Thermodynamic parameters of the formation of deprotonated single-ligand complexes in the Cu(II)−triglycine system in aqueous solutions

Resumo

Heat effects arising from interactions between triglycine solutions and Cu(NO₃)₂ solutions are studied at 298.15 K and ionic strengths of 0.2 to 1.0 (KNO₃) via isothermal calorimetry. Using experimental data, enthalpies of formation are calculated for species CuH₋₁L, CuH₋₂L⁻, and CuH₋₃L²⁻, along with Δ_rH°, Δ_rG°, and Δ_rS° of the complexation process. A relationship is revealed between the structures of deprotonated single-ligand triglycine complexes of Cu(II) and the thermodynamic parameters of their formation.