C-O BOND REDUCTION AND SPLITTING IN 1,4-DIOXANYL RADICALS ADSORBED ONTHE MERCURY-ELECTRODE

Laser-pulse-stimulated photoelectron emission supplemented by time-res olved differential polarography of the intermediates was used to study the reactions of 1,4-dioxanyl radicals (I) adsorbed on the mercury el ectrode. The rate constant, W3, of the one-electron reduction of I inc reased between E of -1.2 and -1.8 V (sce) but was independent of pH be cause of carbanion formation. In addition to reduction, a heterogeneou s conversion of I to radicals II was found to occur with a rate consta nt proportional to the hydrogen ion concentration. Radicals II were re duced in the region between -0.9 and -1.5 V at pH less-than-or-equal-t o 4.3 in a reaction involving one electron and one hydrogen ion. By re ference to the electrode reactions of radicals studied previously, II could be identified as the product of acid-catalyzed beta-cleavage of the ring of I at the C-O bond.