Modular Synthesis of High Performance Energetic Biocidal Bicyclic Compounds Derivated from Iodopyrazoles

Modular synthesis can combine different functional modules to flexibly regulate comprehensive properties and study the diversity of compounds. This study established a modular bicyclic synthesis strategy of combining polynitro energetic module with iodine-containing biocidal module. Compounds 1-6 with high iodine content (48.72-69.56 %) and high thermal stability (T_d: 172-304 °C) were synthesized and exhaustively identified. By modular synthesis, the detonation properties and gas-production of 3-6 improved greatly expanding their biocidal efficacy and maintained the iodine atomic utilization of iodine-containing module. Notably, 4,5-diiodo-3,4',5'-trinitro-1,3'-bipyrazole (5) and 3,5-diiodo-4,4',5'-trinitro-1,3'-bipyrazole (6) exhibit high detonation velocities (D: 5903 m s^-1, 5769 m s^-1, respectively) and highest gas production of 212.85 L mol^-1 and 217.66 L mol^-1 after decomposition. This study diversifies polyiodio-nitro compounds, and also inspire the implementation of similar synthesis strategies to provide family-level synthetic solutions to energetic biocidal materials.