Compounds 1 and 2 displayed limited solubility in proticsolvents, and evidence for stoichiometric host-guest association between 2 and AMP (28) could only be obtained by FAB-MS analysis of a complex precipitated from MeOH (Fig. 2). In contrast, receptor 3 with four triethyleneglycol monomethyl ether side chains was readily soluble in the protic environments, and complexation of isophthalates and