N-diazo-bridged nitroazoles: catenated nitrogen-atom chains compatible with nitro functionalities.

N-diazo-bridged azoles were synthesized based on oxidative coupling of N-aminoazoles. Incorporation of extended catenated nitrogen-atom chains with nitro groups led to compounds with favorable functional compatibilities. This combination gives rise to a series of high-density energetic materials (HEDMs) with high heats of formation, enhanced densities, positive oxygen balances, and good detonation properties while retaining excellent thermal stabilities and relatively low impact sensitivities. Calculated and experimental studies showed the delicate balance between the length of the nitrogen atom chain, energetic performance, and inherent stability, thus, providing a promising strategy for designing advanced energetic materials.