A two-dimensional polyrotaxane with large cavities and channels: A novel approach to metal - Organic open-frameworks by using supramolecular building blocks

A seven-membered molecular necklace composed of six copper ions and six pseudorotaxane units behaves as a secondary building block in the formation of a two-dimensional polyrotaxane network with large voids (see picture). This novel metal-organic framework allows size-selective anion exchange as well as the exchange of coordinated ligands. Thus a new synthetic strategy has been identified for modular porous solids which utilizes large, rigid, interlocked supermolecules as primary or secondary building blocks.