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.

A New Member of the Inverted Cucurbit[n]uril Family.

A new inverted cucurbituril, namely inverted hexamethylcucurbit[3,3]uril (iMe6 Q[3,3]), has been isolated and characterized. It incorporates a single inverted un-substituted glycoluril unit oriented towards the interior of the cavity, shows good solubility in water and organic solvents (DMSO), and exhibits different selectivity for guests to those of iQ[6] and other known Q[6]s.