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Trigonal structures of ABe2BO3F2 (A = Rb, Cs, Tl) crystals
Colin D McMillen1, Jia Hu, Donald VanDerveer
1Department of Chemistry and Center for Optical Materials Science and Engineering Technologies, Clemson University, Clemson, SC 29634, USA.
Acta Crystallographica. Section B, Structural Science
|July 21, 2009
Summary
New fluoroberyllium borates, including thallium fluoroberyllium borate (TBBF), were synthesized and structurally analyzed. Their crystal structures were refined to higher symmetry, revealing trends in this compound family.
Area of Science:
- Inorganic Chemistry
- Crystallography
- Materials Science
Background:
- Fluoroberyllium borates are a class of inorganic compounds with interesting structural properties.
- Previous studies determined the crystal structures of some fluoroberyllium borates in lower symmetry space groups.
Purpose of the Study:
- To synthesize and characterize novel fluoroberyllium borates.
- To reinvestigate and refine the crystal structures of known fluoroberyllium borates for higher symmetry.
- To explore structural trends and crystallographic explanations for physical morphology within this compound family.
Main Methods:
- Hydrothermal synthesis of fluoroberyllium borates.
- Single-crystal X-ray diffraction for structural characterization.
- Crystallographic analysis including space group determination and refinement.
Main Results:
- Successful synthesis of RbBe(2)BO(3)F(2) (RBBF), CsBe(2)BO(3)F(2) (CBBF), and the novel compound TlBe(2)BO(3)F(2) (TBBF).
- Reinvestigation revealed higher symmetry solutions (space group R32) for RBBF and CBBF, improving structural accuracy.
- TBBF was characterized with the same trigonal structure type.
- Structural comparison with KBe(2)BO(3)F(2) elucidated trends within the fluoroberyllium borate family.
Conclusions:
- The crystal structures of RBBF, CBBF, and TBBF were determined and refined in the higher symmetry space group R32.
- Significant structural trends were identified within the fluoroberyllium borate family.
- A crystallographic basis for the observed physical morphology of these compounds was proposed.
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