METAL COMPLEX DERIVED FORM 2-HYDROXY BENZALDEHYDE AND 4-BROMOANILINE SCHIFF BASE WITH COPPER (II) ACETATE: SYNTHESIS, CHARACTERIZATION AND ANTIMICROBIAL ACTIVITIES

ABSTRACT A Schiff base ligand with pale yellow color was obtained on the reaction of 2-hydroxybenzaldehyde with 4-bromoaniline in 1:2 molar ratio which referred to ligand (HL). On complexing the synthesized ligand (HL) with cadmium (II) chloride in 1:2 molar ratio produced a complex compound with brown color which is referred to (M). The synthesized compounds were characterized through various techniques such as solubility, melting point, conductivity and infrared. The results revealed the solubility of the compounds in the different solvents used. The compounds have sharp melting points with molar conductance of 0.11 and 3.77 S cm² mol⁻¹ for free ligand and its complex respectively. The infrared spectrum of the ligand exhibits a band at 3023 cm⁻¹ for phenolic hydroxyl group attached to the ring that disappeared after complexation and band at 1607 cm⁻¹ attributed to azomethine functional group ν(C=N) which shifted after complexing with the metal. This suggests that the coordination is through the azomethine nitrogen and deprotonated oxygen atom of the hydroxyl group which confirms the ligand as ON donor. It could be inferred that the ligand behaved as monobasic bidentate ligand with azomethine nitrogen (N) and phenol oxygen (O) as the coordination site assuming a six coordinate octahedral geometry. The antimicrobial results revealed that the free ligand has activity against Staphylococcus aureus and Escherichia coli at higher concentration (50 µg/mL) while the metal complexes showed activity against Escherichia coli and Candida albicans.