THERMAL-DECOMPOSITION OF RARE-EARTH ELEMENT ENANTHATES

The conditions of formation of Y, La and lanthanide (from Ce(III) to L u) enanthates were worked out, their composition and their solubilitie s in water at 291 K were determined, and the conditions of their therm al decomposition were studied. They were prepared as crystalline solid s with general formula Ln(C7H13O2)3.nH2O, where n = 2-10. On heating, they decompose in two or three steps. They first lose some water molec ules and then decompose to the oxides directly (salts of Y and heavy l anthanides) or via the intermediate formation of Ln2O2CO3 (salts of La , Pr, Nd, Sm and Eu). Only yttrium enanthate dihydrate loses 2 water m olecules on heating to form an anhydrous complex, which decomposes dir ectly to Y2O3. The temperatures of dehydration are similar for all com plexes (323-343 K), while the temperatures of oxide formation vary irr egularly from 823 K for CeO2 to 1078 K for La2O3.