ca,A1,F,,l4-in which are inserted the Na+ ions. Wilkinson and co-workers2' report details of the synthesis of Li2M( NBu') M = Mo and W and reactions of these compounds with AlMe, AlCl ,and GaCl and the crystal structures of W[(-NNBU')~AIX~]~ (X = C1 or Me). The compounds are all extremely moisture-sensitive but thermally stable high-melting solids that can be sublimed at CQ.22°C. Although the methyl compounds are orange the chlorides are intensely coloured; the Mo-A1 compound is green while the W-A1 and W-Ga compounds are purple. The main differences in the structures of dimethyl- and dichloro-aluminium tungsten complexes lie in the A1X2 coordination to the nitrogen atoms with Al-N distances for the dimethyl slightly longer than for the dichloride. The WN geometry is very similar in both with some deviation from ideal tetrahedral angles due to the N2A1 bridging. Using an aluminium dissolution/deposition electrolysis cell TiB2/TiC and TIC sintered specimens of different porosity were tested for erosion resistance on exposure to liquid electrodeposited aluminium at 700 "C to determine whether cathodes coated with such materials can be applied in aluminium chloride electrolysis cells.22 Although not wetted by liquid aluminium the TIC and the TiB2/TiC com- posite were extensively eroded.The densest TiB2 specimens showed the highest resistance against liquid aluminium. A new ZnlAlCl,lMnO galvanic cell suitable to water-activation has been de~eloped.~ The cell's high discharge voltage energy density and discharge capacity are attributed to the strong buffering eflect of AlCl at pH -3. In a paper reporting a study of the reaction between thionyl chloride and cobalt phthal~cyanine,~~ implications for Li/ SOCl2 batteries are discussed. Rest potential measurements of a Li/S0Cl2 cell show that the addition of AlCl stabilizes the LiCl product as LiAlCl,.The 27Al magic-angle sample-spinning (MASS) NMR spectra of several AlC1,-tetrahydrofuran complexes have been The results suggest that the isotropic chemical shifts occur in relatively well-defined regions for 4- 5- and 6-coordinate species (AlCI -103 ppm A1Cl3-THF -99 ppm trans-A1Cl3-2THF -60 ppm trans [AlCl,(THF),]+ -14 ppm) and that theoretically calculated average nuclear quadrupole coupling constants are in good agreement with experimentally determined values obtained from computer simulation of the MASS NMR spectra. Reactions of the tetrahalides of zirconium and hafnium with the Al- AlX aromatic hydrocarbon system have yielded arene complexes of Zr" and Hf11.26 Derivatives of the type Zr(arene) (AlC14)2 and the trinuclear species [zr,cI,( T6-C6Me6)3ln+ have been identified.Two papers by Burford and co-~orkers~~~~* report the crystal structures of five chalcogenophosphine-and diamino chalcogenophosphine-derivatives of 21 A. D. Danopoulos G. Wilkinson B. Hussain-Bates and M. B. Hursthouse J. Chem. SOC.,Dalton Trans. 1990 2753. 22 H. Wendt and S. Dermeik J. Appl. Electrochem. 1990 20 438. 23 T. Yamamoto and T. Shoji J. Appf. Electrochem. 1990 20 1021. 24 A. Bernstein and A. B. P. Lever Inorg. Chem. 1990 29 608. 25 0. H. Han and E. Oldfield Inorg. Chem. 1990 29 3666. 26 F. Calderazzo P. Pallavicini and G. Pampaloni 1. Chem. SOC.,Dalton Trans. 1990 1813. 27 N. Burford B. W. Royan R. E. v. H. Spence and R. D. Rogers J. Chem. SOC.,Dalton Trans. 1990,2111. 28 N. Burford R.E. v. H. Spence and R. D. Rogers J. Chem. SOC.,Dalfon Trans. 1990 3611. 26 S. M. Grimes aluminium trichloride. Cl8Hl5AlCl3PS and Cl8H1,AlCl3PSe crystallize in the mono- clinic and triclinic space groups re~pectively.~' Both crystal structures consist of discrete molecular units with no unusual intermolecular contacts. In contrast to the oxygen analogues the sulphur and selenium derivatives exhibit bent geometries [P-S-A1 109.62(8) P-Se-C1 (Mean) 107.0( l)"]. The A1-S bond length [2.297(2) A] is in the region of those determined for some aluminium sulphides but the Al-Se bond lengths [2.452(2) 2.421(2) A] are slightly longer than those of A12Se3. In their second paper2' the authors present conclusive studies on the chemistry of diaminothio- and diaminoseleno-phosphinicchlorides with aluminium trichloride.The results confirm the formation of covalent complexes for the thio derivatives but demonstrate a small thermodynamic preference for novel dichal- cogeno-diphosphonium ionic alternatives. In the solid state novel dimeric heterocyclic diphosphonium systems have been isolated for the Me2N and Et2N derivatives -[{(Et,N)2PS}2][AlC14]2 and [{(Et2N)2PSe}2][AlC14]2 compounds which although not isostructural have very similar structural features. Both structures consist of discrete cationic and anionic units; the cation is a dimeric structure consisting of two (Et2N),PE+ fragments bound together as a P2E2 four-membered ring (E = S Se) and an AlCl unit is associated with each S centre forming two contacts in a chelate fashion while the chlorine centres of two different anions are associated with each Se centre.The next three papers report studies on the AlC13-1- ethyl -3-methylimidazolium chloride (ImCl) specie^.^^-^' The electrochemistry of Ti'" has been examined29 in acidic (AlC1,-rich) compositions of the ambient- temperature molten salt A1Cl3-ImC1. Combination of TiC14 and Me3A12C13 in an acidic melt has been demonstrated to be a catalytic system for ethylene polymeriz- ation. Hussey and co-workers have published two papers on electrochemical and spectroscopic studies of molybdenum( 11) chloride3' and rhenium( IV) monomeric and dimeric chloride complexes3' in the basic AlC1,-ImCl room temperature molten salt. A third paper by the same authors3' describes the electrochemistry and spectro- electrochemistry of polynuclear rhenium( 111) chloride cluster complexes and their one-electron reduction products in basic A1C1,-1-methy1-3-ethy1imidazo1ium chloride molten salt.The dimeric metal-metal bonded rhenium( 111) complex [Re3C1,2]3- is stable in the chloroaluminate molten salt. A series of novel solid strong acids have been prepared33 by the reaction of inorganic oxides with Al2Cl,. The objective was to create a solid acid with tetrahedral aluminum centres which are expected to be stronger Lewis acids than octahedral aluminum centres. Investigations of the acid sites of these solids by the infrared spectroscopy of adsorbed pyridine calorimetric titrations and solid-state nuclear magnetic resonance confirm that new strong solid acids have been prepared.The systems exhibit high catalytic activity and selectivity for acid-catalysed cracking reactions under very mild conditions where present commercial catalysts do not react. The direct reaction34 between AlC13 and ethyl acetate in n-hexane yields [AlC13(CH3C02C2H,)2] which during crystallization under the influence of 29 R. T. Carlin R. A. Osteryoung J. S. Wilkes and J. Rovang Inorg. Chem. 1990 29 3003. 30 P. A. Barnard I-W. Sun and C. L. Hussey Inorg. Chem. 1990 29 3670. 31 S. K. D. Strubinger I.-W. Sun W. E. Cleland Jr. and C. L. Hussey Inorg. Chem. 1990 29 4246. 32 S. K. D. Strubinger I. W. Sun W. E. Cleland Jr. and C. L. Hussey Znorg. Chem. 1990 29 993. 33 E. E. Getty and R. S.Drago Znorg. Chem. 1990 29 1186. 34 P. Sobota M. 0.Mustafa J. Utko,.and T. Lis J. Chem. SOC.,Dalton Trans. 1990 1809. Al Ga In TI 27 moisture forms a complex of formula [A12(p-CH3C02)2-(p-OH) (CH3C02C2Hs)6] [AlCl,],. In this homobimetallic dioctahedral cation the A13+ ions are bridged by one OH- two CH,CO; anions and three ethyl acetate molecules. As in previous years a large number of papers have been published describing the chemistry of aluminium-oxygen containing materials. Aluminium solutions (0.1 mol dm-3) were hydrolysed at 25 "C by a mild slow procedure involving the addition of NaOH to an aluminium salt.3s The amount of monomeric and polymeric species deduced from 27Al NMR analysis of the solutions is in agreement with that obtained by a spectrophotometric ferron assay technique.It is shown that a minimal number of aluminium species is present the dominant polymer being of the form [A104A112(OH)24( H20)12]7+. This 'Al13' species consists of a tetrahedral A1 sur- rounded symmetrically by 12 octahedral A1 ions. A new method for the synthesis of exceptionally well-ordered layered double hydroxide intercalates containing carboxylate and other organic anions has been de~cribed.,~ The use of these deriva- tives in particular a [Mg3Al]-adipate and toluenesulphonate as precursors to pillared derivatives has been considered with respect to interlayering by the Keggin ion species H2Wl2O2; to form [Mg3A1]-H2W120~~ pillared products. The co-ordination of Al"' with glycolic acid in aqueous solution was in~estigated~~ with the use of 'H 13C 170 and 27Al NMR techniques.High-field 27A1 NMR spectroscopy allowed the observation of 1:1 1 :2 1 :3 and polynuclear complexes of Al"' with glycolic acid. A gradual shift in the 'H 13C and 27Al NMR spectra indicated that ionization of the hydroxy group of co-ordinated glycolate starts at pH 3. 170 NMR measurements showed unambiguously the bidentate co-ordination of oxalic malonic and glycolic acid with Al"'. Solid-state 27Al 'magic-angle' spinning (MAS) and 13C cross-polarization (CP) MASNMR spectroscopy were used to study powdered single cystals of a 2 :6 aluminium(II1)-glycolate complex. Equilibria between H+ aluminium( III) and L-tartaric acid (2,3-dihydroxybutanedioicacid H2L) were studied3* in a 0.6 mol dm-3 Na(C1) medium at 25 "C by e.m.f.titrations (glass electrode) within the limits 1.8 d -log[H+] d 6.7; 0.00018 d B d 0.012moldm-3 0.00018 s C 9 0.042mol dm-2 and 0.5 d C/B d 25 [B and C stand for the total concentrations of aluminium( III) and tartaric acid respectively]. All data can be explained with a mononuclear species together with a series of binuclear complexes of tentative formulae [AlL]+ and [Al,(H-,L)] + and [A12( H-,L)( H-,L)]- respectively. The complex anion [A1,(H-lCit)3-(OH)(H20)]4-has been isolated39 from the reaction of A1(N03)3-9H20 with citric acid (H3Cit) in aqueous solution between pH 7 and 9. The complex [NH,],[Al,(H-,cit) (OH)-(H20)] [N03].6H20 which crystallizes in the monoclinic space group P2Ja consists of the trimeric anionic complex which is surrounded by a hydrogen-bonded network of six water molecules five ammonium cations and a nitrate anion.The core of the anionic complex is composed of a bicyclic aluminium-oxygen framework consist- ing of fused four- and six-membered rings with all three A1 atoms exhibiting distorted octahedral geometry. 35 C. Changui W. E. E. Stone L. Vielvoye and J.-M. Dereppe J. Chem. SOC.,Dalton Trans. 1990 1723. 36 E. D. Dimotakis and T. J. Pinnavaia Inorg. Chem. 1990 29 2393. 37 F. R. Venema J. A. Peters and H. v. Bekkurn J. Chem. SOC.,Dalton Trans. 1990 2137. 38 E. Marklund and L-0. Ohman J. Chem. Soc. Dalton Trans. 1990 755. 39 T. L. Feng P. L. Gurian M. D. Healey and A. R. Barron Inorg. Chem. 1990 29 408. 28 S.M.Grimes The synthesis and characterization of 10 different ionic and a-bonded aluminium(111) porphyrins are rep~rted.~' These compounds were studied by mass spectrometry and IR UV-visible and 'H NMR spectroscopy as well as by electro- chemistry. The spectroscopically investigated compounds are represented by (P)AI C1 and (P)Al(R) where P is the dianion of tetraphenylporphyrin (TPP) or octaethyl- porphyrin (OEP) and R is CH ,n-C,H ,C6H5 ,or C6F4H. The molecular structure of (OEP)Al(CH,) was determined by X-ray diffraction and provides the first structural data for an aluminium porphyrin complex. The Al"' atom in (OEP)AI(CH3) is pentacoordinated and is located 0.465( 1) 8 from the mean nitrogen plane. The electrochemically investigated compounds are represented by (P)AICl and (P)A( R) where P is OEP or TPP is CH3 n-C4H9 or C6H5.An overall mechanism for the oxidation and reduction of each derivative is presented and data for the a-bonded complexes are compared to results obtained under the same experimental conditions for oxidation and reduction of (P)M(R) where M = Gay In or TI. Addition of excess Bu'OH to hydrocarbon solutions of Al,( NMe2)6 yields Al(OBu') as kinetic and thermodynamic products respectively by way of a remark- ably persistant intermediate Alz( NMe,) (OBu') .41In another paper aluminium alkoxides are shown42 to prominently influence the selectivity of reactions involving a single electron transfer stage. An efficient synthesis of (N,N diakyl carbamoyl) germanes from the reaction of triethylgermyllithium with R2NC(0)X (X=CI OMe) in the presence of an equimolar amount of (S-BUO)~AI has been developed.A variety of metal enolates including magnesium boron aluminium zinc and gallium have been prepared43 from (Y -iodo carbonyl compounds and organometallic reagents under mild conditions. The metal enolates thus obtained have been utilized for the stereoselective aldol reaction with aldehydes with the object of elucidating the influence of metal and solvent effects on the erthyro/threo selectivity. Kinetic studies4 of ligand substitution reactions for aluminium gallium and indium have been undertaken and the mechanism and rate of substitution data compared with those in the literature. The authors have found that the relative lability of the ions leading to a trend of greater rate increases in the order Al Ga and In.As in previous years a large number of papers have appeared in the literature which describe studies of and the effect of metal-,45-59 mixed meta1-,60-62 metal 40 R. Guilard A. Zrineh A. Tabard A. Endo B. C. Han C. Lecomte M. Souhassou A. Habbou M. Ferhat and K. M. Kadish Inorg. Chem. 1990 29 4476. 41 M. H. Chisholm V. F. Di Stasi and W. E. Streib in ref. 1 p. 253. 42 A. V. Seleznev D. A. Bravo-Zhivotovskii T. I. Vakul'skaya and M. G. Voronkov in ref. I p. 227. 43 K. Maruoka N. Hirayama and H. Yarnamoto in ref. 1 p. 223. 44 K. Scaito and A. Nagasawa in ref. 1 p. 215. 45 H. Oz and T. Gaurnann J. Caral. 1990 126 115. 46 B. Sen J. L. Falconer T-F.Mao M. Yu and R. L. Flesner J. Catal. 1990 126 465. 47 M. A. Stranwick M. Houalla and D. M. Hercules J. Catal. 1990 125 214. 48 H. C. Tung C-T. Yeh and C-T. Hong J. Catal. 1990 122 211. 49 Y-B. Zhao and Y-W. Chung J. Catal. 1990 124 109. D. Bianchi and J. L. Gas J. Catal. 1990 123 298. D. Bianchi and J. L. Cass J. Catal. 1990 123 310. 52 P. C. L'Argentiere and N. S. Figoli J. Chem. Tech.Biotechnol. 1990 361. 53 J. A. Mieth J. A. Schwarz Y. J. Huang and S. C. Fung J. Catal. 1990 122 202. 54 J. M. Rickard L. Genovese A. Moata and S. Nitsche J. Catal. 1990 121 141. 55 R. W. McCabe and C. Wong J. Cutal. 1990 121 422. 56 A. M. Efstathiou and C. 0. Bennett J. Catal. 1990 124 116. 57 S. Khaja Masthan K. V. R. Chary and P.Kanta Rao J. Catal.. 1990 124 289. Al Ga In TI 29 mixed and o~ide-,~~-~~metal o~ides-,,~’-~~ metal sulphide-supported-alumina catalysts.74 The following papers describe the chemistry of A1203 itself and other Al-oxygen containing species. The reactivity of non-porous alumina prepared by evaporation of A1 in Ar/02 has been investigated7’ and compared with that of high surface area y-alumina for the decomposition of ethanol 1-propanol and t-butanol. The results suggest that transitional non-porous alumina powders may provide good crystalline analogoues to y-alumina and thus could be used as model alumina supports. Light emission76 during the pore-filling of anodic alumina films has been studied and the results suggest that the luminescent brightness arises from the matrix of the porous film.Five papers deal with the reactions of p-alumina type material~.~~-~l It has been found7’ that the addition of more than a certain amount of mixed valent ions would be necessary to render mixed conducting characteristics to p -alumina-type compounds. Based on the assumption that the electronic condu- tion is due to the hopping of small polarons to the nearest neighbouring ions on the octahedral sites in the spinel block of p-alumina similar to that in magnetite the pair approximation of the cluster variation method indicates that the threshold composition of such a mixed valent additive must exceed at least 0.24 of the number of octahedral ions. A Raman and X-ray diffraction of gel-derived boehmite and alkali-doped boehmite samples has revealed the presence of different transition alumina phases at intermediate temperatures before formation at the higher tem- peratures of stable a-alumina or p + p” alumina for alkali-loaded A1203.After final annealing at 1200°C the presence of alkali induces the formation of stable p + p” alumina phases whereas in the absence of alkali a phase identified as @-A1203 is observed at 1000 “C and ,finally stable a-A1203 is obtained at 1200 “C. Electron spin resonance and optical absorption spectroscopies have been used to locate the position of Ce3+ and Nd3+ ions in the Ce3+ doped p” alumina and codoped Ce3+-Nd3+-P” alumina.79 The spectra indicate that Ce3+ ions are found at the mid-oxygen sites in the p”-alumina conduction plane and the site occupations of Ce3+ and Nd2+ ions in the codoped crystals are not changed when both ions are 5x N.K. Nag and F. E. Massoth J. Catal. 1990 124 127. 59 F M. Mulcahy M. J. Fay A. Procter M. Houalla and D. M. Hercules J. Cafal. 1990 124 231. 60 J. Barbier E. Churin and P. Marecot J. Catal. 1950 126 228. 61 Y-X Li and K. J. Klabunde J. Catal. 1990 26 173. 62 B. E. Handy J. A. Durnesic R. D. Sherwood and R. T. K. Baker J. Catal. 1990 124 160. 63 D. Singh J. K. Gehlawat and M. S. Rao J. Chem. Tech. Biotechnol. 1990 127. 64 J. Leyrer D. Mey and H. Knozinger J. Catal. 1990 124 349. 65 A. K. Bandopadhyay J. Das and S. K. Roy J. Catal. 1990 124 241. 66 A. Kurosaki and S. Okazaki Bull. Chem. Soc. Jpn. 1990 63 2363. 67 N.Cardona-Martinez and J. A. Domesic J. Catal. 1990 125 427. hX N. Spanos L. Vordonis Ch. Kordulis P. G. Koutsoukos and A. Lycourghiotis J. Catal. 1990,124,315. 69 N. Spanos L. Vordonis Ch. Kordulis and A. Lycourghiotis J. Catal. 1990 124 301. 70 C. Moreau J. Joffre C. Saenz and P. Geneste J. CataL 1990 122 448. 7’ K. Ishiguro T. Ishikawa N. Kakuta A. Ueno Y. Mitarai and T. Kamo J. Catal. 1990 123 523. 72 R. H. Fish J. N. Michaels R. S. Moore and H. Heinernann J. Catal. 1990 123 74. 73 B. Scheffer P. J. Mangnus and J. A. Moulijin J. Catal. 1990 121 18. 74 L. Jalowiecki J. Grimblot and J. P. Bonnelle J. Catal. 1990 126 101. 75 J. L. Swector and A. K. Datye J. Catal. 1990 121 196. 16 A. Girginov M. Machkova and S. Ikonopisov Electrochim.Acta 1990 35 825. 77 M. Sankararaman R. Kikuchi and H. Sato J. Solid State Chem. 1990 88 239. 78 G. Mariotto E. Cazzanelli G. Carturan R. Di Maggio and P. Scardi J. Solid State Chem. 1990,86,263. 79 J. D. Barrie L. A. Momoda B. Dunn D. Gourier G. Aka and D. Vivien J. Solid State Chem. 1990 86 94. 30 S. M. Grimes present in the same crystal. Lead( II)-p” alumina Pbo.s3Mg0,6,Al,0.33017 ,is a divalent isomorph of the well-known fast ion conductor NaI-P”-alumina and is distinguished by having the highest ionic conductivity of the known divalent p”-aluminas. The electrical properties of this compound are extremely sensitive to the presence of water. Lead( II)-P”-alumina reacts readily with water vapour to form a hydrated compound ~b~.83~go,67~~lo.3~17~( H20), in which x varies from 0 to 0.83.Hydration greatly decreases the ionic conductivity of Pb”-P”-alumina and dehydration of the electrolyte in vacuum results in the chemical reduction of Pb” cations in the conduction layers and an insulator to semiconductor transition. The results of a study of ionic and electronic conductivity in Pb”- and Na’-Pb”-P”-alumina and the influence of hydration of the properties of the material have been reported.80 A new hexaferrite (ideal composition KBaFe23036) with mixed p-alumina and magneto- plumbite structure was synthesizeds1 by the solid-state reaction of the mixture 0.45K2C03.0.55BaC03-6Fe203 at 1300 to 1350 “C.The alternative stacking structure of half cells of K+-P-ferrite and Ba hexaferrite was proposed based on the X-ray powder diffraction pattern of this ferrite.A similar conipound was also found in the Rb20-BaO-Fe203 system. The saturation magnetization of the K-Ba ferrite was very small (1.6 emu/g at 25 “C) compared to that of the Ba hexaferrite and the electronic conductivity of K-Ba ferrite was 0.3 S cm-’ at 300 “C which was too high to measure the ionic conductivity based on the P-alumina structure but the electronic conduction was reduced by MgO doping. The formation of NbA104 at low temperatures by the transformation’2 of a Nb205 solid solution containing 50 mol% A1203 from an amorphous material prepared by the simultaneous hydrolysis of niobium and aluminium alkoxides has been reported. The influences3 of added oxides on the progress of the thermolysis of laponite at 1300°C is the subject of a paper by McWhinnie and Mandair.By contrast with CaO and Na,O which promote the depolymerization of the clay silicate lattice addition of A1203 increases the degree of connectivity as evidenced by the formation of a new alumino-silicate phase such as sillimanite -the spinel MgA1204 was a dominant crystalline phase at higher A1203additions. The compound Sr3A1206 is obtaineds4 as a white powder by solid state reaction between SrC03 and A1203 and crystallizes in the cubic spare group Paj. It possesses an intricate superstructure of the perovskite AB03 type and features such as oxygen and A deficiency and 1:3 B-cation ordering which are present simultaneously suggest that the formula must be written as Sr,/sOl/s(Srl~4A13~4)O~~403/4.A linear relationship between the glass transition temperature and local distortion of calcium aluminate and calcium gallate glasses has been foundsS using a combination of Mossbauer spectroscopy and differential thermal analysis. The defect solid state chemistry of LaMgAl has been investigateds6 using computer atomistic simulation techniques and calculations show that intrinsic disorder in LaMgAll1Ol9 is of Schottky type. Several defect reactions proposed to 80 G. S. Rohrer and G. C. Farrington J. Solid State Chem. 1990 85 299. S. Nariki S. Ho and N. Yoneda J. Solid State Chem. 1990 87 159. 0. Yamaguchi and M. Shirai in ref. 1 p. 367. A. P. S. Mandair and W. R. McWhinnie Polyhedron 1990 9 1709.84 J. A. Alonso I. Rashes and J. L. Soubeyoux Inorg. Chem. 1990 29 4768. T. Nishida H. Ide and Y. Takashima Bull. Chem. SOC.Jpn. 1990 63 548. 86 L. Xie and A. N. Cormack J. Solid State Chem.. 1990 88 543. Al Ga In 77 31 explain the non-stoichiometry of LaMgAl,,019 have been modelled. Another papers7 reports optical absorption and fluroescence measurements on titanium doped lanthanum hexaaluminate LaMgAl,,O, . In the LiMxTi2-x04(M = Cr3' A13+) spinel solid solution systems,8s the M3+ cations substitute at the octahedral sites and thus directly interact with the titanium 3d conduction electrons. The effect is dramatically illustrated in the chromium series where superconductivity is suppressed completely at 2.5% Cr3+ substitution by a magnetic impurity effect.Infrared transmission measurements indicate a metal- nonmetal transition (MNMT) in LiCrXTi2-,O4 at 0.33 < x < 0.40. In the aluminum series the superconducting transition T persists at a high value (>6 K) to x = 0.33 where a MNMT is proposed. Percolation disproportionation and conduction electron concentration are briefly discussed as possible contributing mechanisms for the MNMT in the cation-substituted LiMxTi2-x04 (M = Li+ A13+ C?") system. Large single crystals of a non-stoichiometric oxide with nominal formula A16Ba46C~24084 were grown by slow cooling of a mixture of alumina and cupric oxide in a barium hydroxide-barium chloride The compound has a novel layered structure and all the copper atoms are in unique bowl-shaped rings of composition Cu6015.The crystals are shiny black hexagonal plates and resistance measurements show that the compound is semiconducting. Two new aluminoarsen- ates9' with occluded 1,2-diaminopropane AlAsO,-3 and AlASO4-4 have been pre- pared and characterized. AlAsO,-3 contains octahedrally coordinated Al atoms whereas AlAs0,-4 contains not only octahedrally coordinated Al atoms but also tetrahedrally coordinated ones. In Al-0-As bond force these two compounds are different to a great extent from each other as well as from a-quartz-type AlAsO which contains NO4 and AsO coordination units. When calcined at high tem- perature (e.g. 800 "C) both lose the template completely and the framework arsenic partially. The combined use of temperature-programmed reduction (TPR) Laser- Raman spectroscopy and X-ray diffraction has provided evidence" that phosphoric acid impregnation on y-alumina prior to molybdate incorporation induces the formation of crystalline A12( MOO,) and MOO species.Single crystals of Ni2AlB05 Cu2AlBOs and Co2.l&9B05 have been grown and their structures determined.92 The nickel and cobalt compounds are isostructural with the natural mineral ludwigite while the copper compound is a monoclinically distorted variant of this structure. All three compounds show non-random disorder of the transition metal and Al atoms over four crystallographically distinct metal sites. The remaining papers dealing with aluminium -oxygen containing species report on albumin -phosphates silicates and zeolites.The synthesis and structure of a novel aluminophosphate A1P04-CJ2 with an open framework has been reported.93 The framework structure consists of A105,A105F and PO4 units. Another paper reports on the results of the liquid-phase catalytic semihydrogenation of propargyl 87 B. Martinet D. Gourier A. M. Lejus and D. Vivien J. Solid Stare Chem. 1990 89 147. 88 P. M. Lambert P. P. Edwards and M. R. Harrison J. Solid State Chem. 1990 89 345. 89 P. D. VerNooy M. A. Dixon F. J. Hollander and A. M. Stacy Znorg. Chem. 1990 29 2837. 90 J. Chen R. Xu L. Li Y. Xu and F. Zhou J. Solid State Chem. 1990 87 152. 91 R. Lopez Cordero S. Lopez Guerra J. L. G. Fierro and A. Lopez Agudo J. Card. 1990 126 8. 92 J. A. Hriljac R. D. Brown A. K.Cheetham and L. C. Satek J. Solid Slate Chem. 1990 84 289. 93 L. Yu W. Pang and L. Li J. Solid Stare Chem. 1990 87 241. 32 S. M. Grimes alcohol and its two methyl derivatives using AlP0,-supported nickel catalysts.94 In a note by Prasad and Balakrishnan it is reported9' that the largest pore molecular sieve VP1-5 is a precursor to AlP04-8 which is obtained by calcination of VP1-5 in inert atmosphere or in vacuum in the temperature range 388-733 K. The postsyn- thesis modification of aluminophosphates by reaction of silicon tetra~hloride~~ has been reported. The SiC1,-treated AlPO4-5 samples showed ammonia retentions 50-80% greater than those of the untreated sample and toluene methylation activities three to four times that of the untreated AlPO4-5.However the SiCl treatment conferred to the samples no increase in cumene cracking rates and the pyridine IR spectra over the modified samples showed only Lewis-bound pyridine which was observed in the untreated AlP04-5. In a of the catalytic properties of aluminophosphates AlP04-5 with different phase compositions it has been shown that the catalyst selectivity in methanol conversion depends on the method of preparation. The new dipho~phate~~ K2M03A1Pg028 crystallizes in the triclinic Pi space group and its lattice is built up from Moo6 and A106 octahedra sharing corners with PO4 tetrahedra isotypic with Nao,,MoP207. The tunnels are fully occupied by K+ ions and one kind of octahedral site is occupied by Mo whereas Mo and A1 are randomly distributed over the second site.The catalytic activity of silicoaluminophosphates. (SAPO-5 SAPO- 11 and SAPO-33 type) in the conversion of de~ane~~ and the behaviour of 3-methylpentane and 2,3-dimethylbutane on aluminosilicates under cracking conditions"' are the subject of the next two papers. Finally a 29Si and 27Al MAS NMR study of zeolite p with different Si/Al ratios,'" a physicochemical study of coke formation on [AlI-ZSMS during methanol conver- sion,'02 and a 31PAl and '29Xe NMR study of phosphorus-impregnated HZSM-5 zeolite ~atalysts''~ have been reported. Proton NMR spectra are rep~rted"~ for complexes of Al"' Ga"' and In"' with a variety of 5,5'-disulphonated 2,2'-dihydroxyazobenzenes in D20 solution. Ligand exchange is slow on an NMR time-scale and both 1:1 and 1:2 complexes have been characterized.The spectra of the complexes of A"' and Ga"' show that the metal ions are bound to only one of the nitrogens of the azo groups. In contrast the 1 :2 indium(Ir1) complexes of the two symmetric ligands studied are fluxional and values of AG' are given for the process which 'flips' the metal ions between the two nitrogen atoms. For the 1 :1and 1 :2 aluminium(II1) and the 1 :2 gallium(II1) complexes of asymmetric ligands the expected isomers have been observed and the equilibrium isomer ratios are reported. The structural and spectroscopic characterization of the compounds [A1(NMe2)J2 [Ga(NMe2),12; [(Me2N)2A1{~-N(H)1-Ad)l (l-Ad = 94 F. M. Bautista J. M. Compelo A. Garcia R. Guardeno D.Luna and J. M. Marinas J. Catal. 1990 125 111. 95 S. Prasad and I. Balakrishnan Inorg. Chem. 1990 29 4830. 96 J. L. Brinen and M. G. White J. Catal. 1990 124 133. 97 0. V. Kikhtyanin E. A. Paukshtis K. G. Ione and V. M. Mastikhin J. Catal. 1990 126 1. 98 A. Leclaire M. M. Borel A. Grandin and B. Raveau Acta Crystallogr. Sect. C 1900 46 1368. 99 J. A. Martens P. J. Grobet and P. A. Jacobs J. Catal. 1990 126 299. 100 J. Abbot J. Catal. 1990 126 628. 101 J. Perez-Pariente J. Sanz V. Fornes and A. Corma J. Catal. 1990 124 217. 102 G. Paul Handreck and T. D. Smith J. Catal. 1990 123 513. 103 G. Seo and R. Ryou J. Catal. 1990 124 224. 104 D. F. Evans and N. Iki J. Chem. SOC.,Dalton Trans. 1990 3773. Al Ga In 77 C(3) (4 (b) Figure 1 Dimeric structure of (a) [AI(NMe,),] and (b) [Ga(NMe2),], (Reproduced with permission from Polyhedron 1990 9 257.) 1-adamantanyl) and [{Me(p-NPh,)A1}2NPh( p-C,H,)] has been reported.'05 The structures of [Al( NMe,),] and [Ga( NMe,),] are the first reported structures of tris-dialkylamides of aluminium or gallium.Both possess dimeric structures (Figure la and lb) in the solid with dimethylamide bridges and distorted tetrahedral geometry at the metal. The M2N2 cores display only minor distortions from perfectly square configurations and the terminal -NMe groups display significant deviation from planarity in both compounds. The structure of [(Me2N),AI{p-N( H) 1-Ad}] also possesses an M,N core and each aluminium is bonded to four nitrogens; whilst in [{Me( p-NPh,)AI},NPh( p-C6H4)] both aluminiums possess distorted tetrahedral geometry but one A1 atom is bonded to three nitrogens and one carbon and the other is bonded to two nitrogens and two carbons.A study of the aluminium com- pounds derived from 2,4,6-tri-t-butylanline has led'" to the structure determination of [A1Me{p-NHC6H,Bu;-4,6-C( Me)2CH,-2}]2 containing a central (AlN) square with the adjacent six membered unsaturated alumino-heterocycles in a twisted boat conformation one below and the other above the (A1N)2plane and the two anilide ligands in a transoid arrangement. A PM3 semi-empirical molecular orbital study'" of the structure and bonding in the cage system S4N4 and S4N4X for a range of four electron substituents X (X = N+ P+ C Si B- and Alp) has been carried out.As the electronegativity of X decreases the closed form is increasingly favoured in energy being the lowest energy isomer for X = B- Al- or Si. The structure of the first alumina-phosphacubane has been reported.'08 The white crystalline compound [Bu'Al(p3-PSiPh,)], prepared from Bu;AIH and Ph,SiPH2 in toluene and sub- 105 K. M. Waggoner M. M. Olmstead and P. P. Power in ref. 1 p. 257. I nh P. B. Hitchcock H. A. Jasim M. F. Lappen and H. D. Williams in ref. I p. 245. I07 H. S. Rzepa and J. D. Woollins Polyhedron 1990 9 107. 108 A. H. Cowley R. A. Jones M. A. Mardones J. L. Atwood and S. G. Bott Angew ('hem.. In(. Ed. Engl. I990 29. 1409. 34 S. M. Grimes sequent refluxing in toluene has a distorted cube in which the average A1 -P bond distance of 2.414 8 is slightly less than those observed in A12P2 dimers.2 Gallium Polyphenol-type surfactants bearing 1,2-benzenediol or 1,2,3-trihydroxybenzene units were prepared and applied as flotation collectors for Ga3'.Io9 They are shown to float Ga3' even from strongly alkaline solutions and their characteristics as flotation collectors in concentrated saline solution are highly affected by their solubilities in addition to the stability constants. The structures of gaseous dimethylgallane and dimethylgallium chloride have been determined"' by electron diffraction. The results indicate that the predominant vapour species at low pressures and temperatures of 290-350 K are dimeric molecules with diborane-like structures Me2Ga(p-X),GaMe2 (where X = H or CI) with heavy-atom skeletons conforming to DZhsymmetry.Dimethylgallane thus represents the first gallium hydride containing a Ga(p-H),Ga bridging unit to be characterized structurally it is notable for the shortness of the Ga..Ga distance (2.610 A). A review of the structural and reaction chemistry of gallium and indium dihalides"' has been published. In the system C,H,/ SnCl,/GaCl crystalline (ben- zene)chlorotin( +2) tetrachlorogallate( +3) is obtained.'I2 According to an X-ray structure analysis the solid contains polymeric {([C,H,SnCl][GaCl,]),,, layers built up by [(C,H,SnCl] [GaC1,])2 structural units. A unit consists of a Sn2Clf+ four- membered ring two GaCl tetrahedra at opposite sides of the ring plane and two benzene molecules bound to the tin atoms in a distorted vh-state.The compound ( q6-1,2,4,5-tetramethylbenzene)-( v6-toluene)gallium(I) tetra-chlorogallate(11 I) crystallizes from dilute solutions of equimolar quantities of gal- lium( I) tetrachlorogallate(111) and l ,2,4,5-tetramethylbenzene (durene) in toluene on slow cooling to 0 OC.'13 The crystals of the compound contain centrosymmetrical dimers {[( q6-C6H2Me4)( q6-C,H,Me)Ga]GaC1,) ,in which each gallium( I) centre is hexahapto-bonded to one durene and one toluene molecule. The two aromatic hydrocarbons of these bent-sandwich moieties form an interplane angle of 58". With a metal-to-ring distance of 2.642 A the durene ring is much closer to the Ga' atom than the toluene ring (3.039 A).The Ga' atoms are bridged via two slightly distorted GaCI tetrahedra through contacts with three of the four chlorine atoms. The structure resembles that of the [(C,H,),Ga]GaX complexes with X = C1 Br. A corrigendum of the crystal structure of [H2B(pz)2]2GaC1"4 has been published in which it is reported that the structure can be satisfactorily refined in the centrosym- metric space group C2,c instead of Cc with no surprising features. High-field 'lGa NMR spectra at 122.03 MHz of aqueous solutions of Ga3+ in the presence of oxyanions reveal sulphate phosphate or citrate complexes. In halogen acid solutions the [Ga(H20)J3+ signal is accompanied by that of a mixture of [GaX,( H20)4-n]3~" I09 Y. Koide K. Sakurai H. Shosenji and K. Yamada J.Chem. SOC.,Dalton Trans. 1990 641. I10 P. L. Baxter A. J. Downs M. J. Goode D. W. H. Rankin and H. E. Robertson J. C'hem. Soc. Dalton Trans. 1990 2873. Ill D. G. Tuck in ref. 1 p. 377. I I2 W. Frank Chem. Ber. 1990 123 1233. I13 H. Schmidbaur R. Nowak B. Huber and G. Muller in ref. I p. 283. I I4 R. E. Marsh Inorg. Chem. 1990 29. 1449. Al Ga In TI (X = C1 or Br; n = 1-4) from which a single NMR peak is ob~erved."~ Aqueous solutions of [GaClJ and [GaBr,]- in combination yield one peak due to mixed halides undergoing ligand exchange. The diethyl ether extract of this solution displays the five signals of the complex acids H+ (aq) [GaC1,Br4-,]- (n = 0-4). The Raman spectrum of this system provides a set of v(Ga-Cl),, frequencies.The 170 chemical shift of the [H904]+ ion occurs at 15 ppm. Attempts to investigate the halogen exchange process of gallium mixed-halide species by a two-dimensional 71Ga NMR technique have also been described. The 7'Ga NMR spectra of mixed- ligand halide/thiocyanate complexes are attributable to species [GaX (NCS),-,]- (X = C1 or Br; n = 0-4). Two papers by Kydd and co-w~rkers,'~~~'~~ report NMR studies of the hydrolysis of Ga"' solutions. One NMR study has revealed116 evidence which suggests strongly that a polycationic species structurally analogous to [AlO4Al1~(OH)~~(H~0)~2I7+ with a tetrahedrally coordinated gallium nucleus forms on hydrolysis of [Ga( H20)J3+ solution. In addition pillaring studies revealed that the species intercalated into clay minerals from the gallium solutions has the 'height' in fact 5.6% larger than the size of the A113 cationic unit appropriate to a [Ga04Ga12- (OH),,( H20)12]7+ polycation.Further investigation' l7 has involved quantitative 71Ga and 27Al NMR studies of the base hydrolyses of [Ga(H20)6]3+ and [Al(H20)6]3+ solutions. Through consideration of both the extremely broad nature of the tetra- hedral gallium peak and the high quadrupole moment of the 71Ga nucleus it is proposed that the gallium tridecamer is much more distorted than the aluminium species and that the integrated area of the NMR peak assigned to this species does not accurately represent the amount actually present in solution. The solution chemistry of gallium and indium 3-hydroxy-4-pyridinone complexes in vitro and in uivo have been studied.'18 The pyridinones have different substituents at the ring nitrogen atom R = H CH3 and C2H5.These ligands form ML complexes (n = 1-3) of great stability; the overall stability constants p3 for the 3 :1 complexes are (M = Ga) and (M = In). The effective formation constants (P3efi)of the various ligands for Ga3+ at physiological pH are close to As a practical application of these data comparative metal binding in a simple blood plasma model has been simulated and the result incorporated into the design of biodistribution experiments in mice using these ligands. In another paper"' the stabilities of trivalent metals related to N,N'-bis-(2-hydroxybenzy1)ethylenediamine-N,N'-diacetic acid have been investigated.Alkyla- tion of the aromatic ring significantly increases the basicity of the ligand but lowers the metal ion affinity because of steric affects. The synthesis and characterization of a new hexachelating ligand 1,4,7-tris (2-mercaptoethy1)- 1,4,7-triazacyclononane (TS-TACNH3) and its complex with gallium( 111) has been reported.12' The complex crystallizes out as pale pink needles from dichloromethane in the monoclinic space group P2.,,. There are four molecules of complex and two molecules of solvation I15 M. J. Taylor in ref. 1 p. 207. I16 S. M. Bradley R. A. Kydd and R. Yamdagni J. Chem. Soc. Dalton Trans. 1990 413. S. M. Bradley R. A. Kydd and R. Yamadagni J. Chem. Soc. Dalton Trans. 1990 2653. 1I8 D. J. Clevette D. M.Lyster W. 0. Nelson T. Rihela G. A. Webb and C. Orvig Inorg. Chem. 1990 29 667. I19 R. J. Motekaitis A. E. Marrell and M. J. Welch Inorg. Chem. 1990 29 1463. I20 D. A. Moore P. E. Fanwick and M. J. Welch Inorg. Chem. 1990 29 672. 36 S. M. Grimes (CH2C12) present per unit cell. The gallium is fully chelated in a slighly distorted octahedral environment by the three amine nitrogens and the three thiolate sulphurs. Preliminary results have indicated that 68Ga(TS-TACN) is stable in vivo versus the blood protein transferrin indicating a relatively high stability constant for this hexachelating ligand. An active and very selective catalyst for propane conversion to aromatics near atmospheric pressure and 750-850 K is formed by ball-milling 2-10 wt% Ga as Ga2O3 with HZSM-5 followed by hydrogen reduction at about 850 K for 2h.Microbalance TPR experiments and X-ray diffraction studies along with catalytic testing have helped',' establish that the intimate physical mixture of Ga203 with HZSM-5 the acidity of the zeolite and the hydrogen reduction are all necessary to generate the highly active form of the catalyst. It is suggested that the active species is probably Ga' as a zeolite cation and is not incorporated in the zeolite lattice. From a phase diagram study of the system CaGa2S4-CoIn,S4 a crystal phase of CoGaInS was identified and its crystal structure determined.'" It crystallizes in the trigonal FeGa2S4 type space group Pgml. The system xCoGa,S,-( 1 -x)Coln2S4 is quasibinary and the compound CoGaInS has a large region of homogeneity with a marked dependence on temperature ranging from x = 0.2 to x = 0.8 at 800 "C.The synthesis and characterization of the first examples of pyrazagaboles six- membered heterocycles containing both B and Ga moieties bridged by two exobiden- tate pyrazolyl ligands are described.'23 The structures feature six-membered B-( N-N),-Ga rings having highly asymmetric boat conformations with a mean Ga-N bond distance of 1.977 A. Cowley et ~1.l~~ report the synthesis and structure of a diphosphadigalletane a novel base-stabilized Ga2P ring system. The dimer [{ (Me2NCH2),C6H3}GaPSiPh3],consists of a central Ga,P2 which comprises a rhombus residing on the centre of symmetry. Each Ga is tetracoordinate due to the coordination of one dimethylamine group on each aryl ligand.The synthesis and characterization of two gallium-phosphorus adducts (Me3CCH2)3Ga. P( H)Ph and (Me3SiCH2)3Ga-P( H)Ph2 and the crystal structure of the former are re~0rted.l~~ The most striking structural feature of the compound is the extremely long Ga-P distance of 2.683 8 (cf:related compounds with Ga-P of 2.353 A) which suggests that the material is a relatively weak adduct. The observation that the a-carbon atoms of the substituents on gallium and phosphorus are essentially but not perfectly eclipsed suggests that the long Ga-P distance is probably not related to extreme steric stress. The etch rates in darkness of n-and p-type GaP [1111 and [1111 crystal faces in alkaline Fe(CN):-were measured.'26 The hole injection rate was found to depend on the crystal orientation on the pH of the solution and on the polarization of the electrode.This dependence was explained by differences in position of the valence band edge as observed in impedance measurements. The difference of I21 G. L. Price and V. Kanazirev J. Catal. 1990 126 267. 122 H. Haeuseler H. J. Stork and W. Cordes J. Solid State Chem. 1990 87 15. 123 S. J. Rettig M. Sandercock A. Storr and J. Trotter Can. J. Chem. 1990 68 59. 124 A. H. Cowley R. A. Jones M. A. Mardones J. Ruiz J. L. Atwood and S. G. Bott Angew. Chem. Int. Ed. Engl. 1990 29 1150. 125 M. A. Banks 0.T. Beachley Jr. J. D. Maloney and Rh.D. Rogers in ref. 1 p. 335. 126 H. H. Goossens 1. E. Vernier F.Vanden-Kerchore and W. P. Comes Electrochim. Acta. 1990.35 1351. Al Ga In TI 37 injection kinetics resulted in a difference in morphology between both polar faces after etching. An electrochemical method for the preparation of GaSb polycrystalline thin films has been pre~ented'~~ involving sequential deposition of Sb and Ga films (from an acid SbC1 solution and an alkaline GaC1 solution respectively) and a mild thermal annealing. In Ba,Ga,Sb, a recently synthesized compound there is a Ga4Sbb4- two-dimensional net that probes the limits of the Zintl concept.'28 It is made up of one-dimensional alternating four- and eight-membered Ga-Sb rings linked together into a two-dimensional structure by long but bonding Sb-Sb contacts. The prepar- ation crystal structure and physical properties of a new two-dimensional layered polymeric Zintl phase material K3Ga3As4 has been re~0rted.l~~ The Ga,As;- anionic unit forms a covalently bonded network with each Ga atom bonded to four As atoms and each As atom bonded to three Ga atoms.The structure of V,Sn,Ga is of a new type consisting of two kinds of bands of linked GaVS pentagons and Sn-atom clusters which alternate along the b-axis.',' Finally the bonding properties of a two-dimensional layer containing linear Cu chains and unusual four-coordinate Ga atoms in a Ca,Cu,Ga crystal have been studied.',' The bond length between two Cu atoms bridged by two Ga atoms is slightly increased as compared to the bond length between the two unbridged Cu atoms.The authors first calculated the band structure of a one-dimensional linear Cu chain and then introduced the Ga sublattice thus forming the two dimensional layer. Introducing the Ca atoms to form the full three-dimensional structure has no major effect on Cu-Cu and Cu-Ga bonding but does place one partially filled Ca band in the valence region. It is considered by the authors that Ca,Cu,Ga should be a conductor unlikely to be subject to Peierls distortions. 3 Indium The preparative and spectroscopic studies of the oxidation of indium (I) halides by the substituted o-quinones 3,5-di-t-butyl-o-benzoquinone (TBQ) and phenanthrene- 9,lO-quinone (PQ) have been reported. The reaction mechanism involves an initial one-electron transfer process followed by dimerization and rearrangement reactions.Stationary and non-stationary responses of polycrystalline indium electrodes in NaOH (0.05-4M)solution at 25 "C were studied in order to determine the influence of potential and time during the different stages of indium ~xidation.'~~ The crystal structures of several phosphine oxide and dimethyl sulphoxide com- plexes of indium halides have been determined.'34 The compounds [InC13(Me3P0)2(MeOH)],[InC13Me3P0)2(H20)].H20,[InC1,(PhMe2P0),]-H20 [InCl,( Me2S0)3] and [InBr,( Me,SO),] are fac octahedral but (InC13(Me,PO),] 127 F. Paolucci G. Mengol and M. M. Mussani J. Appl. Electrochem. 1990 20 868. 128 P. Alemany S. Alvarez and R. Hoffmann Inorg. Chem. 1990 29 3070. I29 T. L. T. Birdwhistell E. D. Stevens and C.J. O'Connor Inorg. Chem. 1990,29 3892. 130 J. Ye H. Horiuchi T. Shishido and T. Fukuda Acta. Crystallogr. Sect. C 1990 46 1195. I31 C. Kollmar and R. Hoffmann Inorg. Chem. 1990 29 2466. 132 T. A. Annan R. K. Chadha P. Doan D. H. McConville B. E. McGarvey A. Ozarowski and D. G. Tuck Inorg. Chem. 1990 29 3936. 133 S. B. Saidman E. C. Bellocq and J. B. Bessone Electrochim. Acta 1990 35 329. 134 W. T. Robinson C. J. Wilkins and Z. Zeying J. Chem. SOC.,Dalton Trans. 1990 219. 38 S. M. Grimes has the mer configuration. Triphenylphosphine oxide yields ionic derivatives of the type [InX2( Ph,PO),]+[ InX,]- (X = C1 or Br). Methyldiphenylphosphine oxide gives covalent [InC13( Ph,MePO),] but ionic [InBr,( Ph,MePO),]'[ InBr,]-. The simultaneous determination of In"' and Cd" was in~estigated'~~ by d.c.polarography in the presence of polyethylene glycol (PEG) in 0.1 mol dm-3 hydro- chloric acid. In the presence of PEG the reduction wave height of Cd" decreases and then remains constant while that of In"' does not appear. Thus making it possible to determine both ions simultaneously. Rather poorly crystallized spherical particles of indium"' hydroxide were pro- d~ced',~ by forced hydrolysis at 100°C for 120minutes under the conditions of 6.0 x lo- mol dm- for indium(1Ir) ions 1.0 x lo- mol dmP3 for nitric acid and 1.25 for a concentration ratio [SO:-],/[ In3+],,respectively having an average size of 0.48 pm with relative standard deviation of 0.09. Under similar conditions but in a nitrate solution free from sulphate ions cubic particles of well crystallized indium(111) hydroxide were formed.The structure of the hydrogarnet Ba31n2(0D)12 has been determined13' from time-of-flight neutron powder data. Single crystals of metallic indium oxide were grown for the first time by molten salt electrolysis and their electrical and magnetic properties were inve~tigated.',~ The crystals are the cubic form of indium oxide with a C-type rare earth oxide structure are highly reflective with colours ranging from dark green to green/yellow and are stable up to -1200 K upon exposure to oxidizing atmospheres. The resistivity as a function of temperature on all the crystals showed metallic behaviour up to about 100 K and almost temperature-independent behaviour down to -2 K.The temperature vari- ation of the magnetic susceptibility is Pauli paramagnetic consistent with the observed metallic property. Sintered specimens of cubic Sc,O,-type structure (C- type laj) Sc203 Y203,and In,03 and monoclinic Sm203-type structure (B-type C2/m) Sm203 and powdered specimens of C-type Gd203 were shock-loaded to 2-50 GPa using flyer plates accelerated by a propellant gun.'39 Recovered specimens were studied by X-ray powder diffraction analysis at room and high temperature. In203 transformed to the corundum structure (R3c) in the pressure range of 15- 25GPa although the yield was very small. Two report the direct electrochemical synthesis of indium derivatives along with other d 'O metal ion derivatives of some anionic bidentate oxygen and of 3-hydroxy-2-methyl- 4-pyr0ne.'~' Attempts', to prepare the metal tri-isopropoxides M(OPr') (M = Sc Y In Yb) by various methods always produced the pentanculear oxoalkoxide clusters [M5(p5-0) (p3-OPri),-(p2-OPri) (POri)5] as the stable products.In50(OPr'), was prepared by reaction of anhydrous InCl with NaOPr' in a 1:3 molar ratio in a benzene-isopropanol mixed solvent. X-ray single crystal diffraction showed the presence of the ps-oxygen atom bonded in a square pyramidal configur- 135 T. Kurotu Bull. Chem. SOC.Jpn. 1990 63 597. 136 S. Hamada Y. Kudo and K. Minagawa Bull. Chem. SOC. Jpn. 1990 63 102. 137 S. J. Martin M. O'Keeffe and R. B. Von Dreele J. Solid State Chem. 1990 87 173. 138 Z. S. Teweldemedhin K.V. Ramanujachary and M. Greenblatt J. Solid State Chem. 1990 86 109. 139 T. Atou K. Kusaba K. Fukuoka M. Kikuchi and Y. Syono J. Solid State Chem. 1990 89 378. 140 T. A. Annan C. Peppe and D. G. Tuck Can. J. Chem. 1990 68 423. 141 T. A. Annan C. Peppe and D. G. Tuck Can. J. Chem. 1990,68 1598. 142 D. C. Bradley H. Chudzynska D. M. Frigo M. E. Hammond M. B. Hursthouse and M. A. Mazid Po/yhedron 1990 9 719. Al Ga In 77 39 ation to five metal atoms which had terminal isopropoxo groups trans to the 0x0 atom. The p3-and p,-isopropoxo groups contribute to the distorted octahedral coordination of each metal atom. The variable temperature 'H NMR spectral studies demonstrated a greater lability of the isopropoxide groups in the indium cluster with the p2-and p,-ligands exchanging rapidly above -30°C whilst the terminal ligands were inseparable down to -80 "C.Dibutylindium carboxylates and butylindium thiolates are prominent precursors for the preparation of indium oxide and sulphide thin layers uia a solution pyrolysis process. Their application has been extended'43 to include the preparation of ternary compound thin films taking advantage of the formation of binuclear complexes with organotin oxides or copper( 11) dithiocarbamate complexes. Thus addition of Bu"In(0COEt) to Bu';SnO gave the mixed stannoxane Bu"(EtC0O)In-0-SnBu; (I); while BuiInSPr" and Cu( S,CNBu;) afforded similar bimetallic complexes Bu; In(SPr")Cu(S,CNB;) (VI). Solution pyrolysis of (I) and (VI) gave uniform indium-tin oxide and copper-indium sulphide thin films respectively.Flat band potentials of In2S3 polycrystalline thin films obtained by chalcogeniz- ation of electroplated metallic indium films on Ti substrates with a flowing stream of H2S gas as a function of the redox couple solution concentrations and pH value have been obtained.la Photoelectrochemical characterization of the electrodes was carried out in aqueous polysulphide solutions and the application of the Gartner- Butler model to the semiconductor/ electrolyte interface made it possible to obtain the semiconductor energy gap -a value of 2.06 eV corresponding to direct allowed transition. 119 Sn Mossbauer effect measurements have been perf~rmed'~' on the two forms a and p of In,,Sn,S, over the temperature range 78 d T d 300 K.The effective vibrating mass (Meff)calculated from the temperature dependence of the isomer shift (Meff= 130 and 101 amu respectively) leads to a lattice temperature of 198 and 245 K for the a and p forms. Further studies involving the use of "'Sn Mossbauer spectroscopy and 'Li nuclear magnetic resonance techniques to study the effect of chemical lithiation on the spinel structure of Inl,Sn4S3 have also been ~ep0rted.l~~ Spectroelectrochemical methods were to study the electrochemical behaviour of a novel Prussian blue analogue indium hexacyanoferrate (InHCF) film modified electrodes. It was determined that a one-electron transfer electrode reaction took place for InHCF film modified electrodes and that ion permeability in an InHCF film followed the order Na+ K+ > NHT Li+.Reaction of Bu'Ph with [Me3SiCH,],In in the presence of Ag+ ions leads to [(Me3SiCH2),InPHBu'] which according to an X-ray structure analysis forms a four-membered planar P,In ring with alternating P-In bonds and crystallizes in the monoclinic space group C2/c.14* Reaction'49 of InCl with the phospholyl anion 143 R. Nomura S. Fujii K. Kanaya and H. Matsuda in ref. 1 1990 361. 144 P. Herrasti E. Fatas J. Herrero and J. Ortega Electrochim. Acta 1990 35 345. 145 M. L. Elidrissi-Moubtassim J. Olivier-Fourcade J-C Jumas and M. Maurin J. Solid State Chem. 1990 87 274. 146 M. L. Eldrissi-Moubtassim J. Olivier-Fourcade J-C. Jumas and J. Senegas 1. Solid State Chem. 1990 87 1. 147 Z.Jin and S. Dong Electrochim. Acta. 1990 35 1057. 148 U. Dembowski M. Noltemeyer W. RockensuB M. Stuke and H. W. Roesky Chem. Ber. 1990,123,2335. 149 T. Douglas K. H. Theopold B. S. Haggerty and A. L. Rheingold in ref. 1 p. 329. S. M. Grimes K( 18-crown-6)+-[ PC4Me,] has yielded'50 the indium(rI1)ate complex K( 18-crown-6)+ [(Me4C4P)2 In C12]-. The coordination environment of indium in the complex anion is a distorted tetrahedron consisting of the two phosphorus atoms of vl-phospholyl ligands and two chlorides (Figure 2). The authors believe this to be the product of a disproportionation reaction and although the indium( I) derivative (Me4C4P)In may be formed initially the presence of donor solvents (such as the free crown ether) or heating leads to its decomposition.The first phosphide rep- resentative of the Cr2,C6 structure type viz. Ni2'In2P6 has been re~0rted.l~' It crystallizes in the space group Fm3m. Figure 2 Structure of K( 18-crown-6)+[ (Me,C,P),InC12]- (Reproduced with permission from Polyhedron 1990 9 329.) The structures of [(C,H,),N],[ In2Fe6(C0)24] and [(C2H5),N](2,2'-bi-pyridine)InFe2(CO)8] have been determined.15 The former consists of a central In2Fe2 parallelogram with each In atom linked to an additional [Fe2( CO),( P-CO)~] group in a distorted tetrahedral array. The In,Fe parallelogram sits on a crystallo- graphic site of 2/m symmetry. The latter crystallizes with the Fe(C0,) groups and the bipyridine ligand in a distorted tetrahedral arrangement around the In atom.The [Fe(CO),] groups exhibit trigonal bipyramidal geometries. A phase diagram of the alloy system Cd2,(CuIn),Mn2,Te2 (x + y + z = 1) has been in~estigated'~ in the composition range of 0 < z < 0.80 by differential thermal analysis and X-ray diffraction measurements. Samples were prepared for various lines of constant x/ y ratio and the T(z) data determined for each line. In addition to liquidus and solidus curves the zinc blende -chalcopyrite and Mn-disordered -Mn-ordered transition lines were determined. 150 M. Andersson-Soderberg and Y. Anderson J. Solid State Chem. 1990 85 315. 151 J. M. Cassidy and K. H. Whitmire Acta CrystaNogr. Sect. C 1990 46 f781. M. Quintero E. Guerrero R. Tovar G. S. Perez and J. C. Woolley J. Solid State Chem.1990,87 456. 153 R. D. Fulton R. R. Ryan and J. H. Hall Acta Crystallogr. Sect. C 1990 46 1621. Al Ga In TI 41 4 Thallium The structures of two univalent thallium compounds have been rep~rted.'~~,'~~ Thallium hydrogen phthalate crystallizes in the orthorhombic space group P2,ab and each T1+ is surrounded by oxygen atoms with the six nearest at distances between 2.72 and 3.07 A.154Monoclinic thallium trivanadate TIV308 was prepared from hydrothermal treatment of a mixture of V205 + V203 + T12C03+ H20at 473 K for 24 hours in a sealed tube. The structure155 is built from V(2)05 square pyramidal units which entities share a common edge giving rise to infinite chains of (V20;-)m along the b axis. The V(l) atoms occupy an octahedral coordination between the chains resulting in a packing of corrugated sheets of (V30,)m parallel to the 100 plane.The TI-Te system has been reinvestigated by thermal analysis and X-ray diffrac- tion and the crystal structures of TlTe and Tl,Te have been redetermi~~ed.',~ The TlTe structure which crystallizes in the tetragonal space group (I4/mcm) is described in terms of chains of [Te] connected by the T1' polyhedra coordination whilst the Tl,Te3 structure (tetragonal I4/m) is built up from TlTe6 layers perpendicular to the c-axis and shows the simultaneous presence of T1' and Tl"'. The synthesis of two T1"' diacetonyl compounds and the crystal structure of one of them a diacetonyl complex [T1{CHC(0)Me}2-(p-CF3S03)(bpy)]2 = (bpy bipyridyl) have been reported."' The structure reveals distorted six-coordination of the thallium atom with strong almost linear coordination by the acetonyl carbons longer contacts to the N atoms of the bipyridyl ligand and weak coordination by the oxygen atoms of two triflate ions.A study of the tea~tion'~' between thallium(II1) and thiocyanate ion in aqueous HC104 (0.2-2.0 mol dm3) solutions has shown the complex [TI(SCN)I2' to be reactive yielding final products possibly through a dimer. Two other complexes [Tl2(SCN)I5+ and [HTl(SCN)2]2+ are also formed but are not reactive. A comparative structural study of dimethyl-( pyridine-2-thiolato)thallium(111) and dimethyl-bis(pyridine-2-thiolato)tin(rv)has been re~0rted.l~~ The former crystallizes in the monoclinic space group with the thallium atom coordinated to the two methyl carbons (TI-C 2.159 and 2.199 A) to the pyridine nitrogen (Tl-N 2.494 A) and to two sulphur atoms (TI-S 3.160 and 2.870 A).The following four papers report studies on ternary thallium chalaogenide sys- 160-163 Ba2T1,0S has been reinvestigated16' using X-ray diffraction electron diffraction and energy dispersive X-ray spectroscopy and reported to have a monoclinic structure whilst the impurity phase coexisting with Ba2T1205 was I54 R. Benchrifa M. Leblanc and R. De Papt Acta. Crystallogr. Sect. C 46 177. 155 A. Abba Toure G. Kra R. Eholie J. Olivier-Fourcade and J-C. Jumas J. Solid State Chem. 1990 87 229. I56 J. Vicente J-A. Abad G. Cara and P. G. Jones Angew Chem. Int. Ed. Engl.1990 29 1125. 157 Y. K. Gupta D. Kumar S. Jain and K. S. Gupta J. Chem. SOC.,Dalton Trans. 1990 1915. 158 M. V. Castano A. Macias A. Castineiras A. Sanchez Gonzalez E. M. Martinez J. S. Casas J. Sordo W. Hiller and E. E. Castellano J. Chem. SOC.,Dalron Trans. 1990 1001. 159 W. Zhou R-S Liu and P. P. Edwards J. Solid Stare Chem. 1990 87 472. 160 R. Berger L. Eriksson and A. Meerschaut J. Solid State Chem. 1990 87 283. 161 A. Abba Toure G. Kra R. Eholie J. Olivier-Fourcade J. C. Jumas and M. Maurin J. Solid State Chem. 1990 84 245. 162 R. E. Marsh J. Solid State Chem. 1990 87 467. 163 M. Paranthaman A. Manthiram and J. B. Goodenough J. Solid State Chem. 1990 87 479. 42 S. M. Grimes determined to be Ba4T16013 having an orthorhombic cell.The crystal structure'61 of copper-deficient TlCu5Se3 has been refined the symmetry shown to be tetragonal and the structure found to have features common to other thallium copper chal- cogenides such as T1Cu3Se2 and T1Cu7Se4. Abba Toure et have described the crystal structure of T12GeTe5 as orthorhombic space group Cmmm. Marsh,'62 in a later note questions this description and points out that the author had commented that the crystals of T12GeTe5 appeared to show tetragonal symmetry with possible alternative space groups P4,bc or P4,/mbc. Five papers report studies on thallium-based cuprate system~.'~~-'~' A combination of wet chemical analysis and thermogravimetric analysis has been to identify the origin of oxidation in the thallium cuprate superconductors.It has been demon- strated that oxidation of the Cu02 sheets in T12Ba2Can-iC~n02n+4 is primarily due to an overlap of the T1-6s band with the cr$-,2 and/or T* bands of the CuO sheets and that neither Tl vacancies nor excess oxygen in the T1202blocks is required to render the thallium cuprates superconductive. Three possible superconducting phases have been identified164 in the system Tl-Ca-Ba-CuO all of which share a basic structure related to that of the superconducting phase in the Bi-Sr-Ca-Cu-0 system. Superconductivity with a T,.,,, at 75 f 1 K has been in TI-M- Ba-Cu-0 (M = Ce Th) system for a starting nominal composition of Tl2,,M1Ba2Cu30,. X-ray data show that the compounds are multiphasic with the 2201 phase as the predominant one which is responsible for superconductivity.Only metallic behaviour is observed for pure Tl,Ba,Cu,O and M = Pb or (Pb + Sb) or Te containing phases down to 15 K. The formal oxidation states of Pb and Bi in the single rock salt layer superconductors ASr2Can-lCu,02,+3 (A = Tlo.5 Pbo.5 Tlo,sBio.5 ;n = 2.3) have been examined166 by performing tight-binding band elec- tronic structure calculations on the distorted A03 layers and also molecular orbital calculations on the distorted A06 octahedra. The results show in all cases the oxidation state of T1 is +3 and that the most likely oxidation state of Pb is +4 and that of Bi is either +3 or +5. Liu and co-worker~'~~ report the fundamental changes in the electronic properties of the septenary compound (Tlo.sPbo.s) (Cal-yYy)Sr2Cu2),-S which has the highest superconducting transition temperature (110 K) yet observed in the T~C~B~,CU~O,-~ (1122) structure type as Ca2+ is replaced by Y3+ Superconductivity is observed over the homogeneity range y = 0-0.5 with the superconducting transition temperature showing a maximum (108 K) at y = 0.2.Across the homogeneity range y = 0.6-1.0 the material undergoes a metal-semiconductor transition. Platinum UPD modified electrodes (R/M(UPD) where M = Pb Ti Bi) have been used16* to study electroreduction of 3-nitro-1 H-l,2,4-triazole (NTr) in aqueous acid alkaline and intermediate pH buffer solutions. At these modified electrodes NTr undergoes a four-electron reduction which occurs via an electron-transfer 164 W.Zhou A. Porch I. B. M. Van Damme D. A. Jefferson W. Y. Liang and P. P. Edwards J. Solid State Chem. 1990 88 193. 165 K. A. Thomas U. V. Varadaraju G. V. Subba Rao C. V. Tomy and S. K. Malik J. Solid State Chem. 1990 88 177. 166 D. B. Kang D. Jung and M. H. Whangbo Inorg. Chem. 1990 29 257. 167 R. S. Liu P. P. Edwards Y. T. Huang S. F. Wu and P. T. Wu J. Solid State Chem. 1990 86 334. 168 G. Kokkinidis K. Hasiotis and D. Sazou Electrochim. Acra 1990 35 1957. 169 G. Brun B. Boubali R. M. Ayral and J-C. Tedenac J. Solid Stare Chem. 1990 89 292. Al Ga In Tl mechanism and not by a hydrogenation mechanism as occurs at Pt itself. In strongly basic media the Pt/ M(UPD) surfaces exhibit an expected enhanced catalytic activity for the nitro-group electroreduction compared to that of mercury.The final paper reports'69 the investigation of three isopleth sections AgTlTe-( CuTlTe) AgTlTe-Cu2 Te and AgTlTe-Cu,TlTe, of the quaternary system Ag-Cu-Tl-Te using thermal analysis differential scanning calorimetry and X-ray powder diffraction.

