中文摘要：

采用QCISD（T）／6-311＋＋G（d，p）／／MP2／6-311G（d，p）双水平方法对CHzFz＋O（3P）反应机理进行研究，并运用自然键轨道分析（NBO）法获得消氟与消氟化氢通道中过渡态的电荷分布。研究表明，标题反应存在氢抽提（R1）、氟抽提（R2）、消氟（R3）与消氢（R4）4类通道，各通道的反应能分别为11．1、304．0、78．5和31．3kJ／mol，对应的能垒分别为54．6、351．6、246．8和279．4kJ／mol。与CH3F＋O（3P）及CHF3＋O（3P）反应显著不同，标题反应存在消氟通道，这与过渡态TS3中电负性大的F2原子处于不对称位置密切相关，TS3中来自F2对H1原子的吸引力，使得0原子对H1的吸引作用超过了F1与H1的吸引力，从而促使消氟反应的进行。

英文摘要：

Abstract： By means of the QCISD（T）/6-311＋＋G（d,p）//MP2/6-311G（d,p） dual-level method, the reaction mechanism between CH2 F2 and 0（3 P） were investigated. Meanwhile, the natural bond orbital （NBO） method was employed to calculate the charge of the transition states occurred in the fluorine elimination and the HF elimination channels. The results indicate that the title re- action exists the hydrogen abstraction （R1）, the fluorine abstraction （R2）, the fluorine elimina- tion （R3） and the hydrogen elimination （R4） four reaction channels. The reaction energies of each channel are 11.1, 304.0, 78.5 and 31.3 kJ/mol, respectively, and the corresponding barrier title reaction, which is closely related to the asymmetry position of the high electronegativity F2 atom in the transition state TS3. The attraction interaction between F2 and H1 atoms makes the attraction between O and HI conquer that of F1 and HI, and thus facilitates the fluorine elimina- tion reaction.