CH_2O与H反应机理的量子化学研究

Quantum Chemistry Study on the Reaction Mechanism of CH_2O and H

用密度泛函理论(DFT)的B3LYP方法,在6 311++G(3df,3pd)基组水平上研究了CH2O与H自由基反应的微观机理,全参数优化了反应过程中各反应物、中间体、过渡态和产物的几何构型,在CCSD(T)水平上计算了它们的能量.振动分析结果证实了中间体和过渡态的真实性,从对CH2O与H的反应机理的研究结果看,CH2O与H原子反应为3条反应通道多步反应过程,CH2O与H原子反应的主要反应通道是CH2O+H→TS6→CHO+H2,其主要产物是自由基CHO和H2,与实验结果吻合.

Density function theory was performed to study the reaction mechanism of the reaction of CH_2O with H. The geometric configurations of reactants, intermediates, transition states and products were optimized by B3LYP method at 6-311++G(3df,3pd) level. The energies of stationary points along the pathway were calculated at CCSD(T) level. Intermediates and transition states were confirmed by the results of vibrational analysis. From the results of the reaction mechanism of the reaction of CH_2O with H, one can see that the reaction of CH_2O+H has three pathways and several steps. Comparing the three pathways' activation energies, one can find that the pathway CH_2O+H→TS6→CHO+H_2 is the main reaction pathway and CHO radical and H_2 are the main products, which is in good agreement with experimental results.