Structure–Performance Relationship in Thermally Stable Energetic Materials: Tunable Physical Properties of Benzopyridotetraazapentalene by Incorporating Amino Groups, Hydrogen Bonding, and π–π Interactions

Abstract

Structure−performance investigation has become one of those significant trends for energetic materials and energetic crystallography inevitably. Herein, we report two new energetic materials deriving from a famous thermally stable explosive benzopyridotetraazapentalene, which was first developed by Huynh and Hiskey, et al., at Los Alamos National Laboratory. Owing to the incorporation of amino groups, these two energetic materials exhibit different amusing physical performance. Understanding their structures, properties, performances, and the relationship among them is the basis for the rational design of thermally stable energetic materials. Moreover, for these energetic conjugated systems, the density overlap regions indicator analysis was also employed for necessarily visualizing and quantifying the covalent and noncovalent interactions. It is evident that this strategy of incorporating amino groups into energetic materials increased the coplanarity of the energetic fused ring, owing to the contribution of hydrogen bonding and π−π interactions, which can further decrease their sensitivity. However, we also found that the integrity of intramolecular hydrogen -bonding interaction was the critical factor, which affected the thermal stability of energetic molecules with the amino groups inserting progressively. It is notable that diamino-substituted energetic compound 8 exhibits comparable thermal stability (320 °C) to that of HNS, more dense (d: 1.84 g cm −3 ), higher nitrogen content (37.43%), and lower sensitivity (impact sensitivity: 12 J, friction sensitivity > 360 N), superior to those of HNS. These discoveries can effectively assist the design and preparation of other promising thermally stable energetic materials toward future high-performing energy applications.

Evolving the Scope of 5,5’‐Azobistetrazoles in the Search for High Performing Green Energetic Materials

“…However, since TNT in particular, as well as the decomposition products of RDX, turned out to be toxic, an intensive search for a substitute is underway [4–5] . Suitable substitutes should not only surpass the performance of their predecessors, but also exhibit high thermal stability with low sensitivity [6–7] . Furthermore, the synthesis should be carried out in a few steps with simple processing while being inexpensive and environmentally friendly.…”

Combined X-ray Crystallographic, IR/Raman Spectroscopic, and Periodic DFT Investigations of New Multicomponent Crystalline Forms of Anthelmintic Drugs: A Case Study of Carbendazim Maleate

“…However, most crystals with actual or potential practical application have little in common with the structures from the benchmark sets. Some examples include single-component crystals of larger, conformationally flexible molecules [10][11][12][13][14], fluoroorganic compounds [15,16], and multicomponent crystals [17][18][19], often with short (strong) [20,21] or ionic H-bonds [22]. The applicability of the methods tested against the benchmark sets for modeling the properties of non-model crystals (e.g., organic salts) is unclear.…”

Exploring Application of 1,2,4‐Triazole Energetic Salts: Gas Generating Agent, Propellant and Explosive Compositions

“…The results are shown in Figure 5 and Table 1. Neutral compound 1 starts to decompose at 329 °C, which is comparable to that of traditional heat‐resistant explosive hexanitrostibene HNS ( T onset =318 °C, D=7612 m s −1 ) [23]. Thermal stabilities of salt 3 (271 °C) are comparable with TNT ( T onset =295 °C).…”