Reactivity of certain hydrogen donors and olefins with respect to ?,?-dichloroalkyl radicals

Abstract

The rate constants of hydrogen splitting from hydrogen donors (DH) by the ClCH2(CH2)3CCl2 radicals (R1) were determined by the method of competitive kinetics in the temperature range of 413–433 K. As a competing reaction with splitting of hydrogen from the DH, the isomerization of radicals R1 into ClCH(CH2)3CCl2H radicals with 1,5-migration of hydrogen was chosen, for which log k (sec−1)=9.343 –10.56/2,303RT (kcal/mole) was calculated. It was found that the relative reactivities are similar of R1 and (CH3)3CO radicals (R4) in splitting hydrogen from HD. This makes it possible to predict the values of analogous constants for radicals R1 from known rate constants of splitting hydrogen from various DH by radicals R4. The rate constants of the addition of Cl(CH2)2ĊCl2 radicals (R2) to amethylstyrene and methyl methacrylate were determined. Taking into account the data in [7], where the same constants were determined for styrene, methyl acrylate, acrylonitrile and vinyl methyl ketone, the existence of a linear dependence was shown of the logarithm of the rate constant of the addition of radicals R2 to olefins on the polar properties of the above-enumerated olefins.