Novel bioinspired diiron core complexes with rigid chelating diphosphine ligands for highly efficient catalytic phenol hydroxylation

•Two novel diiron core complexes (μ-budt)Fe2(CO)5(DPEphos) (1) and (μ-budt)Fe2(CO)5(Xantphos) (2) supported by rigid heterocyclic xanthene-like diphosphine ligands were designed and synthesized.•Complex 1 exhibits outstanding catalytic performance, attaining 57.7% phenol conversion and 49.6% DHB yield, both of which are at the forefront of catalytic phenol hydroxylation.•The DFT calculations were performed to optimize the geometrical structures and obtain the frontier molecular orbitals.•The mechanism of phenol hydroxylation using 1 as a catalyst was proposed.•Hydroxyl radicals (•OH) were generated in the catalytic reaction, as demonstrated by electron spin resonance (ESR).