Niobium (IV) fluoride

Crystal structure
__ Nb 4+      __ F -
Crystal system	tetragonal
Space group	I 4 / mmm (No. 139)
Lattice parameters	a  = 4.0876 (5) Å, c  = 8.1351 (19) Å
Coordination numbers	[6] Nb
General
Surname	Niobium (IV) fluoride
other names	Niobium tetrafluoride
Ratio formula	NbF 4
Brief description	black solid
External identifiers / databases
CAS number 13842-88-1 Wikidata Q6343309
properties
Molar mass	168.91 g mol −1
Physical state	firmly
density	4.01 g cm −3
Melting point	> 350 ° C (decomposition)
safety instructions
GHS hazard labeling no classification available
As far as possible and customary, SI units are used. Unless otherwise noted, the data given apply to standard conditions .

Niobium (IV) fluoride is a chemical compound of niobium from the group of fluorides .

Extraction and presentation

Niobium (IV) fluoride can be obtained by decomposing Nb ₂ F ₅ at around 1000 ° C. or by reacting niobium (V) fluoride with niobium.

properties

Niobium (IV) fluoride is a hygroscopic paramagnetic black solid. It has a tetragonal crystal structure of tin (IV) fluoride with the space group I 4 / mmm (space group no. 139) with the lattice constants a  = 4.0876 (5) Å, c  = 8.1351 (19) Å. The compound is stable in a vacuum up to about 300 ° C, but decomposes above 350 ° C into niobium (V) fluoride and niobium (III) fluoride .

${\displaystyle {\ce {2 NbF4 -> NbF5 + NbF3}}}$

Individual evidence

1. ↑ ^{a b c d} William M. Haynes: CRC Handbook of Chemistry and Physics, 97th Edition . CRC Press, 2016, ISBN 978-1-4987-5429-3 , pp. 105 ( limited preview in Google Book search).
2. ↑ This substance has either not yet been classified with regard to its hazardousness or a reliable and citable source has not yet been found.
3. ↑ ^{a b} Jascha Bandemehr, Matthias Conrad, Florian Kraus: Redetermination of the crystal structure of NbF ₄ . In: Acta Crystallographica Section E Crystallographic Communications. 72, 2016, p. 1211, doi : 10.1107 / S2056989016012081 .
4. ↑ Holleman / Wiberg: Subgroup elements, lanthanoids, actinides, transactinides Volume 2: Subgroup elements, lanthanoids, actinides, transactinides, appendices . Walter de Gruyter GmbH & Co KG, 2016, ISBN 978-3-11-049590-4 , p. 1836 ( limited preview in Google Book search).
5. ^ Viktor Gutmann: Halogen Chemistry . Elsevier, 2012, ISBN 0-323-14847-6 , pp. 132 ( limited preview in Google Book search).