Reactions of the unsaturated hydroxo complex [W2Cp2(OH)(μ-PPh2)2(CO)]BF4 with mono- and bidentate ligands having E-H bonds (E = O, S, N).

The title compound reacted with CO at room temperature in the presence of excess HBF(4)·OEt(2) to yield a mixture of the electron-precise complexes [W(2)Cp(2)(μ-PPh(2))(2)(CO)(4)](BF(4))(2) and [W(2)Cp(2)(μ-PPh(2))(2)(CO)(3)(OH(2))](BF(4))(2), with the aquo ligand in the latter complex being easily displaced by simple donors such as acetonitrile. Reaction of the title complex with simple acidic molecules such as HSPh or HBr took place rapidly with elimination of H(2)O to give the 32-electron cations [W(2)Cp(2)(Z)(μ-PPh(2))(2)(CO)](+) [Z = Br, SPh (W-W = 2.8076(9) Å)], which were reversibly carbonylated to give the electron-precise derivatives [W(2)Cp(2)(μ-Z)(μ-PPh(2))(2)(CO)(2)](+).

Reactions of the tetrafluoroborate complex [Mo2Cp2(κ(2)-F2BF2)(μ-PPh2)2(CO)]BF4 with mono- and bidentate ligands having E-H bonds (E = O, S, Se, N, P).

The title compound reacted rapidly with CN(t)Bu at room temperature by displacing the BF(4)(-) ligand and incorporating three molecules of isocyanide to yield the electron-precise complex [Mo(2)Cp(2)(μ-PPh(2))(2)(CN(t)Bu)(3)(CO)](BF(4))(2), which was obtained as a mixture of cis and trans isomers. Reaction with several HER(n) molecules (HER(n) = HSPh, HSePh, H(2)PCy) took place with formal elimination of HBF(4) and spontaneous carbonylation to give the electron-precise cations [Mo(2)Cp(2)(μ-ER(n))(μ-PPh(2))(2)(CO)(2)](+). Reactions with several bidentate ligands (L(2)H) having acidic E-H bonds (2-hydroxypyridine, 2-mercaptopyridine, cathecol, 2-aminophenol, and 2-aminothiophenol) proceeded analogously with deprotonation of these bonds with the preference E = S > O > N.

Topologically unique heterometallic Cu(II)/Li coordination polymers self-assembled from N,N-bis(2-hydroxyethyl)-2-aminoethanesulfonic acid biobuffer: versatile catalyst precursors for mild hydrocarboxylation of alkanes to carboxylic acids.

The facile aqueous medium reactions of copper(II) nitrate with BES biobuffer [(HOCH(2)CH(2))(2)N(CH(2)CH(2)SO(3)H), hereinafter referred as H(3)bes] in the presence of various benzenecarboxylic acids [benzoic (Hba), 3-hydroxybenzoic (Hhba), and 3,5-dihydroxybenzoic (Hdhba) acid] and lithium hydroxide gave rise to the self-assembly generation of three new heterometallic Cu(II)/Li materials, [Li(H(2)O)(4)][Cu(4)(μ(2)-Hbes)(4)(μ(2)-ba)]·H(2)O (1) and [Cu(4)(μ(3)-Hbes)(4)(L){Li(H(2)O)(2)}](n)·3nH(2)O {L = μ(2)-hba (2) and μ(2)-dhba (3)}. They were isolated as air-stable crystalline solids and fully characterized by infrared (IR) and UV-vis spectroscopy and electrospray ionization (ESI)-MS(±), elemental, thermal, and single-crystal X-ray diffraction analyses. The latter revealed that 1-3 have comparable packing patterns and unit cell parameters, being composed of similar [Cu(4)(μ-Hbes)(4)(μ-carboxylate)](-) cores and [Li(H(2)O)(4)](+) cations (in 1) or [μ-Li(H(2)O)(2)](+) groups (in 2 and 3), which are arranged into discrete 0D aggregates in 1 or infinite 3D noninterpenetrating metal-organic networks in 2 and 3.

