A few insensitive energetic nitrogen rich compounds composed of substituted azoles and 3,5-dinitrobenzoic acid: Synthesis, characterization, physicochemical, detonation properties and pyrolytic products

Abstract

Hydrogen bonded proton transfer crystals 1–4 were synthesized, using substituted azoles and 3,5-dinitrobenzoic acid, in a ratio 1:1 and ethanol as solvent at room temperature. The structure elucidation for the synthesized energetic crystals was carried out using spectral techniques such as, IR, 1H, and 13C NMR spectroscopy. The formation of proton transfer complexes occurred due to the transfer of lone pair of electrons from the donor azoles such as 3-nitropyrazole, 1,2,4-triazole, 3-amino-1,2,4-triazole, and 5-aminotetrazole to the acceptor 3,5-dinitrobenzoic acid through N+-H…O− type of hydrogen bond and was ascertained by X-ray crystallographic and proton NMR studies. Mathematical calculations propounded by various scientists are used to determine the explosive properties. The thermal stability was carried out using DSC-TGA studies. Sensitivity parameters were also calculated for the synthesized compounds. The results indicated that the proton transfer complexes are more stable, insensitive to impact, have high energetic parameters and thus classified into the category of High-energy-density materials (HEDMs). The high nitrogen content compounds gives out nitrogen gas (N2) as major detonation product, which will burn cleanly, producing less carbon monoxide and paving the way for new generation of environmentally compatible energetic materials.