N-CnH2n-1)-1,3-Aza-propane-di-thiolate (n = 5, 6, 7)-bridged di-iron complexes as mimics for the active site of [FeFe]-hydrogenases: the influence of the bridge on the di-iron complex

To further understand the effects of 1,3-aza-di-thiolate (ADT) bridges on the structures and properties of di-iron complexes, a novel family of (N-CnH2n-1)-1,3-aza-propane-di-thiolate-bridged di-iron complexes [Fe2(CO)6(CH2S)2N-CnH2n-1] (n = 5, 6, 7) and their PMe3-di-substituted complexes [Fe2(CO)4(PMe3)2(CH2S)2N-CnH2n-1] (n 5, 6, 7) were synthesized as mimics of [FeFe]-hydrogenases. Our studies suggest that the coordination configurations, CO stretching frequencies, 1H and 31P NMR signals, redox potentials and electrocatalytic H2-production processes of di-iron complexes are closely pertinent to the electron-donating abilities and steric chemistry of the ADT bridges. (authors)