The synthesis of macrocyclic chromogenic derivatives of pyrrole and imidazole is described. The complexing properties of these compounds with metal cations were investigated spectrophotometrically in acetonitrile. The synthesized crown ethers were also tested as ion carriers in ion-selective membrane electrodes. The X-ray structure of one isomer of 18-membered pyrrole crown ether is reported. (C) 2003 Elsevier Science Ltd. All rights reserved.