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

Abstract

New compounds with formulae Y(2,4 0-bpy) 1.5 Cl 3 Á8H 2 O (I), Y(2,4 0-bpy) 0.5 Br 3 Á8H 2 O (II), La(2,4 0-bpy)Cl 3 Á5H 2 O (III) and La(2,4 0-bpy) 1.5 Br 3 Á5H 2 O (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 Y 2 O 3 and La 2 O 3 , 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. Keywords Y(III) and La(III) complexes Á 2,4 0-Bipyridine Á TG-DTA Á Mass spectra & Agnieszka Czylkowska