Synthesis, Characterization and Antibacterial Activity of Co(II) and Cu(II) Complexes of N,N'-bis-(salicylidene)-o-tolidine

Co(II) and Cu(II) complexes of Schiff base N,N'-bis-(salicylidene)-o-tolidine (OTSA) are reported and characterized based on elemental analyses, IR, EPR, solid reflectance, magnetic moment, molar conductance and cyclic voltammogram. Their low electrical conductance values indicate that all the complexes are non-electrolytes. The obtained spectral data suggest that Co(II) complexes have distorted octahedral geometry and Cu(II) complexes have pseudo-tetrahedral, distorted octahedral and square-planar geometry, depending on the copper salt and the molar ratio ligand: copper ion used. In all complexes, OTSA acts as binegative tetradentate, around the metallic ion, while in 3 and 6 acts as mononegative bidentate. The synthesized compounds have been tested against Staphylococcus aureus ATCC 25923; Enterococcus faecalis ATCC 29212, Escherichia coli ATCC 25922; Pseudomonas aeruginosa ATCC 27853. A comparative study of the MIC values indicates that the tetracoordinated complexes have better action than the hexacoordinated compounds and the Cu(II) complexes are more active than Co(II) complexes.