高等学校化学学报

高等学校化学学报 ›› 1998, Vol. 19 ›› Issue (4): 586.

• 论文 • 上一篇    下一篇

1,2-C4H6→2-C4H6异构化反应机理的理论研究

雷鸣1, 钱英2, 王艳1, 冯文林1   

  1. 1. 北京师范大学化学系, 北京, 100875;
    2. 北京工业大学化学与环境工程系, 北京, 100022
  • 收稿日期:1997-04-04 出版日期:1998-04-24 发布日期:1998-04-24
  • 通讯作者: 雷鸣,男,25岁,硕士研究生.
  • 作者简介:雷鸣,男,25岁,硕士研究生.
  • 基金资助:

    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

Theoretical Study on the Thermal Isomerization from 1,2-Butadiene to 2-Butyne

LEI Ming1, QIAN Ying2, WANG Yan1, FENG Wen-Lin1   

  1. 1. Department of Chemistry, Beijing Normal University, Beijing, 100875;
    2. Department of Chemistry and Environment Engineering, Beijing Polytechnic University, Beijing, 100022
  • Received:1997-04-04 Online:1998-04-24 Published:1998-04-24

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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.

关键词: 异构化, 过渡态, 从头算方法

Abstract: Ab initio UHF/631G** 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 28683 kJ/mol, which is in good agreement with arrhenius value of 26460 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.

Key words: Isomerization, Transition state, Ab initio method

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