Halogenated Alkylperoxyl Radicals as Oxidants: Effects of Solvents and of Substituents on Rates of Electron Transfer

Article abstract of DOI:10.1021/j100296a056

The peroxyl radicals CCl3O2^., CHCl2O2^., CH2ClO2^., CCl3CCl2O2^., CFCl2O2^., CH3CCl2O2^., CF3CHClO2^., and CBr3O2^. were produced by pulse radiolysis of aerated solutions of the appropriate halogen compound in 2-propanol or 2-propanol-water solutions.Rate constants for one-electron oxidation of chloropromazine by these radicals were determined by kinetic spectrophotometry in various solvent mixtures.The second-order rate constants were found to vary from 1 * 10⁵ to 1 * 10⁹ M^-1 s^-1.They depend very strongly on the solvent polarity and a reasonable correlation is obtained between log k for a certain peroxyl radical and the dielectric constant of the solvent mixture.The rate constants in the same solvent are strongly dependent of the substituents on the methylperoxyl radical and give a good correlation with the polar substituent constants ?^*.