Crystal structure of a two-dimensional metal–organic framework assembled from lithium(I) and γ-cyclo­dextrin

The crystal structure of the polymeric title compound, catena-poly[[diaqualithium]---cyclodextrin(1)-[aqualithium]---cyclodextrin(1)] pentadecahydrate], {[Li2(C48H79O40)2(H2O)3]15H2O}n, consists of deprotonated -cyclodextrin (CD) molecules assembled by lithium ions into metal– organic ribbons that are cross-linked by multiple O—HO hydrogen bonds into sheets extending parallel to (011). Within a ribbon, one Li+ ion is coordinated by one deprotonated hydroxyl group of the first -CD torus and by one hydroxyl group of the second -CD torus as well as by two water molecules. The other Li+ ion is coordinated by one deprotonated hydroxyl and by one hydroxyl group of the second -CD torus, by one hydroxyl group of the first -CD torus as well as by one water molecule. The coordination spheres of both Li+ cations are distorted tetrahedral. The packing of the structure constitute channels along the a axis. Parts of the hydroxymethyl groups in cyclodextrin molecules as well as water molecules show two-component disorder. Electron density associated with additional disordered solvent molecules inside the cavities was removed with the SQUEEZE [Spek (2015). Acta Cryst. C71, 9–18] routine in PLATON. These solvent molecules are not considered in the given chemical formula and other crystal data. Five out of the sixteen hydroxymethyl groups and one water molecule are disordered over two sets of sites.