【摘要】 运用量子化学密度泛函理论UB3LYP/6-311+G*和高级电子相关校正的偶合簇(CCSD(T)/6-311+G*)方法,对CH3CH2,CH3CHCl和CH3CCl2自由基与NO2反应的机理和动力学进行了理论研究,得到了体系的势能面信息和可能的反应机理.根据计算得到的各反应热力学参数及反应能垒,采用传统过渡态理论计算了各反应在温度T=298 K和T=700 K时的速率常数.研究结果表明,该类反应均通过1个中间体和1个过渡态生成产物,产物分别为CH3CHO+HNO,CH3CHO+ClNO和CH3CClO+ClNO.更多还原

【Abstract】 DFT-B3LYP/6-311+G is used to calculate the geometries of reactants,intermediates,transition states and products for CH3CH2,CH3CHCl and CH3CCl2+NO2 reaction.The transition states and intermediates of the reaction are verified by frequency analysis.The intrinsic reaction coordinate(IRC) calculations at the same level were also carried out to check the connection between all the critical structures located on the potential energy surface.Single point energies have been calculated at the CCSD(T)/6-311+G level.The energy barriers,rate constants and thermodynamic quantities of the reaction at T=298 K and T=700 K have also been calculated.The results show that the reaction of the title reactions involve one channel,producing C2H4+HNO2,CH3CHO+ClNO and CH3CClO+ClNO products,respectively.更多还原