Exchanging of NH₂/NHNH₂/NHOH groups: An effective strategy for balancing the energy and safety of fused-ring energetic materials

Two series of fused-ring energetic materials containing NH₂ (Amino)/NHNH₂ (Diazanyl)/NHOH (Hydroxylamino) groups were successfully synthesized and fully characterized. The thermal properties of all newly synthesized energetic compounds were measured using Differential Scanning Calorimetry (DSC). The heat of formation and detonation properties were obtained using the Gaussian 09 and EXPLO5 v6.06.02 programs, respectively. Among them, diazanyl-based compound 10 and hydroxylamino-based compound 11 exhibit excellent density (p ≥ 1.86 g·cm⁻³, good thermal stability (T_d ≥ 202.0 °C), excellent calculated detonation performance (Dv ≥ 8830 m·s⁻¹, P ≥ 29.8 GPa) and good sensitivities (IS ≥ 25 J, FS > 360 N), whose values are comparable to those of RDX. Thus, they have significant potential for application as secondary explosives. In addition, the relationships between the substituents (Amino, Diazanyl, Hydroxylamino) and sensitivities were investigated using Hirschfeld surfaces, 2D fingerprint plots, and electrostatic potential. Results demonstrate that amino group plays an important role in the good thermal stability and insensitive of energetic materials. However, substituting amino groups with diazanyl or hydroxylamino groups can significantly improve the detonation properties of fused-ring energetic materials. These findings provide a reference for the development of the next-generation of advanced fused-ring energetic materials.