ISSN:0260-1818    

DOI:10.1039/IC9908700023

出版商:RSC    

年代:1990

数据来源: RSC

摘要:

4 0,S Se Te By F. J. BERRY Department of Chemistry The Open University Walton Hall Milton Keynes MK7 6AA 1 Introduction Interests in the technologically important properties of chalcogen-containing solids have continued to grow and this has been reflected in the development of programmes of work seeking to make useful materials by new techniques and characterize their structural and physical properties. This is well illustrated by the attention which has been given to high temperature superconductors where the materials of interest are inorganic oxides. The attempts to make new materials by new routes and thence characterize structural properties which are related to the critical temperatures has resulted in the development of a significant literature on this topic.It is therefore no longer appropriate to review this subject in a chapter devoted to the chemistry of the chalcogens and the reader is referred to chapter nine in this Report where the important developments in this area of science are reviewed in detail. 2 Oxygen Dicopper(1) complexes of tpmc [1,4,8,1l-tetrakis (2'-pyridylmethyl)-l,4,8,1l-tetra-azacyclotetradecane] have been synthesized and found' to react with dioxygen at low temperatures (below -60°C). The reactions were shown to form two species of adduct quasi -reversibly and the resulting compounds were characterized by Resonance Raman spectroscopy. The studies are relevant to current interests in the copper-containing metalloproteins called haemocyanins which bind and transport dioxygen in the haemolymph of molluscs and anthropods.The reaction of dioxygen with low-spin five coordinate complexes PFe"'Ar (P = porphyrin dianion and Ar = aryl group) have also been examined and the formation of aryloxy-iron(II1) and aryl-iron( IV) complexes have been described.2 The chemistry and reactivity of the superoxide ion (02'-) has continued to attract attention because of its appearance as a respiratory intermediate and its role as an effective nucleophile in aprotic media. This is illustrated by a study3 of the addition of excess hydroxide ion to dioxygen-saturated dimethyl sulphoxide solutions con- taining aniline which showed the reaction to give two superoxide ions one azoben- zene and one hydrogen peroxide per two aniline molecules. Similar stoichiometries and yields of O2 were achieved with the N-substituted anilines but PhNHNH2 ' E.Asato S. Hashimoto N. Matsumoto and S. Kida J. Chem. SOC. Dalton Trans. 1990 1741. * R. D. Arasasingham A. L. Balch R. L. Hart and L. Latos-Grazynski J. Am. Chem. SOC.,1990,112,7566. S. Jeon and D. T. Sawyer Inorg Chem. 1990. 29 4612. 45 46 F.J. Berry and some other substrates gave lower yields of O2 . Mechanisms for the sub- strate/-OH reduction of 0 via electron-transfer steps were proposed. The oxygen atom transfer reactions of peroxo- and diperoxo-complexes of oxovanadium( v) with (en)2Co( SCH2CH2NH2)2+ have been ~tudied.~ The d'-d' dimers[MO{S2CN-(CH2Ph)2},),0] (M = Mo W) which contain a linear 0x0 bridge have been shown' to photodisproportionate and evidence has been found for oxygen atom transfer from the compound [W02{S2CN(CH2Ph)2}2] to PEt,.The reactions of [ho(NPPh,NPPh21h)C13] with Ph3SiOH and Bu'OH have been found6 to lead to exchange and rearrangement reactions in which the nitrogen atoms which coordinate molybdenum are replaced by oxygen. The crystal struc- turss of [dlo(OPPh,NHPPh2~)O2Cl2] [dl~(OPPh~NPPh~d)~(o)cl], and [dlo(OPPh,NPPh2d202] were reported together with the synthesis of these unexpec- ted products by more direct routes. Stable tris(dimeth1yamino)sulphonium salts of the perfluoroalkoxides FC(0)(CF2),CF20-( n = 0 1,3) and -OCF2(CF2),CF20- (n = 1,3) have been synthesized and characterized.' The C2F3O2- anion generated from oxalyl fluoride has been shown to have an open ground-state structure and not a bridged-fluoride structure as previously proposed.3 Sulphur Theoretical studies of the potential energy surface of the poorly understood allotrope of elemental sulphur S4 have been performed by use of ab inito electronic structure theory.* Sulphur-nitrogen compounds have continued to attract attention. The 14N NMR spectra of a variety of sulphur-nitrogen heterocycles and metal-sulphur-nitrogen complexes have been recorded and the observed shifts correlated with bonding type.' The study is a good illustration of the utility of 14N NMR spectroscopy as a mechanistic tool in sulphur-nitrogen chemistry for reactions in liquid ammonia. The synthesis and electrochemistry of palladium and platinum macrocyclic com- plexes of [181ane N2S4( 1,4,10,13-tetrathia-7,16-diazacyclooctadecane)and Me2 [18lane N,S4-(7,16-dimethyl-1,4,lO,l3-tetrathia-7,l6-diazacyclooctadecane)have been described." The compound S4N402 has been shown" to react with [MCl,(PR,),] in liquid ammonia to produce [M{S2N3(S02NH2)} (PR3)2] (M = Pt PR = PMe2Ph PMePh, PEt, PPr3" or PBu,"; Me = Pd PR = The 4-phenyl-1,2,3,5-dithiadiazole iPh2PCH2CH2PPh2).dimer has been found" to dehalogenate [SSN5]C1 by a novel ring contraction which produces [(Ph( N2S2)2C1]- [S3N3] in acetonitrile and a mixture of [(PhCN,S,),Cl][S,N,] and [PhCN2S2][S3N3] in pentane. The structural properties of the products were described. A. F. Ghiron and R. C. Thompson Inorg. Chem. 1990 29 4457. S. Lee D. L.Stoley A. L. fieingold and N. J. Cooper Inorg. Chem. 1990 29 4391. M. Rietzel H. W. Roesky K. V. Katti H.-G. Schmidt R. Herbst-Irmer M. Nolterneyer,G. M. Sheldrick M. C. R. Syrnons and A. Abu-Raqabah J. Chem. SOC.Dalton Trans. 1990 2387. ' D. A. Dixon W. B. Farnham and B. E. Smart Inorg. Chem. 1990 29 3954. G. E. Quelch H. F. Shaefer and C. J. Marsden J. Amer. Chem. SOC.,1990 112 8719. I. P. Parkin J. D. Woolins and P. S. Belton J. Chem. SOC.,Dalton Trans. 1990 511. 10 A. J. Blake G. Reid and M. Schroder J. Chem. SOC.,Dalton Trans. 1990 3363. I. P. Parkin and J. D. Woolins J. Chem. SOC.,Dalton Trans. 1990 519. 12 A. J. Banister M. I. Hansford Z. V. Hauptrnan A. W. Luke S. T. Wait W. Clegg and K. A. Jorgensen J. Chem. SOC.,Dalton Trans. 1990 2793. 0 S Se Te Hyperfine coupling parameters for coordinating nitrogen atoms in some copper( 11) complexes with planar and tetrahedrally distorted N2S2 coordination structures have been rep~rted.'~ Studies relevant to current interests in the active site of nickel- containing hydrogenases have identified14 an example of sterically protected Ni2+ in a N2S2 donar environment in 1,5-bis(mercaptoethyl)-1,5-diazacylooctane and its methylated derivative.The preparation of the binuclear complex [Pt(1,5-Ph4P2N4S2)(PPh3)I2 in which the dithiatetrazocline ligand exhibits a novel bonding mode has been rep~rted'~ (Figure 1). Figure 1 Structure of [Pt( 1,5-Ph4P2N4S2)( PPh,)] (Reproduced by permission from Inorg. Chern. 1990 29 3068) The P2N4S2 rings were shown by X-ray crystallography to act as chelating (N S) ligands toward one platinum and to form a bridge to the second platinum via the other sulphur atom and thereby give a centrosymmetric dimeric structure.The sulphur atoms were both shown to be three-coordinate and trans to each other and the Pt-S bond lengths were found to be equal. The variable temperature 31P NMR spectra recorded from the compound showed it to be the first example of a metal- lotropic rearrangement in coordination complexes of S-N ligands (Figure 2). The structure of 1,3,2-benzothiazolium chloride sulphur dioxide solvate C6H4S2N+C1-*S02 has been shown16 to consist of discrete planar cationic units chloride anions and SO molecules. Significant contacts were found to exist between the anion and the SO2 molecule (implying some (SO,Cl-) character) and the sulphur centres of the cation such that the solvate adopted a two-dimensional polymeric macrostructure.The centrosymmetric 1,3,2-benzodithiazolyl dimer was shown to contain two C6H4S2N units joined by two long S-S bonds [3.175(1) A] with interplanar spacings of 3.0A between the two c6s2 mean planes (Figure 3). The dimers were found to be linked by very weak S...S contacts into a sheet-like l3 R. Miyamoto Y. Ohba and M. Iwaizumi inorg. Chem. 1990 29 3234. 14 D. K. Mills J. H. Reibenspies and M. Y. Darensbourg Inorg. Chem. 1990 29,4364. Is T. Chivers M. Edwards P. N. Kapoor A. Meetsma J. C. van de Grampel and A. van der Lee Inorg. Chem. 1990 29 3068. 16 E. G. Awere N.Burford R. C. Haddon S. Parsons J. Passmore J. V. Waszczak and P. S. White Inorg. Chem. 1990 29 4821. F. J. Berry PhqP PPh3 Ph3P \ PPh3 Figure 2 Proposed mechanism for the [1,3]-metallotropic rearrangement in [Pt(1,5-Ph4P2N4S2)-( PPh 112 (Reproduced by permission from Znorg. Chem. 1990 29 3068) \3*175(1) Figure 3 Centrosymmetric (C,H,S,N') (Reproduced by permission from Inorg. Chem. 1990 29 4821) infinite two dimensional net. Variable temperature magnetic susceptibility measure- ments showed the solid to be essentially diamagnetic but on melting to become paramagnetic. A new preparative route to salts of the SNS+ cation has been described" which should lead to a wide variety of other SNS+ salts. The method involves the reaction of tin(I1) chloride with N(SCl),'X-(X = AIC14 or SbC16) in liquid sulphur dioxide or CH2C1 to give high yields of SNS+X- and tin(1v) chloride." A. J. Banister and J. M. Rawson J. Chem. Soc. Dalton Trans. 1990 1517 0,S Se Te A very low first oxidation potential of 0.15 V us SCE has been foundI8 to characterize the 12~-electron compound 4,7 dimethyl-4,7dihydro[ 1,2,5]thia- diazolo[3,4-b] pyrazine (Figure 4(a)) which was formed by reduction of the corre- sponding 14n-electron system with potassium and trapping of the dianion with methyl iodide. The compound was shown to react with the electron acceptor shown in Figure 4(b) to give conducting charge transfer complexes (a= 5.6 x 1.OP2 cm-I). (a) (b) Figure 4 (a) 4,7-dimethyl-4,7-dihydro[ 1,231 thiadiazolo [3,4-b] pyrazine and the electron acceptor (b) which gives on reaction conducting charge transfer complexes (Reproducedby permission from Angew.Chem. In?. Ed. Engl. 1990 29 643) The combination of pyridine ligands [NCI,Tc]-and dithionite has been found" to result in the transfer of a sulphur atom to the coordinated nitride and a net five-electron reduction of the Tc to give mer-[(SN)C12( Py),Tc]. Phosphorus-sulphur compounds have also continued to attract attention. The vapour from solid molecular tetraphosphorus decasulphide P4S10 has been examined,' by infrared spectroscopy after trapping in solid argon and shown to contain P4S10 and P4S9. Other phosphorus sulphides (PS PS2) and diphosphorus sulphides (P2S4 P,S,) were also identified.Photolysis of P4S10 and O3 mixtures gave P4S90 and SO,. The kinetics of the redox dissocation of P4S10 dissolved in 1-chloronaphthalene has been studied21 at temperatures between 110 and 150 "C. The phosphorus-containing reaction products inclduded P4S9 and smaller amounts of phosphorus polysulphides. The initial kinetics were described as quasi first order and were unaffected by dilution. The reaction was found to be insensitive to the presence of oxygen and to the addition of sulphur but to be catalysed by the presence of iodine- and bromine-containing compounds. A mechanism involving the initial rate determining fission of P4S10 into two molecules of metastable P,S was proposed. Photolysis of the P4S3.-.03 molecular complex in solid argon with red light has been shown2 to produce two sets of new infrared absorptions which were assigned as terminal PO and symmetric P-S-P stretching modes.These were associated with structural isomers of P4S30 containing terminal oxygen at the apex and base phosphorus positions. Further ultraviolet photolysis gave evidence for the formation of 0x0-bridged P4S30 and a secondary product of composition P4S302. in Y. Yamashita J. Eguchi T. Suzuki C. Kabuto T. Miyashi and S. Tanaka Angew. Chem. fnt. Ed. Engl. 1990 29 643. 19 J. Lu and M. J. Clarke fnorg. Chern. 1990 29 4123. 20 L. Andrews G. C. Reynolds 2.Mielke and M. McCluskey fnorg. Chem. 1990 29 5222. 21 M. C. Dtmarcq J. Chem. Soc. Dalton Trans. 1990 35. 22 Z. Mielke L. Andrews K. A. Nguyen and M.S. Gordon Inorg. Chem. 1990 29 5096. 50 F. J. Berry A novel approach to the synthesis of ring systems containing phosphorus nitrogen and sulphur which takes advantage of the known susceptibility of N-S(Ph) bonds to homolytic cleavage has been described.23 Experimental evidence for the compar- able strength of P-S P-N pr-bonding within the heteronaphthalenic framework has been pre~ented,~ in a report on the spectroscopic and structural properties of the 1,3,2-benzazathuaphospholium system. Phosphorus-3 1 nitrogen-15 and nitrogen-14 NMR studies of a-tetraphosphorus trisulfide isothiocyanates have been reported.25A series of compounds with the general formula R,PE.AlCl (R = Ph or NMe, E = S or Se) have been examined26 by NMR spectroscopy and the results interpreted in terms of the nature of the P-E bond and the character of co-ordinate bonding in the compounds.The molecular structures of gaseous bis(methylsily1)sul- phide and bis(dimethylsily1)sulphide have been determined by electron diffra~tion.,~ The synthesis and characterization of new layered M'M"'P2S6 phases which are well known to exhibit interesting physical properties has continued to attract atten- tion. This is illustrated by the reported2* preparation of single crystals of cuvP& by heating the elements in an evacuated silica tube at 500°C. The compound was found to adopt the M,"P,S,-type structure in which the copper(1) ions fail to occupy every other M'' octahedron (as was observed for the vanadium(II1) cations) but to be distributed on three different crystallographic sites inside and outside the octahedra.A nickel K-edge EXAFS study of lithium-intercalated layered NiPS with various lithium contents has been reported.29 The large modifications in the EXAFS spectra were related to the displacement of reduced nickel atoms from their initial octahedral sulphur sites to tetrahedral sites within the slabs. The intercalation of ferrocene into layered Cd2P2S6 has been achieved by reacting the cobaltacene- intercalated Cd,P2S6 with ferr~cene.~' Incommensurate misfit layer structures of the type MTS3 (M = Sn Pb Bi rare earth elements; T = Nb Ta) have been studied by electron diffraction and high resolution electron micro~copy.~' Single crystals of the n-type semiconducting tin dichalcogenides SnS,-,Se (x = 0,0.3,0.5,1.3 1.85 2) which have a two-dimensional layered structure have been intercalated3 with cobaltocene to give the series of compounds SnS2-,Se (CoCp,),,, (Cp-q5-C5H5).X-Ray photoelectron spectroscopy showed mixed oxidation states for both tin [Sn" Sn'"] and cobalt [Co' Co" Co"']. TWO of the cobalt species were identified as CoCp and [CoCp2]+ and the third tentatively assigned to a Co( qs-C5H5)( q4-CsH5R) complex in which cobalt is formally in the oxidation state Cot (Figure 5). Ultraviolet photoelectron spectroscopy showed the 23 T. Chivers S. S. Kumaravel A. Meetsma J. C. van de Grampel and A. van der Lee Inorg. Chem. 1990 29 4591. 24 N. Burford A. I. Dipchand B. W. Royan and P. S. White Inorg. Chem.1990 29 4938. 25 B. W. Tattershall J. Chem. SOC.,Dalton Trans. 1990 663. 26 N. Burford B. W. Royan R. E. v. H. Spence and R. D. Rogers J. Chem. Soc, Dalton Trans. 1990,2111. 27 D. G. Anderson V. A. Campbell G. A. Forsyth and D. W. H. Rankin J. Chem. SOC.,Dalton Trans. 1990 2125. 28 E. Durand G. Ouvrard M. Evain and R. Brec Inorg. Chem. 1990 29 4916. 29 G. Ouvrard E. Prouzet R. Bred S. Benazeth and H. Dexpert J. Solid State Chem. 1990 86 238 30 G. T. Long and D. A. Cleary J. Solid State Chem. 1990 87 77. 31 S. Kuypers J. van Landuyt and S. Amelinckx J. Solid State Chem. 1990 86 212. 32 C. A. Formstone. E. T. Fitzgerald P. A. Cox and D. O'Hare Inorg. Chem. 1990 29 3860. 0 S Se Te LLs A .Sn 0S Figure 5 Representation of the possible Cot organocobalt species between the SnX layers (Reproduced by permission from Inorg.Chem. 1990 29,3860) intercalates to be either semiconducting (x = 0 0.3 0.5 1.3) or metallic (x = 1.85 2). The preparation structural properties and conductivities of Li2SiS3 phases has been described.33 The compound Na,S has been ~ynthesized~~ by a new solid-gas reaction of Na2C03 with a sulphidizing gas mixture and by a solid-solid reaction of carbon with Na2S04. Two new crystal modifications of Na2S were identified by X-ray powder diffraction in addition to the previously reported antifluorite structure. The structure of CoGaInS has been determined from single crystal X-ray diffraction data and to adopt the FeGa,S layer type structure.The chemistry and thermodynamics of solid and vapour phases in the technologic- ally important Bas-Ga2S3 system has been studied.36 The results were interpreted in terms of a generalized acid-base theory in which solid Bas was considered as a strong base arid solid Ga2S3 as an acid. Chemical interactions in the quasibinary CaS-Ga,S system have also been examined37 by differential thermal analysis X-ray diffraction and microstructural analysis. The thiogallate formation was identi- fied as CoGa2S4 which was found to crystallize as an orthorhombic compound. The structural modifications arising from the addition of various sulphides and oxysul- phides to a'Ga2S3 have been in~estigated.~~ The compounds Cu2GeS3 Cu2SiS3 and Cu2SiSe3 have been dissolved in the ternary compound CuGe2P3 and by use of a modified Bridgman technique have enabled good quality single crystals of single phase compounds to be grown.39 A complete solid solution series in the 33 B.T. Ahn and R. A. Huggins Mat. Res. Bull 1990 25 381. 34 M. Kizilyalli M. Bilgin and H. M. Kizilyalli J. Solid State Chem. 1990 85 283. 35 H. Haeusler H. J. Stork and W. Cordes J. Solid State Chem. 1990 87 15. 36 P. Mukdeeprom-Burckel and J. G. Edwards Mat. Res. Bull. 1990 25 163. 37 N. I. Yagubov T. N. Guliev P. G. Rustamov and E. T. Azizov Mat. Res. Bull. 1990 25 271. 38 M. Guittard M. P. Pardo and A. Chilouet Mat. Rex Bull. 1990 25 563. 39 M. S. Omar Mat. Res. Bull. 1990 25 691. 52 F. J. Berry system CuGe2P3 -Cu2GeS3 was identified.The compound CuGe2P3 failed to form any solid solution with Cu2SiS3 and Cu2SiSe3. The compound In,oSn6S2 has been shown4' to contain octahedrally coordinated In3+ with the Ins octahedra forming layers. The tin(I1) species were shown to occupy trigonal dicapped prismatic sites between the layers. The spinel structure I~,&I,S~~ has been chemically lithiated with n-butyl lithium and the redox processes and structural analysis examined4' by '19Sn Mossbauer spectroscopy and 7Li NMR. 119 Sn Mossbauer spectroscopic studies of the a-and /3 forms of Lr~,,Sn,s~~ were subsequently described.42 Structure field maps for ternary sulphides crystallizing in common AB2X4 structures have been described43 and used to predict possible compositions for new quaternary compounds of the ZnIn2S4 type.Some antimony chalcogenides with lone pairs of electrons have been examined by 121Sb Mossbuer spectroscopy.u The increase in the chemical isomer shift with increasing covalency and distortion of the local antimony environment was quantita- tively explained by a tight-binding band-structure calculation. The structural proper- ties of the Sb2S3-SbBr3-SbI and Sb2S3-PbBr2-PbI glass systems have been investigated by infrared absorption studies45 and interpreted in terms of SbS3 pyramids which are more or less polymerized and connected to various thiohalide antimony or lead entities. A correlation between structure and optical properties was proposed for the Sb2S3-PbBr2-Pb12 glasses. Percolation phenomena have been reported46 during the transition from an ex- plosive to nonexplosive mechanochemical synthesis of some metal chalcogenides.The structure of silver-intercalated titanium disulphide Ag0.167TiS2 has been determined at several temperatures from time-of-flight neutron powder diffraction data47. The results are relevant to current interests in staging pheomena in lamellar transition metal dichalcogenides. The structures of a range of solid solutions of composition Li,Cuo,07Ti2,05S4 formed by intercalating lithium into the host com- pound CU~,~~T~~,~~S~ have been described4' and related to the structure of spinel. The materials are of interest as cathodes in lithium batteries. A new composite- layered sulphide of composition ( PbS)1,12VS2 'PbVS3' has been prepared49 and shown to consist of two kinds of mutually stacked layers.The material of composition (CeS)1,16NbS2 has been shown5' to be a misfit layer compound built of alternate double layers of CeS approximately a (100) slice of NaC1-type CeS and sandwiches of NbS2 in which niobium adopts a slightly distorted trigonal prismatic site. The compound showed metallic conduction properties with 40 A. Likforman M. Guittard and F. Robert J. Solid State Chem. 1990 89 275. 41 M. L. Elidrissi-Moubtassim J. Olivier-Fourcade J.-C. Jumas and J. Sonegas J. Solid Stare Chem. 1990 87 1. 42 M. L. Elidrissi-Moubtassim J. Olivier-Fourcade J.-C. Jumas and M. Maurin J. Solid State Chem. 1990 87 274. 43 H. Haeuseler J. Solid State Chem. 1990 86 275.44 J. Olivier-Fourcade A. Ibanez J. C. Jumas M. Maurin 1. Lefebvre P. Lippens M. Lannoo and G. Allen J. Solid State Chem. 1990 87 366. 45 J. J. Videau B. Tsobgny J. Portier B. Tanguy and P. Hagenmuller Mat. Rex Bull. 1990 25 231. 46 V. Rusanov and Chr. Chakurov J. Solid State Chem. 1990 89 1. 47 G. L. Burt V. G. Young M. J. McKelvy W. S. Glaunsinger and R.B. Von Dreele J. Solid Stare Chem. 1990,84 355. 48 Y. Saidi I. Abrahams and P. G. Bruce Mat. Rex Bull. 1990 25 533. 49 Y. Gotoh M. Goto K. Kawaguchi Y. Oosawa and M. Onoda Mat. Rex Bull. 1990 25 307. 50 G. A. Wiegers A. Meetsma R. J. Haange and J. L. De Boer J. Solid State Chem. 1990 89 328. 0,S Se Te 53 a strong anisotropy. The metal-rich sulphide Ta6,0sNb4,92S4 has been prepared by high temperature techniques and shown to adopt a structure which is more similar to that of niobium-rich sulphides than tantalum-rich ~ulphides.~’ The structure of (LaS)1,14NbS2 has been re-examined5 through a supercell approach using a non- centrosymmetric space group instead of the centrosymmetric one previously reported.Resistivity measurements made on single crystals indicated a metallic behaviour and a transition to a superconducting state below T = 2.43 K. A detailed study of the reactivity of niobium pentachloride with three different organic sul- phurizing agents (CH3)3SiSSi(CH3)3 (CH3)3CSSC(CH3)3 and (CH3)3CSC(CH3)3 has showns3 that the organic agent does not affect the Nb/S ratio of 2.5 in the amorphous niobium sulphide which is formed.The amorphous product was found to be very reactive and to rapidly convert to a crystalline niobium sulphide by heating at high temperature. Single crystal X-ray diffraction of SnTaS at 295 K and 425 K has the unusal linear coordination of tin by sulphur in the neighbouring TaS sandwiches. A new barium tantalum sulphide of composition Ba2TaS5 has been prepared55 by the reaction of CS with a mixture of BaCO and Ta205 and shown to be isostructural with Ba2NbS5. The compound of formula (PbS)1,13TaS2 which was formerly desig- nated ‘PbTaS,’ has been found56 by single crystal X-ray diffraction to be a misfit layer compound characterized by two face-centered orthorhombic unit cells. One was shown to belong to the PbS part of the structure and the other to the TaS part.The compound was shown to be built of alternately double layers of PbS with distorted NaC1-type structure and TaS sandwiches with tantalum in distorted trigonal prisms of sulphur. X-Ray photoelectron spectroscopy and polarized neutron diffraction has been used” to investigate chemical bonding and ion valencies in the ferromagnetic metallic copper chromium chalcogen spinels CuCr2X4. The result showed the presence of trivalent chromium monovalent copper and one hole in the anion valence band per formula unit i.e. Cu+(Cr3+),(S2-),(S*+).The tetrathiometalates [MS4I2- are well known as fundamental structural and reactive entities in transition metal sulphide chemistry and it is therefore notable that new routes of entry to the solution chemistry of niobium- and tantalum-sulphides have led5* to the synthesis of soluble forms of [MS4I3-.Molybdenum- and tungsten-sulphur compounds have continued to attract atten- tion. A method for the chemical deposition of thin films of semiconducting MoS2 and MoSe on glass substrates using sodium dithionite as a reducing agent has been described59. The morphological structural optical and electrical properties of molybdenum sulphide thin films deposited on a glass substrate by simple chemical 5’ X. Yao and H. F. Franzen J. Solid State Chem. 1990 86 88. 52 A. Meerschaut P. Rabu J. Rouxel P. Monceau and A. Smontara Mat. Res. Bull. 1990 25 855. 53 A. Bensalem and D. M. Schleich Mat. Res. Bull. 1990 25 349. 54 A. van der Lee and E. A. Wiegers Mat.Res. Bull. 1990 25 1011. 55 M. Saeki and M. Onoda Mat. Res. Bull. 1990 25 723. 56 J. Wulff A. Meetsma S. van Smallen R. J. Haange J. C. De Boer and G. A. Wiegers J. Solid State Chem. 1990 84 118. 57 A. Payer M. Schmalz R. Schollhorn R. Schlogl and C. Ritter Mat. Res. Bull. 1990 25 515. 58 S. C. Lee and R. H. Holm J. Am. Chem. Soc. 1990 112 9654. 59 S. Pramanik and S. Bhattacharya Mat. Res. Bull. 1990 25 15. 54 E J. Berry methods using molybdenum( VI) ions ammonia hydrazine hydrate and thioacetamide has also been described.60 Model-promoted and sulphur-deficient molybdenum disulphide-based catalysts have been prepared and tested for the hydrosulphurization of thiophene.61 X-Ray diffraction and electron microscopy showed the active catalysts to possess a high degree of disorder in directions representing the edges of the MoS2 crystal.Both Group VIII promotion and sulphur deficiency were found to give similar structural changes in the molybdenum sulphide lattice which could be correlated with increased catalytic activity. The kinetics of the 1:1 complexing of NCS- for H20 substitution at tungsten on the incomplete cuboidal W3IVclusters [W3(p3-S)(p-S)3(H20)9]4+ and [W3(p3-S)(p-O)3(H20)9]4+ has been investigated62 and together with data from [W3(p3-0)(p-O),(H20)J4+ has been used to elucidate the reactivity pattern for the [W30,S4-x( H,0),I4+ series of p-oxo/p-sulphido aqua ions. New fluxional seven-co-ordinate molybdenum( 11)-and tungsten( 11)-complexes have been prepared63 and the structure of the pyridine-2- thionato complex described.The oxidation of sulfur( IV) by dodecatungstocobal- tate(111) in aqueous acid solution has been in~estigated.~~ A variety of manganese( I) carbonyl complexes containing triethylphosphine and monodentate or chelate triethylphosphoniodithiocarboxylato ligands have been obtained by substitution reactions either under mild conditions or by thermal or photochemical methods.65 The products resulting from the thermal reactions between bromo carbonyls and S2CPEt3 were found to be very different from those obtained with S2CP(C6H1,)3 under similar conditions as a result of the electronic and steric differences between the phosphines concerned. The preparation properties and reactions with sulphur dioxide of triphenylphosphine oxide complexes of manganese( 11) thiocyanate have been reported.66 Interests in iron-sulphur proteins have continued to generate considerable activity in studies of compounds containing iron and sulphur.A new series of Fe4S4 active-site analogues for high-potential iron-sulphur proteins have been prepared from [Fe4S4( SBU')~],- and macrocylic tetra-aza tetrathiol ligands where the active site cores are composed of an intramolecular hydrophobic domain formed by 28- 32- 36- 40- and 42-membered rings with methylene backbone^.^' A new type of active site analogue for 4Fe-4S iron-sulphur proteins has been formed in which the active site core is surrounded by an intramolecular hydrophobic domain formed by a 36-membered ring consisting of a methylene backbone.68 The magnetic suspectibility of the high potential protein model [Fe4S4(S-2 4,6-(Pri)&H2)4]- in the [Fe4S4I3+ oxidized state has been examined69 over the temperature range 5-320 K.The 57Fe Mossbauer spectra of salts containing the anions [Fe4S4( SBu'),12- or [FeX,l2-6o K. C. Mandal and A. Mondal J. Solid State Chem. 1990 85 176. 61 A. Sachdev J. Lindner J. Schwank and M. A. Villa Garcia J. Solid State Chem. 1990 87 378. 62 M. Nasreldin A. Olatunji P. W. Dimmock and A. G. Sykes J. Chem. Soc. Dalton Trans. 1990 1765. 63 A. J. Deeming M. Karim and N. I. Powell J. Chem. Soc. Dalton Trans. 1990 2321. 64 M. Ali S. K. Saha and P. Banerjee J. Chem. Soc. Dalton Trans. 1990 187. 65 D. Miguel V. Riera J. A.Miguel F. Diego C. Bois and Y. Jeannin J. Chem. Soc. Dalton Trans. 1990 2719. 66 K. Al-Farham B. Beagley 0. El-Sayrafi G. A. Gott C. A. McAuliffe P. P. MacRory and R. G. Pritchard J. Chem. Soc. Dalton Trans. 1990 1243. 61 T. Tomohiro K. Uoto and H. Okuno J. Chem. Soc. Dalton Trans. 1990 2459. 68 H. Okuno K. Uoto T. Tomohiro and M.-T. Youinou J. Chem. Soc. Dalton Trans. 1990 3375. 69 J. Jordanov E. K. H. Roth P. H. Fries and L. Noodleman Inorg. Chem. 1990 29. 4288. 0 S Se Te 55 (X = C1 or Br) have been interpreted in terms of perturbations exerted by the cations on the field gradient at the iron centres.70 The [Fe4S4(Me2LS3)L’I2-(L’ = RS-,Cl-) clusters have been shown7’ to contain the cubane-like [Fe4S4I2+ core and to be derived from the trithiol Me,L(SH) (L = 1,3,5-tris((4,6-dimethyl-3-mercap-tophenyl)thio)-2,4,6-tris(p-toly1thio)benzene) which as the trianion functions as a semirigid tridentate ligand.The clusters were shown to be analogous to some biological clusters which undergo regiospecific reactions at differentiated iron sites. The cubane-type cluster [Fe,S,( LS3)C1I2- (LS3 = tris[ (4,6-dimethyl-3-mercapto-phenyl)thio]-2,4,6-tris( p-tolylthio) benzene (3-)] has been shown72 to contain iron differentiated in the ratio 3 :1.The cluster was found to undergo substitution reactions at the unique sub-site with stoichiometric cyanide and excess isonitrile in acetonitrile solution to give [Fe4S4(LS,)(CN)]2- and Fe,S4(LS3)(RNC)3]‘- (R = Me Et But C6Hll and 2,6-Me2C,H3). The 57Fe Mossbauer spectra recorded from some deriva- tives demonstrated the existence of a low-spin Fe2+ subsite assigned to the trigonal Fe( RNC) group and a spin-isolated [Fe3S4I0 cluster fragment having the same ground-state electronic structure as singly reduced 3Fe clusters of proteins.In continued studies of nitrogenase substrates the synthesis and characterization of two new doubly bridged double cubanes of the type [[MoF~~S~C~~(C~~,,,)]~ (p2-S) (p2-L)]”- (L = N2H4 n = 4; L = CN- n = 5) which contain Mo-(p2-L)-Mo bridges with the biologically relevant N2H4 ligand and CN- have been reported73 (Figure 6). Figure 6 Preliminary structure of the anion core in [E~,N],[[MOF~,S~C~~(C~~~~)]~( pz-S)-(P2N2H4)IChCN (Reproduced by permission from J. Am. Chem.Soc. 1990 112 8606) The structure of the compound [MoFe,S4( Me2dtc)J2CH2C12 has been deter- mined74 and shown to contain a cubane-like [MoFe3S4I5+ core. Three new cluster complexes (Et4N)3[ Re2Fe,S,( SEt),] (Et4N)2[Re2Fe7S,(SEt),2] and (Et4N)4[ Re,Fe,S,(SEt),,] containing [ReFe,(p,-S),] cubane-type units have 70 D. J. Evans A. Hills D. L. Hughes G. J. Leigh A. Houlton and J. Silver J. Chem. Soc. Dalton Trans. 1990 2735. 71 T. D. P. Stack J. A. Weigel and R. H. Holm Znorg. Chem. 1990 29 3745. 72 J. A. Weigel K. K. P. Srivastava E. P. Day E. Munck and R. H. Holm J. Am. Chem. Soc. 1990 112 8015. 73 P. R. Challen S-M. Koo C. G. Kim W. R. Dunham and D. Coucouvanis J. Am. Chem. Soc. 1990 112 8606. 74 Q. Lin L. Huang H. Liu X. Lei D. Wu B. Kang and J.Lu Znorg. Chem. 1990 29 4131. E J. Berry been isolated in 66-84% yields from systems containing (Et,N)[ ReS,] FeCl, and NaSEt in methanol.75 The cluster structure of [Re2Fe6S,( SEt),] was shown to consist of two terminal cubane-type ReFe,S,( SEt) subclusters which are bridged through the rhenium atom by three p2-SEt sulphur atoms or as in (Et4N)2[Re2Fe7S8(SEt),2] and (Et,N),[Re2Fe,s8(sEt),,] by a trigonal (p2-SEt),Fe(p2-SEt) unit (Figure 7). S(5') Figure 7 Structure of the cluster [Re,Fe2S,(SEt),,l4-(Reproducedby permission from Znorg. Chem. 1990 29 3493) Comparisons of properties were made with the previously reported molybdenum- and tungsten-clusters of the type [M2Fe6S8(SR)9]3- and [M2Fe7S8(SR)12]3-34- with similar structures.Cubane-type clusters of composition NiFe,Q (Q = S,Se) have been prepared by reductive rearrangment of linear [Fe,Q,( SEt),13- species.76 A new iron-sulphur compound Fe6S,( p-SPh)( P-Bu,"),(SPh) has been ~ynthesized~~ by the reaction of Fe(P-Bu,"),(SPh) and (Bu,"N),[Fe,S,(SPh),] in MeCN/THF. The core was found to consist of six Fe2S2 units fused in the form of a basket by the sharing of edges (Figure 8). The mechanism of the reaction of cuboidal [MO,F~S~(H~O),,]~+ with dioxygen has been studied in The solution chemistry of the cuboidal mixed metal complex has also been examined.79 The reactions of the complexes [FeL,X,][FeX,] (L = OPPh or OAsPh,; X = C1 or Br) with sulphur dioxide have been shown" to give some rare examples of iron( 111) complexes of sulphur dioxide of composition [FeL,{OS(O)X},[ FeX,].The isolation of the sulphuric acid derivatives (PPh30)-(PPh,OH)(HSO,) and (AsPh,OH)(HSO,) was also described. Structural aspects of the a transition in stoichiometric iron sulphide FeS have been described and a high temperature phase identified.,' Similar studies of the a transition in off-stoichiometric Fe,-,S crystals were subsequently reported.82 75 S. Ciurli M. Carrie and R. H. Holm Inorg. Chem. 1990 29 3493. 76 S. Ciurli S.-B. Yu R. H. Holm K. K. P. Srivastava and E. Munck J. Am. Chem. Soc. 1990 112 8169. 77 C. Chen J. Cai Q. Liu D. Wu X. Lei K. Zhao B. Kang and J. Lu Inorg. Chem. 1990 29 4878. 78 P. W. Dimmock and A. G. Sykes J. Chem. Soc. Dalton Trans. 1990 3101. 79 D. W.Dimmock D. P. E. Dickson and A. G. Sykes Inorg. Chem. 1990 29 5120. 80 B. Beagley D. G. Kelly P. P. MacRory;C. A. McAuliffe and R. G. Pritchard J. Chem. SOC.,Dalton Trans. 1990 2657. 81 F. Keller-Besrest and G. Collin J. Solid State Chem. 1990 84 194. 82 F. Keller-Besrest and G. Collin J. Solid State Chem.. 1990. 84 211. 0,S Se Te Figure 8 Structure of Fe,S,(p-SPh)( P-Bu,"),(SPh) (Reproduced by permission from Znorg. Chem. 1990 29 4878) Multiple scattering (MS)-Xa methods have been used to calculate the electronic structure of several clusters which contain an octahedral cogs6 core.83 The syntheses and structural determination of IrSe and IrS2 has been repeatedg4 and new structural data described. Iridium thioether chemistry has also attracted attention and the synthesis and structures of [IrL2][PF6I3 and [IrHL,][PF,] (L = 1,4,7-trithiacycIononane)have been reported.85 A series of novel nickel compounds with multidentate thioether thiolate ligands including nitrogen and oxygen donors in S6,S5,0S4,NS4,and S4 donor sets have been synthesized and characterized by spectroscopic methods and X-ray structure analyses.86 The synthesis spectroscopy and electrochemistry of heterocyclic thionato complexes of divalent nickel has been de~cribed.~' The complexes [Ni3Y2(PEt3)J2+ (Y = S or Se) have been foundg8 to 83 G.G. Hoffman J. K. Bashkin and M. Karplus J. Am. Chem. Soc. 1990 112 8705. 84 S. Jobic P. Deniard R. Brec J. Rouxel M. G. B. Drew and W. I. F. David J. Solid State Chem. 1990 89 315.85 A. J. Blake R. 0. Could A. J. Holder T. I. Hyde G. Reid and M. Schroder J. Chem. SOC.,Dalton Trans. 1990 1759. 86 D. Sellmann S. Funfgelder G. Pohlmann F. Knoch and M. Moll. Inorg. Chem. 1990 29 4772. 87 E. S. Raper A. M. Britton and W. Clegg J. Chem. SOC.,Dalton Trans. 1090 3341. 88 F. Lecconi C. A. Ghilardi S. Midollini A. Orlandini A. Vacca and J. A. Ramirez J. Chem. SOC. Dalton Trans. 1990 773. F. J. Berry undergo metathetical reactions with halides and pseudohalides to give both asym- metric monosubstituted [Ni,Y,( PEt,),X]+ and disubstituted [Ni,Y2( PEtJ4X2] derivatives.88 Nickel( III)-sulphur bonding has also been the subject of study during an investigation of tris(xanthate) compounds of trivalent nickel.89 A large family of new quarternary rhenium chalcohalides M+[Re6Y5X9]- (M = alkali metals Cu Ag; Y = S Se; X = C1 Br) has been synthesized by high- temperature reactions and shown to adopt isotypic ~tructures.~~ The crystal structure of KRe,SeSC19 was shown to consist of discrete [Re6Y5X9]- and K+ ions in a rock-salt type structure.An unusual feature is the random distribution of two-types of anions on the eight positions of the first coordination shell surrounding the metallic clusters (Figure 9). It is also interesting to note from the view of the 001 basal plane that the K+ ions occupy a nearly perfect octahedral site formed by six apical chlorine atoms each of which belongs to one of the six neighbouring units. The solubility of these compounds in organic solvents suggests an important future for these materials in further synthesis.d Figure 9 The crystal structure of KRe,Se,Cl shown in the basal plane (full circles Re open circles (Se-Cl); hatched circle C1) (Reproduced by permission from Mat. Res. Bull. 1990 25 1227) The oxidative addition of thiols to binuclear platinum complexes has been described.” The substitution chemistry of the triangulo-platinum clusters [Pt3(p-Co)3-,(p-S02),{P(C6Hll)3}3] (n = 0-3) with carbon monoxide and sulphur dioxide ligands has been described and some mechanistic implications discussed.92 Dimethyl sulphoxide has been shown to substitute one pyridine or substituted pyridine (Xpy = pyridine 4-methylpyridine 3,5-dimethylpyridine 4-chloropyridine or 4-cyanopyridine) from cis-[Pt(Xpy),I,] to form trans-[Pt(Xpy)-(dmso)I,] complexes.93 Infrared- and NMR spectral evidence for the binding of 89 S.B. Choudhury D. Ray and A. Chakravorty Inorg. Chem. 1990 29 4603. 90 A. Perrin L. Leduc M. Potel and M. Sergent Mat. Res. Bull. 1990 25 1227. 91 N. Hadj-Bagheri R. J. Puddephatt L. Manojlovic-Muir and A. Stefanovic J. Chem. Soc. Dalton Trans. 1990 535. 92 S. G.Bott A. D. Burrows 0.J. Ezomo M. F. Hallam J. G. Jeffrey and D. M. P. Mingos J. Chem. SOC.,Dalton Trans. 1990 3335. 93 T. T. B. Ha F. L. Wimmer J.-P. Souchard N. P. Johnson and J. Jaud J. Chem. SOC.,Dalron Trans. 1990. 1251. 0,S Se Te the dmso ligand through sulphur was presented and the trans structure confirmed by X-ray crystallography.Several platinum metal complexes of mixed thia/oxa ionophores have been reported.94 The synthesis and spectroscopic properties of copper compounds with the tri- dentate ligand 1,3-bis (5-methyl-4-imidazolyI)-2-thiapropane have been described.95 The first X-ray structure determinations of crystalline materials isolated from the addition of phenyllithium to cuprous bromide in neat dimethyl sulphide solution have been reported.96 The structural properties of dimethyl sulphide solvates of phenylcopper and lower and higher order lithium phenylcuprate reagents were also described. The complex [NEt,],[ Mo2Cu5S602( Me,NCS,),] has been prepared by the re- action of CuCl Na[S2CNMe2] NEt,Br and [NH4I2[MoS2O2] in dimethylfor- mamide s~lution.~’ The Mo2Cu5S602 framework in the anion was found to consist of two defective cubane-like units OMoS3Cu2 and OMoS3Cu3 linked through two weak Cu-S bonds and bridged by two Me,NCS ligands (Figure 10).The synthesis of the compounds [NEt,],[ M2Cu,S,( Me2NCS2)J [PPh,],[ M2Cu5S6O2(EtzNCs2),] 13‘) Figure 10 Perspective view of the anion [Mo,Cu,S,O,( Me,NCS,),]’-(Reproduced by permission from J. Chem. Soc. Dalton Trans. 1990 1023) 94. A. J. Blake G. Reid and M. Schroder J. Chem. Soc. Dalton Trans. 1990 3849. 95 A. C. van Steenbergen E. Bouwman R. A. G. de Graff W. L. Driessen J. Reedijk and P. Zanello J. Chem. Soc. Dalton Trans. 1990 3175. 96 M. M. Olmstead and P. P. Power J. Am. Chem. SOC. 1990 112 8008. 97 H. Liu R. Cao X. Lei D. Wu G. Wei Z. Huang M.Hong and B. Kang J. Chem. SOC.,Dalton Trans. 1990 1023. 60 F. J. Berry (M = Mo or W) and [NEt4]2[MoCu3S4(Et2NCS2)3]was also reported. Further evidence of sustained interest in systems related to blue copper proteins is illustrated by the reported98 synthesis and characterization of copper( 11) enethiolate complexes derived from (IR)-3-hydroxymethylene bornane-2-thione and 2-aminothia-alkyl- 1 -methylbenzimidazoles (donor set N2SS*) or diamines (donor sets N2S2). Coordina- tion compounds of the new ligand 1,8-bis(3,5-dimethyl-2-pyrazolyl)-3,6-dithiaoc-tane with MC1 (M = Fe Mn Ni Co Zn Cu or Cd) MBr (M = Mn Co Ni or Zn) Cu(BF,), and CuX (X = BF, NCS C1 Br or I) have been described.99 The crystal structure of B~CU~.&~ has shown"' the solid to be derived from five sets of CuS4 tetrahedra one CuS trigonal pyramid and one CuS3 trigonal plane.The edge sharing of two sets of CuS4 tetrahedra gives rise to a three- dimensional network and the material was found to exhibit metallic conductivity. Phases in the PbS-rich region in the Ag2S-PbS-Bi2S3 system have been studied by high resolution transmission electron microscopy. ''' Samples quenched from the melt or melted and annealed at 773 or 973 K were found to contain a number of new chemically twinned phases composed of galena-like slabs four- five- seven- and eight-octahedra wide and joined along twin planes. Whilst ordered phases were found to predominate in the PbS-rich region of the phase diagram both ordered and disordered intergrowths were found in the PbS-poor region.The role of silver in stabilizing slabs of galena-like material five- and eight-octahedra wide and its function in the formation of these twinned phases was discussed. The glass forming region in the AgPO3-Ag,S-AgI system has been determined and some physical chemical properties investigated.'' The results showed that the conduction is essentially ionic in nature and due to silver ions. Electroluminescent polycrystalline ZnS :Mn :Cu Dy(C1) phosphors with different concentrations of Cu+ and fixed concentrations of Mn2+ and Dy3+ have been prepared." The p to (Y phase transformation was found to be inhibited by copper addition and the results associated with the dopant-induced creation of zinc vacancies and subsequent atomic rearrangements.Total energy calculations have been performed for 17 atom ( M~S(S~),ZII,,-~M~,) and 29-atom (MnS(Se),Zn,,-,- Mn,S(Se),,) clusters representing the first second and third neighbours of a central Mn2+ ion in ZnMnS and ZnMnSe lattice^."^ The results showed an energy gain for the Mn clustering as compared with the random impurity distribution. Samples of cobalt-doped ZnS ZnSe CdS and CdSe have been prepared by the direct combination of elements and the limit of cobalt solubility determined."' The antiferromagnetic interactions of cobalt in the zinc-systems was found to be greater than that observed in the cadmium chalcogenides. Some similar observations were 98 L. Casella M. Gullotte E. Suardi M. Sisti R. Pagliarin and P. Zenello J.Chem. Soc. Dalton Trans. 1990 2843. 99 W. G. Haanstra W. A. J. W. van der Donk W. L. Driessen J. Reedijk J. S. Wood and M. G. B. Drew J. Chem. Soc. Dalton Trans. 1990 3123. I00 J. S. Chang H. Y.-P. Hong G. H. Lee and Y. Wang Mat. Res. Bull. 1990 25 863. 101 A. Skowron and R. J. D. Tilley J. Solid State Chem. 1990 85 235. 102 J. M. Reau L. Jun B. Tanguy J. J. Videau J. Portier and P. Hagenmuller J. Solid State Chem. 1990 85 228. 103 P. R. Bote P. K. Patil J. K. Nandagawe and R. D. Lawanger-Pawar Mat. Rex Bull. 1990 25 1257. I04 K. K. Stavrev S. I. Ivanov K. D. Kynev and G. St. Nikolov J. Solid State Chem. 1990 86 136. 105 C.-M. Niu R. Kershaw. K. Dwight. and A. Wold J. Solid State Chem. 1990 85 262. 0 S Se Te 61 made during subsequent studies of iron-doped zinc- and cadmium-chalcogenides.lo6 The incorporation of Zn2+ impurity within calcium sulphide phosphors has been found'" by thermo- and electrothermo-luminescence studies to effect the general features of the glow curves which may be interpreted in terms of thermal and filled excitation of filled traps.Solid solutions of general formulation (NH,),Cd,( S04)x(Se04)3-x K2Mn,(S04)x(Se04)3-x T12Cd2(S04),(Se04)3-,(3 2 x 3 2.75) and (NH4)2Mn2- (S04),(Se04)3-,(3 2 x 2 2.50) have been prepared and used to study the phase transition mechanism for the langbeinites."' Low temperature magnetization measurements have been reported'" for com- pounds of the type EU~~~+EU,- 3+ Lil-,S2 and in some materials have been inter- preted in terms of ferromagnetic cluster formation.Solid solution regions in the pseudo ternary system Yb,S3-YbS-MnS have been structurally characterized.' lo An electron diffraction study of various ytterbium sulphide preparations has confirmed"' the existence of two orthorhombic forms of Yb3S4. Current interests in the ionic conductivity and infrared transmissions of compounds of the type ALnS2(A = Li Na K Ln = Y rare earth element) have continued. This is well illustrated by the reported preparation of LiYS with the hexagonal a-NaFeO structure from isostructural NaYS by ion-exchange in a molten LiCl/KCl mixture at a relatively low temperature.' l2 4 Selenium A decaselenadecalin anion Slo2- has been prepared in over 70% yield by heating a solution of polyselenide in dimethylformamide in the presence of [Ph3PNPPh3]C1 and a trace of iodine.'13 The product was isolated as black crystals corresponding to a [Ph3PNPPh3]+ salt.The two bridgehead selenium atoms in this bicyclo[4.4.0] system (Figure 11) were coordinated to give a distorted pseudo-trigonal bi-pyrammidal geometry. It has been known for a long time that iodine significantly influences the rate of crystallization of elemental selenium. It is therefore interesting to note the use of multinuclear NMR spectroscopy to reveal dissmutation equilibria in a model solution of diselenide with iodine and the intercalation of iodine molecules between the chains of elemental selenium from a loose charge-transfer adduct of the same diselenide with iodine in the solid state.114 A stereochemical study of a-lithio Felenides has been reported during an investiga- tion of lithium-selenium exchange.' l5 The insertion of lithium ions within TlInSe chains has been accomplished by electrochemical techniques in non aqueous gal- 106 J.Dicarlo M. Albert K. Dwight and A. Wold J. Solid Stare Chem. 1990 87 443. 107 P. K. Patil and R. D. Lawangar-Pawar Mar. Rex Bull. 1990 25 25. 1ox M. L. M. Sarrion A. R. Clemente and L. M. Vila J. Solid Srare Chem. 1990 84 308. 109 M. Wintenberger and M. Palazzi Mat. Res. Bull. 1990 25 365. I10 M. Guittard A. Chilourt M. F. Gardette M. Wintenberger and A. Tomas Mat. Rex Bull. 1990,25,1291. 'IL L. C. Ottero-Diaz A. R. Landa-Canovas and B. G. Hyde J. Solid State Chem.1990 89 237. 112 D. 0. Kipp and T. A. Vanderah Mat. Rex Bull. 1990 25 933. 113 D. Fenske G. Krauter and K. Dehnicke Angew. Chem. Int. Ed. Engl. 1990 29 390. I14 W. W. Du Mont A. Martens S. Pohl and W. Saak Inorg. Chem. 1990 29 4847. 11s H. J. Reich and M. D. Bowe J. Am. Chem. SOC.,1990 112 8994. F. J. Berry Se(2') fp Figure 11 Mo1ecu:ar structure of the S ion (Reproduced by permission from Angew. Chem. Int. Ed. Engl. 1990 29 390) vanic cells.' l6 The electrochemical properties during the first discharge were studied and the optical properties of the pure and lithium-inserted samples were examined by FTIR spectroscopy. Given the large number of sulphur-nitrogen compounds that are now known it is interesting that few selenium-nitrogen compounds have been structurally charac- terized.This in part reflects the lack of suitable stable precursors that can be prepared in satisfactory yields. It is therefore interesting to note the rep~rted''~ synthesis in good yield of the new compound Se[N(SiMe,),],. The X-ray crystal structure determination showed the solid to consist of isolated molecules containing V-shaped SeN2 units (Figure 12). Figure 12 Molecular structure of Se[N(SiMe,)2]2 (Reproduced by permission from Znorg. Chem. 1990 29 5140) Single crystals of germanium selenide GeSe have been grown by chemical vapour transport techniques structurally characterized by X-ray diffraction and examined for electrical and photoelectrochemical activity.' '' A novel approach to the synthesis of ring systems containing phosphorus nitrogen and sulphur or selenium has been mentioned earlier.23 The use of NMR spectroscopy 'I6 I.Samaras K. Kambas and C. Julien Mat. Rex Bull. 1990 25 1. M. Bjorgvinsson H. W. Roesky F. Pauer D. Stalke and G. M. Sheldrick Inorg. Chem. 1990,29 5140. N. Le Nagard C. Levy-Clement A. Katty and R. M. A. Leith Mat. Res. Bull. 1990 25 495. 0 S Se Te and X-ray crystallography to characterize compounds of general composition R3PE-A1Cl3(R= Ph or NMe, E = S or Se) has also beeen discussed.26 The growing importance of non-oxide chalcogenide glasses in infrared optics and semiconductor technology is reflected by the development of 31P-77Se spin echo double resonance NMR techniques for the structural characterization of such materials."' Compounds of the type M2X3(M= Sb Bi X = Se Te) have been doped with germanium tin or lead and found to contain one-dimensional superstructures which are amenable to characterization by electron microscopy.120 The materials were described in terms of superstructures built up of sequences of five- and seven-layer lamellae. The compound Se214(AsF,),.S02 has been preparedl2l quantitatively by reacting stoichiometric amounts of selenium iodine and arsenic pentafluoride. The com- pound Se214(Sb2F11)2 was also synthesized from the reaction of selenium and 12Sb2Fl in liquid sulphur dioxide. The 77Se NMRspectra recorded from the two compounds in sulphur dioxide at -70°C indicated the presence of Se;+ and Se13+. X-Ray crystallography showed the crystal packing of Se214(ASF6),.2sO and Se,I,( Sb2F11) to consist of columns of Se212+ ASF,- and SO2and columns of Se,I;+ and Sb2Fl respectively (Figures 13 and 14).The Se214,+ cations in both salts were found to be Figure 13 Crystal packing of Se214(Sb2F,1)2 (Reproducedby permisssion from Inorg. Chem. 1990 29 3529) similar and to adopt the eclipsed configuration with long Se-Se bonds (average 2.841(6)A) (Figures 15 and 16). The significant intraionic interactions between the syn iodine atoms (average 3.673 (4)A) were associated with the distorted trigonal prismatic shape of the cation. The shorter Se-I bonds (average 2.451(5)A) than those observed in SeI,+ (average 2.5 10(2)81) were attributed to 4p.rr-5~7~ bonding with a formal bond order of 1.25 per Se-I bond.The Se2142+ species was envisaged as containing two SeI," radical cations joined by a 6-centre 2 electron T*-T* bond. The results were related to the similar geometries found in the Ses2+ SS2+ and S204,-ions (Figure 16). 119 D. Lathrop and H. Eckert J. Am. Chem. SOC.,1990 112 9017. 120 N. Frangis S. Kuypers C. Manolikas G. Van Tendeloo J. Van Landuyt and S. Amelinckx J. Solid State Chem. 1990 84 314. I21 W. A. S. Nandana J. Passmore P. S. White and C.-M. Wong Inorg. Chem. 1990 29 3529. F. J. Berry C Figure 14 Crystal packing of Se2I2(AsF6),.SO (Reproduced by permission from Inorg. Chem. 1990 29 3529) Figure 15 The se2142+cation in Se2I4(ASF6)2.S02 (Reproduced by permission from Inorg.Chem. 1990 29 3529) Se(1) Se(2) Figure 16 Structure of the Se2142+cation in Se,I4(Sb2Fl1) and the corresponding Se6 atoms in the Ses2+cation in Se8(A1Cl4),in which the two Se3+fragments are represented by shaded thermal ellipsoids (Reproduced by permission from Inorg. Chem. 1990 29 3529) 0,S Se Te A series of three manganese polyselenide anions derived from the reaction of Mn2(CO)lo and polyselenide anions in DMF solution have been isolatfd and characterized.'22 The reaction of Mn2(CO),o with 1 equivalent of K2Se3 in DMF was found to generate [Mn2(Se2)2(C0)6]2-. The reaction of Mn2(CO)lo with 2 equivalents of K2Se produced [Mn2( Se4)2(CO)6]2- which was also obtained from the reaction of [Mn2(Se2)2(C0)6]2- with red selenium. The thermolysis of [Mn2(Se4)2(C0)6]2- in DMF was found to give [Mn(Se,),I2- as the final product of oxidative decarbonylation.All three products were structurally characterized as their [(C6H5)4P]+ salts. Both the carbonyl-containing anions [Mn,( Se2)2( cO),l2-and [Mn2(Se4),(CO),l2- (Figures 17 and 18) were found to consist of two manganese tricarbonyl fragments chelated by a Sen2- chain (n = 2,4). One of the terminal selenium atoms on each manganese also bridges to the second metal centre thereby completing its 18 electron count. Thus each metal centre can be viewed as being Figure 17 The anionic fragment [Mn,( Se,),( C0),l2-(Reproduced by permission from Inorg. Chem. 1990 29 3134) Figure 18 The [Mnz(Se,)2(CO),]2-dimer (Reproduced by permission from Inorg. Chem.1990 29 3134) S. C. O'Neal W. T. Pennington and J. W. Kolis Inorg. Chern. 1990 29 3134. F. J. Berry pseudooctahedrally coordinated by three selenium atoms and three carbonyl ligands. The monomer [Mn(Se,),I2- was found to contain two Se;- chains chelating to a manganese (11) centre in a tetrahedral fashion (Figure 19). Single crystals of cu-Mol5Sel9 have been prepared by the deintercalation of In3MoI5Sel9 with iodine.'23 The binary molybdenum selenide was found to contain Mo,Se and Mo,Se, clusters (Figure 20). Se(17) Figure 19 An enantiomer of [Mn(SeJ2I2-(Reproduced by permission from Inorg. Chem. 1990,29,3134) Figure 20 The Mo6Se8 and Mo,Se, clusters in a-Mo,,Se, (Reproduced by permission from J. Solid State Chem. 1990 85 332) B.D. Davis and W. R. Robinson J. Solid State Chem. 1990 85 332. 0,S Se Te The reaction of WC14(Me2S)2 with Me,SiSePh in CH2C12 solution followed by addition of PPh4Cl has been shown'24 to give a mixture of the two isostructural compounds [PPh4I2[Cl3W(p-Se)( p-SePh),WCl3]-2CH,CI and its mixed oxidation state analogue [PPh4]2[C13W(p-CI)(p-SePh)2WC13]-2CH2C12. The anion [Cl,W(p- SePh),( p-Se) WC1,I2- was found by X-ray crystallography to be confacial biocta- hedral with three selenium atoms in the bridging position (Figure 21). 77Se NMR showed the structure to be retained in solution. Figure 21 Structure of the [Cl,W(p-SePh),( pSe)WCl,]'- anion (Reproduced by permission from Znorg. Chem. 1990 29 3290) The synthesis of NiFe,Se4 cubane-type clusters by the reductive rearrangement of the linear [Fe,Se,(SEt),l3- species has been mentioned earlier in this rep01-t.~~ The phase diagram of the binary CrSe and FeSe systems (1.0 L x d 1.4) has been determined by X-ray- and DTA-meas~rements.'~~ The first example of a diselenoether complex of Co3+,[Co( MeSeCH2CH,SeMe),X2]BPh4 (X = C1 Br or I) has been prepared and characterized by UV-visible and multinuclear NMR spectroscopy.'26 124 J.M. Ball P. M. Boorman J. F. Fait H.-B. Kraatz J. F. Richardson D. Collison and F. E. Mabbs Znorg. Chern. 1990 29 3290. 125 S. Katsuyama Y. Ueda and K. Kosuge Mat. Res. Bull. 1990 25 913. 126 J. L. Brown T. Kemmitt and W. Levason J. Chem. SOC.,Dalton Trans. 1990 1513. 68 F. J. Berry The identification of v2 and 77,(Se)-p2 selenophene( SeI) coordination in Cp*(C0),Re(2,3-v2-SeI) and Cp*(CO),Re( ~2(Se)-p2-SeI)[W(CO)4 (PPh,)] has been re~0rted.l~~ The preparation and characterization of compounds of composition [R(SeSNd(PR3),] [Pt(Se2N2)(pR3)2l3 [R(sesN,H)(PR,),]BF4 and [R(Se,N,H)- (PR3),]BF4 has been described.'28 The M(Se4),,- anions (M = Ni Pd Pt Zn Cd Hg and Mn) have been synthe- sized and characterized.129 The investigation of phases in the CuGe2P3-Cu2GeS3 system has been mentioned earlier.39 The metathetical reaction of the [Ni,Y,( PEt3)6I2+ complex with halides and pseuodhalides to give both asymmetric monosubstituted [Ni,Se,( PEt,),X]+ and disubstituted [Ni3Se,( PEt,),X,] derivatives has also been described.88 The synthesis of the [Cu(C3Se5),I2- and [Ni(C,Se5),l2- anion complexes and the characterization of their spectroscopic and electrical properties has been reported.130 The structure of copper-deficient T1Cu,Se3 has been to be similar to that adopted by other thalium copper chalcogenides such as TlCu,Se and TlCu,Se,. The phases which can exist in the Cu2Se-Bi2Se system have been investigated.', The theoretical study of Mn2+ clustering in Zn,-,Mn,S and Zn,-,Mn,Se has been mentioned previou~ly.'~~ The preparation and properties of cobalt- and iron- doped ZnSe and CdSe have been described. 105,106 The growth and characterization of single crystals of composition Zn,-,Mn,Se(O < x < 0.53) and Zn,-,Fe,Se (0.01 < x < 0.22) has been re~0rted.l~~ Polycrystalline samples of the semimagnetic semiconductors of composition Cdl -,Fe,Se have been structurally characterized by X-ray diffraction technique^.',^ The salts [PPh4I2[ZnC3Se5),] and [PPh,],[Zn( CSe,),] have been prepared and structurally ~haracterized.'~' The compound (NH,),Cd,(SeO4),.3H20 has been synthesized and shown to contain two types of tetrahedrally coordinated selenium atoms which form double chains to give a three dimensional str~cture.'~~ The formation of solid solutions and the characterization of phase transitions in langbeinites of composition M21M211(Se04)3(M1 = NH, K T1) (M" = Cd Mn) has been mentioned earlier.'08 The phase diagram of the La,O,Se-Ga,Sej?ystem has been investigated by X-ray diffra~ti0n.l~~ and DTA showed the two phases of composition (LaO)4Gal,88Se4,89 (LaO)GaSe to undergo phase transformations at high temperatures.5 Tellurium The capacity of the elements sulphur selenium and tellurium to form homo- and hetero-nuclear polycations is well known. Of the tellurium-containing cations Te4,+ and Te2- as well as [Te2Se2]+ [Te3SeI2+ [Te2Se4I2+ [Te3S3I2+ [Te2Se6I2+ and 12' M.-G. Choi and R. J. Angelici J. Am. Chem. Soc. 1990 112 7811. I. P. Parkin and J. D. Woolins J. Chem. Soc. Dalton Trans. 1990 925. lZ9 M. A. Ansari C. H. Mahler G. S. Chorghade Y.-J. Lu and J. A. Ibers Inorg. Chem. 1990 29 3832. 130 G. Matsubayashi and A. Yokozawa J. Chem. SOC.,Dalton Trans. 1990 3013. R. Berger L. Eriksson and A. Meerschaut J. Solid State Chem. 1990 87 283. 132 J. C. Garcia G. Brun B. Liantard J.C. Tedenac and M. Maurin Mat. Res. Bull. 1990 25 241. I33 M. Pemianiuk Mat. Res. Bull. 1990 25 337. 134 E. Dynowska A. Sarem B. Orlowski and A. Mycielski Mat. Res. Bull. 1990 25 1109. 13' G.Matsubayashi K.Akiba and Y. Tanaka J. Chem. SOC.,Dalton Trans. 1990 115. 136 M. L. Martinez A. Rodriguez L. Mestres X. Solans and E. H. Bocanegro J. Solid State Chem. 1990 89 88. 137 M. P. Pardo S. Benazeth M. Guittard and C. Ecrepont Mat. Res. Bull.. 1990 25 1043. 0 S Se Te [Te2Se8I2+ have so far been structurally characterized. It is therefore interesting to note the formation'38 of the new Teg2+ polycation which is analogous to the known homonuclear cations of sulphur and selenium s8*+and Se82+. The cation was found in the new compound Te8[WCl6I2 which was synthesized by the oxidation of tellurium with TeCl .The structure determination showed the compound to contain Teg2+ cations and [wc16]- anions. The Tes2+ ion adopts a bicyclic framework composed of two five-membered rings in envelope conformation (Figure 22). The bicyclic cation was found to be associated to give chains and amenable to description as a tellurium polycation [Ten]n/4+ (Figure 23). Figure 22 Structure of Teg2+ion in TeJ WC~,] (Reproduced by permission from Angew. Chem. Int. Ed. Engl. 1990 29,293) Figure 23 Association of Te;+ cations to form the tellurium polycation [Te,] n'4+ (Reproduced by permission from Angew. Chem. Znt. Ed. Engl. 1990 29,293) Given that the only known property of tellurium nitrides is their highly explosive character it is interesting to record the ~ynthesis'~~ of the stable tellurium nitride of composition (ClTeNSN),N which decomposes at 207 "C.The compound which is therefore the first tellurium nitride that is stable at room temperature was formed from the reaction of tellurium tetrachloride and Me,SiN=S=NSiMe in toluene and was crystallized from dimethylformamide. X-ray crystallography showed three solvent dimethylformamide molecules to be coordinated via their oxygen atoms to the tellurium atoms of (CITeNSN),N (Figure 24). The three tellurium atoms form a puckered twelve-membered ring with the three bridging NSN ligands and a six membered ring with the three bridging chlorine atoms. In the plan view (Figure 24 top) the three tellurium atoms can be seen to be bridged by a further nitrogen atom N( 1).The side view (Figure 24 bottom) shows the trigonal-pyramidal arrangement of the Te,N(l) unit. The Te'" atoms in (ClTeNSN),Nv3DMF adopt a distorted octahedral environment. J. Beck Angew. Chern. In(. Ed. Engl. 1990 29 293. I39 H. W. Roesky J. Munzenberg and M. Noltemeyer Angew. Chem. fnt. Ed. Engi. 1990 29 61. F. J. Berry Figure 24 Crystal structure of (CITeNSN),N.3DMF. Above top view. Below side view of molecule without dimethyljormamide molecules (Reproduced by permission from Angew Chem. Znt. Ed. Engl. 1990 29 61) The synthesis crystal structure and characterization of two dinuclear rhodatel- luraboranes [{(PPh3)2RhTeB,oH,0}2] and [(PPh3)(CO)Rh2Te2B20H20] has been de~cribed.'~' The thallium-tellurium system has been reinvestigated by thermal analysis and X-ray diffra~tion.'~~ The compound of composition TlTe was found to contain a chain-type structure [Te] (with short Te-Te atomic distances of 3.026 and 3.085 A) connected by the T1' polyhedral coordination.The Tl,Te3 structure was found to be built from TlTe6 layers perpendicular to the c-axis and consistent with the simultaneous presence of T1' and Tl"' in a compound of formulation T1'T1'''Te6. The crystal structure of the compound Tl,GeTe has been described'42 in terms of layers parallel to the [OOl] plane and to contain [Ge2Te6I4- anions and Te clusters. The compound Te[N(SiMe,),] has been prepared"' and shown to consist of isolated Te[ N(SiMe3)2]2 molecules with intermolecular Te.-Te distances of 377 pm (Figure 25). 140 G. Ferguson A. J. Lough X. X. Faridoon M. N. McGrath T. R. Spalding J. D. Kennedy and X. L. R. Fontaine J. Chem. SOC.,Dalton Trans. 1990 1831. 141 A. A. Toure G. Kra R. Eholie J. Olivier-Fourcade and J.-C. Jumas J. Sulid Srare Chem. 1990,87 229. 142 A. A. Toure G. Kra R. Eholie J. Olivier-Fourcade J.-C. Jumas and A.Maurin J. Solid State Chem. 1990 84 245. 0,S Se Te LJ Figure 25 Molecular structure of Te[ N(SiMe,),] (Reproduced by permission from Inorg. Chem. 1990 29 5140) The characterization by electron microscopy of continuous series of one-dimensional structures in compounds based on M2X,(M = Sb Bi X = Se Te) has been noted earlier.12' The compound XeF has been to react with cis-(HO),TeF to give a yellow insoluble polymer (XeO,TeF,) which is stable to about 80 "C.The reaction of cis-(HO),TeF with Xe2F3+AsF6- was found to give a material of composition FeXe-OTeF,-O-Xe+AsF,-which when recrystallized in anhydrous HF gave a crystalline solid HF-HO-TeF,-O-Xe+AsF,-.The stabilization of the chain structure in the newly synthesized compound Ta,Te,Si has been associated with both the strong metal-metal and Ta-Si bond-ing.14 Band structure calculations suggested that the compound is a metallic conduc- tor in which the states contributing to the conduction bands are derived from the Ta 5d orbitals. The structure of Ta,Te,Si was shown'45 to be a new structure type and to represent a new class of compounds.The structure was found to be based on square Ta monomers stacked antiprismatically to form an infinite one-dimensional metal atom network. The location of a silicon atom in the centre of each tantalum square antiprism gives rise to the formation of an infinite silicon chain inside the tantalum chain. The bridging by tellurium atoms to each side of the tantalum square leads to the formula Ta,Te,Si. The individual Ta,Te,Si chains are held together by weak Te-Te van der Waals interactions and pack in an orthorhombic unit cell (Figure 26). A side view which clearly illustrates the 10-fold coordination (eight tantalum atoms and two silicon atoms) of silicon and the four-fold coordination of tellurium is shown in Figure 27. MoTe layers have been synthesized by annealing a molybdenum foil under tellurium pressure.'46 The films were found to be stoichiometric and to crystallize 143 L.Turowsky and K. Seppelt Inorg. Chem. 1990 29 3226. 144 J. Li R. Hoffman M. E. Badding and F. J. DiSalvo Inorg. Chem. 1990 29 3943. 145 M. E. Badding and F. J. DiSalvo Inorg. Chem. 1990 29 3952. 146 J. C. Bernede J. Pouzet M. Manai and A. Ben Mouais Mat. Res. Bull. 1990 25 31. F. J. Berry Figure 26 View of the Ta,Te,Si structure parallel to the orthorhombic c-axis. The silicon atoms are indicated by partially hatched circles tantalum atoms by dotted circles and tellurium atoms by open circles (Reproduced by permission from Znorg. Chem. 1990 29 3952) Figure 27 Side view of one repeat unit in the Ta,Te,Si chain (Reproduced by permission from Inorg.Chem. 1990 29 3952) in the hexagonal structure. The c-axis orientation was shown to be essentially perpendicular to the plane of the molybdenum substrate. The reaction of W(CO)6 with pure [(C6H,)&[Te,] has been shown'47 to generate a new 14-membered cluster of composition [(W(C0)3)6(Te2),]2-. The structure of the cluster (Figure 28) is unusual and may be the first in a large class of new transition-metal main-group cages. The synthesis and characterization of the first examples of ditelluroether complexes of cobalt(HI) has been mentioned earlier.'26 The tellurium-centred cubic cluster L. C. Roof W. T.Pennington and J. W. Kolis J. Am. Chem. Soc. 1990 112 8172. 73 0,S Se Te Figure 28 Structure of the cluster [W(CO),),(Te,),]2-(Reproduced by permission from J.Am. Chem. Soc. 1990 112 8172) Ni,Te( P~-T~)~( L)8 has on the basis of extended Huckel molecular orbital calcula- tions for the cluster and its experimentally known-centred analogue Ni9( p4-Te),(PEt3) ,been described as a stable The calculations showed that the interstitial nickel or tellurium atom binds to the empty cluster at the expense of Ni-Ni and Ni-Te bonding within the cluster framework. The interstitial nickel atom compensates by bonding weakly to the framework nickels primarily through its a,,(4s) orbital; the central tellurium atom bonds strongly to both the nickel cube and the face-capping tellurium atoms. Large HOMO-LUMO gaps suggest that 130 or 114 electrons are optimum for Ni8Te( L),.The synthesis and characterization of two new tellurium-containing clusters of composition Fe,Ru(CO),(p,-Te) and Fe2Ru2(CO)ll(p4Te)2 has been re~0rted.l~~ The synthesis and structural characterization of the new clusters of composition RU4(C0)11(p4-Te)2 Ru3(CO)6(PPh3)3(p.,-Te)2 3 and Ru4(CO)10(PPh3) (p4-Te)2 has been de~cribed.'~' The reaction of tetrakis(triphenylphosphine)palladium Pd( PPh3)4 and triethylphosphine telluride Et3PTe in toluene at room temperature has been found"' to produce the compound (Et3P),Pd2Te2 which contains a simple Pd2Te2 four-membered ring and a larger molecular compound (Et3P),Pd,Te6 which was described as an eight-membered ring that is twice bridged by (Et3P)2PdTe units. These clusters were shown to be intermediates in an organometallic synthesis of PdTe.Three isopleth sections AgTlTe-( CuTlTe) AgTlTe-Cu2Te and AgTlTe-Cu2TlTe2 of the quaternary system Ag-Cu-T1-Te have been in~estigated'~~ by thermal analysis differential scanning calorimetry and X-ray powder diffraction. The AgTlTe-based solid solution (Ag,Cu T12Te) limits were determined and the composition-structure I48 R. A. Wheeler J. Am. Chem. SOC.,1990 112 8737. I49 P. Mathur I. J. Mavunkal V. Rugmini and M. F. Mahon Znorg. Chem. 1990 29 4838. I50 P. Mathur B. H. S. Thimmappa and A. L. Rheingold Inorg. Chem. 1990 29 4658. I51 J. G. Brennan T. Siegrist S. M. Stuczynski and M. L. Steigerwald J. Am. Chem. Soc. 1990 112 9233. G. Brun M. Boubali R. M. Ayral and J.-C. Tedenac J. Solid State Chem.1990 89 292. F. J. Berry relations depicted. The phase diagram of Cd2,(CuIn),Mn,Te2(x + y + z = 1) alloys have been determined.'53 The synthesis of an unusual free organotelluride anion and the metal complex [Ag,(TeR),]'- (R = thienyl) has been de~cribed.'~ The preparation and crystal structure determination of Nd2Te40 has been 1-ep0rted.l~~ The structure of the rare earth tellurium oxide was described in terms of an interconnecting network of distorted square anti-prisms which link in two dimensions through edge sharing with TeO polyhedra which link in the same two dimensions through corner sharing. Sheets of (Nd2010),join with those of (TesOzo) to form a three dimensional network. The location and role of the lone pairs was discussed and the structure described in terms of a distorted hcp array of oxygen ions neodymium ions and lone pairs in which tellurium ions occupy selected trigonal bipyramidal sites.M. Quintero E. Guerrero R. Tovar G. S. Perez and J. C. Woolley J. Solid State Chem. 1990 87 456. IS4 J. Zhao D. Adcock W. T. Pennington and J. W. Kolis Inorg. Chem. 1990 29 4358. IS5 A. Castro R. Enjalbert D. Lloyd 1. Rasines and J. Galy J. Solid State Chem. 1990 85 100.

