Abstract

K. Selvaraj* and C. Theivarasu

en new gadolinium (III) nitrate complexes with variously substituted 2,6-diphenylpiperidin-4-ones (L1-L10) have been prepared in ethanol. These complexes with the general formula [Gd(L)(NO3)2(H2O)]NO3H2O have been characterized by elemental analysis, molar conductance, magnetic and thermal studies and infrared spectra. Molecular weights of the complexes were determined by cryoscopic method using camphor as the solvent. Molar conductance data show that these complexes are 1:1 electrolytes. The IR spectral data reveal the participation of water molecules and thermal studies confirm the presence of one lattice-held and two coordinated water molecules. IR spectra, elemental analyses and molar conductance data suggest that these complexes contain one ionic and two bidentate nitrate groups. Although piperidin-4-ones have two coordinating sites, namely the ring nitrogen and carbonyl group, IR spectral evidence is in favour of the ring nitrogen as the coordinating group and not the carbonyl group, thereby indicating that these ligands are monodentate. All the observations lead to the conclusion that the gadolinium has a coordination of seven in these complexes.

Gadolinium(III) complexes; Piperidin-4-ones

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