Synthesis and X-ray characterization of [RhCl(C2H4)(PiPr3)]2. Multinuclear NMR and DFT investigation of its solid-state and solution reaction with dihydrogen. Ethene and propene hydrogenation by the solid Rh-hydrides.

[RhCl(C(2)H(4))(PiPr(3))](2) has been synthesised and structurally characterised. It shows an unusual planar Rh(2)Cl(2) system, with the two phosphine and the two ethene molecules disposed trans to each other. It easily reacts with dihydrogen in solution and in the solid state to afford ethane and a dimeric complex of formula [RhCl(H)(2)P](2).

Low-temperature N-O bond cleavage in nitrosyl ligands induced by the unsaturated dimolybdenum anion [Mo2(eta(5)-C5H5)2(mu-PPh2)(mu-CO)2]-.

The unsaturated anion [Mo(2)Cp(2)(mu-PPh(2))(mu-CO)(2)](-) (1) (Na(+) salt) reacts with the nitrosyl complexes [MCp'(CO)(2)(NO)]BF(4) (M = Mn, Re; Cp' = eta(5)-C(5)H(4)Me) rapidly at about 193 K. Upon warming of the resulting mixtures up to 243 K orange solutions are obtained, shown to contain the corresponding oxo- and nitride-bridged tetracarbonyl complexes [Mo(2)MCp(2)Cp'(mu-N)(mu-O)(mu-PPh(2))(CO)(4)] as the major product, which could be isolated only for M = Re. Above 253 K, however, these compounds experience spontaneous decarbonylation to yield the unsaturated tricarbonyl derivatives [Mo(2)MCp(2)Cp'(mu-N)(mu-O)(mu-PPh(2))(CO)(3)] (Mo-Mo = 2.

Reactivity of the zwitterionic ligand EtNHC(S)Ph2P[double bond, length as m-dash]NPPh2C(S)NEt towards [Ru3(CO)12]. Sulfur transfer and ligand fragmentation leading to the methideylamide [-N(Et)-CH(R)-] micro3-bridging moiety.

The reaction of EtNHC(S)Ph2P[double bond, length as m-dash]NP+Ph2C(S)N(-)Et (HEtSNS) with [Ru3(CO)12] has been carried out under two different experimental conditions: in the first case [Ru3(CO)12], previously turned into the labile intermediate [Ru3(CO)10(CH3CN)2], afforded, at room temperature in dichloromethane, the trinuclear clusters [Ru3(CO)11(CNEt)] (1), [Ru3(CO)9(micro-H)[(micro-S:kappa-P)Ph2PN[double bond, length as m-dash]PPh2C(S)NEt]] (2), [Ru3(CO)9(micro-H)[(micro-S:kappa-P)Ph2PN[double bond, length as m-dash]P(S)Ph2]] (3) and [Ru3(CO)10[(micro-kappa2P)Ph2PNHPPh2]] (3). Ligand fragmentation occurs via loss of EtNC or EtNCS, without sulfur transfer to the cluster core. In the second case, [Ru3(CO)12] reacted with HEtSNS in toluene at 70 degrees C, giving the trinuclear clusters , [Ru3(CO)7(CNEt)(micro3-S)[(micro2-N:eta1-C:kappa1-P)Ph2PN[double bond, length as m-dash]PPh2C(H)NEt]] (6), [Ru3(CO)8)(micro3-S)[(micro2-N:eta-C:kappa-P)Ph2PN[double bond, length as m-dash]PPh2C(H)NEt]] (6) and [Ru3(CO)6(micro3-CO)(micro3-S)(EtNC)[(micro-kappa2P) Ph2PNHPPh2]] (7).

Low-temperature N-O bond cleavage of nitrogen monoxide in heterometallic carbonyl complexes. An experimental and theoretical study.

