Sulfur dichloride
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2008-06-29T15:35:19Z
Alexbot
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robot Modifying: [[es:Cloruro de azufre (II)]]
{{Chembox new
| Name = Sulfur dichloride
| ImageFile = Sulfur-dichloride-2D-dimensions.png
| ImageSize = 160px
| ImageFileL1 = Structure and dimensions of the sulfur dichloride molecule
| ImageFileL1 = Sulfur-dichloride-3D-balls.png
<!-- | ImageSize1 = 140px -->
| ImageNameL1 = Ball-and-stick model of sulfur dichloride
| ImageFileR1 = Sulfur-dichloride-3D-vdW.png
<!-- | ImageSizeR2 = 140px -->
| ImageNameR2 = Space-filling model of sulfur dichloride
| IUPACName = Sulfur(II) chloride
| OtherNames = sulfur dichloride<br /> sulfur chloride<br /> dichlorosulfane;
| Section1 = {{Chembox Identifiers
| SMILES = ClSCl
| CASNo = 10545-99-0
| RTECS = WS4500000
}}
| Section2 = {{Chembox Properties
| Formula = Cl<sub>2</sub>S
| MolarMass = 102.97 g mol<sup>−1</sup>
| Appearance = red liquid at [[Standard conditions for temperature and pressure|STP]]
| Density = 1.621 g cm<sup>−3</sup>, liquid
| Solubility = hydrolysis
| MeltingPt = −121.0 °C (152.15 K)
| BoilingPt = 59 °C (332.15 K)
| RefractIndex = 1.5570
}}
| Section3 = {{Chembox Structure
| Coordination = C<sub>2v</sub>
| Dipole =
}}
| Section7 = {{Chembox Hazards
| ExternalMSDS =
| MainHazards = corrosive
| RPhrases = R14; R34; R37; N; R50
| SPhrases =
}}
| Section8 = {{Chembox Related
| OtherCpds = [[sulfur tetrafluoride|Sulfur tetrafluoride, SF<sub>4</sub>]]<br />[[sulfuryl chloride|Sulfuryl chloride, SO<sub>2</sub>Cl<sub>2</sub>]]<br />[[thionyl chloride|Thionyl chloride, SOCl<sub>2</sub>]]<br />[[disulfur dichloride|Disulfur dichloride, S<sub>2</sub>Cl<sub>2</sub>]]
}}
}}
'''Sulfur dichloride''' is the [[chemical compound]] with the [[chemical formula|formula]] SCl<sub>2</sub>. This cherry-red liquid is the simplest sulfur chloride and one of the most common. It is used as a precursor to [[organosulfur compound]]s.<ref>Schmidt, M.; Siebert, W. "Sulphur" ''Comprehensive Inorganic Chemistry'' Vol. 2, ed. A.F. Trotman-Dickenson. 1973.</ref>
==Chlorination of sulfur==
SCl<sub>2</sub> is produced by the chlorination of either elemental [[sulfur]]. The process occurs in a series of steps, some of which are:
::S<sub>8</sub> + 4 Cl<sub>2</sub> → 4 S<sub>2</sub>Cl<sub>2</sub>; ΔH = −58.2 kJ/mol
::S<sub>2</sub>Cl<sub>2</sub> + Cl<sub>2</sub> → 2 SCl<sub>2</sub>; ΔH = −40.6 kJ/mol
The addition of [[chlorine|Cl<sub>2</sub>]] to S<sub>2</sub>Cl<sub>2</sub> has been proposed to proceed via a mixed valence intermediate Cl<sub>3</sub>S-SCl. SCl<sub>2</sub> undergoes even further chlorination to give SCl<sub>4</sub>, but this species is unstable at near room temperature. It is likely that several S<sub>x</sub>Cl<sub>2</sub> exist where x > 2.
[[Disulfur dichloride]], S<sub>2</sub>Cl<sub>2</sub>, is the most common impurity in SCl<sub>2</sub>. Separation of SCl<sub>2</sub> from S<sub>2</sub>Cl<sub>2</sub> is possible via distillation with [[Phosphorus trichloride|PCl<sub>3</sub>]] to form an [[azeotrope]] of 99% purity
==Use of SCl<sub>2</sub> in chemical synthesis==
*SCl<sub>2</sub> is used in [[organic synthesis]]. It adds to [[alkenes]] to give chloride-substituted thioethers. Illustrative applications are its addition to [[1,5-Cyclooctadiene|1,5-cyclooctadiene]] to give a bicyclic [[thioether]]<ref>Bishop, R. "9-Thiabicyclo[3.3.1]nonane-2,6-dione" Organic Syntheses, Collected Volume 9, p.692 (1998). http://www.orgsyn.org/orgsyn/pdfs/CV9P0692.pdf</ref> and [[ethylene]] to give [[sulfur mustard]] S(CH<sub>2</sub>CH<sub>2</sub>Cl)<sub>2</sub>.<ref>R. J. Cremlyn “An Introduction to Organosulfur Chemistry” John Wiley and Sons: Chichester (1996). ISBN 0 471 95512 4.</ref>
SCl<sub>2</sub> is also a precursor to several inorganic sulfur compounds. Treatment with fluoride salts gives [[Sulfur tetrafluoride|SF<sub>4</sub>]]. Reaction with ammonia affords sulfur nitrides related to [[tetrasulfur tetranitride|S<sub>4</sub>N<sub>4</sub>]]. With H<sub>2</sub>S, SCl<sub>2</sub> reacts to give "higher" sulfanes such as S<sub>3</sub>H<sub>2</sub>.
==Safety considerations==
SCl<sub>2</sub> hydrolyzes with release of [[hydrogen chloride|HCl]]. Old samples contain Cl<sub>2</sub>.
==References==
{{reflist}}
[[Category:Chlorides]]
[[Category:Sulfur halides]]
[[de:Schwefeldichlorid]]
[[es:Cloruro de azufre (II)]]
[[ja:二塩化硫黄]]
[[zh:二氯化硫]]