Synthesis, Characterization and Thermal Study of Some Transition Metal Complexes of N-(4-hydroxybenzylidene)isonicotinohydrazone and Investigation of Their Antibacterial and Antioxidant Properties

Cr3+, Co2+, Ni2+, Cu2+ and Zn2+ ions complexes of the Schiff base ligand, N-(4-hydroxybenzylidene)isonicotinohydrazone (L1), were synthesized and characterized by analytical and physicochemical techniques including conductivity measurements, magnetic susceptibility measurements, IR Spectroscopy, UV-Visible Spectrophotometry and thermogravimetric analysis (TGA). IR data revealed the bidentate nature of the L1. IR, TGA, Magnetic moment measurements and UV-Vis spectra data confirmed the octahedral geometry for the Cr3+, Co2+, and Cu2+ ion complexes, square planar geometry for the Ni2+ complex and tetrahedral structure for the Zn2+ ion complex. The antibacterial activity of the metal complexes derived from the L1 ligand were tested against P. aeruginosa and E. coli. All produced complexes demonstrated strong antibacterial efficacy against P. aeruginosa when compared to standard Kanamycin-30, with the greatest for the Ni2+ complex. On the other hand, when compared to all compounds, the Zn2+ complex demonstrated strong antibacterial efficacy against E. coli. Furthermore, the synthesized metal complexes exhibited moderate antioxidant activity than the L1. The antioxidant activity was found to follow the following sequence: BHT > CuL1 > CrL1 > NiL1 > CoL1 > ZnL1 > L1.