Interaction of beta-cyclodextrin with cadmium(II) ions

Reduction of Cd(II) on a dropping mercury electrode was used to study interaction of p-cyclodextrin with Cd(II) ions. It was found that Cd(II) forms Cdbeta-CD(OH)(2)(2-) hydroxy-complex with the anion of beta-cyclodextrin in alkaline solutions (pH > 11), the logarithm of stability constant being 10.4 +/- 0.1 (20 degreesC; I = 1.0). The calculated value of the diffusion coefficient equal to 1.0 x 10(-6) cm(2)/S shows a large size Cd(II) complex species formation in alkaline solutions containing P-CD. (C) 2003 Elsevier B.V. All rights reserved.