Synthetic and Characterization of Some new Schiff bases Complexes with CoII, NiII, CuII and PdII ions

Abstract

A new ligand (H 4 L) and its complexes with (Co II , Ni II , Cu II and Pd II). This ligand was prepared in two steps, in the first step a solution of terephthaldehyde in methanol reacted under refluxe with 1,2-phenylenediamine to give precursore compound which reacted in the second step with 2,4-dihydroxybenzaldehyde to give the ligand. The complexes were synthesized by direct reaction of the corresponding metal chloride with the ligand. The ligand and complexes were characterized by spectroscopic methods [FT-IR, UV-vis, 1 HNMR, HPLC and atomic absorption], chloride contant in addition to conductivity measurement. The stability constant K and Gibbs free energy ∆G were calculated for [[Ni 2 (H 2 L)Cl 2 ], [Cu 2 (H 2 L)Cl 2 ] complexes using spectrophotometer method. The obtained values indicate that these complexes are stable in their solution. The data of these measurements suggest a distorted tetrahedral geometry for Co II