Gallium (III) fluoride

Crystal structure
__ Ga 3+      __ F -
General
Surname	Gallium (III) fluoride
other names	Gallium fluoride (ambiguous) Gallium trifluoride
Ratio formula	GaF 3
Brief description	colorless odorless solid
External identifiers / databases
CAS number 7783-51-9 22886-66-4 (trihydrate) EC number 232-004-5 ECHA InfoCard 100.029.094 PubChem 82211 Wikidata Q418788
properties
Molar mass	126.718 g mol −1
Physical state	firmly
density	4.47 g cm −3
Melting point	800 ° C
boiling point	> 1000 ° C
solubility	very sparingly soluble in water (24 mg l −1 at 20 ° C)
safety instructions
GHS labeling of hazardous substances no GHS pictograms danger H and P phrases H: 314 P: 301 + 330 + 331-305 + 351 + 338
Thermodynamic properties
ΔH f 0	−1163 kJ mol −1
As far as possible and customary, SI units are used. Unless otherwise noted, the data given apply to standard conditions .

Gallium (III) fluoride is a chemical compound of gallium from the group of fluorides .

Extraction and presentation

Gallium (III) fluoride can be obtained by reacting gallium with hydrogen fluoride .

${\displaystyle \mathrm {2\ Ga+6\ HF\longrightarrow 2\ GaF_{3}+3\ H_{2}} }$

The production by thermolysis of Ammoniumhexafluoridogallat in a fluorine gas stream is possible.

${\displaystyle \mathrm {(NH_{4})_{3}[GaF_{6}]\longrightarrow GaF_{3}+3\ NH_{4}F} }$

The trihydrate GaF ₃ · 3H ₂ O can be obtained by reacting gallium (III) hydroxide or gallium (III) oxide with hydrogen fluoride.

properties

Gallium (III) fluoride is a colorless solid that is resistant to cold and hot water. Gallium (III) fluoride (in contrast to its trihydrate) is very sparingly soluble in water. It can be sublimated without decomposition in a nitrogen protective atmosphere above 800 ° C. Oxide-free gallium (III) fluoride cannot be produced by dehydrating trihydrate in air, in a vacuum or in a flow of fluorine gas. Gallium (III) fluoride, analogous to aluminum fluoride, has a polymeric crystal structure that resembles a distorted rhenium (VI) oxide structure ( trigonal structure, space group R 3 c (space group no.167 ) , a = 5.012 Å , c = 12.99 Å). Like aluminum oxide, it forms complex compounds .

use

Gallium (III) fluoride is used in the manufacture of fluorogallate glasses for optical purposes.

Individual evidence

1. ↑ ^{a b c d e} Georg Brauer (Ed.), With the collaboration of Marianne Baudler u. a .: Handbook of Preparative Inorganic Chemistry. 3rd, revised edition. Volume I, Ferdinand Enke, Stuttgart 1975, ISBN 3-432-02328-6 , p. 239.
2. ↑ ^{a b c d e f} data sheet Gallium (III) fluoride, 99.995% (metals basis) from AlfaAesar, accessed on December 1, 2019 ( PDF )(JavaScript required) .
3. ^ AF Holleman , N. Wiberg : Inorganische Chemie . 103rd edition. Volume 1: Basics and main group elements. Walter de Gruyter, Berlin / Boston 2016, ISBN 978-3-11-049585-0 , p. 1393 (reading sample: Part A - Basics of the chemistry of hydrogen. Google book search ).
4. ^ ^{A b} A. F. Holleman , E. Wiberg , N. Wiberg : Textbook of Inorganic Chemistry . 101st edition. Walter de Gruyter, Berlin 1995, ISBN 3-11-012641-9 , p. 1096.
5. ↑ M. Roos, G. Meyer: Refinement of the crystal structure of gallium trifluoride, GaF ₃ . In: Zeitschrift für Kristallographie , 2001 , 216 , p. 18.