Sulfur dichloride

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Sulfur dichloride
Ball-and-stick model of sulfur dichloride Sulfur-dichloride-3D-balls.png
Ball-and-stick model of sulfur dichloride
Space-filling model of sulfur dichloride Sulfur-dichloride-3D-vdW.png
Space-filling model of sulfur dichloride
IUPAC name
  • Dichlorosulfane
  • Sulfur dichloride
  • Sulfur(II) chloride
Other names
  • Chloro thiohypobromite
  • Dichloro sulfide
  • Sulphur chloride
3D model (JSmol)
ECHA InfoCard 100.031.014 OOjs UI icon edit-ltr-progressive.svg
EC Number
  • 234-129-0
PubChem CID
RTECS number
  • WS4500000
UN number 1828
  • InChI=1S/Cl2S/c1-3-2
  • InChI=1/Cl2S/c1-3-2
  • ClSCl
Molar mass 102.96 g·mol−1
AppearanceCherry-red liquid
Odor Pungent
Density 1.621 g/cm3
Melting point −121.0 °C (−185.8 °F; 152.2 K)
Boiling point 59 °C (138 °F; 332 K) (decomposes)
Insoluble, reacts slowly
−49.4·10−6 cm3/mol
GHS labelling:
GHS-pictogram-acid.svg GHS-pictogram-exclam.svg GHS-pictogram-pollu.svg
H314, H335, H400
P260, P261, P264, P271, P273, P280, P301+P330+P331, P303+P361+P353, P304+P340, P305+P351+P338, P310, P312, P321, P363, P391, P403+P233, P405, P501
NFPA 704 (fire diamond)
234 °C (453 °F; 507 K)
Safety data sheet (SDS) ICSC 1661
Related compounds
Related compounds
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).
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Sulfur dichloride is the chemical compound with the formula SCl2. This cherry-red liquid is the simplest sulfur chloride and one of the most common, and it is used as a precursor to organosulfur compounds. It is a highly corrosive and toxic substance, and it reacts on contact with water to form chlorine-containing acids.


Chlorination of sulfur

SCl2 is produced by the chlorination of either elemental sulfur or disulfur dichloride. [1] The process occurs in a series of steps, some of which are:

S8 + 4 Cl2 → 4 S2Cl2; ΔH = −58.2 kJ/mol
S2Cl2 + Cl2 ↔ 2 SCl2; ΔH = −40.6 kJ/mol

The addition of Cl2 to S2Cl2 has been proposed to proceed via a mixed valence intermediate Cl3S−SCl. SCl2 undergoes even further chlorination to give SCl4, but this species is unstable at near room temperature. It is likely that several SnCl2 exist where n > 2.

Disulfur dichloride, S2Cl2, is the most common impurity in SCl2. Separation of SCl2 from S2Cl2 is possible via distillation with PCl3 to form an azeotrope of 99% purity, however sulfur dichloride loses chlorine slowly at room temperature and reverts to disulfur dichloride. Pure samples may be stored in sealed glass ampules which develop a slight positive pressure of chlorine, halting the decomposition.

Use of SCl2 in chemical synthesis

SCl2 is used in organic synthesis. It adds to alkenes to give chloride-substituted thioethers. Illustrative is its addition to 1,5-cyclooctadiene to give a bicyclic thioether [2] A well tested method for the production of the mustard gas bis(2-chloroethyl)sulfide, is the addition of ethylene to sulfur dichloride: [3]

SCl2 + 2 C2H4 → (ClC2H4)2S

SCl2 is also a precursor to several inorganic sulfur compounds. Treatment with fluoride salts gives SF4 via the decomposition of the intermediate sulfur difluoride. With H2S, SCl2 reacts to give "lower" sulfanes such as S3H2.

Reaction with ammonia affords sulfur nitrides related to S4N4. Treatment of SCl2 with primary amines gives sulfur diimides. One example is di-t-butylsulfurdiimide. [4]

Safety considerations

SCl2 hydrolyzes with release of HCl. Old samples contain Cl2.[ citation needed ]

Related Research Articles

An organochloride, organochlorine compound, chlorocarbon, or chlorinated hydrocarbon is an organic compound containing at least one covalently bonded atom of chlorine. The chloroalkane class provides common examples. The wide structural variety and divergent chemical properties of organochlorides lead to a broad range of names, applications, and properties. Organochlorine compounds have wide use in many applications, though some are of profound environmental concern, with TCDD being one of the most notorious.

