REDUCTIVE CLEAVAGE OF THE C-S BOND IN [NI2(CP)2(MU-SR)2] (CP=ETA-C5H5) BY LIALH4 - CRYSTAL-STRUCTURES OF [NI2(CP)2(MU-SPH)2] AND [NI2(CP)2(MU-ORTHO-(SCH2)2-C6H4)]

The first example of the reductive cleavage of the carbon-sulphur bond in organonickel thiolato complexes [Ni2(cp)2(SR)2] (cp = eta-C5H5) by LiAIH4 is reported. Preliminary mechanistic studies suggest that some kind of hydridic species may play an important role in the reduction. Electrochemical investigation of the bridged thiolatonickel complexes indicates that they undergo reversible one-electron reduction without cleavage of the C-S bond. The molecular structures of [Ni2(cp)2(SPh)2] (1a) and [Ni2(cp)2{0-(SCH2)2C6H4}] (1e) have been determined by X-ray crystallography. The crystal data are: (1a), space group Pbca, a = 8.043(3), b = 12.774(3), c = 19.610(5) angstrom, Z = 4, R = 0.043 for 1 867 observed reflections; (1e), space group P2(1)/a, a = 10.348(3), b = 10.880(3), c = 14.785(4) angstrom, beta- = 97.78(2)-degrees, Z = 4, R = 0.046 for 1 772 observed reflections.