Electrochemical and Electrocatalytic Properties of 2,3,7,8,12,13,17,18-Octamethylporphine Nitro Derivatives

The results on the electrochemical and electrocatalytic properties a number of 2,3,7,8,12,13,17,18-octamethylporphine (OMeP) nitroderivatives in an alkaline solution were obtained and analyzed for the first time. The values of redox potentials of transformation processes of organic ligand and molecular oxygen using the method of cyclic voltammetry were determined. Potentials of redox processes caused by the formation of cationic and anionic forms were determined. The identification of the electroreduction process of the nitro group in the area of ERed/Ox =-0.40 --0.6V is carried out. A general scheme of electrochemical processes of oxidation-reduction of nitro derivatives for octamethylporphyrins in an alkaline solution is proposed. The electrocatalytic activity of compounds in the oxygen reduction reaction (ORR) in an alkaline solution was evaluated. It has been established that all, with the exception of 10,15,20-trinitro-5-(4-nitrophenyl)-2,3,7,8,12,13,17,18-octamethylporphine, do not have high electrocatalytic prop-erties and direct the ORR process by a two-electron mechanism through the intermediate formation of a peroxide ion. The effect of the scanning rate of the potential on the electrochemical parameters and reversibility of the observed processes were shown.