Coordination supramolecular assemblies of a monohydroxycucurbit[7]uril and their potential applications in gas sorption.

Coordination supramolecular assemblies of monohydroxycucurbit[7]uril ((HO)Q[7]) with alkaline earth metal ions (AE2+ ) have been formed in aqueous HCl solution in the presence of tetrachloride cadmium anions ([CdCl4 ]2- ) as a structure directing agent. The driving force for the assembly could be attributed to the interaction of the positive electro-potential outer-surface of (HO)Q[7] molecules with [CdCl4 ]2- anions and ionic dipole interaction of the hydroxyl of (HO)Q[7] molecules with [CdCl4 ]2- anions. Moreover, the porous structure of the (HO)Q[7]/AE2+ -based coordination supramolecular assemblies could result in potential applications in the selective sorption of polar volatile organic molecules, which may be useful in molecular sieves, sensors, absorption and separation.