Covalent Organic Frameworks with Record Pore Apertures

The pore apertures dictate the guest accessibilitiesof the pores, imparting diverse functions to porous materials. It ishighly desired to construct crystalline porous polymers withpredesignable and uniform mesopores that can allow large organic,inorganic, and biological molecules to enter. However, due to theease of the formation of interpenetrated and/or fragile structures,the largest pore aperture reported in the metal-organic frame-works is 8.5 nm, and the value for covalent organic frameworks(COFs) is only 5.8 nm. Herein, we construct a series of COFs withrecord pore aperture values from 7.7 to 10.0 nm by designingbuilding blocks with large conformational rigidness, planarity, andsuitable local polarity. All of the obtained COFs possess eclipsedstacking structures, high crystallinity, permanent porosity, and highstability. As a proof of concept, we successfully employed these COFs to separate pepsin that is similar to 7 nm in size from its crudes and toprotect tyrosinase from heat-induced deactivation

Automated summary

In this study, a series of COFs with different pore apertures were successfully constructed using designed building blocks, demonstrating their potential applications in enzyme separation and protection.