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 with the 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 betwee ...
. Owing to its tendency to
hydrolyse
Hydrolysis (; ) is any chemical reaction in which a molecule of water breaks one or more chemical bonds. The term is used broadly for substitution, elimination, and solvation reactions in which water is the nucleophile.
Biological hydrolys ...
to
hydrochloric acid
Hydrochloric acid, also known as muriatic acid, is an aqueous solution of hydrogen chloride. It is a colorless solution with a distinctive pungent smell. It is classified as a strong acid
Acid strength is the tendency of an acid, symbol ...
, SbCl
5 is a highly corrosive substance and must be stored in glass or
PTFE
Polytetrafluoroethylene (PTFE) is a synthetic fluoropolymer of tetrafluoroethylene that has numerous applications. It is one of the best-known and widely applied PFAS. The commonly known brand name of PTFE-based composition is Teflon by Chemour ...
containers.
Preparation and structure
Antimony pentachloride is prepared by passing
chlorine gas
Chlorine is a chemical element with the 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 them. Chlorine is ...
into molten
antimony trichloride
Antimony trichloride is the chemical compound with the formula SbCl3. It is a soft colorless solid with a pungent odor and was known to alchemists as butter of antimony.
Preparation
Antimony trichloride is prepared by reaction of chlorine with an ...
:
:SbCl
3 + Cl
2 → SbCl
5
Gaseous SbCl
5 has a trigonal bipyramidal structure.
Reactions
This compounds reacts with
water
Water (chemical formula ) is an inorganic, transparent, tasteless, odorless, and nearly colorless chemical substance, which is the main constituent of Earth's hydrosphere and the fluids of all known living organisms (in which it acts as a ...
to form
antimony pentoxide
Antimony pentoxide (molecular formula: Sb2O5) is a chemical compound of antimony and oxygen. It contains antimony in the +5 oxidation state.
Structure
Antimony pentoxide has the same structure as the ''B'' form of niobium pentoxide and can be deri ...
and
hydrochloric acid
Hydrochloric acid, also known as muriatic acid, is an aqueous solution of hydrogen chloride. It is a colorless solution with a distinctive pungent smell. It is classified as a strong acid
Acid strength is the tendency of an acid, symbol ...
:
: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
An oxidizing agent (also known as an oxidant, oxidizer, electron recipient, or electron acceptor) is a substance in a redox chemical reaction that gains or "Electron acceptor, accepts"/"receives" an electron from a (called the , , or ). In ot ...
. 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, monomer molecules together in a chemical reaction to form polymer chains or three-dimensional networks. There are ...
catalyst
Catalysis () is the process of increasing the rate of a chemical reaction by adding a substance known as a catalyst (). Catalysts are not consumed in the reaction and remain unchanged after it. If the reaction is rapid and the catalyst recyc ...
and for the
chlorination Chlorination may refer to:
* Chlorination reaction
In chemistry, halogenation is a chemical reaction that entails the introduction of one or more halogens into a compound. Halide-containing compounds are pervasive, making this type of transform ...
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
Antimony(V) compounds
Chlorides
Metal halides
Oxidizing agents
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