Synthesis and Characterization of Some Seven Coordinated Complexes of Lanthanide(iii) Perchlorates with 4-[n-(4‘- Ethylbenza-lideneamino)]- Antipyrine Semicarbazone as Primary Ligand and Pyridine as Secondary Ligand

Abstract

Mixed ligands complexes of lanthanide(ΙΙΙ) perchlorates obtained from 4-[N-(ethylbenzalideneamino)]-antipyrine semicarbazone (ebaaps) as primary ligand and pyridine(py) as secondary ligand have been synthesized and characterized. The analytical studies on these compounds include elemental analyses, molecular weight determination, molar conductance, and magnetic susceptibility, infrared and electronic spectra. The primary ligand, (ebaaps), in these complexes behaves as neutral tridentate (O,N,N) while the secondary ligand pyridine(py) acts as unidentate nitrogen donor. The general composition of these complexes may be given as [Ln(ebaaps) 2 .py](ClO4) 3 , [ Ln = La, Pr, Nd, Sm, Gd, Tb, Dy or Ho]. The values of nephelauxetic effect (β), covalence factor (b 1/2 ), Sinha parameter (δ %) and the angular overlap parameter (η) of the complexes have been calculated, and their thermal stabilities worked out by TGA.