An experimental and theoretical study on the reaction of Cl with CF3CF2CH2OH

An absolute kinetic study of the reaction of Cl atoms with CF3CF2CH2OH is reported as a function of temperature (T=268377K) and at a total pressure of 100Torr by the Pulsed Laser Photolysis-Resonance Fluorescence (PLP-RF) technique. No pressure dependence of the rate coefficient for the title reaction, k, was observed between 50 and 200Torr of He at 298K. The derived Arrhenius expression in that T-range was k(T)=(2.18 +/- 0.24)x10(12) exp((333 +/- 34)/T) cm(3) molecule(1)s(1), where the uncertainties are +/- 2 sigma. From these results, the average tropospheric lifetime of CF3CF2CH2OH due to the reaction with Cl was estimated to be 50 years, considering a global Cl concentration of 10(3) atomcm(3) and an average temperature of 272K. Additionally, a theoretical study of the Cl+CF3CF2CH2OH reaction has been carried out by ab initio MollerPlesset second-order perturbation treatment with 6-311G** basis set to investigate the reaction mechanism. Molecular energies of the different critical points of the potential energy surface have been calculated at QCISD(T) level. The theoretical study shows that the H-atom abstraction from the CH2 group is the most favourable reaction pathway.