Synthesis,Characterization and Antibacterial Activity of Some Transition Metal Complexes of 2-N-(isatinamino)-3-carboxyethyl-4,5,6,7-tetrahydrobenzo[b]thiophene

Metal complexes of Mn(II), Fe(II), Co(II), Ni(II), Cu(II) and Zn(II) with a Schiff base derived from isatin and 2-amino-3-carboxyethyl-4,5,6,7-tetrahydrobenzo[b]thiophene were synthesised and characterised by elemental analysis, conductance measurements, magnetic susceptibility, UV-Vis, IR, ¹H NMR and EPR spectral studies. The spectral data revealed that the ligand acted as a neutral tridentate, coordinating to the metal ion through the azomethine nitrogen, ester carbonyl and carbonyl oxygen of the isatin moiety. The EPR spectral data indicated that metal-ligand bonds have considerable covalent character. The copper(II) complex was subjected to X-ray diffraction and cyclic voltammetric studies. The ligand and the metal complexes were screened for their antibacterial activity and it has been observed that the metal complexes are more potent bactericides than the ligand.