ISSN:0260-1818    

DOI:10.1039/IC9908700045

出版商:RSC    

年代:1990

数据来源: RSC

摘要:

5 Sc Y the Lanthanides and the Actinides By C.J. JONES School of Chemistry The University of Birmingham Edgbaston Birmingham B 15 2TT 1 Introduction The arrangement of this Chapter is broadly similar to that used last year and once again the primary emphasis is on molecular species. The new format for Annual Reports includes sections on Solid State Chemistry and on Coordination and Organometallic Chemistry which may also contain some material of interest to f-block chemists. During the year review articles on a variety of topics have appeared. These include the extractive metallurgy of the lanthanides and yttrium,' complexes of the lan- thanides and actinides which contain neutral phosphorus donor ligands,2 correla- tions in the phase equilibria chemical equilibria and solution properties of the lanthanide ~eries,~ the quenching of excited states by lanthanide ion chelates in solution macrocyclic complexes of the lanthanide ions,5 CVD of metal organic and other rare earth compounds6 and the exploitation of new synthetic reactions involving rare earth rnetal~.~ Organolanthanide and organoactinide work published in 1982 has been reviewed in an annual survey.8 In the medicinal chemistry sphere a review of 90Y radio-labelling of antibodies has appeared.' 2 Scandium In studies of binary compounds of scandium ab initio MCSCF and multi reference C1 techniques have been used to study the electronic and geometric structures of some scandium nitrides.The contribution of the r-bonds to bond strengths can be equal to or greater than that of the sigma bonds in such systems." The synthesis ' B.T. Kilbourn Am. Ceram. SOC.Bull. 1990 69 874. * M. D. Fryzuk T. S. Hadad and D. J. Berg Coord. Chem. Rev. 1990 99 137. M. Majdan Monatsh. Chem. 1990 121 731. G. E. Buono-Core H. Li and B. Marciniak Coord Chem. Rev. 1990 99 55. ' G. Y. Adachi and Y. Hirashima in 'Cation Binding Macrocycles' ed. Y. Inoue and G. W. Gokel Dekker New York 1990. G. B. Deacon P. MacKinnon R. S. Dickson G. N. Pain and B. 0. West Appl. Organornet. Chem. 1990 4 439. K. Takaki and Y. Fujiwara Appl. Organornet. Chem. 1990 4 292. R. D. Ernst J. Organomer. Chem. 1990 392 51. J. E. Crook Y. C. C. Lee L. C. Washburn T. T. H. Sun B. L. Byrd E. C. Holloway H. S. J. Ju and Z.Steplewski 'Metal Ions Biological Medicine Proc. First Int. Symp.,' 1990,538 ed. P. Collery Libbey Paris 1990. in K. L. Kunze and J. F. Harrison J. Am. Chem. SOC.,1990 112 3812. 75 C. J. Jones structure and properties of the layered metallic compound sco.9312 have been described.' There has been continued interest in organoscandium derivatives and the interac- tions of scandium ions with hydrocarbons. Means of coping with extreme Lewis acidity and strategies for the synthesis of stable mononuclear organometallic deriva- tives of scandium have been considered.12 Complexes containing metal-carbon 0-bonds carbenes and carbynes have been re~iewed'~ and some reactions of Sc+ with propane and cis-or trans-2-butene have been studied in a guided ion beam mass spectrometer.Reaction efficiencies of ca. 100% for butane and ca. 5% for propane were found at low energie~.'~ Correlated ab initio calculations have been used to investigate reaction paths for the interaction of ScC12H with a~etylene'~ and the rates of ethylene insertion into the Sc-C(alky1) bond of ScCp*,R (R = Me Et Pr"; Cp* = C,Me,) have been measured. A model for the transition state of P-hydrogen elimination in Ziegler catalysis has been developed using the results of the latter study.16 The structurally characterized compound [Sc{(77,-C,Me4)SiMe2($-NBut)}( PMe3)(p-H)I2 (1) is a catalyst for olefin oligomerization and may be recovered from its reaction product with propene by treatment with H2.*' An a-agostic interaction has been proposed to explain the deuterium isotope effect observed in the hydrocyclization of 1,Shexadiene to methylcyclopentane by [Sc{(~5-C5Me4)2SiMe2}(PMe3)H].'8 Reactions with carbon oxides have also been studied and ScCp2(SiR3)(thf)(R3 = {SiMe3}3,Bu'Ph2; Cp = C5H5) reacts with C02 to give [ScCp2(p-02CSiR3)],(2 Ln = Sc R = SiMe3) containing bridging carboxylate ligands in which each oxygen binds to one of the two scandium ions." [ScCp,{Si(SiMe,),}(thf)] reacts with CO in benzene to give (3) or in 2-methyltetrahydrofurzn to give (4).The reaction of this latter compound with NCC6H3Me2-2,6 affords (5) as shown by a crystal structure.20 In other reactions involving nitrogen containing ligands ScCp*,Me and hydrazone combine to produce the hydrazido (I-) I' B.C. McCallum D. S. Dudis A. Lachgar and J. D. Corbett Inorg. Chem. 1990 29 2030. W. E. Piers P. J. Shapiro E. Bunel and J. E. Bercaw SYNLETT. 1990 74. l3 M. J. Winter Organomet. Chem. 1990 19 208 14 L. S. Sunderlin and P. B. Armentrout Organomerallics,1990 9 1248 l5 A. K. Rappe Organometallics 1990 9 466. 16 B. J. Burger M. E. Thompson W. D. Cotter and J. E. Bercaw J. Am. Chem. Soc. 1990 112 1566. P. J. Shapiro E. Bunel W P. Schaefer and J. E. Bercaw Organometallics 1990 9 867. 18 W. E. Piers and J. E. Bercaw J. Am. Chem. Sac. 1990 112 9406. 19 B. K. Campion R. H. Heyn and T. D. Tilley Inorg. Chem. 1990 29 4355. 20 B. K. Campion R. H. Heyn and T. D. Tilley J. Am. Chem. Soc. 1990 112 2011. Sc Y the Lanthanides and the Actinides CP2SC 'OA Si(SiMe& (3) (4) complex ScCp*,{N(H)NH,} which in turn reacts with MeCN to give ScCp*,{N(H)C(Me)NNH,} (6) a crystal structure of which reveals a 5-membered-ScNCNN-ring.ScCp*,{ N(H)NMe,} and ScCp*{N( H)C(Me)NNMe2} were prepared similarly and a crystal structure of the latter (7) reveals a four membered -ScNCN- ring.,' The synthesis and crystal structure of ScCp(0EP) (OEPH = octaethylporphyrin) have also been reported., 3 Yttrium and the Lanthanides Two papers have appeared which contain information which may be of some general interest. The first describes a substantial improvement in the resolution of 13C MAS (Magic Angle Spinning) NMR spectra of paramagnetic lanthanide acetates through replacing the protons with deuterium and so removing residual proton couplings.23 The second describes a regression analysis of the relationship between metal radii and metal-Cp distances in over 200 structurally characterized f-block element compounds.24 Metal radius alone was found to be a good predictor of metal-Cp distances in divalent compounds.However in tri-or tetra-valent compounds steric effects are also important. Oxides and Solid State Studies.-The diverse structural features of three families of oxides of stoichiometry BaMLn,O (M = Co Ni Cu Zn Pd Pt; Ln = Nd Sm Eu Gd Dy Ho Er Tm Yb Lu or Y) have been described.*' Some of these features are rationalized with reference to a model which combines results from 21 P. J. Shapiro L. M. Henling R. E. Marsh and J. E. Bercaw Inorg.Chem. 1990 29 4560. 22 J. Arnold and C. G. Hoffmann J. Am. Chem. Soc. 1990 112 8620. 23 A. N. Clayton C. M. Dobson and C. P. Grey J. Chem. SOC.,Chem. Commun. 1990 72. 24 S. C. Sockwell and T. P. Hanusa Inorg. Chem. 1990 29 76. 25 J. K. Burdett and J. F. Mitchell J. Am. Chem. Soc. 1990 112 6571. 78 C.J. Jones MO theory tight-binding band structure calculations and empirical atom-atom potential arguments. In another theoretical study a simple MO method has also been presented by which the antiferromagnetism of La2Cu04 can be understood.26 Examples of the application of spectroscopic methods include the use of secondary ion mass spectrometry to analyse mixed oxides containing lanthanides2' and the application of 89Y MAS NMR spectroscopy to the study of yttrium pyrochlores Y2-,Ln,M207(Ln = Ce Pr Nd Sm Eu Yb; M = Sn Ti).The reduction in 89Y nuclear relaxation times caused by the paramagnetic ion led to shorter spectral accumulation times.28 Other structural work includes a report of the synthesis and structure of YlOIl3C2. The structure consists of centred {Y6112C} and empty {Y618} type clusters condensed by edge sharing.29 Cs3Yb2C19 and Cs3Yb2Br9 have also been synthesized and their magnetic dimer excitations studied by high resolution inelastic neutron ~cattering.~' Structural studies of phosphates include the tetracyclophosphate complexes MLnP4012.6H20(M= K Ln = Yb; M = Cs Ln = Tm) which are isostructural with KErP40126H20.31 The crystal structures of Gdo,,Lno,,P04(Ln = Y Er Yb) and Gdo,75Ybo,25P04 have also been determined.32 Catalysts and Reagents.-Lanthanide compounds have been used as catalysts or reagents in a variety of reactions including polymerization hydrocarbon coupling cyclodimerization hydroamination and hydrolysis.Quantochemical studies have been carried out on models for the active centres in butadiene polymerization catalysed by the Nd- A1 catalytic system.33 The surface concentrations and residence times of intermediates on Sm203 surfaces during the oxidative coupling of methane have also been investigated. Surface carbonates do not appear to be involved in this Isotope labelling experiments have shown that toluene Oxidative methylation using methanol to form c8 hydrocarbons over a lithium promoted Y,03-Ca0 catalyst involves a cross coupling between the methyl and benzyl radicals on the surface.35 In homogeneous reactions the catalysis of 1-octene hydroformylation by heterobimetallic compounds derived from cobalt carbonyl derivatives of lanthanide elements has been reported.36 The alkyl compounds LnCp*{CH(SiMe,),}(Ln = La Ce) are efficient catalysts for the cyclodimerization of MeCECR (R = Me Et Pr").The first step involves the liberation of CH2( SiMe3)2 with the formation of LUC~*,CH,CECR.~~ In a multinuclear NMR study 139La 170 and 13C NMR 26 S. Lee J. Am. Chem. SOC.,1990 112 6777. 27 S. Daolio B. Facchin C. Pagura P. Guerriero S. Sitran and P. A. Vigato Inorg. Chim. Acta 1990 178 131. 28 C. P. Grey M. E. Smith A. K. Cheetham C.M. Dobson and R. Dupree J. Am. Chem. SOC.,1990 112 4670. 29 S. M. Kauzlarich M. W. Payne and J. D. Corbett Inorg. Chem. 1990 29 3777. 30 H. U. Giidel A. Furrer and H. Blank Znorg. Chem. 1990 29 4081. 31 K. K. Palkina S. I. Maksimova R. Yu Khusainova M. T. Chibiskova and A. K. Mustaev Rwss. J. Inorg. Chem. 1990 35 482. 32 D. F. Mullica E. L. Sappenfield and L. A. Boatner Inorg. Chim. Acta 1990 174 155. 33 Z. M. Sabirov and Yu B. Monakov Inorg. Chim. Acta 1990 169 221. 34 K. P. Peil J. G. Goodwin Jr. and G. Marcelin J. Am. Chem. SOC.,1990 112 6129. 35 Y. Osada S. Ogasawara T. Fukushima T. Shikada and T. Ikariya J. Chem. SOC.,Chem Commun. 1990 1434. 36 G. K. I. Magomedov and A. Z. Voskobinikov J. Organomet. Chem. 1990 385 289.37 H. J. Heeres A. Heeres and J. H. Teuben Organometalfics 1990 9 1508. Sc Y the Lanthanides and the Actinides 79 measurements have been used to investigate the structures and stabilities of lan-thanum(111) complexes involved in the lanthanide catalysed 0-alkylation of ethylene glycol by maleate.38 An example of the samarium catalysed intramolecular Tishchenko reduction of p-hydroxy ketones has also been described. This reaction affords the corresponding anti-diol monoesters (Scheme 1 ).39 The organosamarium compounds SmCp* and SmCp*,( thf) catalyse the hydroamination/cyclization of amino-olefins (Scheme 2).40 R R FR, ____+ IS% Sml, RCHO R' = Me Pr' n-CaH, R" = Me Pr' Ph Scheme 1 SrnCp* + H2N ,m -Cp*,Sm-NH Scheme 2 PPh3 PPh3 Scheme 3 The now well known reagent SmI has been used to promote intramolecular reductive cyclometallation in an iridium complex (Scheme 3).41 In regioselective reactions ytterbium metal has been used to promote the cyclodimerization of a$-unsaturated ketones and esters leading regioselectively to cyclopentanol cyclopen- tanone or cyclohexanone derivatives (Scheme 4).42 The ally1 complexes Li[Ln(C,H,),](Ln = Ce Nd Sm Gd Dy) may be prepared from LuCl and 38 C.Zhi J. van Westrenen H. van Bekkum and J. A. Peters Inorg. Chem. 1990 29 5025. 39 D. A. Evans and A. H. Hoveyda J. Am. Chem. Soc, 1990 112 6447. 40 M. R. GagnC S. P. Nolan and T. J. Marks Organometallics 1990 9 1716. 41 P. M. Zizelman and J. M.Stryker Organometallics 1990 9 1713.42 K. Takaki F. Beppu S. Tanaka Y. Tsubaki T. Jintoku and Y. Fukiwara J. Chem. Soc. Chem. Commun. 1990. 516. C. J. Jones Scheme 4 tetra-allyltin in the presence of butyl-lithium. These react with @-unsaturated carbonyl compounds to give 3-hydroxy-1,5-dienes with a high degree of 1,2-regio~electivity.~~ another type of reaction [2-( benzy1oxy)-1-(N-2,6-xyly-In limino)ethyl]samarium has been reported to function as an LY -hydroxyacetyl anion equivalent (Scheme 5).44 - SrnI IIBzOCH,Cl + CNXyl 4BzOCH,-C-SmX (Xyl = 2,6-xylyI) Ac,O R'RCO IIBzCH -C-C( R') (R")0AC Scheme 5 In other examples of reactions mediated by lanthanides the presence of LnCI (Ln = Y Ce Yb) leads to high diastereoselectivity in reactions of alkynyl lithium or alkynyl magnesium reagents with 2-acyl-1,3-0xathiones.~~ The lanthanum complex of the macrocycle (8) has been found to be an effective catalyst for the hydrolysis of the phosphate triester (9).& Finally the use of yttrium(II1) or lanthanoid(II1) phthalocyanine complexes as catalysts for the photo-reduction of methylviologen has been investigated.These complexes can act as photosen~itisers.~' 43 S-i. Fukuzawa K. Sato T. Fujinami and S. Saki J. Chem. SOC.,Chem. Commun. 1990 939. 44 M. Murakami T. Kawano and Y. Ito J. Am Chem. Soc. 1990 112 2437. 45 K. Utimoto A. Nakomura and S. Matsubara J. Am. Chem. SOC., 1990 112 8189. 46 R. W.Hay and N. Govan J. Chem. SOC.,Chem. Commun. 1990 714. 47 K. Kasuga S. Takahashi K. Tsukahara.and T. Ohrio Inorg. Chem. 1990 29 354. Sc Y the Lanthanides and the Actinides 81 Solution Studies.-Interest in the potential application of gadolinium complexes as MRI (Magenetic Resonance Imaging) contrast agents has stimulated work on Gd3+ complexes in solution. Proton magnetic relaxation rates for aqueous glycerol solutions of [Gd( DTPA)I2-( DTPAH5 = diethylenetriamine penta-acetic acid) and [Gd( DOTA)]-( DOTAH4 = 1,4,7,”~tetra-azacyclododecane-N,N’,N’’,N‘’’-tetra-acetic acid) ions over the Lamor frequency range 0.01-200 MHz have been The pH dependence of the spin lattice relaxivity values and hydration numbers of Gd3+ in some linear amino carboxylate complexes have also been determined. Below pH 7 relaxivity values decrease with increasing pH and are higher for ligands with fewer donor atoms.49 The number of water molecules in the first coordination sphere of Gd3+ ions complexed by N-(2-hydroxyethy1)ethy-lenediamine triacetate has been estimated at 3 in the pH range 3 to 10.Proton nuclear magnetic relaxation rates were also reported for this system.50 The kinetics of formation and dissociation of the 1,4,7-triazacyclononane-N,N’,N”-triacetate complexes of Ce3+ Gd3+ and Er3’ have been measured. The rates of dissociation decrease for the smaller lanthanide ions but the formation rates remain similar.51 Apart from the use of Gd3+ in NMR studies thulium and dysprosium complexes have been used as NMR shift reagents in a study by ’Li 31P and 19FNMR of red blood cell morphology membrane potential and Li+ In other NMR studies 13C NMR measurements indicate that Gd3+ binds preferentially to the keto-tautomer of ~-xylo-5-hexulosonate~~ and variable temperature H and 13C NMR data have been used to study the solution structure and dynamics of complexes containing La3+ Pr3+ or Eu3+.55 The kinetics of exchange of 1,1,3,3-tetrarnethyl urea on six coordinated lanthanide( 111) complexes has also been studied by NMR.56 In other solution studies the high stability of the Ln3+ (Ln = Sm Eu Yb) complexes of 1,3,10,13-tetraoxa-7,16-diazacyclooctadecane and cryptate ligands has been found to be enthalpic in origin5’ The stabilities of lanthanide ion complexes with p-nitrophenol and two 1,3-xylyl-crown ether derivatives have also been investi- gated.The phenol OH is the primary binding site in the complexes.58 Eu3+ and Er3+ form up to tris-complexes with nitrate ions in water/methanol mixtures whereas with Nd3+ the bis-nitrate was the highest stoichiometry detected.59 The interaction between Ln(N03)3 and Me,SO in anhydrous MeCN has been studied using FT-IR difference spectra.Coordination numbers ranging from eight to ten were found.60 The coordination of erbium( 111) in aqueous solutions containing halide ions has 48 G. Iternandez M. F. Tweedle and R. G. Bryant Inorg. Chem. 1990 29 5109. 49 C. A. Chang H. G. Brittain J. Telse and M. F. Tweedle Inorg. Chem. 1990 29 4468. 50 G. Hernandez H. G. Brittain M. F. Tweedle and R. G. Bryant Inorg. Chem. 1990 29 985. 51 E. Brucher and A. D. Sherry Inorg.Chem. 1990 29 1555. 52 R. Ramasamy D. Mota de Freitas W. Jones F. Wezemann R. Labotka and C. F. G. C. Geraldes Inorg. Chem. 1990 29 3979. 53 D. Mota de Freitas M. T. Espanol R. Rarnasarny and R. J. Labotka Inorg. Chem. 1990 29 3972. 54 M. M. Caldeira H. van Bekkurn and J. A. Peters. J. Chem. SOC., Dalton Trans. 1990 2707. 55 S. Airne and Mauro Botha Inorg. Chim.Acta 1990 177 101. 56 S. F. Lincoln and A. White Inorg. Chim. Acra 1990 168 265. 51 I. Marolleau J. P. Gisselbrecht M. Gross F. Arnaud-Neu and M. J. Schwing-Weil J. Chem. SOC. Dalton Trans. 1990 1285. 58 A. Cassol P. di Bernardo P. L. Zanonato M. Tolazzi and G. Tomat Inorg. Chim.Acta 1990 171,217. 59 H. B. Silber R. Bakhshandehfar L. A. Contreras F. Gaizer M. Gonsalves and S.Isrnail Inorg. Chem. 1990 29 4473. 60 J. C. G. Bunzli J. P. Metabanzoulou P. Froidevaux and L. Jin Inorg. Chem. 1990 29 3875. 82 C.J. Jones been studied by large angle X-ray diffraction techniques. Water predominates in the inner coordination sphere with halide ions residing in the second sphere.61 The formation of the stibine and arsine complexes [Eu( SbPh3)2]3+ and [EU(ASP~,),,(C~O~)]~+ in PhCN has been reported. No complexation was observed in pure Me2S0.62 The formal potential of the Ce'"-Ce"' couple has been determined in aqueous HC104 and the results interpreted in terms of the eq~ilibria:~ Ce"'(aq) + H,O = [Ce(OH)l3++ H+ 2Ce4+(aq) + 2H20 = [Ce,(0H),l6' + 2H+ Luminescence Studies.-Reviews of the quenching of lanthanide excited states in chelates and solution^,^ and of applications of the lanthanides in time resolved fluorescence imrnunoa~say~~ have appeared.A non-radioactive fluorescent assay of DNA hybridization by the DNA-template-mediated formation of a Tb"'complex has been described.65 In studies of chiral systems time resolved circularly polarized luminescence measurements have been used to study the excited state racemization of [Eu( dpa),13- (dpa = dipidcolinate) which involves an achiral transition state.66 Steady state time resolved chiroptical luminescence experiments have been used to investigate enantioselective excited state quenching in solutions of Ln(dpa),,- (dpa = pyridyine-2,6-di~arboxylate).~~ Laser excited luminescence spectra of Eu3+ doped C-M2Si,07(M = Y Lu Sc) have been simulated by a crystal field splitting model6* and X-ray excited emission of Gd3+ in Gd,(C03)3 -6H20 has been studied.69 Laser induced Eu3+ luminescence spectroscopy has also been used to characterize a series of europium(II1) amino- phosphate complexes in solution.70 Luminescence spectra of hydrated and anhy- drous Na3[Eu{NC5H,(C02)2-2,6}]have been measured and the effects of crystal hydration asse~sed.'~ In a study of the polyoxotungstate K15H,[Eu3( H,O),(SbW,O,,)( W5018)3].25.5H20 characterized by a crystal struc- ture (Figure l) efficient intramolecular energy transfer from the 0-W charge transfer levels to the emitting 'Do level of Eu3+ was found to take place over a distance of at least 6.9 w." Laser induced luminescence and 'H and 13C NMR spectroscopy have been used in a study of Y3+ or Eu3+ binding to some macrocyclic diaza-crown ether ligands carrying pendant carboxylate ligating gro~ps.'~ Complexes of Eu3+ Tb3+,or Gd3+ with p-t-butylcalix[4]arene-tetra-acetamidehave also been studied.The terbium 61 G. Johansson and H. Yokoyama Inorg. Chem. 1990 29 2460. 62 G. F. Payne 0.L. Keller Jr. J. Halperin and W. C. Wolsey J. Chem. SOC.,Dalton Trans. 1990 1993. R. Zingales J. Chem. SOC.,Dalton Trans. 1990 229. 64 P. Mottram and P. Soderback Am. Clin. Lab. 1991 9 36. 65 A. Oser and G. Valet Angew. Chem. Int. Ed. Engl. 1990 29 1167. 66 D. H. Metcalf S. W. Snyder J. N. Demas and F. S. Richardson J. Am. Chem. Soc. 1990 112 469. 67 D. H. Metcalf S.W. Snyder J. N. Demas and F. S. Richardson J. Am. Chem. SOC.,1990 112 5681. 68 C. Chateau J. Holsa and P. Porcher J. Chem. SOC.,Dalton Trans. 1990 1575. 69 G. Blasse and L. H. Brixner Inorg. Chim. Acta 1990 172 45. 70 R. C. Holz G. E. Meister and W. De W. Horrocks Jr. Inorg. Chem. 1990 29 5183. 71 G. M. Murray R. V. Sarrio and J. R. Peterson Inorg. Chim. Acta 1990 176 233. 72 T. Yamase H. Naruke and Y. Sasaki J. Chem. SOC.,Dalton Trans. 1990 1687. 73 R. C. Holz S. L. Klakamp C. A. Chang and W. De W. Horrocks Jr. Inorg. Chem. 1990 29 2651. Sc Y the Lanthanides and the Actinides Figure 1 The crystal structure of K,,H3[E~,(H,0)3(SbW,033)(W,0,,),125.5H20 * (Reproduced by permission from J. Chem. SOC.,Dalton Trans. 1990 1687) complex has a high luminescence quantum yield (0.2) and lifetime (1.5 ms) in aqueous media.74 The Eu3+-ligand charge transfer state has also been observed.75 Coordination Compounds.-A direct synthesis of La( NCS),{O=P( NMe2)3}4 has been achieved using lanthanum metal NH4NCS and O=P(NMe2)3.An X-ray crystal structure of this compound shows a seven-coordinate La3+ ion bound to the nitrogens of three NCS ligands and the oxygens of four O=P(NMe2)3 ligands. Similar reactions are possible with yttrium and e~ropium.'~ There has been continuing interest in the chemistry of alkoxides and a number of cationic yttrium alkoxides have been reported. [Y3(OBu'),C12(thf),] reacts with AgBPh to give a mixture of [Y3(p3-OR)(p3-Cl)(p-OR)3(OR)3(thf)3]BPh4 (10) and [Y2(p-C1)(p-OR)2(OR)2(thf),]BPh, (11).The crystal structures of (lo) (ll) and [Y(OR)Cl(thf),]BPh have been dete~mined.~~ Y,O(OPr'), reacts with acetyl- acetone to give Y2(p3-OAc),(acac),( H20)2(12) (acac = pentane-2,j-dionate) which 74 N. Sabbatini M. Guardigli A. Mecati V. Balzani R. Ungaro E. Ghidini A. Casmati and A. Pochini J. Chem. SOC.,Chem. Commun. 1990 878. 75 M. F. Hazenkamp G. Blasse N. Sabbatini and R. Ungaro Inorg. Chim. Acta 1990 172 93. 76 D. Barr A. T. Brooker M. J. Doyle S. R. Drake P. R. Raithby R. Snaith and D. S. Wright Angew. Chem. Int. Ed. Engl. 1990 29 285. 77 W. J. Evans J. M. Olofson and J. W. Ziller J. Am. Chem. SOC.,1990 112 2308. C.J. Jones was characterized by a crystal structure.78 The synthesis and crystal structure of [Ce2(OPr')8( HOPr',),] (13) have also been reported.Intra molecular hydrogen bonds are present which cause some structural di~tortion.~~ Attempts to prepare M(OPr'),(M = Sc Y In Yb) afforded pentanuclear clusters. The crystal structure ~,-0Pr')~( of [Yb5(p5-0)( p2-OPr'),(OPr'),]-shows a square pyramidal cluster struc- ture with a p5-oxygen atom in the base. (Figure 2).80 Figure 2 The crystal structure of [Yb,(p5-O)(p3-OPri)4(p2-OPri)4(OPri)5]-(Reproduced by permission from Polyhedron 1990 9 719) 78 0. Poncelet L. G. Hubert -Pfalzgraf and J. C. Daran Polyhedron 1990 9 1305. 79 B. A. Vaarstra J. C. Huffmann P. S. Gradeff L. G. Hubert-Pfalzgraf J. C. Daran S. Parraud K. Yunlu and K. G. Caulton Inorg. Chern. 1990 29 3126. 80 D.C. Bradley H. Chudzynska D. M. Frigo M. E. Hammond M. B. Hursthouse and M. A. Mazid Po/-vhedron 1990 9 719. Sc Y the Lanthanides and the Actinides Work on bidentate ligand complexes has included a correlation of NMR contact shift effects and absorbance spectral properties for some lanthanide acetate and haloacetate compounds.81 The crystal structure of Tb(N03)3-6H20 reveals a ten- coordinate terbium centre bound to three bidentate nitrate and four water ligands.82 A number of papers describe compounds which include P-diketonate ligands. The heterobimetallic complexes [Ln( hfac),Cu( satnOH)] [hfac = hexafluoroacetylacetonyl; Cu( satnOH) = N-(3-aminopropyl)salicylaldiminato-hydroxocopper(I1); Ln = Gd Dy] have been prepared and the crystal structure of the dysprosium complex determined (Figure 3).In the gadolinium(II1) complex ferromagnetic coupling was observed between the copper and gadolinium ions.83 Figure 3 The crystal structure of [Dy(hfac),Cu( satnOH)] [hfac = hexafluoroacetylacetonyl; Cu(satn0H) = N-(3-aminopropyl)salicylaldiminatohydroxocopper(I I)] (Reproduced by permission from Inorg. Chem. 1990 29 1750) The crystal structures of [Ln(hfac),(nitp)H,O)] (nitp = 2-isopropyl-4,4,5,5-tetramethyl-4,5-dihydro-1H-imidazoyl-l-oxyl-3-oxide; Ln = Eu ( 14),Gd) have been determined. The gadolinium complex exhibits ferromagnetic coupling of the gadolinium and nitronyl nitroxide radical spin^.^^,*^ An X-ray crystal structure of Yb(acac),(bipy) reveals the presence of eight-coordinate ytterbium.86 The synthesis and crystal structure of [Y3(p3,qZ-OC2H40Me)2(p2, 77,-OC2H40Me),(p2,77' -OC,H,OMe)(acac),] have been reported.The complex con- tains a triangular array of yttrium ions. (Figure 4).87 A number of lanthanide squarate D. F. Mullica and G. A. Wilson Inorg. Chim. Acfa 1990 177 209. 82 E. Moret J. C. G. Bunzli and K. J. Schenk Inorg. Chim. Acta 1990 178 83. 83 C. Benelli A. Caneschi D. Gatteschi 0. Guillou and L. Pardi Inorg. Chem. 1990 29 1750. 84 C. Benelli A. Caneschi A. C. Fabretti D. Galfeschi and L. Pardi Inorg. Chem. 1990 29 4153. 85 C. Benelli A. Caneschi D. Gatteschi L. Pardi and P. Rey Inorg. Chem. 1990 29 4223. 86 N. G. Dzyubenko E. F. Korytnyi L. I. Mortynenko and L. A. Aslanov Russ. J. Inorg. Chem. 1990 35 833.87 0. Poncelet and L. G. Hubert-Pfalzgraf Inorg. Chem. 1990 29 2883. C.J. Jones Figure 4 The crystal structure of [Y3(p3,~2-OC,H40Me)z(pz, ~2-OC,H40Me),(p.,,7'-OC2H40Me)(acac),] (Reproduced by permission from Inorg. Chern. 1990 29 2883) Me HO 0 and oxalate complexes have also been prepared and their structures investigated. A wide variety of coordination modes was found for the squarate ligand.889s9 Other work involving bidentate ligands includes the syntheses of the complexes Ln(HMes)C1,.3H20(Ln = La Sm Eu Gd Tb Dy; H,Mes = 4-methylesuletin) (15):' Ce(HL)3(N03)3 {HL = Ph,P(O)CH,COPh} and CeL(HL)(N03)3. The crys- tal structure of Ce( HL),( N03)3 contains three bidentate nitrate ligands one bidentate HL ligand and two monodentate HL ligands coordinated via the phosphine oxide oxygen." na J.F. Petit A. Gleizes and J. C. Trombe Inorg. Chim. Acta 1990 167 51. 89 J. C. Trombe J. F. Petit and A. Gleizer Inorg. Chim. Acta 1990 167 69. YO C. Bisi Castellani and 0. Carugo Polyhedron 1990 9 939. Y1 R. Babecki A. W. G. Platt and D. R. Russell Inorg. Chim. Arra 1990 171 25. Sc Y the Lanthanides and the Actinides 87 Among the new complexes of nitrogen containing ligands a series of highly reactive ytterbium( 11) complexes containing benzamidinate ligands has been prepared. These include the compounds Yb(Bl),(thf) ; {Bl = PhC(NSiMe,),) Yb(B1),(S2CNMe2) and Yb(Bl),(SePh)(thf) which have been characterized by single crystal X-ray studies. Each contains a six-coordinate ytterbium ion in a highly distorted octahedral en~ironment.~~ Several complexes of Schiff base ligands have also been reported.These include [La(LH),(NO,),]NO,{LH = (16)},93 [LaL$(thf)(p-Cl),] (17) (HL' = HO-C6H4-2-CH=N-C6H,Me3-2,4,5) and [La(L"),( HL")Cl] (18) (HL" = HO-C6H,-2-CH=N-CH2CHzNMe) the latter two of which were characterized by q;DMe Me0 Me2 Me2 H I (sf N-..si) Me2 Me2 crystal ~tructures.~~ Multinuclear variable temperature NMR studies of the tridentate ligand complex [Ln{N(SiMe,CH2PMe2)2}zCl] {( 19) Ln = La or Lu} provide evidence of phosphine coordination to both La and Lu.~~ Several papers have appeared which describe complexes of polypyrazolyl borate ligands. The reactions of LnC1 (Ln = Tb Sm Er) with K[H,B(pz),] (pz = C3H3N2-1,2) afford Ln{H(p-H)B(pz),} and with K[HB(pz),] n[HB(pz),]Cl.In the presence of acetate the dimers [Ln{HB(pz),},(O,CMe)] are formed. The crystal structure of [Sm{ HB(pz),},( O,CPh)] (20) was determined.96 The heteroleptic lan- thanide trispyrazolylborate complexes Ln{HB(pz),},X( Ln = Y La ce Pr Nd Sm 92 M. Wedler M. Noltemeyer U. Pieper H. G. Schmidt D. Stalke and F. T. Edelmann Angew. Chem. Int. Ed. Engl. 1990 29 894. 93 L. Guofa N. Chongwu L. Bin and M. Kunyuan fo/.vhedron 1990 9 2019. 94 P. Blech C. Floriani A. Chiesi-Villa and C. Guastini J. Chem. SOC.,Dalton Trans. 1990 3557. 95 M. D. Fryzuk and T. S. Haddad J. Chem. SOC.,Chem. Commun. 1990 1088. 96 D. L. Reger S. J. box J. A. Lindeman and L. Labioda Inorg. Chem. 1990 29 416.C.J. Jones (20) Eu Tb,Yb or Lu; X = tropolonate; Ln = Y Sm Eu Yb or Lu; X = benzoate and Ln = Y Eu Gd Yb or Lu; X = acetate) have been isolated. The crystal structures of Yb(HB(pz),},(O2C7H5) and Yb{HB(pz),},(O,CPh) reveal monomeric structures containing eight-coordinate Yb3+ ions in each case.97 The heteroleptic complexes Y{HB(~z),}~X (X = o2cC6H4NMe2-4 O2C6H4No2-4) and [Y{HB(~Z)}~(O~CC~H~BU'-~)~]~ have also been prepared.98 Exchange of the biden- tate ligand X among the complexes L~{HB(PZ)~},X = acac PhC(O)CHC(Me)O (X PhC(O)CHC(Ph)O; Ln = a lanthanide element) is slow on the NMR timescale. The kinetics of exchange between S~{HB(~Z)~}~X and Eu{HB(pz),},X are in accord with a model involving two opposing bimolecular reacti~ns.~~ Complexes have been reported with a variety of other polydentate ligands and the lanthanide triethanolamine chelates [Ln{N(CH2CH20H)3}2](CF3S03)3 (Ln = Pr Yb Lu) have been prepared.The crystal structures of the praesodymium and ytterbium complexes reveal a nine-coordinate metal centre with two tetradentate chelating ligands and one coordinated thf molecule.'00 A crystal structure of the gadolinium( 111) complex of (21) reveals a tricapped trigonal prismatic nine-coor- dinate metal centre bound to three amine nitrogens three carboxylate oxygens two I H02C /CozH COZH OOH HOG (211 (22) amide oxygens and a water molecule. The T proton relaxivity of the complex is 4.8 mM-' s-'.''' The complexes CoLa(csalen)(MeOH)( NO3) {csalenH = N,N-ethylenebis(3-carboxysalicylideneimine); (22)) CoNd( csalen)( H,O),( NO3) 97 M.A. J. Moss and C. J. Jones J. Chem. SOC.,Dalton Trans. 1990 581. 98 M. A. J. Moss and C. J. Jones Polyhedron 1990,9 1119. 99 M. A. J. Moss and C. J. Jones Polyhedron 1990,9 697. 100 F. E. Hahn and J. Mohr Chem. Ber. 1990 123 481. 101 M. S. Konings W. C. Dow D. B. Love K. M. Raymond S. C. Quay and S. M. Rocklage Inorg. Chem. 1990. 29 1488. Sc Y the Lanthanides and the Actinides and CoGd(csalen)(H20)(N0,) have been prepared where cobalt is bound to the N202 site and the lanthanide ion to the O4 site of the binucleating ligand.'02 Several macrocyclic ligand complexes have been reported and spectroscopic studies of Ln(OEP)2 (Ln = La Eu Nd) indicate that the electron hole in these compounds is delocalized over both porphyrin moieties on the vibrational and electronic timescales.Approximately one quarter to one third of the intradimer bonding can be attributed to n-n interaction^."^ Electrochemical optical absorp- tion near infrared resonance Raman and EPR data are also reported for the bimetallic systems Ln2(0EP)3 (Ln = La Ce Eu). Again strong intra-ligand n-interactions were found with the electron hole being delocalized over all three rings on the vibronic and electronic time scales.lo4 Bis(tetra-2,3-pyradinopor-phyrazinato)ytterbium(111) has been prepared and its EPR and electronic spectra mea~ured."~ The magnetic susceptibilities of lanthanide phthalocyanines (Pr Nd Gd Ho Er) have been measured.The pyrrolic nitrogen ligand is found to be a weak a-donor and a moderate .rr-donor in these systems.'06 Some complexes of the hexadentate macrocyclic ligand (23) have been studied by X-ray crystallography and [Ln(OAc),(23>]C1.4H2O (Ln = Nd Eu) are isostructural.'07 Homo- and hetero- binuclear lanthanide complexes (24) of a large N406 macrocyclic ligand (LH,) have been prepared. These have the formulae LnLn'(L)( N03)4 (Ln-Ln' = La2 Pr, Sm, Eu2 Gd4 Tb2 or Dy2; La Sm; La Gd; La Eu; Dy Gd; Dy Eu; CI CI (23) (24) 102 Y. Aratake H. Okawa E. Asato H. Sakiyama M. Kodera S. Kida and M. Sakamoto J. Chem. SOC. Dalton Trans. 1990 2941. 103 J. K. Duchowski and D. F. Bocian J. Am. Chem. SOC. 1990 112 3312. 104 J. K. Duchowski and D. F. Bocian Chem.Ber. 1990 112 8807. 105 K. Kasuga K. Nishikori T. Miham M. Handa K. Sogabe and K. Isa Inorg. Chim. Acra 1990,174 153. 106 Padilla and W. E. Hatfield Inorg. Chim. Acta 1990 172 241. 107 F. Benetollo A. Polo G. Bombieri K. K. Fonda and L. M. Vallarino Polvhedron 1990 9 1411. 90 C.J. Jones Gd Eu; Gd Tb;Eu Tb; or La Tb).'08 Thermal decomposition of these complexes affords Ln203 or the heteronuclear oxides LnLn'O .lo9 A series of polyoxotetrazama- crocycle tetra-acetic acid ligands (25) have also been synthesized and their complexa- tion with Dy3+ studied. Paramagnetic shifts were observed in 23Na NMR spectra obtained in the presence of such complexes."o (25) (a = 1 2 3 4) P-Propiolactam (LH = C3H,NO) is metallated at the nitrogen atom in the presence of both mercury( 11) and erbium( 111) ions to form a polymeric metalloma- CrOCyCk [Hg,( L)&,( (Figure 5)."' (a) (b) Figure 5 The crystal structure of the polymeric metallomacrocycle [Hg,( L),Er,( NO,),] ".(a) The erbium coordination environment. (b) Part of the contiguous 48-membered polymeric macrocyclic array (Reproduced by permission from J. Chem. SOC.,Chem. Commun. 1990 851) ion P. Guerriero P. A. Vigato J. C. G. Bunzli and E. Moret. J. Chern. SOC.,Dalton Trans. 1990 641. I09 P. Guerriero S. Sitran P. A. Vigato C. Marega A. Marigo and R. Zanetti Inorg. Chim. Acta 1990 171 103. R. M. Sink D. C. Buster and A. D. Sherry Inorg. Chem. 1990 29 3645. Ill D. M. L. Goodgame A. M. Khaled C. A. O'Mahoney and D. J. Williams J.Chern. SOC.,Chern. Commun. 1990 85 1. Sc Y the Lanthanides and the Actinides 0rganolanthanides.-This year the first divalent organoneodymium complex. [K(thf).],[ NdCp*,Cl,] has been reported and the neodymium( 111) derivatives NdCp*,Cl(thf) NdCp*,( SeC,H,Me,)(thf) and NdCp*,(S2CNMe2) obtained from its respective reactions with Bu'C1 (C,&2Me$e)2 and (Me2NCS,),."2 There are again a number of reports concerning low oxidation state samarium compounds and it has been found that SiCp*,Cl is reduced by SmCp* to give [SrnCp*,C1l3 and SiCp*,. However neither SmI,(thf) nor [SmCp*( p-I)(thf),] reduce SiCp*,C12 .l13 [SmCp*,(thf)2]BPh4 has been synthesized and shown to have a distor- ted tetrahedral arrangement of ligands around the samarium ion.This cation reacts with KCECR (R = Ph CMe,) to give SmCp*,(C=CR)(thf) and the crystal struc- ture of SmCp*,(C=CPh)(thf) has been determined. [SmCp*,(thf),]+ also reacts with KCp* to generate SmCp*,{O(CH2),C,Me5}(thf) which was characterized by a crystal structure.' l4 Sm(C,H,Bu'),(dme) (dme = dimethoxyethane) reacts with PhCECH to form the dimer [S~(C,H,BU'),(~-PHC=C)~~ the crystal structure of which shows an asymmetric alkyne bridging In reactions with alkenes SmCp" and SmCp*,(thf) have been found to isomerize cis-stilbene to trans-stilbene and (SmCp*,),(p-q2 q4-PhCHCHPh) (26) has been isolated. The reaction of I\ Q CH \ "H CP* .Cp' CP' CH2 SmCp" with styrene affords (SmCp*,),(p-q2q4-CH2CHPh) (27) which was charac- terized by its crystal structure.l16 The reactions of SmCp" with a variety of other alkenes have also been studied and a series of ally1 complexes including SmCp*,( q3-CH,CHCHR) (R = H Me Ph) isolated."' The reactions of SmCp* with 1,3-butadiene and 1,Shexadiene afford the bis-ally1 complexes [SmCp*,( p q3-A-)I2 (A = CH,CHCHCH,-; CH,CHCH-).Crystal structures were reported for these compounds and for SmCp*,( T~-CH~CHCHP~)(OC~H~)."~ The divalent ytterbium complex Yb(C,H,Bu'),(thf) has a distorted-tetrahedral ligand arrangement as shown by a crystal structure and reacts with OPPh to give Yb(CSH4Bu')2(0PPh,)( thf).' l8 112 M. Wedler A. Recknagel and F. T. Edelmann J. Organomet. Chem. 1990 395 C26. I13 W. J. Evans T. A. Ulibarri and P. Jutzi Inorg. Chim.Acta 1990 168 5. 114 W. J. Evans T. A. Ulibarri L. R Chamberlain J. W. Ziller and D. Alvarez Jr. Organometallics 1990 9 2124. 115 Q. Shen D. Zheng L. Lin and Y. Lin J. Organomet. Chem. 1990 391 307. 116 W. J. Evans T. A. Ulibarri and J. W. Ziller J. Am. Chem. Soc. 1990 112 219. I17 W. J. Evans T. A. Ulibarri and J. W. Ziller J. Am. Chem. SOC. 1990 112 2314. I18 Q. Shen D. Zheng L. Lin and Y. Lin J. Organomet. Chem. 1990 391 321. C. J. Jones Among other reports of cyclopentadienyl derivatives the synthesis and crystal structure of Dy( q5-C5H,),(thf) have been described.' l9 The structures of the novel heterotrimetallic species YRe,Cp,(thf)H,( PMe,Ph) (28) and LuRe,Cp,H,( PMe,Ph) (29) have also been investigated using NMR and X-ray crystallographic methods.The yttrium complex undergoes fluxional exchange of yttrium between the rhenium centres and the lutetium complex may be a model for the intemediate in such a process.'20 The phenyl lanthanide dichloride complexes LnPhCI2.n(thf) (Ln = Pr Sm Gd; n = 3 4) have been prepared. The crystal structure of GdPhC12 -4(thf) (30) reveals a pentagonal bipyramidal coordination about gadolinium.'21 n cp Several reports of compounds containing linked cyclopentadienyl ligands have appeared. In one such example the salt [Mg,C13 -6(thf)][Yb{C5H,CMe2-)2}C12] -thf (31)contains a pseudo-tetrahedrally coordinated ytterbium( 111) ion.'22 The incorpor- ation of an ether oxygen in the link provides an extra binding site within the bis-cyclopentadienyl ligand and C5H4(CH2)20(CH2)2CSH42- (L2-) has been used 119 Z.Ye S. Wang Y. Yu and L. Shi Inorg. Chirn. Acta 1990 177 97 120 D. Alvarez Jr. K. G. Caulton W. J. Evans and J. W. Ziller J. Am. Chern. Soc. 1990 112 5674. 121 G. Lin Z. Gin Y. Zhang and W. Chen J. Organornet. Chern. 1990 396 307. 122 P. Yan N. Hu Z. Jim and W. Chen J. Organornet. Chern. 1990 391 313. Sc Y the Lanthanides and the Actinides 93 to prepare a series of unsolvated monomeric complexes LnLX (Ln = Y Lu; X = C1 C5H5; Ln = Nd Gd Er Yb X = C,H,) (32) in which the ether oxygen is thought to coordinate to the metal.’, Another cyclopentadienyl-ether ligand C5H4CH,CH20Me- reacts with LnC1 (Ln = La Nd Gd Ho Er Yb and Y) in thf to give [Ln(C5H4CH,CH,OMe),C1] which has been studied by XPS.’24 Cyclo- pentadienyl ligands carrying bulky substituents have been used in the syntheses of the samarium derivatives Sm( q5-C5H3But2),(thf) and [NaSm(q2:7,-C5H4B~t)3(thf)]n which were characterized by X-ray crystal structure^.'^^ The former has the conventional ‘oyster’ structure with an equatorial thf ligand while the latter is polymeric (33) with three C5H4Rut ligands surrounding each Sm ion.Each Na+ 0-L”-But i-cl-X Q (32) (33) ion is T2-bonded to three C5H4Bu‘ ligands. The tris-methylcyclopentadienyl complex Ce( T’-C,H,M~)~ has been found to be a monomer in the gas phase but a tetramer in the solid phase. The structure of the tetramer consists of a square of cerium ions linked through C5H,Me ligands q5-bonded to one cerium and 7’-bonded to another.In contrast Ce( q5-C5H,R) (R = SiMe, But) and Ce{q5-C,H,(SiMe,),} are monomeric in the solid state as well as in the gas phase.‘26 Several hydride complexes have been reported and Na[ Sm(C5H4Bu‘),]thf reacts with AlH to give the samarium(111) complex [Sm( q5-C5H4B~t)2(p3-H)(p2- H),A1H(thf)I2 the crystal structure of which reveals an -SmHAlHSmHAlH-metallocycle (34).12’ The chemistry associated with the lutetium and yttrium com- plexes of ( q5-C,Me,)SiR2( 77’-C5H,) (L-L; R = Me Et) has been investigated and compared with that found for similar complexes containing Cp* or R,Si( q5-C5Me4) in place of L-L. The crystal structures of Lu(L-L){CH(SiMe,),} (R = Me) [Lu(L-L)(p-H)] (R = Et) (35) and {Lu(L-L)}~(~-H)(~-C,H,) were determined.Compared to their Cp* containing counterparts the L-L complexes appear to be deactivated.’28 [LnCp*,Cl,]- (Ln = Sm Nd) react with Li(CH,)(CH,)PRR’ (R = Me R’ = Ph R = R’ = Ph Me But) to give the compounds LnCp*,[(CH,)- (CH,)PRR’] LiC1 which react with hydrogen to produce Cp*H and [M e ,PRR’]C1.’ 123 C. Qian Z. Xie and Y. Huang. J. Organomet. Chern. 1990 398 251. I24 D. Deng B. Li and C. Qian Polyhedron 1990 9 1453. 125 V. K. Bel’sky Yu K. Gunko B. M. Bulychev A. I. Sizov and G. L. Soloveichik J. Organomet. Chern. 1990 390,35. 126 S. D. Stults R. A. Andersen and A. Zalkin Organornetallics 1990 9 115. I27 Yu K. Gun’ko B. M. Bulychev A. I. Sizov V. K. Bel’sky and G. L. Soloveichik J. Organomet. Chem. 1990 390 153. I28 D.Stern M. Sabat and T. J. Marks J. Am. Chern. Soc. 1990 112 9558. 129 W. K. Wong H. Chen and F. L. Chow Polyhedron 1990 9. 875. C.J. Jones A number of reactions of trivalent organo-lanthanide complexes have been described. {SmCp*,},( p-q2:q2-PhCEC-CECPh) is formed from the reaction between [SmCp*,(p-H)] and PhCECH from thermolysis of SmCp*,(C-CPh)- (thf) from SmCp* and PhCECH or from SmCp*,{CH(SiMe,),} and PhC=CH.l3' LuCp,(p-Cl,)Na(dme) reacts with LiSiMe to give [Li(dme),][ LuCp,(SiMe,),] the crystal structure of which contains discrete cations and anions. The two Cp and two SiMe ligands are disposed around the lutetium(II1) centre in a pseudo-tetrahedral arrangement but with an Si-Lu-Si angle of only 90.75 (8)0.131 The reaction of Ln( q5-C,Me5),(CH(SiMe3),} (Ln = La Ce) with acetonitrile results in C-H bond activation and the liberation of H2C(SiMe3),.The other reaction product is [Ln( q5-C5Me5),(pu-CH,CN)] for which the X-ray crystal structure of the lan- thanum complex reveals an eight-membered La-CH,-C=N-La-CH,-C=N ring.'32 The reactions of organolanthanide derivatives with several pnictogen or chalcogen containing ligands have been described. In reactions involving nitrogen heterocycle ligands LuCp,Cl(thf) and YCp*,Cl(thf) react with sodium pyrrolide to give the monomeric species LuCp,( NC4H4) and YCp*,( NC,H,)(thf). The crystal structure of the more highly substituted lutetium derivative LuCp*,( NC4H2Me2-2,5) reveals I30 W. J. Evans R. A. Keyer and J. W. Zitter Organometallics 1990 9 2628.131 H. Schumann J. A. Meese-Marktscheffel and F. E. Hahn J. Organomet. Chem. 1990 390 301. 132 H. J. Heeres A. Meetsma and J. H. Teuben Angew. Chem. Int. Ed. Engl. 1990 29 420. Sc Y the Lanthanides and the Actinides a distorted pseudo-tetrahedral ligand arrangement around 1~tetium.l~~ Bimetallic amide bridged compounds have also been reported and a model to predict whether compounds of general formula [LnCp,X] will be monomeric (n = 1) or associated (n 3 2) has been de~cribed.’~~ The crystal structure of [Yb(q5-C5H4Me)z(NH,)]z was also determined. The bis-diphenylamide complexes [Li(tmed),][ LnCp,( NPh,),] (Ln = Sm Lu) have been prepared and the crystal structure of the lutetium complex shows the pseudo-tetrahedral arrangement of ligands usually found in monomeric complexes of the LnCp,X type.’35 LuCp,{CH( SiMe,),}(thf) reacts with HEPh (E = P As) to give LuCp,(EPh,)(thf).Crystallization of these compounds afforded [LUC~,(~-O-(CH,)~PP~~)], and [LuCp,(thf)},( p-0)] which were characterized by X-ray crystal structure^.'^^ In reactions with chalcogenide compounds Ce( q5-C5H4Bu‘) reacts with REH (R = CHMe or Ph E = 0 S) to give Ce2(q5- C5H4B~t)4(p-ER)Z. Crystal structures of the compounds with R = CHMe reveal planar Ce2E2 units with pseudo tetrahedral coordination geometries about the cerium ions.’,’ The complexes Ln{C5H3(SiMe,),}I(NCMe)2(Ln = La Ce) are useful precursors to compounds such as [Ce{C5H,( SiMe,),} (p-q2-OC) W(C0)Cp-( p-q2-C0),l2 (36) Ln(C,H,(SiMe,),}( NCMe),(F-BF,) and [Ln{C5H3(SiMe3)2}2-(NCMe)( MeOCH,CH,OMe)]BPh of which the latter was structurally charac- teri~ed.‘~~ Cp” Cp”’1yce\ \/ Ce ,/’ \ Cp” Cp” Several papers describe organolanthanide derivatives which contain bridging halide ligands and the first examples of terminal Yb-F bonds have appeared.Fluorine abstraction from perfluoro-olefins may be effected by LnCp*,(L) (Ln = Yb Eu Sm; L = thf or OEt,) or Yb(q5-C5H4Me),(thf) to give LnCp*,F(L) and Yb(q5-C5H4Me),F( L) respectively. The crystal structures of YbCp*,F( L) reveal the pres- ence of terminal fluoride ligands. The crystal structure of Yb5Cp*6( p4-F)( p3-F),(p-F)6 was also reported. (Figure 6).’39 LnC1 (Ln = La Pr Nd) react with MeOCH2CH,C5H,Na to produce Ln( +-K -C5H4CH2CH20Me),Ln( p-Cl)] and 133 H.Schurnann P. R. Lee and A. Dietrich Chem. Ber. 1990 123 1331. 134 A. Hammel and J. Weidlein J. Organornet. Chem. 1990 388,75. 135 H. Schumann E. Palamidis and J. Loebel J. Organomet. Chem. 1990 390,45. 136 H. Schumann E. Palarnidis and J. Loebel J. Organomet. Chem. 1990 384,C49. 137 S. D. Stults R. A. Andersen and A. Zalkin Organomerallics 1990 9 623. 138 P. N. Hazin J. W. Bruno and G. K. Schulte Organometallics 1990 9 416. 139 P. L. Watson T. H. Tulip and I. Williams Organometallics. 1990 9 1999. C.J. Jones Figure 6 The crystal structure of Yb5Cp*,( p4-F)( p3-F)*( P-F)~ (Reproduced by permission from Organornetallics 1990 9 1999) (37) (38) the crystal structure of the lanthanum complex (37) has been determined.14’ SmCpCl(thf)2(p-C1)2SmC12(thf)3 (38) has been synthesized.The crystal structure shows the two different samarium coordination environment^.'^^ GdC13 reacts with one equivalent of NaCp* to give GdCp*Cl,(thf) and [Na( p2-thf){GdCp*(thf)}2(p2-C1)3(p3-C1)2] 6 thf (39).14’ Detailed mass spectrometric studies have been carried out on Ln(L-L)(p-CI) (Ln = Yb Y; L-L = T’-C~H~-S~M~,-C~H~-T’), Ln(77’-C5H4SiMe3)2(p-C1)2and Yb(L-L) (P-CI)~ Y(L-L).’43 4 Actinides During the year reviews of several aspects of actinide chemistry have appeared. The topics covered include the molecular structures and uses of actinide alkoxides with particular emphasis on uranium and thorium compounds,’44 progress in actinide 140 D. Deng C. Qian G.Wu and P. Zheng J. Chem. Soc. Chem. Commun. 1990 880. 141 G. Depaoli P. Zanonato and G. Valle Inorg. Chim. Acta 1990 170 109. 142 Q. Shen M. Qi and Y. Lin J. Organomet. Chem. 1990 399 247. 143 K. Qiao R. D. Fischer G. Paolucci P. Traldi and E. Celon Organometallics 1990 9 1361. 144 W. G. Van der Sluys and A. P. Sattelberger Chem. Rev. 1990 90 1027. Sc Y the Lanthanides and the Actinides extraction ~hemistry,',~ mathematical modelling of actinide extraction equilibria and extraction proce~ses,'~~ and the reactivity of actinides towards inorganic free radicals in irradiated aqueous solution^.'^^ Among the theoretical work published ab initio studies of U2 indicate that the poor overlap of the 5f orbitals does not foster bond formation.However the diffuse 6d and 7s orbitals may give rise to bound states at long bond lengths.'48 The electronic structures of the anions U02C142- NpO2C1t- and have been calculated by the quasi-relativistic Xa scattered wave method and their electronic and X-ray photoelectron spectra inter~reted.',~ A report of luminescence from a bis-porphyrinate actinide complex Th(OEP)2 provides evidence of the low energy (T,T*)state which should arise when porphyrin rings are located within 3 A of one an~ther.'~' A report has also appeared describing the application of 252Cf plasma desorption mass spectrometry to a study of the relative binding constants of cations to crown ether^."^ Coordination Compounds.-This year the first example of a homoleptic dithiolate complex of an f-element has been reported.The crystal structure of [Li(dme)],[U(edt),] (edtH = ethanodithiol; dme = dimethoxyelthane) reveals a dodecahhedral eight-coordinate uranium( IV) centre with lithium ions also bound to the sulphur atoms. No significant U 5f participation in this U-S bonding was thought to occur.'52 Work on halide compounds has included studies of the synthesis and thermal decomposition of [NH4]2[UF10];[ NH4I3[UF8] is formed at 200 "C [NH,][UF6] at 280"C [NH4][U3FI3] at 380"C and UF at 600"C.'53 Pure UBr3 may be prepared by applying high vacuum to a heated sample of [NH,]-[UBr,] -1SMeCN * 6H20.15 Electrocrystallization of the hydrated praesodymium 145 A. M. Rozen J. Radioanal. Nucl. Chem. 1990 143 337. 146 A. M. Rozen V.S. Vlasov V. I. Marchenko and V. N. Rubisov J. Radioanal. Nucl. Chem. 1990 143 357. 147 A. K. Pikaev A. P. Gogolev V. P. Shilov and A. M. Fedoseev Isotopenpraxix 1990 26 465. 148 M. Pepper and B. E. Burstein J. Am. Chem. SOC. 1990 112 7803. 149 V. G. Peishina G. V. Ionova and N. I. Suraeva Russ. J. Inorg. Chem. 1990 35 1178. 150 G. S. Girolami S. N. Milam and K. S. Suslick J. Am. Chem. SOC. 1990 112 4075. N. Malhotra P. Roepstod T. K. Hansen and J. Becher J. Am. Chem. SOC,1990 112 3709. 152 K. Tatsumi I. Matsubara Y. Inoue A. Nakamura R. E. Cramer G. J. Tageshi J. A. Golen and J. W. Gilje Inorg. Chem. 1990 29 4928. 153 S. Mili?ev B. Druiina and B. VolavSek Polyhedron 1990 9 47. 154 E. Zych and J. DroLdLynski Polyhedron 1990 9 2175.C. J. Jones chloride complex of 12-crown-4 has been found to produce different crystal structures from those obtained by slow evaporation of solvent. Electrocrystallization produces complexes which retain three chloride ions in the primary coordination sphere and have a reduced coordination number.lS5 A number of solution studies of actinide containing systems have been presented. Laser flash kinetic spectrophotometric methods have shown that C1- Br- I- and SCN- all quench the excited state uranyl ion in water by a mechanism which involves charge transfer.'56 In work on actinide ions in aqueous media the hydrolysis constants of uranium( IV) and solubility product of amorphous U02-xH20 have been deter- mined the solubility of U02.xH,O(am) was found to be 3-4 orders of magnitude less than previously reported."' In another study small angle neutron scattering has been used examine hydrous Pu4+ polymers in aqueous and organic media.Bragg lines from the X-ray scattering could be identified with those of F%.IO~.'~* Solution studies have shown that phenylene-l,2-dioxydiaceticacid binds to U022+ through the carboxylate but not the ether oxygenslS9 and quantitative measurements of the thermodynamic stability of uranyl complexes based solely on nitrogen coordination by amine ligands have been made in Me2S0.16' NMR data have provided evidence for the stereospecific formation of (D L)-malic acid complexes of uranyl ions.'61 The kinetics of dissociation of thorium( IV) from its complexes with polymaleic acid have also been studied.'62 Structural studies of some polypyrazolylborate complexes of the actinides have been described and the crystal structures of UCpC12[HB(Me2pz),] (40) UCl,[HB(Me,pz),] UC1,[ HB(pz),] and ThCl,[HB(pz),] have been deter-mined.'63 The geometries of the latter two compounds are square antiprismatic 155 R.D. Rogers and L. NGnez Inorg. Chim. Acru 1990 172 173. 156 H. D. Burrows Inorg. Chem. 1990 29 1549. I57 D. Rai A. R. Felmy and J. L. Ryan Inorg. Chem. 1990 29 260. 158 P. Thiyagarajan H. Diamond L. Soderholm E. P. Horowitz L. M. Toth and L. K. Felker Inorg. Chem. 1990 29 1902. 159 L. F. Rao and G. R. Choppin Inorg. Chem. 1990 29 3589. 160 A. Cassol P. DiBernardo R.Portanova M. Tolazzi G. Tomat and P.Zanonato Inorg. Chem. 1990 29 1079. 161 T. Nunes and V. M. S. Gil Inorg. Chim. Acta 1990 170 59. 162 G. R. Choppin and W. Cacheris Inorg. Chem. 1990 29 1370. 163 A. Domingos N. Marques and A. Pires de Matos Poll.vhedron. 1990 9 69. Sc Y the Lanthanides and the Actinides 99 distorted towards bicapped trigonal prismatic the thorium compound exhibiting the larger di~tortion.'~~ Work on alkoxide complexes includes the preparation of U,(OBu'),( HOBu') which reacts with KOBU' to give K[U,(OBu'),] with 0 to give U2(OBuf), and with H20 to give U30(0Bu'),o. The latter compound shows Curie-Weiss behaviour from 90 to 250 K.*65 Reports of work involving bidentate oxygen containing ligands includes a cyclic voltammetry study of [An(acac),] (An = U Th) in thf or MeCN.This reveals two one-electron reductions; the first affords [An"'(acac)]-which slowly loses acac- to give [An"'(a~ac),].'~~ The complexes U02L2(H20) (L = (41) R = Me Ph) have been prepared and crystal structures of U02L2(H20)(R= Me) and U02L2( PrOH) (R = Ph) reveal pentagonal bipyramidal coordination geometries at uranium with bidentate ligands L in the equatorial plane.'67 The crystal structure of UOz( NO,),{ Ph2P( O)CH2S( 0)2NMe2}2 shows the sulphinyl phosphonate ligand to be bound only via the phosphine oxide oxygen with two bidentate nitrates and two 0x0 ligands completing hexagonal bipyramidal coordination about the uranium.16' Molecular peroxo complexes of U02'+ [UO,(O,)(L-L)] (L-L = 1 10-phenanthroline 2,2'-bipyridyl ethylene diamine H,edta and glycine) have also been isolated.The glycine complex oxidizes a variety of substrate^.'^^ R N .-I Ph OH H0' (41) (42) (XzNH S) Several papers report complexes of binucleating ligands and polyfunctional ligands capable of forming complexes containing several metal ions. Mono-and homobinuclear uranyl complexes of the type [U02( H,L*)] and [(U02),( L*) (Solv)] Solv = a coordinating solvent such as Me,SO Me,NCHO H,O; {L*H4 = (42)) have been isolated and the crystal structures of three complexes ~btained.'~' The syntheses and structures of the 1 1 and 2 :1 complexes of (43)are also re~0rted.l~~ A series of heterotetranuclear complexes has been prepared using a 1,3,5,9,11,13-hexaketonic ligand (44) which binds UOZ2+ in the outer sites and divalent metal ions in the inner sites (45).These compounds undergo multi-electron redox proce~ses.'~~ 164 A. Domingos J. Marcalo 1. Santos and A. Pires de Matos Polyhedron 1990 9 1645. 165 W. G. Van der Sluys A. P. Sattelberger and M. W. McElfresh Polyhedron 1990 9 1843. I66 A. Vallat E. Laviron and A. Dormond J. Chem. Soc. Dalton Trans. 1990 921. I67 E. C. Okafor A. B. Uzoukwu P. B. Hitchcock and J. D. Smith Inorg. Chim. Acra 1990 172 97. I68 D. T. Cromer R. R. Ryan S. Karthikeyan and R. T. Paine Inorg. Chim. Acta 1990 172 165. I69 M.Bhattacharjee M. K. Chaudhuri and R. M. Dutta Purkaystha J. Chem. SOC. Dalton Trans. 1990 2883. I70 U. Casellato P. Guerriero S. Tamburini P. A. Vigato and R. Graziani J. Chem.Soc. Dalton Trans. 1990 1533. 171 K. T. Potts J. J. O'Brien and F. S. Tham Inorg. Chim. Acta 1990 177 13. 172 R. L. Lintvedt W. E. Lynch and J. K. Zehetmair Inorg. Chem. 1990 29 3009. 100 C. J. Jones OEtA0' H ) OH OH OH 0 OH (45) (Pyzpyridine) Other reports of coordination compo'unds include the synthesis and crystal struc- ture of the ten-coordinate thorium(IV) complex [Th(C5H,NO)6(N0,)2](N03)2{C5H5N0 the syntheses and =2-1( 1H)-pyrid~ne},'~~ NMR spectra of some o-vanillin semicarbazone or hydrazone uranyl c~mplexes,'~~ the preparation of some uranium(v1) complexes with tetradentate (N202)Schiff base ligand~,'~~ and thorium complexes of XC6H4CH =NC6H4co2H (X =OH C1 OMe N02).176 The magnetic susceptibilities and spectra of UI,(hmpa) (n =3 4 5; hmpa =hexamethylphosphoramide) have been determined and are consistent with the presence of six coordinate uranium centres of formulae [UI~6-,,(hmpa)n]I~n-2~ .177 A series of uranyl dialkylhydromate complexes has been prepared and studied by FAB mass spectrometry.Cluster ions (UO,)+ (n = 1 to 6) were Finally the bifunctional extractant RR'P( =O)-173 D. M. L. Goodgame S. Newnham C. A. O'Mahoney and D. J. Williams Polyhedron 1990,9 491. 174 B. V. Aganvala S. Hingorani and G. A. Nagana Gowda Inorg. Chim. Acta 1990 176 149. 175 B. Erk and N. Giinduz Inorg. Chim. Acta 1990 167 91. 176 W. I. Azeez Inorg. Chim. Acta 1990 176 267. 177 M. Hirose C. Miyake and J. G. H. de Preez Inorg. Chim. Acta 1990 178 17. 178 D.A. Brown and S. Ismail Inorg. Chirn. Acta 1990. 171 41. Sc Y the Lanthanides and the Actinides {CH,)O}P(=O)(OR")(OH) (R = R'= C6H13; R"= C8HI7) has been synthesized and found to form complexes with uranium(v1) and uranium(1v) via both the phosphate and phosphine oxide 0rganoactinides.-During the year an investigation of the interaction of some thorium alkyl derivatives with oxide surfaces has been reported. A 13C CPMAS NMR study has shown that on A1203 MgCl, or Si02-A1203 surfaces ThCp*,R2 (R = 13CH3 or 13CH2-13CH3) ThCp*,R (R = 13CH2Ph) and ThCp,R (R = 13CH3) undergo heterolytic Th-C fission to transfer an alkyl anion to the surface. The dynamics and reactivity of the adsorbed species was investigated Th-CH is far more reactive than Mg-CH in migratory CO insertion reactions.'80 In another study uranium ligand bond disruption enthalpies have been obtained for the U(C9H7)3/U(C9H7)3-I/U(C9H7)3-Me system.'" A kinetic/mechanis-tic/stereochemical/molecular mechanics study of olefin insertion into the An-H bonds of AnCp*(H)(OR) (An = Th U; R= chiral or achiral alkyl group) has been carried out.Maximum diastereoselection occurs with sterically encumbered reagents at low temperatures.'82 The magnetic interaction between uranium(v) centres in some bimetallic compounds has been determined. Antiferromagnetic coupling was observed between the phenyldimide bridged uranium(v) centres in {U(v5-C5H4Me)3}2( 1,4=N-C,H4-N=). However no coupling was observed in {U( q5-C5H4Me)3}2(1,3=N-C6H4-N=).'83 A majority of the papers relating to organoactinides describe synthetic and structural studies.Among syntheses of uranium( ~v) species the reduction of UCp2C1 by sodium amalgam in the presence of RX offers a convenient route to UCp,R. (RX = MeI Bu"Br Pr'Cl CH,=CHCH,CH,Br CH,=CHCH,Cl PhCH,Cl) whereas the oxidative addition of RX to UCp3(thf) affords a mixture of UCp,R and UCP,X.'~~ Alcoholysis of UC1(C5H4R) (R= H Me) with R'OH affords U(C,H,R)(OR'),Cl( R' = Et Pr" Pri Bun The 6,6-dimethylcyclohexadienide ligand (46) offers an alternative to cyclopentadienide in forming organometallic complexes and a series of uranium(1v) complexes has been prepared using this ligand. The compounds obtained include U(46),(BH4), U(46)( BH,) ,[K( 18-crown-6)][U(46)2X2] (X = C1 BH4) U(46),(BH4)(thf) and U(46)2(BH4)(OPPh3).'86 Me I79 R.Arad-Yellin M. Zangen H. Gottlieb and A. Warshawsky J. Chem. Soc. Dalton Trans. 1990 2081. 180 W. C. Finch R.D. Gillespie D. Hedden and T. J. Marks J. Am. Chem. SOC.,1990 112 6221. L. S. Bettonville J. Goffart and J. Fuger J. Organornet. Chem. 1990 393 205. Z. Lin and T. J. Marks J. Am. Chem. SOC.,1990 112 5515. 183 R. K. Rosen R. A. Andersen and N. M. Edelstein J. Am. Chem. SOC.,1990 112 4588. 184 C. Villiers and M. Ephritikhine J. Organomet. Chem. 1990 393 339. I85 B. Delavaux-Nicot and M. Ephritikhine J. Organomet. Chem. 1990 399 77. 186 D. Baudry E. Bulot. and M.Ephritikhine J. Organornet. Chem. 1990 397 169. 102 C. J. Jones Other work involving cyclopentadienyl derivatives has shown that the tetrahy- droaluminate complex UCp3(AlH4) reacts with Bu'NC to give UCp,(CH=NBu') with pyridine to give UCp3(NC&) with MeCN to give UCp,(N=CH)Me and UCp3(NHCH2Me) and with Bu'NCO to give UCp3{N( Bu')CHO}.Reactions with alcohols ketones or aldehydes were found to afford alkoxides whilst CH31 gives The UCp31 and BH3.SMe2 gives UCP~BH~.'~~ crystal structure of U( =CHPMe3)Cp3 has been determined by neutron diffraction. The a-hydrogen is not agostic and the short U-C bond distance (2.293 (1) A} and large U-C-P angle (141.49 (7) A} indicate multiple bond character.ls8 A terminal carbonyl of CoCp(CO) inserts into the U=C bond of U(=CHPMeRPh)Cp (R= Me Ph) to give Cp(OC)COC(OUCp,)=CHPMeRPh (47). The crystal structure of the com- pound with R = Me has been determined."' R Me3SiNA-NSiMea (48)(R' = H) (49)(R = R') The pseudo-trigonal bipyramidal complex UCp3( NCBH3)( NCMe) has been obtained from MeCN solutions of [Bu",N][UCp,( NCBH,),].The Cp ligands occupy the equatorial sites and are p5-bonded. The two co-ligands occupy the axial sites and give an almost linear NUNCB arrangement.'" The complexes UC12(48) (48 = (NSiMe3),CC6H4R R= H Me OMe CF,) and UC1{(NSiMe3)2CC6H4R}3 have been isolated. The sterically more demanding ligand (NSiMe3),CC6H2Rr3( R' = CF, Me) (49) gives only the disubstituted complexes UC1,(49) with uranium. Both ThC12 (49)2 (R' = CF3) and ThC1(48) (R = CF,) were also obtained. The crystal structures of UC1(48)3 (R = H CF,) uc1,(49)2 (R' = CF,) and ThC1,(49) (R' = CF,) were determined.''' Monomeric and dimeric uranium complexes have been prepared using the phospholyl ligand. The reactions were carried out in the presence of borohydride and [U( T'-PC~M~~)~( BH4)2]Z(z= 0 -1) were isolated. An X-ray study of the neutral complex revealed a pseudo-tetrahedral arrangement of two q5-PC4Me4 and two K,-BH~ ligands around uranium. Reduction of this compound afforded (50) which reacted with thf or Ph3P=0 to give the monomeric complexes U( q5-PC4Me4)*( BH4)(L) (L =thf Ph3P=0).'92 187 F. Ossola N. Brianese M. Porchia G. Rossetto and P. Zanella J. Chem. SOC.,Dalton Trans. 1990,877. 188 R. C. Stevens R. Bau R. E. Crarner D. Afzal G. W. Gilje and T. F. Koetzle Organometallics 1990 9 694.189 R. E. Crarner J. H. Jeong R. N. Richrnann and J. W. Gilje Organometallics 1990 9 1141. 190 M. Adam K. Yunlu and R. D. Fischer J. Organomet. Chem. 1990 387 C13. 191 M. Wedler F. Knosel M. Nolterneyer and F. T. Edelrnann 1 Organornet. Chem. 1990 388,21. 192 D. Baudry M. Ephritikhine F. Nief L. Ricard and F. Mathey Angew. Chem. Znf. Ed. Engl. 1990 29 1485. Sc Y the Lanthanides and the Actinides A number of papers report on the chemistry of organoactinides containing the cyclo-octatetraenyl ligand (CSHs2-=COT2-). A facile synthesis of U(COT)C12 has been described and the activation parameters for its reaction with PMe measured. Crystal structures are also reported for U(COT)Cl,( NC5H5), (Sl) and U(C0T)- (acac)2,(52) which have structures of the 'piano stool' type.193 U(BH4)4 reacts with U(COT)2 to give U(COT)(BH,) which forms the adducts U(COT(BH4)2L (L= PPh, thf OPPh,) and the mixed ring derivatives U(COT)Cp(BH4)L (L =thf OPPh3).The crystal structure of U(COT)Cp(BH,),(OPPh,) also reveals a 'piano stool' structure.'94 U(COT)2 reacts with I2 to give U(COT)I,(thf) which is a convenient precursor to other monocyclooctatetraenyl complexes such as U(COT)12(hmpa)2 U(COT)(acac) U(COT)Cp*I and [Li(thf),][U(COT)-(CH2SiMe3)3].'95 The reduced derivative K[ U(COT),] and its 1,l'-dimethyl deriva- tive have been reported along with [Np(C8H7B~')2] and [Pu(COT),]. Rapid electron 193 T. R. Boussie R. M. Moore Jr. A. Streitwiessr A. Zalkin J. Brennon and K. A. Smith Organornetallics 1990 9 2010.194 D. Baudry E. Bulot M. Ephritikhine M. Nieriich M. Lance and J. Vigner J. Organornet. Chem. 1990 388,279. 195 J. C. Berthet J. F. Le Martchal and M. Ephritikhine J. Organornet. Chern. 1990 393 C47. 104 C.J. Jones exchange is observed between compounds containing oxidation state (111) actinides and those containing oxidation state (IV) actinide^.'^^ Some mixed d-blocklactinide heterobimetallic compounds have also been reported. The potential ligands U(C5H4PPh2)n( NEt2)(4-n)( n =1,2,3,4) have been synthesized and the compounds with n =2 or 4 used to prepare the heterobimetallic compounds U(NEt2)2(C5H4PPh2)2Mo(C0)4 and U(C5H4PPh2) (p-C5H4PPh2)2M(CO)4 (M = Mo Cr) (53).19’ lY6 D. C. Eisenberg A. Streitwieser and W.K. Kot Inorg. Chem. 1990 29 10. A. Dormond P. Hepiegne A. Hafid and C. Moise 1. Organornet. Chem. 1990 398 C1.

