Sulfuryl chloride is an inorganic compound with the formula SO
2Cl
2. At
room temperature, it is a colorless liquid with a pungent odor. Sulfuryl chloride is not found in nature.
Sulfuryl chloride is commonly confused with
thionyl chloride
Thionyl chloride is an inorganic compound with the chemical formula . It is a moderately Volatility (chemistry), volatile, colourless liquid with an unpleasant acrid odour. Thionyl chloride is primarily used as a Halogenation, chlorinating reagen ...
, SOCl
2. The properties of these two sulfur oxychlorides are quite different: sulfuryl chloride is a source of
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 ...
whereas thionyl chloride is a source of
chloride
The term chloride refers to a compound or molecule that contains either a chlorine anion (), which is a negatively charged chlorine atom, or a non-charged chlorine atom covalently bonded to the rest of the molecule by a single bond (). The pr ...
ions. An alternative IUPAC name is sulfuryl dichloride.
Sulfur is tetrahedral in SO
2Cl
2 and the
oxidation state
In chemistry, the oxidation state, or oxidation number, is the hypothetical Electrical charge, charge of an atom if all of its Chemical bond, bonds to other atoms are fully Ionic bond, ionic. It describes the degree of oxidation (loss of electrons ...
of the sulfur atom is +6, as in
sulfuric acid
Sulfuric acid (American spelling and the preferred IUPAC name) or sulphuric acid (English in the Commonwealth of Nations, Commonwealth spelling), known in antiquity as oil of vitriol, is a mineral acid composed of the elements sulfur, oxygen, ...
.
Synthesis
SO
2Cl
2 is prepared by the reaction of
sulfur dioxide
Sulfur dioxide (IUPAC-recommended spelling) or sulphur dioxide (traditional Commonwealth English) is the chemical compound with the formula . It is a colorless gas with a pungent smell that is responsible for the odor of burnt matches. It is r ...
and
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 ...
in the presence of a
catalyst
Catalysis () is the increase in rate of a chemical reaction due to an added substance known as a catalyst (). Catalysts are not consumed by the reaction and remain unchanged after it. If the reaction is rapid and the catalyst recycles quick ...
, such as
activated carbon
Activated carbon, also called activated charcoal, is a form of carbon commonly used to filter contaminants from water and air, among many other uses. It is processed (activated) to have small, low-volume pores that greatly increase the surface ar ...
.
:SO
2 + Cl
2 → SO
2Cl
2
The product can be purified by
fractional distillation
Fractional distillation is the separation of a mixture into its component parts, or fractions. Chemical compounds are separated by heating them to a temperature at which one or more fractions of the mixture will vaporize. It uses distillation ...
.
Legacy routes
Sulfuryl chloride was first prepared in 1838 by the French chemist
Henri Victor Regnault.
Older routes include oxidation of thionyl chloride:
:5 SOCl
2 + HgO → ClSSCl + HgCl
2 + 3 SO
2Cl
2
:2 SOCl
2 + MnO
2 → SO
2 + MnCl
2 + SO
2Cl
2
Reactions
Sulfuryl chloride 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 ...
, releasing
hydrogen chloride
The Chemical compound, compound hydrogen chloride has the chemical formula and as such is a hydrogen halide. At room temperature, it is a colorless gas, which forms white fumes of hydrochloric acid upon contact with atmospheric water vapor. Hyd ...
gas and
sulfuric acid
Sulfuric acid (American spelling and the preferred IUPAC name) or sulphuric acid (English in the Commonwealth of Nations, Commonwealth spelling), known in antiquity as oil of vitriol, is a mineral acid composed of the elements sulfur, oxygen, ...
:
:2 H
2O + SO
2Cl
2 → 2 HCl + H
2SO
4
For sulfuryl chloride, this happens at room temperature, but the related
sulfuryl fluoride
Sulfuryl fluoride (also spelled ''sulphuryl fluoride'') is an inorganic compound with the formula SO2F2. It is an easily condensed gas and has properties more similar to sulfur hexafluoride than sulfuryl chloride, being resistant to hydrolysis ...
does not hydrolyse at temperatures up to 150 °C.
SO
2Cl
2 will also
decompose when heated to or above 100 °C, about 30 °C above its boiling point.
Upon standing, SO
2Cl
2 decomposes to
sulfur dioxide
Sulfur dioxide (IUPAC-recommended spelling) or sulphur dioxide (traditional Commonwealth English) is the chemical compound with the formula . It is a colorless gas with a pungent smell that is responsible for the odor of burnt matches. It is r ...
and
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 ...
, which gives the older samples a slightly yellowish color.
