Synthesis and Characterization of Fe(II), Co(II), Cu(II) and Zn(II) Complexes Containing a New Unsymmetrical Tetradentate Schiff-base

For decades, Schiff base moieties have been used extensively as ligands which play a key role in the field of coordination chemistry due to their ease of synthesis, stabilityand applications in various fields. For instance, they have been used as in biological, clinical, catalysis, analytical, and industrial systems [1, 2]. The aim of this research was synthesis of a new unsymmetrical tetradentate Schiff base ligand and its transition metal complexes such as: Fe(II), Co(II), Cu(II), and Zn(II). The ligand, N,N -bis-(2-acetylpyridine)-3,4-diiminobenzoic acid (acpybza), was synthesized by the reaction of 3,4-diaminobenzoic acid and 2-acetyl pyridine with 1:2 molar ratio. The Schiff base ligand was characterized by elemental analysis, UV-Vis, IR, and 1H NMR spectroscopic data. Then, its complexes were synthesized through the reaction of the ligand with the desired metal ions. The complexes were investigated and characterized by thermal analysis, molar conductance, magnetic susceptibility measurements, IR, and UV-Vis spectral data, as well. The results of our investigations clearly stated to the [ML](X)2 formula for all of the complexes. The results of magnetic properties of the complexes revealed that cobalt complex has a low spin square-planar structure, but the Fe(II) complex form a distorted structure