Substituent Effects on Crystal Engineering of DNBT-Based Energetic Cocrystals: Insights from Multiscale Computational Analysis

TL;DR

This paper explores how substituents affect the crystal structure and stability of DNBT-based energetic cocrystals using computational methods.

Contribution

The study provides new insights into substituent effects on crystal engineering and stability of DNBT-based energetic materials.

Findings

DNBT cocrystals show weak C-H⋯O hydrogen bonds and NO2-π stacking interactions that stabilize the lattice.

PA/DNBT has the highest binding energy, leading to greater stability and lower impact sensitivity.

Substituents reduce impact sensitivity while maintaining balanced detonation performance in DNBT cocrystals.

Abstract

The substituent effects on crystal stacking topology and stability of the 5,5-dinitro-2H,2H-3,3-bi-1,2,4-triazole (DNBT) and its three energetic cocrystals with 1,3,5-trinitrobenzene (TNB), 2,4,6-trinitrotoluene (TNT), and picric acid (PA) were systematically investigated through combined density functional theory (DFT) calculations and classical molecular dynamics (MD) simulations. The interaction mechanism and detonation performance of the three energetic cocrystals were implemented to the electrostatic potential (ESP), Hirshfeld surface analysis, radial distribution function (RDF), binding energy, and detonation parameters. In contrast to N-H⋯O interactions in DNBT, three cocrystals exhibited more distinctly weak C-H⋯O intermolecular hydrogen bonds and NO2-π stacking interactions to stabilize the lattice. Notably, the highest binding energy of PA/DNBT shows the largest stability and lowest impact sensitivity is related to the more intermolecular interactions. Although the introduction of substituents slightly affects the crystal density of DNBT crystals, it significantly reduces the impact sensitivity. Moreover, the balanced detonation performance and impact sensitivity of DNBT-based cocrystals make it a candidate to expand the applications of DNBT crystals. These findings contribute to a broadened understanding of construction and design strategies for the energy release mechanisms of energetic compounds with the azoles ring family.

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