<span class="mw-page-title-main">Thionyl chloride</span> Inorganic compound (SOCl2)

Thionyl chloride is an inorganic compound with the chemical formula SOCl2. It is a moderately volatile, colourless liquid with an unpleasant acrid odour. Thionyl chloride is primarily used as a chlorinating reagent, with approximately 45,000 tonnes per year being produced during the early 1990s, but is occasionally also used as a solvent. It is toxic, reacts with water, and is also listed under the Chemical Weapons Convention as it may be used for the production of chemical weapons.

<span class="mw-page-title-main">Phosphorus pentachloride</span> Chemical compound

Phosphorus pentachloride is the chemical compound with the formula PCl5. It is one of the most important phosphorus chlorides, others being PCl3 and POCl3. PCl5 finds use as a chlorinating reagent. It is a colourless, water-sensitive solid, although commercial samples can be yellowish and contaminated with hydrogen chloride.

<span class="mw-page-title-main">Phosphorus trichloride</span> Chemical compound

Phosphorus trichloride is an inorganic compound with the chemical formula PCl3. A colorless liquid when pure, it is an important industrial chemical, being used for the manufacture of phosphites and other organophosphorus compounds. It is toxic and reacts readily with water to release hydrogen chloride.

<span class="mw-page-title-main">Triphenylphosphine</span> Chemical compound

Triphenylphosphine (IUPAC name: triphenylphosphane) is a common organophosphorus compound with the formula P(C6H5)3 and often abbreviated to PPh3 or Ph3P. It is widely used in the synthesis of organic and organometallic compounds. PPh3 exists as relatively air stable, colorless crystals at room temperature. It dissolves in non-polar organic solvents such as benzene and diethyl ether.

<span class="mw-page-title-main">Rhodium(III) chloride</span> Chemical compound

Rhodium(III) chloride refers to inorganic compounds with the formula RhCl3(H2O)n, where n varies from 0 to 3. These are diamagnetic solids featuring octahedral Rh(III) centres. Depending on the value of n, the material is either a dense brown solid or a soluble reddish salt. The soluble trihydrated (n = 3) salt is widely used to prepare compounds used in homogeneous catalysis, notably for the industrial production of acetic acid and hydroformylation.

<span class="mw-page-title-main">Tetrasulfur tetranitride</span> Chemical compound

Tetrasulfur tetranitride is an inorganic compound with the formula S4N4. This gold-poppy coloured solid is the most important binary sulfur nitride, which are compounds that contain only the elements sulfur and nitrogen. It is a precursor to many S-N compounds and has attracted wide interest for its unusual structure and bonding.

<span class="mw-page-title-main">Sulfuryl chloride</span> Chemical compound

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.

<span class="mw-page-title-main">Disulfur dichloride</span> Chemical compound

Disulfur dichloride is the inorganic compound of sulfur and chlorine with the formula S2Cl2.

<span class="mw-page-title-main">Thiophosgene</span> Chemical compound

Thiophosgene is a red liquid with the formula CSCl2. It is a molecule with trigonal planar geometry. There are two reactive C–Cl bonds that allow it to be used in diverse organic syntheses.

<span class="mw-page-title-main">Platinum(II) chloride</span> Chemical compound

Platinum(II) chloride is the chemical compound PtCl2. It is an important precursor used in the preparation of other platinum compounds. It exists in two crystalline forms, but the main properties are somewhat similar: dark brown, insoluble in water, diamagnetic, and odorless.

<span class="mw-page-title-main">Selenium compounds</span> Chemical compounds containing selenium

Selenium compounds commonly exist in the oxidation states −2, +2, +4, and +6.

<span class="mw-page-title-main">Lithium bis(trimethylsilyl)amide</span> Chemical compound

Lithium bis(trimethylsilyl)amide is a lithiated organosilicon compound with the formula LiN(Si(CH3)3)2. It is commonly abbreviated as LiHMDS or Li(HMDS) (lithium hexamethyldisilazide - a reference to its conjugate acid HMDS) and is primarily used as a strong non-nucleophilic base and as a ligand. Like many lithium reagents, it has a tendency to aggregate and will form a cyclic trimer in the absence of coordinating species.

