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化学学报
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化学学报 ›› 2007, Vol. 65 ›› Issue (16): 1568-1572. 上一篇    下一篇

研究论文

二甲胺与亚硝酸反应生成N,N-二甲基亚硝胺的理论研究

闾春林, 刘永东*, 王云海, 钟儒刚   

  1. (北京工业大学生命科学与生物工程学院 北京 100022)
  • 投稿日期:2006-11-09 修回日期:2007-02-20 发布日期:2007-08-28
  • 通讯作者: 刘永东

Theoretical Studies on the N-Nitrosodimethylamine Formation from Dimethylamine and Nitrous Acid

LÜ Chun-Lin; LIU Yong-Dong*; WANG Yun-Hai; ZHONG Ru-Gang   

  1. (College of Life Science & Bioengineering, Beijing University of Technology, Beijing 100022)
  • Received:2006-11-09 Revised:2007-02-20 Published:2007-08-28
  • Contact: LIU Yong-Dong

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应用量子化学计算方法在CCSD/6-311＋G(d,p)//B3LYP/6-311＋G(d,p)水平上对二甲胺(DMA)与亚硝酸作用形成N,N-二甲基亚硝胺(NDMA)的反应机理进行了研究. 分别讨论了DMA与一分子亚硝酸直接反应的途径和两分子亚硝酸先反应生成活性中间体N2O3再与DMA作用的间接反应途径. 计算结果表明, DMA与亚硝酸间接反应的活化能比直接反应的低约55 kJ/mol, 由此可推断DMA与亚硝酸生成NDMA的反应是以两分子的亚硝酸先生成ONNO2再亚硝化DMA为主要反应途径. 这一结论和NDMA的形成速率与亚硝酸的浓度的平方成正比的实验结果相一致.

关键词: N，N-二甲基亚硝胺（NDMA）, 亚硝酸, 二甲胺（DMA）, 密度泛函理论, 从头算

The mechanisms of N-nitrosodimethylamine (NDMA) formation from dimethylamine (DMA) and nitrous acid have been investigated at the CCSD/6-311＋G(d,p)//B3LYP/6-311＋G(d,p) level of the theory. Two different pathways have been taken into account. One was that one molecule of nitrous acid directly reacted with DMA, and the other was that two molecules of nitrous acid reacted first to yield nitrogen trioxide, which then reacted with DMA. It was found that the energy barrier of the indirect reaction of DMA with nitrous acid was lower by around 55 kJ/mol than that of the direct pathway. Therefore, the indirect pathway, involving an active intermediate nitrogen trioxide, is the main pathway of NDMA formation. This conclusion is in good agreement with the experimental results in which the rate of NDMA formation is proportional to the square of the concentration of nitrous acid.

Key words: N-nitrosodimethylamine, dimethylamine, nitrous acid, density functional theory, ab initio