PHOTOLYSIS OF CF3O2CF3 IN THE PRESENCE OF O-3 IN OXYGEN - KINETIC-STUDY OF THE REACTIONS OF CF3O AND CF3O2 RADICALS WITH O-3

Mixtures of CF3O2CF3 (0.65-6.1 x 10(15) molecule cm(-3)) and O-3 (1.3 x 10(15) molecule cm(-3)) in 760 Torr O-2 were photolysed at 254 nm in a static system at 295 K. CF2O and CF3O3CF3 were identified as produc ts by FTIR spectroscopy. From these product concentrations, the observ ed O-3 decay (UV) and the measured photolysis rate of CF3O3CF3, a mech anism was established and the rate constants k(CF3O + O-3) = (2.8 +/- 1) x 10(-15) cm(3) molecule(-1) s(-1) and k(CF3O2 + O-3) = (9 +/- 3) x 10(-16) cm(3) molecule(-1) s(-1) were calculated. For this purpose tw o different methods were employed: one assuming steady state condition s and another using of computer simulations of the O-3 decay. The resu lts are discussed and compared with other investigations. UV absorptio n spectra of CF3O2CF3 and CF3O3CF3 are also presented.