SYNTHESIS, CHARACTERIZATION, PROPERTIES AND THERMAL STUDY OF LANTHANOID ISOTHIOCYANATE COMPLEXES WITH 2,6-LUTIDINE-N-OXIDE (2,6-LNO)

Lanthanoid isothiocyanate complexes of general formula Ln(NCS)3(2,6-LN O)3(H2O)n, where n is 3, for Ln is La, n is 1, for Ln is Ce-Nd and Eu- Tb, and n is 0 for Ln is Tm, Lu, Y, were synthesized and characterized . They behave as non-electrolytes in acetonitrile. The anion is bonded through the nitrogen and 2,6-LNO through the oxygen. The nephelauxeti c parameter, covalent factor and Sinha's parameter and also the oscill ator strength in acetonitrile solution were calculated from the neodym ium absorption spectra. A C3v symmetry and a monocaped trigonal prisma tic geometry, with the water molecule located on the rotation axis, wa s deduced from the emission spectrum of the europium compound. The sim ilarities between the emission spectra of the europium complex and the europium-doped lanthanum and lutetium adducts suggests that the centr al ions are also involved in a C3v symmetry. The TG, DTG and DSC measu rement were recorded in dynamic air and nitrogen atmospheres and inter preted.