A domino reaction from a sensitive azide: the impact of positional isomerism on chemical reactivity featuring ortho azido/nitro substituted derivatives

• Published in: Journal of materials chemistry. A, Materials for energy and sustainability Materials for energy and sustainability, 2024-04, Vol.12 (16), p.9546-9551
• Main Authors: Thaltiri, Vikranth, Singh, Jatinder, Staples, Richard J., Shreeve, Jean'ne M.
• Format: Article
• Language: English
• Subjects: Cascade chemical reactions; Chemical reactions; Detonation; External stimuli; Hexahydro-1,3,5-trinitro-1,3,5-triazine; Metals; Nitrogen; Reactivity; Salts; Sensitivity; Single crystals; Substitution reactions; Tetrazoles; Thermal stability
• ISSN: 2050-7488; 2050-7496
• DOI: 10.1039/D4TA00633J

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 °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.