H＋CH2CO反应机理的G2计算

分别在UQCISD/6-311G(d,p)和G2理论计算水平上，对CH2CO和H反应可能存在的四条反应通道进行了研究，详细分析了每个通道的反应机理;通过振动分析的虚频数和内禀反应坐标(IRC)计算,确认了反应涉及的每一个过渡态.通过反应位能剖面的比较，发现经过一个中间体生成CH3＋CO的一条途径是主反应通道，该通道是个放热反应，总焓变为－146.07 kJ•mol－1，速控步骤的位垒为55.09 kJ•mol－1.理论计算结果较好地解释了实验观察到的主要产物和副产物并存的现象。

Mechanism of the Reaction H+CH2CO:G2 Calculation

The reaction mechanisms and molecular dynamics of the multi-channel reaction H＋CH2CO which might occur through four channels depending on the different initial reaction positions of the reactants CH2CO are detailedly studied. All the calculations are performed at the UQCISD/6-311G (d,p) and G2 theory level. Every transition state is confirmed by the numbers of virtual frequency and the intrinsic reaction coordinate (IRC) paths. The computational results suggest that the reaction channel of forming CH3＋CO through an intermediate is the dominant one. This channel is an exothermic reaction whose enthalpy changes are －146.07 kJ•mol－1 and the calculated potential barrier of the rate-determining step is 55.09 kJ•mol－1. The obtained reaction potential profile can qualitatively explain the experimental coexistence phenomena of the primary products and the other minor products.