A Dynamic Covalent Organic Framework with Entangled 2D Layers.

Dynamic covalent organic frameworks (COFs) represent an emerging class of porous materials with an inherent structural flexibility. However, due to the challenges in their synthesis and structural characterization, research on dynamic COFs remains at an early stage and requires further exploration. Herein, we report the designed synthesis of a novel COF with entangled 2D layers that exhibits interesting dynamic behavior in response to organic vapor exposure. By employing the continuous rotation electron diffraction technique, we precisely resolved the crystal structures of the COF before and after vapor adsorption. Structural analysis revealed that the vapor-induced conformational changes, such as anthracene unit rotation, triggered layer adjustments and reduced entanglement angles, leading to significant pore structure alterations. This study not only introduces a new class of dynamic COFs but also provides a foundation for the rational design of entangled frameworks with structural flexibility for diverse applications.