Abstract
This study highlights for the first time the impact of positional isomerism on chemical reactivity which involves a domino reaction, salt formation, cyclization, and nucleophilic substitution. The unprecedented reactivity occurs upon treating sensitive 5-azido-3,4-dinitropyrazole (1) with nitrogen rich bases. This results in the development of the first examples of fused catenated N-5 pyrazolo[1,5-d]tetrazole-based energetic salts. The compound structures of 1, 2, and 3 were obtained by single-crystal analysis. Compounds 2 (D-v: 9202 m s(-1); P: 32.08 GPa) and 3 (D-v: 8749 m s(-1); P: 31.26 GPa) displayed excellent detonation properties (calculated) and good sensitivities (IS >= 20 J; FS >= 240 N), which are comparable to RDX. The thermal stability of compound 2 (185 degrees C) further suggests its significant potential use as a secondary explosive. Compound 1 exhibits high detonation properties (D-v: 9023 m s(-1); P: 35.3 GPa) and sensitivity to external stimuli (IS: 8 J; FS: 80 N), indicating it has potential as a metal-free primary explosive.