硝酸溴与三重态氧原子反应机理的密度泛函研究

用密度泛函理论方法 (B3LYP) ,在 6 311+G(d ,p)水平上对硝酸溴与三重态氧原子的反应进行了研究 ,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) .对计算得到各可能反应途径的过渡态经内禀反应坐标分析加以了证实 ,对反应途径中的键长和能量的变化作了IRC解析 .在B3LYP优化的基础上利用了耦合簇理论方法 (CCSD(T) )在 6 311+G(d ,p)水平上对各驻点物种的单点能进行了修正 .研究表明 ,存在三种可能的反应途径 ,其产物分别为 :cis BrONO和 3 O2 、trans BrONO和 3 O2 以及BrOO和NO2 .其中第三个通道由于活化能垒较低 ,是主要反应 .

Density Function Theory Study on the Mechanisms of Reaction of BrONO2 with O(3P)

The theoretic study of reaction between BrONO 2 and O(3P) is reported by using the molecular orbital ab initio and density function theory (DFT). Equilibrium structural parameters, harmonic vibrational frequencies, total energy and zero energy of reactants, transition states, intermediates and products during reactions are computed by B3LYP theory level with the basis set 6-311+G(d,p). The transition states and intermediates of the reaction are verified by frequency analysis, and the relationship of reactants, transition states, intermediates and products is affirmed by Intrinsic Reaction Coordinate (IRC) calculation. The activation energy of the reaction has also been calculated. Based on the optimized structure, the single point energy of all species is obtained by CCSD (T) with the basis set 6-311+G(d,p). The results show that there are three exothermic channels and their corresponding products are: cis-BrONO+3O 2, trans-BrONO+3O 2 and BrOO+NO 2. The activation energy of three channels is 91.58, 101.25, 51.17 kJ/mol under B3LYP and 141.19, 148.39, 103.21 kJ/mol under CCSD (T) theory level. The third channel is the dominant channel.