Tungsten (II) bromide

Crystal structure
__ W 2+      __ Br -
General
Surname	Tungsten (II) bromide
Ratio formula	WBr 2
Brief description	yellow green solid
External identifiers / databases
CAS number 13470-10-5 Wikidata Q4096866
properties
Molar mass	343.65 g mol −1
Physical state	firmly
Melting point	400 ° 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 .

Tungsten (II) bromide is an inorganic chemical compound of tungsten from the group of bromides .

Extraction and presentation

Tungsten (II) bromide can be obtained by reacting tungsten (V) bromide with aluminum .

${\displaystyle \mathrm {6\ WBr_{5}+6\ Al\longrightarrow [W_{6}Br_{8}]Br_{4}+6\ AlBr_{3}} }$

It is also possible to show this by reacting tungsten with elemental bromine at over 500 ° C

${\displaystyle \mathrm {6\ W+6\ Br_{2}\longrightarrow [W_{6}Br_{8}]Br_{4}+6\ AlBr_{3}} }$

or by disproportionation of tungsten (IV) bromide in a vacuum at 450 ° C.

${\displaystyle \mathrm {18\ WBr_{4}\longrightarrow [W_{6}Br_{8}]Br_{4}+12\ WBr_{5}} }$

properties

Tungsten (II) bromide is a yellow-green solid that is stable in air. The dihydrate is formed with hydrobromic acid . Reaction with excess bromine results in the bromides W ₆ Br ₁₄ , W ₆ Br ₁₆ and W ₆ Br ₁₈ . It has a crystal structure isotypic to that of molybdenum (II) chloride and tungsten (II) chloride . It crystallizes orthorhombically in the space group Bbem (space group no. 64, position 5) with the lattice parameters a = 1179 pm, b = 1182 pm and c = 1478 pm.

Individual evidence

1. ↑ ^{a b c d e} Georg Brauer (Ed.) U. a .: Handbook of Preparative Inorganic Chemistry. 3rd, revised edition. Volume III, Ferdinand Enke, Stuttgart 1981, ISBN 3-432-87823-0 , p. 1559.
2. ^ Dale L. Perry: Handbook of Inorganic Compounds, Second Edition . Taylor & Francis US, 2011, ISBN 1-4398-1462-7 , pp. 439 ( limited preview in Google Book search).
3. ↑ This substance has either not yet been classified with regard to its hazardousness or a reliable and citable source has not yet been found.
4. ↑ The former name of this group of rooms was Bbam .