Synthesis, characterization and DFT studies of 1, 1′-Bis(diphenylphosphino)ferrocene substituted diiron complexes: Bioinspired [FeFe] hydrogenase model complexes

The reaction of [Fe 2 (CO) 6 ( μ -toluene-3, 4-benzenedithiolate)] 1 and bidentate diphosphine, 1, 1′-bis(diphenylphosphino)ferrocene (dppf) has been studied. New complexes obtained have been characterized by various spectroscopic techniques as bioinspired models of the iron hydrogenase active site. The crystal structure of [Fe 2 (CO) 5 ( κ 1 -dppfO)( μ -toluene-3, 4-benzenedithiolate)] 4 is reported. Graphical Abstract New iron carbonyl complexes were synthesized from the reaction of [Fe 2 (CO) 6 ( μ -toluene-3, 4-benzenedithiolate)] 1 and bidentate diphosphine, 1, 1’-bis(diphenylphosphino)ferrocene (dppf). Complex 2 was catalytically active towards proton reduction in presence of acetic acid. Based on DFT calculations the HOMO and LUMO in complex 2 were found to be localized on the Fe centers of the two {Fe 2 S 2 } units.