Zhu Yang, Gu Zhihui, Zhang Peng, Chu YuQin, Ma Peng
College of Safety Science and Engineering, Nanjing Tech University, Nanjing, 210009, China.
J Mol Model. 2025 Sep 5;31(10):265. doi: 10.1007/s00894-025-06485-7.
High-nitrogen polycyclic compounds have become a research hotspot in the design of new energetic molecules due to their dense nitrogen content, high positive enthalpy of formation, and good structural stability. In particular, the fused structures of triazole and triazine heterocycles can not only enhance energy output but also possess excellent thermal stability. This study focuses on three triazolotriazine energetic compounds: 3,7-dinitro-[1,2,4]triazolo[5,1-c][1,2,4]triazin-4-amine (TTX), 7-nitro-3-(1H-tetrazol-5-yl)-[1,2,4]triazolo[5,1-c][1,2,4]triazin-4-amine (compound 1), and 3,3'-dinitro-[7,7'-bi[1,2,4]triazolo[5,1-c][1,2,4]triazine]-4,4'-diamine (compound 2). By employing quantum chemical calculation methods, the study delves into the stability and initial decomposition effects of these compounds under different external electric fields. The research results indicate that external electric fields have a significant impact on the stability and initial decomposition of triazolotriazine energetic compounds, providing an important theoretical basis for the design and application of energetic materials.
The B3LYP-D3 method combined with the 6-311G(d,p) basis set was used for geometric optimization and frequency analysis on the Gaussian 16 program. All optimized structures were local energy minima on the potential energy surface, with no imaginary frequencies. The M062x method was employed for transition state calculations, and all transition state structures had only one imaginary vibrational mode, which was verified to correctly connect the reactants and products through intrinsic reaction coordinate (IRC) calculations. The Shermo program was used to calculate the Gibbs free energy of the molecules, with all energy results being relative Gibbs free energies with the initial reactants' energy set to zero. VMD and Multiwfn software was utilized for wavefunction analysis.
高氮多环化合物因其高氮含量、高正生成焓和良好的结构稳定性，已成为新型含能分子设计的研究热点。特别是，三唑和三嗪杂环的稠合结构不仅可以提高能量输出，还具有优异的热稳定性。本研究聚焦于三种三唑并三嗪含能化合物：3,7-二硝基-[1,2,4]三唑并[5,1-c][1,2,4]三嗪-4-胺（TTX）、7-硝基-3-(1H-四唑-5-基)-[1,2,4]三唑并[5,1-c][1,2,4]三嗪-4-胺（化合物1）和3,3'-二硝基-[7,7'-联[1,2,4]三唑并[5,1-c][1,2,4]三嗪]-4,4'-二胺（化合物2）。通过采用量子化学计算方法，该研究深入探讨了这些化合物在不同外部电场下的稳定性和初始分解效应。研究结果表明，外部电场对三唑并三嗪含能化合物的稳定性和初始分解有显著影响，为含能材料的设计和应用提供了重要的理论依据。
采用B3LYP-D3方法结合6-311G(d,p)基组在Gaussian 16程序上进行几何优化和频率分析。所有优化结构均为势能面上的局部能量极小值，无虚频。采用M062x方法进行过渡态计算，所有过渡态结构仅有一个虚振动模式，并通过内禀反应坐标（IRC）计算验证其能正确连接反应物和产物。使用Shermo程序计算分子的吉布斯自由能，所有能量结果均为相对于初始反应物能量设为零的相对吉布斯自由能。利用VMD和Multiwfn软件进行波函数分析。
