Ln3+ adsorption into an yttrium-hdehp coordination polymer through exchange with coordinated yttrium ion

Abstract

An exchange between lanthanide ions (Ln3+) in a solution and coordinated yttrium ions (Y3+) takes place in a coordination polymer (CP) formed by Y3+ and di-(2-ethylhexyl) phosphoric acid (Hdehp). Through this cation exchange, Ln3+ is adsorbed on the CP depending on the coordination power with Hdehp. Accordingly, the Ln3+ with the larger atomic number is more preferably adsorbed into the CP. This adsorption is affected by the concentration of H+, CH+, in the solution. For example, at CH+ = 10-5 M, Y3+ is replaced directly by the incoming Ln 3+ with a 1:1 stoichiometry. In a limited higher CH+ region, the CP becomes a gel and the Ln3+/Y3+ exchange is enhanced therein.