[
SO2Cl2 can be used as a source of chlorine in alkane chlorination, initiated by chemicals (usually a peroxide) or light:
:CH4 + SO2Cl2 → CH3Cl + SO2 + HCl
]
Uses
Sulfuryl chloride is used as a source of Cl2. Because it is a pourable liquid, it is considered more convenient than Cl2 to dispense.
Sulfuryl chloride is used in the conversion of C−H to C−Cl adjacent to activating substituents such as carbonyls and sulfoxides:
:
It also chlorinates alkane
In organic chemistry, an alkane, or paraffin (a historical trivial name that also has other meanings), is an acyclic saturated hydrocarbon. In other words, an alkane consists of hydrogen and carbon atoms arranged in a tree structure in whi ...
s, alkene
In organic chemistry, an alkene, or olefin, is a hydrocarbon containing a carbon–carbon double bond. The double bond may be internal or at the terminal position. Terminal alkenes are also known as Alpha-olefin, α-olefins.
The Internationa ...
s, alkyne
\ce
\ce
Acetylene
\ce
\ce
\ce
Propyne
\ce
\ce
\ce
\ce
1-Butyne
In organic chemistry, an alkyne is an unsaturated hydrocarbon containing at least one carbon—carbon triple bond. The simplest acyclic alkynes with only one triple bond and n ...
s, aromatics
Aromatic compounds or arenes are organic compounds "with a chemistry typified by benzene" and "cyclically conjugated."
The word "aromatic" originates from the past grouping of molecules based on odor, before their general chemical properties were ...
, ethers (such as tetrahydrofuran
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 ...
) and epoxide
In organic chemistry, an epoxide is a cyclic ether, where the ether forms a three-atom ring: two atoms of carbon and one atom of oxygen. This triangular structure has substantial ring strain, making epoxides highly reactive, more so than other ...
s. Such reactions occur under free radical
A daughter category of ''Ageing'', this category deals only with the biological aspects of ageing.
Ageing
Biogerontology
Biological processes
Causes of death
Cellular processes
Gerontology
Life extension
Metabolic disorders
Metabolism
...
conditions using an initiator such as AIBN. It convert thiol
In organic chemistry, a thiol (; ), or thiol derivative, is any organosulfur compound of the form , where R represents an alkyl or other organic substituent. The functional group itself is referred to as either a thiol group or a sulfhydryl grou ...
s or disulfide
In chemistry, a disulfide (or disulphide in British English) is a compound containing a functional group or the anion. The linkage is also called an SS-bond or sometimes a disulfide bridge and usually derived from two thiol groups.
In inorg ...
s into the corresponding sulfenyl chloride
In organosulfur chemistry, a sulfenyl chloride is a functional group with the connectivity , where R is alkyl or aryl. Sulfenyl chlorides are reactive compounds that behave as sources of . They are used in the formation of and bonds. According ...
s:
:
Occasionally, sulfinyl chloride
Sulfinyl halide have the general formula R−S(O)−X, where X is a halogen. They are intermediate in oxidation level between sulfenyl halides, R−S−X, and sulfonyl halides, R−SO2−X. The best known examples are sulfinyl chlorides, thermo ...
s result from such reactions. SO2Cl2 can also convert alcohol
Alcohol may refer to:
Common uses
* Alcohol (chemistry), a class of compounds
* Ethanol, one of several alcohols, commonly known as alcohol in everyday life
** Alcohol (drug), intoxicant found in alcoholic beverages
** Alcoholic beverage, an alco ...
s to alkyl chlorides. In industry, sulfuryl chloride is most used in producing pesticides. Phosphorus pentachloride is prepared by the reaction of white phosphorus
White phosphorus, yellow phosphorus, or simply tetraphosphorus (P4) is an allotrope of phosphorus. It is a translucent waxy solid that quickly yellows in light (due to its photochemical conversion into red phosphorus), and impure white phospho ...
with sulfuryl chloride.
Sulfuryl chloride can also be used to treat wool to prevent shrinking.
Precautions
Sulfuryl chloride is toxic, corrosive, and acts as a lachrymator. It releases hydrogen chloride upon contact with water, as well as donor solvents such as dimethyl sulfoxide
Dimethyl sulfoxide (DMSO) is an organosulfur compound with the formula . This colorless liquid is the sulfoxide most widely used commercially. It is an important polar aprotic solvent that dissolves both polar and nonpolar compounds and is ...
and dimethylformamide
Dimethylformamide, DMF is an organic compound with the chemical formula . Its structure is . Commonly abbreviated as DMF (although this initialism is sometimes used for 2,5-dimethylfuran, dimethylfuran, or dimethyl fumarate), this colourless liqui ...
.
References
*
*
Further reading
*
*
*
*
*
{{Refend
Oxychlorides
Sulfuryl compounds
Sulfur oxohalides