Synthesis, spectral studies, and determination of stability constants and thermodynamic parameters for some aromatic diamine transition-metal complexes

The Cu(II) and Zn(II) complexes of aromatic bidentate diamines were prepared and characterized by different analytical and spectral methods. Thermodynamic parameters of complexes of Cu(II) and Zn(II) cations with 1,3-bis(p-aminophenoxy)propane were determined in 60 vol. % DMF-H2O at various ionic strengths (0.07, 0.13, 0.2 M NaNO3) and different temperatures (45, 50, 55, 60 ± 0.1°C) using a spectrophotometric method. The NaNO3 solution was used to maintain the ionic strength. The stability constants show an inverse relationship with ionic strengths. The thermodynamic parameters of 60 vol. % DMF-H2O (ΔG°, ΔH°, ΔS°) based on these formation constants were determined.