Published Paper Details:

The coordination complexes of Co (II), Ni (II) and Cu (II) were prepared from tridentate Schiff base. The Schiff base ligand was synthesized by the condensation of 3-ethoxy- 4-hydroxy benzaldehyde with 2-amino butanoic acid. The ligand and its metal complexes were characterized by elemental analysis, molar conductance, electronic spectra, IR spectra, NMR spectra, electrical conductivity and magnetic susceptibility. The transition metal complexes are colored and stable in air. In the metal complexes the metal -ligand found to be 1:1. A sharp band at 1625 cm-1 is characteristics of the azomethine group present in the Schiff base ligand. This band was shifted to lower frequency (1585 � 1605 cm-1) in all the metal complexes, which indicates the coordination of the azomethine nitrogen to metal ion in complexes. The IR spectra of the free ligand having phenolic (-OH) group showed a broad band at 3450 cm-1, the disappearance of this band in metal complexes indicates the deprotonation of the hydroxyl group and coordinated through oxygen atom. A band at 1690 cm-1 is assigned to ?(C=O) stretching frequency of ligand, which is shifted to lower regions (1612-1640 cm-1) in metal complexes indicating the coordination of oxygen atom with metal ion after deprotonation of -COOH group. The molar conductivity data of the complexes in DMSO solution indicates they are non-electrolytic nature. On the basis of magnetic susceptibility and electronic spectral data Co (II) and Ni (II) complexes have tetrahedral geometry, while Cu (II) complex square planar geometry has been suggested. The synthesized Schiff base complexes exhibit higher antimicrobial activity than the free Schiff base ligand.