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

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