Rational Conversion of Imine Linkages to Amide Linkages in Covalent Organic Frameworks for Photocatalytic Oxidation with Enhanced Photostability

Graphical The amide linked COFs (Am-COF-T and Am-COF-B) prepared through post-synthetic modification, exhibited excellent photocatalytic performance for oxidation of thioethers and coupling of benzylamines with superior stability. Covalent organic frameworks (COFs) and their applications in photocatalysis have been extensively studied, but the instability of imine-linked COFs is an important factor limiting their performance. In this work, two imine-linked COFs were successfully converted to amide-linked COFs through post synthetic modification (PSM). The oxidized COFs presented lower binding energy to O 2 , exhibited higher photocatalytic activity for oxidation of thioethers and coupling of benzylamines with excellent stability. The present work can serve as a reliable reference for the development of novel highly active and stable COF-based photocatalysts.