Synthesis and Characterization of Anhydrous Cerium(III) Acetate, [Ce(CH3COO)3], and its Interconversions to Hydrated Phases

Abstract

We report the synthesis and crystal structure of anhydrous cerium(III) acetate [Ce(CH3COO)3] (1) as well as the interconversions to different hydrated phases. The structure determination of 1 was achieved by Rietveld refinement against powder X-ray diffraction (PXRD). Additionally, the thermal properties of 1 were investigated by thermogravimetry (TG) and variable-temperature PXRD (VT-PXRD) and a complete characterization was performed. 1 was prepared by solvothermal treatment of the sesquihydrate [Ce2(CH3COO)6(H2O)2]& centerdot;H2O (3). The dehydration is reversible and 1 can be transformed back to 3. Using VT-PXRD the transformation of 3 to 1 was studied. The step-wise dehydration does not proceed through [Ce(CH3COO)3(H2O)] (2), instead another hitherto unknown metastable cerium(III) acetate hydrate (4) was observed. It was only possible to determine a sum formula of Ce2(CH3COO)6(H2O)2 for 4.