ISSN:0260-1818    

DOI:10.1039/IC9908700075

出版商:RSC    

年代:1990

数据来源: RSC

摘要:

6 The Noble Metals By S. D. ROBINSON Department of Chemistry King's College London Strand London WC2R 2LS 1 General This chapter is concerned with the coordination chemistry of the noble metals -Ru Os Rh Ir Pd Pt Ag and Au. Organometallic complexes are dealt with in a dedicated chapter elsewhere within this volume and are therefore excluded from the present contribution. The volume of new work is such that coverage is of necessity selective rather than comprehensive. No attempt has been made to cover bio-inorganic chemistry or metal cluster compounds. 2 Ruthenium A new synthesis of RuF has been described and electronic and vibrational spectra assigned.' The catalytic oxidation of organic compounds by ruthenium and osmium 0x0 complexes has been reviewed.," Oxidation of bridged polycyclic alkanes with RuO generated in situ involves the interaction of the highly electrophilic oxoruthenium species with unhindered tertiary C- H bonds.2b The Ru0,-CH,CHO system selectively catalyses oxidative-cleavage of C=C bonds using molecular oxygen to give the corresponding carbonyl compounds.2c Molecular orbital investiga- tions of ruthenium-oxo catalysed olefin oxidations and epoxidations and alcohol oxidations have been described.2d Ruthenium 0x0 species trans-[Ru(O),X4l2-(X = C1 Br) function as two electron catalysts for the oxidation of alcohols to aldehydes and ketones in the presence of N-methylmorpholine-N-oxideas co-oxidant.2e In the presence of the same co-oxidant the cis-dioxoruthenium(v1) complex [Ph,P]-[Ru( 0)2(02CMe)Cl,] catalyses the oxidation of halides alcohols sulphides and phosphines.2f A one step synthesis of the trans-dioxo-ruthenium( v~) complexes R~(0),(0,CR)~py, from barium ruthenate has been described.2R New ruthenium(v1) complexes Ru,(p-O),(O),L [Ru(0),L4I2+,[Ru(O)~C~~L]-and Ru(O)~CI,L (L = pyridine or substituted pyridine) catalyse the oxidation of alcohols using N-methyl- ' A.K. Brisdon P. J. Jones W. Levason J. S. Ogden J. H. Holloway E. G. Hope and G. Stanger J. Chem. Soc. Dalton Trans. 1990 715. * (a) W. P. Griffith Transition Mef. Chem. 1990 15 251; (b) A. Tenaglia E. Terranova and B. Waegell J. Chem. Soc. Chem. Commun. 1990 1344; (c) K. Kaneda S. Haruna T. Imanaka and K. Kawamoto J. Chem. SOC.,Chem. Commun. 1990 1467; (d)T.R. Cundari and R. S. Drago Inorg. Chem. 1990 29 487 2303 and 3904; (e) A. C. Dengel W. P. Griffith A. M. El-Hendawy and J. M. Jolliffe Polyhedron 1990 9 1751; (f)W. P. Griffith J. M. Jolliffe S. V. Ley and D. J. Williams J. Chem. Soc. Chem. Commun. 1990 1219; (g) S. Perrier T. C. Lau and J. K. Kochi Inorg. Chem. 1990 29 4190; (h) A. C. Dengel A. M. El-Hendawy W. P. Griffith C. A. O'Mahoney and D. J. Williams J. Chem. SOC. Dalton Trans. 1990 737. 105 106 S. D. Robinson morpholine- N-oxide iodosylbenzene and in some instances dioxygen as co-oxidant. The crystal structure of R~~(p.-0)~(0)~py has been reported.2h An oxygen- labelling study of water oxidation by [(bipy),OR~ORuO(bipy)~]~+ has been de~cribed.~ The kinetics and mechanism of the reduction of trans-[Ru( O),(TMC)I2+ to [Ru(O)(TMC)(H,0)l2+ (TMC = 1,4,8,1l-tetramethyl-1,4,8,1 l-tetra-azacyclo-tetradecane) in aqueous solution by outer-sphere one-electron reductants have been studied.,” Unusually long Ru-Cl distances [2.406 (3) and 2.370 (4) are a feature of the ruthenium(111) complex cis-[ RuCl,L][ClO,] (L = 1,4,7,10-tetramethyl-1,4,7,10-tetra-azacyclotridecane).4hThe usual saddle-shape geometry of the macrocyclic ligand tmtaa2-(dibenzo[6 i][ 1,4,8,1lltetra-azacyclotetradecane) is destroyed due to the presence of the bulky PMePh ligands in the complex Ru(tmtaa) ( PMePh,)2.4‘ The X-ray crystal structure of the Ru-to-N phenyl migration product [Ru(0EP-N-Ph)Ph][BF,] (OEP = octa-ethylporphyrin dianion) has been reported.’“ Cyclic voltammetry of Ru(OEP)Ph and Ru(0EP)Ph reveals diverse redox and reaction ~hemistry.~’ Resonance Raman and infrared data have been reported for the dioxoruthenium(v1) complexes Ru(O),( p~rphyrin).~‘ Metal-metal double bonds are postulated for the complexes Ru2( DPB) 0s2(DPB) and RuOs( DPB) [DPB = cofacial biphenylene-bridged bi~(porphyrin)].~~ The poly- pyridyl ligand 2,2’ :6’,2’’:6’’,2”’:6”’,2”’’-quinquepyridine (qpy) forms a binuclear com- plex [(tpy)Ru(qpy)Ru(tpy)Cl][ PF,] (tpy = 2,2’ 6’,2”-terpyridine) with a helical structure (1) in which the two ruthenium centres are bridged by the qpy ligand.6” 99 Ru NMR data have been reported for a range of ruthenium polypyridyl com-D.Geselowitz and T. J. Meyer Inorg. Chem. 1990 29 3894. (a) C-.M.Che K. Lau T-C. Lau and C-K. Poon J. Am. Chem. SOC.,1990 112 5176; (b) C-.M. Che W-T. Tang W-.T. Wong H-. W. Lam and T-F Lai J. Chem. SOC.,Dalton Trans. 1990 2077; (c) F. A. Cotton and J. Czuchajowska Polyhedron 1990 9 1221. (a) J. W. Seyler P. E. Fanwick and C. R. Leidner Inorg. Chem. 1990 29 2021; (b)J. W. Seyler and C. R. Leidner Inorg. Chem. 1990 29 3636 (c) 1. R. Paeng and K. Nakamoto J. Am. Chem. SOC.,1990 112 3289; (d) J. P. Collman and J. M. Garner J. Am. Chem. Soc. 1990 112 166. (a) C. J. Cathey E. C. Constable M. J. Hannon D. A. Tocher and M. D. Ward J. Chem. Soc. Chem. Comrnun. 1990 621; (h) G. Orellana A. Kirsch-De Mesmaeker and N. J. Turro. Inorg. Chem.. 1990. The Noble Metals plexes.6h Both 'H and I3C NMR data have been used to probe the effects of small changes in ligand structure on the overall properties of the complexes [Ru(L-L'),I2+ and [Ru(bipy),(L-L')I2+( L-L' = one of nine new pyrazole containing bidentate ligands).6' Charge distribution within ruthenium (and osmium) quinone complexes [M(bipy),(quinone)]" (n = 0 +1 +2) has been investigated.6d Intermetallic coup- lings and electronic spectra of bis( pentaammineruthenium) a,o-dipyridyl trans-polyene complexes have been reported.6e Homoleptic tris N N'-diaryltriazenido complexes of ruthenium (and osmium) have been described.6f The synthesis struc- ture and redox properties of the triaqua [tris( 1-pyrazolyl)methane]ruthenium(11) cation have been reported.6R Low temperature resonance Raman spectra establish that the dinuclear Ru-Ru species formed by oxidation of [Ru(edta)(OH,)]- is the [(edta)Ru-0-Ru(edta)l3-anion (LRu-0-Ru CQ.165°).6h Studies on ruthenium( 11) Schiff base complexes have yielded EPR spectra'" and dioxygen/car- bon monoxide binding data.7b Potassium dihydrobis( 1-pyrazolyl) borate K[ H,B(pz),] undergoes B-N cleavage on reacting with RuCl,( DMSO) to afford Ru(pz),(pzH),( DMS0).7c Heterobinuclear triazole-bridged salts containing the cations (2) and (3) have been characterized by X-ray diffraction methods.'" A significant degree of n-bonding between the cyanamide ligand and ruthenium( 111) is indicated by X-ray diffraction data for [(H3N),Ru(N=C=NAr)][S04](Ar = 2,3-di~hlorophenyl).~~ Ruthenium( II/ 111) carboxylates Ru2CI(02CAr) react with PPh3 in methylcyanide to yield intermediates Ru2( p-OH2)( p-O2CAr),(O2CAr),Cl( MeCN)( PPh,) which subsequently afford the p-0x0 bis( p-carboxylato) species [Ru2(p-0)(p-02CAr),( MeCN),( PPh3)2][C104]2 and RU2(p-O)(pU-02CAr),(OZCAT)2( PPh3)2e9 29 882 (c) P.J. Steel and E. C. Constable J. Chem. SOC.,Dalton Trans. 1990 1389 (d) M-A. Haga K. Isobe S. R. Boone and C. G. Pierpont Inorg. Chem. 1990 29 3795 (e)J. R. Reimers and N. S. Hush Inorg. Chem. 1990 29 3686 (f)S. F. Colson and S. D. Robinson Polyhedron 1990 9 1737 (g) A. Liobet D. J. Hodgson and T. J. Meyer Inorg. Chem. 1990 29 3760 (h) J. Zhou W. Xi and J. K. Hurst Inorg. Chem. 1990 29 160. ' (a) M. M. Taqui Khan D. Srinivas R. I. Kureshy and N. H. Khan Inorg. Chem. 1990 29 2320 (b) M. M. Taqui Khan N.H. Khan R. I. Kureshy A. B. Boricha and Z. A. Shaikh Inorg. Chim Acta 1990 170 213; 1990 174 175; (c) M. M. Taqui Khan P. S. Roy K. Venkatsubramanian and N. H. Khan Inorg. Chim.Acta 1990 176 49. (a) R. Hage J. G. Haasnoot H. A. Nieuwenhuis J. Reedijk D. J. A. De Ridder and J. G. Vos J. Am. Chem SOC.,1990 112 9245; (b) R. J. Crutchley K. McCaw F. L. Lee and E. J. Gabe Inorg. Chem. 1990 29 2576. B. K.Das and A. R. Chakravarty Inorg. Chem. 1990 29 1783 and 2078. S. D. Robinson New work on ruthenium nitrosyl complexes includes synthesis of the species trans-RuCl( NO)( a-dioximato) ,I0" crystal structure determinations for the salts Cs2[RuX4(NO)(H20)]X- H20 (X = C1 Br),'Ob and a reactivity comparison for the cations [RuX(py),(N0)I2+ (X = OH CI).'O' The synthesis and spectroscopic properties of ruthenium (11) thionitrosyl complexes RuX3( NS)L2 (L = PPh ,AsPh, MeCN NEt, Me2C0 and HCONMe,) have been reported.'0d The nitro complexes Ru(q5-C5H5)(N02)L2 (L = PPh or 1/2 diphos) react with HPF to afford the corresponding nitrosyls [Ru( q5-C5H5)( NO)L,][ PF6],.loe Electrochemical oxida-tions of truns-RuCl( NO,)(py) and trans-[Ru(NO,)(H,O)(py),]+ afford truns-[RuCl(O)(py),]+ and trans-[Ru(ONO)(O)py,]+ respectively,"' the latter reaction involves a reversible redox induced N0,eONO isomerization.'Og An efficient syn- thesis Of [RU(OH,)6]2+ salts from hydrated ruthenium dioxide has been described,"" and a low temperature neutron diffraction study of the [RU(oH2)6]3' ion in CsRu(SO,) * 12H20 has been reported."b The elusive [RU(CN)6]3- anion has been isolated as the [Bu,"N]+ salt."' Redox reactions of [Ru2C18(py),12- afford the stable mixed-valence state complexes [Ru2Cl8(py),l3- and [Ru,Cl,(py),]-which are for- mulated as 'Class 111' and 'Class 11' systems respectively.11d New ruthenium crown thioether complexes characterized by X-ray diffraction methods include [Ru( 1,4,7- trithiacy~lononane)~][BPh,]~~~" [Ru( 1,4,7,10,13,16-hexathiacyclo-octadecane)]-[BPh4]2,12a[Ru(2,3,11,12-dibenzo-1,4,7,10,13,16-hexathiacyclo-octadecane)][PF6I2* 2MeN0 ,I2' trans-RuHCl(6,6,13,13-tetramethyl-1,4,8,11 -tetrathiacyclotetra- decane),',' trans-RuHC1(3,3,7,7,11,11,15,15-octamethyl-1,5,9,13-tetrathiacyclo- hexadecane),l2' and [RuCl( PPh,) (1,4,7-trioxa-10,13-dithiacyclopentadecane)]-[PF,] -H20.12d The stable anionic poly-chalcogenide complex anion cis-[Ru(CO)~-(Se,),]'-has been characterized by diffraction method^.'^‘' The chemistry of the tetradentate ligand (4) bound to ruthenium (II)13b*cincludes the novel C-S bond cleavage sequence shown in Scheme 1.(a) J. G. Muller and K. J. Takeuchi Inorg. Chem. 1990 29 2185; (b) N. N. Nevskii N. M. Sinitsyn and A. A. Svetlov Russ. J. Inorg. Chem. 1990 35 653; (c) H. Nishimura H. Matsuzawa T. Togano M. Mukaida H. Kakihana and F. Bottomley J. Chem. Soc. Dalton Trans. 1990 137; (d) K. K. Pandey V. Paleria and D. T. Nehete Synth. React. Inorg. Met.-Org. Chem. 1990 20 1169; (e) L. F. Szczepura and K. J. Takeuchi Inorg. Chem. 1990 29 1772; (f)H. Nagao H. Nishimura Y. Kitanaka F. S.Howell M. Mukaida and H. Kakihana Inorg. Chem. 1990 23 1693; (g) H. Nishimura H. Nagao F. S. Howell M. Mukaida and H. Kakihana Chem. Left. 1990 133. (a) P. Bernard M. Biner and A. Ludi Polyhedron 1990 9 1095; (b) S. P. Best and J. B. Forsyth J. Chem. SOC. Dalton Trans. 1990 3507; (c) S. Eller and R. D. Fischer Inorg. Chem. 1990 29 1289; (d) R. M. Christie G. A. Heath S. A. MacGregor M. Schroder and L. J. Yellowlees J. Chem. SOC.,Chem. Commun. 1990 1445. (a) M. N. Bell A. J. Blake A. J. Holder T. I. Hyde and M. Schroder J. Chem. SOC. Dalton Trans. 1990,3841 (b) D. Sellmann H-P Neuner R. Eberlein M. Moll and F. Knoch Inorg. Chim. Ada 1990 175 231; (c) T. Yoshida T. Adachi T. Ueda T. Tanaka and F. Goto J. Chem. SOC.,Chem. Commun. 1990 342; (d) A. J. Blake G.Reid and M. Schroder J. Chem. SOC.,Dalion Trans. 1990 3849. (a) M. Draganjac S. Dhingra S-P. Huang and M. G. Kanatzidis Inorg. Chem. 1990 29 590; (b) D. Sellmann 1. Barth and M. Moll Inorg. Chern. 1990 29 176; (c) D. Sellmann I. Barth F. Knoch and The Noble Metals 109 Scheme 1 The closely related N,S,-donor ligand (5) afford the products (6) and (7).'3d X-ray crystal structure determinations have been reported for the S-bonded tetramethylene sulphoxide (TMSO) complexes c~~-R~C~,(TMSO),'~"~~ and [(TMSO)H] [tran~-RuCl~(TMS0)~]'~~ The first base-free silylene complexes [($-C5Me5)(PMe3)2Ru=SiR2][BPh4](R = Ph SEt S tolyl-p) have been rep~rted.'~~,~ New molecular hydrogen complexes of ruthenium include [RuH( v2-H2)( P-P),]+ (P-P = diop or Ph2P(CH2),PPh2 n = 2,3,4)'6u*b[RuH(q2-H2){P(0R),},]+ (R = Me Et)'6c and [Ru( q2-H2)( q5-C5H,)(CO)( PR3')]+ (R' = Me Cy Ph).'6d The redox M.Moll Inorg. Chem. 1990 29 1822; (d) D. Sellmann 0. Kappler F. Knoch and M. Moll Z. Naturforsch. Ted B 1990 45 803. 14 (a) D. T. T. Yapp J. Jaswal S. J. Rettig B. R. James and K. A. Skov Inorg. Chim. Acta 1990 177 199; (b)A. Alessio B. Milani G. Mestroni M. Calligaris P. Faleschini and W. M. Attia Inorg. Chim. Acta 1990 177 255. *'(a) D. A. Straus S. D. Grumbine and T. D. Tilley J. Am. Chem. SOC.,1990 112 7801; (b)D. A. Straus C. Zhang G. E. Quimbita S. D. Grumbine R. H. Heyn T. D. Tilley A. L. Rheingold and S. J. Geib J. Am. Chem. SOC.,1990 112 2673. 16 (a)M. Saburi K. Aoyagi H. Takeuchi T. Takahashi and Y.Uchida Chem. Let?. 1990 991; (b) M. Saburi K. Aoyagi T. Takahashi and Y. Uchida Chem. Let?. 1990,601; (c) P. Amendola S. Antoniutti G. Albertin and E. Bordignon Inorg. Chem. 1990 29 318; (d) M. S. Chinn and D. M. Heinekey J. Am. Chem. SOC.,1990 112 5166. 110 S. D. Robinson reactions shown in equation (1) Ru(S2CXR),(PPh,)2=[Ru(S2CXR),(PPh,),lf (X= 0,S) (1) are accompanied by cis/ trans isomerization at the ruthenium ~entre."~,~ The hemi- labile character of the phosphine-ether ligands R2PCH,CH,0Me (R = Me Ph) Me2PCH2k HC H2C H2C H26 and Me2PCH2k HC H20C H2C H2b has been demon- strated by the fluxional behaviour and catalytic activity of their ruthenium( 11) complexes18a3b. The solvent dependent isomerization of RuCl,{ PhP- (CH2CH2CH2PCy2),} has been investigated and the X-ray crystal structure of the fac isomer determined.18' New catalytic reactions involving ruthenium( I I) phosphine complexes include the RuCI2( PPh3)3 catalysed condensation of long chain primary alcohols with secondary amines to form tertiary amines18d and the hydrogenation of aldehydes in aqueous solution using RuC12{ P(C6H4S03Na)3}3 and related water soluble species.lBe The synthesis of binuclear ruthenium (I/I) complexes continues to attract atten- tion new examples include [Ru(p-S2PMe2)( CO),( PPh3)]2,19a [Ru(p-02PPh2)-(C0)2(PPh3)]2,19b [Ru(p-Opy)(CO),L] (L = CO MeCN PPh etc.)'" [RU{HB(~Z),)(CO)~]~,~~~ and the polymeric species [RU(~-O,CM~),(CO>~(L-L)~ [L-L = R2P(CH2),PR2 RSCH,SR; R = Me Ph; n = 14].19' X-Ray diffraction studies have been reported for [{Ru(CO),( PPh3)},{ p-1,2-C6H4( NH)2)1,20a [Ru2(p-RNNNR)( RNNNR)(p-CO),(CO>,(bipy)] (R = p-toly1)20b the bridging C02 derivative [Ru~{~-OC(O)}(CO)~{~-( RO),PN( Et)P(OR),},] 2oc and the trimeric tart- rat0 complex (8).,0d Finally X-ray and electrochemical data have been reported for the 1,8-naphthyridine-2,7-carboxylato d~np)~" (dcnp2-) derivative Ru2( P-O,CM~)~( 3 Osmium Some osmium complexes are mentioned with their ruthenium analogues in the preceding section.The chemistry of osmium in its higher oxidation states continues to attract attention. New dioxo-osmium(v1) complexes include trans-Os(O),(bipy)- (mes), ci~-Os(O)~(PR~)~(mes)~ [mesN2][Os-OS(O),(CNC,H,M~~-~,~)(~~S)~ (o)2(o~02)2(mes)I(mes Os(0)2(~~)2~e2, = 2,4,6-C,~~~e,),~'" and OS(O)~(PY)~- (a) N.Bag G. K. Lahiri and A. Chakravorty J. Chem. Soc. Dalton Trans. 1990 1557; (b) A. Pramanik N. Bag G. K. Lahiri and A. Chakravorty J. Chem. Soc. Dalton Trans. 1990 3823. (a)G. M. McCann A. Carvill E. Lindner B. Karle and H. A. Mayer J. Chem. Soc. Dalton Trans. 1990 3107; (b) E. Lindner and B. Karle Z. Naturforsch Ted B 1990 45 1108; (c) G. Jia 1. Lee D. W. Meek and J. C. Gallucci Inorg. Chim. Acta 1990 177 81; (d) S. Ganguly and D. M. Roundhill Polyhedron 1990 9 2517; (e) E. Fache F. Senocq C. Santini and J. M. Basset J. Chem. Soc. Chem. Commun. 1990 1776. (a)R. W. Hilts and M. Cowie Inorg. Chem. 1990,29 3349; (b) D. S. Bohle and H. Vahrenkamp Inorg. Chem. 1990 29 1097; (c) P.L. Andreu J. A. Cabeza V. Riera Y. Jeannin and D. Miguel J. Chem. Soc. Dalton Trans. 1990 2201; (d) M. M. de V. Steyn E. Singleton S. Hietkamp and D. C. Liles J. Chem. Soc. Dalton Trans. 1990 2991; (e) R. W. Hilts S. J. Sherlock M. Cowie E. Singleton and M. M. de V. Steyn Inorg. Chem. 1990 29 3161. *' (a)S. Garcia-Granda R. Obeso-Rosete J. M. Rubio Gonzales and A. Anillo Acta Crystallogr. Sect. C 1990 46 2043; (b) S. F. Colson S. D. Robinson and D. A. Tocher J. Chem. Soc. Dalton Trans. 1990 629; (c) J. S. Field R. J. Haines J. Sundermeyer and S. F. Woollam J. Chem. Soc. Chem. Commun. 1990 985; (d) G. Suss-Fink J.-L. Wolfender F. Newmann and H. Stoeckli-Evans Angew Chem. Int. Ed. Engl 1990 29 429; (e) J. P. Collin A. Jouaiti J.-P. Sauvage W. C. Kaska M.A. McLoughlin N. L. Keder W. T. A. Harrison and G. D. Stucky Inorg. Chem. 1990 29 2238. (a)B. S. McGilligan J. Arnold G. Wilkinson B. Hussain-Bates and M. B. Hursthouse J. Chem. Soc. The Noble Metals H-\ HO'L\ c C'O\ L L o./ OH I L' 0"',6 'L cO (8) (SiMe3),.,l Electron-transfer chemistry of the luminescent excited states of trans dioxo-osmium(VI ) complexes [Os( O),( N,-macr~cycle)]~+ has been described,21' together with electronic and vibrational spectra,'ld The X-ray crystal structure of trans-Os(O),(OEP) (OEP = octa ethylporphyrin) has been reported2'= and the com- plex has been shown to undergo reduction in the presence of alcohols ROH (R = Et Ph) and thiophenol to afford Os(OEP)(OR) and Os(OEP)(SPh) respectively. Treatment with bromine yields Os(OEP)Br The six-coordinate complex trans-[Os(O),( H2NCMe,CMe,NH,),l2+ is in equilibrium with the five coordinate species Os(O)(HNCMe,CMe,NH)( HNCMe2CMe2NH2)]+ in aqueous The osmyl thiosulphate anion in the salt [Bu~,N]~[OSO~(S,O~)~] provides an example of osmium( VI) in an unusual tetrahedral coordination.21h New homoleptic osmium imido complexes Os(N-2 6-C6H3Pri,)3 and Os(NBu') 22b have been described.Other new imido derivatives include Os(N-2,6-C6H3Pri,),( PMe,Ph) p-O),,22b and OS(O)~( Os,( NBu'),( ~-Bu')~( NBu').''' The reactivities of isoelec- tronic nitrido- methylimido- and 0x0-osmium(v1) complexes [NBu",][Os( N)RJ Os(NMe)% and Os(O)%( R = CH2SiMe3) have been compared.22' Reversible inter- conversion of the osmium(v1) nitrido complex [Os(N)(tpy)Cl,]Cl (tpy = 2,2' 6',2"-terpyridine) and the osmium( 11) amino complex Os(NH3)(typ)C1 has been observed.22d Osmium halides and halo complexes have attracted attention.Dalton Trans. 1990 2465; (b) W. A. Herrmann S. J. Eder P. Kiprof K. Rypdal and P. Watzlowik Angew. Chem. In?. Ed. Engl. 1990 29 1445; (c) V. W-W. Yam and C.-M. Che J. Chem. SOC.,Dalton Trans. 1990 3741; (d) C.-M. Che W.-K. Cheng and V. W-W. Yam J. Chem. SOC.,Dalton Trans. 1990 3095; (e) H. Nasri and W. R. Scheidt Actn Crystallogr. Sect. C 1990 46 1096 (f) C.-M. Che W-H Leung and W-C Chung Inorg. Chem. 1990 29 1841 (g) C.-M. Che M. H-W Lam R.-J.Wang and T. C. W. Mak J. Chem. SOC., Chem. Commun. 1990 820; (h) C. F. Edwards W. P. Griffith and D. J. Williams J. Chem SOC.,Chem.Cornmun. 1990 1523. 22 (a) J. T. Anhaus T. P. Kee M. H. Schofield and R. R. Schrock J. Am. Chem. SOC.,1990 112 1642; (b) A. A. Danopoulos and G. Wilkinson Polyhedron 1990 9 1009; (C) R. W. Marshman and P. A. Shapley J. Am. Chem. SOC.,1990 112 8369; (d) D. W. Pipes M. Bakir S. E. Vitols D. J. Hodgson and T. J. Meyer J. Am. Chem. SOC.1990 112 5507. 112 S. D. Robinson Vibrational spectra and normal coordinate analysis have been reported for mixed chlorobromo-osmates [oSc1&,Br,]2-,23" and I9F NMR spectra have been analysed for the corresponding fluorochloro-osmates [OSF, C1,]2-.23h The synthesis and X-ray crystal structure of cis-OsCI,( MeCN) have been reported.23c Spectroscopic and electrochemical studies have been described for some trans-OsL,X,/[OsL,X,]- systems (L = PR3 AsR, SbR3 SeMe,; X = CI Br) and for related mer and fac OsL3X3/[OsL3X3]+ systems.23d The redox-related species [Os,Br,]- and [0s2Br9l3- have been isolated (as "Bun4]+ salts) and characterized for the first time.23e Two papers on the properties of [os2x8]2- anions describe the synthesis spectroscopic features and X-ray crystal structure of salts containing the hitherto unknown [os218]2- analogue.23Lg In polar solvents cis-OsC1,(Cy2PCH2CH,PCy,) readily dissociates to form the trigonal bipyramidal cation [OsC1(Cy2PCH,CH2PCy2),1+ (Cy = cy~lohexyl).~~ The dihydrogen complex cation [Os(NH,),( H2)I2+ formed by reduction of [Os(NH3)5( O3SCF3)][O3SCF3I2 in methanol or aqueous solution can be oxidized to yield the corresponding osmium( 111) species [Os(NH3),( H2)I3+.,," Protonation of the octaethylporphyrin salt K[Os(OEP)H] with benzoic acid in THF affords the dihydrogen complex Os(OEP)H in ca.30% yield.,,' New bis-axially coordinated (phthalocyaninato)osmium( 11) complexes Os(pc)L2 (L = Me2S0 py pyrazine Bu'NC) have been reported.25' The mutual influence of ligands in the osmium nitrosyl species [Os(NO)(NH3),XI2+ and [Os(NO)X5I2- (X = F CI Br and I) has been investigated by vibrational spectroscopy26. Fast time-resolved infrared spectra have been used to demonstrate the transient existence of (OC)40s=Os(CO) during the flash photolysis of OS,(CO)~(C,H,).~~ 4 Rhodium The tris(3,5-dimethylpyrazolyl)borate complex Rh(H,)( H),{ HB(3,5-Me,p~)~) affords one of the first examples of a transition metal dihydrogen complex stabil- ized by nitrogen donor ligands2'" (see also Ref.25a).An NMR study of the mono- hydrides RhHCl,L (L = PPri3 PCy,) provides evidence for addition of dihydro- gen to form the adducts RhH( H2)C12L2.28h Rhodium derivatives of optically active Schiff base ligands obtained from chiral 6-alkoxy-2-pyridinecarboxaldehydes catalyse hydrosilylations but achieve only low e.e. values.28c Dibasic Schiff bases 23 (a) W. Preetz and K. Irmer Z. Narurforsch Teil B 1990 45 283; (b)A. 0. Alyoubi D. J. Greenslade M. J. Forster and W. Preetz J. Chem. Soc. Dalton Trans. 1990 381; (c) D. Fenske G. Baum H.-W. Swidersky and K. Dehnicke Z. Narurforsch Teil B 1990 45 1210; (d) R. A. Cipriano W. Levason R. A. S. Mould D.Pletcher and M. Webster J. Chem. Soc. Dalton Trans. 1990 339 and 2609; (e) G. A. Heath and D. G. Humphrey J. Chem. Soc. Chem. Commun. 1990 672; (f)W. Preetz P. Hollmann G. Thiele and H. Hillebrecht Z. Narurjorsch. Teil B 1990,45 1416; (g) F. A. Cotton and K. Vidyasagar Inorg. Chem. 1990 29 3197. 24 A. Mezzetti A. Del Zotto and P. Rigo J. Chem. SOC.,Dalton Trans. 1990 2515. 25 (a)W. D. Harman and H. Taube J. Am. Chem. Soc. 1990,112,2261;(b)J. P. Collman P. S. Wagenknecht R. T. Hembre and N. S. Lewis J. Am. Chem. Soc. 1990 112 1294; (c) M. Hanack and P. Vermehren Inorg. Chem. 1990 29 134. 26 E. Yu. Bobkova A. A. Svetlov N. L Rogalevich G. G. Novitskii N. N. Borkovskii and M. N. Sinitsyn Russ. J. Inorg. Chem. 1990 35 546 and 549. 27 F. W. Grevels W.E. Klotzbucher F. Seils K. Schaffner and J. Takats J. Am. Chem. Soc. 1990 112 1995. 28 (a) U. E. Bucher T. Lengweiler D. Nanz W. von Philipsborn and L. M. Venanzi Angew. Chem. Inf. Ed. Engl. 1990 29 548; (b) D. G. Gusev V. 1. Bakhmutov V. V. Grushin and M. E. Vol'pin Inorg. Chim. Acra 1990 175 19; (c) M. E. Wright S. A. Svejda and A. M. Arif Inorg. Chim. Acra 1990 175 The Noble Metals I W I + + r-N N* \ \ S. D. Robinson act as bridging ligands in rhodium(1) complexes L,Rh(Schiff base)RhL [L = P(OR)3 C0]28d and in the rhodium(rr1) cyclometallated product [(Ph2(~h{P(C,H4Cl-o)Ph2}]2(salen).28eA range of tellurium( 11) heterocycles (L) afford rhodium( 111) complexes RhC13L3.28f The redox behaviour and dioxygen activation capacity of the coordinatively unsaturated rhodium( I 11) 3,5-di-tert-butylcatecholate complex [Rh(triphos)(3,5-Bu1Cat.)]+have been investi- gated (Scheme 2).29“ X-Ray crystal structures have been reported for Na( NH4)2[ Rh( NO,),] and its iridium analogue.29h The macrocycle ([181 ane N2S4) (9) reacts with [Rh(H20),]’+ in aqueous methanol to yield the cationic complex RN NR (9) [18]aneN,S, R = H; Me2[18]aneN,S, R = Me [Rh([181 ane N2S4)]3+.29C The 2-aminoethanethiolate (aet) complex fuc( S)-Rh(aet) reacts with Zn2+ ions in aqueous solution to give spontaneously resolved species [{Rh(aet)3}4Zn30]4+ in which each zinc( 11) is tetrahedrally coordinated to the central oxygen atom and the sulphurs of three different Rh(aet) Bond lengths reported for the binuclear rhodium(III/III) peroxo complex (Ph3P)( hfacac),RhO,Rh( hfacac),( PPh,) (hfacac = hexafluoroacetylacetonate) include 0-0 1.397(8) A and Rh-O(O2) 1.988(6) A.30hThe coordination chemistry of rhodium(I1) continues to expand the highlight of 1990 was the isolation and crystallographic characterization of trans-RhCI2(PPh3) -the proposed para- magnetic impurity in Wilkinson’s catalyst.31u The new rhodium( 11) dithiocarbamates Rh(S2CNR2) and Rh( S,CNR,),( PPh,) are also reported to be paramagnetic monomer^.^' ’ The rhodium(II/ 111) 2-anilinopyridine (ap) complexes Rh2(p-ap),(CECR) take up dioxygen at 123 K to afford the corresponding rhodium (LII/III) superoxides Rhz( p-ap),(C~CR)(0,).~~~ Resonance Raman spectra of the binuclear rhodium( II/ 11) complexes Rh2( bridge),L (bridge = acetate acetamidate tri-fluoroacetamidate; L = PPh3 AsPh,) and their one-electron oxidized analogues have afforded values for v(Rh-Rh) in each Solid-liquid crystal phase 13; (d) S.Gopinathan S. A. Pardhy I. R. Unny and C. Gopinathan Inorg. Chim. Acta 1990 169 39; (e) P. Lahuerta J. Latorre R. Martinez-Minez S. Garcia-Granda and F. Gomez-Beltran Inorg. Chim. Acra 1990 168 149; (f) A. Z. Al-Rubaie Y. N. Al-Obaidi and L. Z. Yousif Pol-vhedron 1990 9 1141. 29 (a) C. Bianchini P. Frediani F. Laschi A. Meli F. Vizza and P. Zanello Inorg. Chem. 1990 29 3402; (b)S. A. Gromilov I. A. Baidina V. I. Alekseev A. B. Venediktov and S. P. Khranenko Russ. J. Inorg. Chem. 1990 35 384; (c) A. J. Blake G. Reid and M.Schroder Polyhedron 1990 9 2925. 30 (a) T. Konno K.-I. Okamoto and J. Hidaka Chem. Lerr. 1990 1043; (b) I. V. Kuz’Menko A. N. Zhilyaev M. A. Porai-Koshits and I. B. Baranovskii Russ. J. Inorg. Chem. 1990 35 648. 31 (a) C. A. Ogle T. C. Masterman and J. L. Hubbard J. Chem. Soc. Chew. Commun. 1990 1733; (b) K. K. Pandey D. T. Nehete and R. B. Sharrna Polyhedron 1990 9 2013; (c) C.-L. Yao K. H. Park A. R. Khokhar M.-J. Jun and J. L. Bear. Inorg Chem.. 1990 29. 4033; (d) S. P. Rest. R. J. H. Clark The Noble Metals 115 transitions in binuclear rhodium( 11) n-alkanoates have been probed by Raman I spectr~scopy.~" Aryl phosphines react with Rh,(O,CMe),( MeOH) to afford the 0-and C-metallated products Rh[ p-P{C,H2(OMe)20}{C,H2(OMe~3~2]-(p-O,CMe),Rh (MeOH)32" and [R~,H3Me-m)(C,H,Me-m)2}{p-02CMe} ( H.O,CMe)],( MeC02H)32h respectively.Addition of trans-caryophyllene to Rh,( 02CCF3)4 affords the first structurally characterized axial bis(o1efin) adduct of a dimetal core.32' The chemical and electrochemical oxidation of rhodium (I/I) and iridium ( I/I) complexes containing the M,(p-pz)(p-SBu')( p-dppm) 32d and M,( p-pz)( p-dppm),( Bu'NC) 32e cores (pz = pyrazolate) has been described. X-Ray crystal structures have been reported for (Me,PhP),CIRh( p-CO)(p-CI)(p- SCy)RhCI( PPhMe,) and (Me,PhP)(OC)Rh( p-CO)( p-SCy),RhCI2( PPhMe2).321 Tautomeric mixtures of Rh2( p-NR)(CO),(p-dppm) and Rh,(p-NHR)(CO),(p- dppm-H)(p-dppm) 33a (R = p-tolyl) react with CH,Cl to afford [Rh,(p-N(CH,CI)C,H,Me}(CO),( p-dppm)2]C1.33h Primary and secondary silanes react with Rh,(p-H),(CO),( p-dppm) to yield Rh2( p-SiHR),CO),(p-dppm) and Rh,( p-SiR,)( H),( CO),( p-dppm) re~pectively.'~' New diphosphine-bridged heterobimetallic hydride and carbonyl complexes of rhodium and iridium include (OC)Rh( p-CO)( p-dppm),Ir(CO) which contains an Ir' + Rh' dative bond.33d The P/S donor ligand BzSCH,PPh,(btmp) reacts with rhodium( I) carbonyl species to form trans-RhCl(CO)(btmp), [Rh,(p-C1)(CO),(p-btmp)2][RhC1,(CO)2] Rh,Cl,( p-CO)( p-btm~)~ and when HCI is present Rh,C14(CO),(p-btmp) .33c X-Ray crystal structures have been reported for trans-RhCI(CO)L,[ L = Ph2PCH,NPh2 and PhP(CH2NPh2)2].33' The square-planar rhodium(I) complexes Rh( Pr',PCH,CH,i')( Pr',PCH,CH,Y)CI (Y = OMe NMe,) undergo chelate ring opening to form adducts Rh( Pr',PCH,CH,Y),LCI (L = CO C2H4 C2H2 et~.).~~~ The trinuclear complex Rh3(p-C1)3(C0)4{p-( PhO),PCH,P(OPh),} (10) adopts a novel variant of the more usual trinuclear A-frame structure.33h Rhodium( L) deriva-tives [Rh(C,H,,)L][BPh,] and [Rh(CO)L'][CI] have been prepared from the new chiral C3-symmetric tripodal phosphines L = (11) and L' = (12).34Rhodium and iridium cations [M(CO)( PPh,),( MeCN)]+ react with molybdenum and tungsten 0x0 complexes (C5H5),M'=0 to form novel 0x0-bridged species [(C5H,),M'=O + M(CO)(PPh3)2]t.35 A quasitetrahedral structure has been reported for Rh( SiPh,)- ( PMe3)336a and considerable distortion from planarity is also reported for the cation [Rh( PMe3),]+ and its iridium analogue.36h New trinuclear pyridine-2-thiolate and and A.J. Nightingale Inorg. Chem. 1990 29 1383; (e)0. Poizat D. P. Strommen P. Maldivi A.-M. Giroud-Godquin and J.-C. Marchon Inorg. Chem. 1990 29 4851. 32 (a) S. J. Chen and K. R. Dunbar Inorg. Chem. 1990 29 588; (6) L. Lahuerta R. Martinez-Maiiez J. Paya E. Peris and W. Diaz Inorg. Chim. Acta 1990 173 99; (c) F. A. Cotton L. R. Falvello M. Gerards and G. Snatzke J. Am. Chem. SOC.,1990 112 8979; (d)M. T. Pinillos A. Elduque and L. A. Oro Inorg. Chim.Acra 1990 178 179 (e) L. J. Tortorelli C. Woods and A. T. McPhail Inorg. Chem. 1990 29 2726; (f)H. Schumann S. Jurgis M. Eisen and J. Blum Inorg. Chim.Acta 1990 172 191. 33 (a) Y-W. Ge F. Peng and P. R. Sharp J. Am. Chem. SOC.,1990 112 2632; (6) Y-W. Ge and P.R. Sharp J. Am. Chem. Sor. 1990 112 3667; (c) W.-D. Wang and R. Eisenberg J. Am. Chem Soc. 1990 112 1833; (d) R. McDonald and M. Cowie Inorg. Chem. 1990 29 1564; (e) Y. Fuchita Y. Ohta K. Hiraki M. Kawatani and N. Nishiyama J. Chem. Soc. Dalron Trans. 1990 3767; (J)A. L. Balch M. M. Olmstead and S. P. Rowley Inorg. Chim. Am 1990 168 255; (g) H. Werner A. Hampp K. Peters E. M. Peters L. Walz and H. G. von Schnering Z. Nururforsch. Teil B,1990 45 1548; (h) R. Kumar R. J. Puddephatt and F. R. Fronczek Inorg. Chem. 1990 29 4850. 34 M. J. Burk and R. L. Harlow Angew. Chem. Inr. Ed. Engl. 1990 29 1462. 35 R. S. Pilato D. Rubin G. L. Geoffroy and A. L. Rheingold Inorg. Chem. 1990 29 1986. I6 (a) D. L. Thorn and R. L. Harlow Inorg Chem. 1990 29. 2017; (h)0.Blum J.C. Calabrese F. Frolow S. D. Robinson H I I all-(S)-4 all-(S)-5 [a]D = -329 [.ID = -167 (11) (12) benzothiazole-2-thiolate-bridged complexes of rhodium(I) include [Rh,(p3- bridge),(Co),][Clo,] and [Rh,(p3-bridge)(diene)3][C104].36C The mixed-metal ethoxides L,Rh(p-OEt)2Sn(OEt)2(p-OEt)2RhL2 = diene or (CO),) have been (L characterized thermal decomposition (L = C0-1,5-D) affords rhodium metal and SnO .36d The dioxygen adduct Rh(02)(S2CNMe2)(PPh3) reacts with CO to form a peroxycarbonate Rh(OOCO,)( S,CNMe,)( PPh,) which can be deoxygenated to afford firstly the corresponding carbonate and secondly an unstable C02 add~ct.,,~ 5 Iridium Some iridium complexes are mentioned with their rhodium analogues in the preced- ing section.Hexahaloiridates( IV) (H30)2[ IrBrJ (NH4)2[ IrBr,] and Cs2[ IrCl,] obtained by oxidation of the corresponding iridium( 111) species have been character- ized by X-ray diffraction methods.37" Oxidation of SO3,-by [IrC1,I2- yields exclus- ively SO4,-with no S2062-.376Preparative routes to iridium( 111) amine complexes and D. Milstein Inorg. Chim. Acta 1990 174 149; (c) M. A. Ciriano J. J. Perez-Torrente F. Viguri F. J. Lahoz L. A. Oro A. Tiripicchio and M. Tiripicchio-Camellini J. Chem. Soc. Dalton Trans. 1990 1493; (d) T. A. Wark E. A. Gulliver M. J. Hampden-Smith and A. L. Rheingold Inorg. Chem. 1990 29 4360; (e) Y. Wakatsuki M. Maniwa and H. Yamazaki Inorg. Chem.,1990 29 4204. (a) R. K. Coll J. E. Fergusson B. R. Penfold D. A. Rankin and W.T. Robinson Inorg. Chim. Acta,1990 177 107; (b)R. Sarala and D. M. Stanbury Inorg. Chem. 1990 29 3456; (c) F. Galsbd S. K. Hansen The Noble Metals 117 including [Ir( NH3)6]3+ [IrCl( NH3)J2+ cis and trans [IrCl,( NH3),]+ and mer-IrC13( NH,) have been de~cribed.~~' The redox behaviour of the couples [Ir(X2CNEt,)3]'/[Ir(X2CNEt2)3](X = S Se) has been compared with that of the analogous rhodium and cobalt systems.37d The iridium penthahydride IrH5( reacts with [Cu( MeCN),][ BF,] and Cu(OSO,CF,) to yield [IrH,(MeCN),-(PPr',),][ BF,] and [IrH5( PPri3)2]2CuOS02CF3 re~pectively.~~" Stoichiometric pro- tonation of IrH,L3 (L = PMe,Ph) with HBF affords the salt [IrH,(H2)L3][BF4] which readily loses H2 to form the highly reactive species [IrH2L3]+.38b Rapid reversible q2-coordination of dihydrogen by the monohydrides IrHCl,( PR3)2( R = Pri Cy) has been demonstrated by 'H and 2H NMR 38c and the q2-dihydrogen complex IrH,Cl( q2-H2)( PPri3)2 has been characterized by X-ray diffraction methods.38d Proton-proton quantum mechanical exchange coupling has been seen in the trihydride cations [IrH,(PR,)( q5-C5H5)]+.38e Molecular parameters for cis-[IrH,(THF)( H20)( PPh3)J[ SbF6] are consistent with planar 3-coordinate oxygen for the H20 ligand.38f A neutron diffraction study for cis-[ IrH(OH)( PMe3)4][PF6] reveals evidence of an attractive interaction between the electron deficient H atom of the OH and the electronegative hydride ligand.38g Irradiation of [Ir2(TMB),I2+ (TMB = 2,5-diisocyano-2,5-dimethylhexane) in the presence of cyclohexane affords [Ir2H2(TMB),]2+.38h New iridium( 111) diphosphine complexes Li[IrI,(P-P)] and [IrHI,(P-P)] (P-P = chiral diphosphine) catalyse chemoselective and enan-tioselective hydrogenation of imine~.~~",~ Heterocyclic amines LH undergo oxida- tive addition across [Ir(COD)( PMe3),]C1 to yield amido derivatives IrHCl( L)- (PMe,) (LH = indole pyrrole et~.).,~' Hydrogen transfer from ReH2( q5-C5H5)- (CO) to trans-IrCl(CO)( PPh3)2 via a heterobimetallic Re-Ir intermediate affords equimolar amounts of IrClH2(CO)( PPh3)2 and mer-IrH2C1( PPh3)3.39d A similar transfer from TaH3( q5-C5H5) to IrX(CO)( Ph2PCH2CH2PPh2) generates fac-IrH3(CO)(Ph2PCH2CH2PPh2)and Tax( q5-C5H5)2 (X = Br I).39e The syntheses and crystal structures of the 1,4,7-trithiacyclononane(L) complexes [Ir( and [IrH( q2-L)( q3-L)][ PF6] have been described.,'" A diphos- phine-linked structure has been reported for {C1( OEP)Ir}Ph2PCH,CH2PPh2 { Ir(OEP)Cl} (OEP = octaethylporphyrin diani~n).,'~ The iridium( 111) peroxo com- plex IrCl( q2-02){ (Ph2PCH2),CMe} oxidizes primary alcohols RCH20H to generate the corresponding carboxylates [IrH(02CR){(Ph2PCH2)3CMe}]C1.40C EXAFS and K.Simonsen Acta Chem. Scand. 1990,44,796; (d) A. M. Bond R. Colton and D. R. Mann Inorg. Chem. 1990 29 4665. 38 (a) X. D. He J. Fernandez-Baeza R. Chaudret K. Folting and K. G. Caulton Inorg. Chem. 1990,29 5000; (b) E. G. Lundquist K. Folting W. E. Streib J. C. Huffman 0. Eisenstein and K. G. Caulton 1.Am. Chem. SOC.,1990 112 855; (c) D.G. Gusev V. 1. Bakhmutov V.V. Grushin and M. E. Volpin Inorg. Chim. Acta 1990 177 115; (d) M. Mediati G. N. Tachibana and C. M. Jensen Inorg. Chem. 1990,29,3; (e) D. M. Heinekey J. M. Millar T. F. Koetzle N. G. Payne and K. W. Zilm J. Am. Chem. SOC.,1990 112 909; (f)X-L. Luo G. K. Schulte and R. H. Crabtree Inorg. Chem.,1990 29 682; (g) R. C. Stevens R.Bau D. Milstein 0. Blum and T. F. Koetzle J. Chem. Soc. Dalton Trans. 1990 1429; (h) D. C. Smith R. E. Marsh W. P. Schaefer T. M. Loehr and H. B. Gray Inorg. Chem. 1990,29,534. 39 (a) Y. N. Cheong Chan D. Meyer and J. A. Osborn J. Chem. SOC., Chem. Commun. 1990 869; (b) Y. N. Cheong Chan and J. A. Osborn J. Am. Chem. SOC.,1990,112,9400,(c) F. T. Ladipo and J. S. Merola Inorg. Chem. 1990 29,4172; (d) C. P.Casey and E. W. Rutter Inorg. Chem. 1990 29 2333; (e) P. P. Deutsch J. A. Maguire W. D. Jones and R. Eisenberg Inorg. Chem. 1990 29 686. 40 (a) A. J. Blake R. 0.Could A. J. Holder T. 1. Hyde G. Reid and M. Schroder J. Chem. Soc. Dalton Trans. 1990 1759; (b) K. M. Kadish Y. J. Deng and J. D. Korp Inorg. Chem. 1990 29 1036; (c) C. Bianchini A. Meli M. Peruzzini and F. Vizza J. Am. Chem. SOC.,1990 112 6726. S. D. Robinson studies on [Ir(CNMe),]Cl provide evidence of linear cation aggregation in sol-ution.,l" The binuclear complex [IrCI(CO)( p-dppb)] (dppb = Ph2P(CH2),PPh2) adds SnCl to form an adduct Ir,(SnCI,)Cl,(CO),(p-dppb),in which the Sn atom bridges the two iridium centre^.^" New heterobinuclear nitrosyl complexes [(Ph3P)2(ON)Ir(p-dppn)(p-C1)PdCl][PF,]2(13) and [(Ph,P)Cl,Ir(p-NO)(p-dppn)PdCl][PF,] (14) (dppn = 3,6-bis(2'-pyridyl)pyridazine] have been character- -L 12+ 1' n -N N Pd N'\/ 'Cl O= II 0 ized by diffraction methods.41'+' Oxidative additions of iodine to the pyrazolate- bridged complex 1r2(p-pz)(p-SBu')(CO),{P(OMe>,) and the naphthalene-1,8- diamide-bridged complex Ir2{p-1,8-( NH)2C,oH,}(CO)2( PPh,) 41jhave been described.The 1,8-diisocyano-p-menthane-bridgedcomplexes [Ir,( dimen),-M(PPh,),][PF,] (M = Ag Au) with linear P-Ir-Ag-Ir-P and P-Ir-Ir-Au-P backbones provide examples of 'inside' and 'outside' adducts respe~tively.~'".~ 6 Palladium The palladium salt [Pd( H20),( Ph2PCH2CH2PPh2)][0S02CF3]2and its platinum analogue catalyse the acetalization of aldehydes and ketones.43" The complexes Pd( PPh3)2( BF4)2 Pd( Ph,PCH,CH,PPh,)( BF4)2 and [Pd( 2,6-Bu',C5H3N),- (MeNO,),][ BF,] catalyse linear dimerization of styrene and linear polymerization of p-di~inylbenzene.~~' The reaction of (CF3),P-N=PPh3 with PdC12 gives Pd,Cl,{ (CF,),P= N= PPh3}2 in which the monodentate diphosphazene ligand assumes a non-linear highly delocalized (CF3),P=N= PPh electronic The first 1,5-benzodiazepine complex trans-PdCI,L( PPr,") (L = 7,8-dichloro-2,3-dihydro-2,2,4-trirnethyl-1H-1,5-benzodiazepine) has been chara~terized.~~~ Alkylindole complexes trans-PdCI,L contain indole ligands bound through nitrogen in the 3 H-indole form.43c Terminal arsenido complexes (a) N.Carr J. G. Crossley A. J. Dent J. R. Gouge G. N. Greaves P.S. Jarrett and A. G. Orpen J. Chem. Sor. Chem. Commun. 1990 1369; (b) A. L. Balch B. J. Davis and M. M. Olmstead Inorg. Chem. 1990,29,3066;(c) F. Neve and M. Ghedini Inorg. Chim. Acta 1990,175 11 1; (d)A. Tiripicchio M. Tiripicchio-Camellini F. Neve and M. Ghedini J. Chem. Soc. Dalton Trans. 1990 1651; (e) M. T. Pinillos A. Elduque L. A. Oro F. J. Lahoz F. Bonati A. Tiripicchio and M. Tiripicchio-Camellini J. Chem. Soc. Dalton Trans. 1990 989; (f) M. J. Fernindez J. Modrego F. J. Lahoz J. A. Lopez and L. A. Oro J. Chem. Soc. Dalton Trans. 1990 2587. (a) A. G. Sykes and K. R. Mann Inorg. Chem. 1990,29 4449; (b)A. G. Sykes and K. R. Mann J. Am. Chem Soc. 1990 112 7247. (a) F. Gorla and L. M. Venanzi Helv. Chim. Arm 1990,73 690; (b)Z. Jiang and A. Sen J.Am. Chem. Soc. 1990 112,9655; (c) H. G. Ang Y. M. Cai W. L. Kwik and A. L. Rheingold J. Chem. Soc. Chem. Commun. 1990 1580; (d) M. C. Aversa P. Giannetto G. Bruno M. Cusumano A. Giannetto and S. Geremia J. Chem. Soc. Dalton Trany. 1990 2433; (e) 0. Yamauchi M. Takani K. Toyoda and H. Masuda Inorg Chem.. 1990 29 1856. The Noble Metals [N(CH2CH,PPh2)3M(AsR2)][BPh4] (M = Pd Pt) have been obtained by adding halo arsines AsR2X to zero-valent phosphine complexes.44u The complexes M(MeS2CNMe2)X2 (M = Pd Pt;X = halide) lose methyl halide in DMSO solution to form dithiocarbamate derivatives M( S,CNMe,)( DMSO)X.44h A paper on phos-phoranimine phosphine and arsine ligands includes the X-ray crystal structure of (Hh=PPh2CH2PPh2)bdC1, the first structural example of a phosphoranimine phosphine The trinuclear macrocyclic complexes (15; M = Pd Ni Co; M' = Pd) contain palladium(r1) in a tetrahedral 4s environment.44d (15) M = Ni" Pd" Cu" Co" or Co"'(py)CI M' = Pd" or Cu" X = C1 or NO3 X- Ray crystal structures have been reported for [Pd( Me2[ 181 ane N2S4)]-[PF6I2Me2CO [Pd([18]aneN2S4)][ BPh,], and [Pd2C12([1 8]aneN2S4)][ PF6I2 * 2MeCN (macrocycles 9).44e The polypyridine ligands 2,2' 6',2" 6",2"' quarter pyridine (quarterpy) and 2,2' 6',2" 6",2"' 6"',2"" quinquepyridine (quinquepy) react with { Pd(0,CMe)2}3 to form [Pd(quarterpy)12+ and the double-helical binuclear cation [Pd2( quinquepy)14+ (16) re~pectively.~~" Addition of 4,4'-bipyridyl to Pd(en)- ( NO3) affords the tetranuclear complex [{Pd(en)(4,4'-bipy)}4][N03]8( 17).45hX-Ray crystal structures for the azamacrocyclic complexes [Pd,([ 181 ane N,)C12]- [C1O4I2 (18) and [Pd3([21] ane N,-H)C13][C104]2 (19) reveal a deprotonated secon- dary amino group in the latter.45' Partial coordination of perchlorate is indicated 44 (a) F.Cecconi C. A. Ghilardi S. Midollini S. Moneti A. Orlandini and G. Scapacci J. Chem. Soc. Chem. Commun. 1990 1583; (b) G. Faraglia and S. Stiran Inorg. Chim. Acta 1990 176 67; (c) K. V. Katti R. J. Batchelor F. W. B. Einstein and R. G. Cavell Inorg. Chem. 1990 29 808; (d) V. Ahsen A. Giirek A. Giil and 0. Bek$roglu,'J. Chem. Soc. Dalton Trans. 1990 5; (e) A. J. Blake G. Reid and M. Schroder J. Chem. Soc. Dalton Trans. 1990 3363. 45 (a)E. C. Constable S. M. Elder J. Healy M.D. Ward and D. A. Tocher J. Am. Chem. Soc. 1990 112 4590; (h) M. Fujita J. Yazaki. and K. Ogura J. Am. Chem. Soc. 1990 112. 5645; (r) A. Rencini S. D. Robinson for the palladium(x1) 3,3'-bipyridazine complex [PdL2][C1O4I2 but not for its platinum( 11) analogue.45d Binuclear head-head [Pd2( p-a-pyrid~nato),(en)~][ N0J2 rapidly converts to the head-tail isomer in solution.45e Pyridine-2-thiol (pySH) reacts with PdC12( MeCN) and { Pd(02CMe)2}3 to afford [Pd(pySH),]Cl and Pd2(pyS)4 respectively addition of I2 to the latter product yields Pd412( pyS)6.45f Photogenerated [Pd(CNMe)3]0+ radicals derived from [Pd2(CNMe)6]2+,are rapid and potent reduc- tants for a variety of electron acceptor^.^^" New binuclear palladium( I/I) complexes include (20) (21),466 and (22).46c The palladium(I/x) complex nPh2P PPh2 I I I 1 ArO-Pd-Pd-OAr Ph2 P-PP h 2 AOPh2P PPh2 I1 I I I I CF3C0-Pd -Pd-OC Ph2P-PPh2 0 I1CF) APhlP SCH2Ph I I I I CI-Pd-Pd-Cl PhCH2S-PPh2 (20) (21) (22) [PdCl( Ph2PCH2PPh2)I2 undergoes a novel disproportionation in the presence of PF3 to yield the trinuclear product (23).46d Treatment of PdC12L2 (L = PEt,) with PhN3NHCH2CH2NH2- anions affords the p-amido p-imido complex (24)."6' Trigonal planar coordination has been found for the water soluble alkylation catalyst Pd(PPh,Ar) (Ar = ~?I-C~H$O&).~' A.Bianchi P. Dapporto E. Garcia-Espafia M. Micheloni P. Paoletti and P. Paoli J. Chem. SOC.,Chem. Commun. 1990 1382 (d) H. A. Goodwin D. Onggo B. W. Skelton and A. H. White Aust. J. Chem. 1990 43 1919; (e) K.Matsumoto H. Moriyama and K. Suzuki Inorg. Chem. 1990 29 2096; (f)K. Umakoshi A. Ichimura I. Kinoshita and S. Ooi Inorg. Chem. 1990 29 4005. 46 (a) F. R. Lemke R. M. Granger D. A. Morgenstern and C. P. Kubiak J. Am. Chem. SOC.1990 112 4052; (6) T. E. Krafi C. I. Hejna and J. S. Smith Inorg. Chem. 1990 29 2682; (c) Y. Fuchita K. I. Hardcastle K. Hiraki and M. Kawatani Bull. Chem. SOC.Jpn 1990 63 1961; (d) A. L. Balch B. J. Davis and M. M. Olmstead J. Am. Chem. SOC.,1990 112,8592 (e) S. W. Lee and W. C. Trogler Znorg. Chem. 1990 29 1099. 47 A. L. Casalnuovo and J. C. Calabrese J. Am. Chem. SOC.,1990 112 4324. The Noble Metals 7 Platinum Some platinum complexes are mentioned with their palladium analogues in the preceding section.Dehydrogenation of diethylenetriamine to form the tridentate Schiff base ligand NH,CH,CH=NCH,CH,NH has been observed within the coordination sphere of platinum( IV).,~~ X-Ray crystal structures have been reported for the linear chain platinum(II/Iv) complexes [Pt(en),][PtX,(en),][ClO,] (X = Br I).48bThe reaction of K2[Pt(NO,),] with dilute H2S04 affords K2[Pt2(p-OH),( NO,),] -13H20 and the mixed valence salt K,[ Pt4(P~-O)~( N02)9]3H20 in which a Pt'" (N02)3 unit is 0x0-bridged to three Ptl'( NO2) Unusual C 0-bridging CH2C022- ligands are a feature of the platinum(III/III) acetate complex Cs,[Pt,(p-CH,CO* O),(p-02CMe)2C12]Cl -3H20.48d Stepwise hydrolysis kinetics have been reported for [PtC1,I2- in base49o and for cis-PtC12( NH3) at physiological pH.49b The luminescent T1-Pt unit of the insoluble complex TI,[Pt(CN),] is retained in the soluble derivative (25).49cAn infinite 3D framework (related to PtS) which generates intersecting hexagonal channels of large cross-section has been found for "Me,]-[CUP~(CN),].~~~ The photophysical and photochemical properties of the binuclear platinum(rI/rr) complex anion [Pt2(P2O5H2),I4- continue to be a focus of atten- ti~n.~'"-~ New work on platinum N-donor complexes includes synthesis of (26) 48 (a) F.Schwarz H. Schollhorn U. Thewalt and B. Lippert J. Chem. Soc. Chem. Commun. 1990 1282; (b)J. B. Weinrach S. A. Ekberg S. D. Conradson B. I. Swanson and H. D. Hochheirner Inorg. Chem. 1990 29 981; (c) D. Min R. D. Larsen K. Emerson and E. H. Abbott Inorg.Chem. 1990, 29 73 and 3914; (d) T. Yarnaguchi Y. Sasaki and T. Ito J. Am. Chem. SOC.,1990 112,4038. 49 (a) L. Wu B. E. Schwederski and D. W. Margerurn Inorg. Chem. 1990 29 3578; (6) S. E. Miller and D. A. House Inorg. Chim. Acta 1990 173 53; (c) A. L. Balch and S. P. Rowley J. Am. Chem. Soc. 1990 112 6139; (d) R. W. Gable B. F. Hoskins and R. Robson J. Chem. Soc. Chem. Commun. 1990 762. 50 (a) Y. Huang and B. E. Eichinger Inorg. Chem. 1990 29 565; (b)L. Bar H. Englrneier G. Gliernann U. Klement and K-J. Range Inorg. Chem. 1990 29 1162 and 3630; (c) D. R. Crane and P. C. Ford J. Am. Chem. Soc. 1990 112 6871; (d) T. Yamaguchi Y. Sasaki T. Ikeyarna T. Azurni and T. Ito Inorg. Chim. Acta 1990 172 233. S.D. Robinson the first example of helical chirality in a square planar complex with non-chiral ligands5'" and of (27) a rare example of a hydride stabilized by nitrogen ligand~.~'~ Chiral and meso diastereoisomers of Ph,P(CH,),P( Ph)(CH,),P( Ph)(CH,),PPh,(P,) afford 5-coordinate platinum( 11) hydride and chloride complexes [PtX(P4)][ BF,] (X = H Cl) in which the (P,) coordination approaches New nickel palladium and platinum complexes of 1,2-bis[(diphenylphosphino)methyl]benzene include the binuclear trihydride (28).5' Cross-polarization combined with magic angle spinning affords high resolution solid state I3C and 31P NMR spectra of PtX2(PR3)2 complexes which reveal evidence of distortion from planar it^.^," The electrochemical cleavage of the R-H bond in trans-PtHCl( PEt,) involves formal oxidation of H- to H+ rather than Pt" + Pt1v52bThe reactivity of platinum(I1) .hydroxo hydroperoxo and peroxo complexes towards carbon monoxide and dioxide has been pr~bed.~" The synthesis and X-ray structure of [Pt2(p-OH),( PMe,),][ NO,] have been described.52d Deprotonation of the corresponding triphenylphosphine complex affords the highly basic p-0x0 derivative Pt2(p-0),(PPh3),.LiBF4 in which the lithium is coordinated to two oxygens and two fluorine~.~~~ Deprotonation of the secondary phosphine complexes [Pt{P(CH,CH,PPh,),)( PR,H)][O3SCF3] and [Pt{PhP(CHzCH2PPhz)z}(PR~H)]-[03SCF3] (R = Ph Cy) yields the corresponding terminal phosphido species.53 51 (a) C. Deuschel-Cornioley H. Stoeckli-Evans and A.von Zelewsky J. Chem. SOC.,Chem. Commun. 1991 121; (6) G. Minghetti M. A. Cinellu S. Stoccoro G. Chelucci and A. Zucca Znorg. Chem. 1990 29 5137; (c) P. Briiggeller Znorg. Chem. 1990 29 1742; (d) M. Camalli F. Caruso S. Chaloupka E. M. Leber H. Rimml and L. M. Venanzi Helu. Chim. Acta 1990,73 2263. '* (a)J. A. Rahn L. Baltusis and J. H. Nelson Inorg. Chem. 1990 29 750; (6)L. Chen and J. A. Davies Znorg. Chim. Acta 1990 175,41; (c) F. Porta F. Ragaini S. Cenini 0.Sciacovelli and M. Camporeale Znorg. Chim. Acta 1990 173 229; (d)G. Trovo G. Bandoli U. Casellato B. Corain M. Nicolini and B. Longato Znorg. Chem. 1990 29,4616; (e)W. Li C. L. Barnes and P. R. Sharp J. Chem. SOC., Chem. Commun 1990 1634. 53 A. Handler P. Peringer and E. P. Muller J. Chem.SOC.Dalton Trans. 1990 3725. The Noble Metals Recent work on sulfur/nitrogen ligands has been extended to include their selenium and tellurium analogues and has yielded a range of novel products. These include the complexes Pt(SeSN,)( PR3)2 (Pt(Se,N,)( PR3) ,Pt(TeSN,)( PR3) ,and the cor- responding protonated species [Pt(SeSN,H)( PR3),][ BF4] [Pt(Sy2N2H)-(PR3),][BF4] and [Pt(TeSN,H)(PR3),][BF4] all of which contain PtNXNY metal- locycles (X Y = s Se or Te).54"*b X-Ray crystal structures for the complexes bt{N(R)N(H)C(S)SMe},(R = Pri But) reveal square-planar trans-PtN2S2 chromophores.54' The complexes cis-Pt{Se2P( Se)Ph}( PR3), obtained from cis-PtC12(Pr3) and Ph(Se)PSe,P(Se)Ph in liquid ammonia or THF afford the first examples of molecules containing PtSe2P rings.54d The dithiatetrazocine complex [Pt(1,5-Ph4P2N4S2)(PPh3)l2 has been shown by VT 31P NMR to provide the first example of a metallotropic rearrangement (Scheme 3) involving S N ligand~.~~' The reactions of S4N402 S02C12 and SOC1 with cis-PtCI2( PR3)2 in liquid ammonia afford products of the forms (29) (30) and (31) re~pectively.'~~ The same platinum Ph3P PPh3 PPh3 Scheme 3 H R3P\ /N\/P Pt s / \ /+o R3P N H precursors react with RCH,P(O)(Ph)CH,R (R = COPh) RNHP(O)(Ph)NHR and RNHS(O),NHR (R = H Ph) in the presence of silver(1) oxide to form the metal- locyclic complexes (32) (33) and (34) respectively.54g Platinum( 11) complexes of the new mesocyclic ligand 5-phenyl-1 -thia-5-phosphacyclooctane(35) include the dihalides (36,X = C1 I) and the salt (37).54hX-Ray crystal structures have been (a)P.F. Kelly A. M. Z. Slawin D. J. Williams and J. D.Woollins Polyhedron 1990,9 1567 and 2659; (b) I. P.Parkin and J. D. Woollins J. Chem. SOC.,Dalton Trans. 1990 925; (c) M.Bonamico V. Fares P. Imperatori L. Suber and F. Tarli J. Chem. Soc. Dalton. Trans. 1990 931; (d) I. P.Parkin M. J. Pilkington A. M. Z. Slawin D. J. Williams and J. D. Woollins Polyhedron 1930,9,987;(e)T. Chivers M. Edwards P. N. Kapoor A. Meetsma J. C. van de Grampel and A. van der Lee Inorg. Chem. 1990 29,3068; (s)I. P. Parkin and J. D. Woollins J. Chem. SOC.,Dalton Trans. 1990 519; (g) R. D.W. Kemmitt S. Mason M. R. Moore J. Fawcett and D. R. Russell J. Chem. Soc. Chern. Commun. 1990 1535; (h) S.D.Toto M. M. Olmstead B. W. Arbuckle P. K. Bharadwaj and W. K. Musker Znorg. Chem. 1990 29 691. S. D. Robinson Ph I L2ptq: H R (33) (34) xx \/ Pt /\ I Ph/ ’us Ph reported for the new closo twelve vertex platinaphosphaborane (Me,PhP),-Pt(BloHIoPPh)55a and for [NBzMe3][Pt(Bl0H,,),] which contains B10H,22- frag- ments midway between arachno and nido arrangement^.^^' The ‘A-frame’ complex [Pt2(p-NO)(p-Ph2PCH2PPh2)2C12][ BF,] is the first example with a bridgehead nitrosyl ligand.56a Photolysis of [(Et,P),HPt(p-H)PtH( PEt3),][ BPh,] and [(Et,P),HPt(p-H),Pt( PEt,),][BPh,] affords tr~ns-PtH,(PEt,)~ and [PtH(solvent)- (PEt3),][ BPh4].56h Products obtained by oxidative addition of thiols to Pt2(Ph2PCH,PPh2) include the ‘A-frame’ complex Pt2(p-S)( p-Ph2PCH2PPh2),_ (SBz) .56c Synthesis of the diplatinurn( 1) and triplatinum(I1) complexes (38) and (39) respectively have been described.56d Combined partial hydrolysis and oxidation of the platinum(0) complexes Pt(PF,Ar) affords platinum(I1) products (40) which react further with BF,.Et20 to form (41).56eThe complex Pt{P(CH2CH2CN)3}3 catalyses the addition of PH3 to CH2=CHC@ to form P(CH2CH2CN)3.56f r YR3 -12+ Tt -. ,0’ PPh2 Ph2P-0 \ II PhZP ,o\H /O R3P-P t-Pt-PR3 I I R3p/ Ptb-PPh, FPR3 O-PPh2 (38) 55 (a)S. R. Bunkhall X. L. R. Fontaine N. N. Greenwood J. D. Kennedy and M. Thornton-Pett J. Chem. SOC.Dalton Trans. 1990 73; (b) S. A. MacGregor L. J. Yellowlees and A. J. Welch Acfa Crystallogr.Sect. C 1990,’46 1399. 56 (a) M. Ghedini F. Neve C. Mealli A. Tiripicchio and F. Ugozzoli Inorg. Chim. Acta 1990 178 5; (b) P. Bergamini S. Sostero 0. Traverso and L. M. Venanzi Inorg. Chem. 1990 29 4376; (c) N. Hadj-Bagheri R. J. Puddephatt L. Manojlovic-Muir and A. StefanoviC J. Chem. Soc. Dalton Trans. 1990 535; (d) N. W. Alcock P. Bergamini T. M. Gomes-Carniero R. D. Jackson J. Nichols A. G. Orpen P. G. Pringle S. Sostero and 0. Traverso J. Chem. SOC.,Chem. Cornmun. 1990 980; (e) L. Heuer P. G. Jones R. Schmutzler and D. Schomburg New J. Chem. 1990 14 891; (f)P. G. Pringle and M. B. Smith J. Chem. SOC.,Chem. Commun. 1990 1701. 125 The Noble Metals Me Me ,0-H-0, @ 0 Me !\ /% Me Pt Pt Me Me Me Me F2 (40) Silver The kinetics of oxidation of hydrazinium ion (Ag' catalysed) and of alcohols by ethylenebis(biguanide)silver(111) cations have been in~estigated.~~ The silver( 11) tetraneopentoxyphthalocyanine complex Ag"(TNpc) undergoes electrochemical oxidation to afford [Ag"'(TNpc)]+ and the radical cation [A~"'(TN~c')]~+.~~~ New silver(I) complexes with macrocyclic thioether ligands include [AgL'][ PFJ (L' = 42),s8h[Ag( T~-L~)( q1-L2)][03SCF3] (L2 = 43),58' [Ag2(L3)2][C104]2(L3= 44),5gd and [Ag2( L4)2][BPh4]2 (L4 = 45).58eBinuclear silver( I) complexes [Ag,L][C104]2 have also been reported for a range of bibracchial tetraimine Schiff bases."/ Silver(I) as \ S S \ CSn CJ LJ (43) L' (44) (45) R.Banerjee A. Das and S.Dasgupta 1. Chem. SOC.,Dalton Trans. 1990 1207 and 2271. s8 (a)G. Fu Y. Fu K. Jayaraj and A. B. P. Lever Inorg. Chem. 1990 29 4090; (b) D. Sellmann H.-P. Neuner R. Eberlein M. Moil and F. Knoch Inorg. Chim. Acta 1990 175 231; (c) B de Groot and S. J. Loeb J. Chem. SOC.,Chem. Commun. 1990 1755; (d) C. R. Lucas S. Lui M. J. Newlands J.-P. Charland and E. J. Gabe Can. J. Chem. 1990 68 644; (e) A. J. Blake R. 0. Could G. Reid and M. Schroder J. Chem SOC.,Chem. Commun. 1990 974; (f) H. Adams N. A. Bailey W. D. Carlisle D. E. Fenton and G. Rossi J. Chem. SOC.,Dalton Trans.. 1990 1271. 126 S. D. Robinson carboxylates [Ag,(02CC6H,0H-o)2],59'[Ag2(02CcH20C6H4F-~)2( H202]2 and [Ag2(02CCH20C6H5)2],59b have three different structures based on the carboxylate- bridged Ag2(02CR) unit.The first silver( I) perthiocarboxylates have been described and a tetrahedral arrangement of silver atoms reported for [Ag(S3CC6H4Me-o)] .59c Binuclear structures have been confirmed for the 1,8-naphthyridine complex [Ag2( 1,8-napy)2][C10,]2 59d and the benzamidinato complex [Ag2_ (RN=C(Ph)-NR),] (R = SiMe3).59e However a rhombus of four silver atoms with bridging bis(triazenid0) ligands has been found for [Ag{ PhN3C6H, N3( H)Ph}]4.591 X- Ray crystal structures for the binuclear silver(I) complexes Ag2(02N0)2{Ph2P(CH2),,PPh2}2( 1 or 3) reveal bridging diphosphines and n = weakly chelating nitrato ligand~,~~~ [Ag(p-RN=CH-CH=NR)(03SCF3)], affords the first example of polymeric complexes with this class of bridging ligand.60" Three-coordination has been suggested for the cations of the complex salts [M(PR,R'),]X (M = Cu Ag Au; R R' = Ph Cy C5H9; X = C104 BF,) and has been confirmed for [Ag{PPh2(C5H9)},][ BF4].60b In contrast MeC(CH2PPh2)3AgI has tetrahedral coordination.60' X-Ray crystal structures have been reported for a-tisilver amido selenate Ag,N-Se03 and for the organotelluride anion [A&(TeR),I2-(R = thienyl) 61b the latter species has an Ag tetrahedron with edge-bridging TeR groups.The salt [PPh3MeI2[AgI3] contains a planar trigonal anion.61c X-Ray crystal structure determinations on [AsPh3Me][Ag313Br] 61d and [AsPh4],[Ag&] reveal the polymeric anion (46) and the centrosymmetric anion (47) respectively. Silver(1) in the form of Ag20 or AgN03/NR3 mediates the epoxidation of olefins by iodosylbenzene.61f 9 Gold The new gold tetramethylthiourea (tmtu) complexes [A~(tmtu)~BrJ[ AuBr,] and AuBr(tmtu) have been characterized by X-ray diffraction and infrared spectros- The crystal structure of the dithiolene complex [BU~N][AU(S,C,(CN)~}~] has been reported.62b Attempts to prepare the gold(1Ir) pyrazolato complex [AuCl,(p-3,5-Ph,p~)]~ by treatment of [Au( p-3,5-Ph2pz)l3 with aqua regia afford the AU'~AU~'~ product {Au( p-3,5-Ph2-4-Cl-pz)}3C12 which resists further oxidation.62' The electron transfer properties of the complexes K[AuC14] AuC1(PR3) and 59 (a) E.M. Movsumov A. S. Antsyshkina V. N. Ostrikova K. T. Karaeva and M. A. Porai-Koshits Sou. J. Coord. Chem. 1990 16 281; (b) G. Smith D. S. Sagatys C.A. Campbell D. E. Lynch and C. H. L. Kennard Aust. J. Chem. 1990,43 1707; (c) N. Marsich G. Pellizer A. Camus A. M. Manotti Lanfredi and F. Ugozzoli Znorg. Chim.Acta 1990 169 171; (d) M. Munakata M. Maekawa S. Kitagawa M. Adachi and H. Masuda Inorg. Chim. Acta 1990 167 181; (e) D. Fenske G. Baum A. Zinn and K. Dehnicke Z. Naturforsch Teil B 1990 45 1273; (f)M. Homer A. G. Pedroso C. R. de Menezes Peixoto and J. Beck Z. Naturforsch Teil B 1990 45 689; (g) E. R. T. Tiekink Acta Crystallogr Sect. C 1990 46 235 and 1933. 60 (a) A. M. Arif and T. G. Richmond J. Chem. SOC.,Chem. Commun. 1990 871; (b) A. Baiada F. H. Jardine and R. D. Willett Inorg. Chem. 1990 29 4805; (c) M. Camalli and F. Caruso Inorg. Chim. Acta 1990 169 189. 61 (a)V. Kocman and J.T. Szymahski Can. J. Chem 1990 68 1606 (b) J. Zhao D. Adcock W. T. Pennington and J. W. Kolis Inorg. Chem. 1990,29,4358; (c) G.A. Bowmaker A. Camus B. W. Skelton and A. H. White J. Chem. SOC.,Dalton Trans. 1990 727; (d) G. A. Bowmaker Effendy J. D. Kildea B. W. Skelton and A. H. White Aust. J. Chem. 1990,43,2113; (e) G. Helgesson and S. Jagner J. Chem. SOC.,Dalton Trans. 1990,2413(f) K. A. Jorgensen and E. Larsen J. Chem. SOC.,Dalton Trans. 1990,1053. 62 (a) A. C. Fabretti A. Giusti and W. Malavasi J. Chem. SOC.,Dalton Trans. 1990 3091; (b) J. C. Fitzmaurice A. M. 2. Slawin D. J. Williams and J. D. Woollins Polyhedron 1990 9 1561; (c) R. G. The Noble Metals [Au(PR,),]Cl (R = Et Ph OEt OPh) in non-aqueous media have been investi- gated.62d The kinetics of the replacement of MeOH in trans-[AuCl,Ph(MeOH)] by nucleophiles establish the reactivity sequence NOz-< C1-< Br-< N3-= I-< NCS-< thiourea but the nucleophilic discrimination is less than that observed in other gold( HI) complexes.62e The X-Ray crystal structure of the pyridine-2-thiol complex [Au(pySH),][ClO,] reveals an unprecedented arrangement in which five of the six cations in the unit all are linked by short Au-Au contacts (3.3 A) and the Raptis and J.P. Fackler Znorg. Chern. 1990 29 5003; (d) J. F. Anderson S. M. Sawtelle and C. E. McAndrews Znorg. Chern. 1990 29 2627; (e) E. Ahmed R. J. H. Clark M. L. Tobe and L. Cattalini J. Chern. SOC.Dalton Trans. 1990 2701. S. D. Robinson sixth cation is m~nomeric.~~" Short gold-gold contacts are also a feature of AuBr( PH2 * C6H4Me-2) in the solid state folded chains of gold atoms with alternating Au- Au distances (3.097 and 3.380 A) run through the Electrochemical studies of gold(1) and gold(r1r) diphosphine complexes63c and X-ray crystal structure determinations on the gold(1) species C1AuPh2PCH2AsPh2AuC1 and [Au( Ph2PCH2CH2AsPh2),]C1 63d have been prompted by evidence of anti-tumour activity within this class of compounds.Polynuclear ( Ph2PCH2)2AsPh bridged complexes of gold( 1) (48) (49) and (50) have been obtained from the free ligand and AuC~(SM~~).~~~ The binuclear complex (48) acts as a precursor for the heterometallic complexes (51) and (52).63f The same ligand is encountered in the luminescent Au'Ir' Au' chain complex ( 53).63g The tetradentate phosphine Ph Ph2P As Ph2 P h2 ppAsq P h2 I I 111 Au A' u AII--'-~.~-I I c1 c1 r 1 9-L 2+ L J (Ph2PCH2CH2)3P(PP3) coordinates in 3/ 1 fashion in [Au~(~-PP~)~]C~ and in l/l/l/ 1 fashion in Au4 Cl,(~-?p,).6~~ The linear two coordinate gold(1) complexes AuX(PEt,) (X = C1 Br CN SCN) [AuL(PEt3)]+ (L = SMe, SC(NH2)2 H20) and ( p-S)[Au(PEt3)I2 have been characterized by vibrational and NMR spectros- (a) R.Uson A. Laguna M. Laguna J. Jiminez M. P. Gomez A. Sainz and P. G. Jones J. Chem. Soc. Dalton Trans. 1990 3457; (b) H. Schmidbaur G. Weidenhiller 0. Steigelmann and G. Muller 2. Naturforsch Teil B 1990 45 747; (c) J. V. McArdle and G. E. Bossard J. Chem. SOC.Dalton Trans. 1990 2219; (d) 0.M. N. Dhubhghaill P. J. Sadler and R. Kuroda J. Chem. Soc. Dalton Trans. 1990 2913; (e) A. L. Balch E. Y. Fung and M. M. Olmstead J. Am. Chem SOC. 1990 112 5181; (f)A. L. Balch E. Y. Fung and M. M. Olmstead Znorg. Chem. 1990 29 3203; (g) A. L. Balch V. T. Catalano and M. M. Olmstead J. Am. Chem. SOC.,1990,112,2010; (h)A. L. Balch and E. Y. Fung Inorg. Chem. 1990 29 4764. The Noble Metals The gold thiolate complexes [Au2( p-SCH2Ph)( PPh3),][ NO3] and Au2( p-SPh),C14 dimerize through intermolecular Au- Au interactions to form tetranuclear clusters.64b The packing of dimeric units in Au2( S,CNEt,) produces linear chains of Au atoms with short intermolecular distances (Au-Au 3.004 A).64cThe gold(1) amidinato complex Au,(RN=C(P~)-NR)~ (R = SiMe3) has a short intramolecular Au-Au contact (2.646 A).59eThe structure spectra and redox properties of the luminescent complexes [AuI~C~(CO)(~-P~,PCH,PP~~)~][ PF6] 64d and [Au2(p-Ph2PCH2PPh2),][ PF6I2 64e have been reported.The structure and luminescence of the trinuclear gold( I) complex [Au3{Me2PCH2P( Me)CH2PMe2}2][C104]3 have also been described.64f X-Ray crystal structures have been reported for (C~,P)AU(B,,H,~) Solutions of Au(SO,F) in HS03F 650 and (C~,PAU),(B,H,,).~~~ take up CO to form the linear cation [(OC)Au(CO)]+ which loses CO on removal of solvent to leave the new gold(1) monocarbonyl Au(SO,F)(CO) as a white solid.66a X-Ray crystal structures have been reported for the salts M[Au(CN),] (M = Rb Bu4N or lysidine H).66b*' Gold(1) cyanide complexes Au(CN)(PR,) undergo a reversible ligand scrambling reaction to form [Au( PR3)2]+ and [Au(CN),]-.~~~ The preference for two-coordination in gold( I) chemistry is strengthened by relativistic effects.66e Gold metal dissolves in polybenzimidazole solution under extremely mild aerobic conditions to form a polymeric 'gel' with gold(1) and gold (111) cations bridging between polymer chains.67 64 (a) M.M. El-Etri and W. M. Scovell Inorg. Chem. 1990,29,480; (b)S. Wang and J. P. Fackler Znorg. Chem. 1990 29 4404; (c) D. D. Heinrich J.-C. Wang and J. P. Fackler Acta Clystallogr. Sect. C 1990 46 1444; (d) A. L. Balch V. J. Catalano and M. M. Olmstead Znorg. Chem. 1990 29 585; (e)C.-M. Che H.-L.Kwong C.-K. Poon and V. W.-W. Yam J. Chem. SOC.,Dalton Trans.1990 3215; (f)V. W.-W. Yam T.-F. Lai and C.-M. Che J. Chem. SOC. Dalton Trans. 1990 3747. 65 (a) A. J. Wynd A. J. Welch and R. V. Parish J. Chem. Soc. Dalton Trans. 1990,2185; (b)A. J. Wynd and A. J. Welch J. Chem. Soc. Dalton Trans. 1990 2803. 66 (a) H. Willner and F. Aubke Znorg. Chem. 1990 29 2195; (6) R. J. Schubert and K.-J. Range 2. Naturforsch Teil B 1990 45 629 and 1118; (c) A. H.Schwellnus L. Denner and J. C. A. Boeyens Polyhedron 1990,9,975; (d) A. L. Hormann-Arendt and C. F. Shaw Znorg. Chem. 1990,29 4683; (e) P. Schwerdtfeger P. D. W. Boyd A. K.Burrell W. T. Robinson and M.J. Taylor Znorg. Chem. 1990 29 3593. 67 G. Xue P.Wu Z. Bao J. Dong and R. Cheng J. Chem. Soc. Chem. Commun. 1990,495.

