New Role for an N,N′-Alkylidene Bridge: Taming the Hygroscopicity of Acidic Energetic Materials with Enhanced Stability

Abstract

Hygroscopicity can cause undesirable chemical reactions, affect the stability and compatibility, and also the reduce strength and detonation performance of energetic materials; therefore, it should be avoided for civil and military applications. The existence of acidic protons in the molecule is the main causes of hygroscopicity, and the most common strategy to eliminate acidic hydrogen includes the formation of salts, introduction of N-CH 3 or N-NH 2 groups, etc. In this work, we present the preparation of tricyclic fused-ring energetic compounds derived from bi(1,2,3-triazole) by introducing an N,N′alkylidene bridge which could act as a "buffer" to reduce the external stimuli, therefore resulting in compounds with enhanced thermal stability and reduced sensitivity as well as elimination of the hygroscopicity and acidity in the meantime. Their physical and chemical properties were determined and interpreted by both experimental and theoretical methods. The nonhygroscopicity, good thermal stability (C1, T d = 277 °C; C2, T d = 290 °C), low sensitivity (C1, IS = 30 J, FS > 360 N; C2, IS = 50 J, FS > 360 N), and detonation properties (C1, D = 8287 m s −1 ; P = 29.4 GPa; C2, D = 8027 m s −1 ; P = 25.4 GPa) comparable to those of TATB (D = 8114 m s −1 ; P = 31.2 GPa) make them desirable candidates as high-energy insensitive energetic materials.

Tri-explosophoric groups driven fused energetic heterocycles featuring superior energetic and safety performances outperforms HMX

“…Octogen (HMX) is the most powerful military explosive in current use 6,7 , it has a density of 1.905 g cm −3 , an onset decomposition temperature of 279 °C, detonation velocity of 9144 m s −1 , and detonation pressure of 39.2 GPa. During the last few decades, lots of efforts have been devoted to synthesize CHON-based high explosives [8][9][10][11][12][13][14][15][16] . As shown in Fig.…”

Intramolecular Assembly of Nitrobiazoles and an Ether Bridge: Toward Energetic Materials with Enhanced Energy and Safety

“…14−17 In particular, following the facile and concise design principles, incorporating an N,N′-alkene bridge into polynitrobiazoles has been a popular strategy to access thermostable high-performing energetic materials. 18,19 As seen in Figure 1a, the successive construction of [5,6,5] polynitrobiazoles for practical application but also effectively enhances the stability toward destructive stimuli. The decomposition temperatures of A−F range from 261 to 328 °C.…”

High-Energy and Insensitive Tetrazole-Substituted 2,5-Dinitroiminooctahydroimidazo[4,5-d]imidazole: Synthesis, Characterization, and Energetic Properties

“…Since Nobel’s successful improvement of the explosives manufacturing process, the development of energetic materials has received extensive attention in the military and civilian fields such as propellants, explosives, and so forth. − In the pursuit of high-performance energetic materials, although high energy has always been the primary consideration, there is a growing interest in the safety of energetic materials because of the increasing number of safety-related issues in practical applications. − However, to achieve a good balance between energy and safety remains a great challenge because high energy is mainly at the expense of molecular stability. − Therefore, a high-level energy material with a fine balance between energy and security is highly desirable.…”

“…tetrazole groups were linked to the DNII system through an ethylene bridge (3), a methylene bridge(5), and direct connection(6). These compounds were fully characterized and their detonation properties were investigated (e.g., detonation velocities and detonation pressures).…”