Hydrothermal synthesis and the crystal structure of borate cancrinite (Na,Ca){sub 2}[Na{sub 6}(AlSiO{sub 4}){sub 6}](BO{sub 3}) . 2H{sub 2}O

Journal Article · Sun Jan 15 04:00:00 EST 2006 · Crystallography Reports

DOI:https://doi.org/10.1134/S1063774506010081· OSTI ID:21091516

Khrustalev, V N ^[1]; Samedov, H R ^[2]; Chiragov, M I ^[3]

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1. Russian Academy of Sciences, Nesmeyanov Institute of Organoelement Compounds (Russian Federation)
2. National Academy of Sciences of Azerbaijan, Institute of Chemical Problems (Azerbaijan)
3. Baku State University (Azerbaijan)

Transparent prismatic single crystals of borate cancrinite (Na,Ca){sub 2}[Na{sub 6}(AlSiO{sub 4}){sub 6}](BO{sub 3}) . 2H{sub 2}O are prepared through hydrothermal crystallization. The parameters of the hexagonal unit cell and intensities of 10806 reflections are measured on an Enraf-Nonius CAD4 automated diffractometer. The compound crystallizes in the hexagonal crystal system with the unit cell parameters a = 12.745(4) A, c = 5.180(2) A, V = 728.6(4) A{sup 3}, and space group P6{sub 3}. The structure is determined by direct methods and refined using the full-matrix least-squares procedure in the anisotropic approximation for the non-hydrogen atoms. The refinement of the structure is performed to the final discrepancy factor R{sub 1} = 0.027 for 2889 unique reflections with I > 2 {sigma} (I). In the structure of the borate cancrinite, the AlO{sub 4} and SiO{sub 4} tetrahedra form a zeolite-like framework in which twelve-membered hexagonal channels are occupied by sodium atoms and BO{sub 3} groups, whereas six-membered channels are filled with sodium and calcium atoms and water molecules. The mean interatomic distances are found to be as follows: (Si-O){sub mean} = 1.614 A and (Al-O){sub mean} = 1.741 A in the AlO{sub 4} and SiO{sub 4} tetrahedra, (Na-O){sub mean} = 2.542 A in the seven-vertex sodium polyhedra, and [(Na,Ca)-O]{sub mean} = 2.589 A in the ditrigonal bipyramids.

• OSTI ID: 21091516
• Journal Information: Crystallography Reports, Journal Name: Crystallography Reports Journal Issue: 1 Vol. 51; ISSN 1063-7745; ISSN CYSTE3
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
ALUMINIUM COMPOUNDS
ANISOTROPY
BORATES
CALCIUM COMPOUNDS
CRYSTALLIZATION
HEXAGONAL LATTICES
HYDROTHERMAL SYNTHESIS
INTERATOMIC DISTANCES
LEAST SQUARE FIT
MONOCRYSTALS
SILICATES
SILICON OXIDES
SODIUM COMPOUNDS
SPACE GROUPS
ZEOLITES