采用量子化学密度泛函理论研究了OH抽提1-戊醇分子中α-H和β-H引发的大气反应的机理.在B3LYP/6—311+G(3df,2p)//B3LYP/6—31G(d)水平上对该反应体系的反应物、中间体、过渡态及产物进行了几何构型优化和频率计算,给出了各反应通道的自由能剖面图.计算结果表明:OH抽提1-戊醇分子中α-H和β-H引发的反应通道的主要产物分别为1-戊醛和1-丁醛;生成的产物极性和水溶性增强,易通过成核、水合或吸附反应形成二次有机气溶胶.
The reaction mechanism of the α-H and β-H abstractions from 1-pentanol by OH radical has been studied using density functional theory at the B3LYP/6-31G(d) level. The geometries of the stationary points were optimized, and the harmonic vibration frequencies were calculated. The detailed profiles of the free energy surfaces for the reactions were constructed. The calculation results show that the main products of the α-H and β-H abstraction-initiated channels are 1-pentanal and 1-butanal, respectively. All the products from the two reaction channels can contribute to the formation of secondary organic aerosol through nucleation, hydration or absorption since their polarity and water-solubility are enhanced.