Antimicrobial evaluation of microwave-assisted synthesized chromone derivative schiff base with divalent metal complexes and experimental methodologies

Abstract

Green chemistry concepts are in line with microwave-assisted synthesis as it is thought to be environmentally beneficial. This type of energy has been used widely and effectively in the synthesis of metal complexes and in organic compounds. The recent coordination chemistry accentuates the study of Schiff bases metal complexes properties entering the microscale from the macro level, and similar to peering into the interior structure of compounds. Synthesis of divalent Cobalt, Nickel and Copper complexes with Schiff base (E)-6-methyl-3-(1-(2-phenylhydrazineylidene) ethyl)-4H-chromen-4-one [L₁] as primary ligand and 8-Hydroxyquinoline (L₂) is used as a secondary ligand. Schiff base (E)-6-methyl-3-(1-(2-phenylhydrazineylidene) ethyl)-4H-chromen-4-one [L₁] derived from phenyl hydrazine with 3-formyl-6-methylchromone. The structural investigation was carried out using FTIR, mass spectra, ¹H NMR, ¹³C NMR, and electronic spectra. The thermal behaviour of synthesized complexes was investigated through thermogravimetric analysis (TGA) and differential scanning calorimeter (DSC) techniques. The crystalline nature of complexes was investigated through the powder XRD technique. Analytic data, elemental analysis, and molar conductance characterised novel transition metal complexes with freshly synthesized ligand (L₁). The elemental analysis reveals the molar ratio of metal complexes as 1:1:1 (M:L₁:L₂) and synthesized metal complexes have octahedral geometry. Antimicrobial efficacy was examined using the agar well diffusion method at various concentrations. Given the biological activity, the effectiveness of antimicrobial properties is typically more potent concerning metal complexes than free Schiff base ligands according to biological data.