Acepentalene is a

tricyclic Tricyclics are cyclic chemical compounds that contain three fused rings of atoms. Many compounds have a tricyclic structure, but in pharmacology, the term has traditionally been reserved to describe heterocyclic drugs. They include antidepr ...

anti-aromatic Antiaromaticity is a chemical property of a cyclic molecule with a π electron system that has higher energy, i.e., it is less stable due to the presence of 4n delocalised (π or lone pair) electrons in it, as opposed to aromaticity. Unlike aroma ...

compound. Its molecular formula is . It consists of three five-membered rings fused across three of the five carbon atoms. The central carbon atom in acepentalene is part of all three rings. There are formally five double bonds in acepentalene, so that the molecule formally contains four double bonds on the exterior, and one double bond from the central carbon to the exterior of the ring system. The acepentalene

dianion A dianion is an anion with a net charge of −2. While there exist many stable molecular dianions, such as and , thus far no stable atomic dianion has been found: Electron shielding and other quantum mechanical effects tend to make the addition o ...

, which can be stabilized by two

lithium Lithium (from , , ) is a chemical element; it has chemical symbol, symbol Li and atomic number 3. It is a soft, silvery-white alkali metal. Under standard temperature and pressure, standard conditions, it is the least dense metal and the ...

atoms, is more stable. The

radical Radical (from Latin: ', root) may refer to: Politics and ideology Politics *Classical radicalism, the Radical Movement that began in late 18th century Britain and spread to continental Europe and Latin America in the 19th century *Radical politics ...

anion is also known. The dianion was first synthesized by reacting triquinacene with n-butyllithium and potassium tert-amylate (also called potassium t-pentoxide) in

hexane Hexane () or ''n''-hexane is an organic compound, a straight-chain alkane with six carbon atoms and the molecular formula C6H14. Hexane is a colorless liquid, odorless when pure, and with a boiling point of approximately . It is widely used as ...

solution.

References

{{reflist Antiaromatic compounds