Asymmetric acetylenic thioethers in ruthenium cluster chemistry

The compounds [Ru3(CO)9(μ,η2-SCCR)(μ3,η2-CCR′)] (R=SiMe3, R′=SiiPr3 (1); R=SiiPr3, R′=SiMe3 (2); R=SiiPr3, R′=H (3); R=H, R′=SiiPr3 (4)) have been obtained by cleavage of one S–C bond of the thioethers iPr3SiCCSCCR (R=H, SiMe3) in the presence of Ru3(CO)12. Thermal treatment of [Ru3(CO)9(μ,η2-SCCSiiPr3)(μ3,η2-CCH)] yields to the cluster [Ru4(CO)9(μ-CO)2(μ4-S)(μ4-η2-C(H)C)(CCSiiPr3)] (5) which contains a bridging sulfur atom and a polycarbon chain as a consequence of the rupture of the S–C bond and a C–C coupling reaction. All derivatives have been characterized by spectroscopic data. An X-ray diffraction study was carried out on the species [Ru3(CO)9(μ,η2-SCCSiiPr3)(μ3,η2-CCSiMe3)] and of [Ru3(CO)9(μ,η2-SCCSiiPr3)(μ3,η2-CCH)].