Structure–property relationships of energetic nitrogen-rich salts composed of triaminoguanidinium or ammonium cation and tetrazole-based anions

Abstract

Density functional theory and volume-based thermodynamics calculations have been performed to study the crystal densities, heats of formation (HOFs), energetic properties, and thermodynamics of formation for a series of ionic salts composed of triaminoguanidinium or ammonium cations and tetrazole-based anions. Substitution with NF2, CH2NF2, CF2NF2, or C(NO2)2NF2 groups increased the densities of the salts. The densities of the tetrazole-based salts are affected not only by different substituents but also by different cations. The CN or N3 groups are effective substituents for increasing the HOFs of the salts. The triaminoguanidinium cation is more effective than the ammonium cation for increasing the HOF of the tetrazole-based salts. Substitution with NO2, NF2, or C(NO2)2NF2 groups enhances the explosive properties of the salts. The thermodynamics of formation of the salts reveal that all of the tetrazole-based salts with the triaminoguanidinium or ammonium cation could be synthesized using the proposed reactions. Our calculated methods provide a straightforward and inexpensive route for screening a large number of potentially energetic ionic salts.