BrONO_2光解反应的理论研究

Theoretical study on photodecomposition reaction of BrONO_2

采用密度泛函方法,研究了大气臭氧层主要破坏物BrONO2的光解反应机理,在UB3LYP/6311++G**水平上优化了反应物、产物、中间体和过渡态的几何构型,并在UQCISD(T)/6311++G**水平上计算了单点能量,为了确证过渡态的真实性,在UB3LYP/6311++G**水平上进行了内禀反应坐标(IRC)计算和频率分析.研究结果表明,BrONO2的光解反应有两条反应通道,其中生成BrO+NO2的反应活化能较小(14.89kJ.mol-1),较易发生.

By means of the DFT and QCISD methods,the photodecomposition mechanism of BrONO_2 had been studied.The geometries of the reactants,the transition states and the products are completely optimized at the UB3LYP/6-311++G^(**) level.The single point calculation of the species have been performed by UQCISD(T)/6-311++G^(**)(level).All the transition states are verified by the IRC calculations and frequency analysis at UB3LYP/6-311++G^(**) level.