Abstract
The protonation constants of some α-amino acids (glycine (Gly),
l
-alanine (Ala),
l
-valine (Val),
l
-serine (Ser),
l
-leucine (Leu) and
l
-isoleucine (Ile)) were studied in water and DMSO–water solution mixtures containing 30, 50 and 70 vol-% DMSO; in addition the complex formation equilibria of their copper(II) complexes were studied by potentiometric technique using a combined pH electrode system calibrated in concentration units of the hydrogen ion at 25 ± 0.1 °C under a nitrogen atmosphere, and at an ionic strength of 0.10 mol·dm
−3
NaNO
3
. The protonation constants and the overall stability constants of copper(II) complexes were influenced by changes in solvent composition, and their variations are discussed in terms of solvent and structural properties.