摘要:

11 Titanium Zirconium and Hafnium By S.A. COTTON St Edward's School Woodstock Road Oxford Oxon OX2 7NN UK 1 Introduction This report follows the pattern of recent years in being particularly selective in the area of organometallic chemistry. It covers the available 1994 literature together with some late 1993 papers. 2 Metallocarbohedranes Metcars have been reviewed along with other cluster ions;' later vaporization of Tic and ZrC produces metcars.2 A highlight is the synthesis of the binary metal metcars Ti,Zr -,C and Ti,Hf -,C12 by laser vaporization of mixtures of Zr or Hf with Tic; it is predicted that Ti,Zr,C12 should be more stable than Ti,Zr,C, or Ti,Zr,C,,. Different structures for Ti8C12 have been reviewed4 whilst Hiickel theory has been applied to Ti,C,,.' 3 Halides and Their Complexes The structure of TiBr has been investigated; at low temperatures the a-form contains titanium ions with a distorted octahedron of bromines (Ti-Br = 2.57-2.63 The %1).637 PE spectrum of TiC1 has been measured' whilst the excited and ionized states of TiBr,and TiI were investigated.' TiCl has been used to generate titanium oxychloride modified electrodes.' XANES and EXAFS investigation of methyl acrylate-TiCl complexes indicates 1 M.T.Bowers Acc. Chem. Res. 1994 27 324. 2 S. F. Cartier B. D. May B. J. Toleno J. Purnell S. Wei and A. W. Castleman Chem. Phys Lett. 1994,220 23. 3 S. F. Cartier B. D. May and A. W. Castleman J. Chem. Phys. 1994,100,5384;Chem. Eng. News May 23 1994 35. 4 I. Dance Chem.Aust. 1994 241. 5 G. N. Srinivas H. Srinivas and E. D. Jemmis Proc. Indian Acad. Sci. Chem. Sci. 1994,106,169 (Chem.Abs. 1994,121 187 711). 6 S. 1. Troyanov E. M. Snigireva A. P. Pisarevskii A. I. Yanovskii and Yu. T. Struchkov Russ. J. Inorg. Chem. 1994 39 374. 1 G. Meyer D.J. Hinz and U. Florke Z. Krist 1994,208 370. 8 B. E. Bursten J. C. Green N. Kaltsoyannis M. A. MacDonald K. H. Sze,and J.S. Tse Inorg. Chem. 1994 33 5086. 9 H. Nakatsuji and M. Ehara J. Chem. Phys. 1994 101 7658. 10 S. Ching R.C. Dudek E. A. Tabet W. S. Willis and S. L. Suib Langmuir 1994 10 1657. 153 154 s. A. Cotton that in this Diels-Alder catalyst system titanium is bound to two oxygens and four chlorines.’’Controlled hydrolysis reactions of [TiCl,(NCMe),] and [TiCl (NCMe)] -affords’ the p-0x0-dititanium anion [{TiC1,(NCMe),),(p-O)]2 -and a tetranuc- lear species [{TiCl,(NCMe),),(p-O),].TiCl reacts with AlCl in excess MeCN to give tran~-[TiCl,(NCMe),][AlCl,].~~Reduction of TiCl with sodium gives Na,[TiCl,] which has edge-connected TiCl octahedra. l4 In contrast such reduction in the presence of carbon gives [Ti,C]Cl,, the first titanium halide with octahedral cl~sters.’~ [N,H,],[TiF,] contains [TiF,]’- ions’ and [TeCl,],[MCl,] (M = Zr Hf) contains [MCl,]’- ions.I7 The thermochemistry and lattice energies of hexahalozirconates have been re- viewed18 whilst bond lengths in [HfX6]2- (X = halogen) have been optimized using Hartree-Fock calculations leading to estimated thermodynamic properties and vibrational data.19 CeZrF is isostructural with SmZrF,;” the family LnHf,F isostructural with LnZr,F 1 has been synthesized.,l TiCl reacts with NH forming [TiCl,(NH,),] which gives trans-[TiCl,(tppo)] with tris(piperidin0)phosphine oxide2” and gold TiN films under low pressure CVD conditions.[TiCl,L,] (L = OAsPh, hmpa) are also trans”’ whilst [ZrF,(dmso),] is dimeric [F,(dmso),Zr(p-F),ZrF,(dmso)z].z3The structure of the chiral tetrahy- drofurfuryl ester [TiC1,(C,H70CH,COOCH3)] a precatalyst for ethene polymeriz- ation has been determined.’ ZrI reacts with PMe,Ph forming trans-[ZrI,(PMe,Ph),] ;in contrast ZrC1 reacts with PMe forming [C1,(Me,P),Zr(p-Cl),ZrC13(PMe3)z].25Q A new synthesis of [Zr,C1 ,(PMe,Ph),] has been reported.25b [NBu,] [Zr,I,(PEt,),] contains [I,(Et,P)Zr(p-I),ZrI,(PEtJ-ions with Zr-Zr = 3.171 8 and a Zr-Zr o bond.25c Another q6-complex [Zr,Cl4(PMe,Ph),(q6-~,H5PMe2),], has been obtained from the reaction of ZrC1 with PMe,Ph and sodium amalgam.25d ZrC1 reacts with SnHBu and tertiary phosphines PR, forming novel diamagnetic hydrido clusters [Zr,H,Cl,,(PR3),] (PR = PMe, PEt, PMe,Ph) containing a distorted pyramid of zirconium atoms.’ Anionic phosphides from ditertiary phosphino secondary phosphines l1 X.Assfeld J. Garcia J. I. Garcia J. A. Mayoral M. G. Prietti M. F. Ruiz-Lopez and M. C. Sanchez J. Chem. SOC. Chem. Commun. 1994 2165. l2 G. R. Willey J. Palin and M. G. B. Drew J. Chem. SOC. Dalton Trans. 1994 1799. l3 B.V. Kharisov V. B. Rybakov and S. I. Troyanov Russian J.Coord. Chem. 1994 20 563. l4 D. J. Hinz T. Dedecke W. Urland and G. Meyer Z. Anorg. Allgem. Chem. 1994 620 801. l5 D. J. Hinz and G. Meyer J. Chem. SOC. Chem. Commun. 1994 125. l6 1. Lebanm A Jeshi and A. Rahten Acta Crystallogr. Sect. C 1994 50 842. l7 S.I. Troyanov V. B. Rybakov and Z.A. Fokina Russ. J. Inorg. Chem. 1994 39 356. H. V. Thanh and J. Blazjowski Thermochim. Acta. 1994 236 263. l9 M. Gutowski J. Rak P. Dokurno and J. Blazjowski Inorg. Chem. 1994 33 6187. 2o E. A. Gengina B. A. Maksimov and P. P. Fedorov Russ. J. Inorg. Chem. 1994,39,422. P. P. Fedorov M. D. Val’kovskii 0.S. Bondareva and B. P. Sobolev Russ. J.Inorg. Chem. 1994,38,1611. 22 (a)C. H. Winter J. W. Proscia A. L. Rheingold and T. S. Lewkebandara Inorg. Chem. 1994,33,1227;(b) F.Weller S. Wocadlo H.-J. Mai and K. Dehnicke Z. Krist 1994,209,634;W. Clegg P. A. O’Neil K. W. Henderson and R. E. Mulvey Acta Crystallogr. Sect. C 1993,49 2108. 23 N. W. Alcock W. Errington S. L. Golby S. M. C. Patterson and M.G. H. Wallbridge Acta Crystallogr. Sect. C 1994 50 226. 24 P. Sobota M. Wroblewska S. Szafert and T. Glowiak J. Organomet. Chem. 1994 481 57. 25 (a)F. A. Cotton and W. A. Wojtczak Acta Crystallogr. Sect. C 1994,50 1662; (b)F. A. Cotton and W. A. Wojtczak Inorg. Chim. Acta. 1994,223,93;(c)F. A. Cotton and W. A. Wojtczak Inorg. Chim. Acta. 1994 216 9; (d)F.A. Cotton and W.A. Wojtczak Inorg. Chim. Acta. 1994 217 187. 26 F.A. Cotton J. Lu M. Shang and W.A. Wojtczak J. Am. Chem. Soc. 1994 116 4364. Titanium Zirconium and Hafnium [P(CH,CH,PR,),] - L yield a cornucopia of complexes [ZrCl,L,] [Zr,Cl,L,] [Zr,HCl,L,] and [Zr,Cl,L,] (R = Me); the hydride [Zr,HCl,(P(CH2PMe2)),1 has both phosphide and hydride bridges (l).27 (Reproduced with permission from J.Chem. Soc. Dalton Trans. 1994 977.) Hexanuclear zirconium clusters have been excised from connected Zr species in room-temperature melts.,* A range of hafnium clusters29 includes AHf6C1 14Z (A = Li Na K or nothing; Z = B or C) and AHf,Cl,,C (A = K Cs). 4 Oxides and Other Binary Compounds Activity in this area continues to expand. Ultrathin films of titanium dioxide on a Cu substrate formed from [Ti(OPr'),] by CVD have been studied by XPS and LEED.,' TiO dispersed in a polymer matrix has been synthesized from [Ti(OPr'),] in a plasma glow di~charge.~' Synthesis of TiO thin films from [Ti(OEt),] has been attempted, whilst pyrolysis of gas-phase [TiO(CF,COCHCOCH,),] has given TiO films., Electrophoretic deposition has produced thin layers of nanocolloidal TiO for use in dye-sensitized TiO photovoltaic cells;34" TiO coatings on glass are stable in the pH range 2-9.34bThe kinetics of photooxidation reactions at TiO photoanodes have been studied.21 A. A. Danopoulos P.G. Edwards M. Harman M. B. Hursthouse and J. S. Parry J. Chem. Soc. Dalton Trans. 1994 977. 28 C.E. Runyan and T. Hughbanks J. Am. Chem. Soc. 1994 116 7909. 29 R.-Y. Qi and J.D. Corbett Inorg. Chem. 1994 33 5727. 30 Y.M. Wu and R.M. Nix J. Mater. Chem. 1994,4 1403. 31 P. J. Ratcliffe J. Hopkins A.D. Fitzpatrick C. P. Barker and J. P. S. Badyal J. Mater. Chem. 1994 4 1055. 32 M. Ritala M. Leskela and E. Rauhala Chem. Mater. 1994 6 556. 33 M.V. Kandybin I. K. Igumenov and I.V. Yushina Zh. Neorg. Khim. 1994 39 773. 34 (a)D.Matthews A. Kay and M. Gratze1,Aust. J.Chem. 1994,47,1869; (b)A. Mills D. Worsley and R. H. Davies J. Chem. SOC.,Chem. Commun. 1994 2677. 35 A. Wahl M. Ulmann A. Cannoy and J. Augustynski J. Chem. SOC. Chem. Commun. 1994,2277. 156 S. A. Cotton ZrO, currently studied as a catalyst support has been synthesized from [Zr(tmhd),] by MOCVD; the deposition of such films has been monitored by IR spectro~copy.~~ The role of sulfate or molybdate in stabilizing tetragonal zirconia has been examined.37 X-Ray diffraction of ZrO nanopowder has been interpreted in terms of a disordered monoclinic phase.,* Mixed (Zr,Ti)O gels used as precursors for ZrTiO have been prepared by the sol-gel process.39 TiH and TiH formed when the elements react at ca.700 "C are suggested for the storage of solar thermal energy.,' TiS has been synthesized from [Ti(OPr'),] and H,S via a sol-gel process.41 TiN has potential for the synthesis of sintered materials syntheses have been reported from the reaction of TiCI with NH and H2;42a solid-state reactions of TiCI with Li,N;42b and the CVD reaction of [Ti(NMe,),] with NH3.42C,d Synthetic routes to nitrides have been extensively reviewed., TiC1 complexes of chelating amines have been suggested as possible precursors for TiN;, the structure of one such complex [TiCI,(Me,NCH,CH,NMeH)] has been determined.The reactions of TiCI with amines such as t-butylamine gives45 imide complexes e.g.[{TiC1,(NBut)(H,NBut)} J; imide species may be important intermediates in the deposition of TIN films by CVD. PE spectra of TiN and Tic surfaces have been reported.46 ZrP and HfP have been synthesized from the reaction of MCI with Na,P at 550°C.47 ZrP has nine- coordinate Zr (tricapped trigonal prism).48 ZrQ (Q = s Se) intercalate various sandwich corn pound^.^^ Hf,Te has an unusual layered stru~ture.'~ 5 Alkoxides Thiolates Amides and Imides Many applications of alkoxides e.g. [Ti(OPr'),] to the synthesis of binary compounds such as TiO have been noted above (see e.g.refs 3&33) as has the use of amides in the synthesis of TiN.[KZr,(OBu'),] and [K2Zr,(0Bu'),,] have been ~ynthesized;~' the latter has a structure in which trigonal bipyramidal [Zr(OBu),] -ions encapsulate the potassium ions. CVD of [Zr(ORF),] [RF = OCH(CF,), OCMe -,,(CF,),,] onto borosilicate glass gives ZrF films5 The chiral (S,S,S)-triisopropanolamine(LH,) 36 J. Si S.B. Dew and C.Y. Tang J. Muter. Res. 1994 9 1721; B. J. Goyuld M.E. Pemble and W. R. Flavell J. Muter. Chem. 1994 4 1815. 37 P. Afanasiev C. Geantet and M. Breysse J. Muter. Chem. 1994 4 1653. 38 L.E. Depero and P. Levrangi J. Solid State Chem. 1994 110 190. 39 J. A. Navio F. J. Marchena M. Macias P. J. Sanchez-Soto and P. Pichat J. 7'herm. Anal. 1993,40 1095. 40 G. Friedlmeier M. Wierse and M. Groll Z. Phys. Chem. (Munich) 1994 183 175.41 M.A. Sriram and P.N. Kumta J. Am. Ceram. Soc. 1994 77 1381. 42 (a)J. P. Dekker P. J. van der Put H. J. Veringa and J. Schoonman,J.Muter. Chem. 1994,4,689; (b)E. G. Gillan and R.B. Kaner Znorg. Chem. 1994,33 5693; (c) B. H. Weiller and B. V. Partido Chem. Muter. 1994 6 260; (d) A. Intemann H. Koerner and F. Koch J. Electrochem. Soc. 1994 140 3215. 43 D. M. Hoffman Polyhedron 1994 13 1169; R. T. Paine J. F. Janik and M. Fan Polyhedron 1994 13 1225; L.H. Dubois Polyhedron 1994 13 1329. 44 S.R. Drake K. D. Sanderson M. B. Hursthouse and K. M.A. Malik Polyhedron 1994 13 181. 45 T. S. Lewkebandara P.H. Sheridan M. J. Heeg A. L. Rheingold and C. H. Winter Znorg. Chem. 1994,33 5879. 46 S.V. Didziulis J.R. Lince T.B. Stewart and E.A. Eklund Inorg.Chem. 1994 33 1979. 47 A. L. Hector and I. P. Parkin J. Muter. Chem. 1994 4 279. 48 M. Huber and H. J. Deiseroth Z. Krist. 1994 209 370. 49 H.-V. Wong J. S. 0.Evans S. Barlow S. J. Mason and D. O'Hare Znorg. Chem. 1994 33 5515. R. L. Abdon and T. Hughbanks Angew. Chem. Znt. Ed. Engl. 1994 33 2328. 51 D. J. Teff J. C. Huffman and K. G. Caulton Znorg. Chem. 1994 33 6289. 52 J.A. Samuels W.-C. Chiang C.-P. Yu E. Apen D.C. Smith D.V. Baxter and K.G. Caulton Chem. Muter.. 1994 6 1684. Titanium Zirconium and Hafnium reacts with [Ti(OPr'),] to form monomeric [TiL(OPr')]; this can be chlorinated with acetyl chloride to give [TiClL].53 With MeSH (seven mols) [Ti(NMe,),] forms [NH2Me2][(MeS),Ti(p-SMe),Ti(SMe),]; with four mols of MeSH the product is Ti(SMe) which is trimeric (2).54 In both cases the coordination geometry is trigonally distorted from octahedral.[Ti(NMe,),(NRAr),] [R = C(CD,),Me; Ar = 3,5-C6H,Me,] react with excess Me1 to form tetrahedral [TiI,(NRAr),];55 the structure of [TiCl(NRAr),] has also been described. N-alkylated azatitanatranes [TiCl(N(CH,CH,NR),)] (R = Me Et Pr') and [Ti(OSO,CF,)(N(CH,CH,NEt),}] have trigonal bipyramidal coordination (3).56 (2) (3) X = CI,OSO;!CF3 The amide aryloxide [Ti(OC6H,But5-2,6)(NMe2),]has a distorted tetrahedral coordination geometry.57 6 Complexes of Macrocycles 1,4,7-triisopropyl- 1,4,7-triazacyclononane (tiptacn) reacts with [TiCl,(NCMe),] to form [TiCl,(tiptacn)] ; other complexes include [Ti(NCS),(tiptacn)] and binuclear [(Ti(NCS),(tiptacn)),(p-0)] which has a linear Ti-0-Ti unit." Oxidation of [TiBr,(Me,tacn)] yields [TiBr,(Me,tacn)] +,which is the precursor for a range of + titanium(1v) complexes including [TiBrJOMe) -,(Me,tacn)] (x = 0 1 2).Those with x = 0 have been structurally characterized. Two titanium(1v) q2-peroxo com- plexes [TiX,(O,)(Me,tacn)] (X = NCO C1) (synthesized by oxidation with air and H,O,) have been structurally characterized. The new titanyl complexes [TiOCl,(Me,tacn)] and [TiO(NCX),(tipacn)] (X = S 0)have been reported; the Ti=O distance in [TiOCI,(Me,tacn)] is 1.637 A.59 Hydrogen reduction of [Zr(CH,SiMe,),(oep)] results in the quantitative formation of square pyramidal [Zr(CH,SiMe,)(~ep)l.~' [HfCl,(tpp)] reacts with benzene-l,2- dithiol (H,bdt) forming [Hf(bdt)(tpp)] in which the two sulfur atoms are in an eclipsed 53 W.A.Nugent and R. L. Harlow J. Am. Chem. Soc. 1994 116 6142. s4 W. Stuter K. Kirschbaum and D. M. Giolando Angew. Chem. Int. Ed. Engl. 1994 33 1981. 55 A. R. Johnson P. W. Wanandi C.C. Cummins and W. M. Davis Organometallics 1994 13 2907. 5b M. Schubart L. O'Dwyer L.H. Gade W. -S. Li and M. McPartlin Inorg. Chem. 1994 33 3893. '' V. M. Visiglio P. E. Fanwick and I. P. Rothwell Acta Crystallogr. Sect C 1994 50 896. 58 P. Jeske K. Wieghardt and B. Nuber Inorg. Chem. 1994 33 47. 59 P. Jeske G. Haselhorst T. Weyhermuller K. Wieghardt and B. Nuber Inorg. Chem. 1994 33 2462. 6o H. Brand and J. Arnold Angew. Chem. Int. Ed. Engl. 1994 33 95. 158 S. A. Cotton position relative to two opposing pyrrole nitrogen atoms.61 The EPR spectra of the cation radicals of [Zr(oep),] and [Zr(acac),(oep)] show g values very close to the free electron value.62 Bromination of [Zr(acac),(oep)] yields [Zr(3-Br-acac),(oep)].The UV spectra of asymmetric bis(porphyrin) sandwiches have been reported.63 7 Phosphates and Phosphonates [Til.7Alo.3(P04)3] frameworks are found in the ion-exchangers [LiTi2(P04)3] and The [Lio~3Ti,~7A10~3(P0,)3].65 new non-linear optical materials [KO~,MO~,TiO~,OPO,] (M = Nb Ta) have been synthesized.66 The compound [Zr,(NaP04),.6H,0] the completely sodium-ion exchanged form of the ion- exchanger [Zr(HPO,),H,O] has a layer structure similar to that of the parent67a whilst [Zr(PO,)F(dmso)] is also layered.67b The structure of a mixed phos-phate/phosphonate where one phosphate has a large organic complexing group has been determined .6 7c The use of acid zirconium phosphates and phosphonates as proton conductors and for solid state gas sensors has been reviewed68 whilst copper zirconium phosphate and the mixed phosphonate [Zr{03P(CH,)3COOH}o~75(03POH)l,25] catalyse the poly- merization of aniline.69 Zirconium polyimine phosphonates are active complexing agents for both anions and cation-anion pairs.70 Several pure and mixed phosphon- ates [Zr(O,PR,)(O,PR',),] with reactive functional groups (R = Bz CH=CH, etc.) incorporate small molecules and ions from solution.Zirconium phosphonate monolayers and multilayers have been made by self-assembly of organophosphonic acids at a zirconium octadecylphosphonate Langmuir-Blodgett film.72 Second harmonic generation has been observed in zirconium phosphate and phosphonate multilayers incorporating polar azo dyes.7 Grazing angle X-ray diffraction has been used74 to determine film thicknesses in self-assembled hafnium- 1 ,lo-decanediyl- bis(phosphonate) multilayers.Zirconium viologen phosphonates such as [Zr{0,PCH,CH,(bipyridinium)CH2CH2P03}X2] (X = C1 Br) undergo photolysis with a colour change from white to blue and generation of the dialkylviologen radical cation;75 thin films also containing colloidal platinum can be reduced with dihydrogen " S. Ryu D. Whang H. Yeo and K. Kim Inorg. Chim. Acta. 1994,221 51. 62 J. W. Buchler M. Eberle P. Hammerschmitt J. Huettermann and R.Kappl Chem. Ber. 1994,126,2619. 63 G.S. Girolami P. A. Gorlin and K. S. Suslick Inorg. Chem. 1994,33 626. 64 W.T. A. Harrison T. E. Gier and G. D. Stucky Acta Crystallogr. Sect. C 1994,50 1643. '' N. Hirose and J. Kuwano J. Mater. Chem. 1994 4 9. '' K. K. Rangan B. R. Prasad C. K. Subramanian and J. Gopalakrishnan J. Chem. SOC. Chem. Commun. 1994 141. " (a) D. M. Poojary and A.M. Clearfield Inorg. Chem. 1994 33 3685; (b) D. M. Poojary B. Zhang and A. M. Clearfield J.Chem. SOC.,Dalton Trans. 1994,2453; (c)B. Zhang and A. M. Clearfield Angew. Chem. Int. Ed. Engl. 1994 33 2324. 68 G. Alberti M. Casciola and R. Palombari Efectrokhimiya 1993 29 1436 (Chem. Abstr. 1994 120 207.392). 69 G. L. Rosenthal J. Caruso and S.G. Stone PoEyhedron 1994 13 1311. '* C.Y. Ortiz-Ada C. Bhardwaj and A. Clearfield Inorg. Chem. 1994 33 2499. " G. L. Rosenthal and J. Caruso J. Solid State Chem. 1993 107 497. '' H. Byrd S. Whipps J.K. Pike J. Ma S. E. Nagler and D. R. Talham J. Am. Chem. SOC. 1994,116,295. 73 H. E. Katz W. L. Wilson and G. Scheller J. Am. Chem. Suc. 1994 116 6636. 74 A. C. Zeppenfeld S.L. Fiddler W. K. Ham B. J. Klopfenstein and C. J. Page J.Am. Chem. SOC.,1994,116 9158. 75 L. A. Vermeulen J. L. Snover L. S. Sapochak and M. E. Thompson J. Am. Chem. Soc. 1993,115,ll. 767. Titanium Zirconium and Hafnium 159 and can photochemically reduce water to dihydrogen .76 [Zr{O ,PCH,CH (bipyridin- ium)CH,CH,P0,)F,]~2H2~ has an unusual layer str~cture.~' A Na,Zr,Si,PO ,-sodium aluminosilicate composite has been examined as a solid-state Na' ion conductor and used as an electrochemical CO sensor.78 8 Borohydrides [Zr,H,(BH,),(PMe,),] has the structure [(BH,),(Me,P),Zr(p-H),Zr (PMe3),(BH4),] ; the borohydrides are probably bidentate.79 Polymer-supported [Zr(BH,),] is a regenerable catalyst for reduction of various aldehydes and ketones.80 [Zr(BH,),] reacts with HSBu' to form clusters [Zr,S,(SBu'),(BH,),(thf),] and [Z~,S,(SBU'),(BH,)~(~~~)~];~' core.Other bridged both have a [Z~-,-s)~(p,-s)~]~+ thiolates result from similar reactions with tetrabenzylzirconium. 9 Other Complexes In three different salts Ba[Ti(edta)(H,0)]C1.6H20 Na,[Ti(edta)(H,O)] ,.NaC1.7H2O and K[Ti(edta)(H2O)].2.5H,O, the [Ti(edta)(H,O)]- has seven-coordinate monocapped trigonal prismatic titanium; in contrast it is pentagonal bipyramidal in Na[Ti(edta)(H,0)]-2H,0.82 TiO reacts with KOH and oxalic acid to form K2[TiO(C,0,),].2H,0 which has chelating oxalates and eight-membered rings of four titanium and four oxygen atoms.' Decomposition of the peroxotitanate(1v) complex [Ti(02)(C204)2]2- is initiated by small amounts of a reducing agent such as titanium(1u) or chromium(II) and occurs by a radical route.84 The reaction of TiCl with Bu'COOH in a 2.5 1ratio gives the dinuclear compound [{TiC1,(0,CBu')(Bu'C0,H)}2(p-O)], which has an 0x0 bridge and two bridging carb~yxlates;'~ at higher temperatures [Ti3C1,(0,CBu'),0,] and [{TiCI(O,CBu'),),(p-0)] are formed.Carrying out the reaction with a 1 1 ratio results in [Ti,Cl (0,CR) (RCO ,H )] .' [{ TiCl (p-0)(0,CEt)(Et CO H)} ,] and [Ti3C1,(p-O)(p3-O)(02CEt)5] have [Ti(p-O)(p-O,CEt),Ti] and [Ti3(p-0)(p3-O)] cores respectively.Titanium carboxylate films that can be supported on silica glasses have been developed.87 Another example of the usefulness of alkoxides and amides as starting materials is the reaction of [Ti(NMe,),] with 1,2-(HS),C,H,; the resulting homoleptic thiolate [NH,Me,],[Ti(S,C,H,),] has an unusual skew-trapezoidal bipyramidal TiS coordination geometry.88 76 J.L. Snover and M.E. Thompson J. Am. Chem. Soc. 1994 116 765. 77 D. A. ;Poojary L. A. Vermeulen E. Vicenzi A. Clearfield and M. E. Thompson Chem. Mater. 1994,6 1845. " S. Nakayama and Y. Sadaoka J. Mater. Chem. 1994 4 663. 79 S.C. Mayo M. Brown and V. K.Lloyd Acta Crystallogr. Sect C 1994,50 367. B. Tamami and N. Goudarzian J. Chem. SOC. Chem. Commun. 1994 1079. " D. Coucouvanis A. Hadjikyriacou R. Lester and M. G. Kanatzidis Znorg. Chem. 1994 33 3645. T. Mizuta J. Wang and K. Miiyoshi Bull. Chem. SOC.Jpn. 1994 66,3662. 83 A. Fester W. Bensch and M. Tromel Acta Crystallogr. Sect. C 1994 50 850. 84 N. Shinohara M. Iwasawa and T. Akiyama Bull. Chem. SOC. Jpn. 1994 67 1033. 85 H. Barrow D. A. Brown N. W. Alcock H. J. Clase and M. G. H. Wallbridge J. Chem.SOC.,Dalton Trans. 1994 195. 86 H. Barrow D.A. Brown N. W. Alcock W. Errington and M.G. H. Wallbridge J. Chem. Suc. Dalton Trans 1994 3533. 87 D. D. Dunuwila C. D. Gagliardi and K. A. Berglund Chem. Muter. 1994 6 1556. '' M. Konemann W. Stuer K. Kirschbaum and D.M. Giolando Polyhedron 1994 13 1415. 160 S. A. Cotton Titanates often have interesting properties. Thus CaTiO is a potential semiconduc- tor; it and other calcium titanates have been synthesized by the sol-gel process.89 The structure of hexagonal BaTi0,has been refined” and grain boundary atomic structure in SrTiO directly determined.” The structure of LiTi,O, superconducting below 11.5K has been determined9 whilst phases in the BaO-Li,O-TiO system particularly the Li’ ion conductor BaLi,Ti,O have been examined.93 A fibrous alkali-metal titanate based on [Ti8O18l4-and [Ti80,,12- units has been character- i~ed;~, the new cerium compounds Ce,TiO, Ce,Ti,O, and Ce,Ti,O, are isotypic with La,TiO, La2Ti207 and Nd,Ti,O, re~pectively.~’ 10 Organometallics Unstable eight-coordinate titanium@) carbonyl species [TiX,(CO)(dmpe),] have been reported96 whilst isolable zirconium(rv) carbonyls have been made in the form of [Zr(q2-COMe)(CO)(C,R,)2][BMe(C,F,),19‘ (R = H Me) and [Zr(0)(q3-C3H5)Cpz][BPh4].98 [Zrnp,] (np = neopentyl) has been used as a precursor for thin films of zirconium99 whilst [{Zr(p-Cl)np,) ,] has a linear symmetric chain structure in which each zirconium has trigonal bipyramidal coordination.loo Tetraaza[ 141an- nulenezirconium(1v) complexes with butadiene ligands have been reported. lol A highlight is the discovery that [ZrCl,(thf),] reacts with potassium naphthalenide to give [Zr(q4-CloH8)3]2- which has a trigonal structure (4) (rather than the anticipated ‘sandwich’ [Zr(q6-C,oH8)2]2-).102 89 G.Pfaff Chem. Muter. 1994 6 58. 90 J. Akimoto Y. Gotoh and Y. Oosawa Acta Crystallogr. Sect. C 1994 50 160. 91 M. M. McGibbon N. D. Browning M. F. Chisholm A. J. McGibbon S.J. Pennycook V. Ravikumar and V. P. Dravid Science 1994 266 102. 92 J. A. Camps M. Velez C. Cascales E. Gutierrez Puebla M. A. Monge I. Rashes and C. Ruiz-Valero J. Cryst. Growth 1994 142 87. 93 L. M. Torres-Martinez C. Suckut R. Jimminez and A. R. West J. Muter. Chem. 1994 4 5. 94 T. Sasaki M. Watanabe Y. Fujiki and Y. Kitami Chem. Muter. 1994 6 1749. 95 A. Preuss and R. Gruhn J. Solid State Chem. 1994 110 363. 96 M. D. Spencer and G. S. Girolami J. Organomet. Chem. 1994 483 99. 97 Z. Guo D.C. Swenson A. S. Guram and R.F. Jordan Organometallics 1994 13 766.98 D. M. Antonelli E. B. Tjaden and J. M. Stryker Organornetallics 1994 13 763. 99 D. C. Smith R. R. Rubiano M. D. Healy and R. W. Springer Muter Res. SOC.Symp. Proc. 1993,282,643 (Chem. Ahstr. 1994 120 149.145. loo L.K. Hoyt J.L. Pollitte and Z. Xue Inorg. Chem. 1994 33 2497. L. Giannini E. Solari C. Floriani A. Chiesi-Villa and C. Rizzoli Angew. Chem. Znt. Ed. Engl. 1994,33 2204. M.Jang and J. E. Ellis Angew. Chem. Int. Ed. Engl. 1994 33 1973. Titanium Zirconium and Hafnium The structures have been reported of Ti"Cp species such as [TiX(dmpe),Cp] (X = C1 Me H) and [Ti(q2-BH,){q2-(Me,PCH2)3SiBu')Cp*],103 of the Ti"'Cp complex [Ti"'{q2-C2(SiMe,),)Cp(q5-C5Bz5)] and [TiC12Cp(q5-C,Bz5)].'04 MCp (M = Zr Hf) systems with Group IV-VI or transition metal anionic ligands have been reviewed.'O5 Valence force field parameterization of zirconocene dichlorides has been reported.lo6 [TiMe,Cp,] has the expected pseudotetrahedral structure and is isostructural with the zirconium and hafnium analogue^;"^ [TiCl,(C,HMe,),] is probably similar.'08 [ZrCl,Cp*] is dimeric [C1,Cp*Zr(p-Cl),ZrCp*C12].109 [ZrF,Cp*] reacts with AlMe,to form an unusual cluster species [MeCp*Zr(p-F),(p,- F,AlMe,),ZrCp*Me];' lo [MCl,(NCMe),Cp] (M = Zr Hf) undergo halogen ab- straction with SbCl,,' '' forming cations such as [M(NCMe),Cp13 + [MC1(NCMe),Cpl2 +,and [MCl,(NCMe),Cp] . The pentahapto coordination of + the permethylindenyls [TiCl,(q5-C,Me7)] and [ZrC1,(q5-C,Me,),] is also ob- served in the bridged indenyl complex [TiCI,{ (p-CH,),(C,H,),) .'I3 A different type of ethylene bridge is observed in [Cp,(Me)Zr(p-CH,CH,)Zr(Me)Cp,].' l4 [TiMe,Cp*][BMe(C,F,),] is a carbocationic ethene polymerization catalyst'" whilst the structure of the zwitterion [ZrMe(p-Me)B(C,F5),{q-C5H3(SiMe3),},] has been determined.l16 The latter has a bridging methyl with an unusually long Zr-C distance.B(C,F,),reacts with [ZrBz,{q-C5H,(SiMe,),),1 to form ionic [ZrBz{q- C,H,(SiMe,),} ,][B(C,F,),Bz] which remains ionic in toluene solution under alkene polymerization conditions. Cationic zirconium and hafnium isobutyl complexes have been studied as models for a-olefin polymerization.' ' [ZrH(thf)Cp;][BPh,] inserts butene reversibly at room temperature forming [Zr(CH,CHMe,)(thf)Cp;][BPh,] which reacts with PMe forming [Zr(CH,CHMe,)(PMe,)(thf)Cp',][BPh,]; the last has a B-agostic structure and undergoes B-elimination above -13"C.The simple cationic benzyl [ZrBz,] was also studied as a model for Ziegler-Natta insertion'18 + because it inserts a-olefins to form isolable [ZrBz,(CH,CHRCH,Ph)] adducts. + Ring-substituted titanocene bis(thi0cyanates) exhibit ambidentate behaviour; both [Ti(NCS),(C5H4But),] and [Ti(SCN),(C,H,Bu'),] have been synthesized and the structure of the latter determined. Asymmetric [TiCl,(C5H,Bu~)(C,H,But)] has also been prepared."' Lewis bases (e.g. L = im or PMe,) react with [TiCl,Cp,] to a limited extent to produce [Ti"'ClLCp,]; this reacts with propane-l,3-dithiol forming successively [(Ti"'C1Cp,),(p-SCH2CH,S)I and [(Ti"'(SCH,CH,CH,S)Cp,),l.[{TiCl(SCH,CH,S)Cp),] and [TiCl(SCH,CH,CH,S)Cp] were also made. In con- '03 Y. You s.R. Wilson and G. s.Girolami Organometallics 1994 13 4655. lo4 G. Schmid U. Thewalt M. Polasek K. Mach and P. Sedmera J. Organomet. Chem. 1994 482 231. lo5 E. Hey-Hawkins Chem. Rev. 1994 94 1661. '06 U. Howeler R. Mohr M. Knickmeiet and G. Erker Organometallics 1994 13 2380. lo' U. Thewalt and T. Wohrle J. Organomet. Chem. 1994,464 C17. lo' S. M. Jiang Y. Wang J. Xu and Y. -Q. Ling Jiegou Huaxue (Chin. J. Struct. Chem.) 1994 13 206. A. Martin M. Mena and F. Palacios J. Organomet. Chem. 1994 480 C10. 'lo A. Herzog H. W. Roesky Z. Zak and M. Noltemeyer Angew. Chem. Int. Ed. Engl. 1994 33 967. G. R. Willey M. L. Butcher and M. G. B. Drew J. Chem.SOC. Dalton Trans. 1994 3285. D. O'Hare V. Murphy G. M. Diamond P. Arnold and P. Mountford Organometallics 1994,13,4689. 'I3 S. Parkin S. R. Hitchcock H. Hope and M. H. Nantz Acta Crystallogr. Sect. C 1994 50 169. 'I4 T. Takahashi K. Kasai N. Suzuki K. Nakajima and E. Negishi Organometallics 1994 13 3413. 115 R. Quyoum Q. Wang M.-J. Tudoret M.C. Baird and D. J. Gillis J. Am. Chem. SOC. 1994 116 6435. M. Bochmann S.J. Lancaster M. B. Hursthouse and K. M. A. Malik Organometallics 1994 13 2235. 'l7 Z. Guo D. C. Swenson and R. F. Jordan Organometallics 1994 13 1424. 11' C. Pellecchia A. Grassi and A. Zambonelli Organometallics 1994 13 298. '' I. Jibril S.T. Abu-Orabi S. A. Klaib L. Zsolnai and G. Huttner J. Organomet. Chem. 1994 467 189. 162 S.A. Cotton trast [TiCl,Cp] forms the adducts [TiCl,LCp] (L = PMe, PHEt,); small quantities of EPR-active [TiCl,L,Cp] (L = PMe, PHEt, im Meim) were also obtained. [{TiCl(SCH,CH,S)Cp},] reacts with PMe and (PhS) forming [{Ti(SPh)(SCH,CH,S)Cp},] whilst [TiCl(SCH,CH,CH,S)Cp] correspondingly forms [Ti(SPh)(SCH,CH,CH2S)Cp].'20Radical routes are implicated in many of these reactions. Further titanium(II1) phosphide dimers have been made. 12' Reaction of [TiCl,Cp,] with KPHR (R = But SiPh, C6H2-2,4,6-Bu',) gives [(Ti(p-PHR)Cp,},] in the first two cases but the super-mesityl forms the fulvalenide [{CpTi(PH,)},(p-q5,q5-CloHg)] (5). The phosphorus-bridged species [Zr,(p-P)CpX] [Zr,(p-P,)Cp:] and [Zr{ q-P,K(thf),.,}Cp~] have been made', (6). CP\ /CP* *,a-P-Zr CP CP* The first amino acid complexes derived from the antitumour agent [TiCl,Cp,] have been characterized in the form of compounds [Ti(aa),Cp,]Cl (aa = glycine alanine and 2-methylalanine); the amino acids bond only through the carboxylate group.'23 TiC1 reacts with C&k to form the arene complex [TiCl,(q-C,Me,)][Ti,Cl,] the cation of which has a piano-stool structure.124 The complex [TiCp(q-C,H,)] has been used as a volatile precursor for TiN thin films125 and its photoelectron spectrum (together with those of similar compounds with other metals) has been assigned.', [(Ti@-Cl)(thf)(q-cot)),] reacts with KTp and KTp' to give the half-sandwiches [TiL(q-cot)] (L = Tp or TP').',~ Other monomers 120 T.T.Nadasdi and D.W. Stephan Inorg. Chem. 1993 32 5933.12' J. Ho and D. W. Stephan Inorg. Chem. 1994 33,4595. 122 M.C. Fermin J. Ho and D.W. Stephan J. Am. Chem. Soc. 1994 116 6033. 123 T. M. Klapotke H. Kopf I. C. Tornieporth-Oetting and P. S. White Angew. Chem. Int. Ed. Engl. 1994 33 1518; T.M. Klapotke H. Kopf I. C. Tornieporth-Oetting and P.S.White Angew. Chem. Int. Ed. Engl. 1994,33 1518; T. M. Klapotke H. Kopf I. C. Tornieporth-Oetting and P. S. White Organometal-lics 1994 13 3628. lZ4 E. Solari C. Floriani K. Shenk A. Chiesi-Villa C. Rizzoli M. Rosi and A. Sgamellotti Inorg. Chem. 1994 33 2018. 125 R. M. Charatan M.E. Gross and D. J. Eaglesham J. Appl. Phys. 1994 76 4377. 126 J.C. Green N. Kaltsoyannis K.H. Sze and M. MacDonald J. Am. Chem. SOC.,1994 116 1994. Titanium Zirconium and Hafnium such as [Ti(PhC(NSiMe,),)(thf)(q-cot)] have also been reported.The sandwiches [M(C,H,(SiMe,),)] (M = Ti Zr) have been synthesized; the zirconium compound has a solid-state structure (7)where one ring is bound in a conventional q8-mode whilst the other has a peculiar y3-attachment.lZ8 The titanium compound has one ring (Reproduced with permission from J. Chem. SOC.,Dalton Trans. 1994 2867.) intermediate in hapticity between q3 and q4. In solution the two rings of the zirconium compound are indistinguishable by NMR spectroscopy down to 193K; for the Ti compound they are only equivalent above 328 K. U. Kilimann M. Noltemeyer M. Schafer R. Herbst-Irmer H.-G. Schmidt and F.T. Edelmann J. Organomet. Chem. 1994 469 C27. 12* F.G. N. Cloke J. C.Green P. B. Hitchcock S. C. P. Joseph P. Mountford N. Kaltsoyannis and A. McCamley J. Chem. SOC.,Dalton Trans. 1994 2867.

ISSN:0260-1818    

DOI:10.1039/IC9949100153

出版商:RSC    

年代:1994

数据来源: RSC

摘要:

12 Vanadium Niobium and Tantalum By H. SLOAN Consulting Chemist 40 Wendan Road Newbury Berkshire RGl4 7AF UK 1 Introduction Vanadium peroxide complexes have been reviewed.' Aspects of interest in this group have appeared in reviews on amidine ligands' and EPR spectroscopy of low-spin d5 c~mplexes.~ 2 Hydrides Protonation of [TaH(CO)Cp,] at -78 "C by a stoichiometric amount of HBF;Et,O in CH,Cl gave4 trans-[Ta(H),(CO)Cp,] + and the thermally stable isomeric dihydro- gen complex [Ta(H,)(CO)Cp,] . The proportions of the two products show little + variation with temperature. Determination of the relaxation times from the NMR spectra for the two complexes enabled the relaxation for the H-H interaction to be separated unambiguously and the H-H distance in the dihydrogen complex to be estimated at 0.84(5)1$.The addition of a solution of chlorocatecholborane to a suspension of Li[TaH,Cp,] in toluene at -78°C also gave' the endo- and exo-isomers (1) and (2).The crystallographic and NMR data show the boryl form for the boron-donor ligand rather than an agostic borane. The H-H distance of 2.31(20) A in the exo isomer rules out a dihydrogen formulation though deterministic difficulties for such a heavy metal atom complex are possible. ' A. Butler M. J. Clague and G.E. Meister Chem. Rev. 1994 94 625. J. Barker and M. Kilner Coord. Chem. Rev. 1994 133 219. P.H. Rieger Coord. Chem. Rev. 1994 135/136 203. S. Sabo-Eitenne B. Chaudret H. A. el Makarim J.-C. Barthelat J.-P. Daudey C. Moi'se and J.C. Leblanc J.Am. Chem. Soc. 1994 116 9335. D. R. Lantero D. H. Motry D. L. Ward and M. R. Smith 111 J. Am. Chem. SOC. 1994 116 10811. 165 I66 H. Sloan 3 Carbonyl Compounds The hydride [TaH(CO),(dppe)] reacted6 in benzene with the radical *C(C,H,BU'-p) to give the 17-electron tantalum@) complex [Ta(CO),(dppe)]. It is highly reactive to halogen donors in situations where [TaH(CO),(dppe)] and the anion [Ta(CO),(dppe)] -react slowly if at all. Separation and purification difficulties prevented X-ray structural studies. The magnetic moment at 298 K (1.7 pB)corre-sponds to a single unpaired electron but the moment is strongly temperature dependent decreasing smoothly to 1.4 pBat 213 K suggesting some dimerization. The enthalpy change estimated from NMR studies suggests any metal-metal bonding is much weaker than for later transition metals.Differences in solid and solution IR and Raman spectra indicated possible bridging carbonyl group@) in the dimer. 4 Nitrides and Nitrogen-donor Ligands Ab initio RHF and CI calculations for various model fragments involving vanadium and dinitrogen have been made7 in order to cast light upon the activation of the N ligand towards reduction or bond breaking. Mononuclear complexes are suggested to have poorly activated dinitrogen while vanadium@) is needed for activation in dinuclear compounds with bridging dinitrogen. Reduction of [VCl,(thf),] by M (M = Na Li) in the presence of phosphines and N produces' a wide range of dinitrogen-phosphine-vanadium complexes with mono- di- tri- and tetraphosphines.The complexes are generally labile the most stable being cis-and trans-M[V(N,),(dmpe),]. Dinitrogen is replaced by CO or CNBu'. NMR spectroscopic data indicate close interaction of the end-on dinitrogen ligands with lithium ions. Large cations (K+ [NEt,]') do not give stable complexes and addition of crown ethers to complex lithium or sodium leads to immediate decomposition of the dinitrogen complexes. The reaction of [VCl,(thf),] with three equivalents of LiNR (R = Ph Pr' Cy) gave' the tetrahedral tris(amide) complex (3) (Scheme 1). The phenyl derivative is thermally stable and easily isolated. The two alkyl derivatives reacted readily with dinitrogen to give (4) which has an end-on bridging N group but which is surprisingly unreactive.The bond distances and angles suggest little change from a N=N triple bond in the complex though the lack of an oxidation wave in the cyclic voltammogram and the diamagnetism of the complex are more in accord with a V(v) centre. If [VCl,(thf),] is reacted with six equivalents of LiNPri at a higher temperature the paramagnetic complex (5) is formed. While ligand oxidation occurs to form the C=C double bond there is no change in the oxidation state of the vanadium atom. Other studies by the same group illustrate the considerable variation in structures obtained" depending upon the substituents R of LiNR,. Reaction of the azasilavanadocyc- lobutane ring of the monomer (6) led to ring expansion (Scheme 2) while the same reaction with the dimer (7) gave an ionic complex." M.D.Koeslag and M.C. Baird Organometallics 1994 13 11. H. Gailus C. Woitha and D. Rehder J. Chem. SOC. Dalton Trans. 1994 3471. ' N. Re M. Rosi A. Sgamellotti C. Floriani and E. Solari Inorg. Chem. 1994 33 4390. J.-I. Song P. Berno and S. Gambarotta J. Am. Chem. Soc. 1994 116 6927. lo P. Berno S. Hao R. Minhas and S. Gambarotta J. Am. Chem. SOC. 1994,116,7417; P. Berno R. Minhas S. Hao and S. Gambarotta Organometallics 1994 13 1052. l1 P. Berno and S. Gambarotta J. Chem. Soc. Chem. Commun. 1994 2419. Vanadium Niobium and Tantalum 167 thf /Vc:”R2 iii R2N NR, 1 I (3) (5) (4) Reagents i 3LiNR (R = Ph Pr’ Cy); ii Hexane N (R = Pr’ Cy) iii 6LiNPr Scheme 1 Si \/ -4-f i Me,SiN’ ‘CH I Me,SiN ,NSiMe ‘V/ V (Me3Si)2N/\ py (Me3Si),N’ ‘py ,V-O\ iii (Me,Si),N \ ,v/ N(SiMe,) o\ AdNsiMe3 /‘ \ Me r N(SiMe,), I -i (Me,Si),N N(SiM+) lCN Me,SiN’ ‘CH N(SiMe,) \;/ I (Me,Si),N/ ‘NSiMe ‘Si’ Me/ ‘Me (7) Reagents i RNC; ii CO 3d; iii py; iv CO 5m Scheme 2 168 H.SEoan The EPR spectrum of fluid and frozen solutions of [V(bipy),] in thf confirm' the delocalization of the odd electron into the n* orbitals of the bipy ligands. [V(NSiMe,)Cl,] reacted' with PCl,R (R = Ph, MePh, Me,Ph Me,) in CH,Cl giving [V(NPR,)Cl,]. Adding one or two equivalents of Me,SiNPPh to the triphenyl derivative gave [V(NPPh,),Cl,] and [V(NPPh,),Cl,] . Further addition of Me,SiNPPh to the latter produces only a small equilibrium concentration of a tetrakis(phosphoranimat0) species.However the unusual reaction between [V(NPPh,),Cl -,I (n = 1-3) and ammonia gave [V(NPPh,),]Cl with a tetrahedral cation. ,'P and 51V NMR spectra show well-resolved V-P coupling indicating the retention of the tetrahedral structure in solution. NMR spectra suggest dimeric structures for the mono and diphosphoraminato complexes and a trigonal bipyramidal structure for the triphosphoraminato complex. The reaction of [VCl,(thf),] with [Li2(thf)2(ttp)] gave' the six-coordinate [VCl(thf)(ttp)] with vanadium displaced out of the plane of ttp towards the chloro ligand. The V-0 bond length is relatively short reflecting the unoccupied antibonding orbitals. Chemical oxidation of [VO(oep)] gave' the n-cation radical [VO(H,O)(oep ')][SbCl,] where the vanadium atom is displaced from the plane of the oep moiety towards the 0x0 group which is trans to the aquo ligand.A model for the intra- and intermolecular ferromagnetic couplings involving the vanadium atom and the oep' radical was developed from EPR measurements in the solid state. The reaction of [TaCl,] with the [Li,(oep)(thf),] gave the sandwich complex [Ta(oep),][TaCl,] where the cation has the two porphyrin rings staggered with respect to each other. The separation of the two N planes is only 2.40A. The electronic spectrum suggests a strong interaction between the two oep systems. Similar reaction of [TaMe,Cl,] with [Li,(oep)(thf),] gave entry to a series of half-sandwich' compounds including [TaCl,(oep)] and [TaMe,(oep)] .+ 5 Other Pnictide-donor Ligands Ab initio SCF calculations for trans-[NbCl,(PR,),] gave a Jahn-Teller distorted ,E ground state; the predicted geometry is in agreement with the known X-ray structure but not with the previously reported interpretation of the EPR spectrum. Addition of Na,E (E = P As Sb Bi) to [VCl,] resulted'* in a solid-liquid metathesis reaction initiated immediately and accompanied by a red-white flash and sublimation of NaCl and E. The vigour of the reaction decreases P > As > Sb > Bi. The product VE is most readily formed with phosphorus but diminishes in favour of free E in the same order. The reactions of [VCl,] with phosphines and phosphine oxides inv~lved'~ reduction of vanadium(1v) to vanadium(m) though quite different products were formed in each case.This contrasts with the known reactions with [NbCl,] and [TaCl,] where the A.L. Rieger J. L. Scott and P.H. Rieger Inorg. Chem. 1994 33 621. l3 A. Aistars R.J. Doedens and N. M. Doherty Znorg. Chem. 1994,33 4360. l4 L.M. Berreau J.A. Hays V.G. Young Jr. and L.K. Woo Inorg. Chem. 1994 33 105. l5 C. E. Schultz H. Song Y. J. Lee J. U. Mondal K. Mohanrao C. A. Reed F. A. Walker and W. R. Scheidt J. Am. Chem. Soc. 1994 116 7196. l6 D. Y. Dawson H. Brand and J. Arnold J. Am. Chem. Soc. 1994 116 9797. l7 F.A. Cotton M.B. Hall and M.A. Pietsch Inorg. Chem. 1994 33 1473. l8 A. L. Hector and I. P. Parkin Inorg. Chem. 1994 33 1727. lq F.A. Cotton J. Lu and T. Ren Inorg.Chim. Acta 1994 215 47. Vanadium Niobium and Tantalum oxidation states are conserved. Reaction with PEt gave tran~-[PHEt,l(VCl,(PEt,)~] and mer-[VCI,(OPEt,),] the latter arising from phosphine oxide as an impurity in the phosphine or produced in situ during the reaction. Reaction with PMe gave the only dinuclear product [V,Cl,(PMe,),] an edge-sharing bioctahedral complex with chlorine bridges; one vanadium has trans phosphine ligands and the other cis (8). Mer-trans-[VC1,(PMe2Ph)2(OPMe2Ph)] has been reported previously but differen- ces in the cell dimensions and the space group appear to relate to crystal purity. [Ta(silox),] reacted2’ with EH2Ph (E = N P in benzene at 25 “C; E = As in toluene at -78 “C) to give unstable [TaH(silox),(EHPh)]; the NMR spectra are consistent with a trigonal bipyramidal structure.The hydride decomposed with hydrogen elimination to give [Ta(silox),(EPh)]; the arsenic complex has a tetrahedral Ta atom. The [PJ ion is known as a Cp analogue in for example [Fe(P,)Cp*]. Ring opening of the P ligand occurs2’ when this complex is photolysed with [Ta(CO) Cp”] giving [Cp”TaP,FeCp*] (9). The intermediate [Cp*Fe(p-y5 :yl-P,)Ta(CO),Cp”] isolated after a short period of photolysis is a key precursor for the preparation of (9);CO may be eliminated thermally or photolytically. The ‘H and ‘P NMR spectra of (9) are consistent with the crystal structure; the Ta-Fe distance (2.845A) indicates a metal-metal bond. 6 Oxygen-donor Ligands It is known that peroxovanadium compounds of the type M[VO(O,),L] (M = K NH,) are stabilized when L is a bidentate ligand.A structural determination showed22 that the complex with L = N0,phen is a pentagonal bipyramid with the 0x0 ligand and one nitrogen donor from the chelate in axial positions. Only one isomer is present of the two that might be expected from the asymmetrical positioning of the nitro group. Reaction of [VOCI,] with an alcohol and then with KTp gave2 [VOCl(OR)Tp] (R = Me Et Pr’ But) and [VO(OR),Tp] (R = Pri). When KTp’ is used steric factors are more important in that dialkoxides are formed with smaller R (Me or Et) but chloro-monoalkoxides otherwise. These alkoxides underwent facile hydrolysis to a variety of 0x0-bridged multinuclear species including the cyclic tetramer [(V02Tp),] which has a non-planar butterfly V404 core.A large series of known and new alkoxides and 1,2-diolate compounds of vanadium has been characterized,, particu- ” J. B. Bonanno P.T. Wolczanski and E. B. Lobkovsky J. Am. Chem. Soc. 1994 116 11 159. ’ M. Detzel T. Mohr 0.J. Scherer and G. Wolmershauser Angew. Chem. Int. Ed. Engl. 1994,33 11 10. 22 A. Shaver J. B. Ng R. C. Hynes and B.I. Posner Acta Crystallogr. Section C 1994 50 1044. 23 C. J. Carrano M. Mohan S. M. Holmes R. de la Rosa A. Butler J. M. Charnock and C. D. Garner Inorg. Chem. 1994 33 646. z4 D.C. Crans R. A. Felty H. Chen H. Eckert and N. Das Inorg. Chem. 1994 33 2427. 170 H. Sloan larly using solid-state 51V and 13C NMR spectroscopy. The parameters obtained correlate with the local vanadium coordination environments for compounds with crystalline disorder and complex solution equilibria.The molecular geometry about vanadium is very sensitive to minor changes in the ligands. The reaction of [NbCl,] with aromatic organic acids and ethanol gavez5 [{NbCl,(OEt)2}2(p-0,CR)~](R = Ph p-C,H,R'; R = F C1 I Me) over a range of molar ratios of the starting materials. The bridging carboxylate groups are unsymmet- rical and the crystal structure includes dimers indicating n-71 interactions of the benzoate ligands. [TaO(OR),] (R = But mes) [TaO(SR),] (R = But p-tol) [TaS(OR),] (R = But,mes) and [TaS(SR),] (R = But,p-tol) were obtained2 from the reaction of [TaOCl,] or [TaSCl,] with LiOR or LiSR. [TaCl,] and an excess of LiOmes gave [TaCl,(Omes),] and [TaCl,(Omes),].All of these products are mononuclear. [TaCl,] and ethanol gave the symmetrical binuclear complex [TaCl,(OEt),] with two bridging ethoxy groups and trans chloro ligands. { [NbO(OC,H3Pr~-2,6),},] hasz7 a distorted trigonal bipyramidal geometry about each niobium atom and asymmetrical bridging 0x0 groups. A redetermination of the structure of [V,O(E-his),].2H,O by X-ray crystallography and resonance Raman spectroscopy has shownz8 that the unusually small V-0-V angle (153.9') at the bridging 0x0 ligand is the result of two strong intramolecular hydrogen bonds. The spectroscopic data show that the angle opens to about 180' in solution. Colloidal suspensions of [Zn(OPr'),] prepared by alcoholysis of [Zn{N(SiMe,),},],were foundz9 necessary toenable thereaction with [{Ta(OPr'),},] giving [ZnTa,O,(OPr'),].Metathesis of ZnI and K[Ta(OPr'),] in 1 :2 stoichiometry gave the same product. Using a 1 1 stoichiometry in the latter reaction gave [{ZnTa,I(p,-O)(p-O)(p-OPri)3(OPri)4}~] (lo) a centrosymmetric dimer with dis- torted tetrahedral zinc having iodide as its only terminal ligand and distorted octahedral tantalum. The Ta-0-Ta bridges are nearly linear (175.3'). (10) Under reducing conditions aqueous vanadium-oxo solutions reacted,' with squaric acid to give (lla). Without reducing agents the two paramagnetic mixed- valence complexes (llb) and (12) were obtained; (llb) is produced by hydrolytic displacement of the bridging squarate ligand from (12). The complexes (1 la) and (1lb) 25 D.A. Brown M. G. H. Wallbridge W.-S. Li M. McPartlin and I. J. Scowen,Inorg. Chim. Acta 1994,227 99. 26 F. Preuss G. Lambing and S. Miiller-Becker Z. Anorg. Allg. Chem. 1994 620 1812. 27 V. M. Visciglio P. E. Fanwick and I. P. Rothwell Acta Crystallogr. Section C 1994 50 900. R. S. Czernuszewicz Q. Yan M. R. Bond and C. J. Carrano Inorg. Chem. 1994 33 61 16. 29 S. Boulmaiiz L.G. Hubert-Pfalzgraf S. Halut and J.C. Daran J. Chem. Soc. Chem. Commun. 1994,601. 'O M.I. Khan Y.-D.Chang Q.Chen,J. Salta Y.-S. Lee C. J. O'Connor and J. Zubieta,Inorg. Chern. 1994 33 6340. Vanadium Niobium and Tantalum contain unusual combinations of terminal and/or bridging aquo groups. The V-Obridge distances in (11b) are different and the O=V-0-V=O core is unusual in adopting a cis configuration as opposed to the usual trans structure.Similar reaction in methanolic solution with oxalic acid gave (13) which has an unusual disposition of the {VOCl) moiety in the plane of the bridging oxalate ligand. The trans influence of the terminal 0x0 group is reflected in the unequal V-O, distances. (lla) X=O (llb) X=OH Me /Me '0 0 (12) (1 3) The reaction of [VCl,] with [(LiOSiPh2),0.O.2thQ gave3' (14) where the vanadium(1v) is square pyramidal. The two six-membered vanadasiloxane rings are roughly planar and at an angle of 153"in a structure about vanadium that is like that of [VO(acac),]. In solution while weak coordination of a sixth ligand is observed with the acac complex the lithium-coordinated thf groups appear to prevent access to the sixth coordination site on vanadium.31 M. Motevalli D. Shah S.A. A. Shah and A. C. Sullivan Organometallics 1994 13 4109. 172 H. Sloan 0 ph2Y ''SiPh2 I II Ph,Si ,SiPh2 0 7 Other Chalcogen-donor Ligands The salts [NEt,][M(E),(SBu')] (M-Nb Ta; E = S Se) are obtained3 by reacting MC1 withNaSBu' E,and [NEt,]Clin MeCN. UsingNaOMegave [Nb(S),(OMe)12-. X-Ray analysis showed quite regular tetrahedral structures for these anions. Fusing together [NbS,Cl,] and KNCS dissolution in water and adding an appropriate organic cation gave3 salts of [{Nb(NCS),},(q2 :q2 :,u,-S,),]~-. The NCS ligands are easily replaced by bidentate 1,l-dithioacid ligands to give [Nb,S,(detc),] [Nb,S,(S,COR),] (R = Et Pr' Cy) and [Nb,S,(S,P(OPr'),),] with retention of the Nb,(S,) core.While the Nb-Nb distances support some bonding the bond order is significantly less than one; each niobium atom is in a distorted square anti-prismatic environment. [VOCl,(thf),] reacted3 with the sodium salt of mercaptopyridine N-oxide to give square pyramidal [VO(SONC,H,),] (15) with an apical 0x0 group. This product reacts with SOC1 to form the paramagnetic dichloro complex (16).The reaction of [NbVO(detc),] with B,S gave35 [NbvS(detc)3] [NbV(S,)(detc),] and [Nb',V(p,-S,) (detc),] in proportions depending upon the reaction conditions. The second of these products has a dodecahedra1 structure analogous to that of its tantalum counterpart. CI (0-...fP) s' 's 32 D.Coucouvanis S.-J. Chen B. S. Mandimutsira and C. G. Kim Inorg. Chem. 1994 33 4429. 33 M. Sokolov A. Virovets V. Nadolinyi K. Hegetschweiler V. Fedin N. Podberezskaya and V. Fedorov Inorg. Chem. 1994 33 3503. 34 W. Tsagkalidis D. Rodewald D. Rehder and V. Vergopoulos Znorg. Chim. Acta 1994 219 213. 35 X.F. Yan B.L. Fox E.R.T. Tiekink and C.G. Young J. Chem. SOC.,Dalton Trans. 1994 1765. Vanadium Niobium and Tantalum 8 Halide ligands Reaction of [NbCl,] with Haza gave3 octahedral [NbCl,(Haza)] and [NbCl,(Haza),] in solution. Some oxidative coupling of Haza occurs giving the counter ion in the isolated salt [H2aza-aza][Nb0C1,(Haza)]~0.5CH2C1,. This has a distorted octahedral structure with the Haza ligand coordinated through N-7 (of the six-membered ring).The salt [H,aza-aza][NbOCl,] was also isolated. The distorted octahedral anion showed disorder of the trans 0x0 and chloro ligands and in the niobium position which is displaced towards the 0x0 group. The face-sharing bioctahedral anions [Nb2C16(p-C1)3)3- [Nb,Cl,(p-Cl),-(p-tht)I2- and [Ta,C1,(p-C1),(p-tht)12-have been ~haracterized,~ as tetraalkylam- monium salts. There is a slight variation of Nb-Nb distance when the cation is changed. The metal-metal distances indicate double bonds and though ab initio and SCF calculations suggest the n interaction is weak it is sufficient to explain the temperature-independent paramagnetism of these compounds. The "V NMR chemical shifts for the seven-coordinate complexes [vx(Co) -Jpm)] (pm = potentially m-dentate phosphine coordinated through n centres) have been used3* to arrange the ligands X in the magnetochemical series of ligand strengths alkenyl E alkyl < SiMe < H 2 Br E I < OOCR < C1 s N < CN.Preparative methods for the alkenyl and halogen complexes are reported. The reaction of [VCl,(NCMe),] with SiMe,I in refluxing MeCN gave39 [V(NCMe),][I,]. The magnetic moment of 3.66 pB is slightly low for vanadium(I1). The cation is octahedral with slight departures from the ideal angles that appear related to the disymmetry of the anion. [V2C13(thf)6][AlCl,Et,] reacted with SiMe,I in thf at 0°C to give [VI,(thf),] which has proved to be a useful starting material for vanadium-iodide complexes. Treatment with depe gave trans-[VI,(depe),] .The V-I bond length is 2.779 % and from the few known vanadium-iodide bond distances there is a rough inverse correlation of distance with vanadium oxidation state. This contrasts with V-P bond distances which show very little variation. 9 Clusters The triply bonded diniobium cluster (17) formed4' in low yield by the reaction of [Nb,Cl,(tht)(thf),] with Na/Hg and py has the shortest Nb-Nb bond (2.6054 %,)for face-sharing bioctahedral niobium and tantalum compounds. The Nb-N distances trans to tht are longer than those trans to a bridging chloride ligand. The trinuclear cluster anion [Nb,(p3-O),(H30),(p-S04)6]5 -catalyses the chemi- cal and electrochemical reduction of sulfuric acid to H2S.41The triangulo-(V,Cl,) unit is formed42 easily in solution from mononuclear vanadium(I1) compounds.For 36 J. Poitras and A. L. Beauchamp Can. J. Chem. 1994 72 1675. 37 F.A. Cotton X.Feng P. Giitlich T. Kohlhaas J. Lu and M. Shang Inorg. Chem. 1994 33 3055. 38 F. Sussmilch F. Olbrich H. Gailus D. Rodewald and D. Rehder J. Oryanomet. Chem. 1994,472 119. 39 P. B. Hitchcock D. L. Hughes G. J. Leigh J. R. Sanders,J. de Souza C. J. McGarry and L. F. Larkworthy J. Chem. Soc. Dalton Trans. 1994 3683. 40 F. A. Cotton and M. Shang Inorg. Chim. Acta 1994 227 191. 41 E. A. Paul T. H. Batten M. A. May W. R. Sayers P. E. Shelton,T. Kojima,and V. Katovic Inorg. Chem. 1994 33 630. 42 D. L. Hughes L. F. Larkworthy G. J. Leigh C. J. McGarry J. R.Sanders G. W. Smith and J. S. de Souza J. Chem. Soc. Chem. Commun. 1994 2137.174 H. Sloan example [VCl,(tmeda),] or [V,Cl,(thfj,][A1Cl,Et2] and tmeda react with SiMe,I in boiling thf to give [V3(p,-Cl),(p-Cl),(tmeda),3I (18). The equilibrium 3[VCl,(tmeda),]~[V,Cl,(tmeda),]+ + C1-+ 3 tmeda is facile. Reaction of [VCl,(EtOH),] with KI and tmeda in MeOH/thf led to the co-crystallization of ),]I and [V3(p-C1),(p3-C1)(p3-OMe)(tmeda with (18) n 0 S = trneda similar structures to that of (18). The triangulo-(V,Cl,) unit with chloride or methoxide in the apical positions appears to have considerable stability and there is evidence that compounds previously formulated as [VX,L,] may be trinuclear with this type of unit present. Melting a niobium ampoule containing RbBr [NbBr,] S and Nb in uucuoover five days gave4 Rb,[Nb,SBr,,] as the main product.This has a trigonal prismatic niobium cluster anion linked by bromide bridges to adjacent ions. The 18 bromine atoms associated with each Nb group form three layers of six in a hexagonal format above between and below the two triangles of niobium atoms and the sulfur atom sits in the centre of the niobium prism. Three bromo ligands in each of the outer layers bridge within the adjacent niobium triangle and all six in the middle layer are bridging between the triangles. Calculations suggest low order bonding between the niobium atoms of 0.25 (triangular edge) and 0.05 (rectangular edge). [NBu,][Ta,Cl 8] reacted44 with triflic acid to form the cluster anion ~a,Cl,,(Tf),]” which has a (Ta,Cl,,) core with a slightly distorted octahedron of tantalum atoms.The CF moieties are rotationally disordered. The triflates are readily substituted by other ligands. 10 Metalates The hydrothermal reaction of V,O, V,O, C(CH,OH), [NH2Me,]C1 and [NH ,Et]Cl gave4 the neutral pol ymetalate [V ,O 20 ((OCH ,)&CH ,OH} (H 20)4]. The structure consists of two V808((OCH2)3CCH20H},(H20)2units connected through four p-0x0 groups. The eight tris(a1koxide j ligands are accommodated on triangular sites which alternate between a triangular face of a central vanadium VO octahedron and a triangular cavity between three such octahedra. 43 H. Womelsdorf and H.-J. Meyer Angew. Chem. Znt. Ed. Engl. 1994 33 1943. 44 V.O. Kennedy C. L. Stern nd D. F. Shriver Znorg. Chem. 1994 33 5967. 45 M.I.Khan Y.-S.Lee C.J. O’Connor and J. Zubieta J. Am. Chem. SOC. 1994 116 5001. Vanadium Niobium and Tantalum Reaction of [VCl,(dmf)Tp] with Na,[PO,(OPh)J gave46 (19) an unusual discrete molecular complex in the vanadium(1v)-phosphate series. A cubic-type structure has each vanadium atom coordinated to three phosphate ligands each of which coordinates three vanadium atoms. The reaction of diphenyl phosphate with [VO(acac)Tp] demonstrated the reduced nuclearity that follows from restrictions in the vanadium coordination sphere by giving the simple dimer [{VOTp},{ p-nn (19) N N N = Tp O,P(OPh),}]. Conversely [VCl(H,O)(pzBu'),] which has a more open vanadium coordination sphere reacts with the monophenylphosphate to give the two-fold symmetrical complex (20) with three differently coordinated vanadium atoms.0 (20) One terminal 0 on each phosphorus not shown. Hydrogen bonding of aqua ligands not shown. N = t-butyl pyrazdyl. The cation of [PPh,],[V70,,(0,PPh),C11 formed47 from the reaction of [PPh,] [VO,Cl,] and H,PO,Ph has an anion consisting of a spherical shell of corner-sharing VO square pyramids and organophosphate tetrahedra acting as a cage for the chloride ion. Other polyvanadoph~sphates~~ and polyvanadophosphonates49 with 46 L. M. Mokry J. Thompson M. R. Bond T. Otieno M. Mohan and C. J. Carrano Inorg. Chem. 1994,33 2705. " Y.-D. Chang J. Salta and J. Zubieta Angew. Chem. Int. Ed. Engl. 1994 33 325. O8 J. Salta Q. Chen Y.-D. Chang and J. Zubieta Angew. Chem. Int. Ed. Engl. 1994 33 757.O9 Q.Chen and J. Zubieta J. Chem. SOC.,Chem. Commun. 1994,1635. 176 H. Sloan encapsulated chloride(s) and polyvanadoar~enates~~ with encapsulated methanol or water molecules have been reported; sulfate51 is the inclusion species in [AS,MO,V,O,,(S~,)]~- carbonate5 in [V,503,(C03)]7- and fluorides3 in [V,O,(PhPO,),F]”-(n = 1,2). The formation of the different clusters is related to the template effect of the included species. The mixed-valence vanadium(v)/(Iv) complex [NH,] ,[(VO)(V,O,) (AsO,),(HAsO,)] was obtained54 from the reaction of [VCl,] As205 NH,Cl and NHMe in water at 150°C for 144h. The structure has an octahedral-tetrahedral framework with both V=O.-V=O chains and isolated binuclear units with a V,03 core. The reaction of [PPh,][VO,Cl,] with H,AsO,Ph in acetonitrile at 100 “C under pressure gaves5 [(V,O,)(Ph,As,O,,)]; an unusual structure with a V,O core straddled by the cup-shaped arsenate ligand results from thermal condensation of the starting arsenical acid.50 M.I. Khan and J. Zubieta Angew. Chem. Int. Ed. Engl. 1994 33 760. 51 A. Miiller E. Krickemeyer S. Dillinger H. Bogge and A. Stammler J.Chem. SOC.,Chem. Commun. 1994 2539. 52 T. Yamase and K. Ohtaka J. Chem. SOC.,Dalton Trans. 1994 2599. ’’ Q. Chen and J. Zubieta J. Chem. SOC. Chem. Commun. 1994 2663. 54 R. C. Haushalter L. Mayer S. S. Dhingra M. E. Thompson Z. Wang and J. Zubieta Inorg. Chim. Acta 1994 218 59. ’’ J. Salta Y.D. Chang and J. Zubieta J. Chem. Soe. Chem. Commun. 1994 1039.

ISSN:0260-1818    

DOI:10.1039/IC9949100165

出版商:RSC    

年代:1994

数据来源: RSC

摘要:

