COMPLEX-FORMATION OF METAL-IONS WITH SULFONATED CROWN-ETHERS IN WATERAS ION SIZE-SELECTIVE MASKING REAGENTS

A new type of water-soluble sulfonated crown ether has been prepared a nd utilized as an ion size selective masking reagent with a view to es tablishing a highly selective extraction-separation system. In the syn ergistic extraction of alkaline earths with 4-benzoyl-3-methyl-1-pheny l-5-pyrazolone and trioctylphosphine oxide in cyclohexane, the extract ion of these with larger ionic radii shifted to a higher pH region on adding the sulfonated crown ether to the aqueous phase, giving improve d separations. A similar result was achieved in the extraction of lant hanides into cyclohexane with bis(2-ethylhexyl)phosphoric acid. The co mplex formation of alkaline earth and lanthanide ions with the sulfona ted crown ethers in the aqueous solution were evaluated via the solven t extraction method.