Bright coloured Co (II) and Ni (II) complexes of an azo ligand were synthesized. This ligand was previously synthesized from the coupling reaction between 4,5-diphenyl imidazole and 4,4-diaminodiphenylmethane in 1:2 molar ratio (4,4-diaminodiphenylmethane and 4,5-diphenyl imidazole). The synthesis process of the complexes involved the reflux reaction between the azo ligand with both metal salts. The synthesized complexes were characterized by FTIR, UV.-Visible, molar conductivity and atomic absorption.  From the obtained characteristic data of the FTIR spectra, the coordination between the two metals and the azo ligand occurs by the coordination with the nitrogen atom of the azo group and one of the nitrogen atoms in the imidazole both rings. The molar conductivity test confirm the non- electrolytic nature of both complexes, while the atomic absorption agrees with the expected complexes formula. Therefore, the octahedral structure for the two complexes is suggested. The anti-corrosion activity of the synthesized compounds were investigated under two temperatures (298 and 308 K) with 0.03 gm of each compound was tested. According to the results cobalt (II) complex shows a better anti-corrosion activity (93%) in comparison with the ligand and nickel (II) complex.

KEY WORDS: Cobalt(II) and nickel(II) azo complexes, Imidazole derivative, Anti-corrosion effect

Bull. Chem. Soc. Ethiop. 2024, 38(4), 963-971.                                                         

DOI: https://dx.doi.org/10.4314/bcse.v38i4.12