Combination of 5-amino-4-nitro-1,2-dihydro-3 <i>H</i> -pyrazol-3-one and azine frameworks for insensitive, heat-resistant energetic materials

5-Nitro-1,2,4-triazol-3-one (NTO) is an important insensitive and high-energy aromatic ketone compound in energetic materials. However, its relatively low thermostability (Td: 236.0 °C) limits its application in heat-resistant energetic materials. In this study, we utilized an NTO analogue (5-amino-4-nitro-1,2-dihydro-3<i>H</i>-pyrazol-3-one, ANPO) to prepare a series of new heat-resistant energetic compounds, NPX-10-NPX-14, whose thermal decomposition temperatures range from 311 °C to 386 °C, around 75-150 °C higher than that of NTO. At the same time, these five new heat-resistant energetic compounds exhibited low impact sensitivity (IS > 50 J) and friction sensitivity (FS > 360 N), such as NTO, demonstrating their potential as insensitive, heat-resistant energetic materials. In addition, the effects of structures on sensitivity and thermal stability are studied using quantum chemical methods. This work is expected to prompt further research on energetic pyrazolone in molecular design and offers guidance for the development of new heat-resistant energetic materials.