[FeFe]-hydrogenase active site mimics containing pyridyl-functionalized phosphine ligands: Synthesis, characterization and electrochemical investigation

Abstract Three dinuclear iron complexes containing pyridyl-functionalized phosphine ligands, [(μ-EDT)Fe2(CO)5(Ph2PPy-4)] (1), [(μ-EDT)Fe2(CO)5 (Ph2PCH2Py-4)] (2), [(μ-PDT)Fe2(CO)5(Ph2PCH2Py-4)] (3) (where Py is pyridyl ring, EDT is SCH2CH2S, PDT is SCH2CH2CH2S), were prepared as the active site models of [FeFe]-hydrogenases. The molecular structures of 1–3 were fully characterized by IR and NMR (1H, 13C, 31P) spectroscopies and X-ray crystallography. The electrochemical properties of 1–3 in CH3CN were investigated by cyclic voltammetry in the presence of acetic acid and found to be potential candidates for electrocatalytic H2 evolution. In addition, the self-assembling behavior of 1 with zinc tetraphenylporphyrin (ZnTPP) was studied by UV–vis spectroscopy.