High dielectric constant and relaxation mechanism of water with hydrated copper(II) ions in a cucurbit[8]uril-based supramolecular architecture

The dielectric properties of water confined in nanochannels of a cucurbit[8]uril-based supramolecular architecture containing water and hydrated copper(II) ions were investigated in the frequency range of 10 ² to 5 × 10 ⁷ Hz at various temperatures around room temperature. Two relaxation processes were revealed and studied. The low-frequency dispersion described by the fractional power law is related to the relaxation of hopping charge carriers. The second orientational polarization contribution follows the Kohlrausch-Williams-Watts relaxation law with the characteristic relaxation time almost independent of temperature and gives rise to an exceptionally large static dielectric constant (∼500). The data suggest the existence of a third relaxation process with the characteristic frequency significantly larger than the measurement frequencies used in this work.