The reaction of Na[RuCp(CO) 2] with [MnCp'(CO) 2(NO)]BF 4 gives the corresponding heterometallic derivative [MnRuCpCp'(mu-CO) 2(CO)(NO)] (Cp = eta (5)-C 5H 5; Cp' = eta (5)-C 5H 4Me). In contrast, the group 6 metal carbonyl anions [MCp(CO) 2L] (-) (M = Mo, W; L = CO, P(OMe) 3, PPh 3) react with the Mn and Re complexes [M'Cp'(CO) 2(NO)]BF 4 to give the heterometallic derivatives [MM'CpCp'(mu-N)(CO) 3L] having a nitride ligand linearly bridging the metal centers (W-N = 1.81(3) A, N-Re = 1.

Synthesis, characterization, and reactivity of ruthenium diene/diamine complexes including catalytic hydrogenation of ketones.

Thermal reactions between [RuCl2(diene)]n (diene = 2,5-norbornadiene, nbd; 1,5-cyclooctadiene, cod) with an excess of N,N,N',N'-tetramethylethylene diamine (tmeda) afforded derivatives [RuCl2(diene)(tmeda)] (diene = nbd, 1; cod, 2) as a mixture of cis and trans isomers. When thermolysis was performed under H2 mixtures of hydride species [RuCl(H)(diene)(tmeda)] (diene = nbd, 3; cod, 4) and the bis-tmeda adduct trans-[RuCl2(tmeda)2] (5) were obtained in different ratios depending upon the reaction conditions and reaction times. Heating polymeric Ru(II) precursors in toluene in the presence of a 5-fold excess of the bulkier N,N,N',N'-tetraethylethylene diamine (teeda) resulted in a rare diamine dealkylation process with formation of trans-[RuCl2(nbd)(Et2NCH2CH2NHEt)] (6) and trans-[RuCl2(cod)(EtHNCH2CH2NHEt)] (7) in high yields.

Trapping a pseudo-Hofmann rearrangement on a ruthenium cluster.

In the clusters [Ru3(micro(3)-NPPh(3))(micro(3)-OSiMe(3))(micro-X)(micro(C,O)-OC[double bond]NPPh(3))(micro-CO)(CO)6] (X = NCO, 2; X = Cl, 3), which were prepared by a pyrolytic reaction of Ph(3)PNSiMe(3) with Ru(3)(CO)12, the ligands result from a cluster-mediated pseudo-Hofmann rearrangement involving the micro-NCO, micro(C,O)-Ph(3)P[double bond]N-CO and micro(3)-NPPh(3) fragments.

Insertion reactions of alkynes and organic isocyanides into the palladium-carbon bond of dimetallic Fe-Pd alkoxysilyl complexes.

Insertion of MeO(2)C-C[triple bond]C-CO(2)Me (DMAD) into the Pd-C bond of the heterodimetallic complex [(OC)(3)F[upper bond 1 start]e{mu-Si(OMe)(2)([lower bond 1 start]OMe)}(mu-dppm)P[lower bond 1 end][upper bond 1 end]d(dmba-C)] (2) (dppm = Ph(2)PCH(2)PPh(2), dmba-C = metallated dimethylbenzylamine) and [(OC)(3){(MeO)(3)Si}F[upper bond 1 start]e(mu-dppm)P[upper bond 1 end]d(8-mq-C,N)] (3) (8-mq-C,N = cyclometallated 8-methylquinoline) yielded the sigma-alkenyl complexes [(OC)(3)F[upper bond 1 start]e{mu-Si(OMe)(2)([lower bond 1 start]OMe)}(mu-dppm)P[lower bond 1 end][upper bond 1 end]d{C(CO(2)Me)=C(CO(2)Me)(o-C(6)H(4)CH(2)NMe(2))}] (7) and [(OC)(3)F[upper bond 1 start]e{mu-Si(OMe)(2)([lower bond 1 start]OMe)}(mu-dppm)P[lower bond 1 end][upper bond 1 end]d{C(CO(2)Me)[double bond, length as m-dash]C(CO(2)Me)(CH(2)C(9)H(6)N)}] (8), respectively. The latter afforded the adduct [(OC)(3){(MeO)(3)Si}F[upper bond 1 start]e(mu-dppm)P[upper bond 1 end]d{C(CO(2)Me)=C(CO(2)Me)(CH(2)C(9)H(6)N)}(CNBu(t))] (9) upon reaction with 1 equiv. of Bu(t)NC.

