Vanadium (III) fluoride

Crystal structure
__ V 3+      __ F -
General
Surname	Vanadium (III) fluoride
other names	Vanadium trifluoride Vanadium fluoride (ambiguous)
Ratio formula	VF 3
Brief description	yellow-green powder
External identifiers / databases
CAS number 10049-12-4 EC number 233-169-6 ECHA InfoCard 100.030.141 PubChem 66230 Wikidata Q903861
properties
Molar mass	107.94 g mol −1
Physical state	firmly
density	3.36 g cm −3
Melting point	1400 ° C
boiling point	800 ° C
solubility	almost insoluble in water
safety instructions
GHS labeling of hazardous substances danger H and P phrases H: 301-311-314-331 P: 261-280-301 + 310-305 + 351 + 338-310
As far as possible and customary, SI units are used. Unless otherwise noted, the data given apply to standard conditions .

Vanadium (III) fluoride is a chemical compound from the group of fluorides . It is in the form of a gray to green powder.

Extraction and presentation

Vanadium (III) fluoride can be obtained from vanadium (III) oxide . Either the direct synthesis by reaction with hydrogen fluoride or the reaction with ammonium hydrogen difluoride and subsequent thermal decomposition of the hexaammonium salt is used for this purpose.

${\displaystyle \mathrm {V_{2}O_{3}\ +\ 6\ (NH_{4})HF_{2}\ \longrightarrow \ \ 2\ (NH_{4})_{3}VF_{6}\ +\ 3\ H_{2}O} }$

${\displaystyle \mathrm {(NH_{4})_{3}VF_{6}\ {\xrightarrow {\Delta T}}\ \ 3\ NH_{3}\ +\ 3\ HF\ +\ VF_{3}} }$

A synthesis from vanadium (III) chloride and hydrogen fluoride is also possible.

${\displaystyle \mathrm {VCl_{3}\ +\ 3\ HF{\xrightarrow {\ }}\ 3\ HCl\ +\ VF_{3}} }$

properties

The crystal structure ( trigonal , space group R 3 c (space group no.167 ) , a = 516.8 pm, c = 1343.8 pm) of vanadium (III) fluoride consists of mutually tilted and corner-linked in all directions of space Octahedra . Vanadium (III) fluoride turns black on contact with sodium hydroxide solution .

use

By reaction with oxygen may Vanadium (V) Oxytrifluoride be obtained.

${\displaystyle \mathrm {2\ VF_{3}+O_{2}\longrightarrow 2\ VOF_{3}} }$

Web links

• Freepatents online: Method for the preparation of high surface area metal fluorides

Individual evidence

1. ↑ ^{a b c d} Web elements: Vanadium trifluoride .
2. ↑ Data sheet vanadium (III) fluoride from AlfaAesar, accessed on April 1, 2010 ( PDF )(JavaScript required) .
3. ↑ ^{a b} Data sheet vanadium (III) fluoride from Sigma-Aldrich , accessed on April 25, 2011 ( PDF ).
4. ^ BJ Sturm, CW Sheridan: "Vanadium (III) Fluoride", Inorganic Syntheses 1963; Vol. 7, pp. 52-54, ISBN 0-88275-165-4 .
5. ↑ P. Daniel, A. Bulou, M. Leblanc, M. Rousseau, J. Nouet: Structural and vibrational study of VF ₃ . In: Materials Research Bulletin , 1992 , 38 , pp. 127-220 doi: 10.1016 / 0025-5408 (90) 90175-2
6. ↑ University of Freiburg: Vanadium trifluoride structure .
7. ↑ Gurdeep Raj: Advanced Inorganic Chemistry Vol-1 . 1975, ISBN 81-87224-03-7 , pp. 1204 ( limited preview in Google Book search).