Synthesis and Properties of Trinitromethyl-Functionalized 4-Amino-5-nitro-7H-pyrazolo[3,4-d][1,2,3]triazine-2-oxide Derivatives

Through combining the highly energetic trinitromethyl group with the stable 4-amino-5-nitro-7H-pyrazolo[3,4-d][1,2,3]triazine-2-oxide (PTO) framework, a series of neutral energetic derivatives (NPX-15, NPX-16, and NPX-17) and energetic salts (NPX-15·N₂H₅⁺, NPX-15·K⁺, and 3) were synthesized. Among these compounds, NPX-15 and NPX-16 exhibit notable characteristics, including high oxygen balances (OB_CO = 13.9 and 20.7%, respectively) and exceptional energetic properties, with detonation velocities (ν_D) of 9039 and 8924 m s^-1, respectively. Furthermore, near-infrared laser ignition tests were performed on the three newly synthesized neutral compounds (NPX-15, NPX-16, and NPX-17), revealing that NPX-16 exhibited remarkable laser ignition performance. As for the synthesized energetic salts, NPX-15·N₂H₅⁺ and NPX-15·K⁺ display both high-energy properties (ν_D = 8476 m s^-1; ν_D = 8950 m s^-1) and good safety (IS = 40 J; FS = 360 N), while salt 3 shows particularly high density and excellent decomposition temperature.