Pitfalls in the synthesis of polyimide-linked two-dimensional covalent organic frameworks†
The well-known reaction of amines with carboxylic acid anhydrides to produce highly stable imide moieties has been extended in the literature to the synthesis of two dimensional polyimide-linked covalent organic frameworks (2D-COFs). We report a detailed study of these reactions to determine whether the reported polymerizations are producing the reported COFs. The studies include variations of reaction temperature, time, heating method, and monomer structures to establish whether formation of ordered crystalline material is occurring. The results of these studies indicate that a specific, previously reported polyimide COF is likely not produced with the order or exact structure as reported.