Theoretical Investigation of the Reaction of CF3CHFOCH3 with OH Radical

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• 作者：Hao Sun ; Hongwei Gong ; Xiumei Pan ; Lizhu Hao ; ChiaChung Sun ; Rongshun Wang ; Xuri Huang
• 刊名：Journal of Physical Chemistry A
• 出版年：2009
• 出版时间：May 21, 2009
• 年：2009
• 卷：113
• 期：20
• 页码：5951-5957
• 全文大小：182K
• 年卷期：v.113,no.20(May 21, 2009)
• ISSN：1520-5215

文摘

A direct ab initio dynamics method was used to study the mechanism and kinetics of the reaction CF₃CHFOCH₃ + OH. Two reaction channels, R1 and R2, were found, corresponding to H-abstraction from a CH₃ group and a CHF group, respectively. The potential energy surface (PES) information was obtained at the G3(MP2)//MP2/6-311G(d,p) level. The standard enthalpies of formation for the reactant (CF₃CHFOCH₃) and products (CF₃CHFOCH₂ and CF₃CFOCH₃) were evaluated via isodesmic reactions at the same level. Furthermore, the rate constants of two channels were calculated using the canonical variational transition state theory (CVT) with small-curvature tunneling (SCT) contributions over a wide temperature range of 200−3000 K. The dynamic calculations demonstrate that reaction R1 dominates the overall reaction when the temperature is lower than 800 K whereas reaction R2 becomes more competitive in the higher temperature range. The calculated rate constants and branching ratios are both in good agreement with the available experimental values.