Polynitro-Functionalized Azopyrazole with High Performance and Low Sensitivity as Novel Energetic Materials

Abstract

The development of energetic materials is still facing a huge challenge because the relationship between energy and sensitivity is usually contradictory: high energy is always accompanied with low sensitivity. Here, a high-energy, low-sensitivity energetic polynitro-functionalized azopyrazole (TNAP) and its energetic salts have been synthesized. The structural characterization of these compounds was analyzed by elemental analysis, 1H and 13C NMR spectroscopies, and infrared spectroscopy. The single-crystal structure of compounds K2TNAP, TNAP, 5, and 6 was obtained by X-ray diffraction, and K2TNAP is a novel energetic metal–organic framework. The calculated detonation properties of TNAP (9040 m s–1 and 36.0 GPa) are superior to that of RDX (8796 m s–1 and 33.6 GPa). In addition, TNAP also has lower mechanical sensitivity (IS > 40 J, FS = 244 N) and higher decomposition temperature (Td = 221 °C) than RDX (IS = 7.4 J, FS = 120 N, and Td = 204 °C). These experimental results suggest that TNAP may become a new candidate for secondary explosives.

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

“…Our new strategy to construct 1,2,3,5-tetrazine-2oxide developed in this work is much safer and easier to be handled. The structure of BITE-101 and its intermediates were fully characterized by IR, 1 H and 13 C NMR spectroscopy as well as by elemental analysis and the spectra were listed in Supplementary Information.…”

“…DANP was prepared from the literature's method 28 . 1 H and 13 C NMR spectra were recorded on Bruker AVANCE 400 nuclear magnetic resonance spectrometer. DMSO-d 6 was employed as a solvent and locking solvent.…”

“…1 H NMR (400 MHz, DMSO-d 6 ) δ 9.09 (d, J = 159.5 Hz, 2H), 7.55 (s, 2H), 5.90(s, 2H). 13 Synthesis of 5-amino-3, 4-trinitro-1H-pyrazole-1-carboximidamide (2) About 10 mL of 30% H 2 O 2 was added into a 100 ml flask and cooled by an ice-salt bath, 10 mL of 60% H 2 SO 4 was added dropwise while maintaining the temperature <0 °C. Then 3, 5-diamino-N', 4-dinitro-1Hpyrazole-1-carboximidamide (1, 1.15 g, 5 mmol) was added to the mixed solution at 0 °C in batches after the addition was completed.…”

“…1 H NMR (400 MHz, DMSO-d 6 ) δ 9.88 (s, 1H), 8.82 (s, 1H). 13 To a 50 mL flask containing 3 ml 100% HNO 3 cooled to 0 °C was added 100 mg Compound 2 (100 mg, 0.384 mmol) in batches, after then, the reaction mixture was slowly warmed up to room temperature and stirred for another 3 h. After the reaction was completed it was monitored by TLC (Solvent combination: EA:PE = 1:1; R f = 0.5). Then, the reaction mixture was poured into ice water to precipitate a yellow solid.…”

“…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.…”