Synthesis and characterisation of mixed ligand dinuclearmetal(II) complexes of anthranilic acid and pyridine-2-aldoxime

Abstract

Mn(II), Ni(II), Co(II), Cu(II), Zn(II) and Cd(II) complexes of anthranilic acid (L₁H) and pyridine-2-aldoxime (L₂H) were synthesized in an alkaline medium. The resulting complexes were characterized by CHN analysis, infrared and UV-Visible spectroscopies, molar conductance and magnetic susceptibility measurements. The CHN analyses showed the stoichiometries adopted by the mixed ligand complexes weredinulear[M₂L₁L₂(OH)₂].xH₂O (M = Mn, Co, Cd), [Ni₂(L₁)₂(OH)₂], [Cu₂(L₂)₂Cl₂].C₂H₅OH and [Zn₂L₁L₂(SO₄)(H₂O)₂]. The infrared spectra establishedthe coordination ofL₁H as a bidentate anthranilate (L₁^–) through the carboxylate oxygen and amine nitrogen, and the deprotonated L₂H was bound to the metal ions through the pyridine and oxime nitrogen atoms. The reflectance spectra and magnetic moments of the metal complexes gave credence to their arrangement in a tetrahedral geometry. The conductance measurements revealed that the behavior of the complexes as non-electrolytes in DMF. Cd(II) complex showed promising inhibitory activity against Staphylococcus aureus, Bacillus subtilis, Escherichia coli, Pseudomonas aeruginosa and Candida albicans.

Keywords: Mixed ligand, dinuclearcomplexes, anthranilic acid, pyridine-2-aldoxime, spectral properties