Synthesis, characterisation and antimicrobial activities of mixed ligand complexes of Mn (II), Fe (II) and Co(II) containing N,N'-bis (o-anisaldehyde) p-phenylenediamine (tetradentate schiff base) and gylcine

Abstract

Complexes of Mn(II), Fe(II) and Co(II) containing N, N’-bis[o-anisaldehyde]p-phenylenediamine tetradentate Schiff base as primary ligand and glycine as secondary bidentate ligand have been synthesized by reflux in 1:1:1 mole ratio and characterized both analytically and spectroscopically. Molar conductance measurement (69.02 to 86.30Ω^–1 cm² mol^–1) of the complexes indicated they are weak electrolyte and magnetic susceptibility measurement shows values in range of 4.53 to 5.59BM indicating their paramagnetism. The infrared data suggested that the Schiff base coordinated via the two nitrogen atoms of the azomethine groups (1628 to 1680 cm^-1) and the oxygen atoms of the adjacent methoxy groups (1341 to 1389 cm^-1), while glycine coordinated via the nitrogen atom of the amino group (3060-3324 cm^-1) and the oxygen atom of the carboxylate anion. Based on the analytical and spectroscopic data the complexes may be assigned an octahedral geometries and molecular formulae of the form [M(L)Gly], where M = Mn, Fe and Co, L=Schiff base and Gly = glycine. The Schiff base and its mixed ligand complexes were screened for antimicrobial activity against Staphylococcus aureus, Escherichia coli, Salmonella typhi, Mucor inducus and Aspergillus fumigatus. The complexes exhibited enhanced antimicrobial activity (10mm to 18mm) at 60 µg/disc as compared to 10mm activity of the uncoordinated Schiff base at the same concentration.

Keywords: Mixed ligand complex; Schiff base, Glycine, p-phenylenediamine, o-anisaldehyde