Reactions of [(μ-H)Os3(CO)10(μ-OMe)] and [(μ-H)Os3(CO)9(μ-OMe)(MeCN)] with dppm, dppe, dppp, and PPh2H: X-ray crystal structures of [(μ-H)Os3(CO)8(μ-OMe)(μ2-η2-dppm)] and [(μ-H)Os3(CO)9(μ-OMe)(PPh2H)]

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.

The reactions of [(μ-H)Os3(CO)10(μ-OMe)] (1) and its monoacetonitrile derivative [(μ-H)Os3(CO)9(μ-OMe)(MeCN)] with diphosphines (dppm, dppe and dppp) and monophosphine (PPh2H) are described. The structures of the products formed depend on the phosphine used. The crystal structures of two new compounds are reported.Figure optionsDownload as PowerPoint slide