Thermal decomposition of rare earth element 2,4-dihydroxybenzoates in air

Abstract

The conditions of the formation of rare earth 2,4-dihydroxybenzoates were studied, and their quantitative composition and solubilities in water at 293 K were determined. The IR spectra and X-ray diffraction patterns of the hydrated complexes were recorded and their thermal decompositions in air were investigated. During heating, the hydrated complexes Ln(C 7H 5O 4) 3 · nH 2O ( n = 2, 4) lose water of crystallization in one step, then decompose to the oxides, with intermediate formation of very unstable Ln 2(C 7H 5O 4) 3 and Ln 2O(C 7H 4O 4) 2 compounds, with the exception of cerium which forms only Ce 2(C 7H 5O 4) 3.