SYNTHESIS AND CHARACTERIZATION OF COBALT(II), NICKEL(II), COPPER(II) AND ZINC(II) COMPLEXES WITH ACETYLACETONE BIS-BENZOYLHYDRAZONE AND ACETYLACETONE BIS-ISONICOTINOYLHYDRAZONE

Acetylacetone bis-benzoylhydrazone (PhCONHN=CMe)2-CH2(LH2) and acetyla cetone bis-isonicotinoylhydrazone (NC5H4CONHN=CMe)2CH2(L'H-2) complexe s of the types [ML] and [ML'] (M = Co(II), Ni(II), Cu(II) or Zn(II)) h ave been prepared and characterized. All the complexes are non-electro lytes and the cobalt(II) complexes are low-spin, the nickel(II) comple xes are diamagnetic and the copper(II) complexes are paramagnetic. The ligands chelate via two C=N groups and two deprotonated enolate group s. The e.s.r. spectra of the copper(II) complexes indicate a tetragona lly distorted dimeric structure. The X-ray diffraction parameters for [CoL] and [NiL'] correspond to a tetragonal crystal lattice.