Monothiocarboxylate complexes of osmium(III) with fluoro-thiolates and dimethylphenylphosphine co-ligands. X-ray crystal structures of [Os(SR)2(SOCCH3)(PMe2Ph)2] (R=C6F5 or C6F4H-4)

Article abstract of DOI:10.1016/0277-5387(94)00435-H

Treatment of the pentacoordinated complexes [Os(SR)3(PMe2Ph)2] (R=C6F5 or C6F4H-4) with R'COSH (R'=CH3 or C6H5) in acetone gave the blue paramagnetic osmium(III) derivates [Os(SC6F5)2(SOCR')(PMe2Ph)2] (1) and [Os(SC6F4H-4)2(SOCR')(PMe2Ph)2] (2). Mass spectrometric data are given. X-ray crystallography has shown that 1 (R'=CH3) and 2 (R'=CH3) have an octahedral structure with trans-thiolates, cis-phosphines and a chelating monothioacetate ligand. The electrochemical reduction of these compounds was studied by cyclic voltammetry in DMF. The potential at which the compounds undergo reduction was found to be nearly independent of the nature of the substituent group on the monothiocarboxylate ligand and slightly more dependent on the identity of the substituent group on the thiolate ligands, the reduction becoming easier for the more electron-withdrawing thiolate derivatives.