Synthesis and characterization of two 1,2,4-oxadiazole-furazan-based nitrate ester compounds as potential energetic plasticizers

Two novel energetic compounds, 3-nitroxymethyl-5-(4-nitro-furazan-3-yl)-1,2,4-oxadiazole (4) and 3-nitroxymethyl-5-(4-azido-furazan-3-yl)-1,2,4-oxadiazole (5), were synthesized. Both of them were fully characterized, and the structure of 4 was further confirmed by X-ray single crystal diffraction. The thermal behaviors, detonation performances and the sensitivities of 4 and 5 were also investigated by differential scanning calorimetry (DSC), EXPLO5 program and BAM standard techniques. In addition, the electrostatic potential energy surface (ESP) was studied by Multiwfn program and density functional theory at B3LPY/6-31G (d, p). Both compounds have low melt-point, good energetic performance and mechanical sensitivity, which endow them with promising properties as plasticizing ingredients in propellant formulations.