13 Chromium Molybdenum Tungsten By H. SLOAN Consulting Chemist 40 Wendan Road Newbury Berkshire RG 14 7AF UK 1 Introduction Reviews have appeared on the redox chemistry of chromium(1v) complexes'' and on peroxo and superoxo complexes of this Group.lb Aspects of the chemistry of the chromium group have been included in reviews or highlights on amidine2 ligands EPR spectroscopy of low-spin d5 com~lexes,~ organometallic aqua ions,4 photoelectron spectroscopy of transition metal molecule^,^ disproportionation of SO on transition metal complexes,6 polar metal-metal bonds,7 the relationship between n-bonding features and orientation of ligands,8 high oxidation state alkylidene comple~es,~ stereochemical effects in C-C and C-H bond formation," and stereochemical effects in sulfenyl-substituted complexes.' The proceedings" of the symposium 'Photochemis- try and Photophysics of Coordination Compounds' contains work of relevance to this group.2 Bond-stretch Isomerism A further example of isomers believed to differ only in bond lengths has been shown to result from one of the so-called isomers being a mixture of the compound with other closely related species. The 'green isomer of [WOCl,L][PF,]' (L = 1,4,7-Me,tacn) has been shown13 to be a ternary mixture of the blue isomer with a W"0 species and a (n)E. S.Gould Coord. Chem. Rev. 1994,135/136,651;(b)M. H. Dickman and M. T. Pope Chem. Rev. 1994 94 569. J. Barker and M. Kilner Coord. Chem. Rev. 1994,133 219. P.H. Rieger Coord. Chem. Rev. 1994 1351136 203.U. Koelle Coord. Chem. Rev. 1994 135/136 623. ' J.C. Green Acc. Chem. Res. 1994 27 131. G.J. Kubas Acc. Chem. Res. 1994 27 183. M. Herberhold and G.-X. Jin Angew. Chem. Int. Ed. Engl. 1994 33 964. V.C. Gibson Angew. Chem. Int. Ed. Engl. 1994 33 1565. R.R. Schrock Pure Appl. Chem. 1994 66 1447. I" J. W. Faller M. R. Mazzieri J. T. Nguyen J. Parr and M. Tokunaga Pure Appf.Chem. 1994,66 1463. S. L. Griffiths C. F. Marcos S. Perrio S. P. Saberi S. E. Thomas G. J. Tustin and A. T. Wierzchleyski Pure Appl. Chem. 1994,66 1565. 'Proceedings of the 10th International Symposium Photochemistry and Photophysics of Coordination Compounds' July 1993 Sendai Japan ed. H. Kobayashi and T. Ohno Coord. Chem. Rev. 1994 132. l3 P. J. Desrochers K.W. Nebesny M. J. LaBarre M. A. Bruck G. F. Neilson R. P. Spertine J. H. Enemark G. Backes and K. Wieghardt Inorg. Chem. 1994 33 15. 177 178 H. Sloan cis-Wv'O species. Bond-stretch isomerism has been confused with spin-state isomer- ism.14 3 Metalates I8,W NMR spectroscopy showsI5 that all three main types of polytungstate anion in aqueous solution undergo replacement of tungsten by molybdenum. In para- tungstate-A [W7024]6- any or all of the tungsten atoms may be replaced whereas only a single substitution occurs with a-metatungstate a-[H,W 12040]6 -,or para- tungstate-B [H,W,,O,,]lO- at the site furthest from the centre of the anion. Ba3[Mo,,02,] prepared16 by heating BaMoO, MOO, and Mo in intimate powder mixture at 1230 "C in the presence of water vapour has an anion of four trans-edge- sharing octahedra of molybdenum atoms with 0x0 bridges on all edges.A notable feature of the linear arrangement of the four octahedra is the alternating short (bonding) and long (non-bonding) distances between the apical molybdenum atoms. Reaction of [NBu,][Mo60,,] with organic isocyanates in hot py ledi7 to substitution of terminal 0x0 groups by imido groups to give the anions [Mo6019-,(NR)~2- (R = Bu,n = 1; R = cy; IZ = 1; R = 2,6-Pr\C6H3,t~ = 1,2,4 5). Structural analysis of the di- and tetra-substituted derivatives showed a preference for substitution at adjacent molybdenum atoms despite the apparent adverse steric considerations. There is a linear relation between degree of substitution and reduction potential for these compounds indicating superior electron-donor ability of the imido compared with 0x0 groups.A-~-[NBu4],[PMo~W,0,,] reactedI8 with PPh in MeCN to give OPPh and an oxygen-deficien t two-electron reduced species A-P- [NBu,] ,[PMoV'Moy W,O ,I. While retaining the Keggin-type structure a corner-sharing bridging oxygen atom is removed from between two molybdenum(v1) atoms. The anion [HP04{ WO(0,)2)4] -contains" one bridging and one non-bridging peroxo ligand in each {WO(O,),} group; IR Raman and NMR spectra indicate retention of the solid state structure in solution. When aqueous solutions of sodium diphosphate or methylenediphosphonic acid are added to sodium tungstate solution the anions [w~2036(o~PxPo~),]'6-(X = 0 CH,) are formed" rapidly at room temperature.The Cs,,Na salt has structure (1) in the solid state and in solution which is a ring of WO tetrahedra held in a position like the seam ofa tennis ball by the four diphosph(on)ate groups. There are relatively weak bonds from phosphate oxygen to tungsten and saddle-shaped cavities may hold Cs+ or Na' ions. The structure2' of the [Mo,,O,,(P,~,)]~- anion is essentially made up of two fused (PM09034) units with a constrained linear P-0-P bond (177.7') having an eclipsed conformation. Comparison of electrochemical and spectral data for [PM 10,9{Mo(N0))]4- l4 P. Giitlich H. A. Goodwin D. N. Hendrickson Angew. Chem.,Znt. Ed. Engl. 1994,33,425; compare the comment in G. Parkin and R. Hoffmann Angew. Chem. Znt. Ed. Engl.1994 33 1462. l5 I. Anderson J. J. Hastings 0.W. Howarth and L. Pettersson J. Chem. Soc. Dalton Trans. 1994 1061. l6 G. L. Schimek D. A. Nagaki and R.E. McCarley Znorg. Chem. 1994 33 1259. J. B. Strong R. Ostrander A. L. Rheingold and E.A. Maatta J. Am. Chem. Soc. 1994 116 3061. I. Kawafune and G. Matsubayashi Bull. Chern. SOC. Jpn. 1994,67 694. l9 L. Salles C. Aubry R. Thouvenot F. Robert C. Doremieux-Morin G. Chottard H. Ledon Y. Jeannin and J.-M. BrCgeault lnorg. Chem. 1994 33 871. *' U. Kortz G. B. Jameson and M.T. Pope J. Am. Chem. Soc. 1994 116 2659. 21 U. Kortz and M. T. Pope Znorg. Chern. 1994 33 5643. Chromium Molybdenum Tungsten 16-(1) Two terminal 0x0 groups on each tungsten not shown. One terminal 0x0 group on one phosphorus of each P,O bridge not shown.(M = Mo W) where an MO unit in the parent Keggin structure has been replaced by the (Mo(N0)) unit show2 that the electron-withdrawing effect of the nitrosyl ligand is opposed to the overall increase in charge of the metalate framework. For [PW 10,,{Mo(N0))]4- 183W NMR spectra indicate delocalization of the molyb- denum d electrons onto the polytungstate core. Solid-state magic-angle-spinning NMR spectroscopy has proved23 to be a useful tool (in conjunction with FT-IR spectroscopy) to probe the local symmetry within the Keggin structure using K,[BWl,04,]~1 1H,O. The X-ray crystal structure analysis of the anion [Pd2Wlo036]8- showedz4 that two [w,o,8] groups bridge the two square planar palladium atoms. Reaction of acetone oxime with [a-Mo,0,,14-in refluxing MeOH gave2’ [Mo,01,(p-ONCMe,),]2-(2) while with [MoO,(acac),] at room temperature it gave [Mo,O,,(OM~)~(ONHCM~~)~] (3).The anion (2) has a ring of four alternating MOO and p-0 groups with novel p4-7c2N :rc20coordination for an oxime ligand on each side of the ring. Complex (3) contains doubly and triply bridging methoxy ligands; the differences in the Mo-0 bond distances of various types are less than the range found for (2). Reductive nitrosylation of [Mo,~,,]~- with acetone oxime in refluxing MeOH gave2 [{MO(NO)(OM~)(ONCM~,)~),] which reacted with [Mo,0,12- to form [Mo40,,(N0)(0Me)(0NCMe2),] (4) which contains the novel p3-rcN:rc20 coordination mode for one of the oxime ligands. 4 Cubanes Reduction of [NH,][WS,] and Na2[Mo,0,(cys),]~4H,0 with NaBH gives mix- tures of sulfur-bridged clusters from which the incomplete cubanes [MoW,S 22 A.Proust M. Fournier R. Thouvenot and P. Gouzerh Inorg. Chim. Acta 1994 215 61. 23 A. R. Couto C. N. Trovao J. Rocha A. M. V. Cavaleiro and J. D. Pedrosa de Jesus J. Chem. Soc. Dalton Trans. 1994 2585. 24 S.J. Angus-Dunne R. C. Burns D. C. Craig and G.A. Lawrance J. Chem.Soc.,Chem. Commun. 1994,523. 25 A. Proust P. Gouzerh and F. Robert J. Chem. Soc. Dalton Trans. 1994 819. 26 A. Proust P. Gouzerh and F. Robert J. Chern. Soc. Dalton Trans. 1994 825. 180 H. Sloan 2-0 CMe 0 0 12- 0, Mo 0’ ‘0 (H20)9]4+ and [Mo,WS,(H,O),]~+ were isolated27 as [O,Stol-p] -salts and the nta derivatives [MoW2S,(Hnta),12- and [Mo2WS4(Hnta),12 -were obtained.In all four compounds the molybdenum and tungsten atoms are statistically disordered. Spectroscopic evidence shows little change of binding energy on replacing Mo with W or vice versa compared to the Mo and W parents consistent with the softness of the bridging sulfur atoms. [Mo,S,Cl,] reacted28 with PPh and py to give the incomplete cubane (5). The incomplete cubane [MO,S,(H,O)~]~+ reacted2’ with [Cr(H,O),]’ + giving the cubane [Mo,C~S,(H,O),,]~+. Substitution of H20 at chromium by NCS- occurs but not at molybdenum; the kinetic behaviour indicates the presence of chromium(III) with an inverse correlation with hydrogen ion concentration similar to the relationship known for [Cr(H20),]3f and [Mo(H20)J3+.The incomplete cubane [W3S,(H20)9]4+ (6) reacted3’ with copper metal with solid CuCl or with solutions of Cu+ to form [W3CuS,(H20),o]5 +.The molybdenum analogue gave [Mo~CUS,(H~O),,]~+ with copper metal but the corresponding pentacation with Cu+ or CuC1. Complex (6) reacted3’ with nickel metal in 7 M HC1 to give solutions of the single cubane (7) analogous to the copper complex above and crystalline (8) with a centrosymmetric double-cubane structure. In (8) the Ni-Ni distance (2.561A) is close to that of nickel metal. The cubane [NH2Me2] ’’ T. Shibahara M. Yamasaki T. Watase and A. Ichimura Znorg. Chem. 1994 33 292. 28 J. Mizutani H. Imoto and T. Saito Chem. Lett. 1994 2117. 29 C.A. Routledge M. Humanes Y.-J. Li and A. G. Sykes J. Chem. Soc. Dalton Trans.1994 1275. 30 M. Nasreldin C.A. Routledge and A.G. Sykes J. Chem. SOC.,Dalton Trans. 1994 2809. 31 T. Shibahara T. Yamamoto and G. Sakane Chem. Lett. 1994 1231. Chromium Molybdenum Tungsten 7 18+ (8) Aqua ligands not shown [W3SnS,C13(SCN),] was obtained3 by the reaction of [W3S,I4+ with SnC1,-2H20 [NH,Me,]Cl and NaSCN in aqueous HC1. The chloride ligands are bonded to the tin and the thiocyanate to the tungsten atoms of the core so that both the tungsten and tin atoms have octahedral coordination. The Sn-W and Sn-S distances are relatively long suggesting little W-Sn interaction. Reaction of [NH,],[WS,] TlBr and [NBu",Br in the solid state gave33 the complex [NBu",[TIWS,] which has infinite anionic chains of incomplete cubane-like [WTl,S,] units with a zigzag face-sharing arrangement.The corner-sharing dicubane [{MO~OS~(H~O),},I~]~+ (9) was obtained3 from the reaction of the incomplete cubane [Mo~OS~(H,O)~]~+ with indium metal in HS0,tol-p solution. Oxidation with HC1 gives the starting material. 5 Quadruple Metal-Metal Bonds The metal atoms of [Mo,(O,CCPh3),]~3CH,CI2 do not experience3' any axial interactions and there is a resulting decrease of the Mo-Mo quadruple bond distance compared with that of [Mo2(0,CR),]. On irradiation with visible light the quadruply bonded [Mo,(O,P(OPh),),] is oxidized36 by 1,2-dichloro-a1kanes and -alkenes to a + mixed-valence molybdenum(I1)/ (111) complex [Mo,(O,P(OPh),},] with an Mo-Mo bond distance 0.05 8 longer than that of the parent complex.The resulting 32 A. Muller V. P. Fedin E. Diemann H. Bogge E. Krickemeyer D. Solter A.M. Giuliani R. Barbieri and P. Adler lnorg. Chem. 1994 33 2243. 33 J.-P.Lang J. Liu M.-Q. Chen J.-M. Lu G.-Q. Bian and X.-Q. Xin J. Chem. SOC.,Chem. Commun. 1994 2665. 34 G. Sakane Y. Yao and T. Shibahara Inorg. Chim. Acta 1994 216 13. 35 F. A. Cotton L. M. Daniels P.A. Kibala M. Matusz W. J. Roth W. Schwotzer W. Wang and B. Zhong lnorg. Chim. Acta 1994 215 9. 36 T.-L.C. Hsu 1.-J. Chang D. L. Ward and D.G. Nocera Inorg. Chem. 1994 33 2932. 182 H.Sloan lower steric strain in the phosphate rings leads to planar Mo,O systems that are orthogonal to each other. (9) Aqua ligands not shown. (10) X = CI,Br Nn N = bipy 6 Triple Metal-Metal Bonds ,'P{ 'H) NMR spectroscopy has been used37 to characterize the cis-trans interconver-sion of [W,C14(NHBu'),(PR,),].The rates of isomerization are slowed considerably by the presence of small amounts of free phosphine though there is no large variation of rates with concentration up to 0.4 M. Two competing mechanisms are proposed. 7 Face-and Edge-sharing Bioctahedral Complexes Acidification of [WS J2-by HX (X = C1 Br) in the presence of bipy gave38 the isomorphous edge-sharing complexes (10). The diamagnetism and W-W bond distance of 2.8179 (Cl) and 2.822A (Br) support a W-W single bond. Reaction of [MCl,(PMe,),] (M = Mo W) with sulfur donors such as SPMe gave39 the edge- sharing bioctahedral complexes [M,(p-Cl)(p-S)Cl,(PMe,),l formed by the initial product [MSCl,(PMe,),] reacting with the starting material.The central [Mo2(p- Cl)(p-S)] core of the dimolybdenum compound is symmetrical with a single Mo-Mo bond of 2.6956 A; the Mo-S distances are short (2.274 2.285 A). Corresponding cornproportionation reactions with oxygen analogues result in complete transfer of oxide or chloride ligands. The Mo-Mo distances of the edge-sharing bioctahedral complexes [(MOC~,(RSCH,CH,SR)}~(~-SP~)~] [R = Et (2.769 A) Pr (2.682 A)] are typical of double bonds. One method of preparation of the second of these complexes involved4' S-C bond cleavage in the reaction of [M02C18]4-With PrSCH,CH,SPr. [NBu~],[Mo,0,(0,CH,S)3]~2H,0 was the major product crystallized4' from the reaction of molybdate with excess of thiogIycoIlic acid.This face-sharing bioctahedral complex produced by reduction of the initially formed [MoO,(O,CCH,S),]~- has one bridging 0x0 group and one doubly bridging thioglycollate ligand (1 1 ). Carrying out the reaction in the presence of dmso leads to the evolution of Me,S. Reaction of [MoCl,] with EtOH in chloroform gave4 [{ MoCl,O}(p-OEt),(p-HOEt){ MoC1,0}] having a distorted face-sharing bioctahedral structure. The three oxygen bridges are unusual and this is the first example of a bridging EtOH ligand. The 31 H. Chen F.A. Cotton and Z. Yao Inorg. Chem. 1994 33 4255. 38 C. Simonnet-Jegat R. A. Toscano F. Robert J.-C. Daran and F. Secheresse J. Chem. SOC.,Dalton Trans. 1994 1311. 39 K.A. Hall and J.M. Mayer Inorg. Chem. 1994 33 3289. 40 J. L. Deavenport R.T.Stubbs G. L. Powell E. L. Sappenfield and D. F. Mullica Inorg. Chim. Acta 1994 215 191. 41 A. Cervilla E. Llopis J.A. Ramirez A. Domenech P. Palanca M.T. Picher C.A. Ghilardi and A. Orlandini J. Chem. Soc. Dalton Trans. 1994 175. 42 C. Limberg S. Parsons A. J. Downs and D. J. Watkin J. Chem. SOC.,Dalton Trans. 1994 1169. Chromium Molybdenum Tungsten l+ -Ph 1+ CI I-thf-CI -(14)N N=phen Mo-Mo distance (2.69 A) corresponds to a single bond. SCF-Xa-SW calculations for [Mo,X,I3-(X = C1 Br I) that metal-metal interactions are significantly reduced in the order Cl > Br > I. 8 Triangular and Other Cluster Complexes A simple one-pot reaction of [CrX,].xH,O RCOOH and pyridine was developed4 for the preparation of (12).Two independent cations are present in each unit cell of the crystal structure with N-Cr-O,,,,, being almost linear and an equilateral Cr,O moiety. Differences in the Cr-Ocentte (cation 1 1.883,2 1.903 A) and Cr-N (cation 1 2.25,2 2.04 A) bond distances were found. The reaction of[WCl,] with NaCBHEt,] in thf in the presence of 0 gave45Na[W3(p3-o)(p-C1),c16(thf),], the first eight-electron triangular trinuclear cluster complex without acetate as a bridging ligand. The anion (13) has C3(3) symmetry and the small cation packs well with an approximately octahedral arrangement of chloride ligands from the anions without the need for additional solvate molecules. Tetranuclear oxochromium complexes such as [Cr,O,(O,CMe),(phen)J C1.l .5CH,Cl2.6H,O (14) were obtained46 by heating PhCN solutions of a bidentate ligand and [Cr,0(0,CR),L3]3+.Complex (14) has a ‘butterfly’core [Cr,O,] akin to 43 G. A. Medley and R. Stranger Inorg. Chem. 1994 33 3976. 44 A. Harton M. K. Nagi M. M. Glass P. C. Junk J. L. Attwood and J. B. Vincent Inorg. Chim. Acta 1994 217 171. 45 F.A. Cotton L.M. Daniels and Z. Yao Inorg. Chem. 1994 33 3195. 46 T. Ellis M. Glass A. Harton K. Folting J. C. Huffman and J. B. Vincent Inorg. Chem. 1994,33 5522. 184 H. Sloan those of recent Fe and Mn complexes; FAB MS proved to be a valuable tool for the characterization of such Cr-0 assemblies. The structures of [(Mo,B~,)X,]~- (x= F c1 Br I) in [NBu,]' [PPh4]+ and [AsPh,] + salts showed47 increasing Mo-Mo bond length and compression of the Br cube with increasing atomic number of X.I9F NMR spectroscopy of [(Mo -,W,C1,)F,]2-has established, assignments for the various signals and reveals that isomers with like metal atoms in trans positions in the octahedral M array are favoured statistically over those with unlike atoms. The cluster [Mo,0,Cl,(p3- O)2(p2-OEt),(p,-C1)2] (1 5) exhibits49 a chair configuration (16) with three Mo-Mo single bonds and highly distorted p3-oxygen bridges. A modified method for the preparation of Mo$g cluster units in one step from [Mo,Cl,,] by reaction with NaSH and NaOBu in refluxing Bu"0H-py has been devised. An intermediate [Mo,S,(py),] (x= about 4) not isolated reacts further in strongly coordinating solvents such as n-propylamine to forms0 the well-characterized [MO,S,(py),].The complexes [Mo,SgL,] (L = py pyrrolidine pip) all contain the core (17) with equatorially disposed N-donor ligands. The Mo-Mo and Mo-S bond lengths show little variation and the Mo-N bond distance of 2.297 8,indicates weak Mo-N bonding. The reaction of cubane [M0~Cu~0,(5-Cl-Hsaladhp)(OMe)~] with an excess of bipy in MeCN gave5' [M0~CuO,(5-Cl-Hsaladhp)~(bipy)~]. This is a 1 1 electrolyte in n (18) N N = bipy -0 N 0=5-CI-Hsoladhp 47 W. Preetz D. Bublitz H. G. von Schnering and J. Sassmannshausen 2.Anorg. Allg. Chem.,1994,620,234. 48 P. Briickner G. Peters and W. Preetz 2. Anorg. Allg. Chem. 1994 620 1669. 49 C. Limberg S. Parsons and A.J. Downs J. Chem. Soc. Chem. Commun. 1994 497. S.J. Hilsenbeck V.G.Young Jr.and R.E. McCarley Inorg. Chem. 1994 33 1822. s1 A. N. Papadopoulos A.G. Hatzidimitriou A. Gourdon and D. P. Kessissoglou Inorg. Chem. 1994 33 2073. Chromium Molybdenum Tungsten water probably with a copper-containing cation and a molybdenum anion. In the crystal the [Cu(bipy),] group is coordinated by an 0x0 bridge to the central [MOO,] moiety in an Mo-O-Mo-O-Mo chain (18). The EPR spectrum shows the unpaired electron on the copper(I1) atom. The reaction of Na[M,O,(O,CEt) with [Cr(CO),] or of [M(CO),] with CrC13.6H,0 in propionic anhydride at 120 "C formeds2 insoluble Na,Cr,[M,O,(O,CEt),] (19) (M = Mo W). Isostructural vanadium species were also obtained by reacting [M(CO),] with NaV0,.2H20 (19) (M' = V). 9 Hydride and Dihydrogen Complexes The enthalpies of reaction in proton- and electron-transfer reactions for various complexes of the chromium group have been determined5 and used in a study of metal-hydride and metal-metal bond energies.1- (19) O-Opropionate ligand (20) All 0atoms are from (This ligand shown for one half OCH2Bdalkoxide ligands. of the symmetric ion only.) M'= Cr V [Mo,(OCH,Bu'),] reacteds4 with a deficiency of KH/[18]crown-6 in thf to give (20) with a hydride ligand bridging all four molybdenum atoms. Despite the known difficulty of locating hydrogen atoms by X-ray crystallography other physical and chemical properties support this structure including the signal in the NMR spectrum for the hydride ligand at 6 = -15.2. The reaction of [W,H(CO),(NO)(thf)] with PBu' gave55 [~,~(~~),(~~)(~~u',)] [PHBu',][W,H(CO),,] and [PHBu',] [W,(p-H)(CO),,(NO)].The anion [W,(p-H)(CO) 3(NO)] -was more conveniently prepared and isolated as the PPN salt from the reaction of [W,H(CO),(NO)] and [PPN][WH(CO),] and reacts with nucleophiles to form [PHBu',][W,(p-H),(CO),,(NO)L] [L = PMe (21) PPh, P(OEt), CNMe]. The three tungsten atoms in (21) are octahedral the central tungsten atom having &oriented hydrogen bridges to the other two metal atoms which show no evidence of direct interaction with each other. The nitrosyl ligand is bonded to the central tungsten atom and is trans to one of the hydrogen bridges and cis to the other. The oxidative addition of H to 52 L. Xu H. Liu D. Yan J. Huang and Q. Zhang J. Chem. SOC. Dalton Trans.1994 2099. 53 G. Kiss S.P. Nolan and C.D. Hoff Inorg. Chim. Acta 1994 227 285. 54 T. A. Budzichowski M. H. Chisholm J. C. Huffman and 0.Eisenstein Angew. Chem.,Int.Ed. Engl. 1994 33 191. 55 J. T. Lin S. Y. Wang A. C. Yeh T. Y. R. Tsai S.-M. Peng G. H. Lee and Y. S. Wen Inorg. Chem. 1994,33 1948. 186 H. Sloan *ON-W-H-W(CO)5 1- Me,P'i (21) The ion with ligands marked interchanged also occurs in the crystal. Reagents i LiHBEt or BuLi H,; ii Bu'Li or Bu'CH,Li LiMe LiNMe,; iii Bu'Li or Bu'CH,Li or KN(SiMe,),; iv Bu'Li LiNMe,; v BuLi Scheme 1 [WCl,(PMe,Ph),] at room temperature in toluene gave56 an improved synthesis of [WH,Cl,(PMe,Ph),] which has an unexpected stereochemically rigid structure. It undergoes exchange with D by a dissociative mechanism.Reaction of [WH,Cl,(PMe,Ph),] with LiCBDEt,] gave one isotopomer of [WDH,Cl(PMe,Ph),] similarly stereochemically rigid. Attempts at nucleophilic substitutionof both chloro ligands led to dehydrohalogenation and ortho metalation of one of the Ph groups on a phosphine ligand (Scheme 1). The complexes [Cr(CO),(PR,),] (R = Cy Pr') reacted57 under 6Opsi of H to give [Cr(H,)(CO),(PR,),]. They dissociate completely to the starting materials in solution at atmospheric pressures but may be isolated as crystalline solids. An X-ray structural determination showed trans phosphine ligands and a side-on dihydrogen ligand with the shortest known ligated H-H bond [0.67(5) A]. The solid state 'H NMR spectra of the Cy complex indicate an H-H distance of 0.85(1) A.The H,-M a-bonding strength increases Mo < Cr x W but the 4-H back-bonding increases Cr < Mo < W.Barriers to rotation of the dihydrogen ligand are 1.17 (Cr) 1.32 (Mo) and 1.9kcal mol-I (W) from solid state NMR spectroscopy. The bis(dinitrogen) complexes trans-[Mo(N,),{ (ArCH,),PCH,CH,P(CH,Ar),} ,] [Ar =Ph C6H4Me-y C,H,F-y (y=2,3,4); C,H,OMe-x (x =2,4)] were obtained5* by reduction of [MoCl,] with Mg under nitrogen in the presence of the diphosphine. For the Ar = Ph or 2-methylphenyl complexes refluxing with ethyl acetate in benzene under argon gave the formally 16-electron complexes 56 H. Rothfuss J.C. Huffman and K. G. Caulton Znorg. Chem. 1994 33 2946. 57 G.J. Kubas J. E. Nelson J. C. Bryan J. Eckert L. Wisniewski and K.Zilm Inorg. Chem. 1994,33,2954. 58 X.-L. Luo G.J. Kubas C.J. Burns and J. Eckert Inorg. Chem. 1994 33 5219. Chromium Molybdenum Tungsten 187 [Mo(CO)((ArCH,),PCH,CH,P(CH,Ar),),l which showed the effects of agostic Mo . H-C interactions in the NMR spectra. These 16-electron complexes reacted readily with small molecules to form the trans adducts [MO(CO)L(A~CH,),PCH,CH,P(CH,A~)~}~]q2-H2 N, SO,). Such q2-H (L = coordination established by IR NMR and neutron scattering spectroscopies and X-ray structural studies is in contrast to the dihydride form when Ar is replaced by electron-donating alkyl groups. There is no evidence for a dihydrogen/dihydride equilibrium in these complexes. 10 Carbon-donor Ligands A theoretical study of the structures and bond energies of [M(CO),] gave 59 the first dissociation energies Cr 37 Mo 40 W 46 kcal mol- (all 2 kcal mol- ').Adsorp-tion of the Group 6 carbonyls [M(Co),] on active zirconia occurs6' uia 0-bonding with labilization of CO ligands. The stability of the adducts toward (reversible) decarboxylation was found to be in the order W > Cr > Mo. The electrochemical reduction of trans-[W (CN)Cl(dppe),] in the presence of phenol gave6' trans-[WCl(CNH,)(dppe),] which was oxidized chemically or electrochemi- cally to the paramagnetic cation trans-[WCl(CNH,)(dppe),] +.An X-ray structural analysis suggests that the CNH group is best described as an iminomethylenium ligand [=C=NH,] +.The complex appears to be a facile 2H-transfer agent. 11 Silicon-donor Ligands The formally 16-electron complex [Mo(CO)(R,PC,H,PR,),] (R = Et) reacted6 with silanes SiH,R; to give complexes (22) where the silane is coordinated to molybdenum through a side-on Si-H a-bond which is significantly lengthened (1.77A).This side-on Si-H coordination is cisto the CO ligand. NMR spectroscopy showed that primary silanes SiH,R' form similar complexes in equilibria but isolation was not possible. 12 Nitrogen-donor Ligands The reaction of [WO,] and NaNH at 350-750°C gave63 Na,[WO,N] and Na,[WO,N,]. The former has a tetragonal pyramidal anion with nitrogen at the apex. A convenient synthesis of [WNCl,] from the reaction of [WCl,] with [Me,SiN,] in refluxing dce gave6 [WNCl,.l.ldce). Heating in U~CUUto remove the solvate and subsequent sublimation gave crystals of a tetramer [(WNCl,),] (23) with a planar W,N ring containing alternating short and long W-N bonds laverages 1.696 and 2.082 8 respectively).W-Cl-W bridging bonds link the tetrameric units to give octahedral disposition around tungsten. A computational study of metal-N coordination for the model compounds trans-[MA,(N,),] (M = Mo A = PH, SH,; M = W A = PH,) and trans-59 A.W. Ehlers and G. Frenking J. Am. Chem. SOC. 1994 116 1514. 6o E. E. Plater0 and M. P. Mentruit Inorg. Chem. 1994 33 1506. 61 D.L. Hughes S. K. Ibrahim H. M. Ali and C.J. Pickett J. Chem. SOC. Chem. Commun. 1994 425. X.-L. Luo G.J. Kubas J.C. Bryan C. J. Burns and C. J. Unkefer J. Am. Chem. SOC. 1994 116 10312. 63 H. Jacobs D. Ostermann and B.Harbrecht Z. Anorg. Allg. Chem. 1994 620 535. 64 M.R. Close and R.E. McCarley Inorg. Chem. 1994,33 4198. 188 H. Sloan awl CI’ I CI CI (22) R = Et R’ = Ph (23) Dashed bonds are bridges to adjacent molecules. [MoClA,(N,)] (A = PH, SH,) demonstrate^^^ a qualitative correlation with respect to metal-ligand bonding. A detailed structural study of [Cr(NH,)5(NCO)][N0,]2 has enabled66 the ligand field states and energy levels to be characterized including the influence of the second coordination sphere nitrate anions. The red form of [NBu,] ,[Cr(NCS),] with a temperature independent magnetic moment of 4.76 pB was shown67 to contain planar [Cr(NCS),I2- anions with essentially equal Cr-N bond distances (2.010 2.012A). The blue form which is antiferromagnetic was shown to contain the dinuclear anion (24).The Cr-N distances of (24) are similar to those of the red salt but the Cr-S distance is long (2.72 A); the Cr-Cr separation is 5.837 A.The reaction between [NH,][MoBr,(H,O)] and py in MeCN at room temperature resulted68 in a mixture of cis-and trans-[pyH] [MoBr,(py),] which were separated on the basis of solubility. Boiling MeCN leads to irreversible cis to trans isomerization. The cis isomer is oxidized by Br to trans-[MoBr,(py),]. SCN y-C-N-T< SCN\ NCS 1 NCS ,Cr,-N -C -S SCN NCS Complexes with the strong n-donor nitrosyl and the n-acceptor 0x0 ligands have been prepared69 (Scheme 2). Compound (25)has a nearly linear Mo-N-0 system with a short Mo-NO bond (1.761 A).The Mo-O,, distance is very short (1.775 A) indicative of double-bond character. Neither the 0x0 nor the hydroxy ligands are involved in hydrogen-bonding between molecules in the crystal. The 3d electrons of chromium(1Ir) and the unpaired electron of the nitroxide radical in [CrCl(tpp)L] 65 R. J. Deeth and C.N. Field J. Chem. SOC.,Dalton Trans. 1994 1943. 66 T. Schonherr R. Wiskemann and D. Mootz Inorg. Chim. Acta 1994 221 93. h7 L. F. Larkworthy G. A. Leonard D. C. Povey S. S. Tandon B. J. Tucker and G.W. Smith J. Chem. SOC. Dalton Trans. 1994 1425. J.V. BrenEiE I. Leban and B. Modec Z. Anorg. Allg. Chem. 1994 620 950. 69 J. Bohmer G. Haselhorst K. Wieghardt and B. Nuber Angew. Chem. Int. Ed. Engl. 1994 33 1473. Chromium Molybdenum Tungsten iv acetone/NaOH n-hexane; v H+;vi acetone/NaOH n-hexane [NBuJBr; vii H+ (L = 1,4,7-triisopropyl-tacn) Scheme 2 [L = 3-and 4-(N-oxy-t-butylamino)pyridine]interact ferro- and antiferro-magneti- cally to produce quintet and triplet ground states respe~tively.~~ An unusual y-nitrido binuclear molybdenum(1v) species [Mo,(p-N)Cl,py,] was obtained71 by the abstraction of an ally1 group by pyridine from the molybdenum(v1) complex.[MoCl,(thf)(NCH2CHCH2)]. This product is paramagnetic (yeff= 6.06 yB) with the two Mo-N bonds differing in length by only 0.18 (1.887 and 1.793A) and an almost linear Mo-N-Mo system (176.4").The Mo-Cl bonds trans to the nitrido ligand are lengthened compared with the cis chloro groups and the octahedral geometries about molybdenum are staggered with respect to each other.The sterically hindered porphyrin tmp forms72 monomeric [Mo(tmp)] in contrast to dimeric [MoLlz (L = tpp ttp). All three complexes react with [SiMe,(N,)] in chloronaphthalene solvent to form the nitrido complexes [MoN(L)] (L = tpp ttp tmp). These reacted readily with electrophiles e.g. HCL gave [Mo(NH)(L)Cl] but the tmp complex readily decomposed in air in the solid state to the starting material. The Mo-nitrido bond is very short (1.63 A) for the tmp complex consistent with a triple bond. There is no noticeable tendency for coordination at the site trans to the nitrido ligand. Reversible C-N bond formation occurred7 on addition of acetone or benzaldehyde to trans-[Mo(NH)(Tf')(syn-Me8[l6)aneS,)]Tf (26) (Scheme 3).In (26),the axial imido group trans to the triflate ligand has a strongly shielded proton resonance in the NMR spectrum. The Mo-N-H linkage is essentially linear (172") with a hydrogen-bond to the triflate counter anion so that the N-H stretching frequency is at markedly lower energy than in other molybdenum-imido complexes. In (27) the Mo-N-C linkage is 'O M. Kitano N. Koga and H. Iwamura J. Chem. SOC. Chem. Commun. 1994,447. Y. Du A.L. Rheingold and E.A. Maatta J. Chem. Soc. Chem. Commun. 1994 2163. 72 J.C. Kim W.S. Rees Jr. and V.L. Goedken Inorg. Chem. 1994,33 3191. 73 T.Yoshida T. Adachi N. Yabunouchi T. Ueda and S. Okamoto J. Chem. SOC. Chem. Commun. 1994 151. 190 H. Sloan R’ \ R+OH H BPh3 11 (i) I i Mo Mo -I I N3 Tf Reagents i HTf; ii RR‘CO; iii NaBPh,; iv on standing in n-hexane; v NaBPh [Mo = Mo(Me,[16]aneS4)] Scheme 3 (31) “ \ (30) R= MeorOMe.(iii) I (29) L= thf or py. Reagents i I,; ii PR,; iii thf or py Scheme 4 closer to linearity (174.4”) than the parent imido compound. The zwitterionic complex (28)has proved74 a source for tungsten(1v) imido complexes (29)and (30) bearing two carbonyl ligands (Scheme 4). The isolated intermediate (31) has W-N bond length 1.758 and bond angle W-N-C 177.0”. Six-coordinate bis(imido) complexes with electronically and sterically different imido ligands were prepared75 by simultaneous addition of two amines to a suspension of Na,MoO in dme or for t-butylimido-containing products by treatment of the bis-t-butylimido complex with an amine or aniline in dme (Scheme 5),or by inter-metal exchange of ligands between [Mo(NR’),Cl,(dme)] and [Mo(NR”),Cl,(dme)].This type of exchange is more facile with four-coordinate species. The structure of (32) contains two molecules in the asymmetric unit cell. The Mo-N distances for the adamantyl imido ligands are the same (1.716 1.7158,) and much shorter than for the pentafluorophenylimido ligands (1.759 1.775 A) as expected for an electron releasing l4 P.C. McGowan S.T. Massey K.A. Abboud and L. McElwee-White J. Am. Chem. Soc. 1994,116,7419. ’’ A. Bell W. Clegg P. W. Dyer M. R. J. Elsegood V. C. Gibson and E. L. Marshall J. Chem. Soc. Chem. Commun. 1994 2247. Chromium Molybdenum Tungsten Reagents i NH,R' NH,R2 Me,SiCl NEt, dme; ii NH2Bu' Me,SiCl NEt, dme; iii NH2(C,F,) dme Scheme 5 (33) B-N rN = Tp' LN I I i - ii- 0 CI,,II ,CI M6 CI'I .IIO O*PPtl P Ph3 Reagents i ally1 azide; ii OPPh,; iii exposure to atmosphere Scheme 6 adamantyl group and the n-bonding interaction in the N-phenyl bond. The Mo-N-C angles in one of the molecules are similar (Mo-N, = 160.0' Mo-N = 162.8') while the second molecule shows significant differences (172.6' 152.0' respectively). This suggests that inter-ligand steric interactions are of more importance than electronic effects in such imido complexes. Reaction of [WH(CO),Tp'] with tosyl azide in refluxing thf gave76 the amido complex [W(CO),(NHtos)Tp'] (33) as the anti isomer. This is oxidized by AgTf or '' P.J. Perez P.S. White M. Brookhart and J. L. Templeton Inorg. Chem. 1994 33 6050. 192 H. Sloan iodine to the imido complex [W(CO),(Ntos)Tp’]X (X = Tf I,) which reacts with LiBH to give (33). With PMe, the cationic complex gave [W(CO),(PMe,),Tp’]X [W(CO)(PMe,)(Ntos)Tp’]X and [tosN=PMe,]. Ally1 azide efficiently oxidized [MoCl,(thf),] to the unstable allylimido complex [MoCl,(thf)(NCH,CH=CH)] (34) which reacted77 with Ph,PO to give the cis,mer product (35) (Scheme 6) via substitution and reduction at the Mo centre. This contrasts with the tungsten analogue where only substitution of the thf ligand occurs. The diazene complex tran.s,trans-[W(CO),(NO)(PPh,),(NH=NH)][S03CF3] re-acted7* with amines NH,R (R = H Me NH,) to give trans,trans-[W(CO),(NO)(q’-OSO,CF,)(PPh,)] trans,trans-[WH(CO),(NO)(PPh,),] and transpans-[W(CO),(NO)(NH,NH,)(PPh,)lCSO,CF,I.Monitoring the reaction at -78 ‘C by NMR spectroscopy and ,H and I3C labelling revealed an intermediate in the formation of trans,trans-[WH(CO),(NO)(PPh3),],uiz. the neutral six-coordinate formyl complex trans-[W(CH0)(CO)(NH,R)(NO)(PPh3),]. [MoO,(acac),] and disubstituted hydrazine hydrohalides [RR’NNH,]X (R = R’ = Ph; R = Ph R’ = Me; X = Cl Br I) give79 [Mo(NHNRR’)(NNRR’)(acac)X,] with both hy- drazido(1-)and hydrazido(2-) ligands these ligands adopting bent and linear end-on conformations respectively in the chloro complexes. The reaction of [MF(NNH,)(dppe),][BF,] (M = Mo W) with 2,5-dimethyoxytetrahydrofuranin the presence of HBF gaveg0 the 1-pyrrolylimido complex (36) which has an almost linear W-N-N moiety (173.8’) and an N-N bond (1.41 A) longer than for hydrazido complexes.The pyrrole can be liberated in high yield by reduction with LiAlH under mild conditions. The pyrrole ring in (36) underwent p-selective electrophilic substitu- tion. Reduction of [MoCl,(thf),] with a Na dispersion or Na/Hg under nitrogen gave” low yields of trans-[Mo(N,),(dippe),] which reacted slowly with H to give the known complex [MoH,(dippe),] . The complex trans-[Mo(N,) (dippe),] and HBF in ether gave trans-[MoF(NNH,)(dippe),][BF,] with an almost linear Mo-N-N moiety (175.3’). When the reduction of [MoCl,(thf),] is carried out under argon the 16-electron paramagnetic complex [MoCl,(dippe),] is formed.This reacts with CO in thf to give seven-coordinate [MoCl(CO),(dippe),]Cl and is oxidized by AgCBF,] in CH,Cl ,to give 15-electron trans-[M oC1 (dippe) ,][BF,] . [MoCl,(NHNRPh)(NNRPh)(acac)] (R = Me Ph) reacted8 with PMe -,Ph (n = 1-3) in MeCN to form [MoCl,(NNRPh),(PMe,-,Ph,)] (rn = 1,2) F (36)M = Mo W (37) i’ Y. Du A. L. Rheingold and E. A. Maatta Inorg. Chem. 1994 33 6415. 78 T.-Y. Cheng J. C. Petters and G. L. Hillhouse J. Am. Chem. SOC.,1994 116 204. i9 C. Bustos C. Manzur D. Carrillo F. Robert and P. Gouzerh Inorg. Chem. 1994 33 1427. *’ H. Seino Y. Ishii and M. Hidai J. Am. Chem. SOC.,1994 116 7433. *’ M. Jirnenez-Tenorio M. C. Puerta P. Valerga and D. L. Hughes J. Chem.SOC.,Dalton Trans. 1994,2431. 82 C. Bustos C. Manzur D. Carrillo F.Robert and P. Gouzerh Inorg. Chem. 1994 33 4937. Chromium Molybdenum Tungsten 193 [MoCl,(NNPh,),(PPh,)] (37) or [MoCl,(NNMePh),(PPh,),] (38). The last readily loses one molecule of phosphine to give [MoCl,(NNMePh),(PPh,)]. All three of the triphenyl phosphine complexes gave back the starting material on refluxing in MeCN with excess acac. Compound (37) has a distorted bipyramidal structure and (38) has a distorted octahedral structure. [WCl,] reacteds3 with [Cl,P=NSiMe,] to give [WCl,(N=PCl,)] and possibly cis-[WCl,(N=PCl,),]. The analogous reaction with [Cl,PhP=NSiMe,] gave cis- [WCl,(N=PCl,Ph),]. Gallium trichloride reacted with [WCl,(N=PCl,)] to give [WCl,(N=PCl,)][GaCl,] in which the anion is weakly coordinated to the cationic tungsten complex via a single chloride bridge.The compound [WCl,(N=PCl,)] has a nearly linear W-N-P system (176.2') and in cis-[WCl,(N=PCl,Ph),] the W-N-P systems are slightly bent (162 158.5'). Complex (39a) reacteds4 rapidly in hydrocar- bon solvent with a large range of substituted pyridines and bipyridines. From the NMR spectra of the products (39b) a thermal equilibrium between the singlet ground state for the d2-W(1v) metal centre and a triplet excited state involving through-bond coupling to the ligand protons was observed and the singlet-triplet transition energy has been estimated. There are detailed correlations involving the chemical shifts of the four hydrogen atoms of each heterocyclic ring. 13 Phosphorus-donor Ligands Various physical properties of [M(CO),{P(OCH,),CMe)] (M = Cr Mo W) have provideds5 evidence for the n-acid behaviour of the bicyclic phosphite ligand.There is a highly deformable n-component in the metal-phosphorus bonding and a n-delocalized P-M-CO,,,, system. In mer,trans-[Cr(CO),(CS)(P(OPh),),], there is 50 50 dis- orders6 of the thiocarbonyl ligand with the trans carbonyl ligand. The 31PNMR spectrum shows two phosphorus chemical shifts due to the crystallographic in- equivalence of the phosphite ligands. The reaction of lithium bis(dipheny1phosphino)methanidein thf with [CrCl,(thf),] gaves7 the novel dinuclear complex (40) as blue crystals. An X-ray diffraction analysis showed the square planar and distorted square pyramidal coordination of the different chromium atoms in the molecule.The Cr-Cr distance is long for direct bonding and the magnetic moment (6.07~~) is slightly lower than that expected for a combination of high-spin Cr(n) and low-spin Cr(I1). [Mo(CO),(nbd)] reacteds8 with diphosphine L (L = dppp or dpph) in refluxing CH,Cl under N to give mononuclear [Mo(CO),L]. An X-ray crystal structure analysis established the presence of the large chelating ligands in contrast to the bridged dinuclear complexes prepared by other methods. The most significant structural aspect is the larger P-Mo-P angle compared with similar smaller chelated complexes. The strained phosphorus heterocycles (41) and (42) reacteds9 with [Mo(CO),] in benzene to give fac-[Mo(CO),(PhPCH,CH,C H2)J andfac-[Mo(CO),(PhPCH,C respectively. An X-ray structural determination 83 C.H.Honeyman A.J. Lough and I. Manners Inorg. Chem. 1994 33 2988. 84 C.E. Kriley P.E. Fanwick and I. P. Rothwell J. Am. Chem. Soc. 1994 116 5225. 85 M. J. Aroney M. S. Davies T. W. Hambley and R.K. Pierans J. Chem. Soc. Dalton Trans. 1994 91. 86 Y. Huang H. L. Uhm D.F. R. Gilson and I. S. Butler Inorg. Chem. 1994 33 804. *' S. Hao J.-I. Song H. Aghabozorg and S. Gambarotta J. Chem. Soc. Chem. Commun. 1994 157. C.-H. Ueng and J.-L. Hwang Inorg. Chim. Actu 1994 218 9. 89 Y. B. Kang M. Pabel A. C. Willis and S. B. Wild J. Chem. Soc. Chem. Commun. 1994,415; idem ibid 1994 1403. 194 H. Sloan (39a) L = PMePhp (39b) L = substituted py or pipy showed the thermal ellipsoid for the central carbon in the former to be elongated perpendicular to the C-P-C plane consistent with positional disorder over two sites.Calculations on the parent phosphetane (41) indicate two conformers of C,symmetry with a low barrier to ring flipping of 5.81 kJmol-'. The phenyl groups of the phosphetane complex are anti to the carbonyl ligands in contrast to the phosphirane complex where they are syn to the carbonyls. The cocondensation of molybdenum vapour and the phosphaalkyne Bu'CP gaveg0 [Mo(q4-P,C,Bu',),] (43).A structural determination showed that the two phosphorus atoms of one of the rings are oriented either side of the plane of the Mo atom and the ring centres while the other two ligands have the phosphorus atoms in this plane. The Mo-C bond lengths for the unique ligand are unusually long (2.518 and 2.535A) the other Mo-C bond lengths being within expected ranges (2.256 and 2.255A).Amino(ary1)carbene tungsten complexes have been converted" into complexes of the unknown 2H-1-aza-2-phosphirenes (Scheme 7). Compound (44) has one signal in the 31P NMR spectrum with the large 'J, coupling constants characteristic of direct W-P bonding. The X-ray crystal structure determination shows a W-P bond distance of 2.470A. Further reaction of (44) with [W(CO),(thf)] showed its nucleophilic character giving (45)with retention of the three-membered ring. The NMR signals for the phosphorus and the carbon atoms of the ring are shifted downfield compared with those of (44). The reaction of (dmp),PO and [Cr(CO),] in refluxing toluene gave9 (Scheme 8) two isomers of [Cr,(CO),(dmpPO),] (46) as well as [Cr,(CO),(dmpPO),] (47) analogous to the known complexes of (R,NPO) (R = Pr' Cy; n = 4,5).Traces of the novel cyclohexaphosphane (48) having a Cr-Cr distance of 4.700 8 were also formed. 90 F.G.N. Cloke K. R. Flower P.B. Hitchcock and J. F. Nixon J. Chem. Soc. Chem. Cornmun. 1994,489. 91 R. Streubel J. Jeske P. G. Jones and R. Herbst-Inner Angew. Chem. Int. Ed. Engl. 1994 33 80. 92 X. Sun E. H. Wong M. M. Turnbull B. E. Waltermire,R. L. Ostrander and A. L. Rheingold J. Chem.SOC. Chem. Cornmun. 1994 231. Chromium,Molybdenum Tungsten ,tol-P (CO),W=C NH2 + CI P = C (SiMe,) Reagents i Et,O NEt,; ii [W(CO),(thf)] Scheme 7 RZPO i + ___c + Reagents i toluene reflux Scheme 8 14 Antimony- and Arsenic-donor Ligands Solutions of K3E in en reactedg3 with toluene solutions of [M(CO),L] (M = Cr W L = mesitylene; M = Mo L = chpt) in the presence of 2,2,2-crypt giving [K(2,2,2- crypt)],[M(CO),(E,)] (49).The complexes have norbornadiene-like q4-E moieties q-bound to C,,-M(CO),. Ligand exchange does not occur in the absence of oxidants. The phosphorus compounds have large ‘JpPpcoupling constants for the ‘olefinic’ P-P groups. There are intense charge-transfer bands for all the compounds and a low energy n3-n4 transition for the phosphorus compounds. The unique E atom furthest from the metal centre is nucleophilic and reactions to form (50) occur readily. The reaction of Na,Sb with [Mo(CO),(bipy)] in en and addition of 2,2,2-crypt gave94 the 93 S.Charles B. W. Eichhorn A. L. Rheingold and S.G. Bott J. Am. Chem. SOC. 1994 116 8077. 94 U. Bolle and W. Tremel J. Chem. SOC. Chem. Commun. 1994 217. 196 H. Sloan anion (49 M = Mo E = Sb) with a tetradentate antimonide ligand. The Mo-Sb distances are identical within experimental error (2.942 to 2.95 1 A) and significantly longer than the sum of the covalent radii. Crystal structure determinations for [M(CO),(EPh,)] (M = W E = P; M = Mo W E = As Sb) have been made” to enable a systematic study of the nine M/E compounds (M = Cr Mo W; E = P As Sb). Trends in bond lengths and angles are rationalized in terms of steric and electronic interactions. There is little variation in the torsion angles between M(CO) and EPh groups.Trends for other ligands in [M(CO),L] were also compared. (49) (50) M=Mo,W R = H . (M’(CO),(en)) E = P,AS Sb 15 Oxygen-donor Ligands Magnetic circular dichroism spectra were found96 to display temperature and field dependence consistent with paramagnetic ground states for [MOCl,] -(M = Cr Mo) and [WOCl,(H,O)J -.Assignments for the ligand-field and charge-transfer states have been made. While chromate anion is known to form bridges this has not previously been observed with the dichromate anion. Such a bridge was foundg7 in [Mn,(p-1,5- Cr,O,),(bpy),] where the spatial arrangement of the metal atoms is octahedral; there is no metal-metal bonding. The cis-dioxo anion [MoO,(NCS),]’- has proved9* to be a facile 0x0-transfer agent. The octahedral arrangement around the molybdenum atom shows considerable distortion in the N,O plane with 0-Mo-0 being 104.2’ and N-Mo-N being 79.2’.The reaction of [CoCp,] and [MoV1(SPh)O,Tz’] in toluene gave9’ the green paramagnetic salt [CoCp,][MoV(SPh)02Tz’]~toluene which reacted readily with oxygen in the air to give the starting material. The [MOO,] moiety in the anion has longer Mo-0 bonds (1.742A) and a larger 0-Mo-0 angle (112.1’) than that of the precursor (1.702 and 1.698 A and 103.9’). The moderate Mo-0 bond increase is consistent with a largely non-bonding metal-based HOMO containing the unpaired electron while the greater angle suggests repulsion between the d’ electron and the Mo-0 n-electrons. 95 M. J. Aroney I. E. Buys M. S. Davies and T.W. Hambley J.Chem. SOC.,Dalton Trans. 1994 2827. 96 D. M. Sabel and A. A. Gewirth Inorg. Chem. 1994,33 148. 97 B.C. Dave and R.S. Czernuszewicz Inorg. Chem. 1994 33 847. 98 H. Arzoumanian R. Lopez and G. Agrifoglio Inorg. Chem. 1994 33 3177. 99 Z. Xiao R. W. Gable A.G. Wedd and C.G. Young J. Chem. SOC. Chem. Commun. 1994 1295. Chromium Molybdenum Tungsten The reaction of [WCl,(PMe,Ph),] with [TlOR,] (R = CH,CF,) gavel'' trans ~is,cis-[W(OR,),Cl,(PMe,Ph)~].The resulting ligand field leads to enhanced oxygen- to-tungsten n-donation and a relatively unreactive molecule. The W-0 bonds are short (1.844 1.852 A) and the W-Cl bonds are long (2.4865,2.4772A) compared with those of related compounds. Polypyridine complexes of ruthenium(rI1) and iron(I1r) react''' with the superoxochromium complex ion [Cr(H,0)5(0,)]2f to give [Cr(H,0),I3+ and dioxygen in the first reported case of chemically induced oxidative homolysis of a superoxo metal complex.Methanolic NaNO convertedlo2 [MBr,(CO),(PPh,),] (M = Mo W)into eight-coordinate [M(NO,),(CO),(PPh,),]. IR and NMR spectroscopy with 15N labelling established the O,O-chelating nature of the nitrito ligand and the magnetic equivalence of the pairs of ligands. The oxidation of pyridine to pyridine N-oxide by H,O is cataly~ed"~ by [MO4I2- (M = W Mo). The catalyst reacted with the N-oxide produced to form [MO(O,),(pyO),] (M = W Mo) which also catalyse the oxidation. A structural analysis showed one of the N-oxide ligands and the 0x0 ligand at the apices of the pentagonal bipyramidal molecule.Raman and NMR spectra indicate the retention in solution of the solid state configuration. Dinuclear complexes [W,O,L,(HL),] [L = pin (51) chpd cocd] were ob-tainedlo4 by hydrolysis in alcoholic solution of [W(eg)(pin),] [W(chpd),] and [W(cocd),] respectively. The tungsten atoms are symmetrically substituted with an 0x0 bridge between them. Hydrogen-bonding between ligands reinforces the bridge as in (51).The reaction of [MoO,(detc),] with acetylhydroxamic acid in acetone gavelo5 the salt [NH,Et,][cis-Mo'VO,(MeCONHO-O,O)(MeCONO-O,O)] (52),which has a novel hydrogen-bonded polymeric structure. There are distinctly shorter Mo-0 and longer N-0 bonds for the hydroximate ligand compared with those of the hydroxamic acid ligand. The first example of selective decomposition of a single t-butoxide ligand to give hydride and 0x0 ligands at a dimetal centre is providedlo6 by the room temperature decomposition of [W,(OBu'),] -[believed to have structure (53) by analogy with the loo H.Rothfuss J.C. Huffman and K.G. Caulton Inorg. Chem. 1994 33 187. lo' A. Bakac J.H. Espenson and J.A. Janni J. Chem. SOC.,Chem. Commun. 1994 315. lo* R.D. Feltham and E. Rajaseelan Inorg. Chim. Acta 1994 218 195. lo3 W. P. Griffith,A. M. Z. Slawin K. M. Thompson and D. J. Williams J.Chem. Soc.,Chem. Commun. 1994 569. Io4 A. Lehtonen and R. Sillanpaa J. Chem. SOC.,Dalton Trans. 1994 2119. S. P. Lin M.A. Khan and K. M. Nicholas J. Chem. SOC.,Chem. Commun. 1994 2425. lo6 T.A. Budzichowski M. H. Chisholm and W.E.Strieb J. Am. Chem. SOC. 1994 116 389. 198 H. Sloan But 7-1- (56) iii I Ar I N Ar\ II N-.O-Bu‘ Reagents i excess PhNCO; ii excess PhNCS; iii excess PhNCO Scheme 9 molybdenum analogue] to (54). The W-W distance (2.4447A) in (54) is typical of a double bond and the W-(p-0) bond lengths (1.916 1.888 A) are inconsistent with a bridging hydroxide ligand. NMR spectroscopy indicates equivalence of the butoxide ligands even at -80 “C and there is a clear bridging hydride resonance. Treatment of (55) with excess PhNCO (Scheme 9) gavelo7 the bis(carbamate) complex (56) as a result of isocyanate insertion at both alkoxide ligands. In contrast PhNCS gave a thioureato-N,N complex (57) by reaction at one of the imido ligands.In (56)the Mo-0 bond trans to the ‘linear’ Mo-N-Ar ligand is shorter than that trans to the ‘bent’ Mo-N-Ar contrary to expectation. Complex (57) has a Mo-N bond length and a Mo-N-C angle corresponding to a triple Mo-N bond and the two alkoxide ligands have different Mo-0 bond lengths consistent with different .n-donation to the metal. The butoxide ligand with significant bending at oxygen is acting as a lo7 V.C. Gibson C. Redshaw W. Clegg and M. R. J. Elsegood J. Chem. SOC.,Chem. Commun. 1994,2635. Chromium,Molybdenum Tungsten one-electron donor. The reaction of [Cy,Si,O,(OSiMe,)(OH),] with TlOEt afforded [Cy,Si 709 (OSiMe,)(OTl),] which upon addition of [Mo(CHCMe,Ph)(NAr)(OSO,CF,)(dme)] (Ar = 2,6-PriC,H,) gavelo8 a molyb- denum silsesquioxane complex with the probable structure (58a) or (58b).Compound (58)has high catalytic activity for olefin metathesis over a variety of functional groups. 16 Sulfur-donor Ligands and Sulfides The acidification of [WS,12-with HCl in MeCN in the presence of bipy gave"' [WO(S,),(bipy)] having a pentagonal bipyramidal form with the 0x0 ligand and one of the bipy nitrogen atoms in the axial positions. The W-N, bond (2.32A) is longer than W-N, (2.15A). The same compound obtained by reaction of [Ni(bipy),]Cl with [WS,12 -crystallizes with a different stacking in the lattice. The dark-green material of empirical formula Mo,S,Cl,CH,Cl, obtained from the treatment of [Mo(CO),] with S,Cl, reacted1 lo with L to give green [{MoCl,L),(p- S,)(p-L)] [L = tht (59) BzSMe thfJ and with SMe to give brown [{MoCl,(SMe,),}(p-S,)(p-S){MoCl,(SMe,)}](60).Diamagnetic (59) has each mo- lybdenum in a distorted pentagonal bipyramidal structure with a symmetrically disposed shared face comprising the side-on S group and a rare tht bridge. The bridging sulfur of the tht ligand is at the apical position with respect to each molybdenum atom. Paramagnetic (60) also has a face-sharing bipentagonal pyramidal structure with the bridging S in an apical position for both metal atoms. However the terminal ligands are asymmetric giving formal oxidation states IV and v. lo' F.J. Feher and T.L. Tajima J. Am. Chem. SOC. 1994 116,2145. C. Simonnet-Jegat N. Jourdan F. Robert C. Bois and F. Secheresse,Inorg. Chim. Acta 1994,216,201. 'lo D.L. Hughes J. D. Lane R. L. Richards and C. Shortman J. Chem. SOC.,Dalton Trans. 1994 621. 200 H. Sloan The reaction of [MoO(S,CNR,),][BF,] with boron sulfide in CH,Cl gavel" [Mo,(p-S,),(S,CNR,)4][BF4]2 (61) (R = Et Pr' Bu') and [Mo(S,CNR,),][BF,]. Reaction of [WS(S,)(S,CNR,),] with SiIMe in CH,Cl gave [W,(p-S,)2(S,CNR,),]I[13] (61) (R = Et Bu'). Both of these cations have two symmetric side-on bridging S ligands and a metal-metal single bond (MG-Mo 2.808 A; W-W 2.792 A). The hydrothermal reaction of molybdenum and K,S powders in aqueous caesium chloride at 150 "C gave' the mixed-cluster compound Cs,[Mo,S(S,),] [Mo,S(S2),(S,)]~O.5H,O with anions (62) and (63). Bonding distances in the Mo-S ring suggest weaker n-bonding interactions than in other compounds with this moiety though other bond distances in both anions are comparable.The cluster [Mo,S,BrJ2-was obtained1I3 by y-irradiation of polymeric [Mo,S,Br,] in conc. HBr. The structure showed a short S -* Br contact between anions which have the known form (64). 2+ (61) M = Mb W (64) Dashed lines demote short Br....S contracts between ions. Blue diamagnetic [{W(CO),L),(p-S)] (L = Tp' Tp*) were formed1I4 by the reaction of [WBr(CO),Tp'] or [WH(CO),L] with propylene sulfide in refluxing 1,2-dichloroethane. The structures have short W-S distances with nearly linear W-S-W moieties. The new ligand [B(CH,SMe),]- (RTt R = CH,SMe) has been 111 C.G.Young T. 0.Kocaba X.F. Yan E. R. T. Tiekink L. Wei H. H. Murray 111 C. L. Coyle and E.I. Steifel Inorg. Chem. 1994 33 6252. C. C. Raymond P. K. Dorhout and S. M. Miller Inorg. Chem. 1994 33 2703. V. P. Fedin A. Muller K. Filipek R. Rohlfing H. Bogge A. V. Virovets and J. 0.Dziegieiewski. Inorg. Chim. Acta 1994 223 5. S. Thomas E. R.T. Tiekink and C.G. Young Inorg. Chem. 1994 33 1416. Chromium Molybdenum Tungsten characterized' l5 and has some promise as an alternative to the poly(pyrazoy1) borate + ligands. Its [NBu,] salt reacted with [Mo(CO),(chpt)] to give [Mo(CO),(RTt)] -(face-capping ligation through three sulfur atoms) which reacts readily with HBF to give [MoH(CO),(RTt)]. The reaction of [Mo(S,)(S,CNEt,),] with meta-perchlorobenzoic acid in CH,Cl at 0 "C gave116 [Mo(S,O)(S,CNEt,),]. This has a distorted pentagonal bipyramidal structure with the S,O ligand coordinated in an q2-S,S' fashion.The complexes [W(SPh),(CO),(phen)] (65) or [W(SPh),(CO)(P(OMe),}] reacted' l7 quantitatively with SO to give (66); high CO pressures did not reverse the reaction. The S-0 bond is long (1S858 A) compared with other known q2-S0 complexes. Complex (66) spontaneously loses sulfur and CO to give the dioxo complex (67) with no retarding influence of CO though the starting material (65) cannot be oxidized by dioxygen directly to (67). Ph Ph Ph Ph Ph Ph n (65) N N=phen (66) (67) (Oa,Ob-alternative position of disordered0) The tetragonal pyramidal anion of [NE~,],[MO'~OL,] (L = a,2-toluenedithiolate) with an apical 0x0 ligand is noticeably inert."' This may be due to the narrow Salkane-Mo-Salkane angle preventing coordination trans to the 0x0 ligand or to the two strong Mo-Salkane bonds preventing rearrangement from the trans to the cis-dioxo structure or both.For the series of complexes [Mo(NO)(SR),Tp'] the formal redox potential changes"' in the order R = CH,CONHMe > CH,CONMe > C,H,NMe > C,H,CONHMe > Et > Bu and the v(N0) band increases in energy in the same order. In the crystal structure the complex with R = CH,CONHMe shows an intraligand N-H * -S hydrogen-bond whereas the complex with R = C,H,CONHMe shows an N-H * 0 bond. [W(CO),(phen)(NCEt)] under-went120 oxidative addition with disulfides to give the formally 16-electron complex [W(CO),(phen)(SR),]. The rate of reaction is in the order R = But << Me < Bz < Ph and the reaction proceeds through coordination of the disulfide S,R,.The 16-electron complexes readily react reversibly with CO and phosphines. Thermodynamic studies of the binding of CO indicate a W-CO bond strength of the order of 8 kcal mol- some 40 kcal mol- weaker than in [w(co)6]. P. Ge B. S. Haggerty A. L. Rheingold and C. G. Riordan J. Am. Chem. SOC. 1994 116 8406. M. A. Halcrow J. C. Huffmann and G. Christou Inorg. Chem. 1994 33 3639. 'I7 R. F. Lang T. D. Ju C. D. Hoff J. C. Bryan and G.J. Kubas J. Am. Chem. SOC. 1994 116 9747. N. Ueyama M. Kondo H. Oku and A. Nakarnura Bull. Chem. SOC.Jpn. 1994 67 1840. J. Huang R. L. Ostrander A. L. Rheingold Y. Leung and M. A. Walters J. Am. Chem. SOC.,1994,116 6769. R. F. Lang T.D. Ju G. Kiss C. D. HdT J.C. Bryan and G.J. Kubas Inorg. Chem. 1994 33 3899. 202 H. Sloan Me3P PMe3 H\/ SH :w H/\ SH Me3P PMe3 (69) Reagents i H,Se; ii excess H,Se; iii excess H,S; iv RCHO; v excess PMe,; vi Bu'NC Scheme 10 17 Selenium- and Tellurium-donor Ligands The reaction of [W,(O,CPr),] or [WCl,] with K,Te in en gave',' low yields of [WOTe,12-isolated as the [PPh,]' salt. The anion contains short W-Te bonds (2.5481) and there is a trend of decreasing W-0 distance for [WOE,I2- in the order E = 0 > S > Te. A theoretical study of the bonding of the model compound [W(PH,),E,] (E = 0,S Te) indicates', an increasing covalent a-bonding contribu- tion on passing from 0to Te while the .n-bonding levels remain relatively unchanged.H,Se is readily dehydr~genated"~ by reaction with trans-[WH(PMe,),(q2-CH2PMe,)] under similar conditions to the reaction involving H2S (Scheme 10). However the intermediate (68) contrasts with the intermediate (69) found with H2S. As in the analogous S and Te complexes the diselenide (70) has labile phosphine ligands which may react reversibly with aldehydes to give (71); the equilibrium constant is much closer to that of the Te analogue. The 18-electron complexes (68) (70) and (72) possess W-Se bond lengths longer (2.375 to 2.445 A) than those reported for other terminal Se complexes. The formally 16-electron complex (71) has bond lengths of 2.313 and 2.321 A. The NMR spectra show a large range of more than 1700 ppm for the chemical shifts of these selenido complexes.[Se,(a-Cp),] was reduced'24 to the diselenide ligand when reacted with sources of M(CO) (M = Cr W) such as [W(CO),(thf)] giving [M(CO),(Se,Cp,)] (73) (M = Cr W). While compounds of this type have been characterized previously the reductive reaction occurring here is new. The bond lengths in the M(CO) fragment are typical with shortening of the M-C bond trans to the diselenide. The Se-C distances are longer than D. R. Gardner J.C. Fettinger and B. W. Eichhorn Angew. Chem. Int. Ed. Engl. 1994 33 1859. N. Kaltsoyannis J. Chem. Soc. Dalton Trans. 1994 1391. D. Rabinovitch and G. Parkin Inorg. Chem. 1994 33 2313. C. M. Bates C. P. Morley and M. Di Vaira J. Chem. Soc. Chem. Commun. 1994 2621. Chromium Molybdenum Tungsten the sum of the covalent radii.[W(CO),(TePh,)] an almost regular octahedral structure about tungsten but there is considerable distortion of the C-Te-C angle compared with that of the free telluride. 18 Halide Ligands The structure of the hexabromochromate anion in [NH,C,H4Br-4],[CrBr6] Br3.2AcOH shows126 little departure from octahedral chromium with all the Br-Cr-Br angles at 180" or within one degree of 90"; the Cr-Br distances are 2.513 to 2.521A. Deuterium NMR spectroscopy of mer-[MX,(py-d,),] (M = Cr Mo; X = F C1 Br NCS) has establi~hed"~ criteria for the structural relationships within the series. Assignment of the various absorption bands has been made',' by detailed IR and Raman spectroscopic studies of mono- and bidentate oxygen and nitrogen donor adducts of molybdenum and tungsten chlorides and 0x0-chlorides.Reaction of Li[N(SiMe,CH,PPh,),] with CrC1,nthf gave' 29 the binuclear chloride- bridged complex [(Cr(N(SiMe,CH,PPh2)2})2(~-Cl)2]. This complex is paramagnetic at room temperature with a magnetic moment corresponding to four unpaired electrons on each chromium atom; at lower temperatures it exhibits antiferromagnetic behaviour. It is converted into mononuclear [CrMe(N(SiMe2CH,PPh2),)1 by reaction with LiMe; reaction with hydrogen gave dinuclear [(Cr(N(SiMe,CH,PPh2),))2(p-H)2]. The latter is strongly antiferromagnetic. The magnetic coupling correlates with the Cr-Cr distance the bridged dichloride has a Cr-Cr bond length of 3.64 A while the bridged dihydride has a Cr-Cr bond length of 2.641 A.An improved method for the preparation of seven-coordinate [MBr,(CO),(NCMe),] (M = Mo W) has enabled13' the products of their reaction with EPh (E = P As Sb) namely [MBr,(CO),(NCMe)L] to be compared with the diiodo analogues. The bromide and iodide complexes (74) (E = Sb) are isostructural with a capped trigonal prismatic form; NMR spectroscopy confirms retention of the same structure for the diiodide (74) in solution. lZ5 W.-F. Liaw M.-H. Chiang C.-H. Lai S.-J. Chiou G.-H. Lee and S.-M. Peng Znorg. Chem. 1994,33 2493. lZ6 D. M. Halepoto L. F. Larkworthy D. C. Povey R. A. Siddiqui and G. W. Smith Znorg. Chim.Acta 1994 227 167. lZ7 S. Kaizaki and J.I. Legg Znorg. Chim. Acta 1994 218 179. 12' K. Dreisch C. Persson and C. Anderson J.Chem. Res. (S) 1994 218; J. Chem. Res. (M) 1994 1301. lZ9 M.D. Fryzuk D.B. Leznoff S.J. Rettig and R.C. Thompson Znorg. Chem. 1994 33 5528. I3O P. K. Baker M. B. Hursthouse A.I. Karaulov A. J. Lavery K. M.A. Malik D. J. Muldoon and A. Shawcross J. Chem. SOC.,Dalton Trans. 1994 3493. 204 H. Sloan 19 Heterometallic Complexes [M2(CO)l,]2-reacted'31 with SnCl to form [{M(CO),}2(p-SnC12)]2- (M = Cr Mo W). In all three complexes the M-Sn-M angle is close to 130".The chromium complex is readily oxidized in thf to [{Cr(CO),>,{ Sn,(p3-0),(p3-OH)4)] with a central core of octahedrally disposed tin atoms each bridged by two 0x0 and two hydroxy ligands and each with a terminal Cr(CO) group. 13' B. Schiemenz B. Antelmann G. Huttner and L. Zsolnai Z.Anorg. Allg. Chem. 1994 620 1760.

ISSN:0260-1818    

DOI:10.1039/IC9949100177

出版商:RSC    

年代:1994

数据来源: RSC

摘要:

14 Manganese Technetium and Rhenium By J. D. CRANE School of Chemistry University of Hull Kingston-upon- Hull North Humberside HU6 7RX UK 1Manganese The volatile manganese@) alkoxide [MnL,] [HL = Bu'C(OH)(CH20Pri),] is re- ported to sublime at 85 "C/lO- mbar and is proposed to be mononuclear in both the gas phase and the solid state.' The high-spin manganese@) complex [MnL'] + adopts a trigonal prismatic geometry in the solid state even though this ligand can readily accommodate a pseudo-octahedral geometry for other transition metals (Fe2 + Ni2+). The low-spin manganese@) complex [MnL2] has been structurally character- ized and the Mn-S/Mn-N bond lengths (2.35/1.91 A) are much shorter than found in closely related high-spin complexes of either manganese@) (2.72/2.14 A) or manga- nese(II1) (2.50/1.95 A).3The structures of the mononuclear complexes cis-[Mn"(phen),(NCS),] and [Mn11(phen)(0,CCH,NMe3)(N03)(H,0),] + and of the linked dinuclear complex [{Mn"(phen) (H ,O)},{p-O,C(CH,),CO,}] have been + In addition the latter complex acts as a particularly efficient catalyst for the disproportionation of H,O (catalase activity).The polymeric systems C{Mn"(bipy)("N),},l C~c~~:'~~~PY~4~~,~-~~~~~~~2~,}1~~~~412~,1, and [{K [Mn"L3 (H ,O)] -2.25H,0I,] have been structurally characterized and their magnetic properties in~estigated.'-~ The magnetic properties of a range of materials containing combinations of high-spin manganese@) centres and nitroxide radicals have also been reported."-12 Acrystallographic and spectroscopic study of the valence tautomerism of the W.A.Herrmann and N. W. Huber Chem. Ber. 1994 127 821. N. Arulsamy J. Glerup and D.J.Hodgson Inorg. Chem. 1994 33 3043. S. Karmakar S. B. Choudhury and A,. Chakravorty Inorg. Chem. 1994 33 6148. S. R. Holleman 0.J. Parker and G. L.Breneman Acta Crystallogr. Sect. C 1994 50 867. X.-M. Chen Y.-J.Zhu Y.-J. Xu and X.-Y. Huang Polyhedron 1994 13 1393. M. T. Casey M. McCann M. Devereux M. Curran C. Cardin M. Convery V. Quillet and C. Harding J. Chem. Soc. Chem. Commun. 1994 2643. R. Cortes L. Lezama J. L.Pizarro M.I.Arriortua X. Solans and T. Rojo Anyew. Chem. Int. Ed. Engl. 1994,33 2488. * J. Cano G. De Munno J. Sanz R. Ruiz F. Lloret J. Faus and M. Julve J. Chem. Soc.Dalton Trans. 1994 3465. P.-A. Marioni W. Marty H. Stoeckli-Evans and C. Whitaker Inorg. Chim. Acta 1994 219 161. lo K. Inoue and H. Iwamura J. Am. Chem. Soc. 1994 116 3173. l1 K. Inoue and H. Iwamura J. Chem. Soc. Chem. Commun. 1994 2273. l2M. Kitano Y. Ishimaru K. Inoue N. Koga and H.Iwamura Inorg. Chem. 1994 33 6012. 205 206 J. D.Crane HOOC COOH L' H4L3 bis(catecho1ate) complex [MnL,L,] (H,L = Hz-3,6-Bu:cat L = (4-Bu'py) has shown that at room temperature the complex may be best described as [Mn"L,L',] whereas at higher temperatures the monosemiquinone form [Mn"'L(L )LJ is favoured. The octahedral manganese(m) complexes [MnCl,(phen)(H,O)] and cis-[MnCl,(phen),] have been structurally characterized and both display the + expected Jahn-Teller distortion (axial elongation).14y1 In contrast the complex [Mn"'(L4),] -displays a pseudo-Jahn-Teller axial compression presumably due to ligand imposed constraints. The structures and spectroscopic properties of various mononuclear manganese(II1) complexes with tridentate ligands containing combina- tions of pyridine/phenolate/imine/amine/alkoxide/thiolatedonor groups have also been The crystal structure of [Mnm1L5] shows that the putative 0 second metal coordination site is far from ideally organized for the binding of a second metal." However the solubility of [Mn"'L5] in methanol was found to be greatly increased in the presence of K or La3 + ions indicating some degree of complexation. + CI H,L~ H3L5 The first mononuclear side-on peroxo manganese(Ir1) complex (1) (L = [(3,5-Pr\pz),BH]-) has been reported.23 Interestingly both brown and blue forms of this compound have been prepared depending on the temperature and/or solvent mixture used; crystal structure determinations of both forms indicate that the difference probably arises from the degree of intramolecular hydrogen bonding to the peroxo l3 A.S.Attia 0.-K. Jung and C.G. Pierpont Inorg. Chim. Acta 1994 226 91. l4 G. Swarnabala K. R. Reddy J. Tirunagar and M. V. Rajasekharan Transition Met. Chem. 1994,19,506. '' K. R. Reddy and M. V. Rajasekharan Polyhedron 1994,13 765. l6 M.S. Shongwe M. Mikuriya E.W. Ainscough and A.M. Brodie J. Chem. SOC.,Chem. Commun. 1994 887. l7 N. Arulsamy and D. J. Hodgson Inorg. Chem.1994 33 4531. R. Mukhopadhyay S. Bhattacharjee and R. Bhattacharyya J. Chem. SOC.,Dalton Trans. 1994 2799. l9 M. Mikuriya H. Takebayashi and K. Matsunami Bull. Chem. SOC.Jpn. 1994 67 3128. 2o S. Dutta and A. Chakravorty Polyhedron 1994 13 1811. R. Shukla P. K. Bharadwaj J. van Hall and K. H. Whitmere Polyhedron 1994 13 2387. 22 A. Aguiari E. Bullita U. Casellato P. Guerriero S. Tamburini P. A. Vigato and U. Russo Inorg. Chim. Acta 1994 219 135. 23 N. Kitajima H. Komatsuzaki S. Hikichi M. Osawa and Y. Moro-oka J. Am. Chem. Soc. 1994 116 11 596. Manganese Technetium and Rhenium group. Although this complex has been shown to decompose readily at room temperature to the previously reported dinuclear species [Mny(p-O),L,] initial studies with phosphines and thioethers as substrates have indicated that it displays only limited 0x0-transfer reactivity.Mononuclear [MnL6(py)] and dinuclear [Mn,(L6),] five-coordinate manganese(II1) complexes of the bilindione derivative (H3L6) have been structurally ~haracterized.,~ Complexes of H,salen H,salpn and H,salophen derivatives continue to be of interest as potential models for manganese biosites. Hydrogen-bonded dimers have been structurally characterized for both manganese(I1) and manganese(II1) complexes; these dimers are formed by two LMn-OH,-L'Mn interactions and are proposed to persist upon diss~lution.~~-~~ In some cases aqueous solutions of these and related complexes have been shown to generate dioxygen upon photolysis in the presence of p-benzoquinone and a mechanism based on the extraction of hydrogen radicals from the bridging water molecules by photo-excited p-benzoquinone has been postu- lated.27.28 Both bridging and bidentate carboxylate ligands have been reported for a series of closely related manganese(m) salen derivative^.^^ An unusual ten-membered chelate ring has also been characterized in a manganese(u1) Schiff base complex.30 Hexacyanomanganate anions have been used as building blocks for three new ferrimagnetic materials K,Mn"[Mn"( CN),] Mn',"Mn"'(CN),] ,-12H,0 and CSM~"[M~"'(CN),].O.~H,~.~~ A single crystal magnetization study of low-spin Cs,K[Mn"'(CN),] has shown that the ligand field model developed for the iron(rr1) analogue was applicable with the need for only minor changes in the ligand field parameter^.^ The magnetic properties of manganese(III)/copper(n) polymeric com- plexes of bridging oximato ligands have been inve~tigated.~~ 24 A.L.Balch M. Mazzanti B.C. Noll and M.M. Olmstead J. Am. Chem. SOC. 1994 116 9114. 25 M. R. Bermejo A. Garcia-Deibe J. Sanmartin A. Sousa,N. Aurangzeb C. E. Hulme C. A. McAuliffe R. G. Pritchard and M. Watkinson J. Chem. SOC. Chem. Commun. 1994 645. 26 C. A. McAuliffe A. Nabhan R. G. Pritchard M. Watkinson M. Bermejo and A. Sousa Acta Crystallogr. Sect. C 1994 50 1676. 21 N. Aurangzeb C.E. Hulme C.A. McAuliffe R.G. Pritchard M. Watkinson M.R. Bermejo A. Garcia-Deibe M. Rey J. Sanmartin and A. Sousa J. Chem. SOC. Chem. Commun. 1994 1153. 28 M. Watkinson A. Whiting and C. A. McAuliffe J.Chem. SOC. Chem. Commun. 1994 2141. 29 N. Aurangzeb C. E. Hulme C. A. McAuliffe R. G. Pritchard M. Watkinson M. R. Bermejo and A. Sousa J. Chem. SOC.,Chem. Commun. 1994 2193. 30 M.R. Bermejo A. Garcia-Deibe M. Rey J. Sanmartin A. Sousa N. Aurangzeb C.E. Hulme C.A. McAuliffe R.G. Pritchard M. Watkinson and M. Helliwell J. Chem. SOC.,Dalton Trans. 1994 1265. 31 W. R. Entley and G. S. Girolami Inorg. Chem. 1994 33 5165. 32 A. B. Blake B. N. Figgis P. A. Reynolds L. M. Engelhardt B. Moubaraki and K. S. Murray J.Chem. Soc. Dalton Trans. 1994 1121. 33 F. Lloret R. Ruiz B. Cervera I. Castro M. Julve J. Faus J. A. Real F. Sapifia Y. Journaux J. C. Colin and M. Verdaguer J. Chem. SOC. Chem. Commun. 1994 2615. 208 J. D. Crane H4L7 Aerial oxidation of the manganese(II1) dimeric complex [LiMn2(L7),] -in the presence of a Li' sequestering agent yielded the oxomanganese(v) complex [MnOL7] - which was structurally ~haracterized.~~ Preliminary studies have also shown that the 0x0 ligand in this square pyramidal complex may be oxidatively transferred to suitable substrates such as alkenes and phosphines.The non-oxo chemistry of manganese(vI/vII) has been further developed exploiting the recent synthetic availability of the dark green manganese(vI1) complex [M~(NBu'),C~].~' A selection of the principle reactions of this compound is summarized in Scheme 1. Scheme 1 The dinuclear complex [Mn:'(p-N3)2(terpy),(N,),1 has been structurally character- ized and contains two end-on (p-l,l)azido bridges,36 therefore representing a model 34 F.M. MacDonnell N. L. P. Fackler C. Stern and T. V. O'Halloran J. Am. Chem. Soc.. 1994 116,7431. 35 A. A. Danopoulos G. Wilkinson T. K. N. Sweet and M. B. Hursthouse J. Chem. SOC.,Dalton Trans.,1994 1037. 36 R.Cortes J. L. Pizarro L. Lezama M.I. Arriortua and T. Rojo Inorg. Chem. 1994 33 2697. Manganese Technetium and Rhenium for one of the bridging modes of the previously described polymeric structure [(Mn"(bipy)(NNN),},] .8 In this case the two manganese@) centres (Mn-Mn = 3.525 A Mn-N-Mn = 104.6') are ferromagnetically coupled with J = + 2.43 cm- '. Ferromagnetic couplings (J = +0.51 and + 1.56cm-respective-ly) have also been reported for the two dimangnese(I1) bis(pheno1ate) bridged complexes [Mn,(p-OAr),(bipy),(OAr),l (Ar = 2,4,6-Y3C6H2;Y = CI Br).37 Fur- thermore the low temperature measurements (1 .l-50 K) for these systems indicated a degree of intermolecular ferromagnetic coupling (J = +0.006 and +0.13 cm -' respectively).Examples of sulfur and selenium analogues of the [Mn!&XAr),12 + core have also been structurally characterized in the complexes [Mn2(2,6-(Me,Si) C,H,S},(thf)] and [Mn2(p-2,4,6-Pr~C6H,Se}2((Me3~i)2N)2(thf),].38+39 ?' Dinuclear manganese@) complexes of the macrocyclic ligand H,L8 [Mn,(p-X) + L8] ,have been prepared with a range of bridging groups (X = C1-,Br -,N; ,NCS - MeCO; CF,CO; CCl,CO;) of which the chloro-bridged complex has been structurally chara~terized.~~ The catalase activity of these complexes depends on the nature of X.It was therefore proposed that the dissociation of the bridging group is the rate-determining step and is probably necessary to provide a coordination site for H,02. A similar requirement for bridging-ligand dissociation prior to catalase activity has been reported for the complex [(2)12' (Figure l).41 In this case the reaction with H202is proposed to proceed by two consecutive two-electron processes of which the second was found to be 7-9 times faster than the first. Consistent with this proposal no spectroscopic evidence was found to indicate the presence of any mixed-valence manganese(Ir/rrr) or manganese(m/Iv) intermediates. The catalase activity of the asymmetric dinuclear manganese@) complex [Mn2(p-0,CMe),L9(NCS)] has also been in~estigated.~~ + The [Mny(p-O)(p-O,CMe)] core has been structurally characterized4 in complexes of the ligands LIO and L1 '.The methylated ligand L1' was found to enhance the stability of the dimanganese (III/III) state and unlike the corresponding complex of 37 M. Wesolek D. Meyer J. A. Osborn A. De Cian J. Fischer A. Derory P. Legoll and M. Drillon Angew. Chem. Int. Ed. Engl. 1994 33 1592. 38 H.-0. Stephan and G. Henkel Inorg. Chim. Acta 1994 219 1. 39 M. Bochmann A. K. Powell and X. Song Inorg. Chem. 1994 33,400. 40 T. Nagata Y. Ikawa and K. Maruyama J. Chem. Soc. Chem. Commun. 1994,471. 41 P. J. Pessiki and G.C. Dismukes J. Am. Chem. Soc. 1994 116 898. 42 C. Higuchi H. Sakiyama H. Okawa R. Isobe and D. E. Fenton J. Chem.SOC.,Dalton Trans.,1994,1097.43 N. Arulsamy J. Glerup,A. Hazel] D. J. Hodgson C. J. McKenzie and H. Toftlund Inorg. Chem. 1994,33 3023. 210 J. D.Crane step I x 2H+ + 2Mnn 2Mn" 02 H202 Figure 1 L'O the dimanganese(m/Iv) form could no longer be generated electrochemically. The electrochemically induced rearrangements of the triply bridged complexes [Mnyl(p- + + O)(p-0,CMe),(L12),]2 and [Mn','I/1V(p-O),(p-02CMe)(L'2), J2 have also been in~estigated.~~ Terminal water ligands bound to manganese(1v) centres are present in the complex [Mn2(p-O),(p-0,CMe)(bipy),(H,0),]3+, in which the metals are only relatively weakly antiferromagneticaly coupled (J = -43.7 cm-The 0x0 bridges of the dimanganese(1v) complex [Mn,(p-O),(salpn),] have been successively proto- nated with triflic to yield [Mn,(p-O){p-OH)(~alpn)~]+ and the previously unreported [Mn,(p-OH),(~alpn),]~ +.With each protonation EXAFS studies show that the Mn-Mn distance lengthens from 2.73 to 2.83 to 2.93& and magnetic susceptibility measurements show that the magnitude of the antiferromagnetic coupling of the metal centres decreases from J = -92 to -48 to -6 cm-'.A series of bis(p-0x0)-dimanganese(m/rrI),(m/rv),and (rv/~~)~~ complexes has been prepared with ligands L" and LI3. Two of the mixed-valence complexes were structurally characterized and in both cases the oxidation states were localized; the manganese(II1) ions could be readily identified by their characteristic Jahn-Teller distortions. In all cases the metals were strongly antiferromagnetically coupled with J < -100cm-'.pp p p NH "H CMe Nb6 Nb(INMe \ \ L'O L" L' Li2 The dimanganese(III/Iv) and (IV/IV) complexes [Mn,(p-O),(L'4)4]"+ (n = 3,4) have both been structurally ~haracterized.~' In addition a characteristic stretching mode at 44 S. Mahapatra T.K. Lal and R. Mukherjee Inorg. Chem. 1994,33 1579. 45 K. R. Reddy M. V. Rajasekharan,S. Padhye F. Dahan and J.-P. Tuchagues Inory. Chem. 1994,33,428. 46 M. J. Baldwin T. L. Stemmler P. J. Riggs-Gelasco M. L. Kirk J. E. Penner-Hahn and V. L. Pecoraro J. Am. Chem. SOC.,1994 116 11 349. 47 J. Glerup P.A. Goodson A. Hazell R. Hazell D.J. Hodgson C.J. McKenzie K. Michelsen U. Rychlewska and H. Toftlund Inorg. Chem. 1994 33 4105. 48 B.C. Dave and R. S.Czernuszewicz Inorg. Chim. Acta 1994 227 33. Manganese Technetium and Rhenium 211 695cm-' for the Mn"-O bond in the [Mn,(p-O),]"' core was identified using resonance Raman spectroscopy of the 60/1 '0isotope derivatives of both complexes. An improved synthesis of the mixed-valence complex [Mn (p-O),(phen),I3 + has been reported along with the molecular structure of its acetic acid/water ~olvate.~~ The bipy analogue of this complex has been investigated as a notably robust catalyst for the oxidation of saturated hydrocarbons to alcohols and ketones by alkylhydroperox- ides.50 The manganese(rrr/Iv) complex [Mn,(p-O),(L15),] displays much higher + catalase activity5 than the structurally similar complex [Mn2(p-O),(tmpa),l3 . A + dimer of bis(p-0x0) (dimanganese(rrI/Iv) cores linked through hydrogen-bonded terminal water ligands has also been structurally characterized.52 Q ,YNH Li4 HLi5 The synthesis of the trimanganese(rv) complex [Mn3(p-O),(bipy),(H20)2]4+ from the dimanganese@r/rv) complex [Mn (p-0),(bipy),] has been investigated in + detail. 3,54 A linear trimanganese(rrI/n/rIr) complex [Mn,(p-OH) (p-O,CMe),L,] [L = HB(3,5-Pr\pz),] has been prepared by the reaction of the corresponding dimanganese(1r) complex [Mn,(p-OH)(p-O,CMe)L,] with excess H,0,.55 Linear trimanganese(1r) complexes with carboxylate or thiolate bridges have also been rep~rted.'~*~~ A chainlike tetramanganese(I1) complex [Mn,Li6I2 with phenolate + bridges has been structurally characterized and shown to display ferromagnetic co~pling.~' In contrast the tetramanganese(r1) cluster in [Mn,(P,W,,O,,),-(H20)2]16-exhibits antiferromagnetic co~pling.'~ Heterocubane tetramanganese(11) complexes of formula [Mn,(p3-Te),(XPr'),l4- (X = S Se) have been structurally characterized and are surprisingly stable.6o In particular despite the high negative charge on these clusters they are found not to undergo any reversible electrochemical oxidations. A benzoate ligand bridging three manganese(r1r) ions and formally 49 R. Manchanda G.W. Brudvig S. de Gala and R. H. Crabtree Inorg. Chem. 1994 33 5157. 'O S. Menage N.-N. Collomb-Dunand-Sauthier,C. Lambeaux and M. Fontecave J. Chem. SOC. Chem. Commun. 1994 1885. " Y. Nishida T. Akamatsu K. Tsuchiya and M. Sakamoto Polyhedron 1994 13 2251.52 H. Kawasaki M. Kusunoki Y. Hayashi M. Suzuki K. Munezawa M. Suenaga H. Senda and A. Uehara Bull. Chem. SOC.Jpn. 1994 67,1310. '3 R. Manchanda G. W. Brudvig and R. H. Crabtree New J. Chem. 1994 18 561. 54 B.C. Dave and R.S. Czernuszewicz New J. Chem. 1994 18 149. " N. Kitajima M. Osawa S. Imai K. Fujisawa Y. Moro-oka K. Heerwegh C. A. Reed and P. D. W. Boyd Inorg. Chem. 1994 33,4613. '6 Z.J. Zhong X.-Z. You and T.C. W. Mak Polyhedron 1994 13 2157. 57 M. Mikuriya F. Adachi H. Iwasawa M. Handa M. Koikawa and H. okawa Bull. Chem.SOC.Jpn.,1994 67,3263. " J.C. Jeffery P. Thornton and M. D. Ward Inorg. Chem. 1994 33 3612. 59 C. J. Gomez-Garcia J. J. Borras-Almenar E. Coronado and L. Ouahab Inorg. Chem. 1994,33 4016. 6o H.-0.Stephan and G. Henkel Anyew. Chem. Int. Ed. Engl. 1994 33 2322. 212 J. D. Crane occupying the missing corner of a cubane core has been characterized in the mixed-valence tetranuclear complex [Mn4(p3-O),(dbm)3(02CPh)4] (3).61This com- plex and the chainlike tetramanganese(1v) cluster [Mn4(p-O)6(bipy)6]4+ (4) have been proposed as potential models for high oxidation state forms of the oxygen-evolving complex of photosystem II.62 The tetramanganese(II1) butterfly cluster [Mn4(p3- O)2(dbm)2(02CPh)6(EtOAc)2)] contains two weakly bound EtOAc ligands and their facile replacement with more strongly binding bridging ligands has enabled the successful linking of these units to yield both dimeric and polymeric structures which have been structurally ~haracterized.~ The multinuclear complexes [Mn,04(02CPh)l 2(H20)2{ Et2C(C02)2)212-CMngFe40 12 (OzCMe)1dHZ0)41 and [Mn,,0,2(0,CEt),6(H20)4] -have also been structurally characterized and their magnetic properties investigated in core of (3) core of (4) 2 Technetium The synthesis and chemistry of 99mT~ radiopharmaceuticals has been reviewed.67 The dark green technetium(1) complex [TcCl(dppe),] has been structurally characterized and shown to react reversibly with H to form the yellow complex [Tc(q2- H2)Cl(dppe)2].68 The presence of an q2-H ligand is confirmed by the crystallographic and spectroscopic data which moreover are very different from those of the trihydride [Tc'I'H (dppe),] and the previously reported isomeric trans-dihydride + [Tc"'H,Cl(dppe),].The structures of trans-[Tc'(H,O),(dppe),] and trans-[Tc'Cl(NO)(diars),] have also been rep~rted.~~.~' + Several ditechnetium(11) com- plexes of general formula [Tc,Cl,(PR,),] (PR = PEt, PPr PMePh, PMe2Ph) have been prepared by the reduction of the corresponding [TC'~C~,(PR,),] complexes 61 S. Wang H.-L. Tsai K. S. Hagen D. N. Hendrickson and G. Christou J. Am. Chem. Soc. 1994,116,8376. 62 C. Philouze G. Blondin J.-J. Girerd J. Guilhem C. Pascard and D. Lexa J. Am. Chem. Soc. 1994,116 8557. 63 S. Wang H.-L. Tsai K. Folting J. D. Martin D. N. Hendrickson and G. Christou J. Chem. Soc. Chem. Commun. 1994 671. 64 M.W. Wemple H.-L. Tsai W.E. Streib D.N. Hendrickson and G. Christou J. Chem. Soc. Chem. Commun. 1994 1031. 65 A. R. Schake H.-L.Tsai R. J. Webb K. Folting G. Christou and D.N. Hendrickson Inorg. Chem. 1994 33 6020. 66 H.-L. Tsai H. J. Eppley N. de Vries K. Folting G. Christou and D. N. Hendrickson J. Chem. SOC. Chem. Commun. 1994 1745. " K. Schwochau Angew. Chem. lnt. Ed. Engl. 1994 33 2258. 68 A. K. Burrell J.C. Bryan and G.J. Kubas J. Am. Chem. SOC. 1994 116 1575. 69 R. Hubener U. Abram and W. Hiller Acta Crystallogr. Sect. C 1994 50 188. 70 H. J. Banbery and T. A. Hamor Acta Crystallogr. Sect. C 1994 50 44. Manganese Technetium and Rhenium 213 with zinc These complexes which contain electron-rich Tc-Tc triple bonds with eclipsed geometries may be reversibly electrochemically oxidized to the corresponding [Tc,]~ + and [Tc216+ species. A near perfect trigonal bipyramidal geometry with three equatorial thiolate ligands has been reported for the techne- tium(II1) complex [Tc(N(CH,CH,S),}(PPh,)]; a minor by-product of the synthesis is proposed to be the corresponding octahedral bis(phosphine) complex [Tc{N(CH,CH,S),}(PPh,),] .72 The syntheses of a range of monodiazenido techne- tium complexes starting either from [TcCl(NNAr),(PPh,),] (Ar = 4-C1C6H,) or directly from [TcO,]- have been de~cribed.~ A typical example is the reaction with the dianion of H,salen to yield [Tc(NNAr)(salen)(PPh,)] which was structurally characterized.The reaction of [TcO,] -with ArNHNH,-HCl followed by the addition of bipy gave a high yield (92%) of [TcCl(NNAr)(bipy),]+ which represents an important development in the chemistry of these derivatives since [99"Tc0,] -is the favoured starting material for the synthesis of 99mT~ radiopharmaceuticals.Reaction of [TcO,]-with derivatives of the bidentate ligand HL17 in the presence of Na,S,O as reducing agent yields mononuclear technetium(1v) complexes [TcLi7] of potential + use as kidney imaging Derivatives of chelating N,S tetradentate ligands remain popular for the synthesis of technetium(v) 0x0 and nitrido complexes as potential new imaging agent^.^^'^^ OQ+ HO Me HL" (R = Et pOMeC6H4) The tetranuclear technetium(v) complex [Tc,N,(SC(NH,),)(edta),] contains the first structurally characterized cyclic [Tc,N,] core with alternating TcEN triple + and Tc-N single bonds of average length 1.69 and 1.998 re~pectively.~~ The technetium(v) phenylimido complexes [TcX,(NPh)(PPh,),] (X = C1 Br) react with various aromatic thios (ArSH) to yield the complexes [TcVO(SAr),]- The [TcV(NPh)(SAr),] - and [TC~(NP~)(SA~),(PP~,)].~* chemistry of [TcV"(NAr),I] (Ar = 2,6-Pr\C6H,) has been investigated a representative selection of which is summarized in Scheme 2.79 Interestingly whereas the reduction of [TcV"(NAr),I] with sodium metal yielded the staggered 'ethane-like' dimer [Tc;'(NAr),] the corresponding reaction with a less sterically hindered imido ligand (Ar' = 2,6-Me,C6H,) yielded the doubly bridged dimer [TcT'(p-NAr'),(NAR'),] .The 71 C.J. Burns A. K. Burrell F.A. Cotton S. C. Haefner and A. P. Sattelberger,Inorg. Chem. 1994,33,2257. 72 H. Spies M. Glaser H.-J. Pietzsch F. E.Hahn 0.Kintzel and T. Lugger Angew. Chem. Int. Ed. Engl. 1994 33 1354. 73 J. R. Dilworth P. Jobanputra R. M. Thompson D. C. Povey C. M. Archer and J. D. Kelly J. Chem. SOC. Dalton Trans. 1994 1251. 74 D. S. Edwards S. Liu M. J. Pokier Z. Zhang G. A. Webb and C. Orvig Inorg. Chem. 1994 33 5607. 75 J. P. O'Neil S. R. Wilson and J. A. Katzenellenbogen Inorg. Chem. 1994 33 319. 76 G. Cros H. B. Tahar D. de Montauzon A. Gleizes Y. Coulais R. Guiraud E. Bellande and R. Pasqualini Inorg. Chim. Acta 1994 227 25. 77 J. Baldas S.F. Colmanet Z. Ivanov and G.A. Williams J. Chem. SOC. Chem. Cornmun. 1994 2153. 78 T. Nicholson J. Cook A. Davison and A.G. Jones Inorg. Chim. Acta 1994 218 97. 79 A. K. Burrell D. L. Clark P. L. Gordon A. P. Sattelburger and J. C. Bryan J.Am. Chem. SOC.,1994,116 3813. 214 J. D. Crane structure and EPR spectrum of the technetium(v1) nitrido complex mer-[TcNCl,(bipy)] has also been reported.80 [ ~ ArN\:cSNAr 2Na . ArN:c=NAr] AUC1(PPh3) ArN\:cSNAr // \I ArN ArN// 'Au(PPh3) ArN ArN NAr \\ I/ ArN=p-T$=NAr ArN NAr Scheme 2 3 Rhenium The reaction of [ReH,L] (L = cis-Ph,PCH=CHPPh,) with the phosphines PPh or dppm yielded the complexes [ReH,L(PPh,)] [ReH,L(PPh,),] [ReH,L(q'-P-dppm)] and [ReH,L(y2-P,P'-dppm)] which were investigated by variable tempera- ture NMR spectroscopy.81 Protonation of [ReH,L] at -80 "C gave [Re(q2-H,)H,L] which upon warming was found to rearrange cleanly to a dirhenium species tentatively proposed to be [Re,(p-H),H,L,]. The reaction of 1,2-(Me2HSi),C,H (H,L) with [ReH,(PPh,),] yields the chelating disilyl complex [ReH,L].82 Only three hydride ligands could be tentatively identified in the crystal structure.However the overall disposition of the P/Si ligands combined with NMR spectroscopic studies (T,data) indicated the possible presence of one q2-H2 ligand with a long H-H distance of 1.4-1.681. An elongated y2-H2 ligand has also been proposed for the complex tran~-[Re(q~-H,)Cl(dppe),l,~~ the rhenium analogue of the previously discussed technetium complex.68 The sunlight-promoted reaction of nitriles with the dinitrogen complex trans-[ReCl(N,)(dppe),] has been used to prepare a wide variety of cis-[Re'Cl(NCR)(dppe),] derivatives which were found to undergo reversible one- electron oxidations in the range -0.20 to -0.02V (us.SCE).84 The formally rhenium(1) and rhenium@) thionitrosyl complexes [ReCl,(NS)(PMe,Ph),] and [ReCl,(NS)(PMe,Ph),] with mer- and trans-phosphines respectively have also been structurally ~haracterized.~' Several rhenium complexes of 'non-innocent' ligands have been prepared. The complexes [ReC12(L'8),(0SiMe,)] [ReCl,(L' 8)2] [Re2 (p-O),(L'8)4(NCMe)4]4+ and [Re20,(L'8)4] are best considered as containing neutral isodiazene ligands (form a) rather than hydrazido(2 -) ligands (form b) and therefore 'O B. Lorenz P. Kranke K. Schmidt R. Kirmse R. Hubener and U. Abram 2.Anorg. Allg. Chern. 1994,620 921. X. L. R. Fontaine T. P. Layzell and B. L. Shaw J. Chem. SOC.,Dalton Trans. 1994 917. 82 M.L. Loza S. R. de Gala and R.H. Crabtree Inorg. Chem. 1994 33 5073. 83 M. Kohli D. J. Lewis R. L. Luck J.V. Silverton and K. Sylla Inorg. Chern. 1994 33 879. 84 M. F. C. Guedes da Silva J. J. R. Fraustro da Silva and A. J. L. Pombeiro J. Chem. SOC.,Dalton Trans. 1994 3299. '' U. Abram and S. Ritter 2. Anorg. Allg. Chem. 1994 620 1223. Manganese Technetium and Rhenium have formal metal oxidation states of 111 111 IV/IV and 11/11 respectively; the last has a Re-Re single bond of length 2.696 A.86 In contrast the catecholate complexes [Re(NNPh,),(cat),] -and [Re(NNPh),(cat),] -(two forms) have been tentatively assigned formal metal oxidation states of VII and L'~ (form a) H2L" (form b) Three examples of seven-coordinate rhenium(II1) have been structurally character- ized as the complexes [ReX(terpy),12+ (X = OH- C1- NCS-).In addition NMR spectroscopic studies confirmed that the structure with two equivalent asymmetric terpy ligands is retained in solution.88 More conventional five-coordination has been reported for the thiolate complexes [Re"'(N(CH,CH,S),]X] (X = PPh, CNR) and Re"'(Ph,PCH,CH,S),(SR)] (R = alkyl ar~l).~,,~~ The quantitative oxidation of the imine-rhenium(II1) complex (5) to the amidate-rhenium@) complex (6)with different oxidants (H,O or Ce4+) has been described and rationalized by investigation of the redox chemistry of both the starting material and the final product." The reaction of [ReVOCl,] -with NH(PPh,) under various conditions yielded the oxidized ligand complexes [Re"'Cl(H,O)(HL)] [Re'VC14(HL)] and [Re"Cl,(L)] -[HL = Ph2PN(H)P(0)Ph2].9' CI The rhenium(v) complex trans-[Re(NPh)(OEt)L ''1 has been structurally charac- + terized and shown to undergo a reversible one-electron red~ction.~ Reaction of (2-py),CO with [RevOC1,(PPh3),] yields the complex [ReVOC12(q3-N,N,0-(2- py),C(O)OH)] containing the fac-bound monodeprotonated hydrated form of the ligand.' A similar metal-promoted ligand hydration has also occurred for the 86 A.A. Danopoulos G. Wilkinson and D. J. Williams J. Chem. Soc. Dalton Trans. 1994 907. 87 P.B. Kettler Y.-D. Chang and J. Zubieta Inorg. Chem. 1994 33 5864. 88 J. Rall F. Weingart D. M. Ho M. J. Heeg F. Tisato and E. Deutsch Inorg. Chem. 1994 33 3442. 89 T. Maina A. Pecorale A. Dolmella G. Bandoli and U.Mazzi J. Chem. Soc. Dalton Trans. 1994,2437. 90 M. Menon A. Pramanik N. Bag and A. Chakravorty Inorg. Chem. 1994,33 403. 91 R. Rossi L. Marvelli A. Marchi L. Magon V. Bertolasi and V. Ferretti,J. Chem.Soc.,Dalton Trans. 1994 339. 92 M.A. Masood B. P. Sullivan and D. J. Hodgson Inorg. Chem. 1994 33 5360. 93 G. Bandoli A. Dolmella T.I. A. Gerber J. G. H. du Preez and H. J. Kemp Inorg. Chim. Acta 1994,217 141. 216 J. D. Crane formation of complex (7).94 The catecholate complexes [ReVO(cat),] -and [ReVO(cat),(PPh,)] -adopt square pyramidal and octahedral geometries respective- ly. However the latter complex is unusual as the PPh ligand is coordinated cis to the 0x0 group in the solid state; NMR spectroscopic studies indicated the facile dissociation of PPh in solution.95 Reaction of [ReVOCl,(PPh,),] with excess diars and RSH (R = Ph Et) under mild conditions yielded [ReVOCl(diars)(SR),]; more vigorous conditions96 resulted in reduction to the rhenium(n1) complexes trans-[Re(diars),(SR),] +.The octahedral complexes [ReVO(q3-B(pz),)(XCH,CH,Y)] (X/Y = O/O O/S S/S) have been prepared. The reaction of the first of these derivatives (X/Y = O/O) with HCl provided an improved high yield synthesis of [ReVOCl,(~3-B(pz),}] which was subsequently reduced by a range of phosphines to yield the rhenium(II1) complexes [ReCl,{q3-B(pz),}L] (L = PEt, PEt,Ph PEtPh, PPh3).97 The reaction of [ReH,(PPh,),] with the disulfide Ar,S (Ar = 2,6-Me,C,I-I,) gave the orthodox product [ReVO(SAr),(PPh,)]. However the same reaction with the corresponding thiol ArSH yielded the rhenium(m) complex [Re(SAr),(PPh,)(PHPh,)] in which one P-Ph bond had been reductively cleaved.98 Li9 (7) The synthesis spectroscopy and redox behaviour of the luminescent rhenium(v) nitrido complex [ReN(dppe),(NCMe)12 + have been reported.99 Several rhenium complexes containing isothiocyanates have been prepared of which [ReVN(NCS),(PPh3),(NCMe)] [ReVN(NCS),(PMe,Ph),] and [Re'(NS)(NCS) (PMe,Ph),] have been structurally characterized.' O0*' O1 The controlled reaction of [ReVNC1,(PMe,Ph),] with [detc] -yields the complexes [ReVNCl(detc)(PMe,Ph),l and [ReVN(detc),(PMe,Ph)] as intermediates in the synthesis of the known final product [ReVN(detc),].'02 Several reactions of the different ligands present in the rhenium(v) complexes of general formula [ReNCl(PR,),L] [HL = PhC(NH,)=NC(=S)NR;] have been reported with the structurally charac- terized products being [ReN(PMe,Ph)(SAr)L] [ReN(PMe,Ph),(q2-S,S-mnt)], and 94 G.Bandoli T.I.A. Gerber R. Jacobs and J.G.H. du Preez Inorg. Chem. 1994 33 178. 95 P.B. Kettler Y.-D. Chang J. Zubieta and M.J. Abrarns Inorg. Chim.Acta 1994 218 157. 96 L. Chang M. J. Heeg and E. Deutsch Inorg. Chem. 1994 33 1614. 97 A. Paulo A. Dorningos A. P. de Matos I. Santos M. F.N.N. Carvalho and A. J. L. Pombeiro Inorg. Chem. 1994 33,4729. 98 J. R. Dilworth J. Hu S.-X. Liu J.A. K. Howard and D.C. Povey Inorg. Chim.Acta 1994 223 63. 99 V. W.-W. Yarn and K.-K. Tarn J. Chem. Soc. Dalton Trans. 1994 391. loo R. Hubener U. Abrarn and J.Strahle Inorg. Chim. Acta 1994 216 223. lo' R. Hubener U. Abrarn and J. Strahle Inorg. Chim. Acta 1994 224 193. lo' R. Ritter and U. Abram 2. Anorg. Allg. Chem. 1994 620 1443. Manganese Technetium and Rhenium [ReCl (PMe,Ph),{ q' -N-NCMe,CH,C(O)Me)] .'03p1 O4 Rhenium(v) 0x0 and nitrido complexes of tetradentate N2S2 ligands continue to be of interest as model systems for potential 99mT~ radio pharmaceuticals. 5,7 6*1 5-1 O7 A range of [ReV"03X] derivatives (X = F C1 Br CN NCS) has been cleanly prepared by the reaction of [Re,O,] with ZnC1 or [NBuilX (X # C1).'08 Subsequent complexation with bipy (and similar ligands) formed the six-coordinate adducts of general type [ReV"03X(bipy)]. A trioxorhenium group coordinated to the face of a triangular platinum cluster has been structurally characterized' O9 in the unusual complex [Pt3(p3-Re03)(dppm),] .The structures of [HgReO,] and [HgReO,] have + been reported; the former consists of [O,ReOHgHgOReO,] molecules whereas the latter contains discrete [ReO,] -ions within a [{ [Hg,O] +}J lattice.' lo The synthesis of the rhenium(vI1) complex [ReCl(NBu'),(Tp')] has also been reported.' '' + Nj p" NH OH CNH OH Several tetrabridged dirhenium(II1) complexes [Re,(p-L),Cl,] of substituted amides [HL = RC(0)NHR'; R/R = Me/Ph Ph/H Ph/Ph] have been prepared and struc- turally characterized and are proposed to have significantly larger 6-6" orbital separations than their carboxylate analogues.' ' Similar quadruply bonded Re-Re compounds bridged by dimethyladenine or 7-azaindole have also been reported.' The dirhenium(II1) complex [Re2(p-O)(phen),Cl,] has been structurally character- + ized (Re-0-Re angle = 170") and shown to display reversible electrochemical oxidations to the (III/IV) and (IV/IV) forrn~."~ The linear dirhenium(v) core [O=Re-O-Re=0I4+ core has been characterized in a series of complexes with the U.Abram and S. Ritter Inorg. Chim. Acta 1994 216 31. lo4 S. Ritter and U. Abram 2. Anorg. Allg. Chem. 1994 620 1786. lo' L. G. Marzilli M. G. Banaszczyk L. Hansen Z. Kuklenyik R. Chi and A. Taylor Jr. Inorg. Chem. 1994 33 4850. lo6 L. M. Schultze L. J. Todaro R. M. Baldwin E. F. Byrne and B. J. McBride Inorg. Chem.,1994,33,5579. lo' J.E. Anderson C.M. Murphy S.M. Sawtelle and D.S.Edwards Inorg. Chim. Acta 1994 225 323. W.A. Herrmann F. E. Kiihn C.C. Ramiio M. Kleine and J. Mink Chem. Ber. 1994 127 47. lo9 J. Xiao R. J. Puddephatt L. ManojloviC-Muir K. W. Muir and A. A. Torabi J. Am. Chem. SOC.,1994 116 1129. 'lo M. S. Schriewer-Pottgen and W. Jeitschko 2. Anorg. Allg. Chem. 1994 620 1855. J. Sundermeyer J. Putterlik M. Foth J.S. Field and N. Ramesar Chem. Ber. 1994 127 1201. F.A. Cotton J. Lu and T. Ren Polyhedron 1994 13 807. '13 A.-M. Lebuis and A. L. Beauchamp Inorg. Chim. Acta 1994 216 131. T. Takahira K. Umakoshi and Y. Sasaki Chem. Lett. 1994 2315. 218 J. D. Crane reduced salpn ligand H2L2' and related tetradentate ligands.' The dirhenium(v1) compound [Re,(NAr),] (Ar = 2,6-PriC6H3) has been prepared by the reduction of [ReV"I(NAr),] with sodium The synthesis.and crystal structure of the mixed-valence tetrarhenium(m/Iv) complex [Re4(p3-S),(p-S0,)4(CN),o]8 (8) has -also been reported. ' M.R.A. Pillai C.L. Barnes and E. 0.Schlemper Polyhedron 1994 13 701. l6 A. Miiller E. Krickemeyer H. Bogge H. Ratajczak and A. Armatage Angew. Chem.,Int. Ed. Engl. 1994 33 770.

