摘要
利用B3LYP理论研究了N(4S) +CH3 X (X =H ,F ,Cl)反应体系的直接氢抽提过程 ,分别得到了各反应物、产物和过渡态的优化构型和谐振频率 .同时应用了 6 31G(d) ,6 311+G(d ,p)和 6 311++G(2d ,2p)基组 ,考察其大小对反应体系中各物种构型及能量的影响 .理论计算表明 ,随着基组的增加 ,反应势垒逐渐降低 ,反应吸热减少 .对比取代甲烷的情形 ,结果表明反应过程中卤素原子具有典型的诱导效应 ,降低了抽提势垒 .
Hydrogen abstraction reaction between N( 4S) and CH3X (X=H, F, Cl) is explored using the B3LYP method. Optimized geometries and harmonic frequencies of reactants, products and transition states are obtained. The 631G(d), 6311+G(d,p) and 6311++G(2d,2p) basis sets are employed in present calculations, in order to investigate effects of the size of the basis sets. Results show that the activation barriers and reaction endothermic values are reduced with increasing of the basis sets. Additionally, compared with reactions involving CH4, CH3F and CH3Cl, the present results suggest that the inductive effect of halogen atom lowers the activation barrier for hydrogen abstraction.
出处
《化学学报》
SCIE
CAS
CSCD
北大核心
2002年第11期1909-1914,共6页
Acta Chimica Sinica
基金
国家自然科学基金 (No.2 9873 0 46)
国家重点基础研究基金 (973计划
No.G19990 75 3 0 4)
高等学校博士学科点专项科研基金 (No .19990 3 5 82 8)资助项目
