Benzene-1,2-dithiol is the

organosulfur compound Organosulfur compounds are organic compounds that contain sulfur. They are often associated with foul odors, but many of the sweetest compounds known are organosulfur derivatives, e.g., saccharin. Nature abounds with organosulfur compounds—sulf ...

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 ...

CH(SH). This colourless viscous liquid consists of a benzene ring with a pair of adjacent

thiol In organic chemistry, a thiol (; ), or thiol derivative, is any organosulfur compound of the form , where R represents an alkyl or other organic substituent. The functional group itself is referred to as either a thiol group or a sulfhydryl gro ...

groups. The

conjugate base A conjugate acid, within the Brønsted–Lowry acid–base theory, is a chemical compound formed when an acid donates a proton () to a base—in other words, it is a base with a hydrogen ion added to it, as in the reverse reaction it loses a ...

of this diprotic compound serves as chelating agent in

coordination chemistry A coordination complex consists of a central atom or ion, which is usually metallic and is called the ''coordination centre'', and a surrounding array of bound molecules or ions, that are in turn known as ''ligands'' or complexing agents. Man ...

and a building block for the synthesis of other organosulfur compounds.Karlin, K. D.; Stiefel, E. I., Eds. “Progress in Inorganic Chemistry, Dithiolene Chemistry: Synthesis, Properties, and Applications” Wiley-Interscience: New York, 2003.

Synthesis

The compound is prepared by ortho-lithiation of

benzenethiol Thiophenol is an organosulfur compound with the formula C6H5SH, sometimes abbreviated as PhSH. This foul-smelling colorless liquid is the simplest aromatic thiol. The chemical structures of thiophenol and its derivatives are analogous to pheno ...

using

butyl lithium Butyllithium may refer to one of 5 isomeric organolithium reagents of which 3 are commonly used in chemical synthesis: * ''n''-Butyllithium, abbreviated BuLi or nBuLi * ''sec''-Butyllithium, abbreviated ''sec''-BuLi or sBuLi, has 2 stereoisomers, ...

(BuLi) followed by sulfidation: :CHSH + 2 BuLi → CHSLi-2-Li + 2 BuH :CHSLi-2-Li + S → CH(SLi) :CH(SLi) + 2 HCl → CH(SH) + 2 LiCl The compound was first prepared from 2-aminobenzenethiol via

diazotization Diazonium compounds or diazonium salts are a group of organic compounds sharing a common functional group where R can be any organic group, such as an alkyl or an aryl, and X is an inorganic or organic anion, such as a halide. General propert ...

. Alternatively, it forms from 1,2-dibromobenzene.

Reactions

Oxidation mainly affords the polymeric disulfide. Reaction with metal dihalides and metal oxides gives the dithiolate complexes of the formula LM(SCH) where LM represents a variety of metal centers, e.g. (CH)Ti.

Ketone In organic chemistry, a ketone is a functional group with the structure R–C(=O)–R', where R and R' can be a variety of carbon-containing substituents. Ketones contain a carbonyl group –C(=O)– (which contains a carbon-oxygen double b ...

s and

aldehyde In organic chemistry, an aldehyde () is an organic compound containing a functional group with the structure . The functional group itself (without the "R" side chain) can be referred to as an aldehyde but can also be classified as a formyl gro ...

s condense to give the heterocycles called

dithiane A dithiane is a heterocyclic compound composed of a cyclohexane core structure wherein two methylene bridges (-- units) are replaced by sulfur centres. The three isomeric parent heterocycles are 1,2-dithiane, 1,3-dithiane and 1,4-dithiane. 1,3 ...

s: :CH(SH) + RR’CO → CH(S)CRR’ + HO

Related compounds

3,4-Toluenedithiol, also called dimercaptotoluene (CAS#496-74-2), behaves similarly to 1,2-benzenedithiol but is a solid at ambient temperatures (m.p. 135-137 °C). Alkene-1,2-dithiols are unstable, although metal complexes of alkene-1,2-dithiolates, called

dithiolene Dithiolene metal complexes are complexes containing 1,2-dithiolene ligands. 1,2-Dithiolene ligands, a particular case of 1,2-dichalcogenolene species, are unsaturated bidentate ligand wherein the two donor atoms are sulfur. 1,2-Dithiolene metal ...

complexes, are well known.

References

{{Reflist Thiols Benzene derivatives Foul-smelling chemicals