物理化学学报 >> 1994, Vol. 10 >> Issue (07): 591-596.doi: 10.3866/PKU.WHXB19940704

研究论文 上一篇    下一篇

合成环氧乙烷新途径的从头算研究

陈宝吉, 陈德展, 刘奉岭, 宁世光   

  1. 山东师范大学化学系，济南 250014
  • 收稿日期:1992-12-30 修回日期:1993-04-05 发布日期:1994-07-15
  • 通讯作者: 宁世光

An Ab initio Study on a New Pathway for the Synthesis of Oxirane

Chen Bao-Ji, Chen De-Zhan, Liu Feng-Ling, Ning Shi-Guang   

  1. Department of Chemsitry, Shandong Teachers University, Jinan 250014
  • Received:1992-12-30 Revised:1993-04-05 Published:1994-07-15
  • Contact: Ning Shi-Guang

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摘要：

在MP4/6-31G*//RHF/6-31G*理论水平上，对单态甲撑插入甲醛中碳氧双链生成环氧乙烷的反应(CH2_(~1A)＋CH_2O→C_2H_4O)进行了从头算研究。发现其反应历程由两步组成：1) 反应物沿反应坐标接近，体系能量单调下降，生成平而松散环状的分子复合物(MC)；2) 分子复合物沿反应坐标经由一过渡态(TS)重排为产物环氧乙烷，此步的势垒只有36.99 kJ·mol~(-1)。进而计算了该反应的热力学函数和动力学性质，并进行了讨论。当设法将甲醛引入产生活性中间体CH_2(~1A)的体系中，该反应有可能成为在室温下制备环氧乙烷的非催化途径。

关键词: 合成, 环氧乙烷, 甲撑, 甲醛, 从头算法

Abstract:

The synthetic reaction, CH_2O+CH_2 (~1A)=C_2H_4O, has been studied by means of ab initio method at the MP4/6-31*//RHF/6-31G* level. The results indicate that the reaction proceeds in two steps. The first step involves the formation of molecular complex(MC). In this step, the energy of the reaction system descends and there is no potential barrier. The second step is the rearrangement of MC to oxirane with potential barrier of 36.99 kJ·mol~(-1); this step is the rate control step for the overall reaction. The thermody-namic and kinetic properties of the synthetic reaction are calculated and discussed. This synthetic reaction might be a new pathway for the synthesis of oxirane.

Key words: Synthesis, Oxirane, Methylene, Formaldehyde, Ab initio