Interactions of polymer-small molecule complex with cupric (II) ions in aqueous ethanol solution

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 potenti ometry. It was found that hydrogen bond is formed between P4VP and 4-amino benzoic acid. Dissolution was assessed visually at room temperature using d imethyl formamide, dimethyl sulfoxide, methanol, ethanol, ethanol-water. Af ter dissolution of PEC in aqueous-ethanol (50% v/v) solution, the interacti on of PEC with Cu2+ ions has been investigated by potentiometric titration. The average number of ligands coordinated with the central metal ion and t he stability constants of PEC-metal complex were determined. (C) 2001 Elsev ier Science Ltd. All rights reserved.