فولوالن

Also known as bicyclopentyliden-2,4,2',4'-tetraene, 1,1'-Bi[cylopentadienylidene], Bicyclopentadienylidene, [5,5']Bicyclopentadienylidene, 5-(2,4-cyclopentadien-1-ylidene)-1,3-cyclopentadiene

Fulvalene (bicyclopentadienylidene) is the member of the fulvalene family with the molecular formula C10H8. It is of theoretical interest as one of the simplest non-benzenoid conjugated hydrocarbons. Fulvalene is an unstable isomer of the more common benzenoid aromatic compounds naphthalene and azulene. Fulvalene consists of two 5-membered rings, each with two double bonds, joined by yet a fifth double bond. It has D2h symmetry.