Gas phase photochemistry of perfluoropropyl fluoride and perfluoropropyl chloride

The photolysis of perfluoropropyl fluoride and perfluoropropyl chloride vap our was studied in the 12.9-79.0 Torr and 6.1-40.7 Torr pressure ranges, us ing light of 232-240 and 254 nm, respectively. The products found were CF3C F2COF: CO, C4F10 and COF2; CF3CF2COCl: CO, CF3CF2Cl, C4F10 and Cl-2. The qu antum yield for the decomposition of CF3CF2COF was 0.4 +/- 0.06, independen tly of the total pressure and light intensity while for CF3CF2COCl it was 1 .01 +/- 0.06 at 254 nm taken as phi((C2F5Cl+2C4F10)). When the photolysis w as made in the presence of hydrogenated compounds, a clear hydrogen abstrac tion took place in both the reactions, indicating the existence of radicala ry mechanisms. No net effect of mechanisms and quantum yields were found on the length of the carbon chain with respect to the perfluoro acetyl halide s. Mechanisms for the decomposition of perfluoroacyl halides are discussed. (C) 1999 Elsevier Science S.A. All rights reserved.