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Fluoride Containing Guest Species in Alumosilicates: Tetrafluoroborate in the Sodalite Na 8 Al 6 Si 6 O 24 (BF 4 ) 2
Author(s) -
Lezhnina Marina M.,
Jordan Edgar,
Klimin Sergej A.,
Löns Jürgen,
Koller Hubert,
Mavrin Boris N.,
Kynast Ulrich
Publication year - 2009
Publication title -
zeitschrift für anorganische und allgemeine chemie
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.354
H-Index - 66
eISSN - 1521-3749
pISSN - 0044-2313
DOI - 10.1002/zaac.200801112
Subject(s) - sodalite , calcination , crystallography , rietveld refinement , ion , raman spectroscopy , crystal structure , chemistry , emission spectrum , fluoride , analytical chemistry (journal) , infrared spectroscopy , inorganic chemistry , spectral line , zeolite , catalysis , physics , organic chemistry , astronomy , optics , biochemistry , chromatography
Abstract In the course of investigations on optical properties resulting from the interaction of fluorides with alumosilicate host materials and rare earth guests, a well defined BF 4 – ion wasfound to be incorporated within the sodalite of composition Na 8 Al 6 Si 6 O 24 (BF 4 ) 2 . The resulting cubic molecular structure, which was determined by Rietveld methods (space group P 4 $\bar{3}$ n , a = 906.91 pm, wRp = 0.045, Rp = 0.027), contains one anion in each sodalite cage and is, contrarily to expectations, thermally stable. NMR spectroscopic investigations indicated a fast rotatory motion of the BF 4 – tetrahedra at room temperature and agreed with the tetrahedral BF 4 – ions found in IR and Raman spectra. Preliminary attempts to obtain a luminescent material by incorporation of Eu 3+ through aqueous ion exchange only yielded low rare earth concentrations, giving rise to characteristic red emission lines at 581 nm ( 5 D 0 → 7 F 1 ) and 615 nm ( 5 D 0 → 7 F 2 ) in a 1:2 intensity ratio. The material unexpectedly exhibited a strong broad band emission at 520 nm after calcination under Ar, which is attributed to the formation of an Eu 2+ species. Further calcination under air partially reestablished the Eu 3+ emission.