Catalytic property of [FeFe]-hydrogenase model complex: [(μ-dmedt)Fe2(CO)5](μ-DPPF-O) (DPPF = 1,1′-bis(diphenylphosph ino)ferrocene) for the selective phenol hydroxylation

Abstract

A novel [FeFe]-hydrogenase biomimetic catalyst [(μ-dmedt)Fe2(CO)5](μ-DPPF-O) (1) was prepared by CO-substitution in the (μ-dmedt)[Fe2(CO)6] complex with DPPF in THF. Confirmation of the catalyst structure was determined by FTIR, 1H NMR, 13C NMR, 31P NMR and single crystal X-ray diffraction. Complex 1 exhibited better catalytic reactivity for phenol hydroxylation than the all-carbonyl complex (μ-dmedt)[Fe2(CO)6]. The dihydroxybenzene selectivity of 94.0% and phenol conversion of 42.9% were obtained under the optimal reaction conditions. The relationships between electron density of the FeFe bond and the catalytic activity of these complexes were revealed, which showed that the more electron rich the FeFe bond is, the better catalytic hydroxylation activity was achieved.