Synthesis and characterization of some lanthanide complexes of 2,6-diacetylpyridine 2-thenoylnicotinoyldihydrazone

The complexes of the type [Ln(H2dapthnh)Cl(H2O)2]-Cl2[Ln=La, Pr, Nd, Sm, Eu, Gd, Tb and Dy; H2dapthnh 2,6-diacetylpyridine- 2-thenoylnicotinoyldihydrazone] have been synthesized by reacting [Ln(Hdapth)Cl2(H2O)3]Cl [Hdapth=2,6-diacetylpyridinemono (2-thenoylhydrazone) with nicotinoylhydrazine in ethanol and characterized by analytical, molar conductance, IR, 1H NMR, electronic and FAB mass data. The position and shape of the hypersensitive transitions 4I9/2 -> 4G5/2, 2G7/2 in the neodymium complex indicate eight coordinate geometry around the Ln(III) ions. The symmetry of the eight coordinate Eu(III) and Tb(III) complexes has been determined from the emission spectra. (author)