Recent Progress on Nitrogen-Rich Energetic Materials Based on Tetrazole Skeleton

Assembly of thermostable fused compounds with oxidizers for laser-ignited energetic materials

“…The yield of 1 was 90%. 1 Preparation of compound 2 0.2 g ICM-104 was dissolved in 5 ml 70% HClO 4 aqueous to form a clear colorless solution at 40 °C. After slow solvent evaporation at room temperature (15-25 °C) for several days, colorless cuboid single crystals suitable for single crystal X-ray diffraction analysis were obtained.…”

“…With the advancement of the aerospace industry and weaponry equipment, there are emerging demands for energetic materials that simultaneously possess high thermal stability, low mechanical sensitivities, and meet the criteria for high energy density. [1][2][3][4] Typical energetic materials, such as trinitrotoluene (TNT), 5 1,3,5-trinitro-1,3,5-triazacyclohexane (RDX), 6 1,3,5,7-tetranitro-1,3,5,7-tetrazocine (HMX), 7 and 2,4,6,8,10,12-hexanitro-2,4,6,8,10,12-hexaazaisowurtzitane (CL-20), 8 release their energy from the oxidation of the carbon backbone within their molecules, and high energy densities usually mean that they contain more oxidizing substituent (such as -NO 2 ), which leads to increased sensitivity and decreased stability. 9 In recent years, energetic nitrogen-rich fused ring compounds have attracted considerable interest, owing to their high nitrogen content, high heat of generation, and excellent stability.…”

“…Due to this unique polycyclic coplanar structure and large π-π conjugation system, the fused ring compounds exhibit good thermal stability. 13,14 In recent years, fused ring compounds, such as 8-nitropyrazolo [1,5-a] [1,3,5]triazine-2,4,7triamine, 15 2-nitro- [1,2,4]-triazolo[1,5-a][1,3,5]triazine-5,7diamine, 16 and [1,2,4]triazolo [4,3-b][1,2,4,5]tetrazine, 17 have been reported to be of excellent thermal stability (T d > 300 °C) and low mechanical sensitivities (IS > 40 J, FS > 360 N). However, the N atom on the ring occupies the modification site of the energetic functional group, which is unfavorable for further energetic chemical modification.…”

Synthesis and detonation characters of 3,4,5-1H-trinitropyrazole and its nitrogen-rich energetic salts

“…However, they often suffer from being environmentally unfriendly, involving harsh synthetic methods and so on. 7 The design and synthesis of new high-energy density materials have been long-term goals. The critical challenge to developing competitive EMs is balancing the energy and sensitivity properties.…”

Exploring the Correlation between Azido-Tetrazolo Tautomerizations and Isomer Structures: Electron Density of Bonding N Atoms and N–N Bond Polarity

“…Recently, nitrogen-rich heterocycles, relying on high-energy N–N bond energy storage and release, have been expected to break through the energy bottleneck faced by traditional CHON energetic materials and have become an important development direction in the field of energetic materials. − Notably, tetrazole compounds play an important role in the research of new high-energy density compounds and have potential applications in gas generators, propellants, pyrotechnic materials, and high-energy explosives, owing to their high enthalpy of formation, low vapor pressure, and high stability. − Therefore, various approaches have been developed for the construction or introduction of the tetrazole backbone. − …”