Reactivity studies of a pseudo three-coordinate vanadium(II) complex: Synthesis of terminal oxo and sulfido complexes of vanadium(IV) and S–S and Se–Se reductive bond cleavage reactions

Abstract

Terminal oxo and sulfido complexes in the form of (nacnac)V E(Ntol 2) (nacnac = [ArNC(CH 3)] 2CH −, Ar = 2,6-(CHMe 2) 2C 6H 3, Ntol 2 = −N(C 6H 4-4-Me), E = O ( 1), S ( 2)) were isolated from treatment of the masked three-coordinate vanadium(II) complex, (nacnac)V(Ntol 2), with C 5H 5NO and S 8, respectively. Both vanadium(IV) species, 1 and 2, have been characterized by room temperature X-band EPR spectroscopic studies, and in the case of complex 1, a single crystal molecular structure confirmed the presence of a terminal oxo moiety. Moreover, reaction of (nacnac)V(Ntol 2) with diphenyl–disulfide and diphenyl–diselenide results in the reductive cleavage of these compounds to produce the vanadium(III) complexes (nacnac)V(XPh)(Ntol 2) (X = S, ( 3), Se ( 4)). A molecular structure of the phenylsulfide complex, 3, confirmed formation of the d 2 complex resulting from reductive cleavage of the S–S bond.