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| Names | |||
|---|---|---|---|
| IUPAC names Disulfur dichloride Dichlorodisulfane | |||
| Systematic IUPAC name Chlorosulfanyl thiohypochlorite | |||
Other names
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| Identifiers | |||
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3D model (JSmol) | |||
| ChemSpider | |||
| DrugBank | |||
| ECHA InfoCard | 100.030.021 | ||
| EC Number |
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| MeSH | Sulfur+monochloride | ||
| RTECS number |
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| UNII | |||
| UN number | 3390 | ||
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| Properties | |||
| S2Cl2 | |||
| Molar mass | 135.02 g·mol−1 | ||
| Appearance | Light-amber to yellow-red, oily liquid[1] | ||
| Odor | pungent, nauseating, irritating[1] | ||
| Density | 1.688 g/cm3 | ||
| Melting point | −80 °C (−112 °F; 193 K) | ||
| Boiling point | 137.1 °C (278.8 °F; 410.2 K) | ||
| Decomposes, with loss ofHCl | |||
| Solubility | Soluble inethanol,benzene,ether,THF,chloroform,CCl4[2] | ||
| Vapor pressure | 7 mmHg (20 °C)[1] | ||
| −62.2·10−6 cm3/mol | |||
Refractive index (nD) | 1.658 | ||
| Structure | |||
| C2 | |||
| 2 atsulfur atoms | |||
| gauche | |||
| 1.60D[2] | |||
| Hazards | |||
| GHS labelling: | |||
    | |||
| Danger | |||
| H301,H314,H332,H400 | |||
| P260,P264,P270,P271,P273,P280,P301+P310,P301+P330+P331,P303+P361+P353,P304+P312,P304+P340,P305+P351+P338,P310,P312,P321,P330,P363,P391,P405,P501 | |||
| NFPA 704 (fire diamond) | |||
| Flash point | 118.5 °C (245.3 °F; 391.6 K) | ||
| 234 °C (453 °F; 507 K) | |||
| Lethal dose or concentration (LD, LC): | |||
LCLo (lowest published) | 150ppm (mouse, 1 min) (1 ppm = 5.52 mg/m3)[3] | ||
| NIOSH (US health exposure limits): | |||
PEL (Permissible) | TWA 1 ppm (5.52 mg/m3)[1] | ||
REL (Recommended) | C 1 ppm (5.52 mg/m3)[1] | ||
IDLH (Immediate danger) | 5 ppm[1] (1 ppm = 5.52 mg/m3) | ||
| Safety data sheet (SDS) | ICSC 0958 | ||
| Related compounds | |||
Related sulfur chlorides/oxychlorides | |||
Related compounds | |||
Except where otherwise noted, data are given for materials in theirstandard state (at 25 °C [77 °F], 100 kPa). | |||
Disulfur dichloride (ordisulphur dichloride by theBritish English spelling) is theinorganic compound ofsulfur andchlorine with theformulaS2Cl2.[4][5][6][7] It is an amber oily liquid.
Sometimes, this compound is incorrectly namedsulfur monochloride (orsulphur monochloride by the British English spelling), the name implied by itsempirical formula SCl.
S2Cl2 has the structure implied by the formulaCl−S−S−Cl, wherein thedihedral angle between theCla−S−S andS−S−Clb planes is 85.2°. This structure is referred to asgauche, and is akin to that forH2O2. A rareisomer ofS2Cl2 isS=SCl2 (thiothionyl chloride); this isomer forms transiently whenS2Cl2 is exposed toUV-radiation (seethiosulfoxides).
Disulfur dichloride is a yellow liquid that fumes in moist air due to reaction with water:
It is produced by partial chlorination of elementalsulfur. 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:[8]
Excess chlorine producessulfur dichloride, which causes the liquid to become less yellow and more orange-red:
The reaction is reversible, and upon standing,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 ofdichloropolysulfanes:
Disulfur dichloride can be purified by distillation from excess elemental sulfur.
S2Cl2 also arises from the chlorination ofCS2 as in the synthesis ofthiophosgene orcarbon tetrachloride.
S2Cl2hydrolyzes tosulfur dioxide and elementalsulfur. When treated withhydrogen sulfide,polysulfanes are formed as indicated in the following idealized formula:
It reacts withammonia to givetetrasulfur tetranitride as well asheptasulfur imide (S7NH) and related S−N ringsS8−n(NH)n (n = 2, 3).[9]
With primary and secondaryalkoxide equivalents, it forms disulfoxylate esters:
In principle the subsequent addition of base should givesulfoxylate esters, but typically induces disproportionation to aldehydes and alcohols instead.[10]
S2Cl2 has been used to introduceC−S bonds. In the presence ofaluminium chloride (AlCl3),S2Cl2 reacts withbenzene to give diphenyl sulfide:
Anilines (1) react withS2Cl2 in the presence ofNaOH to give 1,2,3-benzodithiazolium chloride (2) (Herz reaction) which can be transformed intoortho-aminothiophenolates (3), these species are precursors tothioindigodyes.
It is also used to preparemustard gas viaethylene at 60 °C (the Levinstein process):
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 ofS2Cl2 include the manufacture ofsulfur dyes,insecticides, andsynthetic rubbers. It is also used in coldvulcanization ofrubbers, as apolymerizationcatalyst forvegetable oils and for hardeningsoft woods.[11]
S2Cl2 can be used to producebis(2-chloroethyl)sulfideS(CH2CH2Cl)2, known as the mustard gas:[11]
Consequently, it is listed in Schedule 3 of theChemical Weapons Convention. Facilities that produce and/or process and/or consume scheduled chemicals may be subject to control, reporting mechanisms and inspection by theOrganisation for the Prohibition of Chemical Weapons.
