Graphite-like Packing Modes Facilitating High Thermal Stability: A Comparative Study in the Polymorphs of Planar Energetic Molecules

• Published in: Crystal growth & design 2021-06, Vol.21 (6), p.3175-3178
• Main Authors: Cao, Yilin, Lai, Weipeng, Yu, Tao, Ma, Yiding, Liu, Yingzhe, Wang, Bozhou
• Format: Article
• Language: English
• ISSN: 1528-7483; 1528-7505
• DOI: 10.1021/acs.cgd.1c00277

Graphite-like packing structures have aroused the attention in the community of energetic materials because of their good balances between energy and safety. Nevertheless, the detailed relationship between different packing modes and performance is still lacking, leading to a handful of advanced graphite-like energetic materials. Here, five compounds with polymorphs containing graphite-like packing structures were screened out from over 1000 experimentally measured nitro crystals. As a comparative study, the results show the importance of intermolecular interactions in view of the nearly same molecular conformation existing in each group of polymorphs. Tiny differences in close contact populations lead to different packing modes and material features, including crystal density, packing coefficient, thermodynamic stability, thermal decomposition behavior, and so on. Interestingly, graphite-like structures always exhibit the lowest thermal decomposition activity compared with other packing modes, indicative of low thermal sensitivity. Hopefully, these findings can promote the development of advanced graphite-like energetic materials.