Mimicking sMMOH chemistry: trapping the Sc3+-bound nonheme FeIII–O–O–FeIII adduct prior to its conversion into an FeIV2(μ-O)2 core

Abstract

Di-iron systems that activate O₂ to form high-valent, oxo-bridged Fe^IV₂ or Fe^IIIFe^IV products are of great interest to bio-inorganic chemists due to their relevance to the chemistry of soluble methane mono-oxygenase (sMMOH), which incorporates both atoms of O₂ gas into a diiron(IV) complex with an Fe₂O₂ diamond core. In this study, the [Fe^III₂(Me₃NTB)₂(μ-O)(μ-O ₂)]²⁺ adduct (Me₃NTB = tris((1-methyl-1H-benzo[d]imidazole-2-yl)methyl)amine) reacts with two Sc³⁺ to break the O–O bond that in turn forms the target Fe^IV(μ-O)₂Fe^IV product. This study provides the first evidence that a Lewis acid can interact directly with a diferric-peroxo complex to initiate O–O bond cleavage, as evidenced via vibrational and X-ray absorption spectroscopy.