Vanadium (III) chloride

Crystal structure
__ V 3+      __ Cl -
General
Surname	Vanadium (III) chloride
other names	Vanadium trichloride Vanadium (III) chloride Vanadium trichloride
Ratio formula	VCl 3
Brief description	hygroscopic, dark purple, liquid crystals with a pungent odor
External identifiers / databases
CAS number 7718-98-1 15168-15-7 (hexahydrate) EC number 231-744-6 ECHA InfoCard 100,028,859 PubChem 62647 Wikidata Q421260
properties
Molar mass	157.30 g mol −1
Physical state	firmly
density	3.0 g cm −3 (20 ° C)
Melting point	> 300 ° C (decomposition)
solubility	soluble in water with decomposition soluble in ethanol not soluble in ether
safety instructions
GHS labeling of hazardous substances danger H and P phrases H: 302-314 P: 280-305 + 351 + 338-310
MAK	no MAK, as carcinogenic
Toxicological data	350 mg kg −1 ( LD 50 ,  rat ,  oral )
As far as possible and customary, SI units are used. Unless otherwise noted, the data given apply to standard conditions .

Vanadium (III) chloride is a chemical compound made up of the elements vanadium and chlorine , which is often used as a starting material for the production of vanadium (III) complex compounds. It belongs to the chloride class and forms a hexahydrate VCl ₃ · 6 H ₂ O, a green, hygroscopic powder.

Extraction and presentation

Vanadium (III) chloride is obtained from vanadium (IV) chloride VCl ₄ by heating (160-170 ° C.) .

${\displaystyle \mathrm {2\ VCl_{4}\longrightarrow 2\ VCl_{3}+Cl_{2}} }$

Vanadium (III) chloride can also be obtained from the elements:

${\displaystyle \mathrm {2\ V+3\ Cl_{2}\longrightarrow 2\ VCl_{3}} }$

Vanadium and chlorine gas react at a molar ratio of 2: 3 to form vanadium (III) chloride.

Alternatively, a synthesis from vanadium (III) oxide and thionyl chloride or vanadium (V) oxide and sulfur (I) chloride is possible.

${\displaystyle \mathrm {V_{2}O_{3}+3\ SOCl_{2}\ {\xrightarrow {}}\ 2\ VCl_{3}\ +\ 3\ SO_{2}} }$

${\displaystyle \mathrm {2\ V_{2}O_{5}+6\ S_{2}Cl_{2}\ {\xrightarrow {}}\ 4\ VCl_{3}+5\ SO_{2}+7\ S} }$

If air is excluded, it can also be obtained from solutions of the hexahydrate, which can be separated from aqueous, acidic solutions of vanadium (III) chloride by cooling and saturating with hydrochloric acid .

${\displaystyle \mathrm {V_{2}O_{3}+6\ HCl+9\ H_{2}O\ {\xrightarrow {}}\ VCl_{3}\cdot \ 6\ H_{2}O} }$

properties

Physical Properties

Vanadium (III) chloride forms very hygroscopic, odorless, light red, pink-red to violet dissolvable crystals. It is soluble in acidified water. It has a trigonal-rhombohedral crystal structure with the space group R 3 c (space group no. 161) and the lattice parameters a = 601.2 and c = 1734 pm. Vanadium (III) chloride forms octahedral structures in the crystal , with each vanadium ion being octahedral surrounded by six chloride ions. The hexahydrate is present as green hygroscopic crystals.

Chemical properties

When heated in a vacuum or in air at over 400 ° C, it breaks down into vanadium (II) chloride and vanadium (IV) chloride .

${\displaystyle \mathrm {2\ VCl_{3}\ {\xrightarrow {\Delta T}}\ VCl_{2}+VCl_{4}} }$

When heated (~ 675 ° C) with hydrogen , vanadium (III ) chloride is reduced to vanadium (II) chloride .

${\displaystyle \mathrm {2\ VCl_{3}+H_{2}\ {\xrightarrow {\Delta T}}\ 2\ VCl_{2}+2\ HCl} }$

When reacting with carbon dioxide, oxygen or vanadium (III) oxide, vanadium (III) oxychloride is formed .

${\displaystyle \mathrm {V_{2}O_{3}+VCl\ {\xrightarrow {}}\ 3\ VOCl} }$

use

Vanadium (III) chloride is used as a starting material for the production of vanadium (III) complex compounds, e.g. B. Tetrahydrofuran - or acetonitrile derivatives (VCl ₃ (THF) ₃ or VCl ₃ (MeCN) ₃ ).

It can also be used to produce vanadium by reduction with magnesium or hydrogen and as a catalyst in polymerizations.

Individual evidence

1. ↑ ^{a b c d e f g h} Entry on vanadium (III) chloride in the GESTIS substance database of the IFA , accessed on February 13, 2017(JavaScript required) .
2. ↑ ^{a b c d e f g h i j} Georg Brauer (Ed.) U. a .: Handbook of Preparative Inorganic Chemistry. 3rd, revised edition. Volume III, Ferdinand Enke, Stuttgart 1981, ISBN 3-432-87823-0 , pp. 1407, 1409-1410.
3. ↑ Data sheet vanadium (III) chloride (PDF) from Fisher Scientific , accessed on February 13, 2014.
4. ^ AF Holleman , E. Wiberg , N. Wiberg : Textbook of Inorganic Chemistry . 102nd edition. Walter de Gruyter, Berlin 2007, ISBN 978-3-11-017770-1 , p. 1550.
5. ↑ Inorganic Syntheses, Inc .: Inorganic Syntheses . John Wiley & Sons, 2009, ISBN 0-470-13267-1 , pp. 129 ( limited preview in Google Book search).
6. ^ Catherine E. Housecroft, AG Sharpe: Inorganic Chemistry . Pearson Education, 2005, ISBN 0-13-039913-2 , pp. 605 ( limited preview in Google Book search).
7. ^ Heyn: Inorganic Synthetic Chemistry: An integrated practical course , pp. 18–20; ISBN 3540529071 .