Acta Phys. -Chim. Sin. ›› 2010, Vol. 26 ›› Issue (09): 2331-2336.doi: 10.3866/PKU.WHXB20100907

• CHEMICAL KINETICS AND MOLECULE DYNAMICS • Previous Articles     Next Articles

Ab initioMolecular Dynamics Investigation on the Production Channels for the Reaction of O- with CH3F

WU Li-Xia, YU Feng, LIU Jing, DAI Jing-Hua, ZHOU Xiao-Guo, LIU Shi-Lin   

  1. Hefei National Laboratory for Physical Sciences at the Microscale, Department of Chemical Physics, University of Science and Technology of China, Hefei 230026, P. R. China
  • Received:2010-04-12 Revised:2010-05-24 Published:2010-09-02
  • Contact: ZHOU Xiao-Guo E-mail:xzhou@ustc.edu.cn
  • Supported by:

    The project was supported by the National Natural Science Foundation of China (20603033, 10979042) and National Key Basic Research Programof China (973) (2007CB815204).

Abstract:

H-atom abstraction and H2O production channels for the reaction of O- with CH3F were reinvestigated using the ab initio molecular dynamics method at the B3LYP/6-31+G(d,p) level of theory and based on the Born-Oppenheimer approximation. The reactive trajectories were initiated at the transition state of H-atom abstraction. Thermal sampling at 300 K was chosen to determine the initial conditions. Additionally, the energies added to the transition vector of the barrier were restricted to 2.1, 36.8, and 62.8 kJ·mol -1, separately, to reveal the impact of different initial collision energies on the reaction pathways. The results of all the trajectory calculations demonstrate that the H-atom abstraction channel is the dominant production channel. Therefore, our calculations are consistent with previous experimental conclusions. Furthermore, the dynamic reaction pathways for H-atom abstraction and the H2O production channels on the exit-channel potential energy surface are described based on our calculations and thus a comprehensive reaction mechanismis revealed at the microscopic level.

Key words: Ab initio molecular dynamics, Atomic oxygen radical anion, Methyl fluoride, Reaction mechanism, Transition state