共查询到20条相似文献,搜索用时 15 毫秒
1.
David J. Cox Glyn R. John Brian F.G. Johnson Jack Lewis 《Journal of organometallic chemistry》1980,186(3):C69-C71
The clusters Os6(CO)18 Os7(CO)21 and Os8(CO)23 are reduced to the anoins [Os6(CO)18]2?, [Os7(CO)20]2? and [Os8(CO)22]2?, respectively, by the action of nitriles RCN (R = Me, Et, CH2C(Me)); the kinetics of the reaction of Os6(CO)18 with EtCN have been examined and reveal a third order dependence on nitrile concentration. 相似文献
2.
Kabir SE Raha AK Hassan MR Nicholson BK Rosenberg E Sharmin A Salassa L 《Dalton transactions (Cambridge, England : 2003)》2008,(32):4212-4219
The reaction of [Ru(3)(CO)(12)] with Ph(3)SnSPh in refluxing benzene furnished the bimetallic Ru-Sn compound [Ru(3)(CO)(8)(mu-SPh)(2)(mu(3)-SnPh(2))(SnPh(3))(2)] which consists of a SnPh(2) stannylene bonded to three Ru atoms to give a planar tetra-metal core, with two peripheral SnPh(3) ligands. The stannylene ligand forms a very short bond to one Ru atom [Sn-Ru 2.538(1) A] and very long bonds to the other two [Sn-Ru 3.074(1) A]. The germanium compound [Ru(3)(CO)(8)(mu-SPh)(2)(mu(3)-GePh(2))(GePh(3))(2)] was obtained from the reaction of [Ru(3)(CO)(12)] with Ph(3)GeSPh and has a similar structure to that of as evidenced by spectroscopic data. Treatment of [Os(3)(CO)(10)(MeCN)(2)] with Ph(3)SnSPh in refluxing benzene yielded the bimetallic Os-Sn compound [Os(3)(CO)(9)(mu-SPh)(mu(3)-SnPh(2))(MeCN)(eta(1)-C(6)H(5))] . Cluster has a superficially similar planar metal core, but with a different bonding mode with respect to that of . The Ph(2)Sn group is bonded most closely to Os(2) and Os(3) [2.786 and 2.748 A respectively] with a significantly longer bond to Os(1), 2.998 A indicating a weak back-donation to the Sn. The reaction of the bridging dppm compound [Ru(3)(CO)(10)(mu-dppm)] with Ph(3)SnSPh afforded [Ru(3)(CO)(6)(mu-dppm)(mu(3)-S)(mu(3)-SPh)(SnPh(3))] . Compound contains an open triangle of Ru atoms simultaneously capped by a sulfido and a PhS ligand on opposite sides of the cluster with a dppm ligand bridging one of the Ru-Ru edges and a Ph(3)Sn group occupying an axial position on the Ru atom not bridged by the dppm ligand. 相似文献
3.
Two-dimensional (2D) 59Co correlation spectroscopy (COSY)/double-quantum-filtered (DQF)COSY experiments are reported for three tetrahedral mixed-metal clusters HFeCo3(CO)11L with L = PPh3, P(OMe)3, and PCy3 (Cy = cyclohexyl) in which the L-substituted Co center is chemically different from the other two. The 2D 59Co COSY and DQFCOSY NMR spectra of these clusters in solution prove the existence of a scalar coupling constant between the 59Co nuclei. To determine this value for each cluster, 2D 59Co COSY and DQFCOSY NMR spectra have been simulated by numerical density-matrix calculations. The predicted spectra mimic well the features of the experimental spectra if a scalar coupling is introduced between the Co nuclei. It was initially observed that the scalar coupling constants between the Co nuclei obtained from the 2D COSY and DQFCOSY NMR spectra differed significantly. In contrast to the 2D COSY spectra, the diagonal and cross peaks are of comparable intensity in the 2D DQFCOSY spectra, which leads to a considerable increase in the accuracy of the determination of the scalar coupling constant. 相似文献
4.
