Coordination-driven self-assembly of M10L8 metal-organic bi-capped square antiprisms with adaptable cavities.

A family of polyhedral metal-imidazolate cages based on the flexible bi-imidazole ligand L and Cu2+ ions have been synthesized and characterized, featuring an unusual Cu10L8 bicapped square antiprism structure (or Johnson solids, J17) with an adaptable cavity. These metal-organic cages encapsulate anions, and they will expand or compress after they are filled with different-sized anions.