ISSN:0260-1818    

DOI:10.1039/IC9949100205

出版商:RSC    

年代:1994

数据来源: RSC

摘要:

15 Iron Cobalt and Nickel By S. A. COTTON St Edward’s School Woodstock Road Oxford Oxon OX2 7NN UK 1 Introduction The literature has been surveyed in similar fashion to recent years so that most 1994 publications together with some late 1993 material were considered. Important review publications include a detailed classification and analysis of crystallographic data on nickel coordination compounds.’ Increasing interest in nickel chemistry is signalled by a review of simple models for nickel-based biological systems;2 nickel L-edge X-ray absorption spectra of a range of structurally characterized nickel complexes have been examined and also related to such system^.^ A special volume on metal dioxygen chemistry includes inter alia articles on metal-dioxygen complexe~,~~ iron and cobalt lacunar complexes as oxygen carriers,4b synthetic haem dioxygen complexes,4’ and reactions of non-haem centres with di~xygen,,~ as well as other articles of greater bio-iron relevance.2 Simple Binary and Coordination Compounds of Oxygen Nitrogen and Halogen Donors A report on gas-phase anionic neutral and cationic [FeO,] species’ complemented recent studies on matrix-isolated iron oxide derivatives.6 In contrast ferrate(v) ions have been generated by reducing K,Fe04 with pulse radiolytically generated free radicals in neutral and acid solution; study of the rate law indicates7 that in acidic solution three protonated forms of the ferrate(v) ions formulated as H,FeO, [H,FeO,]- and [HFeO,]’- exist in addition to [Fe0,13-.A modern determina- tion of the structure of FeCI shows the existence of three polytypes with Fe-Cl distances of 2.375-2.376 81.’ Low-temperature determinations show that the structure M. Melnik T. Sramco M. Dunaj-Jurco A. Sirota and C. E. Holloway Rev. Inorg. Chem. 1994 14 1. M. A. Halcrow and G. Christou Chem. Rev. 1994 94 2761. J. van Elp G. Peng B. G. Searle S. Mitra-Kirtley Y.-H. Huang M. K. Johnson 2.H. Zhou and M. W. W. Adams J. Am. Chem. Soc. 1994 116 1981. (a) I. M. Klotz and D. M. Kurtz Chem. Rev. 1994,94,567; (b) D. H. Busch and N. W. Alcock Chem. Rev. 1994,94,585;(c) M. Momenteau and C. A. Reed Chem. Rev. 1994,94,659; (d) A. L. Feig and S.J. Lippard Chem. Rev. 1994 94 759. D. Schroder A. Fiedler J. Schwarz and H. Schwarz Inorg. Chem.1994 33 5094. vide S.A. Cotton Ann. Rep. Prog. Chem. Sect. A Inorg. Chem. 1992 89 169; 1993 90,180. ’ J. D. Rush and B. H. J. Bielski Inorg. Chem. 1992 33 5499. S. I. Troyanov Russian J. Inorg. Chem. 1994 38 1821. 219 220 S. A. Cotton of [Fe,(CO),,] becomes more symmetrical on cooling.' Some different methods for depositing CoAs and COP thin films from organometallic precursors have been evaluated" whilst the hydrides MMgNiH (M = Sr Yb Eu) contain tetrahedral [NiH,] -anions.' Simple Complexes.-0-donors. Interest continues in iron carboxylates. The mono- meric iron@) complexes [Fe(OAc)(HB(3,5-Pr\pz),}] [Fe(0,CBut)(HB(3,5-Pripz)},] (both square-pyramidal iron) and [Fe(OBz)(NCMe)( HB(3,5-Pripz),}] (octahedrally coordinated iron) have been synthesized.' The unsolvated species [Fe(OBz)(HB(3,5-Pr~pz),}]binds a-donors (e.g.py dmso) at its vacant site whilst it also forms a dioxygen adduct stable below -20 "C which appears to be a dimeric p-peroxo bridged species; this adduct undergoes irreversible oxidation above -20 "C to a trimeric ferric complex.Using the tetradentate carboxylate ligand Hbpg [bpg = N,N-bis(2-pyridylmethyl)glycine]permits the i~olation'~ of the tetranuclear iron@) species [Fe,(bpg),(0,CPh)3]2 ; exposure to oxygen results in the known + (p-oxo)diiron(m) species [Fe,(p-O)(bpg),(O,CPh)] +.The structure of Na,[Feox,] 5H,O has appeared.14 [Fe,(p3-O)(02CPh),(H2~)3](N0,)~5Me2C0,'S [NH,Et,] 2[Fe3(p3-O)(0,CCy)6~3]~2MeCN~~y~~2H,'6 and [Fe3(p3-o)(o2CMe),(H20),] (N03).4H,0" have the familiar trinuclear ~,-OXO structure.On the other hand FeF reacts with pivalic acid and NHEt to form [{FeF(O,CMe,),},]~NHEt, which has a cyclic iron core with fluoride and pivalate bridges.' * Increased microwave dielectric loss in mixed-valence trinuclear p,-oxoiron carboxylates has been attributed to dynamic electron delocalization.'' Full details of the ferric wheel [{Fe(OMe) (0,CCH,Cl)} 0] have appeared.20 There is interest in phosphates. RbFe(HPO,),has an intersecting tunnel structure with corner-sharing FeO octahedra" whilst ferric phosphite Fe,(HPO,), has face-sharing octahedra.22 Several t-butylphosphonates including ButPO,Co(O,PBut)~H,O have been made;, it has both tetrahedral and octahedral cobalt(i1) centres. An open-framework cobalt(r1) phosphate [enH,][CoPO,], has tetrahedrally coordinated D.Braga L. Farrugia F. Grepioni and B.F.G. Johnson J. Organomet. Chem. 1994 464 C39. lo Y. Senzaki and W. L. Gladfelter Polyhedron 1994 13 1159. B. Huang K. Yvon and P. Fischer J. Alloys Compd. 1994 204 L5. l2 N. Kitajima N. Tamura H. Amagai H. Fukui Y. Moro-oka Y. Mizutani T. Kitagawa R. Mathur K. Heerwegh C.A. Reed C. R. Randall L. Que Jr and K. Tatsumi J. Am. Chem. Soc. 1994 116 9071. l3 S. Menage H. Fujii M. P. Hendrich and L. Que Angew. Chem. Int. Ed. Engl. 1994 33 1660. l4 Y. Zheng Q.-J. Wu W.-W. Xie L.-N. Zhang Z.-Y. Zhu and G.-X. Fu Jiegou Huaxue 1994 13 216. D. Fu G. Wang W. Tang and K. Yu Wuji Huaxue Xuebao (Chinese J. Inorg. Chem.) 1994,10,63 (Chem. Abstr. 1994 121 25434). l6 N.V. Gerbeleu Yu. T. Struchkov 0.S. Manole and G. A. Timko Dokl. Adad. Nauk 1993,332,183 (Chem. Abstr. 1994 121 25 374). l7 K. I. Turte S.G. Shova F. A. Spatar M. D. Mazus and T.I. Malinovsky Zh. Strukt. Khim. 1994,35,112 (Chem. Abstr. 1994 121 123 898). N. V. Gerbeleu Yu. T. Struchkov 0.S. Manole and G. A. Timko Dokl. Adad. Nauk 1993,331,184 (Chem. Abstr. 1994 120 93954). l9 S. K. Shaikhutdinov Mendeleev Commun. 1994 217. *O K. L. Taft C. L. Delfs G. C. Papaefthymiou S. Foner D. Gatteschi and S.J. Lippard J. Am. Chem. Soc. 1994 116 823. 21 K.-H. Lii and L.-S. Wu J. Chem. SOC.,Dalton Trans. 1994 1577. 22 J. Ensling P. Giitlich R. Schmidt and T. Kneip Inorg. Chem. 1994 33 3595. 23 J. Le Bideau A. Jouanneaux C. Payen and B. Bujoli J. Chem. SOC.,Dalton Trans.1994 1319. 24 J. Chen R. H. Jones S.Natarajan M. B. Hursthouse and J. M. Thomas,Angew. Chem. Int. Ed. Engl. 1994 33. 639. Iron Cobalt and Nickel 221 (Reproduced with permission from J. Chem. Soc. Chem. Commun. 1994 1825.) Volatile iron and cobalt alkoxides with a functionalized ether ligand have been synthesized e.g. [M(OC(CF3)(CH20Bu')2}2](M = Co Fe).25 New cobalt aryloxide complexes Na,[Co(OAr),]-nthf (Ar = halogenated phenyl) probably have tetrahed- rally coordinated cobalt(II);26 cobalt powder reacts with dmso/MeI forming [Co(dm~o),]I,.~~ An accurate determination of the structure of [NH4]2[Ni(H20)6][S0,]2 reveals Ni-0 distances of 2.041-2.067 [NiBr2(l,10-diaza-l8-crown-6)] has nickel bound to two bromines two nitrogens and two oxygen atomsz9 [Ni(m-xbp),][ClO,] [xbp = N,N'-m-phenylenedimethylenebis(pyridin-2-one)]has a singular three-dimen- sional network structure involving 48-membered rings ( l).,' One methyl group is removed from the ligand when [Ni(NCMe),][BF,] reacts with tmpp.The resulting nickel([[) complex [Ni(tmpp-O),] has a square-planar NiO,P chromophore. On oxidation it forms a stable nickel(II1) complex [Ni(TMPP- O),][BF,] with an octahedral NiO,P chr~mophore;~' the EPR spectrum shows clearly resolved 31Phyperfine coupling. 25 W.A. Herrmann and N. W. Huber Chem. Ber. 1994,123 821. '' A. I. Ibrahim Transition Met. Chem. 1994 19 561. 27 V. V. Tkachev E. A. Lavrent'eva 0.S. Roshchupkina I. P. Lavrent'ev and L. 0.Atomyan Koord. Khim. 1994 20 674. 28 L.Kh.Minacheva M.B. Ganeralova I.K. Kireeva V.G. Sakharova A.Yu. Tsivadze and M.A. Porai-Koshits Russ. J. Inorg. Chem. 1993 38 1553. 29 T. H. Tahirov T.-H. Lu C.C. Huang and C.S. Chung Acta Crystallogr. Sect. C 1994 50 668. 30 D. M.L. Goodgame S. Menzer A.M. Smith and D.J. Williams J. Chem. Soc. Chem. Commun. 1994 1825. 31 K. R. Dunbar J.-S. Sun and A. Quillevere Znory. Chem. 1994,33 3598. 222 S. A. Cotton Halide complexes. Charge-transfer and ligand-field transition energies have been determined for [FeCl,] -using the energy-of-motion coupled cluster (EOM-CC) approach., Density function calculations have been applied to optimizing geometries of [MCl4l2- ions (M = Cr-Ni Zn).33 [pyH],[Fe,Br,] contains two [FeBr,]- tetrahedra; it orders antiferromagnetically at 7.4K.34Chloroferrates with [M(en)3]3 + (M = Cr Co) as counter-ions have been studied as potential molecular ferromagnets; both [Cr (en)J [FeC1,ICl;H ,O and [Cr (en),] [FeCl4]Cl2-9H,O have been character- ized.,' N-donors.A highlight is the use of a triamido amine ligand to produce an iron(rv) cyanide complex (2).36The structures have been reported of the traditional N-bonded N nitro complexes LiCNMe,] ,[Co (NO ,)6] 'and K4[Ni (NO ,),I -H 0,both contain- ing MN coordination spheres; when the latter is dehydrated at 100"C KNO and K,[Ni(NO,),(O,N)] the latter with a chelating nitrite are formed (reversibly). Several papers report the properties of complexes of heterocyclic N-donors including the structures of [CoBr2(2-Brpy),] (tetrahedral),39" [C0C1,(3,5-Me,py),],~~~ [C0F,(3,5-Me,py),].nH,O,~~~ (all octahedral).Binuclear and [C0Br,(3-Mepy),]~~~ pyrazine complexes [{Co(H20),),(p-pyrazine)][S04],~2H,0 and [Co,(p-pyra-zine)(SO,),] ,have been examined4' whilst powder diffraction methods have been used to determine the structures of [NiX,(pyridazine)] (X = C1 Br) confirming long- assumed polymeric str~ctures;~~ the Mn Fe and Co analogues are isomorphous (3). As usual cobalt ammines continue to provide a rich vein for study. Powder methods have been applied4 to the classic linkage isomerism [Co(NH,),(NO,)] 32 N. Oliphant and R. J. Bartlett J. Am. Chem. Soc. 1994 116 4091. 33 K. Waizumi H. Masuda H. Einaga and N. Fukushima Bull. Chem. Soc. Jpn. 1993,66 3684. 34 C.B. Lowe A.J.Schultz R. Shaviv and R.L. Carlin Inorg. Chem. 1993 33 3051. 35 M.C. Moron F. Palacio J. Pons J. Casabo X. Solans K. E. Merabet D. Huang X. Shi B. K. Teo and R. L. Carlin Inorg. Chem. 1993 33 746. 36 C. C. Cummins and R. R. Schrock Inorg. Chem. 1994,33 395. 37 V. Adovasio F. Lina M. Nardelli and G. Pelizzi Acta Crystallogr. Sect. C. 1994 33 871. 38 I. E. Grey M. A. Hitchman G. L. Rowbottom N. V. Y. Scarlett and J. Wilson J. Chem.Soc.,Dalton Trans. 1994 595. 39 (a)L. Hiltunen L. Niinisto,G. Kenessey G. M. Keseru and G. Liptay Acta Chem.Scand. 1994,48,456;(b) J. Kansikas M. Leskela G. Kenessey P. E. Werner and G. Liptay Acta Chem.Scand. 1994,48,951; (c)G. Kenessey K. Lashgari G. Machula and G. Liptay Acta Chem. Scand. 1994,48,705; (d)G.Kenessey L. Parkanyi P. E. Werner G. M. Keseru T. Wadsten L. K. Bihatsi and G. Liptay Struct. Chem. 1994,5,123. 40 T. Fetzer R. Jooss A. Lentz and T. Debeardemaeker 2. Anorg. Ally. Chem. 1994 620 1750. 41 N. Masciocchi P. Cairati L. Carlucci G. Ciani G. Mezza and A. Sironi J. Chem.SOC.,Dalton Trans. 1994 3009. 42 N. Masciocchi A. Kolyshev V. Dulepov E. Boldyreva and A. Sironi Inorg. Chem. 1994 33 2579. Iron Cobalt and Nickel (Reproduced with permission from J. Chem. SOC.,Dalton Trans. 1994 3009.) Br t-)[Co(NH,),(ONO)]Br ; cobalt(m) pentaammine pyridone complexes also exhibit linkage isorneri~m."~ The structure of cis-[CoBr(NH,)(en),]Br has been reported." Monomeric violet [Fe(phen)(mes),] features tetrahedral coordination of iron(r1) with two a-bonded mesityls; it reacts with amino acids forming monomeric amino acid complexes like [Fe(phen)(prolinat~),].~~Thin films of poly-[Fe(vbipy),] [PF& (vbipy = 4-methyl-4'-vinyl-2,2'-bipyridyl) undergo vbipy displacement by [NEt,]CN in MeCN forming poly-[Fe(vbipy),(CN),].poly-vbipy ; this binds silver ions which can be reduced electro~hemically.~~ Crystalline ESR-silent [Fe(bipy),] has been obtained by electrocrystallization.47[Fe(phen),][ClO,] ,is nearly isomorphous with the cobalt and copper analogue^.,^ Structures are rep~rted~~?~' of salts of trans-[CoCl,(en),]+ and tran~-[CoCl(H,O)(en),]~+as well as three isomers of [Co(en)(eddp)] + (eddp = ethylenediamine-N,N'-dipropi~nate).~ [Co,(bpym) (H,O),][NO,] and [C0,(bpyrn)(H,O)~][SO,],-2H,ohave 2,2'-bipyrimidine- bridged dimeric cations whilst in [Co,(bpym),(NCS),] the bpym ligands are both bridging and terminal.52 [Ni(N-Meim),][I,] contains octahedrally coordinated nickel.53 [Ni(NCO),(bipy),] has cis geometry5 whilst several nickel(11) complexes of substituted phenanthrolines have been synthesized and studied electrochemically; 43 P.M. Angus and W.G. Jackson inorg. Chem. 1994 33 477. 44 I. Bernal J. Cetrullo and W.G. Jackson J. Coord. Chem. 1993 28 89. 45 C. P. Magill C. Floriani A. Chiesi-Villa and C. Rizzoli Inorg. Chem. 1994 33 1928. 46 M. Bakir S. G. Mackay R. W. Linton B. P. Sullivan and T.J. Meyer inorg. Chem. 1994 33 3945. 47 E. Perez-Cordero R. Buigas N. Brady L. Echegoyen C. Arana and J.-M. Lehn Helv. Chim. Acta 1994 77 1222.48 L. L. Koh Y. Xu A.K. Hsieh B. Song F. Wu and L. Ji Acta Crystallogr. Sect. C 1994 50 884. 49 M. Kita K. Kashiwabara J. Fujita H. Tanaka and S. Ohba Bull. Chem. Soc. Jpn. 1994 67 2457. V. Janickis and K. Mary Acta Chem. Scand. 1994 48 461; 465. N. Sakagami T. Yasui H. Kawaguchi T. Ama and S. Kaizaki Bull. Chem. Soc. Jpn. 1994 67 680. '' G. De Munno M. Julve F. Lloret J. Faus and A. Caneschi J. Chem. SOC. Dalton Trans. 1994 1175. 53 K.-F. Tebbe and S. Nafepour Acta Crystallogr. Sect. C 1994,50 1566. 54 M. K. Urtiaga J. L. Pizarro R. Cortes A. Goiii and J. I. R. Larramendi Acta Crystallogr. Sect. C 1994,50 56. 224 S. A. Cotton [NiC1,{2,9-di(2-methoxyphenyl)-l,l0-phen}] is approximately tetrahedral.55 Most [Ni(diamine),][X] (diamine = en pn etc.) complexes lose one mol of amine on heating forming truns-[NiX,(diamine),] rather than the cis isomer.56 The structure of [Ni(en),][Ni(CN),] has been reported57 and the polarized d-d spectra of [Ni(en),] [NO,] assigned.58 Age cannot wither nor custom stale the infinite variety of thermochromic nickel(i1) diamine complexes; [NiL2][NO,],-2H,O (L = N'-iso-propyl-2-methylpropyl- 1,2-diamine) loses water at 140 "C then undergoes a reversible yellow (square planarkgreen (octahedral) thermochromism at 1780C.59A highlight is the isolation of both isomers offuc- and mer-[Ni(dien),][NCS], the syrn-fac isomer being the more stable at room temperature; both were crystallographically character- ized.,' Several publications have again explored azide-bridged complexes.In general end-to-end azide bridges lead to antiferromagnetic coupling whilst end-on coordina- tion leads to ferromagnetic coupling. [Ni(N3),(2,2-dimethy1propane-l,3-diamine)] is an infinite two-dimensional antiferromagnetic polymer with a weak 3D ferromagnetic interaction.61 [(Ni2(dpt)2(p-o~)(p-N3)}],, [dpt = bis-(3-aminopropyl)amine]has an alternating chain6 with local spin S = 1 whilst [{Ni,(trenpy),(p-N3)}][C10,] [trenpy = N,N-bis(2-aminoethyl)-N'-(2-pyridylmethyl)ethane-l,2-diamine] exhibits antiferromagnetic coupling.63 [cis-(p-N,){Ni(bipy),)],X (X = CIO, PF,) have two cis end-to-end bridging azides., Several complexes with end-on bridges such as [{Ni(en),},(p-N,),][ClO,] and [{Ni(en)(p-N3),}] have been reported.65 [{ Ni(dmpd)(p-N,),)] (dmpd = 2,2-dimethylpropane- 173-diamine) has alternating end-on and end-to-end bridges,66 exhibiting antiferromagnetic behaviour.Studies of thiocyanato-bridged complexes are now beginning. The nickel(I1) chain complex { [Ni(p-NCs)(en),][PF,]} has cis-bridging thiocyanate~,~ whilst [{NIL@- NCS)(SCN)},] [L = bis(3-aminopropyl)-methylamine] has a one-dimensional structure with single thiocyanate bridges.,* [(Ni2( l72-diamino-2-rnethyl- propane) (NCS),} (p-NCS),] ,[Ni( 1,2-diamino-2-methy1propane),(NCS),]~H20 has an interesting structure with both di- and mononuclear species present in the same crystal.69 Several cobalt complexes [CoX(N-N)(terpy)]X (N-N = bipy phen or substituted phenanthroline; X = weak ligand or counteranion) have been ~ynthesized;~' 55 M.A. Masood D. J. Hodgson and P. S. Zacharias Inorg. Chim. Acta 1994 221 99. 56 Y. Ihara and M. Toda Thermochim. Acta 1994 237 167. 57 J. Cernak I. Potocnak and M. Dunaj-Jurco Z. Krist. 1994 209 757. 58 A.J. Bridgeman K. M. Jupp and M. Gerloch Inorg. Chem. 1994 33 5424. 5y C. Pariya A. Ghosh and N. R. Chaudhuri J. Chem. Res. (S) 1994 428. 6o A. K. Mukherjee S. Koner A. Ghosh N. R. Chaudhuri M. Mukherjee and A. J. Welch J. Chem. Soc. Dalton Trans 1994 2367. J. Ribas M. Monfort X. Solans and M. Drillon Inorg. Chem. 1994 33 742. " A. Escuer R. Vicente X. Solans and M. Font-Bardia Inorg. Chem. 1994 33 6007. 63 G. A. McLachlan G. D. Fallon R. L. Martin B. Moubaraki K. S. Murray and L. Spiccia Inorg. Chem. 1994,33,4663. 64 R. Cortes K. Uritaga L.Lezama J. L. Pizarro A. Goiii M. I. Arriortua and T. Rojo Inorg. Chem. 1994 33 4009. 65 J. Ribas M. Monfort C. Diaz C. Bastos and X. Solans Inorg. Chem. 1994 33 484. 66 J. Ribas M. Monfort B.K. Ghosh and X. Solans Angew. Chem. Int. Ed. Engl. 1994 33 2087. '' M. Monfort C. Bastos C. Diaz J. Ribas and X. Solans Inorg. Chim. Acta 1994 218 185. R. Vicente A. Escuer J. Ribas and X. Solans J. Chem. Soc. Dalton Trans. 1994 259 69 M. Monfort J. Ribas and X. Solans Inorg. Chem. 1994 33 4271. 70 D. Ramprasad A. G. Gilicinski T. J. Markley and G. P. Pez Inory. Chem. 1994 33 2841. Iron Cobalt and Nickel [Co (terpy)(3,4,7,8- tetramethylphen)(O SCF )] [CF SO3] has coordinated triflate. In polar organic solvents some of these complexes react irreversibly with dioxygen forming 2 1 Co :0 complexes which have p-peroxo bridges e.g.[(C0(terpy)(bipy)},(p-O,)][PF,]~~2Me,~~. In less polar solvents the triflates in particular are reversible dioxygen carriers. Interest continues in cobalt(I1) and (111) complexes of encapsulating ligand~.~' Most of these involve N coordination of the metal but several with N4S2 donors have been reported.72 The structure of one cobalt(I1) complex shows irregularity in the Co-S distances (2.288 and 2.495 A) whilst another cobalt(1r) complex has the unusual in-solution magnetic moment of 2.88 pB.Self-exchange rates have been calculated for many of the cobalt (II)/(III) couples. 3 Complexes of Tertiary Phosphines Photolysis of cis-[FeH,(dmpe),] in the presence of thiophenes gives products (4) formed by insertion into both C-H and C-S bonds.73 [Fe(N,)(depe),] reacts with CO to form trigonal bipyramidal [Fe(q2-C02)(depe),]; this reacts with MeX (X = I CF,SO,) to generate [FeX(CO)(depe),] and Me,0.74 Some more dihydrogen H R=H,Me R (4) (Reproduced with permission from J.Chem. SOC.,Chem. Commun. 1994 557.) + complexes [Fe(H,)HL,] [L = P(C,H4R-4),CH2CH2P(C6H4R-4),; R = CF, CH,] have been ~ynthesized~~ as well as the corresponding dihydrides [Fe(H),L,]. Mossbauer spectra have been reported for a number of hydrides [FeHL(L-L),]' (L = H, CO N, Cl CN RCN NH, etc.; L-L = dppe depe etc.);it is concluded that n-bonding in the dihydrogen complexes is more significant than in CO or N complexes.76 Another addition to the select ranks of compounds with Fe"'-I bonds is provided by [FeI,{o-C,H4(QMe,),)][BF4] (Q = P As); EXAFS data indicate that in '' G.A.Bottomley I. J. Clark I. 1. Creaser L. M. Engelhardt R. J. Geue K. S. Hagen J. M. Harrowfield G. A. Lawrance P. A. Lay A. M. Sargeson A. J. See B. W. Skelton A. H. White and F. R. Wilner Aust. J. Chem. 1994,47,143; R. J. Geue P. Osvath A.M. Sargeson K. R. Acharya S. B. Noor T. N. G. Row and K. Venkatesan Aust. J. Chem. 1994,47,511; I. I. Creaser T. Komiya A. M. Sargeson A. C. Willis and K. Yamanari Aust. J. Chem. 1994,47 529; P. V. Bernhardt A.M. T. Bygott R. J. Geue A. J. Hendry B. R. Korybut-Daszkiewicz P. A. Lay J. R. Pladziewicz A. M. Sargeson and A. C. Willis Inorg. Chem. 1994,33 4553. -'T. M. Donlevy L. R. Gahan and T. W.Hambley Inorg. Chem. 1994 33 2668. '3 I. E. Buys L. D. Field T. W. Hambley and A. E. D. McQueen J. Chem. SOC.,Chem. Commun. 1994 557. '4 S. Komiya M. Akita N. Kasuga M. Hirano and A. Fukuoka J. Chem. SOC.,Ckem. Commun. 1994,1115. '5 E. P. Cappellani S. D. Drouin G. Jia P. A. Maltby R. H. Morris and C. T. Schweitzer J.Am. Chem. SOC. 1994 116 3375. l6 R.H. Morris and M. Schlaf Znorg. Chem. 1994 33 1725. 226 S. A. Cotton comparison with the iron@) analogues the bonds between Fe and P or As are longer but the more ionic Fe-I bonds are shorter.77 The complexes [Co (S,O-S,S’)(dmpe),] [ClO,] and [Co (S,PMe,)(dmpe),] [BF,] have been obtained from the reaction of [Co(dmpe),][BF,] with elemental sulfur in methan~l-benzene.~~ Possibly the most interesting complex in this section results from the latest chapter in the reactions between metals and R,QX (Q = pnictogen X = halogen).[CoI,(SbPh,),] synthesized from coarse Co powder and SbPh,I, is an addition to both the select ranks of non-octahedral cobalt(m) complexes and paramagnetic cobalt(m) corn pound^.^^ It has a trigonal bipyramidal structure (equatorial iodides) and an unusual magnetic moment (4.4pB). Additions to the band of structurally characterized cobalt(m) phosphine complexes are49 trans-[CoC1,(dmpe),][C1O4] trans-(C1,Cl)-cis-(P,P)-[CoC12(NH,CH,CH2PMe,),] [PF,] fac-[CoCl,(mmtp)] and fac-[Co(CN),(mmtp)]-2H20 [mmtp = l,l,l-tris(dimethylphosphinomethyl)ethane].80 New cobalt phosphide complexes includ- ing the fluxional [CO(P(CH,CH,PM~,),}{[P(CH,CH,PM~~)~]~}] (5) have been made.(Reproduced with permission from J. Chem. Soc. Dalton Trans. 1994 971.) An important benchmark structure to be reported is that of distorted tetrahedral [Ni(PEt3)4].82 [NiCl,{PR,(CH,),PR,}] (n = 2 3) react with NaOR (R = Me Et Pri) forming [Ni{ PR2(CH,),PR,},]83 under a N atmosphere and [Ni(CO),(PR,(CH,),PR,}] when the synthesis is carried out under CO; the reaction proceeds via alkoxides such as [Ni(OMe){ PR,(CH,),PR,},]. Complexes [Ni(L- L),I2+ and [NiX(L-L),]’ [L-L = C,H,(PPh,), etc.] undergo two successive one- electron reductions; the EPR parameters of the nickel(1) species [Ni(PPh,R),] are + very sensitive to the nature of R.84 [(Ni(O2CCPhMe,),(PPh3)),1has a lantern-type dimeric structure (Ni-Ni = 2.759 A).85 77 N.R. Champness W. Levason R.D. Oldroyd and S. R. Preece Inorg. Chem. 1994 33 2060. 78 M. Kita K. Kashiwabara J. Fujita S. Kurachi and S. Ohba Bull. Chem. SOC.Jpn. 1993 66,3686. ’’ S. M. Godfrey C. A. McAuliffe and R.G. Pritchard J. Chem. SOC. Commun. 1994 45. 8o K. Kashiwabara M. Kita J. Fujita S. Karachi and S. Ohba Bull. Chem. SOC. Jpn. 1994 67 2145. P. G. Edwards P. W. Read M. B. Hursthouse and K. M. A. Malik J. Chem. Soc.,Dalton Trans. 1994,971. 82 M.B. Hursthouse K.J. Izod M. Motevalli and P. Thornton Polyhedron 1994 13 151. 83 A. Sacco and P. Mastrorilli J. Chem. SOC.,Dalton Trans. 1994 2761. 84 G.A. Bowmaker and J.P. Williams J. Chem. Soc. Dalton Trans. 1994 1231. ’* S. Husebye M. Kato K. Maartmann-Moe Y. Muto M. Nakashima and T. Tokii Acta Chem.Scand. 1994,48 628. iron Cobalt and Nickel 227 4 Complexes with S Se and Te Donors The new two-coordinate high-spin iron@) compounds [Fe{N(SiMe,),)(SR)] and [Fe(SR),] (R = C6H,Me,-2,6) have been synthesized; they involve bent S-Fe-N (118.9") and S-Fe-S (120.2") linkages respectively and weak Fe-aryl ring n-interaction.86 Four coordinate iron(x1) selenolatoiron(I1) complexes [Fe(SeR),(PRj),] [R = C6H,Pr\-2,6; (PR;) = (PMe,Ph) or depe] have been synthesized and crystallographically ~haracterized.~ [Fe([9]aneS3),] [Sb,Cl,] has six-coordinate iron(xx).88 Isotopic labelling has enabled assignment" of the Resonance Raman spectra of iron(m) tetrathiolates such as [Fe(SR),]-(R = Me Et) and [Fe(S,-o-xylyl),] -. High-spin [FeCI3([9]S3)] involves distorted octahedral coordina- tion of iron(~rr)." In the area of spin-equilibrium compounds a possible assignment" of triplet signals in the EPR spectra of [Fe(S,CNR,),] to a limiting resonance form involving iron(n) and an unpaired electron on a radical ligand has been disproved and instead assigned to a [Fe(NO)(S,CNR,),] impurity,92 whilst unequivocal assignments of EPR signals from high and low-spin isomers of [Fe{ PhC(S)CHC(O)Ph),] have been made.92a Bis(isopropylxanthato)nickel [Ni(S,COCHMe,),] is near-~lanar;~ [PPh,] [Ni(SC6H,Cl),] has tetrahedrally coordinated A toroidal thiolate [Ni,(SCH,CH,CH,S),] has been ~haracterized~~ whilst [{Ni(SCH,C6H,C1-p),}6] has a hexagonal prismatic of nickel atoms.96 5 Complexes with Porphyrins and Other Macrocycles More general aspects of this work are dealt with in Chapter 20.This section begins with porphyrins and related species before proceeding with other macrocycles. Interest continues in iron@) species. Reaction of a tetraethylcorrole ligand with [Fe,(CO),] affords97 [Fe"'(octaethylcorrole)] (isolable as the square pyramidal adduct [Fe1"(py)(octaethylcorrole)]); aerial oxidation gives the 0x0-bridged tet- ravalent iron(1v) compound [(p-0){Fe'v(octaethylcorrole)),l. This can be converted into [Fe'VCl(octaethylcorrole)]and [Fe~vPh(octaethylcorrole)].[NO complexes of Fe(octaethylcorro1e) are described in Section 7 (page 23 11.Several oxoiron(rv) species have been described; oxo(tetramesitylporphyrin)iron(Iv) is stable at room temperature in solvents such as benzene.98 Rate constants for the oxidation of styrene by six oxoiron(1v) porphyrin cation radicals show an axial ligand effect on rea~tivity.~~ 86 J.J. Ellison K. Ruhlandt-Senge and P. P. Power Angew. Chem. Int. Ed. Engl. 1994 33 1178. '' C.E. Forde R. H. Morris and R. Ramachandran Inorg. Chem. 1994 33 5647. 88 G. R. Willey J. Palin M.T. Lakin and N. W. Alcock Transition Met. Chem. 1994 19 187. 89 R. S. Czernuszewicz L.K. Kilpatrick S.A. Koch and T.G. Spiro J. Am. Chem. Soc. 1994 116 7134. 90 J. Ballester 0.J. Parker and G. L. Breneman Acta Crystallogr. Sect. C 1994 50 712. 91 S.Yarish N. V. Duffy E. Gelerinter W. Dietzsch,N. Law and R. Kirmse Inorg. Chim. Acta 1994,217,101. 92 (a) S. A. Cotton Potyhedron 1994 13 2579; (b) R. Kirmse S. Saluschke E.Moller E. J. Reijerse E. Gelerinter and N. V. Duffy Angew. Chem. Int. Ed. Engl. 1994 33 1497. 93 Z. Travnicek R. Pastorek and J. Marek Coll. Czech. Chem. Commun. 1994 59 616. 94 M. Kockerling and G. Henkel Z. Krist. 1994 209 186. 95 J. Sletten and J.A. Kovacs Acta Chem. Scand. 1994 48 929. 96 J. Cai and B. Kang Jiegou Huaxue 1993 12 397. (Chern. Abstr. 1994 121 25 463). 97 E. Vogel S. Will A. S. Tilling L. Neumann J. Lex E. Bill A. X. Trautwein and K. Wieghardt Angew. Chem. Int. Ed Engl. 1994 33 731. 98 J.T. Groves Z. Gross and M. K. Stern Inorg. Chem. 1994 33 5065. 99 Z. Gross and S. Nimri Inorg. Chem. 1994 33 1731. 228 S. A. Cotton The oxidation of metal porphyrinogens of Fe Co and Ni leading to oxidation of the ligand skeleton is being examined.'" The absorption and MCD spectra of a number of iron@) phthalocyanine derivatives [FeL,(pc)] (L = NH, im 1-Meim py Mepy CO CN- etc.) have been analysed."' Some iron and cobalt 'picnic basket' porphyrins reversibly bind dioxygen at room temperature.'02 Studies of dioxygen binding show that the oxygen affinity increases as the basket size decreases indicating that a dipole-dipole interaction between the 0 and an amide group may stabilize the dioxygen adduct.Several structures of simple macrocyclic complexes have appeared this year. The structure of the first model phosphito ferrous porphyrin [Fe{ P(OMe),},(aPyG- tetra(4-methoxyphenyI)porphyrin}] has been determined.'03 Isolated monomeric + [Fe(tpp)] cations are found in [Fe(tpp)][Ag(Br,CB 1H6)2]104a whilst in [Fe(H,O)(tpp)][ClO,] the cations are associated into dimeric units with a n-n intera~tion;"~~ spectroscopic data are consistent with an admixed intermediate spin state (S = 3/2 5/2).In [Fe(4-CNpy),(tpp)][C104] the two pyridines have relative perpendicular alignments; spectroscopic data are interpretedio5 in terms of the unusual ground state (dxz,dyz)4(dxy)'. The structures of the square-pyramidal alkyl [FeMe(tap)] (tap = tetra-p-anisylporphyrin) and acyl [Fe(COBu")(tap)] have been determined; reaction of a number of acyls with dioxygen gives [Fe(OCOR)(por- phyrin)] and [{Fe(porphyrin)),(p-0)] rather than any Fe02 ('ferryl') species.lo6 The structures of the high-spin five-coordinate [Fe(N,)(tpp)] and of the low-spin six-coordinate [Fe(N,)L(tpp)] (L = 1-Meim 1,2-Me2im) have been determined.'07 Crystalline [Fe(O,SCF,)(tpp)] provides the first example of solid state spin equili- brium for a five-coordinate iron(rr1) porphyrin with two distinct lattice sites.'08 The [FeCl(tpp)]/NaBH system catalyses the reduction of nitrobenzene to anilinelog whilst iron(II1) P-polynitroporphyrins catalyse the oxygenation of alkenes and hydroxylation of alkanes by O,.' lo Halogenation of iron(II1) porphyrins causes considerable saddling of the macrocyclic ring and a large positive shift in the iron(m)/iron(II) redox potential. It is suggested that the ability of octabromotet- rakis(pentafluorophenyl)porphyriniron(IIr)chloride to catalyse the hydroxylation of light alkanes by 0 under mild conditions occurs through a radical-chain reaction rather than involving iron(1v) 0x0 species." ' Spin densities in low-spin iron(II1) porphyrins have been mapped' l2 using COSY and NOESY techniques.The loo S. De Angelis E. Solari C. Floriani A. Chiesi-Villa and C. Rizzoli J. Am. Chem. Soc. 1994 116 5691; 5702. E.A. Ough and M.J. Stillman Inorg. Chem. 1994 33 573. lo' J. P. Collman X. Zhang K. Wong and J.I. Brauman J. Am. Chem. SOC.,1994 116 6245. lo3 L. Toupet N. Legrand A. Bondon and G. Sirnrnoneaux Acta Crystallogr. Sect. C 1994 50 1014. (a) Z. Xie R. Bau and C. A. Reed Angew. Chem. Int. Ed. Engl. 1994,33,2433;(b) B. Cheng M. K. Safo R. D. Orosz C. A. Reed P. G. Debrunner and W. R. Scheidt Inorg. Chem. 1994 33 1319. lo' M.K. Safo F.A.Walker A.M. Raitsimiring W. P. Walters D. P. Dolata P.G. Debrunner and W. R. Scheidt J. Am. Chem. Soc. 1994 116 7761. A. L. Balch M. M. Olmstaed N. Safari and T.N. St. Claire Inorg. Chem. 1994 33 2815. lo' Y. Zhang W. A. Hallows W. J. Ryan J. G. Jones G. B. Carpenter and D. A. Sweigart Inorg. Chem. 1994 33 3306. lo' J. A. Gonzalez and L. J. Wilson Inorg. Chem. 1994 33 1543. S. Sakaki T. Kimura T. Ogata H. Hasuo and T. Arai New. J. Chem. 1994 18 231. "'J. F. Bartoli P. Battioni W.R. De Foor and D. Mansuy J. Chem. Soc. Chem. Commun. 1994 23. M. W. Grinstaff M.G. Hill J. A. Labinger and H. B. Gray Science 1994 264 1311. H. Tan U. Sirnonisa N. V. Shakhirev and F. A. Walker J. Am. Chem. Soc. 1994 116 5784. Iron Cobalt and Nickel electrochemistry of the porphycenes [FeX(etiopc)] has been studied' ' (etiopc = 2,7,12,17-tetraethyl-3,6,13,16-tetramethylporphycene;X = C1 Ph); they undergo one-electron reduction at the ring rather than the metal.p-0x0 porphycene complexes [Fe,(p-O)(porphycene),l undergo four reversible oxidations and four reversible reductions yielding [Fe,(p-O)(porphycene),l" (n = -4 to +4);again the first two reductions occur at the ring rather than the metal." EXAFS studies on [CoCl(pc)] and [CoCl(py)(pc)] yield Co-N and Cox1 bond lengths.' l5 [Co(oep)] is isomorphous with [Fe(oep)] [Cu(oep)] and one form of [Ni(oep)]; it has a planar porphyrin core in contrast with the ruffled [M(tpp)] systems. The order of M-N bond lengths is Fe > Co > Ni < CU,"~ reflecting trends in the ionic radii of the metals (Table 1).Table 1 M-N bond lengths in isomorphous series of[M(oep)] and [M(tpp)] (A) Fe co Ni cu [M(oep)l 1.996 1.971 1.952 1.998 CM(tPP)l 1.972 1.949 1.928 1.981 The structures of the cobalt@) species [Co(N',N'-dimethylaminopy)(oep)] the cobalt(1Ir) compounds [CoMe(oep)] and [CoMe(py)(oep)],' ' and of a nickel@) porphrazine octamine have been described.' '' The synthesis and structure of fac-[FeCl,( 1,3,5-trirnethyltriazacyclohexane)]have been described. The sterically encumbered ligands N,N',N"-triisopropyl- 1,4,7- triazacyclononane and N,N',Nf'-triisobutyl-1,4,7-triazacyclononane do not complex with FeCl.6H,0.1 2o On the other hand 1,4,7-tris(pyrazol-3-ylmethyl)-1,4,7-triazacyclononane L forms [FeL][ClO,] and [NiL)[C10,],~O.5H2O the latter having a NiN chromophore.' 21 The base hydrolysis of (tacn)(3-thiapentane-1,5-diarnine)cobalt(111) has been studied and the structure of Na[ (tacn)Co(p-OH),Co(tacn)]C12[C10,],~2H,0 determined.' 22 Among complexes of tetradentate macrocycles an interesting report concerns 0 adducts of lacunar cobalt(I1) cyclidene macrocycles (6); the affinity for dioxygen is controlled by both steric and electronic factors.The structure of [Co(O,)(l-Meim)(MeMeC6[16]cy~lidene)][PF~]~shows a Co-0-0 angle of 121'. EPR spectroscopic parameters and redox potentials are affected by ligand changes.' 23 The K. M. Kadish F. D'Souza E. Van Caemelbecke P. Boulas E. Vogel M. A. Aukauloo and R. Guilard Znorg. Chem. 1994 116,4475. K. M. Kadish P. Boulas F.D'Souza M. A. Aukauloo R. Guilard M. Lausmann and E. Vogel Inorg. Chem. 1994 116,471. 'I5 M. Endregard D.G. Nicholson R. J. Abraham I. Marsden and B. Beagley Actu Chem. Scund. 1994,48 5640. W. R. Scheidt and I. Turowska-Tyrk Znorg. Chem. 1994 33 1314. J.S. Summers J.L. Petersen and A.M. Stolzenberg J. Am. Chem. Soc. 1994 116 7189. 'I8 N. S. Mani L. S. Beall T. Miller 0.P. Anderson H. Hope S. R. Parkin D. J. Williams A. G. M. Barrett and B. M. Hoffman J. Chem. SOC. Chem. Commun. 1994 2095. 119 R.D. K"ohn and G. Kociok-Kohn Angew. Chem. Znt. Ed. Engl. 1994 33 1877. J. L. Sessler J. W. Sibert and V. Lynch Znorg. Chim. Actu 1994 216 89. M. Di Vaira F. Mani and P. Stoppioni J. Chem. SOC.,Dalton Trans. 1994 3739. E. Larsen S. Larsen G. B. Paulsen J.Springborg and D.-N. Wang Acta Chem. Scund. 1994,48 107. lZ3 D. H. Busch P. J. Jackson M. Kojima P. Chmielewski N. Matsumoto J. C. Stevens W. Wu D. Nosco N. Herron N. Ye P.R. Warburton M. Masarawa N. A. Stephenson G. Christoph and N. W. Alcock Znorg. Chem. 1994 33 910. 230 s. A. Cotton Co-N bonds of cis-[CoC1,(C-rac-5,12-dimethyl-l,4,8,1l-tetraazacyclotetradecane)] c1124a are rather longer than those in a complex of a non-macrocycle trans-[CoC1,(2,5,9,12-tetraazatridecane)][C104].'24b A third trans isomer of [CoCl,(meso- 5,12-dimethyl-l,4,8,11-tetraazacyclotetradecane)][ClO4] has been characterized and its aquation kinetics studied.'25 + Adducts of the classic macrocycle complex [Ni(taab)I2 (taab = tetrabenzo[b,f,j,n] [1,5,9,13]tetraazacyclohexadecine) with py im dmf and bipy have been prepared and the structure of [Ni(py),(taab)][BF,] determined.', Several nickel(1) and (11) complexes of N macrocycles have been examined structurally .I2 Comparison of [Ni"(htim)][ClO,] with [Ni'(htim)][ClO,] (htim = 2,3,9,10-tetramethyl-1,4,8,11-tetraazacyclotetradecane) indicates a lengthening of the Ni-N bonds from 1.948-1.969 8 in the Ni(I1) complex to 2.053-2.083 A in the Ni(1) analogue attributed to the placing of an extra electron in the dx2-y2orbital and reduction of ligand-field strength.Nickel(1) and (11) complexes of an octaaza macrohexacyclic ligand (N donor) have been prepared and the structure of the nickel(I1) complex determined.'28 A nickel complex of a N macrocycle with a pendant OH group (with a water molecule completing the six-coordination) has been synthesized.' 29 The structure of the nickel(II1) complex [Ni(N0,),(cyc1am)][C10,] features monodentate nitrate^;'^' the Ni-N bond length (1.973 8,) is some 0.11 8 shorter than in nickel@) analogues.Complexes have been reported with the thioethers [12]aneS4 [14]aneS4 and [16]aneS, including [Ni,Cl,L,][BFJ,. The cations contain two six-coordinate nickel atoms each cis-bound to a macrocycle and linked to the other by chloride bridge^.'^' The smaller ligand [9]aneS3 forms the triply bridged dimeric cation + [LNi(pCl),NiLl3 . The mixed thioaza hexadentate crown [18]aneN,S affords octahedral [Ni( [1 8]aneN2S,)] [PF,] ,and [Co( [1 8]aneN2S,)] [PF,] ,.' 124 (a)T. H. Tahirov T.-H. Lu B.-H. Chen T.-Y.Chi and C.-S. Chung Acta Crystallogr. Sect. C 1994,50 1686; (6) T.-H. Lu C.-Y. Lai and (2.3.Chung Acta Crystallogr. Sect. C. 1994 50 202. 12' B.-H. Chen C.-Y. Lai Y. Yuan and C.4. Chung J. Chem. SOC.,Dalton Trans. 1994 2959. 126 M. Li Z. Xu J. Li X. You H. Wang Y. Yang Y. Yu and D. Zhu Gaodeng Xuexiao Huaxue Xuebao 1993 14 745 (Chem. Abstr. 1994 120 123 323). 12' D.J. Szalda E. Fujita R. Sanzenbacher H. Paulus and H. Elias Inorg. Chem. 1994 33 5855. 128 M.P. Suh I.S. Kim S.-J. Cho and W. Shin J. Chem. SOC. Dalton Trans. 1994 2765. N. F. Curtis A.R. Davis and F. W. B. Einstein Aust. J. Chem. 1994 47 1885. I3O A. McAuley T. Palmer and T. W. Whitcombe Can. J. Chem. 1993 71 1792. 13' A. J. Blake M. A. Halcrow and M. Schroder J. Chem. SOC.,Dalton Trans.1994 1463. Iron Cobalt and Nickel 23 1 6 Schiff Base and Related Complexes The two-step spin-equilibrium compound [Fe{ 5-NO2-sal-N(1,4,7,10)}] is discussed in Section 11 (p. 236). Five-coordinate N-donor Lewis base adducts of cobalt (11) Schiff base complexes having a distorted trigonal bipyramidal CoS,N environment exhibit spin equilib- ria.', The reactivity of cobalt(r1) Schiff base complexes towards 0 and NO has been examined. 34 Both [Co (nbsal),] and [Co (t bsal ),I (n bsal = N -n- bu tylsalicylidineimi- nate; tbsal = N-t-butylsalicyclidineiminate) have distorted tetrahedral structures; the distortion is much greater in the t-butyl compound. The n-butyl compound reacts with 0 and NO; the t-butyl compound reacts with neither. Five-coordinate cobalt Schiff base complexes act as 0 activating sites in whilst other five-coordinate complexes (involving N,-donors not Schiff bases) reversibly absorb dioxygen and have been proposed as separators to remove 0 from gaseous mixtures.'36 Cobalt(i1) Schiff base complexes have been shown to catalyse the oxidation of secondary alcohols to ketones in the presence of dioxygen and 2-methylpropanal' 37 whilst [Co(salen)] has been used in the electrochemical reduction of benzyl chloride.' 38 The structure of an octahedral cobalt(m) Schiff base complex has been reported.' 39 A study of nickel(I1) Schiff base complexes has included electrochemical oxidation and reduction to EPR-active nickel(1) and (111) complexe~;'~~ this and another study report a number of structures.I4' Donor-acceptor bis(salicylaldiminato)nickel(II) complexes show sizeable nonlinear optical responses'42 whilst paramagnetic liquid- crystal nickel(I1) compounds have also been re~0rted.l~~ 7 Nitrosyl Complexes An iron@) thiolate [Fe{HSCH2CH(SH)CH,SO3),] removes NO from flue gas as [Fe{HSCH,CH(SH)CH,SO,),(NO)x] (x = 1 2); the NO can be reduced elec- trochemically to ammonia.'44 [{ Fe(p-Cl)(NO),},]activates dioxygen in the presence of bidentate phosphines (PP) such as dppe thus yielding nitrato complexes [Fe(NO,),Cl(OPPO)]; when [Fe2(p-Cl),(p-PP)(NO)4] reacts with O, the product is ionic [Fe(N0,),(OPPO)2][FeC14].'45Both products transfer oxygen to phosphines and catalyse the oxidation of cyclohexene.The reaction of [Fe(dppe)(NO),] with [N,C6H,F-p][PF6] results in insertion of the arenediazo group into one Fe-P bond giving [Fe{Ph,PCH,CH,P(Ph),NN(C6H4F-p)}(N0),][PF6],which contains a 13' A.J. Blake G. Reid and M. Schroder J. Chem. Soc. Dalton Trans. 1994 3291. 133 A. L. Nivorozhkin H. Toftlund and M. Nielsen J. Chem. SOC.,Dalton Trans. 1994 361. 134 H. Bahron L. F. Larkworthy A. Marecaux D. C. Povey and G. W. Smith J. Chem. Cryst. 1994,24,145. 135 D.E. De Vos T. Thibault-Staerzyk and P.A. Jacobs Angew. Chem. Int. Ed. Engl. 1994 33 431. 136 Eur. Put. Appl. EP 583748 (Chem. Abstr. 1994 120 337785. 13' S. J. S. Kalra T. Punniyamurthy and J. Iqbal Tetrahedron Lett. 1994 35 4847. 13' A.J. Fry and A.H. Singh J. Ory. Chem. 1994 59 8172. 139 Y. Elerman M. Kabak I. Svoboda and M. Geselle Actu Crystallogr.Sect. C 1994 50 1694. F. Azevedo M. A.A. F. de C. T. Carrondo B. de Castro M. Convery D. Domingues C. Freire M. T. Duarte K. Nielsen and I. C. Santos Inorg. Chim. Acta. 1994 219 43. 14' G. Reck B. Schulz A. Zschunke 0.Tietze and J. Haferkorn Z. Krist. 1994 209 969. 14' S. diBella I. Fragala I. Ledoux M. A. Diaz-Garcia P. G. Lacroix and T.J. Marks Chem. Mater. 1994,6 881. 143 K. Griesar Y. Galyametdinov M. Athanassopoulou 1. Ovchinnikov and W. Haase Advanced Muter. 1994 6,381. 144 E.K. Pham and S.-G. Chang Nature (London) 1994 369 139. 145 V. Munyeajbo P. Guillaume and M. Postel Inorg. Chim. Actu 1994 221 133. 232 S. A. Cotton chelating ligand binding iron through P and an q2-N=N group.'46 EPR signals due to [Fe(NO)(S,CNR,),] in samples of [Fe(S,CNR,),] have been assigned,' and [Fe(NO)(S,COEt),] has been identified in [Fe(S,COEt),].92u Two interesting studies concern macrocyclic complexes of iron.EXAFS has been employed to probe the Fe-N-0 angle in complexes of known structure such as [Fe(salen)(NO)] then used to assign an angle of 156( f5)" in [Fe(NO)(edta)]. 147 The series [Fe(octaethylcorrole)(NO)]fl+ (n = -2 -1 0 + 1 or +2) has been inves- tigated and the structures of [Fe(octaethy1corro1e)(N0)]"+ (n = 0 1)determined;14* the EPR spectrum of [Fe(octaethylcorrole)(NO)] indicates that it is best formulated + as an iron(m) tetrapyrrole n-cation radical rather than an iron(1v) nitrosyl. 8 Iron Binding Agents Nature uses these binding agents to solubilize iron(m) at physiological pH; various iron-binding ligands that enhance iron(II1) availability (e.g.nta edtaj considerably improve degradation rates of aromatic hydrocarbons in low-oxygen aquifer sedi- ment~.~~'~ Chelators are being developed to control iron levels in the body.'49b Tripodal ligands having six convergent hydroxyl groups have been synthesized. They have complexing abilities towards iron(m j comparable to hydroxamate siderophores but lower than those of catecholate sider~phores.'~' 9 Polynuclear Iron Complexes with 0x0 Hydroxo and Related Bridges These represent an area of continued growth. Most compounds reported are iron(II1) complexes but the first crystallographically confirmed neutral p-0x0 iron@) complex has been made."' Reaction of FeC1 with NHR,/CO gives oligomeric [{Fe(O,CHR,),},]; the ethyl compound is hexameric [Fe,(O,CHR,),,].Controlled hydrolysis (R = Pr') gives [Fe4(p4-O)(02CHPri,),] (7). A different type of iron(I1) complex' 52 is binuclear [Fe,(salmp),l2 -[salmp = bis(salicylidenamino)-2-methyl-phenolate(3-)] (8). Mechanistic studies of the reaction of dioxygen with binuclear iron(n) complexes indicate a second order rate law; a mechanism involving a p-peroxo complex in the first step has been suggested (9).153 Two dinuclear iron(m) citrate complexes containing [Fe,(~it),(H,0),]~ -and [Fe2(Hcit),I3-ions have been characterized. The former has an Fe,O bridge in which the two oxygens are supplied by bridging citrates; the latter has three bridging citrates. In each case the iron has octahedral c~ordination.'~~ The p-0x0 diiron(II1) complex [Fe,O(H,O),(bipy),] 146 F.L. Atkinson N.G. Connelly J. G. Crossley and A. G. Orpen J. Chem. Soc.,Dalton Trans. 1994,1161. 14' T. E. Westre A. Di Cicco A. Filipponi C. R. Natoli B. Hedman E. I. Solomon and K. 0.Hodgson J. Am. Chem. Soc. 1994 116 6757. 148 M. Autret S. Will E. Van Caemelbecke J. Lex J.-P. Gisselbrecht M. Gross E. Vogel and K. M. Kadish 1.Am. Chem. Soc. 1994 116,9141. 149 (a)D. R. Lovley J. C. Woodward and F. H. Chapelle Nature (London) 1994,370,128; (b)S. Singh Chem. Ind. June 20 1994 452. 15* P. Baret C. Beguin D. Gaude G. Gellon C. Mourral J.L. Pierre G. Serratrice and A. Favier Tetrahedron 1994 50 2077. 151 D. B. Dell'Amico F. Calderazzo L. Labella C. Maichle-Mossmer and J.Strahle J. Chem. Soc. Chem. Commun. 1994 1555. 152 M. P. Hendrich E. P. Day C.-P. Wang B. S. Synder R. H. Holm and E. Munck Znorg. Chem. 1994,33 2848. '53 A. L. Feig and S.J. Lippard J. Am. Chem. Soc. 1994 116 8410. 154 I. Shweky A. Bino D.P. Goldberg and S.J. Lippard Inorg. Chem. 1994 33 5161. Iron Cobalt and Nickel (7) (Reproduced with permission from J. Chem. Soc. Chem. Commun. 1994 1555.) qo-0) -NYN-a0- 234 S.A. Cotton [CIO,], together with hydrogen peroxide as oxidant is an efficient catalyst for the conversion of alkanes into alcohols and ketones. It is very effective at decomposing hydrogen peroxide and also converts Me,S into Me,SO and benzene into phen01.'~' Other compounds with a single p-0x0 bridge include [Fe,O,(H,O),L][ClO,] [L = tris{( l-methylimidazol-2-yl)methyl)amine],'56 which features a slightly bent bridge (162") and which is an alkane functionalization catalyst and two complexes of tris(2-pyridylmethy1)amine (tpa); the structures of [(tpa)(HO)Fe(p-O)Fe(H,O)(tpa)] [ClO,] and [(tpa)ClFe(p-O)FeCl(tpa)][ClO,] have been reported.The former has a bent bridge (Fe-0-Fe = 138.9') with significantly different Fe-0 distances (1.780 1.839A) whilst the latter is symmetric; the coordinated water and OH groups in the former are linked by an intramolecular hydrogen bond. [(tpa)(HO)Fe(p-0) Fe(H,O)(tpa)][ClO,] reacts with sulfate to give the dibridged complex [(tpa)Fe(p- O)(p-SO,)Fe(tpa)][ClO,] , and promotes the hydrolysis of acetonitrile forming the (p-acetamido-N,O-) bridged [(tpa) Fe(p-O)(p-CH,CONH)Fe(tpa)][C104]3.i 57 All these compounds exhibit strong antiferromagnetic coupling.An independent study confirmed the hydrolysis reaction of MeCN and suggested (10) a mechanism and also reported the structure of [(tpa)(C10,)Fe(p-O)Fe(H,0)(tpa)][C104]3. A related complex of 5-ethyltpa [(5-Et-tpa)(HO)Fe(p-O)Fe(H20)(5-Et-tpa)][C104]3, also has a H,O bridge.15' J 0 (tpa)Fey IFeIn(tpa) "Y"" 7 (tpa)Fern' \Fenx(tpa)I I:<I;;C Me (10) [Fe,(p-O)(p-OH)(6-tla)2][C104]3 is the first compound with an Fe,(p-O)(p-OH) core [6-tla = tris{(6-methyl-2-pyridyl)methyl)amine].159 A general method has been developed for the synthesis of hydroxo-bridges by protonation of the 0x0-bridged analogues in ether.16' This has the structural effect of expanding the bridging core lS5 S.MCnage J. M. Vincent C. Lambeaux and M. Fontecave J. Chem. SOC. Dalton Trans. 1994 2081. 156 R. M. Buchanan S. Chen J. R. Richardson M. Bressan L. Firti A. Morvillo and R. H. Fish Inorg. Chem. 1994 33 3208. 15' A. Hazel] K. B. Jensen C. J. McKenzie and H. Toftlund Inorg. Chem. 1994 33 3127. 158 E. C. Wilkinson Y. Dong and L. Que J. Am. Chern. SOC. 1994 116 8394. 159 Y. Zang G. Pan and L. Que J. Am. Chem. SOC. 1994 116 3653. I6O P. N. Turowski W. H. Armstrong S. Liu S.N. Brown and S.J. Lippard Inorg. Chem. 1994 33 636. Iron Cobalt and Nickel lengthening the Fe-0 and Fe-Fe distances and reducing the Fe-Fe antiferromagnetic coupling. Phosphate and acetate-bridged cations such as [Fez(p-OH)@-+ O,CMe),Tp,] and [Fe,(p-OH)(p-O,P(OPh),),Tp2] + have been characterized.16' A preorganized cleft-shaped dicarboxylate ligand has been used in the synthesis of a (p-oxo)bis(p-carboxylato)diiron(m)compound.' 61 Carbonate and sulfate bridges are reported'62 in [Fe2(p-O)(p-0,C)(bispicMe,en)2]2+ and [Fe2(p-O)(q-0,S)(bi-+ spicMe,en),12 [bispicMe,en = N,N'-bis(2-pyridylmethyl)-N,N'-bis(methyl)-1,2-ethanediamine] whilst another carbonate bridge is found in [Fe (p-O)(p-0,C)(nta),14+ (1 l).163Several cores of higher nuclearity have attracted attention.An [Fe402]'+ core with bridging acetates and terminal bipy is found in [Fe,O,(OA~),(bipy),]C1.~~~ Hexanuclear clusters with p-0 p-OH and p-amino acid bridges are found in Na[Fe6(o),(oH),(ami),(phen)8](N03)9~10H,0.'65 The mag- netic properties of compounds with [Fe'Q'(p,-o)] and [Fe',"Fet(p6-o),] cores have also attracted attention.'66 0 0 i 0 10 Other Cluster Complexes A review of developments in cluster chemistry includes a number of iron c~rnplexes.'~~ Heterometal clusters [MFe4C1s6(PEt,),] (M = V Mo) have a cuboidal Fe,S fragment bridged to the heterometal by three p2-S atoms; [VFe,ClS6(PEt,),] exhibits the first spin-state equilibrium in an iron-sulfur cluster.Reduction with NaSR gives [MFe,S,(SR)(PEt,),] (R = Ph Et). Kinetic studies on [Fe,S,X,I2- (X = C1 Br) show that the substitution of the first halide by thiolate is catalysed by protonation of the cubane core.169 Oxidation of cobalt(I1) benzoate in MeCN or dmf with hydrogen 16' S.P. Watton A. Masschelein J. Rebek and S.J. Lippard J. Am. Chem. SOC. 1994 116 5196. A. Arulsamy P. A. Goodson D. J. Hodgson J. Glerup and K. Michelsen Inorg. Chim. Acta 1994,216,21. T. Fujita S. Ohba Y. Nishida A. Goto and T. Tokii Acta Crystallogr. Sect. C. 1994 50 544. X. Yu and W. Pan Jiegou Huaxue (Chinese J. Struct. Chem.) 1993 12 271 (Chem. Abstr. 1994 120 337 609). T. Tokii K. Ide M. Nakashima and M. Koikawa Chem. Lett. 1994 441. 166 (a) A. Cornia D. Gatteschi and K. Hegetschwiller Inorg. Chem. 1994 33 1559; (b) K. L. Taft G. C. Papaefthymiou and S.J. Lippard J. Am. Chem. Soc. 1994 116 1511. D. Gatteschi A. Caneschi L. Pardi and R. Sessoli Science 1994 265 1054. '" W. Cen F. M. MacDonnell M. J. Scott and R. H. Holm Inorg. Chem. 1994 33 5809.R.A. Henderson and K.A. Oglieve J. Chem. Soc. Chem. Cornmun. 1994 377. 236 S.A. Cotton peroxide gives [Co804(0,CPh),,(NCMe),(H2~)], which has a CO404 cubane core.' 70 11 Complexes with Unusual Magnetic Properties including Spin-crossover Compounds It has been polemically argued' that spin-equilibrium compounds are examples of 'bond-stretch isomerism'. Spin equilibria in iron@) compounds have been reviewed with particular attention to LIESST (light-induced excited spin state trapping).'72 The use of magnetic fields to shift diamagnetic low-spin eparamagnetic high-spin equilibria has been studied optically in cobalt compounds and with a dilatometer for iron compounds.' 73 The first spin-transition-based thermally addressed optical display device has been described.' 74 [VFe4ClS,(PEt3),] exhibits the first spin-state equilibrium in an iron-sulfur cluster.'68 Iron(rr) Complexes.-The magnetic properties and structure of the two-step spin- equilibrium compound [Fe{ 5-N02-sal-N(1,4,7,10)}] have been studied over a range of temperatures; there are two S = 2 to S = 0 spin-state interconversions each involving half of the Two solvates cis-[Fe(NCS),(tap),].xMeCN (tap = 1,4,5,8-tetraazaphenanthrene; x = 0.5 1) have been studied.The hemisolvate is high spin down to 4.2 K but the monosolvate exhibits a continuous high to low spin conversion on cooling from 280 to 110K.The crystal structures of both forms were determined and suggest that differences in metal-ligand bond lengths and trigonal distortion account for the difference in magnetic behaviour.On cooling the high-spin form the spin-state change is accompanied by a shortening of the Fe-N(tap) and Fe-N(CS) bonds by some 0.23 8 and 0.12 8 respectively as well as a lessening of trigonal distortion to produce a more symmetrical octahedral geometry.' 76 The effect of pressure on the spin-state transition and its hysteresis in [Fe(NCS),(bt),] (bt = 2,2'-bi-2-thia~oline)'~~ has been examined. Two groups have studied 1,2,4-1H-triazole (Htrz) complexes. The spin equilibria in [Fe(Htrz),(trz)]X (X = BF, PF, and ClO,) are thermochromic and also exhibit S = 2= S = 0behaviour with hysteresis in their spin state transition^.'^^ They have potential in memory devices. The effect of magnetic dilution in the series [Fe,Ni -,(NCS),(btr),].H,O (btr = 4,4'-bis-1,2,4-triazole) is to smooth the transi- tion curves and also to shift the transition temperat~re.'~~ Similar studies in K.Dimitrou K. Folting W.E. Streib and G. Christou J. Chem. SOC. Chem. Commun. 1994 1385. P. Giitlich H.A. Goodwin and D.N. Hendrickson Angew. Chem. Int. Ed. Engl. 1994,33 425. P. Giitlich A. Hauser and H. Spiering Angew. Chem. Int. Ed. Engl. 1994 33 2024. 173 A. G. M. Jansen J. Lejay H. Wiegelmann P. Wyder and W. Bronger Z. Phys. Chem. (Munich) 1993,182 1. 174 C. Jay F. Groliere 0.Kahn,and J. Groeber Mol. Cryst. Liq. Cryst. Sci. Technol. Sect. A 1993,234,255 (Chem. Abstr. 120 90 593). 17' D. Boinnard A. Bousseksou A. Dworkin J. -M. Savariault F. Varret and J.-P. Tuchagues Inorg.Chem. 1994 33 271. 176 J.A. Real M.C. Muiioz E. Andrts T. Granier and B. Gallois Inorg. Chem. 1994 33 3587. 177 E. Konig G. Ritter H. Grunstadel J. Dengler and J. Nelson Inorg. Chem. 1994 33 837. K. H. Sugiyarto and H. A. Goodwin Aust. J. Chem. 1994,47,263;J. Kroeber J.-P. Audiere R. Claude E. Codjovi 0. Kahn J.G. Haasnoot F. Groliere C. Jay A. Bousseksou J. Linares F. Varret and A. Gonthier-Vassal Chem. Mater. 1994 6 1404. J.-P. Martin J. Zarembowitch A. Dworkin J. G. Haasnoot and E. Codjovi Inorg. Chem. 1994,33,2617. Iron Cobalt and Nickel 237 [Fe,Co -,(NCS),(btr),].H,O have been reported.180 The effect of dilution is to decrease the temperature of the spin transition in [Fe,Zn -,(4-amino-l,2,4-triazole] [NO,] (x = 0.01-0.8) and increase the proportion of the high-spin isomer.'81 There are six p-MeOptrz bridges between the central iron and the two flanking metal ions in the linear trinuclear species [Fe,(H,O),(p-MeOptrz),][BF,] and [Fe (H,O),(p-MeOptrZ),] [tOSylate] 6.4H2O [p-MeOptrz = 4-(p-methoxyphenyl)-lY2,4-triazole].All three iron ions in the former are high spin but the central Fe2 + ion in the latter (and in the anhydrous complex) exhibit gradual spin conversion centred at 245 and 330 K respectively.'82 Thermal and LIESST effects have been studied in [Fe(mtz),][ClO,] (mtz = 1-methyl-lH-tetra~ole).~ 83 The pure compound possesses two different iron sites one remaining high spin to 4.2K7 the other exhibiting a high to low spin change below 100K. Dilution with zinc affects both the transition temperature and the rate of change.The direction of high to low spin interconversion is affected by the wavelength of the light. Parallel behaviour from different iron sites is seen in [F~(~~Z),][BF,],.'~~ As a step towards ligand-driven light-induced spin-state transitions based on cis-trans photoisomerizable ligands the compounds trans-[Fe(NCS),(stpy),] (stpy = cis or trans-4-styrylpyridine) were studied.lgS The isomer with the trans ligand exhibits a crossover on cooling to 108K whilst the isomer based on the cis ligand remains high spin. Fe2 + encapsulated in hexaammine cages exhibits spin equilibria. 86 Hydrated and anhydrous [Fe(bpp),]X [bpp = 2,6-bis(pyrazol-3-yl)pyridine; X = PF, BF, NO, Br I] exhibit spin-equilibrium behaviour that depends on both the anion and the degree of hydration.Ig7 The transition is displaced to lower temperatures in the anhydrous species and is only partial above room temperature for the hydrated species.The transition is discontinuous for the hydrated compounds; the iodide exhibits a narrow hysteresis. The structures of low-spin [Fe(bpp),]1,.4H2O and [Fe(bpp),][BF4],.3H,0 both show Fe-N 195pm; the NH groups of the pyrazoles are involved in a hydrogen-bonding network with the anions and lattice water. Another investigationlg8 of [Fe(bpp),][PF,] has shown it to exhibit a sharp high to low spin transition in the range 16Cb185K as well as LIESST and reverse LIESST at low temperatures. The metastable high-spin state can be trapped by rapid cooling. [Fe(pzapt),] [Hpzapt = 2-(pyrazin-2-ylamino)-4-pyridin-2-yl)thiazole)]has an FeN chromophore; it can be obtained as the anhydrous compound and with varying degrees of ~olvation.'~~ The spin transition observed depends on the trapped solvent molecule; the transition occurs below room temperature for the benzene solvate but the chloroform solvate and the unsolvated compound are largely low spin at room temperature.The room temperature crystal structure of [Fe(pzapt),].1.5C&6 reveals 180 J.-P. Martin J. Zarembowitch A. Bousseksou A. Dworkin J. G. Haasnoot and F. Varret Inorg. Chem. 1994 33 6325. L.G. Lavrenova V.N. Ikorskii V.A. Varnek. I.M. Oglezneva and S.V. Larionov Zh. Strukt. Khim. 1993 34 145 (Chem. Ahstr. 120 288595). 18' M. Thomann 0.Kahn J.Guilhem and F. Varret Inorg. Chem. 1994 33 6029. T. Buchen P. Poganiuch and P. Gutlich J. Chem. Soc. Dalton Trans. 1994 2285. R. Hinek P. Gutlich and A. Hauser Inorg. Chem. 1994 33 567. 185 C. Roux J. Zarembowitch B. Gallois T. Granier and R. Claude Inorg. Chern. 1994 33 2273. L. L. Martin R. L. Martin and A.M. Sargeson Polyhedron 1994 13 1969. lH7K. H. Sugiyarto D.C. Craig A.D. Rae and H. A. Goodwin Aust. J. Chem. 1994,47 869. la' T. Buchen P. Gutlich and H.A. Goodwin Inorg. Chem. 1994,33 4573. B. J. Childs D. C. Craig K. A. Ross M. L. Scudder and H. A. Goodwin Aust. J. Chem. 1994,47 891. 238 S. A. Cotton bond lengths consistent with the presence of both spin isomers. Both [Fe(pzapt),] and [Fe(papt),] [Hpapt = 2-(pyridin-2-ylamino)-4-pyridin-2-yl)thiazole] exhibit a spin equilibrium in MeOH.+ Both thefac and mer isomers of [Fe(amp),12 [amp = 2-(aminomethy1)pyridinel have been substituted into the supercages of Y-Zeolite.''* The mer isomer is high spin down to liquid nitrogen temperatures whereas thefac isomer changes from high spin to low spin on cooling from 293 to 78 K. The compounds [Fe(4-X-bzimpy),][C1O4] [bzimpy = 2,6-bis(benzimidazol-2'-yl)pyridine]exhibit spin-crossover behaviour in solution that depends on both the solvent and the ligand sub~tituent.'~' Intersystem crossing rates from the high-spin to the low-spin state in [MFe(pic),]Cl,-ROH (M = Zn or Mn; R = Me or Et) have been in~estigated.'~ Iron(1m) Complexes.-Crystalline [Fe(O,SCF,)(tpp)] provides the first example of a solid-state spin equilibrium for a five-coordinate iron(m) porphyrin with two distinct lattice sites.'*7 Studies'93 of solutions of [Fe(acpa),][PF,] [acpa = N-(1-acetyl-2-propylidene)-N-(2-pyridylmethyl)amine]indicate a high-spin/low-spin transition temperature of ca.200 K; a rate constant of 10 s-' has been estimated for the low-temperature tunnelling process in the high-spin to low-spin relaxation consider- ably above the lo- to lop6s-' range generally observed for iron(I1) compounds. Spin equilibria in iron(II1) complexes of a pentadentate ligand have been re~0rted.l~~ EPR signals have been unequivocally assigned to the high and low-spin isomers of [Fe{ PhC(S)CHC(0)Ph)3].92" Cobalt Comp1exes.-[Co1,(SbPh3),] is a rare paramagnetic cobalt(n1) compound (4.4pB).79 The series [Co(dmvi),(phen) -,)+ (dmvi = dimethylviolurato) is low spin for x = 2 3 high spin for x = 0 but exhibits a spin equilibrium for x = 1;'95 magnetic EPR and structural data were reported for the spin-equilibrium compound [Co(dmvi)(phen),][ClO,] at 294 and 92 K.The trinuclear cobalt@) bis(2-py- ridy1)amido (dpa) complex [Co,Cl,(p,-dpa),] has a most unusual structure a kind of super lantern (12). Each of the amides bridges all three metal atoms but in contrast to the nickel and copper analogues the three cobalts are bound asymmetrically. Thus two are associated into a diamagnetic dimeric pair (Co-Co = 2.290A) and the other has essentially square pyramidal coordination (Co-Co = 2.472 A) and exhibits spin-crossover behaviour Several reports have concerned cobalt semiquinone complexes that exhibit taut omeric equilibria.Thus [Co"'( 9,lO-p hen) (3,6-p hen) (3,6-d bsq) (3,6-d bcat )] (,ueff= 1.78pB at 5 K) transforms into [Co"(9,10-phen)(3,6-dbsq),] (peff= 6.04pBat 340 K); the solution transition temperature is 265 K but in the solid state this occurs over a wide range (dbsq = di-t-butylsemiquinonato; dbcat = di-t-butyl-cate~holato).'~~ In contrast trigonal prismatic [C0"(5-NO,-l,lO-phen)(3,6-dbsq)~] has peff= 4.6~~ over a wide temperature range in the solid state but does show a 190 Y. Umemura Y. Minai N. Koga and T. Tominaga J. Chem. Soc. Chem. Commun. 1994 893. 19' W. Linert M. Enamullah V. Gutmann,and R. F. Jameson Monatsh. Chem. 1994,125,661; W. Linert M. Konecny and F. Renz J.Chem. Soc. Dalton Trans. 1994 1523. 192 A. Vef U. Manthe P. Gutlich and A. Hauser J. Chem. Phys. 1994 101 9326. 193 S. Schenker and A. Hauser J. Am. Chem. SOC. 1994 116 5497. 194 Y. Maeda Y. Noda H. Oshio Y. Takashima and N. Matsumoto Hyperfne Interact. 1994 84 471. '95 J. Faus M. Julve F. Lloret J. A. Real and J. Sletten Inory. Chem. 1994 33 5535. 196 E.C. Yang M. C. Cheng M.-S. Tsai and S. M. Peng J. Chem. SOC.,Chem. Commun. 1994 2377. 19' 0.-S. Jung and C.G. Pierpont J. Am. Chem. SOC. 1994 116 1127. Iron Cobalt and Nickel 239 (Reproduced with permission from J. Chem. Soc. Chem. Commun. 1994 2377.) transition in toluene solution below 200 K. Other studies have revealed the structures and magnetic properties of [Co1"(trneda)(3,6-dbsq)(3,6-dbcat)] and trigonal prismatic [Co1'(dafl)(3,6-dbsq),] (dafl = 4,5-diazafluoren-9-one).98 [Co"(bupy ) (3,6-dbsq),] (bupy = 4-t-butylpyridine) shows evidence for the tautomeric equilibrium but not the iron ana10gue.l~~ [Co1"(3,6-dbsq),] is octahedral and has an S = 1/2 ground state below 77 K.,O0 Iron and nickel complexes of 2,4,6,8-tetra-t-butylphenoxazin-l-one (phenoxbq) include [Fe1r1Cl,(phenoxbq),][FeC14] which undergoes reduction to the trigonal bipyramidal semiquinone complex [Fe"'Cl(phenoxsq),] in which the semiquinone radicals couple antiferromagnetically with the metal giving peff= 3.78 pB at room temperature.201 As noted above a cobalt(1r) complex of an encapsulating ligand has the unusual solution moment of 2.88 ,uB.72 Nickel Complexes.-Some nickel complexes exhibiting unusual behaviour have been noted in Section 2.The structure and orientation-dependent magnetic susceptibility of the S = 1 1D Heisenberg antiferromagnet [NMe,][Ni(NO,),] have been re-ported.202 19' 0.-S. Jung and C.G.Pierpont Inorg. Chem. 1994 33 2227. 199 A.S. Attia 0.-S. Jung and C.G. Pierpont Inorg. Chim. Actu 1994 226 91. '""C. W. Lange B. J. Conklin and C. G. Pierpont Inorg. Chem. 1994 33 1276. '01 A.M. Whalen S. Bhattacharya and C.G.Pierpont Inorg. Chem. 1994 33 347. '"'L.-K. Chou K.A. Abboud D.R. Talham W. W. Kim and M. W. Meisel Chem. Muter. 1994,6 2051.

ISSN:0260-1818    

DOI:10.1039/IC9949100219

出版商:RSC    

年代:1994

数据来源: RSC

摘要:

