Bonding, Activation, and Stabilization of Small Molecules by Molybdenum—Sulfur and Iron—Sulfur Systems

In quest for model compounds for oxidoreductases with [MoS] and/or [FeS] centers, coordination, activation, and stabilization of CO, NO, N2, N2H2, N2H3, N2H4, NH3, NH2O, and NH2 by Mo and Fe sulfur ligand complexes was investigated. Reduction of NO to NH2OH was achieved at [Mo(NO)('S4')] centers. [Mo(η2-N2H3)(NO)('S4')] and [MoIV(CO)2('buS2')2] model structure and, potentially, function of the Mo centers in [Fe/Mo] nitrogenases. [Fe(L)('NHS4')] complexes (L = CO, N2H2, N2H4, NH3) yield a new model for the active centers of [Fe/Fe] and possibly also [Fe/Mo] nitrogenases. ('NHS4'2- = 2,2'- bis(2-mercaptophenylthio)diethylamine(2-); 'S4'2- = 1,2-bis(2-mercaptophenylthio) ethane(2-); 'buS22- = 3,5-di(tertiarybutyl)-benzene-l,2-dithiolate(2-)).