Catalytic reduction of O(sub 2) by pyrazine derivatives

The catalytic reduction of molecular oxygen O(sub 2) by four kinds of pyrazine derivatives-2,3,5,6-tetramethylpyrazine, 2,3-dimethylquinoxaline,2,3-diphenylquinoxaline, and phenazine is studied by cyclic and rotating disk voltammetry and molecular orbital calculations. It was possible to compare the reactivity of both one-electron reduced forms (the radicals) and two-electron reduced forms of the derivatives toward O(sub 2) in this acidic solution.