Mechanistic Insight into the Nitric Oxide Dioxygenation Reaction of Nonheme Iron(III)-Superoxo and Manganese(IV)-Peroxo Complexes

Abstract

Reactions of nonheme FeIII–superoxo and MnIV–peroxo complexes bearing a common tetraamido macrocyclic ligand (TAML), namely [(TAML)FeIII(O2)]2−and [(TAML)MnIV(O2)]2−, with nitric oxide (NO) afford the FeIII–NO3complex [(TAML)FeIII(NO3)]2−and the MnV–oxo complex [(TAML)MnV(O)]−plus NO2−, respectively. Mechanistic studies, including density functional theory (DFT) calculations, reveal that MIII–peroxynitrite (M=Fe and Mn) species, generated in the reactions of [(TAML)FeIII(O2)]2−and [(TAML)MnIV(O2)]2−with NO, are converted into MIV(O) and.NO2species through O−O bond homolysis of the peroxynitrite ligand. Then, a rebound of FeIV(O) with.NO2affords [(TAML)FeIII(NO3)]2−, whereas electron transfer from MnIV(O) to.NO2yields [(TAML)MnV(O)]−plus NO2−. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim