Vanadium (II) bromide

Crystal structure
__ V 2+      __ Br -
General
Surname	Vanadium (II) bromide
other names	Vanadium dibromide Vanadium (II) bromide Vanadium dibromide
Ratio formula	VBr 2
Brief description	pale brown, crystalline solid
External identifiers / databases
CAS number 14890-41-6 PubChem 21871976 Wikidata Q1306078
properties
Molar mass	210.75 g mol −1
Physical state	firmly
density	3.23 g cm −3
boiling point	800 ° C
solubility	dissolves in water with formation of [V (H 2 O) 6 ] 2+ ions
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 .

Vanadium (II) bromide is a chemical compound of the elements vanadium and bromine . It is a pale orange-brown, crystalline solid that boils at 800 ° C.

Extraction and presentation

Vanadium (II) bromide can be obtained by reducing vanadium (III) bromide with hydrogen at 400 ° C:

${\displaystyle \mathrm {2\ VBr_{3}+H_{2}\longrightarrow 2\ VBr_{2}+2\ HBr} }$

It can also be obtained by bromination of vanadium .

${\displaystyle \mathrm {V+Br_{2}\longrightarrow VBr_{2}} }$

properties

Physical Properties

Vanadium (II) bromide is a light brown solid that turns pink when hot. It is more hygroscopic than vanadium (II) chloride , but not as sensitive as vanadium (III) bromide . With water it forms a violet solution from which the blue-violet needles of the hexahydrate can be isolated. It has an octahedral crystal structure , similar to that of cadmium iodide , with the space group P 3 m 1 (space group no. 164) and the lattice parameters a = 3.768 Å , c = 6.180 Å.

Chemical properties

Vanadium (II) bromide is a powerful reducing agent that even reduces nitrogen to hydrazine in the presence of magnesium hydroxide .

It dissolves in water with the formation of [V (H ₂ O) ₆ ] ²⁺ ions: ${\displaystyle \mathrm {V^{2+}+6\ H_{2}O\longrightarrow [V(H_{2}O)_{6}]^{2+}} }$

Individual evidence

1. ↑ ^{a b c} Vanadium (II) bromide on webelements.com
2. ^ ^{A b c d} A. F. Holleman , E. Wiberg , N. Wiberg : Textbook of Inorganic Chemistry . 102nd edition. Walter de Gruyter, Berlin 2007, ISBN 978-3-11-017770-1 , p. 1550.
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. ↑ Lothar Kolditz: Inorganic Chemistry Part 2 . VEB Deutscher Verlag der Wissenschaften, Berlin 1980, p. 641.
5. ↑ ^{a b} 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. 1413.