Synthesis and characterization of novel polymer-supported ion-complexing reagents : applications of the Wadsworth-Emmons reaction

A phosphonic acid resin with maximized site density was synthesized to evaluate the benefits of interligand cooperation. The resin was prepared by grafting poly(vinylbenzyl chloride) chains onto a cross-linked poly(vinylbenzyl chloride) network through pendant vinyl groups. Vinyl moiety functionalization was accomplished via the Arbuzov and Wadsworth- Emmons reactions. The complexing ability of the resin was evaluated with Eu(III) and Cu(II) in a variety of matrices. A sulfonated resin was produced to maximize accessibility into the polymer matrix. The complexing ability of the sulfonated resin was evaluated with several metal ions in various solvents. A binding constant evaluation was performed on the unsulfonated resin with Cu(II). The binding constant was three times the binding constant of the ungrafted resin. The effect of heightened interligand cooperation was evident in the increased binding strength.

An encapsulated solvent impregnated resin (SIR) was prepared, characterized, and evaluated. Macroporous copolymer beads were functionalized with surface vinyl groups via the Arbuzov and Wadsworth- Emmons reactions. The functionalized support was impregnated with an organo-phosphorus extractant and coated with poly(glycidyl methacrylate-co-N,N-methylenebisacrylamide). The experimental variables were evaluated to determine the optimum encapsulation conditions. The extractant retention of the resin was evaluated with sequential load/strip cycles. The bis(2- ethylhexyl) hydrogen phosphate impregnated resin (75-150 µm) retained a high Cu(II) complexing ability (>90%) for five contact periods after encapsulation. The complexing ability of the uncoated resin decreases sharply after the first contact period due to extractant loss.