Linear thermodynamic relationships for the ternary system copper(II)–5-substituted 1,10-phenanthroline-α-amino acid

The heats of formation of the ternary complexes copper(II)–5- substituted 1,10-phenanthroline–α-amino acid and the heats of protonation of the ligands have been determined in aqueous solution at 25.0 ± 0.1 °C and ionic strength 0.1 mol dm–3(KNO3) by means of a calorimetric method. A number of linear thermodynamic relationships have been found to exist between the energy changes upon formation of the ternary complexes and thus upon protonation of the ligands.