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

Through combining the highly energetic trinitromethyl group with the stable 4-amino-5-nitro-7<i>H</i>-pyrazolo[3,4-<i>d</i>][1,2,3]triazine-2-oxide (PTO) framework, a series of neutral energetic derivatives (<b>NPX-15</b>, <b>NPX-16</b>, and <b>NPX-17</b>) and energetic salts (<b>NPX-15·N</b>_<b>2</b><b>H</b>_<b>5</b>^<b>+</b>, <b>NPX-15·K</b>^<b>+</b>, and <b>3</b>) were synthesized. Among these compounds, <b>NPX-15</b> and <b>NPX-16</b> 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 (<b>NPX-15</b>, <b>NPX-16</b>, and <b>NPX-17</b>), revealing that <b>NPX-16</b> exhibited remarkable laser ignition performance. As for the synthesized energetic salts, <b>NPX-15·N</b>_<b>2</b><b>H</b>_<b>5</b>^<b>+</b> and <b>NPX-15·K</b>^<b>+</b> 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 <b>3</b> shows particularly high density and excellent decomposition temperature.