Methyl nitrate energetic compounds based on bicyclic scaffolds of furazan-isofurazan (isoxazole): syntheses, crystal structures and detonation performances

Improvement of Thermal Stability and Sensitivity of Furazan/Furoxan via Ring Closure Generation of Vicinal Amino-Nitro Structure

Energetic compounds that display high thermal stability and insensitivity properties are essential for applications in mining, gas drilling, etc. In this work, a novel 4-nitro-5-aminoisoxazole energetic moiety oriented to enhance thermal stability and decrease the sensitivity of furazan/furoxan analogues was constructed. The generation of a vicinal amino-nitro structure can be effectively realized in one step by a green and mild ring-closing reaction of nitroacetonitrile potassium salt with chloroxime in aqueous solution. Seven new energetic compounds with good thermal stability (Td: 155.8∼270.3 °C) and low sensitivity (IS: >40 J, FS: 96∼192 N) were synthesized. The nitro-furazan and isoxazole combined product exhibits the advantages of both skeletons, with energetic properties (Dv = 8350 m s-1, P = 30.1 GPa) that may find value in insensitive energetic materials. This strategy promises to achieve a balance between energy levels and stability of furazan/furoxan analogues and offers a new way for the design and synthesis of highly thermally stable compounds that meet special applications.