物理化学学报 >> 2014, Vol. 30 >> Issue (1): 34-42.doi: 10.3866/PKU.WHXB201311121

理论与计算化学 上一篇    下一篇

甲苯-2,4-二异氰酸酯与仲胺类化合物反应中的质子转移过程

王晓轩1, 胡伟2, 贵大勇1, 池旭辉2, 王明良1, 田德余1, 刘剑洪1, 马新刚2, 庞爱民2   

  1. 1 深圳大学化学与化工学院, 广东深圳 518060;
    2 湖北航天化学技术研究所, 湖北襄樊 441003
  • 收稿日期:2013-07-15 修回日期:2013-11-12 发布日期:2014-01-01
  • 通讯作者: 王明良 E-mail:wangml@szu.edu.cn
  • 基金资助:

    国防973 (613142)，国家自然科学基金(20673073)，深圳市功能高分子重点实验室开放基金(FP20130007)资助项目

Proton Transfer in Reaction between 2,4-Diisocyanatotoluene and Amine Compounds

WANG Xiao-Xuan1, HU Wei2, GUI Da-Yong1, CHI Xu-Hui2, WANG Ming-Liang1, TIAN De-Yu1, LIU Jian-Hong1, MA Xin-Gang2, PANG Ai-Min2   

  1. 1 College of Chemistry and Chemical Engineering, Shenzhen University, Shenzhen 518060, Guangdong Province, P. R. China;
    2 Hubei Institute of Aerospace Chemotechnology, Xiangfan 441003, Hubei Province, P. R. China
  • Received:2013-07-15 Revised:2013-11-12 Published:2014-01-01
  • Contact: WANG Ming-Liang E-mail:wangml@szu.edu.cn
  • Supported by:

    The project was supported by the National Defense Foundation of China (973) (613142), National Natural Science Foundation of China (20673073), and Foundation of Shenzhen Key Laboratory of Functional Polymer, China (FP20130007).

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摘要：

采用密度泛函理论B3LYP/6-31+G(d，p)方法研究了甲苯-2，4-二异氰酸酯(2，4-TDI)与仲胺类化合物反应过程中的质子转移效应. 研究发现甲醇分子对反应有显著的催化效应，可使反应能垒大幅降低，这表明含活泼氢的化合物会加速质子转移过程，从而加快反应速率. 2，4-TDI与甲基-N-甲基氨基甲酸酯的催化加成反应为一步反应，其反应过渡态呈六元环结构；而2，4-TDI与N-甲基对硝基苯胺、二苯胺、1，2-二氢-2，2，4-三甲基喹啉等芳香胺类化合物的催化加成反应经历了两步反应，其中第一步为速率控制步骤. 研究表明，在与2，4-TDI的反应中，芳胺化合物的活性高于甲基-N-甲基氨基甲酸酯的活性，计算的反应活性顺序与实验结果一致.

关键词: 密度泛函理论, 质子转移, 甲苯-2,4-二异氰酸酯, 聚氨酯反应

Abstract:

The effects of proton transfer on the reaction between 2,4-diisocyanatotoluene (2,4-TDI) and active-hydrogen-containing amine compounds were calculated using density functional theory (DFT) at the B3LYP/6-31+G(d, p) level. The energy barriers are significantly reduced when a methanol molecule serves as a proton transporter or a reactive catalyst, indicating that the labile hydrogen-containing compound plays a key role in accelerating the reaction rate and proton transfer. The catalytic addition of 2,4-TDI and methyl N-methylcarbamate follows a one-step mechanism, with a transition state characterized by a sixmembered ring. However, the catalytic additions of 2,4-TDI and aromatic amines such as N-methyl-p-nitroaniline, diphenylamine, and 1,2-dihydro-2,2,4-trimethylquinoline involve two steps, with the first step as the rate-limiting step. The reactions between 2,4-TDI and aromatic amines have lower energy barriers than that between 2,4-TDI and methyl N-methylcarbamate. The aromatic amines are more active than methyl N-methylcarbamate in the reaction with 2,4-TDI, which is in a good agreement with experimental results.

Key words: Density functional theory, Proton transfer, 2,4-Diisocyanatotoluene, Urethane formation

MSC2000: 

  • O643.12