Reaction of pentafluoroethyl radicals with cyanogen chloride

Abstract

The reaction of C₂F₅ radicals with cyanogen chloride was studied between 293 and 573 K, using perfluoroethyl iodide as the free-radical source.

The main product, C₂F₅Cl, is formed via an addition reaction or by abstraction of a chlorine atom by C₂F₅. The reactions involved are C₂F₅+ ClCN → C₂F₅Cl + CN (2), C₂F₅+ ClCN ⇌ C₂F₅ClCN (3), C₂F₅+ ClCN → C₂F₅Cl + CN (4), C₂F₅+ C₂F₅ [graphic omitted] C₄F₁₀.

The Arrhenius plot shows pronounced curvature. The following rate constants were obtained for reaction (2) and (4) log [(k₂//_k^½c)/cm mol^–½ s^–½]= 6.91 – 57.10 kJ mol^–1/2.303 RT, log [(k₃//_k^½c)/cm mol^–½ s^–½]= 2.32 – 20.55 kJ mol^–1/2.303 RT were k_c is the rate constant for C₂F₅ combination.

The results are compared with those for the reaction of CF₃ with ClCN.