Ritimukta Sarangi,*, § and Wonwoo Nam*,†

ABSTRACT: We report the first example of a mono-nuclear nonheme manganese(III)−hydroperoxo complex derived from protonation of an isolated manganese(III)− peroxo complex bearing an N-tetramethylated cyclam (TMC) ligand, [MnIII(TMC)(OOH)]2+. The MnIII-hydroperoxo intermediate is characterized with various spectroscopic methods as well as with density functional theory (DFT) calculations, showing the binding of a hydroperoxide ligand in an end-on fashion. The MnIII− hydroperoxo species is a competent oxidant in oxygen atom transfer (OAT) reactions, such as the oxidation of sulfides. The electrophilic character of the MnIII−hydro-peroxo complex is demonstrated unambiguously in the sulfoxidation of para-substituted thioanisoles. Manganese(III)−peroxo (MnIII−O2) and manganese-(III)−hydroperoxo (MnIII−OOH) species have bee