Unveiling the Potential of Thiophene-Functionalized Porous Organic Polymers for Bromine Adsorption and Selective Separation from Iodine

Bromine is a significant environmental threat due to its corrosive nature and contribution to ozone layer depletion. It often coexists with iodine and forms interhalogen complexes (IBr), which require an effective and selective bromine adsorption strategy. Leveraging the electrophilic nature of bromine, we designed an electron-rich thiophene-based porous organic polymer (POF-2). This material exhibits exceptional efficiency for bromine adsorption (2.86 g g-1) and rapid uptake kinetic from aqueous solutions, driven by noncovalent charge transfer interactions. POF-2 also demonstrates selective capture of bromine from a bromine-iodine mixture in cyclohexane. The material's electron-rich sites exhibit a stronger orbital interaction with the σ* orbital of bromine compared to iodine, leading to the observed selectivity in cyclohexane.