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

Complexes of Cu(II) with five arylazopyrazolones derived from isoniazid and substituted phenylazoethyl-acetoacetates and two Co(II) complexes with N1-isonicotinoyl-3-methyl-4-phenylazopyrazoline have been synthesised. The arylazopyrazolones act as neutral bidentate ligands, bonding to the metal through the azo nitrogen and hydroxyl oxygen. The complexes are non-electrolytes in DMSO and acetonitrile, showing that the anions are coordinated to the metal. Analytical, magnetic and electronic spectral data indicate an octahedral geometry for the chloro complexes and tetrahedral geometry for the bromo complexes of Cu(II). The Co(II) complexes are tetrahedral irrespective of the nature of the anion.