Synthesis, characterization and electrocatalytic H2 production of phosphine-substituted CpFe complexes

Abstract

Reaction of Ph2P(Se)CSNHPh with Cp2Fe2(CO)4 in refluxing toluene affords complexes CpFe(CO)(k2P,S-Ph2PC(S)NPh) (1) and CpFe(CO)2(kP-P(Se)Ph2) (2). Further, reactions of 2 with 1 equiv of PPh2R in the presence of Me3NO generate complexes CpFe(CO)(kSe-SeP(Se)Ph2)(L) (3, L = PPh3; 4, L = PPh2Py). Unlike 2, reactions of CpFe(CO)2(kP-P(S)Ph2) with PPh2R under the same conditions give the corresponding phosphine-substituted complexes CpFe(CO)(kP-P(S)Ph2)(L) (5, L = PPh3; 6, L = PPh2Py). All the new compounds have been characterized by elemental analyses, IR, 1H NMR, 13C NMR and 31P NMR spectroscopy and structurally determined by X-ray crystallography. Electrochemical studies indicate that using HOAc or TFA as a proton source complexes 1–6 can catalyze H2 evolution.