The effect of pH on Cu2+ complex formation with poly-4-vinylpyridine☆

Abstract The formation of coordinatively unsaturated complexes of Cu 2+ with poly-4-vinylpyridine in an acid medium has been established, using optical and ESR spectroscopy. The composition of the complexes does not depend on the initial ratio of component concentrations and is determined by electrostatic factors, influencing the conformational state of the macromolecule. The question of applying potentiometric methods for studying the complexing of metal ions with polycationic ligands is discussed. A method is proposed for a quantitative description of the complexing process using the efficiency constant for linking metal ions and coordinative capacity of the polymeric ligand.