F2 laser (158 nm) photolysis of CO2 and hydrofluorocarbon systems

Abstract F 2 laser (158 nm) photolysis of gas mixtures of CO 2 and hydrofluorocarbons (HFCs) gives the corresponding alcohols and ketones. The initial step of photolysis is a bond breaking reaction to give CO and an electronicaly excited oxygen atom O( 1 D). The excited atom is partially inserted into the HFC CH bonds and is partially quenched to the triplet atom O( 3 P). The dependence of the yields of the alcohols on the gas pressure and the size of the HFC can be explained in terms of the formation of hot alcohols and collisional relaxation. The insertion rate constant of O( 1 D) has been estimated to be (1.5±0.3) × 10 −11 cm 3 molecule −1 s −1 for CF 3 CF 2 CH 3 based on the quantum yield of CF 3 CF 2 CH 2 OH production.