Two Novel CL-20 Cocrystals with Different Performances Obtained by Molecular Similarity Combined with Hydrogen Bonding Pairing Energy: An Effective Strategy to Design and Screen Energetic Cocrystals

The development of energetic cocrystals currently faces a significant challenge in effectively screening cocrystals. In this study, a simple and effective method was utilized to evaluate the possibility of cocrystal formation between CL-20 (2,4,6,8,10,12-hexanitrohexaazaisowurtzitane) and azole isomers. This method combined molecular similarity with the hydrogen bonding pairing energy. As a result, two novel CL-20 energetic cocrystals, namely, (1) 1:2 CL-20/3,4-MDNP (1-methyl-3,4-dinitropyrazole) and (2) 2:1 CL-20/3,5-MDNP (1-methyl-3,5-dinitropyrazole), were successfully prepared through solvent evaporation. It is worth noting that cocrystal 2 exhibits desirable safety and detonation properties, making it a potential high-energy insensitive explosive substitute for RDX (1,3,5-trinitro-1,3,5-triazacyclohexane). Additionally, this work provides a simple and feasible method for rapidly screening energetic cocrystals and simultaneously offers further insights into the design and formation mechanism of energetic cocrystals.