Rate constants for the reaction of OH radicals with CHF2Cl, CF2Cl2, CFCl3, and H2 over the temperature range 297–434 °K

Abstract

Rate constants for the reaction of OH radicals with CHF₂Cl, CF₂Cl₂, CFCl₃, and H₂ have been determined over the temperature range 297–434 °K using a flash photolysis–resonance fluorescence technique. The following Arrhenius expressions were obtained: k₁(CHF₂Cl) =1.21×10⁻¹²e^{−(3250±300)/RT} cm³ molecule⁻¹ sec⁻¹, k₁(CF₂Cl₂) −15 cm³ molecule⁻¹ sec⁻¹ (T=297–424 °K), k₁(CFCl₃) −15 cm³ molecule⁻¹ sec⁻¹ (T=297–424 °K), k₁(H₂) =5.9×10⁻¹² e^{−(3990±300)/RT} cm³ molecule⁻¹ sec⁻¹. The rate constants for the reaction of OH radicals with H₂, which were used to check the experimental system, are in good agreement with literature values. The atmospheric significance of the reaction of OH radicals with CHF₂Cl is briefly discussed.