16 Copper By D.W. SMITH Department of Chemistry University of Waikato Hamilton New Zealand 1 Copper(r) Chemistry Mononuclear Species.-Starting with studies of copper(1) species in solution transport and compressibility measurements on Cu+ in MeCN PhCN and MeCN/PhCN mixtures are reported.'",b The structure of [Cu(NH,),] + in solution has been studied by EXAFS.lc Sequential bond dissociation energies D, have been determined by MS for [Cu(H,O),]+; the sequence D,-D > D,-D is the same for all [M(H,O),]+ (M = 3d element).Id Linear two-coordination has been established in [CUIL],~" where L is the sterically demanding tris(2,4,6-trimethoxyphenyl)phosphine in [Li(dme),] and [CU{S~C(S~M~,),),],~~ also in the first copper<arbene complex [CuCl(thiazolylidene)]; the molecules are loosely associated as dimers uialong (2.91 A) Cu-C1 interactions.2c Trigonal CuSBr coordination is found in [NEt,][CuBr,L] (L = N-methyl-imida~oline-2-thione).~" The first 1-aminopyrene (L) copper(1) complex is [CuL,] [ClO,].MeOH with approximately T-shaped CuN coordination; stacking of the pyrene rings imposes a two-dimensional structure.3b [CuL,],[SO,] (L = ethylenethiourea) has trigonal CuS coordination with long axial Cu-0 contacts (2.83A).,' [CuX(piperidine)(PPh,)] (X= C1 Br I) contains trigonal CuXNP but intermolecular association makes a dimeric formulation more appr~priate.~~ CuOP (a)J. Singh T. Kaur V. Ali and D. S. Gill J. Chem. Soc. Faraday Trans. 1994,90 579; (b)D. S. Gill R. Singh V. Ali J. Singh and S. K.Rehani J. Chem. Soc. Faraday Trans. 1994 90 583; (c)G. Lamble A. Moen and D. G. Nicholson J. Chem. Soc. Faraduy Trans.,1994,90,2211; (d)N. F. Dalleska K. Honma L. S. Sunderlin and P.B. Armentrout J. Am. Chem. SOC. 1994 116 3519. (a)L. J. Baker G. A. Bowmaker R. D. Hart P. J. Harvey P. C. Healy and A. H. White Inorg. Chem. 1994 33 3925; (b)P.J. Bonasia G.P. Mitchell F.J. Hollander and J. Arnold Inorg. Chem. 1994,33 1797; (c) H. G. Raubenheimer S. Cronje P. H. van Rooyen P.J. Olivier and J. G. Toerien Angew. Chem. Znt. Ed. En& 1994 33 672. (a)S. Ramaprabhu N. Amstutz E. A. C. Lucken and G.Bernardinelli J. Chern. Res. (S) 1994,368; (b)M. Munakata J. Dai M. Maekawa K.-S. Takayoshi and J. Fukui J. Chem. Soc. Chem. Commun. 1994,2331; (c) G. A. Bowmaker C. Pakawatchai B.W. Skelton P. Thavornyutikarn Y. Wattanakanjana and A. H. White Aust. J. Chem. 1994.47 15; (d) G.A. Bowmaker J. V. Hanna R. D. Hart P. C. Healy and A. H. White J. Chem.Soc.,Dalton Trans.,1994,2621 ;(e)D. J. Darensbourg M. W. Holtcamp B. Khandelwal and J. H. Reibenspies Inorg. Chem. 1994,33,531;v) W. E. Lynch D. M. Kurtz S.Wang and R. A. Scott J. Am. Chem. Soc. 1994,116 1 1030; (g) T.N. Sorrell M. L. Garrity J. L. Richards and P. S. White Inorg. Chim. Acta 1994,218,103; (h)M. A. El-Sayed,K. Z. Ismail T. A. El-Zayat and G. Davies Inorg. Chim. Acta 1994 217 109; (i) R. Kivekas J. Ruiz and E. Colacio Acta Chern. Scand. 1994 48 382. 241 242 D. W.Smith three-coordination with strong intramolecular hydrogen bonding is the main structural feature of [Cu( OOCCH,COOH)(PPh,),] but the analogous succinate complex -which is stable to decarboxylation -is polymerized via intermolecular hydrogen bonding and by formation of long (2.37A) Cu-0 bonds to complete distorted tetrahedral c~ordination.~" A monomeric complex [CuLlX [X = ClO, PF, CF,SO, L = tris(1-ethyl-4-methylimidazolyl)phosphine],is proposed as a haemocyanin model; reaction with 0 gives a p-q2 :q2-peroxodicopper(u) species.,f A similar dioxygen adduct is formed by [CuL][BF,] where L is an N ligand with one py and one Him group.3g However the reaction of 0 with [(CuBrL),] (L = N,N'-Et,en) gives a tetrameric mixed-valence ~omplex.~" [Cu(SCN),I2 -is the first discrete homoleptic thiocyanatocuprate(~).~~ Among mononuclear complexes containing tetrahedral four-coordinate copper(I) a model for nitrite reductase may be found in the first mononuclear copper(1tnitrite complex [Cu((q'-N)-NO,)(Pr',-tacn)] which on treatment with AcOH gives a copper(i1) complex plus NO.4a The reduction of NO to N,O is catalysed by [cu(NCMe)(Pr:-ta~n)][PF,],~~while [Cu(HB(pzR2-3,5),)(N0)] (R = Me or Ph) mediates the disproportionation of NO to N,O + NO .4c Other structurally charac- terized four-coordinate copper(1) complexes include [Cu(LH)(PPh,),] (LH = benzene-1,2-dioxyacetic acid),4d [CuL][BF,] [L = N,N'-bis(2-(diphos-phin0)phenyl)ethane- 1,2-diamine a tetradentate N,P ligand]? and [Cu(LH)(PPh,),] (LH = 0-methyl-1,l -dithiooxalic acid) the first example of ex- clusively end-on coordination for thi~oxalate.,~ The electrochemical oxidation of copper metal in MeCN continues to provide convenient routes to copper(1) complexes for example [Cu(O,CCH -nFn)(PPh3)2]; the coordination geometry is a distorted tetrahedron with one long Cu-0 bond and a large P-Cu-P angle (135-137°).4g [CuL][BF,] [L = tris(4-(2-thienyl)-3-aza-3-butenyl)amine] exhibits distorted tet- rahedral CuN coordination; surprisingly the copper atom prefers the hard nitrogen atoms to the soft sulfur the shortest Cu-S contact being at 3.27 Derivatives of 1,4,5,8,9,12-hexaazatriphenyleneact as bidentate ligands towards copper(1); both homoleptic [CuL,] and heteroleptic [CULL'] have been characterized by MS4' Studies on the reaction of [Cu(OAr)(PPh,)(phen)] with 0 have illuminated the role of copper(1) in the catalysis of the oxidation of phenols to o-quinones.,j In [CuL,][ClO,].EtOH [L = 2-(aminophenyl)diphenylphosphine] L is bidentate leading to distorted tetrahedral c~ordination.,~ A rare example of trigonal bipyramidal five-coordinate copper(1) has been found in [C~(PPh,),(terpy)][CI0,J.~' Bi- Oligo- and Polynuclear Species.-Binuclear copper(1) complexes which may serve as models for such biological compounds as tyrosinase and haemocyanin continue to (a) J.A. Halfen and W. B. Tolman J. Am. Chem. SOC.,1994,116 5475; (b)S. Mahapatra J. A. Halfen and W. B. Tolman J. Chem. SOC. Chem. Commun. 1994 1625; (c) C.E. Ruggiero S. M. Carrier and W. B. Tolman Angew. Chem.,Int. Ed. Engl. 1994,33,895;(d)M. Deveraux M. McCann J. F. Cronin C.Cardin M. Convery and V. Quillet Polyhedron 1994,13,2359;(e)F. Tisato F. Refosco G. Bandoli G. Pilloni and B. Corain J. Chem. SOC.,Dalton Trans. 1994,2471;(f) P. Strauch B. Dempe R. Kempe W. Dietzche J. Sieler and E. Hoyer Z. Anorg. Allg. Chem. 1994,620,498; (9)R. D. Hart P. C. Healy G. A. Hope D. W. Turner and A.H. White J. Chem. SOC. Dalton Trans. 1994 773; (h) J. F. Gallagher E.C. Alyea G. Ferguson and Z. Xu Actu Crystullogr. Sect. C,Cryst. Struct. Commun. 1994,50,16;(i)C. Moucheron C. 0. Dietrich-Buchecker J.-P. Sauvage and A. van Dorsselaer J. Chem. SOC.,Dalton Trans. 1994 885; (j)L. M. Sayre and D.V. Nadkarni J. Am. Chem. SOC.,1994 116 3157; (k) E. W. Ainscough A.M. Brodie S. L. Ingham and J. M. Waters Inorg. Chim. Actu 1994 217 191; (I) E. W. Ainscough A.M.Brodie S. L. Ingham and J. M. Waters J. Chem. SOC.,Dalton Trans. 1994 215. Copper 243 attract attention. Several pertinent reviews have appeared on hydrolase models," haerno~yanin,~~ theoretical calculations on dioxygen CuiO complexes in gene~al,~" and on the spectra of binuclear dioxygen complexe~.~" Work continues on the reactions of dioxygen with copper(1) complexes of binucleating ligands having two tripodal pyridyl quinolinyl or imidazolyl moietiesSf-j (see also ref. 3f). More supramolecular assemblies containing two copper(r) centres have been studied. A trefoil knot complex using 1,3-phenylene groups as spacers between phen ligands has been isolated in gram quantities (30% yield).6a Dicopper(1) double helicates (tetrahedral CuN,) have been prepared incorporating a biphenyl-3,3'-diyl spacer.6b Another double helicate having both CuN and CuN coordinations with a short (2.57 A) Cu-Cu distance is [Cu2(6,6"-Ph2terpy),][PF,] ,; the ligand donor set determines the gross structural features while the sterically demanding substituents determine the detailed geometry.6c [Cu,L,][PF,], where L is 6,6-Me2bipy attached to 2,6-naphthalene or 2,7-pyrene via ether bridges contains equal numbers of helical and non-helical molecules.6d Among more mundane dicopper(1) complexes three-coordination is found in [(Cu(p-X)L},] [X = Cl Br I; L = P(o-tolyl),]; the adduct [{Cu(p-X)(NCMe)L),] has four-c~ordination.~' Monophosphoalkenes (L) react with CuCl in MeCN to give [Cu(p-Cl)(NCMe)L},] ;diphosphoalkenes give cubane-like [CU,C~,L,].~~ [Cu2{p2-(ql-N:ql-O)-NO,}L,][PF,] (L = Pr',[9]aneN3) the first binuclear nitrite complex of copper(1) and a possible model for nitrite reductase has a planar CuN0,Cu bridge with tetrahedral CuN and CuN,O; the copper(I)/copper(Ir) oxidation product is described below in Section 4.7cPyridazine (L) bridges three-coordinate copper(r) in and [CU,(~-L),(NCM~),][PF~],,~~ in [{Cu(p-L)L'},] [BF,] (L' = 2-cy-an~guanidine).~' Trigonal bipyramidal five-coordination is found in [Cu,L] [BFJ, where L is a furan-based hexaiminocryptand (cf.ref. 4j).7f The electrocatalytic reduction of CO is mediated by [(CU(NCM~)(~-PP~,~~~~)},][PF~],.~~ Bridging selenolate appears in [{CU[S~C(S~M~,),](PC~,)),].~~ [(CuBrL(p-L')),] [L = P(m-tolyl), L' = pyridine-Zthione] has tetrahedral CuS,PBr c~ordination.~~ The discrete (a) M.Gobel Angew. Chem. Int. Ed. Engl. 1994 33 1141; (b) K.A. Magnus H. Ton-That and J. E. Carpenter Chem. Reo. 1994,94 727; (c)N. Kitajima and Y. Moro-oka Chem. Reo. 1994,94 737; (d)1. Bytheway and M. B. Hall Chem. Rev. 1994,94 639; (e) E. 1. Solomon F. Tuczek D. E. Root and C. A. Brown Chem. Reo. 1994,94 827; v) K. D. Karlin M. S. Nasir B. I. Cohen R. W. Cruse S. Kaderli and A.D. Zuberbuhler J. Am. Chem. Soc. 1994 116 1324; (9) N. Wei N.N. Murthy Z. Tyeklar and K.D. Karlin Inorg. Chem. 1994 33 1177; (h) N. Wei D.-H. Lee N.N. Murthy Z. Tyeklar K.D. Karlin S. Kaderli B. Jung and A. D. Zuberbuhler Inorg. Chem. 1994,33,4625; (i)N. Wei N. N. Murthy Q. Chen J. Zubieta and K.D. Karlin Inorg. Chem.,1994,33,1953;(j) M. Becker S. Schindler and R. van Eldik Inorg. Chem. 1994 33 5370. (a)C. 0.Dietrich-Buchecker J.-P. Sauvage A. De Cian and J. Fischer J. Chem. Soc.,Chem. Commun. 1994 2231; (b) E.C. Constable M. J. Hannon A. J. Edwards and P. R. Raithby J. Chem. Soc. Dalton Trans. 1994 2669; (c) E.C. Constable A.J. Edwards M.J. Hannon and P.R. Raithby J. Chem. Soc. Chem. Commun. 1994 1991; (d) A. Bilyk and M. M. Harding J. Chem. Soc. Dalton Trans. 1994 77. ' (a)G.A Bowmaker J.V. Hanna R. D. Hart P. C. Healy and A. H. White Aust. J. Chem. 1994,47,25; (h) A. Jouaiti M. Geoffroy and G. Bernardinelli J. Chem. Soc. Dalton Trans. 1994 1685; (c) J. A. Halfen S. Mahapatra M. M. Olmstead and W. B. Tolman J. Am. Chem. Soc. 1994,116,2173;(d)M.Maekawa M. Munakata T. Kuroda-Sowa and Y. Nozaka J. Chem. Soc. Dalton Trans. 1994,603; (e)M. J. Begley P. Hubberstey C. E. Russell and P. H. Watson J. Chem. Soc. Dalton Trans. 1994,2483; v) W. J. Evans R. E. Golden and J. W. Ziller Acta Crystallogr. Sect. C Cryst. Struct. Commun. 1994,50 1005; (9)R. J. Haines R.E. Wittrig and C.P. Kubiac Inorg. Chem. 1994 33 4723; (h) P. Aslanidis S.K. Hadjikakou P. Karagiannidis B. Kojis-Prodic and M. Luic Polyhedron 1994 13 31 19; (i) G. Hu and E. M. Holt Acta Crystallogr. Sect. C Cryst. Struct. Commun. 1994,50,1578;(j)S. Ramaprabhu R. Ferretti E. A. C. Lucken and G. Bernardinelli Inorg. Chim. Acta 1994 227 153. 244 D. W. Smith planar [{CuI(p-I)},12- ion occurs in [NaL],[NaL(H,O)],[Cu,I,][Cu,I,] (L = 15-cr0wn-5),~' and in [PM~P~,][CU,I,].~~ Among oligonuclear copper(1) species the reaction of [Cu(NCMe),] + with MeNCS gives [Cu[{p3-SC(=NCH3)](OEt)),] where the copper atoms are arranged in butterfly fashion with trigonal CuS,N coordination.'" A new iodocuprate(1) ionsb is while is [CU,I,(~~-I)(~~-I)~]~-,the novel [{CU,B~(~-B~),},]~-found in the [NMe,Ph]+ salt.8c [{CuL},] (LH = 3,5-Ph2pz) has linear CuN coordination with em-bidentate L.8d Most oligonuclear complexes studied this year are heterometallic.CuCN in MeCN reacts with [MSe,12- (M = Mo W)to give [Cu(CN)(p-Se),MSe2l2 -and [Cu(CN)(p-Se),M(p-Se),Cu(CN)]-,; both have trigonal CuCSe coordination and in the latter the threemetal atoms are almost collinear." Aqueous [Mo\"S,(H,O),] 4+ reactssf with CuCl to give the cuboidal [MO,CUS,(H,O),,,]~+.In this and in the tungsten analogue,8g CuS,O coordination provides a further example of 'hard + soft' donors in the same coordination sphere (cf. ref. 3e). Cytochrome c oxidase is an important heterometallic complex. An iron(I1) porphyrin with a [9]aneN substituent at the ring binds CuBr to give a complex which binds dioxygen irreversibly.8h The first ironsopper-sulfur cluster is [NEt,][Fe6Cu,(p4-S),(CO),,(PPh3)2],containing three CuS,C and two CuS,P tetrahedra.8' Other oligonuclear systems are discussed under 'Photochemistry of Copper(1) Compounds' below. Newly characterized polymeric copper(1) compounds include [Cu(pyrazine)] (infinite chains with linear CuN coordination);'" [Cu (p-Br),L2In [Cu,(p-Cl),L,], and [cU6(p-I)&3]" [L = cyclo-(EtAsO),; all tetrahedral CUX,AS,];'~ [cu2(p- L),(OC1O3)],[C10,] (L = 2,1,3-benzothiadiazole; CuN coordination two-dimen- sional structure with cu6 rings);" and [Cu,X,L] (X = C1 Br L = 1-cyanoguanide coordinating via the CN nitrogen atom) which contain both trigonal CuNX and tetrahedral CuX chain^.'^ [CuL,],[PF,] [L = N,N'-ethylenebis(pyrro1idin-2-thione] is a metallamacrocycle with chains of spiro-linked 18-membered rings and CuS coordination.'" [cU(4,4'-bipY),],[PF6]" self-assembles into a concatenated diamondoid network with tetrahedral CuN c~ordination.'~ [Cu (p-X),(p- phenazine)].(X = C1 Br I) exhibits different forms of polymerization depending on X.9g [Cu,(OAc),(dppe)] consists of chains of Cu dimers linked by weak Cu-0 interactions.9h This paragraph deals with polynuclear complexes and extended solids containing (a) T.Kuroda-Sowa M. Munakata M. Miyazaki and M. Maekawa Acta Crystallogr. Sect. C Cryst. Struct. Commun. 1994,50,1026; (b)G. Hu and E. M. Holt Acta Crystallogr. Sect. C Cryst. Struct. Commun. 1994,50 1576; (c)G. Hu and E. M. Holt Acta Crystallogr. Sect. C Cryst. Struct. Commun. 1994,50 1890; (d)G. A. Ardizzoia S. Cenini G. La Monica N. Maschiocchi and M. Moret Inorg. Chem. 1994,33 1458; (e)R. J. Salm and J. A. Ibers Inorg. Chem. 1994,33,4216;v) M. Nasreldin Y. -J. Li F. E. Mabbs and A. G. Sykes Inorg. Chem. 1994,33,4283; (9)M. Nasreldin C. A. Routledge and A. G. Sykes,J.Chem. SOC. Dalton Trans. 1994,2809; (h)J. P. Collman P.C. Herrmann B. Boitrel X. Zhang T.A. Eberspacher and L. Fu J. Am. Chem. SOC. 1994,116,9783;(i) B. Zhuang B. Pau L. Huang and P. Yu Inorg. Chim. Acta 1994,227 119. (a)A. Maschiotti M. Moret P. Cairati A. Sironi G. A. Ardizzoia and G. La Monica J. Am. Chem. Soc. 1994,116,7668; (b)W. S. Sheldrick and T. Hausler Z. Anorg. Allg. Chem. 1994,620,334;(c)M. Munakata T. Kuroda-Sowa M. Maekawa M. Nakamura. S. Akiyama and S. Kitagawa Inorg. Chem. 1994,33,1284; (d)M. J. Begley 0.Eisenstein P. Hubberstey S. Jackson C. E. Russell and P. H. Watson J. Chem. SOC. Dalton Trans. 1994 1935; (e) Z. Atherton D. M. L. Goodgame D.A. Katahira S. Menzer and D.J. Williams J. Chem. Soc. Ckem. Commun. 1994 1423; (I) L. R. MacGillivray S. Subramanian and M. J. Zawarotko J. Chem. Soc. Chem. Commun. 1994,1325; (g) M. Munakata T.Kuroda-Sowa M. Maekawa A Honda and S. Kitagawa J. Chem. Soc. Dalton Trans. 1994 2771; (h) D.J. Darensbourg E.M. Longridge B. Khandelwal and J. H. Reibenspies J. Coord. Chem. 1994 32 27. Copper 245 copper(1) combined with the heavier elements of Groups 15 and 16. The huge cluster [Cu,,P,o{P(SiMe,),},(PEt3)18] can be structurally related to Cu3P.'OU ~b initio calculations have been performed on small clusters [Cu,Se] and [CU,S~(PR,),],,'~~ while [Cu,,E,(PR,),] (E = S Se) and [Cu,oSlo(PPh,),] have been characterized.loc [{Cu(SCF,)} lo(NCMe)8] contains CuS,N CuS, CuS,N and CuS,N tetrahedra.lod The layered solids KCu,AsS and KCu,AsS have been prepared in supercritical amine solvents such as en; the former contains both CuS and CuS,As tetrahedra while the latter has a complex structure in which slabs are linked by CuS zigzag chains.'O' Copper(1) in Cu,SbS is three-coordinate; EHMO calculations support the postulate of weak metal-metal interactions (the shortest Cu-Cu distance is 2.62 A).lof KCuCe,S and K,Cu,CeS are the first examples of layered Group l/copper/cerium chalcogenides containing CuS tetrahedra; the latter is formulated as (Kf),(Cu+),(Ce3+)(S2-)3(S-).10q Cu\Pt11Pt',vS8 also contains CuS tetrahedra.loh [NEt,],[Cu,SbTe,,] contains a novel Zintl anion in which the copper atoms are bonded to [SbTe,]'- and [Te,14- with an edge-bridged Cu,Te tetrahedron."' MCuTeS (M = Rb Cs) consists of [CuTeS,],"- layers with corner-sharing CuS tetrahedra and TeS pyramids.' Oj Te-Te bonding in CuTe NaCuTe and K,Cu,Te has been assessed by means of EHMO calculations.10k Photochemistry of Copper(1) Compounds.-Studies of the luminescence of [Cu(CN),XI2-(X = C1 Br I) continue.' Photoelectrochemical cells with TiO,/ZnO ceramic electrodes are sensitized by [CuL,]' (L = 2,9-Ph2phen).' The photophysics of [Cu,(p,-q'-C,R)(dppm),] (R = Ph But) is interpreted in terms of the formation of a mixed-valence Cu\Cu" species.' Id The cubane-like species [WCu,Br,(p,-S),] behaves as a non-linear optical chromophore.'le A concise overview of recent work on the photochemistry/photophysics of [{ Cu(p,-X)L),] species (X = C1 Br I; L = amine) has appeared.llf Ab initio calculations on these species have cast doubts upon the validity of simple excited-state models in the interpretation of their photophysics.' lq Diffusion-limited quenching of the cluster- centred excited state of [{Cu(p,-I)py},] by [FeCp,]' has been studied."h Photo-physical studies have also been reported for mono- di- and tetrameric copper(1) complexes with polypyridines.' li The photoinduced electron transfer between + [CuL(PPh,),] or [CuL(PPh,(m-C,H,SO,)} ,]-(L = 2,9-Me2phen) and viologen derivatives has been examined.' 'j lo (a)D.Fenske and W. Holstein Angew. Chem. Int. Ed. Engl. 1994,33,1290;(b)A. Schafer and R. Ahlrichs J. Am. Chem. Soc. 1994,116,10686;(c)S. Dehnen A. Schafer D. Fenske and R. Ahlrichs Angew. Chem. Int. Ed. Engl. 1994,33,746;(d)A. L. Rheingold S. Munavalli D. I. Rossman and C. P. Ferguson Inorg. Chem. 1994,33 1723; (e) J. E.Jerome P.T. Wood W.T. Pennington and J. W. Kolis Inorg. Chem. 1994 33,1733;v) A. Pfitzner Z. Anorg. Allg. Chem. 1994,620,1992; (9)A. C. Sutorik J. Albritton-Thomas C. R. Kannewurf and M. G. Kanatzidis J. Am. Chem. Soc. 1994,33 7706; (h) P. J. Gross and M. Jansen Z. Anorg. Allg. Chem. 1994,620 1909; (i) S. S. Dhingra and R.C. Haushalter J. Am. Chem. Soc. 1994,116 3651; 0)X. Zhang and M. G. Kanatzidis J. Am. Chem. Soc. 1994,116,1890; (k) S. Seong T. A. Albright X. Zhang and M. G. Kanatzidis J. Am. Chem. Soc. 1994 116,7287. l1 (a)A. Horvath C. E. Wood and K. L. Stevenson Inorg. Chem. 1994,33,5351;(b)A. Horvath C. E. Wood and K. L. Stevenson J. Phys. Chem. 1994 98 6490; (c) N. Alonso-Vante J.-F. Nierengarten and J.-P. Sauvage J. Chem. Soc.,Dalton Trans. 1994,1649; (d)V.W.-W. Yam W.-K. Lee P. K.-Y. Yeung and D. Phillips J. Phys. Chem. 1994,98,7545;(e)S. Shi W. Ji J. P. Lang and X. Q. Xin J. Phys. Chem. 1994,98 3570; v) P.C. Ford Coord. Chem. Rev. 1994,132 129; (9)M. Vitale C.K. Ryu W.E. Palke and P.C. Ford Inorg. Chem. 1994,33,561;(h)D. Tran C. K. Ryu and P. C. Ford Inorg. Chem. 1994,33,5957;(i) A. Juris and R.Ziessel Inorg. Chim.Acta 1994,225,251;0)S. Sakaki H. Mizutani Y. Kase and T. Hamada Inorg. Chim.Acta 1994 225 261. 246 D.W. Smith 2 Copper-Oxygen Chemistry Here we cover work on mixed oxides oxoacid salts etc. containing copper in any oxidation state as well as complexes which may serve as precursors to mixed oxides. Evidence of room-temperature superconductivity in the Bi-Sr-Cu-0 systems has been reported.'," La,-,M,CuO (M = Na K) provide a new range of superconduct- ing phases.'2b The magnetic structure of the oxygen-deficient perovskite YBaCuFeO (square pyramidal CuO,) has been studied.'," Another perovskite LaMn,-,Cu,O (0 < x < 0.5) catalyses the oxidation of CO; XPS/Auger studies indicate that the oxidation number of copper is +2.12dIn a new series of rare earth oxocuprates LnCu,O (Ln = La Nd Sm Eu) copper (+ 2.5) has square planar coordination with corner sharing to give a three-dimensional structure; both ferro- and antiferromagnetic properties have been described.' 2e The incorporation of carbonate into Y,Ba,Cu,O, -,lowers Tc.12f LaCaCuGaO contains elongated CuO octahedra.'," The same 4 + 2 coordina-tion is found in CuMW,O (M = In Y) which unequivocally contain copper(I1); however with M = Tb the coordination is best described as 3 + 1 (distorted tetrahedral).'3b In contrast the 2 + 1 coordination found in CuMMo,O (M = Pr Tb) clearly indicates copper(^),' 3c as does the near-linear two-coordination in CuTbW,O,.' 3d The first ternary lead(n)-copper(I) oxide PbCu,O has linear two-coordinate ~0pper.l~~ Powder neutron diffraction fails to reveal any structural change associated with the spin-Peierls transition of CuGeO at 14K.13f In Ba,,Cu~,Cu~'Zn,O, the copper(I1) atoms have square pyramidal coordination while the copper(m) atoms have square planar coordination.' 3g In Cu,Co(BO,) and Cu,Bi,V,O, the copper(I1) atoms have 4 + 2 c~ordination,'~~,' does as Cu,Sn(BO,),O,; but Cu,Ti,(B,O,),(BO,),O contains six square CuO and three square pyramidal CuO centres per formula unit.',j Sr,CuO +d has been prepared by pulsed laser deposition.' 3k The new basic carbonate TiCu(OH)CO consists of (CuOH)i+ chains bridged by carbonate giving 4 + 2 c~ordination.'~' Looking now at copper(I1) compounds containing discrete oxoanions the X-ray structure of anhydrous Cu(ClO,) has at last been reported; the anions are triply bridging and the copper atoms have 4+ 2 c~ordination.'~"BaCu,(AsO,) reveals l2 (a)R.S. Burrows and D. H. McDaniel Angew. Chem. Int. Ed. Engl. 1994 33 897; (b) S. L. Stoll A.M. Stacy and C. C. Torardi Inorg. Chem. 1994 33 2761; (c) A. W. Mombru C. Christides A. Lappas K. Prassides M. Pissas C. Mitros and D. Niarchos Inorg. Chem.1994,33,1255; (d)Y. Yasuda Y. Fujiwara N. Mizuno and M. Misono J. Chem. SOC.,Faraday Trans. 1994,90,1183; (e)S. W. Keller V. A. Carlson D. Sandford F. Stenzel A. M. Stacy,G. H. Kwei and M. Alario-Franco J.Am. Chem. SOC.,1994,116,8070; v) C. Kruger H. Schwer J. Karpinski K. Conder E. Kaldis C. Rossel and M. Maciejewski Z. Anorg.Allg. Chem. 1994 620 1932. l3 (a) A. V. Luzikova A. L. Kharlanov E. V. Antipov and H. Muller-Buschbaum Z. Anorg. Allg. Chem. 1994 620 326; (b) H. Muller-Buschbaum and H. Szillat Z. Anorg. Allg. Chem. 1994 620 642; (c) H. Muller-Buschbaum and 0. Sedello 2. Anorg. Allg. Chem. 1994 620 647; (d) T. Gressling and H. Muller-Buschbaum Z. Anorg. Allg. Chem. 1994,620 1850; (e)H. Szillat and C. L. Teske Z. Anorg. Allg. Chem. 1994 620 1307; v) M.A.Green M. Kurmoo J.K. Stalick and P. Day J. Chem. SOC. Chem. Commun. 1994,1995;(9)M. Scheikowskiand H. Muller-Buschbaum Z. Anorg. Allg. Chem. 1994,620,313; (h) J. Schaefer and K. Bluhm 2.Anorg. Allg. Chem. 1994,620,1051;(i) G. B. Deacon B. M. Gatehouse and G. N. Ward Acta Crystallogr. Sect. C Cryst.Struct. Commun. 1994,50,1178;(j)J. Schaefer and K. Bluhm Z. Anorg. Allg. Chem. 1994,620 1578; (k)A. M. Morales P. Yang and C.M. Lieber J. Am. Chem. Soc. 1994 116 8360; (I) A. Adam and Y.Q. Zheng Z. Anorg. Allg. Chem. 1994,620 1707. l4 (a)F. Favier S. Bargues J. L. Pascal C. Belin and M. Tillard-Charbonnel J. Chem. SOC. Dalton Trans. 1994 3119; (b) D. Osterloh and H. Muller-Buschbaum 2.Anorg. Allg. Chem. 1994 620 651; (c) J. Le Bideau C. Payen P.Palvadeau and B. Bujoli Inorg. Chem. 1994,33,4885; (d)M. Berraho A. Vegas M. Copper 247 trigonal bipyramidal CuO c~ordination.'~' Cu30(MeP03),.2H20 contains both square pyramidal 4 + 1 and tetragonal octahedral 4 + 2 coordination p~lyhedra.'~' Tetragonal octahedral coordination is also found in [NH,]2[Cu(03PF)2(H,0),] (axial water). 4d Formation constants for [Cu(0H),l2 -have been meas~red.'~" The year has seen a flurry of activity in the study of the aluminosilicate ZSM-5 impregnated with copper(iI) which catalyses the reduction of NO.lSa-gThere is a degree of conflict among these reports with regard to the nature of the copper binding sites and the partial reduction to copper(1) on heating claimed by some workers to be crucial to catalytic activity.Clarification of these matters is awaited. Copper metal particles on ordered A1203 films also catalyse the decomposition of NO.15hEPR studies are reported on the interactions between copper(I1) and various adsorbates (including NO) on copper-exchanged K-L zeolite.' 5i Volatile copper(1r) complexes (especially alkoxides) have aroused interest as precursors to mixed oxides; two pertinent reviews have appeared. Examples reported include the cubane-like and readily sublimable [{Cu(OEt)(trnhd)),].'"" The bridging ligand 1,3-bis(dimethylarnino)-2-propanolate(L) is employed in bimetallic Group 2-copper complexes such as [CaCu(O,CCF,)L,] [{ SrCu(O,CCF,),L,),] and [{SrCu2(OH)(OCCF,)2L3)2],'6d as well as in the copper-lanthanide species ~Cu~~0~CCF~~~L~~~Y2~02ccF~~~L~~~ cCu4 (0Ac)6L2 (H2 )6i and [L~CU,(O~CCF~),L~].'~' [La2Cu,(p-OMe)2(p-L4)(N03)4(HL)2(MeOH)4] In (HL = 6-methyl-2-pyridone) the metal atoms form a Z shape with the two coppers (flattened tetrahedral four-coordinate) bridged by methoxide while L bridges copper and the terminal lanthanum atoms; the complex decomposes on heating to La2Cu04.16f Several copper-zirconium alkoxides are reported; on partial hydrolysis followed by oxidation [Cu~Zr2(OPri),,] gives [Cu~Zr,(p4-0)3(p2-OPri)lo(OPri)8] in which one quadruply bridging oxygen has rigorously square planar coordination!' 6g [Cu(hfpd),] and [Cu1(hfpd)(2-butyne)] have been studied as precursors for copper deposition on silicon electronic devices.'6h The thermal decomposition of acetates in triethylene glycol furnishes precursors to '1,2,3'.' 6i 3 Copper@) Complexes Mononuclear Systems.-HaEogenocuprates(I1).The only fluorocuprate(11) reported Martinez-Ripoll and M. Rafiq Acta Crystallogr. Sect. C Cryst. Struct. Commun. 1994 50 666; (e)E. Norkus and A. Vaskelis Polyhedron 1994 13 3041. I5 (a) N. W. Hayes W. Grunert G. J. Hutchings R. W. Joyner and E. S. Shpiro J. Chem. Soc. Chem. Commun. 1994,531; (b)K. Ebitani M. Morokuma J.-H. Kim and A. Morikawa J. Chem. SOC.,Faraday Trans. 1994,90,377; (c)A.V. Kucherov J.L. Gerlock H.-W. Jen and M. Shelef J.Phys. Chem. 1994,98 4892; (d)J. Dedecek and B. Wichterlova J. Phys. Chem. 1994,98 5721; (e)M. Anpo M. Matsuoka Y. Shioya H. Yamashita E. Giamello C. Mortera M. Che H. H. Patterson S. Webber S.Ouellette and M. A. Fox J. Phys. Chem. 1994,98,5744; v) W. Grunert N. W. Hayes R. W. Joyner E. S. Shpiro M. R. H. Siddiqui and G. N. Baeva J. Phys. Chem. 1994,98 10 832; (9)S. C. Larsen A. Aylor A. T. Bell and J. A. Reimer J.Phys. Chem. 1994,98,11533;(h)M. -C. Wu and D. W. Goodman J. Phys. Chem. 1994,98,9874; (i) J.-S. Yu and L. Kevan J. Phys. Chem. 1994 98 12436. l6 (a)D. C. Bradley Polyhedron 1994,13,1111;(b)R. C. Mehrotra A. Singh and S. Sogani Chern. SOC. Rev. 1994,23,215; (c)S. Wang J.-C. Zheng J. R. Hall and L. K. Thompson Polyhedron 1994,13 1039; (d)S. R. Breeze and S. Wang Inorg. Chem. 1994,33,5113;(e)S. Wang Z. Pang K. D. L. Smith and M. J. Wagner J. Chem. Soc. Dalton Trans. 1994 955; v) A. J. Blake V. A. Cherepanov A.A. Dunlop C. M. Grant P.E. Y.Milne J. M. Rawson and R. E. P. Winpenny J. Chem. SOC. Dalton Trans. 1994 2719; (9) J. A. Samuels W.-C. Chiang J. C. Huffman K. L. Trojan W. E. Hatfield D. V. Baxter and K.G. Caulton Inorg. Chem. 1994,33,2167; (h)J. Farkas M. J. Hampden-Smith and T.T. Kodas J. Phys. Chem. 1994 98,6753,6763; (i) H. Stephan K. Gloe U. Wiesner and G. Krabbes Z. Anorg. Allg. Chem. 1994,620,1915. 248 D. W. Smith this year is Na,CuScF, with the usual 4 + 2 c~ordination.'~" Gaseous CuCl has potential as an IR laser oscillating on the 2A,+211g tran~iti0n.l~' [HL] [CuCl,(H,O)]Cl (L = 4,5-diazafluoren-9-one) contains a square planar anion al- though the 'ionic' chloride is better regarded as semicoordinated being 2.80 A from the copper; hydrogen-bonding between this chloride and the coordinated water molecules leads to moderately strong antiferromagnetism.' 7c [LH,][CuCl,] (L = N,N-dimethylguanidine) contains the familiar D, anion.' 7d [NEt,],[CuCl,],~H,O con-tains two distinct anions.One with the copper atom at a 4 site has strictly D, symmetry though with less pronounced flattening from tetrahedral than usual. The other anion is associated with the water molecule and the coordination geometry could be described as a distorted square pyramid.' 7e EHMO calculations (with distance-dependent off-diagonal elements) have illuminated the dynamics of the D3JC2v conversion of [CuC1J3- which occurs at the phase transition (280K) in [cO(NH3),][cUC1,] vibronic coupling appears to have a key role.'7f The complex [3-chloroanilinium] 8[CuC16]C14 was reported in 199 1 to have a compressed octahed- ral anion but EXAFS and EPR spectroscopy have confirmed a disordered elongated octahedron.' 7g,h XAS has been used to measure the degree of covalency in the Cu-Cl bond in various chlorocuprates(r1); on distorting square [CuC1,I2 -towards tetrahed- ral there is a decrease in the covalency of the singly occupied orbital but an increase in the extent of total chlorine-to-copper donation.',' In [(Tl( 18-crown-6)),CuBr4] [TlBr,], the copper atom occupies a strictly tetrahedral site.However the large thermal parameters which are little affected by cooling to 115 K indicate disordered Jahn-Teller distortion.' 7j [ET],[CuBr,] and [ET],[CuBr,Cl,] contain square planar [CuX,12- anions.'7k3' In [Hampy],[Cu,Br,][Cu,Br,(H20),] both the dicop- per species are planar with two bridging bromines and in the aqua species trans water molecules.' 7m Complexes with N-donor Ligands.Here we cover complexes where the principal ligands furnish only nitrogen atoms as donors beginning with aliphatic amines and derivatives. The kinetics of formation of copper(1r) complexes with NH3 and MeNH in aqueous solution have been studied.' The rate of water exchange in the coordination sphere of l7 (a)P. Dahlke and D. Babel Z. Anorg. Allg. Chem. 1994,620,1692; (b)S. Churassy J. B. Koffend P. Crozet and I. Russier J. Phys. Chem. 1994,98,7991; (c)S. Menon C. Balagopalakrishna M. V. Rajasekharan and B. L. Ramakrishna Inorg. Chem. 1994,33,950; (d)P. Lemoine A. Tomas B. Viossat and N.-H.Dung Acta Crystallogr. Sect. C Cryst. Struct. Commun. 1994,50 1437; (e)A. Mahoui J. Lapasset and J. Moret Acta Crystallogr. Sect. C Cryst. Struct. Commun. 1994,50,358;U G. S. Nikolov Inorg. Chem. 1994,33 1144; (g) P.J. Ellis H. C. Freeman M.A. Hitchman D. Reinen and B. Wagner Inorg. Chem. 1994,33 1249;(h)H. Stratemeier B. Wagner E. R. Krausz R. Linder H.-H. Schmidke J. Pebler W. E. Hatfield L. ter Haar D. Reinen and M. A. Hitchman Inorg. Chem. 1994,33,2320;(i) S. E. Shadle B. Hedman K. 0. Hodgson and E. I. Solomon Inorg. Chem. 1994 33,4235; 6)N. S. Fender S. S. Finegan D. Miller M. Mitchell LA. Kahwa and F.R. Fronczek Inorg. Chem. 1994 33 4002; (k) S. Hebrard G. Bravic J. Gaultier D. Chasseau M. Kurmoo D. Kanazawa and P. Day Acta Crystallogr. Sect. C Cryst.Struct. Commun. 1994,50,1892;(1) P. Guionneau G. Bravic J. Gaultier D. Chasseau M. Kurmoo D. Kanazawa and P. Day Acta Crystallogr. Sect. C Cryst. Struct. Commun. 1994 50 1894; (m) H. Place and R. D. Willett Acta Crystallogr. Sect. C Cryst. Struct. Commun. 1994 50 862. l8 (a)I. Fabian J. Chem. Soc. Dalton Trans. 1994 1355; (b) D.H. Powell A.E. Merbach I. Fabian S. Schindler and R. van Eldik Inorg. Chem. 1994,33 4468; (c) M. R. Sundberg and M. Klinga Polyhedron 1994,13 1099; (d)M. R. Sundberg M. Klinga and R. Vggla Inorg. Chim. Acta 1994 216 57; (e)A.C. Stergiou S. Papastephanou and C. Tsiamis Polyhedron 1994,13,2285;(f) R. Subraminian B. A. Sastry G. Ponticelli and Z. Matovic Polyhedron 1994 13 993; (9)T. H. Tahirov T. -H. Lu K. Shu and C.-S. Chung Acta Crystallogr.Sect. C Cryst. Struct. Commun. 1994,50,512;(h)T. H. Tahirov T.-H. Lu Y.-L. Liu and C.-S. Chung Acta Crystallogr. Sect. C Cryst. Struct. Commun. 1994 50 514; (i) T. H. Tahirov T.-H. Lu K. Shu and C.S. Chung Acta Crystallogr. Sect. C Cryst. Struct. Commun. 1994 50 518; (j) Copper 249 copper(I1) is strongly affected by the presence of tren:'8b the rate of exchange for [Cu(tren)(H,0)I2 is three orders of magnitude slower than for [Cu(H,O),]'+. + [Cu(tn),(H20),]X2 (X = 2-nitrobenzoate) is claimed to be the first trans bis(tn)copper(n) complex; the non-coordination of the weakly basic anion is note- worthy. '8c [CuX(tn),]X (X = 3,5-dinitrobenzoate) has square pyramidal coordination with a fairly long (2.25 A) apical bond to monodentate X.'8d Another trans complex is [Cu(ONO2),(2,2-Me,-tn),] (axial oxygens).' Extensive EPR and electronic spectral studies have been performed on mixed-ligand complexes [CULL'] [BPh,], where L and L' are different polyamines.'8s Thecrystal structures ofseveral copper(r1)complexes with polyamines have been reported.[Cu(OC103)L][C10,] (L = 5,5-dimethyl-4,7-diazadecane- 1,lO-diamine) exhibits square pyramidal coordination with a long (2.46 A) apical Cu-0 bond,'8g while [CuL][ClO,] (L = 2,5,8,12,15-~entaazahexadecane) has trigonal bipyramidal coordination.'8h However [Cu(OC103),L] [L = N,N'-bis(3-aminopropy1)-trans- 1,2-diaminocyclohexane] has tetragonal4 + 2 coordination with axial Cu-0 distances of 2.53 and 2.5681.18' In [Cu(H2O)L]*2H,O (LH = N,N'-dialanyl- 1,2-diaminopropane) apical water completes square pyramidal CuN,O coordination.'8j Chiral cyclens (isomers of substituted [12]aneN,) give CuN,Cl chromophores ranging from trigonal bipyramidal to square pyramidal.' 8k [CULL'] [CIO,] (L = Me,dien L' = p-diketonate) have square pyramidal coordination with apical oxygen.'8' [Cu(OS0,)(Me6tren)].8H,0has trigonal bipyramidal coordina- tion.""' A method of incorporating the Jahn-Teller effect into molecular mechanics calculations on Cu"N6 chromophores is described.' 8n This paragraph covers monomeric copper(I1) complexes with bipy ,phen and related ligands.[Cu(NCS)(phen),] + is the first five-coordinate copper(I1) complex containing N-bonded thiocyanate (equatorial).' 9a [CuBr(phen),][ClO,] is also trigonal bi- pyramidal with equatorial bromine.19b [Cu(NCS),(bipy)] has long (3.22 A) Cu-S contacts completing 4 + 2 CuN,S c~ordination.'~" [CuL(bipy)]X (HL = 4-halogenophenylalanine X = NO, ClO,) is square pyramidal five-coordinate with the DL-aminoacid but square planar with the L form.'9d [Cu(FBF3),(bipy)(2-cy-anoguanidine),] has 4 + 2 coordinate copper with two bipy nitrogens and two CN nitrogens in the equatorial plane and long (2.60A) axial Cu-F bonds;' 9e this is the first example of cis-bis(2-cyanoguanidine) and hydrogen-bonding appears to assist the coordination of [BF,] -. Ligands L obtained from the condensation of 2,9-diformyl- phen and o-substituted aromatic primary amines give monomeric complexes [CuL] when the o-substituent is F C1 Br or CH,; with OMe or SMe substituents loose dimers are formed and these complexes are effective carriers for Cu2 across organic + liquid membranes.' sf The four-electron reduction of dioxygen is catalysed by T.H.Tahirov T.-H. Lu K. Shu and S.-C. Chung Acta Crystallogr. Sect. C Cryst. Struct. Commun. 1994 50,710; (k) N. Azuma Y. Kohno F. Nemoto Y. Kajikawa K. Ishizu T. Takakuwa S. Tsuboyama K. Tsuboyama K. Kobayashi and T. Sakurai Inorg. Chim. Acta 1994,215,109;(I) N. Shintani E. Nukui H. Miyamae Y. Fukuda and K. Sone Bull. Chem. Soc. Jpn. 1994,67,1828; (m)G. Anderegg and V. Gramlich Helu. Chim. Acta 1994 77 685; (n) P. Comba and M. Zimmer Inorg. Chem. 1994 116 5368. l9 (a)O.J. Parker,J. L. Manson and G. L. Breneman,Acta Crystallogr. Sect. C Cryst. Struct. Commun. 1994 50 1201; (b)0.J.Parker G. T. Greiner G. L. Breneman and R.D. Willett Polyhedron 1994,13 267; (c) 0.J. Parker B. L. Wilson and G. L. Breneman Acta Crystallogr. Sect. C Cryst. Struct. Commun. 1994,50 1681;(d)T. Sugimori H. Masuda and 0.Yamauchi Bull. Chem. SOC.Jpn. 1994,67,131;(e)A.S. Batsanov P. Hubberstey and C. E. Russell J. Chem. Soc. Dalton Trans. 1994 3189; (f) S. Ameerunisha and P. S. Zacharias Polyhedron 1994,13,2327;(g)Y. Lei and F. C. Anson Inorg. Chem. 1994,33,5003;(h)C.-C.Su and C.-B. Li Polyhedron 1994 13 825; (i) R. Cortes L. Lemaza J. I. R. Larramendi M. Instausti J. V. Folgado G. Madariaga and T. Rojo J. Chem. Soc. Dalton Trans. 1994 2573. 250 D. W.Smith copper(I1kphen complexes adsorbed on graphite electrode^.'^^ [Cu(FBF,)(4-Meim)(terpy)(H,O)][BF,] and [Cu(FBF3),(3-Meim)(terpy)] both have tetragonal 4 + 2 (or 4 + 1 + 1)c~ordination."~ [Cu(N,)Cl(terpy)] is the first complex contain- ing both halide and pseudohalide in the same coordination sphere (square pyramidal apical C1).I9' We turn now to other heterocyclic N-donor ligands.The absolute configuration of tv~ns-[Cu(OClO,),(py)~] has been determined the right-handed screw arrangement of py ligands confers chirality.20" [Cu(H,O),L,][NO,] [L = 3-(2-pyridyl)triazolo[1,5-~]pyridine]is the first copper(I1) complex with a triazolopyridine ligand (4 + 2 coordination).20b The effects of differing ligand field strengths for L' in [CULL'] (L = 2,2'-dipyridylamine L = tridentate azouracil derivative) T e apparent from EPR spectroscopy and X-ray studies on these square pyramidal ' Jmplexes.20c Trigonal bipyramidal coordination is found in [CuX,L] [X = Cl By NO,; L = 1-.,Od (pyridin-2-yl)-3-methyl-3,6-diazaheptane] [Cu(O,)L][ClO,] [L = tris{ (6- pivaloylamino)-2-pyridylmethyl}amine] is an EPR-silent superoxocopper(I1) com- plex with a Cu-0-0 angle of 108" and an 0-0 distance of 1.24 A; the coordination geometry is trigonal bipyramidal CUN,~.~'" 'Side-on' coordination of superoxide in a monomeric copper(I1) complex is achieved by steric inhibition of dimerization in [Cu(O,)L] [L = HB(~-BU'-~-P~'~Z),].~~~ [(CuCl,L),] (L = 2,6-diacetyl-pyridinedioxime) is not a chloride-bridged dimer but contains two independent monomeric molecules both having square pyramidal CuN,Cl coordination; analysis of a number of similar structures reveals a linear relationship between the axial copper-chlorine distance and the deviation of the copper atom from the basal plane.20g New tripodal polyimidazole ligands L give trigonal bipyramidal complexes [CUCIL],'~~ while analogous complexes with quinolyl-containing tripods are trigonal bipyramidal.20' cis-Diaquacopper(I1) complexes catalyse the hydrolysis of phosphon- ate esters but at high concentrations dimerization leads to loss of catalytic activity; this can be rectified by using a complex such as [CuCl,L] [L = bis(2-benzimidazolyl-methyl)amine square pyramidal CuN,Cl,] which undergoes hydrolysis to give a diaqua species but dimerizes with only one aqua bridge leaving one terminal water on each copper.20j [CuL,][I,} (LH = I-methylimidazole) is square planar the closest copper-iodine contact is at 3.40 A.20k[Cu(ONO,),L,(H,O),] (L = 1-phenyltet-raazole) has 4 + 2 coordination with axial nitrate.," ESEEM studies are reported for mixed-ligand copper(I1) complexes with dien and pyrazole/pyridazine.*'" The cop- '' (a)Y.Agnus M. Labarelle R. Louis and B. Metz Acta Crystallogr. Sect. C Cryst. Struct. Commun. 1994 50 536; (b)L. P. Battaglia M. Carcelli F. Ferraro L. Mavilla C. Pelizzi and G. Pelizzi J. Chem. SOC. Dalton Trans. 1994,2651;(c)J. M. Moreno J. Ruiz J. M. Dominguez-Vera E. Colacio D. Galisteo and R. Kivekas Polyhedron 1994,13,203; (d)A. Castineiras C. Vazquez R. Carballo C. Maichle-Mossmer and J. Strahle Polyhedron 1994,13,435; (e)M. Harata K. Jitsukawa H. Masuda and H.Einaga J. Am. Chem. Soc. 1994,116,lO 817; (f) K. Fujisawa M. Tanaka Y. Moro-oka and N. Kitajima J.Am. Chem. Soc. 1994 116 12 079; (g) K. A. Abboud R. C. Palenik and G. J. Palenik Acta Crystallogr. Sect. C Cryst. Struct. Commun. 1994,50,525;(h)S. Chen J. F. Richardson and R. M. Buchanan Inorg. Chem. 1994,33,2376; (i) N. Wei N. N. Murthy and K. D. Karlin Inorg. Chem. 1994,33,6093;(j)D. Wahnon R. C. Hynes and J. Chin J. Chem. SOC. Chem. Commun. 1994,1441; (k)K.-F. Tebbe and S. Nafepour Acta Crystallogr. Sect. C Cryst. Struct. Commun. 1994,50 171 ;(1) A. V. Virovets N. N. Podberezskaya L. G. Lavrenova and G. A. Bikzhanova Polyhedron 1994,13,2929;(m)F. Jiang and P. Peisach Inorg. Chem. 1994,33,1348;(n) M. Parvez and W. J. Birdsall Acta Crystallogr. Sect.C Cryst. Struct. Commun. 1994 50 540; (0)R. Sillanpaa R. Kivekas L. Escriche J. Casabo and G. Sanchez-Castello Acta Crystallogr. Sect. C Cryst. Struct. Commun. 1994,50 1062; (p) P. M. van Berkel W. L. Driessen R. Hamalainen J. Reedijk and U. Turpeinen Inorg. Chem. 1994 33 5920; (4)A. J. Bridgeman S. J. Essex and M. Gerloch Inorg. Chem. 1994,33 541 1 ; (r) M. A. Hitchman Comments Inorg. Chem. 1994 15 197. Copper 25 1 per(I1) complex formed when [CuL(NO)] [L = 3,5-R2HB(pz),] is allowed to stand in an atmosphere of NO contains bidentate nitrite.& In trans-[CuL2(NH,),].3H,0 (LH = 5-methylpyrimidine-2,4-dione) the copper atom is bonded to ring nitrogen atoms in the 3-position7 giving square CuN coordination.20" [CuCl,L] [L = 2,6-bis(2-pyrimidinylthiomethyl)pyridine] has square pyramidal coordination with a long apical (2.78 8,) copper-sulfur interaction.200 [CuClL],[CuCl,] and [CuClL] [BF,] [L = bis{2-(3,5-dimethyl-l-pyrazolyl)ethyl}amine] both contain monomeric cations with distorted tetrahedral CuN,Cl coordination.20P A new treatment of the vibronic intensities of d-d transitions in trans-[CuCl,L,] (L = py derivative) involves normal coordinate analyses of the complexes and ligand field analysis.204 Of related interest is a short review of vibronic effects on the spectra and stereochemistry of four- and six-coordinate copper(I1) complexes.20r In the field of porphyrin and phthalocyanin complexes EXAFS has been applied to the mechanism of the substitution of mercury(1r) for copper(I1) in porphyrins.21"3b Copper(r1) complexes with n-cation radicals continue to attract attention.The diamagnetism of [Cu(Et,-tpp)][ClO,] is interpreted in terms of antiferromagnetic exchange between copper(I1) and the radical ligand rather than copper(III).2 Similar behaviour is exhibited by copper(i1) complexes with 'short basket handle' por- phyrins.'ld EPR spectroscopy has been used to examine ring distortion in copper(I1) chlorophylls.2le Complexes with Oxygen or (Oxygen plus Nitrogen) Donor Ligands. Most copper(I1) complexes with oxygen donor ligands were dealt with in Section 2. Among others a redetermination of the crystal structure of [CuL,][SO,] (L = ethane-1,2-diol) which shows the expected 4 + 2 coordination is mainly of interest on account of the ligand conformations.22" An EPR spectroscopic study of [CuL,] (L = ethylacetoacetate) in chloroform shows the presence of two species in equilibrium in one of which there is opening of a chelate ring2,' [CwLL'(H,O]-H,O (H2L= methyl P-D-xylopyranose; L' = 1,2-diaminocyclohexane) has square pyramidal coordination with apical water.,," [CuL,(py),] (HL = ferrocene carboxylic acid) exists in two isomeric forms one with monodentate and the other with bidentate L.22d This paragraph covers complexes containing one or more chelating oxygen-donor ligands together with other types in the coordination sphere.[CuL,(py),] (LH = 3,4-dimethoxy-trans-cinnamic acid) has 4 + 2 coordination with bidentate carboxylate groups occupying equatorial and axial positions.23a [CuL(tmeda)]X (HL = 2,4-X diacetyl-5-hydroxy-5-methyl-3-phenylcyclohexane = NO, BPh,) has square planar CuN,O c~ordination.~,~ [Cu(OAc),L,] (L = 4-Mepy) has trans 4 + 2 c~ordination.~ 3c " (a)H.Ohtaki Y. Inada S. Funahashi M. Tabata K. Ozutsumi and K. Nakajima J. Chem. SOC. Chem. Commun. 1994 1023; (b)M. Tabata and K. Ozutsumi Bull. Chem. SOC. Jpn. 1994 67 1608; (c)M. W. Renner K. M. Barkigia Y. Zhang C.J. Medforth K. M. Smith and J. Fajer J. Am. Chem. Sac. 1994,116 8582; (d)M. Ravikanth A. Misra,T. K. Chandrashekar,S. Sathaiah and H. D. Bist Inorg. Chem. 1994,33 392; (e)Y. Nonomura N. Yoshioka and H. Inone Inorg. Chim. Acta 1994 224 181. " (a) I. Labadi L. Parkanyi R. Grobelny and J. Mrozinski Polyhedron 1994 13 2767; (b) B.S. Prabhananda N. D. Yordanov and N.Patev Polyhedron 1994,13,469;(c)M. Klaassen and P. Klufers Z. Anorg. Allg. Chem. 1994,620,1631; (d)A. L. Abuhijleh J. Pollitte and C. Woods Inorg. Chim. Actu 1994 215 131. 23 (a)M. G.B. Drew A. P. Mullins and D. A. Rice Polyhedron 1994,13 1631; (b)Y. Y. Lim W. Chen L. L. Tan and K. H. Lim Polyhedron 1994,13,2379;(c)M. J. Jedrzejas R. L. R. Towns R.J. Baker S. A. Duraj and A. F. Hepp Acta Crystallogr. Sect. C Cryst. Struct. Commun. 1994 50 1442. 252 D. W.Smith We now look at ligands containing both nitrogen and oxygen donor atoms. Monomeric copper (11) complexes with both tri- and tetradentate tripodal ligands having phenolate and benzimidazole pendants have been studied.,," cis-Square CuN,O coordination is found in [CuL,] (L = 2-ethoxycarbonylamino-6-methyl-pyridine N-o~ide)~~' and [CUL].H,O.~~' [Cu(OClO,),L] (L = 2,2'-bipyridyl N-oxide N-oxyl biradical) has 4 + 2 coordination and strong intermolecular antifer- romagnetic [CuL,]-A [LH = bis(l-methyliminomethyl-2-naphthol A = acceptor molecule e.g.173,5-trinitrobenzene] are donor-acceptor complexes with one-dimensional ~tacking.~," A potentially heptadentate Schiff base derived from the condensation of tren with 2-hydroxyacetophenone gives a copper(I1) complex in a zwitterionic form with square CuN,O coordination.24f Na[CuL2(N,)].2H,O has square pyramidal coordination with apical a~ide.,,~ In [CuL,]C12.2dma (L = cytosine) the coordination is best described as square CuN, with weak axial Cu-0 interactions; the chlorides are hydrogen-bonded to the ligand~.,,~ In [Cu(NCS),L] (L = 4,7-dimethyl-4,7-diazadecanediamide) axial amide oxygens com- plete 4 + 2 c~ordination.~~' The highlight in this area must be a study of [H,O][CuL] [L = [9]aneN,-1,4,7-triyltrimethylenetri~(phenylphosphinate)].The X-ray structure both at room temperature and at 135K shows a slightly distorted octahedral coordination geometry having strictly C symmetry. The EPR spectrum is isotropic at room temperature but a dynamic Jahn-Teller effect is frozen out at 8.6K with extraordinarily high g-values of g, = 2.58 and g1 = 2.14.,,j Complexes with Phosphorus and Sulfur Donor Ligands. A stable copper(r1) phosphine complex [CuL] [BF,] [L = N,N'-bis(2-diphenylphosphino)phenyl-1,2-dia-minoethane] has been obtained by controlled potential oxidation of the copper(1) ~omplex.~ 5a The tn analogue similarly prepared is proposed as a copper-selective hydrophobic e~tractant.,'~ Resonance Raman spectra support the view that [Cu(SR)(HB(3,5-Pr~pz),}][R = But Bus CPh, C,F,) may serve as models for blue copper proteins.5c Copper@) complexes with polyimidazole-thioether ligands have also been proposed as blue protein models.25d The thermal decomposition of [Cu(SCPh3){HB(3,5-Pr\pz),}] gives [Cu2(S,)(HB(3,5-Pr\pz),),] which is the first example of p-q2 :q2-disulfide in a copper(r1) Ligands 24 (a) R. Uma R. Viswanathan M. Palaniandavar and M. Lakshminarayanan J. Chem. SOC. Dalton Trans. 1994 1219; (b)D.X. West E. J. Zaluzek and S. P. Pavkovic Acta Crystallogr. Sect. C Cryst.Struct. Commun. 1994,50,173;(c)E. Labisbal J. Romero J. A. Garcia-Vazquez A. Sousa E. E. Castellano and J. Zukerman-Schpektor Actu Crystallogr. Sect. C Cryst. Struct. Commun. 1994,50 1043; (d)D. Luneau J. Laugier P. Rey G. Ulrich R. Ziessel P. Legoll and M. Drillon J. Chem. Soc. Chem. Commun. 1994,741; (e)M. Shiotsuka Y. Okaue N. Matsumoto H. Okawa and T. Isobe J. Chem. SOC.,Dalton Trans. 1994 2065; (f) D. E. Fenton G. P. Westwood A. Bashall M. McPartlin and I. J. Scowen J. Chem. Soc. Dalton Trans. 1994 2213; (9) M. A. S. Goher and F. A. Mautner Polyhedron 1994 13 2149; (h) A. Panfil A. Terron J. J. Fiol and M. Quiros Polyhedron 1994 13 2513; (i) J.-L. Lin T.-H. Lu T.H. Tahirov Y.-L. Liu T.-Y. Chi and C.-S. Chung Acta Crystullogr. Sect. C Cryst. Struct. Commun.1994,50 1003; 0') E. Cole R. C. B. Copley J.A. K. Howard D. Parker G. Ferguson J. F. Gallagher B. Kaitner A. Harrison and L. Royle J. Chem. Soc. Dalton Trans. 1994 1619. 25 (a)F. Tisato F. Vallotto G. Pilloni F. Refuse C. Corvaja and B. Corain J. Chem. Soc. Chem. Commun. 1994,2397; (b)Y. Cheng D. J. Schiffrin P. Guerriero and P. A. Vigato Inorg. Chem. 1994,33,765;(c)D. Qiu L. Kilpatrick N. Kitajima and T.G. Spiro J. Am. Chem. Soc. 1994 116 2585; (d)K.C. Tran J. P. Battioni J.L. Zimmermann C. Bois G.J.A.A.Koolhaas P. Leduc E. Mulliez H. Boumchita J. Reedijk and J. C. Chottard Inorg. Chem. 1994,33,2808;(e)K. Fujisawa Y. Moro-oka and N. Kitajima J. Chem. Soc. Chem. Commun. 1994,623;(f) U. Sivagnanam and M. Palaniandavar J. Chem. Soc. Dalton Trans. 1994,2277; (9)J.M. Desper and S. H. Gellman Angew. Chem. Int. Ed. Engl. 1994,33,319;(h)C. R. Lucas and S. Liu J. Chem. SOC.,Dalton Trans. 1994 185. Copper 253 R(CH,),S(CH,),S(CH,),S(CH,),R (m = 1,2 R = benzimidazol-2-yl) and RCH,(SCH,CH,),SCH,R give tetragonal CuN,S complexes with interesting redox behaviour and ligand folding.25f Other non-macrocyclic polythioether ligands yield square pyramidal copper(1r) complexes with a weak sixth bond to e.g. perchlorate oxygen. 5g [CuLIX (L = 3,6,9,12,1 Spentathiaheptadecane X = CF,SO, ClO,) also square pyramidal CuS systems have the highest E values among cop- per(II)-t hioether systems.25h Binuclear Copper(1r) Complexes.-It is convenient to classify these as containing 'simple' bridges or more complicated binucleating ligands.The distinction is of course not always clear-cut. Complexes with bridging carboxylates are included in the former category. Bridged Binuclear Complexes. [{ Cu(p-O,CH),(dmso)) ,] has the familiar syn-syn bridged structure with strong antiferromagnetic coupling.26a However syn-anti carboxylate bridging is found in [{CuL(Hpz)} ,][H,L = 5-((2-carboxyphenyl)azo)-1,3-dimethylbarbituric acid] .26b [NPr,],[{CuCl,(p-Cl)},] contains discrete non-planar anions as is usual for hexachlorodicuprates(r1)with bulky cations which allow no cation-anion hydrogen bonding.26c [{CuCl(p-C1)L},] (L = 2-ethoxycyanopyridine26d or 4,7-Ph,~hen,~") has square pyramidal copper with long apical Cu-C1 interactions. Volatile alkoxo-bridged species have been discussed in Section 2.Here we note [{Cu(NCS)(p-OCH(Me)CH,NPr\)},] whose magnetic properties appear to be complicated by a phase transition.26f In [Cu,(p-q2 :q2-0,)L,] [CF,SO,] (L = 1,4,7-Pr';[9]aneN3) the C-H bonds of the Pr' groups are labile.26g In [Cu,(l ,2-p-CO,)(LH2)(H,O),]~2H,O (LH = ascidiacyclamide a cyclic peptide) copper has square pyramidal CuN,O coordination and the Cu-Cu distance of 4.43 8 leads to weak ferromagnetism.26h A study of the very high field magnetization of [Cu,(p-ox)(tmeda) (2-MeHim),][PF6] reveals the inadequacy of a purely molecular description both inter- and intramolecular interaction parameters are required.26' FTIR studies of the liquid-crystal phase transition of anhydrous [Cu,{O,C(CH,),CH,},] (n = 4-8 10,12 14 16) indicate a change from bridging to chelating ligation on melting.26j Trigonal bipyramidal CuN,O coordination is found in [Cu2(p-L)(phen),]L.13H2O (LH = benzene-1,2-dioxyacetic acid).26k [{Cu(p- 26 (a)F.Sapina M. Burgos E. Escriva J.-V. Folgado D. Beltran and P. Gomez-Romero Inorg. Chim. Acta 1994,216,185; (h)E. Colacio J.-M. Dominguez-Vera R. Kivekas and J. Ruiz Inorg. Chim. Acta 1994,218 109; (c)G. Hu and E. M. Holt Acta Crystallogr. Sect. C Cryst. Struct. Commun. 1994 50 1212; (d)P. Byers M. G. B. Drew M. J. Hudson N. S. Isaacs and A. Upadhaya Polyhedron 1994,13 345; (e)A.M. Atria R. F. Baggio M. T. Garland and E. Spodine Acta Crystallogr. Sect. C Cryst. Strud. Commun. 1994 50 864; v) M. Mikuriya M. Yamamoto and W. Mori Bull. Chem. Soc. Jpn. 1994 67 1348; (9) S.Mahapatra J. A. Halfen E. C. Wilkinson L. Que and W. B. Tolman J. Am. Chem. Soc. 1994,116,9785;(h) A. L. van den Brenk K. A. Byriel D. P. Fairlie L. R. Gahan G. R. Hanson C. J. Hawkins A. Jones C. H. L. Kennard B. Moubaraki and K.S. Murray Inorg. Chem. 1994 33 3549; (i) P. Bergerat 0.Khan P. Legoll M. Drillon and M. Guillot Inorg. Chem. 1994,33,2049;(j)M. F. R. Molta M. L. T. S. Duarte and R. Fausto J. Chem. Soc. Faruday Trans. 1994,90,2953;(k)M. McCann M. Deveraux C. Cardin and M. Convery Polyhedron 1994 13 221; (I) G. Speier S. Tisza Z. Tyeklar C. W. Lange and C. G. Pierpont Inorg. Chem. 1994,33,2041; (m)J. Garcia-Tojal M. K. Urtiaga R. Cortes L. Lezama M. I. Arriortua and T. Rojo J. Chem. Soc. Dalton Trans. 1994 2233; (n) E.G. Bakalbassis J. Mrozinski S.P. Perlepes N. Hadjiliadis F. Lianza and A. Albinati Polyhedron 1994 13 3209; (0)M. A. Romero J. M. Salas M. Quiros M. P. Sanchez J. Romero and D. Martin Inorg. Chem. 1994,33,5417; (p)C. Fujii M. Mitsumi M. Kodera K.-I. Motoda M. Ohba N. Matsumoto and H. Okawa Polyhedron 1994 13 933; (4) N. Arulsamy J. Glerup and D. J. Hodgson Inorg. Chem. 1994,33,2066;(r)N.-E. Ghermani C. Lecomte C. Rapin P. Steinmetz J. Steinmetz and B. Malaman Acta Crystullogr. Sect. B Struct. Sci. 1994 50 157. 254 D. W.Smith L)(py),},] (LH = 3,5-di-t-butylcatechol) is obtained from the reaction of copper metal with the quinone in pyridine; each copper has square pyramidal coordination.26’ In [(CuX(p-L)},] (X = C1 Br LH = pyridine-2-carbaldehyde thiosemicarbazone) L is tridentate and the coppers are bridged by sulfur atoms.26m Five-coordination between square pyramidal and trigonal bipyramidal is found in [(Cu(p-C1)ClL) ,] [L = 2-(2’-pyridyl)quinoxaline a bidentate N ligand] .26n Trigonal bipyramidal coordination occurs in antiferromagnetic [{ CuBr(p-Br)L,},] (L = 5’7-dimethyl[1,2,4] triazolo [1,5-a]pyrimidine).260 ~Cu2(~~L)(MeoH)2(bi~~~2~~pF6~2 (L = chloranilate) is also weakly antiferromagnetic with a Cu-Cu distance of 7.66 Hydrogen-bonding links the monomeric units in [(CuL(LH)},][ClO,], where LH is a cis-N,O ligand formed by the template condensation of 2-aminoethanol formaldehyde and ammonia.264 A preliminary X-ray charge density study on [(Cu(heptanoate),},] is reported.26‘ Comptexes with Binucleating Ligands.‘H NMR spectroscopy seems an unlikely tool for probing the structures of copper(I1) complexes but COSY cross-signals observed between hyperfine-shifted signals in [Cu,(p-OH)(p-L)][ClO,] (LH = 2,6-bis[{bis(2-pyridylmethyl)amino}methyl]-4-methylphenol) allow a complete assignment of the spectrum.27a2,5-bis(2-pyridylthio)thiadiazole(L) is a tetradentate N binucleating ligand in [Cu,(p-Br),Br,L] where the copper atoms have square pyramidal coordination; the weak antiferromagnetism suggests that thiadiazole is less effective as a superexchange bridge than pyridazine or phthala~ine.,~’ Related work includes the observation of isotropic antiferromagnetic exchange via double 1,2,4-triazolato bridges.27‘ Another binucleating N ligand 1,2,4,5-tetrakis(benzimidaz01-2-yl)ben-zene (L) forms [(Cu(y-C1)L),][Cu2(p-C1),L(dmf),]C1,~12dmf;the first cation as written is ‘open’ while the second has a ‘closed’ metallacyclic structure.27d An unsymmetrical binucleating ligand H,L has salicylidene and 1-methyl-3-oxobut- 1-enyl end groups attached to 1,3-diaminopropan-2-01; in [Cu,L(p-pz)] with an exogenous pyrazolate bridge both moderately strong intramolecular and weaker intermolecular antiferromagnetism have been reported.27e Another case of fairly strong antiferromagnetism is found in [Cu,(C,O,),(bpym)(H,O),] where bipym is bis(bidentate) copper has the usual square pyramidal coordination and the Cu-Cu distance is 5.38 A.27J Stronger antiferromagnetism is observed in [Cu,LL’12 + 27 (a)R.C. Holz and J. M. Brink Inorg. Chem. 1994,33,4609; (b)S.S.Tandon L. Chen L. K. Thompson and J.N. Bridson Inorg. Chem. 1994,33,490; (c) P. M. Slangen P. J. van Koningsbruggen K. Goubitz J. P. Haasnoot and J. Reedijk Inorg. Chem. 1994,33,1121; (d)S.K. Tandon L.K. Thompson J. N. Bridson and J. C. Dewan Inorg. Chem. 1994,33 54; (e)P. K. Kruger B. Moubaraki K. S. Murray and E. R. T. Tiekink J. Chem. Soc. Dalton Trans. 1994,2129;v) 1. Castro J. Sletten L. K. Glaerum F. Lloret J. Faus and M. Julve J. Chem. SOC. Dalton Trans. 1994,2777;(g) S.-L. Ma D.-Z. Liao Z.-H. Jiang S.-P.Yan and G.-C. Wang Polyhedron 1994,13,1647; (h) C.-Y. Jin S.-L. Ma and D.-Z. Liao Polyhedron 1994,13,2881; (i) Z.N. Chen W.X. Tang and K.B. Yu Polyhedron 1994 13 783; 0’) C. R.K. Rao H. Aneetha B. Srinivas P.S. Zacharias and A. Ramachandraiah Polyhedron 1994 13 2659; (k) A.Andres C. Bazzicaluppi A. Bianchi E. Garcia-Espana S. V. Luis J. F. Miravet and J. A. Ramirez J. Chem. SOC. Dalton Trans. 1994,2995;(I) M. Mukherjee A. K. Mukherjee S. K. Dutta K. K. Nanda and M. Helliwell Acta Crystallogr. Sect. C Cryst. Struct. Commun. 1994,50,542;(m)Y.Y. Lim W. Chen L. L. Tan X. Z. You and T. M. Yao Polyhedron 1994,13,2861; (n)T. H. Tahirov T.-H. Lu K. Shu and C.-S. Chung Acta Crystallogr. Sect. C Cryst. Struct. Commun. 1994,50,708; (0)R. C. Holz J. M. Brink F. T. Gobena and C. J. O’Connor Inorg. Chem. 1994,33,6086;(p) K. Nonoyama W. Mori and M. Nonoyama Polyhedron 1994,13,891;(9) S. S. Tandon L. K. Thompson M. E. Manuel and J. N. Bridson Inorg. Chem. 1994,33 5555;(r)Y. Nakao M. Oonishi,T. Uzu H. Kashihara S.Suzuki M. Sakai and Y. Fukuda Bull. Chern.SOC. Jpn. 1994,67,2586;(s)H. Adams N. A. Bailey D. E. Fenton Q.He M. Ohba and H. Okawa Inory. Chim. Acta 1994 215 1. Copper 255 [LH = N,N'-bis(2-aminoethyl)oxamide,L' = bipy phen etc.] .27g*h trans-Oxami-dato bridging is found in [Cu(p-L)Cu(Him),][ClO,] and [CU(~-L)CU(N,),].~~' A dicopper(I1) complex with a Schiff base obtained from the condensation of 3,3'-dimethyl-4,4'-diaminobiphenyland pyridine-2-aldehyde catalyses the two-electron oxidation of ascorbic a~id.'~j [Cu,LCl,] (L = 2,5,8,1l-tetraaza[ 12lparacyclophane) is the first example of a dicopper(I1) complex with a tetraazamacrocycle containing a continuous set of N-donors (with a benzene spacer) linked by ethylenic Other binucleating ligands for copper(I1) include 2,6-bis(aminomethyl)-4-methyl-phenolate,' 71 1,1,2,2-tetraacetylethanediide,' 7m N,N'-diglycyl- 1,2-diamin0ethane,,~" N,N'-(2-hydroxy-5-methyl-1,3-xylylene)bis(~-carboxymethylglycine),'7o and an N,N'-disubstituted imidazole with 4,5-dicarboxamide From studies on a series of dicopper(I1) complexes with binucleating diazine ligands and (11-1 ,1-N,) bridges it is concluded that contrary to earlier assertions azide bridging in this mode can propagate antiferromagnetic coupling provided that the bridging angle is large enough.27q Dicopper(I1) complexes with binucleating ligands having imidazole groups with two exogenous bridging ligands such as N, OAc NCS etc.have been studied.27r Finally [(CuL),][ClO,] [HL = 2-(bis(2-pyridylethyl)aminomethyl)phenol] where the oxygen-bridged copper atoms are five-coordinate is proposed as a model for galactose o~idase.,~~ Oligonuclear Copper(I1) Complexes.[Cu,(p-Cl),L,]Cl (L = [14]aneN,) has a cen- trosymmetric cation.28a [Cu,(hfpd),(p-L),] where L is an alkyl nitronyl nitroxide biradical is a seven-spin cluster with complex magnetic coupling.28b The angular tricopper(I1) complex [Cu,(p-oA~),(bipy),(H~o)][PF~]~ may provide a model for ascorbic oxidase there is strong ferromagnetic coupling between the two closest copper atoms (3.20 A).28cA remarkable organocopper(I1) cation occurs in [Cu,(p- Ph),L2][CU5Ph6] (L = Me,dien). The metal atoms are collinear the terminal coppers having trigonal bipyramidal CuN,CCu coordination while the central copper has distorted tetrahedral CuC coordination; the Cu-Cu distances of 2.39 and 2.42 8 are consistent with single bonds.28d Reactions of [{Cu(p-L),},] (LH = 6-chloro-2-pyridone) produce several oligomers; MeOH gives [Cu,(p-L),(p-OMe),] with a Cu parallelogram while reaction with [(Cu(OAc),(H,O)),] gives [Cu,(p4-O),(OAc),L,] with an edge-sharing 0-centred bitetrahedron.28e A new type of quadruply bridging oxygen is reported in [Cu,(p,-O)(p,-X),L,] [X = Br OBz LH = 2,6-bis(morpholinomethyl)-4-methylphenol].28f The complex [Cu,(p2-O),( PhN,C,H,N,(H)Ph),] is obtained from the reaction of [Cu(NH,),I2+ with 1,2-bis(phenyltriazeno)benzene;the oxygen atoms bridge opposite edges of the Cu tetrahedron.28g The most remarkable Cu complex of the year is surely the thermally stable peroxide [Cu,L,(p4-(~1)4-02)(p2-OMe)2(p4-02C102)][C104]: quadruply-'' (a)V.Bulach D. Mandon J. Fischer R. Weiss E. Bill C. Butzlaff and A.X. Trautwein New. J. Chem. 1994,18 709; (b)A. Caneschi L. David F. Ferraro D. Gatteschi and A. C. Fabretti Inorg. Chim. Acta 1994,217,7;(c)S. Meenakumari S. K. Tiwary and A. R. Chakravarty Inorg. Chem. 1994,33,2085;(d)X. He K. Ruhlandt-Senge P. P. Power and S. H. Bertz J. Am. Chem. Soc. 1994,116,6963; (e)A. J. Blake C. M. Grant P. E.Y. Milne J. M. Rawson and R. E. P. Winpenny J. Chem. SOC.,Chem. Commun. 1994 169; v) S. Teipel K. Grieser W. Haase and B. Krebs Inorg. Chem. 1994 33 456; (g) M. Homer J. Bordinhao J. Beck and J. Strahle Z. Anorg. Allg. Chem. 1994,620,107;(h)J. Reim and B. Krebs Angew. Chem.Int. Ed. Engl. 1994,33,1969;(i) A. J. Blake R. 0.Gould C. M. Grant P. E. Y. Milne and R. E. P. Winpenny,Polyhedron 1994,13,187;0)A. J. Blake R. 0.Gould C. M. Grant P. E. Y. Milne D. Reed and R. E. P. Winpenny Angew. Chem.,Int. Ed. Engl. 1994,33,195;(k)J. A. Real G. De Munno R. Chiappetta M. Julve F. Lloret Y. Journaux J.-C. Colin and G. Blondin Angew.Chem. Int. Ed. Engl. 1994,33,1184. 256 D. W. Smith bridging peroxide and perchlorate are in the same complex!2sh Na[Cu,L,,][NO,] (LH = 2-hydroxy-6-methylpyridine) acts as a ligand-transfer agent between copper(I1) and iron@) or cobalt(rI).28' With the same L [Cu,L,,][Pb(NO,),] provides an example of a copper-containing metallacrown; six coppers occupy carbon positions in the crown octahedral1 y surrounding the seventh.'j [Cu (OH) (bpym) (H ,O),] [NO,] 6 has a hydroxo-bridged corner-sharing cubane structure with intramolecular ferromagnetic interactions; the shortest Cu-Cu distances are 2.9-3.5 A.28k Heterometallic Complexes Containing Copper(l1). Here -in contrast to the hetero- metallic systems described in Section 2 of interest mainly as precursors to mixed oxides etc. -we consider systems where magnetic properties and/or biological interest are paramount. [CaCuL4(ON02)2(H,0)],[Ca(ONOz)4(H,0)]betaine) can be viewedz9" as (L = containing eight-coordinate [CuL412+ ions perturbed by Ca2+ as can [{CaCu(OOCCH2NEt,)4(ON0,)(H,0)}z][N0,]4~5Hz0.29b A large series of het- erobimetallic complexes containing [Cu(p-L)ML'] cores [LH = 3,9-dimethyl-4,8-dia~aundeca-3~8-diene-2,lO-dione dioxime L' = Me [9]aneN, M = Cr"' Mn" Mn"' Fe" Fell' Co'' CoIII Ni" Zn"] has been prepared.29c Another series containing copper(I1) and M(Iv) (M = Si Ge Sn Ti Zr) is obtained from the template condensation of [Cu(tn),12 + with a large 2,5-di0ne.,~~ [Cu(terpy)(p-ox)VO(ox) (H ,O)].H,O is ferr~magnetic,~~" while [Cu(p-L)M"] [M = Mn Fe Co L = N,N'-bis(3-carboxylsalicylidene)trimethylenediamine] are weakly antiferr~magnetic.,~~ [CuLMnCl] (H,L = biphenylene-bridged bisporphyrin) reacts reversibly with 02.29g The exchange coupling constant for the Mn"-Cu"-Mn" system [{ Mn(Me,-[ 141 aneN4)},CuL][CF,SO,],-2H2O [L = 1,3-propylenebis(oxamato)(-4)] has been de- termined29h from the intensity of a spin-forbidden transition around 25 000cm-'.A study of the magnetic properties of [Cu(pc)(p-L)Fe"(NCS),(p-L)Cu(pc)](L = N-o-tolyl-2-imidazolaldimine) focuses upon the effects of the copper atoms on the iron spin crossover.29i The linear Cu-N-C-Fe bridging in [CU(Me,tren)(p-NC)Fe(Oep)(py)]+ may be relevant to the inactivation of cytochrome c oxidase by ~yanide.'~',~ A linear + Cu-0-Fe bridge occurs in [Cu(trnpa)(p-O)Fe1"L'] [LH; = tetrakis(2,6-di-29 (a) X.-M. Chen and T.C. W. Mak Inorg. Chem. 1994 33 2444; (h)X.-M. Chen and T.C. W. Mak Polyhedron 1994,13,1087;(c)F.Birkelbach M. Winter U. Florke H.-J. Haupt C. Butzlaff M. Lengen E. Bill A. X. Trautwein K. Weighardt and P. Chaudhuri Inorg. Chem. 1994,33,3990; (d)K. S. Siddiqi F. Arjmand M. Rahman S. Tabassum and S. A. A. Zaidi J. Chem.Res. (S) 1994 84; (e)R. Cortes M. K. Urtiaga L. Lemaza M. I. Arriortua and T. Rojo Inorg. Chem. 1994,33,829;(f) Z. W. Yu R. J. Tao X. Y. Zhou D. M. Jin and D.Z. Liao Polyhedron 1994 13 951; (g) R. Guilard S. Brandes A. Tabard N. Bouhmaida C. Lecomte P. Richard and J.-M. Latour J. Am. Chem. Soc. 1994 116 10202; (h) C. Mathoniere and 0.Khan Inorg. Chem. 1994,33,2103;(i) C. F. Shue Z. C. Lee H. H. Wei M. C. Cheng and Y. Wang Polyhedron 1994 13,2259; 0')S.C. Lee M. J. Scott K. Kauffmann E. Munck and R. H. Holm J. Am. Chem. SOC.,1994,116,401;(k)M. J. Scott S. C. Lee and R. H. Holm Inorg. Chem. 1994,33 4651; (I) K. D. Karlin A. Nanthakumar S. Fox N.N. Murthy N. Ravi B. H. Huynh R. D. Orosz and E. P. Day J. Am. Chem. Soc. 1994,116,4753; (m)R. Cortes L. Lezama J.I. R. Larramendi M. Insausti J. V. Folgado G. Madariaga and T. Rojo J. Chem. Soc. Dalton Trans. 1994,2573; (n)E. Colacio J. M. Dominguez-Vera A. Escuer R. Kivekas and A. Romerosa Inorg. Chem. 1994,33,3914;(0)F. Lam R.-J. Wang T. C. W. Mak and K. S. Chan J. Chem. SOC.,Chem. Commun. 1994,2439;(p) S.-Y. Yu Q.-H. Luo X.-Y. Xu M.-C. Shen and L.-R. Huang Polyhedron 1994 13 1583; (4)Y.-T. Li Z.-H. Jiang S.-L. Ma X.-Y. Li D.-Z. Liao S.-P.Yan and G.-L. Wang Polyhedron 1994,13,475;(r)A. N. Papadopoulos A. G. Hatzidimitriou A. Gourdon and D. P. Kessissoglou Inorg. Chem. 1994,33 2073; (s)T. Hosokawa M. Takano S.-I. Murahashi H. Ozaki Y. Kitagawa K. Sakaguchi and Y. Katsube J. Chem. SOC.,Chem. Commun. 1994,1433;(t)A. Schreiber 0.Krizanovic E. C. Fusch B. Lippert F. Lianza A.Albinati S.Hill D. M.L. Goodgame H. Stratemeier and M.A. Hitchman Inorg. Chem. 1994 33 6101. Copper 257 fluorophenyl)porphyrin] a cytochrome c oxidase model (cf ref. 8f); the Fe-0 and Cu-0 bonds are very short and the ground state has S = 2.29' Some interesting copper-nickel systems have been reported. [(C~,~,,Ni,~,,(terpy)(p-N,)~}~] has end-on azide bridging giving 4 + 2 coordination about copper with a ferromagnetic intera~tion.~~"' Unusual asymmetric bridging is reported in the case of [Cu(OClO,)(p- L)Ni(Me,[ 12]aneN3)][C10,] [LH = a,m-bis(1,3-dimethy1-5-nitrosouracil-6-y1)aminopropanel.29n A Ni"-Cu" complex is formed with a binucleating Schiff base-pyridine ligand.290 [CuL(p-im)Zn(tren)][ClO,] [L = (2-acetyl-pyridineimino)ethyl] is proposed as a model for superoxide dism~tase.~~P [CuGd(p-L)(phen),][ClO,] [LH = N,Nf-bis(2-aminoethyl)oxamide],where the copper has square CuN coordination is weakly antiferr~magnetic.,~~ An oxomolybdate-cop- per(I1) cluster has been reported in the form of [CuMo,O,(HL),(bipy),] [LH = 5-chloro-1,3-dihydroxy-2-methyl-2-(salicylideneamino)propane] which contains a (bipy),Cu-0-Mo bridge.29r [CuClL,(p-Cl)PdCl(p-Cl),PdCl],(L = pyrrolidin-2-one) catalyses the oxidation of alkenes as in the Wacker process.29s A Pt!$Y system has been identified in trans-[PtL,(pL),Cu(p-Lf),PtL2] (L = NH, MeNH, HL' = 2-~yridone).,~' Polycopper(z1) Complexes.Beginning with chain polymers [Cu,LL'] [LH = N,N'-bis(2-aminopropyl)oxamide L'H = fumaric acid] consists of alternating chains of copper atoms bridged by both L and L' (square CuN,O,) with strong antiferromag- netism.," [CuClL(H,O)] (LH = quinic acid) is a chain polymer (4 + 2 coordina- tion).," Alternating chains having respectively ferro- and antiferromagnetic interac- tions occur in [Cu,(tim)Cl,],.30c Complex bridging leads to 4 + 2 coordination in [Cu(p-~2-pyridazine)(p-OH)(p-02NO)]n.30d The first example of end-to-end cyanate bridging is reported in [CU(~-NCO)L],[C~O,]~ (L = N,N,N',N",N"-penta methyl-3-azapentane-1 ,5-diarnine).,Oe [Cu(p-L)(H,O),] (LH = 2,2'-bipyridyl-3,3'-dicarboxylic acid) is another weakly antiferromagnetic chain polymer having square pyramidal coordination.30S [Cu,(OAc),L,] [L = 2-(aminoethy1)pyridinel forms one-dimensional chains with alternating Cu,(OAc) and [CU,(OAC),L,]~ -units linked by syn and anti bridging acetates.30g In K2[Cu,(OAc),][Cu(OAc),1 dimers and monomers are similarly linked into chains.30h A helical chain polymer [CuL,];nEt,O 30 (a) Z.N.Chen W.X. Tang F. M. Miao and J. L. Wang Polyhedron 1994 13 2543; (b) I. Bkouche-Waksman Acta Crystallogr. Sect. C Cryst. Struct. Commun. 1994 50 62; (c)J.J. Borras-Almenar E. Coronado J. Curely R.Georges and J.C. Gianduzzo Inorg. Chem. 1994 33 5171; (d)L. Carlucci G. Ciani M. Moret and A. Sironi J. Chem. Soc. Dalton Trans. 1994 2397; (e)R. Vicente A. Escuer E. Penalba X. Solans and M. Font-Bardia J. Chem. Soc. Dalton Trans. 1994 3005; v) Z. J. Zhong X.-Z. You and Q.-C. Yang Polyhedron 1994,13,1951;(9)J. Val0 and M. Nasakkala Acta Chem. Scand.1994 48,20; (h)C. A. Crawford E. F. Day W. E. Streib J. C. Huffman and G. Christou Polyhedron 1994 13 2933; (i) R. W. Saalfrank 0.Struck K. Peters and H. G. von Schnering Inorg. Chim. Acta 1994,222,s; (j) E. G. Bakalbassis and A. Terzis Inorg. Chim. Acta 1994,218,167;(k)M. Ferigo P. Bonhote W. Marty and H. Stoeckli-Evans J. Chem. Soc. Dalton Trans. 1994 1549; (I) G. de Munno D. Viterbo A. Caneschi F. Lloret and M. Julve Inorg. Chem. 1994,33,1585; (m)F. A. Mautner and M. A. S. Goher Polyhedron 1994 13,2141; (n)Z.N. Chen J. Qiu Z. K. Wu D.G. Fu K. B. Yu,and W. X. Tang J. Chem. SOC. Dalton Trans. 1994 1923; (0)Z. N. Chen J. Qiu W. X. Tan and K. B. Yu Inorg. Chim. Acta 1994,224 171; (p) Z. N. Chen D. G. Fu K. B. Yu and W. X. Tang J. Chem. SOC. Dalton Trans. 1994 1917; (4)Z.N. Chen S. X. Liu J. Qiu Z.M. Wang J.L. Huang and W. X. Tang J. Chem. SOC. Dalton Trans. 1994 2989; (r)S. Kawata S. Kitagawa M. Kondo I. Furuchi and M. Munakata Angew. Chem. Int. Ed. Engl. 1994 33 1759; (s) T. Nozaki H. Ushio G. Mago N. Matsumoto H. Okawa Y. Yamakawa T. Anno and T. Nakashima J. Chem. SOC.,Dalton Trans. 1994 2339; (t) R.J.H. Hafkamp M.C. Feiters and R.J.M. Nolte Angew. Chem. Int. Ed. Engl. 1994,33,986;(u)M. F. Ottaviani S. Bossmann N. J. Turro and D. A. Tomalia J. Am. Chem. SOC. 1994 116 661. 258 D. W.Smith (HL = (S)-methyloxycarbonyl pyrrolidine) is self-assembled from (S)-pyroglutamic acid and [{Cu(OAc),(H,0)},].30i Phthalate (L) forms the bridges in the antiferromag- netic chain polymer [C~(p-L)(pip),],,.~~j 2,3,5,6-tetrakis(aminomethyl)pyrazine(L) is a new bis(tridentate) ligand in the 'ladder' polymer [Cu,Cl,L],Cl,, where copper has square CuN,Cl coordination with long (2.87 A)axial Cu-C1 contacts.30k In diamag- netic [Cu,(H30,)(p-bipym)(H,0)2][C104]3 the chains are connected to form a two-dimensional network by HO -.-H .* .OH bridges.," In [Cu(N,),L] (L = 3,4-lutidine) and [Cu,(N,),L,] (L = 2,ti-lutidine) the coppers are bridged by ,u-(1,l) azide;,Om but three different modes of bridging are found in [Cu,(N,),L,],[ClO,] [LH = N,N'-bis(aminoethyl)oxamide] The same oxamidate L forms two-dimen- sional sheet polymers [Cu,L(L'),],[ClO,], (L' = 4,4'-bipy or pyrimidine)300J' and [Cu,LL'(H,O)],[ClO,] (L'H = pyridine-4-carboxylic acid);,'q the latter has an unusual triply bridging carboxylate linking the monomeric units into sheets.All of these oxamidate-bridged complexes are strongly antiferromagnetic. In [CULL'] (H,L = chloranilic acid L' = pyrazine) the bridging L form chains which are linked by L into a two-dimensional net~ork.~" The self-assembly of [[{Cu(HL)),]"+ where LH is a tetradentate Schiff base appears to be partly controlled by the ligand field strength of HL.,OS pH-tunable supramolecular structures can be obtained with Cu2+ and gluconamide-containing imida~ole.~~' The formation of starburst dendrimers -macromolecules having fractal symmetry -containing Cu2 has been studied by EPR + spectroscopy.,OU 4 Mixed-valence and Copper(rr1) Complexes In [Cu~(PR3),Cu"(p-00CCH2C00),] the copper(1) atoms are four-coordinate for R = Ph but three-coordinate for R = Cy; the copper(I1) atoms are square planar CUO,.~~' (L) to give [Cu',Cu"Cl,L] CuCl reacts with 1,3-dithiacyclohexane-2-thione which contains the unique tetragonal Cu"Cl,S coordination.lb [Cu"(,u-CN)(phen),Cu'CN(phen)] [NCS] ,.2H,O has trigonal bipyramidal Cu"N and tet- rahedral Cu'C,N p~lyhedra.~" A dicopper(1) azacryptate undergoes one-electron oxidation to give a Cu'Cu" system with a singly deprotonated pyrrole The copper(I1) atoms in the discrete cations in [Cu~(p-OCH,CH,CH,NH,),][Cu~I,] are collinear the anions form polymeric chains.31e The EPR-silent [Cu,Br,(dmf),(H,O)] contains trigonal bipyramidal Cu"Br,O and tetrahedral Cu'Br units. If The copper(1)-semiquinone/copper(Ii)-catecholate tautomerism has been studied by EPR spectroscopy; the replacement of a nitrogen-donor by sulfur favours copper(^).^ lg A copper-copper bond is formed in [Cu,] + complexes with binucleating macrobicyclic ligands; EPR spectroscopic studies show that the unpaired electron is in the antibonding MO arising from overlap of the d, orbitals of the two equivalent coppers.lh This year has seen remarkable developments in copper(r1r) chemistry. Square 31 (a)D. J. Darensbourg M. W. Holtcamp B. Khandelwal K. K. Klausmeyer and J. H. Reibenspies Inorg. Chem. 1994,33 2036; (b)C. Bellitto F. Bigoli P. Deplano M. L. Mercuri M. A. Pellinghelli G. Staulo and E. E. Trogu Inorg. Chem. 1994,33,3005; (c)I. Potochak M. Dunaj-Jurco M. Kabesovc D. Miklos and V. Kettmann Acta Crystallogr.Sect. C Cryst. Struct. Commun. 1994 50 380; (d) Q. Lu V. McKee and J. Nelson J. Chem. Soc. Chem. Commun. 1994,649; (e)S. Myllyviita and R.Sillanpaa J. Chem. SOC. Dalton Trans. 1994,2125; v) A. J. Blake R. L. Dorse J. M. Rawson and R. E.P. Winpenny Polyhedron 1994 13,2793; (g)J. Rall and W. Kaim J. Chem. Soc. Faraday Trans. 1994,90 2905; (h)C. Harding J. Nelson M. C.R. Symons and J. Wyatt J. Chem. Soc. Chem. Commun. 1994 2499. Copper 259 [Cu(CF3),] -occurs in the 1,1,2-trichloroethane solvate of K,[ET],[Cu(CF,),] the first example of a superconducting (T,= 4 K) organic cation-radical salt with an organometallic anion. Another o-organocopper(rrr) species has been implicated in the mechanism of the decomposition of a copper(rr1) tripeptide complex to a copper(1) species; the first step involves decarboxylation with formation of a Cu"'-C bond.32b Square Cu"'S coordination is found in 1,2-and 2,3-dithiolate~.~~"*~ Ba4K[Cu(0,Te0,)(OH),][OH],~6H20and related compounds with square Cu"'0 coordination have been prepared both electrochemically and by ozone oxidation from copper(r~).~~" Square Cu"'N coordination is found in [Li(thf),][CuL] (LH = meso-octaeth ylporphinogen).2s Corrigenda Owing to editorial error the article 'Copper' by D. W. Smith in last year's volume contained mistakes. The article should have read thus. Page 210 line 6 [piperazinium],[(Cu(p-I),),1 line 13 [PPh,],[Cu,Te,,] line 22 [CuL,],X line 29 [Cu2Se,(SC,H3),(p-WSe4)]2-Page 21 1 line 2 (n = 1,2) line 18 [Cu,Br,(dppm),] line 26 (X = ClO,,NCS) Page 212 line 13 [C~,(p-dppm)I,]~+ ref.76 J. Phys. Chem. Solids 1993 54 15 357 Page 21 3 line 11 LiCuM30 (M = Nb Ta) line 17 M"CuSi0 (M = Ca Sr Ba) ref. 94 Acta Crystallogr. Sect. B Struct. Sci. ref. 107 2.Anorg. Allg. Chem. 1993 619 1287 Page 214 line 17 The d-d spectra of square planar bis( 1,3-diketonato)copper(rr)complexes ref. 121 C. J. Simmons M. A. Hitchman H. Stratemeier and A. J. Schultz J. Am. Chem. SOC. 1993 115 11 304. Page 216 ref. 144 Acta Crystallogr. Sect. B Struct. Sci. 32 (a)J.A. Schlueter U. Geieser J. M. Williams H. H. Wang W.-K. Kwok J. A. Fendrich K. D. Carlson C.A. Achenbach J. D. Dudek D. Nauman T. Roy J. E. Schriber and W. R. Bayless,J. Chem. SOC.,Chem.Commun. 1994 1599; (b)S. Goldstein G. Czapski H. Cohen D. Meyerstein and R. van Eldik Inorg. Chem. 1994,33,3255;(c)T.-M. Yao X.-Z. You C. Li L.-F. Li and Q.-C. Yang Acta Crystallogr. Sect. C Cryst. Struct. Commun. 1994 50 67; (d) R. D. Bereman G. Chung B. W. Knight P. Singh and T. W. Welch J. Coord. Chem. 1994 32 51; (e) M. Wu Q. Su Y. Ren G. Hu S. Du X. Cao and Z. Wu Polyhedron 1994,13,2489; (f) S. De Angelis E. Solari C. Floriani A. Chiesi-Villa and C. Rizzoli J. Am. Chem. SOC. 1994 116 5691. 260 D. W.Smith Page 217 line 1 [Cu(HCpz3),12+ line) (py[Cu(O,SPh),:18 J line 19 [L = 1,2,6,7-tetracyano-3,5-dihydropyrrolizinide(1-) J Page 220 line 15 [L = HB(3,5-Pr\pz),] Page 221 line 19 [H2dmpz][Cu2C1,{N3P30(dmpz),)1 line 22 [Cu2(p-C12)L] Page 222 line 7 CCu,L(~2-~O,),(NO,)2(~2-~H)2(H2~~21"~3J~ Page 223 line 3 [{ Cu3L,(dien)(H20)2}.3H20]n

ISSN:0260-1818    

DOI:10.1039/IC9949100241

出版商:RSC    

年代:1994

数据来源: RSC

摘要:

