Ethenedithione or ethylenedithone is an unstable chemical substance with formula S=C=C=S made from carbon and sulfur.
Ethenedithione can exist as a gas at low pressure and high temperature, but is unstable when condensed or under higher pressure.
It can be stabilized as a ligand binding two cobalt atoms.
Other occurrences as a ligand are in TpW(CO)<sub>2</sub>(C<sub>2</sub>S<sub>2</sub>)<sup>âÂÂ</sup> and [TpW(CO)<sub>2</sub>]<sub>2</sub>Ni(C<sub>2</sub>S<sub>2</sub>)<sub>2</sub>, where Tp is trispyrazolylborate.
Ethenedithione can be made by the flash vacuum pyrolysis of 2,5-Dithiacyclopentylideneketene.
Also it has been made by dissociative ionization of tetrathiapentalenedione, and then neutralisation of ions produced.
C<sub>2</sub>S<sub>2</sub> is made along with carbon subsulfide and carbon monosulfide, in an electric discharge in carbon disulfide vapour.
In its ground state it is a triplet state (<sup>3</sup>ã<sub>g</sub><sup>âÂÂ</sup>). Ethenedithione can be trapped in a matrix of solid argon without decomposition.
The infrared spectrum contains a prominent line at 1179.3 cm<sup>âÂÂ1</sup> due to asymmetric C=S stretch of the most common isotopes.
Over 60 K, ethenedithione polymerises. Possible polymerisation products include polythiene.