Ionothermal synthesis of {beta}-NH{sub 4}AlF{sub 4} and the determination by single crystal X-ray diffraction of its room temperature and low temperature phases
- EaSt Chem School of Chemistry, University of St. Andrews, Purdie Building, North Haugh, Street Andrews, Fife, Scotland KY16 9ST (United Kingdom)
{beta}-NH{sub 4}AlF{sub 4} has been synthesised ionothermally using 1-ethyl-3-methylimidazolium hexafluorophosphate as solvent and template provider. {beta}-NH{sub 4}AlF{sub 4} crystals were produced which were suitable for single crystal X-ray diffraction analysis. A phase transition occurs between room temperature (298 K) and low temperature (93 K) data collections. At 298 K the space group=I4/mcm (no. 140), {alpha}=11.642(5), c=12.661(5) A, Z=2 (10NH{sub 4}AlF{sub 4}), wR(F {sup 2})=0.1278, R(F)=0.0453. At 93 K the space group=P4{sub 2}/ncm (no. 138), {alpha}=11.616(3), c=12.677(3) A, Z=2 (10NH{sub 4}AlF{sub 4}), wR(F {sup 2})=0.1387, R(F)=0.0443. The single crystal X-ray diffraction study of {beta}-NH{sub 4}AlF{sub 4} shows the presence of two different polymorphs at low and room temperature, indicative of a phase transition. The [AlF{sub 4/2}F{sub 2}]{sup -} layers are undisturbed except for a small tilting of the AlF{sub 6} octahedra in the c-axis direction. -Ionothermal synthesis, the use of an ionic liquid as the solvent in materials preparation, has been used to prepare {beta}-NH{sub 4}AlF{sub 4}, and structural characterisation indicates that there are two versions of the structure, a low temperature primitive phase at 93 K and a high temperature body-centered phase at 298 K.
- OSTI ID:
- 21015617
- Journal Information:
- Journal of Solid State Chemistry, Vol. 180, Issue 1; Other Information: DOI: 10.1016/j.jssc.2006.09.024; PII: S0022-4596(06)00510-X; Copyright (c) 2006 Elsevier Science B.V., Amsterdam, The Netherlands, All rights reserved; Country of input: International Atomic Energy Agency (IAEA); ISSN 0022-4596
- Country of Publication:
- United States
- Language:
- English
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