摘要
采用自洽场分子轨道ＵＨＦ／６－３１Ｇ＊＊从头算法，研究了１，２－Ｃ４Ｈ６→２－Ｃ４Ｈ６异构化反应机理，优化了基态势能面上反应物、过渡态、中间体和产物的几何构型，并对各驻点能量进行了零点能校准．结果表明该反应经历一个１－甲基环丙烯生成产物比经两步氢迁移反应历程更易发生．
Ab initio UHF/6 31G ** method was employed to study the reaction mechanisms of the thermal isomerization from 1,2 butadiene to 2 butyne, which involves two reaction pathways. The geometries of the reactant, the intermediates, the transition states and the product for the reaction are optimized by Berry technique. Each transition states was further confirmed by having one and only one imaginary vibrational frequency. In addition, the zero point energies were calculated for correcting the energies of stationary points. As an important intermediate, 1 methylcyclopropene play a significant part in the isomerization. The calculated activation energy of the pathway proceeding in multisteps via 1 methylcycloproene etc is 286 83 kJ/mol, which is in good agreement with arrhenius value of 264 60 kJ/mol. The results indicate that the thermal rearrangement of 1,2 butadiene to 2 butyne via 1 methyl cyclopropene is more energetically favourable than that via two step hydrogen shift process.
出处
《高等学校化学学报》
SCIE
EI
CAS
CSCD
北大核心
1998年第4期586-590,共5页
Chemical Journal of Chinese Universities
基金
国家教育委员会基金
吉林大学理论化学计算国家重点实验室资助
关键词
异构化反应
过渡态
丁二烯
丁炔
Isomerization, Transition state, Ab initio method
