One electron reduction of CCl4 in oxygenated aqueous solutions: a CCl3O2-free radical mediated formation of Cl- and CO2

Product yields have been determined after one-electron-induced reduction of CCl4 in aqueous solutions containing t-butanol and various concentrations of oxygen. It was shown that CCl3 radicals add oxygen to form CCl3O2 radicals, which eventually yield three chloride ions and CO2. A constant ratio of G(Cl-)/G(CO2) = 4 is found in solutions containing 1.5 X 10(-4) M or more oxygen. Competing reactions of the CCl3 radical increase this ratio at lower oxygen concentrations. The rate constant for the oxygen addition to CCl3 radicals was determined by pulse radiolysis to 3.3 X 10(9) M-1 s-1. Possible reaction mechanisms leading to the observed end products are discussed.