Selective removal of Cr2O72- in aqueous solution by nonporous pure crystals of cucurbit[6]uril.

Cucurbit[6]uril (Q[6]) could serve as a selective absorbent for the toxic anion Cr2O72-, which was demonstrated by the results of UVvis, ICP, XPS, SEM, and EDS experiments. Single-crystal X-ray diffraction analysis revealed that capture capacity could be attributed to the outer-surface interactions of cucurbit[n]uril between Cr2O72- and the outer surface of Q[6]. [ABSTRACT FROM AUTHOR]