Synthesis and crystal structure of a new microporous zirconosilicate, MCV-2
- Author(s)
- Stanislav Ferdov, Uwe Kolitsch, Ognyan Petrov, Vladislav Kostov-Kytin, Christian Lengauer, Ekkehart Tillmanns
- Abstract
We report the hydrothermal synthesis and crystal structure of a new microporous, octahedral-tetrahedral zirconosilicate, Ba2Na(Na 0.5,(H2O)0.5)2Zr2Si 6O19 • 3H2O (simplified Ba 2(Na,H2O)3Zr2Si6O 19 • 3H2O), which we designate as MCV-2. It represents the first example of a Ba-Na-zirconosilicate. The compound has orthorhombic symmetry, space group Cmca (no. 64), with a = 16.258(3), b = 20.806(4), c = 12.339(2) A°, V = 4173.8(13) A°3, Z = 8. The complex crystal structure has been solved from single-crystal X-ray diffraction data (Mo-Ka radiation, CCD area detector, 293 K, 2?max = 60°, Rint = 3.9%) and refined to R1(F) = 5.03% and wR2 all = 10.84% for 2458 'observed' reflections with Fo = 4s(Fo). The structure of MCV-2 is built up from two crystallographically non-equivalent, isolated ZrO6 octahedra (d av(Zr-O) = 2.085 and 2.084 A°) sharing all their corners with isolated, non-linear (horseshoe-shaped) Si3O10 trisilicate groups and Si6O18 groups of six-membered rings of SiO4 tetrahedra. Average Si-O bond lengths range from 1.617 to 1.628 A°. The resulting open framework hosts channels oriented in different directions. These channels are filled with one ten-coordinated Ba site, two Na sites (eight- and four-fold coordinated; the latter site has an ideal occupancy of Na0.5H2O0.5) and two water molecules. MCV-2 contains two different PME ('polyhedral microensembles') types (C-2 and G as defined by [G.D. Ilyushin, V.A. Blatov, Acta Crystallogr. B58 (2002) 198]), a very unusual feature for a mixed octahedral-tetrahedral framework. Œ 2005 Elsevier Inc. All rights reserved.
- Organisation(s)
- Department of Mineralogy and Crystallography
- External organisation(s)
- Bulgarian Academy of Sciences (BAS)
- Journal
- Microporous and Mesoporous Materials
- Volume
- 81
- Pages
- 79-86
- No. of pages
- 8
- ISSN
- 1387-1811
- Publication date
- 2005
- Peer reviewed
- Yes
- Austrian Fields of Science 2012
- 1051 Geology, Mineralogy
- Portal url
- https://ucrisportal.univie.ac.at/en/publications/c4c35682-ceb1-40c1-9c32-888d17bc5aee