Sulfur dichloride is the

chemical compound A chemical compound is a chemical substance composed of many identical molecules (or molecular entities) containing atoms from more than one chemical element held together by chemical bonds. A molecule consisting of atoms of only one element ...

with the

formula In science, a formula is a concise way of expressing information symbolically, as in a mathematical formula or a ''chemical formula''. The informal use of the term ''formula'' in science refers to the general construct of a relationship betwe ...

. This cherry-red liquid is the simplest sulfur chloride and one of the most common, and it is used as a precursor to

organosulfur Organosulfur chemistry is the study of the properties and synthesis of organosulfur compounds, which are organic compounds that contain sulfur. They are often associated with foul odors, but many of the sweetest compounds known are organosulfur der ...

compounds. It is a highly corrosive and toxic substance, and it reacts on contact with water to form chlorine-containing acids.

Chlorination of sulfur

is produced by the chlorination of either elemental

sulfur Sulfur ( American spelling and the preferred IUPAC name) or sulphur ( Commonwealth spelling) is a chemical element; it has symbol S and atomic number 16. It is abundant, multivalent and nonmetallic. Under normal conditions, sulfur atoms ...

disulfur dichloride Disulfur dichloride (or disulphur dichloride by the British English spelling) is the inorganic compound of sulfur and chlorine with the Chemical formula, formula . It is an amber oily liquid. Sometimes, this compound is incorrectly named ''sulfur ...

. The process occurs in a series of steps, some of which are: :; ''ΔH'' = −58.2 kJ/mol :; ''ΔH'' = −40.6 kJ/mol The addition of to has been proposed to proceed via a mixed valence intermediate . undergoes even further chlorination to give , but this species is unstable at near room temperature. It is likely that several exist where ''n'' > 2.

Disulfur dichloride Disulfur dichloride (or disulphur dichloride by the British English spelling) is the inorganic compound of sulfur and chlorine with the Chemical formula, formula . It is an amber oily liquid. Sometimes, this compound is incorrectly named ''sulfur ...

, , is a common impurity in . Separation of from is possible via distillation with to form an

azeotrope An azeotrope () or a constant heating point mixture is a mixture of two or more liquids whose proportions cannot be changed by simple distillation.Moore, Walter J. ''Physical Chemistry'', 3rd e Prentice-Hall 1962, pp. 140–142 This happens beca ...

of 99% purity. Sulfur dichloride loses chlorine slowly at room temperature, converting to disulfur dichloride and eventually higher sulfanes. Pure samples may be stored in sealed glass ampules which develop a slight positive pressure of chlorine, halting the decomposition.

Use of in chemical synthesis

is used in

organic synthesis Organic synthesis is a branch of chemical synthesis concerned with the construction of organic compounds. Organic compounds are molecules consisting of combinations of covalently-linked hydrogen, carbon, oxygen, and nitrogen atoms. Within the gen ...

. It adds to

alkenes In organic chemistry, an alkene, or olefin, is a hydrocarbon containing a carbon–carbon double bond. The double bond may be internal or at the terminal position. Terminal alkenes are also known as Alpha-olefin, α-olefins. The Internationa ...

to give chloride-substituted thioethers. Illustrative is its addition to

1,5-cyclooctadiene 1,5-Cyclooctadiene (also known as cycloocta-1,5-diene) is a cyclic compound, cyclic hydrocarbon with the chemical formula , specifically . There are three configurational isomers with this structure, that differ by the arrangement of the four C� ...

to give a bicyclic

thioether In organic chemistry, a sulfide (British English sulphide) or thioether is an organosulfur functional group with the connectivity as shown on right. Like many other sulfur-containing compounds, Volatile organic compound, volatile sulfides have ...

A well tested method for the production of the

mustard gas Mustard gas or sulfur mustard are names commonly used for the organosulfur compound, organosulfur chemical compound bis(2-chloroethyl) sulfide, which has the chemical structure S(CH2CH2Cl)2, as well as other Chemical species, species. In the wi ...

bis(2-chloroethyl)sulfide, is the addition of ethylene to sulfur dichloride:R. J. Cremlyn “An Introduction to Organosulfur Chemistry” John Wiley and Sons: Chichester (1996). . : is also a precursor to several inorganic sulfur compounds. Treatment with fluoride salts gives via the decomposition of the intermediate sulfur difluoride. With , reacts to give "lower" sulfanes such as . oxidizes to . Reaction with ammonia affords sulfur nitrides related to . Treatment of with primary amines gives sulfur diimides. One example is di-''t''-butylsulfurdiimide.

Safety considerations

hydrolyzes Hydrolysis (; ) is any chemical reaction in which a molecule of water breaks one or more chemical bonds. The term is used broadly for substitution reaction, substitution, elimination reaction, elimination, and solvation reactions in which water ...

with release of HCl. Old samples contain .

References

{{Chlorides Sulfur chlorides Sulfur(II) compounds