【作者】 汪敬；

【导师】 田安民；

【作者基本信息】 四川大学 ， 物理化学， 2002， 博士

【摘要】 本文结合从头计算分子动力学（ab initio molecular dynamics，AIMD）方法和量子化学的密度泛函理论（density functional theory，DFT）深入详细地研究了四种5-取代-1-H-四唑衍生物（5-NO₂-1-H-四唑，5-NH₂-1-H-四唑，5-H-1-H-四唑和5-N₃-1-H-四唑）分子的单分子热分解反应机理。 借助于VASP程序包，我们分别对不同温度下的反应轨迹进行了分子动力学模拟计算。用Gaussian 98程序在B3LYP／6-31G（d）的水平上优化了28个过渡态和32个极小点结构，相应的高精度单点计算则分别在MP2／6-31G（d,p），MP4／6-31G（d,p）和CCSD（t）／6-31G（d,p）水平上进行。得到的能量和其他的高级计算均能较好地吻合。此外，还在HF／6-31G（d）水平下计算了6个过渡态和8个极小点的优化构型。理论计算得到的反应通道包括：5-NO₂-1-H-四唑分子的四条热分解反应途径、5-NH₂-1-H-四唑分子的三条热分解反应途径、5-H-1-H-四唑分子的六条热分解反应途径以及5-N₃-1-H-四唑分子的三条热分解反应途径。结果表明，四种衍生物热分解的主要反应途径都是直接开环反应。根据反应活化能对它们的感度进行排序，得到了与实验撞击感度结果完全一致的结论，证明两者之间的确存在着良好的平行关系。这对于四唑衍生物的起爆机理以及新型安全钝感起爆剂的设计和合成具有一定的理论指导意义。更多还原

【Abstract】 Using Ab Initio Molecular Dynamics (AIMD) method and Density Functional Theory (DFT), we report the mechanisms of thermal decompositions of four kinds of tetrazole derivatives, which are 5-NO2-1-H-tetrazole, 5-NH2-1-H-tetrazole, 5-H-1-H-tetrazole and 5-N3-1-H- tetrazole.For the ab initio molecular dynamics studies on the unimoleculars decomposition of the four tetrazole derivatives, dissociation trajectories are simulated at different temperatures using the VASP package. Based on these results, further calculations of 32 minimum points and 28 transition state structures are performed using Gaussian 98 at B3LYP/6-31G(d) level, whereas MP2/6-31G(d,p), MP4/6-31G(d,p) and CCSD(t)/6-31G(d,p) are used for the high accuracy single point calculation. The energy calculation is in good agreement with previously reported high level calculations. Also 8 minimum points and 6 transition state are optimized under HF/6-31G(d) level. The reaction channels reported in the thesis include four thermal decomposition pathways of 5-NO2-1-H-tetrazole, three thermal decomposition pathways of 5-NH2-1-H-tetrazole, six thermal decomposition pathways of 5-H-l-H-tetrazole and three thermal decomposition pathways of 5-N3-1-H-tetrazole. It is discovered that the direct ring rupture channel is the main pathway during the thermal decompositions of the four tetrazole derivatives. Following the reaction activation energies, the relative magnitudes of sensitivity appeare to be in the same order of the experimental sensitivity. This demonstratesthat there existed parallel relationships between them.更多还原