Structural study of the two new caesium sulfate and selenate tellurate Cs2SO4·Te(OH)6 and Cs2SeO4·Te(OH)6

• Published in: The international journal of inorganic materials Vol. 3; no. 7; pp. 861 - 873
• Main Authors: Dammak, Med, Mhiri, T, Jaud, J, Savariault, J.M
• Format: Journal Article
• Language: English
• Published: Elsevier Ltd 01.11.2001
• Subjects: Caesium tellurate; Crystal structure; Caesium tellurate; Crystal structure
• ISSN: 1466-6049; 1466-6049
• DOI: 10.1016/S1466-6049(01)00094-0

Two new alkali tellurates Cs2SO4·Te(OH)6 (CsSTe) and Cs2SeO4·Te(OH)6 (CsSeTe), are obtained by action of telluric acid H6TeO6 with respectively, caesium sulfate Cs2SO4 and caesium carbonate Cs2CO3 and selenic acid H2SeO4. CsSTe is rhombohedric, R3, with a=b=7.4790(3) Å, c=16.6370(6) Å, Z=3, V=805.92(5) Å3 and ρmeas=3.656 g/cm3. Its atomic arrangement is described by some planes of pure octahedra TeO6 altering with planes of pure tetrahedra SO4 perpendicular to some directions. CsSeTe is monoclinic, P21/c, with a=12.817(6) Å, b=7.519(3) Å, c=12.432(5) Å, β=111.16(2)°, V=1117.3(8) Å3, Z=4 and ρmeas=3.795 g/cm3. Its structure exhibits infinite TeO66− and SeO42− planes where the alkali cations are intercalated. In both structures a network of strong hydrogen bonds connects the different components in the building of the crystal.