Reactivity of the unsaturated triosmium cluster [Os-3(CO)(8){Ph2PCH2P(Ph)C6H4}(mu-H)] with thiols

The reaction of the unsaturated cluster [(mu -H)Os-3(CO)(8) {Ph2PCH2P(Ph)C6 H4}] 2 with C2H5SH, CH3CH(CH3)SH and C6H5SH are reported. The reaction of 2 with C2H5SH yields the new complexes [Os-3(CO)(8)(mu -SC2H5)(eta (1)-SC2H5 ) {Ph2PCH2P(Ph)C6H4}(mu -H)] 9 and [Os-3(CO)(8))( SC2H5)(Ph2PCH2P)(Ph) C6H4 }] 8 in 24 and 57% yields respectively and the known compound [(Os-3(CO)(8) )(mu -SC2H5)(mu -dppm)(mu -H)] 7 in 5% yield. Compound 9, which exists as t wo isomers in solution, converts into 8 almost quantitatively in solution a t 25 degreesC and more rapidly in refluxing hexane. Compound 8 reacts with H-2, at 110 degreesC to give 7 in high yield (86%). Treatment of 2 with pro pane-2-thiol yields [Os-3(CO)(8){mu -SCH(CH3)CH3} {Ph2PCH2P(Ph)C6H4}] 10 an d [(Os-3 (CO)(8){mu -SCH(CH3)CH3} {eta (1)-SCN(CH3)CH3} {Ph2PCH2P(Ph)C6H4} (mu -H)] 11 in 75 and 3% yields respectively while with C6H5SH, [(Os-3(CO)( 8)(mu- SC6H5)(mu -dppm)(mu -H)] 6 is obtained as the only product in 75 % y ield. In both 8 and 10, the thiolato ligand bridges the Os-Os edge which is also bridged by the metallated phenyl group. The neu compounds have been c haracterized by elemental analyses and spectroscopic methods (IR, H-1 and P -31 NMR). The molecular structures of 7, 8, 9 and 10 are reported as determ ined by X-ray diffraction studies.