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

We report the synthesis and crystal structure of anhydrous cerium(III) acetate [Ce(CH 3 COO) 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 [Ce 2 (CH 3 COO) 6 (H 2 O) 2 ]·H 2 O ( 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(CH 3 COO) 3 (H 2 O)] (2) , instead another hitherto unknown metastable cerium(III) acetate hydrate ( 4 ) was observed. It was only possible to determine a sum formula of Ce 2 (CH 3 COO) 6 (H 2 O) 2 for 4 .