AbstractThe reactionwas investigated in the gas phase over the range 80–225°C using the photolysis of heptafluoroisopropyl iodide as the source of radicals. The rate constant, based on the value of 1013.36cm3mol−1s−1for the recombination ofi‐C3F7radicals, is given by\documentclass{article}\pagestyle{empty}\begin{document}$$ {\rm log(}{{k_3 } \mathord{\left/ {\vphantom {{k_3 } {{\rm cm}^{\rm 3} }}} \right. \kern-\nulldelimiterspace} {{\rm cm}^{\rm 3} }}{\rm mol}^{ - 1} {\rm s}^{ - 1}) = (13.10 \pm 0.20) - {{(14000 \pm 280)} \mathord{\left/ {\vphantom {{(14000 \pm 280)} \theta }} \right. \kern-\nulldelimiterspace} \theta } $$\end{document}where θ = 2.303RT/cal mol−1. Arrhenius parameters for chlorine abstraction from CCl4by CF3, C2F5,n‐C3F7, and some hydrogenated radicals