SYNTHESIS AND STRUCTURAL STUDIES OF SOME LANTHANIDE COMPLEXES OF SALICYLALDEHYDE ANTHRANOYL HYDRAZONE

Abstract

Lanthanide complexes of the types Ln(sah)(OAc)·xH₂O and Ln′(Hsah)₂(X)·xH₂O [Ln=Y, La, Nd, Gd, Tb and Dy; Ln′=Pr and Sm, X=NO₃ and Cl; H₂sah=salicylaldehyde anthranoyl hydrazone were synthesized and characterized by various physico-chemical techniques. The complexes are coloured and highly soluble in methanol, DMSO and DMF. Dehydration studies indicate the presence of both lattice-held and coordinated water molecules. IR, electronic and ¹H NMR spectra have been recorded to establish the bonding sites of the ligand. Solution-state conductance measurements indicate the non-electrolytic nature of all of the complexes while solid-state electrical conductivity studies show Nd(sah)(OAc)·4H₂O to be a semiconductor. Optical band gap measurements show the Pr, Sm and Dy complexes are direct band gap materials. X-ray diffraction patterns of selected complexes indicate orthorhombic structures.

Acknowledgments

The authors thank the Head, Department of Chemistry, Faculty of Science, Banaras Hindu University, for providing laboratory facilities, Prof. D. Pandey, School of Materials Science, Institute of Technology, Banaras Hindu University, for permitting the use of the X-ray facility, the Central Drug Research Institute, Lucknow for elemental analyses and the Director, Royal Drug Research Laboratory, Kathmandu, Nepal, for recording the electronic spectra. One of the authors (TRR) thanks the Council of Scientific and Industrial Research, New Delhi, for financial assistance in the form of a research project [No. 01(1437)/97/EMR-II].