Sulfur dichloride

Structural formula
General
Surname	Sulfur dichloride
other names	Sulfur (II) chloride Dichloromonosulfane
Molecular formula	SCl 2
Brief description	red-brown liquid with a pungent odor
External identifiers / databases
CAS number 10545-99-0 EC number 234-129-0 ECHA InfoCard 100,031,014 PubChem 25353 Wikidata Q409028
properties
Molar mass	102.97 g · mol -1
Physical state	liquid
density	1.62 g cm −3 (at 15 ° C)
Melting point	−65 ° C
boiling point	59.5 ° C
Vapor pressure	218 h Pa (20 ° C)
solubility	reacts with water
Refractive index	1.557 (14 ° C)
safety instructions
GHS hazard labeling from  Regulation (EC) No. 1272/2008 (CLP) , expanded if necessary danger H and P phrases H: 314-335-400 EUH: 014 P: ?
As far as possible and customary, SI units are used. Unless otherwise noted, the data given apply to standard conditions . Refractive index: Na-D line , 20 ° C

Sulfur dichloride is a chemical compound from the group of sulfur chlorides . It is a dark red, toxic, hydrolysis-sensitive liquid with a characteristic odor reminiscent of chlorine .

history

One of the first uses of sulfur dichloride took place in 1846. At that time, Alexander Parkes used sulfur dichloride dissolved in carbon disulfide (CS ₂ ) for the cold vulcanization of rubber . During the First World War, sulfur dichloride was used to manufacture the warfare agent S-mustard .

Extraction and presentation

In the laboratory, sulfur dichloride is produced by reacting disulfur dichloride with chlorine gas . The direct reaction of sulfur with chlorine is also possible, a mixture of disulfur dichloride and sulfur dichloride being obtained. The two liquids can be separated by distillation under a protective gas atmosphere.

${\displaystyle \mathrm {S_{8}+4\ Cl_{2}\longrightarrow 4\ S_{2}Cl_{2}} }$

${\displaystyle \mathrm {S_{2}Cl_{2}+\ Cl_{2}\rightleftharpoons 2\ SCl_{2}} }$

properties

Physical Properties

Sulfur dichloride is a moderately exothermic compound with an enthalpy of formation of −49 kJ / mol. It is not stable at room temperature and decomposes in an equilibrium reaction to form disulfur dichloride and chlorine. Stabilization is possible by adding phosphorus trichloride or phosphorus pentachloride .

Sulfur dichloride has C _2v symmetry. The sulfur atom is tetrahedral surrounded by the two chlorine atoms and the two lone pairs of electrons. The bond angle between Cl-S-Cl is about 103 degrees, the bond length d (Cl-S) = 2.01  Å .

use

Sulfur dichloride can be used as a sulfiding and chlorinating agent in synthesis. It reacts with unsaturated compounds such as allyl phenyl ethers or allyl phenols to form the corresponding thia heterocycles or sulfones .

safety instructions

Since sulfur dichloride can be used to produce mustard gas in a relatively simple way , production, use and, above all, export are regulated and monitored by law.

Individual evidence

1. ↑ ^{a b c d e f g} Entry on sulfur dichloride in the GESTIS substance database of the IFA , accessed on February 19, 2017(JavaScript required) .
2. ↑ David R. Lide (Ed.): CRC Handbook of Chemistry and Physics . 90th edition. (Internet version: 2010), CRC Press / Taylor and Francis, Boca Raton, FL, Index of Refraction of Inorganic Liquids, pp. 4-140.
3. ↑ Entry on Sulfur dichloride in the Classification and Labeling Inventory of the European Chemicals Agency (ECHA), accessed on February 1, 2016. Manufacturers or distributors can expand the harmonized classification and labeling .
4. ↑ G. Brauer (Ed.): Handbook of Preparative Inorganic Chemistry. 2nd Edition. Tape. 1, Academic Press 1963, pp. 370-371.