17 The Noble Metals By G. REID Department of Chemistry University of Southampton High field Southampton SO1 7 1 BJ UK 1 Introduction The format of this review parallels that of last year describing key developments in the chemistry of the noble metals reported in the major scientific journals during 1994. Again due to space restrictions the review cannot be comprehensive but will focus on the coordination chemistry of these elements with aspects of their organometallic and cluster chemistry also being discussed. 2 Ruthenium [RuC1(=C=C=C=C=CPh2)(dppe),][PF6] is the first isolated and fully character- ized pentatetraenylidene metal complex and a key intermediate in the formation of allenylidene complexes. Activation of terminal alkynes with cis-[RuCl,(dppe),] leads either to monoalkynyl or bis(alkyny1) ruthenium complexes.These are precursors to trans-[Ru(CCR)(NH,)(dppe),][PF,] and [Ru(CCPh)(=C=C=CPh,)(dppe),] [PF,].' The [RuH,(PPh,),]-catalysed condensation of nitriles with alcohols in the presence of H20proceeds efficiently under neutral conditions giving the corresponding esters and lactones. Tetrakis primary and secondary phosphine complexes of ruthenium and osmium trans-[MCl,(PHR,),] (R = Ph Cy) and trans-[MCl,(PH,Ph),] exhibit reversible M"/M"' redox couple^.^ Several ruthenium(I1) complexes of formula trans-[RuX,(L- L)2] (X = Cl Br; L-L = bidentate selenoether or telluroether ligand) have been prepared of which [RUC~,(P~S~(CH,),S~P~)~] has been crystallographically charac- terized. These complexes also exhibit reversible Ru"/Ru"' redox couples.[RuCl,(PPh,),] reacts with azine phosphines to give complexes showing strong agostic Ru-H-C interactions with But Me aryl or alkenyl groups. D. Touchard P. Haquette A. Daridor L. Toupet and P. H. Dixneuf J. Am. Chem. SOC.,1994,116,ll 157. D. Touchard C. Morice V. Cadierno P. Haquette L. Toupet and P. H. Dixneuf J. Chem. Soc. Chem. Commun. 1994 859. T. Naota Y. Schichijo and S.-L. Murahashi J. Chem. Soc. Chem. Commun. 1994 1359. A. J. Blake N. R. Champness R. J. Forder C. S. Frampton C. A. Frost G. Reid and R. H. Simpson J. Chem. SOC. Dalton Trans. 1994 3377. N. R. Champness W. Levason S. R. Preece and M. Webster Polyhedron 1994 13 881. S. D. Perera and B.L. Shaw J. Chem. SOC. Chem. Commun. 1994 1201.261 262 G. Reid [RuH,(H,),(PCy,),] reacts with N, CO, CS, pyrazole phenol and cyclohexanone via initial substitution of one or two dihydrogen ligand~.~ [RuHCl(dippe),] forms the 16-electron five-coordinate species [RuH(dippe),] in alcohol. This reacts with CO + CNBu' or nitriles to give trans-octahedral complexes or with H to give [RuH(H,)(dippe),]+. The hydrido hydrogen complexes react with 0 to give trans-[RuH(q2-0,)(dippe),] ,which has been structurally characterized.8 + [Ru(H),(dmpe),] is protonated by weak organic acids such as MeOH EtOH and thiols to give the dihydrogen complex [RuH(q2-H2)(dmpe),] . The weakly bound H + ligand is easily displaced by alkane and arene thiols to give trans-monothiolate hydrides.' The ruthenium(I1) complexes [RuHCl(CO)(PPh ,)(L-L)] (L-L = dppm dppe dppp dppv and dppf) catalyse the hydrogenation of cyclohexene." The synthesis and photochemical and photophysical properties of ruthenium(11) and osmium(I1) bis(terpy) complexes in covalently linked multicomponent systems have been reviewed,' and the long-range metal-metal coupling in dinuclear Ru(terpy) systems with conjugated bridging ligands has been investigated.Spectroscopic and electrochemical measurements have also been made on rigid rod-like dinuclear Ru"/Os"(terpy)-type complexes. CalixC41arene-linked Ru"(bipy) complexes exhibit luminescent pH sensor action; the Ru"(bipy) unit acts as the luminophore and the phenolic functions of the calixC4larene fragment act as the acid-base sites.l4 The synthesis photophysics and redox properties of the luminescent complexes [Ru(bipy),(p-2,3-dpp)PtMe,12 + [2,3-dpp = 2,3-bis(2-pyridyl)pyrazine]and its Ru"-Cl,-Pt" and Ru"-C1,-Pd" ana-logues have been reported. These systems exhibit red ,MLCT emission at room temperature. l5 Electrocatalytic reduction of CO on a carbon/[{R~~(CO),(bipy)}~] modified electrode leads to the selective and quantitative formation of CO even in pure aqueous electrolyte.16 Electrochemical CO reduction by [Ru(C0)(bipy)(terpy)l2 gives + several identifiable products. The multi-electron reduction of CO at -20 "C appears to be as~ociated'~ with the thermal lability of [Ru(CO)(bipy)(terpy)] and CRu(CHO)(bipy WrPY 11+ . Reduction of (1) to (2a) and (2b) is photocatalysed under regio-control by + [Ru(py)(bipy)(terpy)I2 and [Ru(py),(L-L)J2+ (L-L = bidentate ligand)." The photocatalysis proceeds through photosubstitution of a py ligand and subsequent photoformation of [RuH(bipy)(terpy)] + or [RuH(py)(L-L),] .The pendant polymer + M.L.Christ S. Sabo-Etienne G. Chung and B. Chaudret Inorg. Chem. 1994 33 5316. M. Jimenez-Tenorio M. C. Puerta and P. Valerga Inorg. Chem. 1994 33 3515. L.D. Field T. W. Hambley and B. C. K. Yew Inorg. Chem. 1994,33 2009. lo S. Huh Y. Cho M.-J. Jun D. Whang and K. Kim Polyhedron 1994 13 1887. J.-P. Sauvage J.-P. Collin J.-C. Chambron S. Guillerez C. Coudret V. Bolzani F. Barigalletti L. De Cola and L. Flamigna Chem. Rev. 1994 94 993. lZ J. -P. Sutter D. M. Grove M. Beley J.-P.Collin,N. Veldman A. L. Spek J.-M. Sauvage and G. van Koten Angew. Chem. Int. Ed. Engl. 1994 33 1282; M. Beley S. Chodorowski-Kimmes J.-P. Collin P. Laine J.-P. Launey and J.-P. Sauvage Angew. Chem. Int. Ed. Engl. 1994,33 1775. l3 F. Barigelletti L. Flamingni V. Balzani J.-P. Collin J.-P. Sauvage A. Sour E. C. Constable and A. M. W. Cargill Thompson J. Am. Chem. Soc. 1994 116 7692. l4 R. Grigg J. M. Holmes S. K. Jones and W. D. J. A. Norbert J. Chem. SOC. Chem. Commun. 1994 185. l5 V. W.-W. Yam V. W.-M. Lee and K.-K. Cheung 1.Chem. SOC.,Chem. Commun. 1994 2075. l6 M.-N. Collomb-Dunand-Sauthier,A. Deronzier and R. Ziessel,J. Chem. SOC.,Chem. Commun. 1994,189. l7 H. Nagao T. Mizukawa and K. Tanaka Inorg. Chem. 1994,33 3415. 0.Ishitani N. Inoue K. Koike and T.Ibusuki J. Chem. Soc. Chem. Commun. 1994 367. The Noble Metals CONHZ Q -(JCONH2 + fyONH2 I Y Y Bz Bz Bz complex [Ru(2,2’- biquinoline)(pvbpy )] [ClO,] [pv bpy = poly (4-met hyl-4’-vinyl- 2,2’-bipyridine] has been prepared and its UV/VIS absorption and luminescence properties investigated.” The bis-cyclometallating ligand (3) has been employed to construct binuclear ruthenium and/or osmium species with the M-M distance fixed at 11A. Luminescence in the heterometallic species is centred on the osmium moiety.,’ ‘H NMR spectro- scopic and HPLC evidence supports the formation of an intermediate with a monodentate 3,3‘-dmbipy ligand in the photosubstitution of [Ru(bipy),(3,3’dmbipy)] 2i in aqueous solution.21 Polymeric films of [(Ru(CO),(bipy)},] generated by reduction of cis-[Ru(CO),(bipy),][PF6] in C0,-saturated solution is discussed in relation to the electrocatalytic reduction of CO to CO.,* Q Q Resonance Raman and EPR spectroscopic data indicate, the formation of ruthenium(III) (IV) and (v) species as well as a ligand radical n-cation in the catalytic water oxidation by [(Ru(H20)(bipy)2~,(p-O)]4+.Treatment of the ruthenium(1v) species [(RuCl(p-Cl)(q3 :q3-Cl0Hl6)},] with varying molar ratios of AgNO gives nitrato complexes including [RuCl(N0,)(q3 :q3-CloH16)] and [Ru(N0,),(q3 :q3-Cl0HI6)] in which the NO group is ~helating.,~ The hexanuclear ruthenium cluster [Ru,(p-CO),(CO) 5(p4-S)(p-SH)(p3-pyS)] (pyS = C5H,NS) consists of two Ru units linked by two Ru-Ru bonds and a l9 Y.Sun and M.K. DeArmond Inorg. Chem. 1994 33 2004. 2o M. Beley S.Chodoroowski,J.-P. Collin J.-P.Sauvage L. Flarnigni and F. Barigelletti Inorg. Chem.,1994 33 2543. S. Tachiyashiki H. Ikezawa and K. Mizumachi Inorg. Chem. 1994 33 623. 22 S. Chardon-Noblat M.-N. Collomb-Dunand-Sauthier A. Deronzier R. Ziessel and D. Zsoldos fnorg. Chem. 1994 33,4410. 23 Y. Lei and J.K. Hurst Inorg. Chem. 1994 33 4460. 24 J. W. Steed and D. A. Tocher Polyhedron 1994 13 167. 264 G. Reid pyramidal p4-S ligand. The Ru core adopts a boat c~nfiguration.~' Methylation of [M(oep)]- (M = Ru 0s) or addition of MeMgBr to the dimer [{M(oep)},12+ yields the M"' monoalkyl species [MMe(oep)]. [RuPh(oep)] undergoes one-electron reduction and subsequent treatment with Me1 gives the ruthenium(1v) species [R~MePh(oep)].~~ Dioxoruthenium(v1) picket-fence porphyrin complexes which involve optically active a-methoxy-a-(trifluoromethy1)phenylacetylunits on both sides of the porphyrin plane have been prepared.Oxidation of racemic PBzMePh by the cr,fl,a,/3 isomer gives the optically active phosphine oxide with retention of configuration at phosph~rus.~ The trans-dioxo ruthenium(1v) complex [RuO(tmp),] oxidizes alcohols via bis(a1koxy) species. The trans-bis(isopropy1) complex has been characterized crystal- lographically.28 Reaction of [RuCl,(NCPh),] with [Li,L'(thf),] (H,L' = rneso-octaethylporphyrinogen) results in a four-electron oxidation and formation of [RuL(NCPh),] involving two hemiporphyrin fragments linked by two sp3 carbon^.^' The (spectro)electrochemistry of Ru"'(phtha1ocyanine) complexes incorporating C1- pyridine dmso and CN- axial ligands has been studied.In each case the first oxidation occurs at the phthalocyanine ligand giving a n-cation radical species whereas the site of the first reduction depends upon the specific nature of the axial ligand~.~' The ruthenium(1r) species (4),incorporating chelating azomethine ligands is oxidized by 30% H,O in CH,Cl to afford the corresponding amide complex (5) which has been structurally characterized. Electrochemical studies on these species are reported. ' The q4-cyclopentadienone complex [RuBr(q4-C,H,0)Cp] reacts with Br to give the q3-allyl complex [RuBr(y3-C,H40Br)Cp] while reaction of [RuBr(cod)Cp] with 3-bromocyclopent-4-ene-1-one gives the cyclopentenoyl complex [RuBr,(q3-CsHsO)Cp].32 [{RuCl,Cp*),] reacts with Me,SiTeR (R = p-tolyl Ph) generating the Ru"Ru" complexes [Cp*Ru(p2-RTeTeR)(p2-TeR),RuCp*], while with Me,SiSeR the Ru"'Ru"' species [Cp*Ru(p,-SeR),RuCp*]Cl are obtained.Two of the triply bridged species (6) and (7) have been structurally ~haracterized.~~ 25 B. R. Cockerton and A. J. Deeming Polyhedron 1994 13 2085. " J.-P. Collman E. Rose and G. D. Venburg J. Chem. Sue. Chem. Commun. 1994 11. 27 P. Le Maux H. Batiri and G. Simonneaux J. Chem. Soc. Chem. Commun. 1994 1287. S.Y.S. Cheng N. Rajapaksa S.J. Rettig and B.R. James J. Chem. Soc. Chern. Commun. 1994 2669. 29 U. Piarulli C. Floriani A. Chiesi-Villa and C. Rizzoli J. Chem. Soc.Chem. Commun. 1994 895. 30 T. Nyokong J. Chem. Soc. Dalton Trans 1994 1359. 3' M. Menon S. Choudhury A. Pramanik A.K. Deb S.K. Chandra N. Bag S. Goswami and A. Chakravorty J. Chem. SOC. Chem. Commun. 1994 57. 32 K. Kirchner K. Merelter and R.Schmid J. Chem. Soc. Chem. Commun. 1994 161. 33 H. Matsuzaka T. Ogino M. Nishio M. Hidai Y. Nishibayashi and S. Uemura J. Chem. Soc. Chem. Commun. 1994 223. The Noble Metals 265 R RR l+ I /R II Te ,Te Cp'R(~'&Cp' Cp' RU-Te-Te Se / I R' R R New oxometallocyclic complexes have been prepared by reacting Ru"(arene j complexes with dialkylamino-substituted propargylic alcohols (Scheme 1 j. Deuterium labelling experiments show that these occur via 1,2-migration of a dialkylaminophenyl s~bstituent.~~ Ru NMe2 L = PPh3 PMe3 R=H,Me Scheme 1 Enantioselective hydrosilylation of C=N bonds of nitrones with SiH,Ph using [Ru,Cl4(NEt3j{ (Sj-(-j-p-tolbinap) 2] (p-tolbinap = 2,2'-bis(di-p-tolylphosphino-l,1-binaphthyl j as catalyst at 0 "C gives the corresponding optically active N,N-disubstituted hydroxylamines in high e.e.[RuI(dppej{ $-C,H,(C,,H j}] [C1oH19 = ( + )-neomenthyl] with CF,SO,R (R = Me Et) gives the alkyl iodide species [Ru(IR j(dppe j{q 5-C,H,(C ,H 9))] [CF,SO 3]. These complexes alkylate prochiral nucleophiles regenerating the iodide prec~rsor.~ Trinuclear complexes of the form [LNaMI'NaL] [M = Ru 0s; L = 1,4,7-tris(4-butyl-2-mercaptobenzy1)-1,4,7-triazacyclononane] have been prepared. An X-ray structure of the ruthenium(Ivjcomp1ex shows an octahedral MS central core with two trigonal prismatic terminal LNa units having an N,S donor set.37 The structurally characterized complexes [R~(H,O)(bipy)(Me,tacnj]~ and [Ru(O)(bipyj-+ + (Me,tacn)12 exhibit reversible Ru"/Ru"' and RU"'/RU'~ redox couples; the ruthe- 34 D.Pilette S. Moreau H. LeBozec P. H. Dixneuf J. F. Corrigan and A. J. Carty J. Chem. SOC. Chem. Commun. 1994 409. 35 S.-I. Murahashi S. Watanabe and T. Shiota J. Chem. SOC. Chem. Commun. 1994 725. 36 D. D. Pathak H. Adams and C. White J. Chem. Soc. Chem. Commun. 1994 733. 37 K. Mochizuki F. Kesting T. Weyhermuller K. Wieghardt C. Butzlaff and A. X. Trautwein J. Chem. SOC. Chem. Commun. 1994 909. 266 G. Reid nium(1v)-oxo species is a good oxidant for alkene epo~idation.~~ Ligand (8) coordinates to ruthenium(i1) to yield [Ru(LH)I3 + in which the pendant bipy groups coordinate to the near-octahedral ruthenium(r1) centre leaving the aza macrocycle non-coordinating.In aqueous solution the aza functions trap a single proton within the cavity between the macrocycle and the ruthenium(r1) ion.39 The X-ray structure of [Ru(O,CCF,)O,(Me,tacn)] shows a cis-diox-oruthenium(v1) unit [Ru=O = 1.715(9) 1.719(9) A]. This complex catalyses alkene epoxidation and alkane hydroxylation by PhIO and Bu'OOH.~' Hydrolysis of [RuCl,(tacn)] and [RU,Cl,(dtne)] [dtne = 1,2-bis(1,4,7-triazacyclonon-l-yl)ethane] in alkaline aqueous solution in the presence of Cog -yields [Ru,(tacn),(p-OH),@- CO,)] Br and [Ru,(dtne)(p-O),(p-co3)][PF6].4' Studies of the kinetics and mechanism of reduction of trans-[RuO,(Me,[ 141 aneN4)I2+ by I- suggest4 a process involving 0-atom transfer from RuV1to I-.+ [R~(NCMe),([9laneS,)]~ is a convenient precursor for other thioether half-sandwich complexes such as [(RU(~-S,CNM~,)([~]~~~S,)),]~ + and [RuTp([9] aneS,)] which have been structurally ~haracterized.~ + Ruthenium-ammine com-plexes form adducts with 18-crown-6 via hydrogen-bonding between the protons and the ether oxygen^.^^ A newly synthesized ruthenium(r1) calix[4]arene derivative exhibits anion recogni- tion for halides dihydrogen phosphate and hydrogen sulfate anions. The monotopic '' W.-C. Cheng W.-Y. Yu K.-K. Cheung and C.-M. Che J. Chem. SOC.,Dalton Trans. 1994 51.39 P. Sheldon W. Errington P.Moore S.C. Rawle and S.M. Smith J. Chem. Soc. Chem. Commun. 1994 2489. 40 W.-C. Cheng W.-Y. Yu K.-K. Chueng and C.-M. Che J. Chem. SOC. Chem. Commun. 1994 1063. 41 A. Geilenkirchen P.Neubold R. Schneider K. Wieghardt U.Florke H.-J. Haupt and B.Nuber J.Chem. Soc. Dalton Trans. 1994 451. 42 T.-C. Lau K.W. C. Lau and K. Lau J. Chem. SOC.,Dalton Trans. 1994 3091. 43 C. Landgrafe and W.S. Sheldrick J. Chem. SOC.,Dalton Trans. 1994 1885. 44 I. Ando D. Ishimura K. Ujimoto and K. Kurihara Inorg. Chem. 1994 33 5010. The Noble Metals 267 derivative selectively recognizes4’ H2P0 even in excess HSO and C1-. New phospholyl complexes of ruthenium(r1) and rhodium(1) have been prepared using the bulky 2,5-bis(t-butyl)phospholide anion [Bu\C,H,P] - which promotes C COO^-dination over y ‘-coordination.The X-ray structure of [RuCp*(q’-Bu\C,H,P)] is reported.46 Dmf solutions of RuC1,-NR,I-NR are extremely reactive for the direct catalytic hydroesterification of ethene with methyl formate in the absence of C0.47 In the presence of NaIO or [NBu:][IO,] as cooxidant the dioxoruthenium complex trans-[Ru0,(bipy)(10,(0H),}]~1.5H20 is an efficient catalyst for alkene epoxida- tions and the oxidation of primary alcohols to aldehydes and of secondary alcohols to ketones under mild condition^.^^ An X-ray structure of the [2.2]paracyclophane (c16H16) complex [RU,(CO)6(p q3:q3-CI6Hl6)] shows that one aromatic ring bridges the Ru-Ru unit via two enyl interactions [Ru-Ru = 2.838(3)A].49 The complexes [RuH,(SiEt3),(q6-arene)] and [RhH(SiEt,),Cp*] catalyse the transfer dehydrogenative coupling of SiHEt in the presence of a proton acceptor via an q2-silene complex giving the carbosilane dimer HSiEt,CHMeSiEt and 2,2-dimethylbutane.” The ruthenium(I1) complex (9) reacts with phenylacetylene in refluxing thf to give the ruthenium(r1) vinylidene (lo) which reacts with H2S to give the yl-thioaldehyde (1 1) quantitatively.Further reactions of this unusual q’-2-phenylethanethial complex are also disc~ssed.’~ [Ru(SSR)- (CO)(PPh,)Cp] and [Ru(SSSR)(CO)(PPh,)Cp] incorporating unusual polysulfur ligands are prepared by reacting [Ru(SH)(CO)(PPh,)Cp] with RS,phth (x= 1,2; phth = phthalimid~).’~ The potentially tetradentate ligand (12) acts as a tridentate chelate to iron(Ir) ruthenium(n) and osmium(I1) centres allowing the non-coordinat- ing pyridyl group to react with electrophiles to give cationic derivatives.’ Single crystal X-ray data on [Ru(ND,),][SCN] at 92K have been analysed by various electron-density model^.'^ The CO stretching frequency of [RuHX(CO)(PBu\Me),] reveals how the donor power of ligand X varies (X = alkoxides aryloxides siloxides etc.).” The mechanism of the rearrangement activity towards unfunctionalized olefins of the [RU(H20),I2+ ring-opening meta- thesis polymerization catalyst has been in~estigated.’~ Reaction of coordinatively unsaturated [Cp*Ru(p-SR),RuCp*] (R = Pr’ 2,6-Me2C6H,) with phenylhydrazine gives [Cp*Ru(p :q1 :ql-PhN=NH)(p-SR),RuCp*] and also effects the catalytic disproportionation of N,H4 into NH and N uia a 45 P.D. Beer Z. Chen A. J. Gouldren A. Greeve D. Hesek F. Szemes and T. Weer J. Chrm. SOC.,Chem. Commun. 1994 1269. 46 D. Carmichaell L. Ricard and F. Mathey J. Chem. SOC.,Chem. Commun. 1994 1167. 47 C. Legrand Y. Castanet A. Mortreux and F. Petit J. Chem. SOC.,Chem. Commun. 1994 1179. 48 A. J. Bailey W. P. Griffith A. J. P. White and D. J. Williams J. Chem. Sac. Chem. Commun. 1994 1833. 49 A.J. Blake P.J. Dyson B.F.G. Johnson and C.M. Martin J. Chem. SOC.,Chem. Commun. 1994 1471. 5” P.I. Djurovich A. R. Dolich and D.H. Berry J. Chem. SOC. Chem. Commun. 1994 1897. ” C. Bianchini L. Glendenning M. Peruzzini A. Romerosa and F.Zanobini J. Chem. SOC.,Chem. Commun. 1994 2219. 52 A. Shaver and P.-Y.Plouffe Inorg. Chem. 1994 33 4327. ” E. C. Constable and A. M. W. Cargill Thompson J. Chem. Soc. Dalton Trans. 1994 1409. 54 B.N. Figgis P. A Reynolds and A. N. Sobolev J. Chem. Sac. Dalton Truns. 1994 1429. ” J.T. Poulton M. P. Sigalas K. Folting W. E. Streib 0.Eisenstein and K.G. Caulton Inorg. Chem. 1994 33 1476. ” T. Karlen and A. Ludi J. Am. Chem. SOC.,1994 116 11 375. 268 G. Reid p-diazene intermediate.57 The new ruthenium(II1) complex [RuCl,( 13),]Cl and related bis-( 13) complexes exhibit remarkably low Ru"'/Ru" potential^.^^ The water-soluble ruthenium(r1) complex cis-[RuCI,( 14)J is an effective catalyst for the regioselective conversion of unsaturated aldehydes into unsaturated alcohols.59 Et2N wNEt2 The mixed-valence Ru"/Ru'~ cation [iodo- 1 ,l'-biruthenocenium] -t has been struc- turally characterized,60 and the first [2]ruthenocenophane involving an ethylene linkage between the Cp rings has been reported.Ring-opening polymerization using this strained complex is discussed." Ah initio SCF calculations on the bonding in [RuX(PR,)Cp] (X = halide OMe OSiH,) [Ru(OMe)(PH,),Cp] and [RuMe(PH,),Cp] have been used to evaluate possible X-Ru a-bonding.62 Detailed MO calculations on the confacial bioctahedral nonahalides [Ru,C1J3 -and [Ru,Br913- have been performed and the CT band energies and intensities inter~reted.~, Detailed NMR spectroscopic studies on trans,cis-[RuX,(CO),(terpy)] (X = C1 Br I) have shown that the terpy ligand oscillates between equivalent bidentate 57 S. Kuwata Y.Mizobe and M. Hidau Inorg. Chem. 1994 33 3619. 58 S.J. Slattery N. Gokaldas T. Mick and K.A. Goldsby Inorg. Chem. 1994 33 3621. '' D.J. Darensbourg F. Joo M. Kannisto A. Katho J. H. Reibenspies and D. J. Daigle Inorg. Chem. 1994 33 200. 6o M. Watanabe I. Motoyama M. Shimoi and T. Iwamoto Znorg. Chem. 1994 33 2518. J. M. Nelson A. J. Lough and I. Manners Angew. Chem. Int. Ed. Engl. 1994,33 989. 62 C.C. Bickford T.J. Johnson E. R. Davidson and K.G. Caulton Inorg. Chem. 1994 33 1080. " G.A. Heath and J. E. McGrady J. Chem. Soc. Dalton Trans. 1994 3759. The Noble Metals modes.64 Condensation of Ru or 0s atoms with mixtures Of C,F and a second arene at 77 K affords [M(q4-C,F,)(q6-arene)] (M = Ru 0s; arene = C,H,Me,-1,3,5; C,H,Me,-1,3; C,H,).,’ + The [RuCp*] fragment activates, the C-S bond of cyclohexenesulfide and 1,3-dithiane to give [(RU(SM~)(SCH,CH=CH,)C~*},]~ and + A [{Ru[C,M~,CH,S(CH,)~SM~]],]~+.series of ruthenium thiol and thiolate complexes including mixed-valence and mixed-metal (Ru/Rh) systems has been synthesized from [{RuC1(p-Cl)},(q3 :q3-ClOHl6)] and alkane and arene thi~ls.,~ NH=C(CF,)NH undergoes a condensation reaction in the presence of certain ruthenium osmium and iridium hydrides to give NH and N,N’ chelate complexes such as [RuH(CO)(PPh,),{NHC(CF,)NH}].68 Spectroelectrochemical and flash photolysis reductions of [{ Ru(phen),),(hat)14+ and [Ru(tap),12 + (hat = 1,4,5,8,9,12-hexaazatriphenylene tap = 1,4,5,8-tet-raazaphenanthroline) have been investigated.,” Optically active [RuCl,(bipy),] is produced upon photodissociation of enantiomeric [Ru(bipy),]Cl by visible light in CH C1 ,solution.Detailed studies on the reaction of [RuHCl(PPh,),] with olefins suggest that the reaction proceeds by two mechanisms namely dissociation of a PPh ligand and direct attack of the olefin on the parent c~mplex.~’ Insertion of the [Ru(bipy),12+ fragment into the catecholate binding sites of two conjugated ligands gives (15) and (16)in which the redox-active bridging ligands display a five-membered redox series.72 Reaction of [Ru,(p-CO)(p-C,R,)Cp,] (R = Ph C,F,) with [M(CO),] (M = Fe Ru) or [co2(co)8] affords new rotameric tri- and tetranuclear p-alkyne cl~sters.~ 64 E. W. Abel K. G.Orrell A. G.Osbourne H. M. Pain and V. Sik J.Chem. Soc. Dalton Trans. 1994 11 1. 65 A. Martin A.G. Orpen A. J. Seeley and P.L. Timms J. Chem. Soc. Dalton Trans. 1994 2251. 66 D. Randon J. Delbeau X.-D. He S. Sabo-Etienne and B. Chaudret J. Chem. Soc. Dalton Trans. 1994 1895. 67 G. Belcham J. W. Steed and D. A. Tocher J. Chem. Soc. Dalton Trans. 1994 1949. M. B. Hursthouse M. A. Mazid S. D. Robinson and A. Sahajpal J. Chem. Soc. Dalton Trans. 1994,3615. 69 L. Tan-Sien-Hee and A.K.-D. Mesmaeker J. Chem. Soc. Dalton Trans. 1994 3651. 70 A. Yamagishi K. Naing Y. Goto M. Taniguchi and M. Takahashi J. Chem. Soc. Dalton Trans. 1994 2085. 71 G. Alibrandi and B.E. Mann J. Chem. Soc. Dalton Trans. 1994 951. 72 L. F. Joulie E. Schatz M. D. Ward F. Weber and L. J. Yellowlees J. Chem. Soc. Dalton Trans.1994,799. 73 K. J. Adams J. J. Barker J. P. H. Charmant C. Ganter G. Klatt S. A. R. Knox A. G. Orpen and S. Ruile J. Chem. Soc. Dalton Trans. 1994 477. 270 G. Reid [RuH(PMe,)Cp] reacts with chlorosilanes to give [Ru(SiR,)(PMe,),Cp] (SIR = SiHCl, SiMeHCl SiMeCl, SiMe,Cl) via HCl elimination. NMR spectro- scopic evidence is presented for an agostic Ru-H-Si intera~tion.~ [Ru(q5- Me,C,SiSi(SiMe,),)Cp*] is a stable silacyclopentadienyl derivative of ruthe-nium(~~).~~ Oxygen-induced methyl C-H activation in a Cp* ligand of [(RuCl,Cp*),] has been observed.76 The kinetics and mechanism of homogeneous carbonylation of nitroaromatics by [Ru(CO),{C(O)OCH,},(dppe)] have been investigated in detail.77 The optically active ruthenocenyl diphosphines (17) and (18) are efficient chiral ligands for catalytic asymmetric reactions.78 The synthesis and X-ray structure of [Ru(=SiMe,)(PMe,),Cp*][BPh,] a base-free silylene complex with no n-donor stabilization have been rep~rted.~' Ru PPb (17) R= Et (18) R= Me Several ruthenium and osmium cluster compounds incorporating facially bound arene and cyclopentadienyl ligands have been synthesized and fully characterized.80 The low temperature X-ray structure of [Ru,C(CO),,(p3-o :q2:q3-C5H,CPh,)] prepared from [Ru,C(CO) 7] with diphenylfulvene in the presence of Me,NO also shows an unusual facial bonding mode.81 The structures and reactivity of triruthenium clusters incorporating aryloxide and alkoxide ligands have also been studied.82 Under 80 atmospheres of CO the hexanuclear cluster [Ru,RhC(CO),,Cp*] yields [Ru,(CO),,] [Ru5C(CO),,] and [Ru,RhC(CO),,Cp*].The Ru species has a square-based pyramidal metal framework.83 The mixed-metal clusters [Ru,RhC(CO),,(cod)Y] (Y = H AuPEt, AuPPh,) are prepared by treatment of 74 F.R. Lemke J. Am. Chem. SOC. 1994 116 11 183. 75 W.P. Freeman T.D. Tilley and A.L. Rheingold J. Am. Chem. SOC.,1994 116 8428. 76 L. Fan M. L. Turner M. B. Hursthouse K. M. A. Malik 0.V. Gusev and P. M. Maitlis,J. Am. Chem.SOC. 1994,116 385. 77 J.D. Gargulak and W. L. Gladfelter J. Am. Chem. SOC. 1994 116 3792. 78 T. Hayashi A. Ohno S. Lu Y. Matsumoto E. Fukuyo and K. Yanagi J. Am. Chem.SOC.,1994,116,4221. 79 S.K. Grumbine and T.D. Tilley J. Am. Chem. SOC. 1994 116 5495.80 A. J. Blake P. J. Dyson R. C. Gash B. F. G. Johnson and P. Trickey J. Chem. SOC.,Dalton Trans. 1994 1109; D. Braga P. Sabatino P. J. Dyson A. J. Blake and B. F. G. Johnson J. Chem. SOC.,Dalton Trans. 1994,393; B. F.G. Johnson A. J. Blake C. M. Martin D. Brago E. Parisini and H. Chen J. Chem. SOC. Dalton Trans. 1994,2167;D. Braga P. J. Dyson F. Grepioni B. F. G. Johnson and M. J. Calhorda Inorg. Chem. 1994 33 3218. 81 A. J. Blake P. J. Dyson B. F.G. Johnson D. Reed and D. S. Shephard J. Chem. SOC. Chem. Commun. 1994 1347. 82 D. J. Darensbourg R. Fontal S. S. Cjojnocki K. K. Klausmeyer and J. H. Reibenspies Inorg. Chem. 1994 33 3526. 83 B. F. G. Johnson J. Lewis H. Curtis T. Adatia M. McPartlin and J. Morris J. Chem. SOC.,Dalton Trans. 1994 243.The Noble Metals 271 [Ru,RhC(CO),,(cod)] -with HBF,.Et,O [AuCl(PEt,)] and [AuCl(PPh,)] respect- ively. The structure of the Au(PPh,) derivative consists of a central Ru,Rh octahedron with one Ru face capped by a p3-Au(PPh,) fragment.84 Gaseous NO reacts with [Ru,(C,R)(CO)J (R = But SiMe,) to give CRu,(C,R)(CO)9(NO)I while [Ru6C(C0) 15 -and [Ru6C(C0) 14(N0)(C3H 5)1 are obtained from the clusters [Ru6C(C0),6]2-and [Ru~C(CO)~~(C,HJ- .85 Oxidative addition of R,PO,H to [Ru,(CO),,] yields oligomeric [{Ru,(p2 :p :q2-O,PR,),(CO),),] which yield dimeric ruthenium(1) species including [Ru,(p :q2-O,PPh,),(CO),(PPh,),] upon treatment with Lewis bases.86 The trinuclear clusters [Ru3(p3-CI)(p3-S)Cp;] and [Ru,(p,-S)(p,-SPr’)Cpjl involving tricapping sulfide ligands were obtained by reacting [Ru,(p,-O),Cp;] with Li,S or Li2S/NaSPri.87 Several ruthenium clusters incorporating (alkylthio)alkynes RCCSC,H (R = Me Ph) have been characterized.88 [MX(CO),(PPh,),(q’-L)][S03CF3](M = Ru 0s; X = C1 Br; L = hydrazine hydroxylamine diazene) involve monodentate coordination of L.89 The desulfuriz- ation of benzo[b]thiophene by S/Ru exchange has been achieved yielding [RU3(CO)8(C8H6)] Stereoselective synthesis of chiral sulfoxides is achieved by .’O coordination of the thioether precursor to an enantiomerically pure [Ru(diphos- phine)Cp] + fragment and oxidation with dimethyldi~xirane.’~ [Ru,(C0),(qs :ql-CSH4),] containing the first Ru,C,ring is formed by insertion of C,H units into the Ru-Ru bonds in [Ru,(CO),,].’~ 3 Osmium The five-coordinate species [OsX(dcpe),] + (X = H C1) react with 0 to give the stable peroxo complexes trans-[OsX(O,)(dcpe),] .The structure of the peroxo-hydride + oxmium(I1) cation shows side-on bonding of the peroxo ligand [Os-0 = 2.037(8) 2.045(8); 0s-H = 1.83(9);0-0 = 1.45(1)A].93 Both mono- and binuclear osmium(11) derivatives [OsX,L,] and [LOs(p-X),OsL,][PF,], are formed from the reaction of [OsX,(PPh,),] with L [L = l-(diphenylphosphine)-2-(2-pyridyl)ethane;X = C1 Br]. The binuclear species dissociate in solution to give five-coordinate c~mplexes.’~ Several organoosmium(v1) complexes of PMe, PPh, and dppe have been prepared. Unlike inorganic nitridoosmium(v1) complexes the alkyls are not reduced by basic phosphines.’ [OsH,(PMe,Ph),] +,characterized by neutron diffraction and having H * * * H separations as short as 1.49 A is a catalyst precursor for olefin hydrogenation and 84 T.Adatia H. Curtis 3.F. G. Johnson J. Lewis M. McPartlin and J. Morris J. Chem. SOC.,Dalton Trans. 1994 3069. 85 T. Chihara K. Sowamura H. Ogawa and Y. Wakatsuki J. Chem. SOC.,Chem. Commun. 1994 1179. C. M. Barnes D. S. Bohle and S. K. Madsen Inorg. Chem. 1994 33 641 1. Y. Mizobe K. Hashizume T. Murai and M. Hidai J. Chem. SOC. Chem. Commun. 1994 1051. 88 S. Jeannin Y. Jeannin F. Robert and C. Rosenberger Inorg. Chem. 1994 33 243. 89 T.-Y. Cheng A. Ponce A. L. Rheingold and G. L. Hillhouse Angew. Chem. Int. Ed. Engl. 1994,33 657. 90 A. J. Arce Y. De Sabctis A. Karam and A. J. Deeming Angew. Chem.Int. Ed. Engl. 1994 33 1381. 91 W.A. Schenk J. Frisch W. Adam and F. Prechtl Angew. Chem. Int. Ed. Engl. 1994 33 1609. 92 A. J. Arce Y. De Sanctis J. Manzur and M. V. Capparelli Angew. Chem. Int. Ed. Engl. 1994 33 2193. 93 A. Mezzatti E. Zangrando A. Del Zotto and P. Rigo J. Chem. SOC.,Chem. Commun. 1994 1597. 94 A. Del Zotto A. Mezzetti and P. Rigo J. Chem. SOC.,Dalton Trans. 1994 2257. 95 P. A. Shapley R.M. Marshman J. M. Shusta Z. Gebeyehu and S. R. Wilson Inorg. Chem. 1994,33,498. 272 G. Reid hydrof~rmylation.'~ NaBH reacts with [OsH,Cl,(PPr',),] to give [OsH,(q2- H,BH,)(PPr\),] which generates [OsH,(PPr\),] in MeOH. Spectroscopic and theoretical studies incidate H H separations of ca. 1.6 8 for the three H- ligands in the q2-BH ~ornplex.'~ Several new Os(q2-H,) compounds have been prepared and characterized spectroscopically and crystallographically.98 The structure of [Os(q2-H2)(0,CMe)(en),][PF6] involving trans-en ligands has been determined both by X-ray and neutron diffraction [Os-H = 1.59(l) 1.69(2)A; H-H = 1.34(2)A].99 A quantum chemical study of the influence of the trans ligand on geometries spin-spin coupling constants bonding and charge distributions has been performed for stretched molecular hydrogen complexes of osmium(II).'o" Pulsed laser photolysis of [OsH,(PP,)] with hydrocarbons has shown that the kinetic selectivity per reactive C-H bond for methane over cyclohexane exceeds 520 following photodissociation of H,."' The osmium(r1) complexes (19) and (20) which incorporate chelating phosphinoester ligands react with alkynols HCCCPh(R)OH (R = Me Et) to give the octahedral carbyne complexes (21) and (22) [Os-C(carbyne) = 1.72(1)8 in (21)].'02 OMe 0 C GI w2 II 0 Reduction of [Os(O,SCF,),(NH,),] in cyclic ether solvents yields a dihydrogen complex incorporating a cis carbene ligand derived from the cyclic ether." The synthesis and electrochemistry of tetra- and pentaammine osmium(r1) complexes 96 T.J. Johnson A. Albinati T. F. Koetzle J. Ricci 0.Eisenstein J. C. Huffman and K. G. Caulton Inorg. Chem. 1994 33 4966. 97 M. A. Esteruelas Y. Jean A. Lledos L.A. Oro N. Ruiz and F. Volatron Inorg. Chem. 1994,33 3609. 98 M. A. Esteruelas F. J. Lahoz L. A. Oro E. Oiiate and N. Ruiz Inorg. Chem. 1994 33 787. 99 T.Hasagawa S. Parkin H. Hope R. K. McMullan T. F. Koetzle and H. Taube J. Am. Chem. Soc. 1994 116 4352. loo J.S. Craw G.S. Bacskay and N.S. Hush J. Am. Chem. Soc. 1994 116 5937. lo' R. Osman D. I. Pattison R. N. Perutz C. Bianchini and M. Peruzzini J. Chem. Soc. Chem. Commun. 1994 513. B. Weber P. Steinert B. Windmulier J. Wolf and H. Werner J. Chem. Soc. Chem. Commun. 1994,2595. lo3 Z.-W. Li and H. Taube J. Am. Chem. Soc. 1994 116 11584. The Noble Metals involving unsaturated ligands have been studied.' O4 Metal L(m)-edge EXAFS studies on OsF and IrF, recorded in anhydrous HF solution reveal M-F bond lengths of 1.821(1) and 1.817(1) A respectively. There is also evidence for further solvation spheres due to hydrogen-bonded HF at ca. 3.2 and 3.4A.l" [Os,(CO),,] reacts with XeF in aqueous HF solution to afford cis-[OsF,(CO),] uia oxidative addition together with several other minor products.'06 The crystal structure of Na,[Os(CN),(NO)].H,O has been reported together with some reactions of the coordinated NO ligand.lo7 The molecular structure of Rb,[Os,Br,] shows 0s-0s = 2.799(1)A.Calculations suggest greater M-M interac- tions in this system compared to the ruthenium analogue.'" An X-ray structure of [Os(NAr),tpp] (Ar = C,H,NO,) shows strongly bent organoimido ligands [Os-N-C = 142.0(4) 144.8(3)o].'09 Treatment of [OsO,(porph)] (porp = ttp oep) with SOC1 yields [OsCl,(porph)] which reacts with LiR (R = Ph Me,SiCH,) to give [OsR,(porph)]. The X-ray structure of [Os(CH,SiMe,),(tpp)] is reported.' lo Reduction of [Os(O,SCF,),(NH,),] in acetone in the presence of various ligands yields compounds such as [Os(NH3),(NCMe),l2 + [Os(NH,),(bipy)12 ' [Os(NH,),(q2 :q2-diene)I2+ and [0s(NH,),(q6-arene)l2 + .The tetrakis-amine com- plexes all exist as cis isomers.' ' ' A series of diamagnetic osmium(1v) thiolate complexes has been prepared and their spectroscopic properties discussed in terms of isomerism in solution.' l2 The molecular structure of [Os(NBu'),] in which the NBu'ligands form a distorted tetrahedral arrangement around the central 0s atom has been determined in the gas phase by electron diffraction.' l3 Vacuum pyrolysis of [0s3(C0),,(NCMe),] at T > 260 "C gives the dianions [Os 7(cO)36l2- and [os,o(CO)40]2 -,the largest osmiumxarbonyl clusters reported to date.' l4 The triosmium clusters [Os,H(CO)lo{p-SC(NPh)(NHPh)fl and [0s,H(C0) {p,-SC(NP h)(NHP h)}] both of which have been structurally charac- terized are readily decarbonylated in visible light yielding [Os,H(CO),(p,- SC(NPh)(NHPh))]."s The unsaturated cluster [Os,H(CO) { Ph,PCH,P(Ph)C,H,)] reacts with [Au(PPh,)][PF,] to give the mixed metallic species [Os,AuH(CO),{Ph,PCH,P(Ph)~6H4}PPh3)][PF6], whereas HBF gives [Os,H,(CO),{ Ph,PCH2P(Ph)C,H,}][BF4].The crystal structure of the former obtained using synchrotron radiation shows that the Au(PPh,) fragment bridges the unsaturated 0s-0s edge.l1 F.S. Nines and H. Taube Inorg. Chem. 1994 33 3111; 3116. S.A. Brewer A.K. Brisdon J.H. Holloway and E.G. Hope Polyhedron 1994 13 749.S.A. Brewer J.H. Holloway and E.G. Hope J. Chem. SOC. Dalton Trans. 1994 1067. lo' L. M. Baraldo M.S. Bessega G.E. Rigotti and J.A. Olabe Znorg. Chem. 1994 33 5890. S. F. Gheller G. A. Heath D. C. R. Hockless D. G. Humphrey,and J. E. McGrady Znorg. Chem. 1994,33 3986. lo9 J.A. Smieja K. M. Omberg and G. L. Breneman Inorg. Chem. 1994,33 614. 'lo W.-H. Leung T.S.M. Hun K.-Y. Wong and W.-T. Wong J. Chem. SOC.,Dalton Trans. 1994 2713. 'I1 Z.-W. Li W.D. Harman P.A. Lay and H. Taube Inorg. Chem. 1994 33 3635. M. Arroyo J. A. Chamino D. L. Hughes R. L. Richards P. Roman P. Sosa and H. Torrens J. Chem. Soc. Dalton Trans. 1994 1819. D. W. H. Rankin H. E. Robertson A. A. Danopoulos P. D. Lyne D. M. P. Mingos and G. Wilkinson J. Chem. SOC. Dalton Trans.1994 1563. '14 L. H. Gade B. F.G. Johnson J. Lewis M. McPartlin H. R. Powell P. R. Raithby and W.-T. Wong J. Chem. SOC. Dalton Trans. 1994 521. "'E. W. Ainscough A. M. Brodie S. L. Ingham,T. G. Kotch A. J. Lees J. Lewis and J. M. Waters J.Chem. SOC.,Dalton Trans. 1994 1. M. M. Harding B. Kariuki A. J. Mathews and A. K. Smith J. Chem. Soc. Dalton Trans. 1994 33. 274 G. Reid Reaction of [Os,(p-Cl)(CO) ,]-with [Au(PPh,)] affords the cluster species .+-[Os3{p-AuOs(CO),(PPh,))(p-Cl)(CO),,I uia insertion of an Os(CO) fragment into a gold-phosphine bond.' The mixed PdOs cluster [Os,Pd(CO),,(bipy)] contains a monocapped octahedral metal core with the palladium atom occupying one vertex of the octahedron.' '* K[Os,H,(CO),,] has been prepared under mild conditions on silica.l1 A trinuclear osmium cluster involving an unusual face-capping carbene coordination mode has been structurally characterized.' 2o 4 Rhodium An X-ray structure of the mixed phosphathia macrocyclic complex [RhC12(Ph2[ 141 aneP2S2][PF,] exhibits a trans-dichloro arrangement at the metal centre.The related square planar complexes [M(Ph2[14]aneP,S2)][PF6]2 (M = Pd Pt) have also been synthesized and show similar P2S2 coordination."' The synthesis of a series of five-coordinate rhodium(1) half-sandwich complexes [RhLL'( [9]aneS,)] + (L = C2H4 L = C2H4 PPr', PCy,; L L' = 1/2(cod) 1/2(nbd) l/2(C4H,); L = CO L' = PPh,) has been reported.'22 Several rhodium(1rr) cage complexes have been obtained by rapid metal-template reactions of rhodium(II1) hexaamine complexes with paraformaldehyde and nit- romethane.The larger cavity homologues exhibit a strongly enhanced metal-centred phosphorescence in water at 77 K.123The bonding in the cofacial oeprhodium dimer [{Rh(oep)),l2+ is thought to involve Rh"-Rh" and interporphyrin cation radical n-n interactions.' 24 Dinuclear rhodium(1) and iridium(1) complexes of a new salen-type ligand (23) exhibit smectic A liquid crystalline behaviour. 125 The reactivity towards H and CO of a rhodium(r1)-salen derivative has been studied.lz6 Five-coordinate rhodium(II1) alkyl Schiff base complexes react with H upon photolysis to give the hydride species (24) which in turn inserts CO to give the formyl complex (25) via a rhodium(i1) intermediate.12 The synthesis structure and reactivity of the tridentate ligand complex [RhCl(PPh2(CH2CH2PPh2),}]are reported.'" The synthesis and crystal structures of dinuclear rhodium(i1) phosphine-phenoxide species incorporating bulky phosphine ligands have been reported."' The rhodium(1) complex [Rh(y3-(SePPh,),CH)Cp*] [ClO,] involves tridentate coordination of the anionic methanide diselenide ligand to C.Cathey J. Lewis P. R. Raithby and M. C. Ramirex de Arellano J. Chem. Soc. Dalton Trans. 1994 3331. 'I8 S. Cahn and W.-T. Wong J. Chem. SOC.,Dalton Trans. 1994 1065. D. Roberto E. Cariati R. Psaru and R. Ugo Organometallics 1994 13 734. 120 A J. Edwards M. A. Gallop B. F. G. Johnson J. U. Kohler J. Lewis and P. R. Raithby Angew. Chem. Int. Ed. Engl. 1994 33 1093.12' N. R.Champness C.S. Frampton G. Reid and D. A. Tocher J. Chem. Soc. Dalton Trans. 1994,3031. 122 A. J. Blake R. 0.Gould M.A. Halcrow and M. Schroder J. Chem. Soc. Dalton Trans. 1994 2197. 123 R. J. Geue M. B. McDonnell A. W.H. Mau A.M. Sargeson and A. C. Willis J. Chem. Soc. Chem. Commun. 1994 667. 124 S. Lee M. Miati and B. Wayland J. Chem. Soc. Chem. Commun. 1994,2299;Y. Ni J. P. Fitzgerald P. Carroll and B. B. Wayland lnory. Chem. 1994 33 2029. 12' P. Berdague J. Courtieu and P.M. Maitlis J. Chem. SOC. Chem. Commun. 1994 1313. 126 A. G. Bunn M. Wei and B. B. Wayland Organometallics 1994 13 3390. 12' D. J. Anderson and R. Eisenberg Inorg. Chem. 1994 33 5378. 12' S. A. Westcott G. Stringer S. Anderson N. J. Taylor and T. B. Marder Inory.Chem. 1994,33 4589. K.R. Dunbar J. H. Matonic and V. P. Saharan Inorg. Chem. 1994 33 25. The Noble Metals CO M = Rh Ir the metal via a CSe donor set.130 Electrochemical oxidation of basic solutions containing hydrolysed Rh3+ results in the formation of blue solutions thought to contain superoxo-rhodium(I1r) rather than higher oxidation state rhodium species.'31 The heterobinuclear hydroperoxo complex [Cp*Ir(p-pz),Rh(OOH)(dppe)][BF4] has been prepared by protonation of [Cp*(pz)Ir(p-pz),Rh(dppe)] in the presence of dioxygen (vOH= 3490 voo = 823 cm- I) and characterized crystallographically [0-0 = 1.432(8)& Rh-0 = 2.021(5)A].132 Io3Rh NMR chemical shift correlations for a range of rhodium(II1) complexes with cyanide and S-donor ligands have been discussed in terms of their ligand field parameters.* 33 Reaction of [Rh,(O,CMe),] with tcne gives two different polymeric species of formula [(Rh (O,CMe),(tcne)),].X-Ray structural studies show that the tcne units act as 1,l-bridges in one and trans-1,2-bridges in the other.'34 The synthesis and crystal structures of three eclipsed cofacial oligomeric complexes of rhodium involving three-layered bonding of 9,lO-phenanthroquinonediimine ligands have been reported. These complexes contain synergic multi-layered metal-metal [Rh'Rh' Rh"'Rh'] and ligand-ligand bonds.' 35 Addition of Me,S to [Rh,(p-CO)(p-CF3C,CF3)Cp,l induces an unusual intramolecular rearrangement to give [Rh,(p-SCH,Me)p-C(CF3)CH(CF,)}Cp,].1 36 Complex (26) undergoes three discrete one-electron oxidations indicating signifi- 130 M.Valderrama R. Contreras M. Basunan and D. Boys Polyhedron 1994 13 1101. 131 I. J. Ellison R. D. Gillard M. Moszner M. Wilgocki and J. J. Ziolkowski Polyhedron 1994 13 1351. 132 D. Carmona M. P. Lamata J. Ferrer J. Modrego M. Perales F.I. Lahoz R. Atencio and L. A. Oro J. Chem. Soc. Chem. Commun. 1994 575. 133 M.C. Read J. Glaser I. Persson and M. Sandstrom J. Chem. Soc. Dalton Trans. 1994 3243. 134 F.A. Cotton Y. Lim and J. Lu Inorg. Chirn. Acta 1994 221 1. 135 S.4. Chern G.-H. Lee and S.-M. Peng J. Chem. Soc. Chem. Commun. 1994 1645. 136 M.P. Devery and R. S. Dickson J. Chem. Soc. Chem. Commun. 1994 1721. 276 G. Reid cant communication between the metal centres.' 37 Spectroscopic evidence (IR solid-state 'P NMR) has been obtained for [SiO][RhH2(PMe3),] the first example of a cationic organometallic complex bound to a silica surface by ion pairing.'38 Reaction of ten molar equivalents of LiNHPh with [RhCI(PR,),] or [{RhCl(PR,),},] (R = Ph Et) gives Li[Rh(PR,),(NHPh),] which has been characterized by multinuc- lear ('H,,'P{ 'H} and lo3Rh{lH}) NMR spectro~copy.'~~ The synthesis and reactions of C (Rh (CO )2 {v '-(27)I {Po,V4-(27I}%I CBF4I2 and C{RhCl{v '-(27)){p-0,~~-(27)})21 have been re~0rted.l~' Rh(cod) I Rh(d) Rh(cod) Dinuclear (si1oxy)rhodium complexes [Rh2(cod)(p-OSiPh,)2] and [Rh,(CO),(p- OSiPh,),] have been studied as potentia1 models for rhodium complexes bound to silica.14' Structural and spectroscopic data and MM2 calculations have been obtained for [Rh,(dimen),12+ (dimen = 1,8-dii~ocyanomenthane).'~~ [Rh,Cl,(p-SbPr\)(p-CR,),] is the first example of a compound involving a bridging stibine ligand.14 Detailed studies (structural EPR spectroscopic and theoretical) of the bonding in triazenido-bridged dirhodium complexes have been reported.The redox pairs [Rh,(CO),(L)(L'){p-PhNC(Me)NPh)2]o'+ [L = L' = PPh,; L = L' = P(OPh),; L = PPh, L' = P(OPh),] show Rh . . . Rh distances of ca. 2.9 8 in the neutral species and ca. 2.7w in the oxidized species.'44 Iodide abstraction from [{Rh,(p-I)(C0)(bipy)(p-RNNR),},][FT6] (R = p-tolyl) using Ag[PF6] provides a conveni- ent route to a range of triazenido-bridged dirhodium complexes with the [Rh214+ core.145 The ionic bimetallic species [RuC~(PP~,~~),][R~C~,(CO)~] is obtained upon reaction of [RuCl(PPh,py),]Cl with [{ RhCl(CO),} ,]and exhibits greater catalytic activity for hydroformylation of styrene than the monometallic species 13' R.Winter D. T. Pierce W. E. Geiger and T. J. Lynch J. Chem. SOC.,Chem. Commun. 1994 1949. 13' S. L. Scott P. Dufour C. C. Santini and J.-M. Basset J. Chem. SOC.,Chem. Commun. 1994 201 1. 139 J.-J. Brunet G. Commenges D. Neibecker K. Philippot and L. Rosenberg Inorg. Chem. 1994,33,6373. 140 J. M. Kessler J. H. Nelson J. Fischer A. De Ckan W. H. Bearden and N. Fujii Inorg. Chem. 1994,33 4319. 14' A. Vizi-Orosz R. Ugo R. Psaro A. Sironi M. Moret C. Zucchi F. Ghelfi and G. Palyi Inorg. Chem. 1994 33 4600. 14' V. M. Miskowski S.F.Rice H. B. Gray R. F. Dallinger S. J. Milder M. G. Hill C. L. Exstrom and K. R. Mann Inorg. Chem. 1994 33 2799. 143 P. Schwab N. Mahr J. Wolf and H. Werner Angew. Chem. Int. Ed. Engl. 1994,33,97. D.C. Boyd N.G. Connelly G.G. Herbosa M.G. Hill K.R. Mann C. Mealli A.G. Orpen K.E. Richardson and P. H. Reiger Inorg. Chem. 1994 33 960. 145 N.G. Connelly T. Einig G. G. Herbosa P. M. Hopkins C. Mealli A. G. Orpen G. M. Rosair and F. Viguri J. Chem. SOC.,Dalton Trans. 1994 2025. The Noble Metals 277 [R~Cl(PPh,py),][AsPh,1.'~~ Rhodium(1) complexes of the mixed phosphinephos- phite ligand (28) and its enantiomer catalyse the asymmetric hydroformylation of 1,2-disubstituted olefins; (E)-and (Z)-but-2-ene (E)and (2)-1-phenylprop-1-ene and indene yield the corresponding oxoaldehydes in up to 97% e.e.147 The role of (29) as a catalyst precursor for the dehydrogenative coupling of primary silanes (SiH,R R = Bun p-tol) has been investigated and a possible mechanism proposed.The species [R h (p-SiHBu") (dippe),] and [Rh (p-q -SiH tol) ,(p-SiH to1 )(dippe) ,] have been structurally ~haracterized.'~~ gPAr2 A wide range of alkanes have been selectively converted into alkyl esters by using peracids such as H20, Bu'O,H and rn-CPBA in the presence of rhodium catalysts including [Rh,O(OAc),(H,O),] [OAc] [Rh(acac),] [(RhCl(CO),) J [RhCI(PPh,),] and [Rh2(OAc)4].'49 CH,I reacts with CO in alcohols (ROH) in the presence of [Rh,(OAc),] as catalyst to give the doubly carbonylated (malonate) species CH,(CO,R) as well as CH,(OR) at room temperat~re.'~' The rhodium(1) arsine dimer [(RhCl(AsPh,),},] is an efficient catalyst for the transfer dehydrogena- tion of alkenes under an H atmosphere.'5' Various vinylidene allene and alkenylidene rhodium(1) complexes incorporating Pr\AsCH,CH,OMe have been ~ynthesized.'~~ Cationic rhodium(1) complexes of the new chiral P/O ligand (30),e.g.[Rh(cod)(30)]+ have been used successfully in the enantioselective hydroformylation of olefinic substrates including styrene 2-vinyl- naphthalene methylacrylate and vinyl acetate.' 53 High pressure NMR spectroscopy has been employed in the study of imine hydrogenation catalysed by rhodium(1) phosphine complexes. The complexes [Rh,(p- H)(p-X)(diphosphine),] (X = C1 I OMe) were characterized in situ.' 54 Rhodium triethylphosphine complexes prepared in situ from [Rh,(OAc),] and PEt,catalyse the 146 D.Drommi F. Nicolo C.G. Arena G. Bruno F. Faraone and R. Gobetto Inorq. Chirn. Acra 1994,221 109. 14' N. Sakoi K. Nozaki and H. Takaya J. Chem. Soc. Chem. Commun. 1994 395. 148 M. D. Fryzuk L. Rosenberg and S. J. Rettig Inorq. Chim. Am 1994 222 345. 14' K. Nomura and S. Uemura J. Chern. SOC. Chem. Cornmun. 1994 129. "'W.S. Weston R.C. Gash and D.J. Cole-Hamilton J. Chem. Soc. Chern. Commun. 1994 745. J.A. Miller and L.K. Knox J. Chem. SOC. Chem. Commun. 1994 1449. P. Schwab and H. Werner J. Chem. Soc. Dalton Trans. 1994 3415. 153 C. T. Arena F. Nicolo D. Drommi,G. Bruno,and F. Faraone J. Chem. Soc. Chem. Commun. 1994,2251. l'' G. E. Ball W.R. Cullen M. D. Fryzuk W. J. Henderson B. R. James and K. S. McFarlane Inorg. Chern. 1994,33 1464. 278 G. Reid carbonylation of ally1 or benzyl halides to carboxylic acid esters in ethanol in the absence of base and without double bond migration. The selectivity towards ester formation is in the order C1 > Br > I.”’ [RhCl(CO)(PR,),] (R = Me Et) react with CHJ to give for example [RhClI(CH,l)(CO)(PEt,),] involving mutually trans CH,I and I ligands.lS6 Photolysis of [MH,(PMe,)Cp] (M = Rh Ir) in a doped (CH, N, CO) argon matrix generates the 16-electron species [M(PMe,)Cp]. In a CH,-doped argon matrix [MHMe(PMe,)Cp] is ~btained.’’~ [Rh(CCPh)(PPh,),(nbd)] acts as an initiator for the polymerization of phenylacetylene which proceeds rapidly at room temperature in the presence of 4-(dimethylamino)pyridine.’ 58 Parahydrogen-induced polarization has revealed new intermediates in hydrogenation catalysed by [RhCl(PPh,),].l 59 The mechanism of rhodium(1)-catalysed olefin hydroboration has been studied theoreti- cally.’60 The rhodium(In)-catalysed tail-to-tail dimerization of methyl acrylate has been studied in detail.’61 The species [RhHI,(CO),] -and [RhI,(OCEt)(CO),] -,both key intermediates in rhodium-catalysed carbonylation of ethylene have been characterized.62 A catalytic cycle for the synthesis of epoxides from aldehydes and sulfur ylides mediated by sulfides and [Rh,(OAc),] has been proposed.163 The structure of [Rh(H2)(dppm)Cp*][BF4] containing an elongated H-H bond has been determined by single crystal neutron diffraction.64 The organometallic products from the photochemical reaction of trans-[RhCl(CO)(PMe,),] with C& have been identified,16’ and the mechanism of photochemical carbonylation of C& catalysed by this compound studied.’66 The photoinitiated activation of C-H bonds in neopentane by [Rh(CO),Cp*] has been studied and Rh-Kr and Rh-alkane intermediates identified.167 lS5 M. C. Sirnpson M. J. Payne and D. J. Cole-Hamilton J. Chem. Soc. Dalton Trans. 1994 2899. R. C. Gash D. J. Cole-Hamilton R. Whyrnan J.C. Barnes and M. C. Sirnpson J. Chem. Soc. Dalton Trans. 1994 1963. 157 M.G. Partridge A. McCarnley and R.N. Perutz J. Chem. SOC.,Dalton Trans. 1994 3519. Y. Kishirnoto P. Eckerle T. Miyatake T. Ikariya and R. Noyori J.Am. Chem. Soc. 1994,116 12 131. S. B. Duckell C. L. Newell and R. Eisenberg J. Am. Chem. SOC. 1994 116 10548. D.G. Musaev A.M. Mebel and K. Morokuma J. Am. Chem. Soc. 1994 116 10693. E. Hauptrnan S. Sabo-Etienne P. S. White M. Brookhart J. M. Garner P. J. Fagan and J. C. Calabrese J. Am. Chem. Soc. 1994 116 8038. D.C. Roe R. E. Sheridan and E.E. Buiiel J. Am. Chem. Soc. 1994 116 1163. V. K. Aggarwa1,H. Abdel-Rahrnan R. V. H. Jones,H. Y.Lee and B. D. Reid J. Am. Chem. Soc. 1994,116 5973. 164 W.T. Klooster T. F. Koetzle G. Jia T.P. Fong R.H. Morris and A. Albinati J. Am. Chem. SOC. 1994 116 7677. S.E. Boyd L.D. Field and M.G. Partridge J. Am. Chem. Sac. 1994 116,9492. G.P. Rosini W.T. Boese and A.S. Goldrnan J.Am. Chem. Soc. 1994 116 9498. 167 A. A. Bengali R. H. Schultz C. B. Moore and R.G. Bergrnan J. Am. Chem. SOC. 1994 116 9585. The Noble Metals Bis(allyl)rhodium(m) supported on silica titania or alumina reacts with CO in a series of steps giving hexa-1,5-diene on alumina and titania and propene on silica.'68 Photolysis of the Rh'(CO) species on Al,O gives an active surface intermediate Rh'(CO) which oxidatively adds a C-H bond of cycl~hexane.'~~ The rhodium carbonyl clusters [Rh,,(C0),,I2- and [Rh,(CO),,)]- are formed on y-Al,O and on MgO from chemisorbed [Rh(CO),(acac)] in the presence of C0.170 The tetranuclear rhodium complex [(Rh,(p2-CH,),Cp~},(p4-S)]2 is obtained' 71 + from [Rh,(p,-CH,),(p,-SH)Cp*] by the stepwise abstraction of SH-by Ag +.Both + mononuclear cationic and polynuclear anionic rhodium carbonyls have been identified as active species in the acid-catalysed homogeneous water gas shift reaction employing [Rh,(CO),,] and aqueous pyridine.17 Multinuclear NMR studies show that the cluster anion [Rh,N(CO),,] -reacts with [AuCl(PPh,)] to give [Rh6N(CO),,{Au(PPh,)}].i73 The first trigonal prismatic rhodiumxarbido cluster [Rh6C(CO),,(PPh,)12- has been ~haracterized.'~ 5 Iridium A new type of H .-H .. -H interaction has been identified in [IrH(q1-SC5H4N H>,(q2- SC,H,N)(PCy,)][BF,] and [IrH(q'-SCsH4N H),(ql-SC,H,NH),(PCy3)][BF4], in-volving N-H * ..H(Ir) +. * H-N atoms contained in ten-membered bicyclic rings defined by two monodentate S-bound 2-pyridiniumthiolate ligands.'75 Intramolecular N-H * * * X-Ir (X = H F) H-bonding interactions have been identified in a series of metal hydride species e.g. (31) and (32).176Addition of I to [Ir,(p-NH(p-tol- yl)],(CO),] gives the Tr"-Ir" dimer [Ir,I,(p-NH(p-tolyl)) ,(CO),] involving a single metal-metal bond of length 2.591(1) A."' [Ir(CO)Cl(PPh,),] reacts with NSF to give the unusual structurally characterized thiazyldifluoride complex (33) which is readily hydrolysed giving the corresponding Tr-NSO complex. 78 H A PPh3 (31) R = H Ph (32) (33) 168 P. Dufour S. L. Scott C. C. Santini F. Lefebvre and J.-M. Basset Inorg. Chem. 1994 33 2509. 169 J. C. S. Wong and J.T. Yates J. Am. Chem. Soc. 1994 116 1610. 170 S. Kawi 2. Xu and B. C. Gatts inorg. Chem. 1994 33 503.171 T. Nishioka V. Y. Kukushkin K. Isobe and A. Vazquez de Miguel Inorg. Chem. 1994 33 2501. 172 G. Fachinetti G. Fochi and T. Funaioli inorg. Chem. 1994 33 1719. 173 T. Blum B. T. Heaton J. A. Iggo J. Sabounchei and A. K. Smith J. Chem.SOC.,Dalton Trans. 1994,333. 174 T. Blum M. P. Brown B. T. Heaton A. S. Hor J.A. Iggo J. S.Z. Sabounchei and A. K. Smith J. Chem. SOC.,Dalton Trans. 1994 513. 175 S. Park R. Ramachandran A. J. Lough and R. H. Morris J. Chem.SOC.,Chem. Commun. 1994,2201; A. J. Lough S. Park R. Ramachandran and R.H. Morris J. Am. Chem. Soc. 1994 116 8356. 176 E. Puris J.C. Lee and R. H. Crabtree J. Chem. Sac. Chem. Commun. 1994 2573. 1 ?I M.K. Kolel-Veetil J. F. Curley P. R. Yadav and K. J. Ahmed Polyhedron 1994 13 919. 178 P.G. Watson E.Lork and R. Mews J. Chem. SOC.,Chem. Commun. 1994 1069. 280 G. Reid Reaction of [{ IrCl(cyclooctene),},] with four molar equivalents of AgO,CCF in situ gives a highly active system for metathesis and isomerization of acyclic olefins. The function of the silver salt in this mixture is disc~ssed.'~~ Treatment of [IrCl(CO),(p- toluidine)] with azine phosphines of the type (2,E)-PPh,CH,C(Bu')=NN=C(Q)R (Q= H Me) activates oxidative addition of C-H bonds in arenes heterocycles alkenes or aliphatic hydrocarbons to give cyclometallated iridium(II1) hydrides. ' Several square planar C,N chelate complexes of the anionic ligand (34) including [ML(cod)] (M = Rh Ir) and [PtCI(L)] have been prepared."' [{Ir(p-Cl)(cod)),] reacts with HSR (R = C,F,) in the presence ofbase to give [{Ir(p-SR)(cod)),] while in the absence of base the mixed-valence species [(cod)Cl(SR)Ir(p-SR),Ir(cod)] is formed.' 82 Thermolysis of [{IrH,Cp*} ,] in thiophene gives the desulfurization product [Ir,(p-S)(p-1,2-q2-3,4-q2-C4H6)Cp:]. Butadiene is released upon addition of C0.183 The fluxionality and hydrogen-bonding capability of [IrH,X(PBu'R),] (X = C1 Br; R = Me Ph) has been investigated in detail by solution NMR spectroscopy.'s4 The iridium(II1) complex [IrH(CH=CH,)(C,H,)Tp'] can thermally activate two mol- ecules of C& and forms the dinitrogen complexes [IrPh,(N,)Tp'] and [Ir2Ph4(p- N,)Tp;] .' The coordination ring-opening and hydrogenation of benzo[b]thiophene has been achieved at [Ir(triphOS)(q4-C,H6)]Y (Y = BF, PF,).' 86 The reactivity of the Ir-0 bond of [IrPh(silica)(PMe )Cp*] which incorporates silica as a ligand has been studied.lg7 Oxidative addition of alkyl halides RI to [RhI,(CO),] -gives the acyl species [RhI,(COR)(CO)] - whereas with [1rI2(CO),] - the alkyl species [IrI,R(CO),] -are obtained.'88 The competitive formation of C-H and C-Si bonds by reductive elimination of [IrHMe(SiR,)(PMe,),] (R = OEt Ph Et) has been inves- tigated generating silametallacycles in certain cases.89 The iridium(1) and rhodium([) complexes [M(35),] + have been prepared and the Mo 179 M. B. France J. Feldman and R.H. Grubbs J. Chem. Soc. Chem. Commun. 1994 1307. 180 S.D. Perera and B.L. Shaw J. Chem. Soc. Chem. Commun. 1994 1203. 181 I. C. M. Wehman-Ooyevaar G.M. Kapteijn D. M. Grove W. J. J. Smeets A. L. Spek and G. van Koten J. Chem. Soc. Dalton Trans. 1994 703. 182 I. Fonseca E. Hernandez J. Sanz-Aparicio P. Terreros and H. Torrens J. Chem. Soc. Dalton Trans. 1994 781. 183 W. D. Jones and R. M. Chin J. Am. Chem. SOC. 1994 116 198. 184 B.E. Hauger D. Gusev and K.G. Caulton J. Am. Chem. SOC.,1994 116 208. 185 E. Gutierrez A. Monge M. C. Nicasio M. L. Poveda and E. Carmona J.Am. Chem. SOC.,1994,116,791. I86 C. Bianchini A. Meli M. Peruzzini F. Vizza S. Moneti V. Herrera and R. A. Canchez-Delgado J. Am. Chem. SOC. 1994 116 4370. 1R7 T.Y. Meyer K.A. Woerpel B. M. Novak and R.G. Bergman J. Am. Chem. SOC. 1994 116 10290. 188 P. R. Ellis J. M. Pearson A. Haynes H. Adams N. A. Bailey and P. M. Maitlis Organometallics 1994,13 3215.189 M. Aizenberg and D. Milstein Angew. Chem. Int. Ed. Engl. 1994 33 317. The Noble Metals 281 (35) R = Et Pr' Bu' and MI*derivatives studied by EPR spectroscopy. [Tr(35),] reacts with 0 reversibly + to give peroxo species; CO uptake is also disc~ssed.'~' NMR evidence is presented for the formation of both cis-and trans-[IrH(H,)Br,(PPr\),] from [IrHBr2(PPr\)2] and H in s~lution.'~' Derivatives of Vaska's complex trans-[IrCl(CO)(PPh,),] are obtained in high yield from the reaction of PR with cis-[IrCl(CO),(p-t~luidine)].'~~[{IrCl(CO)2)x](x= 2 n)have been formed by mild carbonylation of [(TrCl(cyclooctene),),] supported on ~i1ica.l~~ A general route to the facial tris-cyclometalated complexes [Rh(ppy),] [Ir(ppy ),I and [Ir(thpy),] [ppyH = 2-phenylpyridine thpy = 2-(2-thienyl)pyridine] has been reported together with the X-ray structure of [Ir(thpy)3].194 Addition of [IrCl(CO)(PPh,),] to C6,0 yields [IrC1(CO)(PPh,),(q2-C600)], the structure of which shows the epoxide functionality occupying the same hexagonal face of the fullerene as the iridium atom.'95 The double addition products [C~O(I~C~(CO)(PM~,),}~]'~C~H~ and [{IrC1(CO)(PMe,),),(C,,O)I'2c6H6 have two iridium atoms at opposite ends of the fullerene in the solid state.'96 Crystallization of [IrCl(CO)(PPh,),(q2-C,,)] enables the partial separation of C, isomers; and X-ray study showed the isolated species to be the D, i~0mer.l~~ Several organometallic macrocyclic half-sandwich complexes of iridium(1) of the form [IrL,([9]aneS,)][PF6] (L = 2C2H4 C,H, cod) have been prepared.VT 'H and 13C NMR spectroscopic studies suggest that the [1r([9]aneS3)] + fragment is highly ele~trophilic.'~~ [IrAg(cod)(p-O2CCF,),1 comprises an infinite chain with trifluoroacetate ligands linking adjacent iridium(1) and silver(1) atoms [Ir-Ag = 2.9097(5) 2.9078(5) A] .199 Tetrairidium and diiridium/dirhodium sulfur cubane complexes can be formed via the dimerization of two doubly unsaturated sulfido complex intermediates.200 The tetranuclear cluster [Ir4(p-H)(CO),(Ph,PCCPh)(p-PPh,)] reacts with the phosphaalkyne Bu'CP to give [Ir4(p- CO),(p4-q4-Ph2PC(H)C(Ph)PCBu')(p-PPh2)], which shows an unusual 2-phos- phabutadienylphosphine fragment.," 190 P. Barbaro C. Bianchini F.Laschi S. Midollini S. Moneti G. Scapacci and P. Zanello Inorg. Chem. 1994,33 1622. 19' V.I. Bakhmutov A. B. Vymenits and V.V. Grushin Inorg. Chem. 1994 33 4413. 192 M. Rahum and K. J. Ahmed Inorg. Chem. 1994 33 3003. 193 D. Roberta E. Cariati R. Psaro and R. Ugo Organometallics. 1994 13 4227. 194 M.G. Columbo T.C. Brunold T. Reidener H.U. Giidal M. Fortsch and H.-B. Biirgi Inorg. Chem. 1994 33 545. 195 A. L. Balch D. A. Costa J. W. Lee B.C. Noll and M. M. Olmstead Inorg. Chem. 1994 33 2071. 196 A. L. Balch J. W. Lee B.C. Noll and M. M. Olmstead Inorg. Chem. 1994 33 5238. '97 A. L. Balch A. S. G. Ginwakka J. W. Lee B.C. Noti and M. M. Olmstead J. Am. Chem. SOC. 1994,116 2227. 19' A. J. Blake M. A. Halcrow and M. Schroder J. Chem. SOC.,Dalton Trans. 1994 1631.199 J. Feldman and J.C. Calabrese Inorg. Chem. 1994 33 5995. D.A. Dobbs and R. G. Bergman Inorg. Chem. 1994 33 5329. M. H. A. Benvenutti P. B. Hitchcock J. F. Nixon and M. D. Vargas J. Chem.SOC.,Chem. Commun. 1994 1869. 282 G. Reid [Ir,(C0),o]3-and [Ir,H(C0),,]4- both of which involve a face-sharing bi- octahedral metallic framework are prepared by base-induced condensation of [Ir4(CO)l,].202 A new type of soluble hybrid homogeneous/heterogeneous iridium-polyoxoanion catalyst of average composition [NBu~)~~~~~N~~~~~~ [Irc,300(P4W30Nb60~~~)c,3,] has been isolated.203 The reproducible synthesis of isolable and soluble 2&30 8 Ir300-900 nanoclusters has been achieved.,' 6 Palladium Reaction of [Pd(NCMe),][BF,] with two molar equivalents of tmpp at -44 "C yields the brick-red palladium(1r) complex [Pd(tmpp),][BF,] ,involving a distorted octahedral [P,O + O,] coordination set [Pd-P = 2.216(4) 2.215(4) Pd-0 = 2.195(7) 2.177(8) Pd * 0 = 2.671(7) 2.632(7) A].205 The crown thioethers L [L = (36)(37)] react with palladium(r1) to give [PdL(NCMe)][BF,] which are metalloreceptors of o-aminopyridine derivatives via Pd-N(py ) bonding and second sphere hydrogen-bonding of the NH group to the ether oxygens.206 The binuclear macrocyclic species [Pd2C12(Me6[ 18]aneN6)][PF,] shows N coordination of the aza-crown to each Pd" centre with a terminal CI-ligand completing the distorted square-planar arrangement around each metal ion.207 Palladium(I1) complexes of thiaporphyrins (38) and (39) have been synthesized and chemically reduced to give ligand radical complexes.The structure of CPd(39 j] shows the Pd" atom in the plane of the three N atoms with the thiophene function tilted out of the plane giving N,S coordination.208 The syntheses structures and reactivity of five-coordinate trigonal bipyramidal alkene complexes of Pd" and Pt" have been reviewed.," The palladium(r1) analogue (40)of Carboplatin has been prepared by the reaction of [Pd(NH3)J2+ with H,cbda. It is stable towards hydrolysis and attack by Cl- in water for several hours at 295 K; an X-ray study has confirmed it to be isostructural with Carboplatin.210 202 R. D. Pergola F. Cea L. Garlaschelli,N. Masciocchi and M. Sanson J. Chem. SOC.,Dalton Trans. 1994 1501.203 Y. Lin and R.G. Finke Inorg. Chem. 1994 33 4891. 204 Y. Lin and R. G. Finke J. Am. Chem. Soc. 1994 116 8335. 205 K.R. Dunbar and J.-S. Sun J. Chem. SOC. Chem. Commun. 1994 2387. 206 J.E. Kickham and S.J. Loeb Inorg. Chem. 1994 33 4351. 207 A.J.Blake G. Reid and M. Schroder Polyhedron 1994 13 2135. 208 L. Latos-Grzynski J. Lisowski,P. Chmielewski M. Grzeszczuk M. M. Olmstead and A.L. Balch Inorg. Chem. 1994 33 192. 209 V. G. Albano G. Natrile and A. Panunzi Coord. Chem. Rev. 1994 133 67. 210 K. J. Barnham M. I. Djuran U. Frey M. A. Mazid and P. J.Sadler J. Chem.SOC.,Chem. Commun. 1994 65. The Noble Metals Ph I I Ph (38) Ar = Ph (39)Ar = p -tdyl Small organophosphine dendrimer complexes incorporating up to fifteen phosphor- us atoms have been reported.The palladium(I1) complexes catalyse the electrochemical reduction of CO to C0.,l1 [PdX,(PPh,),] (X = Cl Br I) react reversibly with RH (RH = p-xylene toluene benzene n-hexane cyclohexane) to produce the pallad- ium(1v) complexes [PdHRX,(PPh,),] via thermal C-H bond cleavage. These palladium(1v) complexes eliminate HX in the presence of base giving [PdXR(PPh,),] .2 Deuterium-labelling experiments and 'H NMR spectroscopy have provided evidence for a n-ally1 palladium intermediate in the quinone-based palladium-catalysed allylic acetoxylation of cyclohexene.2 ' Migratory insertion of allene 1,l-dimethylallene and tetramethylallene into alkyl and acyl palladium(11) complexes of bipy and terpy-based ligands occurs quantitatively to give very stable highly substituted q3-allyl complexes and a very unusual ql-allylpalladium(II) terpy Treatment of trans-[PdCl,(PCy,),] with PCy in concentrated alkali in the presence of 18-crown-6 gives the palladium(0) species [Pd(PCy,),] in high yield.215 The coordination of L (L = dibenzyl disulfide dibenzyl diselenide) with palladium(rr) and platinum(I1) gives trinuclear complexes [(MC1,),L,].2'6 The amino spirocyclic cyclotriphosphazene (41) forms a stable chelate complex [PdC1,(41)] in which one of the nitrogen atoms of the diaminoalkane moiety and an adjacent phosphazene ring nitrogen atom bond to the metal.A similar complex with (42) hydrolyses readily to give mono- and bimetallic complexes.2 ' In solution at 65 "C oligomeric [(Pd(SO,F),(CO),),] rearranges to give cis-[Pd(SO,F),(CO),] incorporating significantly reduced .n-back-donation and non- classical Pd-CO bonding.* * Cyclo-[Pd,(p-CO),][SO,F] contains planar [Pd,(p- CO),]" cations linked by bidentate bridging SO,F-anions into a polymeric sheet.," The complexes [NH,Me,-,],[M(dmit),] (M = Ni Pd Pt) have been fully characterized and their electrical properties and electronic band structure inves- *I1 A. Miedaner C. J. Curtis R. M. Barkley and D. L. DuBois Inorg. Chem. 1994 33 5482. 212 A.N. Vedernikov A. I. Kuramshin and B.N. Solomonov J. Chem. Soc. Chem. Commun. 1994 121. 'I3 H. Grennberg V. Simon and J.-E. Backvall J. Chem. Soc. Chem. Commun. 1994 265. '14 R. E. Rulke D. Kliphuis C.J. Elsevier J. Fraanje K. Goubitz P. W. N. van Leeuwen and K.Vrieze J. Chem. Soc. Chem. Commun. 1994 1817. 'I5 V.V. Grushen C. Benisimon and H. Alper Inorg. Chem. 1994 33,4804. 216 W. Baratta P. S. Pregosin A. Bacchi and G. Aelizzi Inorg. Chem. 1994 33 4494. 217 A. Chandrasekaran S. S. Krishnamurthy and M. Nethaji Inorg. Chem. 1994 33 3085. 'I8 C. Wang H. Willner M. Bodenbinder R. J. Batchelor F. W. B. Einstein and F. Aubke Inorg. Chem. 1994,33 3521. C. Wang M. Bodenbinder H. Willner S. Rettig J. Trotter and F. Aubke Inorg. Chem. 1994,33,779. 284 G.Reid n HN ,NH N’Pa N I1 I Me2N-P +P-NMe2 Me2N’ \NMe2 tigated.,,’ Dynamic NMR spectroscopic studies on square planar cis-[M(C,F,),(terpy)] (M = Pd Pt) show that the terpy ligand oscillates between bidentate modes via a twist mechanism with rotamers occurring at low temperature through restricted rotation of the pendant C,H,N ring and the C,F rings.221 Reaction of [(Li(thf)(Ph,P,N,S,R]J with [MCl,(PEt,),] (M = Pd Pt) gives trans-[MC1(PEt,),(q’-S-Ph4P2N4S2R)] which exhibit fluxional behaviour involving M-S bond rotation.222 Pd Pt and Rh complexes of the water-soluble phosphine (43) formed by direct sulfonation of dppe have been prepared and their catalytic activity towards the hydroformylation of oct-1 -ene investigated.223 S03H S03H I I S03H SO~H In square planar platinum and palladium complexes the ‘insertion’ of CO into M-C bonds has been shown to involve migration of the alkyl group to the CO rather than CO The new M-M complexes [Pd2(PMe3)6]2+ and [PdPt(PMe3),12 + are prepared via comproportionation reactions.In the former the two mutually perpendicular square planar palladium environments are connected by a Pd-Pd bond of length 2.598(1) Several binuclear palladium(1) complexes of isocyanide with [C,Ph,] -and tris(pyrazo1-1-y1)borate ligands have been characterized.226 The ’*’B. Pomarede B. Garreau I. Malfant L. Valade P. Cassoux J.-P. Legros A. Audouard L. Brassard J.-P. Ulmet M.-L. Doublet and E. Canadell Inorg. Chem. 1994 33 3401. E. W. Abel K.G. Orrell A.G. Osborne H. M. Pain V. Sik M. B. Hursthouse and K. M.A. Malik J. Chem. Soc. Dalton Trans. 1994 3441. 222 T. Chivers M. Edwards R. W. Hilts M. Parvez and R. Vollmerhaus Inorg. Chem. 1994 33 1440. 223 T. Bartik B.B. Bunn B. Bartik and B. E. Hanson Inorg. Chem.1994 33 164. 224 P. W. N. M. van Leeuwen C. F. Roobeek and H. van der Heijden J. Am. Chem. Soc. 1994,116. 12 117. 225 W. Lin S. R. Wilson and G.S. Girolami Inorg. Chem. 1994 33 2265. 226 T. Tanase T. Fukushima T. Nomura and Y. Yamamoto Inorg. Chem. 1994 33 32. The Noble Metals oxidative addition of Si-X (X = H Me SiH,) to Pd(PH,) is much less exothermic than to Pt(PH,) although the activation barriers are similar.227 [PdCl,(NCPh),] reacts with substituted hydrazines R,P(E)NMeNH (R = OMe OEt OPh Ph; E = S 0) to give the metallocyclic compounds [Pd{NH,MeN(E )PR,})C1,].228 Related palladium(I1) and platinum(I1) complexes of dichlorophosphino4imethyl hydrazine and carboxylate appended phosphorus hy- 29 drazines have also been ~repared.~ The secondary phosphine complexes [MCl(PHCy,),][PF,] (M = Pd Pt) have been characterized by multinuclear ('H ,'P and 19,Pt) NMR spectroscopy.230 Reaction of [PdCl,(PHCy,),] with NaOPh gives the dimeric species [{ PdCl(PHCy,)(p-PCy,)} ,] or [{Pd(p-PCy,)C1(PCy,0Ph)),].231 [Pd,(PHCy,),(p-PCy,)(p :q3-C,H,)] reacts with PhEH (E = S Se) to give trans-[Pd(EPh),(PHCy,),] or the mixed-valence cluster [Pd,(p- EPh)(p-PCy,),(EPh)(PHCy The synthesis and spectroscopic data of platinum and palladium complexes of the chalcogen-substituted diazenes (44) and (45) have been reported together with a crystal structure of [Pd(PPh,)(45)].233 Electrochemical oxidation of [Pd(46),I2 -and [Pd(47),I2- yields [{Pd(46)),I2- and [{Pd(47)},] respectively structural data on which have been presented.234 (44) E=S (45) E=Se (47) The metallalactam complexes [M{CH(COMe)C(O)NR}L,] [M = Pd L = bipy; M = Pt L = (PPh,), cod dppp; R = Ph C,H,OMe] are obtained in high yield from cis-[MCl,L,] and acetoacetanilide or u-or p-acetoacetanisidide in the presence of Ag,O.,, Reaction of cis-[Pd(C,F,),(thf),] with benzyldimethylamine affords cis-[Pd(C,F,),(C,H,CH,NMe,)] a four-coordinate compound containing an un- usual q l-arene-palladium interaction; the amine acts as a bidentate chelating ligand.236 The functionalized phosphine (48) reacts with palladium(i1) and platinum(I1) 227 S.Sakaki M. Ogawa Y. Musashi and T. Arai lnorg. Chem. 1994,33 1660. 228 M. Wang E. W. Volkert P. R. Singh K. K. Katti P. Lusiak K. V. Katti and C. L. Barnes Inorg.Chem. 1994,33 1184. 229 V. S. Reddy and K.V. Katti lnorg. Chem. 1994 33 2695; P. R. Singh H. Jimenez K.V. Katti W. A. Volkert and C. L. Barnes lnorg. Chem. 1994 33 736. 230 R. J. Forder I. S. Mitchell G. Reid and R. H. Simpson Polyhedron 1994 13 2129. 231 M. Sommovigo M. Pasquali P. Leoni and U. Englert lnorg. Chem. 1994,33 2686. 232 M. Sommovigo M. Pasquali F. Marchetti P. Leoni and T. Beringhelli Inorg. Chem. 1994 33 2651. 233 T. Chivers K. McGregor and M. Parvez lnorg. Chem. 1994 33 2364. 234 C. Faulmann J.-P. Legros P. Cassoux J. Cornelisson L. Brassard M. Inokuchi H. Tajima and M. Tokumoto J. Chem. SOC.,Dalton Trans. 1994 249. 235 W.Henderson J. Fawcett R. D. W. Kemmitt C. Proctor and D. R. Russell J. Chem. Soc. Dalton Truns.1994 3085. 236 L. R. Falvello J. Fornies R. Navarro V. Sicilia and M. Tomas J. Chem. Soc. Dalton Trans. 1994 3143. 286 G. Reid species to give metallocyclic species; trans trans-[{PdCI(p-L)},] consists of two trans-PdC1,units linked by two L molecules in a head-to-tail arrangement giving a 12-membered metalla~ycle.~~~ A range of complexes [MCl,L,] (M = Pd Pt; L = RECH,ER; R = Me Ph; E = S Se Te) involving monodentate ligation of L to square planar M(II) centres has been prepared.238 The azine phosphines (49) and (50) form bidentate chelate complexes with [PdCl,(cod)] and tridentate complexes with [PdCl,]’-. Reactions of (49 j and (50) with platinum rhodium and iridium precursors are also discussed.239 IR and I3C NMR spectroscopic studies suggest that CO exchange in [MX,(CO)]- (M = Pd Pt; X = C1 Br) is first order in both CO and complex concentration and slower than C2H4 exchange in analogous ethene and halide complexes.240 Solid-state thermolysis of [MCl2(2,4’-R-bipy)] (M = Pd Pt; R = H Me Bu C,H,, C8HI7 C,,H,,) affords the cyclometallated complexes [MC1,(2,4’-R-bipy-H)] .241 Tri- and tetranuclear palladium@) and platinum(I1) compounds with double thiolato bridges are formed by the reaction of cis-[M(C,F,),(thf),] with [M’(SC,F,)4]2-or [M;(SC6F,),l2-(M = Pd Pt; M’ = Pd Pt).242 Several palladium(I1) complexes of the tripodal phosphine [HC(PPh,),] involving various ligation modes have been characterized by a combination of NMR spectroscopic and X-ray structural stu- dies.243 Encapsulation of cubic palladium crystallites inside carbon gives worm-like carbon nanostru~tures.~~~ Self-assembly of robust palladium(11) and platinum@) metallomac- rocyclic boxes (51) and (52) has been achieved in high yield.245 Similarly [M(C,H,CN-p),(dppp)] (M = Pd Pt) reacts with [M’(OSO,CF,),(dppp)] (M’ = Pd Pt j to give tetranuclear metallocyclic compounds.246 Palladium(1v) and platinum(1vj complexes have been prepared using the rigid bidentate ligands bis (p-t olylimino jacenaphthene and bis (p heny1imino)camphane .247 237 S.LoSchiavo G. DeMunno F. Nicolo and G. Tresoldi J. Chem. Soc. Dalton Trans. 1994 3135. 238 A. F. Chiffey J. Evans W. Levason and M. Webster J. Chem. Soc. Dalton Trans. 1994 2835. 239 K.K. Hii S.D. Perera and B. L. Shaw J. Chem.Soc. Dalton Trans. 1994 3589. A. Olsson A. Roodt M. Bojczuk B. T. Heaton and L. I. Elding J. Chem. Soc. Dalton Trans. 1994,3723. 241 S. Wimmer and F.L. Wimmer J. Chem. Soc. Dalton Trans. 1994 879. 242 R. Uson J. Fornies M. A. Uson M. Tomas and M. A. Ibaiiiz J. Chem. SOC.,Dalton Trans. 1994 401. 243 J. Fornies,F. Martinez R. Navarro M. Tomas and E. P.Urriolabeitia,J. Chem.Soc. Dalton Trans. 1994 505. 244 Y. Wang J. Am. Chem. Soc. 1994 116 397. 245 P. J. Stang and D. H. Cao J. Am. Chem. Soc. 1994 116,4981. 246 P. J. Stang and J. A. Whiteford Organometallics 1994 13 3776. 247 R. van Asselt E. Rijnberg and C.J. Elsevier Organometallics 1994 13 706. The Noble Metals a+ 1 (51) M= Pd (52) M = Pt 7 Platinum The homoleptic thioether macrocyclic complexes [PtL][PF,] (L = [12]- [14]- and [16]aneS,) and [Pt2([28]aneS,)][PF6] have been prepared.An X-ray structure of [Pt([12]aneS4)][PF,],-MeCN illustrates the bad size-match between the Pt” ionic radius and the small cavity offered by the 12-membered thiacro~n.,~ The plati- num(1v) selenoether macrocyclic complexes trans-[PtX,([ 16]aneSe4)][PF,], the first platinum(1v) complexes incorporating Se,X2 donor sets have been prepared and characterized by 77Se and 195Pt NMR spectroscopy and a crystal structure (X = Cl).249 The macrocyclic complexes (53t(55) prepared by the reaction of aqueous K,PtCl with the bipyridyl crown ether exhibit antineoplastic properties.250 (53) n = 1 (54) n =2 (55)n =3 EXAFS and XANES studies on a platinum-phthalocyanine film indicate that the structure comprises non-planar concave discotic molecules packed orthogonal to the stacking The complexes [MC1{(Ph2PCH2CH,),SO)][C10,] (M = Pt Pd) have been prepared; the platinum(I1) complex shows tridentate ligation via one S and 248 A.J.Blake A.J. Holder G. Reid and M. Schroder J. Chem. SOC.,Dalton Trans. 1994 627. 249 W. Levason J. J. Quirk G.Reid and C. S. Frampton Inorg. Chem. 1994 33 6120. 250 A. Grund and B.K. Keppler Angew. Chem. Int. Ed. En& 1994 33 186. 251 Y. H. Chang K. H. Choi W.T. Ford S. J. Cho and R. Ryoo J. Chem. SOC.,Chem. Commun. 1994,785. 288 G. Reid both P NMR spectroscopic studies of the kinetics and thermodynamics of the competitive binding of L-methionine L-histidine and 5'-monophosphates of guanosine adenosine thymidine and cytidine to [PtCl(dien)] in aqueous solution + show that guanosine monophosphate selectively displaces S-bound methionine.The possible implications for DNA platination by anticancer drugs in vim are discussed.253 trans-[PtCl(OH)(NH,),]*H,O the first hydrolysis product of trans-[PtCl,(NH,),] has been isolated and structurally ~haracterized.,~ [Pt(cbdca-o)(NH,),(~-Met-s)], a ring-opened adduct of the anticancer drug Carboplatin has been identified spectros- copi~ally.~~~ The first examples of four-membered ring platinalactam complexes [Pt{CH(CN)C(O)N (CO,Et)}L,] were obtained in high yield from the Ag,O- mediated reaction of cis-[PtCl,L,] (L = PPh,; L = cod dppe) with ethyl N-cyanoa~etylcarbamate.~~~ [{ PtCl,(HN=C(OH)Bu')},] is the first example of a trinuclear chloro-bridged platinum(I1) complex with mutually perpendicular coordina- tion planes for the three platinum atoms.257 The binuclear platinum(I1) complexes of tetraphos-1 cis,meso-[Pt,Cl,( tetraphos- 1)] and cis,rac-[Pt,Cl,( tetraphos- 1)] have been structurally ~haracterized.,~~ The trimetallic complexes (56)and (57)(cis,cis,cis and cis,trans,cis isomers respectively) involving 1,1,1-tris(dipheny1phos-phinomethy1)ethane were identified by 31Pand 195Pt NMR spectroscopy.259 X (W (57) A Pt, dendrimer has been obtained from the oxidative addition of 4,4'-bis(bromomethyl)-2,2'-bipyridine to [PtMe,(Bu\bipy)] and introduction of [Pt,Me,(p-SMe,),].260 Oxidative addition of dimethylplatinum(I1) species to 1,2,4,5- tetrakis(bromomethy1)benzene also affords large dendrimeric organoplatinum com- plexes including a Pt:; complex.261 The electronic structure and reactivity of [Pt(q-O,)(PR,)] complexes have been investigated using ab initio MO-LCAO calculations.262 Vibrational spectra in the 2-500 cm-region of several polymeric chain and dimeric platinum species show the vpt2 modes occur between 5 and 55 cm-263 Deprotonation deuteriation and substitution of the backbone of some 252 S.-Y.Siah P.-H. Leung and K.F. Mok Polyhedron 1994 13 3253. 2s3 K. J. Barnham M. I. Djuran P. del Socorro Murdoch and P. J. Sadler J. Chem. Soc. Chem. Cornmun. 1994 721. 254 J. Arpalahti R. Sillanpaa and M. Mikola J. Chem. Soc. Dalton Trans. 1994 1499. 255 K. J. Barnham U.Frey P. del Socorro Murdoch J. Ranford and P. J. Sadler J. Am. Chem.Soc. 1994,116 11 175. 25h W. Henderson B.K. Nicholson and A.G. Oliver J. Chem. Soc. Dalton Trans. 1994 1831. 257 R. Cini F. P. Intini G. Natik and C. Pacifico J. Chem. Soc. Dalton Trans. 1994 3753. *" K. Dillinger W. Oberhauser C. Bachmann and P. Bruggeller Inorg. Chim. Acta 1994 223 13. 259 A. R. Khan S.M. Socol and D. W. Meek Inorg. Chim. Acta 1994 221 221. 260 S. Achar and R. J. Puddephatt Angew. Chem. Int. Ed. Engl. 1994 33 847. 261 S. Achar and R.J. Puddephatt J. Chem. Soc. Chem. Commun. 1994 1895. 262 P. Fantucci S. Lolli and M. Pizzotti Inorg. Chem. 1994 33 2779. 263 P. D. Harvey K.D. Truong K.T. Aye M. Drouin and A.D. Bandrank Inorg. Chem. 1994 33 2347. The Noble Metals 289 azine diphosphine complexes of platinum and palladium have been studied and the crystal structures of two platinum(I1) complexes reported.264 The synthesis and dynamic NMR spectroscopic studies of rhodium(r) and plati- num(1r) complexes of silyl-substituted dialkenyl thioether selenoether and tellu- roether ligands together with three crystal structures have been reported.265 The luminescent behaviour of square planar platinum(1r) dithiolate complexes has been studied.266 The cyclic platinum(r1) thiolate species [Pt{SCH,C(O)C H,}(PPh,),] reacts with RX (MeI EtBr PhCH,Cl) to give the thioether complexes [PtX{ RSCH,C(O)C H,} (PPh,)] .267 [PtHCl(PPh,),] and [IrH,Cl(CO)(PPh,),] re-act with c60 in refluxing EtOH/benzene to form [Pt(~2-C6,)(PPh,),] and [IrH(Co)(~2-C60)(PPh3)2] respectively.268 The platinum(1v) species [PtIMe,(dppe)] undergoes competitive reactions involving reductive elimination of ethane and formation of MeI.269 The thermal chemistry of vinyl halides adsorbed onto Pt(ll1) surfaces has been studied using TPD and RAIRS spectroscopies.270 K,[PtH,] prepared under a high pressure of H, has the same structure as K,[PtC16].271 The kinetics and mechanism of oxidation of SO by [Pt(CN),C1,I2- in acidic aqueous solution have been probed.”’ [Pt(PPh,),] reacts with (PhCNSSN) in MeCN to give the mononuclear species [Pt(SNCPhNS-S,S)(PPh,)JMeCN which decomposes in toluene to give an unusual trimetallic species [Pt3(p-SNCPhNS-S,S),(PPh,),]-2PhMe involving a linear Pt chain.273 The first examples of platinum-phosphine dimers with bridging 0x0 and hydroxo ligands have been Acetylated 8-aminoquinoline coordinates to plati- num(rI) giving a complex containing new three-centre N-H * * * Pt bonds identified by H and 5N NMR spectroscopy and X-ray crystallography [Pt * * -H(N) = 2.2(1) A].275 [Pt(PPh,),(C,H,)] reacts with AsC(C,H,Bu\) to give [Pt(PPh,),{y2- AsC(C,H,Bu\)}] the first example of a metal complex derived from an ar~aalkyne.’~~ FTIR spectroscopy has shown that CO is activated and couples with ethylene over the silica supported platinum-tin complex cis-[PtCl(SnC1,)(PPh,),]-sili~a.~~~ Complex (58) is obtained when cis-[PtClMe((S,S)-bdpp}] or cis-[PtMe(SnCl,){(S,S)-bdpp}] [(S,S)-bdpp = (2S,4S)-2,4-bis(diphenylphosphino)pentane]is treated with CO at 1-150 bar and 193-213K.278 Addition of one electron and one proton to trans-[Pt(pbo),] 264 S.D.Perera B.L. Shaw and M. Thornton-Pett J. Chem. Soc. Dalton Trans. 1994 3311. 265 E. W. Abel J. R. Koe M. B. Hursthouse K. M. A. Malik and M. A. Mazid J. Chem. Soc. Dalton Trans. 1994 2637; 2645. 266 J. M. Bevilacqua and R. Eisenberg Inorg. Chem. 1994 33 2913; J. M. Bevilacqua J. A. Zuleta and R. Eisenberg Inorg. Chem. 1994 33 258. 261 W. Henderson B. K. Nicholson and R. D. W. Kemmitt J. Chem. Soc. Dalton Trans. 1994 2489. 268 S. Schreiner T.N. Gallaher and H. K. Parsons Inorg. Chem. 1994 33 3021. 269 K.I. Goldberg J.-Y. Yan and E.L. Winter J. Am. Chem. Soc. 1994 116 1573. 270 F. Zaera and N. Bernstein J. Am. Chem. Soc. 1994 116 4881.271 W. Bronger and G. Auffermann Angew. Chem. Int. Ed. Engl. 1994 33 11 12. 212 J. Berglund R. Voigt S. Fronaeus and L. 1. Elding Inorg. Chem. 1994 33 3346. 213 A. J. Banister I. B. Gorrell S.E. Lawrence C. W. Lehmann 1. May G. Tate A. J. Blake and J. M. Rawson J. Chem. Soc. Chem. Commun. 1994 1779. 274 J. J. Li and P. R. Sharp Inorg. Chem. 1994 33 183. 215 A. Albanati F. Lianza P.S. Pregosin and B. Miiller Inorg. Chem. 1994 33 2522. 276 P. B. Hitchcock C. Jones and J. F. Nixon J. Chem. Soc. Chem. Commun. 1994 2061. 277 J. Llorca P. R. de la Piscine J. Salis and N. Hums J. Chem. Soc. Chem. Commun. 1994 2573. 278 I. Toth T. Kegle C.J. Elsevier and L. Kollar Inorg. Chem. 1994 33 5708. 290 G. Reid [Hpbo = PhN=NC(Ph)=NOH)] gives cis-[Pt(pbo)(Hpbo)] ,.79 Electrochemical and spectroscopic studies suggest [Pt (R,dtc),] and [PtX (R ,dtc),] (R,dtc = S,CNR,; X = Br I) do not give palladium(rrr) intermediates. However oxidation of [Pt(q’-S2CNEt2)(q3-P2P’)][P,P’ = Ph,P(CH,),P(Ph)(CH2),PPh2] gives280 the moderately stable platinum(r1r) species [Pt(S2CNEt2)(q3-P2P’)I2+. fac-[PtXMe,L,] (L = pyridazine 4-methylpyridazine) undergo 1,2-M-N metallo- tropic shifts which interconvert linkage isomers.28’ The complex [PPh,] ,[Pt(As3S5),] is a cage compound formally containing platinum(1v) coordinated to four S and two As atoms in an octahedral geometry; [PPh4],K[Pt,(AsS4),].1.5H,0 shows square planar platinum(r1) bound to four S donors.282 The 25-atom cluster [Pt,{Au(PPh,)) ,,Ag,,Cl,] shows two identical icosahedral platinum-centred subunits linked by a common Ag vertex.283 Several platinum-gold phosphine clusters are effective catalysts for H,-D equilibration and provide a model for H activation on bimetallic surfaces.284 The reaction (isotope exchange) between D,(g) and H,0(1) in a pyridine solution of [Pt{Au(PPh,),)] [NO,] has been investigated in The 19’Pt NMR spectra of [Pt,(OAc),(MeCONH)] and [Pt,(OAc) (MeCONH),] each involving four chemically distinct platinum nuclei have been analysed.286 The di- and trinuclear platinum complexes [NBu,],[(C,F,),Pt(p- cc 12 (p-CCR)2 Pt(C6F 5 )21 and LNBu4l 2 [(C6F 5 )2Pt (p-CCR)2 Pt(p-CCR),Pt(C6FJ2] (R = Ph But SiMe,) involve double acetylide bridges.287 The reaction of [{ PtAg,(C,F,),(CCR),),] with two molar equivalents of PPh gives [PtAg,(C6F5),(p-~2,~-~~R)(p3-~-~~R)(PPh3)2] (R = Ph But) containing unsymmetrical edge-bridging alkynyl ligands.288 Several homo- and heterodinuclear complexes containing alkynyl bridges have been prepared including cis,trans-[(Co)(C6F5),Pt(p-~2-CCPh)Pt(CCPh)(PPh)(PPh3)2].28’ Several penta- and hexanuclear 279 C.K.Pal S. Chattopadhyay C. Sinha and A. Chakravorty Inorg. Chem. 1994,33 6140. 280 A.M. Bond R. Colton D. A. Fiedler J. E. Kevekordes V. Tadesco and T. F. Mann lnorg. Chem. 1994 33 5761. 281 E. W. Abel E. S. Blackwell P.J. Heard K. G. Orrell V. Sik M. B. Hursthouse and K. M. A. Malik J. Chem. Soc. Dalton Trans. 1994 445. 282 J.-H. Chou and M.G. Kanatzides Inorg. Chem. 1994 33 5372. 283 T. G. M. M.Kappen P. P. J. Schlobos J. J. Bour W. P. Bosman J. M. M. Smits P.T. Beurskems and J. J. Steggerda lnorg. Chem. 1994 33 754. 284 M.A. Aubart B.D. Chandler R.A.T. Gould D.A. Krogstad M.F.J. Schoondergang and L.A. Pignolet Inorg. Chem. 1994 33 3724. 285 M. A. Aubart J.D. F. Koch and L.H. Pignolet Inorg. Chem. 1994 33 3852. 286 T. Yamaguchi K. Abe and T. Ito Inorg. Chem. 1994,33 2689. 287 J. Fornies E. Lalinde A. Martin and M.T. Moreno J. Chem. Soc. Dalton Trans. 1994 135. 288 I. Ara J. Fornies E. Lalinde M. T. Moreno and M. Tomas J. Chem. Soc. Dalton Trans. 1994 2735. 289 J. R. Berenguer J. Fornies E. Lalinde F. Martinez E. P. Urriolabeitia and A. J. Welch J. Chem. Soc. Dalton Truns. 1994 1291. The Noble Metals 29 1 platinum clusters including [Pt5(p-S02)3(CNC8H9),] have been characterized spectroscopically and by X-ray cry~tallography.~~~ [Pt,Ru6(p3-H)(p-H)(co)20(p3-PhC,Ph)] is an effective catalyst for the hydrogenation of diphenylacetylene to (Z)-~tilbene.,~' 8 Silver A highly stable molecular CO species has been identified for the first time by in situ FTIR spectroscopy (v = 2337 cm-') on a polycrystalline silver catalyst.292 IR spectroscopic data and manometric measurements indicate that at high pressures of CO the silver(1) salt of the anion [Nb(OTeF,),] -takes up three equivalents of CO reversibly to give [Ag(co),][Nb(OTeF,),] both in the solid-state and in 1,1,2- C,Cl,F3 solution.293 [Ag(CO)] + and [Ag(CO),] have been characterized spectros- + copically and crystallographically both of which indicate little or no Ag to CO ~c-back-bonding.~~~ Schiff-base condensation of tris(3-aminopropy1)aminewith 2,5- dimethoxy- 1,3-phenyIenedialdehyde in the presence of AgNO affords a binuclear silver(1) cryptate [Ag,L][ClO,] (L = C48H6,N,O,) involving distorted trigonal N coordination at each silver(1) centre.295 Discrimination of the order of lo9 in favour of silver(1) over lead@) has been achieved using an S,N donor macr~cycle.~~~ Nickel-coordinated and metal-free tetraalkylthio-substituted phthalocyanines have been prepared and their complexa- tion to silver(1) and palladium(I1) via the S-donors studied.297 Silver(1) complexes with meso-octaethyltetraoxoporphyrinogento give pseudo-octahedral species containing axial a-C-H bonds.298 The structures chemistry and applications of silver clusters in zeolites have been reviewed.299 In situ FTIR spectroscopic studies have shown that methyl formate is dissociatively chemisorbed onto the conventional (1 11) and (1 10) faces of a polycrystalline silver catalyst which contains nucleophilic adsorbed-oxygen specie^.^" Oxidation of [Fe(C0),I2- by Ag' proceeds via progressive formation of struc- turally characterized AgFe clusters such as [Ag{ Fe(CO),),j3- CAg4b2-Fe(C0)4)4I4-7 and CAg,b,-Fe(CO)4} 2{P3-Fe(CO)4) 21 -,01 An [&,I4 + cluster is obtained by the interaction of silver(1) with the marine peptide metabolate ~estiellamide.~'~ The electronic structure of Ag,Pb,06 has been reported.3o3 290 J.L. Haggitt and D. M. P. Mingos J.Chem. Soc. Dalton Trans. 1994 1013. 291 R.D. Adams T.S. Barnard Z. Li W. Wu and J.H. Yamamoto J. Am. Chem. Soc. 1994 116 9103. 292 G.J. Millar J. Seakins J. B. Metson G. A. Bowmaker and R.I>.Cooney J. Chem. Soc. Chem. Commun. 1994 525. 293 J. J. Rack B. Moasser J. D. Gargulak W. L. Gladfelter H. D. Hochheimer and S. H. Strauss J. Chem. SOC. Chem. Commun. 1994 685. 294 P.K. Hurlburt J. J. Rack J.S. Luck S. F. Dec J.D. Webb 0.P. Anderson and S.H. Strauss J. Am. Chem. SOC. 1994 116 10003. 295 Y. Shu-Yan L. Qin-Hui S. Meng-Chang Z. Zheng H. Xiao-Yun,and W. Qiang-Jin Polyhedron 1994,13 2467. 296 K.R. Adam D.S. Baldwin A. Bashall L.F. Lindoy M. McPartlin and H.R. Powell J. Chem. Soc. Dalton Trans. 1994 237. 297 I. Giirol V. Ahsen and 6.Belaroglu J.Chem. SOC.,Dalton Trans. 1994 497. 298 C. M. Kretz E. Gallo E. Solari C. Floriani A. Chiesi-Villa and C. Rizzoli J. Am. Chem. SOC.,1994,116 10 775. 299 T. Sun and K. Seff Chem. Rev. 1994,94 857. 300 G. J. Millar J. B. Metson G. A. Bowmaker and R. P. Cooney J. Chem.SOC.,Chem. Commun. 1994,1717. V. G. Albano F. Azzaroni M. Clapalucci G. Langoni M. Monari S. Mulley D. M. Prosperio and A. Sironi Inorg. Chem. 1994 33 5320. 292 G. Reid Reaction of Ag with heavy alkali metal sulfides in supercritical amines generates two new species RbAg,S and CsAg,S, both of which have open channeled structure^.^'^ Silver(1) selenolate and tellurolate complexes [Ag(SeC(SiMe,),),] and [Ag(ER)(PCy,)] [E = Se Te; R = C(SiMe,),] have been ~ynthesized.,'~ The intramolecular M-M interaction in the d"-d8 species [MPt(CN),(dppm),] + (M = Ag Au) has been investigated spectroscopically and crystallographically [Pt *.* Ag = 3.002(1)81.]306 The five-coordinate complexes [M(PPh,),(terpy)] [ClO,] (M = Cu Ag) have been prepared. The X-ray structures show discrete monomers of distorted trigonal bipyramidal geometry with equatorial PPh ligands.,07 The compounds AMTeS (A = K Rb Cs; M = Cu Ag) represent a new class of compounds based on the [TeS,I2- anion; [MTeS,]:- layers in which M is tetrahedrally coordinated are separated by cations.308 The silver nitride derivative Ag,,Ca,N involves Ca,N octahedra embedded in a matrix of Ag.,09 9 Gold The first examples of trimetallic vertex-sharing biicosahedral clusters + + [(Ph,P) ,Au ,Ag ,,PtCl,] and [(Ph,P),,Au ',Ag ,NiCl,] ,have been structurally ~haracterized.~'' The gold cluster [Au,O,(PMe,),][BF,], formed from [AuCl(PMe,)] Ag,O and NaBF, involves a tetrahedral Au core with two edge-bridging external gold atoms.,' * Reaction of [{Au(CCPh)),] with dppm affords the photoluminescent trinuclear species [AU,(CCP~),(,U~-~~~~>,ICA~(CCP~)~] which involves a triangular arrangement of the three gold atoms.31 The tetranuclear gold(1) species [((pta)3Au)2Au,(i-mnt)2] (pta = phosphat-riazaadamantane i-mnt = [S,C2(CN),]2-) prepared by the reaction of [Au(pta),]Cl with K,[i-mnt] shows each gold atom of the anion interacting differently with the [Au(pta),]+ units to give unsupported Au' .. . Au' interaction^.^'^ New mono- di- and trinuclear gold(Ir1) tris(dipheny1phosphino)methanide complexes have been characterized.l4 Reduction of [AuCl,] -by NaBH in water/toluene in the presence of alkanethiol gives solutions of 1-3 nm gold particles.315 The chemical vapour deposition of gold from [AuR(PMe,)] (R = Et Me) occurs at very low temperatures on various metal and semiconductor substrates.316 [N(PPh,),][Au(SH),] the first 302 P. Wipf S. Venkatramen C. P. Miller and S.J. Greib Angew. Chem. Int. Ed. Engl. 1994 33 1516. 303 T. D. Brenman and J.K. Burdett Inorg. Chem. 1994 33 4794. 304 P.T. Wood W.T. Pennington and J. W. Kolis Inorg. Chem. 1994 33 1556. 3"s P.J. Bonasia G.P. Mitchell F. J. Hollander and J. Arnold Inorg. Chem. 1994 33 1797. '06 H.-K. Yip H.-M. Che K.-K. Cheung C.-M. Che and Y.Wang Inorg. Chem. 1994 33 1644. 307 E. W. Ainscough A.M. Brodie S. L. Ingham and J. M. Waters J. Chem. SOC.,Dalton Trans. 1994,215. 308 X. Zhang and M.G. Kanatzidas J. Am. Chem. Soc. 1994 116 1890. 309 G.J. Snyder and A. Simon Angew. Chem. Int. Ed. Engl. 1994,33 689. 310 B. K. Teo H. Zhang and X. Shi Inorg. Chem. 1994 33 4086. 311 K. Angermaier and H. Schmidbauer Inorg. Chem. 1994 33 2071. 312 C.-M. Che H.-K. Yip W.-C. Lo and S.-M. Peng Polyhedron 1994 13 887. 313 J. P. Fackler R. J. Staples and Z. Assefa J. Chem. Soc. Chem. Commun. 1994 431. E.J. Fernandez M.C. Gimeno P.G. Jones B. Ahrens A. Laguna M. Laguna and J.M. Lopez de Lazuriaga J. Chem. SOC.,Dalton Trans. 1994 3487. 31s M. Brust M. Walker D. Bethell D. J. Schiffrin and R. Whyman J. Chem. Soc.Chem. Commun. 1994 801. 3'6 M. M. Banaszak Hall P. F. Seidler S. P. Kowalczyk and F.R. McFeely Inorg. Chem. 1994 33 510. The Noble Metals 293 homoleptic hydrogensulfido complex has been synthesized. The dinuclear gold(I1) complex [Au2{p-(CH2),PPh,}{p-S2CN(CH2Ph)2}Br2] involving two different bridging ligands has been structurally characterized [Au-Au = 2.5653(10)A.l3I8 Several di- and trinuclear gold(r) complexes with bridg- ing dithiolate ligands have also been ~repared.~' The tetranuclear species [AU~(PP~~)~(~~-S)][CF,SO,]~~~CH,C~~ involves a sulfur atom occupying the apical position of the tetragonal pyramidal frarnew~rk.~~' There is spectroscopic evidence for the formation of monolayers from organosulfides on gold via a dissociative chemisorp- tion process involving C-S bond cleavage.321 Thiol S-H bond cleavage and reactivity (t-butyl thioalcohol benzenethiol) adsorbed onto Au(l11) surfaces has been studied by temperature programmed reaction spectroscopy .The catalytic decomposition of NO to N, N,O and 0 at low temperatures over excess Au' in NaY zeolite has been investigated by FTIR spectroscopy. The decomposition is thought to proceed uia sequential formation of N203 and N,O intermediates at 300-673 K.323The gradual anionic character of gold in ternary perovskite-type oxides such as Rb,AuO has been monitored using XANES showing that the ionic character decreases with the introduction of lighter and more electronegative alkali metals.324 The IVCT transitions between gold(1) and gold(m) ions in Cs,Au,X (X = Cl Br I) have been assigned using polarized reflectance spectra., These species undergo a tetragonal-to-tetragonal phase transition at 1 1 9 and 5.5 GPa respectively due to a Jahn-Teller transition driven by the Au'Au"' to Au" transition.32 The ethylenediamine extracts of K2AuTe6 or KAuBiTe react with [NEt,]Br to give [NEt,][Au,Te J;the anion contains q3-Te:- ligands coordinated to Au3+ ions which are linked via a q2-Te;- ligand.327 The synthesis and spectroscopic characteriz- ation of cationic and neutral oligonuclear organophosphinegold(1) complexes with SeR- ligands (R = Ph CH,Ph C6H4NH,-4 C,H4C1-4 and naphthyl) which show distortions of the coordination geometry at selenium and short Au * * * Au have been reported.High resolution neutron powder diffraction studies on the structure of the pseudosymmetric layer compound TlAu(CN) shows Au .* -Au distances of ca. 3 8 at 5 K indicating significant Au-Au overlap.329 The photoluminescence properties of the low-dimensional rare earth gold and silver cyanide compounds have been inves- tigated.,,' Calculations on AuX,{Au(PR,)} suggest that coordination of Au(PR3) 317 J. Vicente M.-T. Chicote P. Gonzalez-Herreo P.G. Jones and B. Ahrens Angew. Chem. Int. Ed. Engl. 1994,33 1852. 318 M. Bardaji M. C. Gimeno P. G. Jones A. Laguna and M. Laguna Organometallics 1994 13 3415. 319 M.C. Gimeno P.G. Jones A. Laguna M. Laguna and R. Terroba Inorg. Chem. 1994,33 3932. 320 F. Canales M. C. Gimeno P.G. Jones and A. Laguna Angew. Chem.Int. Ed. Engl. 1994 33 769. 321 C.-J. Zhong and M.D. Porter J. Am. Chem. SOC. 1994 116 12 117. 322 D. M. Jaffey and R. J. Madix J. Am. Chem. Soc. 1994 116 3012; 3020. j2' T. M. Salama T. Studo B. Ohnishi and M. Ichikawa J. Chem. SOC. Chem. Commun. 1994 2749. 324 C. Feldman and M. Jansen J. Chem. Soc. Chem. Commun. 1994 1045. 325 N. Kojima and H. Kitagdwa J. Chem. SOC.,Dalton Truns. 1994 327. N. Kojima M. Hasegawa H. Kitagawa T. Kitagawa and 0.Shimomura J. Am. Chem. Soc. 1994,116 11 368. 327 S. S. Dhingra and R. C. Haushalter Inorg. Chem. 1994 33 2735. 328 W. Eikens C. Kienitz P.G. Jones and C. Thome J. Chem. SOC.,Dalton Trans. 1994 83. 329 P. Fischer A. Ludi H. H. Patterson and A. W. Hewitt Inorg. Chem. 1994 33 62. 330 Z. Assefa and H. H. Patterson Inorg.Chem. 1994 33 6194. 294 G. Reid units to main group fragments results in electronic interactions which reduce the Au-Au bonding.,,' [Au,Cl,(dmpm)] and [AuCl,(dmpm),] react with excess LiR (R = Me C,H,OMe-p) to yield the corresponding alkyl gold species which are emissive in the solid state and in UV/VIS absorption and emission data and extended Hiickel MO calculations suggest [Au,R,(dppm)] (R = Me Ph) involve weak Au(I)* Au(r) interactions.,, The naphthyridinephosphine (59) reacts with d" metal salts to give the metallamacrocyclic species [Au,KL,I3 and [Ag,L,I3+ both of + which are emissive in solution. The former shows trigonal planar coordination at each gold(r) ion via the phosphine functions with an encapsulated six-coordinate K ion + bound via the three naphthyridine functions.334 Several dinuclear gold(1) ring complexes with two different bridging ligands have been prepared by the reaction of [Au,(p-dppe)] with [Au2(p-L),]"+ (n = 0 L = dithiocarbamates; n = 2 L = diph~sphines).~~' Three- and four-coordinate bis(phosphine)-xanthate complexes of gold have been characterized and their electronic structures and luminescence [F~,(CO),P{AU(PP~,)}~]~+ in-volves a seven-coordinate P atom linked to a distorted square planar Au array and a trigonal Fe array.337 A new family of gold-isonitrile metallomesogens [AuCl(CNR)] shows smectic A and C phases over a wide temperature range.338 Photophysical and photochemical properties of a luminescent cyclometalated + gold(rrr) complex [AuC1(2,9-diphenyl- 1 ,lo-phen)] have been investigated.,, The X-ray structure of the luminescent one-dimensional gold(r) polymer [(Au,L(CCPh),},] [L = 2,6-bis(diphenylphosphino)pyridine]shows Au,L(CCPh) repeating units with the closest Au * -Au interactions being 3.252(1)A.340 [NEt,],[Zn(C,S,),] reacts with chlorogold(1) complexes to give di- tri- or tetranuc-lear gold(1) species in which the [C,S,f2- ligand adopts an unprecedented p3-or p-bridging mode.,,' The gold(1)-olefin complex [Au,Cl,(mnt)(dppv),] has been synthesized.342 331 J.K.Burdett 0.Eisenstein and W. B. Schweizer Inorg. Chem. 1994,33 3261. 332 V. W.-W. Yam and S.W.-K. Choi J. Chem. Soc. Dalton Trans. 1994 2057. 333 X. Hong K.-K. Cheung C.-X. Guo and C.-M. Che J. Chem. SOC. Dalton Trans.1994 1867. 334 R.-H. Uang C.-K. Chan S.-M. Peng and C.-M. Che J. Chem. Soc. Chem. Commun. 1994 2561. 335 M. Bardaji N. G. Connelly M. C. Gimeno J. Jimenez P.G. Jones A. Laguna and M. Laguna J. Chem. Soc. Dalton Trans. 1994 1163. 336 Z. Assefa R. J. Staples and J. P. Fackler Inorg. Chem. 1994 33 2790. 337 D. L. Sunick P.S. White and C. K. Schauer Angew. Chem. Int. Ed. Engl. 1994 33 75. 338 T. Kaharu R. Ishii and S. Takahashi J. Chem. Soc. Chem. Commun. 1994 1349. 339 C.-W. Chan W.-T. Wong and C.-M. Che Inorg. Chem. 1994 33 1266. 340 S.-J. Shieh X. Hong S.-M. Peng and C.-M. Che J. Chem. SOC. Dalton Trans. 1994 3067. 341 E. Cerrada A. Laguna M. Laguna and P.G. Jones J. Chem. SOC.,Dalton Trans. 1994 1325. 342 R. M. Davila R. J. Staples and J. P. Fackler Organometallics 1994 13 418.

