Potential energetic salts of 5,5′-methylenedi(4H-1,2,4-triazole-3,4-diamine) cation: Synthesis, characterization and detonation performance

1,2,3-Triazole and 1,2,4-triazole have been vigorously used in energetic materials research. Among these two, 1,2,4-triazole has been a widely used backbone in designing new energetic materials with improved performance. This study showed the synthesis of nitrogen-enriched dianionic energetic salts (3–6) based on methylene bridged 3,4-diamino-1,2,4-triazole combined with nitrate, perchlorate, picrate, and azide anions. Structures of 5,5′-methylenedi(4H-1,2,4-triazole-3,4-diamine) and its salts 4 and 5 were confirmed by single-crystal X-ray diffraction studies, showing a strong hydrogen-bonding network owing to the presence of –NH2 groups, numerous oxygen and nitrogen atoms in the structure. The DSC results indicate acceptable thermal stabilities with the observed decomposition temperatures over 180 °C. All the compounds are dense (1.70–1.86 g cm−3) and exhibit reasonable detonation velocities (7.49–8.99 km s−1) and pressures (21.9–28.2 GPa). Interestingly, salt 6 possess detonation velocity comparable to that of RDX. These properties illustrate that incorporating a methylene bridge in a 3,4-diamino-1,2,4-triazole ring can effectively support the progress of mechanically insensitive and thermally stable energetic compounds in future research.