Vanadium(III) chloride
Encyclopedia
Vanadium trichloride is the inorganic compound
with the formula
VCl3. This purple salt is a common precursor to other vanadium(III) complexes.
. VCl3 is paramagnetic and has two unpaired electrons.
at 160-170 °C under a flowing stream of inert gas, which sweeps out the Cl2
. The bright red liquid converts to a crusty purple solid. Further heating of VCl3 decomposes with volatilization of VCl4, leaving VCl2. Upon heating under H2 at 675 °C (but less than 700 °C), VCl3 reduces to greenish VCl2.
, but the formula is deceptive. The salt is described by the formula [VCl2(H2O)4]Cl.2H2O. In other words, two of the water molecules are not bound to the vanadium, whose structure resembles the corresponding Fe(III) derivative. Removal of the two bound chloride ligands from [VCl2(H2O)4]+ in aqueous solution gives the green ion [V(H2O)6]3+.
With tetrahydrofuran
, VCl3 forms the red/pink adduct VCl3(THF)3. With acetonitrile
, one obtains the green adduct VCl3(MeCN)3.
When treated with KCN, VCl3 converts to [V(CN)7]4-. It is common for early metals to adopt high coordination numbers (more than 6) with compact ligands. Complementarily, larger metals can form complexes with rather bulky ligands. This aspect is illustrated by the isolation of VCl3(NMe3)2, containing two bulky NMe3 ligands.
)3 forms from VCl3.
This species binds CO and, under appropriate conditions, N2.
Inorganic compound
Inorganic compounds have traditionally been considered to be of inanimate, non-biological origin. In contrast, organic compounds have an explicit biological origin. However, over the past century, the classification of inorganic vs organic compounds has become less important to scientists,...
with the formula
Chemical formula
A chemical formula or molecular formula is a way of expressing information about the atoms that constitute a particular chemical compound....
VCl3. This purple salt is a common precursor to other vanadium(III) complexes.
Structure
VCl3 has the common BiI3 structure, a motif that features hexagonally closest-packed chloride framework with vanadium ions occupying the octahedral holes. VBr3 and VI3 adopt the same structure, but VF3 features a structure more closely related to ReO3Rhenium trioxide
Rhenium trioxide is a red solid with a metallic lustre. It is the only stable trioxide of the Group 7 elements .-Structure:...
. VCl3 is paramagnetic and has two unpaired electrons.
Preparation and reactions
VCl3 is prepared by heating VCl4Vanadium tetrachloride
Vanadium tetrachloride is the inorganic compound with the formula VCl4. This bright red liquid is a useful reagent for the preparation of other vanadium compounds.-Synthesis, bonding, basic properties:...
at 160-170 °C under a flowing stream of inert gas, which sweeps out the Cl2
Chlorine
Chlorine is the chemical element with atomic number 17 and symbol Cl. It is the second lightest halogen, found in the periodic table in group 17. The element forms diatomic molecules under standard conditions, called dichlorine...
. The bright red liquid converts to a crusty purple solid. Further heating of VCl3 decomposes with volatilization of VCl4, leaving VCl2. Upon heating under H2 at 675 °C (but less than 700 °C), VCl3 reduces to greenish VCl2.
-
- 2 VCl3 + H2 → 2 VCl2 + 2 HCl
Complexes
VCl3 forms many adducts and derivatives with a broad scale of colours. VCl3 dissolves in water to give the hexahydrateWater of crystallization
In crystallography, water of crystallization or water of hydration or crystallization water is water that occurs in crystals. Water of crystallization is necessary for the maintenance of crystalline properties, but capable of being removed by sufficient heat...
, but the formula is deceptive. The salt is described by the formula [VCl2(H2O)4]Cl.2H2O. In other words, two of the water molecules are not bound to the vanadium, whose structure resembles the corresponding Fe(III) derivative. Removal of the two bound chloride ligands from [VCl2(H2O)4]+ in aqueous solution gives the green ion [V(H2O)6]3+.
With tetrahydrofuran
Tetrahydrofuran
Tetrahydrofuran is a colorless, water-miscible organic liquid with low viscosity at standard temperature and pressure. This heterocyclic compound has the chemical formula 4O. As one of the most polar ethers with a wide liquid range, it is a useful solvent. Its main use, however, is as a precursor...
, VCl3 forms the red/pink adduct VCl3(THF)3. With acetonitrile
Acetonitrile
Acetonitrile is the chemical compound with formula . This colourless liquid is the simplest organic nitrile. It is produced mainly as a byproduct of acrylonitrile manufacture...
, one obtains the green adduct VCl3(MeCN)3.
When treated with KCN, VCl3 converts to [V(CN)7]4-. It is common for early metals to adopt high coordination numbers (more than 6) with compact ligands. Complementarily, larger metals can form complexes with rather bulky ligands. This aspect is illustrated by the isolation of VCl3(NMe3)2, containing two bulky NMe3 ligands.
Precursor to organometallics
The reactive species V(mesitylMesitylene
Mesitylene or 1,3,5-trimethylbenzene is an aromatic hydrocarbon with three methyl substituents attached to the benzene ring. It is prepared by distillation of acetone with sulfuric acid or by trimerization of propyne in sulfuric acid, which, in both cases, acts as a catalyst and dehydrating agent....
)3 forms from VCl3.
-
- VCl3(THF)3 + 3 LiC6H2-2,4,6-Me3 → V(C6H2-2,4,6-Me3)3(THF) + 3 LiCl
This species binds CO and, under appropriate conditions, N2.