disulfur dichloride
{{Chembox
| Verifiedfields = changed
| Watchedfields = changed
| verifiedrevid = 476993527
| ImageFile = Disulfur-dichloride-2D-dimensions.png
| ImageName = Wireframe model of disulfur dichloride
| ImageFileL1 = Disulfur-dichloride-3D-balls.png
| ImageNameL1 = Ball and stick model of disulfur dichloride
| ImageCaptionL1 = {{color box|yellow}} Sulfur, S;
{{color box|lime}} Chlorine, Cl
| ImageFileR1 = Disulfur-dichloride-3D-vdW.png
| ImageNameR1 = Spacefill model of disulfur dichloride
| ImageFile2 = Дитиодихлорид.jpg
| IUPACName = Disulfur dichloride
Dichlorodisulfane
| SystematicName = Chlorosulfanyl thiohypochlorite
| OtherNames = {{ubl|Bis[chloridosulfur](S–S)|Dimeric sulfenic chloride|Sulfur monochloride (incorrect name)}}
| Section1 = {{Chembox Identifiers
| StdInChI_Ref = {{stdinchicite|correct|chemspider}}
| StdInChI = 1S/Cl2S2/c1-3-4-2
| StdInChIKey_Ref = {{stdinchicite|correct|chemspider}}
| StdInChIKey = PXJJSXABGXMUSU-UHFFFAOYSA-N
| CASNo = 10025-67-9
| CASNo_Ref = {{cascite|correct|CAS}}
| CASNo1_Ref = {{cascite|changed|??}}
| CASNo1 = 85408-26-0
| CASNo1_Comment = (isobutenate)
| DrugBank = DB14647
| UNII_Ref = {{fdacite|correct|FDA}}
| UNII = NJ7YR2EV0D
| PubChem = 24807
| ChemSpiderID = 23192
| ChemSpiderID_Ref = {{chemspidercite|correct|chemspider}}
| ChemSpiderID1_Ref = {{chemspidercite|changed|chemspider}}
| ChemSpiderID1 = 19158348
| ChemSpiderID1_Comment = (isobutenate)
| EINECS = 233-036-2
| UNNumber = 3390
| MeSHName = Sulfur+monochloride
| RTECS = WS4300000
| SMILES = ClSSCl
| InChI = 1/Cl2S2/c1-3-4-2
| InChIKey = PXJJSXABGXMUSU-UHFFFAOYAK
}}
| Section2 = {{Chembox Properties
| Formula = {{chem2|S2Cl2}}
| S=2|Cl=2
| Appearance = Light-amber to yellow-red, oily liquid
| Odor = pungent, nauseating, irritating
| Density = 1.688 g/cm3
| Solubility = Decomposes, with loss of HCl
| SolubleOther = Soluble in ethanol, benzene, ether, THF, chloroform, carbon tetrachloridePradyot Patnaik. Handbook of Inorganic Chemicals. McGraw-Hill, 2002, {{ISBN|0-07-049439-8}}
| MeltingPtC = −80
| BoilingPtC = 137.1
| RefractIndex = 1.658
| VaporPressure = 7 mmHg (20 °C)
| MagSus = −62.2·10−6 cm3/mol
}}
| Section3 = {{Chembox Structure
| Coordination = 2 at sulfur atoms
| MolShape = gauche
| PointGroup = C2
| Dipole = 1.60 D }}
| Section7 = {{Chembox Hazards
| ExternalSDS = [http://www.inchem.org/documents/icsc/icsc/eics0958.htm ICSC 0958]
| NFPA-H = 2
| NFPA-R = 1
| NFPA-F = 1
| GHSPictograms = {{GHS02}}{{GHS06}}{{GHS07}}{{GHS09}}
| GHSSignalWord = Danger
| HPhrases = {{H-phrases|301|314|332|400}}
| PPhrases = {{P-phrases|260|261|264|270|271|273|280|301+310|301+330+331|303+361+353|304+312|304+340|305+351+338|310|312|321|330|363|391|405|501}}
| FlashPtC = 118.5
| AutoignitionPtC = 234
| IDLH = 5 ppm{{PGCH|0578}} (1 ppm = 5.52 mg/m3)
| PEL = TWA 1 ppm (5.52 mg/m3)
| LCLo = 150 ppm (mouse, 1 min) (1 ppm = 5.52 mg/m3){{IDLH|10025679|Sulfur monochloride}}
}}
| Section8 = {{Chembox Related
| OtherFunction = {{ubl|Sulfur dichloride|Thionyl chloride|Sulfuryl chloride}}
