Atmospheric chemistry of trans-CF₃CH=CHF: products and mechanisms of hydroxyl radical and chlorine atom initiated oxidation

Abstract. Smog chamber/FTIR techniques were used to study the products and mechanisms of OH radical and Cl atom initiated oxidation of trans-CF₃CH=CHF in 700 Torr of N₂/O₂ diluent at 295±1 K. Hydroxyl radical initiated oxidation leads to the formation of CF₃CHO and HC(O)F in yields which were indistinguishable from 100% and were not dependent on the O₂ partial pressure. Chlorine atom initiated oxidation gives HC(O)F, CF₃CHO, CF₃C(O)Cl, and CF₃C(O)CHFCl. The yields of CF₃C(O)Cl and CF₃C(O)CHFCl increased at the expense of HC(O)F and CF₃CHO as the O₂ partial pressure was increased over the range 5–700 Torr. The results are discussed with respect to the atmospheric chemistry and environmental impact of trans-CF₃CH=CHF.