SYNTHESIS AND CHARACTERIZATION OF SOME LANTHANIDE(III) CHELATES OF SOME SCHAFFER ACID AZO DYES

A series of trivalent lanthanide chelates of the type {[}Ln(PHNSA) (H2O)n] (2 Cl) (where Ln3+ = Pr, Nd, Sm, Eu, Gd, Dy, Er, Yb or Lu; PHNSA = 2-(X)-phenylazo-2-hydroxynaphthalene-6-sulphonic acid; X = H, Cl, OCH3, CH3 and SO3H) have been synthesized and characterized by elemental and thermal analysis, molar conductance, IR, H-1 NMR (for diamagnetic complexes), electronic spectra and magnetic susceptibility measurements. IR data along with those of the H-1 NMR unequivocally proved that the coordination of the ligands to the metal ions took place in a bidentate fashion through the oxygen of the hydroxyl group and the nitrogen of the azo group. The mapetic moment values showed little deviation from Van Vleck values.