ISSN:0260-1818    

DOI:10.1039/IC9908700105

出版商:RSC    

年代:1990

数据来源: RSC

摘要:

7 Fe Co Ni By S. A. COlTON Felixstowe College Felixstowe Suffolk IP11 7NQ 1 Introduction These elements have remained a very active area of research so that particularly in order to give coverage of 1989-90 it has been necessary to be selective in choosing material. The material has been grouped by ligand/topic and each area is then subdivided by metals. Emphasis throughout is on studies on compounds isolated in the solid state. 2 Simple Binary and Coordination Compounds of Oxygen Nitrogen and Halogen Donors A highlight is the synthesis of FeI ,unobtainable hitherto by conventional methods. It was obtained’ in 10-15 mg quantities by the reaction hexane Fe(CO),I + $I2 7FeI + 4CO The resulting very reactive black solid gives a deep purple solution in CH2C12 but is decomposed both by light and donor solvents.It is (understandably) difficult to obtain pure but Mossbauer and magnetic data suggest that it contains four- coordinate iron (HI),with peff-5.9~~. The reaction of FeI with the stoichiometric amount of I and thiourea (tu) affords black pseudo-tetrahedral (X-ray) FeI,.tu reduced by excess ligand2. Other complexes394 with this geometry are FeC1,eTHF and FeC13[0=P(C6H2(0Me)3]; previously it had been well-characterized only for FeX4- of which family Et4N+ (FeC1,X)- (C = C1 Br) have been characteri~ed.~ Several fluoroferrates in a variety of oxidation states have been studied colourless CsFeF has the BaTiO structure6 and M,FeF (M = NH,,K,iBa) have FeF octahedra showing truns-corner~,~ Rb2[ FeF,(OH,)] has isolated octahedra’ whilst the iron(1v) compound CS2FeF6 has the K2MnF structure.’ Study of FeCI solutions ’ K.B. Yoon and J. K. Kochi Inorg. Chem. 1990 29 869. * S. Pohl U. Bierbach and W. Saak Angew. Chem. 1989 101 796. ’ F. A. Cotton R. L. Luck and K. Son Acta Crystallogr. Sect. C 1990 46 1424. K. R. Dunbar S. C. Haefner and A. Quillevere Polyhedron 1990 9 1695. D. J. Evans A. Hills D. L. Hughes and G. J. Leigh Acta Crysfallogr. Sec. C 1990 46 1818. R. Hoppe and G. Benner 2. Anorg. Allg. Chem. 1990 580 50. ’J. L. Fourquet and H. Duroy Eur. J. Solid State Inorg. Chem. 1989 26 413; J. L. Fourquet A. Le Bail H. Duroy and M. C. Moron ibid. 1989 26 435; A. Le Bail A. Desert and J. L. Fourquet J. Solid State Chem. 1990 84 408. €3. Wallis V.Beutrup and G. Reck Eur. J. Sold Sfate Inorg. Chem. 1990 27 681. Yu. M. Kiselev N. S. Kopelev Yu. D. Perfil’ev and Y. F. Sukhoverkhov Zh. Neorg. Khim. 1990 35 1704. 131 132 S. A. Cotton continues” with Raman spectra over the range 25-300 cm-’ detecting only FeC1,- and FeC12( H20),+. Fe(OH2)6SnF6 has the expected octahedral coordination” of iron with hydrogen-bonding between the coordinated water and fluorines of the anions. There is interest in making iron oxide (Fe203 and Fe,O,) films for e.g. in magnetic recording tape by decomposing compounds such as Fe(acac) either in an oxygen plasma or as a coating in a suitable solvent.12 Fe(Ph3PO),’+ reacts with oxidizing agents to form13 the binuclear [(Ph3P0),FeO2Fe(OPPh3);+]; X-ray diffraction c~nfirms’~ the structure of Fe( Ph3PO),C12+FeCl,- which along with related compounds reacted with SO2 forming” [Fe( Ph,QO),( S02X)2]+FeX4- (Q = P As; X = C1 Br).The structure of Fe(Hedta)(H,O) has been redetermined with some changes in Fe-0 distances.16 There has been an enlightening ESR study” of ‘FeO,’ tris chelates of ligands like oxalate; spectra show dependence on counter- ion degree of hydration and in some cases temperature but excellent agreement was obtained with simulated spectra using D values in the range 0.045-0.20 cm-’ and A values surprisingly in the range 0-0.31 (caveat emptor). Charge-density X-ray diffraction experiments18 on Cs2KFe(CN) describe the bonding in near- octahedral Fe(CN):- in terms of a loss of 1.4e- from Fe3+ by t2,-to-CN back bonding and a gain of 1.Oe- by CN to egu bonding; the ground state splitting is over 200cm-’.NMR CMR and ESR of the low spin Fe(en)(CN),- and [FeMe(H)N.CH,CH,N( H)Me)(CN),]- permit separation of the isotropic shifts into Fermi contact shifts and dipolar shifts.” Two monomeric FeC13 complexes with N-donors have been characterized. FeC13[ bis( benzimidazol-2-yl-methyl)amine] adopts a N3C13 mer-octahedral structure with irregular Fe-Cl distances2’ whilst FeCl [2,6-bis[N-(2-pyridylethyl)iminomethyl]-4-methylphenoxy]has a FeC130N2 coordination sphere.20 Structures have been re~orted~l-~ for Co(H20),(X) (X = BrO, PhS03 SiF,); octahedral coordination is also found2 in CoSO (and NiSOJ. [Co( PMe3),]+BPh4- reacts25 with O2in MeCN to form [Co( Me,PO),( MeCN),]( BPh4)2 via an intermedi- ate [Co(PMe3),02]+ ( 880 cm-’).The structure of tetrahedral CoC12( Me,PO) has been determined2 and electronic spectra of [Co( M~P~,ASO)~( N03)]+N0,- interpreted in terms of a new ligand field 10 K. Murata D. E. Irish and G. E. Toogood Can. J. Chem. 1989 67 517. I’ A. Benghalem M. Leblanc and Y. Calage Acfa Crystallogr. Sect. C 1990 46 2453. l2 Chem. Abstr. 1989 110 164 887; 1989 111 69 536 166 030. l3 D. T. Sawyer M. S. McDowell L. Spencer and P. K. S. Tsang Inorg. Chem. 1989 28 1166. 14 E. Durcanska T. Glowiak J. Kozisek I. Ondrejkovicova and G. Ondrejovic Acta Ctystallogr. Secf. C 1989 45 410. l5 B. Beagley D. G. Kelly P. P. MacRory C. A. McAuliffe and R. G. Pritchard J. Chem. SOC. Dalton Trans.1990 2657. 16 T. Mizuta T. Yamamoto K. Miyoshi and Y. Kushi Inorg. Chim. Acta 1990 175 121. ” D. Collison and A. K. Powell Inorg. Chem. 1990 29 4735. l8 B. N. Figgis E. S. Kucharski J. M. Raynes and P. A. Reynolds J. Chem. SOC.,Dalton Trans. 1990,3597. 19 Y. Kuroda M. Goto and T. Sakai Bull. Chem. SOC. Japn. 1989 62 3614. 20 (a) M. Mikuriya K. Kushida H. Nakayama W. Mori and M. Kishita Inorg. Chim. Acta 1989 165 35; (b) H. Adams N. A. Bailey J. D. Crane D. E. Fenton J. M. Latour and J. M. Williams J. Chem. SOC. Dalton Trans. 1990 1727. 21 A. C. Blackburn J. Gallucci and R. E. Gerkin Acra Crystallogr. Sect. B 1990 46 712. 22 V. A. Jeronimo L. A. Guerrero M. A. Santos G. A. Ramirez An. Quim Sec. B 1988 84 194. 23 G. Cherrier and R. Saint-James Acta Crystallogr.Sect. C 1990 46 184. 24 M. Wildner Z. Kristallogr. 1990 191 223. 25 M. Dartiguenave Y. Dartiguenave M. J. Oliver and A. L. Beauchamp J. Coord. Chem. 1990,21,275. 26 M. J. Menu M. Simard A. L. Beauchamp H. Koenig M. Dartiguenave Y. Dartiguenave and H. F. Klein Acta Crystallogr. Sect. C 1989 45 1697. Fe Co Ni 133 scheme.27 Some Co(N03),(R3P0) complexes have been studied by XPES.28 Co-59 NMR studies made on some cobalt(r1) dike ton ate^,^ whilst cobalt(II1) acetate has been re-examined and shown to consist of a mixture of species mainly ~xo-centred.~' Co-59 NMR spectra have been used to optimize the synthesis3' of Co(imi-da~ole)~(ClO~)~ by oxidation of the Co" analogue. Among cobalt ammines the preparation of K[ cis-Co( NO2),( NH3),] by ammoniolysis of Na,Co( com-pletes the nitro-ammine series;, X-ray analysis shows some close nitro oxygen contacts., Study of [Co( NH,),C03](C03)-H20 shows ammonia to have a stronger trans-effect than carbonate.33 Another liquid ammonia synthesis reacted KNH with CO(NH3)6(ClO4)3 to afford34 [(NH,),CO(NH,),CO(NH~)~]~+, the first complex with a triple amido bridge (1).Improved syntheses of C~(en),~+ have and C~(bpy),~+ H2 N been described,35 using chlorine as the oxidant. Various ethylenediamine complexes have been structurally characterized,3638 including [Co( en),hfac]C104 [Co(en),L]+ (L = a-or P-cyclodextrin) and cis-[Co(en),(NO,),]~NO,-; in the last named the cations are in the lowest energy state unlike previous studies. The cation of [Co(en)(tn)(tmd)]Co(CN) [tn = NH2(CH,),NH2; tmd = NH,(CH,),NH,] is unusual in having 5 6- and 7-membered metal-chelate rings.39 The cation [Co(en),( H,O)(CO0H)l2+ has been reinvestigated and characterized4' as the ester trans-[Co(en),(CF3C02)(cooEt)]+PF6-. At pH > 5 the latter is present in solution as [Co(en),(OH)(CO,Et)]' which undergoes slow ester hydrolysis.[Co(tren)X]ClO (tren = N,N-bis(2-aminoethyl)ethane-1,2-diamine;X = H2P207 H3P3010) have been made4' and the structure of the first-named determined. Hydrolysis of the phosphate groups is facilitated by 'assisting' complexes probably via phosphate bridges. [Co(tren)( N02)2]CI has4 a very similar cis-N-Co-N geometry to that in Co(tren)CO,+ contrasting to that in the corresponding 1,4,7,11 -tetraaza-cyclo- decane; this may be related to their ability to hydrolyse phosphate diesters.Other 27 N. D. Fenton and M.Gerloch Inorg. Chem. 1989 28 2975. 28 C. A. Strydom and H. J. Strydom Inorg. Chim. Acra 1989 159 191. 29 S. C. Busse and E. H. Abbott Inorg. Chem. 1989 28 488. 30 A. B. Blake J. R. Chipperfield S. Lau and D. E. Webster J. Chem. SOC. Dalton Trans. 1990 3719. 3' G. Navon and R. Panigel Inorg. Chem. 1989 28 1405. 32 T. Fujihara K. Yamanari and S. Kaizaki Chem. Lett. 1990 1679. 33 I. Bernal and J. Cetrullo Srruct. Chem. 1990 1 227. 34 W. Frank K. Hoffman and L. Heck Angew. Chem. 1990 102 1178. 35 D. C. Jackman and D. P. Rillema J. Chem. Educ. 1989 66 343. 36 W. Purcell J. G. Leipoldt and Y. Kitamura Inorg.Chim. Acta 1990 177 151. 37 K. Yamanari M. Nakamichi and Y. Shimura Inorg. Chem. 1989 28 248. 38 I. Bernal J. Cetrullo and S. Berhane Struct. Chem. 1990 1 361. 39 H. Tahazawa S. Ohba Y. Saito H.Ichida and K. Rasmussen Acra Crystallogr. Seer. C 1990,46,2354. 40 N. E. Katz D. J. Szalda M. H. Chou C. Crevtz and N. Sutin J. Am. Chem. SOC. 1989 111 6591. 41 L. M. Engelhardt E. A. Keegan G. A. Lawrence and A. H. White Aust. J. Chem. 1989 42 1045. 42 J. Chin M. Drovin and A. G. Michel Acta Crvsfallogr.,Sect. C 1990 46 1022. 134 S. A. Cotton amine complexes studied included43 [Co(tren)( salicyclaldehyde)12+ and [Co(tetraa~adecane)salicylaldehyde]~+; a number of complexes of substituted quin- quepyridines have been madeM of the type CoLCI and (CoL2)Xz (X = PF6 C104) -CoL2C12 exhibits 7-coordination with the ligand wound helically round (2) the 6 (2) (Reproduced by permission from Inorg.Chem. 1990 29 1589) cobalt. An improved synthesis has been given45 for the isomers of tris(g1ycinato) cobalt and the crystal structure determined46 (both isomers were present in the crystal); similarly all three geometric isomers of bis( [L-methioninato) cobalt( 111) have been examined structurally4’ (3). Tris(P-aminoethanolato) and tris(2- pyridinethiolato) cobalt49 have been characterized as the fuc-and mer-isomers 0 trans-S trans-N trans-0 (3) respectively. The structure of C~(dien),(ClO~)~ has been determined” and interest in amino-acid complexes continue^.^"^^ Chloro( nitrilotriethanolato) cobalt( 11) has a monomeric tbp structure with quadridentate triethan~lamine.~~ The cellular ligand- 43 E.Toyota and Y. Yamamoto Brell. Chem. Soc. Japn. 1989 62 3817. 44 K. A. Gheysen K. J. Potts H. C. Hurrell and H. D. Abrurna Inorg. Chem. 1990 29 1589. 4s G. B. Kauffman M. Karbassi and E. Kyuno Inorg. Synth. 1989 25 135. 46 J. C. Dewan Acta Crystallogr. Sect. C 1988 44 2199. 47 T. W. Harnbley Acra Crystallogr. Sect. B 1988 44,601. 48 A. P. Gulya Yu. V. Kokuvnov. J. G. Shova M. D. Mazus V. F. Rudik E. N. Kiryak and Yu. A. Buslaev Dokl. Akad. Nauk SSSR 1989 305 627. 49 E. C. Constable C. A. Palmer and D. A. Tocher Inorg. Chim. Acta 1990 176 57. 50 M. D. Mazus V. A. Neverov and T. I. Malinovskii Koord. Khim.1990 16 117. ” A. P. Arnold and W. G. Jackson Inorg. Chem. 1990 29 3618. 52 M. J. Jun Y. B. Park and S. R. Choi Polyhedron 1989 8 1205. 53 A. Radha M. Seshasayee V. Kumar and G. Aravanmudan Acta Crvstallogr. Sect. C. 1989 45 882. Fe Co Ni 135 field approach has been applied to two types of complex one with pseudo-tetrahedral CoN2C12 chromophores the other with tbp CON~X,~~ as well as the nickel analogues. Co(pyO)C12.H20 has a polymeric chain structure with both pyridine N-oxide and chloride bridging in order to attain octahedral c~ordination.~~ Cobalt(111) complexes of:the tridentate (0,N) ligand N-(2-hydroxyphenyl)salicylamideare oxidized chemi- cally or electrochemically to cobalt( IV) complexes.56 Octahedral Ni(OH2)62+ ions have been structurally characterized in the ~hlorate,~~ br~mate,~~ benzenesulph~nate~~ and salts.Distorted octahedral coordination with bidentate nitrates is found6' in Ni( Ph,AsO),( NO3) whilst Ni( Me,POCH,NH2)3C12.3H20 has fac-N303 coordination of nickel.61 Nickel (ethy- lene glycolate) Ni(OCH2CH20) has been assigned a Ni(OH) type structure;62 the related Ni(OCH2CH20Et) reacts with Ti(OCH2CH20Et) on heating to form NiTiO .63 At last Ni(~y)~( NO3) has been characterized by X-ray diffraction; 6-coordination is obtained with one monodentate and one bidentate nitrate.64 Single- crystal polarized electronic spectra are available65 for Ni(py),C12 and Ni(q~in)~Cl,. NiCl,,-ions have been characterized as PPh4 and Na( 15-crown-5)~alts.~~ Among continuing activity on complexes of bidentate amines perhaps the most interesting report6' is that NiL3,+ (L e.g.en pn etc.) are oxidized by chlorine to unstable orange NiL33+; some are stable for a few weeks in a glove-box. EXAFS measurements suggest a very slight shortening of Ni-N distance on passing from Ni" to Nil". Two paper^^'-^^ have described thermal induced isomerization of complexes of the type NiL2( NO3),. n H20 (L = N,N-dimethyl-1,2-ethanediamine)and NiLi( NCS) (L' = N-methylpropane-l,3-diamine),including the structure of cis-NiL:( NCS),; others have examined complexes of nickel with purine and pyrimidine bases7' and n~cleotides,~' like [Ni(en),(adenine)]C12 and [Ni(en)( L)( H20),] (L = 5-GMPH 5-IMPH) all involved octahedral coordination. Attempted Schiff-base formation between en and PhCOCH2COPh in the presence of Ni2+ failed 6-coordinate ci~-Ni(PhC0CHC0Ph)~(en) being obtained instead.' Bis(cis-1,2-cyclo-54 N.D. Fenton and M. Gerloch Inorg. Chem. 1990 29 3718 3726. 55 M. Nieuwenhuyzen W. T. Robinson and C. J. Wilkins Polyhedron 1990 9 2315. 56 M. Koikawa M. Gotoh H. Okawa S. Kida and T. Kohzuma J. Chem. SOC.,Dalron Trans. 1989 1613. 57 J. C. Galucci and R. E. Gerkin Acra. Crystallogr. Sect. C 1990 46 350. 58 J. C. Gallucci R. E. Gerkin and W. J. Reppart Acra Crystallogr. Secr. C 1990 46 1580. 59 S. E. Groh P. J. Riggs C. J. Baldacchini and A. L. Rheingold Inorg. Chim. Acta 1990 174 17. 60 C. M. de P. Marques and K. Tomoita J. Coord. Chem. 1990 21 367. 6' N. Dodoff J. Macicek 0.Angelorva S. Varbanov and N. Spassovska J. Coord. Chem. 1990 22 219. 62 K. Tekaia-Elhsissen A. Delahaye-Vidal G. Nowogrockii and M. Figlarz Compr. Rend. Acad. Sci. Sect. 2 1989 309 469. " F. Schmidt and A. Feltz Z. Chem. 1990 30 228. 64 J. L. Atwood S. G. Bott and R. L. Vincent J. Crystallogr. Specrrosc. Res. 1990 20 631. 65 M. M. Seifollahi and J. R. Perumareddi Polyhedron 1970 8 2283. 66 K. Ruhlandt-Senge and U. Muller Z. Naturforsch Teil B 1990 45 995. 67 J. Evans W. Levason and R. J. Perry J. Chem. SOC.,Dalton. Trans. 1990 3691. 68 S. Koner A. Ghosh and N. R. Chaudhuri J. Chem. SOC.,Dalton Trans. 1990 1563. 69 A. K. Mukherjee M. Mukherjee S. Ray A. Ghosh and N. R. Chaudhuri J. Chem. SOC. Dalron Trans. 1990 2347. 70 J. Cervantes J.J. Fiol A. Terron V. Moreno J. R. Alabert M. Aguilo M. Gomez and X. Solaus Inorg. Chern. 1990 29 5168. 7' J. J. Fiol A. Terron A. M. Calafat V. Moreno M. Aguilo and X. Solaus J. Inorg. Biochem. 1989,35 191. 12 A. J. Jircitano R. F. Henry and R. R. Hammond Acra Crwallogr.. Secr. C 1990 46 1799. 136 S. A. Cotton 0 (Reproduced by permission from Znorg. Chirn. Acta 1990 174 263) hexanediamin0)nickel chloride is square planar.73 Among complexes of connected pyridine rings [Ni(4-pheny1-terpy),]Cl2-10H2074and dimeric Ni(terpy)( N3),-2H20 (4) both feature distorted octahedral coordination the latter showing a ferromagnetic interaction.75 [Ni(quaterpyridine)( MeCN),]( PF6)2 has axial acetonitriles with the tetra-dentate ligand occupying the equatorial sites76 and [Ni( quinquepyridine)- [OAc)](PF6),.3MeCN has a double-helical structure (Figure 1) with non-equivalent nickels both ~ctahedral.~' Terpyridine coordinates meridionally as does diethyl- enetriamine (L) in several complexes7s Ni( dien),X,.n H20 (X = NO3 CF3S03C103BF4). The structure of the octahedral Ni"' complex trans-dibromo( 1,4,8,1 l-tetrazaundecane) nickel( 111) perchlorate has been determined.79 Three have reported complexes of mixed (N S) donors with nickel (and also cobalt). When Ni(tren)Cl reacts with NaMNT (MNT = 1,2 S2C2(CN),) the products2 is Ni(tren)22+ Ni( MNT)22- rather than exhibiting mixed coordination to the same nickel ion. Complexes of tertiary phosphines.-A long-overdue reinvestigations3 of iron( 111) complexes of tertiary phosphines has led to the isolation of FeC13(PR3)2 (R = 73 S.Garcia-Girauda M. R.Diaz and F. Gomez-Beltran Acra Crystallogr. Sect. C 1991 47 181. 74 E. C. Constable J. Lewis M. C. Liptrot and P. R. Raithby Inorg. Chim. Ada 1990 178 47. 75 M. I. Arriortua A. R.Cortes L. Lezam T. Rigo X.Solaus and M. Font-Bardia Inorg. Chim. Acta 1990 174 263. 76 E. C. Constable S. M.Elder J. Healy and D. A. Tocher J. Chem. SOC.,Dalton Trans. 1990 1669. 77 E. C. Constable M. D. Ward M. G. B. Drew and G. A. Forsyth Polyhedron 1989 8 2551. 78 S. Koner A. Ghosh and N. R. Chaudhuri Transition Me?. Chem. 1990 15 394. 79 J. C. A. Boeyens and E. L. Oosthuizen J. Crysrallogr. Spec. Res. 1990 20 617. 80 E. Bouwman C. E. Westheide W. L.Driessen and J. Reedijk Inorg. Chim. Acra 1989 166 291. 81 M. A. Turner W. L. Driessen and J. Reedijk Inorg. Chem. 1990 29 333). 82 G. J. Colpas M. Kumar R. Day and M. J. Maloney Inorg. Chem. 1990 29 4779. 83 J. D. Walker and R. Poli Inorg. Chem. 1989 28 1793. Fe Co Ni 137 (a) (b) Figure 1 (a) Crystal structure of one enantiomer of [N~,(QP),(OAC)][PF,]~. (b) Space-filling depiction of the cationic core of [Ni,(QP),(OAc)][ PF,] emphasizing the double helical geometry (Reproduced by permission from Polyhedron 1989 8 2551) Me Ph cyclo-C,H,,) the first two have tbp structures (X-ray) but differing magnetic properties (R = Ph S = 2; R = Me S = 5)The Me,P complex has much shorter Fe-P bonds than the PPh3 complex (2.335 A uersus 2.64 A); it is unexpectedly ESR silent.Spin equilibria are suggested for the PMe3 and Pcy systems. With the bulky phosphines 1:1 complexes FeCl,-PR (R = But cy) have been ~btained,'~ evidently pseudotetrahedral (X-ray for PBu,'). The low-spin six-coordinate FeCl,( PMe3) has been detected8 in solution by ESR. Another iron(II1) complex to be ~haracterized~~ crystallographically is Fe(Me2P.CH2.CH2PMe2)2C12+FeC14-. Iron( 11) phosphine complexes are much better established; current interest in hydride complexes motivates much present Thus FeH,( PR3)4 (PR3 = P(OEt) PPh(OEt),) affords FeH( q2-H,)( PR3)4+ on protonation;86 this in turn undergoes substitution of the dihydrogen ligands by various Lewis bases L forming FeHL(PR,),+ (L = CO RNC RCN PR3):FeH4(PR3) (PR = PEtPh,) is87 Fe( H)2( q2-H2)( PR,),; with N2 it forms Fe( H),N,( PR,) .The dihydrogen complex has the structure (5)with Fe-H 1.538 8 (trans to H2) and 1.514 8 (trans to PEtPh2); the H2 ligand has an unusual staggered orientation relative to the Fe-H add Fe-P axes. Turning to bidentate phosphines two gro~ps~~,~~ have examined the reduction of FeCl,(R2PCH2CH2PR2) to FeHCl(P-P) (P-P = R2PCH2CH2PR2; R = Me Et Ph etc.) FeH,(P-P) and FeH(H,)( P-P)2+. 84 J. D. Walker and R. Poli Inorg. Chem. 1990 29 756. 85 L. D. Field A. V. George and T. W. Hambley Polyhedron 1990 9 2139. 86 G. Albertin S. Antoniutti and E. Bordignon J. Am. Chem. SOC.,1989 111 2072. 87 L. S. Van der Sluys J. Eckert 0. Eisenstein J. H. Hall J. C. Huffman S. A. Jackson T. F. Koetzle G.J. Kubas P. J. Vergamini and K. G. Caulton J. Am. Chem. SOC. 1990 112 4831. 88 M. V. Baker and L. D. Field J. Orgnnometallic Chem. 1988 354,351; M. V. Baker L. D. Field and D. J. Young Appl. Organomef.Chem. 1990 4 551. 89 E. P. Cappelani P. A. Maltby R. H. Morris C. T. Schweitzer and M. R. Steele Inorg. Chem. 1989 28 4431. 138 S. A. Cotton (5) (Reproduced by permission from J. Am. Chem. SOC.,1990 112 4831) The cis and trans-dihydrides have been studied by NMR; the cis isomers are fluxional. cis-FeH,(P-P) (R = Me) activates amide N-H bonds.” Borohydrides with unsupported borohydride bridges have been made” the most stable of these compounds FeH(P-P),EH4 has R = Me. FeH,(H,)(P-P)’ reacts with mercaptans (RSH) to form complexes FeH(RS)(P-P) and Fe(RS),(P-P) both of which exist in solution as cis-and trans-isomers.The structure of Fe(SCH,CH,S)(P-P) has been determined.92 FeH,( PP,) (PP = P(CH2CH,CH,PMe2)3) is cis-octahedral; on protonation it forms a fluxional trihydride which low-temperature NMR93 shows to be FeH(q2-H2)(PP3)+. The related tetradentate ligand PP (PP; = P(CH2CH2PPh2),) affords the analogous [FeH( H,)( PP$)]+BPh4- cis-octahedral in the solid state and in solution at low temperatures but tbp at ambient tem~erature.~~ This complex ion is a selective catalystg5 for the hydrogenation of terminal alkynes to alkenes. Redox properties of PP,’ complexes of iron and cobalt have been studied electrochemically and claimed to be a diagnostic tool to distinguish between H and (7’-H,) complexe~;~~ some paramagnetic hydrides have been isolated and studied by ESR.[Co( PMe3)4]+BPh4- has a distorted tetrahedrally coordinated cation.97 CoH( N2)- (PPh3)3 has been shown9* to be an active catalyst for olefin isomerization and C-H 90 D. R. Schaad and C. R. Landis J. Am. Chem. SOC.,1990 112 1629. 91 M. V. Baker and L. D. Field Appl. Organomet. Chem. 1990 4 551. 92 S. E. Boyd L. D. Field and T.W. Harnbley Inorg. Chem. 1990 29 1496. 93 N. Barnpos and L. D. Field Inorg Chem. 1990 29 587. 94 C. Bianchini M. Peruzzini and F. Zanobini J. Organomet. Chem. 1988 354,C19. 95 C. Bianchini A. Meli M. Peruzzini F. Vizza F. Zanobini and P. Frediani Organometallics 1989,8,2080. 96 C. Bianchini F. Laschi M. Peruzzini F.M. Ottaviani A. Vacca and P. Zanello Inorg. Chem. 1990 29 3394. 97 L. C. Ananias de Carvalho Y. Peres M. Dartiguenave Y. Dartiguenave and A. L. Beauchamp Acta Crystallogr. Sect. C 1989 45 159. 98 M. Brock and A. Heesing Chem Ber. 1989 122 1925. Fe Co Ni 139 bond activation; CoH(CO)(Pcy,) has a tbp structure99 with axial hydride and phosphine; the equatorial carbonyls leaning towards the hydride. Photoreduction of Co(acac) under a CO atmosphere in the presence of phosphines"' traps sub- stituted carbonyl species like [Co(CO)( o-C6H4( PPh2)2]2+PF6- (tbp equatorial co); similar reactions have been carried out with iron Ligand-field irradiation of solutions of cis-[CoCl,( R2PCH2CH,PR,),]+ (R = M~Bu).[COC~,(M~,P(CH,)~PM~~)~]+ and CoCl( H,O)[ Me2PCH2CH2PMe2],+ causes isomerization to the trans- form."' In the presence of (PhPCH,),CMe(tppme) Co(BF4) reacts" with a mixture of PAs3S3 and P2As2S3 forming (tppMe)Co(AsQS)+BF,- (Q = P As) as a mixture in the crystal.The binuclear low-spin species [Co(tppme)N,],( BPh4) has been charac- terized; lo3 the cations contain square-pyramidal Co" ions. One of the most interesting reports is that Co[Ph,P(CH,),PPh,]X (n = 4,5; X = C1 Br) are oxidized by NOX to Co[ Ph2P(CH2),PPh2]X3 -unusual cases of 5-coordinate cobalt( 111);~'~they have magnetic moments of 3pB,putting them into the rare category of paramagnetic Co"' compounds. Nitrosyl complexes Co(NO),(P-P)+ (P-P = alkyl or aryl- substituted ditertiary phosphine) have been rnade,lo5 formed by disproportionation of Co(NO)(P-P),+.The structures of a number of significant nickel complexes have been determined. For example Ni( PPh,) has trigonal-planar nickel the structure showinglo6 the close approach of three o-phenyl hydrogens to the nickel (2.74-3.09A) with implications for ortho-metallation; Ni( dppe) has distorted tetrahedral coordination of nickel.'" The structures of the 'classic' complexes NiX2(PPh3) (X = C11°8 I1O9) have been determined and confirm (distorted) tetrahedral geometries. (See Table 1 Table 1 Structures of Nix,( PPh,) X C1 Ni-P(A) 2.3180 Ni-X (A) 2.2075 Br 2.33 2.34 I 2.382 2.5307 for comparative distances for the Nix2( PPh,) family.) Ni(dppe)Br was synthe- sized"' by heating NiBr2(Ph2P.CH=CH,) in butanol at 135 "C in a reaction involv- ing successive Michael reversion and addition reactions; nickel is square-planar four-coordinate as in Ni(dppe),(NO,) and Ni( ~~S-P~PCH=CHPP~,),(C~O,)~ .ll1 The binuclear (NiC12)L (L = Et,P(CH,),( Ph)PCH,P(Ph(CH,),PEt)) has been studied for both meso and ruc forms of the ligand nickel being square-planar in 99 J.S. Leigh and K. H. Whitmire Acta Crystallogr. Sect. C 1989 45 210. 100 J. T. Lin S. Y. Wang S. K. Yeh and Y. L. Chow J. Organomet. Chem. 1989 359 C17. 101 K. Oguni T. Ohishi M. Kita K. Kashiwabara and J. Fujita Bull Chem. SOC.Japn. 1989 62 588. 102 M. DeVaira P. Stoppioni and M. Peruzzini J. Organomet. Chem. 1989 364 399. 103 A. Bencini C. A. Ghilardi S. Midollini and A. Orlandini Inorg. Chem. 1989 28 1958. 104 W.Levason and M. D. Spicer J. Chem. Soc. Dalton Trans. 1990 719. 10s A. Del Zotto A. Mezzetti and P. Rigo Inorg. Chim. Acta 1990 171 61. 106 D. G. Dick D. W. Stephan and C. F. Campana Can. J. Chem. 1990,68,628. 107 H. Hartung U. Baumeister B. Walther and M. Maschmeier Z. Anorg. Allg. Chem. 1989 578 177. I08 L. Brammer and E. D. Stephens Acta Crystallogr. Sect. C 1989 45 400. 109 R. W. Humphry A. J. Welch and D. A. Welch Acta Crystallogr. Sect. C 1988 44 1717. 110 J. A. Rahn A. Delian and J. H. Nelson Inorg. Chem. 1989 28 215. Ill . A. F. Williams Acta Crystallogr. Sect. C 1989 45 1002. 140 S. A. Cotton A series of nickel hydrides trans-NiH(X)( Pcy,) has been ~tudied"~ for a wide range of X (X = Me Ph CN SCN OR SR OCOR etc.).The hydride ligand is abstracted by Me1 (in C-donor derivatives) and also inserts CO; with more strongly bound hydride (trans-to S 0)no such reactions occur. There is a correlation between vNi-H and the hydride shift in the NMR spectrum. (MeCN)Ni( Pcy,) is a tetramer,lI4 made from the reaction of Ni(COD) with PMe3 and crystallizing the product from MeCN involving ring structure rather resembling cyclooctatraene (6). A number of nickel nitrosyl complexes both mono and binuclear have been obtained for diphosphines."' H3C "y3 ,CH3 I C-Ni-N-C I/ \I N Ni-Pcy, I I cy,P-Ni N I\ /I C-N-Ni-C -CH3 I I Complexes with S and Se Donor Ligands.-This section is concerned with complexes where S and Se are the primary donor atoms. Clusters are discussed on page 150.The oxidation of Fe(S,CNMe,) by excess FeCl has been to take place in three stages involving FeCl( S2CNMe2)? and Fe( S2CNMe2),+ intermediates. Magnetic properties and Mossbauer spectra of a number of Fe(S2QX) chelates (X = NR2 Q = C X = Ph, Q = P) involving high- low-and spin-equilibria systems continue to be both spin isomers are in the ESR spectrum of Fe( Se2CNEt2) . Bond lengths in the low-spin iron( 111) complex [Fe([9]aneS3),13' are longer than in the corresponding iron( 11) species.I2' The crystal structures of a number of Fe" and Co complexes of S2P( P-C~H,M~)~ have been determined;121 6-coordination is found in most of them. In Co(S2CNR,R,) (R,R2 = (CH2)4; R = R = CH,Ph Et Pi')', the CoS distances show little dependence on the substituent.The redox properties of Co(Y,CNR2) (Y = S Se) have been compared'23 with the corresponding Rh and Ir compounds; unexpectedly the CoIV system is less reactive than the RhIV one. The species Co(S,CNR,) reacts with 'Iz S. A. Laneman F. R. Fronczek and G. G. Stanley Inorg. Chem. 1989 28 1872. 113 M. Y. Darensbourg M. Ludwig and C. G. Riordan Inorg. Chem. 1989 28 1630. 1 I4 J. Sieler D. Walter 0. Lundquist and L. Andersen Z. Anorg. A/g. Chem. 1988 560 119. I IS A. Del Zotto A. Mezzetti V. Novrelli P. Rigo M. Lanfranchi and A. Tiripicchio J. Chem. SOC.,Dalton Trans. 1990 1035. I I6 H. Carbacho and J. A. Gnecco Bol. SOC.Chil. Quim. 1989 34 27. 117 B. Leon and D. K. Straub Inorg. Chim. Acta 1989 156 13; 17. IIX B.S. Manhas and S. Bala Polyhedron 1988 7 2465. 119 W. Dietzch N. V. Duffy E. Gelerinter and E. Sinn Inorg. Chem. 1989 28 3079. I20 A. J. Blake A. J. Holder T. 1. Hyde and M. Schroeder J. Chem. SOC.,Chem. Commun. 1989 1433. 121 K. Korschbaum K. Greiwe K. Muller H. Strasdeit B. Krebs and G. Henkel Z. Nufurforsch Teil B 1990 45 497. 122 P. C. Healy J. W. Connor B. W. Skelton and A. H. White Aust. J. Chem. 1990 43 1083. I23 A. M. Bond R. Colton and D. R. Mann Inorg. Chem. 1990 29 4665. I24 P. C. Healy B. W. Skelton and A. H. White J. Chem. Sac. Dalton Trunr. 1989. 971. Fe Co Ni 141 copper(1) halides in MeCN to afford unusual clusters in (Co[S,CN(CH2),].3CuBr.MeCN Cu3Br clusters 'hold' the chelates together whilst ~[CO(S,CNBU,)~].SC~I has CuI,Cu units built into Cu616 steps.', Co( MeCS.CHCSMe),.L (L = PPh3 py etc.) form 0 adducts detected by ESR at 77 K.'26 2-Mercaptophenol (H,mp) forms complexes'27 with Co Ni and Fe; in (Et,N),[Co(mp)(Hmp)] has p = 2.38~~; DMSO it is rapidly oxidized to Co(mp),-(p = 3.261~).Several crystal structures have been rep~rted;'~~,'~~~'~~ Ni( S2CNPr,) Ni(S2CNPrH), and Ni(S,COCH,CH,OMe) are all planar. Among adducts Ni[S,P(OEt),]-PPh is square ~yramidal'~' Ni[S,P(OBu),] (imidazole) and Ni(Phen)[S2P(OBu)2]+S2P(OBu)2-are ~ctahedral,'~' as is Ni( S2COCH2)- (CH20Me)2(2,2'-bipyridy1).'32Ni( S,CNEt,),(phen) has been studied'-'-' in solution and thermodynamic parameters for its formation derived. A new synthesis of Ni( S2PR2)2 (R = Et PhO Me,CHO) from Ni[ P(OPh)3]4 and [R2PS2) is given,134 as has one for Ni(S,CNRMe) where R is a weak nitrogeneous base.13s Et,N+[ Ni( S,COEt),]- has octahedral the unstable Ni( S,COEt) has been doped into cobalt(Ii1) hosts and studied by ESR.Chelates involving a 5-membered ring include Ni(S2CH2CH2S)22- and Ni[ SC(Me)C( Me)S],,- which are square planar the latter named being oxidized at a rather low potential (-0.75 V) to a Ni"' complex also believed to be square planar (ESR).'37 The complexes M[ (PhCH,)SC( Ph) :C( Ph)S] (M = Ni Pd Pt) are isomorphous square planar'38 (and photosensitive in solution). Nickel( 111) complexes attract attention because of their relationship to the stability of Ni3+ in hydrogenases. The Nil' complex with pyridine-2,6-dimethanethiol (H,pmdt) however although reduced to the Nickel(1,Ir) dimer [Ni(pmdt).],- does not seem to afford a Ni"' complex.'39 The unstable xanthates have already been mentioned they disproportionate readily.'36 2Ni( S2COR)3 $2Ni(S2COR) + ROCS-SS-CSOR.However Ni( S,-norbor- nane),,-(square planar) is oxidized to a stable Ni"' complex,'40 and Ni(1,2-S2- cyc10C~H~~)~~-is reversibly oxidized to the Ni"' ana10gue.l~'A salt of Ni(dmit),- (H,dmit = 4,5-dimercapto-l,3-dithiole-2-thione)has been characterized struc-turally; the square-planar NiS units do show some short S-S intermolecular 126 E. P. Talzi K. Karshalykov and V. M. Nekipelov Koord. Chim. 1989 15 256. 127 B. Kang L. Weng H. Liu D. Wu L. Huang C. Lu J. Cai X. Chen and J. Lu Inorg. Chem. 1990 29 4873. J.Kamenicek R. Pastorek F. Brezina G. Kratcochvil and Z. Travnicek Coll. Czech. Chem. Commun. 1990 55 1010. 129 B. F. Abraham B. F. Hoskins E. R. Tiekink and G. Winter Ausr. J. Chem. 1988 41 1117. 130 S. Liu C. Lin Y. Yu D. Zhu Z. Xu S. Gou and X. You Acra Crystallogr. Sect. C 1991 41 43. 131 (a) J. Huang Y. Yu Z. Xu and X. You Acra Crystallogr. Secr. C 1990 46 991; (b) Y. Yu D. Zhu S. Liu C. Lin Z. Xu S. Gou and X. You Jiegou Huaxue 1990,9 73; Chem. Absrr. 113 221 775. A. J. Edwards B. F. Hoskins and G. Winter Acra Crystallogr. Secr. C 1990 46 1786. F. P. Emmenegger Inorg. Chem. 1989 28 2210. J. Losada M. Moran and C. Muro Transition Mer. Chem. 1989 14 127. I32 I33 134 135 C. C. Hadjikostas G. A. Katsaulos M.P. Sigalas C. A. Tsipis and N. V. Duffy Polyhedron 1989,8,2637. I36 S. B. Choudhury D. Ray and A. Chakravorty Inorg. Chem. 1990 29 4603. 137 N. Baidya P. K. Mascharak D. W. Stephan and C. F. Campagno Inorg. Chem. 1990 177 233. I38 C. Zhang H. K. Reddy E. 0.Schlemper and G. N. Schrauzer Inorg. Chem. 1990 29 4100. 139 H. J. Krueger and R. H. Holm Inorg. Chem. 1989 28 1148. I40 S. Fox Y. Wang A. Silver and M. Millar J. Am. Chem. Soc. 1990 112 3218. 141 T. Yamamura H. Arai H. Kurihara and R. Kuroda Chem. Leu. 1990 1975. 142 S. A. Cotton contacts responsible for its high condu~tivity.'~~ Attempted oxidation of one nickel(11) tholate has led to ligand 0xidati0n.l~~ New ligand syntheses promise sustained interest in nickel-sulphur chemistry.'44 Little work has been reported with Se donors.In addition to Fe(Se,CNR,) touched on earlier,"' other comparative of thioether analogues are poss- ible with complexes such as CoLX,+ (L = MeQ(CH,),QMe; Q = S Se; X = C1 Br) being reported among others (Geometric isomers being isolated in some cases). [Ni( Se4),I2- has been made exhibiting square-planar c~ordination.'~~ Compounds with a-bonds to Carbon.-Protonation of Li(THF),+Co( Mesityl),- yields'47 Co(Mesityl) which is a bis(mesity1) bridged dimer (7). Reaction of lithium alkyls with CoC1 in tetramethylethylenediamine (TMED) has led to the isola- ti~n'~' of tetrahedral (TMED)CoR (R = CH2SiMe3 CH2CMe3) [L~(TMED)+],[CO(CH,S~M~~),]~-(tetrahedrally coordinated cobalt) and [Li(TMED),'][CoC1(CH(SiMe3),),]-in which the cobalt is 3-coordinate.The route of the reaction of 1-norbornyl lithium (norli) with CoCl is solvent-dependent; in THF Li(THF),+Co(nor),- is formed whilst in pentane the established cobalt( rv) alkyl Co(nor) is produced; the crystal structure of the Cot" compound shows tetrahedral coordination of cobalt with rather short Co-C bonds (1.97 A). On oxidation the cobalt(v) compound Co(nor),+BF,- is produced; cyclic voltammetry shows that the three compounds are related by reversible redox reaction^.'^^ The structure of the complexes [Co(dimethylglyoxime H)(adamantyl)L] (L = NH,Ph 4Me,Npy) have been determined both are 6-co0rdinate.'~~ Electron transfer in the cleavage of Co-C bonds by Iz in compound^'^'^'^^ such as RCoL,(py) (L = 142 D.Reefman J. P. Cornelissen J. G. Haasnoot R. A. G. De Graaff and J. Reedijk Inorg. Chem. 1990 29 3933. I43 M. Kumar R. 0. Day G. J. Colpas and M. J. Maroney J. Am. Chem. SOC.,1989 111 5974. 144 D. Sellrnann S. Funfgelder G. Pollmann F. Knoch and M. Moll Inorg. Chem. 1990 29 4772. 145 J. J. Jenkinson W. Levason R. J. Perry and M. D. Spicer J. Chem. SOC.,Dalton Trans. 1989 453; J. L. Brown T. Kemmitt and W. Levason J. Chem. SOC.,Dalton Trans. 1990 1513. 146 R. M. H. Banda J. Cusick M. L Scudder D. C. Craig and I. G. Dance Polyhedron 1989,8 1995. I47 K. H. Theopold J. Silvestre E. K. Byrne and D. S. Richeson Organometallics 1989 8 2001. 