Atmospheric Chemistry of CF3CF=CF2: Kinetics and Mechanism of Its Reactions with OH Radicals, Cl Atoms, and Ozone

Smog chamber/FTIR techniques were used to study the OH radical, the Cl atom, and ozone initiated oxidation of CF 3 CF CF 2 in 700 Torr of air at 296 K. Relative rate methods were used to measure k (OH + CF 3 CF CF 2 ) = (2.4 ± 0.3) × 10 -12 and k (Cl + CF 3 CF CF 2 ) = (2.7 ± 0.3) × 10 -11; absolute techniques were used to derive an upper limit of k (O 3 + CF 3 CF CF 2 ) < 3 × 10 -21 cm 3 molecule -1 s -1 . OH radical and Cl atom-initiated atmospheric oxidation of CF 3 CF CF 2 gives COF 2 and CF 3 C(O)F in molar yields of 100%. The atmospheric lifetime of CF 3 CF CF 2 is approximately 9 days with degradation proceeding via reaction with OH radicals to give trifluoroacetic acid in a molar yield of 100%. Results are discussed with respect to previous measurements of k (OH + CF 3 CF CF 2 ) and k (O 3 + CF 3 CF CF 2 ) and the potential importance of CF 3 CF CF 2 as a source of trifluoroacetic acid.