A new series of artificial receptors for binding carboxylates has been developed. The receptors are based on the hydrogen bonding abilities of secondary squaramides as binding subunits. The data reveal the formation of 1:1 complexes in highly competitive media. Using convenient spacers, receptors for di-and tri-carboxylates that incorporate two and three squaramide subunits have been prepared. The complexes are characterized by nmr and, when possible, by FAB spectral analysis. (C) 1998 Elsevier Science Ltd. All rights reserved.