Search

[Display omitted] Reactions of the electron defficient triosmium [Os 3 (CO) 9 (μ 3 -η1,κ1-C 9 H 6 N)(μ-H)] with Ph 3 EH (E = Si, Ge, Sn) have been investigated. The reactions of quinoline-capped triosmium cluster [Os 3 (CO) 9 (μ 3 -η1,κ1-C 9 H 6 N)(μ-H)] (1) with Ph 3 EH (E = Si, Ge, Sn) have been investigated. Cluster 1 reacts with Ph 3 EH in refluxing benzene to afford [Os 3 (CO) 9 (EPh 3)(μ-η1,κ1-C 9 H 6 N)(µ-H) 2 ] (2a , E = Si; 2b , E = Ge; 2c , E = Sn) and [Os 3 (CO) 8 (EPh 3)(μ 3 -η1,κ1-C 9 H 6 N)(µ-H) 2 ] (3a , E = Si; 3b , E = Ge; 3c , E = Sn). Control experiments confirm that 2 is a precursor of 3. Cluster 2 is formed via oxidative-addition of E–H bond to 1 whose decarbonylation leads to the formation of 3. The molecular structures of all the new clusters (except 3c) have been determined by X-ray crystallography. Both 2 and 3 exist as a pair of isomers in solution, and their fluxionality in solution has been probed by VT NMR experiments. [ABSTRACT FROM AUTHOR]

Abstract: Treatment of [(μ-H)Os3(CO)10(μ-OMe)] (1) with dppm {dppm=bis(diphenylphosphino)methane} at 110°C gave the known compound [Os3(CO)10(μ2-η2-dppm)] (2) and the new compound [(μ-H)Os3(CO)8(μ-OMe)(μ2-η2-dppm)] (3). A similar reaction of 1 with dppe {dppe=bis(diphenylphosphino)ethane} afforded two products, [(μ-H)Os3(CO)8(μ-OMe)(μ1-η2-dppe)] (5) and [(μ-H)Os3(CO)8(μ-OMe)(μ2-η2-dppe)] (6) which differ in the mode of bonding of the dppe ligand. The reaction of 1 with dppp {dppp=bis(diphenylphosphino)propane} at 110°C gave exclusively [(μ-H)Os3(CO)8(μ-OMe)(μ2-η2-dppp)] (7) which exists as two isomers in solution. Compounds 2, 3, and 5–7 are also obtained in almost similar yields from reactions of [(μ-H)Os3(CO)9(μ-OMe)(MeCN)] (4) with the appropriate diphosphine at ambient temperature. The reaction of 1 with PPh2H at 110°C gave the new compounds [(μ-H)Os3(CO)9(μ-OMe)(PPh2H)] (8) and [(μ-H)2Os3(CO)7(μ-PPh2)2(PPh2H)] (10) and the previously reported compound [(μ-H)2Os3(CO)8(μ-PPh2)2] (9). The molecular structures of 3 and 8 were determined by single crystal X-ray diffraction. In compound 3, the dppm ligand bridges the same Os–Os edge as the hydride and the methoxide ligand. In 8, the PPh2H ligand occupies a ‘pseudo’ axial site on one of the osmium atoms bearing the bridging hydride and methoxide ligand. [Copyright &y& Elsevier]

The reactions of [Os3(CO)10(MeCN)2], [Ru3(CO)12], [(μ-H)Os3(CO)8{Ph2PCH2P(Ph)C6H4}], [Os3(CO)10(μ-dppm)] and [Ru3(CO)10(μ-dppm)] with 2-mercapto-1-methylimidazole are reported. The labile cluster [Os3(CO)10(MeCN)2] reacts with 2-mercapto-1-methylimidazole at 25 °C to give [(μ-H)Os3(CO)10{μ-SC&z.dbnd6;NCH&z.dbnd6;CHN(CH3)}] (1) whereas the corresponding reaction of [Ru3(CO)12] with the ligand at 68 °C gives [(μ-H)Ru3(CO)9{μ3-η2-SC&z.dbnd6;NCH&z.dbnd6;CHN(CH3)}] (2). Both [(μ-H)Os3(CO)8{Ph2PCH2P(Ph)C6H4}] and [Os3 (CO)10(μ-dppm)] react with 2-mercapto-1-methylimidazole at 25 and 110 °C, respectively, to give [(μ-H)Os3(CO)8{μ-SC&z.dbnd6;NCH&z.dbnd6;CHN(CH3)(μ-dppm)] (3). In contrast [Ru3(CO)10(μ-dppm)] reacts with 2-mercapto-1-methylimidazole at 68 °C to yield the known compound [Ru3(CO)7(μ3-CO)(μ3-S)(μ-dppm)] (4). The structures of 1–3 have been determined by X-ray crystallography. [Copyright &y& Elsevier]