Atmospheric Chemistry of n-CxF2x+1CHO (x = 1, 3, 4): Mechanism of the CxF2x+1C(O)O2 + HO2 Reaction

Smog chamber/FTIR techniques were used to study the gas-phase reaction of C x F 2 x +1 C(O)O 2 ( x = 1, 3, 4) with HO 2 radicals in 700 Torr of air, or O 2, diluent at 296 ± 2 K. The reactions proceed by three pathways leading to formation of C x F 2 x +1 C(O)OOH and O 2, C x F 2 x +1 C(O)OH and O 3, or C x F 2 x +1 C(O)O radicals, OH radicals, and O 2 . Carboxylic acid yields were 38 ± 4% ( x = 1), 10 ± 2% ( x = 3), and 8 ± 2% ( x = 4). Results are discussed with respect to the potential for the atmospheric degradation of fluorotelomer alcohols, C x F 2 x +1 CH 2 CH 2 OH, to contribute to the environmental burden of fluorinated carboxylic acids, C x F 2 x +1 C(O)OH. Rate constants for the reactions of Cl atoms with C x F 2 x +1 C(O)OH and C x F 2 x +1 C(O)OOH were determined to be k (Cl+C x F 2 x +1 C(O)OH) < 2 × 10 -17 and k (Cl + C x F 2 x +1 C(O)OOH) = (2.9 ± 0.7) × 10 -16 cm 3 molecule -1 s -1 in 700 Torr of N 2 at 296 ± 2 K.