A nuclear resonance study of tris(2-arylazophenolato)cobalt(III)

Tris-chelates of cobalt(III) derived from a few 2-arylazophenols are reported. A convenient method of synthesis involves the reaction of hexamminecobalt(III) chloride with the sodium salt of the ligand. No evidence could be obtained for the existence of the sterically unfavourable cis form. A claim that tris(2-phenylazo-4-methylphenolato)Co^III can be exist in cis and trans forms cannot be reconciled with nuclear resonance and other data. Nor did we succeed in isolating the cis form