This study focused on the synthesis, of metal complexes prepared from N-Phenyl Gamma Acid (NPGA) as potential antimicrobial agents. In the method, NPGA is nitrosated with NaNO₂ and H₂SO₄ to give an oxime (confirmed by color change on addition of FeSO₄). The complexes were then slightly metallized using Cu²⁺ and Zn²⁺, followed by FTIR and UV-visible spectroscopy. The results showed that the new material has distinct spectral features for Cu-(II) and Zn (II)- complexes, which confirms the formation of these two metal-complexes. Finally, the prepared metal complexes were investigated their ability to dye natural leather. Where the Cu-complex gave deeper hue development than corresponding un-metallized dye, while Zn- complex showed balance color properties. A study has demonstrated metal complexes deepen intensity and permanence of the dye, with far superior results than covalent attachment (Zn-complex is more effective).

Keywords: Metal complex, oxime synthesis, nitrosation, leather dyeing, FTIR spectroscopy