Extraction and solution thermodynamics of complexation of alkali and alkaline-earth cations by calix[4]arene amides

Abstract

The extracting properties of nine new calix[4]arene tetraamides towards the entire alkali cation series and strontium have been determined. One of the amides bearing propargyl (prop-2-ynyl) residues on the nitrogen atoms has also been tested in Complexation in methanol for the same cations. The enthalpies and entropies of Complexation of alkali and alkaline-earth cations by the diethyl and pyrrolidinyl tetraamides in methanol and of alkali cations by the diethyl tetraamide in acetonitrile have been determined for the first time from calorimetric measurements. The data are compared with data for calixarene esters and solvent effects are discussed in the light of earlier results.