CHF_2CF_2CH_2OCHF_2与OH自由基反应机理的理论研究

Theoretical study on the mechanism of CHF_2CF_2CH_2OCHF_2 with OH radical

采用从头算和密度泛函方法研究了多通道反应CHF2CF2CH2OCHF2+OH→产物的反应机理.首先在BMK/6-311+G(d,p)水平下优化了稳定点的几何构型并计算了振动频率;然后在BMC-CCSD水平下,对势能面进行高水平能量校正.结果表明,此反应存在提氢和取代两类反应通道,但是无论从动力学还是从热力学分析,提氢反应通道才是主要的反应通道,且从-CH2-基团上提取氢原子的提氢通道是主要的反应通道.

The mechanism of CHF2CF2CH2OCHF2with OH radical was theoretically investigated by ab initio and density functional theory（DFT）.First,the geometries and frequencies of all the stationary points were optimized at the BMK/6-311＋G（d,p）level.Second,the energy profiles were further refined at the BMC-CCSD level of theory.The calculations demonstrate that H-abstraction channels and displacement channels are included in the reaction.However,the H-abstraction reaction is the major channel from both the thermodynamic and kinetic viewpoints.In addition,for the considered H-abstraction channels,the H-abstraction from-CH2-site is the most favorable.