Vanadium(III) bromide, also known as vanadium tribromide, is the
inorganic compound with the formula VBr
3. It is a green-black solid. In terms of its structure, the compound is
polymeric
A polymer (; Greek '' poly-'', "many" + ''-mer'', "part")
is a substance or material consisting of very large molecules called macromolecules, composed of many repeating subunits. Due to their broad spectrum of properties, both synthetic an ...
with octahedral vanadium(III) surrounded by six bromide ligands.
VBr
3 has been prepared by treatment of
vanadium tetrachloride
Vanadium tetrachloride is the inorganic compound with the formula V Cl4. This bright red liquid serves as a useful reagent for the preparation of other vanadium compounds.
Synthesis, bonding, basic properties
With one more valence electron than ...
with
hydrogen bromide
Hydrogen bromide is the inorganic compound with the formula . It is a hydrogen halide consisting of hydrogen and bromine. A colorless gas, it dissolves in water, forming hydrobromic acid, which is saturated at 68.85% HBr by weight at room tempe ...
:
::2 VCl
4 + 8 HBr → 2 VBr
3 + 8 HCl + Br
2
The reaction proceeds via the unstable vanadium(IV) bromide (VBr
4), which releases Br
2 near room temperature.
Like
VCl3, VBr
3 forms red-brown soluble complexes with dimethoxyethane and
THF
Tetrahydrofuran (THF), or oxolane, is an organic compound with the formula (CH2)4O. The compound is classified as heterocyclic compound, specifically a cyclic ether. It is a colorless, water- miscible organic liquid with low viscosity. It is ...
, such as
mer-VBr
3(THF)
3.
Aqueous solutions prepared from VBr
3 contain the cation ''trans''-
Br2(H2O)4sup>+. Evaporation of these solutions give the salt trans-
Br2(H2O)4r.
[Donovan, W. F.; Smith, P. W. "Crystal and Molecular Structures of Aquahalogenovanadium(1ii) Complexes. Part 1. X-Ray Crystal Structure of trans-Tetrakisaquadibromovanadium(III) Bromide Dihydrate and the lsomorphous Chloro-compound" Journal of the Chemical Society, Daltor Transactions." 1975, pages 894-896.]
Further reading
*Stebler, A.; Leuenberger, B.; Guedel, H. U. "Synthesis and crystal growth of A
3M
2X
9 (A = Cs, Rb; M = Ti, V, Cr; X = Cl, Br)" Inorganic Syntheses (1989), volume 26, pages 377–85.
References
{{Bromides
Bromides
Metal halides
Vanadium(III) compounds