Reproducibility challenges in activating two-dimensional polymers and three-dimensional covalent organic frameworks

Two-dimensional polymers and three-dimensional covalent organic frameworks are crystalline, permanently porous macromolecules. Removing guest molecules from the pores of these materials reliably is challenging because extreme capillary forces are generated when evacuating nanoporous structures. Herein, we outline the most common approaches for isolating and activating these materials. We also note how some methods, such as thermal activation under vacuum, introduce significant challenges with reproducibly activating porous organic materials. Throughout this discussion, we highlight emerging approaches that are most reliable for activating a wide range of materials without damaging their porosity or crystallinity. We also discuss what material features lead to more robust scaffolds towards activation. We hope this review can serve as a resource for experts and newcomers in this field as they determine what activation protocol to use on as-synthesized materials. Removing guest molecules from the pores of 2D polymers and 3D covalent organic frameworks is difficult to control, yet important for their properties. This Review discusses challenges in the reliable isolation and activation of these materials and discusses alternative strategies to mitigate this variability.