On the lifetime of trifluoromethyl radical in aqueous solution

Radiolysis of aqueous solutions of CF₃Cl produces CF₃ radicals which can readily be trapped as the addition product to nitromethane anion. Intercomparison of the effects of scavengers on the esr signals of this adduct radical and on the production of fluoride ion indicates that CF₃ reacts with water with a period of ∼30 msec. Conductometric pulse radiolysis studies in the presence of 1 mM methanol, where OH radicals are rapidly removed from the system, show that no significant hydrolysis of CF₃ occurs on the millisecond time scale. In the absence of methanol, however, secondary reactions which produce a large yield of HF occur at shorter times. This HF can be accounted for by reactions involving combination of CF₃ radicals with OH. It is expected that the CF₃OH produced from such a combination will eliminate HF rapidly. However, it also appears from the magnitude of the increase in conductivity that CF₂O must hydrolyze completely within the period of these conductivity experiments. From the limiting growth period at high doses the period of the initial hydrolysis of CF₂O is estimated to be ∼10 μsec.