A Fluorine-Functionalized 3D Covalent Organic Framework with Entangled 2D Layers

Constructing three dimensional (3D) covalent organic frameworks (COFs) through the entanglement of two dimensional (2D) nets is a promising but underdeveloped strategy. Herein, we report the design and synthesis of a fluorine functionalized 3D COF (3D-An-COF-F) formed by entangled 2D sql nets. The structure of 3D-An-COF-F was determined by the combination of continuous rotation electron diffraction technique and modelling based on the chemical information from real space. Interestingly, compared to the isostructural 3D-An-COF without F atoms, 3D-An-COF-F showed an improved CO₂ sorption ability and higher CO₂/N₂ selectivity. Our study not only demonstrated the generality of constructing 3D COFs with entangled 2D nets by introducing bulky groups vertically in planar building blocks, but also will expand the diversity of 3D COFs for various applications.