Kinetic parameters of abstraction reactions of OH radical with ethylene, fluoroethylene, cis- and trans-1,2-difluoroethylene and 1,1-difluoroethylene, in the temperature range of 200–400 K: Gaussian-3/B3LYP theory

Rate coefficients for the hydrogen abstraction reactions of the ethylene, fluoroethylene, cis- and trans-isomers of the 1,2-difluoroethylene and 1,1-difluoroethylene with the OH radical were computed using TST coupled with G3B3 theory between 200 and 400 K. IRC calculations were performed to confirm the existence of all the transition states. The rate coefficients for the reactions (five test molecules + OH radical) were computed to be k1 = (1.03 ± 0.42) × 10−13 exp[−(1400 ± 114)/T], k2 = (2.46 ± 1.76) × 10−14 exp[−(1956 ± 198)/T], k3 = (4.09 ± 3.6) × 10−15 exp[−(2447 ± 250)/T], k4 = (1.39 ± 0.91) × 10−17 exp[−(1720 ± 180)/T] and k5 = (1.78 ± 0.11) × 10−17 exp[−(1993 ± 176)/T] cm3 molecule−1 s−1 respectively. The atmospheric lifetimes of these compounds due to the hydrogen abstraction reactions are computed to be 48.2, 1502.8, 5.3 × 104, 7.1 × 105 and 1.5 × 106 years, respectively.