Biocompatible β-cyclodextrin-based metal-organic frameworks

β-Cyclodextrin (β-CD) is a cyclic heptasaccharide, part of the family of molecules which are widely used in several biological applications. The unique cone-shape of cyclodextrins with multiple binding sites make them a well-suited building block for constructing porous crystalline solids, such as metal-organic frameworks (MOFs). However, owing to the symmetry constraints, progress in the coordination chemistry of β-CD with alkali and alkaline earth metal cations has been limited and there is less understanding of this chemistry compared to its analogues of α-CD and γ-CD. In this work, synthetic conditions were optimised to obtain two MOF structures with β-CD as the organic linker, one each with Na⁺ and K⁺ cations. As well as structural determination, detailed solid-state characterization is reported for both the MOFs. The structure analysis helps shed light on the binding tendencies of β-CD and these structures will further facilitate the deployment of biocompatible building blocks for the development of reticular solid materials.