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, differential 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·s⁻¹, 32.8 ​GPa), which are comparable to those of RDX (8795 ​m·s⁻¹, 34.9 ​GPa), demonstrate that it is effective to improve the properties of energetic compounds by constructing oxygen-containing fused-ring backbone.