Synthesis, characterization, and biological activity of Cu(II), Ni(II), and Zn(II) complexes of a tridentate heterocyclic Schiff base ligand derived from thiosemicarbazide and 2-benzoylpyridine

Ni(II), Cu(II), and Zn(II) complexes of the tridentate heterocyclic ligand, 2-(phenyl(pyridin-2-yl)methylene)hydrazine-1-carbothioamide (HL) have been synthesized characterized by various spectroscopic techniques elemental analyses. Infrared spectroscopy shows that ligand coordinates to metal ions through azomethine pyridine nitrogen atoms as well sulfur atom thioamide group form a chelate system. In vitro screening against four bacterial strains (Staphylococcus aureus (ATCC 43300), Klebsiella pneumoniae 700603), Methicillin resistant staphylococcus 33591), Shigella flexneri (NR 518)) fungal (Candida albicans 29444), Candida 29445), 29451), krusei (HM 1122)) indicate Cu(II) complex showed good antibacterial activity on 33591) while moderate some fungi strains. Antioxidant studies reveal are more potent than eliminate free radicals, with Ni(II) showing best radical scavenger.