Symmetry-Shearing Chemistry Enabled Interdigitated 2D Covalent Organic Frameworks with Interlayer Mortise-and-Tenon Interlocks for Efficient Photocatalytic CO2 Fixation.

Abstract

The development of porous organic frameworks with innovative architectures and enhanced structural stability is a central challenge in reticular chemistry. Herein, we report the rational design and synthesis of interdigitated two-dimensional (2D) covalent organic frameworks (ID-COFs) constructed via symmetry-shearing chemistry, incorporating porphyrin-based light-harvesting units and catalytically active magnesium centers into crystalline, porous frameworks. Unlike traditional strictly planar π-π stacked 2D COFs, the resulting ID-COFs feature unique cage-like cavities and mortise-and-tenon interlocked architectures, significantly enhancing both the accessibility of catalytic sites and structural stability. Notably, ID-COF-Mg exhibits excellent photocatalytic performance for the cycloaddition of CO2 and epoxides under mild conditions. Comprehensive theoretical calculations further reveal that the Mg-porphyrin active centers serve as key electron donors, effectively facilitating the formation of ring-opening intermediates from epoxides. This work not only provides a novel strategy for constructing porous organic frameworks through covalent-supramolecular codriving but also offers an advanced photocatalyst for CO2 cycloaddition reactions.