Sulfuryl chloride

Sulfuryl chloride is an inorganic compound with the formula SO2Cl2. At room temperature, it is a colorless liquid with a pungent odor. Sulfuryl chloride is not found in nature, as can be inferred from its rapid hydrolysis.

Sulfuryl chloride
Structure and dimensions of sulfuryl chloride
Ball-and-stick model of sulfuryl chloride
Sulphuryl chloride 25ml.jpg
IUPAC name
Sulfuryl chloride
Other names
Sulfonyl chloride
Sulfuric chloride
Sulfur dichloride dioxide
3D model (JSmol)
ECHA InfoCard 100.029.314
EC Number
  • 232-245-6
RTECS number
  • WT4870000
UN number 1834
Molar mass 134.9698 g mol−1
Appearance Colorless liquid with a pungent odor. Yellows upon standing.
Density 1.67 g cm−3 (20 °C)
Melting point −54.1 °C (−65.4 °F; 219.1 K)
Boiling point 69.4 °C (156.9 °F; 342.5 K)
Solubility miscible with benzene, toluene, chloroform, CCl4, glacial acetic acid
1.4437 (20 °C)[1]
GHS pictograms GHS05: CorrosiveGHS07: Harmful
GHS Signal word Danger
H314, H335
P260, P261, P264, P271, P280, P301+330+331, P303+361+353, P304+340, P305+351+338, P310, P312, P321, P363, P403+233, P405, P501
NFPA 704 (fire diamond)
Flammability code 0: Will not burn. E.g. waterHealth code 3: Short exposure could cause serious temporary or residual injury. E.g. chlorine gasReactivity code 2: Undergoes violent chemical change at elevated temperatures and pressures, reacts violently with water, or may form explosive mixtures with water. E.g. white phosphorusSpecial hazard W: Reacts with water in an unusual or dangerous manner. E.g. sodium, sulfuric acidNFPA 704 four-colored diamond
Flash point Not flammable
Related compounds
Related sulfuryl halides
Sulfuryl fluoride
Related compounds
Thionyl chloride
Chlorosulfonic acid
Sulfuric acid
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).
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Infobox references

Sulfuryl chloride is commonly confused with thionyl chloride, SOCl2. The properties of these two sulfur oxychlorides are quite different: sulfuryl chloride is a source of chlorine whereas thionyl chloride is a source of chloride ions. An alternative IUPAC name is sulfuroyl dichloride.


Sulfur is tetrahedral in SO2Cl2 and the oxidation state of the sulfur atom is +6, as in sulfuric acid.


SO2Cl2 is prepared by the reaction of sulfur dioxide and chlorine in the presence of a catalyst, such as activated carbon.[2]

SO2 + Cl2 → SO2Cl2

The product can be purified by fractional distillation.

Legacy routesEdit

Sulfuryl chloride was first prepared in 1838 by the French chemist Henri Victor Regnault.[3]

Legacy routes include oxidation of thionyl chloride:

SOCl2 + HgO → ClSSCl + HgCl2 + SO2Cl2
2 SOCl2 + MnO2 → SO2 + MnCl2 + SO2Cl2


Sulfuryl chloride reacts with water, releasing hydrogen chloride gas and sulfuric acid:

2 H2O + SO2Cl2 → 2 HCl + H2SO4

SO2Cl2 will also decompose when heated to or above 100 °C, about 30 °C above its boiling point.

Upon standing, SO2Cl2 decomposes to sulfur dioxide and chlorine, which gives the older samples a slightly yellowish color.[2]


Sulfuryl chloride is used as a source of Cl2. Because it is a pourable liquid, it is considered more convenient than Cl2 to dispense. It is used as a reagent in the conversion of C−H to C−Cl adjacent to activating substituents such as carbonyls and sulfoxides. It also chlorinates alkanes, alkenes, alkynes, aromatics, ethers (such as tetrahydrofuran) and epoxides. Such reactions occur under free radical conditions using an initiator such as AIBN. It can also be used to convert thiols or disulfides into their corresponding sulfenyl chlorides, though sulfinyl chlorides result from thiols in some cases.[4] SO2Cl2 can also convert alcohols to alkyl chlorides. In industry, sulfuryl chloride is most used in producing pesticides.

Sulfuryl chloride can also be used to treat wool to prevent shrinking.


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 and dimethylformamide.


  1. ^ Patnaik, P. (2002). Handbook of Inorganic Chemicals. McGraw-Hill. ISBN 978-0-07-049439-8.[page needed]
  2. ^ a b F. Fehér (1963). "Sulfuryl Chloride". In G. Brauer (ed.). Handbook of Preparative Inorganic Chemistry, 2nd Ed. 1. NY,NY: Academic Press. pp. 382–384.
  3. ^ Regnault, Victor (1838). "Sur l'acide chlorosulfurique et la sulfamide" [On sulfuryl chloride and sulfamide]. Annales de Chimie et de Physique. Série 2 (in French). 69: 170–184.
  4. ^ Page, P. C. B.; Wilkes, R. D.; Reynolds, D. (1995). "Alkyl Chalcogenides: Sulfur-based Functional Groups". In Ley, Steven V. (ed.). Synthesis: Carbon with One Heteroatom Attached by a Single Bond. Comprehensive Organic Functional Group Transformations. Elsevier. pp. 113–276. ISBN 9780080423234.

Further readingEdit