Synthesis, characterization and antitumor activity of manganese(II), cobalt(II), nickel(II), copper(II), zinc(II) and platinum(II) complexes of 3- and 5-substituted salicylaldehyde benzoylhydrazones

Abstract

Complexes of Mn(II), Co(II), Ni(II), Cu(II), Zn(II) and Pt(II) with 3- and 5-substituted salicylaldehyde benzoylhydrazones (XSBH, X = H, 3-NO 2, 3-CH 3O, 5-Br, 5-Cl, 5-CH 3 or 5-NO 2) were prepared and characterized by elemental analyses, conductance measurements, magnetic moments (300−78 K) and spectral studies. On the basis of these studies the following structures are suggested: distorted octahedral for Mn(XSBH) 2, dimeric, low-spin, five- coordinate for Ni(XSBH)Cl·2H 2O, dimeric, high-spin, five-coordinate for Co(XSBH)Cl·2H 2O, dimeric four- coordinate for Zn(XSBH) and a square-planar structure for M(XSBH)Cl·H 2O (M = Cu(II) or Pt(II)). The polycrystalline ESR spectra of Cu(II) complexes are isotropic and indicate a d x2− y2 ground state in square-planar stereochemistry. All the metal(II) complexes were screened for their antitumor activity against the P388 lymphocytic leukaemia test system in mice and were found to possess no significant activity at the dosages used.