Vacuum-UV photolysis of oxygenated aqueous ethanol solutions with a Xe-plasma lamp yields relatively high concentrations of superoxide radical in short time periods. The superoxide radical in this system is identified by its absorption spectrum (λmax = 240 nm, ε = 2350 M-1 cm-1), ESR spectrum in a glass at low temperatures with the characteristic low-field g∥ = 2.072 and high-field g⊥ = 2.006, second-order decay kinetics (kobsd = 22 M-1 s-1 in 12 M ethanol containing 0.01 M KOH; kobsd = 8.7 × 105 M-1 s-1 in 12 M ethanol containing 0.085 M H2SO4), and reactivity with cytochrome c. Two mechanisms for O2- formation, consistent with experimental results, are proposed for the photolysis of dilute and concentrated ethanol solutions.
|Number of pages||3|
|Journal||Journal of the American Chemical Society|
|Publication status||Published - 1982|