Toward Pore Size-Selective\nPhotoredox Catalysis Using\nBifunctional Microporous 2D Triazine-Based Covalent Organic Frameworks

The design and synthesis\nof photoactive metal-free 2D\nmaterials\nfor selective heterogeneous photoredox catalysis continue to be challenging\ndue to issues related to nonrecyclability, and limited photo- and\nchemical stability. Herein, we report the photocatalytic properties\nof a triazine-based porous COF, <b>TRIPTA</b>, which is found\nto be capable of facilitating both SET (single electron transfer)\nfor photocatalytic reductive debromination of phenacyl bromide in\nabsence of oxygen and generation of reactive oxygen species (ROS)\nfor benzylamine photo-oxidation in the presence of oxygen, respectively,\nunder visible light irradiation. Inspired by the latter results, we\nfurther systematically investigated different-sized benzylamine substrates\nin this single-component reaction and compared the results with an\nanalogous COF (<b>Micro-COF-2</b>) exhibiting a larger pore\nsize. We observed a marked improvement in the conversion of larger-sized\nsubstrates with the latter COF, thereby demonstrating angstrom-level\npore size-selective photocatalytic activity of COFs.