Electrochemical and ESR-study of the mechanism of organic compound oxidation in the presence of mediators—Radical cations of substituted pyrazin-di-N-oxydes

Electrochemical and Electron Paramagnetic Resonance Study of the Mechanism of Oxidation of Phenazine-di-N-oxide in the Presence of Isopropyl alcohol at Glassy Carbon and Single-Walled Carbon Nanotube Electrodes

“…The irreversibility of the electrode process of PhenDNO oxidation is explained by the interaction of PhenDNO and its radical cation with active sites on the surface of SWCNT electrode (end and edge defects). The deviation from the reversible oxidation of the Fe(CN) 6 3-/Fe(CN) 6 4− pair on the SWCNT electrode was explained in [24] by the weak binding interaction between the electrode material and the ions in solution.…”

“…Previously [3,5,6], we obtained data on the diverse effects of water (as a base) and acid additions on the catalytic currents of oxidation of aromatic di-N-oxides in the presence of a number of substrates. Thus, the catalytic current of the oxidation of pyrazine-di-N-oxides in the presence of cyclohexane [5,6] increased threefold at the addition of 1 M Н 2 O.…”

“…The detection of the same intermediate in CH 3 OH and CH 3 OD indicated that CH 3 group of alcohol was involved in formation of the intermediate. To explain the results obtained in [1][2][3][4][5][6][7][8], the E 1 C 1 E 2 C 2 mechanism of two-stage electrode process characterized by catalytic current at the second electrode stage was suggested. The overall two-electron catalytic oxidation of the organic substance in complex with aromatic di-Noxide radical cation was assumed to occur.…”

“…Previously, it was found [1][2][3][4][5][6][7][8] that electrochemically generated aromatic di-N-oxide radical cations are carriers of active oxygen that is capable of activating the C-H bond of the substrate. The mechanism of the oxidation of phenazine-di-N-oxide (PhenDNO), pyrazine-di-N-oxide, and its substituted derivatives in the presence of organic compounds (alcohols, ethers, cyclohexane) was studied by cyclic voltammetry [1][2][3][4][5][6][7][8].…”

“…The mechanism of the oxidation of phenazine-di-N-oxide (PhenDNO), pyrazine-di-N-oxide, and its substituted derivatives in the presence of organic compounds (alcohols, ethers, cyclohexane) was studied by cyclic voltammetry [1][2][3][4][5][6][7][8]. In the study of the oxidation of PhenDNO in methanol and its deuterated derivatives CH 3 OD and CD 3 OD by EPR electrolysis [3], EPR spectra of radical intermediates were recorded with g-factor of 2.0023 in CH 3 OH and CH 3 OD and 2.0023 and 2.0036 in CD 3 OD.…”