148 R. S. Hay-Motherwell G. Wilkinson B. Hussain and M. B. Hursthouse Polyhedron 1990 9 931.149 E. K. Byrne and K. H. Theopold J. Am. Chem. SOC.,1989 111 3887. N. B. Pahor L. Randaccio E. Zangrando and P. A. Marzilli J. Chem. SOC.,Dalton Trans. 1989 1941. 151 K. Ishikawa S. Fukuzumi and T. Tanaka Inorg. Chem. 1989 28 1661. 152 S. Fukuzumi T. Coto K. Ishikawa and T. Tanaka J. Chem. Soc. Chem. Commun. 1989 260. Fe Co Ni 143 dimethylglyoxime) and cis-CoR,(bipy),+ has been studied (e.g. R = Me Et PhCH,). New nickel methyls include'53 (TMED)NiMe from alkylation of (TMED)Ni(acac),; it is stable to 79 "C. The TMED ligand can be replaced by bipy or Me2PCH2CH2PMe2.[ NiMe( PMe3)4]+BF4- reacts'54 with chelating ligands (L-L) forming [NiMe(PMe,),(L-)I+; these are rigid where L-L is phen or bipy but fluxional when dppe or dmpe the latter tending to dissociate one molecule of PMe,.Steric effects prevent the planar Ni(CH2SiMe3)(PMe3)3+BF4-from coor- dinating a fourth molecule of phosphine. Some of these compounds insert CO to form acyls. Other methyls NiMe(PMe)L (L = 8-quinolinate i02C(CH2)nC02 with n = 0-4) have been made;'55 the oxalate is a dimer (8) whilst the oxinate is a square-planar monomer with 0 trans to methyl (9). The structure of the syn and anti-isomers of trans-Ni(C6H4Me-2)( PMe,Ph) both square-planar have been determined.'56 The compounds NiX(CH2Ph)(Pcy3) (X = C1 CN) react with oxygen rapidly yielding the phosphine oxide benzaldehyde and benzylalcohol as the organic products; the reaction is believed to proceed via a 1 1 O2 add~ct.'~' A 5-coordinate alkyl [Ni( Me)( NS3R)] has been generated and it undergoes CO inser- tion to yield a characterized acy1,lS8 (NS3R = N(CH2CH2SR),; R = Pri).Alkylamides (and Compounds with Low Coordination Numbers).-Several more com- pounds in this category have been reported. The most interesting of these is Co(btsa) (btsa = N(SiMe3),) prepared,'59 like its Mn"' analogue by a route avoiding reduc- tion of a Co"' starting material by Li(btsa) Co(btsa) + Br-N(SiMe,) -* Co(btsa) + iBr2 The olive green compound (m.p. 86-88 "C) has peff= 4.73~~ (at 297 K); besides being the first 3-coordinate Co"' compound it is a rare high-spin d6 cobalt(m) compound. The Co-N bond length is considerably shorter than the Fe-N bond in the corresponding d5 compound; see Table 2 for a comparison of M-N bond length in the do-d6 tris (btsa) complexes.The corresponding M" silylamides are amido-bridged dimers with three coordinate metals in the solid state (10). Use of the bulker N(SiMePh,) ligand affords16' the 2-coordinate compounds I53 W. Kaschube K. R. Poerschke and G. Wilke J. Organometallic Chem. 1988 355 525. 154 M. Bochmann I. Hawkins M. B. Hursthouse and R. L. Short J. Chem. SOC.,Dalton Trans. 1990 1213. 155 H. F. Klein T. Wiemer M. J. Menu M. Dartiguenave and Y. Dartiguenave Inorg. Chim. Acta 1988 154,21. 156 M. K. Miki M. Tanaka N. Kasai and M. Wada J. Organometallic Chem. 1988 352 385. 157 G. Favero S. 1. Mohamud A. Turco and U. Vettori Gazz. Chim. Hal. 1989 119 407. 158 P. Stavrupoulos M. Carrie M. C. Muetterties and R.H. Holm J. Am. Chem. SOC.,1990 112 5385. I59 J. J. Ellison P. P. Power and S. C. Shoner J. Am. Chem. SOC.,1989 111 8044. I60 H. Chen R. A. Bartlett H. V. R. Dias M. M. Olmstead and P. P. Power J. Am. Chem. SOC.,1989 111 4338. 144 S. A. Cotton Table 2 M-N bond lengths in M[N(SiMe3),I3 M sc Ti V Cr Mn Fe co Ionic radius (A)' 0.745 0.670 0.640 0.615 0.645 0.645 0.610 E.C. do d' d2 d3 d4 d5 d6 M-N (A) 2.047 (6)2 1.929 (4) 1.919 (5) 1.903 (6) 1.890 (3) 1.917 (4) 1.870 (3) 'Ionic radius quoted for high-spin 6-coordinate for comparison. *Pyramidal; other compounds are planar. Me3 Me3 s\ /S1 Me3Si N ,SiMe3 \ /\ N-M\ /M-N / \ Me3% N SiMe3 /\ Me3Si SiMe (10) M[N(SiMePh,),] (M =Fe Co); the M-N bond lengths are 1.916 and 1.898A respectively with N-M-N bond angles 169" and 147"respectively.Their magnetic moments are 5.07pB(Fe) and 4.42pB(Co); NMR and absorption spectra were reported. Fe[ N( SiMe2Ph),] is also 2-coordinate. Another approach16' to low-coordinated metal amides involves the use of the -N(R)B(mesityl) ligand; the lone pair on the nitrogen atom is involved in bonding to boron and is thus unavailable in N -P M bridge formation. Thus M[N(rnesityl)B(mesityl),] (M =Fe Co Ni) and related systems have been synthe- sized and characterized structurally and by spectroscopy (NMR ESR UV-VIS all high spin). In some cases (R =Ph) there are pronounced deviations from linearity ascribed to intramolecular metal-ipso carbon interactions. Fe( NPh,) reacts with C,H,Li to give Fe(C,H,) and Li,[Fe(NPh,),]Et,O (can this be 4-coordinate?) by disproportionation; Li[ Fe( NPh,),]-Et,O has also been synthesized.'62 For the 3-coordinate alkyl CoC1[CH(SiMe3),],- see page 142.Porphyrins and other Macrocyc1es.-Porphyrins and similar macrocycles are dealt with in the first part followed by other macrocyclic ligands. Immense activity in this area means that it has been difficult to select material. Usual abbreviations are used for tetraphenylporphyrin (TPP) and octaethylporphyrin (OEP). Iron porphyrin structures reported include FeTPP( 1-R imidazole) (R =vinyl ben~yl)'~~. FeTPP( PMe2Ph)4+C104-,'64 FeTPP( im),+Cu( MNT),-. 165 FeOEP(OTeF5)(THF)166 all 6-coordinate and Fe( 0EP)OMe) (5-~00rdinate).'~' H. Chen R. A. Bartlett M.M. Olmstead P. P. Power and S. C. Shoner J. Am. Chern. Soc. 1990 112 1048. 162 H. 0.Froehlich and H. Francke Z. Chem. 1988 28,413. 163 M. K. Safo W. R. Scheidt and G. P. Gupta Znorg. Chem. 1990 29 626. 164 L. Toupet P. Sodano and G. Simmoneaux Acta Crystallogr. Sect. C,1990 46 1631. 165 B. R. Serr C. E. L. Headford C. M. Elliott and 0.P. Anderson Acta Crystallogr. Sect. C 1990,46,500. 166 P. J. Kellett M. J. Pawlik L. F. Taylor R. G. Thompson M. A. Levstik 0. P. Anderson and S. H. Straws Znorg. Chem. lq89 28 440. 161 K. Hatano and T. Uno Bull. Chem. SOC.Japn. 1990 63 1825. Fe Co Ni 145 Substituted porphyrins with ‘protection’ for binding sites include ‘cross-strapped”68 and ‘picket-fen~e”~~-’~~ varieties the latter frequently using tetrakis (o-pivalamido- phenyl)porphyrin( L).Structures determined include FeL( N02)2- (6-coordinate low spin Fe3+),’69 FeL(2-Me(imH)) (5-coordinate high-spin Fe2+)17’ and [FeL(im)- (imH)] (6-coordinate low-spin FeZ+).l7’ Thiaporphyrin and pheophytins have attracted the structures of Fe(STPP)Cl (S = 2 p = 5.2~~) and Ni(STPP)Cl (S = 1 p = 3.3pB) being determined; as expected they have 5-COOr- dinate sp geometry (STPP = 21-thiaporphyrin). The rate of Co-C bond formation in the reaction of alkyl halides with Co” macrocycles (e.g. corrin) has been studied17’ and the structure of Co( hemiporphyrazinato)( 1 -Me(imH)),+( dete~rnined,’~~ as has the n-cation radical [Ni(OEP)]z(C104)2.’77 Reduction of both nickel porphyrins and thiaporphyrins to Ni’ species has been studied by ESR.”’ Nickel( 1)tetraphenylthiaporphyrin forms a 5-coordinate SOzadduct and also binds N-donor bases.’78 Nickel(II)(porphyrazineoctathiolate) coordinate^'^^ bis(t-buty1)tin using peripheral donor atoms (1 1).The p-carbido species [Fe(phthalo- cyanine)],C and derivatives [LFepc],C (e.g.L = py 1-meim Me2C0 etc.) formally contain”’ iron(1v); the structures of M(pc)C12 (M = Co Fe) molecular semi- R\ R R’ R 168 Y. Uemori and E. Kyuno Znorg. Chim. Acta 1989 165 115. I69 N. Hasri J. A. Goodwin and W. R. Scheidt Znorg. Chem. 1990 29 185. 170 D. Mandon F. Ott-Woelfel J. Fischer R. Weiss E. Bill and A. X. Trautwein Znorg. Chem. 1990 29 2442. 171 E. Tsuchida T. Komatsu E. Hasegawa and H. Nishide J. Chem.SOC.,Dalton Trans. 1990 2713. 172 D. Mandon R. Weiss M. Franke E. Bill and A. X. Trautwein Angew. Chem. 1989 101 1747. 173 L. Latos-Grazynski J. Lisowski M. M. Olmstead and A. L. Balch Znorg. Chem. 1989 28 1183. 174 H. Horio K. Kadano H. Inoue T. Shirai and E. Fluck J. Radioanal. Nucl. Chem. 1989 136 159; 137 277. 175 A. Bakac and J. H. Espenson Znorg. Chem. 1989,28,4319. 176 A. Marzatto G. Vale and D. A. Clemente Acta Crystallogr. Sect. C 1990 46 1764. 177 H. Song R. C. Orosz C. A. Reed and W. R. Scheidt Inorg. Chem. 1990 29 4274. 178 P. Chmieltwski M. Gzeszczuk L. Latos-Grazynski and J. Lisowski Znorg. Chem. 1989 28 3546. 179 C. S. Velasquez W. E. Broderick M. Sabat A. G. M. Barratt and B. M. Hoffman J. Am. Chem. SOC. 1990 112 7408.I80 C. Ercolani M. Gardini V. L. Goedken G. Pennesi G. Rossi U. Russo and P. Zanonato Inorg. Chem. 1990,28 3097. 146 S. A. Cotton conductors have been determined and discussed on the MI1'-phthalocyanine cation radical model.'" Five-coordinate sp iron(1v) has been reportedlg2 for a complex FeClL- (L = macrocycle tetra-amide) 7-coordinate (pentagonal bipyramid) iron( 11) in'83 Fe( 15- crown-5)Br2 and 6-coordinate iron( 111) (distorted trigonal prism) in'84 FeL'Br (L' = 1,2-bis(1,4,7-triaza-l-cyclononylethane). New cryptate complexes of Fe Co and Ni have been reported for a N6 cage ligand apparently supporting stable +1 oxidation stateslg5 and Co"' and Fe"' complexes of another encapsulating N donor reported.lg6 FeC1 complexes with various crown ethers;lg7 FeX2(16[ane]S4) (X = Br I) are high-spin owing to the halogens being weakly bound.lg8 Interest is awakening in iron'89 and cobalt'90 complexes of 'pendant-arm' macrocycles.Cobalt is 7-coordinate19' in [Co( 15-crown-5)( MeCN)2]4. Cobalt( 111) complexes of crown ethers using N2S or S3 donor sets have been made.'92,'93 Cobalt (and nickel) complexes of tetra-azamacrocycles have been shown to bind C02 in the Co' state and O2in the Co" state.'94 Several structure^'^^-'^^ have been determined including [CoL(CO)]ClO, truns-CoLC12 and cis-[CoL(C03)]C104 (L = 5,7,7,12 14,14-hexamethyl-1,4,8,1l,l-tetra-azacyclotetradeca-4,1 l-diene),lg5 the first-named having a linear Co-C-0 group. [Co(hexacyclen)13+ has been obtained as both fuc- and rner-is~mers,'~~ the structure of the unstable fuc-isomer being determined.'99 The structure of encapsulated hydrophobic Co"' complexes have been deter-mined.200,201 Nickel macrocycle complexes continue to be a fertile field.New ligands are synthesized more and more structures determined pendantarm macrocycles are a new area and there is increasing interest in unusual oxidation states. Nickel achieves 6-coordination in an unusual way in [Ni( 18-crown-6)( EtOH),]( PF6),- bound to three adjacent crown ether oxygens and to three EtOH molecules;202 in [Ni( 17-ane-N5)H20]Br2.3H20 nickel achieves 6-coordination with the help of a 181 B. Moubaraki M. Ley D. Benham and J. P. Sorbier Acta Crystallogr. Sect. C 1990 46 379. 182 T. J. Collins K. L. Kostka E.Munck and E. S. Uffelman J. Am. Chem. SOC.,1990 112 5637. 183 S. B. Larson S. H. Simonsen J. N. Ramsden and J. J. Lagowski Acta Crystallogr. Sect. C 1990,46 1930. 184 A. Geilenkirchen K. Wieghardt B. Nuber and J. Weiss 2.Narurforsch Teil B 1989 44 1333. 185 J. Hunter J. Nelson C. Harding M. McCann and V. McKee J. Chem. SOC.,Chem. Commun. 1990,1148. 186 A. S. Rothin H. J. Banbery F. J. Berry T. A. Hamor C. J. Jones and J. A. McCleverty Polyhedron 1989 8 491. 187 K. B. Yatsimirskii E. V. Rybak-Akimora and G. G. Talamova Dokl. Akad. Nauk SSSR Ser. B 1989 50; Chem. Abstr. 111 246 676. 188 A. Hills D. L. Hughes M. Jiminez-Tenorio G. J. Leigh A. Houlton and J. Silver J. Chem Soc. Chem. Commun. 1989 1774. 189 U. Auerbach U. Eckert K.Wieghardt B. Nuber and J. Weiss Znorg. Chem. 1990 29 938. I90 P. V. Bernardt G. A. Lawrance and T. W. Hambley J. Chem. SOC. Dalton Trans. 1989 1059. 191 W. Massa T. Ernst and K. Nehnicke Z. Narurforsch Teil B 1990 45 563. 192 T. W. Hambley L. R. Gahan and G. H. Searle Acta Crystallogr. Sect. C 1989 45 864. 193 H. J. Kuepper K. Wieghardt S. Steenken B. Nuber and J. Weiss Z. Anorg. Allg. Chem. 1989 573 43. 194 M. H. Schmidt G. M. Miskelly and N. S. Lewis J. Am. Chem. SOC.1990 112 3420. 195 D. J. Szalda E. Fujita and C. Creutz Znorg. Chem. 1989 28 1446. 196 D. J. Szalda C. L. Schwarz J. F. Endicott E. Fujita and C. Creutz Znorg. Chem. 1989 28 3214. 197 S. Reimer M. Wicholas B. Scott and R. D. Willett Acta Crystallogr. Sect. C 1989 45 1694.198 G. H. Searle Bull. Chem. SOC.Japn. 1989 62 4021. 199 G. H. Searle and E. R. T. Tiekink J. Coord. Chem. 1989 20 229. 200 A. A. Achilleos L. R. Gahan T. W. Hambley P. C. Healy and D. M. Weedon Znorg. Chim. Acta 1989 157 209. 20I L. R. Gahan T. M. Donlevy and T. W. Hambley Znorg. Chem. 1990 29 1451. 202 S. B. Larson S. H. Simonsen J. N. Ramsden and J. J. Lagowski Acta Crystallogr Sect. C 1989,45 161. Fe Co Ni 147 water molecule203 whilst in [Ni( 12-ane-N4)(H20)2](C104)2*H20 two waters cis-coordinate.204 Solution X-ray diffraction studies suggest that Ni(cyclam)C12 is square planar but on addition of ammonia 6-coordinate Ni( cyclam)( NH3)3+ forms with an increase of Ni-N from 1.98 to 2.09A (cyclam = 1,4,8,11-tetra-azacyclotetradecane).205Six-coordination is also found in other com- plexes; whilst [Ni( 12-ane-N,)-( H202)]2(C404)(C104)2 has the cis structure already noted the nickel oxalate complex of the 1,7-dimethylmacrocycle is a dimer with oxalate bridges [Ni2( Me2- 12-ane-N4)2C204]2+.206 Studies of large polyazamacro- cycles [3k]aneNk (k = 7-12) indicate that [21]aneN7 only forms monomers but larger rings form dinuclear complexes;207 thus in (Ni[21]aneN7)2+ one N is uncoor- dinated and [Ni([30]aneN),,( H20)2]2+ has each nickel bound to five nitrogens and one water.1,3,6,9,11,14-Hexa-azatricycle[ 12.2.1.1.6.91 octadecane potentially hexadentate is tetra and penta dentate in the nickel complexes studied.'08 Studies of macrocycles carrying pendant groups have included groups that may or may not ~oordinate,~'~-~~' or may be polymerized;212 sometimes it has the function of inhibiting coordination.213 7-A~a-1,4-dithiacyclononane ([9]aneNS2) forms the octahedral Ni[ (9)aneNS2](C104)2 which both oxidation and reduction to ESR active Ni3+ and Ni+ species.Some of these complexes can be oxidized to Ni"' species stable in solution as with 1-oxa and l-thia-4,7-diazacyclononane, the complexes being characterized by ESR2" etc. but a good example of comparative solid state studies is [NiC12(Mez[ 14]aneN4)]"" (x = 0 1) where crystallographic216 study of both compounds indicates that on passing from the (+2) to the (+3) state the Ni-C1 and Ni-N bonds shorten by about 0.09 A. Schiff Base and Related Complexes.-IR of the oxygen adduct of Fe(sa1en) formed by co-condensation at 25 K show two bands due to 0-0 stretching one ascribed to the dimer [Fe(~alen)]~O~-Iron( 111)(salen) complexes with bidentate bridging ligands (e.g.oxalate squarate) have been studied magnetically; an improved synthesis of Fe( salen)N03 was also Fe( sa1en)OAc catalyses 203 J. C. Boeyens S. M. Dobson and E. L. Oosthuisen J. Crystallogr. Spectros. Rex 1990 20 407. 204 B. Scott K. J. Brewer L. 0. Spreer C. A. Craig J. W. Otros M. Calvin and S. Taylor J. Coord Chem. 1990 21 303. 205 H. Ohtaki and H. Seki J. Macromol-Sci. Chem. A 1990 27 1305. 206 A. Bencini A. Bianchi E. Garcia-Espana Y. Jeannin M. Julve V. Marcelino and M. Phloche-Levisales Inorg. Chem. 1990 29 963. 207 A. Bencini A. Bianchi M.Castello P. Dapporto J. Fans E. Garcia-Espana M. Micheloni P. Paoletti and P. Paoli Inorg. Chem. 1989 28 3175. 208 L. I. Myachina G. V. Romanenko N. V. Podberezskaya L. A. Sheludyakova and S. V. Lanonov Zh. Neorg. Khim. 1989 34 669. 209 K. P. Balakrishnan H. A. A. Omar P. Moore N. W. Alcock and G. A. Pike J. Chem. SOC. Dalton Trans. 1990 2965. 210 M. Di Vaira F. Mani and P. Stoppioni J. Chem. SOC. Chem. Commun. 1989 126. 211 G. De Martino Norante M. Di Vaira F. Mani S. Mazzi and P. Stoppioni Znorg. Chem. 1990,29 2822. 212 J. Cameron and S. Graham J. Chern. SOC.,Dalton Trans. 1989 1599. 213 H. E. Tweedy N. W. Alcock N. Matsumoto P. A. Padolik N. A. Stephenson and D. H. Busch Znorg. Chem. 1990 29 616. 214 A. McAuley and S.Subramanian Znorg. Chem. 1990 29 2830. 215 L. Fabbrizzi and D. Prosperio J. Chem. SOC. Dalton Trans. 1989 229. 216 M. Yamashita and H. Miyamae Znorg. Chim. Acta 1989 156 71. 217 L. M. Proniewicz T. Isobe and K. Nakamoto Inorg. Chim. Acta 1989 155 91. 218 F. Lloret M. Julue J. Fans X. Solans Y. Journeaux and I. Morgenstern-Badarau Inorg. Chem. 1990 29 2232. 148 S. A. Cotton oxidation of N,N-dimethylaniline~~'~ and also reacts with quinizarin (H,qz) form- ing the binuclear (Fesalen),qz claimed,,' as a model for iron binding by anthra- cycline drugs. Adducts of the type Fe(acen)(THF)FeCl (acen = N,N-ethylene-bis(acety1acetoneiminate) involve22' both 5-coordinate Fe"' and 4-coordinate Fe"'. (12). Ten new oxygen-carrying cobalt" Schiff base complexes have been described,222 as has a student laboratory experiment223 based on the oxygen- carrying properties of Co(sa1en).The structure of Co(sa1,pen)py has been described224 (sa1,pen = 2,5-bis(salicylideneamino) 1-pentanoate) as involving dis- torted octahedral geometry. Several studies of nickel complexes include the report225 of the structure of Ni(salen)ZnEt adduct in which the zinc is weakly bound to the oxygens of the Schiff base and several struct~res~~~-~~' including a redetermination of226 bis( salicylideneaminato) nickel. Cellular ligand-field calculations have been reported23' for two complexes. Electrochemical oxidation of bis( 3,5-dichlorosalicyl- aldehyde)-o-phenylenediiminatonickel affords the corresponding Ni"' complex whose adducts with pyridines have been studied by ESR and electronic spectra.232 Several syntheses and structures have been for sulphur-containing species including an improved synthesis233 for the thio analogues of Ni( salen) (Scheme 1).0x0-bridged Species and Models for Oxygen-containing Proteins.-This section will be concerned with the 'models' that do not involve 'haem' systems or iron- sulphur clusters. Complexes like [Fe(TPA),O(CO,)]( C104) (TPA = tris( 2-pyridylmethy1)amine) have double bridges (0,C03) between the two iron 2'9 S. Murata M. Miura and M. Nomura J. Org. Chem. 1989 54 4700 220 M. J. Maroney R. 0. Day T. Psyris L. M. Fleury and J. P. Whitehead Inorg. Chem. 1989 28 173. 221 E. Solari F. Corazza C. Floriani A. Chiesi-Villa and C.Guastini J. Chem. Soc. Dalton Trans. 1990 1345. 222 D. Chen A. E. Martell and Y. Sun Inorg. Chem. 1989 28 2647. 223 D. J. Aymes and M. R. Paris J. Chem. Educ. 1989 66 854. 224 J. Ondracek F. Jursik J. Maixner and B. Kratochvil Acta Crystallogr. Sect. C 1990 46 1821. 225 S. J. Dzugan and V. L. Goedken J. Organomet. Chem. 1988 356 249. 226 B. Kamena B. Kaitner G. Ferguson and T. N. Waters Acta Crystallogr. Sect. C,1990 46 1920. 227 D. Britton and L. H. Pignolet Acrn Crystallogr. Sect. C 1989 45 819. 228 B. Kamenar B. Kaitner A. Stefanovic and T. N. Waters Acta Crystallogr. Sect. C,1990,46 1627; 1923. 229 S. Brooker and V. McKee J. Chem. Soc. Dalton Trans. 1990 3183. 230 G. V. Romanenko V. V. Podberezskaya L. 1. Myachina and V.V. Bakakin Zh. Strukt. Khim. 1989 30 130. 23 1 M. J. Duer and M. Gerloch Inorg. Chem. 1989 28 4260. 232 B. De Casto and C. Freire Inorg. Chem. 1990 29 5113. 233 T. Yamamura M. Tadokoro and R. Kuroda Chem. Lett. 1989 1245. 234 T. Yamamma M. Tadokoro M. Hamagachi and R. Kuroda Chem. Left. 1989 1481. Fe Co Ni 149 n Reagents i en C,H6 reflux; ii NiCIJEtOH Scheme 1 atoms;235 ( LFeOFeCl,) has unusually strong iron-iron coupling for a single O-bridge.236 Use of a bridging carboxylate rn-phenylenedipropionate(MPDP) permits synthesis of compounds like [Fe,O( MPDP)(4,4-Me2bipy)C12] with labile terminal sites -occupied by chloride cis to the 0 bridge in the place where O2 bonds in haeme~ythrin.~~' Hydrolysis of [L,Fe,(a~ac),O]~+ (L = N,N',N"-trimethyl-l,4,7-triazacyclononane)one hydrolysis yields238 a strongly anti-ferromagnetically coupled tetramer [L4Fe4O2(0H),l4+ with an adamantane like core.A variety of other binuclear complexes with this ligand like [L,Fe,(p-0) (p-S04)].3H20 have been made; the latter compound antiferromagnetically coupled with J = -97 cm-' is suggested as a model for ~teroferrin,~,~ as has [L2Fe2(p-0)(p-Similar models have been made using tosylated tri-azacy~lononane.~~' The dimer [Fe2(bmp)(p-02CPh)12+ (bmpH = 2,6-bis[ (bis( 1-methyl-imidazol-2-yI)methyl)amino]methyl-4-methylphenol) exhibits valence trapping with Fe"'-0 and Fe'"-O distances in the phenoxobridge of 2.126 and 1.951 A; there is weak antiferromagnetic exchange242 with J = -2.5 cm-' Alcoholysis of FeCl,( PBu,') produces Cl,Fe( ~-0Et)~FeCl,*- with J = -24.6 ~m-'.~~ One p-sulphide dimer has been reported.243 Inelastic neutron spectros- copy has been applied244 to study magnetic interactions in the trinuclear carboxylates 235 R.E. Norman R. C. Holz S. Menage L. Que J. H. Zhang and C. J. O'Connor Inorg. Chem. 1990 29 4629. 236 P. Gomez-Rornero E. H. Witten W. M. Reiff and G. B. Jameson Inorg. Chem. 1990 29 5211. 237 R. H. Beer W. B. Tolman S. G. Bott and S. J. Lippard Inorg. Chem. 1989 28 4557. 238 (a) K. Wieghardt K. Pohl V. Bossek B. Nuber and J. Weiss Z. Naturforsch Teil B 1988 43 1184; (b) S. Drueke K. Wieghardt B. Nuber J. Weiss E. L. Bominaar A. Sawaryu H. Winkler and A. X. Trautwein Inorg. Chem. 1989 28 4477.239 K. Wieghardt S. Drueke P. Chaudhuri V. Floerke H. J. Haupt B. Nuber and J. Weiss Z. Naturforsch. Teil B 1989 44,1093. 240 S. Drueke K. Wieghardt B. Nuber J. Weiss H. P. Fleischhauer S. Gehring and W. Haase J. Am. Chem. Soc. 1989 111 8622. 24 1 J. L. Sessler J. W. Sibert and V. Lynch Inorg. Chem. 1990 29 4143. 242 M. S. Mashuta R. J. Webb K. J. Oberhausen J. F. Richardson R. M. Buchanan and D. N. Hendrickson 1. Am. Chem. Soc. 1989 111 2745. 243 P. Berno C. Floriani A. Chiesi-Villa and C. Guastini J. Chem. Soc. Dalton Trans. 1989 551. 244 R. P. White J. 0. Al-Basseet R. D. Cannon G. J. Kearley and U. A. Jayasooriya fhysica B 1989 156157 367. 150 S. A. Cotton (13) (Reproduced by permission from J. Am. Chem. SOC.,1990 112,9629) Fe,MO(RCOO) (M = Mn Co Fe).[Fe3O(RCOO),(H20),]+ (R = CH,Cl) reacts with Fe(NO,) in MeOH to afford a remarkable ‘ferric wheel’ decamer (13) [Fe(OMe)2(02CCH2C1)]l,, with 10coplanar irons.245 [Fez( DBE),(0COPh),](ClO4) (DBE = 2-[bis(benzimidazoylmethyl)amino]ethanol) has bridging oxygens from the DBE lignds (and terminal carboxylates) affording antiferromagnetically coupled Fe3+ ions (J = -20.5 ~m-’).,~ Interest is sustained in the stability and structure of iron chelating agents usually very selective for Fe3+ such as carbo~ylates~~’~~~~ and a ligand that is a model for the metal binding site of the anti-cancer drug ble~mycin.’~~ The green pigment ferroverdin has already been characterized now synthetic models have been studied;250 iron complexes of the anti-tumour agent 2-formylpyridinethiosemicar-bazone have been e~arnined.’~’ Cluster Complexes.-A most useful overview has appeared on structure and bonding in M4S4 clusters.2s2 Activity centres on Fe/S clusters as models for ferredoxin and nitrogenase as well as Ni/S clusters that often involve phosphine ligands.245 K. L. Taft and S. J. Lippard J. Am. Chem. SOC.,1990 112 9629. 246 S. Menage and L. Que Inorg. Chem. 1990 29 4293. 247 S. K. Larsen B. G. Jenkins N. G. Memon and R. B. Lauffer Inorg. Chem. 1990 29 1147. 248 M. R. McDevitt A. W. Addison E. Sinn and L. K. Thompson Inorg. Chem. 1990 29 3425. 249 S. J. Brown M. M. Olmstead and D. K. Mascharak Inorg. Chem. 1990 29 3229. 250 P. Basu S. Pal and A. Chakravorty J.Chem. SOC.,Dalton Trans. 1990 9. 251 A. Abras H. Beraldo E. 0. Fantini R. H. IJ. Borges M. A. Da Rocha and L. Tosi Inorg. Chim. Acfa 1990 172 113. 252 S. Harris Polyhedron 1989 8 2843. Fe Co Ni 151 Resonance Raman and IR spectra have been reported253 for some two-iron complexes in which eight bands involve Fe-S stretching. Syntheses include254 Fe4S4(cyclo-C5H,oNS2)4 in which all the irons are Fe3+ and the reaction macrocyclic ligands with [Fe4S4( SBU~)~]~- to afford clusters surrounded by hydro- phobic domains. A semirigid tridentate thiol ligand has been used256 to spare three of the iron corners of Fe4S4 cages in order to permit 'manipulation' of the fourth corner. The fluoroborate Fe(BF4)2.6H20 reacts with Et3P,257 then Li2S to form the basket-type cage Fe,S,( PEt3),+ (14).This does not exhibit clean redox reactions as the Fe clusters with more highly oxidized cores tend to adopt prismane-type structures. Interest in synthesis of clusters with mixed Mo/ Fe cores continues.258i259 Reactions of CoBr2 with Na2S4 affords a cluster with an octahedral group of cobalts Co6S8(PPh3)6 each face is p.,-bridged by S all cobalts being surrounded by four sulphurs and one phosphorous in a distorted square pyramidal environment.260 Mixed cobalt-nickel clusters of the established cubane type CO~N~~(OM~)~L~(M~OH)~ have been made26' (e.g. L = acac). Among homoleptic nickel thiolate clusters [Ni3( SEt),12- reacts262 with water to form [Ni( SEt)2]6 [Ni( S(CH2)3NMe2)2]6 has a hexagonal-prismatic core with NiS4 faces,263 and 253 (a) S.Han R. S. Czernuszewicz and T. G. Spiro J. Am. Chem. Soc. 1989 111 3496; (b) S. Han R. S. Czernuszewicz T. Kirnura M. W. W. Adarns and T. G. Spiro J. Am. Chem. Soc. 1989 111,3505. 254 Q. Liu L. Huang Y. Yang and J. Lu Chinese Sci. Bull. 1989 34 348; Chem. Abstr. 114 113 896. 255 H. Okuno K. Uoto T. Tornohiro and M. T. Youinou J. Chem. Soc. Dalton Trans. 1990 3375. 256 T. D. P. Stack J. A. Weigel and R. H. Holm Inorg. Chem. 1990 29 3745. 257 B. S. Snyder and R. H. Holm Inorg. Chem. 1990 29 274. 258 T. Tomohira K. Uoto and H. Okuno Chem. Express 1989 4 697. 259 B. Kang H. Liu J. Cai L. Huang Q. Lin D. Wu L. Weng and J. Lu Transition Met. Chem. 1989 14 427. 260 M. Hong Z. Huang X.Lei G. Wei B. Kang and H. Liu Inorg. Chim. Acta 1989 159 1. 26 I M. A. Yarnpol'skaya G. S. Matuzenko N. V. Gerbeleu Yu. A. Sirnonov and A. A. Dvorkin Zh. Neorg. Khim. 1989 34 1209. 262 T. Yamarnura Bull. Chem. Soc. Japn. 1988 61 1975. 263 M. Capdevita P. Gonzalez-Duarte J. Sola C. Foces-Foces F. Hernandez Cano and M. Martinez-Ripoll Polyhedron 1989. 8 1253. 152 S. A. Cotton [Ni( SPri),I4 has a cubane-like framework (Ni4Sx) with again planar coordination of The ‘reduced’ cluster NixS(SBuL)9- has six nickels in a trigonal prism with the other two capping trigonal faces.264 Other ~lusters~~~~~~~ include Ni( 1,-MeNC)( ~~-I)(dppm),+I- and Ni3S2( PEt3)6,+ (and the Se analogue) which under- goes substitution of 1 or 2 phosphines by halides and pseudohalides (They also can react with co and H2S.) Reduction267 of NixC12S6( PPh3) form NixS6( PPh3)x and another witches’ brew synthesis268 (NiCI,/PPh,-Na,S in DMF-THF yields NiI5Sl5( PPh,) chain structure of 4 octahedra sharing faces).Compounds with Unusual Magnetic Properties.-[Tetrakis(2-pyridylmethyl)ethyl-enediamine]iron( 11) perchlorate containing an octahedral FeN chromophore with a trigonal twist is the first compound to convert between spin states faster than the Mossbauer tirne~cale.,~~ It is low-spin at 298 K but at 365 K there are equal amounts of high- and low-spin forms in the solid state; the effect is intramolecular. The low-spin-high-spin change is associated with an incresing Fe-N bond length and greater trigonal distortion.Fepy4( NCS)2 reacts with the bidentate L-L (phen and 2,2’-bipyrimidine) to form Fe( L-L)py,( NCS) which exhibit sharp high-low spin transitions (a 3” range in the case of the bpym complex) Mossbauer data giving evidence for lattice rearrangement.270 Fe( bpym)(~y)~( NCS) has pyridines trans and thiocyanates cis. Complexes of 2,2’-bithiazole(2bt) Fe(2bt),X2 (X = ClO, BF,) and the nickel analogues have been ~ynthesized,’~~ the iron compounds exhibiting a spin equilibrium. Of these the perchlorate exists in two crystalline forms with different proportions of the spin isomers. Similar behaviour has been noted for FeL,X (L = 6-meth~l-2,2’-bipyridine;~~~ x=clo4 BF, PF,; L= 2-(pyridin-2-yI)q~inoline,~~~ X = C104 BF4); two forms of Fe(pyq),(ClO,) have been made one high spin between 89 and 300 K the other showing a gradual change from high-spin to low-spin on cooling over this range.The mbpy salts show spin- pairing on cooling but some high-spin form is present even at low temperatures; the structure of Fe(mbpy)3(C10,)2 shows that the steric effect of the methyl group distorts the cation and weakens coordination the weaker ligand field compared to the low-spin Fe(bpy),’+ would account for the acccessibility of the high-spin state. A range of 1,2,4-triazole complexes have been made274 -FeL,X,.nH,O (X = Br BF, C104) and FeL,Br,; the 3:l complexes are further examples of FeN chromophores exhibiting spin-equilibria -in this case the spin change is accom- panied by a pronounced (rose-white) thermochromism.The 1-methyltetrazole com- 264 T. Krueger B. Krebs and G. Henkel Angew Chem. 1989 101 54. 265 K. S. Ratcliff P. E. Fanwick and C. P. Kubiak Pol-vhedron 1990 9 1487. 266 F. Cecconi C. A. Ghilardi S. Midollini A. Orlandini A. Vacca and J. A. Ramirez J. Chem. SOC. Dalton Trans. 1990 773. 267 D. Fenske and J. Magull Z. Narurforsch. Teil B 1990 45 121. 26X M. Hong Z. Huang and H. Lin J. Chem. Soc. Chem. Cornrnun. 1990 1210. 269 H. R. Chang J. K. McCusker H. Toftlund S. R. Wilson A. X. Trautwein H. Winkler and D. N. Hendrickson J. Am. Chem. Soc. 1990 112 6814. 210 R. Claude J. A. Real J. Zarembowitch 0. Kahn L. Ouahab D. Grandjean K. Boukheddaden F. Varret and A. Dworkin Inorg. Chem. 1990 29 4442. 27 I D. C. Craig H.A. Goodwin D. Onggo and A. D. Rae Ausrl. J. Chem. 1988 41 1625. 212 D. Onggo J. M. Hook A. D. Rae and H. A. Goodwin Inorg. Chim. Acta 1990 173 19. 27’ L. G. Lavrenora V. N. Ikovskii V. A. Varnek I. M. Olezneva and S. V. Larionov Koord. Khim. 1990 16 654. 214 P. Poganiuch S. Deautins and P. Gutlich J. Am. C‘hem. Soc. 1990 112 3270. Fe Co Ni 153 plexes Fe(mtz),X (X = BF4 PF6) have continued to be studied; the tetrafluoroborate exhibits light-induced excited spin-state trapping.275 Kinetics of spin-state isomeriza- tion have been studied by pulsed-laser phot~perturbation.~~~ In the field of iron( 111) complexes one of a tetradentate isoselenosemicarbazide ligand has been found to exhibit ,A -2T2 spin-state isomerism,277 as does a complex of 7-amino-4-methyl-5-aza-3-hepten-2-one another compound where both spin-isomers have been detected by ESR.278 An iron( 111) complex of N-salicyl-N’-2-furanthiocarboxyhydrazine (H,Sfth) Fe( H2Sfth),C13 also exhibits this effect.279 For complexes of sulphur ligands see p.140) The cobalt complexes of interest in this period are the paramagnetic alkylamides (p. 143) and 5-coordinate phosphine complexes of cobalt(rI1) (p. 139). In the field of nickel complexes a number of complexes of N,N-dimethyl-1,2- ethylenediamine( L) have been studied.280 Some exhibit deaquation-anation accom- panied by cis-trans isomerism on heating; paramagnetic cis-[NiL2( BF,)H,O]+BF,- changes to a square planar diamagnetic complex on heating and [NiL2](C104)2 is thermochromic.(NiC12)3L has an unusually high moment (4.1~~ at 28 “C). High- spin-low-spin equilibria have been noted in complexes NiL(pic)(X) (L = a-thionaphthoic acid; Hpic = picolinic acid; X = C1 Br I N03).281 Nickel com- plexes of N,N’,N”,N’’’-tetrakis-( 2-pyridylmethy1)- 1,4,8,1 l-tetra-azacyclotetra- decane (tpmc) of the formula Ni2tpmc(C10,) and Ni2Br2(tpmc)( CIO,) have been isolated Ni2(tpmc)(C10,) exists in orange (square planar diamagnetic) and blue (Scoordinate p = 2.96~~) forms.282 Reviews.-Many reviews relevant to these metals have been published often with a biological flavour. Topics include spin-equilibria in iron( 11) complexe~,~~~~~~~ metal complexes of pyridine~,~~ and di-imines,286 cobalt( 111) hex am mine^,^^^ cobalt and nickel thiocyanate systems,288 leaving groups on inert metal complexes (obviously especially relevant to CO”’)~~~ metal-promoted reactions of phosphate derivatives290 (ditto) homoleptic 2,2’-bipy complexes,291 iron bio-availability and coordination chemistry of hydroxamic acids,292 the redox chemistry of hydroxo-bridged 275 P.Adler P. Poganivch and H. Spiering Hyperfine Interact. 1989 52 47. 276 J. J. McGarvey I. Lawthers K. Heremans and H. Toftlund Inorg. Chem. 1990 29 252 277 M. S. Byrke M. A. Yampol’skaya N. V. Gerbeleu V. V. Zelentsov K. I. Turte K. M. Indrichan B. Ya Kuyavskaya and M. D. Revenko Zh. Neorg. Khim. 1988 33 3559. 278 J. P. Costes F. Dahan and J. P. Laurent Inorg. Chem. 1990 29 2448. 279 N. K. Singh U. Sharma S. Agarwal and M. J.M. Campbell Polyhedron 1990 9 1065. 2x0 S. Koner A. Ghosh and N. R. Chaudhiri Bull. Chem. Soc. Japn. 1990 63 2387. 28 I S. K. Agawal and D. Kumar Orient J. Chem. 1990 6 150. 2x2 G. Vuckovic E. Asato N. Matsumoto and S. Kida Inorg. Chim. Acta 1990 171 45. 283 H. Toftlund Coord. Chem. Rev. 1989 94 67. 284 P. Gutlich and A. Hausner Coord. Chem. Reu. 1990 97 1. 2x5 D. A. Thornton Coord. Chem. Rev. 1990 104 251. 2R6 D. J. Stufens Coord. Chem. Rev. 1990 104 39. 2x7 P. Hendry and A. Ludi Adu. Inorg. Chem. Radiochern. 1990 35 117. 2x8 J. Bjerrum Coord. Chem. Rev. 1990 100 119. 28Y G. A. Lawrence Ado. Inorg. Chem. Radiochem. 1989 34 145. 290 P. Hendry and A. M. Sargeson Progr. Inorg. Chem. 1990 38 201. 291 E. C. Constable Adv.Inorg. Chem. Radiochem. 1989 34 1. 292 A. L. Crumbliss Coord. Chem. Rev. 1990 105 155. 793 A. G. Lappin and A. McAulay. Adu. Inorg Chem. Radiorhern.. 1988. 32 241. 154 S. A. Cotton complexes (again very relevant to and two on macrocyclic complexe~~~~~~~~ (one in particular reviewing the variety with pendant More specifically biological are 4Fe-4S cubane cl~sers,~~' cysteine-dinuclear Fe sites in biology,298*299 containing oligopeptide models for Fe- Spr~tein,~" electron transfer in polynuclear complexes301 the iron-cofactor in nitr~genase,~'~ nitrosyl complexes of Fe-S clusters,303 and nickel in metalloprotein~.~~~ 294 J. Springborg Adv. Inorg. Chem. Radiochem. 1988 32 56. 295 D. H. Busch and N. A. Stephenson Coord.Chem. Rev. 1990 110 119. 296 P. V. Bernhardt and G. A. Lawrence Coord. Chem. Rev. 1990 104 297. 297 R. H. Holm S. Ciurli and J. A. Weigel Prog. Inorg. Chem. 1990 38 1. 298 L. Que and A. E. True hog. Inorg. Chem. 1990 38 97. 299 J. B. Vincent G. L. Oliver-Lilley and B. A. Averill Chem. Rev. 1990 90 1447. 300 A. Nakamuta and N. Ueyama Adv. Inorg. Chem. Radiochem. 1989,53 39. 301 G. Blondin and J. Girard Chem. Rev. 1990 90 1359. 302 B. K. Burgess Chem. Rev. 1990 90 1377. 303 A. R. Butler C. Glidewell and M-H. Li Adv. Inorg. Chern. Radiochem. 1988 32 336. 304 R. Cammack Adv. Inorg. Chem. Radiochem. 1988 32 297.

