Disulfur dichloride
Disulfur dichloride (or disulphur dichloride by the British English spelling) is the inorganic compound of sulfur and chlorine with the formula Template:Chem2.[1][2][3][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.
Template:Chem2 has the structure implied by the formula Template:Chem2, wherein the dihedral angle between the Template:Chem2 and Template:Chem2 planes is 85.2°. This structure is referred to as gauche, and is akin to that for [[Hydrogen peroxide|Template:Chem2]]. A rare isomer of Template:Chem2 is Template:Chem2 (thiothionyl chloride); this isomer forms transiently when Template:Chem2 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:
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:[5]
- Template:Chem2, ΔH = −58.2 kJ/mol
Excess chlorine produces sulfur dichloride, which causes the liquid to become less yellow and more orange-red:
- Template:Chem2, ΔH = −40.6 kJ/mol
The reaction is reversible, and upon standing, Template:Chem2 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:
Disulfur dichloride can be purified by distillation from excess elemental sulfur.
Template:Chem2 also arises from the chlorination of [[Carbon disulfide|Template:Chem2]] as in the synthesis of thiophosgene or carbon tetrachloride.
Reactions
Template:Chem2 hydrolyzes to sulfur dioxide and elemental sulfur. When treated with hydrogen sulfide, polysulfanes are formed as indicated in the following idealized formula:
It reacts with ammonia to give tetrasulfur tetranitride as well as heptasulfur imide (Template:Chem2) and related S−N rings Template:Chem2 (n = 2, 3).[6]
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.[7]
Applications
Template:Chem2 has been used to introduce C−S bonds. In the presence of aluminium chloride (Template:Chem2), Template:Chem2 reacts with benzene to give diphenyl sulfide:
Anilines (1) react with Template:Chem2 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):
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 Template:Chem2 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.[8]
Safety and regulation
Template:Chem2 can be used to produce bis(2-chloroethyl)sulfide Template:Chem2, known as the mustard gas:[8]
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
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- ↑ Holleman, A. F.; Wiberg, E. Inorganic Chemistry Academic Press: San Diego, 2001. Template:ISBN.
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- ↑ R. J. Cremlyn An Introduction to Organosulfur Chemistry John Wiley and Sons: Chichester (1996). Template:ISBN
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- ↑ F. Fehér "Dichlorodisulfane" in Handbook of Preparative Inorganic Chemistry, 2nd Ed. Edited by G. Brauer, Academic Press, 1963, NY. Vol. 1. p. 371.
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- ↑ Template:Unbulleted list citebundle
- ↑ a b Script error: No such module "citation/CS1".
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