Nitrogen-rich prismane-based cage compounds: impact of pentazole substitution on detonation and explosive performance

Abstract

Context

This research explores the impact of systematic addition of pentazole group on the explosive properties of prismane-based compounds on hexanitroprismane and hexaminoprismane. Replacing the NO₂ and NH₂ groups with N₅ in prismane cage-based molecules enhances the material’s energy density and stability, leading to more powerful and stable explosives. The structure-property relationship of the designed molecules is studied using DFT approach. These cage-based compounds exhibit potential as high-energy density explosive compounds reaching up to the level of CL20. Systematic addition of pentazole ring in the prismane cage improves stability and heat of formation. Functionalizing prismane with one pentazole ring can improve the HOF by 300 to 400 kJmol⁻¹. The impact of the number of pentazole rings on density is opposite in nature in -NO₂ and -NH₂ containing sets of molecules. The same trend is observed in the values of D, P, and Q of both sets of molecules as the number of pentazole group increased in the prismane. Insertion of a single pentazole ring in prismane for the nitro group substituted molecules has a better impact on improving the impact sensitivity. Pentazole group substitution enhances the energetic properties of prismane-based high energy density compounds, offering a promising avenue for the development of novel, high-performance explosives with tailored detonation characteristics.

Methods

Density functional theory (DFT) using Gaussian 16 software was used for all quantum chemical calculations. The optimization of the geometry of the designed compounds is performed at two different levels, e.g., B3LYP/6–311 + + G(d,p) and B3PW91/6-31G(d,p). Molecular surface and other properties are visualized using GaussView 6.0 software. The heat of formation (HOF) of the molecules is estimated using isodesmic reactions. The multiwfn program was used for the calculation of molecular surface properties.