Topological regulation of covalent organic frameworks for boosting photoredox and nickel catalysis

초록

Covalent organic frameworks (COFs) demonstrate significant promise in metallaphotocatalysis due to their tailorable porosity and optoelectronic properties. While existing research predominantly focuses on embedding catalytically active sites through monomer design and linkage regulation, the critical impact of framework topology-a higher-order structural parameter-on catalytic performance remains underexplored. Herein, we introduce the first study elucidating the paramount role of topology in sp2 carbon-conjugated COF-based metallaphotoredox catalysis for C-N, C-P, and C-O cross-coupling reactions. Novel kgm and sql topoisomers-perylene-based (PrCN) and pyrene-based (iCN and CN) COFs, respectively-were synthesized via Knoevenagel condensation and subsequently coordinated with nickel to yield catalysts (NiCN, iNiCN, and NiPrCN). Remarkably, the kgm-topology NiPrCN catalyst exhibited significantly enhanced coupling efficiency and stability compared to sql counterparts, enabling efficient late-stage modifications of bioactive molecules. This superior synergy stems from its optimized mass transport/charge transfer efficiency inherent to the kgm architecture. Our findings underscore topology engineering as a pivotal strategy for optimizing photocatalytic performance in cooperative metallaphotocatalysis.

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