Free radical yields in the radiolysis of gaseos hexafluoroethane

Abstract

The radiolysis of gaseous hexafluoroethane yields CF₄(G= 2.5), C₃F₈(G= 0.31) and C₄F₁₀(G= 0.10) as major products. In the presence of Br₂, Cl₂ or HCl these products are scavenged and replaced by yields of CF₃ and C₂F₅ scavenged products. The yields of these scavenged products are independent of pressure above 5 mol % scavenger and are ∼G= 2.6 for both CF₃ and C₂F₅ radicals. In the presence of chlorine and HCl, not all the CF₄ is scavengeable even though the CF₃ and C₂F₅ radical yields are independent of scavenger concentration. Statistical combination–cross combination ratios may be used to reconcile the observed radical yields with the yields of stable fluorocarbon products. Competition kinetics in the Br₂+ Cl₂+ BrCl system indicate that some of the CF₃ scavenged products are due to either hot radicals or ions.