Two Ce(SO4)2·4H2O polymorphs: Crystal structure and thermal behavior
Artikel i vetenskaplig tidskrift, 2007

Syntheses, crystal structures and thermal behavior of two polymorphic forms of Ce(SO4)2·4H2O are reported. The first modification, α-Ce(SO4)2·4H2O (I), crystallizes in the orthorhombic space group Fddd, with a=5.6587(1), b=12.0469(2), c=26.7201(3) Å and Z=8. The second modification, β-Ce(SO4)2·4H2O (II), crystallizes in the orthorhombic space group Pnma, with a=14.6019(2), b=11.0546(2), c=5.6340(1) Å and Z=4. In both structures, the cerium atoms have eight ligands: four water molecules and four sulfate groups. The mutual position of the ligands differs in (I) and (II), resulting in geometrical isomerism. Both these structures are built up by layers of Ce(H2O)4(SO4)2 held together by a hydrogen bonding network. The dehydration of Ce(SO4)2·4H2O is a two step (I) and one step (II) process, respectively, forming Ce(SO4)2 in both cases. During the decomposition of the anhydrous form, Ce(SO4)2, into the final product CeO2, intermediate xCeO2·yCe(SO4)2 species are formed.

X-ray diffraction

cerium sulfate

thermogravimetry

differential scanning calorimetry

tetrahydrated ceric sulfate

sulfate decomposition

Författare

Barbara M. Casari

Göteborgs universitet

Vratislav Langer

Chalmers, Kemi- och bioteknik, Oorganisk miljökemi

Journal of Solid State Chemistry

0022-4596 (ISSN) 1095-726X (eISSN)

Vol. 180 1616-1622

Ämneskategorier

Oorganisk kemi

DOI

10.1016/j.jssc.2007.02.017