| OtherFunction_label = sulfur chlorides/oxychlorides
| OtherCompounds = {{ubl|Hydrogen disulfide|Disulfur difluoride|Disulfur dibromide|Disulfur diiodide|Dimethyl disulfide|Diphenyl disulfide|Diselenium dichloride}}
}}
}}
Disulfur dichloride (or disulphur dichloride by the British English spelling) is the inorganic compound of sulfur and chlorine with the formula {{chem2|S2Cl2}}.Holleman, A. F.; Wiberg, E. Inorganic Chemistry Academic Press: San Diego, 2001. {{ISBN|0-12-352651-5}}.{{OrgSynth | first1 = W. W. | last1 = Hartman | first2 = L. A. | last2 = Smith | first3 = J. B. | last3 = Dickey | title = Diphenylsulfide | collvol = 2 | collvolpages = 242 | volume = 14 | pages = 36 | year = 1934 | prep=cv2p0242}}R. J. Cremlyn An Introduction to Organosulfur Chemistry John Wiley and Sons: Chichester (1996). {{ISBN|0-471-95512-4}}{{cite journal| author=Garcia-Valverde M., Torroba T.|title= Heterocyclic chemistry of sulfur chlorides – Fast ways to complex heterocycles |journal= European Journal of Organic Chemistry|volume=2006| pages= 849–861|year= 2006|doi= 10.1002/ejoc.200500786| issue=4}} It is an amber oily liquid.
Sometimes, this compound is incorrectly named sulfur monochloride (or sulphur monochloride by the British English spelling), the name implied by its empirical formula SCl.
{{chem2|S2Cl2}} has the structure implied by the formula {{chem2|Cl\sS\sS\sCl}}, wherein the dihedral angle between the {{chem2|Cl^{a}\sS\sS}} and {{chem2|S\sS\sCl^{b}|}} planes is 85.2°. This structure is referred to as gauche, and is akin to that for Hydrogen peroxide. A rare isomer of {{chem2|S2Cl2}} is {{chem2|S\dSCl2}} (thiothionyl chloride); this isomer forms transiently when {{chem2|S2Cl2}} is exposed to UV-radiation (see thiosulfoxides).
Synthesis, basic properties, reactions
Disulfur dichloride is a yellow liquid that fumes in moist air due to reaction with water:
:{{chem2|16 S2Cl2 + 16 H2O → 8 SO2 + 32 HCl + 3 S8}}
It is produced by partial chlorination of elemental sulfur. The reaction proceeds at usable rates at room temperature. In the laboratory, chlorine gas is led into a flask containing elemental sulfur. As disulfur dichloride is formed, the contents become a golden yellow liquid:F. Fehér "Dichlorodisulfane" in Handbook of Preparative Inorganic Chemistry, 2nd Ed. Edited by G. Brauer, Academic Press, 1963, NY. Vol. 1. p. 371.
:{{chem2|S8 + 4 Cl2 → 4 S2Cl2}}, ΔH = −58.2 kJ/mol
Excess chlorine produces sulfur dichloride, which causes the liquid to become less yellow and more orange-red:
:{{chem2|S2Cl2 + Cl2 ⇌ 2 SCl2}}, ΔH = −40.6 kJ/mol
The reaction is reversible, and upon standing, {{chem2|SCl2}} releases chlorine to revert to the disulfur dichloride. Disulfur dichloride has the ability to dissolve large quantities of sulfur, which reflects in part the formation of dichloropolysulfanes:
:{{chem2|8 S2Cl2 + n S8 → 8 S_{n+2}Cl2}}
Disulfur dichloride can be purified by distillation from excess elemental sulfur.
{{chem2|S2Cl2}} also arises from the chlorination of Carbon disulfide as in the synthesis of thiophosgene or carbon tetrachloride.
