摘要
本文用LCAO-MO-SCF ab initio方法,对OH^-+CH_3F→CH_3OH+F^-反应进行了过渡态理论及前线轨道理论的量子化学研究。以4-31G为基组,计算了反应进程的势能曲线,得到了过渡态的几何构型,并用MP2方法进行了电子库仑相关效应的校正,反应潘化能的计算值与实验数据较为一致。用前线轨道理论对反应中分子重新组合过程进行了轨道分析,较全面地解释了该反应的机理。
The S_N2 reaction. OH^-+CH_3F→CH_3OH+F^-has been studied by means of ab initio LCAO-MO SCF methods at HF/4-31G level and MP2/4-31G level. The complete geometry optimization of reactants, products, clustors and transition state have been performed. We have calculated the potential energy curve versus reaction coordinate and the double-well potential energy curve is obtained in accordance with ion-molecule reactions. At the MP2 level we have obtained △H° and E_a of this reaction which are in close agreement with theft found experimentally.We have calculated the vibrational frequencies of TS and get the harmonic vibrational mode of virtual vibration. From this mode we can obtain a clear physical picture for this reaction.
出处
《化学学报》
SCIE
CAS
CSCD
北大核心
1990年第10期955-960,共6页
Acta Chimica Sinica
