Copper(II) Complexes of Ligands Containing Alcoholic Hydroxy Groups

Abstract Potentiometric and calorimetric methods were used to determine the thermodynamic parameters of formation of the copper(II) complexes of L-3-hydroxy-2-aminopropionic acid. D.L-3-amino-2-hydroxypropionic acid, D.L-4-amino-3-hydroxybutyric acid, 1,3-diaminopropan-2-0l and L-(+)-threo-2-amino-1-phenylpropane-1,3-diol at 25°C at an ionic strength I = 0.2 mol dm−3 (KCl). The thermodynamic data, together with electronic and ESR spectra and the magnetic behaviour of the complexes formed, indicated that in the monomeric complexes the deprotonation and coordination of the alcoholic hydroxy group occurs only at high pH. However, if the alcoholic hydroxy group is adjacent on both sides to further donor groups that are able to form strong coordinate bonds, then its metal ion induced deprotonation becomes more favoured and polynuclear alkoxo-bridged complexes are formed even at pH ∼ 5.