ISSN:0260-1818    

DOI:10.1039/IC9908700131

出版商:RSC    

年代:1990

数据来源: RSC

摘要:

Ti Zr Hf By S. A. COlTON Felixstowe College Felixstowe Suffolk IPl1 7NQ 1 Introduction The literature for 1989-90 has been covered though much of the organometallic chemistry of these elements in particular is not reviewed here. Particular trends discernible are the intense activity in the field of alkoxides and increased success in the chemistry of the lower oxidation states of zirconium in particular. 2 Halides and their Complexes The halide ZrI has a chain structure’ involving infinite chains of confacial ZrI octahedra distorted because of Zr-Zr pairing (Zr-Zr = 3.17,3.50 A). The reduc- tion of TiBr by Ti and A1 is reported’ to afford respectively a-TiBr and Ti(A1Br4)*; structures are reported for them and for HfF,. ZrC1 reacts4 with N204 to give Zr( NO3),.Structures are reported’ foi a whole range of zirconium chloride cluster phases stabilized by interstitial atoms (H B C Be Fe) which can form derivatives with suitable Lewis bases. Structures like that of (Zr,Cl,,Be)( EtNH,) (Figure 1) are related to that of the well established NbgC112~+ systems. New complexes of trivalent zirconium and hafnium are M2C16 (Pri2PCH2CH2PPri2), (M = Zr Hf) and Hf,CI,( PMe’Ph) (Figure 2) prepared by reduction of the tetrachlorides in the presence of the ligand. They are diamagnetic with a single metal-metal bond (around 3.09 A). ZrC1 (pinacolone) ,7 HfCl,(THF) ,8 CrCl,( MeCN) ,9 and TiC1,(Me3C.NC) lo are all cis-in the solid state. Among a range of titanium complex species character- izedll-13 are cis-TiCl,( Et,O) mer-TiBr,py trans-TiC12py4+ trans-Tipy,Cl,- I A.Lachgar D. S. Dudis and J. D. Corbett Inorg. Chem. 1990 28 2242. * S. I. Troyanov V. B. Rybakove and V. Ionov Zh. Neorg. Khim. 1990 35 882. G. Benner and B. G. Mueller Z. Anorg. Allg. Chem. 1990 588 33. A. A. Natsina E. A. Ukraintseva 1. I. Yakovlev and V. A. Logvinenko Zh. Neorg. Khim. 1989,34 2409. R. P. Ziebarth and J. D. Corbett J. Solid State Chem. 1989 80 56; F. Rogel and J. D. Corbett J. Am. Chem. SOC.,1990 112 8198. P. M. Morse S. R. Wilson and G. S. Girolami Inorg. Chem. 1990 29 3200; F. A. Cotton P. A. Kibala and W. A. Wojtczak Inorg. Chim. Acta 1990 177 1. ’B. Galeffi M. Simard and J. D. Wuest Inorg. Chem. 1990 29 951. S. A. Duraj R. L. Towns R. J. Baker and J. Schupp Acta Crystallogr.Sect. C 1990 46 890. J. Guery M. Leblanc and C. Jacoboni Eur. J. Solid Stare Inorg. Chem. 2989 26 289. 10 T. Carofiglio C. Foriani A. Chiesi-Villa and C. Guastini Inorg. Chem. 1989 28 4417. I’ S. 1. Troyanov G. N. Mazo V. B. Rybakov and K. V. Budkina Koord. Khim. 1990 16 466. Z. Janas P. Sobota and T. Lis Polyhedron 1988 7 2655. l3 P. Sobota M. 0. Mustafa and T. Lis Polvhedron. 1989 8 2013. 155 156 S. A. Cotton Figure 1 The Cluster (Zr&l12Be)(EtNH2)6 (Reproducedby permission from J. Am. Chem. Soc. 1990 112 81985) Figure 2 The structure of Hf2C16 (PMe,Ph) (Reproducedby permission from Inorg. Chim. Acta 1990 177 1) trans-TiCl,(THF),-and trans-TiCl,( THF),+. The compound [TiCl,(THF)-(APPY)].THF (APPY = (acetylmethy1ene)triphenylphosphorane-0) is trans; similar Zr and Hf compounds have been made.' Zr2C18(CH3COOEt)2 (two C1 bridge~)'~ and Ti,Cl,( POCl3),( PO2CI2) (two bridging dichlorophosphates)16 have been structurally characterized.ZrC1 reacts with formamidel7 and dimethylsul- phoxide" to give ZrL;+(Cl-),. Octahedra of MX6,-are found in (Ph,P),ZrX (X = c1,F),19*20(Et4N)2MC16 14 J. A. Albanese D. L. Staley A. L. Rheingold and J. L. Burmeister Inorg. Chern. 1990 29 2209. l5 P. Sobota M. 0. Mustafa and T. Lis J. Organornet. Chern. 1989 377 69. 16 P. P. K. Claire G. R. Willey and M.G. B. Drew J. Chern. SOC. Dalton Trans. 1989 57. " S. I. Troyanov N. N. Kulikova and K. N. Nikitin Koord. Khirn. 1990 16 1221. 18 N. N. Kalikova S. I. Troyanov K. N. Nikitin and S.0.Gerasimova Zh. Neorg. Khirn. 1989,34 2693. 19 E. Hartman K. Dehnicke D. Fenske H. Goesmann and G. Baum Z. Naturforsch TeilB. 1989,44 1155. 20 J. Larsen K. Boubeker P. Batail and J. Lucas Muter. Res. Bull. 1989 24 845. Ti,Zr Hf 157 (M = Zr Hf),,l and (amin~guanidinium),ZrF,;~~ [Na-l5-crown-5],ZrF,Cl4 has cis- anions.” Among dinuclear complexes octahedral coordination is found in (Ph3C),Hf2Cllo23 and SC13+ Ti2C19-,24 whilst (N2H6)5 (Zr2F13) has face-joined ZrF units with bicapped trigonal prismatic c~ordination.~~ CsTi2C17 has2 octahedrally coordinated Ti3+; the structure can be regarded as TiC1 groups sharing cis-edges to form TiC1 Cl,, ribbons that are interconnected by one chlorine to afford layers [Ti(C1)C14/,C11/,]-.Detailed syntheses are reported for M3Ti2X9 (M = Rb Cs; X = C1 Br).27 Among peroxyfluoro complexes K3Ti( 02),F3 has pentagonal bipyramidal coordi- nation28 (axial F); reaction of ZrOC1 with KF/H,02 yields l&Zr3F,2(02)3-2H202-2H20 with bidentate bridging peroxo groups.29 3 Alkoxides Aryloxides Amides and Imides This is a very active field of research since hydrolysis yields metal oxide films whose colours can be influenced by UV-irradiation or doping with metals like In3+ V5+ or rare earths to name some studied this Both Ti(OC6H4CMe3) and Ti(OC6HMe4) s~nthesized~~ from TiCl and the appropriate phenol have pseudo-tetrahedral structures; the latter can be reduced to the Ti”’ analogue. Zirconium isopropxide has been isolated and ~haracterized~~ as the dimeric adduct Zr2(0Pri8).2PriOH.It has two bridging alkoxides (1) and the two hydrogens bridge alkoxide groups attached to different zirconiums causing pronounced bending of these oxygens towards each other (but note Reference 6); it is fluxional at 25°C in toluene solution but more than one species is seen at ” K. Ruhlandt-Senge A. D. Bacher and U. Mueller Acta CrysfaUogor. Sect. C. 1990 46 1925. 22 B. V. Bukvetskii A. V. Gerasimenko and R. L. Davidorich Koord. Khim. 1990 16 1479. 23 F. Calderazzo 0. Pallavicini G. Pampaloni and P. F. Zanassi J. Chem. SOC.,Dalton Trans. 1990 2743. 24 S. I. Troyanov V. B. Rybakov N. I. Timoshenko and Z. A. Fokina Zh. Neorg. Khim. 1990 35 1683. 25 A. Rahten I. Leban S. Milicev and B. Zeniva J. Crystallogr.Spectrosc. Res. 1990 20 9. 26 . J. Zhang and J. D. Corbett Z. Anorg. Allg. Chem. 1990 580 36. 27 A. Stebler B. Leuenberger and H. U. Guedel Inorg. Synth. 1989 26 377. 28 A. V. Gerasimenko B. V. Bukvetskii B. N. Chernyshov and N. A. Didenko Zh. Neorg. Khirn.,1990 35 1611. 29 B. N. Chernyshov N. A. Didenko B. V. Bukvetskii A. V. Gerasimenko V. Y. Kavun and S. S. Sergienko Zh. Neorg. Khim. 1989 34 2786. 30 R. P. Mueller J. Steinle and H. P. Boehm Z. Naturforsch. Teil B. 1990 45 864. ” S. Doeuff and C. Sanchez C. R. Aoad. Sci. Sec. 2. 1989 309,531. 32 A. Siggel and M. Jansen Z. Anorg. Allgm. Chem. 1990 582 93. 33 R. T. Toth and D. W. Stephan Can. J. Chem. 1991 69 172. 34 B. A. Vaaststra J. C. Huffman P. S. Gradeff L. G. Hubert-Halzgraf J.C. Daran S. Parraud K. Yunhi and K. G. Caulton Inorg. Chem. 1990 29 3126. 158 S. A. Cotton -80 "C. The hafnium analogue is isomorphous. Titanium isopropoxide has been studied as a reagent for the synthesis of chirally pure syn-P-hydroxy-a-methylcar-boxylic acids;35 it reacts readily with 1,2-dithiols and with other thiols in the presence of various N-donor ligands to afford complexes.36 Full details of the synthesis of dimetallcalix[8]arene complexes from titanium and zirconium alkoxides have been given.37 Ti(OPr') reacts3' with MOPr' (M = Li Na K) forming MTi (OPri)5; the lithium compound is a dimer with 5-coordinate titanium centres linked by lithium bridges and all are fluxional dimers in solution at room temperature. Other mixed- metal alk~xides~~*~' synthesized include the hydrocarbon-soluble Ba,Zr,( OR), LiZr,(OR),(ROH) and KZr(OR) (R = Pri).Ti (OR) (R = Et Pr) react with acetylacetone affording substituted alkoxides; a mixture is obtained for the ethoxide but Ti(OPr'),(acac) has been isolated41 as a 5-coordinate monomer used to make various TiO based colloids uia the sol-gel route?l Partial hydrolysis of a similar mixed compound of zirconium led to the isolation42 of Zr40(OPr'),(acac), it has a 4-coordinate oxygen as the centre zirconium being 7-coordinate. Ti604(OR),(OAc) (R = Pr' Bu) have octahedrally coordinated (these clusters are obvious sol-gel intermediates and exhibit reversible photochr~mism)?~ The role of different alkoxides and of the carboxylate in varying association bridging and resistance to hydrolysis are discussed.The first well-characterized titanium and zirconium metallasiloxanes have been described.45 The dialkyls Zr(OR),R' (R = 2 6-Bu'(C6H3); R = Me PhCH) react with a-diimines (e.g. phen bipy) in different way~.~~ The dimethyls give 6-coordinate adducts of the type Zr(OR),Me,(bipy). An X-ray diffraction study of Zr(OR),Me,(4 4'-dimethyl(bipy)) shows that the bulky aryloxides are forcing the coordinated methyl groups towards the bipyridyl ligand (2). Such a steric effect presumably influences the benzyls to produce an intramolecular alkylation of the diimine. Room temperature carbonylation of Zr(OR),R in the presence of certain pyridines leads to acylation of the pyridine Study of chlorine-containing alkoxides shows that ZrC13(OPr').2THF is mer in solution:' as is (ZrC13) (c~c~o-C~H~~O,).~THF?* TiC12[O-(2 6-Me&H3)]2 (THF) is one of a number of aryloxides isolated with the general formula MC1 (OR),-,(THF) (x = 1,2; M = Ti Zr Hf); its structure (3) shows trans-chlorides 35 C.Siege1 and E. R. Thornton J. Am. Chem. SOC.1989 111 5722. 36 J. Jones and J. A. Douek Polyhedron 1989 8 2893. 37 G. E. Hofmeister E. Alvarado J. A. Leary D. I. Yoon and S. F. Pedersen J. Am. Chem. SOC.,1990 112 8843. 38 M. J. Hampden-Smith D. S. Williams and A. L. Rheingold Znorg. Chem. 1990 29 4076. 39 B. A. Vaartstra J. C. Huffman W. E. Streib and K. G. Caulton J. Chem. SOC.,Chem. Commun. 1990 1750. B. A. Vaarstra W. E. Streib and K. G. Caulton J.Am. Chem. Soc. 1990 112 8593. 41 A. Leaustic F. Babonneau and J. Livage J. Chem. SOC.,Chem. Muter. 1989 1 240 248. 42 P. Toledano M. In and C. Sanchez C.R. Acad. Sci Ser. ZZ Univers. 1990,311 1161. 43 S. Doeuff Y. Dromzee F. Taulelle and C. Sanchez Inorg. Chem. 1989 28 4439. 44 P. I. Lazziz A. Larbot C. Guizard J. Durand L. Cot and J. Joffre Acta Crystallogr. Sect C 1990,46 2332. 45 M. A. Hossain M. B. Hursthouse A. Ibrahim M. Mazid and A. C. Sullivan J. Chem. Soc. Dalton. Trans. 1989 2347. 46 L. M. Kobriger A. K. McMullen P. E. Fanwick and I. P. Rothwell Polyhedron 1989 8 77. 47 C. H. Zambrano A. K. McMullen L. M. Kobridger P. E. Fanwick and I. P. Rothwell J. Am. Chem. Soc. 1990 112 6565. 48 B. Galeffi M. Shard and J. D. Wuerst Inorg.Chern. 1990 29 955. Ti Zr Hf 159 Me .I/ *Ir\ Me "0 3 (3) cis-tetrahydrofurans and (surprisingly on steric grounds) aryl~xides.~~ MCl(OBu') (M = Zr Hf) react with LiSi(SiMe) to form (Bu'O),M-Si(SiMe,),. The zirconium compound has the shortest Zr-Si bond (2.753 A) yet reported." Lower-valent titanium alkoxides have been studied as precursors for ceramic powders and as mild reducing agent^.''-^ Thus reduction of Ti(OR)4 (R = Bun But Me,Si CH,CH,OEt) with Mg or Li affords species like LiTi(OR)4. These can be used to synthesize other bilnetallic alkoxides. Several structural studies of Ti"' aryloxides have been reported. TiC12(2 ~-BU',C~H~O)(THF)~ has a trigonal bipyramidal structure with axial THFs.'~ [NaTi( 2 6-Me,C6H30)4.py] is a dime8' in which some phenoxides are both monohapto (via oxygen) and polyhapto (through ring-metal bonding) (4).[TiC1(2 6-PhzC,H30)2]2 is a dimer with 4-coordinate titanium thanks to chlorine bridges the phenoxides being terminal.56 Deep purple paramagnetic Ti(2 6-Pr1,C6H30) (4-phenylpyridine) has a monomeric tbp structure with two axial phenylpyridines (Ti-N 2.236 A); the equatorial phenylpyridine is more tightly bound (Ti-N 2.090 A) and is believed to have undergone a 1-electron reduction so that the compound is regarded as a Ti"' deri~ative.~~ The amides MCl[N(SiMe,),] (M = Ti Zr) react with MeLi forming the 4- coordinate alkyls M( Me)[ N( SiMe,),],. The titanium compound is photosensitive (UV or sunlight) in both solid state and solution undergoing reduction to the established Ti"' compound (Scheme 1).The zirconium compound is stable to sunlight but undergoes an internal metallation in solution when exposed to UV radiati~n.'~ Using the ligand N(CH2CH2NEt2)2 affords ZrCl3.L and TiX2L (X = C1 Me Ph) believed to be 6- and 5-coordinate (5) and (6) respectively. The coloured titanium compounds have magnetic moments in the range 1.41-1.73 pB.59 Imides Ti(NR).L,(OR') (L = 4-pyrrolidinopyridine; R = Ph CMe,; R' = 2,6-Pri2C6H30) have been synthesized,6' they have tbp structures with axial pyridines 49 N. Kanehisa Y. Kai N. Kasai H. Yasuda Y. Nakayama K. Takei and A. Nakamura Chem. Lett. 1990 2167. R. H.Heyn and T. D. Tilley Inorg. Chem. 1989,28 1768. 51 L. I. Vyshunskaya V.V. Drobotenko and T. P. Samarina Zh. Obsch. Khim. 1988,58 1332. 52 E.Ger. Patent DD270528 (1989); Chem. Abstr. 1990,112,138 596. 53 F. Schmidt A. Feltz R. Colditz and K. Gustav Z. Anorg. Allgm. Chem. 1989,574,218. 54 M. Mazzanti C. Floriani A. Chiesi-Villa and C. Guastini J. Chem. SOC. Dalton Trans. 1989 1793. 55 L. D. Durfee P. E. Fanwick and I. P. Rothwell Angew. Chem. 1988,100,1218. 56 J. E. Hill J. M. Nash P. E. Fanwick and I. P. Rothwell Polyhedron 1990 9 1617. 57 L. D. Durfee J. E. Hill J. L. Kerschner P. E. Fanwick and I. P. Rothwell Inorg. Chem. 1989,28 3095. D. C.Bradley H. Chudzynska J. D. J. Backer-Dirks M. B. Hursthouse A. A. Ibrahim M. Motevalli 58 and A. C. Sullivan Polyhedron 1990,9 1423. 59 A. R. Wills P.G. Edwards M. Harman and M. B. Hursthouse Polyhedron 1989,8 1457;A. R. Wills and P. G. Edwards J. Chem. SOC. Dalton Trans. 1989 1253. 60 J. E.Hill R. D. Profilet P. E. Fanwick and I. P. Rothwell Angew. Chem.. 1990 102.713. 160 S. A. Cotton / Me I Me MCl[N(SiMe,),] 5MMe[N(Si Me,& %= Ti) (M = Ti Zr) \(M = Zr) Ti[ N(SiMe,),] (Me,Si),N CH N(SiMe,) + CH + C,H (Me,Si),N ”‘zr” \N’ \Zr” \N(SiMe,), I SiMe + CH, Scheme 1 (7). TiPh,(OR”) (R” = 2,6-Ph,C6H30) reacts with aniline to form Ti(NHPh),(OR) that in turn reacts with 4-pyrrolidinopyridine yielding Ti( NPh)L2(0R),. Some rather similar zirconium compounds have been described;61 however Zr(NPh)L,(OR”’) (8) (R”’= 2,6-But,C6H30) and Zr(NC6H3Pri2)L,(NH.C6H3Pri2) are square-pyramidal with trans-pyrrolidinopyridines and relatively long Zr-N (imide) distances of 1.84-1.87 A.R.D. Profilet C. H. Zambramo P. E. Fanwick J. J. Nash and 1. P. Rothwell Inorg. Chem. 1990,29,4362. Ti,Zr Hf 161 /@? -N tot But U 4 Porphyrins and Related Systems A trans-octahedral structure has been c~nfirmed~~,~~ for TiY,(TPP) (Y = F C1;TPP = tetraphenylporphyrin) similar to that established for the analogous bromide. Reaction of TiF2( porph) (porph = TPP octaethylporphyrin tetra-p- tolyl- porphyrin) with (C5H5),TiX5 (X = S Se) gives TiX,(~orph).~~ Crystallographic study of TiS,(tetra-p-tolylporphyrine) shows that the S2 group is bound side-on (Ti-S 2.283,2.371 A). Unlike the halides the catechol and toluenedithiolate deri- vates of Ti(TPP) are cis.TiF,(TPP) is reduced to TiF(TPP) by Zn/Hg; adding F- to the Ti”’ compound gives TiF,(TPP)- also made by electrochemical reduction of TiF2(TPP). EXAFS spectra have been obtained for a number of compounds; where available X-ray data agree well on interatomic distances.63 Reaction of TiCl,(pc) (H2pc = phthalocyanine) with Na,pc at 190°C in 1-chloronaphthalene gives66 [5.5’ :19,19’-bi(phtha1ocyaninato)ltitanium a ‘sandwich’ compound in which the two rings are ‘stapled’ together with two inter-ring C-C bonds (Figure 3.) The rings are staggered with square-antiprismatic coordination Figure 3 Structure of the ‘stapled’ phthalocyanines (Reproduced by permission from J. Chem. Soc. Dalton Trans. 1990 1971)65 62 A. Noerlund Christensen A.Grand M. S. Lehmann and D. E. Cox Acta Chem. Scand. 1990 44 103. 63 J. C. Marchon J. M. Latour A. Grand M. Belakhovsky M. Loos and J. Goulon Znorg. Chern. 1990 29 57. 64 R. Guilard C. Ratti A. Tabard P. Richard D. Dubois and K. M. Kadish Znorg. Chern. 1990 29 2532. 65 C. Ercolani A. M. Paoletti G. Pennesi G. Rossi A. Chiesii-Villa and C. Rizzoli J. Chern. Soc. Dalton Trans. 1990 1971. 66 J. Silver P. J. Lukes P. K. Hey and J. M. O’Connor Polyhedron 1989 8 1631. 162 S. A. Cotton of titanium. Zrpc exhibits electrochromic behaviour but is inferior to lanthanide phthalocyamines.66 The titanium complex of the macrocycle H2L (9) TiOL has a 5-coordinate sp structure6’ with the Ti atom 0.75 8 above the basal plane and a very short (1.653 8,) Ti-0 bond showing multiple-bond character.This Ti0 moiety forms heterometallic adducts with groups ranging from Mo(CO) to Fe(salen)Cl the Ti-0 bond lengthening to 1.706 8 on bonding to Fe(sa1en)Cl. 5 Other Complexes Ti( D20)63+ a classic transition metal complex ion has been re-examined6* by ESR ENDOR and electron spin-echo studies. Spectra were interpreted in D, symmetry (the distortion being ascribed to the Jahn-Teller effect) with gll = 1.994 and g = 1.896 obtained for an amorphous solid of a D,O/isopropanol mixture. Deuterium hfs was seen on g .Ab initio MO calculations are in good agreement with experiment the ground state is 2A,,with the d electron mainly in dZ2. Schiff-base complexes MLCl,(THF) have been made69 for a variety of tetradentate Schiff bases (e.g.L = salen salphen acen; M = Zr Hf); these are pseudo-pentagonal-bipyramidal with axial chlorines as shown by X-ray diffraction for M(salphen)Cl,.THF and Zr( acen)Cl,.THF. Recrystallization from toluene gives the unsolvated 6-coordinate MLCl (cis-chlorines) as also69 in Zr( N-methylsalicyl- ideneimine)2C12. Red TiCl,(acen) (10) and blue TiCl(acen) (1 1) have been made” the latter by NaH reduction of TiCl,(acen) (on reduction the Ti-0 and Ti-Cl bonds lengthen by ca. 0.07 A with Ti-N essentially unchanged). On oxidation Cl(acen)Ti-0-Ti(acen)CI is obtained a dimer with a linear bridge (Ti-0 CI Me L (10) L = c1 (11) L = THF 67 C. H. Yang J. A. Ladd and V. L. Goedken J. Coord. Chem. 1988 19 235. 68 H. Tachikawa T.Ichikawa and H. Yoshida J. Am. Chem. Soc. 1990 112 977,983. 69 F. Corazza E. Solari C. Floriani A. Chiesi-Villa and C. Guastini J. Chem. Soc. Dalton Trans.,1990,1335. 70 M. Mazzanti J. M. Rosset C. Floriani A. Chiesi-Villa and C. Guastini J. Chem. Soc. Dalton Trans. 1989 953. Ti,Zr Hf 163 1.813 A). A range of titanium compounds have been made for various silylated Schiff bases involving both the neutral and deprotonated forms.71 ZrL (LH = salicylaldehyde) reacts with 3,3-diaminobenzidine to yield a linear condensation polymer based on the tetrasalicylidine-3,2-diaminobenzidineligand.72 A highlight73 in zirconium chemistry is the synthesis of a blue crystalline dinitrogen complex in which the N2 molecule acts as a side-on bridging ligand (12).Ti(dmpe),Cl (dmpe = Me2PCH2CH2PMe2) reacts with MBH (M = Li Na) to yield Ti(dmpe)( q2-BH4) a stable paramagnetic compound with weakly bound borohydride~.~ MC14 (M = Zr Hf) species react with NaBH in 1,2-dimethoxyethane (DME) to form Na( DME)3M( BH4)3 ;Ph4P and Bu4N salts have also been obtained.75 IR spectra indicate a mixture of bi- and tri-dentate borohydrides (unlike M(BH4) where all borohydrides are tridentate). NMR shows M(BH4)5- to be fluxional. The polypyra~olylborate~~ ZrLC13 (L = HB(3,5-Me2C3N2H)3)reacts with various phenols HOC6H4Z to afford ZrL(OC6H,Z)3 featuring trigonally distor- ted octahedral coordination of zirconium; the phenyl rings lie in clefts between the pyrazolyl rings (Figure 4). Figure 4 (Reproduced by permission from Polyhedron 1989 8 845) 71 A.De Blas A. Rodriquez A. Macias R. Bastida A. Sousa 0. Ferro and A. Diaz An. Quim. Ser. B 1988 84 287. 72 R. D. Archer and B. Wang Inorg. Chem. 1990 29 39. 73 M. D. Fryzuk T. S. Haddad and S. J. Rettig J. Am. Chem. Soc. 1990 112 8185. 74 J. A. Jensen and G. S. Girolarni Inorg. Chem. 1989 28 2107. 75 V. D. Makhaev A. P. Borisov G. N. Boiko and B. B. Tarasov I. Akad. Nauk SSSR Ser. Khim. 1990,1207. 76 R. A. Kresinski T. A. Harnor L. Isarn C. J. Jones and J. A. McCleverty Pol.vhedron 1989 8 845. 164 S. A. Cotton 6 Organometallics Only some highlights are dealt with here. The alkyls MMe,(dippe) and [Li(tmed)],MMe (dippe = PI-' PCH,CH2ppr'2; M = Zr,Hf) have been made demonstrating the proven role of coordinative saturation towards stability.77 [Li(tmed)],ZrMe has been shown by X-ray diffraction to be the first ML complex to have a trigonal prismatic geometry ascribed to a second-order Jahn-Teller distortion.Variable-temperature NMR studies indicate that this structure is retained in solution. The gas-phase structure of CH3TiC13 has been determined by electron- it is assigned C3 symmetry with Ti-CI 2.185 A Ti-C 2.047 A and diffra~tion;~~ LClTiC 105.6'. A number of studies have appeared concerning Zr"' compounds of the type (CSH,-,R,)ZrX produced in various ways such as shown in Scheme 2. Zirconium f hv / isobutene + (C,H,),ZrI( CH,CHMe,) isobutane Scheme 2 (III) compounds with unsubstituted rings are unstable with respect to disproportion- ation to (C,H,),ZrX2 and (CSH,),Zr.Nevertheless the structure of the diamagnetic (CSHs)2ZrI,Zr(CSHs)2had been determined,79 with a long Zr-Zr distance (3.669 A) indicating no metal-metal bond. [(C,H,Me),ZrI] and [(CsH3( SiMe3)2)2ZrC1] " are similarly dimeric but monomeric adducts [CsH,( SiMe3),]ZrC1L (L = THF PMe,) have been characterized in solution by their ESR spectra which show hfs due to both 91Zr and 31P.Using even bulkier substituents the monomeric paramag- netic (CsH3B~12)2 MCI have been mades2 (M = Zr Hf). The complex (CSMe5).Zr( C8H8) has a sandwich structure isostructural with the Ti anal~gue.'~ The thermally labile (CsHS)Zr(mesityl) has been synthesized and 77 P. M. Morse and G. S. Girolarni J. Am. Chem. Soc. 1989 111 4114.78 P. Briant J. C. Green A. Haaland H. Moellendal K. Rypdal and J. Tremrnel J. Am. Chem. SOC.1989 111,3434. 79 Y. Wielstra S. Garnbarotta A. Meetsrna and J. L. DeBoer Organometallics 1989 8 250. 80 Y. Wielstra S. Gambarotta A. Meetsrna and A. L. Spek Organometallics 1989 8 2948. A. Antinolo M. F. Lappert G. A. Lawless and H. Olivier Polyhedron 1989 8 1882. 82 I. F. Uravovskii V. I. Ponornarev I. E. Nifantiev and D. A. Lernenovskii J. Organornet. Chem. 1989 368 287. 83 R. D. Rogers and J. H. Teuben J. Organornet. Chern.. 1989 359 41 Ti Zr Hf 165 an X-ray analysis shows that the ortho-methyl groups protect the zirconium atom from The compound undergoes CO insertion at 0 "C. At room-temperature it decomposes by solvent-dependent routes in ether affording a dimer with a triple-decker structure.Reaction of (C5H,),ZrCl with AlC13 yields (C5H5),ZrCl.( AlClp the Zr-Cl-A1 link has a weakly bound chlorine (Zr-C1 is 0.2A longer than in the other Zr-C1 bond) implicated in the functioning of this model system for Ziegler- Natta catalysts. (C,H5)2Zr (cyclo-C4H4)CH3 stable at 0 "C as a waxy solid eliminates methane on warming to 35 "C affording a cyclobutane complexs6 that was trapped by adduct formation (13). It undergoes insertions with a range of unsaturated groups. Relevant reviews cover areas such as centered zirconium chloride clusters,s7 metal alkoxides as precursors for ceramic materialsBs and a related one on heterometallic alkoxidess9 complexes of group 3 and 4 elements with phosphines" and carbonyl coupling reactions using low-valent titanium." 84 P.Berno S. Stella C. Floriani A. Chiesi-Villa and C. Guastini J. Chem. Soc. Dalton Trans. 1990 2669. 85 M. V. Gaudet M. J. Zaivorotko T. S. Cameron and A. Linden J. Organomet. Chem. 1989 367 267. 86 R. A. Fisher and S. L. Buchwald Organometallics 1990 9 871. 87 R. P. Ziebarth and J. D. Corbett Acc. Chem. Res. 1989 22 256. nu D. C. Bradley Chem. Rev. 1989 89 1317. 89 K. G. Caulton and L. G. Hubert-Pfalzgraf Chem. Rev. 1990,90 969. 90 M. D. Fryzuk T. S. Hadad and D. J. Berg Coord. Chem. Rev. 1990 99 137. 9' J. E. McMurray Chem. Rev. 1989,89 1513.

ISSN:0260-1818    

DOI:10.1039/IC9908700155

出版商:RSC    

年代:1990

数据来源: RSC

摘要:

