Carbazole–triazine based donor–acceptor porous organic frameworks for efficient visible-light photocatalytic aerobic oxidation reactions

Abstract

We report the synthesis of a series of carbazole–triazine based donor–acceptor (D–A) POFs and their photocatalytic activities for aerobic oxidation reactions. The simultaneous introduction of a carbazole-based electron donor and a triazine-based electron acceptor in D–A POFs stabilizes the charge transfer state and enables an efficient triplet–triplet energy transfer to generate ¹O₂. Meanwhile, systematic variation of the D–A distance results in the tunable photoredox properties and consequently the efficiency for generation of reactive oxygen species (ROSs). Upon visible light excitation, all three D–A POFs exhibit excellent capability to promote three aerobic oxidations: sulfide oxidation, oxidative amine coupling, and Mannich reactions. This systematic study validates the design principle of D–A POFs as high-performance photo-oxidation catalysts with wide substrate scope and excellent stability and recyclability.