Synthesis, characterization and olefin/CO exchange reactions of pyrazolylborato complexes of copper(I).

New bis(pyrazolyl)borato olefin complexes of copper(I) of general formula Cu[BH2(3,5-(CF3)2Pz)2](olefin) have been prepared (olefins: coe = cyclooctene, van = 4-vinylanisole, clsty = 4-chlorostyrene, tevs = triethylvinylsilane, fn = fumaronitrile). The structures of Cu[BH2(3,5-(CF3)2Pz)2](L), L = coe, van, tevs, fn, have been determined by X-ray diffraction methods. Considering the two N atoms of the bis(pyrazolyl)borate ligand and the midpoint of the C-C double bond of the coordinated olefin, the compounds with L = coe, van and tevs contain a copper atom in a trigonal planar coordination.

Experimental and computational studies on the solvent-controlled cluster isomerism of Ru3(H)(CO)9(NPPh3) and related dynamics.

The species Ru3(H)(mu3-NPPh3)(CO)9 occurs in the solid state as two isomers, characterized either by one capping hydride and three CO bridges (1a) or by one bridging hydride and all terminals COs (1b); key intermediates for the formation, fluxionality and solvent-dependent interconversion of the isomers are highlighted through a DFT MO analysis.

Zwitterionic metalates of group 11 elements and their use as metalloligands for the assembly of multizwitterionic clusters.

Reaction of RNHC(S)PPh2NPPh2C(S)NR (HRSNS; R = Me, Et) with M(I) (M = Cu, Ag, Au) salts afforded zwitterionic complexes of the general formula [M(RSNS)] (M = Cu, Ag, Au). The ligand was found in the solid state in S,S-kappa2 and S,N,S-kappa3 coordination fashions. [Cu(RSNS)] and [Ag(RSNS)] can be used as metalloligand building blocks for the assembly of pentanuclear multizwitterionic Cu5, Cu3Ag2 and Ag5 core clusters of the general formula [M'2{M(RSNS)}3]2+ (M = Cu, M' = Cu, Ag; M = M' = Ag) upon reaction with suitable M' salts.

Cyclic enolates of Ni and Pd: equilibrium between C- and O-bound tautomers and reactivity studies.

2-acylaryl complexes of Ni and Pd containing chelating diphosphines react with KtBuO to give metallacyclic enolate complexes. While coordination through the carbon atom is preferred in the case of Pd, the nickel O-enolate compounds are formed as the corresponding O-tautomers. Slow equilibration between O- and C-enolate tautomers is observed for the nickel complex with an unsubstituted enolate function (M-O-C=CH(2)).

On the reaction of Ph2PNHPPh2 with RNCS (R=Et, Ph, p-NO2C6H4): preparation of the zwitterionic ligand EtNHC(S)Ph2P==NPPh2C(S)NEt (HSNS) and the zwitterionic metalate [(SNS)Rh(CO)].

The reaction of Ph(2)PNHPPh(2) (PNP) with RNCS (Et, Ph, p-NO(2)(C(6)H(4))) gives addition products resulting from the attack of the P atoms of PNP on the electrophilic carbon atom of the isothiocyanate. When PNP is reacted with EtNCS in a 1:2 molar ratio, the zwitterionic molecule EtNHC(S)PPh(2)==NP(+)Ph(2)C(S)N(-)Et (HSNS) is obtained in high yield. HSNS can be protonated (H(2)SNS(+)) or deprotonated (SNS(-)), behaving in the latter form as an S,N,S-donor pincer ligand.

Nucleophilic substitution on a Ru-coordinated Cp ring by a carborane anion.

The Cp ring in [RuCl(Cp)(PPh3)2] undergoes an apparent nucleophilic attack by the carbanion carb- (Hcarb = 2-Me-1,2-dicarba-closo-dodecaborane), to give an H-/carb- exchange process, which is favoured by coordination of the hydride to the ruthenium centre.

Heteronuclear rhodium, palladium, platinum, and gold organoimido complexes from dinuclear organoamido rhodium precursors.

