Synthesis, Characterization and Antibacterial Activity of Copper(II) and Cobalt(II) Vanillin-Aniline Schiff base Complexes

Abstract

Two novel Copper (II) and Cobalt (II) complexes of aniline-vanillin schiff base were synthesized, characterized and examined for their antibacterial activity. The structures and geometry of schiff base and complexes were determined on the basis of elemental analysis (H, C and N), ¹H NMR, ¹³C NMR, FT-IR spectra, AAS and magnetic susceptibility measurements. The electronic spectra of Cobalt(II) complex exhibited band at 438nm due to (d-d) electronic transition type ⁴T₁g ⁴T₁g (F) suggesting a high spin octahedral geometry whereas the electronic spectra of Copper(II) complex exhibited band at 404nm and 533nm due to LMCT and (d-d) electronic transition ³A₂g ³T₂g type, respectively, suggesting a low spin a distorted octahedral geometry. The synthesized schiff base, Copper (II) and Cobalt (II) complexes were screened for their antibacterial activity against Escherichia coli, S.aureus, K.pneumonia and Protein mirabilis. The schiff base showed better activity (17mm zone of inhibition) towards K. pneumonia compared to that of gentamicine (15mm zone of inhibition) whereas both the schiff base and Copper (II) complex displayed promising activity (12 and 13mm zone of inhibition, respectively) against E. coli compared to that of gentamicine (14mm zone of inhibition).

Keywords: Antibacterial activity, synthesis, schiff base, vanillin, metal complexes