Theoretical investigation of the kinetics for the hydrogen abstraction reaction of 1,1,1,2-tetrafluoroethane (HFC-134a) by chlorine radical

The hydrogen abstraction reaction of 1,1,1,2-tetrafluoroethane (HFC-134a) by chlorine radical is investigated by theoretical calculations. Equilibrium geometries and harmonic vibrational frequencies of the reactants, transition state, and products are calculated using high-level ab initio methods. Rate constants of forward and backward reactions for the temperatures from 200 to 1000 K are calculated using classical transition state theory with Eckart tunneling correction, fitted in the expressions kf (T) = 1.19 × 10−23T3.93exp (−1110/T), and kb (T) = 8.86 × 10−24T3.32exp (−959/T) cm3 molecule−1 s−1 for forward and backward reactions, respectively, and are in reasonable agreement with the available experimental values.