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

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 (T_d = 221 °C) than RDX (IS = 7.4 J, FS = 120 N, and T_d = 204 °C). These experimental results suggest that TNAP may become a new candidate for secondary explosives.