N-Trinitroethylamino functionalization of nitroimidazoles: a new strategy for high performance energetic materials

Abstract

An N-functionalized strategy, including N-amination and N-trinitroethylamination, was utilized for the synthesis of nitroimidazole-based energetic materials, giving rise to a new family of highly insensitive N-aminonitroimidazoles and oxygen-rich N-trinitroethylaminonitroimidazoles with good to excellent properties. These new energetic materials were fully characterized by IR, ¹H, and ¹³C NMR, elemental analysis, and some high performance compounds were further confirmed by ¹⁵N NMR (4a, 4d, 6a, 6b, and 6d), as well as single crystal X-ray diffraction (6a and 6b). N-Functionalization of nitroimidazoles not only gives rise to the N-aminonitroimidazoles as impact insensitive and thermally stable materials (IS > 40 J; T_d: 144–308 °C), but also provides a series of N-trinitroethylaminoimidazoles, which have favorable densities (1.75–1.84 g cm⁻³), good detonation properties (P: 27.6–35.9 GPa; v_D: 7815–8659 m s⁻¹), and moderate thermal stabilities (136–172 °C). These properties are better than some known energetic compounds, such as TNT (P: 19.5 GPa; v_D: 6881 m s⁻¹) and TATB (P: 31.2 GPa; v_D: 8114 m s⁻¹), and are comparable to RDX (P: 35.0 GPa; v_D: 8762 m s⁻¹).