Synthesis, Characterization, and Study of the Antimicrobial Activity for Complexes of Metal ions (Cu+2, Co+2, and Ni+2) Derived from Ligands of Schiff Bases

Background This study investigated the synthesis and antimicrobial properties of metal complexes derived from Schiff base ligand (HL). a Schiff base moiety known as imine that is formed by the reaction of primary amines with carbonyl compounds. The aim is to achieve the possibility of antimicrobial activity in these compounds and understand their structural characterization to enhance the medicine industry related to them. Methods The ligand was synthesized by condensing coumarin and hydrazine hydrates, followed by activation with 3-acetyl pyridine. Ligands were then used to synthesize complex metals such as cobalt (II), nickel (II), and copper (II). Results Various methods were used to characterize the synthesized compounds. The FT-IR spectra confirmed the coordination of the ligand with the metal centers of the azomethine nitrogen and carbonyl oxygen atoms. Electronic spectra provided information on the geometry and electronic transitions of the complexes. Furthermore, X-ray diffraction (XRD) analysis was carried out to investigate the crystal structure of the ligand-cobalt complex. Conclusions The antimicrobial activity of ligands and metal complexes was studied using various bacterial and fungal strains. The results showed that all compounds showed some antimicrobial activity. However, none are as effective as the prophylactic antibiotic amoxicillin. Among the synthesized compounds, copper (II) complexes showed superior activity, especially against Gram-negative bacteria.