A Wavy Two-Dimensional Covalent Organic Framework from Core-Twisted Polycyclic Aromatic Hydrocarbons

Abstract

A high degree of crystallinity is an essential aspect in two-dimensional covalent organic frameworks, as many properties depend strongly on the structural arrangement of the different layers and their constituents. We introduce herein a new design strategy based on core-twisted polycyclic aromatic hydrocarbon as rigid nodes that give rise to a two-dimensional covalent organic framework with a wavy honeycomb (chairlike) lattice. The concave-convex self-complementarity of the wavy two-dimensional lattice guides the stacking of framework layers into a highly stable and ordered covalent organic framework that allows a full 3D analysis by transmission electron microscopy revealing its chairlike honeycomb facets and aligned mesoporous channels. Remarkably, the waviness of the framework does not disrupt the interlayer π-π stacking that shows charge transporting properties similar to those of planar covalent organic frameworks. The implementation of core-twisted aromatics as building blocks for covalent organic frameworks brings new possibilities in the design of highly ordered organic materials.