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化学学报
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化学学报 ›› 2011, Vol. 69 ›› Issue (06): 725-730. 上一篇    下一篇

研究论文

PCl5与NH4Cl反应生成六氯环三磷腈的链引发反应机理的理论研究

田倩倩1,2，廖黎琼1,2，梁晓艳1,2，付一政1,2，刘亚青*,1,2   

  1. (1中北大学山西省高分子复合材料工程技术研究中心 太原 030051)
    (2中北大学材料科学与工程学院 太原 030051)
  • 投稿日期:2010-08-18 修回日期:2010-10-22 发布日期:2010-11-15
  • 通讯作者: 刘亚青 E-mail:fuyizheng@nuc.edu.cn
  • 基金资助:

    973;山西省青年科学基金;太原市大学生创新创业专项

Theoretical Study on Initiation Reaction Mechanism of Hexachlorocyclotriphosphazene Synthesized by PCl5 and NH4Cl

Tian Qianqian1,2 Liao Liqiong1,2 Liang Xiaoyan1,2 Fu Yizheng1,2 Liu Yaqing*,1,2   

  1. (1 Research Center for Engineering Technology of Polymeric Composites of Shanxi Province, North University of China, Taiyuan 030051)
    (2 College of Materials Science and Engineering, North University of China, Taiyuan 030051)
  • Received:2010-08-18 Revised:2010-10-22 Published:2010-11-15
  • Contact: Yaqing Liu E-mail:fuyizheng@nuc.edu.cn

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采用密度泛函理论(DFT)方法研究了五氯化磷与氯化铵反应生成六氯环三磷腈的链引发过程的微观反应机理. 在GGA-HCTH/DND理论水平下优化了反应路径上存在的反应物、中间体、过渡态及产物的几何构型, 并通过频率分析确认了过渡态的结构. 计算结果表明, 该链引发是一个非常复杂的反应过程, 反应路径上存在多种中间体和过渡态, 并且这一过程为吸热反应, 必须在加热条件下才能发生. 其中IM2经由过渡态TS2脱掉一个氯化氢生成IM3的路径的能垒最低, 仅为12.18 kJ/mol. IM5＋PCl5经由过渡态TS5脱掉一个氯化氢生成IM6的过程能垒最高, 值为174.83 kJ/mol, 故这一步骤是整个反应的速控步骤. 得到的产物为[Cl3P…N…PCl3]＋ , 与实验吻合.

关键词: 六氯环三磷腈, 链引发, 反应机理, 密度泛函理论, 过渡态

The chain initiation reaction mechanism of hexachlorocyclotriphosphazene, which was synthesized by phosphorus pentachloride and ammonium chloride was investigated by using the density functional theory (DFT) of quantum chemistry. At the GGA-HCTH/DND level, the geometry optimizations of reactants, intermediates, the transition states and the products were performed. All of the transition states were verified by the frequency analysis method. The results showed that the chain initiation reaction was a very complex procedure so there were various intermediates and transition states along reaction paths and the product was [Cl3P…N…PCl3]＋ which was agreed well with experimental results. This reaction was an endothermal process, and it only took place when heated. For this reaction paths, IM2→TS2→IM3＋HCl had the lowest energy barrier, only 12.18 kJ/mol|while the fifth procedure (IM5＋PCl5→TS5→IM6＋HCl) was the rate-controlling step, and it had the highest energy barrier 174.83 kJ/mol.

Key words: hexachlorocyclotriphosphazene, chain initiation, reaction mechanism, density functional theory, transition state