Stable 2D Heteroporous Covalent Organic Frameworks for Efficient Ionic Conduction

Two-dimensional (2D) covalent organic frameworks (COFs) feature open and ordered one-dimensional column nanochannels which offer immense possibilities for incorporation of various guests for specific functions. However, the relatively low chemical stability of most COFs originating from the dynamic covalent linkages hinders their practical application. In this work, a highly crystalline and heteroporous dibenzo[g,p]chrysene-based COF (DBC-2P) was synthesized and served as a host material for ionic conduction. DBC-2P exhibits excellent stability both in strong acid and base due to the large conjugated DBC-based knot that reinforces the interlayer interactions. Subsequent encapsulation of linear polyethylene glycol (PEG) and PEG-LiBF₄ salt into the nanochannels of DBC-2P affords a hybrid material with a high ionic conductivity of 2.31×10^-3 S cm^-1 . This work demonstrates an efficient post-synthetic strategy for the development of new COF-polymer composites with intriguing properties.