Monothiocarboxylate complexes of osmium(III) with fluoro-thiolates and dimethylphenylphosphine co-ligands. X-ray crystal structures of [Os(SR) 2(SOCCH 3)(PMe 2Ph) 2] (R = C 6F 5 or C 6F 4H-4)

Abstract

Treatment of the pentacoordinated complexes [Os(SR) 3(PMe 2Ph) 2] (R = C 6F 5 or C 6F 4H-4) with R'COSH (R′ = CH 3 or C 6H 5) in acetone gave the blue paramagnetic osmium( III) derivatives [ Os( SC 6 F 5) 2( SOCR′)( PMe 2 Ph) 2] ( 1) and [ Os( SC 6 F 4 H-4) 2 ( SOCR′)( PMe 2 Ph) 2]( 2). Mass spectrometric data are given. X-ray crystallography has shown that 1 (R′ = CH 3) 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.