A Polysulfane is a chemical compound of formula H2Sn, where n > 1. Polysulfanes consist of unbranched chains of sulfur atoms terminated with hydrogen atoms. Compounds containing 2 – 8 concatenated sulfur atoms have been isolated, longer chain compounds have been detected, but only in solution.. H2S2 is colourless, higher members are yellow with the colour increasing with the sulfur content. Even a trace of alkali will cause chemical decomposition, and containers need to be treated with acid to remove any traces of alkali. In the chemical literature the term polysulfanes is sometimes used for compounds containing −(S)n, e.g. organic polysulfanes R1−(S)n−R2.

<span class="mw-page-title-main">Sulfenyl chloride</span> Chemical group (R–S–Cl)

In organosulfur chemistry, a sulfenyl chloride is a functional group with the connectivity R−S−Cl, where R is alkyl or aryl. Sulfenyl chlorides are reactive compounds that behave as sources of RS+. They are used in the formation of RS−N and RS−O bonds. According to IUPAC nomenclature they are named as alkyl thiohypochlorites, i.e. esters of thiohypochlorous acid.

<span class="mw-page-title-main">Selenium monochloride</span> Chemical compound

Selenium monochloride is an inorganic compound with the formula Se2Cl2. Although it is called selenium monochloride, a more descriptive name might be diselenium dichloride. It is a reddish-brown, oily liquid that hydrolyses slowly. It exists in chemical equilibrium with SeCl2, SeCl4, chlorine, and elemental selenium. Selenium monochloride is mainly used as a reagent for the synthesis of Se-containing compounds.

<span class="mw-page-title-main">Sulfur tetrachloride</span> Chemical compound

Sulfur tetrachloride is an inorganic compound with chemical formula SCl4. It has only been obtained as an unstable pale yellow solid. The corresponding SF4 is a stable, useful reagent.

<span class="mw-page-title-main">Perchloromethyl mercaptan</span> Chemical compound

Perchloromethyl mercaptan is the organosulfur compound with the formula CCl3SCl. It is mainly used as an intermediate for the synthesis of dyes and fungicides (captan, folpet). It is a colorless oil, although commercial samples are yellowish. It is insoluble in water but soluble in organic solvents. It has a foul, unbearable, acrid odor. Perchloromethyl mercaptan is the original name. The systematic name is trichloromethanesulfenyl chloride, because the compound is a sulfenyl chloride, not a mercaptan.

<span class="mw-page-title-main">Titanocene pentasulfide</span> Chemical compound

Titanocene pentasulfide is the organotitanium compound with the formula (C5H5)2TiS5, commonly abbreviated as Cp2TiS5. This metallocene exists as a bright red solid that is soluble in organic solvents. It is of academic interest as a precursor to unusual allotropes of elemental sulfur as well as some related inorganic rings.

Bis(2-chloroethyl)sulfide is the organosulfur compound with the formula (ClCH2CH2)2S. It is a prominent member of a family of cytotoxic and blister agents known as mustard agents. Sometimes referred to as mustard gas, the term is technically incorrect: bis(2-chloroethyl)sulfide is a liquid at room temperature. In warfare it was dispersed in the form of a fine mist of liquid droplets.


  1. F. Fehér "Dichloromonosulfane" in Handbook of Preparative Inorganic Chemistry, 2nd Ed. Edited by G. Brauer, Academic Press, 1963, NY. Vol. 1. p. 370.
  2. Bishop, Roger (1992). "9-Thiabicyclo[3.3.1]nonane-2,6-dione". Organic Syntheses . 70: 120.; Collective Volume, vol. 9, p. 692
  3. R. J. Cremlyn “An Introduction to Organosulfur Chemistry” John Wiley and Sons: Chichester (1996). ISBN   0-471-95512-4.
  4. Kresze, G.; Wucherpfennig, W. (1967). "New Methods of Preparative Organic Chemistry V: Organic Syntheses with Imides of Sulfur Dioxide". Angewandte Chemie International Edition in English. 6 (2): 149–167. doi:10.1002/anie.196701491. PMID   4962859.