Thermochimica Acta, Vol.228, 137-146, 1993
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-LNO)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 nephelauxetic parameter, covalent factor and Sinha’s parameter and also the oscillator strength in acetonitrile solution were calculated from the neodymium absorption spectra. A C3v symmetry and a monocaped trigonal prismatic geometry, with the water molecule located on the rotation axis, was deduced from the emission spectrum of the europium compound. The similarities between the emission spectra of the europium complex and the europium-doped lanthanum and lutetium adducts suggests that the central ions are also involved in a C3v symmetry. The TG, DTG and DSC measurement were recorded in dynamic air and nitrogen atmospheres and interpreted.