Hydroquinone-assisted assembly of coordination polymers from lanthanides and cucurbit[5]uril

Abstract

Coordination polymers have been assembled from a series of eight different lanthanide ions (Ln³⁺) and cucurbit[5]uril (Q[5]) in the presence of hydroquinone (Hyq) as an organic structure inducer. X-ray diffraction analysis has revealed three distinct configurations of the coordination polymers formed with increasing atomic number of the lanthanide. The coordination of light lanthanide cations to Q[5] leads to the formation of linear one-dimensional coordination polymers; the coordination of intermediate lanthanide cations such as Eu(III) or Gd(III) leads to the formation of Q[5] pairs in which the two Q[5] molecules are connected by the Eu(III) or Gd(III) ions; and the coordination of heavy lanthanide cations to Q[5] leads to the formation of homochiral one-dimensional helical coordination polymers.