F+CH_3OH碰撞反应机理和反应势能面

Reaction Mechanism and the Potential Energy Surface of F+CH_3OH

在MP2 (full) /6 3 11+ +g(d ,p)水平上详细研究了氟原子与甲醇抽氢反应的多通道反应机理 ,得到了各条通道中涉及的驻点的构型和振动频率及其能量 ,给出了两张完整的反应势能面 .结果表明 ,氟原子从C原子上抽氢时有一条明显的最低能量通道 ,而从氧原子上抽氢时要涉及多条分支通道和多个驻点构型 ,给出了各分支通道的势能面示意图 ,结果表明以形成五元环状过渡态通道为优势通道 .计算得到经途径 1生成CH2 OH时反应放热 170 .62kJ/mol,经分支途径 6生成CH3 O自由基时反应放热 119.41kJ/mol。

Multiple-paths hydrogen abstraction reactions of fluorine with CH3OH have been investigated at the MP2 (full)/6-311 + + g(d, p) level. The potential energy surfaces (PES) for H-abstraction reaction from carbon atom and oxygen atom were given respectively. The results indicate that there is only one minimum energy path for hydrogen abstraction from carbon atom, while multiple paths were found for hydrogen abstraction from oxygen atom. All the stationary structures, frequencies as well as PES sketch of all channels were given, in which the dominant channel is by a five-member ring transition state. The calculated heat of reaction is 170.62 kJ/mol for channel 1, 119.41 kJ/mol for branch channel 6. The results are in good agreement with experimental data.