COPPER(II) AND COBALT(II) COMPLEXES OF ARYLAZOPYRAZOLONES

Complexes of Cu(II) with five arylazopyrazolones derived from isoniazi d and substituted phenylazoethyl-acetoacetates and two Co(II) complexe s with N1-isonicotinoyl-3-methyl-4-phenylazopyrazoline have been synth esised. The arylazopyrazolones act as neutral bidentate ligands, bondi ng to the metal through the azo nitrogen and hydroxyl oxygen. The comp lexes are non-electrolytes in DMSO and acetonitrile, showing that the anions are coordinated to the metal. Analytical, magnetic and electron ic spectral data indicate an octahedral geometry for the chloro comple xes and tetrahedral geometry for the bromo complexes of Cu(II). The Co (II) complexes are tetrahedral irrespective of the nature of the anion .