Preparation, Structure and Electrochemical Property of a Pyrazole-substituted Diiron Dithiolate Complex

摘要

A pyrazole-substituted diiron dithiolate complex [Fez(p-pdt)(CO)5(3,5-Me2Pz)] (1, 3,5-MezPz = 3,5-dimethylpyrazole) was prepared as a biomimetic model for the active site of [FeFe]-hydrogenase by CO-substitution of aU-carbonyl complex [Fe2(μ-pdt)(CO)6] with 3,5-Me2Pz. The molecular structure was confirmed by MS, IR, 1H NMR, elemental analysis and single-crystal X-ray analysis. Complex 1 crystallizes in the triclinic system, space group PI with a = 9.108(7), b = 9.743(8), c = 11.192(9)A, a = 109.235(5), fl = 101.914(9), y = 96.605(6). In CH3CN solution, reversible transformation between 1 and the acetonitrile-substituted species [Fe2(p-pdt)- (CO)5(NCCH3)] was detected by both IR and cyclic voltammetry (CV). The electrochemical proton reduction catalyzed by 1 in the presence of acetic acid was also studied in CH2C12.