The 254 nm gas phase photochemistry of perfluoroacetyl chloride in the presence of O-2

The photolysis at 254 nm of perfluoroacetyl chloride (CF3COCl) in the gas phase and with O-2 in excess yielded CO2, CF2O, CF3OOOCF3, CF3COF and Cl-2 as products. It was observed that the ratio of CF3COCl consumed to Cl-2 formed was 2:1 and that the rate of disappearance of CF3COCl was faster in the presence than in the absence of O-2. The quantum yields of formation of the main products obtained in typical runs followed the relationship phi(CF3COCl) = phi(CF2O) + 2X phi(CF3OOOCF3) + phi(CF3COF) = 2X phi(Cl2) > 1 within experimental error, although individual experiments showed varying amounts of each product. From these results, we postulate that F atoms are released as a result of photolysis. Also some evidence is presented that is consistent with the formation of CF3OC(O)OyC(O)OCF3 (where y can be 2, 3 or 4) when the photo-oxidation is carried out in the presence of O-2 and CO. (C) 1997 Elsevier Science S.A.