Antimony pentachloride is a chemical compound with the formula SbCl
5. It is a colourless oil, but typical samples are yellowish due to dissolved
chlorine
Chlorine is a chemical element; it has Symbol (chemistry), symbol Cl and atomic number 17. The second-lightest of the halogens, it appears between fluorine and bromine in the periodic table and its properties are mostly intermediate between ...
. Owing to its tendency to
hydrolyse to
hydrochloric acid, SbCl
5 is a highly corrosive substance and must be stored in glass or
PTFE
Polytetrafluoroethylene (PTFE) is a synthetic fluoropolymer of tetrafluoroethylene, and has numerous applications because it is chemically inert. The commonly known brand name of PTFE-based composition is Teflon by Chemours, a spin-off fro ...
containers.
Preparation and structure
Antimony pentachloride is prepared by passing
chlorine gas into molten
antimony trichloride:
:SbCl
3 + Cl
2 → SbCl
5
Gaseous SbCl
5 has a trigonal bipyramidal structure.
Reactions
This compounds reacts with
water
Water is an inorganic compound with the chemical formula . It is a transparent, tasteless, odorless, and Color of water, nearly colorless chemical substance. It is the main constituent of Earth's hydrosphere and the fluids of all known liv ...
to form
antimony pentoxide and
hydrochloric acid:
:2 SbCl
5 + 5 H
2O → Sb
2O
5 + 10 HCl
The mono- and tetrahydrates are known, SbCl
5·H
2O and SbCl
5·4H
2O.
This compound forms adducts with many Lewis bases. SbCl
5 is a
soft Lewis acid and its
ECW model parameters are E
A = 3.64 and C
A = 10.42. It is used as the standard Lewis acid in the
Gutmann scale of Lewis basicity.
It is also a strong
oxidizing agent. For example aromatic ethers are oxidized to their radical cations according to the following stoichiometry:
:3SbCl
5 + 2 ArH → 2(ArH+)(SbCl
6−) + SbCl
3
Applications
Antimony pentachloride is used as a
polymerization
In polymer chemistry, polymerization (American English), or polymerisation (British English), is a process of reacting monomer molecules together in a chemical reaction to form polymer chains or three-dimensional networks. There are many fo ...
catalyst and for the
chlorination of organic compounds.
Precautions
Antimony pentachloride is a highly corrosive substance that should be stored away from heat and moisture. It is a chlorinating agent and, in the presence of moisture, it releases hydrogen chloride gas. Because of this, it may etch even stainless-steel tools (such as needles), if handled in a moist atmosphere. It should not be handled with non-fluorinated plastics (such as plastic syringes, plastic septa, or needles with plastic fittings), since it melts and carbonizes plastic materials.
[Shekarchi, M.; Behbahani, F. K ''Catal. Lett.'' 2017 ''147'' 2950. doi:10.1007/s10562-017-2194-2]
References
External links
{{Chlorides
Antimony(V) compounds
Chlorides
Metal halides
Oxidizing agents