N-Methylene-C bridged tetrazole and 1,2,4-triazole energetic salts as promising primary explosives

Abstract

The development of energetic materials with acceptable sensitivity and high energy is a crucial target in explosive research. Primary explosives serve as special metastable energy materials extensively employed in military and civilian activities. Numerous studies are focused on identifying new candidates for this category. However, these newly developed primary explosives often suffer from drawbacks such as the inclusion of heavy metal ions or azide groups, which can lead to environmental concerns and compromised safety levels. In this study, a series of high-energy salts based on nitrogen-rich heterocycles linked by N-methylene-C, which are free from heavy metal ions and azide groups, were designed and synthesized. The molecular structures of the involved compounds were confirmed using single-crystal X-ray diffraction. Additionally, Hirshfeld and independent gradient model analyses of these compounds were conducted to investigate the intermolecular interactions and elucidate the relationship between the interactions and the molecular stabilities. Finally, the thermal stability, energetic properties and electrical initiation properties of compounds 4, 6·2H₂O, and 7 were investigated and the results indicate that these compounds are potential primary explosives.