Synthesis, Spectral Characterization and Biological Activity of Metal(II) Complexes of 2,4,5-Trimethoxybenzaldehyde-S-Benzyldithiocarbazone

Abstract

2,4,5-Trimethoxybenzaldehyde was condensed with S-benzyldithiocarbazate to give Schiff base 2,4,5-trimethoxy benzaldehyde-S-benzyldithiocarbazone (BBTC), which was used for complexation with Mn(II), Fe(II) and Co(II) metal ions. The complexes were formulated as M(BBTC)2X2 where X is Cl−, NO3− and CH3COO−. The FTIR spectra of the metal complexes in comparison to that of free ligand suggested the coordination through azomethine nitrogen and thion sulphur forming six membered chelating with metal ion. The magnetic susceptibility and electronic spectral bands revealed octahedral symmetry (Oh) around Mn(II) but tetragonally distorted octahedral symmetry (D4h) of Fe(II) and Co(II) complexes. The positive value of Dt for Fe(II) (68.42-135.2 cm-1) and Co(II) (263-280 cm-1) clearly indicated elongation along z-axis in these complexes which was also supported by the less value of Dq(z) than Dq(xy) for the metal complexes. The ligand as well as its metal complexes have been found active against the bacteria Escherichia coli and Staphylococcus aureus, and antibacterial activity of the free ligand has been observed to have enhanced in metal complexes.