Mortise-and-Tenon Molecular Joint Covalent Organic Frameworks With Tunable Topology for Photothermal-Catalytic Cross-Dehydrogenative Coupling.

Abstract

The controllable regulation of dimensionality and interpenetration in covalent organic frameworks (COFs) is crucial for optimizing photocatalytic performance, yet the translation of 3D COFs from structural construction to functional customization remains challenging. Here, we successfully designed a series of mortise-and-tenon molecular joint COFs by rationally engineering a twisted tetraphthaldehyde ligand bearing π-conjugated "clips". Stepwise extension of the "clips" enables topological evolution from 2D to twofold interpenetrated 3D, and ultimately to noninterpenetrated 3D structure. Notably, DHP-CuPor-COF with noninterpenetrated 3D structure amplifies light-harvesting efficiency and substrate accessibility, enabling superior photothermal conversion and catalytic performance over its 2D and twofold interpenetrated 3D counterparts. To the best of our knowledge, it delivers highly efficient photothermal-catalytic C─X (X = O, S) bond formation for selective transformation of phenolic compounds via cross-dehydrogenative coupling (CDC) reactions (conv., >90% and yield, >80%), markedly outperforming conventional thermal catalysis. The high efficiency arises from the synergistic of open 3D channels, abundant Cu-porphyrin active sites and strong photothermal effect. This work provides an innovative strategy to tune the topological chemistry of COFs for advanced photocatalytic applications.