The pursuit of high density and high detonation velocity has been a central objective throughout the history of energetic materials development. By synergistically incorporating nitramine (−N–NO2) and gem-dinitromethyl (−CH(NO2)2) groups, a series of novel polynitro energetic compounds were successfully designed and synthesized. Notably, compound 1 exhibits outstanding properties (ρ = 1.91 g·cm–3, Td = 274.3 °C, P = 40.86 GPa, D = 9439 m·s–1), along with relatively low mechanical sensitivity (IS = 30 J, FS = 320 N), positioning it as a promising candidate to replace RDX and HMX. Single-crystal X-ray diffraction analysis revealed the formation of dense intermolecular hydrogen-bonding networks and extensive π–π stacking interactions within the crystal lattice of compound 1, with these noncovalent interactions collectively contributing to its high density and exceptional thermal stability. Furthermore, controlled experiments and mechanistic studies elucidated the parallel formation pathways of compounds 1 and 2 during nitration, providing a synthetic rationale for the design of analogous polynitro structures. This work demonstrates that the synergistic modification of nitrogen-rich heterocyclic skeleton with nitramine and gem-dinitromethyl groups represents an effective strategy for enhancing both the energy density and safety of energetic materials, offering a new design paradigm for the development of next-generation high-energy, insensitive compounds.
Gao et al. (Thu,) studied this question.