Dithiin

Dithiin /daɪ.ˈθaɪ.ɪn/ is a class of heterocyclic compounds, with the parent members having the formula (C2H2)2S2.

Akin to the behavior of cyclooctatetraene, they instead adopt nonplanar structures.

For example, the acetal HSCH2CH(OEt)2 converts upon heating to the parent 1,4-dithiin.

They tend to be unstable with respect to loss of sulfur and formation of the thiophene derivative:[2] They are often claret-colored.

Some occur as flower pigments in plants of the family Asteraceae.