Chromoionophoric calix[4]arenes (8,9) containing dissociable OH and quaternary pyridinium indicator groups have been synthesized, Optical measurements of the target molecules performed in various solvents in the presence of weak base and alkali cations revealed Li+, Na+ and Ca2+ recognition depending on the binding sites. Solvato- and halochromism of betaines 10,11 formed in situ upon complexation were also observed. (C) 1997 Elsevier Science Ltd.