A complex was prepared by mixing ethanol solutions of poly(4-vinyl pyridine) (P4VP) and 4-amino benzoic acid. The complex (PEC) formation was studied by C-13 NMR, IR spectroscopy, differential scanning calorimetry and potentiometry. It was found that hydrogen bond is formed between P4VP and 4-amino benzoic acid. Dissolution was assessed visually at room temperature using dimethyl formamide, dimethyl sulfoxide, methanol, ethanol, ethanol-water. After dissolution of PEC in aqueous-ethanol (50% v/v) solution, the interaction of PEC with Cu2+ ions has been investigated by potentiometric titration. The average number of ligands coordinated with the central metal ion and the stability constants of PEC-metal complex were determined. (C) 2001 Elsevier Science Ltd. All rights reserved.