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Two series of both nitrogen-rich and thermostable energetic materials as well as their energetic salts based on hetarenecarboxylic acids are now described. Among these new compounds, the neutral compounds 3...

An N-nitrated trinitroethylamino azoxyfurazan derivative reported here possesses oxygen balance of near zero (+2.5%) and exhibits outstanding properties (ΔfHm, 962.1 kJ mol−1; D, 9458 m s−1; P, 41.2 GPa).

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Nitrogen-rich cation 5-amino-1H-1,2,4-triazole-3-carbohydrazide and its derivatives were synthesized by a new molecular design strategy based on the energetic moiety combination. All derivatives were fully characterized by vibrational spectroscopy (IR), multinuclear (1H, 13C) NMR spectroscopy, elemental analysis, differential scanning calorimetry (DSC), and impact and friction-sensitivity tests. The structures of compounds 1-4, 7 and 8 were further confirmed by single-crystal X-ray diffraction and six different types of crystal packing were surprisingly discovered. The results show that the extensive hydrogen bonding interactions between the cations and anions lead to a complex 3D network, which contribute greatly to the high density, insensitivity and thermal stability of the 5-amino-1H-1,2,4-triazole-3-carbohydrazide salts. It is also found that the cationic form of 5-amino-1H-1,2,4-triazole-3-carbohydrazide can decrease the sensitivity and elevate the nitrogen content of the target salts effectively. Some of these salts exhibit reasonable physical properties, such as good thermal stability (up to 407 °C) and reasonable impact sensitivities (IS = 5-80 J). In addition, theoretical detonation properties of the energetic salts obtained with EXPLO 5 (version 6.02) confirm them as competitively energetic compounds comparable to those of RDX or HMX.

An increasing attention has been witnessed to the field of crystal engineering of energetic materials very recently. This study revealed the synthesis, structure, and energetic properties of 4,6-dinitro-1-(4-amino-1,2,4- triazole-2-yl)-1H-indazole (3) with two polymorphic forms, α-3 and β-3. The 4,6-dinitro-indazole derivative α-3 with a wave-like stacking structure was synthesized by one-step reaction at room temperature. Interestingly, the β-3 could be formed at 78 °C. It is noteworthy that plate-shaped α-3 crystals could transform to β-3 with needle-shaped crystals. The single-crystal diffraction data revealed that β-3 is nearly coplanar and features closer layer-by-layer package structure, thereby exhibiting increases of 0.08 g cm–3 (4.7%), 36.6 kJ mol–1 (6.1%), 667 m s–1 (9%), 3.4 GPa (15.5%), 88 °C (49%), 6 J (23%), and 97 N (43%) in density, heat of formation (ΔH), detonation velocity (D) and pressure (P), decomposition temperature (T dec), impact sensitivity (IS), and friction sensitivity (FS) compared to α-3, respectively. Compared to TNT, the β-3 (D = 8061 m s–1, P = 25.4 GPa, IS = 32 J, FS = 320 N) possesses better detonation properties and sensitivities. Based on experimental results and theoretical analysis, this study provides an effective strategy for improving the performance of energetic materials in molecular design and crystal configuration.

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It is still an urgent problem in the field of energetic materials to explore the synthesis of heat-resistant compounds with balanced energy and thermal stability through simple synthetic. Recently, fused...