Molecule-guided synthesis of conjugated microporous polymers with imidazole derivative units for efficient capture of volatile iodine

Radioactive iodine as a harmful fission product can be released in the environment and bring unpredictable risks to humans even at trace. Porous organic materials with flexible units and high porosity are potential adsorbents for iodine removal. Herein, four molecule-guided conjugated microporous polymers (ImCMPs) with imidazole derivative units were synthesized by Sonogashira-Hagihara coupling reactions and used for the capture of iodine in vapour and solution. With the permanent nanopores, conjugated networks and N-rich units, ImCMPs all show higher uptakes of volatile iodine than the corresponding monomers which have strong adhesion ability to iodine. Remarkably, the vapour iodine uptake of ImCMP-1 up to 2.36 g g−1 at 80 °C, and ImCMP-1 with privileged imidazolyl unit and highest specific surface area possesses the exceptional potential for encasing iodine. This result provides a persuasive approach for design synthesis of excellent adsorbents.