CH3SOx(x=0，1)与三线态Oy(y=1，2，3)反应机理的理论研究

Theoretical Study on the Reaction Mechanism of CH_3SO_x (x=0,1) and ~3O_y (y=1,2,3)

采用B3LYP方法和6-311G(d,p)基组对CH_3S及其氧化后继物CH_3SO与O_y(y=1,2,3)反应形成酸雨的微观机理进行了理论研究.对反应势能面上的各驻点进行几何构型全优化.振动分析和IRC计算证实了中间体和过渡态的真实性和相互连接关系.找到了7条生成SO_2的反应途径,其中CH_3S与O直接反应得到产物CH_3和SO最容易进行;CH_3S先与O_3反应,其产物再与O_3反应得到CH_3SO_2,CH_3SO_2最后分解得到CH_3S和SO_2较容易进行,其它的反应较难进行.

The reaction mechanism of CH3SOx （x=0, 1） with ^3Oy （y=1, 2, 3） has been studied at B3LYP/6-311G （d, p） level. Geometries of the stationary points have been optimized. Vibration analysis and intrinsic reaction coordinate （IRC） calculation at the same level have been applied to validation of the connection of the stationary points. The calculated results show that there are seven channels on the reaction surface of SO2 formation, in which the reaction between CH3S and O would occur the most easily. The channel in which CH3S reacts with O3 first to form CH3SO, then CH3SO reacts with O3 to afford CH3SO2, and finally CH3SO2 decomposes to give CH3S and SO2 could also occur easily. These two channels should be the dominant reaction channels.