Calixarene-facilitated transfer of alkali metal ions across the polarised liquid-liquid interface

The transfer of sodium and potassium ions across the water-1,2-dichloroethane interface by the neutral ionophore tetraethyl-p-tert-butyl calix[4]arene tetraacetate has been investigated using voltammetric methods. The electrochemical data has been used to determine the stoichiometry of the metal : ligand complex and the appropriate association constants between the metal ions and the ligand in the organic phase. This data is correlated with structural studies, including the crystal structure of the Na+-calixarene complex, which is reported for the first time.