Synthesis and Crystal Structure of a Binuclear Gadolinium(III) Complex Bridged by Cucurbit[6]uril

A new cucurbit[6]uril bridged binuclear complex {[Gd(H2O)6]2[Q6(H2O)]}Cl6·4H2O, where Q6 represents cucurbit[6]uril, has been synthesized and characterized by X-ray diffraction. The crystal structure shows that the complex has an extended cucurbit[6]uril-bridged structure consisting of two gadolinium(III) ions, in which each gadolinium(III) ion is coordinated with two neighboring carbonylic oxygen atoms of Q6 and six oxygen atoms of water molecules that leans toward one side of the portal. One disordered guest water molecule resides in the Q6 molecule cavity and occupies two different positions. Hydrogen bonds assemble the complex to three- dimensional supramolecular structure.