The kinetics of radiation-induced hydrogen abstraction by CCl3 radicals in the liquid phase: Cyclohexene

The kinetics of hydrogen abstraction from cyclohexene by CCl₃ radicals were studied in CCl₄ solution as a function of cyclohexene concentration and temperature in the range of 26–140°C. The CCl₃ radicals were produced both by radiolysis of CCl₄ and by photolysis of CCl₃Br. The rate constant for the reaction was found to be given by the equation where θ = 2.303 RT kcal/mol. This activation energy leads to C? H bond strength for the allylic hydrogen of 85 ± 1 kcal/mol, which means a resonance stabilization energy of 11 ± 1.5 kcal/mol for the C-C₆H₁₁ radical.