Post-synthetic ligand cyclization in metal–organic frameworks through functional group connection with regioisomerism

A covalent connection between two orthogonal functional groups (-NH2 and -OH) in metal-organic frameworks (MOFs) has been developed. This post-synthetic ligand cyclization (PSLC) was successfully demonstrated to synthesize a benzoxazole-functionalized MOF from a Zr-based UiO-66-2,3-(NH2)(OH) under microwave irradiation. In contrast, the regioisomeric UiO-66-2,5-(NH2)(OH) only produces a non-cyclized formamide-functionalized MOF.