1D电子态氧原子与二氟甲烷反应势能面和产物分支比的RRKM计算

Theoretical calculations of the potential energy surface and RRKM study of product branching ratios for O （ 1 D） ＋ CH2F2

用MP2/6-311G(d,p)方法优化了1D电子态氧原子与二氟甲烷反应势能面上的稳定点,用CCSD(T)/6-311+G(3df,2p)方法对优化得到的结构进行能量精算。研究表明,标题反应的反应机理是插入机理,形成中间体CHF2OH和CH2FOF。用RRKM(Rice-Ramsperger-Kassel-Marcus)理论研究了不同碰撞能时经过中间体CHF2OH的产物分支比。CHF2OH的主要分解通道是HF消去和C—O键断裂通道,其主要分解产物是氢氟碳氧和氟化氢,碳氟氧氢和氟化氢以及碳氢氟二和羟基。由于CHF2OH比CH2FOF稳定,标题基态反应的主要产物是CHF2OH的主要产物。标题反应也可在激发态势能面上发生抽取反应,此反应对碳氢氟二和羟基产物通道有一定贡献。

The ground state potential energy surface of O（ID） ＋ CH2F： reaction has been studied by using CCSD（T）/6- 311 ＋ G（3df,2p）//MP2/6-311 G （d, p） method. The calculations gave an insertion mechanism of the title reaction. Two intermediates, CHF2 OH and CH2 FOF, formed. The branching ratios of the products formed though CHF2 OH have been carried out by using RRKM （Rice-Ramsperger-Kassel-Marcus） theory at different eollisional energies. The main decomposition channels of CHF2 OH are HF elimination and C-O decomposition channels. The main products of CHF2OH are HFCO ＋ HF, CFOH ＋ HF and CHF2 ＋ OH. Since CHFzOH is more stable than CH2FOF, the main products of the ground state reaction are the main products of CHF2OH. The reaction can also proceed through the abstraction mechanism on the excited-state potential energy surface, which provides some contribution to the CHF2 ＋ OH channel.