Abstract

A total of four new lanthanide complexes of {(5-phenyl-1,3,4-oxadiazol-2-yl)thio}acetic acid (ligand, HL) with the metal ions [La(III), Nd(III), Gd(III) and Dy(III)] have been successfully prepared in alcoholic medium. The complexes obtained are characterized quantitatively and qualitatively by using microelemental analysis, Fourier transform infrared spectroscopy (FTIR) spectroscopy, ultraviolet-visible spectroscopy, mass spectroscopy, ¹H & ¹³C NMR, magnetic susceptibility and conductivity measurements. From the spectral study, all the complexes were obtained as monomeric structure and the metals centre moieties are six-coordinated with distorted octahedral geometry. The preliminary in vitro antibacterial screening activity revealed that complexes 1 to 4 showed a significant activity compared to the ligand, HL and all the complexes exhibited antimicrobial activity especially againstEscherichia coli.

Key words: {(5-phenyl-1,3,4-oxadiazol-2-yl)thio}acetic acid, lanthanide complexes, in vitroantibacterial activity.