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Potential Insensitive and High-Energy Materials Based on a Pyrazole-Triazine-Oxadiazole Skeleton
Zhi Li1, Xiangyu Niu1, Caijin Lei1
1School of Chemistry and Chemical Engineering, Nanjing University of Science and Technology, Xiaolingwei 200, Nanjing 210094, P. R. China.
Organic Letters
|April 13, 2026
Summary
New pyrazole-triazine-oxadiazole compounds offer enhanced thermal stability and detonation performance. These heat-resistant materials show promise as safer, high-energy alternatives to existing explosives like HNS and RDX.
Area of Science:
- Organic Chemistry
- Materials Science
- Energetic Materials
Background:
- Development of heat-resistant compounds with low sensitivity and high stability is crucial for advanced applications.
- Existing high-performance explosives like HNS and RDX have limitations in thermal stability or sensitivity.
Purpose of the Study:
- To synthesize novel compounds based on the pyrazole-triazine-oxadiazole skeleton.
- To evaluate the thermal stability, sensitivity, and detonation performance of the synthesized compounds.
- To explore potential replacements for conventional heat-resistant explosives.
Main Methods:
- Construction of the pyrazole-triazine-oxadiazole skeleton via cyclization of a hydroximoylamine group.
- Synthesis of target compounds including 3-(5-amino-1,2,4-oxadiazol-3-yl)-4,7-diamino-8-nitropyrazolo-[5,1-c][1,2,4]triazine (4) and 7-amino-3-(5-amino-1,2,4-oxadiazol-3-yl)-8-nitro-1H-pyrazolo[5,1-c][1,2,4]triazin-4-one (10).
- Characterization of properties including thermal stability (Td) and detonation velocity (Dv).
Main Results:
- Compounds 4 and 10 exhibited high thermal stability (Td = 343 °C and 325 °C) and superior detonation performance (Dv = 8317 m·s⁻¹ and 7937 m·s⁻¹) compared to HNS.
- Oxidation of compound 4 unexpectedly yielded a ring-opened product (6).
- A high-energy compound, 3-(5-amino-1,2,4-oxadiazol-3-yl)-7-[(nitroamino)]-8-nitro-1H,4H-pyrazolo[5,1-c][1,2,4]triazin-4-one (8), was synthesized and showed comparable detonation velocity to RDX but with improved sensitivity and thermal stability.
Conclusions:
- The synthesized pyrazole-triazine-oxadiazole derivatives demonstrate significant potential as advanced heat-resistant explosives.
- Compounds 4 and 10 are promising alternatives to HNS due to their enhanced thermal and detonation properties.
- Compound 8 presents a viable high-energy explosive option with a favorable balance of performance and safety characteristics.
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