Imidazolium‐Functionalized Chemically Robust Ionic Porous Organic Polymers ( i POPs) toward Toxic Oxo‐Pollutants Capture from Water

Fabricating new and efficient materials aimed at containment of water contamination, in particular removing toxic heavy metal based oxo‐anions (e. g. CrO 4 2− , TcO 4 − ) holds paramount importance. In this work, we report two new highly stable imidazolium based ionic porous organic polymers ( i POPs) decorated with multiple interaction sites along with electrostatics driven adsorptive removal of such oxo‐anions from water. Both the i POPs (namely, i POP‐3 and i POP‐4) exhibited rapid sieving kinetics and very high saturation uptake capacity for CrO 4 2− anions (170 and 141 mg g −1 for i POP‐3 and i POP‐4 respectively) and ReO 4 − (515.5 and 350.3 mg g −1 for i POP‐3 and i POP‐4 respectively), where ReO 4 − anions being the non‐radioactive surrogative counterpart of radioactive TcO 4 − ions. Noticeably, both i POPs showed exceptional selectivity towards CrO 4 2− and ReO 4 − even in presence of several other concurrent anions such as Br − , Cl − , SO 4 2− , NO 3 − etc. The theoretical binding energy calculations via DFT method further confirmed the preferential interaction sites as well as binding energies of both i POPs towards CrO 4 2− and ReO 4 − over all other competing anions which corroborates with the experimental high capacity and selectivity of i POPs toward such oxo‐anions.