THE METAL COMPLEXES OF NOVEL SCHIFF BASE CONTAINING ISATIN: CHARACTERIZATION, ANTIMICROBIAL, ANTIOXIDANT AND CATALYTIC ACTIVITY STUDY
Objectives: The aim of our work was to synthesize novel mixed ligand-metal complexes and evaluation of antimicrobial, antioxidant assay, and analysis of catalytic oxidation of cyclohexane. Methods: The complexes were characterized by means of various physicochemical techniques such as elemental analysis, molar conductance, magnetic susceptibility, infrared (IR), electronic absorption, 1H NMR (proton magnetic resonance), and mass spectral studies. The antimicrobial screening study was done by disc diffusion method. The catalytic activity of the complexes was observed in the oxidation of cyclohexane using eco-friendly hydrogen peroxide as oxidant. Results: On comparing the 1H NMR and IR spectral data of free ligand and its complexes, it was found to be azomethine (CH=N) proton which is formed in the free ligand. During complexation, the azomethine proton is coordinated to the metal ion and the phenolic oxygen is coordinated to the metal ion by deprotonation. The analytical data and mass spectra of the ligand and the complexes confirm the stoichiometry of metal complexes as being of the (MLY)Cl type and the metal to ligand ratio is 1:1. The antimicrobial, antioxidant, and catalytic potential were evaluated and the result shows the better activity of the complexes than the ligand. Conclusion: It was found to be copper(II) and zinc(II) complexes which are effective against all the bacteria when compared to standard drug streptomycin. Copper(II) complex was found to be effective antibacterial agent against Aspergillus niger and Aspergillus flavus in comparison to the standard drug Nystatin. The zinc complex exhibited good catalytic activity.