Reaction of i-heptafluoropropyl radicals with cyanogen chloride

Abstract

The gas-phase reaction of i-C₃F₇ radicals with cyanogen chloride has been studied between 70 and 330 °C, using heptafluoro-2-iodopropane as the free-radical source.

The main product, 2-chloroheptafluoropropane, is formed via chlorine-atom abstraction by i-C₃F₇: i-C₃F₇+ ClCN → C₃F₇Cl+CN (6) for which log₁₀[(k₆/k^½_c)/cm mol^–½ s^–½]= 6.27–14.41/2.303 RT was obtained. At lower temperatures the Arrhenius plot shows curvature. This was interpreted as the occurrence of another reaction producing C₃F₇Cl, which could be i-C₃F₇+ ClCN ⇌ C₃F₇ClCN (9, –9) C₃F₇ClCN → C₃F₇Cl + CN. (10)

The results are compared with those for the reaction of other perfluoroalkyl radicals with ClCN.