Synthesis and Structural Studies on Transition Metal Complexes Derived from 1-(2- Thienyl)-1-ethanole-1H-benzimidazole-2-yl-hydrazone

Abstract

Transition metal complexes of Cr(III), Fe(III), Mn(II), Co(II), Ni(II), Cu(II) and Zn(II) with 1-(2-thienyl)-1-ethynyl-1H-benzimidazole-2-yl-hydrazone (TEBH) have been synthesized. The ligand and its metal complexes were characterized by analytical data, conductance measurements, thermogravimetric and differential thermal analyses, magnetic susceptibility measurements, infrared, ¹H NMR, electronic, mass and ESR spectral studies. All the complexes possess the general formulae [M(II)LCl₂×H₂O] and [M(III)LCl₃], where L = TEBH. Infrared spectral data suggest that the ligand TEBH behaves as a neutral tridentate ligand with N : N : S donor sequence. On the basis of spectral and analytical data it is proposed that all the complexes possess an octahedral geometry. The ligand and its metal complexes were screened for their physiological activities against E. coli and S. aureus. The order of activity has been found to be Ni(II) > Cr(III) > Co(II) > Fe(III) > Cu(II) > Zn(II) > ligand against E. coli and Cu(II) > Ni(II) > Cr(III) > Zn(II) > Fe(III) > Mn(II) > ligand against S. aureus.