Treatment of the organoamido complexes [Rh(2)(mu-4-HNC(6)H(4)Me)(2)(L(2))(2)] (L(2) = 1,5-cyclooctadiene (cod), L = CO) with nBuLi gave solutions of the organoimido species [Li(2)Rh(2)(mu-4-NC(6)H(4)Me)(2)(L(2))(2)]. Further reaction of [Li(2)Rh(2)(mu-4-NC(6)H(4)Me)(2)(cod)(2)] with [Rh(2)(mu-Cl)(2)(cod)(2)] afforded the neutral tetranuclear complex [Rh(4)(mu-4-NC(6)H(4)Me)(2)(cod)(4)] (2), which rationalizes the direct syntheses of 2 from [Rh(2)(mu-Cl)(2)(cod)(2)] and Li(2)NC(6)H(4)Me. Reactions of [Li(2)Rh(2)(mu-4-NC(6)H(4)Me)(2)(CO)(4)] with chloro complexes such as [Rh(2)(mu-Cl)(2)(CO)(4)], [MCl(2)(cod)] (M = Pd, Pt), and [Ru(2)(mu-Cl)(2)Cl(2)(p-cymene)(2)] afforded the homo- and heterotrinuclear complexes PPN[Rh(3)(mu-4-NC(6)H(4)Me)(2)(CO)(6)] (5; PPN=bis(triphenylphosphine)iminium), [(CO)(4)Rh(2)(mu-4-NC(6)H(4)Me)(2)M(cod)] (M = Pd (6), Pt(7)) and [(CO)(4)Rh(2)(mu-4-NC(6)H(4)Me)(2)Ru(p-cymene)] (8), while the reaction with [AuCl(PPh(3))] gave the tetranuclear compound [(CO)(4)Rh(2)(mu--4-NC(6)H(4)Me)(2)[Au(PPh(3))](2)] (9).

Reactivity of Ph2P(Se)CH2C6H4CH2P(Se)Ph2 with [M3(CO)12] (M=Ru or Fe). Synthesis and characterization of the new carbene cluster [Ru3(mu3-Se)(mu3-H)(mu2-PPh2)(CO)6(mu2-CHC6H4CH2PPh2)].

The reactions of [M3(CO)12] (M=Ru or Fe) with 1,2 bis[(diphenylphosphino)methyl]benzene diselenide (dpmbSe2) in hot toluene afford a variety of phosphine-substituted selenido carbonyl clusters. They belong to the following three families: (i) 50-electron clusters with a M3Se2 core (2, 3, 5-7), (ii) 48-electron clusters with a M3Se core (1, 8), (iii) 34-electron clusters with a M2Se2 core (4). All these species derive from the P=Se bond cleavage.

Intramolecular dealkylation of chelating diamines with Ru(II) complexes.

N,N, N',N'-Tetraethylethylenediamine undergoes simple or double intramolecular dealkylation reactions in the presence of the complexes [RuCl2(diene)]n (diene = cod, nbd) or trans-[RuCl2(diene)(morfoline)2 at 80 degrees C to afford chelating amine ligands which contains one or two N-H functionalities.

Reactivity of the heterometallic clusters [HMCo3(CO)12] and [Et4N][MCo3(CO)12] (M = Fe, Ru) toward phosphine selenides, including selenium transfer. Crystal structures of [HRuCo3(CO)7(mu-CO)3(mu-dppy)], [MCo2(mu3-Se)(CO)7(mu-dppy)], and [RuCo2(mu3-Se)(CO)7(mu-dppm)] [dppy = Ph2(2-C5H4N)P, dppm = Ph2PCH2PPh2].