Synthesis of cationic allyl complexes from trinuclear carbonyl clusters of iron,ruthenium and osmium
V.V. Krivykh T. Asunta O.V Gusev M.I. Rybinskaya 《Journal of organometallic chemistry》1980,338(1):55-58
Thermal and photochemical reactions of trinuclear carbonyls of Fe, Ru, Os with allyl alcohol in acidic meclium as well as their reactions with (CH3)3NO · 2H2O with subsequent protonation have been studied. Cationic mononuclear allyltetra-carbonyl complexes of Fe, Ru, Os and a cationic Os cluster with π-allyl ligand, have been obtained. 相似文献
5.
Cooke CE Ramnial T Jennings MC Pomeroy RK Clyburne JA 《Dalton transactions (Cambridge, England : 2003)》2007,(18):1755-1758
N-Heterocyclic carbene transfer reactions were attempted using IMesAgCl and two osmium clusters. The products isolated from these reactions suggest that NHC transfers can be unpredictable. 相似文献
6.
M. Abdul Mottalib Derek A. Tocher Ebbe Nordlander 《Journal of organometallic chemistry》2007,692(22):5007-5016
Tris(2-thienyl)phosphine, P(C4H3S)3, reacts with [Os3(CO)12] at 110 °C to give the phosphine-substituted derivatives [Os3(CO)11{P(C4H3S)3}] (1), [Os3(CO)10{P(C4H3S)3}2] (2) and [Os3(CO)9{P(C4H3S)3}3] (4), as well as the C-H activated product [Os3(μ-H)(CO)9{μ-P(C4H2S)(C4H3S)2}{P(C4H3S)3}] (3), in which the bridging ligand is equatorially coordinated to two osmium atoms. Thermolysis of 2 in refluxing toluene results in the formation of 3. Compound 1 can also be prepared in high yield from [Os3(CO)11(NCMe)]. The reaction of [Os3(μ-H)2(CO)10] with tris(2-thienyl)phosphine at room temperature afforded [Os3(μ-H)2(CO)9{P(C4H3S)3}] (5) and [Os3H(μ-H)(CO)10{P(C4H3S)3}] (6), with the ligand coordinated through the phosphorus atom whereas at elevated temperature the cyclometallated compounds [Os3(μ-H)(CO)9{μ3-P(C4H2S)(C4H3S)2}] (7) and [Os3(μ-H)(CO)8{μ3-P(C4H2S)(C4H3S)2{P(C4H3S)3}] (8) were obtained in addition to 5. Heating 6 in refluxing heptane furnished 5 via loss of one carbonyl ligand. Thermolysis of 1 and 3 in refluxing toluene gives 7 and 8, respectively, in good yields. In 3, the μ-P(C4H2S)(C4H3S)2 ligand is coordinated through the phosphorus to one Os atom and through a σ-Os-C bond to the second osmium atom. Compound 7 contains the μ3-P(C4H2S)(C4H3S)2 ligand bound through phosphorus to one Os atom, through a σ-Os-C bond to another and by an η2 (π)-interaction to the third osmium atom. Compounds 1, 2 and 4 contain the ligand coordinated exclusively through the phosphorus atom. The crystal and molecular structures of 2, 3, 5, 6 and 7 are reported. 相似文献
7.
The reaction of the triosmium cluster anion, [Os(3)(micro-H)(CO)(11)][PPN] (PPN = [N(PPh(3))2]+), with [AgPF(6)] in the presence of [Ir(PPh(3))2(CO)Cl] in THF at room temperature affords two new high-nuclearity osmium-silver clusters, [Os(13)Ag(9)(CO)48][PPN] (1) and [Os(9)Ag(9)(micro3-O)2(CO)30][PPN] (2), and an iridium complex, [Ir(PPh(3))2(CO)Cl(O(2))] (3). 相似文献
8.
