Metal-induced different structures of four cyclopentanocucurbit[5]uril-based complexes

Abstract

In this paper, four supramolecular complexes were constructed by using cyclopentanocucurbit[5]uril (CyP5Q[5]) with CrCl3, CoCl2, HgCl2 and Pb(ClO4)2 respectively in 3 mol/L hydrochloric acid aqueous solution, and then Single-crystal X-ray diffraction was employed to characterize these supramolecular complexes: [C45H56Cl3CrN20O13(1), C45H60Cl8Co3N20O15(2), C45H64Cl6Hg2N22O13(3) and C90H112Cl8Pb4N40O55(4)]. Interestingly, complex 4 is completely different from the other three complexes in that the Pb2+ is coordinated with all the five carbonyl groups of the CyP5Q[5] to form a one-dimensional supramolecular chain. It is worth noting that complex 3 is different from complex 1 and complex 2 in the way of coordination in which the central Hg2+ ion is not coordinated with water molecules but with two chloride ions, and with five portal carbonyl oxygen atoms of the CyP5Q[5], while the central Co2+ or Cr3+ is only partially coordinated with portal carbonyl oxygen atoms of the CyP5Q[5].