ANTIMICROBIAL AND ANTIOXIDANT ACTIVITY OF NEW TRANSITION METAL COMPLEXES DERIVED FROM 5-(2-(4-METHOXYPHENYL)-1H-BENZO [D] IMIDAZOL-1-YL) QUINOLIN-8-OL

New pharmacologically active transition metal complexes of Co(II), Ni (II), Cu (II), and Zn(II) have been synthesized with the ligand 5-(2-(4-methoxyphenyl)-1H-benzo [d] imidazol-1-yl) quinolin-8-ol (2). Different analytical and spectroscopic tools were used to analyze the compounds, including elemental analysis, FTIR, 1H-NMR, mass spectra, electronic spectra, magnetic measurement, and molar conductance techniques. FTIR confirmed that the ligand coordinates the metal ion to form a mononuclear complex via the oxygen and nitrogen atoms of the phenolic and quinoline rings. For Co(II) and Zn(II) complexes, tetrahedral geometry is recommended, whereas square-planar geometry is proposed for Ni(II) and Cu(II) complexes. The antibacterial activity of the ligand and its metal complexes were assessed using the disc diffusion method, and minimum inhibitory concentration (MIC) was determined in the broth dilution technique. The antimicrobial activity results showed that the metal complexes were shown to be more active than the free ligand. Besides, Cu(II) complex was shown to be the most potent antioxidant using the DPPH and hydroxyl radical scavenging methods, with IC₅₀ values of 17.3 and 21.5 μg/mL, respectively.