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化学学报
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化学学报 ›› 2005, Vol. 63 ›› Issue (23): 2163-2168. 上一篇    下一篇

研究论文

水溶液中亚硝基甲烷与甲醛肟之间互变异构反应的理论研究

梁国明1, 任译2   

  1. 1. 重庆师范大学化学学院, 重庆, 400047;
    2. 四川大学化学学院, 成都, 610064
  • 投稿日期:2004-11-16 修回日期:2005-06-29 发布日期:2014-02-14
  • 通讯作者: yiren57@sina.com
  • 作者简介:任译,E-mail:yiren57@sina.com
  • 基金资助:

    重庆市教委科技(No.kj050805)资助项目.

Theoretical Study of the Tautomerization of Nitromethane to Formaldoxime in Aqueous Solution

LIANG Guo-Ming1, REN Yi2   

  1. 1. College of Chemistry, Chongqing Normal University, Chongqing 400047;
    2. College of Chemistry, Sichuan University, Chengdu 610064
  • Received:2004-11-16 Revised:2005-06-29 Published:2014-02-14

PDF

475

被引次数

25

采用超分子-连续介质(PCM)模型,在密度泛函B3LYP/6-311++G**水平上对水溶液中亚硝基甲烷异构化反应的机理进行了理论研究.结果表明,在水溶液中亚硝基甲烷可以通过两条反应途径(Ⅰ和Ⅱ)经质子迁移得到更稳定的重排产物--反式甲醛肟,但优势反应途径与在气相反应不同.在水溶液中亚硝基甲烷异构化反应最有可能的途径Ⅰ是通过氢迁移先生成顺式甲醛肟,然后绕N-O键旋转生成更稳定的反式甲醛肟.并且由于水分子的催化作用使得反应活化能从气相中240.6和196.2 kJ/mol分别降低至水溶液中的61.7和92.1 kJ/mol.

关键词: 亚硝基甲烷, 甲醛肟, 水助互变异构反应, 密度泛函

The mechanism of the tautomerization of nitromethane to formaldoxime in aqueous solution has been investigated at the level of B3LYP/6-311++G** using the supramolecular/continuum model. Calcu-lated results indicate that the isomerization of nitromethane to more stable trans-formaldoxime can proceed via two different reaction channels, but the favorable reaction pathway in aqueous is different from the one in the gas phase. It is more favorable that the tautomeric reaction involves the formation of cis-formaldoxime and a subsequent rotation about the N—O bond to form the trans-formaldoxime in aqueous solution. More-over, the activation energies were reduced from 240.6 and 196.2 kJ/mol in the gas phase to 61.7 and 92.1 kJ/mol in aqueous solution, respectively, due to the catalysis of water.

Key words: nitromethane, formaldoxime, water-catalyzed tautomerization, density functional theory