Redox Chemistry in the Reaction of Oxovanadium( V ) with Thiolate‐Containing Ligands: the Isolation and Characterization of Non‐Oxo Vanadium( IV ) Complexes Containing Disulfide and Thioether Groups

The reactions of V V O(O‐ i Pr) 3 with [PS3′]H 3 and [PS3]H 3 {[PS3′]H 3 = P(C 6 H 3 ‐5‐Me‐2‐SH) 3 , [PS3]H 3 = P(C 6 H 4 ‐2‐SH) 3 } led to the formation of [V IV (L)] [L = P2S4′ ( 1a ), P2S4 ( 1b )], where L was formed by the oxidative coupling of two PS3′ or PS3 ligands by a disulfide bond. When the reaction of V V O(O‐ i Pr) 3 with [PS3′]H 3 was conducted in the presence of methoxide followed by the addition of a cation, [V IV (PS3′)(PS2S Me ′)]X [X = N(C 2 H 5 ) 4 ( 2a ), N(C 2 H 5 ) 3 (CH 2 Ph) ( 2b )] was isolated, where PS2S Me ′ is a bis(benzenethiolato)phenylmethylthioetherphosphane ligand generated from the methylation of one thiolate group in PS3′. The structures of complexes 1a , b and 2a , b , determined by X‐ray crystallography, contain six‐ and seven‐coordinate non‐oxo vanadium( IV ) centers, respectively, with an octahedral geometry for 1a , b and a pentagonal‐bipyramidal geometry for 2a , b . The electronic, magnetic, and electrochemical properties of these complexes were determined by UV/Vis and EPR spectroscopy, SQUID measurements, and cyclic voltammetry. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2006)