Tang Li, Zhu Weihua
Institute for Computation in Molecular and Materials Science, School of Chemistry and Chemical Engineering, Nanjing University of Science and Technology, Nanjing, 210094, China.
J Mol Model. 2022 Sep 22;28(10):326. doi: 10.1007/s00894-022-05327-0.
The decomposition mechanisms of energetic CL-20:2,4-dinitro-2,4-diazapentane (DNP) and CL-20:2,4-dinitro-2,4-diazaheptane (DNG) co-crystals at high temperatures (1000, 2000, and 3000 K) were studied by density functional tight-binding molecular dynamics (DFTB-MD) simulations. At different temperatures, their decomposition mechanisms are very different. At 1000 K, conformational changes are observed only for the CL-20:DNG co-crystal, in which the CL-20 changes from β-CL-20 to γ-CL-20. When the temperature is increased to 2000 K, CL-20, DNP, and DNG begin to decompose, and there are five paths for the main initial mechanisms. Further increasing the temperature to 3000 K promotes a more complete decomposition. The initial reactions of CL-20 in the two co-crystals have two channels. There are two initial decomposition channels in the DNP molecule and only one channel in the DNG molecule. As the temperature increases, the decomposition products of the two co-crystals are different. Our work may provide the in-depth understanding of the decomposition mechanisms of high-energy CL-20-based co-crystals at high temperatures.
通过密度泛函紧束缚分子动力学（DFTB-MD）模拟研究了高能CL-20与2,4-二硝基-2,4-二氮杂戊烷（DNP）和CL-20与2,4-二硝基-2,4-二氮杂庚烷（DNG）共晶在高温（1000、2000和3000 K）下的分解机理。在不同温度下，它们的分解机理差异很大。在1000 K时，仅观察到CL-20:DNG共晶发生构象变化，其中CL-20从β-CL-20转变为γ-CL-20。当温度升至2000 K时，CL-20、DNP和DNG开始分解，主要初始机理有五条路径。进一步将温度提高到3000 K会促进更完全的分解。两种共晶中CL-20的初始反应有两个通道。DNP分子有两个初始分解通道，DNG分子只有一个通道。随着温度升高，两种共晶的分解产物不同。我们的工作可能为深入了解高能CL-20基共晶在高温下的分解机理提供帮助。
