Rate constants for reactions of (perhaloalkyl)peroxyl radicals with alkenes in methanol

A number of halogenated peroxyl radicals were produced in methanolic solutions through the radiolytic reduction of halocarbons in the presence of oxygen. Rate constants for the reactions of these radicals with unsaturated organic compounds were measured by competition kinetics with chlorpromazine as the reference compound. The rate constants were in the range 5 × 10⁴ to 2 × 10⁸ L mol^-1 s^-1 and generally increased with increasing fluorine substitution on the peroxyl radical and increasing substitution of alkyl groups about the double bond in the alkene. Limits on the rate constants with increasing substitution, however, suggested an additional effect of steric hindrance. Similar results were found for the oxidation of chlorpromazine by several of these haloperoxyl radicals.