Synthesis, structure and properties of neutral energetic materials based on N-functionalization of 3,6-dinitropyrazolo[4,3-c]pyrazole

摘要

3,6-Dinitropyrazolo[4,3-c]pyrazole (DNPP, 4) was prepared using an efficient modification process. Various neutral energetic derivatives of DNPP were synthesized from N-functionalization of imide (NH) group. All compounds were fully characterized by H-1 and C-13 nuclear magnetic resonance spectroscopy, infrared spectroscopy, elemental analysis, and differential scanning calorimetry (DSC). The crystal structures of compounds 4 center dot 2H(2)O, 12 and 15 were confirmed by single-crystal X-ray diffraction, showing extensive hydrogen-bonding. The densities of neutral derivatives ranged from 1.74 to 1.95 g cm(-3), and all compounds have positive heats of formation in the range of 18.8 to 863 kJ mol(-1). Based on the measured densities and calculated heats of formation, theoretical performance calculations, including detonation pressures (27.1-41.5 GPa) and velocities (7819-9364 m s(-1)), were carried out using the Gaussian 09 program and Kamlet-Jacobs equations, and they compare favorably with those of TNT and RDX. These properties make them potential and competitive for use as new high energy-density materials.