TRANSITION-METAL COMPLEXES OF ALIZARIN YELLOW-R, ITS MIXED-LIGAND ANDMIXED-METAL CHELATES

The entitled transition metal complexes were produced via the interact ion of the chloride salts Of Fe(III), Co(II), Ni(II) and Cu(II) with A lizarin Yellow R, alone and mixed with pyrogallol in aqueous media and in the presence of ammonia except Fe(III). The characterization of th ese complexes was achieved using microchemical analyses, infrared and Nujol mull electronic spectra. They were neutral with no chloride ions either in or outside the coordination sphere, all with melting points higher than 300-degrees-C. It was deduced that the active donating si tes of the ligands towards the central metal ion were the phenolate an d carboxylate oxygen atoms with no participation of the azo nitrogen i n chelation. Oxygen bridges were involved in the homo and hetero Cu(II ) complexes. Also, the participation of the neutral molecules (i.e. H2 O, NH3) and hydroxyl ions in the composition of these complexes were o bserved. An octahedral spatial configuration was suggested for these m etal chelates.