Selective anion exchange and tunable luminescent behaviors of metal-organic framework based supramolecular isomers.

Owing to the conformational (cis or trans) flexibility of a N-donor ligand, the combinations of the same and Cd(ClO4)2 under variable solvent templates afforded two supramolecular isomers based on two-dimensional metal-organic frameworks. Both compounds contain weakly coordinating ClO4(-) anions attached to the metal centers. Both frameworks showed facile anion exchange behaviors with various kinds of foreign anions. Moreover, both frameworks showed anion-driven structural dynamism and exhibited the preferential uptake of strongly coordinating anions over others. Anion-regulated modulation in luminescent behaviors was also observed in both cases.