Ln<sup>3+</sup> Adsorption into an Yttrium-Hdehp Coordination Polymer through Exchange with Coordinated Yttrium Ion

Abstract

An exchange between lanthanide ions (Ln) in a solution and coordinated yttrium ions (Y) takes place in a coordination polymer (CP) formed by Y and di-(2-ethylhexyl) phosphoric acid (Hdehp). Through this cation exchange, Ln is adsorbed on the CP depending on the coordination power with Hdehp. Accordingly, the Ln with the larger atomic number is more preferably adsorbed into the CP. This adsorption is affected by the concentration of H,  H C , in the solution. For example, at  H C =10 M, Y is replaced directly by the incoming Ln with a 1:1 stoichiometry. In a limited higher  H C region, the CP becomes a gel and the Ln/Y exchange is enhanced therein.