Heterobimetallic cuboidal [Mo3NiS4] and [W3NiS4] cluster diphosphane complexes as molecular models in hydrodesulfurization catalysis

• DOI: 10.1016/j.poly.2005.04.004
• Publication Date: 2005-06-01T13:39:48Z
• Authors: Marta Feliz; Rosa Llusar; Santiago Uriel; Cristian Vicent; Michael Brorson; Konrad Herbst
• Keywords: 01 natural sciences; 0104 chemical sciences

Abstract Treatment of the cationic, incomplete cubane-type sulfido clusters [M3S4X3(diphos)3]+ (M = Mo, W; X = Cl, Br; diphos = dmpe (1,2-bis(dimethylphosphanyl)ethane), dppe (1,2-bis(diphenylphosphanyl)ethane)) with an excess of [Ni(cod)2] (cod = 1,5-cyclooctadiene) afforded the heterobimetallic single cube clusters [M3NiS4X3(diphos)3(CH3CN)]+ as PF 6 - salts. The acetonitrile ligand could be substituted by pyridine, tetrahydrothiophene and carbon monoxide in CH2Cl2 at room temperature, modelling the catalytic sites of heterogeneous Ni–MoS2 hydrodesulfurization catalysts. X-ray crystal structure analyses of [Mo3NiS4Cl3(dmpe)3(CH3CN)]BPh4 and [W3NiS4Br3(dmpe)3(CO)]PF6 are reported. Electrochemical studies by cyclic voltammetry reported for all heterobimetallic [M3NiS4] clusters show two quasireversible oxidation processes, the molybdenum complexes being ca. 0.2 V more difficult to oxidize than the tungsten analogues.