Functional models of nonheme diiron enzymes: kinetic and computational evidence for the formation of oxoiron(iv) species from peroxo-diiron(iii) complexes, and their reactivity towards phenols and H2O2

Abstract

The reactivity of the previously reported peroxo adducts [Fe₂(μ-O₂)(L¹)₄(CH₃CN)₂]²⁺, and [Fe₂(μ-O₂)(L²)₄(CH₃CN)₂]²⁺, (L¹ = 2-(2′-pyridyl)benzimidazole and L² = 2-(2′-pyridyl)-N-methylbenzimidazole) towards H₂O₂ as catalase mimics, and towards various phenols as functional RNR-R2 mimics, is described. Kinetic, mechanistic and computational studies gave direct evidence for the involvement of the (μ-1,2-peroxo)diiron(III) intermediate in the O–H activation process via formation of low-spin oxoiron(IV) species.