Analytical and thermal investigations of new solid Y(III) and La(III) complexes

Abstract

New compounds with formulae Y(2,4′-bpy)1.5Cl3·8H2O (I), Y(2,4′-bpy)0.5Br3·8H2O (II), La(2,4′-bpy)Cl3·5H2O (III) and La(2,4′-bpy)1.5Br3·5H2O (IV) were prepared and characterized by chemical and elemental analysis, IR spectroscopy and powder X-ray diffraction. The thermal properties of compounds in the solid state were studied using TG-DTA techniques under dry air atmosphere. The thermal behavior of investigated compounds was studied in the temperature range 298–1273 K. They are stable up to 323 K. The complexes decompose in several stages, accompanied by endo- and exothermic effects. In all cases, the first step of pyrolysis is partial or total dehydration. When the temperature rises, deamination takes place. The solid final products of decomposition are Y2O3 and La2O3, respectively. Additionally, for all complexes mass spectrometry was used to analyze principal volatile thermal decomposition and fragmentation products evolved during pyrolysis under dry air atmosphere.