Vanadium(V) chloride
{{Chembox
| ImageFile = V2Cl10.png
| ImageSize =
| ImageAlt =
| ImageFile2 = V2Cl10-from-xtal-2013-3D-balls.png
| IUPACName =
| OtherNames = vanadium pentachloride
|Section1={{Chembox Identifiers
| CASNo = 1421358-80-6
| PubChem = 13643901
| SMILES = Cl[V](Cl)(Cl)(Cl)Cl
| SMILES1 = Cl[V-]1(Cl)(Cl)(Cl)[Cl+][V-]([Cl+]1)(Cl)(Cl)(Cl)Cl
| SMILES1_Comment = dimer
| StdInChI=1S/5ClH.V/h5*1H;/q;;;;;+5/p-5
| StdInChIKey=RPESBQCJGHJMTK-UHFFFAOYSA-I
}}
|Section2={{Chembox Properties
| Cl=10|V=2
| MolarMass =
| Appearance = black solid
| Density = 2.69 g/cm3
| MeltingPt =
| BoilingPt =
| Solubility = }}
|Section3={{Chembox Hazards
| MainHazards =
| FlashPt =
| AutoignitionPt = }}
}}
Vanadium(V) chloride is the inorganic compound with the formula VCl5. It is a black diamagnetic solid. The molecules adopt a bioctahedral structure similar to that of niobium(V) chloride.{{cite journal|author1=Tamadon, Farhad |author2=Seppelt, K. |title=The Elusive Halides VCl5, MoCl6, and ReCl6|journal=Angewandte Chemie International Edition|year=2012|volume=52|issue=2|pages=767–769|doi=10.1002/anie.201207552|pmid=23172658}}
Preparation and reactions
Chlorine cannot oxidise vanadium(IV); chlorination of vanadium metal will yield only vanadium(IV) chloride. Vanadium(V) chloride is instead prepared from vanadium pentafluoride with excess boron trichloride as a chlorinating agent:
:{{chem2|2 VF5 + 10 BCl3 -> [VCl5]2 + 10 BF2Cl}}
It is unstable at room temperature, releasing gaseous chlorine and giving vanadium(IV) chloride:
:{{chem2|[VCl5]2 -> 2 VCl4 + Cl2}}
In contrast, the heavier analogues {{chem2|NbCl5|link=Niobium(V) chloride}} and {{chem2|TaCl5|link=Tantalum(V) chloride}} are stable and not particularly oxidizing.