=Reactions=
{{chem2|S2Cl2}} hydrolyzes to sulfur dioxide and elemental sulfur. When treated with hydrogen sulfide, polysulfanes are formed as indicated in the following idealized formula:
:{{chem2|2 H2S + S2Cl2 → H2S4 + 2 HCl}}
It reacts with ammonia to give tetrasulfur tetranitride as well as heptasulfur imide ({{chem2|S7NH}}) and related S−N rings {{chem2|S_{8−n}(NH)_{n}|}} (n = 2, 3).{{cite book |doi=10.1002/9780470132401 |chapter= Chapter VI |title=Inorganic Syntheses |year=1967 |last1=Tyree Jr. |first1=S. Y.|volume= 9 |isbn=9780470131688}}
:{{chem2|16 NH3 + 6 S2Cl2 → S4N4 + S8 + 12 NH4Cl}}
With primary and secondary alkoxide equivalents, it forms disulfoxylate esters:
:2 ROH + S2Cl2 + 2 NEt3 → (R–O–S)2 + 2 [HNEt3]Cl
In principle the subsequent addition of base should give sulfoxylate esters, but typically induces disproportionation to aldehydes and alcohols instead.{{unbulleted list citebundle|{{cite journal|doi=10.1021/jo01019a044|journal= The Journal of Organic Chemistry|volume=30|number=8|date=1 Aug 1965|orig-date=11 Jan 1965|title= Organic Esters of Bivalent Sulfur. I. Dialkoxy Disulfides|first1=Q. E.|last1=Thompson|first2=M. M.|last2=Crutchfield|first3=M. W.|last3=Dietrich|first4=E.|last4=Pierron|pages= 2692–2696}}|{{cite journal |doi=10.1021/jo01019a046 |title=Organic Esters of Bivalent Sulfur. III. Sulfoxylates |date=1965 |last1=Thompson |first1=Q. E. |journal=The Journal of Organic Chemistry |volume=30 |issue=8 |pages=2703–2707 }}}}
Applications
{{chem2|S2Cl2}} has been used to introduce C−S bonds. In the presence of aluminium chloride ({{chem2|AlCl3}}), {{chem2|S2Cl2}} reacts with benzene to give diphenyl sulfide:
:{{chem2|8 S2Cl2 + 16 C6H6 → 8 (C6H5)2S + 16 HCl + S8}}
Anilines (1) react with {{chem2|S2Cl2}} in the presence of NaOH to give 1,2,3-benzodithiazolium chloride (2) (Herz reaction) which can be transformed into ortho-aminothiophenolates (3), these species are precursors to thioindigo dyes.
It is also used to prepare mustard gas via ethylene at 60 °C (the Levinstein process):
:{{chem2|8 S2Cl2 + 16 H2C\dCH2 → 8 (ClCH2CH2)2S + S8}}
If the reaction is performed at a temperature under 30 °C, the sulfur stays in "pseudo-solution" and avoids the problems associated with the sulfur that is formed during the reaction.
Other uses of {{chem2|S2Cl2}} include the manufacture of sulfur dyes, insecticides, and synthetic rubbers. It is also used in cold vulcanization of rubbers, as a polymerization catalyst for vegetable oils and for hardening soft woods.{{cite book |doi=10.1002/14356007.a25_623 |chapter=Sulfur Halides |title=Ullmann's Encyclopedia of Industrial Chemistry |year=2000 |last1=Lauss |first1=Hans-Dietrich |last2=Steffens |first2=Wilfried |isbn=3527306730}}
Safety and regulation
{{chem2|S2Cl2}} can be used to produce bis(2-chloroethyl)sulfide {{chem2|S(CH2CH2Cl)2}}, known as the mustard gas:
:{{chem2|S2Cl2 + 2 H2C\dCH2 → S(CH2CH2Cl)2 + "S"}}
Consequently, it is listed in Schedule 3 of the Chemical Weapons Convention. Facilities that produce and/or process and/or consume scheduled chemicals may be subject to control, reporting mechanisms and inspection by the Organisation for the Prohibition of Chemical Weapons.
References
{{reflist}}
{{Commons category|Disulfur dichloride}}
{{sulfur compounds}}
{{Chlorides}}