A Contribution to the Stereochemistry of Earth Alkaline Selenites: Synthesis and Crystal Structure of Ca(SeO₃)(Se₂O₅), Ba(SeO₃), and Ba(Se₂O₅)

Author(s)

Gerald Giester, Christian Lengauer

Abstract

The compds. Ca2(SeO3)(Se2O5), Ba(SeO3), and Ba(Se2O5) were obtained at low-hydrothermal conditions from aq. solns. of SeO2 by reaction with the resp. alk. earth carbonate. The crystal structures were detd. by direct methods from single crystal x-ray diffraction data. Ca2(SeO3)(Se2O5): space group P.hivin.1, Z = 2, a = 5.517(1), b = 8.210(2), c = 8.716(2) .ANG., alpha = 92.47(2), beta = 95.92(2), gamma = 97.15(2)°, V = 389.0(2) .ANG.3, R1 = 0.017; Ba(SeO3): space group P21/m, Z = 2, a = 4.677(2), b = 5.645(2), c = 6.851(3) .ANG., beta = 107.16(2)°, V = 172.8(1) .ANG.3, R1 = 0.022, Ba(Se2O5): space group P21/c, Z = 4, a = 4.553(1), b = 11.724(3), c = 9.758(2) .ANG., beta = 92.66(2)°, V = 520.3(2) .ANG.3, R1 = 0.027. All 3 compds. have framework structures; in the case of Ca2(SeO3)(Se2O5), subunits of edge-sharing CaOn polyhedra forming sheets parallel to (010) can be emphasized. Ba(SeO3) belongs to the structure type of KClO3. In Ba(Se2O5), chains of face-sharing BaO9 polyhedra along [100] are present. The Ca atoms are 7- and 8-coordinated with mean Ca-O bond lengths of 2.42 and 2.48 .ANG., the Ba atoms have 9 O ligands with mean Ba-O bond lengths of 2.87 .ANG..

Organisation(s)

Department of Mineralogy and Crystallography

Journal

Monatshefte für Chemie

Volume

129

Pages

445-454

No. of pages

10

ISSN

0026-9247

DOI

https://doi.org/10.1007/PL00000101

Publication date

1998

Peer reviewed

Yes

Austrian Fields of Science 2012

105113 Crystallography, 104011 Materials chemistry

Keywords

Portal url

https://ucrisportal.univie.ac.at/en/publications/a-contribution-to-the-stereochemistry-of-earth-alkaline-selenites-synthesis-and-crystal-structure-of-caseo3se2o5-baseo3-and-base2o5(c0369ec2-15db-4d24-a371-f895e32d50a1).html