title: Theoretical Studies of the Reactions CFx H3-x COOR+Cl and CF3 COOCH3 +OH.
abstract: The mechanism and kinetics of the reactions of CF(3)COOCH(2)CH(3), CF(2)HCOOCH(3), and CF(3)COOCH(3) with Cl and OH radicals are studied using the B3LYP, MP2, BHandHLYP, and M06-2X methods with the 6-311G(d,p) basis set. The study is further refined by using the CCSD(T) and QCISD(T)/6-311++G(d,p) methods. Seven hydrogen-abstraction channels are found. All the rate constants, computed by a dual-level direct method with a small-curvature tunneling correction, are in good agreement with the experimental data. The tunneling effect is found to be important for the calculated rate constants in the low-temperature range. For the reaction of CF(3)COOCH(2)CH(3) +Cl, H-abstraction from the CH(2) group is found to be the dominant reaction channel. The standard enthalpies of formation for the species are also calculated. The Arrhenius expressions are fitted within 200-1000 K as kT(1) =8.4×10(-20) T (2.63) exp(381.28/T), kT(2) =2.95×10(-21) T (3.13) exp(-103.21/T), kT(3) =1.25×10(-23) T (3.37) exp(791.98/T), and kT(4) =4.53×10(-22) T (3.07) exp(465.00/T).
authors: Faculty of Chemistry, Institute of Functional Material Chemistry, Northeast Normal University, 130024 Changchun (People's Republic of China).
authors: Feng-Yang
authors: FY
authors: Bai
authors: Faculty of Chemistry, Institute of Functional Material Chemistry, Northeast Normal University, 130024 Changchun (People's Republic of China).
authors: Xiao-Le
authors: XL
authors: Zhu
authors: Faculty of Chemistry, Institute of Functional Material Chemistry, Northeast Normal University, 130024 Changchun (People's Republic of China).
authors: Zi-Man
authors: ZM
authors: Jia
authors: Faculty of Chemistry, Institute of Functional Material Chemistry, Northeast Normal University, 130024 Changchun (People's Republic of China).
authors: Xu
authors: X
authors: Wang
authors: Faculty of Chemistry, Institute of Functional Material Chemistry, Northeast Normal University, 130024 Changchun (People's Republic of China).
authors: Yan-Qiu
authors: YQ
authors: Sun
authors: Faculty of Chemistry, Institute of Functional Material Chemistry, Northeast Normal University, 130024 Changchun (People's Republic of China).
authors: Rong-Shun
authors: RS
authors: Wang
authors: Faculty of Chemistry, Institute of Functional Material Chemistry, Northeast Normal University, 130024 Changchun (People's Republic of China). panxm460@nenu.edu.cn.
authors: Xiu-Mei
authors: XM
authors: Pan
keywords: H-abstraction; computational chemistry; hydrofluorinated esters; rate constants; transition state