Theoretical Calculation of Cocrystal Components for Explosives: A Similarity Function of Energetic Supramolecules

Abstract

Coordinating energy and sensitivity of explosives is a common challenge in the research field of energetic materials. Cocrystallization technology has alleviated the conflict between the energy and safety of high-energy explosives to a certain extent and has aroused the interest of researchers. Cocrystal component screening is the primary challenge in the preparation of energetic cocrystals. In this study, we developed a similarity function for explosives based on the molecular structure, polarity, and solubility. By calculating the similarity between 1,3,5,7-tetranitro-1,3,5,7-tetrazocane (HMX)- and 2,4,6,8,10,12-hexanitro-2,4,6,8,10,12-hexaazaisowurtzitane (CL-20)-based cocrystal explosive components, the applicability of the similarity function was demonstrated, and six possible energetic cocrystal component formulations were preferentially selected from 18 new energy-containing ligands, which are HMX/3,6-diamino-1,2,4,5-tetrazine-1,4-dioxide (DATAD), HMX/1,3,3-trinitroazetidine (TNAZ), HMX/4-amino-3,5-dinitro-pyrazole (LLM-116), HMX/2-oxo-1,3,5-trinitro-1,3,5-triazacyclohexane (Keto-RDX), CL-20/TNAZ, and CL-20/Keto-RDX, respectively. The energetic supramolecular similarity function can achieve rapid screening of cocrystal explosive components and guide the experimental synthesis of energetic cocrystals.

Thermally Stable and Insensitive Energetic Cocrystals Comprising Nitrobarbituric Acid Coformers

“…Azole-based energetic cocrystals have also been reported, such as 5,5′-dinitro-3,3′-bi-1,2,4-triazole (DNBT) with 5-amino-3-nitro-1,2,4-triazole (ANTA) and 3,6-dinitropyrazolo­[4,3- c ]-pyrazole (DNPP) with 3,4-dinitropyrazole (3,4-DNP), which adopts a 2:1 molar ratio with high crystallographic densities varying from 1.858 to 1.889 g cm –3 . Recently, several cocrystals have been reported based on CL-20, BTF, and HMX with different coformers. − In 2022, Bellas and Matzger reported cocrystals based on an energetic oxidizing salt to achieve a melt-castable energetic material . These studies have emphasized that cocrystallization is a valuable technique for enhancing the performance of explosives and pioneered the way for tailored energetic materials and further motivated the exploration of a library of energetic components for cocrystallization and rational design.…”