摘要
作者用量子化学从头计算UMP2(full)方法,在6 31G 水平上研究F和Cl原子与甲烷分子之间的反应机理,优化了反应物、产物、中间体和过渡态的几何构型,在Gaussian 3(G3)和G3MP2水平计算了它们的能量,研究结果表明:F原子在与甲烷分子反应过程中有氢键生成,键能为:3.71kJ/mol,而Cl原子甲烷分子在反应过程中则无此现象.同时作者还对F和Cl原子与甲烷分子在之间反应动力学速率常数进行了计算,作者的理论计算结果显示F原子与甲烷分子之间反应活性比Cl原子与甲烷分子之间反应活性强.F原子易与甲烷分子生成含有氢键的化合物,且很快分解生成化学性质非常稳定的HF,能同F+O3反应竞争.
ab initio UMP2(full) method was performed to study the reaction mechanism of F and Cl atoms with methane.The geometry configuration of reactants, products, intermediates and transition states were optimized at UMP2(full)/631G* level and the energies of stationary points along the pathways were calculated at Gaussian3(G3) and G3MP2 level. The results show that the hydrogen bond forms during the process of the reaction F+CH4, the energy is 3.71kJ/mol. In addition, fluorine atoms react readily with methane to form the intermediate with a hydrogen bond, which easily result in the elimination of HF with stable properties. That is to say, the reaction F+CH4 is prior to the reaction F+O3 whe there is a competition between methane and ozone. But there is no hydrogen bond in the reaction Cl+CH4.
出处
《四川大学学报（自然科学版）》
CAS
CSCD
北大核心
2002年第6期1107-1110,共4页
Journal of Sichuan University(Natural Science Edition)
