Yunlu Li*, Mei Xue*, Bangjin Sun, Zhenlong Tu, Xinzhong Wang*

Cite this article: Chin. J. Struct. Chem., 2023, 42: 100002. DOI: 10.1016/j.cjsc.2022.100002

Publication date: April 15, 2023

Keywords: Melt-castable energetic materials; Non-covalent interactions; Fluorinated nitrobenzene; Chemical compatibility; Insensitivity

ABSTRACT

Searching for insensitive melt-castable energetic materials is still facing great challenges. In this work, we developed a promising strategy that is regulating the ratio of non-covalent interaction by fluorine atoms to regulate the melting point to develop new melt-castable energetic materials. Using this method, a highly symmetric 1,2-difluoro-4,5-dinitrobenzene (DFDNB) was synthesized in one step and fully characterized. DFDNB has a desirable melting point (83.2 °C), high decomposition temperature (> 400 °C), acceptable detonation properties (6786 m s−1, 21.5 GPa) but superior safety performance (> 40 J, > 360 N), and excellent chemical compatibility with 1,3,5-trinitro-1,3,5-triazine (RDX) that make it a promising insensitive melt-castable energetic material. A detailed study based on crystal stacking, electrostatic potential, and intermolecular weak interactions in DFDNB and its isomers or analogs demonstrates that non-covalent interactions including the C–F⋯H, N–O⋯H hydrogen bonding, and C–F⋯O halogen-like bonding play an important role in regulating the melting point.