Guest-Anion-Induced Rotation-Restricted Emission in UiO-66-NH₂ and Advanced Structure Elucidation

We report the guest-anion-induced photoluminescence enhancement of metal–organic frameworks (UiO-66-NH2), first based upon diffraction and computational evidence. found that only limited anions, namely, carbonate fluoride, can lead to a significant in photoluminescence, whereas their related such as acetate chloride, cannot. The optimized crystal structures reveal guest fluoride ions interact with four framework amino functional groups through hydrogen bonding (ca. 1.6–1.7 Å) ultimately forms quaternary (?N(H))4···X– molecular bridge around nodal center. Hence, hydrogen-bonded not restricts intermolecular C–C rotation linker molecules but also greatly perturbs electronic densities between anions groups.