Construction of Covalent-Organic Frameworks (COFs) from Amorphous Covalent Organic Polymers via Linkage Replacement.

Covalent-organic frameworks (COFs) as porous crystalline materials show promising potential applications. However, developing facile strategies for the construction of COFs directly from amorphous covalent organic polymers (COPs) is still a great challenge. To this end, we report a novel approach for easy preparation of COFs from amorphous COPs through the linkage replacement under different types of reactions. Four COFs with high crystallinity and porosity were constructed via the linkage substitution of polyimide-linked COPs to imine-linked COFs as well as imine-linked COPs to polyimide-linked COFs. The realization of the linkage substitution would significantly expand the research scope of COFs.