An efficient synthetic method for cage-like energetic frameworks with high energy density and appropriate oxygen balance†

Organic cage-like 3D frameworks can serve as crucial skeletal structures for the development of prospective energetic materials owing to their high inherent density, symmetrical structure, and flexible design. Herein, we present an efficient synthesis method for all-bridge carbon-substituted polynitroheteroadamantanes and their structural isomers for the first time. A series of novel energetic compounds (1–5) containing five or six explosophoric groups with four distinct frameworks (adamantane, proadamantane, homonoradamantane and twistane) was synthesized. All the five compounds exhibited high density (ρ > 1.85 g cm⁻³) and excellent detonation performance (D > 8500 m s⁻¹, P > 34 GPa). In addition, they all possessed reasonable oxygen balance (OB_co > 10%), which was superior to that of the classical highly explosive RDX (OB_co = 0%). Furthermore, constructing the cage-like frameworks within two synthetic steps represented a significant advancement in the synthesis of cage-like compounds. This efficient synthetic method followed a concise route, exhibited time efficiency and possessed excellent molecule diversity of the raw material. These unique properties showed that cage-like frameworks have potential applications as high energy density materials.