ClONO_2与Br反应机理的密度泛函理论研究

Density Function Theory Study on the Mechanisms of Reaction of ClONO_2 with Br

用密度泛函理论方法(B3LYP),在6-31G*水平上对ClONO2与Br反应进行了研究,计算了反应中各驻点物种的平衡构型、振动频率、总能量和零点能(ZPE).计算得到各可能反应途径的过渡态,并经过内禀反应坐标分析加以证实.研究表明,存在如下三种可能的反应途径:Br+ClONO2→BrCl+NO3,Br+ClONO2→ClO+BrONO,Br+ClONO2→BrOCl+NO2,其中第一个反应通道的反应活化能垒最低,为2.33kJ/mol,是主反应通道.

The reaction mechanism of reaction of ClONO2 with Br has been studied with density function theory, B3LYP/6 - 31G＊ method. The geometries of reactants, transition states, intermediates and products have been optimized. The viberational frequency, energy and zero point energy（ZPE） were obtained. The transition states of various possible reaction pathways were obtained and verified by internal reaction coordinate（IRC） analysis. The results show that there have three reactive channels： Br ＋ C1ONO2→BrC1 ＋ NO3, Br ＋ ClONO2→ClO ＋ BrONO,Br＋ ClONO2→BrOCl ＋ NO2. The activation energy of the first channel is 2.33kJ/mol. It is a main reactive channel.