Vanadium(III) thiolate complexes, [V(PS3")(Cl)]- [1a; PS3" = P(C6H3-3-(MeSi)-Si-3-2-S)(3)(3-)] and [V(PS3')(Cl)]- [1b; PS3' = P(C6H3-5-Me-2-S)3(3-)], were synthesized and characterized. Complex la serves as a precursor for the catalytic reduction of hydrazine to ammonia. The spectroscopic and electrochemical studies indicate that hydrazine is bound and activated in a V-II state.