Functional monomers and polymers, 56. Effects of ionic strength on the structure of Cu(II)· poly(vinylimidazole) and Cu(II)· imidazole complexes in aqueous solution

The effect of ionic strength on the structure of Cu(II) complexes of imidazole and poly(4(5)-vinylimidazole) in aqueous solution was studied by viscometric, spectrophotometric, and electron spin resonance (ESR) techniques. Frequency of the center of the absorption band in visible region (λ_max) and ESR spectra of the polymeric Cu(II) complex were different from those of the low-molecular-weight Cu(II) complex. The spectra of polymeric Cu(II) complex were different in the presence of sodium perchlorate, but it was not the case for the low-molecular-weight Cu(II) complex. The reduced viscosity of the polymeric Cu(II) complex and the polymeric ligand decreased with a rise of the concentration of sodium perchlorate. It was proposed that the conformational change in the polymeric ligand resulted in a structural change of the Cu(II). poly(4(5)-vinylimidazole) complex.