Construction of Hydrazone-Linked Macrocycle-Enriched Covalent Organic Frameworks for Highly Efficient Photocatalysis

Covalent organic frameworks (COFs) are an emerging class of crystalline porous materials with tailor-made functionalities for improved photocatalytic activity. However, limited choice of building blocks greatly restricts the photochemical performance and application scope of COFs in photocatalysis. Herein, a covalent hybridization approach is reported to address these issues by knitting rigid macrocyclic struts, namely, pillararenes, into the extended network of COFs. Varying different ratios of pillararenes with unique conformations and electron-rich cavities can not only generate a confined molecular space for exciton migration and carrier transport but also create new interfaces to interplay with photogenerated charge carriers, leading to high performance in promoting efficient oxidation of amines to imines. This work paves the way for constructing macrocycle-derived COFs and provides a promising molecular platform for photocatalysis through predesign and functionalization of the pore surface.

Automated summary

Covalent organic frameworks (COFs) are emerging porous materials with tailor-made functionalities for improved photocatalytic activity. This study reports a covalent hybridization approach of integrating rigid macrocyclic struts (pillararenes) into the extended network of COFs, leading to enhanced photochemical performance. It provides a new strategy for constructing macrocycle-derived COFs and demonstrates their potential in efficient catalytic reactions.