BrONO2与Cl（^2P3／2）的反应机理

The Reaction Mechanism Between BrONO2 and Cl(2P3/2)

采用密度泛函理论 (DFT)B3LYP方法 ,在 6 3 1G 基组下 ,研究了Cl(2 P3/2 ) +BrONO2 →BrCl +NO3和Cl(2 P3/2 )+BrONO2 →Br+ClONO2 的反应机理 .计算得到各可能反应途径的过渡态 ,并通过内禀反应坐标 (IRC)分析加以证实 .反应Cl(2 P3/2 ) +BrONO2 →BrCl +NO3有两种可能的反应途径 ,其活化能垒相差比较大 .途径I和途径II的活化能垒分别为 89.5kJ·mol- 1 和 61.2kJ·mol- 1 ,该反应为放热反应 ,放出的热量为 73 .4kJ·mol- 1 .反应Cl(2 P3/2 ) +BrONO2 →Br +ClONO2 的活化能垒为 47.8kJ·mol- 1 ,该反应为吸热反应 ,吸收的热量为 6.3kJ·mol- 1 ,这与大部分实验者的推论相一致 .反应Cl(2 P3/2 ) +BrONO2 →Br +ClONO2 的活化能垒比较低 ,为 47.8kJ·mol- 1 ,认定反应容易进行 .反应Cl(2 P3/2 ) +BrONO2 →BrCl+NO3途径II的活化能垒低 ,主要按途径II的反应途径进行 .

The reaction mechanism of reaction Cl( 2P 3/2 )+BrONO 2→BrCl+NO 3 and the reaction Cl( 2P 3/2 )+BrONO 2→Br+ClONO 2 has been studied with Gaussian 98, B3LYP/6-31G*method. The transition states of various possible reaction pathways are obtained and are verified by internal reaction coordinate (IRC) analyzing. The first reaction has two possible reaction pathways, the activity barriers of which are 89.5 kJ/mol and 61.2 kJ/mol, respectively. The reaction is an exothermic one and the heat given by it is 73.4 kJ/mol. The second reaction, whose activity barrier is 47.8 kJ/mol, is an endothermic one and the heat absorbed is 6.3 kJ/mol, which is consistent with the deduction of most experimentalists. Since the second reaction and the pathway II of the first reaction have lower activity barriers, they are ones of relatively easy proceeding.