Fig. 1: Formation of single-crystal 2D COFs.
From: Single-crystal 2D covalent organic frameworks for high-capacity methane storage

a Schematic assembly of single-crystal GZU-1, GZU-2 and GZU-3 2D COFs. b A unit cell of GZU-1 containing ABCDEF 6-fold alternating stacking (AAl6) structure with multiple C-H···π interactions between the substituents and frameworks to stabilize its permanent porosity.