The dissociation constants of cephradine, cefepime were evaluated at room temperature by spectrophotometric and potentiometric measurements. Also, the dissociation constants of their complexes with iron (III) nickel (II) and copper (II) in the presence of water and different percentages of ethanol–water media were calculated potentiometry. Regression analysis is applied for correlating the different parameters based on an equation that relates the wavenumbers of the absorption band maxima (υmax) to the solvent parameters; refractive index (n), dielectric constant (D), empirical Kamlet–Taft solvent parameters, π*(dipolarity/polarizability), α (solvent hydrogen-bond donor acidity) and β (solvent hydrogen-bond acceptor basicity) by using the SPSS program. The results help to assign the solute-solvent interactions and the solvatochromic potential of the investigated compounds.