A Kinetic and Mechanistic Study of the Reactions of OH Radicals and Cl Atoms with 3,3,3-Trifluoropropanol under Atmospheric Conditions

Abstract

Product distribution studies of the OH radical and Cl atom initiated oxidation of CF₃CH₂CH₂OH in air at 1 atm and 298 ± 5 K have been carried out in laboratory and outdoor atmospheric simulation chambers in the presence and absence of NO_x. The results show that CF₃CH₂CHO is the only primary product and that the aldehyde is fairly rapidly removed from the system. In the absence of NO_x the major degradation product of CF₃CH₂CHO is CF₃CHO, and the combined yields of the two aldehydes formed from CF₃CH₂CH₂OH are close to unity (0.95 ± 0.05). In the presence of NO_x small amounts of CF₃CH₂C(O)O₂NO₂ were also observed (3CHO is removed from the system to give mainly CF₂O. The laser photolysis−laser induced fluorescence technique was used to determine values of k(OH + CF₃CH₂CH₂OH) = (0.89 ± 0.03) × 10^-12 and k(OH + CF₃CH₂CHO) = (2.96 ± 0.04) × 10^-12 cm³ molecule^-1 s^-1. A relative rate method has been employed to measure the rate coefficients k(OH + CF₃CH₂CH₂OH) = (1.08 ± 0.05) × 10^-12, k(OH + C₆F₁₃CH₂CH₂OH) = (0.79 ± 0.08) × 10^-12, k(Cl + CF₃CH₂CH₂OH) = (22.4 ± 0.4) × 10^-12, and k(Cl + CF₃CH₂CHO) = (25.7 ± 0.4) × 10^-12 cm³ molecule^-1 s^-1. The results from this investigation are discussed in terms of the possible importance of emissions of fluorinated alcohols as a source of fluorinated carboxylic acids in the environment.