A series of macrocyclic polyether-diester ligands containing a proton-ionizable 4- hydroxypyridine subcyclic unit has been prepared. These new macrocyclic ligan& form stable Complexes with both akylammonium perchlorate salts and with alkylamines. The crystal structure for one of these complexes with an alkylamine shows that the hydroxy proton has been donated to the amine with the resultant formation of a 4-pyridone unit. ...