2,2'-Bithiophene

It is a colorless solid, although commercial samples are often greenish.

X-ray crystallography shows that the two rings are coplanar,[3] unlike the situation for biphenyl.

A number of bi- as well as terthiophenes exist naturally, invariably with substituents at the positions flanking sulfur.

In terms of the biosynthesis, bithiophenes are proposed to be derived from polyacetylenic precursors, which in turn are the products of dehydrogenation of oleic acid.

According to some hypotheses, these polyalkynes form labile 1,2-dithiins via a reaction with H2S2 or its equivalent.