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Title: 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

Abstract

{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.

Authors:
 [1];  [1];  [2]
  1. EaSt Chem School of Chemistry, University of St. Andrews, Purdie Building, North Haugh, Street Andrews, Fife, Scotland KY16 9ST (United Kingdom)
  2. EaSt Chem School of Chemistry, University of St. Andrews, Purdie Building, North Haugh, Street Andrews, Fife, Scotland KY16 9ST (United Kingdom), E-mail: rem1@st-andrews.ac.uk
Publication Date:
OSTI Identifier:
21015617
Resource Type:
Journal Article
Resource Relation:
Journal Name: Journal of Solid State Chemistry; Journal Volume: 180; Journal 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)
Country of Publication:
United States
Language:
English
Subject:
37 INORGANIC, ORGANIC, PHYSICAL AND ANALYTICAL CHEMISTRY; ALUMINIUM FLUORIDES; LAYERS; LIQUIDS; MONOCRYSTALS; PHASE TRANSFORMATIONS; SOLVENTS; SPACE GROUPS; SYNTHESIS; TEMPERATURE RANGE 0065-0273 K; TEMPERATURE RANGE 0273-0400 K; TETRAGONAL LATTICES; X-RAY DIFFRACTION

Citation Formats

Parnham, Emily R., Slawin, Alex M.Z., and Morris, Russell E. 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. United States: N. p., 2007. Web. doi:10.1016/j.jssc.2006.09.024.
Parnham, Emily R., Slawin, Alex M.Z., & Morris, Russell E. 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. United States. doi:10.1016/j.jssc.2006.09.024.
Parnham, Emily R., Slawin, Alex M.Z., and Morris, Russell E. Mon . "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". United States. doi:10.1016/j.jssc.2006.09.024.
@article{osti_21015617,
title = {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},
author = {Parnham, Emily R. and Slawin, Alex M.Z. and Morris, Russell E.},
abstractNote = {{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.},
doi = {10.1016/j.jssc.2006.09.024},
journal = {Journal of Solid State Chemistry},
number = 1,
volume = 180,
place = {United States},
year = {Mon Jan 15 00:00:00 EST 2007},
month = {Mon Jan 15 00:00:00 EST 2007}
}
  • The structures of two ferroic chloroantimonates(III): [(CH{sub 3}){sub 2}NH{sub 2}]{sub 3}[Sb{sub 2}Cl{sub 9}] (DMACA) and [(CH{sub 3}){sub 3}NH]{sub 3}[Sb{sub 2}Cl{sub 9}] (TMACA) were determined in their low-temperature phases. The structure of DMACA was investigated at 100 and 15K, and TMACA at 15K. The structures consist of two-dimensional inorganic layers and organic cations bound together by the N(C)-H...Cl hydrogen bonds. All of the organic cations in both compounds at all studied temperatures are ordered. There is no indication of the structural phase transition in the structure of DMACA below 242K. The geometry and distortions of the [SbCl{sub 6}]{sup 3-} octahedra inmore » both compounds is discussed. The monoclinic Pc space group was found for both compounds: DMACA a=9.3590(5), b=9.0097(4), c=14.1308(7)A, {beta}=95.229(4){sup o}, R{sub 1}=0.0240, wR{sub 2}=0.0491 and a=9.3132(4), b=9.0008(3), c=14.1088(5)A, {beta}=95.010(3){sup o}, R{sub 1}=0.0230, wR{sub 2}=0.0482 at 100 and 15K, respectively; TMACA a=9.8652(5), b=9.1129(4), c=15.0964(7)A, {beta}=89.988(4){sup o}, R{sub 1}=0.0239, wR{sub 2}=0.0611 at 15K.« less
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