The reactivity of [HMCo3(CO)12] and [Et4N][MCo3(CO)12] (M = Fe, Ru) toward phosphine selenides such as Ph3PSe, Ph2P(Se)CH2PPh2, Ph2(2-C5H4N)PSe, Ph2(2-C4H3S)PSe, and Ph2[(2-C5H4N)(2-C4H2S)]PSe has been studied with the aim to obtain new selenido-carbonyl bimetallic clusters. The reactions of the hydrido clusters give two main classes of products: (i) triangular clusters with a mu3-Se capping ligand of the type [MCo2(mu3-Se)(CO)(9-x)L(y)] resulting from the selenium transfer (x = y = 1, 2, with L = monodentate ligand; x = 2, 4, and y = 1, 2, with L = bidentate ligand) (M = Fe, Ru) and (ii) tetranuclear clusters of the type [HMCo3(CO)12xL(y)] obtained by simple substitution of axial, Co-bound carbonyl groups by the deselenized phosphine ligand. The crystal structures of [HRuCo3(CO)7(mu-CO)3(mu-dppy)] (1), [MCo2(mu3-Se)(CO)7(mu-dppy)] (M = Fe (16) or Ru (2)), and [RuCo2(mu3-Se)(CO)7(mu-dppm)] (12) are reported [dppy = Ph2(2-C5H4N)P, dppm = Ph2PCH2PPh2].

Hydrogen Bonding and Isomerism Arising from the Coordination Modes of Bridging Benzimidazole-2-thiolate Ligands in Tetranuclear Rhodium Complexes.

Reaction of the dinuclear complex [Rh(2)(&mgr;-HBzimt)(2)(cod)(2)] with [Rh(2)(&mgr;-Cl)(2)(cod)(2)] (cod = 1,5-cyclooctadiene) gives the neutral tetranuclear complex [Rh(4)(&mgr;-HBzimt)(2)Cl(2)(cod)(4)] (2) in dichloromethane and the trinuclear cationic complex [Rh(3)(&mgr;-HBzimt)(2)(cod)(3)]Cl (3) in methanol, respectively. The ionization ability of the solvent seems to be the driving force to give 3, while the ability to coordinate a further RhCl(cod) fragment leads to 2 in poorer ionizing media. The complexes [M(4)(&mgr;-HBzimt)(2)Cl(2)(diolefin)(4)] (M = Rh, diolefin = tetrafluorobenzobarrelene (tfbb) (5); M = Ir, diolefin = cod (6)), formally analogous to 2, were isolated from the reactions of the appropriate complexes [MCl(H(2)Bzimt)(diolefin)] and [M(acac)(diolefin)] in acetone.

A New Type of Doubly Silylamido-Bridged Cyclopentadienyl Group 4 Metal Complexes.

Doubly bridged di(silyl-η-amido)cyclopentadienyltitanium and -zirconium complexes and their related cations as the [(PhCH )B(C F ) ] salts have been isolated (see structure of the Ti derivative). The neutral benzylzirconium complex was a very efficient catalyst in the presence of methylaluminoxane for producing high molecular weight polyethylene and ethylene-1-hexene copolymers.

Stepwise Construction of Polynuclear Complexes of Rhodium and Iridium Assisted by Benzimidazole-2-thiol. NMR and X-ray Diffraction Studies.

Reactions of [M(2)(&mgr;-Cl)(2)(cod)(2)] (cod = 1,5-cyclooctadiene, M = Rh, Ir) with benzimidazole-2-thiol (H(2)Bzimt) afford the mononuclear complexes [MCl(H(2)Bzimt)(cod)] (M = Rh (1), Ir (2)) for which a S-coordination of the ligand is proposed based on their spectroscopic data. The dinuclear complexes [M(2)(&mgr;-HBzimt)(2)(cod)(2)] (M = Rh (3), Ir (4)) are isolated from the reaction of [M(acac)(cod)] and benzimidazole-2-thiol. They contain the monodeprotonated ligand (HBzimt(-)) bridging the two metals in a &mgr;(2)-(1kappaN,2kappaS) coordination mode and in a relative cis,cis-HT arrangement.

Steric Crowding and Redox Reactivity in Platinum(II) and Platinum(IV) Complexes Containing Substituted 1,10-Phenanthrolines.

The effect of the phenanthroline substituents on the structure and reactivity of platinum(II) and platinum(IV) complexes has been investigated. The X-ray crystal structures of the compounds [PtI(2)(4,7-Ph(2)phen)].CHCl(3) (1dz.