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 H 2 O 2

The reactivity of the previously reported peroxo adducts [Fe 2 (μ-O 2 )(L 1 ) 4 (CH 3 CN) 2 ] 2+ , and [Fe 2 (μ-O 2 )(L 2 ) 4 (CH 3 CN) 2 ] 2+ , (L 1 = 2-(2′-pyridyl)benzimidazole and L 2 = 2-(2′-pyridyl)- N -methylbenzimidazole) towards H 2 O 2 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.