Preparation, properties, spectral (IR, electronic, FAB-MS and PXRD) and magnetic characterization of some lanthanide complexes containing tridentate thiosemicarbazone ligand

Schiff bases, containing 'S' donor atom, such as benzophenonethiosemicarbazone (btscH), salicylidenethiosemicarbazone (stscH) and bis-salicylidenethiosemicarbazone (bstscH) have been reacted with methanolic solution of LnCl(3)center dot 7H(2)O (Ln = La-III Ce-III) followed by addition of the saturated solution of KOH (in EtOH) in different molar ratio(s), afforded a variety of lanthanum(III) chloride Schiff base complexes of the type, [Cl(2)Ln(L)center dot 4H(2)O] and [ClLn(L)(2)center dot 3H(2)O] (where L = btscH, stscH, bstscH and Ln = La-III and Ce-III). These complexes have been characterized by elemental analysis, molar conductance, spectral (IR, UV-Visible and FAB-mass) as well as magnetic studies. X-Ray powder diffraction on two of the complex was recorded on Rigaku Model D/Max-2200 PC using Cu-K alpha, radiation (lambda = 1.5406 angstrom). The crystallite size of the complexes [ClLa(bstsc)(2)center dot 3H(2)O] (6) and [C1Ce(bstsc)(2)center dot 3H(2)O] (12) were found to be 280 and 191 angstrom respectively. On the basis of these physico-chemical data a tentative structure for these complexes have been proposed. These complexes were found to be soild and were soluble in Lewis bases such as in DMF and DMSO or pyridine.