Supramolecular Alternating Donor–Acceptor Assembly toward Intercalated Covalent Organic Frameworks

Abstract

Conventionally, <i>z</i>-direction modulation of two-dimensional covalent organic frameworks (2D-COFs) is difficult to achieve because they rely on spontaneous π-π interactions to form 3D architectures. Herein, we report a facile construction of a novel intercalated covalent organic framework (Intercalated-COF) by synchronizing operations of supramolecular donor-acceptor (D-A) interactions (A unit: 2,5,8,11-tetra(<i>p</i>-formylphenyl)-perylene diimide (PDI) <b>1</b>; D unit: perylene <b>3</b>, as intercalator) in the vertical directions, with polymerizations (by only reacting <b>1</b> with <i>p</i>-phenylenediamine <b>2</b>) in the lateral directions. In this Intercalated-COF, the PDI-based covalent 2D layers are uniformly separated by perylene guest layers. This supramolecular strategy opens the possibility for <i>z</i>-direction modulation of 2D-COFs through "intercalating" various guest molecules and thus may contribute to the exploration of advanced applications of these porous and crystalline frameworks.