Synthesis and characterization of oxygen-containing imidazo[1,2-d][1,2,4] oxadiazole fused-ring energetic compounds

Oxygen plays an important role in improving the oxygen balances and densities of energetic compounds. In this study, a series of oxygen-containing imidazo[1,2-d][1,2,4]oxadiazole building block-based energetic compounds (3-8) were synthesized and fully characterized. In addition, the structures of compounds 3-7 were determined using single-crystal X-ray diffraction. The properties of compounds were evaluated based on their density, dif-ferential scanning calorimetry, impact and friction sensitivities, heat of formation, and detonation performances. The insensitive properties of compound 6 (IS > 40 J, FS > 360 N) and its detonation properties (8682 m center dot s(-1), 32.8 GPa), which are comparable to those of RDX (8795 m center dot s(-1), 34.9 GPa), demonstrate that it is effective to improve the properties of energetic compounds by constructing oxygen-containing fused-ring backbone.