CH3•自由基和HNCO反应机理的理论研究

采用密度泛函理论的B3LYP方法, 在6-311＋＋G(d,p)基组水平上研究了CH₃^{•自由基与HNCO的微观反应机理, 优化了反应过程中的反应物、中间体、过渡态和产物, 为了获得更精确的能量信息, 还计算了体系在反应途径上各驻点的能量. 振动分析和IRC分析结果证实了中间体和过渡态的真实性, 计算所得的键鞍点电荷密度的变化情况也确认了反应过程. 对于CH₃•自由基与HNCO反应, 找到了七条可行的反应通道, 对结果的分析表明: 通道CH₃•＋HNCO→TS7→IM4→TS9→IM5, 控制步骤活化能最低, 是该反应的主要通道. 在该反应体系中质子迁移过程反应活化能不高, 也是能发生的.}

Theoretical Study on the Reaction Mechanism of CH3• Radical with HNCO

The reaction mechanism of CH₃^{• radical with HNCO has been investigated by B3LYP method of density functional theory, while the geometries and harmonic frequencies of reactants, intermediates, transition states and products have been calculated at the B3LYP/6-311＋＋G(d,p) level. To obtain more accurate energy result, stationary point energies were calculated. The vibration analysis and the IRC analysis testified the authenticity of intermediates and transition states. Seven feasible reaction pathways of this reaction have been studied. The results indicate that the pathway CH₃•＋HNCO→TS7→IM4→TS9→IM5 is the most energetically favorable and the major pathway. In the reaction system, the activation energy of the proton transfer process is not very high, and it can also happen.}