Immobilized Phosphate Ligands with Enhanced Ionic Affinity through Supported Ligand Synergistic Interaction

Abstract

The ability of a secondary group to influence the metal ion affinities of a primary ligand immobilized on crosslinked polystyrene beads is reported. The secondary groups were glycol units, ‐(CH2CH2O)1‐4‐, and their effect on phosphate ligands was studied. The affinities of Pb(II), Cd(II), Cu(II), Ni(II), Zn(II), Fe(III), Y(III), La(III), Eu(III), Lu(III), and U(VI) were quantified from HNO3, HCl, and H2SO4 solutions in concentrations up to 4 N. Affinities were highest for U(VI) and the trivalent ions. The glycol units enhanced the extent of metal ion complexation by the phosphate ligands through coordination of the metal ion and not through an auxiliary group effect (where there would be a direct interaction between the glycol units and the phosphate ligand) as indicated by the similarity in the FTIR spectra of the four phosphorylated glycol resins. At least two glycol units are needed for synergistic cooperation between the glycol and phosphate in binding metal ions.