Imidazole‐Linked Covalent Organic Polymers: Sustainable Materials for Greenhouse Gas Capture, Iodine Vapor Adsorption, and CO 2 Cycloaddition

Abstract

Addressing the dual challenges of radioiodine pollution and rising CO 2 emissions, we report a series of five robust imidazole‐based covalent organic polymers ( iCOP1–5 ) synthesized via a microwave‐assisted, one‐pot [3 + 2] cyclopentannulation reaction. The design strategy leverages a nitrogen‐rich tetra‐ethynyl imidazole synthon ( DIA ) and diverse dibrominated polycyclic aromatic hydrocarbons (PAHs) ( 2–6 ), enabling efficient heteroatom incorporation and extended π‐conjugation. Comprehensive porosity analysis using argon sorption measurements revealed high surface areas of up to 545 m 2  g −1 and average pore volumes of 0.33 cm 3  g −1 . The presence of nitrogen heteroatoms and PAH backbones facilitates strong guest–host interactions, leading to outstanding CO 2 uptake of 221 mg g −1 at 273 K under ambient pressure. Remarkably, these materials also demonstrated exceptional iodine vapor adsorption capacities, reaching up to 3.25 g g −1 . Furthermore, iCOP1–5 function as highly active heterogeneous catalysts for the cycloaddition of CO 2 with styrene oxide, delivering cyclic carbonate (4‐phenyl‐1,3‐dioxolan‐2‐one) with excellent yields (up to 97%) and selectivity. The polymers exhibit excellent thermal and chemical stability and retain structural integrity over multiple adsorption–desorption cycles, highlighting their potential as multifunctional platforms for gas capture and catalytic CO 2 valorization.