The intramolecular integration of carbonyl and N-nitroamino groups to effectively balance the energy and sensitivity of N-nitroamino-functionalized bisazoles

In this study, employing an innovative method by introducing the N-nitroamino groups into bis(1,2,4-oxadiazoles) skeleton for the first time, a fine balance between high detonation properties and mechanical stability of N-nitroamino-functionalized bisazoles was achieved. A novel compound N,N'-(5,5′-dioxo-[3,3′-bi(1,2,4-oxadiazole)]-4,4′(5H,5′H)-diyl)dinitramide (3) was synthesized using straightforward three-step synthetic routes. Compound 3 not only has a high crystal density of 1.932 g cm⁻³ at 296 K, but also competes well in impact and friction sensitivities of 10 J and 160 N among all reported energetic N-nitroamine analogues. Meanwhile, the energy level (detonation velocity: V_D = 9106 m s⁻¹; detonation pressure: P = 36.6 GPa) of 3 is much superior to that of benchmark explosive 1,3,5-trinitro-1,3,5-triazacyclohexane (RDX, V_D = 8801 m s⁻¹; P = 33.6 GPa) and approaches 1,3,5,7-tetranitro-1,3,5,7-tetrazocane (HMX, V_D = 9144 m s⁻¹; P = 39.2 GPa). Additionally, with a striking high density of 1.929 g cm⁻³, hydroxylammonium salt 8 (V_D = 9507 m s⁻¹; P = 40.1 GPa) exhibits a prominent detonation performance comparable to the ε-2,4,6.8,10,12-hexanitro-2,4,6,8,10,12-hexaazaisowurtzitane (ε-CL-20, V_D = 9455 m s⁻¹; P = 46.7 GPa). This work may give new insight into improving the mechanical stability of energetic materials and is beneficial for developing novel high-energy–density compounds with excellent overall performance.