The reactions of C 2 F 5 radicals with benzene in the vapor phase

C 2 F 5 radicals were generated in the presence of benzene vapor by the reaction\documentclass{article}\pagestyle{empty}\begin{document}$$({\rm C}_{\rm 2} {\rm F}_{\rm 5} {\rm CO})_2 {\rm O} + hv \to {\rm CO} + {\rm CO}_2 + 2{\rm C}_{\rm 2} {\rm F}_5 $$\end{document} The radicals react with the benzene by addition and pseudo H abstractionThe rate constant k add for the addition reaction (7) is given by\documentclass{article}\pagestyle{empty}\begin{document}$$\log k_{add} /k_{c^{1/2} } {\rm cm}^{{\rm 3/2}} {\rm mole}^{ - 1/2} \sec ^{ - 1/2} = (4.49 \pm 0.10) - (4210 \pm 150)/\theta $$\end{document} where θ = 2.303 RT cal/mole and k c is the rate constant for combination of C 2 F 5 radicals. The addition becomes reversible above 110°C. The reactions of CF 3 and C 2 F 5 radicals with benzene vapor are compared.