Abstract
The Co(II), Ni(II), and Cu(II) chelates with four heterocyclic azo compounds have been prepared and characterized. Characterization of the solid so obtained was accomplished by elemental and thermogravimetric analysis, electronic and IR spectra, as well as conductivity measurements. The dyes are characterized by high tendency towards complex formation with neutral molecules coordinated to the metal ion as bidentate ligands. The different bands observed in the visible spectra of methanolic solutions of the complexes have been assigned to the possible electronic transition type (L-M CT and d-d).