Abstract New proton-ionizable macrocyclic polyether ligands containing the 4-pyridone subcyclic unit have been prepared by reacting 4-THP blocked-2, 6-pyridinedimethanol with various oligoethylene glycol ditosylates. The 18-crown-6 ligand containing the 4-pyridone subcyclic unit, 4, forms stable complexes with alkali metal and organic ammonium cations. The crystal structure of 4 proves the 4-pyridone structural unit. The crystal structure of the ...