Novel azo-based benzimidazole Schiff base ligand and its Co(II), Ni(II) Cu(II) complexes: computational and biological studies.

AbstractA novel azo-based benzimidazole Schiff base ligand (FDSBI) was synthesized by the condensation reaction of 2-aminobenzimidazole with 4-fluorodiazenyl-salicylaldehyde. The ligand and its metal complexes were studied by elemental analysis, spectral analysis, and magnetic susceptibility measurement. The absorption spectra of the complexes evidence octahedral geometry. The structural properties of the Schiff base and its metal complexes were also proved by the treatment of density functional theory (DFT) calculation. Thermogravimetric analysis proved the coordinated and lattice water molecules. Cyclic voltammetry technique has been used to study the redox behavior of the copper (II) complex. The <italic>in vitro</italic> antibacterial and antifungal activities of the Schiff base and its coordinated compounds were screened against bacterial species (<italic>Staphylococcus aureus, Salmonella typhi, Escherichia coli, Bacillus subtilis) and Fungi (Candida albicans, Aspergillus niger)</italic> using well diffusion method. The obtained results have suggested that the metal complexes showed significant biological activity than ligand. The <italic>in vitro</italic> antioxidant activity of both the ligand and its metal (II) complexes was assessed through the utilization of the DPPH stable free radical. The result shows that the ligand possesses better antioxidant properties than metal (II) complexes. The second harmonic generation efficiency was analyzed for the ligand, demonstrating its potential application in nonlinear optical material. [ABSTRACT FROM AUTHOR]