alkali and alkaline-earth cations by a series of calix[4]arenes bearing various combinations of primary, secondary and tertiary amide substituents. Four mixed calix[4]arene amides have been synthesized. Upon N-alkyl to N-H substitution on the amide binding sites, the binding strength of cations is reduced in methanol, and further, the extraction of cations from water into dichloromethane becomes highly inefficient