Acta Phys. -Chim. Sin. ›› 2011, Vol. 27 ›› Issue (02): 337 -342.doi: 10.3866/PKU.WHXB20110201

• THEORETICAL AND COMPUTATIONAL CHEMISTRY • Previous Articles     Next Articles

Mechanism and Kinetics of the CH3OCF2CF2OCH3+Cl Reaction

CUI Feng-Chao, YU Hong-Bo, WANG Qin, YE Wan-Li, LIU Jing-Yao   

  1. State Key Laboratory of Theoretical and Computational Chemistry, Institute of Theoretical Chemistry, Jilin University, Changchun 130023, P. R. China
  • Received:2010-09-27 Revised:2010-11-12 Published:2011-01-25
  • Contact: LIU Jing-Yao E-mail:ljy121@jlu.edu.cn
  • Supported by:

    The project was supported by the National Natural Science Foundation of China (20333050, 20303007, 20973077) and Program for New Century Excellent Talents in University, China (NCET).

Abstract:

A direct density functional theory dynamics method was used to determine the mechanism and kinetics of the CH3OCF2CF2OCH3+Cl reaction. Potential energy surface information was obtained at the BB1K/6-31+G(d,p) level. The hydrogen abstraction channels and displacement processes of the two stable conformers (SC1 and SC2) of CH3OCF2CF2OCH3 were taken into consideration. Theoretical rate constants of the individual H-abstraction channels (one from SC1 and two from SC2) were calculated by improved canonical variational transition state theory (ICVT) with a small-curvature tunneling (SCT) correction. The overall rate constant (kT) was obtained by considering the weight factor of each conformer from the Boltzmann distribution function and the contribution of the two conformers to the whole reaction was discussed. The calculated kT(ICVT/SCT) at 296 K agrees well with the experimental value. Since experimental data were lacking for other temperatures, a three-parameter rate constant temperature expression for the total reaction within 200-2000 K was fitted to: kT=0.40×10-14T1.05exp(-206.16/T).

Key words: Density functional theory, Direct dynamics, Rate constant, Improved canonical variational transition state theory, CH3OCF2CF2OCH3

MSC2000: 

  • O641