The development of transition metal cluster chemistry is traced from the early discoveries of metal-metal bonded systems through to some recent developments made in the area of high nuclearity osmium and rutherium cluster carbonyls. Emphasis is placed on developments made in the physical techniques used to establish the structures of the cluster complexes in the solid state and in solution. Recent developments in synthetic methods which lead to “rational” cluster synthesis are described, and the electron counting rules used to rationalise the observed structures of carbonyl clusters are reviewed. New high nuclearity cluster structures are described, and emphasis is placed on the ability of these systems to undergo reversible redox chemistry without the metal frameworks rearranging. This contrasts the situation observed for low nuclearity clusters, and illustrates the potential of the higher nuclearity clusters to act as electron sinks. 相似文献
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Summary The XAsFe4(CO)14 (X = Cl, Br) clusters have been prepared and characterised and a new synthesis under mild conditions has been found for As2Fe3(CO)9. The latter complex has at least two isomeric structures in solution.A preliminary account of this work was given in a lecture.The terms pnicogen and pnictide have been introduced as group names for the group Va family of elements analogous to the use of chalcogen and chalcogenid as group names for the group VIa elements. 相似文献
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Kettle SF Boccaleri E Diana E Iapalucci MC Rossetti R Stanghellini PL 《Inorganic chemistry》2002,41(14):3620-3627
The spherical harmonic model (SHM), previously used for the analysis of the terminal nu(CO) vibrations of transition metal carbonyl clusters, is applied to the corresponding bridging CO modes. The model is applicable, although the spectra show a greater sensitivity to the molecular geometry than is the case for their terminal counterparts. The reasons for this sensitivity are discussed. When both micro(2) and micro(3) CO groups are present in a molecule, a spectral distinction may not be apparent. 相似文献
16.
Comparison of the results of the electrochemical reduction of trinuclear osmium carbonyl halides with linear structure, Os3(CO)12X2, and nonlinear structure, Os3(CO)10(-X)2 (X=I, Br, and Cl) with mononuclear carbonyl halides of transition metals indicates covalent nature of the metal-halogen bonds in these compounds. Chemical dissociation does not occur upon dissolving the trinuclear osmium carbonyl halides in acetonitrile and the cleavage of the Os-X bonds is a result of the electrochemical reduction. The observed order for ease of reduction of the trinuclear osmium carbonyl halides coincides with the change in the E1/2 values in the reduction of the mononuclear carbonyl halides of transition metals and alkyl halides.Translated from Izvestiya Akademii Nauk SSSR, Seriya Khimicheskaya, No. 2, pp. 459–460, February, 1990. 相似文献
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The interaction between the osmium clusters [Os3(CO)12], [Os3(CO)10(mu-H)2], [Os3(CO)10(mu-H)(mu-OH)], and a series containing a free functional group, viz., [Os3(CO)10(mu-H)(mu-S--EH)] (where -- =alkylwedge chain or an aromatic ring, E=COO, S or O), with SiO2, ZnO and In2O3, was examined by ToF-SIMS and IR spectroscopy. While the interaction with the silica surface is mostly via an O atom or the functional group, the interaction with the ZnO and In2O3 surfaces is more complex. 相似文献
19.
The historical background of and the incentive for using ruthenium carbonyl clusters as homogeneous catalysts are outlined.
Keeping in view the possible solutions the uncertainties arising from declusterification and metal colloid formation are discussed.
All ruthenium cluster-catalysed reactions are broadly classified as reactions with or without carbon monoxide as one of the
reactants and the basic differences between such reactions are highlighted. Some of the factors of special relevance to cluster-catalysed
reaction systems are mentioned. The reactions involving carbon monoxide are then discussed. These include water-gas-shift
reaction, carbon monoxide hydrogenation, hydroformylation, reductive carbonylation of nitrobenzene and other carbonylation
reactions. Hydrogenation, transfer hydrogenation, isomerisation and a few other reactions are then discussed. For all these
reactions, special emphasis is laid on well-characterised cluster complexes that have been proposed as catalytic intermediates.
Finally an attempt has been made to identify the path that future research in cluster catalysis is likely to follow. 相似文献
20.
Brian F.G. Johnson Jack Lewis David Pippard 《Journal of organometallic chemistry》1978,160(1):263-274
Methods by which the reactivity of transition-metal osmium carbonyl clusters may be modified are explored. 相似文献