Solvents Influence Upon Complex Formation of 7-Chloro-4-hydrazinoquinoline Schiff Base Ligand and Transition Metal(II) by Using Conductometric Method

摘要

7-Chloro-4-hydrazinoquinoline Schiff base was synthesized and characterized by elemental analyses, IR, ~1H NMR, electronic spectra and mass spectrometry. The complex formation of Schiff base hydrazone ligand with Co(U), Ni(II), Cd(II), Zn(II), Cu(II) and Fe(III) in 75 % (v/v) ethanol -water, acetone-water and isopropanol-water mixtures at 30,40 and 50 °C, assigned that the ligand behaves as a monoprotic. The stability constants of the formed complexes decreased with increasing temperature, reflecting that the complexation process is an exothermic process. Thermodynamics parameters are computed and analyzed in order to investigate the bond character between metal and ligand. The calculated values for AG, AH and AS suggested that the complexation process is spontaneous. The calculated dissociation constant of ligand (HL) depends on the relation between the basicity of the ligand and dielectric constant of different solvents.