高等学校化学学报 ›› 1988, Vol. 9 ›› Issue (9): 935.

• 论文 • 上一篇    下一篇

亚硝酸甲酯光解反应的从头算和Cl研究

于建国, 刘若庄   

  1. 北京师范大学化学系
  • 收稿日期:1987-04-15 出版日期:1988-09-24 发布日期:1988-09-24
  • 通讯作者: 于建国
  • 基金资助:

    国家自然科学基金

Ab imtio and CI Studies on the Photolysis of Methyl Nitrite

Yu Jianguo, Liu Ruozhuang   

  1. Department of Chemistry, Beijing Normal University, Beijing
  • Received:1987-04-15 Online:1988-09-24 Published:1988-09-24

摘要: 用从头算和MP2方法求得亚硝酸甲酯的基态、第一和第二激发态解离为CH3O和NO自由基的解离能分別为238.14、68.99和-183.97kJ/mol,而CH3O和NO易于生成甲醛和硝酰。由CI方法求出的亚硝酸甲酯直接生成甲醛和硝酰的基态和激发态反应曲线表明,该反应难以按这种机理进行。因此,以上计算支持了实验提出的亚硝酸甲酯光反应生成甲醛和硝酰的两种机理中的光解离机制。

关键词: 亚硝酸甲酯, 光解反应, 从头算, CI

Abstract: The photolysis of methyl nitrite has been theoretically studied. The ab initio and MP2 calculations with STO-3Gbasis set show that both the S0 and T1 states of trans-CH3ONO are more stable than the corresponding states of its cis-isomer. With the same method, the bond dissociation energies of the ground state,first excited (n→π*) and second excited states (n→π*) of CH3ONO, withrupture of the bond between Nand Oatoms to producing CH2O·and·NO radicals, are calculated to be 238.14, 68.99 and -183.97 kJ/mol, respectively, which supports the experimental fact that methyl nitrite is easy to proceed the photodecomposition. The photoelimination of the CH3ONO (to produce CH,Oand HNOmolecules) is also investigated by ab inition and CIcalculations. The relationship of energies among S0, T1, S1, T2 and S2 states along reaction path shows that the reaction rate of the photoelimination could not be fast, this is also in accord with the low quantum yield measured experimentally.

Key words: Methyl nitrite, Photolysis, Ab initio, CI

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