Simple and mixed complexes of cobalt(II) and cobalt(III) ions

Bivalent and trivalent cobalt complexes with 1-(2-pyridylazo)-2-naphthol (PAN), PAN+1, 10-phenanthroline and PAN+2, 2′-bipyridyl were prepared and characterized by physico-chemical and magnetic measurements. The spectral studies suggest that PAN behaves as a bidentate ligand and is coordinated to metal ions through oxygen and (pyridine) nitrogen, whereas 1, 10-phenanthroline and 2, 2′-bipyridyl are coordinated through (pyridine) nitrogen. The tentative ν(M−O) and ν(M−N) band assignments in the lower i.r. region, and magnetic moment data favour four coordination for the complexes studied.