initiation reaction was determined from the sum of the rates of the termination reactions. The Arrhenius expression for this reaction at the high-pressure limit was obtained from a nonlinear least-squares fit to the experimental data using the Troe factorization method, k1∞ = (9.6 ± 2.5) × 1019 exp (−(392 ± 18) kJ mol-1/RT) s-1. The rate constants for hydrogen abstraction, k2, and chlorineabstraction, k3