Synthesis, structural studies and bio-activity of some metal(II) complexes with glyoxal salicylaldehyde acyldihydrazones

Abstract

Complexes of the type [M(gssdh)]Cl and [M(gspdh)]Cl, where M = Co(II), Ni(II), Cu(II), Zn(II) and Cd(II), Hgssdh = glyoxal salicylaldehyde succinic acid dihydrazone and Hgspdh = glyoxal salicylaldehyde phthalic acid dihydrazone, have been synthesized and characterized by elemental analyses, molar conductance, magnetic moments, electronic, ESR and IR spectra and X-ray powder diffraction studies. The metal complexes are insoluble in common organic solvents and are 1 : 1 electrolytes. The magnetic moment values and electronic spectra indicate a spin–free octahedral geometry for all Co(II), Ni(II) and Cu(II) complexes. ESR spectral parameters of Cu(II) complexes suggest an elongated tetragonally–distorted octahedral stereochemistry around copper. Both ligands are monobasic hexadentate ligands coordinating through three >C=O, two >C=N– and a deprotonated phenolate group to the metal. X-ray powder diffraction parameters for three of the complexes correspond to an orthorhombic crystal lattice. The complexes show appreciable activity against various fungi and bacteria.