ISSN:0260-1818    

DOI:10.1039/IC9949100261

出版商:RSC    

年代:1994

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18 Scandium Yttrium the Lanthanides and the Actinides By S.A. COTTON St Edward’s School Woodstock Road Oxford Oxon OX2 7NN UK 1 Introduction The available 1994 literature has been surveyed together with some late 1993 papers. Interest in the post-actinides has been sustained’ and several up-to-date overviews of activity in the area have appeared.2 Suggestions of stable superheavy elements with deformed nuclei have led to continuing synthetic ~tudies.~ Atoms with a deformed neutron shell at N = 162 and P = 108 are thought to be more stable to spontaneous fi~sion,~ a view supported by the isolation of 26’ 106 and 266 106 with estimated half lives of 2-30 s and 1&30 s respectively.’ Meanwhile two new elements have been made this year. Bombardment of ’O*Pb with 62Ni is reported to lead to 269110 with a half-life 0.5 ms detected by the chain6a 2691 10 -+ 265108-+ 261106+ 257104 Similarly bombardment of 209Bi with 64Ni is reported to lead to 272111 with a half-life of ca.1.5 milliseconds detected by the chain6b 272111-+ 268109-+ 264107+260105-+ 256103 Confirmation of the synthesis of Element 106 led to suggestions7 by the discoverers of the name Seaborgium. Subsequent recommendations (Table 1) for naming elements 101-109 from the IUPAC Commission on Nomenclature of Inorganic Chemistry rejected this deeming it inappropriate to name an element after a living person.* The August 1995 IUPAC Council meeting will consider these proposals. Meanwhile the American Chemical Society’s Nomenclature Committee votedg to support earlier S.A. Cotton Ann. Rep. Progr. Chem. Sect. A lnorg Chem. (a) 1992 89 243; (h) 1993,90 250. (a)D. C. Hoffman Chem. Eng. News May 2 1994,24; (b) D. C. Hoffman Radiochim. Acta 1993,61,123;(c) J. V. Kratz J. Alloys Compd. 1994 213/214 20; (d) G. T. Seaborg in ‘Kirk-Othmer Encyclopedia of Chemical Technology’ John Wiley 1993 4th Ed. Vol. 1 438. Science 1993 262 1515. Yu. Ts. Oganessian J. Alloys Compd. 1994 2131214 50. R. W. Lougheed K. J. Moody J. F. Wild E. K. Hulet J. H. McQuaid Yu. A. Lazarev Yu. V. Lobanov Yu. Ts. Oganessian V. K. Utyonkov F. Sh. Abdullin G.V. Buklanov B. N. Gikal S. Iliev A.N.Meznetsev A. N. Polyakov I. M. Sedykh I. V. Shirokovsky V.G. Subbotin A M. Sukhov Yu. S. Tsyganov and V. E. Zhuchko J. Alloys Compd. 1994 2131214 61.(a)Chem. Eng. News November 28 1994 5; Science November 25 1994,266 1311; (h) Chem. Eng. News January 2 1995 7; Science January 6 1995 267 29. Chem. Eng. News March 21 1994 5. Chem. Eng. News October 10 1994,4; Chem. Ind. October 17 1994,799; Pure Appl. Chem. 1994,66,2420. Chem. Eng. News November 21 1994 8; December 5 1994 25. 295 296 S. A. Cotton TabIe 1 Suggested names for the synthetic elements Atomic No. Name Symbol ACS Proposal 101 Mendelevium Md Mendelevium 102 Nobelium No Nobelium 103 Lawrencium Lr Lawrencium 104 Dubnium Db Rut herfordium 105 Joliotium J1 Hahnium 106 107 Rutherfordium Bohrium Rf Bh Seaborgium Nielsbohrium 108 Hahnium Hn Hassium 109 Meitnerium Mt Meitnerium American proposals; the 25-year old argument thus continues! In view of the proposals for naming element 109 an article on Lise Meitner is timely." Seaborg has authored an excellent short summary of the principles and patterns undergirding fblock chemis- try;" a summary of systematic trends in lanthanide complexation has also been published.' Volume 17 of the series 'Handbook on the Physics and Chemistry of Rare Earths' contains eight reviews mainly of interest to the phy~icist.'~ Volume 18 ho~ever,'~ features a number of important up-to-date reviews and is probably the single most useful.f-element publication this year.After an initial article on the origin of the actinide concept,' there follows a series of comparisons between lanthanide and actinide compounds on relativistic effects;' 5b absorption and luminescence spectra;' 5c separ-ation chemistry;lSd redox and thermochemical data;' 5e hydrides;' sf halides;' 5g binary oxides;' 5h speciation in strongly acidic media;' 5i hydration numbers and hydroly- sis;' solution chemistry;'sk and biochemistry.'"The biochemistry of the actinides has also been briefly treated e1sewhere.l6 An up-to-date review on gadolinium and dysprosium complexes as contrast agents has appeared.17 Two new volumes of the Gmelin handbook are relevant to this chapter; one deals mainly with the carbonate and thiocyanate chemistry of the lanthanides18" whilst the other covers the compounds of thorium with Si P As Sb Bi and Ge.'8b Reviews on organolanthanides cover a detailed general treatment' 9a (from 1985); very recent developments;' 9b Chinese I" R.Sime Chem. Br. 1994 482. G. T. Seaborg Radiochim. Acta 1993 61 11 5. E.N. Rizkalla Radiochim. Acta 1993 61 181. l3 'Handbook on the Physics and Chemistry of Rare Earths' ed K. A. Gschneider Jr Le Roy Eyring G. R. Choppin and G. H. Lander Vol. 17 North Holland 1993. l4 'Handbook on the Physics and Chemistry of Rare Earths' ed K. A. Gschneider Jr Le Roy Eyring G. R. Choppin and G. H. Lander Vol. 18 North Holland 1994 I5 (a)G. T. Seaborg in ref 14 p. 1; (bK. Balasubramainian in ref 14 p. 29; (c)J. V. Beitz in ref. 14 p. 159; (d) K. L. Nash in ref. 14 p 197;(e)L. R. Morss. in ref. 14 p. 239; u) J. W. Ward and J. M. Haschke in ref. 14 p. 293; (9)H. A. Eick in ref. 14 p. 365; (h)R. G. Haire and L. Eyring in ref.14 p. 413; (i) S. A. Kinkead K. D. Abney and T. A. O'Donnell in ref. 14 p. 507; (j)E. N. Rizkalla and G. R. Choppin in ref. 14 p. 529; (k) G. R. Choppin and E. N. Rizkalla in ref. 14 p. 559; (I) J. R. Duffield D. M. Taylor and D. R.Williams in ref. 14 p. 591. l6 D.R. Williams J. Alloys.Cornpd. 1994 213/214 318. A.D. Watson J. Alloys Compd. 1994 207/208 14. lR(a)'Gmelin Handbook of Inorganic and Organometallic Chemistry' Syst. No 39 Supplementary Volume C12b Springer-Verlag Heidelberg 1994; (b) 'Gmelin Handbook of Inorganic and Organometallic Chemistry' Syst. No 44 Supplementary Volume C12b Springer-Verlag Heidelberg 1993. Is) (a)C. J. Schaverien Adv. Organomet. Chem. 1994,36,283; (b)R. D. Fischer Angew. Chem. lnc. Ed. Engl. 1994,33,2165;(c) S. Qi Rare Earths 1994 12 52; (d)J.W. Gilje and H. W. Roesky Chem. Rev. 1994,94 895; (e)T. Imamoto 'Lanthanides in Organic Synthesis' Academic Press 1994. Scandium Yttrium the Lanthanides and the Actinides 297 work;Igc and hydrolysis products.lgd A book on their applications in organic synthesis has appeared."" The potential of unsaturated organometallics of U and Th in polymer synthesis has been reviewed.20 2 Scandium Two articles have discussed the position of scandium (and yttrium) in relation to the lanthanides in the context of the enthalpies of solution of the anhydrous halides.,' The structure of ScCl has been refined22 using neutron-diffraction data (BiI type) whilst Na,[ScF,] has the cryolite str~cture.~ Crystallization of hydrated ScX,(X = C1 Br) from propanol leads to [(H,O),SC(~-OH)~SC(H~O)~]X~~~H~O with seven-coordinate SC,~ whilst hydrated scandium picrate is [S~(pic)~(H~O),](pic)(Hpic)-8.2 H20 with six-coordinate scandium.25 Studies on anhydrous Sc(O,SCF,) indicate that triflate functions as a bidentate ligand [probably six-coordinate Sc in contrast to nine- coordinate Ln(0,SCF,),].26 Rb,Sc(NO,) has two monodentate and three bidentate nitrate^.'^ Sr,Sc(BO,) and Ba,Sc(BO,) [the latter a member of the Sr,Ln(BO,) family with layer structures (Ln = Dy-Lu and Y also)] have six-coordinate scan- dium.28 Conditions for the synthesis of different crystalline phases of the solid electrolyte Na,Sc,(PO,) have been examined.29 Trends in Sc+-alkyl bond strengths have been studied;,' [Sc(CH2CHMe,)(PMe,){SiMe(q5 -C,Me,),)] undergoes Ziegler-Natta related re- action~.,~ [ScRCp:] insert Te to afford [Sc(TeR)Cpz] (e.g.R = Bz) whilst [Sc(CH,SiMe,)Cp;] similarly inserts Se. Binuclear selenides and tellurides [Cp:Sc(p- E)ScCp:] (E = Se or Te)32 have been prepared whilst [Sc,(p-Te)(PMe,),(SiMe2(q5-C,H,Bu')},] also has a linear telluride bridge., 3 Yttrium and the Lanthanides Speedier X-ray diffraction techniques make studies of the lanthanide contraction increasingly facile. Such studies have concerned zircon-type MVO (M = Sc Y Ce Pr Nd Tb Ho Er Tm Yb and Lu),,,~ the decatungstolanthanoate ions [LnW,,O,,] (Ln = Pr Nd Sm Gd Tb and the terpyridyl complexes [Ln(terpy)Cl,]-~H,O.~~' Detailed study has been made of an extensive family of lanthanide picrate hydrates;34d the earlier lanthanides (La-Tb) form 2o M.A.Katkova and M. R. Leonov Sou. Radiochem. 1993 35 367. 21 T. Mioduski J. Radioanal. Nucl. Chem. Letters 1993 176 371; Comments lnorg Chem. 1993 14 263. 22 H. Fjellvig and P. Karen Acta Chem. Scnnd. 1994 48 294. 23 P. Dahlke and D. Babel Z. Anorg. Allg. Chem. 1994 620 1686. " A.B. Ilyukhin and S. P. Petrosyants Russ. J. Inorg. Chem. 1994 39 1449. 25 J. M. Harrowfield B. W. Skelton and A.H. White Aust. J. Chem. 1994 47 397. 26 M.E. M. Hamidi and J.-L. Pascal Polyhedron 1994 13 1787. G. Meyer and S. Stockhause Z. Kristallogr. 1994 209 180. 28 P.D. Thompson and D. A. Keszler Chem. Muter. 1994,6,2005; J. R. Cox and D. A. Keszler Chem. Muter. 1994 6 2008. 2q I.G. Gusakovskaya and S.I.Pirumova Russian J. Inorg. Chem. 1994 39 1221. 3o J.K. Perry and W. A. Goddard J. Am. Chem. Soc. 1994 116 5013. 31 S. Hajela and J. E. Bercaw Organometallics 1994 13 1147. 32 W. E. Piers D.J. Parks L. R. Macgillivray and M. J. Zawarotko Organometallics 1994 13 4547. 33 W. E. Piers G. Ferguson and J. F. Gallagher Inorg. Chem. 1994 33 3784. 34 (a)B. C. Chakoumakos M. M. Abraham and L. A. Boatner J. Solid State Chem. 1994 109 197; (b)T. Ozeki and T. Yamase Acta Crystallogr. Sect. R 1994,50 128; (c) C.J. Kepert W. M. Lu B. W. Skelton and A. H. White Aust. J. Chem. 1994,47,365; (d)J. M. Harrowfield W. M. Lu B. W. Skelton and A. H. White Aust. J. Chem. 1994 47 321; 339; 349; 359. 2' 298 S. A. Cotton [Ln(pic),(H,O),] + ions and the smaller lanthanides and yttrium form [Ln(pic)(H,0),I2+ ions (Ln = Dy-Lu Y).Binary and Related Compounds with Non-metals.-A new boride YB,, is reported,' whilst vacuum laser ablation of hydrated lanthanide oxalates leads to cluster ions Ln,O; ;the cluster distribution depends on the accessibility of the +2 +3 and +4 states for the lanthanide in question.36 Hydrogen reduction of CeO leads to an expansion of the lattice due both to reduction of Ce4+ and H insertion into the lattice.37 M4C7 (M = Ho Y)38 contain both C4-and Ci- ions. Anhydrous lanthanide halides react at 400 "C with Li,N to give LnN39n whilst Na,As Na3Sb and Na3Bi similarly react39b with LnC1 giving LnAs LnSb LnBi Eu,Sb3 and Yb,Sb4. Similar metathetic syntheses3'" of GdQ from GdI and Na3Q (Q = P As Sb) have been reported.F-type Er,S3 has six- seven- and eight-coordinate erbium4'' whilst Yb,S3 contains six-coordinate ytterbium;40b Nd,(SO,) reacts with CS vapour above 800 "C to give Nd,S,.40c Sm,Te and SmTe have quasi-two-dimensional metallic ~haracter.~' Huckel theory has been applied to predicting the structures of rare earth ~elenides.~~ The electronic structure of layered LnB,C compounds has been analy~ed;~," GdB,C also has a layered whilst Y,I,C is isotypic with the layered Gd,Br,C .43c New quaternary intermetallics Ln,Ni,B,C are superconductors around 10K.44 Halides and Complexes.-Molten ErCl is believed to contain [ErC1,I3 -octahedra.45 Improved structures are reported46 for LnC1,.7H20 (Ln = La Pr) and LnC1,-6H20 (Ln = Nd Lu). Thermal dehydration of CeC1,.7H2O established the existence of CeCl,.xH,O (x = 6,3,2,1); the hexahydrate has47 monomeric [CeCl,(H,O),]+ ions whilst the trihydrate has a structure based on a chain of [CeCl,,,Cl(H,O),] units.35 Y. Tanaka S. Okada and Y. Ishigawa J. Alloys Compd. 1994 205 281. 36 J. K. Gibson J. Phys. Chem. 1994 98 11 321. 37 C. Lamonier G. Wrobela and J. P. Bonnelle J. Chem. Soc. Dalton Trans. 1994 1927. 38 H. Mattausch T. Gulden R. K. Kremer J. Horakh and A. Simon Z. Naturforsch. B 1994 49 1439. j9 (a) J.C. Fitzmaurice A. Hector A.T. Rowley and I.P. Parkin Polyhedron 1994 13 235; (b) J.C. Fitzmaurice I. P. Parkin and A. T. Rowley J. Muter. Chem. 1994,285; (c)R. E. Treece J. A. Conklin and R.B. Kaner Inorg. Chem. 1994 33 5701. 40 (a)C. M. Fang A.Meetsrna G. A. Wiegers and G. Boom J.Alloys Compd. 1994,201,255; (b)Z. El Fadli P. Lemoine M. Guittard and M. Tomas Acta Crystallogr. Sect. C 1994,50,166;(c) M. Skrobian N. Sato M. Saito and T. Fujino J. Alloys Compd. 1994 210 291. 41 E. DiMasi B. Foran M.C. Aronson and S. Lee Chem. Muter. 1994 6 1867. 42 S. Lee and B. Foran J. Am. Chem. Soc. 1994 116 154. 43 F. Wiitkar S. Kahlal J.-F. Halet J. -Y. Saillard,J. Bauer and P. Rogl J. Am. Chem. Soc. 1994,116,251; F. Wiitkar J.-F. Halet J.-Y. Saillard P. Rogl and J. Bauer Inorg. Chem. 1994,33 1297; Hj. Mattausch H. Borrrnann and A. Simon Z. Krist. 1994 209 281. 44 G.J. Miller J. Am. Chem. Soc. 1994 116,6332; R. J. Cava H. W. Zandbergen B. Batlogg H. Eisaki H. Takagi J. J. Krajewski W. F. Peck and S. Uchida Nature (London) 1994,372,245;R.J. Cava H. Takagi H. W. Zandbergen J. J. Krajewski W. F. Peck T. Siegrist B. Batlogg R. B. Van Dover R. J. Felder K. Mizuhashi J. 0. Lee H. Eisaki and S. Uchida Nature (London) 1994 372 252; T. Siegrist H. W. Zandbergen R. J. Cava J. J. Krajewski and W. F. Peck Nature (London) 1994 372 254. 45 Y. Iwadate T. Iida K. Fukushima J. Mochinaga and M. Gaune-Escard Z. Naturforsch. A 1994,49,811. 46 C. J. Kepert B. W. Skelton and A. H. White Aust. J. Chem. 1994 47 385. 47 G. Reuter H. Fink and H.-J. Seifert Z. Anorg. Allg. Chem. 1994 620 665. Scandium Yttrium the Lanthanides and the Actinides 299 Metallothermic reduction of ScC1 and PrI with caesium in the presence of carbon48a affords CS,[SC,C]C~,~ and Cs,[Pr,C,]I,,. Reduction of TbCl similarly gives48b Cs,[Tb,o(C,),]Cl ,,which has dimeric clusters based on two edge-sharing octahedra.Cs[ Er (C,),]I 8 and [Er ,o(C,),]Br are made likewise.48c Transition metals stabilize reduced praesodymium cluster bromides like [Pr6Br loZ] (Z = Co Ru 0s) and [Pr,Br,Z] (Z = Ru Co Os Rh Tr Pt); Pr and Fe react with I to form [Pr,,I,,Fe,]. Corresponding reactions of Gd Mn and I give [Gd,I,Mn] and [Gd517Mn].49 [Ln,Br,Os] are semiconductors.50 Aqua-ions and Salts.-In addition to the authoritative review,' 5j Monte Carlo simulations of the metal-water interactions for Ln3 '(as) ions have been reported," agreeing with a change in coordination number from nine to eight in mid-series and with a dissociative mechanism for the ennea-aqua ions. X-Ray diffraction studies have been reported for lanthanum nitrate solutions showing the number of coordinated waters increasing from seven to nine as the water :salt ratio rose from 15 1to 100 l.' The complex [terpyH,],[Tb(H2O),]C1,-8/3H2Ocontains53 a 'pure' aqua ion formed even in the presence of a large excess of chloride ions (see also crown-ether complexes).139La and I7O NMR spectroscopy has been used to investigate the coordination sphere of lanthanum nitrate5 in MeCN solutions; europium(II1) perchlorate nitrate and chloride complexes in aqueous solution have been studied by luminescence spectrosc~py.~~ [Ce(NO,),(H,O),(H,O)] hass6 12-coordinate cerium (six bidentate nitrates). Anhydrous [Pr(ClO,),] is to have tridentate perchlorates with a Pr-0 distance of 2.51 8 whilst in polymeric [La{O,P(OMe),},] lanthanum is octahedrally coordinated5* by six oxygens from six bridging ligands.[Ln(O,SCF,),] have been widely used for years. Now [Ln(O,SCF,),] (Ln = Sm Yb) have been prepared59by reduction of the lanthanide(II1) analogues and used as pinacol coupling catalysts. Complexes.-[LnCl,(thf),l are a synthetically important soluble form of the halides; an improved synthesis from the lanthanide metals and SiMe,Cl in methanol is reported.60 [YCl,(thf) .5] is confirmed to be [trans-YC1 (thf),][ trans-YCl,(t hf),] whilst [YCl,(thf),] has a chain structure with double chlorine bridges and pentagonal bipyramidal coordination.61 [NdBr,(PriOH),(thf),]62 and [{CeCl,(PriOH),},] (a 48 (a)H. M. Artelt T. Schleid and G.Meyer Z. Anorg. Allg. Chem. 1994,620 1521;(b) H. M. Artelt and G. Meyer Z. Anorg. AUg. Chem. 1994,620,1527;(c)S. Uhrlandt H. M. Artelt and G.Meyer Z. Anorg. A"g. Chem. 1994,620 1532. 49 R. Llusar and J. D. Corbett Inorg. Chem.,1994,33,849; Y. Park and J. D. Corbett Inorg. Chem. 1994,33 1705; M. Ebihara J. D. Martin and J.D. Corbett Inorg. Chem. 1994 33 2079. 50 K. Ahn T. Hughbanks K.D.D. Rathnayaka and D.G. Naugle Chem. Muter. 1994,6,418. '' S.Galera J. M. Llusch A. Oliva J. Bertran F. Foglia L. Helm and A. E. Merbach New J. Chem.,1993,17 773. 52 S.P. Petrun'kin and V.N. Trostin Russiun J. Inorg. Chem. 1993 38 1576. 53 C.J. Kepert B. W. Skelton and A.H. White Aust. J. Chem. 1994 47 391. 54 Z. Chan and C. Detellier Can. J. Chem. 1993 33 2000. 5s M.J. Lochhead P. R. Walmsley and K. L. Bray Inorg. Chem. 1993 33 2000. 56 N. Guillou J. P. Auffredic M. Louer and D. Louer J. Solid State Chem. 1994 106 295. 57 J.L. Pascal M. El Haddad H. Rieck and F. Favier Can. J. Chem. 1994 72 2044. sa G. F. Zeng X. Guo C. Y. Wang Y. H. Lin and H. Li Jiegou Huaxue (Chin. J. Struct. Chem.),1994,13,24. 59 T. Hanamoto Y. Sugimoto A. Sugino and J. Inaga SYNLETT 1994 377. " S.-H. Wu Z.-B. Ding and X.-J. Li Polyhedron 1994 13 2679. 6' P. Sobota J. Utko and S. Szafert Inorg. Chem. 1994 35 5203. 62 H. Y. Sun H. Huang G. X. Xu Z. S. Ma and N.C. Shi Chin. Chem. Lett. 1994 5 255. 300 S. A. Cotton dimer with two bridging chlorides6,) both have seven-coordinate lanthanides. Among lanthanide(I1) complexes [LnI,(thf),] (Ln = Eu Sm) react with N-rnethylimidaz~le~~ giving [LnI,(Meim),] which on crystallization affords dimeric [{ LnI(p-I)(Meim),],].[SmI,(thf),] reacts with Meim to give square antiprismatic [Sm( Meim),]I ,. cis cis cis-[Ln(carbazole) (thf) (dme)] ,cis-[Ln(carbazole) (thf),] (Meim),] have been chara~terized.~~ and tr~ns-[Ln(carbazole)~ Several solvated ytterbium(I1) and samarium(I1) complexes mainly with diethylene glycol dimethyl ether (dime) have been characteri~ed,~~ notably [Yb(dime),I2’ [Yb(dime),(NCMe),12+ [Yb(dime)(NCMe)J2+ and [Yb(py),(NCMe),]’+. These have tricapped trigonal prismatic square antiprismatic square antiprismatic and pentagonal bipyramidal coordination respectively. Distorted square antiprismatic [La(dmso),13+ ions are found67 in [La(dmso),][Cr(NCS),] and octahedrally bound [Yb(hmpa),12 + ions in [yb(hmpa),][anthra~ene],.~~ Dioxan complexes [Ln(NO,),(dioxan),] have been reported.69 The presence of coordinated solvent molecules is generally best deduced from diffraction studies allowing assignment of eight-coordinated [LaCl,(phen),(H,0)].MeOH.70 The complexes [Ln(NCS),(H,O)(phen),] (La = La-Yb except Pm) are believed to be [Ln(NCS)(H,O)(phen),] [NCS] ,.” Three papers discussing complexes of rather more unusual 0-donors are of interest.Using the bidentate ligands {(MeO),P(O)),C(OH)Ph and (MeO),P(0)OCHPhP(O)(OMe)2,ten-coordinate complexes [Ln(NO,),L,] are ~btained.~’ The ligand N,N’-butylenebis(2-pyridone) (L) forms a complex [(NO,),NdL,Nd(NO,),] with a triple helical str~cture.~ Complexes of 2-((diphenyl- phosphino)methyl}pyridine N,P-dioxide and 2,6-bis{ (dipheny1phosphino)methyl)py-ridine N,P,P’-trioxide with lanthanide nitrates have been examined.74 Structures have been reported for the neutral diketonates [E~(dbm),(bipy)],~~ [EU(C,H,COCHCOCF,),(~PP~,)~],~~ [Ho(Me,CCOCHCOMe,),(pivalic and acid)].77 [Carbene adducts of Ln(tmhd) (Ln = Eu Y) are discussed on p.307.1 [Gd(hfpd),(OCMe,)(H,O)] has square antiprismatic coordination whilst [Gd4(p3- OH)4(p~-H,o),(H,0)4(hfpd)8] has a M406 core.78 63 M. Schafer R. Herbst-Irmer U. Groth and T. Kohler Actu Crystallogr. Sect. C 1994 50 1256. 64 W.J. Evans G. W. Rabe and J. W. Ziller Inorg. Chem. 1994 33 3072. 65 C.T. Abrahams G. B. Deacon B. M. Gatehouse and G.N. Ward Acta Crystullogr.Sect. C 1994,50,504; W. J. Evans G.W. Rabe and J. W. Ziller Organometullics 1994 13 1641. J. P. White H. Deng E. P. Boyd J. Gallucci and S.G. Shore Inorg. Chem. 1994 33 1685. 67 T. G. Cherkasova Russian J. Inorg. Chem. 1994 39 1316. D. M. Roitershtein A. M. Ellern M. Yu. Antipin L. F. Rybakova Yu.T. Struchkov and E.S. Petrov Russian J. Coord. Chem. 1993 19 759. 6y Yu.N. Medvedev M. L. Kuznetsov and B.V. Lokshin Russian J. Inorg. Chem. 1994 39 1657. 70 G. J. Mao Z.4. Jin and J.-Z. Ni Jiegou Huaxue (Chin. J. Struct. Chern.) 1994 13 377. 71 A.A. Khan and K. Iftikhar Polyhedron 1994 13 3199. 72 A. W. G. Platt D. Simpson J. Fawcett and D. R. Russell Inorg. Chim. Actu 1994 223 43. 73 D. M.L. Goodgame S. P. W. Hill and D. J. Williams Polyhedron 1993 12 2933.74 B. M. Rapko E. N. Duesler P. H. Smith R.T. Paine and R. R. Ryan Inorg. Chem. 1994 33 2165. 75 M.-Z.Wang L.-P. Jin,G.-L.Cai,S.-X. Liu,J.-H. Luang W.-P. Qin,and S.-H. Huang J. RareEarths 1994 12 166. 76 H.-Y. Li Y.-S. Yang Y.-Q. Huang and S.-Z. Hu Jiegou Huuxue (Chin.J. Struct. Chem.) 1994 13 371. 7’ N. P. Kuz’mina Z. An’Tu A. P. Pisarevskii L. 1. Martynenko and Yu.T. Struchkov Russian J. Coord. Chem. 1994 20 665. ’’J. C. Plakatouras I. Baxter M. B. Hursthouse K. M. A. Malik J. McAleese and S. R. Drake J. Chem.Soc. Chem. Commun. 1994 2455. Scandium Yttrium the Lanthanides and the Actinides Second-harmonic generation from monolayers of hemicyanine salts of [Ln(tta),] -has been reported" whilst the structure and fluorescence spectrum of the ethylpyridin- -ium salt of [E~(tta)~] (tta = a-thenoyltrifluoroacetonato) has been determined.80 Another anionic complex has been used to prepare a photoactive bilayer lipid membrane.81 Carboxylates and Their Complexes.-The structure of anhydrous Pr(OAc) shows nine- and ten-coordinate praesodymium;B2 [Er,(H20)(0,CHMe,)6]~H,0 has a polymeric chain structure with eight and nine-coordinate erbiums linked by bi- and tridentate bridging carb~xylates.~~ Terbium p-nitrobenzoate hydrate has dimeric units [Tb,(H,0),(0,C6H4N0,)6] linked into linear chains84n whilst yttrium salicylate tetrahydrate has [Y,(H,O),(O,C,H,OH -o)~]dimers with bridging chelating and bridging-chelating carbo~ylates.~~~ ex-[Tb(bipy)2(H,0)(0,CC13)3] hibits eight-coordination; lanthanum is eight-coordinate in dimeric C{La(biPY)(H20)(0,CC1,),},1.85 Alkoxides and Alky1amides.-In contrast to the three-coordinate silylamides and diisopropylamides the lanthanides do not form simple homoleptic dimethylamides.Reaction of NdC1 with LiNMe gives an adduct [Nd(NMe,),(LiCl),] which with MMe (M = Al Ga) gives86 bridged [Nd(NMe,),(MMe,),] (1). A peralkyl [Nd{(p- Me),(GaMe,)},] has also been reported. Alkylation of Ln(OBu') with AlMe gives related mixed alkyl/alkoxy-bridged [Ln(p-0But),(p-Me),(A1Me,),l (Ln = Pr Nd Y).87 Other interesting reports include the $-arene-bridged dimers [Ln,(2,6-(Prio)2c6H3}6] which dissolve in thf to form the adducts [Ln(2,6-(Pr'O),C6H,},(thf),] with conventionally bound alkoxides.88 The aryloxides 79 K.Z. Whang W. Jiang C. H. Huang G.X. Xu L. G.Xu T. K. Li X. S. Zhao and X. M. Xie Chem. Lett. 1994 1761. 'O C. Huang X. Zhu F. Guo J. Song Z. Xu C. Liao and Z. Jin Beijing Daxue Xuehao Ziran Kexueban 1992 28 428 (Chem. Ahstr. 1994 120 93867). '' Y.J. Xiao X.X. Gao C. H. Huang and K.Z. Whang Chem. Muter. 1994,6 1910. 82 A. Lossin and G. Meyer Z. Anorg. Allg. Chem. 1994 620 428. 83 S. 1. Troyanov N. D. Mirofanova and M. V. Gorbacheva Russian J. Coord. Chem. 1994 19 868. 84 J.F. Ma Z. S. Jin and J.Z. Ni Acta Crystallogr. Sect. C 1994 50 1008; 1010. 85 Y. Cheng N. Dong H. Huang W. Lu C. Chen B. Huang and G. Wu Chin.J. Znorg. Chem. 1994,10,247. 86 W. J. Evans R. Anwander R. J. Doedens and J. W. Ziller Angew. Chem. Int. Ed. Engl. 1994 33 1641. 87 P. Biagini G. Lugli L.Abis and R. Millini J. Organomet. Chem. 1994 474 C16. D.M. Barnhart D. L. Clark J.C. Gordon J.C. Huffman R. L. Vincent J.G. Watkin and B. D. Zwick Inorg. Chem. 1994 33 3487. 302 S. A. Cotton K[Ln{ 2,6-(PriO),C6H,},] have aryloxide anion chains bridged by K-arene interac- tion~.~~ Silanol ligands with alkylamide groups enable the isolation9' of volatile monomers like five-coordinate [Y(OSi(Bu')[(CH,),NMe2]2}3]in which one amide is uncoor- dinated. Several volatile hexafluoro-t-butoxides have been made.91 Four coordination is foundg2 in [(thf),Li(p-Cl)NdR,] [R = N(SiMe,), OCBu'j] whilst three-coordinate ytterbium@) exists in [{Yb(p-X)X),] (X = OAr OCBu;) and [(Yb(p-X)(NR,)},] (X = OAr OCBu;; Ar = 2,6-Bu\-4-MeC6H,; R = Another divalent compound is94 trigonal bipyramidal [Sm(OAr),(thf),].thf (Ar = 2,6-Bu',-4-MeC6H,).The four-coordinate amides [Ln(NPr\),(thf)] and [Li(thf)Ln(NPri),]95 (Ln = La Y Lu) have been made. Lanthanide metals react with organic disulfides to form thiolates such as [Yb(py),(SAr),] and [Yb(py),(SAr),] (Ar = 2,4,6-trii~opropylphenyl).~~ Lanthan-ide(I1) selenolate and tellurolate complexes,97 usually obtained as etherates are possible precursors to lanthanide monochalcogenides; M(TePh) (M = Yb Eu) crystallize as one-dimensional polymers such as [Eu(TePh),(thf),] and [Yb(TePh),(thf),.1/2(thf)]m.[Ln{ESi(SiMe,),},(tmeda),] (Ln = Eu Yb; E = Se Te) have been reported and the structures of [Yb{ SeSi(SiMe,),),(tmeda),] and [Eu,(p-dmpe)(dmpe),{TeSi(SiMe3)}4] determined; the ytterbium-tmeda complexes eliminate E(Si(SiMe,),} at 200 "C affording YbSe and YbTe.Complexes of Polyamine Polycarboxylates Related Complexes and NMR Imaging Agents.--Gd and Dy complexes as contrast agents have been reviewed;17 an overview appeared in an article on metal complexes targeting parts of the body.98 Molecular sieve based contrast agents have been described.99 Na[Y (dota)(H2O)].4H,O has a capped square-antiprismatic structure;"' a similar geometry is adopted by the yttrium complex of N,N"-bis(benzylcarbamoy1-methy1)diethylenetriamine-N,N',N"-triacetic acid. The kinetics of formation and dissociation of [Eu(dota)] -and [Yb(dota)] have been investigated"' and an NMR spectroscopic study of [Yb(dota)] -shows two conformations related by slow inter- and intramolecular exchange.lo2 Stability constants have been measured for the Gd and Y complexes of dota do3a 89 D.L. Clark J. C. Gordon J. C. Huffman R. L. Vincent-Hollis J. G. Watkin and B. D. Zwick Inorg. Chem. 1994 33 5903. 90 P. Shao D. J. Berg and G. W. Bushnell Inorg. Chem. 1994 33 3453. 91 D. C. Bradley H. Chudzynska M. B. Hursthouse M. Motevalli and R. Wu Polyhedron 1994,13,1;D. C. Bradley H. Chudzynska M. B. Hursthouse and M. Motevalli Polyhedron 1994 13 7. 92 F. T. Edelmann A. Steiner D. Stalke J. W. Gilje S. Jagner and M. Hakansson Polyhedron 1994,13,539. 93 J. R. van den Hende P. B. Hitchcock and M. F. Lappert J. Chem. SOC. Chem. Commun. 1994 1413. 94 G.-Z. Qi Q. Shen and Y.-H. Lin Acta Crystallogr. Sect. C 1994 50 1456. 9s H.C. Aspinall and M. R. Tillotson Polyhedron 1994 13 3229. 96 K. Mashima,Y. Nakayama H. Fukumoto N. Kanehisa Y. Kai and A. Nakamura,J. Chem.Soc. Chem. Commun. 1994,2523. 97 (a)D. V. Khansis M. Brewer J. Lee T. J. Emge and J. G. Brennan J.Am. Chem. SOC.,1994,116,7129; (b) D. R. Cary and J. Arnold Inorg. Chem. 1994,33,1791; (c)A. R. Strzelecki C. L. Likar B. A. Helsel T. Utz M.C. Lin and P.A. Bianconi Inorg. Chem. 1994 33 5188. 98 D. Parker Chem. Br. 1994 818. 99 K. J. Balkus and I. Bresinska J. Alloys Compd. 1994 207/208 25. loo D. Parker K. Pulukkody F. C. Smith A. Batsanov and J. A. K. Howard J. Chem. SOC.,Dalton Trans. 1994 689. E. Toth E. Briicher I. Lazar and I. Toth Inorg. Chem. 1994,33,4070. V. Jacques and J. F. Desreux Inorg. Chem. 1994 33 4048.Scandium Yttrium the Lanthanides and the Actinides and Hp-do3a [l0-(2-hydroxypropyl)-1,4,7,10-tetraazacyclododecane-1,4,7-triacetic acid]; the Gd and Y complexes of hp-do3a are isostructural'03 (again capped square-antiprismatic nine-coordination). The cation of [{ La(H,O)(dtpa-dien)),] [CF3S03],-18H,0 is a carboxylate-bridged dimer in the solid state whilst that of [{Eu(dtpa-dien ))4] [CF SO3] ,*6CF SO,Na-20H,O is a carbox ylate- bridged tet-ramer; in solution the europium tetramer dissociates and binds a water m01ecule.'~~ Binuclear La and Y complexes of 9,14-dioxo- 1,4,7,10,13-pentaaza- 1,4,7-~yclopen- tadecanetriacetic acid have nine-coordinate lanthanide~."~ The dissociation kinetics of Ce and Gd complexes ofbis(amide) ligands derived from dtpa have been studied.'06 Lanthanide pol yamine carboxylates and complexes of macrocycles with pendant amide groups show promise as catalysts for RNA cleavage;'07 such complexes have considerable stability in aqueous solution. O8 A ligand based on a tetraaza macrocycle with four attached phosphinate groups forms stable eight-coordinate lanthanide complexes; although water does not enter the coordination sphere the Gd complex is a promising outer-sphere MRI agent.'" Other Applications of Lanthanides in Organic Chemistry.-A europium texaphyrin complex conjugated to DNA induces site-selective hydrolysis of RNA.' lo Cleavage of the phosphate diester backbone of DNA is achieved by cerium(II1) and dioxygen.' Ceric ammonium nitrate catalyses the hydrolysis of two nucleoside cyclic monophos- phates112 whilst binding of Ce3+ to lactoferrin stimulates' l3 oxidation to Ce4+.The catalytic effects of lanthanide-cyclodextrin complexes have been reviewed.l l4 Lan-thanide-cyclodextrin complexes have been used to probe their optical purity' ' whilst the cerium-y-cyclodextrin complex hydrolyses di- and tripeptides.' l6 SmI continues to be a popular reactant,'17 for example including radical cyclizations of halo- and carbonylhydrazones and intramolecular C-glycoside formation. Poly(pyrazoly1)borates and Related Compounds.-Each of the ytterbium(r1) and (111) compounds [Yb(Tp'),] and [Yb(Tp'),][03SCF3] shows approximate octahedral coordination; the Yb-N bond lengths are ca. 0.16A longer in the ytterbium(I1) compound.' ' Using a bulky hydrotris(3-t-butyl-5-methylpyrazolyl)borate ligand (Tp") affords monomeric ytterbium(I1) compounds with just one pyrazolylborate lo3 K.Kumar C. A. Chang L.C. Francesconi D. D. Dischino M. F. Malley J. Z. Gougoutas and M. F. Tweedle Inorg. Chem. 1994 33 3567. Io4 J. Franklin and K. N. Raymond Inorg. Chem. 1994 33 5794. lo5 M. B. Inoue M. Inoue and Q. Fernando Acta Crystullogr. Sect. C 1994 50 1037. '06 K.Y. Chou K. S. Kim and J.C. Kim Polyhedron 1994 13 567. lo' J.R. Morrow and V. M. Shelton New J. Chem. 1994 18 371; S. Amin J. R. Morrow C.H. Lake and M.R. Churchill Angew. Chem. Int. Ed. Engl. 1994 33 773. lo' K. O.A. Chin J. R. Morrow C. H. Lake and M. R. Churchill Inorg. Chem. 1994 33 656. lo9 S. Aime A. S. Batsanov M. Botta J.A.K. Howard D. Parker K. Senanayake and G. Williams Inorg. Chem. 1994 33 4696. 'lo D. Magda R.A. Miller J.L. Sessler and B. L. Iverson J. Am. Chem. SOC. 1994 116 7439. 'I1 R.K. Takasaki and J. Chin J. Am. Chem. SOC. 1994 116 1121. '12 J. Sumaoka S. Miayma and M. Koniyama J. Chem. Soc. Chem. Commun. 1994 1755. '13 C.A. Smith E. W. Ainscough H. M. Baker A.M. Brodie and E. N. Baker J. Am. Chem. Soc. 1994,116 7889. '14 R. Breslow Recl. Trav. Chim. Pays-Bas 1994 113 493. 115 T.J. Wenzel M. S. Bogyo and E. L. Lebeau J. Am. Chem. Soc. 1994,116 4858. M. Yashiro T. Takarada S. Miyama and M. Komiyama J. Chem. Soc. Chem. Commun. 1994 1757 'I7 C. F. Sturino and A. G. Fallis J.Am. Chem.Soc. 1994,116,7447; D. Mazeas T. Skrydstrup,0.Doumeix and J,-M. Beau Angew Chem.Int. Ed. Engl. 1994 33 1383. G.H. Maunder A. Sella and D.A. Tocher J. Chem. SOC. Chem. Commun. 1994 885. 304 S. A. Cotton bound to ytterbium for example [Yb(Tp”)IL,] (L = thf Bu‘NC n = 1; L = 3,5-lutidine n = 2) [Yb(Tp”){N(SiMe,),)] and [Yb(Tp”){CH(SiMe,),]].’ l9 Syntheses are reported of [Ln(Bu\pz),(thf),] and [Ln(Bu\pz),(OPPh,),] (Buipz = 3,5-di-t-butylpyrazolato). The compound [Er(Bu\pz),(thf),] has eight-coordinate erbium with chelating pyrazolate ligands.I2’ A new bulky tripodal ligand tris-[3-(2’-pyridyl)pyrazol-l-yl]hydroborate (L) forms a monomeric complex [EuF(MeOH),L][PF,] in which the ligand is hexaden- tate.’ ’ Complexes of Crown Ethers and Related Ligands.-Interest in crown ethers and related ligands continues. Structural characterization has been achieved for [Pr(NO,),( 18-crown-6)] and [Ln(NO3),(H2O),]-18-crown-6 (Ln = Y Eu Tb-Lu);12 [LnC1,(15- crown-5)] and [Er(H,O),].15-~rown-5;’~~ and [La(NO,),(H,O),(MeOH)(bipy)] .15-~rown-5.’~~ [La(N0,),(12-crown-4)(H20)] and [Yb(NO,),( 12-crown-4)] have 11-and ten-coordinate lanthanides respectively’ 25 whilst lanthanum is ten-coordinate in [La(NCS),( 18-crown-6)(dmf)].26 [LaCI,( 12-crown-4)(MeOH)] is eight-coordi- nate.70 4-t-butylbenzo-15-crown-5 (L) forms [La(NO,),L.OSMeCN] in which the lanthanum is ll-~oordinate;’~~ the geometry is broadly similar to those of the benzo-15-crown-5 and cyclohexyl- 15-crown-5 analogues. Benzo- 15-crown-5 has been used with a diaphragm electrolyser to extract europium in the presence of picrate.12* Europium is ten-coordinate’ *’ in [Eu(NO,),(NCMe)( 16-crown-5)I + (in contrast to 11-coordinate La in [La(NO,),( 16-crown-5)I).However the smaller lutetium does not coordinate to 16-crown-5; [Lu(NO,),(H,O),] molecules hydrogen-bond to the crown ether. [GdC12(NCMe)(dibenzo-18-crown-6)][SbC16] has nine-coordinate gadolinium with a roughly planar hexadentate crown ether giving a 2 :6 1 coordina- tion geometry.’30 In contrast [{Dy2Cl,(dibenzo-18-crown-6)2),][Dy,C1,(NCMe)2] contains dimeric cations (and anions) linked by double chloride bridges.’,’ Calorimet-ric titration of lanthanide nitrates with N-benzylmonoaza-18-crown-6has yielded stability constants and thermodynamic parameters; stability rises to a maximum at Gd decreasing slightly thereafter.’, Cryptates are much less studied but structures of two ten-coordinate lanthanum complexes were reported.’ 33 119 L.Hasinoff J. Takats X. W. Zhang A. H. Bond and R. D. Rogers J. Am. Chem. Soc. 1994,116 8833; G. H. Maunder A. Sella and D.A. Tocher J. Chem. Soc. Chem. Commun. 1994 2689. lz0 J. E. Cosgriff G. B. Deacon B. M. Gatehouse H. Hemling and H. Schumann Aust. J. Chem. 1994,47 1223. A. J. Amoroso A. M. C. Thompson J. C. Jeffery P. L. Jones J. A. McCleverty and M. D. Ward J. Chem. Soc. Chem. Commun. 1994 2751. R.D. Rogers and A.N. Rollins J. Chem. Cryst. 1994 24 321. lZ3 R.D. Rogers and A.N. Rollins J. Chem. Cryst. 1994 24 531. 124 Z.P. Li and R. D. Rogers 1. Chem. Cryst. 1994 24 415. 12’ J.-G. Mao Z.-S. Jin and F.-L. Yu Jiegou Huaxue (Chin.J. Struct. Chem.) 1994 13 276. J.-G. Mao Z.-S. Jin and J.-Z. Ni Jiegou Huaxue (Chin. J. Struct. Chem.) 1994 13 329. ’” J.-G. Mao R.-Y. Wang and Z.3. Jin Jiegou Huaxue (Chin. J. Struct. Chem.) 1994 13 56. 12* Z. Y. Fu F. Kong M. Qin B. H. Wang B. Zhao and S. H. Miao J. Chem. SOC.,Chem. Commun. 1992 1753. J.-G. Mao Z.-S. Jin J.-Z. Ni and L. Yu Polyhedron 1994 13 313. G. R. Willey P. R.Meehan M. D. Rudd H. J. Clase and N. W. Alcock Inorg. Chim. Acta 1994,215,209. 13’ G. Crisci and G. Meyer Z. Anorg. Allg. Chem. 1994 620 1023. 132 Y. Liu T. B. Lu M.Y. Tan Y. Inoue and T. Hakushi J. Rare Earths 1993 11 246. 133 J.G. Mao and Z.S. Jin Polyhedron 1994 13 319. Scandium Yttrium the Lanthanides und the Actinides 305 Complexes of Macrocyclic Ligands particularly Porphyrins and Phthalocyanines- Syntheses are reported for some cerium(rv) bis(porphyrinates);' 34 NMR spectroscopy shows that the two porphyrin rings do not rotate with respect to each other even at 140"C.COSY NMR spectral data have been reported for cerium(1v) porphyrins.'35 The lanthanide ion has square antiprismatic coordination in the isostructural series [PPN][Lu(pc),] (Lu = La-Tm).'36 Detailed characterization has been reported of the compounds [Lu(2,3-nc),] and [Lu(2,3-nc)(pc)] (2,3-nc = 2,3-naphthalocyaninate) in which the unpaired electron is delocalized over the two macrocycles.' 37 Bis(phtha1ocyaninato)lutetium complexes with long-chain alkyl substituents on the pyrrole rings display three kinds of discotic mesophase and also three primary colours of electrochromism.' 38 The synthesis has been reported of a triple-decker sandwich [Lu2( 1,2-naphtha~yaninato)~].' 39 The first yttrium porphyrinogen complex has been prepared.140 Three studies of hexaaza macrocycle complexes have a~peared.'~' Two report the structures of ten- and 12-coordinate lanthanum complexes; another series of com-plexes is believed to have a N303 macrocycle coordinating the lanthanide~.'~~ Spectroscopic Studies.-Luminescence studies have been reported for europium(II1) in sol-gel derived hosts.143 A similar study of europium complexes of ligands potentially useful as contrast agents has correlated the energy of the 7F0- 'Do transition with the sum of the partial charges of the donor atoms.144 Formation of ternary complexes between Eu3-+ diketonates and 1,lO-phenanthroline leads to a synergistic increase in the intensity and position of the 7F 45D0 The use of phenanthroline tran~iti0n.l~' complexes of europium(II1) in luminescent probes for DNA assay for example has been reviewed.146 Europium(n1) fluorescence has been used to identify two metal binding sites in bovine a-lactalbumin. 147 Europium and terbium fluorescent chelates have been used as medical fluoroimmunoassay (FIA) labels' 48 whilst luminescent europium and terbium complexes of a branched macrocycle with two bipy ligands built into the ring and two coordinating phosphinate sidearm groups (2) have been synthesized as possible FIA species.'49 CD spectra of terbium complexes with anthracycline anticancer drugs have been 134 J.W. Buchler and M. Nawra Inorg. Chem. 1994,33,2830;J. W. Buchler V. Eiermann H. Hanssum G. Heinz H. Ruterjans and M. Schwarzkopf Chem. Ber. 1994 127 589. 135 E. M. Davoras G.A. Spyroulias E. Mikros and A. G. Coutsolelos Inorg. Chem. 1994 33 3430. 136 M. S. Haghighi A. Franken and H. Homberg Z. Naturforsch. B 1994 49 812. 13' F. Guyon A. Pondaven P. Guenot and M. L'Her Inorg. Chem. 1994 33 4787. 13' T. Komatsu K. Ohta T. Fujimoto and 1. Yamamoto J. Muter. Chem. 1994 533. 139 F. Guyon A. Pondaven and M. L'Her J. Chem. SOC. Chem. Commun. 1994 1125. J. Jubb S. Gambarotta R. Duchateau and J. H. Teuben J. Chem. SOC. Chem. Commun. 1994 2641. 14' (a)F. Benetollo G. Bombieri and L. M. Vallarino Polyhedron 1994,13,573; (b)S. W. A.Bligh N. Choi E. G. Evagoorou W.-S. Li and M. McPartlin J. Chem. SOC.,Chem. Commun. 1994,2399; (c)K. Kasuga T. Moriguchi K. Yamada M. Hiroe M. Handa and K. Sogabe Polyhedron 1994 13 159. 14' R. Bandin R. Bastida A. de Bals P. Castro D. E. Fenton A. Macias A. Rodriguez and R. Rodriguez J. Chem. SOC.,Dalton Trans. 1994 1185. 143 L.R. Matthews and E.K. Knobbe Chem. Muter. 1993 5 1697. 14' S. T. Frey C. A. Chang J. F. Carvalho A. Vandarajan L. M. Schultze K. L. Pounds and W. D. Horrocks Inorg. Chem. 1994,33 2882. 145 S.T. Frey M. L. Gong and W. D. Horrocks Inorg. Chem. 1994 33 3229. 146 P.G. Sammes and G. Yahioglu Chem. SOC.Rev. 1994 23 327. 14' J.-C.G. Bunzli and J.-M. Pfefferle Helu. Chim. Acta 1994 77 323. I*' H. H. Shi and Y. S. Yang J. Alloys Compd.1994 2071208 29. 149 N. Sabbatini M. Guardigli F. Bolletta I. Manet and R. Ziessel Anyew. Chem. Int. Ed. Engl. 1994,33 1501. 306 S. A. Cotton reported. 50 MCD of Eu3 + in LaF and Na,[Eu(oxydiacetate)3]~2NaC104~6H,0has been assigned.' '' The potential of erbium-doped fibres as optical amplifiers for intercontinental communication has been reviewed' 52 whilst erbium-doped K,LaX5 (X = C1 Br) exhibit upconversion lumine~cence.'~~ EPR linewidth studies of gadolinium(II1) complexes including MRI contrast agents have investigated water-exchange and electronic rela~ation.''~ A "'Eu Mossbauer study of several organometallics found evidence" for 4forbital covalence in [Eu(thf)Cp,] (but not in several other cyclopentadienyls). 0rganometallics.-Immense activity in this area means a selective report here.A distinguished highlight is the work of Marks and his synthesizing and characterizing chiral organolanthanides for asymmetric catalysis; others have also synthesized asymmetric complexes.' 5771s8 Another highlight is the synthesis of the first lanthanide carbenes. Both mono- and biscarbene derivatives of [SmCp;] which may be regarded (3)as analogues of [Sm(thf),Cp;] (n = 1,2) have been reported as thermally stable solids. [Eu(tmhd),] and [Y(tmhd),] also from addu~ts.'~~ [Sm(thf),Cp;] itself reacts with [(MeO),P(S)S] with elimination of one Cp* ligand producing dinuclear [(SmLCp*),] [L = S,P(OMe),] in which the dimethyldithiophosphate ligands are triply bridging due to the coordination of the methoxy oxygen atoms.'60 Several ytterbium(i1) compounds including the alkyls [Yb(CHR,),(OEt,),] and lSo H.Be1 Haj-Tayeb M. M. L. Fiallo A. Garnier-Suillerot T. Kiss and H. Kozlowski J. Chem. SOC.,Dalton Trans, 1994 3689. 151 C. Gorller-Walrand Radiochim. Acta 1993,61,21;C. Gorller-Walrand P. Verhoeven J. D'Olieslager L. Fluyt and K. Binnemans J. Chem. Phys. 1994 100 815. E. Desurvire Physics Today Jan 1994 20. lS3 K. Kramer and H.-U. Gudel J. Alloys Compd. 1994 207/208 132. lS4 D. H. Powell G. Gonzalez V. Tissieres K. Micskei E. Brucher L. Helm and A. E. Merbach J. Alloys Compd. 1994 2071208 20. lSs G. Depaoli U. Rosso,G. Valle F. Grandjean A. F. Williams,and G. J. Long,J. Am. Chem. SOC.,1994,116 5999. 156 M. A. Gkrdello V. P. Conticello L.Brard M. Sabat A. L. Rheingold C. L. Stern and T. J. Marks J.Am. Chem. SOC. 1994,116,10212;M. A. Giardello V. P. Conticello L. Brad M. R. Gagne and T. J. Marks J. Am. Chem. SOC. 1994 116 10241. Is' P. Van de Weghe C. Bied J. Collin J. Maralo and I. Santos J. Organomet. Chem. 1994 475 121. 158 H. Schumann M. Glanz and H. Hemling Chem. Ber. 1994 127 2363. A. J. Arduengo M. Tamm S.J. McLain J. C. Calabrese F. Davidson and W. J. Marshall J. Am. Chem. SOC. 1994,116,7927;H. Schumann M. Glanz J. Winterfeld H. Hemling N. Kuhn and T. Kratz Chem. Ber. 1994 127 2369. 160 M. Rieckhof M. Noltemeyer F. T. Edelmann 1. Haiduc and I. Silaghi-Dumitrescu J. Organomet. Chem. 1994 469 C19. Scandium Yttrium the Lanthanides and the Actinides Na[Yb(CHR,),] (R = SiMe,) have been reported,16' as have the synthesis and structures of trans-[(Yb(thf),(SiPh,),] and [Yb(thf)4(GePh,),].'62 A diene-bridged dilanthanum complex [(thf),12Ln(p-q4:q4-PhCH=CHCH=CHPh)LaI,(thf),](4) has been re~0rted.l~~ NMR spectroscopic studies have been reported for dynamic allyls [Li(dioxan),][Ln(C,H,),] (La Ce Pr Nd Sm and Y).164Reaction of [(SmClCp,},] with NaC-CCH,OCH,CH=CH in thf affords a complex of an unusual cyclohexan-4-yne ligand [Sm(thf)(q'-C6H 5)Cp,] (5).'65 Structures have been determined of [LnCl,(thf),Cp] (Ln = Sm,'66 Y,167 Eu"' 1 (with the new complexes [Eu(NCX),(thf),Cp] [X = S 01 also reported).[ErCl,(thf),(q-C,H,Bz)] is similar. ''* Pseudotetrahedral structures are reported for [Ln(thf)Cp,] (Ln = Ce Er Sm and DY).'~~ The structure of [Ce(thf)Cp,] is curiously distorted and merits rein~estigation.'~~" [Ln{O=P(OEt),}Cp,] have been syn- thesized (except for Pm); several properties are reported to exhibit a tetrad effect.'70 The structures of [Sm(thf)(ind),] and [Sm(thf),(fl~orenyl)~] have been deter- mined.'71 Decamethylsamarocene forms the adducts [Sm(NH,Bu')Cp$] and [Sm(N- Meim),Cp;].72 A range of dimeric decamethylsamarocene derivatives has been rep~rted'~~?'~~ including [Sm,(p-O)Cp,*] [Sm,(p-E)(thf),CpX] (E = S Se Te) 161 P. B. Hitchcock S.A. Holmes M.F. Lappert and S. Tian J. Chem. SOC. Chem. Commun. 1994 2691. L.N. Bochkarev V. M. Makarov Y. N. Hrzhanovskaya L. N. Zakharov G.K. Fukin A. 1. Yanovsky and Yu.T. Struchkov J. Organomet. Chem. 1994 467 C3. 163 K.Mashima H. Sugiyama and A. Nakamura J. Chem. SOC.,Chem. Commun.. 1994 1581. 164 F. F. Li Y.T. Jin X. T. Zhang and F. K. Pei Chin. Chem. Lett. 1994,5,393;F. F. Li Y. T. Jin J. M. Ren Y.F. Sun F.K. Pei and F. S. Wang J. Rare Earths 1994 12 142. S. W. Wang Y.F. Yu Z. W. Ye C. T. Qian and X. L. Jin J. Chem. SOC. Chem. Commun. 1994 1097. 166 C. -T.Qian,D.-M.Zhu,J.Sun,P.-J.Zheng,andJ.Chen,Jiegou Huaxue(Chin. J.Struct.Chem.) 1994,13,19. X. Zhou Z. Wu H. Ma Z. Xu and X. You Polyhedron 1994 13 375. 16* F.-X. Gao G.-C. Wei Z.-S. Jin W.-Q. Chen and Z. Yin Jiegou Huaxue (Chin. J. Struct. Chem.) 1994,13 247. 169 (a)W. Chen G. Lin J. Xia G. Wei Y. Zhang and Z. Lin J. Organomet. Chem. 1994,467,75;(b)Z. Wu Z. Xu X. You X. Zhou X. Huang and J. Chen Polyhedron 1994,13,379;(c)S.Wang Y. Yu Z. Ye C. Qian and X. Huang J. Organomet. Chem. 1994 464 55. I7O B. Kanellakopulos R. von Ammon C. Apostolidis E. Dornberger R. Maier J. Miiller and X. Zhang J. Organomet. Chem. 1994 483 193. 171 W. J. Evans T. S. Gummersheimer T. J. Boyle and J. W. Ziller Organometallics 1994 13 1281. 17* W. J. Evans G. W. Rabe and J. W. Ziller J. Organomet. Chem. 1994 483 39. W. J. Evans and S. L. Gonzales J. Organornet. Chem. 1994,480,41;W. J. Evans G. W. Rabe J. W. Ziller and R. J. Doedens Inorg. Chem. 1994,33,2719;W. J. Evans G. W. Rabe and J. W. Ziller J. Organomet. Chem. 1994 483 21. W. J. Evans G. W. Rabe M. A. Ansari and J. W. Ziller Angew. Chem. Int. Ed. Engl. 1994 33 2110. 308 S. A. Cotton (Reproduced with permission from J.Chem. Soc. Chem. Commun. 1994 1581.) (Reproduced with permission from J. Chem. Soc. Chem. Commun. 1994 1097.) [Sm,(,u-E)Cp,*] and [Sm,(,u-q' ;q'-C,)CpX]. Most remarkable is [Sm,Se ,Cpg] 174 with an octahedron of Cp*Sm units surrounding the selenium core. The first pentamethylcyclopentadienyleuropium(m) is [{E~(OB~')(,~-OBU')C~*),~,'~~ whilst [(YHCp;} ,] undergoes selective metallation at the 2-position by pyridine; the resulting [Y(2-pyridyl)Cp;] has a rich chemistry.' 76 [Li(thf),][Yb(NPh,),(q'-175 W. J. Evans J. L. Shreeve and J. W. Ziller Organometallics 1994 13 731. 176 B.-J. Deelman W. M.Stevels,J. H. Teuben M. T. Lakin and A. L. Spek Organometallics 1994,13 3881. Scandium Yttrium the Lanthanides and the Actinides 309 C,H,Bu')] and [Li(drne),][Nd(NPh,),Cp,] have structures based on ion pairs with pseudo tet rahedrall y coordinated lanthanides ;' in [Li (thf) (p-Cl)Nd(q ,-C ,H4But),] there is a bridging chloride completing the tetrahedral coordination.' 78 The synthesis has been reported of [{Ln(p-ER)(q-C,H,Bu'),},] (Ln = Y Lu; E = S Se; R = Ph Bu Bz) along with the structure of [(Lu(p-SePh)(q-C,H,Bu'),),.' 79 [LnCp,] (Ln = Dy Lu) react with butan-1-01 to form [(Ln(p-OCHMeCH,CH,)Cp,),] which dehydrogenate under reflux to form [(Ln(p-OMeC=CHCH3Cp,),1 .I8' Several open pentadienyl complexes such as [Sm(2,4-dimethylpentadienyl),l and [Yb(2,4-dimethylpentadienyl),(dme)] have been characterized.' ' The chemistry of complexes of functionalized cyclopentadienyl ligands develops.In [LnCIL;] (L' = q'-C,H,CH,CH,OMe) (Ln = La Pr Nd Sm Gd Dy-Lu Y) the lanthanum'82 compound is dimeric [(La,(p-Cl),Lk),]; lanthanum binds to both ether oxygens giving it a formal coordination number of ten.The Dy and Yb compounds are both monomers again with both ether oxygens coordinated. [LnClL;] (Ln = La Y) undergo metathesis with NaI to form [LnIL;] both monomers having the two ether oxygens c00rdinated.I~~ The tetrahydroborates [Ln(BH,)L,] (Ln = La Pr Nd Sm Gd) are also monomers with ether-oxygen coordination;' 84 the earlier lanthanides probably have tridentate borohydrides whereas the later lanthanides and yttrium have bidentate borohydrides. [LnIL;] (Ln = Sm Yb) react with K[Co(CO),] forming [Ln(thf)L;][C0(C0),];'~~they can also be prepared by the redox reaction between [Ln(thf)L;] and [co,(c0)8].The ytterbium compound is fluxional in solution. [{Ln(p-CI)L',},] (Ln = La Pr Ho and Y) react with NaH to form dimeric [(Ln(p-H)L;},]; the hydrolysis product [{Ho(p-OH)L,},] has also been characterized.'86 [SmIL;] and [LnI,(thf),L'] are both monomers.187 The absorption and luminescence spectra of trigonal [SmL,] have been assigned.'88 Several publications involve bridged dicyclopentadienyl ligands. Thus [(Sm(p- Cl)(thf)(q5,q'5-C,H,CMe,CMe2CsH4)}2] is a dimer with two bridging chlorides'89 whilst [Ln(thf)Cp(q5,q'5-C,H4CMe2CMe~C5H4)] (Ln = Nd Sm Gd Yb) are mono- mer~.~~~ [PrCZ(thf)(qs,q'5-C,H,SiMeOSiMe2CsH4)] is possibly dimeric whilst [{YbCl(q5,q'S-C,H,SiMe,OSiMe,C,H,)) ,]has two chlorine bridges.191 0ther sys- tems studied involve furan-bridged and 2,6-dimethylene bridged cyclopentadienyls.'92 17' L. Mao Q. Shen and S.C. Jin Polyhedron 1994 13 1023; J. Guan Q. Shen S.C. Jin and Y.H. Lin Polyhedron 1994 13 1695. J. Guan Q. Shen S.C. Jin and Y. Lin Acta Crystallogr. Sect. C 1994 50 891. 179 1.P. Beletskaya A.Z. Voskoboynikov A. K. Shestakova A. 1. Yanovsky G. K. Fukin L. N. Zacharov Yu.T. Struchkov and H. Schumann J. Organomet. Chem. 1994 468 124. In' Z. Wu Z. Xu X. You X. Zhou and X.Y. Huang J. Organomet. Chem. 1994 483 107. D. Baudry F. Nief and L. Ricard J. Oryanomet. Chem. 1994 482 125. ln2 C. Qian B. Wang D Deng J. Hu J. Chen G. Wu and P. Zheng Inorg. Chem. 1994 33 3382. C. Qian X. Zheng B. Wang D Deng and J. Sun J. Organomet. Chem.1994 466 101. in4 D. Deng X. Zheng C. Qian J. Sun and L. Zhang J. Oryanomet. Chem. 1994,466,95. D. Deng X. Zheng C. Qian J. Sun A. Dormond D. Baudry and M. Visseaux J. Chem. Soc. Dalton Trans. 1994 1665. In' D. Deng Y. Jiang C. Qian G. Wu and P. Zheng J. Organomet. Chem. 1994 470 99. lR7 D.L. Deng C.T. Qian F.S. Song and Z.Y. Wang Science in China 1994 37 1168. 1nn C. Qian B. Wang N. Edelstein H. Reddmann C. Hagen and H. D. Amberger J. Alloys Compd. 1994 2071208 87. lnY C. D. Sun G. C. Wei Z. S. Jin and W.Q. Chen Polyhedron 1994 13 1483. 19" C.D. Sun and W.Q. Chen J. Rare Earths 1994 12 139. 19' J. Griper R. D. Fischer and G. Paolucci J. Oryanomet. Chem. 1994 471 87. 192 C. Qian J. Graper and R. D. Fischer J. Organomet. Chem. 1994 471 97. 310 s.A. Cotton An improved synthesis is reported'93 for the series [Ln(AICl,),(q-C,Me,)] (Ln = Nd Sm Gd Yb) along with the structure of the ytterbium compound; a mixed [Nd(AlCl,),(q-C,H6)]/A1R,system catalyses the polymerization of butadiene and of isoprene.194 Several reports have involved cot complexes. Lanthanide metals react with cot in warm thf in the presence of one mol of iodine to form [LnT(thf),(C,H,)] (Ln = La-Pr x = 3; La = Nd x = 2; La = Sm x = 1)195whilst use of a catalytic amount of iodine gives the samarium@) compound [{ Sm(thf)(C,H,)},]. Use of 1,2-dibromoethane or PCl,Ph in place of iodine gives dimeric [{ sm(p-X)(thf)(q-C,H,)},] ;using dialkyl disulfides or diary1 diselenides results in [{ Sm(p-ER)(thf)(q-C,H,)},]. The triflate [(Y (p-03SCF,)(thf)(q-C8H8)},]has been prepared as a convenient starting material for the synthesis of mono(cot) complexes of yttrium;'96 similar compounds [{ Ln(p-O,SCF,)(thf),(q-cot)),] (Ln = Ce Pr Nd Sm) have also been synthesized19' from the anhydrous triflate [Ln(CF,SO,),] and K,[C,H,] in thf.A similar reaction starting with LnI affords [LnI(thf),(q-c,H,)] (Ln = Nd Sm) mentioned above (the structures of the Nd members of both series have been confirmed). The iodides in particular have potential as synthetic starting materials as they are more soluble than the dimeric chlorides traditionally used. [{Dy(p-OCH,CH,CH,CH=CH,)(thf)(q-C H ,)},I synthesized from [{ Dy (p-C1 )(t hf),( q-C,H )} ,] and NaOCH,CH,CH,CH=CH, also has a dimeric structure.' 98 [Li(thf),] [Ce(C,H,),] obtained in poor yield from the reaction of [{Ce(p-Cl)(thf),(q-C8H8)),] and LiCH(SiMe,) has a 'sandwich' anion.'99 In [Na(thf),Ce(C,H,),] one cot ring bridges the metals so that it is [(thf)3Na(p-C8H,)Ce(q-C8H8)].The mixed sandwiches [Ln(thf),(q-C,Me,Et)(q-C,H,)] (Ln = Y La Nd Sm Gd x = 1; Ln = Tm Lu x = 0) [Ln{q-C5H,(SiMe,),)(C8H8)] (Ln = Pr Dy) and [Pr(q-C,Ph,)(q-C,H,)] have all been made.," [Lu(q-C,Me,Et)(q-C,H,)] reacts with Hacac to form [Lu(acac),(q-C,Me,Et)]; the structures of both were reported.The purple cerium(1v) sandwich molecule [Ce{q8-1 ,3,6-C8H,(SiMe,),},] is rather more air-stable than the purple Oil [ce{ q8-1,4-c 8H6( SiMe,) }21.,' ' Increasing numbers of diphosphinomethanide compounds have been reported; [Sm(q3-Ph,PCHPPh,),] is a monomer (R = Ph),02" whilst the methyl analogue [{Sm(p-Me,PCHPMe,)(Me2PCHPMe~)z}2], (6) is dimeric.202b Amongst other compounds [Lu(thf)(C(SiMe,)(PMe,),},] is seven-~oordinate.~'~ 4 Actinides Binary Compounds and Complexes.-Thermolysis of mixtures of MCl (M = Th U) 193 H.A.Liang Q. Shen J. W. Guan and Y. H. Lin J. Organomet. Chem. 1994 474 113. IY4 J.-Y. Hu H.-Z. Liang and Q. Shen J. Rare Earths 1993 11 304. 195 K. Mashima Y. Nakayama A. Nakamura N. Kanehisa Y. Kai and H. Takaya J. Organomet. Chem. 1994,473,85; K. Mashima Y. Nakayama N. Kanehisa Y. Kai and A. Nakamura J. Chem. SOC.,Chem. Commun. 1993 1847. 196 U. Kiliman and F. T. Edelmann J. Organomet. Chem. 1994 469 C5. 19' U. Kiliman M. Schafer R. Herbst-Irmer and F. T.Edelmann J. Organomet. Chem. 1994 469 ClO. 198 S. Zhang G. Wei W. Chen and J. Liu Polyhedron 1994 13 1927. U. Kiliman M. Schafer R. Herbst-Irmer and F.T. Edelmann J. Organornet. Chem. 1994 469 C15. H. Schumann J. Winterfeld M. Glanz R. D. Kohn and H. Hemling J.Organomet. Chem. 1994,481,275. U. Kiliman R. Herbst-Irmer D. Stalke and F. T. Edelmann Angew. Chem. Int. Ed. Engl. 1994,33,1618. '02 (a)S. Hao J.-I. Song H. Aghabozorg and S. Gambarotta J. Chem. SOC.,Chem. Commun. 1994 157; (b) H.H. Karsch G. Ferazin and P. Bissinger J. Chem. Soc. Chem. Commun. 1994 505. '03 H.H. Karsch G. Ferazin H. Kooijman 0. Steigelman A. Schier P. Bissinger and W. Hiller J. Organomet. Chem. 1994,482 151. 19' Scandium Yttrium the Lanthanides and the Actinides 311 (Reproduced with permission from J.Chem. SOC. Chem. Commun. 1994 505.) and alkali metal pnictides or chalcogenides has been used to prepare actinide pnictides or chalc~genides.~~~ The synthesis of [M(porphyrin),] (porphyrin = tpp oep; M = Th U) has been reported; oxidation affords [M(porphyrin),]"+ (n = 1,2). A comparison of the structures of [M(tpp),]"+ (n = 0,l) shows a decrease in the interplanar distance on oxidation.205 A thorium dialkylphosphide complex under- goes double insertion with CO to give (7) a secondary alcohol derivative.206 Amongst [UX3L4] (X = I L = thf dme py; X = Br L = thf) systems [UI,(thf),] has a pentagonal bipyramidal structure;207 another Lewis base adduct is [U13(NCMe)4].208 R=Me (7) (Reproduced with permission from J.Chem. SOC.Chem. Commun. 1994 1249.) Two reports have appeared concerning poly(pyrazoly1)borates. The uranium(rr1) compound [UITp;] features2'' unprecedented side-on coordination of one of the 204 J.C. Fitzmaurice and I. P. Parkin New J. Chem. 1994 18 825. 205 G. S. Girolami P. A. Gorlin S.N. Milam K. S. Suslick and S. R. Wilson J. Coord. Chem. 1994,32,173. 206 P. G. Edwards M. B. Hursthouse K. M. A. Malik and J. S. Parry J. Chem. SOC.,Chem. Commun. 1994 1249. 207 L. R. Avens S. G. Bott D. L. Clark A. P. Sattelberger J.G. Watkin and B. D. Zwick Inorg. Chem. 1994 33 2248. 208 J. Drozdzynski and J. G. H. du Preez Inorg. Chim. Acta 1994 218 203. 209 Y. sun R. McDonald J. Takats V. W. Day and T.A. Eberspacher Inorg. Chem. 1994 33 4433. 312 S.A. Cotton pyrazole rings in one ligand molecule whilst the uranium(1v) compound [UCl,Tp'J forms Lewis base adducts; the structure of the seven-coordinate (capped octahedral) [UCl,(OPEt,)Tp'] has been reported.210 A,[UX,] (A = alkali metal X = C1 Br and I) having the K2[PrCl,] structure have been made;211 [UCl,(tmeda),] (and the thorium analogue) are useful synthons.21 Two welcome additions to the ranks of crystallographically characterized ura- nium(v) complexes are [UF,(bipy)]213 and [UC1,(N(CH2CH2PPr~),),1 the latter being the first well defined uranium(v) phosphine ~ornplex.~ l4 The synthesis of UF from uranium metal and ClF has been reported.215 A novel example of a pseudo-uranyl ion is [UOC14fNP(rn-tolyl),)] -(8) which has a virtually linear N-U-0 grouping and a short U-N bond (1.901A) with obvious multiple bond character.21 60 (Reproduced with permission from J.Chem. SOC. Chem. Commun. 1994 2601.) Among many studies on uranyl compounds the report of the encapsulation of U02+rinside carbon nanotubes stands EXAFS studies on aqueous solutions of the uranyl ion support the presence of the expected ion [U02(H20),]2+; EXAFS and X-ray diffraction studies on uranyl crown ether complexes led to the determination 'lo R. Maier J. Muller B. Kanellakopulos C. Apostolidis A. Domingos N. Marques and A. Pires de Matos Polyhedron 1993 12 2801. "' K. Kramer H. U. Gudel G. Meyer T. Heuer N. N. Edelstein R. Jung L. Keller P. Fischer E. Zych and J. Drozdzynski Z. Anorq. AIIg. Chem. 1994 620 1339.'I2 P. G. Edwards M. Weydert M.A. Petrie. and R.A. Andersen J. Alloys Compd. 1994 2131214 11. '13 L. Amaudet R. Bougon B. Buu M. Lance M. Nierlich and J. Vigner. Inorg. Chem. 1994 33 4510. 'I4 S. J. Coles P. G. Edwards M. B. Hursthouse and P. W. Read J. Chem.Soc. Chem. Commun. 1994,1967. 'I5 I. C. Tornieporth and T. M. Klapoetke Inorg. Chem. 1994 215 5. 'I6 D. R. Brown R.G. Denning and R.H. Jones J. Chem. SOC.,Chem. Commun. 1994 2601. 'I7 S. C. Tsang Y. K. Chem P. J. F. Harris and M. L. H. Green Nature (London) 1994 372 159. Scandium Yttrium the Lanthanides and the Actinides 313 of similar bond lengths.218 The azacrown complex ion [UO,( 18-azacrown-6)I2 has + the hexagonal bipyramidal coordination of uranium2l9 also found220 in Na[UO,(O,CPh),] -.FT-IR spectroscopic studies have been reported for UO; + in MeCN.,,l The uranyl ion has been used as a template for making a hexaaza tetradentate macrocycle complex.222 Functionalized uranyl salens have been shown to act as neutral receptors for anions such as phosphate and The structures of several of the parent salenes and their adducts have been determined as has that of a uranyl salophen-water complex.223b The uranyl complex of a bifunctional salen has been described as a bifunctional receptor for both cations and anions;22 3c a uranyl calix salophen crown ether similarly acts as a receptor for neutral molecules.223d The structures of neptunium(v) compounds including [NH,] [NpO (OOCH),] [(Np02)2(malonate)]~xH,0 (x = 3,4),224b [NpO ,C1] -H 0,2 24c and [(Np02),(N03)2]~5H20,224d continue to be studied.The solubility of Na[NpO,(CO,)] has been determined.225 [MI,(thf),] (M = Np Pu) [PuI,(py),] and the silylamides [M(N(SiMe,),),] have been reported207 and the affinity of plutonium(1v) for N-donors discussed.226 Luminescence from Am3+(aq)227 and from the halides228 of 248Cm has been studied whilst luminescence of californium(u1) polyaminocarboxylates indicates a higher coordination number than for the corresponding europium(rr1) complexes.229 Alkoxides Aryloxides Amides and Thio1ates.-Several important papers have appeared. The Lewis base adducts [Th,(OPr') ,(py),] and [Th,(OCHEt,),(py),] have been characterized; the structure of the former indicates a likely structure for [(Th(OPr'),),] for which an improved synthesis has also been reported.230 Explora- tion of the oxidation chemistry231 of [U(OAr),] (Ar = 2,6-di-t-butylphenoxide)led to the chalcogenide-bridged compounds {(ArO)3U(pY)U(OAr)3] (Y = 0,S) in addi- tion to [UX(OAr),] (X = F C1 Br and I).Oxygen oxidation gives [U(OAr),] whose 218 L. Deshayes N. Keller M. Lance A. Navaza M. Nierlich and J. Vigner Polyhedron 1994 13 1725. 219 M. Nierlich J.-M. Sabattie N. Keller M. Lance and J.-M. Vigner Acta Crystallogr. Sect. C 1994,50,52. 220 A. Bismondo U. Castellato and R. Graziani lnorg. Chim. Acta 1994 223 151. "I J.-V. G. Bnzli and J.-P. Metabanzoulou Helv. Chim. Acta 1994 77 140. 222 W. Radecka-Paryzek and E. Luks Polyhedron 1994 13 899. 223 (a)D. M. Rudkevich W. Verboom Z. Brzozka M.J. Palys W.P. R.V. Stauthamer G.J. van Hummel S. M. Franken S. Harkema J. F.J. Engbersen and D.N. Reinhoudt J. Am. Chem. Soc. 1994,116,4341; (b)A. R. van Doorn W. Verboom D. N. Reinhoudt and S. Harkema Acta Crystallogr. Sect. C 1994,50 1449; (c) D. M. Rudkevich W. Verboom and D.N. Reinhoudt J. Org. Chem. 1994 59 3683; D. M. Rudkevich Z. Brzozka M. Palys H. C. Visser W. Verboom and D. N. Reinhoudt Angew. Chem. Int. Ed. Engl. 1994,33,467; (d)A.M. Reichwein W. Verboom S. Harkema A. L. Spek and D. N. Reinhoudt J. Chem. Soc. Perkin Trans. 2 1994 1167. 224 (a)M. S. Grigor'ev I. A. Charushnikova N. N. Krot A. I. Yanovskii and Yu. T. Struchkov,Russ.J. lnorg. Chem. (Engl. Trans) 1994 39 1267; (b) Sou. Radiochem. (Engl. Trans). 1993 35 388; 394; (c) M.S. Grigor'ev A.A. Bessonov N. N. Krot A. I. Yanovskii and Yu. T. Struchkov Sou. Radiochem. (Engl. Trans) 1993,35 382; (d) M. S. Grigor'ev I. A. Charushnikova N.N. Krot A.1. Yanovskii and Yu.T. Struchkov Russ. J. Inorg. Chem. (Engl. Trans) 1994 39 179. 225 G. Meinrath J. Radioanal. Nucl. Chem. Letts 1994 186 257. 226 N. V. Jarvis and R. D. Hancock Radiochim. Acta 1994 64 15. 22' J. V. Beitz J. Alloys Compd. 1994 2071208 41. 228 N. A. Stump G. M. Murray G. D. Del Cul R. G. Haire and J. R. Peterson Radiochim. Acta 1993,61,129. 229 T. Kimura and G. R. Choppin J. Alloys Compd. 1994 213/214 313. 230 D. M. Barnhart D. L. Clark J. C. Gordon J.C. Huffman and J. G. Watkin Znorg. Chem. 1994,33,3939. 231 L. R. Avens D. M. Barnhart C. J. Burns S. D. McKee and W. H. Smith Znorg.Chem. 1994 33,4245. 314 s.A. Cotton low-temperature VIS/near-IR spectrum has been assigned.,, [U(OAr'),(thf)] (Ar' = 2,4,6-trimethylphenoxide)catalyses aldolization reactions involving aliphatic and aromatic aldehydes.,, Ab initio MO calculations234 on [Np(NH,),] and [U(NH,),] as simple models for the silylamides favour pyramidal structures as known for the methyls.207 Volatile pentane-soluble [MCl{N(CH,CH,NSiMe,)3}] (M = U Th) have been syn-the~ized;~,~ the uranium complex shows that in the solid state the monomers are associated into dimers by asymmetric chlorine bridges. [U(NEt,),] reacts with Pr'SH to give [U(SPr'),] crystallographically confirmed as the octahedral adduct trun~-[U(SPr'),(hmpa),];~~~a similar reaction with Bu'SH gave the trinuclear [U3(p3-S)(p3-SBut)(p2-sBut),(sBU'),1.In contrast [U(NEt,),] reacts with PhSH giving [NEt2H2]2[U(SPh)6] whilst [(Ph,P)Cu(p-SPh),U(p-SPh),Cu(PPh,)] results from a one-pot synthesis from UCl, CuSPh NaSPh and PPh,. Following last year's report that a uranium complex converted 0 into a peroxide complex it is now reported237 that uranyl thiolate complexes react with molecular oxygen to give di-and tetranuclear complexes such as peroxo-bridged [(U0,),(0,)(SC,N2H,),]2 -(HSC,N,H3 = 2-mercatopyrimidine) (9). 0rganometallics.-Theoretical calculations have been reported238 for the actinocenes [M(&H&] (M = Pa Np Pu) and the actinofullerenes U@C, and U@C, whilst a number of reports have concerned thermochemical measurements; values have been determined for Th-H bond energies in [ThH(ind),] and [ThHCp,],239 U-S bond energies in [U(SR)(ind),] and [U(SR)Cp,],240 and An-0 bond energies in [An(OR)Cp,] systems241 (Cp and ind = substituted cyclopentadienyl and indenyl systems).The synthesis of crowded [MCl(q-C,Me,€€),] (M = U Th) has been achieved; variable temperature NMR spectroscopy indicates hindered rotation 232 J. M. Berg J. Alloys Compd. 1994 213/214 497. 233 P. Van de Weghe J. Collin and I. Santos Inorg. Chim. Acta 1994 222 91. 234 P. J. Hay and R. L. Martin J. Alloys Compd. 1994 2131214 196. 235 P. Scott and P.B. Hitchcock Polyhedron 1994 13 1651. 236 P. C. Leverd T. Arliguie M. Ephritikhine M. Nierlich M. Lance and J. Vigner New J. Chem. 1993 17 769.; P. C. Leverd M. Lance M. Nierlich J.Vigner and M. Ephritikhine J. Chem. Soc. Dalton Trans. 1994 3563. 237 D. Rose Y.-D. Chang Q. Chen and J. Zubieta Inorg. Chem. 1994 33 5167. 238 A. H.H. Chang K. Zhao W. C. Ermler and R.M. Pitzer J. Alloys Compd. 1994 213/214 191. 239 X. Jemine J. Goffart M. Ephritikhine and J. Fuger J. Organomet. Chem. 1993 448,95. 240 X. Jemine J. Goffart P.C. Leverd and M. Ephritikhine J. Organomet. Chem. 1994 469 55. 241 J. Goffart X. Jemine F. Wastin and J. Fuger J. Alloys Compd. 1994 213/214 344. Scandium Yttrium the Lanthanides and the Actinides particularly in the U compound (though the U-C bond lengths are unexceptional).z4z Low-temperature X-ray and neutron-diffraction results are reported for the doyen of uranium organometallics [UClCp,] .243 The synthesis of homoleptic [UCpz] has not yet been achieved presumably for a combination of electronic and steric reasons but the mixed sandwich [ucp*(q-c$8)] was isolated as the adducts [U(thf)Cp*(q- C,H,)] and [u(dmbipy)Cp*(r-c8H8)].244 The structure of [ThMe(thf)CpT] + [Bu'CH,CH{B(C,F,)}] has been reported; [ThMeCpT] is an active catalyst for ethene polymerization and hex- 1-ene hydr~genation.'~' Improved syntheses have been reported246 for [ThPh,Cp,*] and [ThMeArylCpT].A kinetic study of CO insertion into the U-C o bond in [MR'(q-C,H,R),] (R R' = H Me Pri Bu') and rearrangement of the resulting acyls has been reported;z47 the route is significantly different from that of the Th analogues. A highlight is the synthesisz48 of a rare uranium cycloheptatrienyl complex (lo) structurally characterized as the [U(thf),(BH,),] -t salt in which the C ring binds uranium on both faces.C (10) (Reproduced with permission from J. Chem. Soc. Chem. Commun. 1994 847.) Various mono(cot) thiolates [(U(SR),(q-C,H,},] have been synthesizedz4' from [U(BH,),(q-C,H,)] and RSH (R = Bun Pr'); the bridge in the butyl thiolate can be cleaved with excess thiol to form the piano-stool anion [U(SR),(q-C,H,)] -. Several organouranium(1v) and (v) compounds such as [u(NEt,),(thf)(q-C,H8)][BPh4]and [U(NEt,),(q-C,H,)] have been reported.*,' Reaction of uranocene with iodine in thf gives [UI,(thf),(q-C,H,)] a convenient material for the synthesis of interesting 242 F.G. N. Cloke S.A. Hawkes P. B. Hitchcock and P. Scott Organometallics 1994 13 2895.P. Raison J. Rebizant C. Apostolidis G.H. Lander A. Delapalme J.M. Kiat P. Schweiss B. 243 Kanellakopulos A. Gonthier-Vassal and P. J. Brown Z. Krist. 1994,209,720;A. Delapalme P. Raison G. H. Lander J. Rebizant P. Schweiss and B. Kanellakopulos Z. Krist. 1994 209 727. A. R. Schake L. R. Avens C.J. Burns D. L. Clark A. P. Sattelberger and W. H. Smith Oryanometallics 244 1993 12 1497. 245 L. Jia X. M. Yang C. Stern and T.J. Marks Organometallics 1994 13 3755. 246 A. F. England C. J. Burns and S. L. Buchwald Organometallics 1994 13 3491. 247 C. Villiers and M. Ephritikhine J. Chem. SOC.,Dalton Trans. 1994 3397. 248 T. Arliguie M. Lance M. Nierlich J. Vigner and M. Ephritikhine J. Chem. SOC.Chem. Commun. 1994 847. 249 P. C. Leverd T. Arliguie M. Lance M. Nierlich J. Vigner and M. Ephritikhine J. Chem. SOC.,Dalton Trans. 1994 501. 250 M. Ephritikhine J. Alloys Compd. 1994 2131214 15. 316 S. A. Cotton mixed-ring and half-sandwich compounds including [UBz,(hmpa),(q-C,H,)I CU(CH,SiMe,),(hmpa)(r-C,H 11 CU(N(SiMe,),)CP(r-C,Hsjl and 9 [U(CH,SiMe3)Cp*(q-C,Hs)].251 Interest continues in the tetramethylphospholyl ligand (tmpl) which is less electron donating than Cp*. The structures of [U(BH,),Cp*] and [UCl,(deme)(tmpl j] were reported and their redox properties compared. 52 A dimeric compound with bridging phospholyl ligands [(U(BH,)(trnpl)(,u-qS,q1-C,Me,P)~,],has been characterized;,, it exists as both cis and trans isomers in toluene.[UX(q-C,H,PPh,),] (X = C1 Me) react with BH,.SMe to form [U(BH,)(q- C,H,PPh,BH,),] via [UCl(C,H,PPh2BH3),] and the transient [UMe(q-C5H,PPh,BH,),].254 [U(C,H,PPh,BH,),] is obtained on reduction. Uranium compounds with phosphorus as a donor atom have been used to prepare heterobi- and trinuclear compounds with U and the d metals Mo W Ru and Rh.,, Chemistry of the Post-actinides.-Developments concerned with the elements them- selves are discussed in Section 1. Solvent extraction studies on Element 104from HCl solutions using triisooctylamine and tributylphosphate indicate general resemblances to the Group IV metals though sometimes the resemblance to plutonium(1v) was more marked.256 Thermodynamic functions of Element 105 have been calculated;257 it is suggested that at high HCl concentration a complex [(l05)OCl5]”- will exist.,,’ 251 J.-C.Berthet J.-F. Le Marechal and M. Ephritikhine J. Organomet. Chem. 1994,480 155. 252 P. Gradoz D. Baudry M. Ephritikhine M. Lance M. Nierlich and J. Vigner J. Oryanomet. Chem. 1994 466 107. 253 P. Gradoz M. Ephritikhine M. Lance J. Vigner and M. Nierlich J. Organomet. Chem. 1994,481,69. 254 D. Baudry A. Dormond and I. A. Abdallaoui J. Organomet. Chem. 1994 476 C15. 255 A. Dormond D. Baudry M. Visseaux and P. Hepiegne J. Alloys Compd. 1994 213/214 1. 256 K. R. Czerwinski K. E. Gregorich N. J. Hannink C. D. Kacher B.A. Kadkhodyan S.A. Kreek D. M. Lee M.J. Nurmia A. Turler G.T. Seaborg and D.C. Hoffman Radiochim. Acta 1994 64 23; K.R. Czerwinski C. D. Kacher K.E. Gregorich T. M. Hamilton N. J. Hannink B.A. Kadkhodyan S.A. Kreek D. M. Lee M. J. Nurmia A. Turler G. T. Seaborg and D. C. Hoffman Radiochim. Acta 1994,64 29. 257 V. Pershina B. Fricke G.V. Ionova and E. Johnson J. Phys. Chem. 1994 98 1482. 25K V. Pershina B. Fricke J.V. Kratz and G.V. Ionova Radiochim. Acta 1994 64 37.

