Synthesis and spectral characterization of some deprotonated rare earth metal complexes

Trivalent rare earth metal complexes of N-(3,4-diaminobenzophenonimino)-2-benzamidoethanamide (Hdabbe) of the type [Ln(dabbe)(2)OH(H2O)(2)], where Ln = La, Pr, Nd, Sm, Eu, Gd, Tb, Dy and Y, have been synthesized and characterized by elemental analyses, electrical conductance, magnetic susceptibility, electronic, IR and NMR (H-1, and C-13) spectral techniques. The bonding parameters beta, b(1/2), % delta and eta were calculated from the electronic spectral bands of the Pr(III), Nd(III), Sm(III) and Dy(III) complexes and suggest weak covalent bond formation in the complexes. The theoretical oscillator strengths (P-calcd) calculated from the Judd-Ofelt equation were found to be in reasonable agreement with the experimental values. The IR and NMR spectral data suggest a uninegative bidentate nature of Hdabbe in the complexes.