高等学校化学学报

高等学校化学学报 ›› 2001, Vol. 22 ›› Issue (5): 800.

• 研究论文 • 上一篇    下一篇

碳前驱体CH3ArCH2NH2热解反应的热力学和动力学DFT研究

王惠1,4, 翟高红2, 杨海峰1, 文振翼2, 史启桢1, 冉新权1, 罗瑞盈3, 杨延清4   

  1. 1. 西北大学化学系;
    2. 西北大学现代物理研究所, 西安 710069;
    3. 北京航空航天大学, 北京 100083;
    4. 西北工业大学材料科学系, 西安 710072
  • 收稿日期:2000-02-21 出版日期:2001-05-24 发布日期:2001-05-24
  • 通讯作者: 王　惠(1962年出生),女,博士,副教授,从事材料计算化学研究.E-mail:xb@pub.xaonline.com E-mail:xb@pub.xaonline.com
  • 基金资助:

    国家自然科学基金(批准号:596820070);陕西省教委专项基金(99KJ100)资助

Studies on Thermodynamics and Kinetics about Pyrolysis Mechanism of Carbon Matrix Precursor CH3ArCH2NH2

WANG Hui1,4, ZHAI Gao-Hong2, YANG Hai-Feng1, WEN Zhen-Yi2, SHI Qi-Zhen1, RAN Xin-Quan1, LUO Rui-Ying3, YANG Yan-Qing4   

  1. 1. Chemistry Department, Northwest University;
    2. Modern Physics Institute, Xi'an 710069, China;
    3. Beijing University of Aeronauticsand Astronautics, Beijing 100083, China;
    4. Department of Material Science, Northwestern Polytechnic University, Xi'an 710072, China
  • Received:2000-02-21 Online:2001-05-24 Published:2001-05-24

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摘要： 在实验研究基础上,通过量子化学理论计算对碳前驱体CH3ArCH2NH2的热裂解机理作了进一步的研究.利用Gaussian98程序包中AM1方法及DFTUB3LYP/3-21G*方法,对化合物5种可能热裂解路径的热力学和动力学计算结果表明,CH3ArCH2NH2热裂解的主反应路径为生成自由基CH3ArCH2·和NH2·,其主反应路径AM1计算的活化能Ea=230.78kJ/mol,DFT计算的活化能Ea=321.18kJ/mol;比较键焓计算的数据与相应的实验数据,发现DFT计算结果与实验结果吻合得较好;通过分析优化的反应物及产物自由基的部分结构参数,了解了理论支持主反应的原因;计算的产物自由基的空间构型表明主反应路径生成的产物自由基相互间若进行稠环缩合反应,将获得分子平面取向性很好的稠环芳烃产物.

关键词: 碳前驱体, 热裂解机理, AM1与DFT, 热力学, 动力学

Abstract: Based on the experiment, the pyrolysis mechanism of carbon matrix precursor CH3ArCH2NH2 was further studied by quantum chemistry computation. Using the AM1 and DFT UB3LYP/321G * method in Gaussian98 program package, thermodynamic and kinetic data were calculated for 5 designed pyrolysis paths of the compound. The calculation result shows that the reaction producing CH3ArCH2·and NH2·is the main pyrolysis reaction path and the calculated activation energy is Ea=230.78 kJ/mol by AM1 method and is Ea=321.18 kJ/mol by DFTmethod, which could be understood by analyzing the geometry parameters, spin densities and charges of some atoms in reactants and free radicals produced. Compared with experimental data of bond enthalpy, the calculated results by DFTcoincide well. The geometry parameters of the produced free radicals also shows that, after the compound CH3ArCH2NH2 as carbon matrix compound are pyrolyzed, the plane orientation of the produced free radicals will benefit the formation of a fused aromatic ring structure.

Key words: Carbon matrix precursor, Pyrolysis mechanism, AM1 and DFT method, Thermodynamics, Kinetics

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