Metallation of Tetradentate N۲O۲ Schiff base with Cd(II), Hg(II) Synthesis, Characterization and Formation Constants Measurement and Thermodynamics Studies

Four Schiff base ligands, salabza-H۲ = N,N'-bis(salicylidene)-۲-aminobenzylamine, were synthesized by condensation of one mmole of ۲-aminobenzylamine and two mmoles of salicylaldehyde and/or two mmoles of substituted salicylaldehyde (۵-OMe, ۵-Br, ۵-CI). All the Schiff bases and their metal complexes are characterized by UV-Vis, FT-IR, IH NMR spectroscopy, elemental analysis and Thermal gravimetry analysis. The formation constants and the Gibbs free energies were measured spectrophotometrically for ۱:۱ complex in methanol in constant ionic strength (I = ۰.۱ mol dm-۳ NaClO۴) and at ۲۵ °C. The data refinement was accomplished with the SQUAD program. The trend of formation constants of H۲L۱ with M(II) follows the order: Cd(II) (۵.۵۰) < Hg(II) (۶.۲۰) Also, the trend of formation constants of ligand toward a given metal (for example Cd) is as follows: H₂L' (p-OMe) (۵.۵۰) > H₂L² (p-H) (۴.۱۳) > H₂L³ (p-Br)

کلیدواژه ها:

Schiff base ، metals Complex ، Thermodynamic