Synthesis, Characterization, Antibacterial and Antioxidant Studies of Isoniazid-based Schiff Base Ligands and Their Metal Complexes

The condensation of aromatic aldehyde with amine results in the formation of Schiff's bases, which are considered to be one of the most significant groups of ligands. Schiff's base metal complexes have received a lot of attention because of their high biological activity. Such include antimicrobial, anticancer, antibacterial, and antifungal activities. The current research is focused on the synthesis and characterization of two Schiff's base ligands obtained from the reaction of isoniazid with 4-(N,N-dimethylamino)benzaldehyde (L1) and 5-nitro-2-furfurldehyde (L2), respectively and their metal complexes with Cu2+, Zn2+, and Ni2+ ions. FT-IR, UV-Vis, conductivity, and magnetic susceptibility (µeff) measurements were used to describe the ligands (L1 and L2) and their complexes. The square planar geometry of Cu2+ and Ni2+ complexes, as well as the tetrahedral geometry of Zn2+ complexes, are supported by the Uv-Vis spectra and magnetic moments data. Their antibacterial effectiveness against various pathogenic microorganisms was evaluated in the presence of standard Kanamycin-30. The CuL2 complex, among all the metal complexes derived from the L2 ligand, exhibited better antibacterial activity against S. aureus than that of Kanamycin-30. When compared to the BHT antioxidant, all Cu2+ complexes showed excellent efficacy.