Extraction of a alkali metal cations using a lipophilic lariat ether having a c-pivot carboxylic acid sidearm

摘要

The extraction of alkali metal cations by the lipophilic, ionizable lariat ether bis-tert-octylbenzo- 14-crown-4-acetic acid (BOB14C4AA) dissolved in either o-xylene or 1-octanol was studied by two-phase potentiometric titration and ion-exchange chromatography. BOB14C4AA extracts alkali metal cations from aqueous chloride solutions predominantly by ion exchange in the range p(H) > 7. From an aqueous mixture of alkali metal halides, BOB14C4AA extracts Li(sup +) cation preferentially up to complete loading. When the alkali metals are extracted individually, however, BOB14C4AA extracts Li(sup +) cation with highest efficiency only up to ca. 45% loading. Both selectivity and efficiency for extraction of Li(sup +) cation are enhanced with 1-octanol diluent as compared to o-xylene diluent.