ISSN:0260-1818    

DOI:10.1039/IC9949100295

出版商:RSC    

年代:1994

数据来源: RSC

摘要:

I9 The Coordination Chemistry of Open-chain Polydentate Ligands By M. D.WARD School of Chemistry University of Bristol Cantock's Close Bristol BS8 1 TS UK 1 Bidentate Ligands %donor Ligands.-[M(bipy),] (M = Fe Ru 0s) were prepared by reductive slectrocrystallization of the +2 complexes and are EPR silent.' [UF,(bipy)] is a mono-capped trigonal prism. Irradiation of [Ru(bipy),(3,3'-Me,bipy)12 affords a + transient species in which the 3,3'-Me,bipy is m~nodentate.~ RU(II) complexes containing 4,4'-(Et,N),bipy display RU(II)/RU(III) couples at unusually low potentials and also undergo ligand-based oxidation^.^ [RuX,L,] [L = 4,4'-(HO,C),bipy or 53'-cHO,C),bipy; X = C1 SCN CN] may be anchored to TiO electrodes via the pendant carboxylate groups and are effective photo-current generators5 (c$ ref.10). The RU(II) complexes of chiral bipy derivatives (1) and (2)perform stereoselective photoreduction of racemic [Co(acac),] .6 Cationic alkylated pyridines bind weakly to the poly(oxoethy1ene) chains of [Ru(3),j2 +,resulting in electron-transfer quenching within the supramolecular a~sembly.~ [Fe(4),I2 mimics biological recognition of + carbohydrate-based antigens by polysaccharides.8 Electrochemical properties of Mn(II) Fe(rI) CO(II) and Ni(1I) complexes with aryl-substituted phenanthrolines such as (5)-(9) were investigated.' [Cu( lo),] sensitizes semiconductors on irradiation" + (cj.ref. 5). The chiral @,a'-diimines (11)-(14) and their complexes [M(CO),L] (M = Cr Mo W) were prepared." CU(I) complexes of 1,4,7,lO-tetraazaphenanthreneand its substituted derivatives have ground-state photophysical properties similar to those of [Cu(phen),]+ but the MLCT excited state is a poorer reductant and a better E.Perez-Cordero.R. Buigas N. Brady L. Echegoyen C. Arana and J.-M. Lehn Hell;. Chim.Actu 1994,77 1222. ' L. Arnaudet R. Bougon B. Buu M. Lance M. Nierlich and J. Vigner Inorg. Chem. 1994 33,4510. S. Tachiyashiki H. Ikezawa and K. Mizumachi Inorg. Chem. 1994 33 623. S. J. Slattery N. Gokoldas T. Mick and K. A. Goldsby Inorg. Chem. 1994 33 3621. R. Argazzi C. A. Bignoi.zi T. A. Heimer F.N. Castellano and G.J. Meyer Inorg. Chem. 1994,33 5741. ' K. Ohkubo T. Hamada H. Ishida M. Fukushima M. Watanabe and H. Kobayashi J. Chem.Soc..Dalton Trans. 1994 239.' M. Seiler H. Diirr I. Willner E. Joselevich A. Doron and J. F. Stoddart,J. Am. Chem.SOC.,1994,116,3399. S. Sakai and T. Sasaki J. Am. Chem. SOC. 1994 116 1587. M.A. Masood D.J. Hodgson and P. S. Zacharias Inorg. Chim. Acta 1994 221 99. lo N. Alonso-Vante J.-F. Nierengarten and J.-P. Sauvage J. Chem. SOC.,Dalron Trans. 1994 1649. 'I B.L. Shaw M. Thornton-Pett and J.D. Vessey J. Chem. SOC.,Dalton Truns. 1994 3597. 317 318 M.D. Ward OW0 (1) R= to-$ OH HO 6- (either enan liorner) HN'n/ 0 (4) (5)R' = R2 = o-tdyl (11) and (12) (13) and (14) (6) R' = R2 =o-MeO-CeH4 (7) R' = R2 = o-EtO-CGH4 (8) A' = 0-tolyl; R2= H (12) (14); R = (9)R' = o-EtO-CeH4; R2 = H (10) R' = R2 = pCeH4CO2Na + oxidant.l2 [Mn111Mn'V(p-O),(py-bim)4] [py-bim = 2-(2-pyridyl)benzimidazole] has pH-dependent electrochemistry due to the acidic benzimidazole groups. ' [M(I5),(H2O),][NO,] (M = Co Cu) have been prepared.14 When coordinated to CU(II)the luminescence of free (16) is quenched by ligand-to-metal electron transfer to give a long-lived charge-separated species.' Other Hornoleptic Ligands.-An extensive series of C,-symmetric chiral chelating diols has been prepared for use in titanium-catalysed asymmetric additions of organo-zinc reagents to aldehydes.l6?l7 The chiral ligand (17) cannot chelate but must be exclusively bridging as in [{TiCI2(p-(l7))),].'* Fe(m) Cr(w) and Mn(IIr) tris(che1ates) of acac derivatives bearing up to six OC1,H25 substituents show mesogenic behaviour despite being octahedral.' l2 K. Karlsson C. Moucheron and A. Kirsch-De Mesmaeker New J. Chem. 1994 18 721. l3 B. C. Dave and R. S. Czernuszewicz Inorg. Chim. Acta 1994 227 33. l4 L. P. Battaglia M. Carcelli F. Ferraro L. Mavilla C. Pelizzi and G. Pelizzi J. Chem. Soc. Dalton Trans. 1994 2651. D. R. McDonald and R.J. Crutchley Inorg. Chem. 1994,33 1899. l6 Y.N. Ito X. Ariza A. K. Beck A. Bohac C. Ganter R. E. Gawley F.N. M. Kiihnle J. Tuleja Y. M. Wang and D. Seebach Helv. Chim. Acta 1994 77 2071. H. Waldmann M. Weigerding C. Dreisbach and C. Wandrey Helu. Chim. Acta 1994 77 21 11. N. W. Eilerts J. A. Heppert M. L. Kennedy and F. Takusagawa Inorg. Chem. 1994 33 4813. l9 H. Zheng and T. M. Swager J. Am. Chem. SOC. 1994 116 761. The Coordination Chemistry of Open-chain Polydentate Ligands Fe RU azP ePPh2 (18) R' = R2= cyclohexyl (20)R = Me (19) R' R2 different (variety of alkyVatyl groups) (21) R= Et R,p PR Me-' "Me H Y H R2PO "'Y) -eDFe (26)R = CsF5 (22)R=PP (24) R=Bu" (27) R = OCH(CF& (23)R = Pr' (25) R = Ph Chiral diphosphines have been popular for use in Rh and Pd-catalysed asymmetric reactions.Ligand (18) gives enantioselectivities of up to 99% in allylic alkylation (with Pd) and asymmetric hydrogenation (with Rh) reactions;20 (19) has both P and C asymmetric centres.,' [PdCI,L] [L = (20) (21)] are more effective catalysts for asymmetric silylation of allylic chlorides than the ferrocenyl-based analogues., Ligands (22)-(25) (PP) are trans-chelating in [RhCI(CO)(PP)] which catalyses asymmetric hydrosilation of ketones.23 Ligands (26) and (27) are intermediate between alkyl phosphites and CO in their electron donor/acceptor proper tie^.^^ [Ni(28),I2+ (meso and rac diastereoisomers) and [NiBr (28)] (one diastereoisomer) are possible asymmetric catalysts for olefin hydrogenation or is~merization.~ [Cu4CI,L,] [L = 1,3-C,H4(CH=PR),] has a cubane-like {Cu,Cl,) core with each ligand L bridging two CU(I) centres.26 Complexes of tetrasulfonated dppe are water soluble and can act as hydroformylation catalysts under phase-transfer condition^.,^ In complexes based on the trans-{MoL,) fragments [L = (RCH,),PCH,CH,P(CH,R),; R = vari-ous aryl substituents] agostic Mo .. . H-C interactions from the aryl groups R affect the coordination of other small molecules (H, CO N,) to the metal centre.,* 'O A.Togni C.Breutel A. Schnyder F. Spindler H. Landert and A. Tijani J. Am. Chem. SOC.,1994,116,4062. A. Togni C. Breutel M. C. Soares N. Zanetti T. Gerfin V. Gramlich F. Spindler and G. Rihs Inorg. Chim. Acta 1994 222 213. '' T. Hayashi A. Ohno S. Lu Y. Matsumoto E. Fukuyo and K. Yanagi J. Am. Chem. Soc. 1994,116,4221. 23 M. Sawamura R. Kuwano and Y. Ho Angew Chem. Int. Ed. Engl. 1994 33 111. 24 E.P. Kiindig C. Dupre B. Bourdin A. Cunningham Jr. and D. Pons Helv. Chim. Acta 1994 77,421. 25 L. Solujic E. B. Milosavljevic J. H. Nelson and J. Fischer Znorg. Chem. 1994 33 5654. A. Jouati M. Geoffroy and G. Bernardinelli J. Chem. Sac. Dalton Trans. 1994 1685.27 T. Bartik B.B. Bunn B. Bartik and B. E. Hanson Inorg. Chem. 1994 33 164. 28 X.-L. Luo G. J. Kubas C. J. Burns and J. Eckert Znorg. Chem. 1994 33 5219. 320 M.D. Ward [Ni(29),] undergoes two oxidations of the Ni-bis(dithio1ene) core in addition to the ferrocene-based oxidation^.^' Re@) and 0x0-Re(v) complexes of diars have been prepared.,' Bidentate selenoethers such as RSeCH,CH,SeR (R = Me Ph) and 1,2-C6H,(SeMe) form complexes [RuX,L,].~' P OPPh (29) (30)R=NMe2 (31) R =OMe (32)R=OH Mixed-donor Ligands.-The structures and electrochemical properties of Pd(n) complexes of (30)-(32) were determined.32 Ligand (33) is an N,O-chelating radical the magnetic properties of mononuclear complexes and layered polymeric complexes in which the nitroxide oxygen acts as an additional bridge were studied., + In [RuCl(dppy ),I [dppy = 2-(dipheny1phosphino)pyridinej one dppy ligand is P-monodentate; in association with [MCl,(CO),] -anions (M = Rh Ir) it catalyses hydroformylation of styrene., Mono- and binuclear OS(II)complexes of pyridyl-2- (CH,CH,PPh,) were prepared.35 [IrLJCl (L = Me,PCH,CH,NH,) and truns,cis-[IrCl,L,][BF,] (L = Ph,PCH,CH,NH,) were prepared., Reaction of planar [IrL,]' [L = 1,2-c,H4(PPh,)(cH=NR)] with 0 and CO depends on the bulk of the group R on the ligand; small R groups favour formation of an Ir(m)-q2-peroxide species.37 Rh(1) complexes of (34) catalyse enantioselective hydro- formylation of ~Iefins.~' fac-[M(aet),] (M = Rh Ir) can use their facial array of three S-ligands to bridge to other metals allowing assembly of high-nuclearity clusters such as [{Rh + (set)3) 4Cd3 (OH)] -+ and [{ Tr (aet ),} (M'),O] [(M') = Coy Zny Z~~.,CO~,,].~~-~~ Complexes of Pd(I1) and Pt(r1) with EtSCH,CH,NH model the interactions of Pt-based drugs with methionine residues., 29 S.B.Wilkes I. R. Butler A. E. Underhill A. Kobayashi and H. Kobayashi J.Chem.SOC.,Chem. Commun. 1994 53. 30 L. Chang M.J. Heeg and E. Deutsch Znorg. Chem. 1994 33 1614. 31 N. R. Charnpness W. Levason S. R. Preece and M. Webster Polyhedron 1994 13 881. 32 M. F. N. N. Carvalho L. M. G. Costa A. J. L. Pornbeiro A. Schier W. Scherer S. K. Harbi U. Verfiirth and R. Herrrnann lnorg. Chem. 1994 33 6270. 33 V. I. Ovcharenko K. E. Vostrikova A. Podoplelov R.Z. Sagdeev G. Rornanenko and V. N. Ikorskii Polyhedron 1994 13 2781. 34 D. Dromrni F. Nicolo C. G. Arena G. Bruno F. Faraone and R. Gobetto Inorg. Chim Acta 1994,221 109. 35 A. Del Zotto A. Mezzetti and P. Rigo J. Chem. SOC. Dulton Trans. 1994 2257. 36 T. Suzuki M. Rude K. P. Sirnonsen M. Morooka H. Tanaka S. Ohba F. Galsbol and J. Fujita Bull. Chem. SOC.Jpn. 1994,67 1013. 37 P. Barbaro C. Bianchini F. Laschi S. Midollini S. Moneti G. Scapacci. and P. Zanello Znorg. Chem. 1994 33 1622. 38 C. G. Arena F. Nicolo D. Drommi G. Bruno and F. Faraone J. Chem.SOC., Chem. Commun. 1994,2251. 39 T. Konno Y. Kageyarna and K. Okarnoto Bull. Chem. SOC.Jpn. 1994,67 1957 40 K. Okarnoto T. Konno and J. Hidaka J. Chem. SOC.,Dalton Trans. 1994 533.41 T. Konno K. Yonenobu J. Hidaka and K. Okarnoto Znorg. Chem. 1994 33 861. 42 T. Konno K. Okamoto and J. Hidaka lnorg. Chem. 1994 33 538. 43 Z. Guo U. Casellato G. Faraglia R. Graziani and S. Sitran J. Chem. SOC.,Dalton Trans. 1994 3231. The Coordination Chemistry of Open-chain Polydentate Ligands 32 1 Neutral TC(III) and Re@) complexes of the S,P-chelates HSCH,CH,PPh2 HSCH,CH(Me)PPh and 1,2-C,H4(SH)(PPh2) have been ~repared.~~,~~ 2 Tridentate Ligands N-donor Ligands.-Tris(pyrazo1yI)borates and Other Face-capping Ligands. These ligands are as popular as ever for preparing model complexes for metalloenzymes. In [{CU"(35)),(pq2 :q2-S,)] the symmetric disulfide bridge is structurally similar to the peroxide analogue.46 [Cu"(02)(36)] contains a side-on s~peroxide.~~ Resonance Raman spectra of [Cu(SR)(35)] analogues of the blue copper protein site were examined.48 In [Mn"'(0,)(3,5-'Pr2-pz)(35)] the side-on peroxide ligand is stabilized by hydrogen-bonding to the monodentate pyrazole ligand 3,5-Pri-pz (cf.ref. 179).4y The magnetic properties of the linear trinuclear complex [{ (35)Mn"'(p-OH)(pu-O,CMe),},Mn"] were e~amined.~' [Co"(O,)(37)] contains a side-bound superoxide whereas [(Co"(37)},(p-02)] contains a bridging per~xide.~' [Zn(OH)(38)] a carbon- ic anhydrase model cleaves esters amides and phosphate ester^.^ ,Fe(I1) complexes of (35)53 and Fe(Irr) complexes of (39)54 are models for non-haem iron proteins. [V(OR),(O)L] and [V(OR)Cl(O)L] [L = (39) (40)] are models for the bro-moperoxidase active site.55 The new ligands (41k(43) are analogues of the phenyl-substituted ligand (44) but the tethering chain between the pyrazolyl and phenyl rings prevents twisting.Several complexes were crystallographically characterized and the 'cone' and 'wedge' angles of the ligands were ~alculated.~~ The new ligand (45) is tridentate in [Co(45),] but unusually bidentate in [Mo(CO),(~~-CH,CM~CH,)(~~)].~~ The substituents on (46) and (47) have a similar sterically hindering effect to Bu' or Pr' substituents at the pyrazolyl C-3 position.58 Four-coordinate Zn(1I) and Cd(rr) complexes of (35) (48) and (49) were ~repared.~' In [CuCl2(H50)] (50) is bidentate with the pendant pyrazolyl group protonated; reaction with HCO affords [(cU(50)},(p-q2 :q2-C03)].60 [MoCl(ER)(NO)(51)] (E = 0,NH; R = Ph o-tolyl) have been prepared.,l The benzyl substituents at the 44 T.Maina A. Pecorale A. Dolmella G. Bandoli and U. Mazzi J. Chem. Soc. Dalton Trans. 1994 2437. 45 F. Tisato F. Refosco G. Bandoli C. Bolzati and A. Moresco J. Chem. SOC.,Dalton Trans. 1994 1453. 46 K. Fujisawa Y. Moro-oka and N. Kitajima J. Chem. Soc. Chem. Commun. 1994 623. 47 K. Fujisawa M. Tanaka Y. Moro-oka and N. Kitajima J. Am. Chem. Soc. 1994 116 12079. 48 D. Qu L. Kilpatrick N. Kitajima and T.G. Spiro J. Am. Chem. Soc. 1994 116 2585. 4g N. Kitajima H. Komatsuzaki S. Hikichi M. Osawa and Y. Moro-oka J. Am. Chem. SOC.,1994 116 11 596. N. Kitajima M. Osawa S. Imai K. Fujisawa Y. Moro-oka K. Heerwegh C. A. Reed and P. D. W. Boyd Inorg.Chem. 1994 33,4613. 51 0.M. Reinaud and K. H. Theopold Inorg. Chim. Acta 1994 116 6979. 52 M. Ruf K. Weis and H. Vahrenkamp J. Chem. Soc. Chem. Commun. 1994 135. 53 N. Kitajima N. Tamura H. Amagai H. Fukui Y. Moro-oka Y. Mizutani T. Kitagawa R. Mathur K. Heerwegh C. A. Reed C. R. Randall L. Que Jr. and K. Tatsumi J. Am. Chem. Soc. 1994 116 9071. 54 P.N. Turowski W.H. Armstrong S. Liu S.N. Brown and S.J. Lippard Inorg. Chem. 1994 33 636. " C.J. Carrano M. Mohan S. M. Holmes R. de la Rosa A. Butler J. M. Charnock and C. D. Garner Inorg. Chem. 1994 33 646. 56 A. L. Rheingold R. L. Ostrander B. S. Haggerty and S. Trofimenko Inorg. Chem. 1994 33 3666. 57 A. L. Rheingold B. S. Haggerty and S. Trofimenko J. Chem. Soc. Chem. Commun. 1994 1973. 58 D.D. Le Cloux M. C. Keyes M. Osawa V. Reynolds and W. B. Tolman Inorg. Chem. 1994,33 6361. 59 A. Looney A. Saleh Y. Zhang and G. Parkin Inorg. Chem. 1994 33 1158. 6o A. L. Rheingold B. S. Haggerty and S. Trofimenko Angew. Chem. Int. Ed. Engl. 1994 33 1983. M. Cano J. V. Heras A. Monge E. Pinilla C. J. Jones and J. A. McCleverty J. Chem. Soc. Dalton Trans. 1994 1555. 322 M. D. Ward (35) R' = R2= d (36) R' = Pr'; R2 = Bu' (37) R' = Me; R2= Pr' (41) R = H; X = (CH& (38) R' = Me; R2 = -4-dCeH4 (42) R = Me; X = (CH2)2 (43) R = H; X = CH2 (39) R' = R~= H (45)R = H; X = +=Cti- (40) R' = R2= Me (44) R' = Me; R2 = Ph (48) R' = H; R2= Bu' (49) R' = Me; R2 = But (50) R' = H R2= cyclohexyl (51) R' = R2 = 4-MeOCeH4 (53)R' = H; R2= Ph C-4 position of the pyrazolyl rings of (52) are oriented away from the metal in [Mo(CO),(N0)(52)] forming a shallow 'inverted bowl' with the B atom at the centre.The variation in stability constants of Group 2 metal ions with variously substituted tris(pyrazoly1)borates provides a basis ofmetal-ion dis~rimination.~~ [In(53)] contains three-coordinate I~(I);~~ In(m) complexes of a variety of poly(pyrazoly1)borates have also been e~amined.~~,~~ Some 'half-sandwich' complexes such as [YbIL,(49)] (where L is a neutral monodentate ligand)67 and [Yb{N(SiMe3),}(49)]68 have been prepared and the crystal structures of the redox-related pair [Yb(40),] and [Yb(40),][CF,S03] were determined (the Yb-N bond lengths increase by 7% on red~ction).~~ In [U"'I(40),] one ligand (40) is coordinated in the usual q3 manner but the second has one 'side-on' pyrazolyl ring in which the N=N bond coordinates like an alkene.70 b2 J.C. Jeffery S. S. Kurek J. A. McCleverty E. Psillakis R. M. Richardson M. D. Ward and A. Wlodarczyk J. Chem. Soc. Dalton Trans. 1994 2559. 63 Y. Sohrin M. Matsui Y. Hata H. Hasegawa and H. Kokusen Znorg. Chem. 1994 33 4376. 64 A. Frazer B. Piggott M. B. Hursthouse and M. Mazid J. Am. Chem. SOC. 1994 116,4127. 65 D. L. Reger S. S. Mason A. L. Rheingold and R. L. Ostrander Znorg. Chem. 1994 33 1803. D. L. Reger S. S. Mason L. B. Reger A. L. Rheingold and R. L. Ostrander Inorg. Chem. 1994,33 1811. 67 G. H. Maunder A. Sella and D.A. Tocher J. Chem. SOC.,Chem. Commun. 1994 2689. 68 L. Hasinoff J. Takats X.W. Zhang A.H. Bond and R.D. Rogers J. Am. Chem. SOC. 1994 116 8833. 69 G. H. Maunder A. Sella and D.A. Tocher J. Chem. SOC.,Chem. Commun. 1994 885. 'O Y. Sun R. McDonald J. Takats V. W. Day and T.A. Eberspacher Inorg. Chem. 1994 33,4433. The Coordination Chemistry of Open-chain Polydentate Ligands 323 Tris(triazo1- 1-y1)borate generally coordinates in the same way as tris(pyra-z~lyl)borates,~'-~~ but can also form oligomeric complexes via bridging of the triazole rings.74 [Cu(NCMe)L]+ [L = (54),(55)] are haemocyanin models reacting with 0 to form p-q2 :q2-peroxide-bridged binuclear CU(II) c~mplexes.~ Ternary CO(II) CU(II) and Zn(I1) complexes of (56),which mimic the carbonic anhydrase (CAH) binding site and the CAH inhibitor acetazolamide closely model real CAH- acetazolamide adducts.Other N-donor Ligands. Seven-coordinate complexes [ReX(terpy),12 + (X = OH C1 NCS) were studied by solution NMR spectrometry and X-ray ~rystallography.~~ [M(PPh,),(terpy)]+ (M = Cu Ag) are trigonal bipyramidal monomers both in solution and the solid state.78 The crystal structures of [MCl,(terpy)-xH,O] were determined for all the lanthanide~.~~ [Ag,(terpy),] + contains a linear Ag array with a helical arrangement of bridging terpyridine ligands." The same bridging mode also occurs" in helical [C~,(6,6"-Ph,terpy),]~+.Terpy can act as a fluxional bidentate ligand with a 'tick-tock' interconversion between equivalent bidentate coordination rn~des.'~,'~ + were isolateds4 as by-products during [RuC1(4'-X-terpy)(q2-4'-X-terpy)] the preparation of [Ru(4'-X-terpy),12 +.[M{4'-(4-pyridyl)terpy}J2+ (M = Fe Ru 0s) were prepared and the effects of protonation or methylation of the pendant 4-pyridyl group on their electrochemical and spectroscopic properties examined.85 4'-(Ferrocenyl)terpy and its homoleptic CO(II) Fe(II) and RU(II) complexes were prepared.86 Covalent attachment of a terpy to the meso position of porphyrins allows preparation of a (porphyrinb { Ru(terpy ),}-(porphyrin) triad which undergoes multistep photo-induced electron tran~fer.'~ Terpy has also been covalently attached to a thymidine residue; incorpor- ation of this into an oligonucleotide permits site-specific RNA cleavage by CU(II).~~ 2,6-Bis(benzimidazolyl)pyridinecan act as a neutral or mono-anionic tridentate donor to transition metal^'^^^^ and lanthanide~.~',~~ 2,6-Bis(pyrazol-l-yl)pyridines 7' C.Janiak J. Chem. SOC.,Chem. Commun. 1994 545. 72 C. Janiak Chem. Ber. 1994 127 1379. 73 K.-B. Shiu W.-N. Guo S.-M. Peng and M.-C. Cheng Inorg. Chem. 1994 33 3010. 74 C. Janiak and H. Hemling J. Chem. SOC.,Dalton Trans. 1994 2947. 75 W.E. Lynch D. M. Kurtz Jr. S. Wang and R.A. Scott J. Am. Chem. SOC.,1994 116 11 030. 76 G. Alzuet L. Casella A. Perotti and J. Borras J. Chem. SOC.,Dalton Trans. 1994 2347. 77 J. Rall F. Weingart D.M. Ho M. J. Heeg F. Tisato and E. Deutsch Inorg. Chem. 1994 33 3442. " E. W. Ainscough A.M. Brodie S. L. Ingham and J. M. Waters J.Chem. SOC.,Dalton Trans. 1994 215. 79 C. J. Kepert L. Weimin B.W. Skelton and A. H. White Aust. J. Chem. 1994 47 365. S. B. Silong J. D. Kildea W. C. Patalinghug B. W. Skelton and A. H. White Aust.J. Chem.,1994,47,1545. 81 E.C. Constable A. J. Edwards M. J. Hannon and P. R. Raithby J. Chem. SOC.,Chem. Commun. 1994 1991. 82 E. W. Abel K. G.Orrell A. G. Osborne H. M. Pain and V. sik J. Chem.SOC.,Chem. Commun. 1994,111. 83 E. W. Abel K.G. Orrell A.G. Osborne H. M. Pain V. Sik M. B. Hursthouse and K. M.A. Malik J. Chem. SOC.,Dalton Trans. 1994 3441. 84 E. C. Constable and A. M. W. Cargill Thompson Inorg. Chim. Acta 1994 223 177. 85 E. C. Constable and A. M. W. Cargill Thompson J. Chem. SOC.,Dalton Trans. 1994 1409. 86 E. C. Constable A. J. Edwards R. Martinez-Maiiez P.R. Raithby and A. M. W. Cargill Thompson J. Chem. SOC.,Dalton Trans. 1994 645. 87 A. Harriman F. Odobel and J.-P. Sauvage J. Am. Chem. SOC. 1994 116 5481. 88 J.K. Bashkin E. I. Frolova and U. Sampath J. Am. Chem. SOC. 1994 116 5981. 89 W. Linert M. Konecny and F. Renz J. Chem. SOC.,Dalton Trans. 1994 1523. S. Wang Y. Cui R. Tan Q. Luo J. Shi and Q. Wu Polyhedron 1994 13 1661. 91 J. Wang Y. Zhu S. Wang Y. Gao and Q. Shi Polyhedron 1994 13. 1405. 92 S. Wang Y. Zhu Y. Cui L. Wang and Q. Luo J. Chem. SOC. Dalton Trans. 1994 2523. 324 M.D. Ward may be bidentate and fluxional or tridentate;93 infac-[ReX(CO),L] [L = (57)-(59); X = halide] coordination of two pyridyl rings is preferred over pyridyl/pyrazolyl c~ordination.~~ Fe(rr) complexes of 2,6-bis(pyrazol-3-yl)pyridineshow spin-crossover behaviour which varies with the nature of the anion and extent of lattice hy- drati~n.~~,~~ The kinetics of electron transfer between the chiral complexes [Co"'L,] + [L = (60) or (61)] and other optically active complexes were mea~ured.~' [RuCl,(q-C,H4)(62)] catalyses the asymmetric cyclopropanation of 01efins.~~ R 0N N+ (57)R' = R2= H R' (62) btJ (58) R' = Me; R2= H co; -0,c (59) R' = H;R2= Me (SO)R=H (61) R=Me Co(rr) CU(II) and Zn(Ir) complexes of (63)99 and (64)'" were prepared.The reactivity of Cu(r) complexes of (65)-(69) with 0 was examined."' [CU(H,O),L]~' [L = bim-CH,NHCH,-bim; bim = 2-benzimidazolyl] catalyses the transesterifica- tion of a phosphate diester.'" [Co~Cl,(dpa),] [Hdpa = di(2-pyridyl)amine] is a quadruply bridged linear trinuclear complex in which each N atom of the dpa ligands coordinates to a different 1lleta1.I'~ The trinucleating bridging ligands (70) and (71) permit three-centre magnetic exchange in triangular molybdenum complexes.' O4 (63) R' = H;R2,R3 = 3,5-dimethylpyrazoCl-yl (64) R' = Et; R2,R3 = 3,5-dimethylpyrazol-l-yl (65) R' = Mr; RZ R3 = pyr (66) R' = CH2Ph; R2,R3 = pyr (67) R' = H R2 R3 = N-methylimidazol-2-yl R (68) R' = CH2Ph;R' R3 = N-methylimidazol-2-yl (70) R = 4-pyridyl (69) R' = H; R2= pyr; R3 = N-butylimidazol-2-yl (71) R = 4-hydroxyphenyl 93 E.W. Abel K. A. Hylands M. D. Olsen,K. G. Orrell A. G. Osborne V. Sik and G.N. Ward J.Chem.SOC. Dalton Trans. 1994 1079. 94 A. Gelling K.G. Orrell A. G. Osborne and V. Sik J. Chem. SOC.,Dalton Trans. 1994 3545. 95 K. H. Sugiyarto D.C. Craig A. D. Rae and H. A. Goodwin Aust. J. Chem. 1994 47 869. 96 T. Buchen P. Giitlich and H. A. Goodwin Inorg. Chem. 1994 33 4573. 97 K. Bernauer E. Fuchs and D. Hugi-Cleary Inorg. Chim. Acta 1994 218 73. 98 H. Nishiyama Y. Itoh H. Matsumoto S.-B. Parjk and K. Itoh J. Am. Chem. Soc. 1994 116 2223. 99 P. M. van Berkel W. L. Driessen R. Hamalainen J. Reedijk and U. Turpeinen Inorg. Chem. 1994,33 5920. I00 W. L. Driessen R. A. G. de Graaff F.J. Parlevliet J. Reedijk and R. M. de Vos Inorg. Chim. Acta 1994 216 43. 101 T.N. Sorrell M. L. Garrity J. L. Richards and P.S. White Inorg. Chim. Acta 1994 218 103.102 D. Wahnon R.C. Hynes and J. Chin J. Chem. Soc. Chem. Commun. 1994 1441. 103 EX. Yang M.-C. Cheng M.-S. Tsai and S.-M. Peng J. Chem. Soc. Chem. Commun. 1994 2377. 104 A. J. Amoroso,J. P. Maher J. A. McCleverty and M. D. Ward J.Chem.Soc. Chem. Commun. 1994,1273. The Coordination Chemistry of Open-chain Polydentate Ligands 325 Homoleptic 0,S and P-donor Ligands.-The dianionic complex (72) acts as a tripodal 0,-donor to p- and d-block metals as in [Co(72),I2- and [M(72),] (M = Ti Nb); its ligand-field strength is less than that of water.lo5 Likewise complexes of (73) with Pb(II) Sn(n) Ga(m) and In(m) have been prepared. 106,107 [B(CH,SMe),]-(L-) acts as a tripodal S donor in [Mo(CO),L]- and [FeL,]; its ligand-field strength is weaker than l,4,7-trithiacyclononane.1'8 CH(PPh,) and its anion [C(PPh,),]- act as bridging ligands in binuclear complexes coordinating two P donors to one metal and one to the other.'" The crystal structure and reactivity of [RhClL] [L = PhP(CH,CH,PPh,),] were exam- ined; this ligand can also bridge."' Complexes of the anionic P,-donors R,PCH,CH,(P-)CH,CH,PR (R = Me Et) with CO(I),'" Zr(Iv),' l2 and Cr(111)~'~ were prepared.The amphiphilic tripodal ligands RC(CH,PPh,) [R = Bun (CH,),CH=CH,] and their complexes [Fe(NCMe),L][BF,], were prepared.' l4 Mixed N,O-donor Ligands.-In [M"'(74),-NaCl] (M = Lu Y) the lanthanide is seven- coordinate by N,O-chelation from each ligand and the chloride; the remaining N,(l(-0)3 binding pocket accommodates the Na' ion.The complex therefore displays cooperative cation/anion binding.' [Cu~(OMe),(C10,)(p4-0,)(75),][C10,]con-tains a peroxide ligand centrally bound to four CU(II) centres.'16 The 0x0-centred tetrahedral clusters [C~~(p~-X),(p~-O)(76)~] (X = Br benzoate) display antifer- romagnetic exchange.' Vanadium(1v) and (v) complexes of a series of O,N,O-tridentate chelates all based on a salicylaldimine core with an additional pendant 0-donor have been 10s U. Kolle T. Ruther N. Le Narvor U. Englert and W. Klaui Angew. Chem. Int. Ed. En& 1994,33,991. 106 D. L. Reger Y. Ding A. L. Rheingold and R. L. Ostrander Inorg. Chem. 1994 33 4226. 107 D. L. Reger Y. Ding A. L. Rheingold and R. L. Ostrander Polyhedron 1994 13 3053. 108 P. Ge B. S. Haggerty A.L. Rheingold and C.G.Riordan J. Am. Chem. SOC.,1994 116 8406. 109 E. J. Fernandez M. C. Gimeno P. G. Jones A. Laguna M. Laguna and E. Olmos J. Chem. SOC.,Dalton Trans. 1994 2891. 110 S. A. Westcott G. Stringer S. Anderson N. J. Taylor and T. B. Marder Inorg. Chem. 1994 33 4589. 111 P.G. Edwards P.W. Read M. B. Hursthouse and K. M. A. Malik J.Chem.SOC.,Dalton Trans. 1994,971. 112 A. A. Danopoulos P.G. Edwards M. Harman M. B. Hursthouse and J. S. Parry J. Chem. SOC.,Dalton Trans. 1994 977. 113 A. R. H. Al-Soudani A. S. Batsanov P. G. Edwards and J. A. K. Howard J. Chem. Soc. Dalton Trans. 1994,987. 114 A. Muth A. Asam G. Huttner A. Barth and L. Zsohai Chem. Ber. 1994 127 305. 115 M. P. Hogerheide J. T. B. H. Jastrzebski J. Boersma W. J. J. Srneets A.L. Spek and G. van Koten Inorg. Chem. 1994 33 4431. 116 J. Reim and B. Krebs Angew. Chem. Znt. Ed. Engl. 1994 33 1969. 117 S. Teipel K. Griesar W. Haase and B. Krebs Inorg. Chem. 1994 33,456. 326 M.D. Ward studied.' ' 8-1 In [Mn1"(77),]Br (77) acts as an O,N,N-donor with the bromide hydrogen-bonded to the two pendant hydroxyethyl arms.'22 The chiral (D or L) ligand (78) made by condensation of salicylaldehyde with. the amino group of histidine coordinates stereospecifically' 23 to (U0,}2t.. Lanthanide (111) complexes of (79) and and [ML2]"+ [M = Fe(m) CO(III),n = 1; M = Ni(rI) n = 0; L = (79) (S1)]"5 were prepared. [Mn"'L,]- [L = (82k(85)] are made water-soluble by the pendant sulfonate groups and all display Mn(III)/Mn(Iv) couples.' 26 Detailed 'H and I3CNMR spectroscopic studies were performed on Ni(u) Pd(II) and Pt(II) complexes of a series of tridentate O,N,O-donors based on azo-phenols such as (86).'27 ,fuc-[Mn1"(87),]+ was prepared.' 28 The crystal structure of [Mn"'(88),] -shows a Jahn-Teller tetragonal compression rather than the more usual elongation.' 29 [{Zn(N0,)(89)},] and [(Cd(N0,)(90)),] are phenolate-bridged dimer~.'~' [Mny(91),][C104] contains a linear Mny chain with two phenolate bridges between each pair of metals and displays ferromagnetic e~change.'~' The chiral ligand /=NR HOQR' 1 HO (H77) R = (CH&NH(CH&OH (H278) R = histidinyl HO d=' (H79) R' = pyr; R2 = H (HBO) R' =Pquinolinyl; R2 = H R2 (H81) R' = py; R2= CI (HS) X = N; R' = R2= S03H R2Wfh' (HS) X = CH; R' = R2 = S03H (H*) X = CH; R' = H; R2 = S03H (H&) X = CH; R' = S03H; R2 = H (H&) X=N; R' = R2= CI w (H87) R' = CH2NMe2; R2 = H ,NH 0 (He) R' = CO2H; R2= CI Me' (H89) R' = py; R2= H 'NH2 118 J.Chakravarty S. Dutta A. Dey and A. Chakravorty J. Chem. SOC. Dalton Trans. 1994 557. 119 X. Wang X. M. Zhang and H.X. Liu Inorg. Chim. Acta 1994,223 193. 120 1. Cavaco J. C. Pessoa D. Costa M. T. Duarte R. D. Gillard and P. Matias J. Chem.SOC.,Dalton Trans. 1994 149. 121 J. Dai S. Akiyama M. Munakata and M. Mikuriya Polyhedron 1994 13 2495. 122 M. Mikuriya H. Takebayashi and K. Matsunami Bull. Chem. SOC.Jpn. 1994,67 3128. 123 S. Panchanan R. Hamalainen and P. S. Roy J. Chem. SOC.,Dalton Trans.1994 2381. 124 W. Bo Y. Shihan and J. Daosen Polyhedron 1994 13 2089. 125 J. R. Dilworth S.D. Howe A. J. Hutson J. R. Miller J. Silver R. M. Thompson M. Harman and M. B. Hursthouse J. Chem. SOC. Dalton Trans. 1994 3553. 126 S. Dutta and A. Chakravorty Polyhedron 1994 13 1811. 127 J. Abildgaard P. E. Hansen J. Josephsen and A. Lycka Inorg. Chem. 1994 33 5271. 128 S. Shukla P. K. Bharadwaj J. V. Hall and K. H. Whitmire Polyhedron 1994 13 2387. 129 M. S. Shongwe M. Mikuriya E. W. Ainscough and A.M. Brodie J. Chem. SOC.,Chem. Commun. 1994 887. 130 S. S. Tandon S. Chander L. K. Thompson J. N. Bridson and V. McKee Inorg. Chim. Acta 1994,219,55. 131 J.C. Jeffery P. Thornton and M.D. Ward Inorg. Chem. 1994 33 3612. The Coordination Chemistry of Open-chain Polydentate Ligands But But i i (92) has two regioisomers (different sites of attachment of the Me group) with two enantiomers each; the solid state and solution structures of [Ni(N,)(92)] and [Ni(py)(92)] were determined.' 32 The Ti(rv) complex of chiral ligand (93) catalyses + enantioselective aldol reactions.' 33 [M"(94),] (M = Ti V Ge Sn) undergo ferromag- netic exchange between the two S = 1/2 ligand radicals; the role of the metal orbitals in mediating the exchange process was disc~ssed.'~~ Similarly in [Rh(95)Cp*] 2+ the two unpaired spins at the ligand termini undergo antiferromagnetic exchange.' 35 Mixed N,S- N,P- and N,C-donor Ligands.-Pyridine-2,6-bis(thiocarboxylate) is an S,N,S-donor in planar Pd(Ir) complexes.' 36 H,N(CH,),S(CH,),NH may act either as a conventionalfac-N,S,N donor or as a deprotonated metallated N,C,N-donor in Co(11r)complexe~.'~~ Mn(I1) complexes of HS(CH,),NH(CH,),NH (x = 2 3) and HS(CH2),NH(CH,),(2-pyridyl) (x = 1 2) are S-bridged oligomers or polymers displaying weak antiferromagnetic exchange.' 38 MeN(CH,CH,EH) (E = S Se; H,L) form octahedral [Ni"L,] and planar complexes [Ni;L,] with a NiF(p-E) core which may be oxidized'39 to [Ni2L2]'+.Ligand (96) acts as a bidentate bridge to Pd(rr) and Pt(rr) (N-donor to one and P-donor to the other),'40 and as a tridentate bridge (N-donor to one metal and N,P-chelating to the other) in [{Ir(cod) Cl}2{p-(96)}].141 In contrast 6-(diphenylphos- phino)-2,2'-bipyridine (dpbp) coordinates as a bipy to one metal and a monodentate P-donor to the other in [Cu:L2(p-dpbp),l2+ (L = MeCN pyridine) which perform electrocatalytic reduction of C0,.142 2,9-Diphenylphenanthroline (Hdpphen) acts as a cyclometallating (via a phenyl ring) N,N,C-donor in [Au"'Cl(dpphen)] ,which is luminescent in fluid solution and a + strong photooxidant.'43 Other Mixed-donor Ligands.-The crystal structures and spectroscopic properties of 132 J.-P.Costes F. Dahan J.-M. Dominguez-Vera J.-P. Laurent J. Ruiz and J. Sotiropoulos Inorg. Chem. 1994,33 3908. 133 E. M. Carreira R.A. Singer and W. Lee J. Am. Chem. SOC.,1994 116 8837. 134 S. Bruni A. Caneschi F. Cariati C. Delfs A. Dei and D. Gatteschi J. Am. Chem. Soc. 1994 116 1388. 135 H. Oshio A. Ohto J. Fujisawa T. Watanabe T.Ho and K. Isobe Chem. Lett. 1994 2353. 136 P. Espinet C. Lorenzo J.A. Miguel C. Bois and Y. Jeannin Inorg. Chem. 1994 33 2052. 137 P. Kofod E. Larsen J. Springborg S. Larsen T. A. Larsen R. J. Geue and G. H. Searle Aust. J. Chem. 1994 47 111. 138 M. Mikuriya F. Adachi H. Iwasawa M. Handa M. Koikawa and H. Okawa Bull. Chem.SOC.Jpn. 1994 67 3263. 139 S. B. Choudhury M. A. Pressler S. A. Mirza R. 0.Day and M. J. Maroney Inorg. Chem. 1994,33,4831. 140 S. Lo Schiavo G. De Munno F. Nicolo and G. Tresoldi J. Chem. SOC.,Dulton Trans. 1994 3135. 141 S. Lo Schkavo M. Grassi G. De Munno F. Nicolo and G. Tresoldi Inorg. Chirn. Acta 1994 216 209. 142 R. J. Haines R. E. Wittrig and C. P. Kubiak Inorg. Chem. 1994 33 4723. 143 C.-W. Chan W.-T. Wong and C.-M.Che Inorg. Chem. 1994 33 1266. 328 M.D. Ward OH (H297) R=NH2 (96) (H298) R=NHPh (H299) R=SMe (H2100) R = SCHZPh (H101) (102) (103) R'=R2=H (104) R' R2 = fused phenyl ring [SnR,(97)] (R = Ph Me) were determined.'44 The magnetic EPR spectroscopic and electrochemical properties of Mn(II1) and Mn(1v) complexes of (97)-( 100) were examined.'45 fac-[M(101),] (M = Co Cu) were prepared.'46 Complexes of a variety of O,N,P-donors (phenol/imine/phosphine) with various first second and third-row transition metals have been prepared and e~amined.'~~*'~~ Ph,P(CH,),SCH,CO,H (Hpso) and Ph,P(CH2),SCH2(2-pyridyl) (psn) are P,S,O- and P,S,N-donors respectively; [Ni(pso),] undergoes a reversible oxidation to Ni(III) whereas [Ni(psn),12 + displays a four-membered redox series Ni(o)-Ni(111).48 The tripodal P,P,O-donor CH,C(CH,PPh,),(CH,OH) is tridentate in [Mn(CO),L] + but only P,P-bidentate in [MnBr(CO),L] and [M(CO),L] (M = Cr Mo W).14' 3 Tetradentate Ligands N-donor Ligands.-Ligands with Two Bidentate Compartments. The magnetic proper- ties of 2,2'-bipyrimidine-bridged binuclear and oligomeric complexes continue to be of interest' 50-152 and 5,5'-R2-2,2'-bipyrimidine(R = But n-hexyl) may allow prepara- tion of soluble polymeric complexes.' s3 Binuclear and polynuclear complexes of (102)-(104) based on photoactive chromophores continue to be intensively st~died."~-'~~ [{(NH3)4Ru},(105)]2"+ (n = 1 2) were prepared; the binuclear 144 J. S. Casas A. Sanchez J. Sordo A. Vazquez-Lopez E.E. Castellano J. Zukerman-Schpector M. C. Rodriguez-Argiielles and U. Russo Znorg. Chim. Acta 1994 216 169. 14' R. Mukhopadhyay S. Bhattacharjee and R. Bhattacharyya J. Chem. Soc. Dalton Trans. 1994 2799. E. Bouwman and J. Reedijk Inorg. Chim. Acta 1994 215 151. 14' K. K. Hii S.D. Perera and B. L. Shaw J. Chem. Soc. Dalton Trans. 1994 3589. T. L. James D. M. Smith and R.H. Holm Inory. Chem. 1994 33 4869. 149 T.-Y. Hsieh M.-C. Cheng S.-M. Peng and S.-T. Liu J. Chem. Soc. Dalton Trans. 1994 3499. "" G. De Munno M. Julve F. Lloret J. Faus and A. Caneschi J. Chem. Soc. Dalton Trans. 1994 1175. G. De Munno C. Bazzicalupi J. Faus F. Lloret and M. Julve J. Chem. Soc. Dalton Trans. 1994 1879. I. Castro J. Sletten L. K. Glaerum F. Lloret J. Faus and M. Julve J.Chem. Soc. Dalton Trans. 1994 2777. '" M. J. Crossley S. Gorjian S. Sternhell and K. M. Tansey Aust. J. Chem. 1994 47 723. lS4 L. M. Vogler C. Franco S. W. Jones and K. J. Brewer Inorg. Chim. Acta 1994 221 55. 15' V. W.-W. Yam V. W.-M. Lee and K.-K. Cheung J. Chem. SOC. Chem. Commun. 1994 2075. S. M. Molnar G. Nallas J.S. Bridgewater and K. J. Brewer J. Am. Chem. Soc. 1994 116 5206. S. Serroni,A. Juris S. Carnpagna M. Venturi G.Denti,and V. Balzani J. Am. Chem. Soc. 1994,116,9086. The Coordination Chemistry of Open-chain Polydentate Ligands N-N (1 10) R = CH2pyr (111) R=pyr (1 12) R =2-benzirnidazolyl (106) X = CH2CH2 (107) x = (CH2)lO (106) X = CHdH(CH2)8NHCH2 (109) X -CH2NH(CH2)3N(Me)(CH2)3NHCH2 complex has an accessible mixed-valence RU(II)/RU(III) state which undergoes inter- valence charge transfer.lS8 Photophysical studies on [((4,7-Me2Phen),Ru"}{p-( 106)){Rh1"(4,4'-Me2bipy),)] + show the presence of several different types of photo-induced intercomponent intera~ti0n.I~~ In contrast the larger separation between the bipy sites means that there are no intercomponent interactions in [(R~(bipy),)~(p-L)]"+ [L = (107t(109)].160A wide variety of ligands with thiadiazole or pyridazine bridging groups of which (1lot(114) are representative was used to prepare binuclear CU(II) complexes with additional halide or azide bridges whose structures and magnetic properties were studied in detail and correlated.161,162 Mono- and binuclear complexes of (115) with (M(NN),) fragments in the binding sites [M = Ru(II),OS(II),Rh(II1); NN = bipy phen] have strongly pH-dependent spectroscopic and redox properties due to the acidic benzimidazole pr0t0ns.l~~ Spectroelectrochemical studies of [(Ru(bipy),},(p-L)],' [L = (116) (117)] show strong metal-metal interactions due to effective Ru(dntL(n*) 0ver1ap.I~~ CO(II) and CU(II) complexes of (118) may have one bridging ligand as in [(dmf)C1,Cu(p-(l18))CuCl,(dmf)] or two e.g.[ClCu{p-(l18)),C~C1]~ + in which the ligands are parallel and stacked.165 Many bis(bidentate) ligands have been specifically designed to form helicates. The triple helix [Coy( 1 19),16+ was resolved and both enantiomers structurally character- ized,'66 and the CO(II)/~O(III) couples of [Co"L,]"+ [L = (1 19) (120)] are sensitive to slight distortions introduced by the pyridyl methyl groups.'67 [Fe2(121),]"+ is also 158 R.R. Ruminski D. Freiheit D. Serveiss B. Snyder and J. E. B. Johnson Inorg. Chim. Acta 1994,224,27. 159 M.T. Indelli C. A. Bignozzi A. Harriman J. R. Schoonover and F. Scandola J. Am. Chem. Soc. 1994 116 3768. 160 I. Sasaki M. Imberdis A. Gaudemer B. Drahi D. Azhari and E. Amouyal New. J. Chem.,1994,18,759. 161 S.S. Tandon L. Chen L. K. Thompson and J.N. Bridson Inorg. Chem. 1994 33 490. 162 S. S. Tandon L. K. Thompson M.E. Manual and J. N. Bridson Inorg. Chem. 1994.33 5555. 163 M. Haga T. Ano T. Tshizaki K. Kano K. Nozaki and T. Ohno J. Chem. Soc. Dalton Trans.,1994,263. 164 M. Haga M. M. Ali S. Koseki A. Yoshimura K. Nozaki and T. Ohno Inorg.Chim. Acta 1994,226 17. 165 S. S. Tandon L. K. Thompson J.N. Bridson and J.C. Dewan Inorg. Chem. 1994 33 54. 166 L. J. Charbonniere G. Bernardinelli C. Piguet A. M. Sargeson and A. F. Williams J. Chem. Soc. Chem. Commun. 1994 1419. 167 C. Piguet G. Bernardinelli B. Bocquet 0. Schaad and A. F. Williams Inorg. Chem. 1994 33,4112. 330 M.D. Ward (116) X=NH (117) X=S (119) R'=Me,R2=H (120) R' = H R2 = Me (125) X =-CH=CH- Y = CH2CH2;R = Me (126) X = nothing; Y = CH,CH,; R = Me (1 27) X =-CH=CH-; Y = 1,3-C6H4;R = 4-C&40H triple helica1.16* Ligands (122)-(124) form mixtures of helical and 'face-to-face' achiral binuclear complexes with Zn(11)'69 and CU(I).' 70 The photophysical properties of + [Cu,L,] [L = (1 29 (126) and 5,5',3",5"'-tetramethylquaterpyridine]were exam- ined.17' The helical complex [Cu2(127),I2 + reacts with ICH,(CH,0CH2),CH21 to D.Zurita P. Baret and J.-L. Pierre New. J. Chem. 1994 18 1143. A. Bilyk M. M. Harding P. Turner and T. W. Hambley J. Chem. SOC.,Dalton Trans. 1994 2783. 170 A. Bilyk and M. M. Harding J. Chem. SOC.,Dalton Trans. 1994 77. 17' A. Juris and R. Ziessel Znorg. Chim. Acta 1994 225 251. The Coordination Chemistry of Open-chain Polydentate Ligands 33 1 give high yields of a 'trefoil knot'.'72 The crystal structures of helicates [Cu,(128),] [PF,] [four-coordinate Cu(r)] and [Ni,(OAc),( 128),][PF,] [six-coordinate Ni(rr)] were determined.'73 Face-capping Tripodal Ligands. Na+ and Li + complexes of tris(2-pyridylmethy1)amine (129) have been prepared.'74 Complexes of (129) with an Fey'(p-0) core have been ~repared,'~~.'~~ acts of which [{Fe'1'(129)),(p-O)(H,0)(OH)]3+as a source of hydroxide and can hydrate acetonitrile.' 76 [{Cu(129))(p-O){ Fe"'(porph)}] (where + porph denotes a porphyrin dianion) is a model for the cytochrome c oxidase active [{Fe"'(130)),(p-O)(p-OH)]3~is the first example of a complex with an Fey'(p-O)(p-OH) core.' 78 In [Cu"(O,)( 131)] + the superoxide ligand is stabilized by (i) encapsulation within the tris(pivaloy1) cavity and (ii) hydrogen-bonding to the NH protons (cf.ref. 49).'79 The ligand series (129) and (132)-(134) contains varying numbers of pyridyl and quinolinyl donors; the structures properties and reactivities of their CU(I) and CU(II) complexes were studied.' 80,181 Cu(r) complexes of (135) and (136) which contain biologically relevant imidazole donors form Cu"(p-0; -) adducts at -80 OC.I8 The EPR spectra electrochemistry and structures of CU(II) complexes of (137) were deterrnir~ed.'~~ is a model for methane [{Fe"'(137)}2(p-O)(H20)2]4+ monooxygenase and catalyses oxygenation of alkanes by BU'OOH.'~~ Trigonal SMe I' 'I 'N (129) R=H SMe (130) R= Me (131) R= NHC(O)BU' (135)X =l;y=2 (138)R=H (132)x = 1;)' =2 (136)X = 2;y = 1 (139)R=Me (133)x = 2;y = 1 (137) X = 3;y = 0) (140)R = CH2Ph (134) x =3;y =O C.0.Dietrich-Buchecker J.-P. Sauvage A. De Cian and J. Fischer J. Chem.Soc. Chem. Commun. 1994 223 1. 173 E. C. Constable M. J. Hannon A. J. Edwards,and P. R. Raithby J. Chem.Soc.,Dalton Trans.1994,2669. 174 S. K. Brownstein P.-Y. Plouffe C. Bensimon and J. Tse Inorg. Chem. 1994 33 354. A. Hazell K.B. Jensen C.J. McKenzie and H. Toftlund Inorg. Chem. 1994 33 3127. E.C. Wilkinson Y. Dong and L. Que Jr. J. Am. Chem. Soc. 1994 116 8394. 177 K.D. Karlin A. Nanthakumar S. Fox N.N. Murthy N. Ravi B.N. Huynh R. D. Orosz and E. P. Day J. Am. Chem. SOC. 1994 116,4753. "' Y. Zang G. Pan L. Que Jr. B.G. Fox and E. Miinck J. Am. Chem. Soc. 1994 116 3653. M. Harata K. Jitsukawa H. Masuda and H. Einaga J. Am. Ckem. Soc. 1994 116 10817. N. Wei N. N. Murthy Q. Chen J. Zubieta and K. D. Karlin Znorg. Chem. 1994 33 1953. lS1 N. Wei N. N. Murthy and K. D. Karlin Inorg. Chem. 1994 33 6093. lS2 N. Wei N. N. Murthy Z. Tyeklar and K. D. Karlin Inorg.Chem. 1994 33 1177. lE3 S. Chen J. F. Richardson and R. M. Buchanan Inorg. Chem. 1994 33 2376. R. M. Buchanan S. Chen J.F. Richardson M. Bressan L. Forti A. Morvillo and R.H. Fish Znorg. Chem. 1994 33 3208. 332 M.D. Ward + bipyramidal [ZnXL] [L = (138b(140); X = nitrate halide] were prepared;ls5 biologically relevant ligands such as amino acids and salicylic acid may also coordinate to the fifth site of the (ZnL)*+ fragment.’86 N(CH,CH,NHAr) form trianions L3 -by loss of the amine protons; an extensive series of trigonal bipyramidal Mo and W complexes was prepared such as [MClL] [MNL] and [Mo(=NMe)L] +.N activation via a p-N dimer is possible.’87 MO(IV) complexes of the trianion of N(CH,CH,NHSiR,) behave similarly.’ 88 Other N-donor Ligands.Potentials of the Ru(II)/Ru(III) Ru(III)/Ru(Iv) and + Ru(Iv)/Ru(vI) couples of trans-[Ru(H,O),(qp)l2 (qp = 2,2’:6’,2”:6”,2”’-quater-pyridine and its 5,5’,3”,5’”-tetramethyl derivative) are pH dependent due to the formation of hydroxo and 0x0 ligands.ls9 Ligand (141) stabilizes a trans geometry in [RuXY(141)]”+ (X Y = a variety of monodentate ligands) whose UV/VIS spectro-scopic properties were studied,’” and [ReV(=NPh)(OEt)( 141)] which undergoes three reductions according to electrochemical studies’ 91 [contrast these with the helical binuclear CU(I) complexes of the similar ligand (1 26)]. Extensive series of oxo- and/or carboxylato-bridged binuclear complexes of Fe(n1) with (142k(144)192 and Mn(rrr) and Mn(rv) complexes with (142) (143) and (145)’93,’94 have been prepared and studied in detail (crystal structures magnetism electrochemistry).Due to its high degree of preorganization and rigidity ligand (146) binds metals with higher stability constants and shows greater size-based selectivity for metal ions than the macrocycle ~yc1am.l~~ and [CrVN(147)]197 both have square pyramidal [C~(H,0)(147)]’~~ structures. [Ni(H20),(148)]C1,’98 and CU(II) complexes of (149) and (150) were prepared; the OMe and SMe groups of the latter two ligands form weak bridges to adjacent CU(II) centres.’ 99 0-,S- and P-donor Ligands.-[NH,][Fe,L,] [L = (151) (152)] are tetrahedral mixed-valence Fe’,”Fe” species with a bridging ligand along each edge of the complex anion; the ammonium cation is trapped in the central cavity.200 Binuclear CU(II) complexes of (153)201 and polymeric Cr(I1I) complexes of (154) and (155)202were 185 R.Gregorzik U. Hartmann and H. Vahrenkamp Chem. Ber. 1994 127 2117. lR6 U. Hartmann R. Gregorzik and H. Vahrenkamp Chem. Ber. 1994 127 2123. M. Kol R. R. Schrock R. Kempe and W. M. Davis J. Am. Chem. SOC. 1994 116,4382. K.-Y. Shis R.R. Schrock and R. Kempe J. Am. Chem. SOC.,1994 116 8804. C.-W. Chan T.-F. Lai and C.-M. Che J. Chem. Soc. Dalton Trans. 1994 895. I9O M.A. Masood B. P. Sullivan and D. J. Hodgson Inorg. Chem. 1994 33 4611. 19’ M. A. Masood B. P. Sullivan and D.J. Hodgson Inorg. Chem. 1994 33 5360. 19’ N. Arulsamy P. A. Goodson D. J. Hodgson,J. Glerup and K. Michelsen Inorg. Chim. Acta 1994,216,21. ‘93 N. Arulsamy J.Glerup A. Hazell D. J. Hodgson C. J. McKenzie and H. Toftlund Inorg. Chem. 1994,33 3023. 194 J. Glerup P.A. Goodson A. Hazell R. Hazell D. J. Hodgson C. J. McKenzie K. Michelsen U. Rychlewska and H. Toftlund Inorg. Chem. 1994,33,4105. 19’ G. D. Hosken and R. D. Hancock J. Chern. SOC. Chem. Commun. 1994 1363. 196 M. Ray R. Mukherjee J.F. Richardson M. S. Mashuta and R.M. Buchanan J. Chem. SOC. Dalton Trans. 1994 965. 19’ N. Azuma T. Ozawa and S. Tsuboyama J. Chem. SOC.,Dalton Trans. 1994 2609. 19’ M. A. Masood and D.J. Hodgson Inorg. Chem. 1994 33 3038. 19’ S. Ameerunishka and P.S. Zacharias Polyhedron 1994 13 2327. *O0 R. W. Saalfrank R. Burak A. Breit D. Stalke R. Herbst-Irmen J. Daub M. Porsch E. Bill M. Muther and A.X. Trautwein Angew. Chem. Int.Ed. Engl. 1994 33 1621. 201 Y.Y. Lim W. Chen L. L. Tan X.Z. You and T. M. Yao Polyhedron 1994 13 2861. 202 R. D. Archer A. Lauterbach and V. 0.Ochaya Polyhedron 1994 13 2043. The Coordination Chemistry of Open-chain Polydentate Ligands (1 42) X = CHzCH2; R = H (143) X = (CH& R = H (144) X = CH2CH2; R = Me (145) X = 1,2cyclohexyl;R = Me aN" NH Me (149) R = OMe (150) R = SMe RO C02R C02R OR prepared. Malonate forms a polymeric network with L~(III).~'~ Citrate also acts as a bis(bidentate) bridge permitting ferromagnetic exchange in its bis-Fe(II1) complex.204 Ligand (156) holds two carboxylate groups ideally preorganized to facilitate formation of (Fe',"(p-O)(p-O,CR),) complexes with a variety of terminal ancillary ligands.,05 In [(Ru(bipy),),(,~-L)]~+ [L = (157) (158)l the bridging ligands are the oxidized (bis-semiquinone) forms of the parent dicatechols; the redox-active bridging ligands 203 F.Marrot and J.-C. Trombe Polyhedron 1994 13 1931. 204 I. Shweky A. Bino D. P. Goldberg and S.J. Lippard Inorg. Chem. 1994 33 5161. 205 S. P. Watton A. Masschelein J. Rebek Jr. and S. J. Lippard J. Am. Chem. Soc. 1994 lJ6 5196. 334 M.D. Ward change reversibly from planar to twisted conformations in different oxidation states so the complexes are prototypical molecular switches.206 The electrochemical properties of a variety of M~(II) complexes MO(III),and MO(IV) of HS( 1,2-C6H,)SCH2CH,S( 1 ,2-C6H4)SH with ancillary ligands such as CO PMe, NO halides NH; and thiolates were examined.207 1,2,4,5-(Ph2P),C,H acts as a bis(bidentate) bridging ligand in binuclear and polymeric complexes of Ni(ii) Pd(Ir) and Pt(i1); metal-metal interactions are ~eak.~~~~~~~ Ph2PCH2(CH,PPhCH2),CH2PPh2 acts as a bis(bidentate) bridge in binuclear Pt(I1) complexes.210 V( -I) complexes of the tetradentate tripodal ligands pp3 and P[(CH,),PR,] (R = Me Et) and some tridentate analogues bind N,.," Mixed N,O-DonorLigands.-'Men'-type Complexes.Deoxygenation2 of [VO( 159)] affords [V'"(l 59)12+ and [((159)V}2(p-O)]2+'; the magnetic properties of an extensive series of 0x0-bridged chains such as [V( 159)0V( 159)0V( 159)0V( 159)] were + studied.,' [VO( 160)] exists as green (mononuclear) and orange (polynuclear linear chain) forms which are inter~onvertible.~'~ [{v(159))2(p-F)]+ was prepared and its crystal structure determined.215 Carboxylate ions may chelate to Mn"'-salen complexes as in [Mn( 161)(02CBu)] or may bridge,216 as in [(Et0H)(159)Mn(p-O2CBu)Mn( 159)(H20)] + [(Mn"( 16l)},(p-O),] may be protonated at the 0x0 bridges giving Mn"(p-O)(p- 0H)Mn'" and MnlV(p-OH),Mn'V cores which weakens the antiferromagnetic coupling and slightly alters the structure^.^'^ [{Mn"'(H,0),(162)}2]2+ with a Mn,(p-H,O) core is a model for photosystem I1 and contains a cleft which allows approach of reagents to the dimetal centre.218 [Mn"'ClL] [L = (163) (164)] are epoxidation catalysts whose diastereoselectivity may be modified by the presence of chiral quaternary ammonium salts.21 [Mn"(H,O),( 165)].(dmso) forms strongly hydrogen-bonded dimers in its crystals.220 The CO(II)/CO(III) redox potentials of a series of [Co(salen)] derivatives depend on the extent of tetrahedral distortion at the metal induced by bulky phenyl substitu- ents.,,' Electrochemical properties of Ni(i1) complexes of (166t(171) have been 206 L.F. Joulie E. Schatz M. D. Ward F.Weber. and L. J. Yellowlees J.Chem.SOC.,Dalton Trans. 1994,799. 201 D. Sellmann H.-J. Kremitzl and F. Knoch Znorg. Chim. Acta 1994 225 163. 208 P.-W. Wang and M.A. Fox Inorg. Chem. 1994,33 2938. 209 P.-W. Wang and M.A. Fox Inorg. Chim. Acta 1994 225 15. 210 K. Dillinger W. Oberhauser C. Bachmann and P. Briiggeller Inorg. Chim. Acta 1994 223 13. 211 H. Gailus C. Woitha and D. Rehder J. Chem. SOC.,Dalton Trans.1994 3471. 212 E. Tsuchida K. Yamamoto K. Oyaizu N. Iwasaki and F. C. Anson Inorg. Chem. 1994 33 1056. 213 D. L. Hughes U. Kleinkes G. J. Leigh M. Maiwald J. R. Sanders and C. Sudbrake J. Chem.SOC.,Dalton Trans. 1994 2451. 214 M. Kerjima K. Nakajima M. Tsuchimoto M. Tanaka T. Suzuta Y. Yoshikawa and J. Fujita Chem. Lett. 1994 949. 215 S. A. Fairhurst D. L. Hughes G. J. Leigh J. R. Sanders and J. Weisner J.Chem.SOC.,Dalton Trans. 1994 259 1. 216 N. Aurangzeb C. E. Hulme C.A. McAuliffe R.G. Pritchard M. Watkinson M. R. Bermejo and A. Sousa J. Chem. SOC.,Chem. Commun. 1994 2193. 217 M. J. Baldwin T. L. Stemrnler P. J. Riggs-Gelasco M. L. Kirk J. E. Penner-Hahn and V. L. Pecoraro J. Am. Chem. SOC.,1994 116 11 349. 218 N. Aurangzeb C.E. Hulme C.A.McAuliffe R.G. Pritchard M. Watkinson M.R. Berrnejo A. Garcia-Deibe M. Rey J. Sanmartin and A. Sousa J. Chem. SOC. Chem. Commun. 1994 1153. 219 S. Chang J. M. Galvin and E.N. Jacobsen J. Am. Chem. SOC. 1994 116 6937. 220 M. Bermejo A. Garcia-Deibe J. Sanmartin A. Sousa N. Aurangzeb C. E. Hulme C. A. McAuliffe R. G. Pritchard and M. Watkinson J. Chem. SOC.,Chem. Commun. 1994 645. 221 M. Hirotsu M. Kojima K. Nakajima S. Kashino and Y. Yoshikawa Chem. Lett. 1994 2183. The Coordination Chemistry of Open-chain Polydentate Ligands R d (H2159) X = (CH& R = H (H2161) X = (CH& R = H (H2162) X = (CH& R = CI (H2166) X = CMe2CMe2;R = H (H2167) X = 1.2-CeH4; R = H (H2171) X = 1,2-C6H4;R = CI (H2172) X = (CH& R = Bu' (H2173) X = 1,2-C6H4;R = Bu' R3 (H2160) R' = R2= H; R3 = OEt; X = 1,2-cyclohexyl (H2163) R' = H; R2= R3= Bu X = 1,2-cydohexyl (H2164) R' = H; R2 = OS/(P*)3; R3 = Bus X = 1,2-cyclohexyl (H2165) R' = H; R2 = NO2;R3 = Br; X = CH(Me)CH2 (H2170) R' = Me; R2 = R3 = H; X = 1,P-cyclohexyl (H2174) R' = R3= H; R2 = CH2NR3+;X = 1,2-C6H4 (H2175) R' = R3 = H; R2= CH2NR3+;X = 2,3-naphthyl (H4176) R' = R3 = H; R2 = OH; X = 1,2-C6H4 (H4177) R' = R3= H; R2 = OH; X = (CHz),; n = 2-5 examined .222,22 Im ido-Cr(v) complexes of salen and its derivatives such as [Cr(=NBu')(l72)] were prepared and their reactions with PPh When + r-hydroxycarboxylic acids (0,O-donor chelates) coordinate to the {Ti'"(159)}2 + fragment the salen ligand adopts a helical fac arrangement with the sense of helicity controlled by the chirality of the a-hydroxycarboxylic Reaction of [Rh"'H( 173)] with CO under irradiation affords [Rh"'(CHO)( 173)] via a d7 Rh(I1) intermediate.226 [MY(166),] (M = a lanthanide) dissociate in solution to + give [M( 166)] and [M(166),] -;the extent of dissociation is dependent on the size of the metal ion.227 Water-soluble CU(II) complexes of (174) and (175) intercalate into DNA via the aromatic linker between the imine atoms.228 Trinuclear Mo-Cu-Mo complexes of (176) and (177) were prepared in which the Mo groups were coordinated at the peripheral phenol sites and undergo an electrochemical interaction across the CU(II) centre.229 222 B.de Castro C. Freire and E. Pereira J. Chem. SOC.,Dalton Trans.1994 571. 223 F. Azevedo M. A. A. F. de C.T. Carrondo B. de Castro M. Convery D. Domingues C. Freire M. T. Duarte K. Nielsen and I. C. Santos Inorg. Chim. Acta 1994 219 43. 224 W.-H. Leung M.-C. Wu K.-Y. Wong and Y. Wang J. Chem. SOC.,Dalton Trans. 1994 1659. 225 K. M. Carroll J. Schwartz and D. M. Ho Inorg. Chem. 1994 33 2707. 226 D. J. Anderson and R. Eisenbers Inorg. Chem. 1994 33 5378. 227 H. Chen and R.D. Archer Inorg. Chem. 1994 33 5195. 228 K. Sato M. Chilira Y. Fujii and A. Komatsu J. Chem. SOC.,Chem. Commun. 1994 625. 229 S. M. Kagwanja C. J. Jones J. P. Maher and J. A. McCleverty Polyhedron 1994 13 2615. 336 M.D. Ward Uranyl complexes of (178)-( 183) have been evaluated as anion binders particularly H,PO, since they contain both a Lewis-acidic site (the {U02j2+fragment) for electrostatic attraction of anions and a hydrogen-bonding pocket (the amide protons).The crystal structures of some H2P0 adducts have been determined which confirm the ditopic nature of the anion binding;230 (181) and (182) selectively transport H2P0 across liquid membranes;231 and (183) not only performs ditopic binding of H,PO; but simultaneously coordinates K+ between the 15-crown-5 fragments and therefore binds both components of the salt KH,P04.232 Other Complexes. CO(II) complexes of Schiff-base ligands such as salen and acacen [H,acacen = bis(acety1acetonato)ethane-1,2-diamine] can activate 0 whilst trapped in zeolite cavitie~.~~~?~~~ [Mn"'ClL] [L = (184) (1S5)] catalyse enantioselective olefin ep~xidation.~,~ Planar Cu(rr) complexes of imidazole-containing ligands of which (186) and (1 87) are representative form imidazolate-bridged polymers [via axial ligation of CU(II)] on depr~tonation.~~~ [VvO(188)]-is the first V(v) complex with amide ligand~.,~~ Li,[Mn',"(l89),] contains a dimeric complex anion to which a Li+ cation is attached via two bridging phenolates; removal of the Li+ with 12-crown-4 destabilizes the dimer,238 which may then be oxidized to [MnvO(189)] -.[M(190)] (M = Cu Ni) undergo electropolymerization at the carbon atoms para to the hydroxyl groups.239 [ML],' [M = Cu Ni; L = (191) (192)] show strong antiferromagnetic exchange between the pendant radical groups of the ligands (cf. ref. 135).240 [(ReV(=O)L},(p-O)] [L = (193)-(195)] were prepared.241 The crystal structures of Li+ Na+ Sr2 +,and Ba2+ complexes of triethanolamine have been determined.242 {Mo~'~,}~ + complexes with triethanolamine and N,N'-dimethyl-N,N'-bis(hydroxyethyl)-l,2-diaminoethane are possible oxygen-transfer agents.243 [MoVL,] -[H,L = HON{CH(Me)CO,H},] has an eight-coordinate structure similar to that of the V(vr) enzyme amavadin; the MO(IV)and MO(VI)states are accessible reversibly.244 [VO(O,)(HL)] [H,L = HO(CH,),N(CH,CO,H),] is a functional model for vanadium haloperoxida~e.~~~ The electrochemical and spectroscopic properties of mononuclear CU(II) complexes of a variety of tripodal 230 D.M. Rudkevich W. Verboom Z. Brzozka M. J. Palys W. P. R. V. Stauthauer G.J. van Hummel S. M. Franken S. Harkema J.F. J. Engbersen and D. N. Reinhoudt J. Am. Chem. Soc. 1994 116 4341. 231 H. C. Visser D. M. Rudkevich W. Verboom F. de Jong and D. Reinhoudt J. Am. Chem. Soc. 1994,116 11 554. 232 D. M. Rudkevich Z. Brzozka M. Palys H.C. Visser W. Verboom and D.N. Reinhoudt Angew. Chem. Int. Ed. Engl. 1994 33 467. 233 D.E. De Vos E. J.P. Feijen. R.A. Schoonheydt and P.A. Jacobs J. Am. Chem. Soc. 1994 116,4746. 234 D. E. De Vos F. Thibault-Starzyk and P.A. Jacobs Angew. Chem. Int. Ed. Engl. 1994 33 431. L35 T. Nagata K. Imagawa T. Yamada and T. Mukaiyama Inorg. Chim. Acta 1994 220 283. 236 T. Nozaki H. Ushio G. Mago N. Matsumoto H. Okawa Y. Yamakawa T. Amo and T. Nakashima J. Chem. Soc. Dalton Trans. 1994 2339. 23' C. R. Cornman K. M. Geiser-Bush and P. Singh Inorg.Chem. 1994 33 4621. 238 F. M. MacDonnell N. L. P. Fackler C. Stern and T. V. O'Halloran J. Am. Chem. SOC.,1994,116,7431. 239 P. Capdeville M. Maumy P. Audebert and B. Plaza New J. Chem. 1994 18 519. 14' D. Luneau J. Laugier P. Rey G. Ulrich R. Ziessel P. Legoll and M. Drillon J. Chem. SOC. Chem. Commun. 1994 741. 241 M.R.A. Pillai C.L. Barnes and E.O. Schlemper Polyhedron 1994 13 701. 242 A. Naiini J. Pinkas W. Plass V. G. Young Jr. and J.G. Verkade Inorg. Chem. 1994 33 2137. 243 P. Barbaro C. Bianchini G. Scapacci D. Masi and P. Zanello Inorg. Chem. 1994 33 3180. 244 H. Yadav E. M. Armstrong R. L. Beddoes D. Collison and C. D. Garner J. Chem.Soc. Chem. Commun. 1994 605. 245 G. J. Colpas B. J. Hamstra J. W. Kampf and V. L. Pecoraro J. Am. Chem. Soc.1994 116 3627. The Coordination Chemistry of Open-chain Polydentate Ligands phhph (H2178) R=H (H2179) R = ptolyl (H21BO) R = nCI8Ha7 (H2181) R = CeH4-4-(nClBHa7) (H2183) R = benzo-15-crown-5 (H2182) R = (CH2)aOCeH4-2-N02 (H2184) X = C(0)R (H2185) R = CO2R (H186) =2 (H187) n =3 " (H4l88) R=Me (H4189) R = Ph H H RyNwNyR ooH (H196) R=pyr;x =l;y =2 (H197) R = 2-benzimidazdyl; x = 1; y = 2 (H2198) R = 2-pyridyl;x = 2; y = 1 (H2199) R = 2-benzimidazolyl; x = 2;y = 1 ligands such as (196t(199) were studied in [C~;(200),]~' is a model for galactose ~xidase.,~' [Fe~(02CPh)3(201)3]2f is a possible ferritin analogue.248 + [Fe;(pbf)(202),] (bf = benzoyl formate) a model for a-ketoacid-dependent iron enzymes undergoes oxidative decarboxylation on exposure to 0 to give a benzoate bridge.249 Other Mixed-donor Ligands.-Five-coordinate TC(III) and Re@) complexes of the NS tripod N(CH,CH,S- ) were evaluated as possible radiopharmace~ticals.~~~ Six-coordinate TC(III)complexes with a variety of N,S,S,N-donor ligands such as (203) 246 R.Uma R. Viswanathan M. Palaniandavar and M. Lakshminarayanan J. Chem. SOC.,Dalton Trans. 1994 1219. 247 H. Adams N.A. Bailey D.E. Fenton Q. He M. Ohba and H. Okawa Inorg. Chim. Acta 1994,215 I. 248 S. Menage H. Fujii M. P. Hendrich and L. Que Jr. Angew. Chem. Int. Ed. Engl. 1994 33 1660. 249 Y.-M. Chiou and L. Que Jr. Angew. Chem. Int. Ed. Engl. 1994 33 1886. 250 H. Spies M. Glaser H.-J. Pietzsch F. E. Hahn 0.Kintzel and T. Lugger Angew. Chem.Int. Ed. Engi. 1994 33 1354. 33% M.D. Ward were prepared with an ancillary N=NR (diazenide) ligand.25’ 0x0-Tc(v) and 0x0-Re(v) complexes of several similar N,S,-donors have been prepared as possible radio pharmaceutical^.^ 54 Mononuclear CU(II) complexes of (204t(206) were studied as possible models for ‘blue’ copper proteins:2ss (H200) x = 2; R = CeH4-2-OH ) (204) R=H (H201) x = 1; H = C02H (H2203) MS (205) R = CH2CH2SMe (H202) x = 1;R = C&i2-2-OH-3,5-Me~ (206)R = CH2-4-irnidazolyl n PPb Ph2P (207) n=2 (208) n = 3 -TNNNMe2 (21 2) The P,N donor set of (207) reversible interconversion between [Cu(207)] and [Cu(207)l2+; [Cu(20%)]+was prepared257 and (20%) was also found + to show high selectivity for CU(II)over many other transition metal di~ations.~’~ The Pd(i1) complex of (209) catalyses both asymmetric allylic alkylation2” and the deracemization of cyclic ally1 esters.260 Planar complexes of d8 transition-metal ions with some tri- and tetradentate mixed pyridyl/phosphine ligands such as pyr-(CH,),PMe(CH,),PMe(CH,),-pyrand pyr-(CH,),P(CH,CH,PPh,) (pyr = 2-py-ridyl) were prepared.261 [Au,K(dpnap),13+ and [Ag,(dpnap)J3+ [dpnap = 2,9-’”J.R. Dilworth P. Jobanputra R. M. Thompson D. C. Povey C. M. Archer and J. D. Kelly J.Chem.SOC. Dalton Trans. 1994 1251. 252 L. G. Marzilli M. G. Banaszczyk L. Hansen Z. Kuklenyik R. Cini and A. Taylor Jr. Inorg. Chem. 1994 33 4850. *’’J.P. O’Neil S.R. Wilson and J.A. Katzellenbogen Inorg. Chem. 1994 33 319. 254 L. M. Schultze L.J. Todaro R. M. Baldwin E. F. Byrne and B. J. McBride Inorg. Chem. 1994,33,5579. 255 K. C. Tran J. P. Battoni J. L. Zimmermann C. Bois G. J. A. A. Koolhaas P. Leduc E. Mulliez H. Boumchita J. Reedijk and J. C. Chottard Inorg. Chem. 1994 33 2808. 2s6 F. Tisato F. Vallotto G. Pilloni F. Refosco C. Corvaja and B. Corain J. Chem. SOC.,Chem. Commun. 1994 2397. 25’ F. Tisato B. Refosco G. Bandoli G. Pilloni and B. Corain J. Chem. SOC. Dalton Trans. 1994 2471. 25R Y. Cheng D. J. Schiffrin P. Guerriero and P.A. Vigato Inorg. Chem. 1994,33 765. 259 B. M. Trost and R.C. Bunt J. Am. Chem. SOC. 1994 116 4089. 260 B. M. Trost and M.G. Organ J. Am. Chem. SOC.,1994 116 10320. 261 A. Hessler J. Fischer S. Kucken and 0.Stelzer Chem. Ber. 1994 127 481. The Coordination Chemistry of Open-chain Polydentate Ligands 339 (Ph,P),-1,S-naphthyridine] were prepared and their photophysical properties studied.262 In [Ag3(210)J3+ each ligand binds one Ag(1) in the tridentate N,N,P- pocket with the third Ag(1) coordinated by the remaining phosphine groups; (210) can also act as a chelating diph~sphine.,~ [Tc(PPh,)L] (L = [P(C6H4S-2),]3-) was prepared.264 The crystal structure of [CoC1(21 l)]Cl confirmed the successful stereoselective synthesis of the new As,,N,P- donor ligand.265 4 Pentadentate Ligands N-and S-donor Ligands.-4’,4”’-diferrocenyl-2,2’ :6’,2”:6”,2“’:6”’,2””-quinquepyridine (Fc,qpy) behaves similarly to the parent quinquepyridine ligand forming mononuc- lear seven-coordinate and binuclear double helical complexes.266 [Cu(2 12)] + (trigonal bi~yramidal)’~~ and [Ni,(,u-N3)(21 3),13+ (with antiferromagnetic exchange across the azide bridge)268 have been prepared.Square pyramidal [C0”(214)] +,a model for the Co(I1)-bleomycin complex,269 reacts with 0 to give the superoxide complex [Co”’(O,)(214)] +. Complexes of CU(II) Ni(II) and Pd(I1) with CH,(CH,SCH,),CH were character- ized; electrochemical studies of the copper complexes show that the +1 state is strongly ~tabilized.’~’ The incorporation of cis-disubstituted rings in (21 5) and (216) overcomes the strong anti conformational preference of SC-CS bonds and renders the backbone more rigid; the CU(II) and Ni(11) complexes of both are octahedral with the ligands being S,-d~nors.*~’ The structures and reactivity of [Fe”(CO),L] [L = (217) (2 1 S)] were examined.72 Mixed-donor Ligands.-The relationship between the structures and magnetic proper- ties of [Cu:(,u-X)L] [L = (219)-(222); X = Ni OH- acetate pyrazolate)] was investigated; the two metals have both endogenous (alkoxide) and exogenous (X) bridges.273 A similar study was performed on [M’,’(ppz)(223)] (M = Cu Ni).274 [Fe”(224),I2-is a model for non-haem iron protein active sites in the Fe Binuclear alkoxide-bridged {V0}2f,(TiR,),’ and {SnR,},’ complexes of (225) and (226) were prepared.276 [Zn(227)] catalyses ester hydroly~is.’~~ Water-soluble monomeric 0x0-vanadium(v) complexes with (228 k(23 1) were prepared; reduction 262 R.-H. Uang C.-K. Chan S.-M. Peng and C.-M. Che J. Chem. SOC.Chem. Commun. 1994 2561. 2b3 F. Lianza A. Macchioni P. Pregosin and H. Riiegger Inorg. Chem. 1994 33 4999. 264 T. Nicholson J. Cook A. Davison and A. G. Jones Inorg. Chim. Actu 1994 218 97. 265 R. J. Doyle G. Salem and A.C. Willis J. Chem. Soc. Chem. Commun. 1994 1587. 266 E. C. Constable R. Martinez-Mafiez A. M. W. Cargill Thompson and J. V. Walker,J. Chem.Soc. Dalton Trans. 1994 1585. 267 S.-Y. Yu Q.-H. Luo X.-Y. Xu M.-C. Shen and L.-R. Huang Polyhedron 1994 13 1583. 268 G. A. McLachlan G.D. Fallon R. L. Martin B. Moubaraki K. S. Murray and L. Spiccia Inorg. Chem. 1994 33 4663. 269 E. Farinas N. Baidya and P. K. Mascharak Inorg. Chem. 1994 33 5970. 270 C. R. Lucas and S. Liu J. Chem. SOC. Dalton Trans. 1994 185. 271 J.M. Desper and S.H. Gellman Angew.Chem. Int. Ed. Engl. 1994 33 319. 272 D. Sellmann G. Mahr and F. Knoch Inorg. Chim. Acta 1994 224,45. 273 Y. Nakao M. Yamashita T. Itoh W. Mori S. Suzuki and T. Sakurai Bull. Chem.SOC.Jpn. 1994,67,260. 274 P. E. Kruger B. Moubaraki K.S. Murray and E. R. Tiekink J. Chem. Sac. Dalton Trans. 1994,2129. 275 M.P. Hendrich E.P. Day C.-P. Wang B.S. Snyder R.H. Holm and E. Munck Inorg. Chem. 1994,33 2848. 276 K. Dey K.K. Nandi and G.B. Kauffman Polyhedron 1994 13 2049. 277 C. 0.Rodriguez de Barbarin N. A. Bailey D. E. Fenton and Q. He Inorg. Chim. Acta 1994 219 205. 340 M.D. Ward H HN~N H2N-: \i$y IN 0 Br (H214) R)= =<" (H3224) X = CH(2-CeH4OH); R = H (H925) X = CH2CH(OH)CH2; R = H (H3226) X = CH2CH(OH)CH2;R = Me In (imine to amine) of the ligands prevents solv~lysis.~~~four-coordinate [Cu(H232)] the protonated aminoethyl side-chain is not coordinated; deprotona- + tion results in axial coordination of this [Fey(p-0,CR)3L] [L = (233)-(236)] contain one phenolate and three carboxylate bridges.280 [R [M~I"(NCS)(~-O,CR)~L] = Ph Me; L = the asymmetric compartmental ligands (237) and (238)] undergo a series of oxidations to the Mn(m)/Mn(Iv) states and show catalase-like disproportionation of H202.281 Bis(thiosemicarbazones) and bis(semicarbaz0nes) of 2,6-diacetylpyridine (H2L) act as N3S2 and N,O donors respectively in pentagonal bipyramidal complexes ''' G.J.Colpas B. J. Hamstra J. W. Kampf and V. L. Pecoraro Inorg. Chem. 1994 33 4669. 279 D. E. Fenton G. P. Westwood A.Bashall M. McPartlin and I. J. Scowen J. Chem. SOC.,Dalton Trans. 1994 2213. S. Sandi-Ureiia and E. J. Parsons Inorg. Chem. 1994 33 302. 281 C. Higuchi H. Sakiyama H. Okawa R. Isobe and D. E. Fenton J. Chem. SOC.,Dalton Trans. 1994,1097. The Coordination Chemistry of Open-chain Polydentate Ligands 34 1 [Sn'VR2L].282,283 The structures and reactivities of [Fe"XL] [L = (239k(242); X = various monodentate ligands such as CO NO PR, N2H4] which are possible nitrogenase models were e~amined.~*~*~~~ Mo nonuclear CU(II) complexes of the N2S3 ligands X(CH2SCH2),X [X =2-benzimidazolyl; 3,5-dimethylpyrazol-l-y1] are blue copper protein models.286 The asymmetric bis(bipy) ligand in (243) in addition to the expected 'bis-bidentate' behaviour can act as an N,N,C-cyclometallating donor at the inner cavity resulting in a bridging (N-and C-donor) pyridyl Me Me>=.^.r (H232) Br (H237) R=Me (H238) R=Et Pl 1 2+ SH HS 5 Hexadentate Ligands Homoleptic Ligands.-Ligands with Two Tridentate Compartments.Mononuclear OS(II)complexes of (244) with ancillary phosphine ligands have long-lived luminescent excited states and a vacant terpy-like coordination site for incorporation into 282 J. S. Casas A. Castiiieiras A. Sanchez J. Sordo and A. Vazquez-Lopez Inorg. Chim. Acta 1994,221,61. 283 G.F. de Sousa C. A. L. Filgueiras A. Abras S. S. Al-Juaid P. B. Hitchcock and J. F. Nixon Inorg. Chim. Acta 1994 218 139. 284 D. Sellmann T. Hofmann and F. Knoch Inorg. Chim. Acta 1994 224 61.285 D. Sellmann T. Becker T. Hofmann F. Knoch and M. Moll Inorg. Chim. Acta 1994 219 75. 2n6 B. Adhikary and C. R. Lucas Inorg. Chem. 1994 33 1376. 287 M.D. Ward J. Chem. SOC.,Dalton Trans. 1994 3095. 342 M.D. Ward R R Rx;IR (244) R=pyr (254) R = CH2NH2 polynuclear species.288 [(Xterpy)R~"(p-L)Os"(Yterpy)]~[Xterpy and Yterpy are + terpyridines with C4'-substituents; L = (245k(247)] undergo Ru" -+ 0s" photoin-duced energy transfer.289 In [{Ru(terpy)),(p-L)]'+ [L = (248)-(251)] the additional ethynyl spacers in the bridging ligands result in substantially longer 3MLCT lifetimes and greater delocalization of metal .n electrons.290 The bis(terpy)ferrocene (252) is a 'ball-bearing' ligand with two metal-binding sites attached to a flexible core.291 Ligand (253) affords trinuclear complexes with two (M(terpy),) chromophores pendant from a metalloporphyrin multi-step photo-induced electron transfer is possible from a RU(II)terminus to a Rh(m) terminus across the p~rphyrin.~~~ [MnC1,(254)-2H20] a is an infinite polymer with (254) bridging adjacent Mn(I1) centres; complexes with CU(II) and Zn(I1) were also prepared.293 The magnetic properties of bi- tri- and tetranuclear Ni(1r) and CU(II) complexes of the compartmental ligands (255b(258) were exam- ined."' In complex (259) the preorganized ligand holds the two CU(II) centres close together; the bis-Cu(I1) site binds dihydroxybenzene guests and will oxidize benzylic alcohols to ben~aldehydes.~~' Bis-Cu(1) complexes of (260) undergo reversible 0 binding accompanied by hydroxylation of the phenyl ring.296 [Cu:(p-X),L] + 288 R.G. Brewer G. E. Jensen and K. J. Brewer Inorg. Chem. 1994 33 124. 289 F. Barigelletti,L. Flamigni V. Balzani J.-P. Collin J.-P. Sauvage A. Sour E. C. Constable and A.M. W. Cargill Thompson J. Am. Chem. Soc. 1994 116 7692. 290 A. C. Benniston V. Grosshenny A. Harriman and R. Ziessel Angew. Chem. Int. Ed. Engl. 1994,33,1884. 291 E. C. Constable A. J. Edwards M. D. Marcos P. R. Raithby R. Martinez-Maiiez and M. J. L. Tendero lnorg. Chim. Acta 1994 224 11. 292 J.-P. Collin A. Harriman V. Heitz F. Odobel and J.-P. Sauvage J. Am. Chem. SOC. 1994 116 5679. 293 M. Ferigo P. Bonhhte W. Marty and H. Stoeckli-Evans J. Chem. Soc. Dalton Truns. 1994 1549. 294 K. Nonoyama W.Mori and M. Nonoyama Polyhedron 1994 13 891. 295 C. F. Martens R. J. M. Gebbink M. C. Feiters and R. J. M. Nolte J. Am. Chem. SOC. 1994 116 5667. 296 K. D. Karlin M. S. Nasir B. I. Cohen R. W. Cruse S. Kaderli and A. D. Zuberbuhler,J. Am. Chem. Soc. 1994 116 1324. The Coordination Chemistry of Open-chain Polydentate Ligands Et Et Et Et (253) H f"-R R = CH2NMe2 R = (CHd2NMe2 R= Wr R = CHz-pyr birnnNwNnbim I < birn bim O PhT Ph (261) n =1 (262) n =2 (bim = N -methyl or N -ethylbentimidamiyl) (259) [L = (261) or (262); X = N3 SCN- acetate] are weakly antiferromagnetically coupled and undergo two coincident CU(II)/CU(I) reductions.297 Other Homoleptic Ligands. The constitutions of mono- and binuclear complexes of H2N{(CH,),NH},(CH2)2{NH(CH,)3}2NH2 with first-row transition metals Cd(II) and Pb(I1) were examined by p~tentiometry.~'~ Whereas [M"L2]2f [M = Fe Co Ni; 297 Y.Nakao M.Oonishi T. Uzu H. Kashihara S. Suzuki M.Sakai and Y. Fukuda Bull. Chrm. SOC.Jpn. 1994 67 2586. 29R J. A. Aguilar A. Bianchi E. Garcia-Espafia,S. V. Luis J. M. Llinares J. A. Ramirez and C. Soriano J. Chem. SOC.,Dalton Trans. 1994 637. 344 M.D. Ward L = pyr-(CH,NHCH,),-pyr] are mononuclear octahedral complexes [{ Fey'(p-O)(p-0,CMe)) ,(p-L),I2+ is a tetranuclear 'dimer of dimer~'.,~~ In [Ru"(H263)I3 + themetal is in a tris(bipy)environment; the triazacyclononane ring is pr~tonated.~" The new tris(pyrazoly1)borate-derived podand (264) and its nine- coordinate complex [Eu"'F(MeOH),(264)][PF6] were prepared and the latter was crystallographically ~haracterized.~'~ The trinucleating ligand (265) was used to prepare [Ag9(265)6]9+ a 3 x 3 molecular grid with each metal four-c~ordinate.~~~ The crystal structures of mono- and binuclear complexes of the new ligand (266) were determined with (PdCl,) and (ReCl(CO),) fragments in the bidentate coordination sites.303 (H4267) X = 0 (He8) X=2H (266) Complexes of Fe(Ir1) with 0 podands based on dihydroxybiphenyl chelates (267) and (268) have stability constants lower than those of tris(catecho1ates) since ligand preorganization is not Mixed N,O-donor Ligands.-Binuclear complexes of N,N'-bis(2-aminoethyl)oxamide and its derivatives may have a transoid symmetric (two N,O binding site^)^^^-^^^ or cisoid asymmetric (N and 0 binding sites) ligand both result in strong 299 N.Arulsamy J. Glerup and D.J. Hodgson Inorg. Chem. 1994 33 3043. 300 P. Sheldon W. Errington P. Moore S. C. Rawle and S. M. Smith J. Chem. SOC.,Chem. Commun. 1994 2489. 301 A. J. Amoroso A. M. W. Cargill Thompson J. C. Jeffery P. L. Jones J. A. McCleverty and M. D. Ward J. Chem. SOC.,Chem. Commun. 1994 2751. 302 P.N. W. Baxter J.-M. Lehn J. Fischer and M.-T. Youinou Angew. Chem. Int. Ed. En& 1994,33,2284. 303 V. J. Catalano W. E. Larson M. M. Olmstead and H. B. Gray Inorg. Chem. 1994 33 4502. 304 G. Serratrice,C. Mourral A. Zeghli C. C. Beguin P. Baret and J.-L. Pierre New.J. Chem. 1994,18,749. 305 Z.N. Chen J. Qiu W.X. Tang and K.B. Yu Inorg. Chim. Acta 1994 224 171. 3"h C.-Y. Jin S.-L. Ma and D.-Z. Liao Polyhedron 1994 13 2881. 307 Z. N. Chen W. X. Tang F. M. Miao and J. L. Wang Polyhedron 1994 13 2543. 308 Z.N. Chen W.X. Tang and K. B. Yu Polyhedron 1994 13 783. 309 S.-L. Ma D.-Z. Liao Z.-H. Jiang S.-P. Yan and G.-L. Wang Polyhedron 1994 13 1647. 310 "' Z.N. Chen W.X. Tang J. Chen P.J. Zheng Y.-T. Li,Z.-H. Jiang,S.-L. Ma,X.-Y. Li,D.-Z. Liao,S.-P.Yan,andG.-L. Wang,Polyhedron 1994,13,475. C.G. Chen and K.B. Yu Polyhedron 1994 13 873. The Coordination Chemistry of Open-chain Polydentate Ligands antiferromagnetic coupling between two CU(II) centre^,^'^-^'^ between CU(II) and lanthanide~,~"and between two Ni(I1) centres.311 Dioxime (269) binds CU(II) in the N cavity and a second transition metal at the peripheral 0,O-site also resulting in antiferromagnetic e~change.~ 12*313 Li gand (270) behaves similarly binding CU(II) at the inner N site but with three possible external 0,O-chelating sites to bind an additional ion such as N~(II).~~ Ligands (271)-(275) have 'inner' and 'outer' binding pockets which share bridging phenolate^.^ "-' Four-coordinate [Co(273)] attaches to the surface of solid CdSe to an extent which is inversely proportional to the 0 concentration; this attachment increases the CdSe photoluminescence so the system is a possible 0 sensor.319 iN/x\ Ni k' R' (H971) X = (CH& R' = OMe; R2= H (H972) X = (CH2)3; R' = OMe; R2 = H (H973) X = (CH2)2; R' = OMe; R2= H (H4274) X = (CH2)3; R' = CO2H; R2= H (Hg75) X = C(Me)2C(Me)2;R' = pyt; R2= But Pyrazine-2,3,5,6-(C02H) is a bridging ligand (two O,N,O binding sites) in coordination polymers of Mn(11).~,'Complexes of the N,03 podands (276) and (277) with radioactive isotopes of Ga(m) and In(m) may have biomedical application^.^^' Ligand (278) is asymmetric with N30 and N,O compartments; [Cu;(p-Cl)(EtOH)(p- (278))]* was prepared.322 In [Co(279)I2+ the helical ligand disposition is stabilized + 312 F.Birkelbach M. Winter U. Florke H.-J. Haupt C. Butzlaff M. Lengen E. Bill A.X. Trautwein K. Wieghardt and P. Chaudhuri lnorg. Chem. 1994 33 3990. 313 R. Ruiz F. Lloret M. Julve M.C. Mufioz and C. BoIs lnorg. Chim. Acta 1994 219 179. 314 E. Colacio J. M. Dominguez-Vera A. Escuer R. Kivekas and A. Romerosa Inorg.Chem. 1994,33,3914. 315 B. Clarke D. Cunningham J. F. Gallagher,T. Higgins P. McArdle J. McGinley M. Ni Cholchuin,and D. Sheerin J. Chem. Soc. Dalton Trans. 1994 2473. 316 Z. W. Yu R.J. Tao X.Y. Zhou D.M. Jin and D.Z. Liao Polyhedron 1934 13 951. 317 A. Aguiari E. Bullita U. Casellato P. Guerriero S. Tamburini P. I. Vigato and U. Russo lnorg. Chim. Acta 1994 219 135. 318 F. Lam R.-J. Wang T.C. W. Mak and K. S. Chan J. Chem. Soc. Chem. Commun. 1994 2439. 319 D. E. Moore G.C. Lisensky and A.B. Ellis J. Am. Chem. Soc. 1994 116 9487. P.-A. Marioni W. Marty H. Stoeckli-Evans and C. Whitaker lnorg. Chim. Acta 1994 219 161. 321 J.E. Bollinger J.T. Mague and D. M. Roundhill Inorg. Chem. 1994 33 1241. 322 P. Kamaras M.C. Cajulis M. Rapta G.A. Brewer and G.B. Jameson J. Am. Chem. Soc. 1994 116 10 334. 346 M.D. Ward by intraligand NH - - 0hydr~gen-bonding.~,~ Binding of metal ions to the N,O site of (280) causes a large shift in the 19F NMR signal due to F- M dative bond formation; the 19FNMR spectrum provides a probe of metal-ion binding.324 Other Mixed-donor Ligands.-Ligands (281)-(283)325,326 and (284)327 have two cyclometallating N,C,N binding pockets at either end of a conjugated bridge; this allows strong electrochemical interactions between ruthenium and RU(II)+OS(II)photoinduced energy transfer.326 C0(11)~~* complexes and F~(II)~,~ + were prepared with the N,O,S,-donors (285)-(288); [Co"L12 [L = (285) (286)] undergo base-induced C-S bond cleavage of the coordinated ligand,328 as do + [Co"'L] [L = (289) (290)].330 Mononuclear Mn(II),Fe(u) and Fe(rr1) complexes of the N,S ligands (291 )-(294) have short metal-to-thioether bonds and are unusually low spin.31 6 Ligands of Higher Denticity Homoleptic Ligands.-A variety of segmental ligands with bi- and tridentate N-donor pockets can afford helical complexes which exploit the preference of different metal ions for different coordination numbers. Thus [Fei1Ag'(295),] + contains octahedral Fe(I1) 323 M. L. Tulchinsky L. I. Demina S. V. Lindeman and Y. T. Struchkov Inorg. Chem. 1994 33 5836. 324 H. Plenio and D. Burth J. Chem. Soc. Chem. Commun. 1994 2297. 325 M. Beley S. Chodorowski-Kimmes J.-P. Collin P. Laine J.-P. Launay and J.-P. Sauvage Angew. Chem. Int. Ed. Engl. 1994 33 1775.326 M. Beley S. Chodorowski J.-P.Collin J.-P. Sauvage L. Flamigni and F. Barigelletti Inorg. Chem. 1994 33 2543. 321 J.-P. Sutter D. M. Grove M. Beley J.-P. Collin N. Veldman,A. L. Spek J.-P. Sauvage,andG. van Koten Angew. Chem. Int. Ed. Engl. 1994,33 1282. 328 P. Chakraborty S. Karmakar S. K. Chandra and A. Chakravorty Inorg. Chem. 1994 33 816. 329 P. Chakraborty S. K. Chandra and A. Chakravorty Inorg. Chem. 1994 33 6429. 330 P. Chakraborty S.K. Chandra and A. Chakravorty Inorg. Chem. 1994 33 4959. 331 S. Karmakar S. B. Choudury and A. Chakravorty Inorg. Chem. 1994 33 6148. The Coordination Chemistry of Open-chain Polydentate Ligands R R\ N-0 0-N’ c,w.3 (H985) x =2;R=Me (H989) x =2 (H$91) x =2;R=Ph (H986) x =3,R=Me (H987) x =2;R =Ph (H90) x = 3 (He) x =2; R =a-naphthyl (H-) x=3;R=Ph (H980) x =3; R=Ph (HW) x =3; R =a-naphthyl (295) R = 1,3-(Me0)2CeHa using the two tridentate ligand sites and tetrahedral Ag(1) using the two bidentate sites and [Ag,Fe(296),I4+ likewise contains two tetrahedral Ag(1) centres and an octahed- ral Fe(r1) (cf.refs 166 167).332,333 [Cu:(NCEt),(297)I2+ reacts with 0 to give ‘open’ products [with one superoxide coordinated to each Cu(rr)] or a ‘closed’ product with a CuF(p-0;-) bridge.334 Sr(n) complexes with poly(ethyleneglyco1s) have crystal structures similar to those of related crown ether complexes.335 The lipophilic ligand (H,298) is capable of selective extraction of Pb(r1) over CU(II).~~~ Dendrimeric ligands such as (299)-(301) containing 332 C.Piguet G. Hopfgartner B. Bocquet 0.Schaad and A. F. Williams J. Am. Chem. Soc. 1994,116,9092. 333 C. Piguet B. Bocquet and G. Hopfgartner Helv. Chim. Acta 1994 77 931. 334 N. Wei D.-H. Lee N.N. Murthy Z. Tyeklar K. D. Karlin S. Kaderli. B. Jung and A. D. Zuberbuhler Inorg. Chem. 1994,33 4625. 335 R.D. Rogers M.L. Jezl and C.B. Bauer Inorg. Chem. 1994 33 5682. 336 T. Hayashita T. Fujimoto Y. Morita and R. A. Bartsch Chem. Lett. 1994 2385. 348 M.D. Wurd multiple P binding sites were prepared; their Pd(1i) complexes catalyse the electrochemical reduction of CO to C0.337 Mixed-donor Ligands.-Compartmental binucleating ligands such as (302)-(3 11) with an endogenous alkoxide or phenoxide bridge between the two compartments are primarily of use for preparing models of binuclear metalloproteins.Thus the mechanism of formation of peroxo-bridged bis-Fe(m) complexes of (302)-(304) was and manganese complexes of (303) in oxidation states ranging from Mn(Ii)/Mn(II) to Mn(m)/Mn(iv) are catalase models.339,340 [Co',"(p-O,CR)(p- 0,)(305)] has peroxide alkoxide and carboxylate ligands simultaneously bridging + the Coy core.341 [{ Mn2(p-0)2(H20)(306)}2]4+ is a dimer of Mn"'(p-O)Mn'" dimers which shows both inter-and intradimer magnetic exchange.342 [RuY'(p-O,CMe),(307)] -undergoes two reductions with a well-defined RU(II)/RU(III) mixed-+ valence state.343 [Fe~1f0,P(OPh)2},L] [L = (308)-(309)] are models for the purple acid phosphatases. 344 [Fe"Fe"'( p-0,CC,H,3),(310)]2f is valence averaged at 293 K according to Mossbauer spectroscopy.345 [CuY(H,0),(3 1l)]-mimics the car-boxylate-rich coordination environment at the active site of aminope~tidases.~~~ Whereas in [Bi(3 12)] the ligand is a conventional seven-coordinating podand (with 337 A.Miedaner C. J. Curtis R. M. Barkley and D. L. DuBois Inorg. Chem. 1994 33 5482. 338 A. L. Feig and S.J. Lippard J. Am. Chem. SOC. 1994 116 8410. 339 P. J. Pessiki S.V. Khangulov D. M. Ho and 6. C. Dismukes J. Am. Chem. SOC. 1994 116 891. 340 P. J. Pessiki and G. Dismukes J. Am. Chem. SOC.,1994 116 898. 341 T. Kayatani Y. Hayashi M. Suzuki and A. Uehara Bull. Chem. SOC.Jpn. 1994 67 2980. 342 H. Kawasaki M. Kusunogi Y. Hayashi M. Suzuki K. Munezawa M. Suenaga H.Senda,and A. Uehara Bull. Chem.SOC. Jpn. 1994 67 1310. 343 T. Tanase M. Kato Y. Yamada K. Tanaka K. Lee Y. Sugihara A. Ichimura,I. Kinoshita M. Haga Y. Sasaki Y. Yamamoto T. Nagano and S. Yano Chem. Lett. 1994 1853. 344 B. Krebs K. Schepers B. Bremer G. Henkel E. Althaus W. Miiller-Warmuth K. Griesar and W. Haase Inorg. Chem. 1994 33 1907. 345 Y. Maeda Y. Tanigawa N. Matsumoto H. Oshio M. Suzuki and Y. Takashima Bull. Chem. SOC.Jpn. 1994 67 125. 346 R. C. Holz J. M. Brink F.T. Gobena and C. J. O'Connor Inorg. Chem. 1994,33,6086. The Coordination Chemistry of Open-chain Polydentate Ligands (H302) R' = R2= pyr; m = n = 1 (H303) R' = R2 = 2-benzimidazolyl;m = n = 1 (Ha) A' = R2 = 6-methyl-pyr; m = n = 1 (H3309) R' = pyr; R2= 2-hydroxyphenyl (H305) R' = R2 = pyr; m = 1; n = 2 (H310) R' = R2 = pyr (H306) R' = R2 =pyr; m = n = 2 (H5311) R' = R2 = C02H (H5307) R' = R2 = C02H; m = n = 1 (H3308) R' = pyr; R2= 2-hydroxyphenyl;m = n = 1 HO (H3312) R' = R2 = H (H6313) R' =OH; R2 = H (H3314) R' = OMe; R2 = H (H3315) R' = CH(OMe)2;R2 = Me 12+ the bridgehead N coordinated),347 (313) and (314) are compartmental comprising an N303 'inner' compartment and an 'outer' 0 ~ompartment;~'~ in lanthanide complexes of (315) the ligand coordinates solely by the six 0atoms with the N atoms not involved in coordination.348 Ligand (3 16) permits the synthesis of linear trinuclear complexes with its separate O,O/N,O,/O,O binding domains; the magnetic properties of a Mn(rI)/Cu(II)/Mn(rr) system were examined.349 Complex (31 7) contains a bis-Mn(m) centre which oxidizes water to 0 on irradiation in the presence of p-benzoquinone and is therefore a functional model of the water-oxidizing manganese protein.350 347 P. K. Bharadwaj A.M. Lee S. Mandal B. W. Skelton and A.H. White Aust. J. Chem. 1994,47 1799. 348 S.J. Archibald A. J. Blake M. Schroder and R. E. P. Winpenny J. Chem. SOC.,Chem. Commun. 1994 1669. 349 C. Mathoniere and 0.Kahn Inorg. Chem. 1994 33 2103. 350 M. Watkinson A. Whiting and C.A. McAuliRe J. Chem. SOC.,Chem. Commun. 1994 2141. 350 M.D. Ward (H5318) R = PCeH4OH (H3319) R = C(O)-NH-CH2Ph V(III)complexes of several polyaminocarboxylates (edta diethylenetriamine pen- taacetic acid and so on) were studied in solution by Raman and NMR spectroscopic methods; monomeric and 0x0-bridged dimeric species were dete~ted.~' Binuclear ruthenium complexes of triethylenetetraamine hexaacetate (L6-) were prepared in oxidation states ranging from (Ru"(H,O)} to RU"'RU'~(~-O).~~~ The stability constants of complexes of (318) with various M(II)and M(III) ions are generally lower than those of the hexadentate 1,2-diaminoethane analogue.353 [Y(H20)(319)]-3H,O which is nine-~oordinate,~~~ and Gd(II1) complexes of a variety of polyaminophos-phonates [e.g.(320)],355 are of interest as possible MRI contrast agents. The electrochemical UV/VIS and EPR spectroscopic properties of Cu(1) and CU(II) complexes of N2S4 and N2S5 ligands such as bim-(CH2),(SCH,CH2S)(CH2),(SCH2CH,S)(CH2),bim [bim = 2-benzimidazolyl; rn = 1,2; n = 2,3] and bim-(CH,SCH,),-bim were examined as a function of chelate ring size.356 351 K.Kanamori K. Ino H. Maeda K. Miyazaki M. Fukugawa J. Kumada T. Eguchi and K. Okamoto Inorg. Chem. 1994,33 5547. 352 S. Zhang and R. E. Shepherd Inorg. Chem. 1994 33 5262. 353 R. Ma I. Murase and A.E. Martell Inorg. Chim. Acta 1994 223 109. 354 D. Parker K. Pulukkody F. C. Smith A. Batsanov and J.A.K. Howard J. Chem. SOC.,Dalton Trans. 1994 689. 355 S. W. A. Bligh C. T. Harding A. B. McEwen P. J. Sadler,J. D. Kelly and J. A. Marriott Polyhedron 1994 13 1937. 356 U. Sivagnanam and M. Palaniandavar J. Chem. SOC. Dalton Trans. 1994 2277.

