The Arrhenius Parameters for the Reactions of O Atoms with Ethene and Five Fluoroethenes

Abstract

Abstract The rate constants for the reactions of ground-state oxygen atoms with ethene and five fluoroethenes have been measured over the temperature range of 240–450 K, using a pulse radiolysis-resonance absorption technique. The rate constants were well expressed by the following Arrhenius expressions: k(O+C2H4)=8.4×106 exp(−712⁄T); k(O+C2H3F)=3.1×106 exp(−622⁄T); k(O+CH2=CF2)=2.4×106 exp(−638⁄T); k(O+cis-CHF=CHF)=1.9×106 exp(−500⁄T); k(O+C2HF3)=3.0×106 exp(−544⁄T); k(O+C2F4)=8.1×106 exp(−634⁄T), in units of m3mol−1 s−1. The change in the preexponential factors with the degree of fluorination is discussed in terms of the conventional transition-state theory.