Synthesis, characterization of some transition metal(II) complexes of acetone p-amino acetophenone salicyloyl hydrazone and their anti microbial activity

Abstract

Complexes of the type [M(apash)Cl] and [M(Hapash)(H₂O)SO₄], where M = Mn(II), Co(II), Ni(II), Cu(II) and Zn(II); Hapash = acetone p-amino acetophenone salicyloyl hydrazone have been synthesized and characterized by elemental analyses, molar conductance, magnetic moments, electronic, ESR and IR spectra, thermal studies (TGA & DTA) and X-ray diffraction studies. The ligand coordinates through two >C=N and a deprotonated enolate group in all the chloro complexes, whereas through two >C=N– and a >C=O group in all the sulfato complexes. The electronic spectra suggest a square planar geometry for Co(II), Ni(II) and Cu(II) chloride complexes and an octahedral geometry for the sulfate complexes. ESR data show an isotropic symmetry for [Cu(apash)Cl] and [Cu(Hapash)(H₂O)SO₄] in solid state. However, ESR spectra of both Cu(II) complexes indicate the presence of unpaired electron in \( {\text{d}}_{{{\text{x}}^{2} - {\text{y}}^{2} }}. \) The X-ray diffraction parameters for [Co(apash)Cl] and [Cu(Hapash)(H₂O)SO₄] complexes correspond to a tetragonal and an orthorhombic crystal lattices, respectively. Thermal studies of [Co(apash)Cl] complex shows a multi-step decomposition pattern. Most of the complexes show better antifungal activity than the standard miconazole against a number of pathogenic fungi. The antibacterial activity of these complexes has been evaluated against E. coli and Clostridium sp. which shows a moderate activity.