Theoretical investigations on the kinetics of H-abstraction reactions from CF3CH(OH)CF3 by OH radicals.

The kinetic studies of the H-abstraction reaction of CF3CH(OH)CF3 with the OH radical, which is predicted to have two classes of possible reaction channels, were carried out. The minimum energy path and energetics were calculated at M062X/6-31+G (d,p) method. The rate coefficients for each reaction channels were evaluated by canonical variational transition state theory (CVT) with the small-curvature tunneling correction (SCT) and zero-curvature tunneling over the wide range of temperature of 200-3000 K. The temperature-dependent rate expression for the title reaction is obtained to be k((Total)) = 2.60 x 10(-22) T-3.04 exp(372.45/T) cm(3) molecule(-1) s(-1); with k((298)) = 3.54 x 10(-14) cm(3) molecule(-1) s(-1). The global warming potentials (GWPs) and atmospheric lifetimes of CF3CH(OH)CF3 are computed in the present investigation. The atmospheric implications and the degradation mechanism of CF3CH(OH)CF3 are discussed. It is concluded that this compound can be suggested as an acceptable substitute to HFCs in terms of its atmospheric lifetime and GWPs.