Reaction of Perfluoroethyl Radicals with Cycloalkanes

Abstract

The reactions of C2F5 radicals with C4 to C7 cycloalkanes have been studied using perfluoroethyl iodide as the source of free radicals. The Arrhenius parameters obtained for the reaction C2F5+ c-RH→C2F5H + c-R were (c-R = cycloalkyl): [graphic omitted] The Arrhenius parameters are compared with those for corresponding CF3 radical reactions. From the activation energies, values for the c-R—H bond dissociation energies are derived using the Evans–Polanyi method. Bond strengths for methylene groups in C5, C6 and C7 cycloalkanes are all close to that for the Pri—H bond dissociation energy in propane.