Bis(diphenylphosphino)ferrocene as an intramolecular bridging ligand in N-functionally substituted 1,3-azapropanedithiolate diiron complexes: synthesis and catalysis of proton reduction

Abstract

Reaction of 1,1′-bis(diphenylphosphino)ferrocene (dppf) with [μ-(SCH2)2NCH2CH2OH]Fe2(CO)6 (A) or [μ-(SCH2)2NCH2CH2SAc]Fe2(CO)6 (C) in refluxing xylene yielded an intramolecular bridging complex [μ-(SCH2)2NCH2CH2OH]Fe2(CO)4(μ-dppf) (1) or [μ-(SCH2)2NCH2CH2SAc]Fe2(CO)4(μ-dppf) (2) in moderate yield. The structures of both complexes were fully characterized by spectroscopic methods and X-ray crystallography, and the electronic structure of 2 was further investigated by UV–vis. The cyclic voltammetry was conducted and the reduction of protons from CF3SO3H (TfOH), HBF4·Et2O, or CF3COOH (TFA) catalyzed by 2 was observed.