1,2-Benzenedithiol


1,2-Benzenedithiol is the organosulfur compound with the formula CH. This colourless viscous liquid consists of a benzene ring with a pair of adjacent thiol groups. The conjugate base of this diprotic compound serves as chelating agent in coordination chemistry and a building block for the synthesis of other organosulfur compounds.

Synthesis

The compound is prepared by ortho-lithiation of benzenethiol using butyl lithium followed by sulfidation:
The compound was first prepared from 2-aminobenzenethiol via diazotization. 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 where LM represents a variety of metal centers, e.g. Ti. Ketones and aldehydes condense to give the heterocycles called dithianes:

Related compounds

, also called dimercaptotoluene, behaves similarly to 1,2-benzenedithiol but is a solid at ambient temperatures.
Alkene-1,2-dithiols are unstable, although metal complexes of alkene-1,2-dithiolates, called dithiolene complexes, are well known.