Alkali and alkaline earth metal ion-sensing studies on two disubstituted diphenyl ethers of tetraethylene glycol

Abstract

The acyclic polyethers 1,11-bis(2-hydroxy-5-formylphenoxy)-3,6,9-trioxaundecane (1) and its dibenzyl ether (2) were evaluated individually, when incorporated with seven different solvent mediators and, in some instances, also with an anion excluder, as possible alkali and alkaline earth metal ion sensors. The response characteristics of the diphenol 1 are more dependent on the solvent mediator used whereas the dibenzyl ether 2 shows a preferential response towards potassium ions regardless of the solvent mediator used. The solvent mediators themselves were also checked for their ion-sensing qualities: tris(2-ethylhexyl) phosphate and dioctyl phenylphosphonate both exhibit a substantial response towards lithium ions; dioctyl sebacate, dibutyl phthalate and bis(2-ethylhexyl) adipate all show some response towards potassium ions.