Atmospheric Degradation Mechanism of CF3OCH3

A smog chamber/FTIR technique was used to study the Cl atom initiated oxidation of CF 3 OCH 3 in 700 Torr of N 2 /O 2 at 296 K. Using relative rate techniques it was determined that k (Cl + CF 3 OCH 3 ) = (1.4 ± 0.2) × 10 -13 and k (Cl + CF 3 OC(O)H) = (9.8 ± 1.2) × 10 -15 cm 3 molecule -1 s -1 . At 700 Torr of N 2 /O 2 diluent at 296 K reaction with O 2 is the only loss mechanism of the CF 3 OCH 2 O • radical. The infrared spectra of the peroxy nitrates CF 3 OCH 2 O 2 NO 2 and CF 3 OC(O)O 2 NO 2 were recorded and compared to the nonfluorinated analogues CH 3 OCH 2 O 2 NO 2 and CH 3 OC(O)O 2 NO 2 . The thermal decomposition rate of CF 3 OC(O)O 2 NO 2 is (2.3 ± 0.1) × 10 -4 s -1 in 700 Torr of N 2 at 295.8 K. The reaction of CF 3 OC(O)O 2 radicals with HO 2 radicals gives CF 3 OC(O)H in a yield of (80 ± 11)%. The results are discussed with respect to the atmospheric degradation mechanism of CF 3 OCH 3 and other ethers.