O2 ELECTROCHEMICAL ACTIVATION WITH Mn(II) COMPLEX FORMATION AND REACTIVITY OF Mn(III)OO INTERMEDIATES

CHRISTELLE HUREAU; CLAUDIA PALOPOLI; SANDRA SIGNORELLA; EZEQUIEL BERNATENE; ELODIE ANXOLABEHERE-MALLART; CLAIRE FAVE; ALEXIS GOSSET

Montpellier

Congreso; Congress SCF 18; 2018

Societe Chimique de France

Transition metal peroxo (M-OO) and hydro-peroxo (M-OOH) adducts are postulated as key intermediates in various catalytic oxygenation reactions like, for instance, transition metal catalyzed oxidation of organic compounds as well as in fundamental enzymatic reactions such as respiration and photosynthesis.In the case of manganese, a number of biomimetic, mononuclear peroxo-manganese(III) complexes have been reported resulting from reaction with dioxygen, superoxide or hydrogen peroxide.[1],[2],[3] Although these complexes have been nicely characterized, a detailed understanding of the structure- reactivity relationship is still limited.We develop complexes that contain redox active metal (Mn, Fe) and various molecular environment inspired from metalloenzymes?s active sites.[4],[5],[6],[7] We use electrochemical (in particular cyclic voltammetry) and Uv-vis spectroelectrochemical methods to study their catalytic properties and characterize possible reactive intermediates, with the aim to access to the mechanism of the catalytic reaction.[4],[5],[6]Using the electrochemical approach, we report here on the reactivity of O2 with two series of Mn complexes (seriesL and Salpn), for which the ligand can be modulated.The modulation influence of the ligand on the experimentally observed reactivity will be rationalized, with the aim of understanding the structure- reactivity relationship.