Controlled Assembly of [3+6] and [4+8] Porous Organic Cages for Rapid Removal of Iodide from Water

Abstract

Research into controlling the self-assembly of discrete porous organic cages (POCs) with specific geometries and functions is difficult, but important for understanding their structure-property relationship, as well as self-assembly behavior in supramolecular chemistry. Herein, we report the self-assembly of two POCs based on the same tetraformyl-functionalized calix[4]resorcinarene (C4RACHO) and 2,4-diaminophenol dihydrochloride (DAP) organic building blocks, including a [3+6] triangular prism (CPOC-201-OH) and a [4+8] square prism (CPOC-401-OH), as determined by single X-ray crystallographic analysis. Both POCs exhibit large intrinsic cavities, rich oxygen sites, and high porosity with Brunauer–Emmett–Teller (BET) specific surface areas up to 966 m²·g^–1. Owing to such virtues, both cages can effectively capture iodine in aqueous media with removal rate > 99% within 2 min.