title: Theoretical studies on dynamics and thermochemistry of the reactions CF(3)CHCl(2)+Cl-->CF(3)CCl(2)+HCl and CF(3)CHFCl+Cl-->CF(3)CFCl+HCl.
abstract: A dual-level direct dynamics study has been carried out for the two hydrogen abstraction reactions CF(3)CHCl(2)+Cl and CF(3)CHFCl+Cl. The geometries and frequencies of the stationary points are optimized at the BHLYP/6-311G(d,p), B3LYP/6-311G(d,p), and MP2/6-31G(d) levels, respectively, with single-point calculations for energy at the BHLYP/6-311++G(3df,2p), G3(MP2), and QCISD(T)/6-311G(d,p) levels. The enthalpies of formation for the species CF(3)CHCl(2), CF(3)CHFCl, CF(3)CCl(2), and CF(3)CFCl are evaluated at higher levels. With the information of the potential energy surface at BHLYP/6-311++G(3df,2p)//6-311G(d,p) level, we employ canonical variational transition-state theory with small-curvature tunneling correction to calculate the rate constants. The agreement between theoretical and experimental rate constants is good in the measured temperature range 276-382 K. The effect of fluorine substitution on reactivity of the C-H bond is discussed.
authors.affiliation: Institute of Theoretical Chemistry, State Key Laboratory of Theoretical and Computational Chemistry, Jilin University, Changchun 130023, People's Republic of China.
authors.forename: Bo
authors.initials: B
authors.lastname: Li
authors.forename: Jing-Yao
authors.initials: JY
authors.lastname: Liu
authors.forename: Ze-Sheng
authors.initials: ZS
authors.lastname: Li
authors.forename: Jia-Yan
authors.initials: JY
authors.lastname: Wu
authors.forename: Chia-Chung
authors.initials: CC
authors.lastname: Sun