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Title: Syntheses and characterization of elpasolite-type ammonium alkali metal hexafluorometallates(III)

Abstract

Crystal structures of three fluorides (NH{sub 4}){sub 2}NaFeF{sub 6}, (Fe), (NH{sub 4}){sub 2}NaGaF{sub 6}, (Ga), and (NH{sub 4}){sub 2}NaCrF{sub 6}, (Cr), as well as a substituted compound [(NH{sub 4}){sub 1-x}K{sub x}]{sub 2}KAlF{sub 6} (x{approx}0.17), (Al), have been refined using single-crystal and powder X-ray diffraction techniques. All these four ammonium hexafluorides have a cubic elpasolite-type structure and crystallize in the space group Fm3-bar m with lattice constants a=8.483(3), 8.450 (3), 8.4472(2) and 8.724(3) A for compounds (Fe), (Ga), (Cr) and (Al), respectively. The effective ionic radius of the ammonium ion calculated from those compounds has a mean value of R=1.729 A for CN=12. An ultraviolet-visible absorption spectrum of (NH{sub 4}){sub 2}NaCrF{sub 6}, measured at room temperature, gives a crystal field (Dq=1575 cm{sup -1}) and Racah parameters (B=758 cm{sup -1} and C=3374 cm{sup -1}). Abnormal anisotropic thermal parameters of fluorine atoms have been observed in the compound (Al), and interpreted to arise from four strong hydrogen bonds (F...H-N) that are distributed in a square form around each fluorine atom. - Graphical abstract: Abnormal anisotropic thermal parameters of fluorine atoms have been observed in the compound [(NH{sub 4}){sub 1-x}K{sub x}]{sub 2}KAlF{sub 6} (x{approx}0.17), and interpreted to arise from four strong hydrogen bonds (F...H-N)more » that are distributed in a square form around each fluorine atom. The endmembers' phase transitions at low temperature are believed to be caused by them.« less

Authors:
 [1]; ; ;  [1];  [2]
  1. Department of Materials Science and Engineering, College of Materials, Xiamen University, Xiamen 361005 (China)
  2. Department of Chemistry, College of Chemistry and Chemical Engineering, Xiamen University, Xiamen 361005 (China)
Publication Date:
OSTI Identifier:
21128366
Resource Type:
Journal Article
Journal Name:
Journal of Solid State Chemistry
Additional Journal Information:
Journal Volume: 181; Journal Issue: 8; Other Information: DOI: 10.1016/j.jssc.2008.03.017; PII: S0022-4596(08)00159-X; Copyright (c) 2008 Elsevier Science B.V., Amsterdam, The Netherlands, All rights reserved; Country of input: International Atomic Energy Agency (IAEA); Journal ID: ISSN 0022-4596
Country of Publication:
United States
Language:
English
Subject:
37 INORGANIC, ORGANIC, PHYSICAL AND ANALYTICAL CHEMISTRY; ABSORPTION SPECTRA; AMMONIUM COMPOUNDS; CHROMIUM COMPOUNDS; CRYSTAL FIELD; CUBIC LATTICES; FLUORIDES; FLUORINE; HYDROTHERMAL SYNTHESIS; IRON COMPOUNDS; LATTICE PARAMETERS; MONOCRYSTALS; PHASE TRANSFORMATIONS; POTASSIUM COMPOUNDS; SODIUM COMPOUNDS; SPACE GROUPS; TEMPERATURE RANGE 0273-0400 K

Citation Formats

Jinxiao, Mi, Key Laboratory of New Processing Technology for Nonferrous Metals and Materials, Shuming, Luo, Huayu, Sun, Xiaoxuan, Liu, and Zanbin, Wei. Syntheses and characterization of elpasolite-type ammonium alkali metal hexafluorometallates(III). United States: N. p., 2008. Web.
Jinxiao, Mi, Key Laboratory of New Processing Technology for Nonferrous Metals and Materials, Shuming, Luo, Huayu, Sun, Xiaoxuan, Liu, & Zanbin, Wei. Syntheses and characterization of elpasolite-type ammonium alkali metal hexafluorometallates(III). United States.
Jinxiao, Mi, Key Laboratory of New Processing Technology for Nonferrous Metals and Materials, Shuming, Luo, Huayu, Sun, Xiaoxuan, Liu, and Zanbin, Wei. 2008. "Syntheses and characterization of elpasolite-type ammonium alkali metal hexafluorometallates(III)". United States.
@article{osti_21128366,
title = {Syntheses and characterization of elpasolite-type ammonium alkali metal hexafluorometallates(III)},
author = {Jinxiao, Mi and Key Laboratory of New Processing Technology for Nonferrous Metals and Materials and Shuming, Luo and Huayu, Sun and Xiaoxuan, Liu and Zanbin, Wei},
abstractNote = {Crystal structures of three fluorides (NH{sub 4}){sub 2}NaFeF{sub 6}, (Fe), (NH{sub 4}){sub 2}NaGaF{sub 6}, (Ga), and (NH{sub 4}){sub 2}NaCrF{sub 6}, (Cr), as well as a substituted compound [(NH{sub 4}){sub 1-x}K{sub x}]{sub 2}KAlF{sub 6} (x{approx}0.17), (Al), have been refined using single-crystal and powder X-ray diffraction techniques. All these four ammonium hexafluorides have a cubic elpasolite-type structure and crystallize in the space group Fm3-bar m with lattice constants a=8.483(3), 8.450 (3), 8.4472(2) and 8.724(3) A for compounds (Fe), (Ga), (Cr) and (Al), respectively. The effective ionic radius of the ammonium ion calculated from those compounds has a mean value of R=1.729 A for CN=12. An ultraviolet-visible absorption spectrum of (NH{sub 4}){sub 2}NaCrF{sub 6}, measured at room temperature, gives a crystal field (Dq=1575 cm{sup -1}) and Racah parameters (B=758 cm{sup -1} and C=3374 cm{sup -1}). Abnormal anisotropic thermal parameters of fluorine atoms have been observed in the compound (Al), and interpreted to arise from four strong hydrogen bonds (F...H-N) that are distributed in a square form around each fluorine atom. - Graphical abstract: Abnormal anisotropic thermal parameters of fluorine atoms have been observed in the compound [(NH{sub 4}){sub 1-x}K{sub x}]{sub 2}KAlF{sub 6} (x{approx}0.17), and interpreted to arise from four strong hydrogen bonds (F...H-N) that are distributed in a square form around each fluorine atom. The endmembers' phase transitions at low temperature are believed to be caused by them.},
doi = {},
url = {https://www.osti.gov/biblio/21128366}, journal = {Journal of Solid State Chemistry},
issn = {0022-4596},
number = 8,
volume = 181,
place = {United States},
year = {Fri Aug 15 00:00:00 EDT 2008},
month = {Fri Aug 15 00:00:00 EDT 2008}
}