Covalent-organic frameworks (COFs) as porous crystalline materials show promising potential applications. However,d eveloping facile strategies for the construction of COFs directly from amorphous covalent organic polymers (COPs) is still agreat challenge.T othis end, we report anovel approach for easy preparation of COFs from amorphous COPs through the linkage replacement under different types of reactions.F our 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.T he realization of the linkage substitution would significantly expand the researchs cope of COFs.

Two two-dimensional covalent organic frameworks (COFs, TJNU-203 and TJNU-204) with high crystallinity and large specific surface areas are rationally fabricated from a three-connected distorted building block and linear linkers. The...

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