Vanadium(III) iodide is the
inorganic compound with the formula VI
3. This paramagnetic solid is generated by the reaction of
vanadium powder with
iodine at around 500 °C.
The black hygroscopic crystals dissolve in water to give green solutions, characteristic of V(III) ions.
The purification of vanadium metal by the
chemical transport reaction
In chemistry, a chemical transport reaction describes a process for purification and crystallization of non- volatile solids. The process is also responsible for certain aspects of mineral growth from the effluent of volcanoes. The technique is ...
involving the reversible formation of vanadium(III) iodides in the presence of
iodine and its subsequent decomposition to yield pure metal:
: 2 V + 3 I
2 ⇌ 2 VI
3
VI
3 crystallizes in the motif adopted by
bismuth(III) iodide
Bismuth(III) iodide is the inorganic compound with the formula Bi I3. This gray-black salt is the product of the reaction of bismuth and iodine, which once was of interest in qualitative inorganic analysis.
Bismuth(III) iodide adopts a disti ...
: the iodides are hexagonal-closest packed and the vanadium centers occupy one third of the octahedral holes.
When solid samples are heated, the gas contains VI
4, which is probably the volatile vanadium component in the vapor transport method. Thermal decomposition of the triiodide leaves a residue of vanadium(II) iodide:
: 2 VI
3 → VI
2 + VI
4 ΔH = 36.6 kcal/mol; ΔS = 38.7
e.u.
The European Union (EU) is a supranational political and economic union of member states that are located primarily in Europe. The union has a total area of and an estimated total population of about 447million. The EU has often been de ...
References
{{Iodides
Iodides
Metal halides
Vanadium(III) compounds