YTTRIUM AND LANTHANIDE NITRATE COMPLEXES OF 2,3-DIMETHYL-4-FORMYL(BENZ HYDRAZIDE)-1-PHENYL-3-PYRAZOLINE-5-ONE

ABSTRACT

Complexes of yttrium and lanthanide nitrates with the Schiff base 2,3-dimethyl-4-formyl(benzhydrazide)-1-phenyl-3-pyrazoline-5-one (L) have been synthesized and characterized by elemental analyses, electrical conductance in non-aqueous solvents and electronic as well as infrared spectra. The complexes have the general molecular formulae [Ln(L)₂(NO₃)]-(NO₃)₂ (Ln=Y, La, Pr, Nd, Sm, Eu, Gd, Dy, Ho or Er). The ligand chelates with the metal ion in a neutral tridentate fashion through both carbonyl oxygens and the azomethine nitrogen in all of these complexes. One of the nitrate ions is monodentately coordinated and the other two remain as counter ions. A coordination number of seven is assigned to the metal in all of these complexes. The covalency parameters evaluated from solid and solution phase electronic spectra suggest weak covalent character of the metal-ligand bond.

ACKNOWLEDGMENTS

The authors are indebted to Mahatma Gandhi University, Kerala, India, for providing laboratory facilities and awarding a Junior Research Fellowship to one of us (GAK). We also thank the Heads of the Regional Sophisticated Instrumentation Centre, Indian Institute of Technology, Chennai, and the Indian Institute of Technology, Mumbai, for some instrumental analyses. Also, we wish to express our heartfelt thanks to Dr. Siby Joseph and Dr. N. T. Madhu, for some fruitful discussions.