ISSN:0260-1818    

DOI:10.1039/IC9949100317

出版商:RSC    

年代:1994

数据来源: RSC

摘要:

20 The Coordination Chemistry of Macrocyclic Ligands By S.L. W. MCWHlNNlE Chemistry Department Brunei University Uxbridge Middlesex UB8 3PH UK 1 Introduction and Overview This review of the coordination chemistry of macrocyclic ligands follows the format of previous years. Once again only the major journals are surveyed and no porphyrin or phthalocyanine coordination chemistry is covered. Pendant-arm macrocycles are discussed in the section appropriate to the parent macrocycle and where a paper refers to macrocycles possessing different donor sets the whole is referenced and discussed in the first section into which one of the ligands falls. This year the majority of papers again covers complexes of tetraaza macrocycles. There has also been a steady increase in the number of papers dealing with bicyclomacrocyclic ligands cryptates and sepulchrates.2 Tridentate Macrocycles Ndonor Ligands.-The complexes [M"'Cl,L] [M = Cr or Fe; L = (1) or (2)] have been synthesized;' the reaction of [Cr"'Cl,(2)] with LiCH,SiMe produced [Cr"'C1(CH2SiMe,),(2)] the crystal structure of which is reported. Syntheses structures and electrochemistry have been reported of [RuY(p-OH),(p- C0,)(4),l2 + and [Ru;.'(p-O),(p-CO,)( 11)J have been reported.' Heterogeneous + electron-transfer rates for [M(3)I3+l2+ (M = Fe Co Ni or Ru) have been determined and the inner-shell effects disc~ssed.~ It appears that variations in the inner-shell entropic contributions can be attributed to differences in the vibrational partition functions between the products and reactants.The structures of [Ru"(bipy)(H,O) + + (4)12 and [R~'~(bipy)0(4)]' have been reported4 and reactivity studies show that [RdV(bipy)0(4)] + oxidizes alkenes to epoxides. The crystallographically character- ized complex [{Cr"'(acac)},(p-H30~)(4)][PF6]s reacts in the solid state at elevated temperature to yield [Cr"'F(acac)(4)] [PF,] and [Cr"'( acac)( 0 PF )[ PF,]together with three equivalents of HF. The products of the reaction of [Ti"'Cl,(NCMe),] with (4) and the isopropyl analogue have been compared. In the former R. D. Kohn and G. Kociok-Kohn Angew. Chem. Int. Ed. Engl. 1994 33 1877. A. Geilenkirchen P. Neubold R. Schneider K. Wieghardt U. Florke H.-J. Haupt and B Nuber J. Chem. SOC. Dalton Trans.1994 457. ' P. W. Crawford and F. A. Schultz Inorg. Chem. 1994 33 4344. W.-C. Cheng W.-Y. Yu K.-K. Cheung and C.-M. Che J. Chem. SOC. Dalton Trans. 1994 57. U. Bossek G. Haselhorst S. Ross K. Wieghardt and B. Nuber J. Chem. SOC.,Dalton Trans. 1994 2041. 35 1 S. L. W. McWhinnie [(Ti"'(NC0),(4)} 2(p-0)] is formed whilst in the latter [Ti"'Cl,L] (L = 1,4,7-triisop-ropyl- 1,4,7-triazacyclonone) is isolated .6 The thiocyanate analogue of the former product has also been synthesized and the exchange coupling in the two bimetallic complexes studied; both display weak antiferromagnetic coupling. A series of cations [Ti'VBr,(OMe),-,(4)]+ (x= 0-3) has been synthesized as well as two per-oxotitanium(1v) complexes of (4).7 Some new octahedral titanyl complexes of the isopropyl substituted macrocyclic complexes are reported in the same work.A series of heterobimetallic complexes has been synthesized by using [Cu"(H,O) (dopnH)]' as a ligand for a series of half sandwich complexes of (4)with Cr(rrr) Mn(rrr) Mn(rr) Fe(rrr) CO(III) CO(II) Ni(rr) CU(II) and Zn(II).8 The structures of a number of these species have been determined and magnetic susceptibility studies have been used to study the strength of the exchange coupling. Molecular mechanics calculations applied to a series of complexes of (3) (5),and (6),have demonstrated that chelate ring fusion plays a critical role in the structure of the comple~es.~ A study of the complexes of (7) with CO(II) Ni(rI) CU(II) Zn(rr) Fe(m) CO(III) Ga(rrI) and Tn(Irr) shows that the ligand imposes octahedral geometry." Biodistribution studies have been carried out on the indium-1 11 and gallium-67 complexes which both demonstrate selective biliary clearance.The tetra(2-methyl-2-hydroxypropyl) substituted derivative of (1 1) forms bimetallic complexes which display an anti configuration with CO(II) Ni(Ir) and Zn(rr) but a syn configuration with CU(II)." Crystallographic studies suggest that the configuration of the copper complex may be due to intramolecular hydrogen bonding. Reaction of Na,(9) with [Ru"Cl,(dmso),] in a 2 :1 ratio leads to the isolation of [(9)NaRuIVNa(9)] in which both the sodium and ruthenium cations are six-coordi- nate.' The ruthenium is octahedrally coordinated by six sulfur donors whilst the sodium atoms are trigonal prismatically coordinated by three nitrogens and three sulfurs.The novel ligand (10) and its Ni(rr) and Zn(r1) complexes have been synthesized.' Both complexes are coordinated by all six nitrogens in a highly distorted octahedral environment. Fe(rr) Mn(rI) CO(II),Ni(rI) CU(II) and Pd(rr) complexes of (12)have been prepared and their properties compared with those of the complexes of (8).14That the complexes of (8)are much more resistant to oxidation than those of (12) is rationalized by molecular mechanics calculations. The dissociation kinetics of the Ce"' complexes of (13) and (35) have been studied and the values obtained are compared with literature values for similar complexes.' The rate constants appear to be affected by the internal cavity size of the ligand.P. Jeske K. Wieghardt and B. Nuber Inorg. Chem. 1994 33 47. ' P. Jeske G. Haselhorst T. Weyhermiiller K. Wieghardt and B. Nuber Inorg. Chem. 1994 33 2462. * F. Birkelbach M. Winter U. Florke H.-J. Haupt C. Butzlaff M. Lengen E. Bill A.X. Trautwein K. Wieghardt and P. Chaudhuri Inorg. Chem. 1994,33 3990. I.V. Pletnev Can. J. Chem. 1994 72 1404. lo E. Cole R. C. B. Copley J. A. K. Howard D. Parker G.Ferguson J. F. Gallagher B. Kaitner A. Harrison and L. Royle J. Chem. Soc. Dalton Trans. 1994 1619. A. J. Blake T. M. Donlevy P. A. England I. A. Fallis S. Parsons S.A. Ross and M. Schriider J. Chem. SOC. Chem. Commun. 1994 1981. l2 K. Mochizuki F. Kesting T. Weyhermiiller K. Wieghardt C. Butzlaff and A. X. Trautwein J.Chern.SOC. Chem. Commun. 1994 909. l3 M. Di Vaira F. Mani and P. Stoppioni J. Chem. Soc. Dalton Trans. 1994 3739. l4 D. Zhang and D.H. Busch Inorg. Chem. 1994 33 5138. K.-Y. Choi K. S. Kim and J.C. Kim Bull. Chem. Soc. Jpn. 1994,67 267. The Coordination Chemistry of Macrocyclic Ligands (1) R=Me (3) R=H (2) R= pi (4) R = Me (5) R = CH2CH2NH2 (6) R = CH2CH2CH2NH2 (7) R = CH,P(O)(Ph)(OH) (8) R = CH2(2-pyridyl) (Hag) R = 3-But-G-(HS)Ph (10) R = CH2(3-pyrazole) R I nR t,5 R (12) R = CH2(2-pyridyl (15) m =l,n =1 (13) R = CHZCOOH (16) m =2,n =1 R R (17) m =2 n =2 Other Donor Sets.-Several Ti(1v) complexes of (14) have been synthesized [Ti"X( l4)] (X = isoproxide or acac) and a variable temperature NMR spectroscopic study has been carried out (X = acac).' The majority of the crystal structures of metal complexes of [9]aneS have been modelled'7 by estimating the M-S bond lengths and using a standard force field.These results suggest that it would be possible to predict the likely structure of the macrocycle with nearly all metals. The crystal structures of 3Sn'vCl,.2[9]aneS and 2SnC1,f 181 aneS,.MeCN have been reported." The first consists of [SnC14([9]aneS,)] cations, + in which the sulfur ligand is coordinated facially to a SnCl unit and [SnC1J2- anions; in the second two SnC1 units are located at opposite ends of the ring cavity with one below and one above the ring. The synthesis of [R~"(NCMe),([9]aneS,)1~ + has allowed its use as a precursor to a series of mixed-ligand sandwich complexe~'~ such as [Ru"([9]aneS3)Tp]+ ; [R~"(NCMe),(PPh,)([9laneS,)1~ gives other half-sandwich + compounds.Cationic half-sandwich Rh(1) compounds of [9]aneS have been syn- t hesized,' and the cry st a1 structures of [Rh"'(C,H ) ([ 9laneS,)I[PF,] [Rh"'(cod)([9]aneS3)][BF,] and [Rh(C4H,)([9]aneS3)][PF,] reported. Crystal l6 P.D. Hampton C. E. Daitch T. M. Alam Z. Bencze and M. Rosay Inorg. Chem. 1994,33 4750. J. Beech P. J. Cragg and M.G. B. Drew J. Chem. Soc. Dalton Trans. 1994 719. '' G.R. Willey A. Jarvis J. Palin and W. Errington J. Chem. SOC.,Dalton Trans. 1994 255. l9 C. Landgrafe and W. S. Sheldrick J. Chem. SOC.,Dalton Trans. 1994 1885. 2o A.J. Blake R.O.Gould M.A. Halcrow and M. Schroder J. Chem. Soc. Dalton Trans. 1994 2197. S. L. W. McWhinnie structures of (15)-(17) have been reported21 together with evidence for their complexation in solution with Ag(1). A series of functionalized 1,4,7-trithiacyc-lononanes such as (18t(20) has been synthesized22 and the coordination chemistry of (18) investigated. The presence of the methyl group did not appear to have any significant effect on the spectroscopic or electrochemical properties of the complexes. Palladium complexes of the cyclophanes (21) and (22) viz. [Pd"(NCMe)L] + [L = (21) or (22)] have been studied as receptors for o-aminopyridine derivative^.^^ The complexes bind the guests uiasimultaneous first- and second-sphere coordination. The crystal structure of [Pd"(23)][BF4] demonstrates that the palladium is coordinated by the four nitrogen atoms and shows a long-range apical interaction to the sulfur atom of the macrocyclic ring.24 (18) R= Me (21) n = 1 (19) R = CHZOH (22)n =3 (20) R = CH,OCH2(GCO,H) 3 Tetradentate Macrocycles N-donor Ligands.-The mechanism of cleavage of the fi-lactam ring of benzylpenicillin by a zinc@) complex of (24)25 and the recognition of nucleobases by a zinc@) complex of an acridine-pendant arm derivative of (24) has been reported.26 The complex cis-[Mo"'C12(25)]C1 which oxidizes slowly on exposure to air is the first example of a cis complex with (25).*' The trans isomer and not the cis isomer of [Fe"'C1,(26)] + was found to activate dioxygen28 in the presence of reducing agents such as aliphatic aldehydes or linolenic acid; hydrogen-bonding between the ligand and the dioxygen is very important in the mechanism of activation.Two series of Ni(I1) complexes of pendant-arm cyclam ligands have been synthesized,' and their application to the photoreduction of CO studied. The two series are distinguished by the identity of the pendant arm; one possesses a quaternary pyridinium pendant whilst the other has a ruthenium bipyridyl moiety attached to the nickel complex. The crystal structure of cis-[Ru"( bipy) (trans-Cr"'(CN) (26)),I4+ has been determined.30,31 The chromium " J. J. H. Edema J. Buter F. S. Schoonbeek R. M. Kellogg F. van Bolhuis and A. L. Spek Inorg. Chem. 1994 33 2448. 22 R.J. Smith S. N. Salek M. J. Went P. J. Blower and N. J. Barnard J. Chem. SOC.,Dalton Trans. 1994 3165. 23 J.E. Kickham and S. J. Loeb Inorg. Chem. 1994 33 4351. 24 B. Chak A. McAuley and T. W. Whitcombe Can. J. Chem. 1994 72 1525. 25 T. Koike M. Takamura and E. Kimura,J. Am. Chem. Soc. 1994 116 8443. 26 M. Shionoya T. Ikeda E. Kimura and M. Shiro J. Am. Chem. Soc. 1994 116 3848. '' C. J.H. Jacobson J. Hyldtoft S. Larsen and E. Pedersen Inorg. Chem. 1994,33 840. '' Y. Nishida and N. Tanaka J. Chem. SOC.,Dalton Trans. 1994 2805. 29 E. Kimura S. Wada M. Shionoya and Y. Okazaki Inorg. Chem. 1994 33 770. 30 X.H. Bu Y.T. Chen M. Shinoya and E. Kimura Polyhedron 1994 13 325. 31 C. A. Bignozzi C. Chiorboli M. T. Indelli F. Scandola V. Bertolasi and G. Gilli J.Chem. SOC.,Dalton Trans. 1994 2391. The Coordination Chemistry of Macrocyclic Ligands 355 atoms are attached to the ruthenium via the cyanide moieties in a Ru-(p-CNtCr mode; linkage isomerism can be induced by heating the complex for several hours. Studies of the dissociation kinetics of the decomposition of Cu(ii) complexes of (24) (25) (27) and (28) have shown32 that a protonation pathway is more important than solvation. The magnetic exchange through hydrogen-bonds between chromium complexes such as [Cr"'(OH)(H20)(26)] ,which crystallizes as a binuclear complex + with cis geometry has been studied.33 The complexes show strong antiferromagnetic coupling. Lithium and sodium complexes of (29) in which the cations are five-coordinate have been ~haracterized.~~ The solvent dependence of the reduction potential of tran~-[Os'~O,(29)] has been studied.35 A shift of ca.600mV was observed over the acceptor number range employed. La(Iir) EU(III) and LU(III) complexes of (3 1) have been ~ynthesized~~ and the crystal structure of [Eu"'(H20)(31)],[CF,S0,1,. 2EtOH.H2O reported. Additionally the ability of the same complexes and of [E~"'(30)]~ + to cleave RNA in solution by transesterification of phosphate diesters has been The crystal structure of Na[Y"'(H20)(32)]-4H20 has been reported38 and compared with the structure of [Zr"'(H20)(32)] in solution. The yttrium complex displays monocapped square antiprismatic geometry whilst NMR spectroscopic studies suggest that the zirconium complex is of lower symmetry.The La(IIr) EU(III) and DY(III) complexes of (33) are remarkably inert to dissociation in water and the crystal structure of [La"'(03SCF3)(33)(EtOH)][CF3S03]2displays ten-coordina- ti~n.~~ In contrast complexes of (34) with EU(III) Gd(iIr) Tb(m) Yb(m) and Y(III) cations are eight-coordinate and preferentially form single diastereoisomers (either RRRR or SSSS at each phosphorus centre).40 The crystal structure of [H30][Y"'(34)] and NMR relaxivity studies of the Gd(i1i) complex are also reported. The formation and dissociation equilibria and kinetics of Gd(iri) complexes of unsymmetrically substituted derivatives of (24) that is (38)-(41) suggest that the formation of [Gd"'L] complexes proceeds via initial coordination of the metal to all the oxygen atoms and at least one nitrogen atom.41 Fourteen azacyclam ligands such as (36) have been prepared using a Ni(I1) template method.42 The crystal structure of [Ni"LI2+ [L is a 3-(4-tolylsulfonate) substituted azacyclam] has been determined and electrochemical investigations suggest that a .n-interaction between the Ni(I1) and the fifth nitrogen affects the reduction potentials.The spectroscopic properties of a series of heterobimetallic complexes of the bicyclam ligand (37) are reported.43 a-Amino-a-methylmalonate is oxidatively decarboxylated on a cobalt complex of 32 W.-J. Lan and C.-S. Chung J. Chem. Soc. Dalton Trans. 1994 191. 33 P. A. Goodson J. Glerup D. J. Hodgson K. Michelsen and U. Rychlewska Inorg. Chem. 1994,33,359. 34 A.W. Herlinger E. D. Funk R. F. Chorak J. W. Siebert and E. Roco Polyhedron 1994 13 69. 35 C. Creutz and M.H. Chou Inorg. Chem. 1994 33 3199. 36 K. O.A. Chin J. R. Morrow C. H. Lake and M. Rowen Churchill Inorg. Chem. 1994,33 656. 37 K. O.A. Chin and J. R. Morrow Inorg. Chem. 1994 33 5036. '' D. Parker K. Pulukkody F.C. Smith A. Batsanov and J.A. K. Howard. J. Chem. Soc. Dalton Trans. 1994,689. 39 S. Amin J. R. Morrow C. H. Lake and M. Rowen Churchill Angew. Chem. Int. Ed. Engl. 1994,33,773. 40 S. Aime A. S. Batsanov M. Botta J. A. K. Howard D. Parker K. Senanayake and G. Williams Inorg. Chem. 1994 33 4696. 4' K. Kumar T. Jin X. Wang J.F. Desreux and M. F. Tweedle Inorg. Chem. 1994 33. 3823. 42 F. Abha G. De Santis L. Fabbrizzi M. Licchelli A. M. Manotti Lanfredi P Pallavicini A.Poggi and F. Ugozzoli Inorg. Chem. 1994 33 1366. 43 K. Mochizuki S. Higashiya M. Uyama and T. Kimura J. Chem. SOC.,Chem. Commun. 1994 2673. S. L. W. McWhinnie (24) I=O,m =O,n =O,O =O,R=H (25) I=l,m =l,n=l,o=O,R=H (26) I=l,m=O,n =l,o=O,R=H (27) I=l,m=O,n=0,0=0,R=H (28) I=l,m =l,n =1.0 =1,R=H (29) I = 1 m =O n = 1 o =0 I?=Me (30)I = 0,m = 0,n = 0,o = 0 R = (CH,),OH (31) I = 0 m = 0,n = 0,o = 0 R = CH2CH(CH3)0H (H432) I = 0,m = 0,n = 0,o = 0 R = CH2COOH (33)I = 0,m = 0,II = 0,O = 0,R = CH&(O)NHZ (H434) I = 0 m = 0,IJ = 0,o = 0 R = CH,P(O)(OH)CH,Ph (H430) I=l,m =l,n =1,0 =l,R=CH&OOH (42).44 Twenty azamacrocyclic ligands including (26) (29) and (42) have been used to prepare Mn(I1) complexes of the form [Mn"CI,L] and their potential for catalytic superoxide dismutase activity assessed.45 Of the complexes tested only those of [15]aneN5 and [16]aneN showed any activity.The selectivity of isomers (43) and (44) for Zn(n) Cd(II) Hg(rr) and Pb(I1) have been compared by measuring stability constants and by determining the crystal structures of certain c~mplexes.~~ Different coordination modes have been observed; smaller cations are incorporated into the macrocyclic cavity whilst larger cations are bound only by the pendant arms of the ligands. Several ligands similar to (43)-(46) have been prepared by template methods using CU(II).~~ Chiral CU(II) complexes with cyclohexyl bridges in place of the ethyl bridges have been prepared with nitro group pendant arms and reduced with zinc to produce metal-free amine pendant arm ligands.The electrocatalytic activities of the Ni(Ir) complexes of (47)-(49) have been compared with that of the cyclam complex.48 The complexes of (48) and (49) are better catalysts than [Ni"(26)I2+ whilst that of (47) is not. The complexes [M"L12+ and [M"(H,L)] [L = (50),M = Cu or Nil have been 44 M. Yashiro S. Miura T. Matsuyama S. Yoshikawa M. Komiyama and S. Yano fnorg.Chem. 1994,33 1003. 45 D. P. Riley and R.H. Weiss J. Am. Chem. SOC. 1994 116 387. 46 P.G. Lye G. A. Lawrence M. Maeder B. W. Skelton H. Wen and A. H. White J. Chem. Soc. Dalton Trans. 1994 793. 41 P. V. Bernhardt P. Comba B. L. Elliott G.A. Lawrance M.Maeder M. A. O'Leary G. Wei and E. N. Wilkes Aust. J. Chem. 1994 47 1171. 48 E. Fujita J. Haff R. Sanzenbacher and H. Elias fnorg. Chem. 1994 33 4627. 357 The Coordination Chemistry of Macrocyclic Ligands ~haracterized.,~ In addition the stability constants of the complexes formed between (50) and five transition metals and Yb3+ have been determined. R?NAN,R3 0 R1/N WN'% (43) X=H (45)R=H (44) x =o (46) R = 0 Template synthesis of a series of ligands including (51)-(53) has been achieved using CU(II) and one of the series has been attached to an exchange resin.50 The attachment has been probed by comparison of the spectroscopic properties of a bound CU(II) cation with those of an unbound complex. A new diastereoisomer of the CO(III) complex of (49) y-trans-[Co"'C12(49)] +,has been synthesized and its properties compared with those of other known dia~tereoisomers.~ Two isomers of [Ni"(47)I2 + have been ~ynthesized~~ by the reduction of [Ni"(54)]2' and the crystal structures of C-RSSR-[Ni1(47)][ClO,] C-RSSR-[Ni1'(47)] [ClO,] C-RRSS-[Ni1'(47)][ClO,] 2 49 Q.-H.Luo S.-R. Zhu M.-C. Shen S.-Y. Yu Z. Zhang X.-Y. Huang and Q.-J.Wu J. Chem. SOC.,Dalton Trans. 1994 1873. 50 A. Bayada G.A. Lawrance M. Maeder and M. A. O'Leary J. Chem. SOC.,Dalton Trans. 1994 3107. 51 B.-H. Chen C.-Y. Lai Y. Yuan and C.4. Chung J. Chem. Soc. Dalton Trans. 1994 2959. 52 D.J. Szalda E. Fujita R. Sanzenbacher H. Paulus and H. Elias Inory. Chem. 1994 33 5855. S. L. W. McWhinnie and [Ni"(54)][C1O4] determined.The binding constants of CO with the Ni(1) complexes have also been quantified. The ligands (55k(57) all form monometallic complexes with copper but only (56) and (57) also form bimetallic complexes.53 Not all of the macrocyclic donor atoms participate in coordination in the monometallic complexes; the crystal structure of [CuyC1,(56)] is reported. A series of co(111) complexes of (26) (58),and (59) of formula tran~-[Co"'R(H,0)L]~+(R = Me Et Pr or Bu) has been synthesized by a photocatalytic procedure which involves the capture of an alkyl radical by an aza macrocyclic cobalt(1r) c~mplex.'~ Metal complexes [M"(H2O)Ll2 + [L = (60) or (61) M = Ni or Cu] and [Zn"LI2+ [L = (60) or (61)] have been synthesized and the crystal structure of [Zn"(60)][BF4] determined." The complexes [Co"C1(62)] and + [Cu"C1,(62)] have been synthesized; electrochemical investigations suggest that the CU(I) complexes are also stable.56 (52) X = H (53)x =o (56) n = 1 (57) n = 2 (58) R= H (59) R= Me (60) R=H (61) R= Me s3 A.Andres C. Bazzicaluppi A. Bianchi E. Garcia-Espaila S. V. Luis J. F. Miravet and J. A. Ramirez J. Chem. SOC.,Dalton Trans. 1994 2995. s4 H. A. A. Omar P. Moore and N. W. Alcock J. Chem. SOC.,Dalton Trans. 1994 2631. s5 S. J. Grant P. Moore H.A. A. Omar and N. W. Alcock J. Chem. SOC. Dalton Trans. 1994 485. " Z. A Siddiqi and V. J. Mathew Polyhedron 1994 13 799. The Coordination Chemistry of Macrocyclic Ligands The N-H hydrogens of [Co1(63)]+ undergo rapid H/D exchange with CD,CN and slower C-H H/D exchange.57 The reaction of [Ni"(64)]2f with nitromethane produces [Ni"(65)I2 + ;the crystal structure of both complexes as their perchlorate salts are reported.58 Intermediates in the template synthesis of [Ni"(66)I2 have been + isolated and the rate constants of some of the interconversions measured.59 Further spectroscopic data have been presented for the bimetallic Fe(I1) complex [FeY(NCMe),(67)l4+ ; a study of the mixed-valence product formed by oxidation suggests that on the Mossbauer timescale it is delocalized or class I11 in nature.60,61 Similar studies on a Ru" bimetallic complex [R~:C1,(67)]~+ suggest that the mixed-valence complex is also valence-averaged.62 [Ni"(68)] has been used as a model for factor F430in the reductive dehalogenation of alkyl halides.Deuteriation studies suggest that the reaction involves not only electron transfer but also nucleophilic substitution of a halide.63 Butadiene Zr(1v) complexes incorporating (68) have been prepared and the crystal structures of [zr1"(Tj4-C,H6)(68)] and [Zr'"(py)(y4-C,H,)(68)] determined.64 Multiply bonded germanium-chalcogen units have been synthesized by bonding the germanium into (69) and the crystal structures of the products have been determined.65 Fe(1) and Fe(rr) complexes of (70) with imidazole axial ligands have been prepared. Crystal structure determinations revealed an alteration in orientation of the axial ligands on changing the oxidation state.66 57 E. Fujita and C.Creutz Inorg. Chem. 1994 33 1729. 58 S.G. Kang M.4. Kim D. Whang and K. Kim J. Chem. Soc. Dalton Trans. 1994 853. 59 N. F. Curtis A. R. Davis and F. W. B. Einstein Aust. J. Chem. 1994,47 1885. 60 H. S. Mountford D. B. MacQueen A. Li J. W. Otvos M. Calvin R. B. Frankel and L. 0.Spreer Inorg. Chem. 1994 33 1748. 61 L.O. Spreer A. Li D.B. MacQueen C.B. Allan J.W. Otvos M. Calvin R.B. Frankel and G.C. Papaefthymiou Inory. Chem. 1994 33 1753. 62 L. 0.Spreer C. B. Allan D.B. MacQueen J. W. Otvos and M. Calvin J. Am. Chem. SOC.,1994,116,2187. 63 T. Arai K. Kashitani H. Kondo and S. Sakaki Bull. Chem. SOC.Jpn. 1994 67 705. 64 L. Giannini E. Solari C. Floriani A. Chiesi-Villa and C. Rizzoli Anyew. Chem. Int. Ed. Engl. 1994 33 2204. 65 M.C. Kuchta and G.Parkin J. Chem. Soc. Chem. Commun. 1994 1351. 66 F. Wiesemann R. Wonnemann B. Krebs H. Keutel and E.-G. Jager Angew. Chem. Int. Ed. Engl. 1994 33 1363. S. L. W. McWhinnie A correlation has been found between the magnitude of the antiferromagnetic exchange coupling constant and the Ni-0-Ni bridge angle in a series of bimetallic Ni(rr) complexes of (71).67,68 Tetrazinc@) and tricobalt(r1) complexes of (72) have been OYOEt R (H268) R=H (H269) R =Me (H272) synthesized and their crystal structures determir~ed.~' The chiral macrocyclic ligand (73) and a large number of monometallic and bimetallic complexes have been pr~duced.~' The dinuclear CU(II) complexes of (74) and (75) have been synthesized along with similar complexes of the larger hexaaza and octaaza analogue^.^ Several crystal structures show the copper to have regular square-planar geometry in each case.The effects of n-rc interactions between bound axial ligands in [Fe"L2(76)] (L is a variety of aromatic N-donor moieties for example pyridine or benzonitrile) and the end phenyl groups of the ligand have been in~estigated.~~ A variety of attractive and repulsive interactions results in variation of the macrocyclic ligand configuration. [Uv'02]2+has been used as a template in the synthesis of (77) leading to the isolation of [UV'O2(77)] [NO,] .7 67 K. K. Nanda R. Das L. K. Thompson K. Venkatsubramanian P. Paul and K. Nag Inorg. Chem. 1994 33 1188. 68 K. K. Nanda L.K. Thompson J.N. Bridson and K. Nag J. Chem.Soc. Chem. Commun. 1994 1337. 69 M.J. Grannas B.F. Hoskins and R. Robson Inorg. Chem. 1994 33 1071. 'O C. Fraser R. Ostrander A. L. Rheingold C. White and B. Bosnich Inorg. Chem. 1994 33 324. P.A. Gugger D.C.R. Hockless G. F. Swiegers and S.B. Wild Inorg. Chem. 1994 33 5671. l2 D.V. Stynes Inorg. Chem. 1994 33 5022. 73 W. Radecka-Paryzek and E. Luks Polyhedron 1994 13 899. The Coordination Chemistry of Macrocyclic Ligands 36 1 $4 c :I (73) (74) (75) Ph ,0-N mN-O ,Ph B B Ph’ ‘0-N N-0’ ‘Ph Other Donor Sets.-Gas-phase complexation studies of a number of polyethers including 12-crown-4 with monopositive alkaline earth metal ions have been reported.74 Ligands (78) and (79) and their dimers have been synthesized; slightly higher yields are obtained with SbCl as a template.75 The chiral recognition properties of a number of crown ether ligands including (80)and (81) towards amino acid esters have been assessed using deuterium-labelled guests.76 The use of FAB mass spectrometry easily enabled detection of binding interactions between host and guest.The complexation properties of some new dicobalt-complexed acetylenic crown ethers such as (82) and (83) towards alkali metals appear to be related to the hole size of the macr~cycle.~~ The results of molecular dynamic investigations on a series of [14]aneS ligands with increasing numbers of methyl substituents have been used to design trithia macrocycles with a set of endodentate sulfurs capable of coordinating to a metal without pre~rganization.~~ Complexes [Niy(p-Cl)2L] (L = [12]aneS4 [14]aneS4 or [16] aneS,) have been isolated by the reaction of NiCl with the appropriate macr~cycle.~~ Although the Ni-Ni distances are similar in each complex the Ni-S distance increases as the size of the ligand hole size increases.CU(II/I) electron-transfer kinetics have been studied using dialcoholic derivatives of [14]aneS4.80 Crystal structures are reported 74 H.-F. Wu and J.S. Brodbelt J. Am. Chem. Soc. 1994 116 6418. i5 Y. Habata F. Fujishiro and S. Akabori J. Chem. Soc. Chem. Commun. 1994 2217. 76 M. Sawada Y. Takai H. Yamada T. Kaneda K. Kamada T. Mizooku K. Hirose Y. Tobe and K. Naemura J. Chem. SOC. Chem. Commun. 1994 2491. ” S.C. Bennett J.C. Jeffery and M.J. Went J. Chem. Soc.Dalton Trans. 1994 3171. ” G.A. Forsyth and J. C. Lockhart J. Chem. SOC.,Dalton Trans. 1994 2243. A.J. Blake M. A. Halcrow and M. Schriider J. Chem. Soc. Dalton Trans. 1994 1463. N.E. Meagher K.L. Juntunen M.J. Heeg C.A. Salhi B.C. Dunn L.A. Ochrymowycz and D.B. Rorabacher Inory. Chem. 1994 33 670. S. L. W. McWhinnie for the two complexes studied. Reversible addition of acetone and benzaldehyde to tran~-[Mo'~(NH)(Tf)(84)]to form a-hydroxyalkylimido complexes" and crystal + structures of the two products are reported. The isomerization of the spirobenzopyran portion of (85) to the open form in (78)n = 0 OMe OMe (79)n = 1 (80) (811 Ph2P-PPh2 (82) R= H (83) R= Me solution82 has been induced by addition of the alkaline earth metals Ca2+ and Sr2+; alkali metal cations had little effect.Pendant arm derivatives of ligands such as (86) and (87)have been synthesized for example (88) and (89),and their interaction with CO(II) CU(II) Ni(II) Zn(II) and Cd(I1) studied.83 Spectroscopic data and stability constants are reported as well as the crystal structures of the complexes formed between (89) and CU(II) and Ni(I1). Data indicate that the pyridine pendant arms participate in coordination to the metals both in solution and in the solid state. EPR studies have been performed on CU(II) complexes of (90)-(94) with various co-ligand~,~~ and several R1 T. Yoshida T. Adachi N. Yabunouchi T. Ueda and S. Okamoto J. Chem. Soc. Chem. Commun. 1994 151. 82 M. Inouye Y. Noguchi and K.Isagawa Angew. Chem. Int. Ed. Engl. 1994,33 1163. 83 K. R. Adam L. F. Lindoy B. W. Skelton S. V. Smith and A. H. White J. Chem. Soc.,Dalton Trans.,1994 3361. 84 V. Felix R. Delgado M.T. S. Amorim S. Chaves A.M. Galvbo M. T. Duarte M. A. A. F. de C.T. Carrondo I. Moura and J. J. R. Frausto da silva J. Chem. SOC.,Dalton Trans. 1994 3099. The Coordination Chemistry of Macrocyclic Ligands 363 crystal structures have been determined. As the macrocyclic ring decreases in size the degree of folding necessary to accommodate the metal increases. Several new tetraphosphorus ligands including (95)-(97) have been ~ynthesized~~ and shown to bind one or two [Mo(CO),] units. The crystal structures of CMo(C0)4(95)1 CMo(C0)4(96)I C(Mo(CO),}2 (WI and C(Mo(CO),) 2 (96)I have 3 been determined.The new diphosphadithia macrocycle (98) has been synthesizeds6 and complexes with Pt(u) Pd(II) and Rh(II1) have been isolated; all three complexes exhibited irreversible reduction processes. The first example of a cationic Pt(1v) complex incorporating selenium donors has been reported and the crystal structure of [Pt'VC12(99)][PFJ determined.87 (86) m =2,n =2,R1=R2=H (90)m = 0,n = 0 R = H (87)m = 2,n = 3,R1= R2= H (91)m = 0.n = 0 R = Me (88)m = 4,n = 3,R' = R2= CH2C5H4N (92)m =l,n =O,R=H (93)m =l,n =1,R=H (89)m = 2,n = 3,R1= H,R2= CH2C5H4N (94)m =l,n =1 R=Me (95)m = n = 1 (98) (99) (96)m =O,n =1 (97)m = 0,n = 4 4 Pentadentate Macrocycles The dissociation kinetics of complexes of Ce(m) and Gd(IrI) with (lOOk(104)have been studied.88As the ring size increases the inertness of the complexes increases reflecting greater participation of the amide oxygen in coordination; the use of (104)leads to an increase in the tendency to dissociate.The stabilities of a series of Zn(I1) and Cd(I1) complexes with ligands including (105)-(109) have been studied" and the crystal 85 F. Laporte F. Mercier L. Ricard and F. Mathey J. Am. Chem. SOC. 1994 116 3306. 86 N. R. Champness C. S. Frampton G. Reid and D. A. Tocher J. Chem. SOC.,Dalton Truns. 1994 3031. 87 W. Levason J. J. Quirk G. Reid and C. S. Frampton Inorg. Chem. 1994 33 6120. 88 K.-Y. Choi K.-S. Kim and J.C. Kim Polyhedron 1994 13 567. 89 K. R. Adam S. P. H. Arshad D. S. Baldwin P. A. Duckworth A. J.Leong L. F. Lindoy B. J. McCool M. McPartlin B. A. Tailor and P.A. Tasker Inorg. Chem. 1994,33 1194. S. L. W. McWhinnie structures of [Zn"( 105)][C104] [Cd"(ClO,)(MeOH)( 109)][C104] [Zn"(NO,) (H20)(108)][C10,]-EtOH and [{Cd"(N0,)(108)),(p-N0,)2]~2EtOH have been determined. The stabilities of the complexes are discussed in terms of the size of the chelate rings. Adducts formed between truns-[VOCl,(H,O),] and 15-crown-5 benzo-15-crown- 5 and 18-crown-6 have been studied using crystallography and EPR spectros~opy.'~ EU(III) extraction from dichloromethane has been achieved by the use of benzo-15- crown-5 in the presence of picrate anion.' Practical and theoretical studies have been carried out to give an insight into solvent effects on the extraction from water of sodium picrate by 15-crown-5.' The ion-pair formation constant in water is determined using regular solution theory and the results are then verified experimentally.The crystal structures of [Eu"'(NO3),(NCMe)(l6-crown-5)][Eu"'(NO~)4(H2O)~]~0.5(16-crown-5) and [Lu"'(N0,),(H20),]~(16-crown-5)have been reported;' both EU(III) cations are ten-coordinate whilst the LU(III)complex is nine-coordinate. Molecular sensors have been designed oiz. [Cr(CO),(q6-benzo-l5-crown-5)]and [Cr(CO),(q6-benzo- 18-crown-6)] in which the ~(CO) modes of vibration shift to higher wavenumber as the concentration of alkali cations in solution increase^.'^ The crystal structure of [Cr(CO),(q6-benzo-15-crown-5)Na(NCS)J is reported. Ligands (112) and (1 13) have /COOH (loo) n =1 (101) n =2 (102) n =3 (103) /'I = 4 (105) X = NH Y = NH m = 2,n = 2 p = 2 (110) X = OTS (1 13) (106) X=S,Y=S,m =2,n =2,p =1 (111) X=l (107) X=S,Y=O,m =2,n =2,p =2 (112) x= OMe (108) X=O,Y=NH,m =2,n =2,p =4 (109) X=NH,Y=O,m =2,n =2,p =2 90 N.Azuma T. Ozawa and K. Ishizu Polyhedron 1994 13 1715. 91 Y. Zhangyu K. Fanqi Q. Mei W. Binghai Z. Bin and M. Shenhua J. Chem. SOC.,Chem. Commun. 1994 1753. 92 Y. Takeda and C. Takagi Bull. Chem. SOC.Jpn. 1994,67 56. 93 J. Mao Z. Jin J. Ni and L. Yu Polyhedron 1994 13 313. 94 C.E. Anson C. S. Creaser and G.R. Stephenson J. Chem. SOC. Chem. Commun. 1994 2175. The Coordination Chemistry of Macrocyclic Ligands 365 been synthesized from (110) and (1 11) respectively in the presence of ~trontium.'~ The electrochemical properties of (1 14) are dependent on the conformation induced by the addition of Group 1 or 2 cation^.'^ 2 :1 complexes are formed with Mg2' and Na' whilst a 1 :1 sandwich complex which has been investigated crystallographically is formed with Ba2'.Monometallic and bimetallic complexes with Cu(rr) are formed with the novel ligands (115) and (116).97 Crystal structures of both complexes are reported. Thermodynamic parameters have been determined for Na' K' Cu2' and Ca2+ with a number of ligands including (117k(122).'* The stability of the complexes is increased by the introduction of coordinating pendant arms. Complexes [ML] X [L = (123) or (124); M = CO(II) Ni(Ii) or CU(II);X = C1 Br or NO,] have been synthesized" and their coordination geometries probed spectroscopically.Octahed- ral square-planar and square-pyramidal geometry is proposed for the Co(rr) Ni(rr) and Cu(rr) complexes respectively. Discrimination of the order of lo6in favour of Ag(i) over Pb(r1) has been found in stability studies for (125).'0° 5 Hexadentate Macrocycles The reactivity of Gd(i1i) and La(1ri) complexes of (126) with salicylaldehyde has been 95 G. Doddi G. Ercolani P. La Pegna and P. Mencarelli J. Chem. SOC.,Chem. Commun. 1994 1239. 96 P.D. Beer Z. Chen A. Grieve and J. Haggitt J. Chem. SOC. Chem. Commun. 1994 2413. 97 C. F. Martens R. J. M. Klein Gebbink M. C. Feiters H. Kooijman W. J. J. Smeets,A. L. Spek and R. J. M. Nolte Inorg. Chem. 1994 33 5541. 98 R. M.Izatt X. Zhang H. An C.Y. Zhu and J. S. Bradshaw Inorg. Chem. 1994 33 1007. 99 M. Shakir and S. P. Varkey Polyhedron 1994 13 791. loo K. R. Adam D.S. Baldwin A. Bashall L. F. Lindoy M. McPartlin and H. R. Powell J. Chem. SOC. Dalton Trans. 1994 237. S. L. W. McWhinnie compared."' Reaction of the La(II1) complex produces [La"'(OTf),( 127)] whilst the Gd(II1) complex unexpectedly produces the Gd(II1) complex of tris(2-(salicy1ideneamino)ethyl)amine. Ni(II)-mediated templates syntheses have been em- ployed to produce (128)-(131),'02 and reaction of [Ni"(128)]2+ with acetic anhydride produces [Nil'( 132)] .In the solid state [Ni"( 129)] forms a coordination polymer + + in which nitrile groups coordinate the nickel atoms held in the neighbouring macrocycle.An unusual CU(I) complex of (133) has been rep~rted.''~ Reaction of (133) with CuCl produces [Cu'Cl(H 133)12+ in which the CU(I) is tetrahedrally coordinated to three nitrogens of the macrocycle and to a chloride and in which the uncoordinated piperidine nitrogens are protonated. [C~;(134)]~ reacts with dioxygen to form a + (p-0,) complex which in turn decomposes to form a product in which one of the aromatic rings is hydroxylated. lo4Monometallic and bimetallic CU(II) complexes of the new macrocycle (135) have been prepared and their protonation constants mea~ured.''~ Crystal structures of the Zn(II) Cd(II) and La@) complexes of (136) have been determined; the helicity of the ligand appears to be dependent on the size of the metal cation.lo6 Complexes of Y(rr~) La(III) Gd(Iri) and DY(III) of (137) are reported along with the crystal structure of the Gd(rI1) complex [Gd"'(H,O),( 137)] C1,-3H,0.'07 Relaxivity studies of the Gd(I1r) complex are also reported as well as the synthesis of the novel ligand (138).The crystal structure of [La"'(O,CMe)(NCS),(139)]shows that the La(rrr) is ten-coordinate."* The lumines- cence properties of the EU(III) Tb(m) and Gd(m) complexes of (140) have been reported;' ''the EU(III) and Tb(II1) complexes present the highest molar extinction coefficients found amongst water-soluble lanthanide complexes of encapsulating ligands. Template synthesis employing Ni(I1) resulted in the formation of [NiY(141)] the crystal structure of which is reported."' The effects of ligating anions on the catalase activity of dinuclear Mn(I1) complexes of (142)-(144) have been studied and the crystal structure of [Mn','C1(l42)][C1O4] is reported.'" Dissociation of the ligating anion is proposed as the rate-determining step in the catalytic decomposition of H,O,.Ab initio studies on complexes of 18-crown-6 suggest that in the gas phase the ligand preferentially binds smaller cations.' However in solution the experimentally observed selectivity is recovered even if only a few water molecules are considered. A weak donor-acceptor complex is formed when (18-crown-6) reacts with potassium thiocyanate in liquid SO,."3 A crystal structure of the product showed it to be lo' M. Kanesato T. Yokoyama and 0.Itabashi Chem. Lett. 1994 2331.lo' M. P. Suh B.Y. Shim and T.3. Yoon Inorg. Chem. 1994 33 5509. lo3 K. Rissanen J. Breitenbach and J. Huuskonen J. Chem. Soc. Chem. Commun. 1994 1265. lo4 M. Becker S. Schindler and R. van Eldik Inorg. Chem. 1994 33 5370. lo5 A. Llobet J. Reibenspies and A. E. Martell Inorg. Chem. 1994 33 5946. lo6 S. W.A. Bligh N. Choi E. G. Evagorou W. -S. Li and M. McPartlin J. Chem. Soc. Chem. Commun. 1994 2399. lo' S. W. A. Bligh N. Choi W. J. Cummins E. G. Evagorou J. D. Kelly and M. McPartlin J. Chem. Soc. Dalton Trans. 1994 3369 lo* F. Benetollo G. Bombieri and L. M. Vallarino Polyhedron 1994 13 573. log N. Sabbatini M. Guardigli I. Manet F. Bolletta and R. Ziessel Inorg. Chem. 1994 33 955. 'lo V. B. Arion N. V. Gerbeleu V. G. Levitsky Y. A. Simonov A. A. Dvorkin and P.N.Bourosh J. Chem. Soc. Dalton Trans. 1994 1913. T. Nagata Y. Ikawa and K. Maruyama J. Chem. Soc. Chem. Commun. 1994 471. l2 E. D. Glendening D. Feller and M. A. Thompson J. Am. Chem. Soc. 1994 116 10657. A. J. Downs A. J. Edwards R. E. Martin and S. Parsons J. Chem. Soc. Dalton Trans. 1994 753. The Coordination Chemistry of Macrocyclic Ligands 36 7 (117) n =1,R=H (118) n =1 R =CH2CH20H (1 19) /I = 1 R=CH,CH,OCH2CH,C5H5N (120) /I =1,R=H (121) n =1 R=CH2CH20H (122) n =1 R =CH2CH2OCH2CH2C5HsN n (128) n =2 X =OH (129) n =2 X =cn (130) n =3 X =OH (131) n =5 X =CN (132) n =2 X =OCO-CH3 (133) (134) =1 (135) n =2 S. L. W. McWhinnie (137) R = H (138) R = Me (139) MeS SMe In In (H2142) n = 2 X = Me (H2143) n = 2 X = Br (H2144) n = 3 X = Me The Coordination Chemistry of Macrocyclic Ligands [K( 18-crown-6)][NCS.S02].The coordination of [MX412 -anions to [M( 18-crown- 6)]"+ (M = Rb T1 or Ba) has been studied;' l4 regular tetrahedral anions favour facial coordination to the cations whilst flattened tetrahedra favour edge coordination. The crystal structures of [U'v02(18-crown-6)][OTfl and [U'V0,(145)][OTfJ2 have been reported.' In both cases the uranyl group is bonded by all six oxygens of the crown to complete a hexagonal bipyramidal coordination geometry. The quenching of fluor- escence by metal cations of various host molecules such as (146)-(148) has been studied.l16 In all cases the most efficient quenching was observed in the presence of Cu2+ and Hg2+ .Extraction studies suggest that (149) can bind two Ag' cations but when the host is oxidized to form an intramolelcular disulfide link the extraction is effectively zero.' The two new hexathia ligands (150) and (151) have been prepared and their conformational and complexing properties investigated.' l8 Whereas (1 50) appears to favour exodentate coordination and aggregation when interacting with metals the complexes [M\(NCMe),(lSl)] (M = Cu or Ag) have beenisolated with the ortho-xylyl ligand. The crystal structure of [Cu'( 1 52),][BF4] reveals that each ligand coordinates the copper with two sulfurs producing a distorted tetrahedral geometry.' l9 Crystallographic and magnetic susceptibility studies of [Cu','(p-OH)(153)] [C104]3~Me2C0'20show that the two copper atoms are bridged by the OH group and are very strongly antiferromagnetically coupled making them virtually diamagnetic.The photochemistry of (154) in the presence of a variety of guests has been investigated.121 When [Pt1'(NH3)2(bipy)]2+ is used as a guest the absorption spectrum is significantly different from that of the sum of the two separate components. CPK model studies suggest that the guest is accommodated within the cylindrical cavity of the host with hydrogen-bond interactions between the amine ligands and the N204 macrocycles. A new series of arborols has been synthesized incorporating components l4 N. S. Fender S. S. Finegan D. Miller M. Mitchell I. A. Kahwa and F. R. Fronczek Inorg. Chem.1994 33 4002. '15 L. Deshayes N. Keller M. Lance A. Navaza M. Nierlich and J. Vigner Polyhedron 1994 13 1725. '16 T. M. Fyles and V. V. Suresh Can. J. Chem. 1994 72 1246. 11' T. Nabeshima H. Furusawa and Y. Yano Angew. Chem. Int. Ed. Engl. 1994 33 1750. 'la B. de Groot S.J. Loeb and G. K. H. Shimizu Inorg. Chem. 1994 33 2663. '19 S.L. Ingham and N. J. Long Angew. Chem. Int. Ed. Engl. 1994 33 1752. lZo D. Wang H. Xiang G. Wang Z. Han X. Yang H. Hu and K. Yu J. Chem.Soc.,Dalton Trans. 1994,3325. R. Ballardini V. Balzani A. Credi M.T. Gandolfi F. Kotzyba-Hibert J.-M. Lehn and L. Prodi J. Am. Chem. SOC. 1994 116 5741. S. L. W.McWhinnie (146) L= (147) L= /-(148) L= n (153) The Coordination Chemistry of Macrocyclic Ligands 371 such as (155).'22 The complexing abilities of the new molecules towards alkali metals have been assessed using extraction studies; the best extractions were achieved for molecules in which the carbonyl groups had been reduced to methylenes.[M"(155)]2' (M = Ni or Co) and [Ni"(156)I2+ have been synthesized and the crystal structure of [Ni"(l 55)][PF6] determined.lZ3 Aerial oxidation of [Cox'( 155)] [PF,] yields a CO(III) complex with a structure assessed to be [Co;'(155)] [PF,],.3H20. Several of Pb(II) Cd(II) and Ag(1) complexes of (157) have been prepared along with two Pb(I1) complexes of (156).124 Structural determinations on [Pb11(MeOH)(H20)(157)][C104]2 and [Hg"(SCN),( 157)I.MeOH show that both metals are seven-coordinate. The crystal structure of trans-[Hg"C12(159)] has the metal coordinated by the chloride anions and only the four oxygen donors of the macr~cycle.'~~ OCH2C02Et PhCH2O R-N OJ OCH2C02Et W W (155) R= H (156) R=Me ono e ,4 NC CN 6 Macrocycles of Higher Denticity The complex [Nilx( 160)12 ,synthesized by a template method displays a strong ligand + field for a square planar Ni(11) complex.'26 A crystal structure determination confirmed the square planar geometry and reduction led to the production of [Ni'(l60)]+ A crystal structure of [Ni~(~3-OH)(~-H,O)2(C10,)(161)][C104],~2Me,CO~HzO re-122 T.Nagasaki 0.Kimura M. Ukon S. Arimori I. Hamachi and S. Shinkai J. Chem. SOC.,Perkin Trans. 1 1994 75. 123 A. J. Blake G. Reid and M. Schroder J. Chem.SOC.,Dalton Trans. 1994 3291. 124 A. Bashall M. McParlin B. P. Murphy H. R. Powell and S. Waikar J. Chem. SOC.,Dalton Trans. 1994 1383. 125 J. W. Sibert S. J. Lange C. Stern B. M. Hoffman and A.G. M. Barrett J. Chem. SOC.,Chem. Commun. 1994 1751. 126 M. P. Suh I.S. Kim S.-J. Cho and W. Shin J. Chem. SOC.,Dalton Trans. 1994 2765. S. L. W. McWhinnie veals that the cation lacks symmetry.'27 The four Ni(11) ions are all in a distorted octahedral environment. All are coordinated by two amine nitrogens two bridging phenoxides and a bridging water molecule; three are coordinated to the triply bridging hydroxide whilst the fourth is coordinated to a perchlorate anion. A template condensation of 1,3-diaminopropane and 3,6-diformylpyridazine led to a compound initially thought to contain (162) but a crystal structure analysis revealed it to be [Pb11(163)][C10,]2.'28 In the cation (163) is folded and both Pb(I1) cations are eight-coordinate.The binding of the phosphate and phosphite anions by various cobalt complexes of (164) has been studied along with the affinity of [Coy(p-+ PO,)( 164)12 for dioxygen.12' Decomposition of [Co','(p-OH)(p-PO,)(p-0,)(164)13+ led to the production of phosphate which was identified by 31P NMR spectroscopy. Me I OH HN NH 1 Me+OH HN NH "' K.K. Nanda K. Venkatsubramanian D. Majumdar and K. Nag Znorg. Chem. 1994 33 1581. lZ8 S. Brooker R. J. Kelly and G.M. Sheldrick J.Chem. SOC. Chem. Cornmun. 1994 487. lZ9 R. J. Motekaitis and A. E. Martell Inorg.Chem. 1994 33 1032. The Coordination Chemistry of Macrocyclic Ligands Association of [(bipy),ClR~~'(p-pz)Ru~''(NH~)~]~+ with various crown ethers including (165) dibenzo-30-crown-10 dibenzo-36-crown-12 and dibenzo-42-crown- 14 has been assessed by monitoring the changes in the energy of the intervalence charge transfer band.'30 The strength of binding of the crown ethers can vary by up to four orders of magnitude as the solvent is varied. The properties of lanthanide complexes of (167) have been compared with those of (166) and (168); the crystal structure of [Pr111(N03)4( 167)].1.2MeOH shows a ten-coordinate Pr(II1) cation.' 3' The stabilities of CU(II) Zn(II) Cd(II) and Pb(I1) complexes of (169t(171) have been determined as has the crystal structure of [Zn11(170)]+2132 The Zn(Ir) is five- coordinate with only the amine nitrogens involved in bonding.7 Cryptands and Cages The crystal structures of [La1*'(H,0)(172)]C12.H,0 and [La"'(Tf)(l72)][Tfl2 reveal X.L. Zhang C.R. Kankel and J.T. Hupp Inorg. Chem. 1994 33 4738. 131 K. D. Matthews I. A. Kahwa and D. J. Williams Inorg. Chem. 1994 33 1382. 132 A. Andres C. Bazzicalupi A. Bencini A. Bianchi V. Fusi E. Garcia-Espaiia P. Paoletti and B. Valtancoli Inorg. Chern. 1994 33 617. S. L. W. McWhinaie the La"' to be ten-coordinate in both cases.133 The cation is coordinated by all the donor atoms of the cryptand and by one monodentate ligand. Ligand (172) is an effective masking reagent in the selective extraction of calcium and strontium from water into cyc10hexane.l~~ The effect of the cryptand is greatest at pH values approaching neutral.The formation of ligated alkali cations from the metal has been used to form salts of n-hydrocarbon anions; the cation [Na(l73)]+ has seven- (169) n =1 R=H (170) n =l,R=Me (171) n =2 R =Me coordinate sodium.' 35 The chromogenic reagents (174) and (175) are both sensitive to Pb(11)'~~ at concentrations of mol dm-3. Additionally (174) binds other doubly charged cations (Ca2+ Sr2+ Hg2+ and Cd2+) more strongly than does (175) but for both ligands these metals are bound less strongly than lead. Several bicyclic hexaammine ligands such as (176)-( 180) and (184) together with some protonated examples have been obtained in their metal-free form by reduction of the CO(III) complexes (which are produced from template syntheses) to their Co(11) ana10gues.l~~ The structures of a number of the ligands and some Zn(II) and Mg(II) complexes are reported.A decomposition product from the attempted synthesis of a CU(II)complex of (184) has been ~haracterized.'~~ A crystal structure analysis revealed an N macrocycle with (CH,NH,Me)+ pendant arms the CU(II) cation being bound to the four nitrogens of the ring and to an apical chloride anion. Species isolated following the reduction of CO(III)complexes have been shown to contain (185) and (186).139Further decomposition products have been isolated from the reaction of [C0"'(187)]~+ following treatment with excess base.',' [C~"(188)]~+has been isolated; its EPR spectrum is consistent with the X-ray structure and an angular overlap treatment of the absorption spectrum led to good agreement between the calculated and experimental g-value.' 41 Treatment of parent CO(III)amino-substituted complexes of (180) and (190) with 133 J.Mao and Z. Jin Polyhedron 1994 13 319. 134 T. Sasaki S. Umetani M. Matsui and S. Tsurubou Chem. Lett. 1994 1195. 135 H. Bock C. Nather Z. Havlas A. John and C. Arad Angew. Chem. Znt. Ed. Engl. 1994 33 875. 136 A. Mason A Sheridan 1.0. Sutherland and A. Vincent J. Chem. Soc. Chem. Commun. 1994 2527. 13' G. A. Bottomley I. J. Clark I. I. Creaser L. M. Engelhardt R. J. Geue K. S. Hagen J. M. Harrowfield G. A. Lawrance P. A. Lay A. M. Sargeson A. J. See B. W. Skelton A. H. Allan and F.R. Wilner Aust. J. Chem. 1994 47 143. 13' J. M. Harrowfield A.M. Sargeson B. W. Skelton and A.H. White Aust. J. Chem. 1994,47 181. 139 1.1. Creaser T. Komorita A.M. Sargeson A. C. Willis and K. Yamanari Aust. J. Chem. 1994,47,529. 140 P. Osvath and A.M. Sargeson Aust. J. Chem. 1994 47 807. 14' T.M. Donlevy L.R. Gahan T.W. Hambley G.R. Hanson K.L. McMahon and R. Stranger Inorg. Chem. 1994 33 5131. The Coordination Chemistry of Macrocyclic Ligands (174) m =l,n =3 (175) m =n =3 (176) R= H (177) R=NH2 (178) R=CI (179) R = NO2 (180) R = (NH3)' (181) R = (NMe,)+ (182) R = NMe2 (183) R = (NMe3)+ formaldehyde and formic acid leads to complexes of (181) (182) (191) and (192). Further methylation employing Me1 led to the isolation of complexes of (183) and (193).'42 Comparisons are made between the conformations of the new and parent complexes and the crystal structure of [Co"'( 183)]' is reported.The self-exchange + reactions together with the redox and magnetic properties of [Co"'( 189)13+ and [C0"(189)]~+have been investigated and the crystal structure of the latter has been determined.'43 It is suggested that methylated derivatives of (176)act in a tetradentate manner with CU(II)and Ni(1I) in both the solid state and in s01ution.l~~ The synthesis of larger cavity analogues of (176) incorporating propyl bridges has proved difficult but models suggested that the use of a metal producing longer M-N bonds than those of CO(III)-Nmight prove profitable. Thus the use of Rh(I1r) has enabled syntheses of complexes of (194b(197);the Rh(III) complex of (190) has been prepared for cornparis~n.~~' Electrochemical studies demonstrate that the Rh(11) state is stabilized by the larger cavity and structural studies have been carried out on [Rh"'(190)]4+ and [Rh"'(194)I3+ Another strategy to achieve larger cavities has employed'46 CO(III); [C0"'(198)]~ was successfully synthesized and then reduced to + [C0"'(199)]~+,the crystal structure of which was determined.142 P. V. Bernhardt A.M. T. Bygott R. J. Geue A. J. Hendry B. R. Korybut-Daszkiewicz P. A. Lay J. R. Pladziewicz A.M. Sargeson and A.C. Willis Inorg. Chem. 1994 33 4553. 143 T. M. Donlevy L. R. Gahan and T. W. Hambley Inorg. Chem. 1994 33 2668. 144 P. V. Bernhardt,J.M. Harrowfield D. C. R. Hockless and A.M. Sargeson Inorg. Chem. 1994,33,5659. 145 R. J. Geue M. B. McDonnell A. W.H. Mau A.M. Sargeson and A. C. Willis J. Chern. SOC. Chem. Commun. 1994 667. 146 R. J. Geue A. Hohn S. F. Ralph A. M. Sargeson and A. C. Willis J. Chem. SOC.,Chem. Commun. 1994 1513. S. L. W. McWhinnie (1 87) R = NO2 (190) R = NH3+ (194) R=NO2 (188) R = (NH,)' (191) R = NHM++ (195) R = NH3' (189) R= H (192) R= NMe2 (193) R = NMe,' (196) R=NOp (197) R = NH3* Various Ni(11) complexes of (200k(202) have been prepared and the structure of [Ni"(200)(C104)]2 reported.147 Ni(1II) complexes have been generated by oxidation + using CO(III) in aqueous media or [NO] + in non-aqueous solution. EPR spectra of the Ni(m) species are sensitive to the co-ligand present.A partially fluorinated cryptand (203) and its complexes with Na+ K' and Rb+ have been synthesized; complexation with CU(I),Ag(I) and Zn(II) has been studied by NMR spectro~copy.'~~ In the crystal structure of the sodium complex as its perchlorate salt the sodium cation is five-coordinate interacting with the four oxygens of the cryptand and the perchlorate anion. Ligand (204) will form a complex'49 incorporating a [Zn,(p-OH)J2+ unit which interacts in solution with deprotonated cytosine or 2-hydroxypyridine; the other hydroxypyridine isomers showed no interaction. The crystal structures of [Zn,(p-OH),(204)I2+ and [Zn2(p-OH)(2- + hydroxypyridonate)(204)]' suggest that the key to the interaction with 2-hy- droxypyridine is the bite angle of the chelate ring formed with a single Zn(rr) centre.The 14' A. McAuley D.G. Fortier D. H. Macartney T. W. Whitcombe and C. Xu J. Chem. SOC.,Dalton Trans. 1994 2071. 14' H. Plenio Inorg. Chem. 1994 33 6123. 149 C. Bazzicalupi A. Bencini A. Bianchi V. Fusi P. Paoletti and B. Valtancoli J. Chem. SOC. Chem. Commun. 1994 881. The Coordination Chemistry of Macrocyclic Ligands (200) x= 0 (201) X=NH (202) x= s bimetallic complex [C~i(H,(205))~' is shown by NMR spectroscopy to have an asymmetric conformation; it is oxidized to the mixed-valence species [Cu"Cu'((205)H,}]2 and the dicopper(I1) species [Cu;((205))] .l50 A crystal struc- + ture of the latter species reveals that one CU(II) is coordinated by two secondary amine nitrogens and two pyrrole nitrogens whilst the other is coordinated by three secondary amine nitrogens and one pyrrole nitrogen.A crystallographic study of [Agi(206)] [ClO,] showed it to be disordered consisting of two differing models.' ' One has each of the two A&) cations coordinated to four nitrogens whilst the other has one Ag(1) coordinated to four nitrogens and the other coordinated to three nitrogens and an oxygen of a perchlorate anion. NMR investigations of complexes formed by (207) show that the ligand only binds one metal; the second site is occupied by three protons transferred from the phenols to the imine nitrogens.' 52 However basic conditions can promote the coordination of a second metal. The crystal structures of various complexes show some degree of disorder; in all cases the metal ions [Pb(u) and Cd(~r)] can best be described as seven-coordinate.Several complexes of (208)-(210) with Fe(III) V(IV) Ti@) and Ga(III) have been studied.' 53 As the ligand cavity increases in size the coordination geometry of the metal changes from trigonal prismatic to pseudo octahedral. Ni(1) and Ni(II) catenates have been prepared and their crystal structures deter- lS0 Q. Lu V. McKee and J. Nelson J. Chem. SOC.,Chem. Commun. 1994 649. 15' G. Morgan V. McKee and J. Nelson Inorg. Chem. 1994 33 4427. 15' M. G. B. Drew 0.W. Howarth G. G. Morgan and J. Nelson J. Chem. Soc. Dalton Trans. 1994 3149. 153 M. Albrecht S.J. Franklin and K. N. Raymond Inorg. Chem. 1994 33 5785.S. L. W. McWhinnie (208) rn = n = 1 (209) rn = 1,n = 2 (210) rn =n =2 mined.'54 The Ni(1) complex of (211) shows regular tetrahedral geometry as expected while the Ni(r1) complex shows highly distorted tetrahedral geometry. The use of Cu(1) templates has led to the synthesis of a double trefoil knot (Figure 1)the crystal structure of which reveals both copper ions with regular tetrahedral geometry.15' Cyclic voltammetry shows that there is an unexpectedly strong interaction between the two copper atoms. 154 C. 0.Dietrich-Buchecker J. Guilhem J.-M. Kern C. Pascard and J.-P. Sauvage Inorg. Chem. 1994,33 3498. 155 C. 0.Dietrich-Buchecker J.-P. Sauvage A. De Cian and J. Fischer J. Chem.SOC.,Chem. Commun. 1994 223 1. The Coordination Chemistry of Iklucrocyclic Liyunds -0 0-Figure 1

ISSN:0260-1818    

DOI:10.1039/IC9949100351

出版商:RSC    

年代:1994

数据来源: RSC