A novel energetic cocrystal composed of CL-20 and 1-methyl-2,4,5-trinitroimidazole with high energy and low sensitivity

Abstract

A cocrystal explosive comprising 2,4,6,8,10,12-hexanitro-2,4,6,8,10,12-hexaazaisowurtzitane (CL-20) and 1-methyl-2,4,5-trinitroimidazole (MTNI) (molar ratio, 1:1) was synthesized. The structure of the cocrystal was characterized by single-crystal X-ray diffraction. Its structure was further determined by powder X-ray diffraction, infrared spectroscopy and differential scanning calorimetry which showed that its morphology was different from the morphology of the mechanical mixture of two raw materials. The decomposition temperature of the cocrystal is lower than that of CL-20 and MTNI. The calculated detonation performance is slightly lower than that of HMX, but the cocrystal has excellent sensitivity performance relative to that of CL-20, even lower than that of RDX. These features make this cocrystal ideal to be used in applications with low-sensitivity requirements.

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

“…Cocrystal technology has emerged as a promising strategy in recent years for tuning the properties of EMs. − Energetic cocrystals are typically formed by combining two energetic molecules in the same lattice through noncovalent bonding, such as hydrogen bonds, π-stacking, and van der Waals forces. − Many energetic cocrystals have been prepared and reported in recent years, such as CL-20-based cocrystals, − BTF (benzotrifuroxan)-based cocrystals, , and TNB (1,3,5-trinitrobenzene)-based cocrystals. − These energetic cocrystals significantly alter the performances of EMs, including their physical and chemical properties, safety, and detonation properties, due to the formation of new cocrystal structures. − Currently, energetic cocrystals are considered an effective method for synthesizing new EMs and simultaneously tuning their properties. However, the development of energetic cocrystals still faces significant challenges, such as selecting suitable coformers and predicting their formation, mainly due to the lack of sufficient energetic coformers and rational prediction methods.…”

“…However, its practical application has been limited by its poor safety . To address these issues, researchers have successfully synthesized a range of CL-20-based energetic cocrystals, including CL-20/nitrobenzene cocrystals and CL-20/nitroazole cocrystals. − The formation of cocrystals effectively reconciles the contradiction between the energy and safety of CL-20. Among the exiting CL-20-based cocrystals, the CL-20/nitroazoles cocrystals tend to have a higher density than CL-20/nitrobenzene cocrystals, such as CL-20/1,4-DNI cocrystals .…”

“…Fortunately, several energetic cocrystals formed by cocrystallizing CL-20 with isomeric explosive molecules have been reported recently, and these isomeric coformers are illustrated in Scheme . − ,, Isomeric explosive molecules, a class of important molecules with the same chemical formulas and similar structures, have the potential to form cocrystals with suitable explosive host molecules. Therefore, using isomeric molecules as new coformers can enhance the quantity and variety of coformers and facilitate the screening of cocrystals in the cocrystal design process.…”

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.…”

Physicochemical and thermodynamic evaluation of ibrutinib cocrystal formation with a long-chain fatty acid

“…[5][6][7][8] Cocrystallization offers great potential to address many of the material property concerns of energetic materials such as explosives, propellants, and pyrotechnics by altering the chemical stability, sensitivity to shock, and oxygen balance compared to individual components. [9][10][11] Zongwei and his coworkers generated novel energetic-energetic cocrystals composed of 2,4,6,8,10,12-hexanitrohexaazaisowurtzitane (HINW) and benzotrifuroxan (BTF) which is more powerful than HINW alone. 12 Utilization of cocrystals for improving pharmaceutical properties has been by far the most widely reported research category among cocrystals.…”