Trithiapentalene
Trithiapentalene is an organic bicyclic molecule containing two sulfur heterocycles. Its 10-π aromatic structure is similar to naphthalene. There has been a literature dispute about whether the connectivity among the three sulfur atoms is a case of rapid tautomerization between two valence tautomers or a 3-center 4-electron bond.
The reactions have been little studied. It forms a dinickel complex upon reaction with bis(allyl)nickel.