9 Electronic Conductors Including High Temperature Superconductors By C. GREAVES School of Chemisrry University of Birmingham B 15 2T 1 Introduction This report is aimed at summarizing the most significant developments in the chemistry of inorganic electronic conductors. Since most of the advances still relate to mixed metal oxide superconductors attention is focused on this area (Section 2). Section 3 describes some of the more significant studies of materials which are not simple oxides or are not intimately linked to high temperature superconductors. 2 High Temperature Superconductors The literature relating to high temperature superconductors has reflected a general advancement in our understanding of the fundamental chemistry and processing characteristics of these systems rather than the discovery of new superconducting phases with even higher critical temperatures which has been a feature of previous years.’ Several general reviews have provided a comprehensive overview of the chemistry2 and structural properties3-’ of these materials.Oxide superconductors are receiving widespread interdisciplinary attention and the borders between chemistry physics and materials science are therefore vague and subjective. In this report seven general areas are considered which are thought to encompass the most significant chemical advances Synthesis; Structure and Composition of the Main Superconducting Families; Electronic Characterization; Cation Substitutions in Known Structure Types; New Superconducting Phases; Intercalation Chemistry; and Experimental Indicators to Possible Mechanisms.Synthesis.-There is currently less emphasis on the development of alternative synthetic procedures (e.g.sol-gel methods) for the common materials. In this section attention is therefore focused on reports of novel ideas or attempts to prepare the ‘high pressure’ YBa2Cu408 (and related materials) under ambient conditions. Studies of the interesting SCD (self-propagating chemical decomposition) synthesis of YBa2Cu307 have continued. These methods involve the use of oxidizing (nitrate) and reducing anions which react exothermically at low temperatures to produce ’ D. P. Hamilton Science 1990 250 374. P. M. Grant Ado. Mater. 1990 2 232. J. D. Jorgensen and D. G. Hinks Neutron News 1990 1 24.B. Raveau C. Michel M. Hervieu D. Groult and J. Provost J. Solid Stare Chem. 1990 85 181. R. J. Cava Science 1990 247. 656. 167 168 C.Greaves highly dispersed homogeneous mixed metal oxides. Spray dried precursors contain- ing nitrate anions and amino acids were found to react at 200 "C in oxygen to form materials which could subsequently be converted to YBa2Cu307 by heating at 910 "C for 10 minutese6 Successful attempts at the synthesis of YBa2Cu,08 at ambient pressure have been reported. It has been suggested that essentially conventional ceramic techniques may be used if the reactants and reaction conditions are carefully ~ontrolled.~-~ Alternative sol-gel routes also appear to allow the use of sufficiently low reaction temperatures (less than 815 "C) to avoid the formation of YBa2Cu307 .lo*ll The partial replacement of Y by Ca (lo%) which raises T by 6 K decreases the phase stability and hence ease of synthesis but by using a mixture of oxides and nitrates a successful synthesis of the doped variant at 1 bar oxygen has been reported.' The decomposition of YBa2Cu408 to YBa2Cu307 has been examined as a function of temperature and pressure and the decomposition found to occur at 877 "C in one atmosphere oxygen.13 The formation of high quality thin films remains a high priority.Of the commonly employed fabrication processes MOCVD relies most heavily on chemical input. This method has produced films of excellent quality from fluorinated precursors T12Ba2CaCu20 from fluorinated P-diketonate complexes of Ba Ca and Cu with a separate step to introduce Tl (T onset 125 K);I4 YBa2Cu307 from trifluoroacetate precursors (J = lo6A cm- at 77 K zero field).I5 Structure and Composition of the Main Superconducting Families.-Our incomplete understanding of even the most widely studied HTSC materials is reflected in the wealth of reports relating to fundamental chemical aspects including stoichiometry structural defects and microstructure.Potentially of great significance is a report of a detectable structural change at 7''in T12Ba,CaCu208 .I6 Using pulsed neutron diffraction (ND) data correlated displacements of Cu and 0 atoms perpendicular to the [CuO,] planes were found to occur. These displacements involving short-range order only were thought to relate to repulsions between holes on the Cu and 0atoms.A comprehensive ND study17 of quenched samples of YBa2Cu307-, 0.07 < y < 0.91 was consistent with the gradual reduction in hole concentration on the [CuO,] planes as y increased. No explanation was found for the plateau in T at 60 K for y -0.4. Detailed discussion of the correlation of T with electron distribution in this phase is presented below. The study also found evidence for the presence of vacancies at the O(4) atom positions which link the chain Cu(1) and layer Cu(2) K. Kourtakis M. Robbins and P. K. Gallagher J. Solid State Chem. 1990 84 88. ' D. M. Pooke R. G. Buckley M. R. Presland and J. L. Tallon Phys. Rev. B 1990 41 6616. U. Balachandran M. E. Biznek G.W. Tomlins B. W. Veal and R. B. Poeppel Physicu C 1990 165 335. S. Jin H. M. O'Bryan P. K. Gallagher T. H. Tiefel R. J. Cava R. A. Fastnacht and G. W. Kammlott Physica C 1990 165 415. LO H. Murakami S. Yaegashi J. Nishino Y. Shiohara and S. Tanaka Jpn. J. Appl. Phys. 1990 29 L445. R. S. Liu R. Janes M. J. Bennett and P. P. Edwards Appl. Phys. Lett. 1990 57 920. l2 R. G.Buckley J. L. Tallon D. M. Pooke and M. R. Presland Physicu C 1990 165 391. 13 T. Mathews and K. T. Jacob Appl. Phys. Lett. 1990 57 511. 14 N. Hamaguchi R. Gardiner P. S. Kirlin R. Dye K. M. Hubbard and R. E. Muenchausen Appl. Phys. Lett. 1990 57 2136. 15 P. C. McIntyre M. J. Cima and M. F. Ng J. Appl. Phys. 1990 68 4183. 16 B. H. Toby T. Egami J. D. Jorgensen and M. A. Subramanian Phys.Rev. Lett. 1990 64 2414. 17 J. D. Jorgensen B. W. Veal A. P. Paulikas L. J. Nowicki G. W. Crabtree H. Claus and W. K. Kwok Phys. Rev. B 1990 41 1863. Electronic Conductors Including High Temperature Superconductors 169 Cu sites and this observation was supported by similar measurements on quenched and annealed samples of low oxygen content.l8 Rapidly quenched samples in this composition range were reported not to show the plateau at 60 K and the formation of O(4) vacancies under these conditions was considered a feasible explanation." In this system two studies have been reported of a tetragonal phase with very high oxygen content YBa2C~306.8 prepared by different Although the average structure appears similar to that of tetragonal materials with lower oxygen content electron microscopy (EM) examination suggested the presence of microdomains of YBa2Cu30 and YBa2Cu308 .21 A non-superconducting sample of YBa2C~306,41 was found to develop a superconducting transition (T = 20 K) on standing at room temperature22 (Figure 1).Neutron diffraction suggested that this ' ' ' ' ' 25r-t ,,, ,,, 1 5 .' 3000 6000 9000 Time(min) Figure 1 Superconducting transition temperature as a function of annealing time at room temperature for quenched YBa2Cu306,41 (Reproduced by permission from Physica C 1990 167 571) resulted from oxygen ordering in the chains and the subsequent injection of holes into the [CuO,] layers. The change in Cu(2)-0(4) distance with time (Figure 2) provided the principal evidence for this conclusion.This phenomenon may be relevant to thermodynamic calculations which supported the possibility that oxygen ordering effects may induce a phase transition at the even lower temperature of 240 K.23 A new 2 fia x 2 fia superstructure has also been observed by high resolution electron microscopy (HREM) in formed within the electron micro~cope.~~ The nature of the oxygen excess in Bi2Sr2CaCu2Os+, has been examined by titrimetric and thermogravimetric analy~is,~' and single crystal X-ray diffraction C. Greaves and P. R. Slater Solid State Commun. 1990 74 591. 19 C. Namgung J. T. S. Irvine and A. R. West Physica C 1990 168 346. 20 H. Shibata K. Linoshita and T. Yamada Jpn. J. Appl. Fhys. 1990 29 L423. 21 V.Caignaert M. Hervieu J. Wang G. Desgardin B. Raveau F. Boterel and J. M. Haussonne Physica C 1990 170 139. 22 J. D. Jorgensen S. Pei P. Lightfoot H. Shi A. P. Paulikas and B. W. Veal Physica C 1990 167 571. 23 L. G. Mamsurova K. S. Pigalskiy V. P. Sakun A. I. Shushin and L. G. Scherbakova Physica C 1990 167 11. 24 T. Krekels T. S. Shi J. Reyes-Gasga G. Van Tendeloo J. Van Landuyt and S. Amelinckx Physica C 1990 167 677. 25 J. T. S. Irvine and C. Namgung J. Solid Stare Chem. 1990 87 29. 170 C.Greaves i Figure 2 Cu(2)-0(4) bond lengths versus annealing time at room temperature for quenched YBa2CU306.41 (Reproduced by permission from Physica C 1990 167 571) (XRD) has rationalized the observed incommensurate modulations with interstitial 0 atoms in the [BiO] layers.26 A single crystal neutron diffraction study of a material with similar composition however suggested a commensurate superstructure with period 102.5 A (19ao) due to oxygen insertion in these 1aye1-s.~' Similar location of interstitial 0 atoms (between [?lo]layers) has been proposed for T12BazCu06+y.2s Scanning tunnelling microscopy (STM) has shown great potential for revealing microstructural characteristics in Bi2Sr2CaCu208+y.The edges of individual [Cu02] and [BiO] layers have been imaged and the former found to be metallic and the latter ~emiconducting.~~ An STM study of Pb-doped materials indicated that Pb distorts and disorders the superstru~ture.~~ The direct observation of planar defects in L~,-,S~,CUO~~ and YBa2Cu40832 has been achieved by HREM.The decomposition of YBa2Cu,08 ('124') has been investigated by HREM33 and found to initially form YBa2Cu30 ('123') and YBa2Cu509('125') The latter phase was shown to have three edge-shared [CuO,] chains whereas YBa,Cu408 and YBa2Cu307 have two and one respectively. Structural changes in Ba,-,K,Bi03 34 and Nd2-,Ce,Cu04 35 as a function of x have also been reported. For the latter system it was suggested that single phase behaviour may occur only for the end member x = 0 and the optimum super- conducting composition x = 0.165. Electronic Characterization.-The importance of photoemission studies for probing the electronic structure of oxide superconductors has been described in three review 26 V.Petricek Y. Gao P. Lee and P. Coppens Phys. Rev. B 1990 42 387. 27 A. I. Beskrovnyi M. Dlouha Z. Jirak S. Vratislav and E. Pollert fhysica C,1990 166 79. 28 Y. Shimakawa Y. Kubo T. Manako H. Igarashi F. Izumi and H. Asano Phys. Rev. B 1990,42,10165. 29 T. Hasegawa and K. Kitazawa Jpn. J. AppL fhys. 1990 29 L434. 30 X. L. Wu Z. Zhang Y. L. Wang and C. M. Lieber Science 1990 248 1211. 31 P. L. Gai and E. M. McCarron 111 Science 1990 247 553. 32 T. Krekels G. Van Tendeloo S. Amelinckx D. M. De Leeuw and M. De Kraan fhysica C 1990 169 457. 33 R. Ramesh S. Jin and P. Marsh Nature (London) 1990 346 420. 34 S. Pei J. D. Jorgensen B. Dabrowski D. G. Hinks D. R. Richards A. W. Mitchell J. M. Newsam S. K. Sinha D. Vaknin and A. J. Jacobson fhys.Rev. B 1990,41,4126. 35 P. Lightfoot D. R.Richards B. Dabrowski D. G. Hinks S. Pei D. T. Marx A. W. Mitchell Y. Zheng and J. D. Jorgensen fhysica C 1990 168 627. Electronic Conductors Including High Temperature Superconductors 171 The inconsistency of data obtained by different groups remains a problem and doubts concerning the assignment of certain features to the bulk superconductor the superconductor surface or contamination are incompletely resolved. Significant surface contamination is known to occur especially for YBa2Cu307 and various approaches have been employed to minimize such effects.36 This problem is exemplified by recent controversy surrounding the assignment of the 0 1s core peak at -531 eV in La2Cu04+y 39,40 to 02-species.The problem is complex and requires consideration of whether the energy is consistent with 02-species whether such ions are present in the bulk or just at the surface and whether other surface contaminants are more likely to be responsible. The characteristics of the band containing the itinerant holes or electrons are of fundamental importance to our understanding of the nature of high temperature superconductivity. The overwhelming experimental evidence now points to the hybridized Cu 3d(x2 -y2)/02p(x y) orbitals at the Fermi energy being largely 0 2p in character for p-type superconductors and Cu 3d in character for n-type (Nd,Ce)2Cu04.4147 However for LaCuO, shifts in the Cu 2p3I2 peak of 2.6 eV relative to CuO have been reported4’ and attributed to holes on Cu.The influence of formal Cu oxidation state on core and Fermi-level photoemission spectra has been reported for the system Bi2Sr2Ca,_,Y,Cu20y.4143 The electronic states of the surface [BiO] layers in Bi2Sr2CaC~208+y have been investigated by angle-resolved photoemission of samples coated with Au films.49 It was concluded that the [BiO] layers were metallic and superconducting for samples that had been oxygen annealed at high temperature but not for as-grown crystals. STM studies of Bi2Sr2CaC~208+y have indicated the superconducting band gap at 4 K to be 26 meV (2A/ kT = 7),” significantly larger than the expected BCS value. An important feature of oxide superconductor research in 1990 has been the attempt to correlate superconducting properties with electronic factors particularly the hole/electron concentration on the [Cu02] layers in copper systems and the results of some of these studies have been revie~ed.~.~~ Unfortunately since charge distributions have necessarily relied largely on indirect assessment from structural 36 R.G. Egdell W. R. Flavell and M. S. Golden Supercond. Sci. Technol. 1990 3 8. 37 F. Al Shamma and J. C. Fuggle Physica C 1990 169 325. 38 G. Margaritondo J. Am. Ceram. SOC.,1990 73 3161. 39 M. Strongin S. L. Qiu J. Chen C. L. Lin and E. M. McCarron Phys. Rev. B 1990 41 7238. 40 N. D. Shinn J. W. Rogers jun. and J. E. Schirber Phys. Rev. E 1990,41 7241. 41 M. S. Golden S. J. Golden R. G. Egdell and W. R. Flavell J. Less-Common Met. 1990 164/165 1084.42 Y. Shichi Y. Inoue F. Munakata and M. Y. Yamanaka Phys. Rev. B 1990,42 939. 43 R. Itti F. Munakata K. Ikeda N. Koshizuka and S. Tanaka Physica E 1990 1651166 1223. 44 J. Fink N. Nucker H. Romberg M. Alexander and P. Adelmann J. Less-Common Met. 1990 164/165 967. 45 I-!. Eisaki H. Tagaki S. Uchida H. Matsubara S. Suga M. Nakamura K. Yamaguchi A. Misu H. Namatame and A. Fujimori Phys. Rev. E 1990 41 7188. 46 Y. Sakisaka T. Maruyama Y. Morikawa H. Kato K. Edamoto M. Okusawa Y. Aiura H. Yanashima Y. Bando K. Iijima K. Yamamoto and K. Hirata Solid State Commun. 1990 74 609. 47 Y. Sakisaka T. Maruyama Y. Morikawa H. Kato K. Edamoto M. Okusawa Y. Aiura H. Yanashima Y. Bando K. Iijima K. Yamamoto and K. Hirata Phys. Rev. E 1990 42 4189.48 K. Allan A. Campion J. Zhou and J. B. Goodenough Phys. Rev. B 1990 41 11572. 49 B. 0.Wells Z-X. Shen D. S. Dessau W. E. Spicer C. G. Olson D. B. Mitzi A. Kapitulnik R. S. List and A. Arko Phys. Rev. Lett. 1990 65 3056. 50 K. Ichimura K. Nomura F. Minami and S. Takekawa J. Phys. Condens. Matter 1990 2 9961. 51 M. W. Shafer and T. Penney Eur. J. Solid State Inorg. Chem. 1990 27 191. 172 C. Greaves data and bond valence sum (BVS) analysis their accuracy and validity have been controversial. The most significant report describes a powder ND study of YBa2Cu30,- (referred to as YBa,Cu,O,) samples prepared by a Zr-gettering te~hnique.~' Bond valence sum values for the cations are shown in Figures 3 and 4 and the proposed correlation of T with Cu(2) BVS is shown in Figure 5.However 2.8' ' 7 6 x in Ba2YCu30 Figure 3 Bond valence sums around Ba and Y as a function of oxygen stoichiometry (Reproduced by permission from Physica C 1990 165 419) 2.5 I I I I I 2.12' I 7 6 x in Ba2YCu~0 Figure 4 Bond valence sums around the chain Cu(1) and plane Cu(2) sites as a function of oxygen stoichiometry (Reproduced by permission from Physica C 1990 165 419) R. J. Cava A. W. Hewat E. A. Hewat B. Batlogg M. Marezio K. M. Rabe J. J. Krajewski W. F. Peck jun. and L. W. Rupp jun. Physica C 1990 165 419. Electronic Conductors Including High Temperature Superconductors 100 I I I I 80 - x. 60 C’ 40 20 0 2.22 i f 0 w 0 z 2.17 a > n Z om 2.1 2 6 x in Ba2YCuS0 Figure 5 Comparison of T and bond valence sum around Cu(2) as a function of oxygen stoichiometry (Reproduced by permission from Physica C 1990 165 419) the apparent correlation of the 60 K T plateau with this BVS (and hence hole concentration on [CuO,] planes) should be treated with caution for the following reasons (i) But for one point (x = 6.35) the Cu(2) BVS appears to decrease uniformly with x.(ii) Changes in oxygen stoichiometry should be reflected in the Cu(1) and Cu(2) BVS values. If the Cu(2) BVS shows a plateau the Cu( 1) data should mirror this behaviour whereas the only noticeable change appears to occur at the Y site. (iii) The data of Jorgensen et all7 do not show this detailed correlation.Furthermore BVS calculations do not allow satisfactory comparison of different superconducting systems (La- Sr- and Ba-classes for example) due to internal strain effects associated with ionic size.53 The partial replacement of La in (La,Sr),CuO by various lanthanide cations confirmed this.54 As the size of the lanthanide substituent decreased T and the hole concentration as deduced by chemical analysis also decreased whereas the Cu-0 distances were consistent with an increased hole density when considered using simple BVS criteria. Attempts have been made to refine BVS calculations to obtain the total hole concentration on the [CuOz] layers and the distribution within the layer (on Cu or O).55-57However 53 M-H. Whangbo and C. C. Torardi Science 1990 249 1143.54 M. A. Subrarnanian,J. Gopalakrishnan and A. W. Sleight J. Solid State Chern. 1990 84 413. 55 J. L. Tallon Physica C 1990 168 85. 56 J. L. Tallon and G. V. M. Williams J. Less-Common Met. 1990 164/165 70. 57 D. M. De Leeuw W. A. Groen L. F. Feiner and E. E. Havinga Physica C 1990 166 133. 174 C.Greaves such an approach has been refuted by Brown,58 who concluded that the hole distribution cannot be inferred in this way. Furthermore he emphasized that BVS rules do not hold for the oxide superconductors and illustrated this with the variation of Ba BVS from 1.79-2.18 in YBa2Cu307-,, depending on y. The problem is associated with internal tensile or compressive strains on atoms in high symmetry structures.Given the limitations of BVS calculations they have nevertheless been used successfully to correlate changes in T induced by pressure variations on samples of YBa2C~307-y .59,60 YBa2Cu408 and Y2Ba4Cu7015 For Bi-and Tl-based superconducting families several reports61d4 have suggested a strong correlation between T and the hole concentration with T,(max) occurring at 0.2-0.3 holes per Cu. Complications could however occur if the Bi and T1 oxidation states were below three which has been implied by XANES (Bi phases)65 and chemical analyses (T1 phases).66 ,05Tl NMR studies on the other hand are consistent with the presence of TI3+ions.67,68 Cation Substitutions in Known Structure Types.-Although a wide variety of new superconductors have been reported many represent fairly minor chemical modifications of known structure types.Examples related to the ‘1212’ series (parent T1Sr2CaCu207) are (Pb,Ca)Sr2(Ca,Y)Cu2O,_ with T up to 80 K;69 (Pb,Sr)Sr2(Ca,Y)Cu207-,,with T up to 75 K;70 (T1,M)Sr2(Ca,Y)Cu207_, M = IVA/VA cations with T up to 100K,71(T~,P~)S~,(C~,Y)CU,O~-~ with T up to 110 K.72 (ll,Pb)Sr,(Ca,Y)C~~0~-~ appears a particularly flexible system the elec- trical characteristics of which can be optimized by controlling the chemical composi- tion and hence hole c~ncentration’~ (Figure 6). The maximum T corresponds to a hole density of 0.18 per Cu. Phases reported which belong to the ‘2212’ and ‘1223’ types are Bi2(Ca,Nd)2CaCu20y (T = 40 K),73 and (T1,Bi)Sr,Ca2Cu309 with T = 115-120 K.74 New Superconducting Phases.-Despite many unsuccessful previous attempts super- conductivity has now been reported for the LazSrCu206 structure.Superconducting 58 I. D. Brown Physica C 1990 169 105. 59 A. W. Hewat P. Fischer E. Kaldis E. A. Hewat E. Jilek J. Karpinski and S. Rusiecki J. Less-Common Met. 1990 1641165 39. 60 J. D. Jorgensen S. Pei P. Lightfoot D. G. Hinks B. W. Veal B. Dabrowski A. P. Paulikas R. Kleb and I. D. Brown Physica C 1990 171 93. 61 P. Somasundaram R. Vijayaraghavan R. Nagarajan R. Seshadri A. M. Umarji and C. N. R. Rao Appl. Phys. Lett. 1990 56 487. 62 M. A. Subramanian P. L. Gai and M-H. Whangbo Muter. Res. Bull. 1990 25 899. 63 W. A. Groen D. M. De Leeuw and G. P. J. Geelen Physica C 1990 165 305. 64 W. A. Groen D.M. De Leeuw and L. F. Feiner Physica C 1990 165 55. 65 R. Retoux F. Studer C. Michel B. Raveau A. Fontaine and E. Dartyge Phys. Rev. B. 1990,41 193. 66 M. Paranthaman A. Manthiram and J. B. Goodenough J. Solid State Chem. 1990 87 479. 67 N. Winzek F. Hentsch M. Mehring H. Mattausch R. Kremer and A. Simon Physica C 1990 168,327. 68 D. M. De Leeuw W. A. Groen J. C. Jol H. B. Brom and H. W. Zandbergen Physica C 1990,166,349. 69 T. Rouillon A. Maignan M. Hervieu C. Michel D. Groult and B. Raveau Physica C 1990 171 7. 70 T. Rouillon J. Provost M. Hervieu D. Groult C. Michel and B. Raveau J. Solid State Chem. 1990 84,375. R. S. Liu W. Zhou and P. P. Edwards Appl. Phys. Lett. 1990 57 2492. 72 R. S. Liu P. P. Edwards Y. T. Huang S. F. Wu and P.T. Wu J. Solid State Chem. 1990 86 334. 73 T. Kawano F. Munakata A. Nozaki T. Ikemachi H.Yamauchi and S. Tanaka Physica C 1990 165 67. 74 M. A. Subramanian P. L. Gai and A. W. Sleight Muter. Res. Bull. 1990 25 101. Electronic Conductors Including High Temperature Superconductors Figure 6 Compositional efects of T with variations in x (Tl:Pb content) or y (Y Ca content) in (a) (Tl,-x Pb,)CaSr,Cu,O,- (b) Tl(Ca,-,.Y,)Sr,Cu,O,- (c) (Tl,-.xPbx)-(Ca0.8Y0.2)Sr2Cu207-z (Reproduced with permission from J. Solid State Chern. 1990 86 334) (La,Sr)2CaC~206, T = 60 and (La,Ca)2CaCu206 T = 45 K,76,77have been synthesized using appropriate precursors and/or high pressure techniques. Both YBa2C~307.7 (T = 92 K)78and YSr2Cu307-, (T = 60 K)79have also been synthe- sized under high oxygen pressure.These materials which are both tetragonal are notable for the very high formal Cu oxidation state (2.8) in the former and the fact that YSr2Cu30 cannot be synthesized under normal conditions. The phases YBa2Cu509 and YBa2Cu,0, have been observed in HREM studies of the decompo- sition of YBa,Cu408 33 and Li intercalation into YBa2CU4O8 ,80. respectively but their electrical characteristics are unknown. The structure of Pb2SrLaCu20,+ ( T = 35 K) has been shown to be related to Pb2Sr2YCu308 but with only a single superconducting layer of linked CuO octahedra rather than the Cu05-Y-Cu05 sandwich in Pb2Sr2YCU308.81 Superconductivity at 28 K has also been found in (P~,CU)(L~,S~)~CUO,,,~~-~~ which can be described as having a very simple '1201' 75 R.J. Cava B. Batlogg R. B. Van Dover J. J. Krajewski J. V. Waszczak R. M. Fleming W. F. Peck jun. L. W. Rupp jun. P. Marsh A. C. W. P. James and L. F. Schneemeyer Nature (London) 1990 345 602. 76 K. Kinoshita H. Shibata and T. Yamada Physica C 1990 171 523. 77 A. Fuertes X. Obradors J. M. Navarro P. Gomez-Romero N. Casan-Pastor F. Perez J. Fontcuberta C. Miravitlles J. Rodriguez-Carvajal and B. Martinez Physica C 1990 170 153. 78 B. Okai Jpn. J. Appl. Phys. 1990 29 L2193. 79 B. Okai Jpn. J. Appl. Phys. 1990 29 L2180. 80 M. A. Senaris-Rodriguez A. M. Chippindale A. Varez E. Moran and M. A. Alario-Franco Physica C 1990 172 477. " K. Nakahigashi H. Sasakura S. Minamigawa and M. Kogachi Jpn.J. Appl. Phys. 1990 29 L1422. 82 S. Adachi K. Setsune and K. Wasa Jpn. J. Appl. Phys. 1990 29 L890 and L1799. 83 S. Sasakura K. Nakahigashi A. Hirose H. Teraoka S. Minamigawa K. Inada S. Noguchi and K. Okuda Jpn. J. Appl. Phys. 1990 29 L1628. 84 K. Nakahigashi H. Sasakura K. Watari and S. Minamigawa Jpn. J. Appl. Phys. 1990 29 L1856. 176 C. Greaves perovskite-related structure. Superconductivity has been reported in CaSr2Cu307 ,85 Y,B~,CU,O~-~and Y2Ba1.5Cao,5C~308+y,87 86 but detailed characterization is still lacking. New materials in which Sr ions separate [CuO,] layers have been synthesized the ‘2212’ phase B~,S~,S~CU,O~+~ 80 K using thin film preparative tech- T,= niquesg8 and the ‘1223’ phase (T1,Pb)Sr2Sr2Cu309 T = 60 K.89Many compounds have also been reported where [L202] blocks (L = lanthanide) with a fluorite configuration interleave two [CuO,] layers.An example based on the normal ‘1212’ type of structure is (Pb,Cu)(Eu,Sr),(Eu,Ce),Cu,O (T = 25 K) where [(Eu,Ce),O,] layers have replaced the conventional Ca/Y atorn~~~’~’ (Figure 7). e :Pb Cu :Eu Ce 8 :Eu Sr :cu 0:o Figure 7 Schematic representation of the structure of (Pb,Cu)( Eu,Sr),( Eu,Ce),CuO (Reproduced by permission from Physica C 1990 169 133) Other examples are the ‘2212’ related Bi2Sr2(Gd,Ce)2Cu2010+y T = 34 K,92 and [Lal/6L1/3Bal/6Sr,/,ce~/6]gcu6o~(L = Eu Gd Dy Ho Y) T = 1540 KY3 h interesting extension to the fluorite block to form [L304] layers has been achieved 85 X.Fei D. F. Lu G. F. Sun K. W. Wong F. T. Chan Z. Z. Sheng Y. Xin P. C. W. Fung C. C. Lam W. Y. Ching and Y. Xu,Solid State Commun. 1990 76 1357. 86 R. G. Kulkarni J. A. Bhalodia M. A. Abdelgadis and P. Boolchand Solid State Commun. 1990,76,159. 87 R. G. Kulkarni G. J. Baldha H. Mohan R. B. Jotania H. H. Joshi V. Skumryev and K. V. Rao Solid State Commun. 1990 73 511. 88 H. Adachi Y. Ichikawa K. Hirochi T. Matsushima K. Setsune and K. Wasa Jpn. J. Appl. Phys. 1990 29 L81. 89 V. Manivannan A. K. Ganguti G. N. Subbanna and C. N. R.Rao Solid State Commun. 1990,74,87. 90 T. Maeda K. Sakuyama S. Koriyama A. Ichinose H. Yamauchi and S. Tanaka Physica C 1990,169 133. 91 K. Yamaguchi T. Takata K. Sakuyama T. Maeda N. Koshizuka H. Yamauchi and S. Tanaka Physica C 1990 170 486.92 T. Arima Y. Tokura H. Takagi S. Uchida R. Beyers and J. B. Torrance Physica C 1990 168 79. 93 T. Wada A. Ichinose Y. Yaegashi H. Yamauchi and S. Tanaka Jpn. J. Appl. Phys. 1990 29 L266. Electronic Conductors Including High Temperature Superconductors 177 in the '1212' related phase (Cu,M)Sr2(Ho,Ce),Cu2011 (M = Pb Fe Al) which appears to be non-supercond~cting.~~ There have been few reports of superconductivity in new mixed metal oxides containing no copper. Evidence for superconductivity in powder samples of Sr- and Ca-doped La2Ni04 has now been rep~rted,~' although the superconducting fraction is very small (-1%)-Controversial claims of superconductivity (T up to 160 K) in the T1-doped Sr-V-0 system have also been made:6 but conclusive confirmation of these properties has not been forthcoming.Intercalation Chemistry.-The intercalation of I2 into Bi2Sr2CaCu208+ has been reported to occur at 150-200 "C to form IBi2SriCaCu208+, T = 80 K.97 Molecular I2 is thought to occupy the planes between the [BiO] layers to give a 23% expansion in the [OOl] direction. The electrochemical incorporation of cations into Bi2Sr2CaCu208+ has also been claimed Li (T increases of up to 20K);98 Cu (superconductivity de~troyed);~~ and Ag (T increases of up to 15 K).99 Lithium insertion into YBa2Cu408 8o has been found to result in the formation of the n = 6 member of the series Y2Ba4Cu6+,,OI4+,, in which there are four adjacent layers of linked square planar Cu04 chains.The electrochemical oxidation of La2Cu04 in aqueous alkaline media has been reported to form superconducting La2CuOq+ .loo,lol Superconductivity in Lio.sNb02 is claimed to be the first example of a layered early transition metal superconducting oxide.lo2 The composition represents a 75% full band and the low T (5 K) provides no evidence that in this part of the Periodic Table low dimensionality will result in higher superconducting transitions than for the three-dimensional spinels. Experimental Indicators to Possible Mechanisms.-Some reported experimental observations appear particularly relevant to theoretical approaches to the mechan- isms of high temperature superconductivity. Tunnelling spectroscopy measurements on (Ba1-,K,)BiO3 and (Ndl-xCex)Cu04-y,103 and inelastic neutron scattering on the latter,lo4 support earlier reports that electron-phonon coupling is primarily responsible for superconductivity in these systems with relatively low critical tem- peratures.Circular dichroism and muon-spin rotation experiments on YBa2Cu30,- and Bi2Sr2CaCu208 have prompted some workers to suggest that in these super- conductors anyons may be involved -these are particles which obey fractional statistics intermediate between fermions and bosons. However the interpretation 94 T. Wada A. Ichinose H. Yamauchi and S. Tanaka Physica C 1990 171 344. 95 K. S. Nanjundaswamy A. Lewicki Z. Kakol P. Gopalan P. Metcalf J. M. Honig C. N. R. Rao and J. Spalek Physica C 1990 166 361. 96 S-P. Matsuda S. Takeuchi A.Soeta T. Doi K. Aihara and T. Kamo Jpn. J. Appl. Phys. 1990,29 L1781. 97 X-D. Xiang S. McKernan W. A. Vareka A. Zettl J. L. Corkill T. W. Barbee 111 and M. L. Cohen Nature (London) 1990 347 145. 98 P. Strobel B. Bonnet C. Mouget and B. Souletie Physica C 1990 172 193. 99 G. A. Scholz and F. W. Boswell Solid State Commun. 1990 74 959. 100 A. Wattiaux J-C. Park J-C. Grenier and M. Pouchard C.R. Acad. Sci. Ser. ZI 1990 310 1047. 101 J-C. Park P. V. Huong J-C. Grenier and A. Wattiaux J. Less-Common Met. 1990 164/165 862. 102 M. J. Geselbracht T. J. Richardson and A. M. Stacy Nature (London) 1990 345 324. 103 Q. Huang J. F. Zasadzinski N. Tralshawala K. E. Gray D. G. Hinks J. L. Peng and R. L. Greene Nature (London) 1990 347 369. 104 J.W. Lynn I. W. Sumarlin D. A. Neumann J. J. Rush J. L. Peng and Z. Y. Li Phys. Rev. Lett. 1990 66,919. 178 C.Greaves of experimental results appears controversial.'05-'08 Magnetic mechanisms have received support from 63Cu NMRlo9 and NQR"' measurements which have implied markedly enhanced antiferromagnetic spin correlations as the temperature is lowered in YBazCU306.64 and La,-,Sr,CuO,. 3 Other Electronic Conductors In this section materials are considered which are considered to be of chemical interest but have at most a marginal connection with oxide superconductors. Examples of oxides oxyhalides and sulphides are discussed below. The mixed metal oxide Ba4CaCU308.61 is a semiconductor and has a cubic perovskite superstructure (a = 8.124 A) with octahedrally coordinated Ca and square planar Cu in the formal octahedral sites of perovskite."' Related tetragonal phases appear to form in the Yb-Ba-Cu-0 system:112 Ba4Yb(Yb,Ba,Cu)Cu20 (a = 5.793 A c = 8.002 A) and Ba,(Yb,Ba)CuO (a = 4.106 A c = 8.033 A).The formation of the normally unstable perovskite form of CaCuO has been observed in RF-sputtered thin filmsii3 and the defect perovskite series LaCu03- has been prepared with Cu oxidation states between I1 and I11 using high oxygen pressure (200-1000 bar) at 900 OC.l14 Tetragonal (0 < y < 0.2) monoclinic (y = 0.33) and orthorhombic (y = 0.5) phases have been characterized. A detailed study of the electrical conductivities of tetragonal SrFe03-, and hexagonal BaFe03- has also been reported.' l5 Whereas SrFe03- appears metallic a hopping mechanism is postulated for BaFe03- due to the increased Fe-0-Fe distance.The antiferromagnetic insulators Ca3Cu204C12 and Ca3Cu204Br2 have been pre- pared"6-"7 and found to have a structure similar to La2SrCu206 but with Cl/Br ions coordinating to Cu in the apical positions. Doping experiments were unsuccess- ful in inducing metallic conductivity.' l7 An interesting new layered oxychloride has been synthesized,l18 which is structurally related to Pb2Sr2YCu308 but is a semi- conductor. In this material the Y layer has been replaced by [(Sr,Pb),Cl] layers (Figure 8) which have a slightly different configuration from the [L202] fluorite blocks discussed in Section 2. K. B. Lyons J. Kwo J. F. Dillon jun.G. P. Espinosa M. McGlashan-Powell A. P. Ramirez and L. F. Schneemeyer Phys. Rev. Lett. 1990 64 2949. 106 R. F. Kiefl J. H. Brewer I. Meck J. F. Carolan P. Dosanjh W. N. Hardy T. Hsu R. Kadono J. R. Kempton S. R. Kreitzman Q. Li A. H. O'Reilly T. M. Riseman P. Schleger P. C. E. Stamp and H. Zhou Phys. Rev. Lett. 1990 64 2082. lo' M. A. M. Gijs A. M. Gemts and C. W. J. Beenakker Phys. Rev. B 1990,42 10789. 108 H. J. Weber D. Weitbrecht D. Brach A. L. Shelankov H. Keiter W. Weber T. Wolf J. Geerk G. Linker G. Roth P. C. Splittberger-Hunnekes and G. Guntherodt Solid State Commun. 1990,76,511. 109 R. E. Walstedt W. W. Warren jun. R. F. Bell R. J. Cava G. P. Espinosa L. F. Schneemeyer and J. V.Wasznak Phys. Rev. B 1990 41 8574. 110 Y. Kitaoka S.Ohsugi K. Ishida and K. Asayama Physica C 1990 170 189. 111 C. Greaves and P. R. Slater Solid State Commun. 1990 73 629. 112 J. Liang X. Chen S. Wu J. Zhao Y. Zhang and S. Xie Solid State Commun. 1990 764 509. 113 I. Yazawa N. Terada K. Matsutani R. Sugise M. Jo and H. Ihara Jpn. J. Appl. Phys. 1990 29 L566. 114 J. F. Bringley B. A. Scott S. J. La Placa R. F. Boehme T. M. Shaw M. W. McElfresh S. S. Trail and D. E. Cox Nature (London) 1990,347 263. J. Hombo Y. Matsumoto and T. Kawano J. Solid State Chem. 1990 84 138. T. Sowa M. Hiratani and K. Miyauchi J. Solid State Chem. 1990 84 178. 117 J. Huang R. D. Hoffmann and A. W. Sleight Muter. Res. Bull. 1990 25 1085. 118 R. J. Cava P. Bordet J. J. Capponi C. Chaillout J. Chenavas T. Fournier E.A. Hewat J. L. Hodeau J. P. Levy M. Marezio B. Batlogg and L. W. Rupp jun. Physica C 1990 167 67. Electronic Conductors Including High Temperature Superconductors Figure 8 The structure of Pb,Sr,Cu,O,Cl in ball and stick (left) and polyhedral (right) repre- sentations. Small solid and open circles are Cu and 0;large open circles C1; shaded circles Pb; intermediate size circles are Sr or Sr/Pb adjacent to the C1 layers (Reproduced by permission from Physica C 1990 167 67) New metallic compounds of the type Cu6O8MX (M = Cu In Sc; X = NO3 C1) have been synthesized by heating appropriate solutions of metal nitrates and chlorides to dryness followed by a higher temperature heat These materials were found to adopt the cubic Ag,O8NO3 structure with a three-dimensional network of linked Cu04 units.There has been considerable recent interest in the metallic mixed metal sulfides which have a misfit layer structure and a generic composition (MS)1+,M'S2 where x = 0.12-0.17 M = Pb Sn La Ce and M' = Ti V Nb Ta.'22-128 The structure of (PbS)1.13TaS2 is typical and is shown in Figure 9. It consists of two distinct alternating blocks each of which can be assigned a different face-centred ortho- 119 I. Yazawa R. Sugise N. Terada M. Jo K. Oka H. Hayakawa and H. Ihara Jpn. J. Appl. Phys. 1990 29 L1480. 120 I. Yazawa R.Sugise N. Terada M. Jo K. Oka and H. Ihara Jpn. J. Appl. Phys. 1990 29 L1693. 121 H. Hayakawa E.Akiba I. Yazawa H. Ihara and S. Ono Jpn. J. Appl. Phys. 1990 29 L1796. 122 J.Wulff A. Meetsma S. Van Smaalen R.J. Haange J. L. De Boer and G. A. Wiegers 1. Solid State Chem 1990,84 118. I23 Y. Gotoh M. Goto K.Kawaguchi Y. Oosawa and M. Onoda Mater. Res. Bull, 1990,25 307. 124 G.A. Wiegers A. Meetsma R. J. Haange and J. L. De Boer J. Solid State Chem. 1990,89,328. 125 A. Meerschaut P. Rabu J. Rouxel P. Monceau and A. Smontara Mater. Res. Bull. 1990 25 855. 126 G. A. Wiegers P. Rabu and J. Rouxel Acta Crystallogr. Sect. B 1990,46 324. 127 M.Onoda K.Kato Y. Gotoh and Y. Osawa Acta Crystallogr. Sect. B 1990,46 487. 128 A. Meerschaut L.Guemas C. Auriel and J. Rouxel Eur. J. Solid State Inorg. Chem. 1990,27 557. 180 C. Greaves Figure 9 Projection ofthe structure of (PbS),,,,TaS along the misfit axis [loo].The Ta atoms at z -$ and z = in the same plane normal to [loo] have the same symbol (+ or -) (Reproduced with permission from J. Solid State Chem. 1990,84 118) rhombic unit cell double layers of PbS (rocksalt structure) interleave TaS layers comprising TaS trigonal prisms. All the materials are highly conducting but anisotropic with the in-plane resistivity (typically 10-5-10-6 Cl m-' at 300 K)'22-'25 being about lo4 lower than that perpendicular to the Whereas (PbS)1,12VS2 the other materials investigated are metallic and is semic~nducting,~~~ indeed undergo a superconducting transition at 2-3 K.I2 The conductivity appears to involve holes in the d(z2) band of the M'S blocks and since this would be expected to be half full electron transfer from the (MS) to the M'S2 blocks has been The new phase BaCu,,,,S,, has been reported'29 and its structure contains edge- sharing of two sets of CuS tetrahedra to form a three-dimensional network.This material is also metallic with a resistivity of ca. lo- Cl m-' at 300 K. J. S. Chang and H. Y-P.Hong Muter. Res. BUM 1990 25 863.

ISSN:0260-1818    

DOI:10.1039/IC9908700167

出版商:RSC    

年代:1990

数据来源: RSC

摘要:

10 New Compounds and Structures By J. T. S. IRVINE Department of Chemistry University of Aberdeen Meston Walk Aberdeen AB9 2UE 1 Introduction The aim of this review is to highlight new and exciting phases and structures that have been reported in 1990. It is hoped not only to reflect current trends in solid state chemistry but also to bring to prominence areas meritorious of increased activity in the future. The scope of this review has been limited to selected new inorganic materials with reasonably defined structures. New compounds formed solely by solid solution formation have not been reported although those with important ionic electronic or magnetic properties will be discussed in other chapters. In organizing this review it was necessary to consider both chemical and structural aspects.In the first instance divisions have been loosely based on the periodic classification as structure types are generally limited to small groups of compositions. Secondary division has largely pertained to structure type. Oxidic materials dominate the literature and these have been subdivided into transition metal and p block oxides. The final section has been devoted to non-oxidic materials. 2 Overview In the past year there has been considerable interest in solid state chemistry reflecting the increasing importance of the materials chemistry area. Much of this activity has followed the surge of interest in superconductivity and has resulted in significant advances in copper and bismuth oxide chemistry. The number of new phases prepared as unwanted side-products in attempts to find new superconductors is quite remarkable.Whilst many of the new compounds and structures bear relation to well known structural families such as the perovskites and tungsten bronzes several more novel structures and phases have also been reported. Some of the most noteworthy recent advances include the misfit layer sulphides and structures formed by intercalation of small molecules into inorganic host lattices. 3 Transition Metal Oxides Vanadates and Titanates. -Interest in the early first row transition metal oxides has been largely inspired by their electrical properties. These materials particularly in the mixed valent state have potential as oxide superconductors and are important as battery electrode materials.181 182 J. T. S. Irvine Two new strontium vanadates Sr2V04 and Sr4V309,8 have been reported. The former has the K2NiF4 structure’ and so is isotypic with Sr2Ti04 and La2Cu04 it has much in common with La2Cu0, as it also is an antiferromagnetic insulator below 5K.’The latter Sr4V309., appears to have the layered Sr4Ti3OI0 structure.2 The structure of P-Pb0.33V205 has been shown to be isotypic with that of the Vanadium bronze P-NQ.33V205,3 Figure l(a). The compound H2V3084 also has a similar structure except that the V308layers are discrete whereas in P-Na0.33V205 the V308 layers are interconnected forming a tunnel structure in which the Na+ ions are located. Conversely I&V205 has a rather different structure Figure l(b) consisting of slabs of V205 with K+ ions between.’ 0 (a1 (b ) Figure 1 (a) Projection 0fp-Pb,,,,~V~0~ structure onto (010) and (b) projection of K,)5V205 structure onto (100) (Reproduced by permission from (a) Acta Crystallogr.Sect. C 1990 46 1587; (b) Acta Crystallogr. Sect. C 1990 46 1590) Two new mixed valence sodium titanates with potential sodium ion conductivity have been rep~rted.~” Nao,5Ti02 has the rhombohedra1 a-NaFe02-type structure with partially occupied Na+ layers interspersed between two close packed oxygen layers surrounding the Ti ions.6 The structure of Na,,7Ti60,,7 consists of a three ’ M. Cyrot B. Lambert-Andron J. L. Soubeyroux M. J. Rey Ph. Dehauht F. Cyrot-Lackmann G. Fourcaudot J. Beille and J.L. Tholence J. Solid State Chem. 1990 85 321. ’ M. Itoh M. Shikano R. Liang H. Kawaji and T. Nakamura J. Solid State Chem. 1990 88 597. K. Kato K. Kosuda T. Hogu and H. Nagasawa Acta Crystallogr. Sect. C,1990 46 1587. Y. Oka T. Yao and N. Yamamoto J. Solid State Chem. 1990 89 372. Y. Kanke K. Kato E. Takayama-Muromachi M. Isobe and K. Kosuda Acta Crystallogr. Sect. C 1990 46 1590. J. Akimoto and H. Takei J. Solid State Chem. 1990 85 31. ’J. Akimoto and H. Takei J. Solid State Chem. 1990 85 8. New Compounds and Structures Ti Na 0 Figure 2 Crystal structure of Na,,7Ti60, viewed along [Ool] (Reproduced by permission from J. Solid State Chern. 1990 85 31) dimensional framework of Ti06 octahedra with the Na+ ions occupying interconnec- ted eight coordinate sites Figure 2.Sodium ions also partially occupy tunnel sites in Na2,44V4P4017(OH) where the framework involves the interconnection of three complex infinite chains built from PO4 tetrahedra and V06 octahedra.' In LiVP207 (V"'+) the Li+ occupy tunnel sites in a P207/V06 framework.' The structure of Mg3Ti4P6024 (Ti"'+) consists of a complex framework of [M2Ot0],[M06] and [PO4] structural units with Ti2P4020 ribbons similar to the ribbons observed in some vanadophosphates." Perovskite Oxides. -The perovskites are a particularly important class of oxides. Interest in these and related phases has further intensified since the advent of high temperature superconductors with particular emphasis on mixed-valence and mag- netically ordered phases.The compound Sr2LaFe308.94 has been shown to be a rhombohedrally distorted perovskite with equivalent Fe sites at room temperature; however at 50K charge disproportionation (equation 1)is observed although there appears to be no periodic structural disproportionation." 3Fe3.66+-+ 2Fe3+ + Fe5+ (1) The structure of the related Fe"'+ anion-deficient perovskite Sr,LaFe,O ,has been shown to consist of octahedral and tetrahedral Fe-0 polyhedra stacked in the sequence OOT Figure 3.12 A cubic anion-deficient perovskite CaLaMgMn05,5+,. has also been rep~rted.'~ A. Le Bail M. Leblanc and P. Amoros,3. Solid State Chem. 1990 87 178. K. H. Lii Y. P. Wang Y. B. Chen and S. L. Wang J. Solid State Chem. 1990 86 143. 10 A. Bermoussa M. M. Borel A.Grandin A. Leclaire and B. Raveau J. Solid State Chem. 1990,84,299. P. D. Battle T. C. Gibb and P. Lightfoot J. Solid State Chem. 1990 84 271. 12 P. D. Battle T. C. Gibb and P. Lightfoot J. Solid State Chem. 1990 84 237. l3 J.-H. Choy G. Demazeau and J. M. Dance J. Solid State Chem. 1990 84 1. 184 J. T. S. Irvine Figure 3 Transition metal polyhedra structure of Sr,LaFe,O (Reproduced by permission from J. Solid State Chem. 1990 84 237) La2-,Sr Ni04+s has been the subject of considerable intere~t,'~ because of its close similarity to the high T superconductor La2+xSrxCu04+s which also has the K2NiF4 structure. A particularly interesting report has been the synthesis of an oxygen deficient nickelate La,.6Sro,4(Ni1+ .15 The oxygen defects in this Nil'+) 03,47 phase which is a nominal d8/d9 compound are located in the Ni02 planes reminiscent of the structural chemistry of YBa2Cu30,- .Cuprates.-Since the discovery of high temperature superconductivity copper oxide chemistry has become one of the most important areas of solid state chemistry and certainly the most prolific. Much of the novel chemistry involves phases closely related to known superconductors although there has also been interest in both binary cuprates and chloroxocuprates. A particular concern has been to prepare mixed-valence cuprates with specific copper oxygen environments. In sodium oxocuprate(III) NaCuO, chains of edge sharing square planar Cu04 units are connected by NaO octahedra.16 In LiCu202 the Cul'+ atoms form double sheets of CuO squares interconnected by Cu'+ atoms coordinated as CuOz d~mbe1ls.l~ A highly oxidized strontium cuprate Sr2Cu03,9 with an apparent formal oxidation state of 3.8 has been reported.18 The structure of this phase appears to be closely related to that of La,CuO, but with vacancies in the Sr Cu and CuO plane oxygen sites.No evidence was found for either peroxide or superoxide by neutron diffraction 14 K. Sreedhar and C. N. R. Rao Mat. Res. Bull. 1990 25 1235. Y. Takeda R. Kanno Y. Sakaro 0. Yamamoto Y. Bardo H. Akinaya K. Takita and J. B. Goodenough Mat. Res. Bull. 1990 25 293. l5 M. Crespin J. M. Bassat P. Odier P. Mouron and J. Choisnet J. Solid Slate Chem. 1990 84 165. 16 J. Pickardt W. Paulus M. Schmalz and R. Schollhorn J.Solid State Chem. 1990 89 308. 17 S. J. Hibble J. Kohler A. Simon and S. Paider J. Solid State Chem. 1990 88 534. l8 R. C. Lobo F. J. Berry and C. Greaves J. Solid State Chem. 1990 88 513. New Compounds and Structures indicating a high hoie concentration in an 02p band." Another strontium cuprate frequently encountered as an impurity in high T superconductor synthesis Sr5-xPb5+xCuy012-6(e.g. x -0.2 y -0.66) has been identified." The copper atoms were found to occupy tetrahedral interstices in the Sr,Pb5012 framework. A subsequent chapter will address the chemistry of high T cuprates; however it is remarkable how few new copper oxide superconductors were reported during 1990 considering the number of new superconductors discovered in the previous few years.Two new layered haloxocuprates Ca3Cu204X2 containing double Cu02 sheets have been reported.20 These phases have very similar copper environments to those observed in the high T superconductors YBazCu3O7-, Bi2Sr2CaC~208+6 and especially La2SrCu206+6 except that the apical ion in the square pyramid coordinat- ing the copper is a halogen rather than an oxygen Figure 4. No evidence has been found to date for superconductivity in these haloxocuprates. o Ca cu 00 0 CI Vacancy Figure 4 Idealized crystal structure of Ca,Cu,O,Cl (Reproduced by permission from J. Solid State Chem. 1990 84 178) Two new copper perovskites have also been discovered both again arising from the search for new superconductors.The compound Bi,,,Cu,Ti,O, has the CaCu,Mn4012 structure21 and LaSrCuAIOs has a structure related to Brownmillerite.22 19 J. S. Kin X. X. Tang A. Manthiram 3. S. Swinnea and H. Steinfink J. Solid State Chem. 1990 85 44. 20 T. Sowa M. Hiratani and K. Miyauchi J. Solid State Chem. 1990 84 178. J. Huang R. D. Hoffman and A. W. Sleight Mat. Rex Bull. 1990 25 1085. 2L I. Bryntse and P.-E. Werner Mat. Rex Bull. 1990 25 417. 22 J. B. Wiley M. Satat S.-J. Hwu K. R. Poeppelmeier A. Reller and T. William J. Solid State Chem. 1990 87 250. 186 J. T. S. Irvine Spinels and Related Structures.-A novel potassium-barium ferrite KBaFe23036 has been preparedz3 with an alternate structure of p-alumina and magnetoplumbite half cells. Niobates and Mo1ybdates.-Although the main area of interest in transition metal chemistry has been in the first row elements there has also been considerable interest in the chemistry of niobium and molybdenum.This is largely due to the intricate structural chemistry of these elements with the formation of tunnel structures metal clusters and layered phases. One of the most important developments in superconductivity in 1990 was the discovery of superconductivity at 5K in Li,Nb02 (x -0.5).z4 This layered phase was prepared by chemical deintercalation of Li from LiNbOz. It is particularly unusual that the analogous sulphide Li NbS2 which has the same MoS2-type structure also exhibits superconductivity at up to 6K. The rich and varied cluster chemistry of Molybdenum continues to arouse much interest.A second oxide SnMOsOg exhibiting Mole clusters2 and a novel compound LaMOgO, exhibiting an Mos cluster2 have been discovered. The Mos cluster is formed by capping of two faces of an M0 cluster Figure 5.26 In the selenide CsMoSez3 new cluster units containing 21 Mo atoms have been dis~overed.’~ Figure 5 Zdea!ized crystal structure of (Reproduced by permission from J. Solid State Chem. 1990 87 35) A new antimony( 111) molybdate KSbMo,O, with a novel layered structure has been reported.z8 In this compound the K+ ions occupy 9 coordinate sites between antimony molybdate units built up from MOO, MOO, and SbO polyhedra Figure 6. Considerable interest has been shown in molybdenum and niobium phosphate framework structures.Two new members of the structural series AMo2(v)+P3Ol3 23 S. Nariki S. Ito and N. Yoneda J. Solid State Chem. 1990 87 159. 24 M. J. Gexlbracht T. J. Richardson and A. M. Stacy Nature 1990 345 24. 25 P. Gougeon M. Potel and M. Sergent Acta Crystallogr. Sect. C 1990 46 1188. 26 H. Leligny M. Ledesert Ph. Labbi B. Raveau and W. H. McCarroll J. Solid State Chem. 1990,87,35. 27 P. Gougeon M. Potel and M. Sergent Acta Ctystallogr. Sect. C 1990 46 2284. 28 K. H.Lii B. R. Chueh and S. L. Wang J. Solid State Chem. 1990 86 188. New Compounds and Structures OK .Sb oMoo0 X Figure 6 View of the structure of KSbMozOs along a-axis (Reproduced by permission from J. Solid State Chem. 1990,86 188) have been synthesized. In p-KMo2P3013 ,29 potassium occupies tunnel sites whereas in E-N~MO~P~O~~,~' the sodium occupies large cage sites in the framework.The first of a related series of compounds the diphosphates of molybdenum(v) has also been synthesized BaMo2P4Ol6 .31 Several new niobium phosphate bronzes with structures closely related to those observed for tungsten bronzes have been observed. KNb3P301532 has a tunnel structure closely related to tetragonal tungsten bronzes K7Nb14P9060 has an inter- growth tungsten bronze type ~tructure,3~ K5-xNb8P6035a hexagonal tungsten bronze structure34 and Na4NbsP6035 a diphosphate tungsten bronze with pentagonal tunne~s.~' A novel ammonium molybdenum bronze (NH4)Mo309 has been prepared by hydrothermal decomp~sition.~~ This phase appears to be isostructural with mono- clinic red K,-,M0309 and is the first well characterized ammonium molybdenum bronze.4 Main Group Oxides Silicates and Germanates.-Silicate chemistry has long been an important area in solid state chemistry. The wide structural variation in silicates continues to engender much interest particularly in attempts to fully systematize silicate and related structures. 29 A. Leclaire M. M. Borel A. Grandin and B. Raveau Acta Crystallogr Sect. C 1990,46 2009. 30 A. Leclaire M. M. Borel A. Grandin and B. Raveau J. Solid State Chem. 1990 89 10. 31 G. Costentin M. M. Borel A. Grandin A. Leclaire and B. Raveau J. Solid State Chem 1990 89 83. 32 A. Leclaire M. M. Borel A. Grandin and B. Raveau J. Solid State Chem 1989 80 12.33 A. Leclaire A. Benabbas M. M. Borel A. Grandin and B. Raveau J. Solid State Chem. 1990.83 245. 34 A. Benabbas M. M. Borel A. Grandin A. Leclaire and B. Raveau J. Solid State Chem. 1990,87 360. 35 A. Benabbas M. M. Borel A. Grandin A. Leclaire and B. Raveau J. Solid State Chem. 1990 89 75. 36 K.-J. Range K. Baner and U. Klement Acta Crystallogr. Sect. C 1990 46 2007. 188 J. T. S. Irvine Two new copper containing silicates have been reported both arising from side reactions of high temperature superconductors with silica. The structure of B~,C~CUS~,O,,~~ consists of six membered rings of SiO tetrahedra linked up to form chains Figure 7. The Ba and Ca atoms occupy eightfold coordinate sites and the Cu occupy square planar sides.In BaCu2Si207 the structure consists of discrete Si207 units with Ba coordinated by 7 0 atoms and Cu occupying a distorted capped square planar site.38 '-a Figure 7 Polyhedral representation of the structure of B~,C~CUS~,O,~ (Reproduced by permission from Acta Crystallogr. Sect C 1990 46 2028) The crystal structure of the solid electrolyte Na,BeSiO has been determined.39 This structure can be described as a cristobalite-related framework with chains of alternating Si04 and BeO corner-sharing tetrahedra. The Na ions are located in cavities in the structure with interconnecting windows between Na sites. The crystal structure of another prospective berryllosilicate solid electrolyte Na10Be4Si401, has also been determined.,' This structure contains the previously unknown Be4Si401710- structural unit Figure 8 with the Na atoms occupying three crystal- lographically different sites between these units.A metastable polymorph of Li2Si205 with the same structure as Na2Si205 has been prepared.,' Lithium was ion-exchanged with Na2Si205 by immersing in molten LiN03 at 300°C. 37 R. J. Angel N. L. Ross L. W. Finger and R. M. Hazen Actu Crystullogr. Sect. C 1990 46,2028. J. Jancczak R.Kubiak and T. Glowiak Acta Crystallogr. Sect. c 1990 46 1383. B. Maksimov R.Tamazyan M. I. Sirota S. Frostang J. Grins and M. Nygren J. Solid State Chem. 39 1990 86 64. 40 L. Eriksson S. Frostang and J. Grins Acta Crystullogr. Sect. C 1990 46,736. R. I. Smith R. A. Howie A. R.West A. Aragin Pifia and M.E. Villafuerte-Castrejin Acta Crystuflogr. 41 Sect. C,1990 46 363. New Compounds and Structures Figure 8 Illustration of the Na,,Be,Si,O, structure the Na-0 coordination environment is illustrated by dashed lines (Reproduced by permission from Acta Crystallogr. Sect. C 1990 46 736) A new lithium germanate Li,Ge5012 has been The germanium atoms are in both octahedral and tetrahedral coordination with half of the Li ions in rectangular channels. The structure of Na2CaGe206 has been found to be closely related to that of its analogue Na2CaSi206?3 The structure contains discrete six- membered rings of Ge04 tetrahedra with the sodium and calcium atoms statistically disordered over six coordinate and eight coordinate sites.Phosphates and Arsenates.-Phosphate units have an important structural role in solid state chemistry occupying a niche between continuous covalent framework structures and purely ionic structures. In 1990 there was particular interest in structures containing discrete condensed phosphate anions. A number of new phases containing the diphosphate (pyrophosphate) P2072- anion have been reported. In (Na2/3 Zr,/3)2P207 Na and Sr are disordered on a site surrounded by a disordered octahedron with each edge of the octahedron corresponding to a line linking two opposite corners of the diphosphate anion.44 Three new copper diphosphates have been reported CaCuP,O, SrCuP207 and BaCaP2O7 the first two of which are isomorphous with a-Ca2P207?5 An important new layered pyr~phosphate~~ has been discovered.The structure of this phase K2C03(P207) consists of rows of COO octahedra joined by P207 groups to form layers with K+ ions occupying sites between the layers Figure9. Several new phases containing the cyclo-hexaphosphate structural unit have been reported. These can be divided into two groups M2+M;+(P6Ol8) xH20 where 42 B. L. Greenberg and G. M. Loiacono Acta Crystallogr. Sect. C 1990 46 2021. 43 F. Nishi and Y. Takeuchi Acta Crystallogr. Sect. C 46 544. 44 S. Gali and K. Byrappa Acta Crysralfogr.,Sect. C,1990 46 2011. 45 A. Boukhan A. Mogine and S. Flandrois J. Solid State Chem. 1990 87 251. 46 P. Lightfoot A K. Cheetham and A. W. Sleight. J. Solid State Chem. 1990 85 275. 190 J.T. S.Irvine Figure 9 View of K,CO~(P,O~)~.~H~O structure along [OlO] (Reproduced by permission from J. Solid State Chem. 1990,85 275) M+ = NH4+ Li+ Na+ and M2+ = Ca2+ Mn2+ and M6+(P6OI8).xH20 where M+= NH4+ and NH30H+.47 A novel layered aluminophosphate with ethylene diamine molecules located between the layers A1P2O8H3+NCH2CH2N+H3 has been synthesized hydrother- mally. The layers are made up from chains of fo~r-rnembered~~ rings of alternating A104 and PO tetrahedra Figure 10. It is thought that the ethylene diamine molecules act as a templating agent during synthesis. The crystal structures of KTiP05 and KSnP05 have been solved and related to differences in their non-linear optical proper tie^.^^ Both compounds have framework structures containing PO4 tetrahedra and M06 octahedra.InKSnP05 the metal atoms are found much closer to the centre of their coordination octahedra than in KTiP05. This appears to lead to a much lower second harmonic generation output 2% for the Sn compound. The structure of the diarsenate Na7Fe3(A~207)4 which is a good sodium ion conductor has been shown to consist of a framework of FeO octahedra sharing corners with As,O~~-units.50 The framework can be described in terms of two sets of layers of composition Fe(As207) and Fe2(A~207)2 with most of the sodium ions being associated with the F~(As~O,)~ layers. A compound containing the unusual triarsenate anion Na,H2As30,0 has been reported.” The triarsenate anions (H2As3Ol;-) are connected by hydrogen bonds to form layers held together with interleaved cations Figure 11.47 M. T. Averbuch-Pouchot Acta Crystallogr.,Sect. C,1990,46,2005.A. Durif and M. T. Averbuch-Pouchot Acta Crystallogr. Sect. C 1990 46 2027. 48 W. Tieli Y. Long and P. Wengin J. Solid State Chern. 1990 89 392. 49 P. A. Thomas A. M. Glazier and B. E. Watts Acta Crystallogr. Sect. B 1990 46 333. 50 C. Masqelier F. d’Yvoire and N. Rodier Acta Crystallogr. Sect. C 1990 46 1584. ’’ A. Driss and T. Jonini Acta Crystallogr. Sect. C 1990 46 1185. New Compounds and Structures Figure 10 View offramework of AlP208.H,+NCH2CH2NH,+structure (Reproduced by permission from J. Solid State Chem. 1990 89 392) Figure 11 Projection ofthe structure of Na,H,As,O, onto the (010) plane (Reproduced by permission from Acta Crystallogr.Sect. C 1990 46 1185) Berates.-A novel family of solid state borates &MM’(B03)6 where A = Sr has been di~covered.~~ Several members of this large and versatile family have been reported e.g. Sr,$Cz( B03)6 Sr$CHO( BO3)6 and Sr,YAl( BO3)6. Atoms M and M’ occupy octahedral sites that are bridged by triangular B03 groups to form a one dimensional chain Figure 12(a). These chains pack in a trigonal manner along the chain axis Figure 12(b). A new phase with a similar formula Ba,Cu(BO,), has been found to have a rather different structure containing discrete Cu2(B03)4 units.53 52 K. I. Schaffers T. Alekel P. D. Thompson J. R. Cox and D. A. Keszler J. Am. Chem. SOC.,1990 112 7068. 53 R. W. Smith and D.A. Keszler Actn Crystallogr. Sect. C 1990 46 370. 192 J. T. S. Irvine (a) Figure 12 Structure of &MM’ (BO,), (a) showing MM‘(BO,) chains (b) projection ofstructure along chain axis (Reproduced by permission from (a) J. Am. Chem. Soc. 1990 112 7068. (b) J. Am. Chem. Soc. 1990 112 7068) The structure of a novel lithium borate Li3B7OI2 has been shown to consist of B307 B308 and B03 structural units which connect by 0 atom sharing to form a three dimensional net~ork.’~ Bismuthates.-Metal bismuthates possess several important properties especially those with perovskite and Aurivillius type structures. Such phases may exhibit ferroelectricity or superconductivity. Replacement of Ba by Sr in Ba(Bi Pb)03 has been observed to reduce the superconducting composition range and lower the maximum superconducting tem- perature.” A novel ordered perovskite Ba4Bi3LiOl was obtained by replacement of Bi by Li.56 Ordering of Li and Bi gave rise to a tetragonal superstructure in Ba4Bi3LiOll as opposed to a face centered cubic superstructure in the related phase Ba4Sb3LiOI2.A novel antimonate La2LiSb06 has been synthesized and its structure determined as a monoclinic GdFe03 type perovskite.” Ca4Bi6OI3 has been synthe- sized and its unusual structure determined.58 The structure is composed of ribbons of edge-shared BiO’ square pyramids linked by Bi205 groups Figure 13.The coordination of the Bi atoms in the Bi205 groups is unusual with three short Bi-0 bonds (-2A) and a short Bi-Bi contact (3.4 A).54 J. Aidong L. Shirong H. Qingzhhen C. Tianbin and K. Derning Acta Crystallogr. Sect C,1990,46 1999. 55 B. Seshadri V. Maniavannan K. P. Rajeev J. Gopalkrishnan and C. N. R. Rao J. Solid State Chem. 1990 89 389. 56 C. Greaves and S. M. A. Katib J. Solid State Chem. 1990 84 82. 57 M. L. Lbpez M. L. Veiga A. Jerez and C. Pico Mat. Res. Bull. 1990 25 1271. 58 J. B. Parise C. C. Torardi M.-H. Whangbo C. J. Rawn R. S. Roth and B. P. Burton Chem. Mater. 1990 2 454. New Compounds and Structures Figure 13 Structure of Ca,Bi,OI3 only Bi-0 bonds shown (Reproduced by permission from Chem. Muter. 1990 2 454) New quaternary pyrochlores of Pb4+ and Bisf (M2+R3+)(Pb4+Bi5')07 have been prepared under high oxygen pressures.59 5 Non-oxide Compounds Sulphides and Se1enides.-Framework Structures.In this section the solid state chemistry of sulfides other than those with layered structures will be discussed. These phases often show close similarity to analogous oxides in both properties and structure. A metastable form of Li2SiS3 with high Li+ ion conductivity has been prepared.60 The structure of the metastable phase appears to be closely related to that of the equilibrium phase which is isostructural with Li2Si03 ;however the one dimensional SiS3*- chains are stretched significantly thereby increasing the Si- S-Si bond angles. LiGaS has been shown to be isostructural with NaFeOz and LiGa02.61 The structure of Pb4Sb4Selo has been shown to be composed of ribbons of square pyramidal (Pb Sb)Se5 groups and isotypic with Cosalite Pb4Bi4(Ag CU)S,~.~~ 59 M.A. Subramian Mat. Res. Bull. 1990 25 107. 60 B. T. Ahn and R. A. Huggins Mat. Res. Bull. 1990 25 381. 6' J. Leal-Gonzalez S. S. Melibary and A. J. Smith Acta Crystallogr. Sect. C 1990 46 2017. 62 A. Skowron and I. D. Brown Acta Crvstallogr. Sect. C 1990 46 2287. 194 J. T. S. Irvine Layered SulJides. There has been considerable interest in misfit layer compounds of the type (MS),TS2 many of which were originally thought to have MTS stoichiometry (M = Sn Pb Bi Re; T = Nb Ta; n = 1.08-1.25). The misfit layer structures are built up alternately of slices of rocksalt-type layers (MS) and sand- wiches (TS,) with T in trigonal prisms of S. Each sublattice generally has centered orthorhombic symmetry but they are mutually incommensurate.Usually the b and c sublattice parameters are equal or only differ by a factor of 2; however along the a axes the lattices are incommensurate. Several examples of such misfit structures have been described in the recent literature (PbS),,,,TaS2 (PbS)1.14NbS2 and (LaS)1,14NbS2 is illustrated in Figure 14. .63 The structure of (YS),,23NbS264 -H-+-t-NbS2 .-ys -w Figure 14 Structure of (YS),,,,(NbS,) projected along [OlO]. (Reproduced by permission from J. Solid State Chern. 1990 88 451) The misfit layer structure of (PbS),.,,VS has been shown to be slightly different to those described above.65 In this monoclinic structure the rocksalt-type PbS layers alternate with distorted Cd1,-type VS layers.The stoichiometries of indium sulphides such as InloSn6S2 ,66 Cal.21nl.9S4 ,6’ and Sro.91n,~lS~7 are similar to those of the misfit layer structures; however their structures are somewhat different. In the indium sulphides the divalent cation 63 J. Wulff A. Meetsrna S. Van Srnaalen R. J. Haange J. L. de Boer and G. A. Wiegers J. Solid State Chem. 1990,84 118. G. A. Wiegers A. Meetsma R. J. Haange J. L. de Boer A. Meerschant P. Rabu and J. Rouxel Actn Crystallogr. Sect. B 1990 46,328. 64 P. Rabu A. Meerschant J. Rouxel and G. A. Wiegers J. Solid Sfate Chem. 1990 88 451. 65 M. Onoda K. Kato Y. Gotoh and Y. Oosawa Acta Crystallogr. Sect. B 1990 46,487. 66 A. Likforman M. Guittard and F. Robert J. Solid State Chem. 1990 89 275.67 D. 0.Kipp C. K. Lowe-Ma and T. A. Vanderah. Chem. Muter. 1990 2 506. New Compounds and Structures 195 occupies bicapped trigonal prismatic sites and the indium occupies octahedral sites. It is the arrangement of these Ins octahedra into edge-shared stepped layers that gives rise to the unusual stoichiometries. Intercalation Compounds. Intercalation of both inorganic and organic molecules and ions into lamellar sulphides is an area of considerable importance. The resulting compounds often exhibit exciting materials properties such as anisotropic supercon- ductivity charge density waves and ferromagnetic ordering. The structure of lithium-ammonia intercalation compounds of TiS2 has been investigated.68 In Lii.23 (ND3)0,3 (TiS2)0.23- it appears that discrete Li+( ND3)3 complexes exist in the TiS2 Van der Waals gap.In compounds with lower Li+ contents e.g. Li+o.ll(ND+4)o.ll(ND3)o.s4(TiS2), the ND3 molecules adopt a more planar coordination.68 Intercalation of pyridine into layered FePS3 has been observed to give rise to ferromagnetic 0rdering.6~ The resulting Fe -,PS3 (pyridinium), (solv) compound exhibits spontaneous magnetization below -90K. Phosphides.-In a search for ceramic materials with low infra-red absorption a new family of ceramic phosphides has been prepared.70 The crystal structure of one member of this series AgZnSmP, has been solved. The phosphorus atoms are hexagonal close packed with alternate Sm and AgZn layers sandwiched between the phosphorus layers. The Sm atoms occupy all the octahedral holes between one pair of phosphide layers and the AgZn atoms occupy all the tetrahedral holes between the next pair.Nitrides Oxynitrides and Cyanides.-A novel ionic nitride Li7PN4 has been synthe- sized and its structure in~estigated.~’ Its structure is related to antifluorite with the nitrogen atoms in a distorted cubic close packed arrangement and the lithium and phosphorus atoms filling the tetrahedral sites. This structure is highly unusual as it contains discrete ( PN4)’- units. The mixed-valent oxynitrides BaCe,O,- N and BaCeLa04-x N, with the CaFe204 structure have been synthesized for x -0.5.72Resistivity measurements indicated charge localization. Some rather elegant metal cyanide structures have recently been dis~overed.’~,~~ A honeycomb polymorph of cadmium cyanide consisting of a Cd(CN) framework which only occupies about one third of the crystal volume Figure 15(a) with butanol and water molecules located in the voids has been described.73 The structure of unsolvated Cd(CN) and its isomorph Zn(CN) have been shown to consist of two interpenetrated diamond like frameworks where the metal atoms are linked by MCNM rods Figure 15(b).74 Halides.-The compounds of the halides offer great potential as solid state materials.Fluorides in particular have been the subject of considerable investigation and 68 v. G. Young M. J. McKelvy W. S. Glaunsinger and R. B. Von Dreele Chem. Muter. 1990 2 75. 69 R. Clement L. Lomas and J. P. Audiere Chem. Muter. 1990 2 641.70 P. Tejedor and A. M. Stacy J. Solid State Chem. 1990 89 227. 71 W. Schnick and J. Luecke J. Solid State Chem. 1990 87 101. 72 G. Lin and H. A. Eick J. Solid State Chem. 1990 89 366. 73 B. F. Abrahams B. F. Hoskins and R. Robson 1. Chem. SOC.,Chem. Commun. 1990 60. 74 B. F. Hoskins and R. Robson. J. Am. Chem. SOC.,1990 112 1546. 196 J. T. S. Irvine Figure 15 (a) Honeycomb-like extended framework of Cd atoms in Cd( CN)2.2/3H,0-BuOH; (b) View of Cd( CN) structure revealing two independent interpenetrating frameworks (Reproduced by permission from J. Chem. Soc. Chem. Commun. 1990,60) New Compounds and Structures offer a range of structures from simple ionic through covalent ion to complete framework.Two new structures which have independent fluoride ions located within a fluoride framework and so may exhibit high ionic conductivity have recently been NaCdAlF has a structure consisting of [A1F5]2,"- chains between which Na+ Cd2+ and independent F- ions are located.75 The structure of NaSr2CrFg can be considered as being built up from isolated CrF octahedra separated by sodium and strontium polyhedra and fluoride ions.76 Other new sodium aluminofluorides have also been reported including a low temperature polymorph of NaCaAlF with the Na2SiF6 Na4Ca4A17F33 has a three-dimensional [Ca4A14F33]4- framework with sodium ions occupying ten coordinate sites in the framew~rk.~~ The crystal structures of K2NaAl3Fl2 and Rb2NaA13F have been shown to be built up from hexagonal tungsten bronze-like layers of (A1F4-) .7g The synthesis of strontium and barium pentafluoroantimonates MSbFs containing square pyramidal SbFs2- units has been reported.79 The structure of the transition metal fluoride Rb2Fe5F17 has been shown to be closely related to the hexagonal tungsten bronzes,80 in contrast the structure of the related compound KSCrIoF3 could not be described as a fluorinated bronze.81 This mixed-valence fluoride has a very complex structure which can be described as an intergrowth between NH4MnFeF5 and Ba2CuV2FI2 type phases and has an unusual pentagonal bipyramidal CrZ+F7- environment.The crystal structures of some oxyhalides have been shown to correspond to the anti-form of the common oxide or halide-type structures Na30Cl and Na30Br crystallize in the anti-perovskite formg2 and Na4012 and Na40Br2 crystallize with anti-K2NiF4 str~cture.'~ 75 A.Hemon and G. Courbion J. Solid State Chem. 1990 86 249. J6 A. Hemon and G. Courbion 1. Solid State Chem. 1990 87 344. 77 A. Hemon and G. Courbion J. Solid State Chem. 1990 84 153. 78 A. Le Bail Y. Gao J. L. Fourquet and C. Jacoboni Mat. Res. Bull. 1990 25 83. 79 C. Gravereau C. Mirambet L. Fournes J. Grannes and L. Lozano Acta Crystallogr. Sect. C,1990,46 2294. H. H. Park P. Graverau A. Tressaud and P. Hagenmuller Mat. Res. Bull. 1990 25 321. 81 Y. Laligant A. Le Bail M. Leblanc and G. Ferey J. Solid State Chem. 1990 85 151. 82 K. Hippler S. Sitta P. Vogt and H. Sabrowsky Acta Crystallogr. Sect.C 1990 46,736. 83 K. Hippler S. Sitta P. Vogt H. Sabrowsky and L. Walz Acta Crysraffogr. Sect. C 1990 46,1359.

ISSN:0260-1818    

DOI:10.1039/IC9908700181

出版商:RSC    

年代:1990

数据来源: RSC