Hydrogen-bonded supramolecular polymer networks for effective removal of perchlorate in water via clustered hydrogen-bonding

Perchlorate is a toxic, explosive, and water-soluble pollutant but while efficient and low-cost removal of ClO₄^- from water is an important challenge, suitable methods for precipitation of ClO₄^- from water are underdeveloped. Here, we demonstrate a hydrogen-bonded supramolecular polymer network crystal (HBPC) for efficient complexation of ClO₄^-. The HBPC network is constructed by an A,A'-bis-pyridyl-hydrazone-phenyl conjugate-functionalized pillar[5]arene (PYP5), which self-assembles via the formation of clustered hydrogen-bonds. Two-pyridyl-hydrazone moieties provide coordination sites while the eight ethoxyl moieties on the pillar[5]arene enable multiple hydrogen bonding motifs to tightly bind to the ClO₄^-. The HBPC network therefore adsorbs ClO₄^- ions and facilitates the separation of these ions from water.