Equilibria in Cu(CH3CO2)2-pyridine-water system. Spectrophotometric,conductometric, and EPR study of the Cu(CH3CO2)2-pyridine-water system

Electronic spectra (340–800 nm; 298.2 K), liquid (298.2 K) and frozen solution (77 K) EPR spectra and electrolytic conductivities (298.2 K) have been measured for Cu(CH₃CO₂)₂ over the whole range of compositions of the mixed pyridine-water solvent. The results have been interpreted in terms of the possible coordination equilibria in the solution. They support the strong tendency of the Cu^II ion to coordinate pyridine molecules in aqueous solutions, revealed by other Cu^II salts. Even small amounts of pyridine were found to withdraw the electrolytic dissociation of the aqueous Cu(CH₃CO₂)₂ solutions, probably, through the enhancement of the Cu^II ion interactions.